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General Introduction to Textiles

A textile is a flexible material comprised of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw wool fibres, linen, cotton, or other material on a spinning wheel to produce long strands known as yarn.[1] Textiles are formed by weaving, knitting, crocheting, knotting, or pressing fibres together (felt).The words fabric and cloth are used in textile assembly trades (such as tailoring and dressmaking) as synonyms for textile. However, there are subtle differences in these terms. Textile refers to any material made of interlacing fibres. Fabric refers to any material made through weaving, knitting, crocheting, or bonding. Cloth refers to a finished piece of fabric that can be used for a purpose such as covering a bed.

Mankind has been endowqed with a resltess nature and is always eager to improve and beautify its own self as well as to embellish and decorate its surroundings. This spirit also applies to Textiles that has always been a symbol of social stature, dignity, prestige of a personwearing those. It is only therefore only natural that a lot of human energy and ingenuity has gone into the improvement of apparel and also the hometextiles for their quality of attractiveness and comfort. At the same time , constant efforts were also made for reduction in their cost of production so as to expand their distribution.

History of transfer of human clothing from skins and barks to woven fabrics is obscure but the earliest efforts made for decoration of dresses with dyeing and printing precesses are fairly well known. There is a general consensus among the researchers that dyeing and printing of fabric is as old as its weaving. According to the Greek mythology, “Ariadne” the Goddess for spinning and weaving is daughtr of “idon” the dyer of wool.

Sources and Types of textilesTextiles can be made from many materials. These materials come from four main sources: animal, plant, mineral, and synthetic. In the past, all textiles were made from natural fibres, including plant, animal, and mineral sources. In the 20th century, these were supplemented by artificial fibres made from petroleum.

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Textiles are made in various strengths and degrees of durability, from the finest gossamer to the sturdiest canvas. The relative thickness of fibres in cloth is measured in deniers. Microfibre refers to fibres made of strands thinner than one denier.

Animal textilesAnimal textiles are commonly made from hair or fur.Wool refers to the hair of the domestic goat or sheep, which is distinguished from other types of animal hair in that the individual strands are coated with scales and tightly crimped, and the wool as a whole is coated with an oil known as lanolin, which is waterproof and dirtproof. Woollen refers to a bulkier yarn produced from carded, non-parallel fibre, while worsted refers to a finer yarn which is spun from longer fibres which have been combed to be parallel. Wool is commonly used for warm clothing. Cashmere, the hair of the Indian cashmere goat, and mohair, the hair of the North African angora goat, are types of wool known for their softness.

Other animal textiles which are made from hair or fur are alpaca wool, vicuña wool, llama wool, and camel hair, generally used in the production of coats, jackets, ponchos, blankets, and other warm coverings. Angora refers to the long, thick, soft hair of the angora rabbit.Wadmal is a coarse cloth made of wool, produced in Scandinavia, mostly 1000~1500CE.Silk is an animal textile made from the fibres of the cocoon of the Chinese silkworm. This is spun into a smooth, shiny fabric prized for its sleek texture.

Plant textilesGrass, rush, hemp, and sisal are all used in making rope. In the first two, the entire plant is used for this purpose, while in the last two, only fibres from the plant are utilized. Coir (coconut fibre) is used in making twine, and also in floormats, doormats, brushes, mattresses, floor tiles, and sacking.

Straw and bamboo are both used to make hats. Straw, a dried form of grass, is also used for stuffing, as is kapok.

Fibres from pulpwood trees, cotton, rice, hemp, and nettle are used in making paper.

Cotton, flax, jute, hemp and modal are all used in clothing. Piña (pineapple fibre) and ramie are also fibres used in clothing, generally with a blend of other fabrics such as cotton.

Acetate is used to increase the shininess of certain fabrics such as silks, velvets, and taffetas.

Seaweed is used in the production of textiles. A water-soluble fibre known as alginate is produced and is used as a holding fibre; when the cloth is finished, the alginate is dissolved, leaving an open area

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Tencel is a man-made fabric derived from wood pulp. It is often described as a man-made silk equivalent and is a tough fabric which is often blended with other fabrics - cotton for example.

Mineral textilesAsbestos and basalt fibre are used for vinyl tiles, sheeting, and adhesives, "transite" panels and siding, acoustical ceilings, stage curtains, and fire blankets.Glass Fibre is used in the production of spacesuits, ironing board and mattress covers, ropes and cables, reinforcement fibre for composite materials, insect netting, flame-retardant and protective fabric, soundproof, fireproof, and insulating fibres.Metal fibre, metal foil, and metal wire have a variety of uses, including the production of cloth-of-gold and jewelry. Hardware cloth is a coarse weave of steel wire, used in construction

Synthetic textiles

A variety of contemporary fabrics. From the left: evenweave cotton, velvet, printed cotton, calico, felt, satin, silk, hessian, polycotton.All synthetic textiles are used primarily in the production of clothing.Polyester fibre is used in all types of clothing, either alone or blended with fibres such as cotton.Aramid fibre (e.g. Twaron) is used for flame-retardant clothing, cut-protection, and armor.Acrylic is a fibre used to imitate wools, including cashmere, and is often used in replacement of them.Nylon is a fibre used to imitate silk; it is used in the production of pantyhose. Thicker nylon fibres are used in rope and outdoor clothing.Spandex (trade name Lycra) is a polyurethane fibre that stretches easily and can be made tight-fitting without impeding movement. It is used to make activewear, bras, and swimsuits.Olefin fibre is a fibre used in activewear, linings, and warm clothing. Olefins are hydrophobic, allowing them to dry quickly. A sintered felt of olefin fibres is sold under the trade name Tyvek.

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Ingeo is a polylactide fibre blended with other fibres such as cotton and used in clothing. It is more hydrophilic than most other synthetics, allowing it to wick away perspiration.Lurex is a metallic fibre used in clothing embellishment

General uses of TextilesTextiles have an assortment of uses, the most common of which are for clothing and containers such as bags and baskets. In the household, they are used in

1. carpeting 2. upholstered furnishings3. window shades4. towels5. covering for tables6. beds and other flat surfacesand in art.

In the workplace, they are used in industrial and scientific processes such as filtering.1. Miscellaneous uses include 2. flags 3. backpacks 4. tents 5. nets 6. cleaning devices, such as handkerchiefs7. transportation devices such as balloons, kites, sails, and parachutes8. strengthening in composite materials such as fibre glass and industrial geotextiles

smaller cloths are used in washing by "soaping up" the cloth and washing with it rather than using just soap.

Textiles used for industrial purposes, and chosen for characteristics other than their appearance, are commonly referred to as technical textiles.

Technical textiles include

1. textile structures for automotive applications2. medical textiles (e.g. implants)3. geotextiles (reinforcement of embankments)4. agrotextiles (textiles for crop protection)5. protective clothing (e.g. against heat and radiation for fire fighter clothing6. against molten metals for welders7. stab protection8. bullet proof vests.

In all these applications stringent performance requirements must be met. Woven of threads coated with zinc oxide nanowires, laboratory fabric has been shown capable of "self-powering nanosystems" using vibrations created by everyday actions like wind or body movements.

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The History of TextilesEarly humans started wearing the skins of a wide variety of mammals that they killed for food. The skins provided both protection and decoration. Over the millennia, through experimentation, mankind began to build up a range of animal and plant fibres that could be used for clothing, fabric, matting and cordage. Some of these natural materials were more readily available and had a widespread use, others such as yucca leaves were more specific to an area and had a limited use.

Clothing and Fabric - Animal skins such as wolf, bear, dear, leopard, moose, rabbit, buffalo and seal. Animal fibres such as silkworm, sheep, goat, camel, rabbit, alpaca, human hair and feathers. Plant fibres such as cotton, flax, ramie, jute, hemp and yucca leaves.

Matting and Cordage – Animal fibres such as goat and human hair. Plant fibres such as flax, esparto grass, bark, vines, hemp and corn straw.

Certain fibres, because of their properties and availability became more important. Linen developed from the wild flax of Mesopotamia, cotton from the area around the River Indus and from Southern Mexico, silk from Northern China and wool from sheep that were originally domesticated in Western Asia as early as 9000BC. These ancient sheep were not woolly, as we know them today, but possessed a hairier coat. Woolly breeds did not appear until about 3000BC.

A history of textiles should probably start with wool, a fibre that was successfully made into fabric as far back as the Stone Age some 1.75 million years ago. By the later Stone Age the art of using vegetable dyes from the arbutus plant and from elderberries was discovered, and by the Bronze Age even more complex dyeing operations such as the application of woad had been introduced. The art and craft of dyeing using natural dyes developed to a remarkable extent with colours being obtained from plants such as madder, saffron and weld, as well as those from the animal world such as Tyrian purple from molluscs and cochineal from insects. One interesting point worth noting is that there were very few natural green dyes available up until the mid 19th century and the birth of the synthetic dye industry. Anyone wanting green had therefore to apply blue and yellow colour to a fabric in two stages. Yellow natural dyes tend to fade to a dirty brown and so that is why Medieval tapestries have blue trees and grass.

Serviceable woollen fabrics have been found in Iraq dating back to 4200BC indicating a thriving trade in wool. It was evidently from Central Asia that sheep and wool were introduced into other areas of the world. Because sheep adapt easily to their environment, many variations of shape, fleece, or other characteristics have developed. The ancestor of the finest wool-bearing sheep is the Spanish Merino, which was bred from a number of earlier breeds, including that introduced into Spain by the Phoenicians. Merinos have become the foundation of the modern global wool raising industry.

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By early Roman times, around 700BC, wool dyeing had been established as arecognised craft.In Britain, the woollen industry had from the Middle Ages become the major industry in the land. As far back as the 14th century, Edward III commanded that the Lord Chancellor should sit on a sack of wool as a reminder of the importance of the trade. At the time, surplus wool was exported to Europe through the network of traders known as the Hanseatic League. Imports included wine from the Rhineland and finished textiles from Bruges. Edward realised that more revenue could be gained by exporting cloth and so heencouraged expert weavers from Flanders to settle here. In medieval towns across the country the trade was partitioned into spinning, weaving, fulling and merchant tailoring, controlled to a great extent by craft guilds who imposed standards and laid down working methods. This system was unchanged until independent clothiers appeared during Tudor times. These capitalists bought wool from the farmer then had it spun up into yarn andwoven by others before fulling, dyeing and finishing the cloth on their own premises.

Across Europe, especially in the Low Countries, powerful urban guild weavers effectively limited the cottage weaving of yarn, holding up the price of cloth. By the 16 th

Century the effect of cheap labour had turned England into a major exporter of fabric.The mechanisation of the textile industry in the late 18th and early 19th century changed the woollen industry forever. The adaptation of the new inventions, so effective in transforming the cotton industry, came later to the woolen industry as it was then a more difficult fibre to process mechanically.Investment was particularly strong in Yorkshire, initially around Huddersfield and Halifax and then on to Bradford, which also had the added advantage of a thriving coal industry. A convenient source of energy for the new steam engines which by then were

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available. The industry quickly died off in traditional woollen processing areas such as East Anglia and the West Country.

Around 3000BC there was an explosion of invention with fibres like cotton, silk and flax becoming more widely used. Spinning and weaving were already well established as domestic crafts. Before the invention of the Spinning Wheel and the later Saxony Wheel, spinning was a slow and tedious task. The spinning of one pound of heavy cotton yarn taking several weeks and one pound of woollen blanket yarn about one week. Spinning would be done between the finger and thumb using a simple spindle and whorl. Even the direction of the rotation was in ancient times dictated more often than not by local tradition. Such was the importance of textiles to a community.

Traditional Spinning Wheel

Weaving was a much less tedious task consuming a spinner’s weekly output in a matter of hours. Even so handloom weaving was an awkward process with the shuttle bearing the yarn being passed slowly across the warp from one hand to the other.

Ancient looms were generally one of five types used throughout the world. All basically doing the same job. These were the horizontal ground loom of ancient Egypt, the vertical framed loom and warp weighted looms of Europe, the simple backstrap loom of the Americas and the widely used treadle loom. Even though the process was slow and laborious these looms, in the hands of an expert, could produce wonderfully complex patterned fabrics with very fine yarn. The art of hand knitting, an alternative to weaving, was practised from the Middle Ages, its origins being unknown. But it was not until the invention of the frame for knitting stockings by William Lee in the year 1589 that knitted garments came to the fore. The

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knitting frame was essentially a weft knitting machine that produced stitches at more than six times the speed of a hand knitter. Knitting did not change again until 1775 when the warp knitting machine was invented, and again in the mid 19th Century when the all important latch needle was introduced. Apart from the introduction of the wheel driven spindle which helped to speed up spinning, the production of fabric changed little until the Industrial Revolution.

The earliest known Old World textiles are linens from Turkey dating back to 6500BC. By 3400BC the manufacture of linen from flax was already an established art in Egypt where both fine and coarse canvas-like linen cloth have been found in burial chambers. The wealthier and more important the person the finer the linen. Some mummies have been found wrapped in as much as 900 metres of very fine linen. The use of linen spread from Egypt through the Mediterranean basin and was carried to north west Europe by the Romans. France, the Low Countries and Ireland became famous for their linen. Ireland especially had an ideal damp climate for spinning and weaving.

Linen Wrapping from Tutenkamun’s Tomb

Surprisingly, up until the 17th century only small amounts of flax were grown in England. This was due in part to competition from the wool industry. The arrival around this time of linen workers from the continent stimulated a demand for the fibre which was met by importation largely from Russia.

Evidence of the origins of silk production are a little vague, but it is known that dyed silk ribbons and fabric were in use in China before 3000BC. More conclusive evidence is

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available around 2600BC with the existence of the earliest written records of the use of dyestuffs.Trade in silk opened up during the Shang dynasty around 1700BC. Early examples of silk being found as far afield as Scandinavia. By the time of the Roman Empire, during the Han dynasty, the Silk Road was well established and sericulture had been introduced into Bactria and India to help relieve the increased demand. Trade could be very lucrative, for example, Purpura (Murex - mollusc) dyed silk garments were only for the very rich, with such garments costing their weight in gold.

The Silk Road – from Chang’an in China through Lanzhou, Wuwei, and Dunhuang. Into Pakistan, Afghanistan, Iran and Iraq and onto the Mediterranean.Most of the early Chinese production of silk was not for export and much of the silk leaving the country was given away as annual tributes or gifts. Chinese emigration eventually spread the knowledge of sericulture across to Korea and Japan. By the time of the Tang dynasty in about 600AD foreign silks from as far a field as Persia were finding their way back to China.

It is interesting to note that the first true factory in England was a silk mill, not wool or cotton as you would expect, constructed in 1718 on the River Derwent near Derby by John and Thomas Lombe. The mill was six storeys high, employed 300 men and was driven by water power. It was a full fifty years ahead of its time.

Cotton, arguably the most important and widely used fibre today dates back again to about 3000BC. Early fabrics being found in Indian tombs. Written descriptions in Hindu hymns dating from around 1400BC of the manufacture of cotton yarn and the weaving of the cloth, suggest that by then the fabric had an important place in Indian culture. It was

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also produced by the early Chinese civilisations and there is evidence of cotton production in pre-IncaPeru (before 2000BC). By the time of Alexander the Great, production techniques had already become quite sophisticated, the beautiful printed cottons of India being worth a mention in his records of conquest. The cultivation of cotton spread to Egypt and the Mediterranean basin. By the 12th century, Venice had become a major cotton manufacturing city, processing cotton from the Mediterranean area into cloth for sale across Europe. Cotton manufacturing eventually spread to Germany in the Middle Ages together with the increased cultivation of dye plants such as woad. The fibre was first imported into England in the 16th century but it was not until the mid 18th century that production increased significantly through a series of inventions which transformed the manufacturing process. The earlier inventions were aimed at merely improving the productivity of the home workers. Increased demand for cotton made it more difficult to supervise the work and quality control became more of a concern, as did the embezzlement of materials. The obvious answer to these problems, together with the increasing size and complexity of the textile machinery itself , was to establish factories where all the manufacturing could be done, and controlled, under one roof.

By the 18th century there was a sudden interest in the mechanisation of all manufacturing processes. In the textile industry, which was a domestic industry at the time, the main bottleneck in production was the speed at which yarn could be spun. The invention of the Spinning Jenny by James Hargreaves in 1764 improved productivity significantly enabling a single operator to spin eight threads at once. However, the thread produced was coarse and did not have the strength required for producing warp threads on looms (warp threads are tensioned and require considerably more strength than weft threads)

The real breakthrough came in the 1771 when Richard Arkwright successfully established a mill based on the use of the automatic continuous spinning machine called the Waterframe. The power for the factory, which was located by the river Derwent in Derbyshire, being supplied by a water wheel. As the mill became more successful Arkwright built homes for the workers around the mill. The resulting village of Cromford was the first planned workers village consisting in the main of three storey terraced houses. The top storey which was connected by doors along the whole row of houses, was used by the employees to make stockings during the evenings. The main advantage of the Waterframe was that it could produce a stronger, higher quality thread. The final step in the early mechanisation of spinning came with the invention by Samuel Crompton in 1779 of the mule. This was a hybrid machine which combined the roller drafting of the water frame with the running twist of the jenny. Fine yarns could now be produced consistently. The importance of the water wheel in the early development of the cottonindustry can be shown clearly by the fact that in the late 18th century there were nearly 100 cotton mills within a 10 mile radius of Ashton-under-Lyne, all on the river Tame and all powered by water.

Water mills had been introduced to Britain as far back as Roman times, but on a much smaller scale. However, by the Domesday census of 1086 there were 5600 of them used for grinding grain, processing wool, hammering metal and making paper.

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It was not until the early 20th century that real progress was made in the synthesis of polymeric synthetic fibres. In the late 1920’s Carothers was given a remit by E.I Du Pont De Nemours Inc to conduct fundamental research into macromolecular materials. In 1928 he discovered the reaction that produces a synthetic polyamide. Over the next seven years this process was refined and by 1935 a pilot process for a condensation polymer from hexamethylene diamine and adipic acid, or nylon 66, was operating. The two chemical components are first mixed in methanolic solution and the nylon salt settles out. A concentrated solution of this salt is heated under pressure in an inert atmosphere to about 270°C. Steam is then bled off and the residue is heated further under vacuum to complete the polymerisation. Nylon was the first major synthetic fibre and from 1938 to 1972 was in the greatest production by weight.

Carothers also demonstrated a number of high molecular weight plastics made from acids and alcohols in the early 1930’s, and patented a workable system in 1935. However, he was making more progress with polyamides and so this work, which was the first step towards polyester, was dropped. In England, during the early years of the Second World War, Whinfield and Dixon conducted research on the terephthalic acid and ethylene glycol system which became the basis for the highly successful polyester fibre. Their choice of polymer condensation reaction gave a product that overcame difficultieswith chemical stability experienced by earlier researchers. Acrylonitrile was known as a chemical substance as far back as 1893, but because of difficulties in dissolving it for spinning no progress was made in converting it to a useable fibre until 1925. It was around this time that melt spinning was invented. There were still problems however, due to the very viscous nature of the polyacrylonitrile melts. Again it wasn’t until the SecondWorld War that progress was made. Researchers in the USA developed a solvent spinning system using dimethyl formamide which produced satisfactory synthetic fibres of the acrylic type. This was marketed as Orlon. Ultimately, two spinning systems were developed, both still in use, a dry evaporative method and a wet method using solvent dissolved polymer extruded into a water bath.

The developments already discussed provided the basis for the expansion of the textile industry. More recent improvements in spinning and weaving technology, such as open end spinning (Vyzkumny Ustav Bavinarsky, 1966) and shuttleless weaving (rapier, air jet, water jet) have helped to increase the efficiency, range, speed and quality of processing.

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Textile Fibre Usage and ProductionBefore any conclusions can be made as to the best options for improving environmental sustainability in the textile industry, trends in fibre usage and production need to be analysed. It is no use recommending the use of a fibre if it is likely that it will always remain in a minority as far as popularity and options for use.

Production of textiles in the years from 1750 to 1900 was limited mainly to the natural fibres, cotton, wool, silk and flax. Restrictions on flax growing in England during the Middle Ages led to a growth in the production of flax in Ireland which became the world’s largest producer of linen. In the late 18 th Century more efficient flax spinning machinery became available, and a number of new factories were built in England, but the popularity and price of cotton goods restricted the use of linen to sailmaking, sacking and furniture. The woollen industry, which had been established in the Middle Ages wasbased on the domestic system. With spinning often done by farm women and the weaving by the men when the farm work was slack. Leeds in Yorkshire eventually became the main centre for the trade of wool cloth to be finished. By the mid 18 th century the town was producing and trading about 80000 pieces of broadcloth per year. In Britain the sudden expansion of the cotton industry can clearly be seen in the amounts of cotton fibre imported between 1700 and 1800. In 1700 there was barely 1000 tonnes of fibre imported, by 1780 this had climbed to about 3000 tonnes. Over the next twenty years with the introduction of widespread mechanisation, there was a nine fold increase to about 26000 tonnes.

By this time the Lancashire textile industry employed about 250000 workers which accounted for 36% of the working population of the north west. The cotton industries location was no accident. The availability of large quantities of water from the Pennines for both power and cloth processing, the proximity of substantial coal supplies for the later transfer to steam power, the salt for bleaching from Cheshire and the good communications by road, canal and rail to ports like Liverpool and Manchester, all added to the attractiveness of the region.The silk industry developed slowly in Britain and it was only in the late 17 th and early 18th

century that significant amounts of cloth were produced. Silk factories were established in Macclesfield, Stockport, Chesterfield, Manchester, Norwich and London. By about 1850 the industry employed about 130000 people in Britain. Small by comparison to cotton, but significant.

If only the evolution of man-made fibres and natural fibres and their respective share in the world production of fibres are considered, this leads to the conclusion that man-made fibres tend to take the place of natural fibres. An obvious conclusion since synthetic fibres alone have risen from zero in the 1920’s to over one third of the market in the early1990’s.

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However, this is not the case. The production of cotton, and even wool to a certain extent, have kept pace with the demand for synthetics. Since 1900, global cotton production has risen from about 3.5 million tones per year to 18.0 million tonnes per year with no signs of tailing off. Wool production doubled between the years 1900 to 1960, from about 1.5 million tonnes to 3.0 million tonnes per year, but since then production has been relatively static.

The demand for silk has been fairly constant since the First World War, at the relatively low level of about 50000 to 60000 tonnes per year, with a dip during the Second World War when production in Japan, the main silk producer at the time, collapsed. Man-made cellulosics grew from a global production of 22000 tonnes in 1920 to nearly 2.5 million tonnes in 1956. Since then production has remained pretty static due to the introduction of other, more useful and attractive, synthetic fibres.

Production of wholly synthetic man-made fibres really started in the late 1930’s, grew slowly and then took off explosively in the 1960’s, rising from 830000 tonnes in 1961 to 4178000 tonnes by 1968. Current world production of synthetics is running at about 18 million tonnes per year with polyester having the largest share of the synthetic market. The principal factor in making polyester the world’s most-used man-made fibre has been the dominant position of polyester/cotton blended fabrics in world markets. In the Far East investment in polyester-fibre plants has been particularly strong.

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Trends over the last thirty years or so therefore suggest that cotton is holding it’s own and that polyester has grown to be by far the most popular man-made fibre. This is likely to hold true in the short to medium term.

Any significant reduction in environmental impact will therefore not come about because of the use of one fibre in preference to another, purely on the basis of a slightly lower cradle to grave impact. There are environmental problems of one kind or another with all of the major fibres in current use. The answer must therefore be to improve processing, to minimise wastage, and to develop new or alternative chemicals and dyes with lower environmental impacts and toxicity. If we look at textile usage in slightly more detail, then in terms of fibre production the global market share of the principal textile fibres in 1994 was approximately as follows :-

The predominance of cotton for the natural fibres, and polyester for the manmade fibres clearly shows up. The two accounting for some 65% of the total textile market. The ‘Others’ category contain the polyamides. Within the textile industry there exists only limited options for fibre substitution. This is particularly true of the synthetic fibres which have been developed to satisfy a need. For example, nylon is dominant in women’s hosiery, some areas of lingerie and carpets, whilst polyester is dominant in the heavy workwear and ‘minimum care’ apparel markets. The consumption of fibres by end use gives a further indicator of trends in usage and subsequent wastage. This following example gives a breakdown of use in the EC for the year 1988/89. For the sake of simplicity all fibre usage has been expressed in terms of four fibre types and five usage categories. Each usage category adds up to 100%.

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Use Synthetic Cellulosic Cotton Wool

Apparel 42.6 10.9 32.9 13.9Carpets 84.7 0.5 1.4 3.4Domestic 42.1 12.3 42.2 3.4Industrial 55.6 21.9 21.3 1.1Tyres 39.4 59.3 1.3 0.0

The apparel category is dominated by polyester and cotton, with a smaller but significant volume of viscose and wool. A similar pattern is true of the domestic category, although the requirement for wool here is only tiny. Carpets use mainly nylon and wool. Industrial fibre usage is dominated by synthetics, which are used across a wide range of applications, from conveyor belts and geotextiles through to medical uses. Tyre production, which is also an industrial usage, but such an important one that it has been separated out here, requires both synthetics and cellulosics for tyre backing materials. It is important to note that the car industry accounts for about 35 to 40% of the total fibre consumed by these last two categories.

The organised recovery of waste textiles can be traced back as far as the old clothiers, many of whom were farmers involved in all stages of textile production. However, the practice of recovering waste is probably as old as the art of spinning and weaving. Shoddy and mungo was invented, as such, by Benjamin Law in 1813. He was the first to take old clothes and grind them down into a fibrous state that could be re-spun into yarn. The shoddy industry which was centred around the towns of Batley, Morley, Dewsbury and Ossett in West Yorkshire, concentrated on the recovery of wool from rags. The importance of the industry can be gauged by the fact that even in 1860 the town of Batley was producing over 7000 tonnes of shoddy. At the time there were 80 firms employing a total of 550 people sorting the rags. These were then sold to shoddy manufacturers of which there were about 130 in the West Riding. Waste cotton garments could not be pulled apart without creating too short a fibre and so waste cotton was generally used as a filling material and for cleaning cloths.

The shades of recovered wool produced by the shoddy trade, especially in the early days, tended because of the nature of the process, and the source of the garments, to be dull. There were lots of greys, blues, and blacks obtained from old uniforms. A lot of this went back into uniforms producing a complete cycle of use.

As more and more fibre blends and cotton appeared, and competition from the Italian recycling industry became stiffer, there was a tendency for the English rag trade to move towards garment sorting and the selling of second hand clothing to the third world. Today there are only about ten rag pulling companies left in the UK, even so, there is still a lot

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of textile waste produced. Typical figures for the waste produced at each stage of processing gives an idea of the potential for the minimisation and the recovery of waste.

Fibrous/Fabric Waste Production

It is worth noting that even in these days of increased environmental awareness, about a million tonnes of textiles are landfilled each year in the UK.

Key Inventions and InventorsJohn Kay (1704 – 1780) – Flying ShuttleThe son of a Lancashire farmer, John Kay patented his idea, the Flying Shuttle, in 1733. This new addition significantly improved the age old process of handloom weaving which relied on the yarn being passed from one hand to the other. The invention involved knocking a shuttle back and forth across the loom by means of a set of cords. This enabled weavers to produce wider fabrics at faster speeds. Failure to get payment for the use of his idea and the destruction of his house in Bury by angry weavers, afraid that the

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new shuttle would destroy their livelihood, forced Kay to emigrate to France where he died a pauper.

Lewis Paul (circa1700 – 1759) - Carding Machine Lewis Paul invented a Roller Spinning machine in 1738, and in 1748 a hand driven carding machine. Both inventions had their limitations when tried out in industrial conditions, but they provided later inventors and entrepreneurs, Arkwright in particular, with a useful starting point from which to develop further ideas.

James Watt (1736 – 1800) – Rotary Steam Engine James Watt was already a renowned engineer and instrument maker when in 1763 whilst reparing a Newcomen engine he discovered a way of making it more efficient. The new engine cooled the used steam in a condenser separate from the main cylinder. The invention was ideal for pumping water out of mines and was significantly more powerful than existing engines. Watt continued to develop the engine and in 1782 came up with the design for a rotary motion engine which would be ideal for driving machinery. By 1783Richard Arkwright was already using a Watt steam engine in one of his textile mills, and by 1800 over 500 had been purchased.

James Hargreaves (1720 – 1788) – Spinning JennyJames Hargreaves, a weaver from Blackburn, had the idea for an improved spinning machine when the family spinning wheel was accidentally knocked over. He saw the potential for a whole row of spindles worked off a single wheel. In 1764 he built the first Spinning Jenny which could spin eight threads at once. By 1770, because the invention had not been patented, the machine had been copied and improved by others to enable eighty threads to be spun at once. The invention of the Jenny caused uproar amongst the traditional Lancashire spinners, a group of whom marched on his house and destroyedhis equipment.

Richard Arkwright (1732 – 1792) – Water FrameThe idea for the Water Frame came from work originally done by a clockmaker from Warrington called John Kay. Arkwright, a wig maker from Preston employed Kay, who had run out of funds, to make the new machine. Arkwright made improvements to the spinning frame which involved three sets of paired rollers that turned at different speeds, producing a strong twisted yarn, and set up a factory by the River Derwent using what was now called the Water Frame. The name change came about because the spinning frame had become too large to be manually operated and so the power of the water wheel had to be used. The invention of the Water Frame produced a need for more cardings.Arkwright turned his attention to this new bottleneck in production. The carding machine invented by Lewis Paul in 1748 was improved by Arkwright in 1775.

The new machine incorporated a crank and comb mechanism producing a continuous film of fibre. Arkwright went on to build factories in Lancashire, Staffordshire, Derbyshire and Scotland. The later factories using the rotary steam engine invented by

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James Watt instead of water power. On his death in 1792 Richard Arkwright was a very wealthy man with an estimated fortune in excess of £500 000.

Samuel Crompton (1753 – 1827) – Spinning MuleThe Spinning Mule, devised by Samuel Crompton in 1779, was a hybrid of the earlier Spinning Jenny and the Water Frame. The Mule which was initially a small hand operated machine produced a strong, yet fine and soft yarn. By the 1790’s a larger steam or water powered version was being built with over 400 spindles. Sadly because Crompton was too poor to apply for a patent he sold the rights to a Bolton manufacturer and made no money from the subsequent sale of his invention.

Edmund Cartwright (1743 – 1823) – Power LoomCartwright, the well educated son of a Nottingham landowner became interested in the new textile industry when visiting a factory owned by Richard Arkwright. In 1784, with the help of a carpenter and blacksmith, he began working on a machine that would improve the speed and quality of weaving. A basic version of the Power Loom was patented in the following year. The invention revolutionised weaving, changing it from a manual process into a mechanical one. The weaver now spent most of his time repairing broken threads. The invention was improved by William Horrocks of Stockport between 1803 and 1814, and subsequently by Richard Roberts of Manchester who effectively invented the definitive power loom.

Joseph Jacquard (1752 – 1834) – Jacquard LoomJacquard, the son of a silk weaver from Lyons, was a failed businessman when in 1801 he developed a loom that used a series of punched cards to control a complex pattern of warp threads. Further work on the idea produced the familiar looped arrangement of cards for the repeat patterns used in cloth and carpet designs. The invention now enabled intricate patterns to be woven without the continual intervention of the weaver.

Jacquard Loom

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One interesting effect of this invention was the adaptation by Charles Babbage of the card system invented by Jacquard in his work to produce an automatic calculator, which eventually led to the development of computers and computer programming.

William Perkin (1838 – 1907) – Synthetic DyesWilliam Perkin studied at the Royal College of Chemistry under von Hoffman and at the tender age of 18 discovered the first synthetic dye, mauveine. He went on to set up his own business and within five years had made his fortune. At 35 he retired from business but continued to experiment leading to the discovery of coumarin, the first synthetic perfume.

Other Key Developments

1785 – Bell develops roller or cylinder printing.

1786 – Bertholet develops method for using chlorine water for commercial bleaching. The use of hydrogen peroxide follows shortly after.

1797 –Bancroft invents a process for steam fixation of prints.

1828 – John Thorp patented the first ringframe for spinning yarn.

1834 – Runge with his work on the distillation of coal tar paved the way for later work done in developing aniline dyes.

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1862 – The first soluble azo dye synthesised by Martius and Lightfoot.1868 – Graebe and Liebermann synthesised alizarin, a synthetic substitute formadder a widely used vegetable dye.

1878 – Von Baeyer successfully synthesised indigo.

1884 – The first direct cotton dye Congo Red was created by Bottinger.

1886 – Northrop automatic bobbin changing loom first used.

1891 – The first commercial rayon plant was built by Chardonnet at Besancon, France.

1901 – Bohn synthesised Indanthrene Blue RS, the first anthraquinone vat dye.

1951 – Polyester manufactured commercially at the DuPont plant in North Carolina.

1953 - Cibalan Brilliant Yellow 3GL introduced. This led the way to fibre reactive dyes. ICI introduced the Procion range of reactives by 1956.

Textile processing techniques

In order to determine the true environmental impact of textile processing, the main types of machinery in current use , together with typical processing routes needs to be described. The pollutants and waste generated by processes together with typical levels or concentrations, emitted or discharged help to provide a more detailed picture of textiles.

For convenience, the whole textile chain has been split in to the seven main sections. These are fibre production, fibre to fabric, preprative treatments, textile coloration, finishing processes, fabric after and recycling and disposal

Fibre production- this includes the details on cotton growing, sheep rearing, sericulture and the generation of man made fibres

Fibre to fabric-which contains information on the types of machinery used in spinning, weaving, knitting and non-woven production

Preprative treatments- which includes details of processes such as singeing, desizing, scouring, and bleaching

Textile coloration- contains different methods used for dyeing and printing.

Finishing processes- includes information on coating and lamination, wet chemical finishing and mechanical finishing processes.

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Fabric aftercare- which contains information on different types of commercial laundry and dry leaning machineries.

Recycling and disposal- looks at the processes involved in textiles, the segregation techniques and different end-uses.

These stages are explained in several CLASSES ahead.

Classes of TextilesThe textiles covers various stratas amd have a gfreat impact on every day life of human beings. In order to determine the true environmental impact of textile processing, the main types of machinery in current use, together with typical processing routes need to be described. The pollutants and waste generated by processes together with typical levels or concentrations, emitted or discharged help to provide a more detailed picture of textiles.

For convenience, the whole textile chain has been split in to the seven main sections. These are fibre production, fibre to fabric, preprative treatments, textile coloration, finishing processes, fabric after and recycling and disposal.

1. Fibre production- this includes the details on cotton growing, sheep rearing, sericulture and the generation of man made fibres

2. Fibre to fabric-which contains information on the types of machinery used in spinning, weaving, knitting and non-woven production

3. Preprative treatments- which includes details of processes such as singeing, desizing, scouring, and bleaching

4. Textile coloration- contains different methods used for dyeing and printing.

5. Finishing processes- includes information on coating and lamination, wet chemical finishing and mechanical finishing processes.

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6. Fabric aftercare- which contains information on different types of commercial laundry and dry leaning machineries.

7. Recycling and disposal- looks at the processes involved in textiles, the segregation techniques and different end-uses.

However a simpler way of describing the above chain can be:-

Ginning Spinning Weaving Pretreatment Dye/Print FINISH

Dispose End use

Ginning It is the process in which the cotton fibres are separated from their seeds and refined a bit.Moreover it is used to effectively bring the cotton fibre in the form that can be easily used by the next big stage of Spinning. Otherwise the attached cotton seed and many other impurities may not allow the effective formation of yarn

A typical spinning Mill

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Spinning It is the process in which the cotton yarn is produced. Not only cotton but many other types of fibres may-be used for the production of yarn. For example the silk filament is used for the production of silk yarn. Similarly the jute threads or many other regenerated and synthetic fibres in the fluid form are used for the preparation for their respective type.

In case of cotton yarn, it can be carded, combed, single ply, double ply and so on

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Spinning process in Pakistan is done in two technologies

1. Ring spun yarn2. Open end spun yarn

Ring spun yarn

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Open end spinning

Weaving The term weaving means to weave or to bring the yarn in a form that make up fabric, by either the interlacement of warp and weft or by the interloping of yarn(commonly called knitting)

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Wet-processingThis is the anther entirely different stage of textile sector. It involves various complicated and important stages, and can be divided as such:-

Pretreatments 1. singe2. desize3. scour4. bleach5. mercerize

Dyeing/Printing

Finishing

End use

PretreatmentsThe term “pretreatments” include all operations of preparing the textile material, such as fibres yarn and woven, knit and non-woven fabrics and garments for the subsequent processes for dyeing printing and finishing. For all practical purposes the pretreatments are carried out along with dyeing and printing and their equipments is part of the wet-processing plant.

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The main objective of pretreatments is to impart textile materials a uniform and high degree of absorptivity to aqueous liquor with the minimum possible damage to the fibrous material. The pretreatments of cotton fabrics, for example, should remove natural all impurities like pectins, wax, protein and husk as well as sizing chemicals comprising of softeners and adhesives. Besides high and uniform absorptivity, the textile material should have adequate degree of whiteness so as not to mar the

The process of pretreatment refers to the application of chemicals and axillaries on the textiles to the features such as

Removal of waxes, pectins, jute strings, rags, Remove hairy fibres on the fibre surface Absorbancy Lusture Ability to absorb dye Removal of pigments Whiteness Swelling of the fibre structure Emerizing(optional) Fibre alignment

The above results are obtained in a continuous range of machines, of which each have a specific operation and working.

Singeing-cum-DesizingIt is the process of removing protruding fibres from the surface of the fabric. Textiles are normally singed in order to improve their surface appearance and wearing properties.  The burning-off of protruding fibre-ends, which are not firmly bound in the yarn, results in a clean surface which allows the structure of the fabric to be clearly seen.   Un-singed fabrics soil more easily than singed fabrics.  Similarly, the risk of cloudy dyeing with singed articles dyed in dark shades is considerably reduced than un-singed articles.

Although textile materials can be singed in yarn, knitted or woven forms, singeing of woven fabrics is much more common as compared to other forms. Two main methods of singeing are direct flame singeing and indirect flame singeing. The important direct flame singeing parameters are:

Singeing position Flame intensity Fabric speed Distance between the fabric and the burner Moisture in the fabric coming for singeing

If any one or more of the above parameters are not optimal, the result may be faulty singeing. There may be singeing faults which are optically demonstrable and are quite easily remedied during the actual working process.

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Special burners, two of which are provided for the machine. These burners have a particular combustion chamber and are provided with water-cooling arrangement. The cloth can be threaded so as to allow singeing of either one or both sides. It is essential to note that the gas consumption per meter of fabric is less as compared with a machine of conventionaldesign.

Both burners are titled away simultaneously (by 45º) by electro-magnets.The Burners can be easily cleaned as a special arrangement has been provided.Slit width and flame length adjustments are provided.Non-return valve is incorporated in burner, which isolates the supply line from the burner chamber.High Singeing speeds, infinitely variable between 80 mtrs. To 150 mtrs/min.Excellent and uniform singeing effect with economical gas consumption.Burners turning away automatically when the machine stops.Efficient dust extraction device.Pre-heating Cylinders of Stainless Steel Construction.Water Cooled adjustable rollers immediately after the Burners to obtain soft, medium or high singeing effectSteam quenching device also provided on request.

Desizingdesizing refers to the removal of starches and sizes from the fabric before the fabric is set for upcoming processes. Desizing can be carries by various purposes, some of which are mentioned

Enzyme DesizingEnzyme desizing is the most widely practiced method of desizing starch. Enzymes are high molecular weight protein biocatalyst that are very specific in their action. Enzymes are named after the compound they break down, for example, Amylase breaks down amylose and amylopectin, Maltase breaks down maltose and Cellulase breaks down cellulose. For desizing starch, amylase and maltase are used. Cellulase, on the other hand, is used for finishing cotton fabrics. Amylase will degrade starch into maltose, a water soluble disaccharide and Maltase will convert maltose into glucose, a simple sugar.

Desizing with AcidsMineral acids will hydrolyze starch by attacking glucosidic linkages. Acid hydrolysis lowers the molecular weight and eventually reduce starch to glucose. Hydrochloric and

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sulfuric acids can be used. One problem with acid desizing is that cellulose fibers are also degraded which is why the method is not used much. One advantage with using acids is that cotton fibers can be demineralized more easily. Insoluble salts are solubilized by acids making the removal of such troublesome metals such as iron more thorough.

De-sizing compartment with 12 /16 mtrs. Contents can be provided with a suitable squeezing mangle.

Sr No

Description

1 TENSION UNIT WITH GUIDE ROLLERS & BARS

2 S.S. PRE-DRYING CYLINDER (OPTIONAL)

3 PRE-BUSHING UNIT WITH SUCTION

4 SINGEING CHAMBER WITH EXHAUST

5 WATER-COOLED ROLLER

6 WATER-COOLED BURNER

7 CARBURETOR WITH BLOWER

8 STEAM QUENCHING DEVICE

9 POST BRUSHING WITH SUCTION (OPTIONAL)

10 DE-SIZING UNIT ST-12/ST-15

11 SQUEEZING MANGLE 3 TONS.

12MAIN DRIVE (A.C. MOTOR WITH FREQUENCY CONTROLLER)

Scouring

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Natural fibers contain oils, fats, waxes, minerals, leafy matter and motes as impurities that interfere with dyeing and finishing. Synthetic fibers contain producer spin finishes, coning oils and/or knitting oils. Mill grease used to lubricate processing equipment mill dirt, temporary fabric markings and the like may contaminate fabrics as they are being produced. The process of removing these impurities is called Scouring.

Even though these impurities are not soluble in water, they can be removed by Extraction, dissolving the impurities in organic solvents, Emulsification, forming stable suspensions of the impurities in water and Saponification, Converting the contaminates into water soluble components.

Certain organic solvents will readily dissolve oils fats and waxes and these solvents can be used to purify textiles. Removal of impurities by dissolution is called Extraction. There are commercial processes where textiles are cleaned with organic solvents. Fabrics processed this way are said to be "Dry Cleaned". Although not widely used as a fabric preparation step, it is an important way of removing certain difficult to remove impurities, where a small amount of residuals can cause downstream problems. Garment dry-cleaning is more prevalent.

For fabrics that do not have to be desized, solvent scouring is an effective way of removing fiber producer finishes, coning and knitting oils. Knitted fabrics made from nylon, polyester, acetate and acrylics, are particularly amenable to this method of preparation. Wool grease is effectively removed by solvent scouring. Solvent Extractions are particularly useful in the laboratory for determining the amount of processing oils added to man-made fibers and the residual amounts of oils and waxes left by aqueous scouring. Properly controlled, fabrics can be produced with very little residual matter.

Schematic of a Continuous Scouring Range

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Bleachingthe process of whitening or depriving objects of colour, an operation incessantly in activity in nature by the influence of light, air and moisture. The art of bleaching, of which we have here to treat, consists in inducing the rapid operation of whitening agencies, and as an industry it is mostly directed to cotton, linen, silk, wool and other textile fibres, but it is also applied to the whitening of paper-pulp, bees'-wax and some oils and other substances. The term bleaching is derived from the A.-S. blaecan, to bleach, or to fade, from which also comes the cognate German word bleichen, to whiten or render pale. Bleachers, down to the end of the 18th century, were known in England as " whitsters," a name obviously derived from the nature of their calling. The operation of bleaching must from its very nature be of the same antiquity as the work of washing textures of linen, cotton or other vegetable fibres. Clothing repeatedly washed, and exposed in the open air to dry, gradually assumes a whiter and whiter hue, and our ancestors cannot have failed to notice and take advantage of this fact. Scarcely anything is known with certainty of the art of bleaching as practised by the nations of antiquity. Egypt in early ages was the great centre of textile manufactures, and her white and coloured linens were in high repute among contemporary nations. As a uniformly wellbleached basis is necessary for the production of a satisfactory dye on cloth, it may be assumed that the Egyptians were fairly proficient in bleaching, and that still more so were the Phoenicians with their brilliant and famous purple dyes. We learn, from Pliny, that different plants, and likewise the ashes of plants, which no doubt contained alkali, were employed as detergents. He mentions particularly the Struthium as much used for bleaching in Greece, a plant which has been identified by some with Gypsophila Struthium. But as it does not appear from John Sibthorp's Flora Graeca, edited by Sir James Smith, that this species is a native of Greece, Dr Sibthorp's conjecture that the

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Struthium of the ancients was the Saponaria qfficinalis, a plant common in Greece, is certainly more probable. Cotton is bleached in the raw state, as yarn and in the piece. In the raw state, and as yarn, the only impurities present are those which are naturally contained in the fibres and which include cotton wax, fatty acids, pectic substances, colouring matters, albuminoids and mineral matter, amounting in all to some 5% of the weight of the material. Both in the raw state and in the manufactured condition cotton also contains small black particles which adhere firmly to the material and are technically known as " motes." These consist of fragments of the cotton seed husk, which cannot be completely removed by mechanical means. The bleaching of cotton pieces is more complicated, since the bleacher is called upon to remove the sizing materials with which the manufacturer strengthens the warp before weaving

A. Bleaching MechanismSodium hypochlorite is the salt of a moderately strong base (OCl-) and a weak acid (HOCl). Solutions are therefore alkaline. The species present in a solution can be understood from the following:Note: Hypochlorous acid (HOCl) is the active bleaching agent.

B. Effect of pHpH has a profound effect on bleaching with hypochlorite.1. If caustic is added to the solution, the equilibrium shifts to the left favoring the formation of the hypochlorite ion (OC1-) at the expense of hypochlorous acid (HC1O). Under strongly alkaline conditions (pH > 10), little to no bleaching takes place. 2. When acid is added, the equilibrium shifts to the right and the HOCl concentration increases. At a pH between 5 and 8.5, HOCl is the major specie present so very rapid bleaching takes place. However, rapid degradation of the fiber also takes place.

3. When the pH drops below 5, chlorine gas is liberated and the solution has no bleaching effectiveness at all.

4. The optimum pH for bleaching is between 9 and 10. Although the concentration of HOCl is small, it is sufficient for controlled bleaching. As HOCl is used up, the equilibrium conditions continue to replenish it. This pH range is used to minimize damage to the fiber. Sodium carbonate is used to buffer the bleach bath to pH 9 to 10.

C. Effect of Time and TemperatureTime and temperature of bleaching are interrelated. As the temperature increases, less time is needed. Concentration is also interrelated with time and temperature. Higher concentrations require less time and temperature. In practice, one hour at 400 C is satisfactory for effective bleaching.

D. Effect of MetalsCopper and iron catalyze the oxidation of cellulose by sodium hypochlorite degrading the fiber. Fabric must be free of rust spots or traces of metals otherwise the bleach will damage the fabric. Stainless steel equipment is required and care must be taken that the

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water supply be free of metal ions and rust from pipes. Prescouring with chelating agents becomes an important step when bleaching withhypochlorites.

Recommended recipes:-

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MercerizingThe term applied to a process, discovered in 1844 by John Mercer, a Lancashire calico printer, which consists in treating cotton (and to a limited extent other plant fibres) with strong caustic soda or certain other reagents, whereby morphological and chemical changes are brought about in the fibre. Thus, if a piece of bleached calico be immersed in caustic soda of 50° Tw. strength (sp. gr. 1.25), it rapidly changes in appearance, becoming stiff and translucent, but when taken out and well washed in running water it loses these properties and apparently reverts to its original condition. On closer examination, however, the fabric is found to have shrunk considerably both in length and breadth, so as to render the texture quite different in appearance to that of the original calico; it is also considerably stronger, and if dyed in the same bath along with some of the untreated fabric is found to have acquired a greatly increased affinity for colouring matters. This peculiar action is not restricted to caustic soda, similar effects being obtained with sulphuric acid of 105° Tw., nitric acid of 83° Tw., zinc chloride solution of 145° Tw., and other reagents. Mercer assumed that a definite compound, corresponding to the formula C12H20010.Na20 is formed when the cotton is steeped in caustic soda, and that this is decomposed by subsequent washing with water into a hydrated cellulose C12H20010H20, which would account for the fact that in the air-dried condition mercerized cotton retains about 5% more hygroscopic moisture than ordinary cotton. This view is strengthened by the observation that when cotton is immersed in nitric acid of 83° Tw. it acquires similar properties to cotton treated with caustic soda. If, after immersion in the nitric acid, it is squeezed and then dried (without washing) in a vacuum over burnt lime, it is found to have formed a compound which corresponds approximately to the formula C 6 H 10 0 5 .HNO 3, which is decomposed by water into free nitric acid and a hydrated cellulose.

When viewed under the microscope, mercerized cotton is seen to have undergone considerable morphological changes, in asmuch as the lumen or central cavity is much reduced in size, while the fibre has lost its characteristic band-shaped appearance and becomes rounded.

In Mercer's time the process, which he himself termed "sodaizing" or "fulling," never acquired any degree of corn mercial success, partly on account of the expense of the caustic soda required, but mainly on account of the great shrinkage (20 to 25%) which took place in the cloth. An important application of the process in calico printing for the production of permanent crimp or "crepon" effects, which was originally devised by Mercer, was revived in1890-1891and is still largely practised by calico printers (see Textile Printing). Another application, also dependent upon the shrinking action of caustic soda on cotton, was patented in 1884 by Depoully, and has for its object the production of crimp effects on piece-goods consisting of wool and cotton or silk and cotton. In the manufacture of such goods cotton binding threads are introduced at definite intervals in the warp or weft, or both, and the piece is passed through cold caustic soda, washed, passed through dilute sulphuric acid, and washed again till neutral. The cotton contracts under the influence of the caustic soda, while both wool and silk remain unaffected, and the desired crimped or puckered effect is thus obtained.

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By far the most important application of the mercerizing process is that by which a permanent lustre is imparted to cotton goods; this was discovered in 1889 by H. A. Lowe, who took out a patent for his process in that year, this being supplemented by a further patent in 1890. Since Lowe's invention did not receive sufficient encouragement, he allowed his patents to lapse and the process thus became public property. It was not until 1895, when Messrs Thomas & Prevost repatented Lowe's invention, that actual interest was aroused in the new product and the process became a practical success. Their patent was subsequently annulled on the ground of having been anticipated.

The production of a permanent lustre on cotton by mercerizing is in principle a very simple process, and may be effected in two ways. According to the first method, the cotton is treated in a stretched condition with strong caustic soda, and is then washed, while still stretched, in water. After the washing has been continued for a short time the tension relaxes, and it is then found that the cotton has acquired a permanent lustre or gloss similar in appearance to that of a spun silk though not so pronounced. According to the second method, which constitutes but a slight modification of the first, the cotton is immersed in caustic soda of the strength required for mercerizing, and is then taken out, stretched slightly beyond its original length, and then washed until the tension slackens.

Not all classes of cotton are equally suited for being mercerized. Thus, in the case of yarns the most brilliant lustre is always obtained on twofold or multifold yarns spun from long-stapled cotton (Egyptian or Sea Island). Single yarns made from the same quality of cotton are only slightly improved in appearance by the process, and are consequently seldom mercerized; and the same applies to twofold yarns made from ordinary American cotton. In piece-goods, long-stapled cotton also gives the best results, but it is not necessary that the yarn used for weaving should be twofold. In the great majority of cases, the mercerizing of cotton, whether it be in the yarn or in the piece, is done before bleaching, but sometimes it is found preferable to mercerize after bleaching, or even after bleaching and dyeing. The strength of the caustic soda employed in practice is generally between 55° and 60° Tw. The temperature of the caustic soda hasj a material influence on its action on the cotton fibre, very much stronger solutions being required to produce the same effect at elevated temperatures than at the ordinary temperature, while, on the contrary, by lowering the temperature it is possible to obtain a good lustre with considerably weaker lyes.

Cotton yarn may be mercerized either in the hank or in the warp, and a great number of machines have been patented and constructed for the purpose. The simplest form of machine for hanks consists essentially of two superposed strong steel rollers, on which the hanks are placed and spread out evenly. The upper roller, the bearings of which run in a slotted groove, is then raised by mechanical means until the hanks are taut. Caustic soda of 60° Tw. is now applied, and the upper roller is caused to revolve slowly, the hanks acting as a belt and causing the lower roller to revolve simultaneously. After about three minutes the caustic soda is allowed to drain off and the hanks are washed by spurt pipes until they slacken, when they are taken off and rinsed, first in dilute sulphuric acid (to neutralize the alkali and facilitate washing), and then in water till neutral. The hanks are then bleached in the ordinary way and may be subsequently dyed, no diminution being

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brought about in the lustre by these operations. Cotton warps are usually mercerized on a machine similar in construction to a four box dyeing machine (see Dyeing), but with the guiding rollers and their bearings of stronger construction and the squeezers at each end of the first box with a double nip (three rollers). The first box contains caustic soda, the second water, the third dilute sulphuric acid, and the fourth water.

For the continuous mercerizing of cotton in the piece much more complicated and expensive machinery is required than for yarn, since it is necessary to prevent contraction in both length and breadth. The mercerizing range in most common use for pieces is constructed on the same principle as the stentering machine used in stretching pieces after bleaching, dyeing or printing, and consists essentially of two endless chains carried at either end by sprocket wheels. The chains carry clips which run in slotted grooves in the horizontal frame of the machine, which is about 40 ft. in length. The clips close automatically and grip the cloth on either side as it is fed on to the machine from the mangle, in which it has been saturated with caustic soda. The stretching of the piece begins immediately on entering the machine, the two rows of clips being caused to diverge by setting the slotted grooves in such a manner that when the piece has travelled about one-third of the length of the machine it is stretched slightly beyond its original width. At this point the piece meets with a spray of water, which is thrown on by means of spurt pipes; and in consequence the tension slackens and the mercerizing is effected. When the piece arrives at the end of the machine the clips open automatically and release it. Thence it passes through a box containing dilute sulphuric acid, and then through a second box where washing with water is effected.

In most large works the caustic soda washings, which were formerly run to waste or were partly used up for bleaching, are evaporated down in multiple effect evaporators to 90° Tw., and the solution is used over again for mercerizing.

Cotton mercerized under tension has not as much affinity for colouring matters as cotton mercerized without tension, and although the amount of hygroscopic moisture which it retains in the air-dried condition is greater than in the case of ordinary untreated cotton, it is not so great as that held by cotton which has been mercerized without tension. By drying cotton which has been mercerized with or without tension at temperatures above 100° C. its affinity for colouring matters is materially decreased.

The cause of the lustre produced by mercerizing has been variously explained, and in some cases antagonistic views have been expressed on the subject. When viewed under the microscope by reflected light, the irregularly twisted band-shaped cotton fibre is seen to exhibit a strong lustre at those points from which the light is reflected from the surface. Cotton mercerized without tension shows a similar appearance. In the yarn or piece the lustre is not apparent, because the innumerable reflecting surfaces disperse the light in all directions. If, however, the cotton has been mercerized under tension, being plastic while

Dyeing

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A colorant is a substance capable of imparting its colour to a given substrate, such as paint, paper or cotton, in which it is present. Not all colorants are dyes. A dye must be soluble in the application medium, usually water, at some point during the coloration process. It will also usually exhibit some substantivity for the material being dyed and be absorbed from the aqueous solution. Most textile dyeing processes initially involve transfer of the coloured chemical, pores, or between fibre polymer molecules, depending on the internal structure of the fibre. or its precursor, from the aqueous solution onto the fibre surface; a process called adsorption. From there, the dye may slowly diffuse into the fibre. This occurs down

The process of applying dyes on to the substrate(fabric) such that the dyes are applied in the solution form, called dye liquor. There are various classes of dyes depending on the type of substrate, and the method of application varies accordingly

Normally the dyes used in the industry for the dyeing of cotton, or other cellulosic, proteinic, regenerated, or synthetic fabrics are following

Direct dyes Reactive dyes Vat dyes Sulphur dyes Azoic dyes Disperse dyes Acid or Anionic dyes, pre-mettalised or mordant dyes Basic or cationic dyes

Direct dyesDirect cotton dyes have inherent substantivity for cotton, and for other cellulosic fibres. Their aqueous solutions dye cotton usually in the presence of an electrolyte such as NaCl or Na2SO4. Direct dyes do not require the use of a mordant and, as their name implies, the dyeing procedure is quite simple. The goods go into the bath followed by the dissolved dyes. The bath is then gradually heated, usually to the boil, and additions of salt promote dyeing.

Many direct dyes are relatively inexpensive. They are available in a full range of hues but are not noted for their colour brilliance. Their major drawback is their poor to moderate fastness to washing. This limits their use to materials where good washing fastness is not critical. The light fastness of dyeings with direct dyes on cellulosic fibres varies from poor to fairly good, although some copper complex direct dyes have very good light fastness. As usual, the deeper the colour of the dyeing, the lower the fastness to wet treatments, and the higher the fastness to light. Various aftertreatments of the dyeings improve the fastness to washing.

In some cases, however, such aftertreatments decrease the light fastness. They also invariably cause a change in hue that makes shade correction and colour matching more difficult. Cotton, and other cellulosic fibres, are dyed with direct, sulphur, vat, reactive or

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azoic dyes – more types than for any other fibre. Each of these classes of dye has its own application methods, dyeing characteristics, cost, fastness properties and colour range, and therefore its own particular advantages and disadvantages.

Within each group, application and performance properties vary considerably so the choice of which dyes to use is often not easy. Direct dyes generally cannot meet today’s more stringent washing fastness requirements for apparel and linens. In recent years, their share of the market has gradually declined in favour of reactive dyes. The latter have very good washing fastness on cellulosic materials and often have bright colours.

Reactive dyesThe idea of immobilizing a dye molecule by covalent bond formation with reactive groups in a fibre originated in the early 1900s. Various chemicals were found that reacted with the hydroxyl groups of cellulose and eventually converted into coloured cellulose derivatives. The rather forceful reaction conditions for this led to the false conclusion that cellulose was a relatively unreactive polymer. Possibly because of this, a number of dyes now known to be capable of covalent bond formation with groups in wool and cotton were not initially considered as fibre-reactive dyes, despite the good fastness to washing of their dyeings. In 1955, Rattee and Stephen, working for ICI in England, developed a procedure for dyeing cotton with fibre-reactive dyes containing dichlorotriazine groups. They established that dyeing cotton with these dyes under mild alkaline conditions resulted in a reactive chlorine atom on the triazine ring being substituted by an oxygen atom from a cellulose hydroxyl group. This is shown where Cell–OH is the cellulose with a reactive hydroxyl group, Dye–Cl is the dye with its reactive chlorine atom, and Cell–O–Dye the dye linked to the cellulose by a covalent bond. The role of the alkali is to cause acidic dissociation of some of the hydroxyl groups in the cellulose, and it is the cellulosate ion (Cell–O–) that reacts with the dye.

The dyeing had very good fastness to washing. The only way the fixed dye can bleed from the cotton is after hydrolysis of the covalent bond between the dye and the cellulose. This requires conditions more forceful than those met with in ordinary washing in hot water. Within about five years of this important development, all the major dyestuff manufacturers were marketing reactive dyes for cotton, and also for wool. Reactive dyes, particularly those used for dyeing cotton, have become one of the major classes of dye because of their good washing fastness, their bright shades and their versatile batch and continuous dyeing methods.

Vat dyesVat dyes are one of the oldest types of dye. Vat dyes in particular give dyeing on cellulosic fibres with the best overall fastness properties. Because of the popularity of

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blue jeans, Indigo is still one of the most important of all dyes in present use. Natural Indigo was obtained by extraction from leaves, by fermentation in wooden vats, the origin of the term ‘vatting’.

Today, Indigo is synthesised from manufactured intermediates. Its application involves reduction to the water-soluble leuco compound, dyeing the cotton and re-oxidation of the leuco dye in the fibres to the insoluble pigment, the three basics steps involved in vat dyeing.

Vat dyes are water-insoluble pigments. They are called dyes because chemical reduction in alkaline solution converts the pigment into a water-soluble leuco form with substantivity for cotton. The vat pigment and the leuco compound often have quite different colours – blue and pale yellow in the case of Indigo – so the progress of the reduction is often easy to observe. After dyeing with the leuco compound, the pigment is regenerated in the dyed cotton by oxidation. The overall process therefore involves three key steps:

(1) reduction of the pigment to the soluble leuco compound, a process calledvatting;

(2) absorption of the leuco compound by the cotton during dyeing;

(3) oxidation of the absorbed leuco compound in the cotton, reforming theinsoluble pigment inside the fibres.

The use of strongly alkaline solutions (pH 12–14) for vatting and dyeing limits theuse of most vat dyes to cellulosic fibres

Sulphur dyes

Sulphur dyes are a type of vat dye used for dyeing cellulosic fibres. The insoluble pigment is converted into the substantive leuco compound by reduction with sodium sulphide and the leuco form is subsequently oxidised inside the fibre. Sulphur dyes are manufactured by heating organic materials with sodium polysulphide in aqueous or alcoholic solution, or by baking with sodium sulphide and sulphur. A variety of organic compounds are used including amines, nitro compounds, and phenols and their derivatives. These dyes almost always contain loosely bound sulphur and liberate hydrogen sulphide when treated with acidic solutions of reducing agents such as stannous chloride.

The chemistry of sulphur dyes is very complex and little is known of the molecular structures of the dyestuffs produced. The Colour Index only gives the structures of the starting materials that are used to produce these dyes and even then the information can be quite misleading. Two products manufactured from the same starting materials are unlikely to have similar properties even though they may have the same CI number. The actual dyestuffs produced from the same materials by different processes may have quite

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different dye contents, dyeing characteristics and environmental impacts. Because of the large amounts of sodium sulphide used in the manufacture and application of these dyes, much of which will eventually be found in the effluent, they pose a significant environmental problem. In this respect, sulphur dyestuffs produced in the developed Western nations are much more environmentally friendly. A variety of structural units have been proposed for various sulphur dyes. It is generally accepted that these dyes are polymeric having sulphur containing aromatic heterocyclic units such as thiazines and thiazoles linked by di- or polysulphide bonds. On treatment of an aqueous dispersion of the insoluble pigment with sodium sulphide, the sulphide links are reduced forming individual heteroaromatic units with thiol groups. These are soluble in the alkaline solution in the form of thiolate ions that have low to medium substantivity for cellulose. Over-reduction is possible if other groups are affected and the more powerful hydros is rarely used as the reducing agent.

After dyeing of the cellulosic material, the thiolate ions in the fibres can be re-oxidised back to the polymeric pigment with di-sulphide bonds linking the aromatic units. Sulphur dyes often have dull yellow vats and sulphide and polysulphide solutions are usually pale yellow. For these reasons, the colour content of a given product cannot be assessed by the usual spectrophotometric method and it is necessary to prepare dyeings and compare their colours

Azoic dyesThese usually are water-insoluble mono- or bisazo compounds precipitated in the fibre by reaction of a diazonium ion with a suitable coupling component. The name ‘azoic dye’ is somewhat confusing, since many soluble dyes are also azo dyes. The name ‘azoic combination’ is preferable.

The production of dyeings with Para Red, one of the first azoic combinations (1880), illustrates the basic principle of dyeing with this type of dye. Cotton fabric was first impregnated with an alkaline solution of 2-naphthol. It was dried and then padded with an acidic solution of diazotised p-nitroaniline (2). A deep red pigment formed in the cotton fibres (3). A final soaping at the boil removed pigment particles adhering to the fibre surfaces. This gave the optimum fastness to washing, light and rubbing, although these were not outstanding. Intermediate drying was necessary because 2-naphthol has poor substantivity for cotton and tended to bleed out of the wet fabric into the diazonium ion bath causing pigment formation, particularly on the fibre surfaces. The introduction of coupling components with much higher substantivity for cotton overcame this problem, and also decreased the migration of the coupling component to the yarn surfaces during the intermediate drying.

Azoic combinations are still the only class of dye that can produce very deep orange, red, scarlet and bordeaux shades of excellent light and washing fastness. The pigments produced have bright colours, and include navies and blacks, but there are no greens or bright blues. The actual hue depends on the choice of the diazonium and coupling components. Their use on cotton today is more and more limited, largely because of the success of fibre-reactive dyes for cotton. Black shades on polyamide, polyester and

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acetate fibres are also often azoic combinations. For azoic dyeing of these artificially-made fibres, a dispersion of the primary amine and coupling component is used. The fibres absorb these like disperse dyes. The amine is then diazotised in the fibre and reacts with the aoupling component to give the azo pigment.

Disperse dyesCotton can be dyed with anionic direct, sulphur, vat, reactive and azoic dyes. These types of dyes, however, are of little use for the dyeing of synthetic fibres. Disperse dyes, on the other hand, are non-ionic. They dye all the synthetic and cellulose acetate fibres using a direct dyeing technique. Only the dyeing temperature varies from one fibre to another. They are thus one of the major classes of dyestuff. The development of disperse dyes for dyeing secondary cellulose acetate fibres in the early 1920s was a major technological breakthrough. Their major use today is for the coloration of polyesters, the most important group of synthetic fibres.

What is a disperse dye? These non-ionic dyes are relatively insoluble in water at room temperature and have only limited solubility at higher temperatures. They do, however, possess substantivity for hydrophobic fibres such as nylon and polyester, in which they are quite soluble. As their name implies, these dyes are present in the dyebath as a fine aqueous suspension in the presence of a dispersing agent. The water dissolves a small amount of the dye in monomolecular form. The hydrophobic fibres then absorb the dye from the solution. Because these dyes are non-ionic organic compounds of relatively low molecular weight, many sublime on heating and dyeing by absorption of the dye vapour is also possible. When cellulose diacetate fibres first appeared in 1921, few of the available ionic dyes were able to successfully colour them. Secondary acetate fibres absorb little water, do not swell and have only small pores. In addition, their surface potential is much more negative than that of cotton and therefore they repel anionic dyes.Although cellulose diacetate fibres will absorb some cationic dyes, and a few acid dyes, there is little or no penetration of the dye unless the fibre is pre-swollen. The dyeings produced using ionic dyes also have poor fastness properties.

Acid, pre mettalised or mordant dyesDespite their different names, these three types of dye have many features in common. They dye both protein and polyamide fibres using similar dyeing methods. In the Colour Index, they are classified as ‘acid dyes’ or ‘mordant dyes’. The name ‘acid dye’ derives from the use of an acidic dyebath. Most pre-metallised and mordant dyes are acid dyes. In the case of mordant dyes, the dyeings are aftertreated with a suitable metal ion mordant, usually chromium. In fact, mordant dyes are often referred to as chrome dyes. The metal in pre-metallised dyes is incorporated into the dye molecule during the manufacturing process.

The dyeing properties of acid dyes vary widely. The acids used in the dyebath range from sulphuric acid (dyebath pH < 2.0) to ammonium acetate (dyebath pH > 6.5). Acid dyes are usually sodium salts of sulphonic acids, or less frequently of carboxylic acids, and are therefore anionic in aqueous solution. They will dye fibres with cationic sites. These are usually substituted ammonium ion groups in fibres such as wool, silk and nylon. These

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fibres absorb acids. The acid protonates the fibre’s amino groups, so they become cationic. Dyeing involves exchange of the anion associated with an ammonium ion in thefibre with a dye anion in the bath.

Acid dyes have molecular weights in the range 300–1000 g mol–1. The dyes with larger molecules have higher substantivity for wool or nylon. Such dyes have slower diffusion in the fibre and therefore less ability to migrate and dye level. The more hydrophobic, high molecular weight dyes therefore have better fastness to wet processes. Their absorption by wool and nylon also involves the interaction o the dye with hydrophobic groups in the fibre. Dyeing is therefore not solely a consequence of simple ionic attraction.

The colour gamut of acid dyes is complete, including greens and blacks. The dyes are available as powders, grains and liquids for continuous dyeing, and as fine dispersions of the less soluble types. The selection of acid dyes for dyeing a particular material is not an easy matter, given the wide range of textile products and fastness properties demanded. Manufacturers recommend groups of selected acid dyes for each type of application. Compatible dyes are selected to have similar rates of dyebath exhaustion, when applied together by the recommended procedure, and similar fastness properties.

Basic or Cationic dyesMany of the initial synthetic dyes, such as Mauveine, had free basic amino groups capable of reacting with acids. They were therefore originally named basic dyes. Molecules of these dyes are invariably organic cations and the are preferably called cationic dyes. They usually have brilliant colours and high tinctorial strength; some are even fluorescent. Many basic dyes are now obsolete because of their very poor light fastness on natural fibres but a few are still used for dyeing paper and leather and for making inks

Cationic dyes will dye fibres with anionic sites by a process of ion exchange. This is usually a simple direct dyeing process. Anionic auxiliary products must be avoided as they may precipitate cationic dyes in the form of an organic salt. In dyeing protein fibres with cationic dyes, acids retard dye absorption by suppressing the dissociation of the anionic carboxylate groups in the fibres, thus making the fibre more cationic and inhibiting adsorption of dye cations. Cationic dyes have very low substantivity for cottonunless excessive oxidation has generated anionic carboxylate groups. For dyeing cotton with cationic dyes, the cotton was usually mordanted with tannic acid fixed with tartar emetic. The insoluble, anionic tannin attracts coloured dye cations , just as it repels dye anions when on a nylon surface after backtanning.

Printing

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Printing is the method of application of dye on to the substrate in the paste form. Printing various designs, shapes and figures of spectacular geometry on the fabric, resulting in the fanciness of the fabric. Printing can be done with various ways, each depending on the machinery used, method used, and the selection of paste. For the printing purposes, the dyes that can be used in the paste form, or the dyes that are mostly used are

Pigments Reactive Vat Disperse

These can be used separately or in the combination with each other. One important difference between dyeing and printing is that there is no concept of dye liquor in priniting. The dye which is in the paste form is applied in the film form over the fabric, and due to this reason unlike dyeing prints are produced in 1 direction only.

Methods of Printing There are various methods for the printing of fabric

Block p[rinting Screen printing Hand printing Spray printing Roller printing Flat screen printing

Machinery usedWith the advancement in technology the printing machines have been improved to to get optimum results. Now days the printing machines that can print on large scale are flat –bed printing machine and roller printing machine. Both have their uses and advantages over each other.

For example the flat bed printing machine give better quality printing, where as rotary screen printing machine gives bulk production. The operation is rather long than the one used in dyeingDesign is first made on paper, than on computer, then it is transferred on the screens and finally printed on the fabric.

Moreover there are different application methods than those used in dyeing. The printing pastes is usually fixed by the help of certain binding agents and fixers.

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Rotary screen Printing

Flat-bed Priniting

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THIS SECTION DEALS WITH

ALL THE FINISHES OPERATION

THE PROCEDURES USED IN FINISHING

THE FINISHING CHEMICALS

TYPES OF FINISHES

SPECIAL FINISHES

OPERATIONS ISED IN SPECIAL FISNIHING

DETAILS AND CHEMISTRY OF SPECIAL FINISHING

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Introduction to textile finishingTextile finishing is a term commonly applied to different processes that the textile materials undergo after pretreatments, dyeing or printing for final embellishments to enhance their attractiveness and sale appeals well as for comfort and usefulness. The term has been used in the past for all the treatments that the fabric may undergo after weaving and knitting but this significance is now conveyed with the phrase “Wet Processing”. Finishing treatments are basically meant to give the textile material certain desirable properties like

Softness Lusture Pleasant handle Drape Dimensional stability Crease recovery Antistatic Non-slip Soil release However these also include finishes that have to meet certain specific end uses

such as water repellency Flame retardency Mildew proofing

Just to named a few common ones

In addition to these some finishing processes that may not be considered as exactly ethical are sometimes given to cover either the faults of the fabric or to give a feel of heavy density to an otherwise lightweight material. This is done by binding clays on the fabric with the help of adhesives like Starches or Polyvinyl Acetate.

The types of finishes required and their methods of application depend upon the nature of fibrous substrate and their arrangement in the yarn or fabric. The properties of fibres such as swelling capacity, chemical reactivity response to heat treatment etc type of finish suitable for particular product. The cotton fabrics for example, are given crease recovery or crease shedding finish that is not always necessary for the wool fabrics. The woolen materials on the other hand, require non-felting or machine washable finish and moth-proofing. The synthetic fibres need heat setting to stabilize their structure and soil-release treatments to make these acceptable to customers. Choice and degree of finish and its equipment are further governed by factors such as structure of yarn , type of weave construction of fabrics i.e woven knitted or non-wovenFollowing dyeing or printing, a textile fabric usually undergoes a series of processes in order to confer or enhance the attributes required for satisfactory in its intended end-uses. These may range from a simple application of starch to more sophisticated processes for crease recovery, water repellency, handle improvement, shrinkage resistance or properties that are obtained by means of chemical treatment, usually from an aqueous batch.

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Finishing of textile material is normally the final embellishing treatment imparted during wet-processing and is of great commercial importance. The finishing treatment not only adds to serviceability but also invariably improve the general sale appeal of the products, by inducting various finishing effects that may-be produced mechanically or chemically.

The finishes may-be classified in different ways but the more common system is their sub-division in to physical/mechanical and chemical processes. The mechanical treatments are mainly, though not exclusively, applicable to the natural fibres and have not changed much with the passage of time. The chemical finishes on the other hand are subject to intensive and high quality research and are undergoing continuous changes to make these ever so more effectual, long lasting, easy to apply an last but not the least cost effective.

With better understanding of the physical and chemical nature of fibres, a great progress has been done in the synthesis of the finishing chemicals; there was a tremendous improvement of the finishing processes in the last half of the century. Around about 1970, a new dimension was given to these developments due to consideration of ecological and toxic effects of the chemicals finishes as well as dyes. The finishing agents using formaldehyde and phosphorous compounds as well as those difficult to biodegradable, became less and less acceptable with the passage of time especially in the developed countries of the world. This situation created a new surge in research for finding finishing agents that are safe not only to human beings but also for all fauna and flora that is likely to come in contact wit these chemicals.

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Fabric finishes are wet or dry treatments that complete a textile. Some finishes are applied wet, some dry, some are cold and some are heated treatments. Often a combination of methods is used to complete the finish. The average interior design fabric is treated with six finishes in order to be salable. Finishes on textiles vary with the end use. In residential settings there are fewer requirements than in nonresidential settings. In nonresidential or contract settings, the design professional first should determine which tests the textiles must pass. This information should be obtainable from the project architect or local fire chief. Documentation of the tests the fabrics will pass when post-finished should be, and in some case must be, provided by the fabric finishing company. The longevity of finishes varies and is categorized into durable and non-durable finishes. A finish that is classified as durable is one that will endure through successive wet or dry cleanings. A non-durable, or soluble finish, is one that will be removed through successive washing or dry cleanings. Whether a finish is durable or non-durable likely will not be apparent. If the quantity of yardage or the nonresidential specification dictates, the design professional should research the finishes to document their durability. This is particularly important with flame-retardant finishes to ensure the finish will meet the required codes.

Standard FinishesTextile finishes applied after the coloring process generally fall into one of two general

categories according to purpose or end result. These categories are: standard, wet or chemical finishes and decorative or mechanical finishes. Let's take a look at the first

category

Standard, chemical or wet finishes augment the textile's durability or ability to perform in a given way. These finishes include antibacterial or antiseptic, anti-static, care-free, flame retardant, insulative, mothproof, soil and water repellent finishes.

Antibacterial or antiseptic finishes are topically applied in the form of bacteriostats -- chemicals that suppress mold and mildew and slow or prevent the rotting process. These finishes are important in health care settings.

Anti-static finishes primarily are for carpeting and wall or furniture upholstery. There are two ways anti-static properties can be applied: by adding chemical inhibitors to the man-made fiber viscose solution, or as a topical application after the carpet or fabric is completed. If added to the viscose, the anti-static finish will be durable. If applied topically then it is a soluble or non-durable finish. This finish is for personal comfort (to reduce shocks after walking across a carpet then touching the light switch, for example), and in office settings where computers or other delicate equipment would be protected against damage by reducing the potential static electricity.

Care-free finishes make a textile easier to care for. Bedding and other fabrics that are washed often and upholstery fabrics that receive much use can benefit from a wrinkle-resistant finish. Some wall and drapery fabrics and some upholstery textiles have a

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permanent wrinkle or pleated appearance. This effect may be accomplished by a permanent press finish. These are topical finishes that are heat-set or calendered into the fabric.

Flame retardant finishes inhibit the rate of ignition, slow flame spread and encourage a fabric to self-extinguish. They are topical applications that are heat-set into the textile and are required for many nonresidential settings in order to meet code. Because of flame retardant finishes, there are far more aesthetically beautiful textiles that may be used in nonresidential settings today than ever before. The durability of finishes may vary, as there are several levels of flame retardant finishes.

Insulative finishes typically are a foam material that is sprayed onto the backs of fabrics to insulate against temperature and noise. They are durable.

Lamination or bonding is the process of joining two textiles through the application of heat, pressure and sometimes adhesives. Vinyl upholstery and clear vinyl laminated fabrics are examples.

Mothproof finishes are topical finishes applied to wool or cellulosic fabrics that may be vulnerable to insect damage. Site location will be one factor in determining the need for mothproofing. The finish may be durable or non-durable.

Soil repellent finishes are available as either durable or non-durable. If the treatment is applied to the fabric when it is manufactured or when it's sent to a fabric finishing company, it is durable. Topical application from a spray can or in the back room of a furniture warehouse is non-durable. Soil repellent finishes hold dirt and oily stains on the surface of the textile for a time so they can be readily removed. It is important to blot the spill quickly, as the soil or spill can work its way into the fibers after a period of time. Soil repellent finishes are very useful in carpeting and upholstery and are desirable in draperies and fabric window shades. There are well-known brand names for soil repellent finishes, such as 3M's Scotchgard[TM] and DuPont's Teflon® finish. However, many products are now on the market, so it is wise to compare the durability of each product.

Water repellent finishes sometimes are added to the soil-repellent finish and can be either durable or non-durable. These finishes make the textile less hydrophilic, or water-absorbing, in order to protect it against moisture damage. Outdoor furniture fabric, drapery fabrics and some nonresidential textiles benefit from water repellent finishes.

Water absorbency finishes enhance the ability to absorb water and aim at making the textile more washable and more able to let go of soil and stains once they are absorbed into the surface.

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DecorativeFinishes Decorative finishes achieve a decorative result or an enhanced aesthetic hand or appearance. A decorative finish may give a fabric its name, such as moiré, plissé or chintz, for example. Some decorative effects are not apparent because they enhance the surface texture of the finish by brightening or dulling it. Some finishes increase the durability of the decorative effect.

Brightening finishes can be either durable or non-durable. They augment the clarity or brightness of the colors in a textile making it look crisp and new for a length of time.

Calendering finishes are applied and pressed into the textile with a calendering machine: a heavy cylinder roller that applies heat and pressure. Starches, glazes or resins can be forced deeper into the textile surface by calendering, and when the roller is engraved specialty textural effects such as Palmer or moiré finishes are achieved. Calendered finishes can be durable or non-durable.

Ciré (chintz) finishes are calendered finishes that use a glaze, usually in the form of a resin, that is applied then pressed into the fabric. The finish may be durable if dry cleaned; but non-durable if washed or wet cleaned.

Delustering finishes, when done to yarns or finished fabrics, takes away the shininess of the textile. Sometimes a high luster in textiles is considered a cheaper look, so a low-luster finish will enhance the richness of a particular fabric or carpeting.

Durable press calendering is the application of resins to a textile that is stretched tight then cured at a very high temperature in order to make it more wrinkle-resistant and to retain its shape. Durable press also is used in the calendering process to add a greater degree of permanence to the embossing. Durable press is a flat curing process.

Embossed finishes involve an engraved or bas-relief (raised) calender roller that presses a three-dimensional pattern into a textile. If the fabric has a pile, such as a velvet or velour, the embossing permanently presses it down to create the embossed effect.

Etch printing or burn-out finishes print a design into a fabric such as a polyester/cotton with an acid compound that burns or etches (dissolves) the cellulosic fiber to reveal a sheer pattern.

Flocked finishes are the adherence of tiny fibers or fine particles to create a pile effect on a fabric through one of two methods:

1. Adhesive is applied to the surface of the fabric, which may be in a design or pattern. The fibers are added with the excess flocked fibers vacuumed off. The adhesive is cured and the fabric brushed and cleaned.

2. Electrostatic flocking uses adhesive on the ground cloth, which is then passed

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through a high-voltage field that charges the fibers causing them to be attracted to the adhesive.

Flocked fabrics can be embossed and printed. Generally, the finish is durable.

French wax finishes are a ciré finish in which resins are applied then calendered. A French wax is the shiniest or highest gloss finish. It is durable when dry cleaned.

Friction calendering is a means of producing a glazed surface with or without the application of starches or resins.

Moiré finishes are created through an embossing method in which the calendering roller is engraved or raised into a watermark design and applied to faille fabric (fine cross-wise or weft ribs). The moiré look also can be achieved by (pigment) printing and jacquared weaves.

Napped finishes are created by brushing-up the fabric fibers to loosen and create a fuzzy finish or depth similar to a short pile.

Panné finishes are created through an embossing method in which a velvet, ribbed velour, or other pile textile is pressed down in one direction.

Plisse finishes are the application of a caustic acid that causes the yarns to pucker. The plissé pattern is typically a plaid or all-over wrinkle.

Resin finishes are the result of a resin -- a natural or synthetic clear, translucent substance -- that when applied to a textile and calendered becomes a lustrous glaze or the basis for waterproofing or soil repellence.

Schreiner calendering involves tiny engraved lines on the calender, which produce an increased luster to a textile without the application of resins or starches.

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Post-finishing Finishes can be applied to fabrics to meet special needs. A fabric finishing company is

one that specializes in treating fabrics prior to their construction into draperies, bedspreads, upholstered furniture or their application to walls.

The key advantage to post-finishing is that a fabric that has the right weight, color, texture and pattern but does not meet a certain requirement still can be specified and installed after it has been treated. This allows far greater latitude in fabric selection for the interiors professional as well as the client.

The process for having fabric finished is as follows:

1. Contract the fabric finishing company of your choice and obtain specifications as to which finishes they are equipped to apply, how long it will take, what guarantees exist, and what the charge is per yard, for example.

2. Send a sample for testing and to evaluate any apparent color or textural surface changes after finishing. Approval of aesthetics, durability and documentation of test results.

3. Add the finishing costs to the job price.

4. Ship the yardage to the fabric finisher (be certain to allow for the sample with a little extra yardage). Allow time for the finishing in the production time frame.

Post-finishes applied to textiles include: flame-retardant finishes, lamination (applying plastic to the face or reverse of fabrics), paper, foam, or latex backing for wall application.

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Mechanical and Chemical Finishing

Machinery for drying and Mechanical finishing

DRYINGIn the present context the function of drying operations is to remove the water from textile fabrics that have been thoroughly wetted in the dyeing process. When material in this condition is withdrawn from a dyebath it readily retains three or four times its own weight of water, a ratio which may fall to two or less if the textile is allowed to drain briefly. Drying processes must reduce this water content to the few percent of the dry fabric weight that is the normal ‘air-dry’ condition.

The later stages of drying must under all practicable circumstances be carried out by evaporation, but thermal drying is inevitably an energy-intensive process. Mechanical drying, achieving removal of liquid water, is much less costly, so the moisture content should be reduced as far as possible in this way. In practice considerations other than those relating only to drying costs will determine the balance between mechanical and thermal drying, but wherever possible maximum advantage should be taken of the cost-effectiveness of mechanical drying. Before dealing with the various techniques of drying it is useful to define the terminology to be adopted in this chapter.

In the textile industry moisture content is most commonly quoted on a ‘dry weight’ rather than a ‘wet weight’ basis, i.e. the moisture is expressed as a percentage of the dry weight of the textile, rather than the total wet weight. This convention will be followed here, with the additional proviso that the dry weight is the ‘oven-dry’, not the less precise ‘air-dry’, value.‘Oven-dry’ implies that a thermal process is employed to remove the last traces of water and leave the material completely water-free. In fact it is extremely difficult to be sure that all the water has been removed without any degradation of the fibre, and in any event the fibre will reabsorb some water from the air extremely rapidly.

Thus the objective of drying processes is to reduce the water content from a value probably well in excess of 100% to a value close to the normal air-dry figure, which for cotton fibres is typically 6-7%. The moisture level attained after mechanical drying will be referred to as the ‘water retention’or just the ‘retention’. The same word could equally well be employed for the value after thermal drying and conditioning, but the longestablished name ‘regain’ is so widely employed that it would only be confusing tointroduce another.

Mechanical dryingThe small amount of regain moisture associated with textile materials at normal levels of atmospheric humidity is bound very strongly to the fibre. Increasing the humidity increases the moisture content, but the water is held progressively less strongly until

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eventually a stage is reached beyond which further uptake consists of effectively unbound water in capillaries and voids in the fabric structure.

The distinction between bound and unbound water is generally considered to occur at the saturation regain, the regain at 100% RH. This distinction cannot be made precisely, nor can the critical regain be accurately determined, because condensation into the smallest capillaries can occur below 100% RH. Although the bonding cannot be precisely defined, the distinction between bound and unbound water is important because mechanical drying, under any practicable condition, can remove only unbound water, and in fact never quite the whole of that. Thus the minimum water retention value for cotton, in the region of 30-35%, represents an absolute limit for mechanical drying.

Three methods of mechanical drying are commonly employed with textile fabrics:mangling, suction drying and centrifuging.

Under the best conditions, which include favourable textile characteristics as well as ideal operating practice, all three methods will achieve a similar level of performance, and the lowest water retention attainable is in the region of 45% for cotton.

Under what may be unavoidable circumstances the retention may be appreciably higher than this figure, but no one process has a clear technical edge over the others. The choice of method therefore depends on various factors, as indicated in the following sections.

ManglingThis is the most important method of removing water from open-width fabrics, and the general appearance of mangles is so well known that a detailed description is unnecessary. It is nevertheless useful to summarise the important features of the machine.

Squeeze mangles are structurally similar to pad mangles, but in squeeze mangling nip uniformity is less critical and it is possible to relax this requirement in favour of a general increase in pressure, resulting in more water removal. This cannot be carried too far, and it is still necessary to have one relatively soft bowl in the nip, providing a cushioning effect to protect the fabric from damage in the event of creasing.

Although it is possible to run a squeeze mangle with a rubber-covered bowl, it is now almost universal practice to fit harder, so-called ‘filled’ bowls running against metal for open-width fabrics. Somewhat more resilience may be desirable in a mangle for fabrics in rope form.

Filled mangle bowls have been made from a wide variety of materials, their common feature being an appreciable radial thickness of the deformable material on a metal shaft, in contrast to the relativelythin layer of rubber on a metal shell in rubbercovered bowls. Modern bowl fillings commonly consist of discs cut from sheets of impregnated synthetic fibres, mounted on the bowl shaft and held with pressure between the end cheeks. These materials provide a good balance between the potentially conflicting requirements of hardness and resilience, and have good resistance to permanent deformation.

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One consequence of this form of bowl construction is a greater susceptibility to lengthwise bending under load, since only the metal shaft contributes to rigidity. In squeeze mangling the nip uniformity is less critical than in padding; so loss of rigidity need not be particularly serious, although it is desirable to have bowls of large diameter, permitting a larger diameter shaft. For particularly wide mangles some form of level pressure loading system may be required, but this is unlikely to be worthwhile below about 2.5 m face length.

The combined effects of nip loading, bowl hardness and bowl diameter may be represented with reasonable accuracy by the average pressure developed in the nip. The nip pressure, in kg/cm2, say, is simply the nip loading in kg/cm divided by the nip width in cm. Bowl hardness and diameter influence this parameter by their effect on the nip width, a ‘tighter’ nip being provided by a harder bowl or a smaller diameter. Diameter only has a significant effect when both bowls are 10 cm or less.

Although this factor was utilised in some important machine designs in the 1950s, it is now largely ignored. Modern bowls, primarily by nature of their hardness, achieve nip pressures of the order of 100 kg/cm2 from applied loading of 60-80 kg/cm, and this represents a good level for efficient water removal. It is claimed that some modern bowl fillings achieve extra water removal by a ‘blotting’ or ‘sucking’ action at the exit from the nip (Figure 7.1). The evidence suggests that this may indeed be significant, but only with some fibres or fabric structures.

Faster fabric throughput increases the amount of water retained by the fabric, but not to a marked extent. A useful practical consequence is that moderate speed changes can be made for other purposes without any significant effect on mangle performance. An increase in temperature at the nip leads to a reduced water retention. It is therefore advantageous where appropriate to mangle at an elevated temperature, if the fabric has come from a hot wash, for example. However, it is unlikely to be profitable to heat an

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immersion tank solely in order to achieve this mangling benefit, as the energy expended might well exceed that saved in the subsequent thermal drying.

Differences in fibre and fabric structure can also influence water retention. These differences can be quite pronounced, e.g. fabrics of light weight and open structure retain, per unit weight of dry fibre, much more water than heavier, tightly woven structures. It is helpful to visualise the situation inside the nip, where the fabric structure effectively holds the bowls apart, with all the voids filled with water. More open structures have a greater proportion of void volume and hence leave the nip with a higher retention.

This phenomenon may be related to the possibly beneficial ‘sucking action’ of some bowl fillings; it is certainly relevant when comparing mangling with suction drying and centrifuging. These other methods of mechanical water removal appear to be less influenced by fabric structure and may therefore be superior to mangling for lightweight, open fabrics.

In one other respect mangling differs from the other processes, in being essentially a water-limiting operation. It does not matter how wet the fabric is as it reaches the nip; under given mangling conditions it will leave with virtually the same retention. Specifically, if a mangled fabric is passed a second time through the same nip, without rewetting, the water retention will decrease by no more than 1%. In mangles the same mechanism provides both water removal and fabric transport. Thus mangle nips are the almost inevitable choice for inter-stage drives in such machines as washing ranges.

Suction dryingIn suction drying water removal is achieved by passing fabric over a narrow slot cut in a box connected to a vacuum pump. This technique is applicable only to openwidth fabric. In this process water is removed in the form of droplets driven from the fabric by the air flowing into the vacuum system. Some evaporation may take place subsequently, but within the fabric the removal is almost wholly mechanical. The rate of removal is remarkably rapid: perfectly satisfactory suction drying can be achieved with a slot 2-3 mm wide. At a speed of 60 m/min a fabric element passes this slot in 2-3 ms, in which time it may discharge more than half its own weight of water.

The most important mechanical variables in suction drying are the vacuum achieved, the fabric speed and the slot width. In practical suction drying the vacuum pump will usually be run at a fixed rate, and the vacuum achieved will depend on the slot width and the density of the fabric, Only under controlled experimental conditions can the variables be studied separately. The effects of changes in vacuum roughly parallel those of nip pressure in mangling; the effects of fabric speed are generally similar in magnitude to those of mangling.

It is natural to expect that suction time is a crucial parameter and that the effect of an increase in speed could be counterbalanced by a corresponding increase in slot width

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(assuming that the vacuum could be kept constant). In fact this turns out not to be the case, and at constant vacuum the slot width alone has very little effect on water retention. Investigation of this paradox has shown that virtually all the water removal occurs in regions close to the slot edges, the central region contributing very little, although it does influence the air flow into the vacuum chamber.In the interests of achieving the highest possible vacuum, therefore, it is desirable to employ a narrow slot. There is, however, no benefit in taking this policy to extremes, since the slot behaves, in respect of air flow, as if it were wider than its actual width. The enhanced air flow at the slot edges presumably accounts for the more effective water removal at these positions.

In view of this phenomenon, the use of multiple slots might be expected to be advantageous and such arrangements have been devised. A second suction slot can remove more water from the fabric (a slot is not a water-limiting device, like a nip),but introduces more air flow and makes it more difficult to maintain the vacuum. In general, the achievement of an adequate level of vacuum is the main practical problem in suction drying. The lower vacuum resulting when more open structures are dried tends to offset the easier water removal that would otherwise be expected in this process.

Suction drying requires a separate mechanism for fabric transport, and the power requirements of vacuum pumps are higher than those of mangles by a factor of two or more. Nevertheless, the process is less severe than mangling and can be employed on fabrics that would be damaged by a squeeze nip. If a fabric drive is already available, e.g. in a thermal dryer, a suction slot can be inserted in a very small space. In these circumstances suction drying, although much less widely used than mangling, has a useful role in mechanical drying.

CentrifugingCentrifuging is the natural choice for drying materials in batch form, such as loose fibre, yarn hanks or packages, and garments. It is also convenient and economical for piece goods that come from processing in rope form as relatively small batches, e.g. from a jet dyeing machine.

The significant variables in this process are the centrifugal acceleration and the duration. The acceleration is determined by the rate of rotation and is proportional to the radius; the figure quoted, commonly in terms of gravitational units, is that for the radius of the centrifuge basket. The goods in the machine will, if free to move, be compressed into a fairly narrow band against the basket wall, but all the water removed must pass through the outer layers. It appears that, while the process is running, the layer adjacent to the basket must always be slightly wetter than the rest, but this difference rapidly disappears when the process stops.

As a batch process, centrifuging readily lends itself to automatic control of duration, but if operated manually it is convenient to stop the operation on cessation of significant discharge from the machine drain. Being intermittent in nature, centrifuging is not readily comparable with continuous processes in terms of productivity, but energy costs can be

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roughly compared. In this respect the centrifuge is intermediate between mangle and suction dryer.

Thermal drying

Thermal drying in some form is essential if a fabric is to be returned to an air-dry condition and the process is inevitably energy-intensive. Interest in its thermal efficiency is by no means a modern phenomenon.

All the energy applied in thermal drying is immediately dissipated into the surroundings as heat (including the heat content of water vapour), but that part associated directly with water evaporation may reasonably be described as the essential heat requirement, in contrast to the losses ascribable, for example, to less than perfect insulation. Provided the energy consumption is related to the weight of water evaporated, rather than to the weight of textile material, there is little variation in the heat requirement over a wide range of conditions of drying temperature and moisture content. The average amount of energy used is about 2.7 MJ per kg of water evaporated. On top of this figure, different drying processes show different levels of heat loss, and different machines of a given type may also vary one from another.

Cylinder dryingThis is the general ‘workhorse’ drying method for open-width fabrics, heat being transferred to the fabric from steam-heated cylinders, typically at a surface temperature up to 160°C. This procedure offers no reliable facility for control of fabric width and tends to impart warpway stretch, or at least to limit any tendency to shrinkage on drying. Simplicity and thermal efficiency are the main advantages of the process, heat losses being restricted to radiation and convection from the exposed parts of the cylinders. Losses are typically in the range 0.6-0.8 MJ per kg of water evaporated under steady running conditions, giving a total energy consumption of approximately 3.4 MJ per kg.

The rate of drying on cylinders is measured by the weight of water evaporated per hour per unit area of contact between cylinder and fabric. Defined in this way the parameter permits reliable comparison between machines comprising different numbers of cylinders of different sizes. Cylinder temperature is the major process variable influencing drying rate, but tension is also important and fabric structure has a marked effect.

Stenter dryingThe stenter is the only drying machine that provides adjustment and control of fabric width in conjunction with the drying operation. The fabric selvedges are held by pins or clips carried by chains which travel the length of the machine, drawing the fabric through a horizontal oven in which it is heated by air jets from above and below.

Stenters are widely employed for various operations other than drying, but in drying the air temperature is commonly restricted to no higher than 160°C (similar to that on

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cylinders), to minimise danger to the fabric should the machine stop. The rate of drying in stentering is measured as in cylinder drying, in terms of the evaporation of water per hour per unit area, the area now being the area of fabric within the oven. This measure is really more significant in stentering than in cylinder drying, because each square metre of heated fabric requires a square metre of floor space. A higher drying rate (achieved, for example, by a better design of air circulation fans or jets) enables a given drying performance to be obtained on a shorter, less expensive machine.

The drying rate is also intimately related to thermal efficiency. In addition to radiation and convection losses from the oven casing, a heat loss results from the ventilation required to discharge the water vapour formed in drying. The problem is not one of loss of water vapour, but the heat loss represented by the air discharged with it.

A lower rate of exhaust is clearly more thermally efficient, but increases the humidity inside the oven. This in turn reduces the rate of drying. Fortunately it is possible to define an optimum humidity that provides only a moderate heat loss together with a rate of drying only a little below the maximum. The optimum humidity is in the range 0.10-0.15 kg water vapour per kg dry air, but the losses rapidly increase if the humidity is allowed to drop much below this range. Control equipment is available to maintain the correct humidity automatically.

Even under optimum exhaust conditions, heat losses in stentering are inevitably greater than in cylinder drying. In a sense this may be regarded as the penalty that must be paid for the specialised fabric control facilities offered by the stenter. The overall energy consumption in this process is likely to be in the region of 4.5 MJ per kg water evaporated.

Apart from only drying stenter is now used for multi finishing as well as dyeing puroses. The details are as such

Stenters have an important role to play in a dyeing and finishing works. As well as drying , heat setting and curing fabric they also has an effect on the finished length, width and properties of the fabric. Fabric can be processed at speeds from 10 - 100 metres/ minute and at temperatures up to and in excess of 200°C. Sophisticated feed and transport mechanisms mean that the fabric is presented to the oven in a way to ensure that the finished product meets customer requirements.

Stenters can be heated in a variety of ways. The most common means of heating nowadays is by direct gas firing, with the burnt gas fumes being fed into the stenter oven. A few units are indirect gas fired but their efficiencies are poor when compared to direct fired systems. Gas fired stenters are highly controllable over a wide range of process temperatures. Thermal oil heating is another method. But this requires a small thermal oil boiler (usually gas fired) and all its associated distribution pipework. Less efficient than direct gas firing with higher capital and running costs. Again can be used over a wide range of process temperatures. Oil itself can be used as a means of heating stenters.

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Because of the problems with incomplete combustion this can only be done indirectly via a heat exchanger. This, as with indirect gas firing is relatively inefficient. Very few stenters nowadays use this mode of heating.

Finally there are a number of steam heated stenters. But because of temperature limitations ( usually a maximum of upto 160°C) they can only be used for drying and not for heat setting or thermofixation.

The air is heated, forced against the fabric and then recirculated. A fraction of this air is exhausted and made up with fresh air. To offer better control stenters are split up into a number of compartments, usually between 2 and 8 three metre sections each fitted with a temperature probe, burner/heat exchanger, fans, exhaust and damper.

For a typical hot air drying job on a stenter the energy breakdown would include the following components :-

COMPONENT GJ/TE FABRIC %     Evaporation 2.54 41.0 Air heating 2.46 39.7Fabric 0.29 4.6 Case 0.39 6.3Chain 0.09 1.5Drives 0.43 6.9      Total 6.20 100

The energy breakdown with hot air drying processes is dominated by both evaporation and air heating. It is therefore imperitive to reduce the moisture content on the fabric and to reduce the exhaust airflow. A lot of stenters are still poorly controlled in that they rely on manual adjustment of exhausts and on some, estimation of fabric dryness.

The main opportunities for energy saving on this type of machine can therefore be classified as follows :-

a) Use less energy intensive methods first.

b) Do not overdry.

c) Turn off exhausts during idling.

d) Dry at higher temperatures.

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e) Shut and seal side panels.

f) Insulation.

g) Optimise exhaust humidity.

h) Heat recovery.

i) Direct gas firing.

a) As with t he contact drying it is important to use less energy intensive methods first such as the mangle, centrifuge, suction slot, air knife or drying cylinders. Even though drying cylinders are about five times more energy intensive than a suction slot, they are still about 1½ to 2 times less energy intensive than a stenter. Drying the fabric down to about 25-30% regain before passing it through the stenter still makes it possible to adjust the fabric width to the customers requirements.

Other techniques used to reduce drying costs include infra-red and radio frequency drying. Gas fired infra-red has been used for the pre-drying of textiles prior to stentering. This can have the effect of increasing drying speeds by upto 50%, thereby relieving production bottlenecks which tend to be around stenters. Typically you could expect the infra-red drying energy requirement to decrease by as much as 50 - 70% when compared to conventional stenter drying.

If an efficient means of pulling the fabric out to width could be devised for a short hot zone length then infra-red could be used to do all the drying. Radio frequency drying is used extensively for the drying and dye fixation of loose stock, packages, tops and hanks of wool and sewing cotton. The energy requirement for radio frequency drying when compared to conventional drying in a steam heated dryer can be as much as 70%. It is however, limited to loose stock and packages and cannot be modified, as yet, to accommodate knitted or woven fabric since the traditional stenter transport mechanism, pins and clips would interfere with the RF drying field causing discharge.

b) As with the contact drying of textiles it is important not to overdry. More so on stenters since it is a more energy intensive drying technique. There are automatic infra-red, radio active (* source) or conductivity based systems which can be linked to the stenter speed control to achieve as close as possible the fabric regain.

c) Commission dyers and finishers tend to operate with relatively small

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batch sizes, and so in some extreme cases the operatives may be required to change over to different fabric qualities every hour. It is common practice to leave the exhausts on during these changeovers, which may take 10 - 15 minutes or more. With the large air heating requirement it is important to isolate the exhausts, or at least partially close them down, wherever possible during periods of idling.

d) If the fabric allows then drying at a higher temperature means that radiation and convection losses become relatively smaller compared to evaporation energy.

e) On older machines the side panels may be damaged thereby upsetting the delicate air balance within the machine. All faulty panels should be repaired or replaced to provide an effective seal around the oven. f) Improving insulation is usually not practicable. Although on some older machines it may be cost effective to insulate the roof panels.

g) When drying there is an optimum exhaust rate which should be adhered to. Since a significant number of stenters still rely on manual control of exhausts, which basically means 'fully open all the time', the potential for energy saving is considerable. Manual control of exhausts is generally very difficult since the expected airflow patterns and the ones found in practice vary considerably. Hence the tendency to leave them fully open.

Optimisation of exhausts can be achieved by controlling the exhaust humidity to between 0.1 and 0.15 kg water/ kg dry air. This is called the Wadsworth criterion. It is not unusual to come across stenters where the exhaust humidity is 0.05 kg water/ kg dry air. Which means a considerable waste of energy. Instruments are available which automatically control the dampers to maintain exhaust humidity within this specified range thereby cutting air losses without significantly affecting fabric throughput. These vary from wet/dry bulb temperature systems to fluidic oscillators measuring the variation in sound through a special filter head.

Where drying of solvent based work is required then the high air losses may not be avoidable for safety reasons. Although many solvent based systems have now been replaced by aqueous systems because of the Environmental Protection Act.

h) Exhaust heat recovery can be achieved using air to air systems such as the plate heat exchanger, glass tube heat exchanger or heat wheel. Efficiencies are generally about 50 - 60%, but there can be problems with

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air bypass, fouling and corrosion.

If other measures are applied first, such as fabric moisture control and exhaust humidity control, then there is usually no or little economic case for such systems.

Air to water systems such as a spray recuperator avoids fouling and cleans the exhaust, but there may be problems with corrosion. There is also the need for secondary water/water heat exchange and of course the problem of coinciding utilisations.

Where stenters are exhausting prohibitive amounts of volatile organics or formaldehyde, then a form of scrubber, electrostatic precipitator or even an incinerator may be required to comply with the statutory limits set under the EPA process guidance notes. In these cases it makes sense to incorporate heat recovery so that at least the installation costs can be recovered.

i) Compared to other stenter heating systems direct gas firing is both clean and cheap. When it was first introduced there were fears that oxides of nitrogen, formed to some extent by exposure of air to combustion chamber temperatures, would either cause fabric yellowing or partial bleaching of dyes. This has since been shown to be unjustified.

b)Unlike steam and thermal oil systems there are no distribution losses to worry about. Heating up times are shorter and thermal capacities less, all leading to lower idling losses.

The universal and modular Monforts stenter principle offers an individual adaptation to all the demanded finishing effects - and at the same time versatile applications for the range.

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 Whether for woven and/or knitted fabrics - with the proven “Qualitex” PLC system, the unrivalled TwinAir system and maintenance-free chain technology, Monforts is synonymous with a stenter technology that is as diverse as the latest fashions.

Monforts offers a large number of individual infeed section combinations. These are designed to match thea requirements of the particular fabric treatment process. The illustrations here show just a few examples.

 

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Without illustration:

Dyeing beam unwinder Combination-scray Loop scray Conveyor accumulator

Operator-friendly, widely proven design principle. Material and hardness of the roll covers can be chosen to suit the desired finishing processes and fabrics. Version with uniform pressure roller also available. A wide range of variants are available, from liquor trough with minimum capacity through to a trough with long dwell section.

  

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Dual-function straightening roller with driven bowed roller, slewing frame and high-precision measuring heads.

 

Synchronised drive systems for efficient pinning and reliable after-pinning even with large overfeeds and highly elastic fabrics. Pneumatic operation for lifting and lowering in process-optimised sequence.

 

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The drive is synchronised with the drive of the stenter chain, thus preventing any shifting of the mesh structure. Long service life of the brush belt as it is not subjected to friction. Suitable for knitted fabric ranges.

 

At a machine stop, the gluing wheel is automatically lowered and continues to rotate in the glue vat so that the glue does not dry on the gluing wheel. Excess glue is stripped off. When the machine starts again, the gluing wheel is automatically raised into working position.

This ensures a continuous, uniform glue bead on the fabric even at machine stops. For maintenance work the gluing wheel can be removed from its mounting without the use of tools. The glue application is controlled by a patented metering system.  

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Modular element for combination drying of the glued selvedges by infrared radiation and convention nozzles. The infrared dryer is switched on and off automatically. Different working lengths available.

 

Predried glued selvedges prevent overdrying of the fabric when passing through the dryer and so permit a higher fabric transport speed. Manufactured from non-rusting materials. Suitable for knitted fabric ranges.

 

Basic configuration

Modular design, thus adaptable to changing performance requirements at any time Optimum accessibility Space-saving construction Overall height only 1,600 mm

Mechanical and electrical equipment

All drive elements are located outside the heated chamber and are accessible from the outside Maintenance-free width adjustment spindles No lubrication points in the chamber All drive motors of maintenance-free design

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Energy management

Special panellings of high-density insulating material for low heat radiation Careful sealing of all connecting positions and chamber accesses Air locks at the fabric entry and exit openings

Service

Motors are accessible from outside the chamber and can be replaced without the use of hoists or cranes The use of standard components provides benefits in maintenance and inventory for the user

Pneumatically operated lifting doors. For comfortable opening and closing of the treatment chambers at the push of a button. No tools required for door operation. Automatic, efficient sealing on closing.

 Wall thickness 150 mm with effective heat and noise insulation. No space required for door opening. With emergency opening mechanism in the event of power failure. Available for Montex stenters and DynAir relaxation dryers.

 

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Energy input as required:

Direct gas heating Oil circulation heating Steam heating Combined electric/steam heating Hotwaterheating Electric heating

Adaptable to the boundary conditions of the particular application and different operating processes for optimum energy utilisation.

 

 

Gas temperature control  

 

Easily accessible burner arrangement with optimum fresh air supply,

Extremely uniform power development even at full load

  

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Large heat exchanger surface areas for quick heating  

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High-efficiency indirect gas heating system practically eliminates yellowing during the treatment of polyamide and elastane-based fabrics, as the combustion gases do not come into contact with the fabric.

 

Lower investment costs and higher efficiency than with a preliminary installation of circulating oil-heated ranges. High thermal energy recovery potential. Subse-quent installation in Montex stenters possible on request.

 

Central process control system (software) for production planning and documentation with a central interface. All process data can be stored in a standardised database (ODBC Open Data Base Connectivity) where all setpoints and actual values are protocolled with read and write access for setpoints.

 

Several machines can be connected at the same time. No additional hardware is necessary. Three levels of network interfacing are possible: Interfacing to your network, output to office PC with graphic presentation (Monforlogic) and interfacing to a process control system to also include machines from other manufacturers.

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Drives

All fabric transport drives are equipped as standard with frequency-controlled 3-phase AC motors.

 

 

Fabric effect / operation

The chain is simple to clean, Set up processes are easy due to controlled start-up and fabric positioning. All types of fabrics may be precisely run and controlled by the four-quadrant drive and three-phase A.C. motor. Consistent fabric tension is maintained during starting and stopping as well as emergency stop or power failure.

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Chain track guide 100 mm high (H100) Option 60 mm high (H60) for reduced nozzle distance (only possible with pin operation).This arrangement results in higher evaporation rates with the same electric energy consumption

 

"Marathon" Chain

Absolutely lubrication-free and maintenance-free chain Production speed up to 150 m/min The chain guide tracks are also lubrication-free and maintenance-free over the full service life of the Montex

Pin version

"Hercules" Chain

Roller chain which runs dry through the machine with fully encapsulated ball bearing longlife lubrication for years (depending upon the process) For running speeds well in excess of 200 m/min Minimum lubricant consumption by the patented direct lubrication system Design as pin chain, clip chain or combined clip/pin chain with special tip guard during pin travel

Without illustration: Special clips for silk and technical fabrics  

Cobined clip pin version  

Vertical maintenance-free chain guidance

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Lubrication and maintenance-free sliding chain Polyimide sliders (aerospace plastic) Slide rails of special steel

The TwinAir Plus system (optional):

A proven design principle has been further optimised to meet the changing demands of the customer and now stands for new performance data in economy and ecology in high quality textile finishing.

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Characteristics

The air outlet openings of the nozzles can be adapted in steps to the fabric width to be treated. Adjustment is controlled automatically from the central control desk.  

Benefits

Up to 20% higher production speed with the same energy input.

 Range of applications

Particularly suitable for frequently changing fabric widths.

The new slot nozzle system for non-elastic high-pile and terry cloth fabrics. Also suitable for dyeing processes on the stenter. No marks or stripes on the fabric caused by the nozzle geometry.

 

No also available as a combination nozzle of round/slot design with manual changeover facility. The staggered arrangement of the nozzle system eliminates the need for costly secondary installations. For a high flexibility of the finishing jobber.

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Automatic correction of the nozzle pressure when changing the treatment temperature. Automatic comparison of the nominal and actual speeds of the fan in the event of changing flow conditions during the process. Alarm function in the event of increased soiling of the circulating air filters.

 

For constant production conditions over the whole batch – and a further contribution to our customers’ quality assurance measures. Only in conjunction with Qualitex 740. Available for all Montex heat treatment machines.

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Automatic adaption of the top and bottom air in the TwinAir System with variable-frequency fan motors and CCD chip evaluation of the distance between the fabric and the nozzle.

 For contact-free drying, to avoid marking and stitch draft and for further relief of the operating personnel. Constant steaming rate of the stenter. Optimum energy utilisation. Only in conjunction with Qualitex 740.

Continuous belt sieve with automatic suction system and high-pressure cleaning for constant optimum air circulation conditions. No energy-consuming air resistance with increasing sieve soiling.

For a constantly high drying capacity, even with high fabric speeds and extreme linting. For further relief of the operating personnel from maintenance work and for a lower energy consumption.

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The exhaust air and fresh air ducts are laid inside the chambers for a space-saving and tidy installation. Exhaust air inlet in each chamber. Individual control of the exhaust air volume per field.

Simple cleaning of the ducts from above. Minimum secondary installations necessary. Simple connection to a Koenig heat recovery module possible. Exhaust air fans with variable-frequency motors.

 

With its worldwide competence, Koenig AG is continuing to provide comprehensive advice on integrated systems for heat recovery and/or exhaust air cleaning. After a consultation, binding concepts are drawn up to link and optimise several heat treatment ranges or whole plants for exhaust air management. Impressive references underline this core competence of Koenig AG.

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For cutting and winding-on without standstills at up to 80 m/min. winding tube diameters up to 700 mm. Winding onto tubes without takeup rod. Short fabric transport distances up to the winder with minimum fabric tension.

Straight selvedges during winding. Low space requirement. Exact piece lengths as the cutting process can be performed automatically when the nominal length is reached. Complete automation possible.

Monforts offers a wide range of delivery section combinations. Even for non-stop production lines right up to the make-up, automatic cutter / winders are available for winding onto tubes without take-up rod and without adhesive tape.

 

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Radiation dryingInfra-red radiation derived from electrical or gas-fired heating elements is another technique commonly employed in fabric drying, most usually to supplement cylinder or stenter drying or to provide rapid predrying.

However the IR energy is generated, the source temperature is very much higher than the temperature of air in a stenter or at the cylinder surface. If the fabric stops for any reason there is an immediate danger of overheating, so care must be taken to protect the fabric from the heat source. If the source is a heated refractory or electrical element of high heat capacity, the only satisfactory procedure is some form of shutter. With a heater of low heat capacity it will normally be sufficient simply to switch it off; such a heat source will also heat-up rapidly when the process restarts.

The efficiency of IR heating depends on the efficiency with which the fabric absorbsthe incident radiation. Fortunately this does not depend too much on the visible colour of the fabric, since most surfaces have enhanced absorptivity in the IR region. Heat losses arise from reflected radiation and from air heated by the fabric in natural or forced convection. In general in this process efficiency is comparable to that of a well run stenter.

Other forms of radiation drying by radio-frequency or microwave heating are only rarely employed on fabrics. The primary technical advantage of these techniques, their ability to penetrate the surface and deliver heat internally, is of little benefit with any but unusually thick fabrics. An economic limitation is the necessity to derive the heat energy by conversion from mains electricity in a process that can hardly be more than 60% efficient.

Heat recovery from thermal dryersIt is not practicable here to attempt a detailed description of heat recovery schemes, but some general remarks are appropriate. Firstly, if waste heat is to be recovered, consideration must be given to where it is to be used. Preferably the heat should be returned to the process itself, since periods of supply and demand are then matched.

Heat delivery to other processes is less likely to be satisfactory, although some general-purpose heat recovery (e.g. in the form of hot water) may be more viable. Heat recovery from general heat dissipation (such as radiation or convection losses) is unlikely to be worthwhile.

A stenter discharges hot air at 140-150°C, and an air/air heat exchanger will preheat cold air to 100-120°C. This can make a useful contribution to the heat demand of the process, provided the stenter can be made to accept this air in preference to obtaining ambient air.

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Much more heat could be recovered by condensing the water vapour generated by the drying process. Unfortunately, under the conditions normally existing in drying, a worthwhile degree of condensation can only be achieved at a relatively low temperature. A large amount of heat may be recovered, but at too low a temperature to be readily usable. Different conditions arise if drying can be carried out in what is effectively superheated vapour. Various designs and one or two experimental systems have been investigated, and these may form the basis of much more efficient thermal drying processes in the future.

Process control in dryingIt has long been recognised that overdrying reduces the productivity of thermal dryers and is wasteful of energy. Among the earliest of on-line process controls were moisture meters for attachment to the delivery end of dryers, particularly stenters, to enable fabrics to be dried to the correct air-dry regain. Numerous sensing techniques were evaluated to determine the moisture content of the fabric after drying, but the oldest established technique remains the most popular, namely a measurement of electrical resistance usually made through the thickness of the fabric between a series of small insulated rollers and an earthed guide roller.

The output of such a device is an electrical signal representing the moisture content. It is nowadays the normal practice to link this signal to a device that controls the machine speed in order to maintain a predetermined final regain. The greatest benefits of automatic control of final regain are evident in stentering, the most expensive drying process. Additional types of control instrumentation have generally been developed with this process in mind. Automatic control of heat losses from the stenter exhaust may be derived from a sensor measuring the exhaust humidity. Certain other stenter functions, related to processes other than drying, may also be automatically controlled. The whole may be combined into an integrated control system that takes account of the interaction between the different individual process control loops.

MECHANICAL FINISHING

Mechanical finishing is a general term to describe processes carried out on a prepared and dyed fabric in order to improve its suitability for the desired end use, the aftertreatment being provided purely by mechanical means. Such processes are designed either to change the dimensions of the fabric, or to change its surface appearance, handle or properties.

Some of these mechanical processes do not give results that are permanent. In many instances this may not be a serious limitation, but if greater permanence is required it may usually be achieved by incorporating a suitable chemical reactant. This chapter, however, deals only with the mechanical operations themselves.

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Dimensional changes: compressive shrinkageThis operation results in a final product with a reduced tendency to shrinkage in use. Many of the processes in preparation and dyeing subject fabrics to warpway tension, so that a woven fabric reaches a state in which much of the crimp in the warp threads has been removed. In use such fabrics will tend to relax towards a condition with a more even balance of crimp between warp and weft, with consequent warpway shrinkage. This tendency can be reduced or even eliminated by subjecting the fabric to a shrinking process before it leaves the finishing works.

There are several variants of compressive shrinking machinery, but all rely essentially on forcing a reduction in length of the fabric by holding it firmly in contact with a rubber blanket or similar surface that is initially stretched and then allowed to contract. The mechanism must incorporate a device for adjusting the stretch of the blanket at the fabric entry in order to control the degree of shrinkage imposed. The yarn movement necessary to accommodate the warpway shrinkage is facilitated by the application of heat and moisture during the process.

RaisingThis is a process in which fibres or fibre loops are pulled from the surface of the yarns to produce a nap on the surface of the fabric. The machine used almost universally to raise cotton and synthetic fabrics is the so-called double-action cylinder raising machine, in which the mechanical action is provided by rotating rollers covered with card wire.

A number of effects can be produced by raising, this being as dependent on the characteristics of the fabric as on the differences that can be applied by the machine. Nevertheless, the operation of a raising machine requires quite subtle adjustments of processing conditions, and considerable experience and skill are needed. In particular it is important to recognise that this process is essentially destructive, since it depends on the pulling of fibres partially free from the yarn structure. The fabric must be initially strong enough to allow for the consequent loss in strength, and the process must be operated with fine control to avoid tearing the fabric to pieces. In atypical cylinder raising machine the raising rollers, which may number between 12 and 24, are mounted in bearings on two circular side plates so that they form in effect the outer surface of a cylinder. The fabric passes over this cylinder, making contact with the wire on each roller over a small arc. The card wire tips are angled, facing forward (in the direction of fabric travel) and backward on alternate rollers; the rollers are known respectively as ‘pile’ and ‘counterpile’.

This feature is the reason for the name ‘double action’. The fabric contacts the raising rollers first at the front of the machine, near the bottom of the cylinder, and leaves at the back, having been in contact for about three-quarters of the circumference.

In operation the shaft carrying the side plates revolves and the individual raising rollers rotate in their bearings, driven by belts engaging with pulleys on their shafts. The pile roller drive is at one side, counterpile at the other. The fabric also moves so that the overall motion can be very difficult to follow. However, it may be deduced (or taken for

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granted if preferred!) that by suitably adjusting the roller speeds relative to that of the cylinder it is possible to achieve a balance such that the card wire tips at the outside circumference are moving forward at just the speed of the fabric. This is the ‘neutral point’, at which no raising action occurs and which forms the starting point for the process.

Raising action is provided by slightly increasing the speed of the pile rollers or slightly reducing that of the counterpile, or more usually by both together. The result is that the card wire tips move at a speed slightly different from that of the fabric. Raising is not effected by a smooth combing action; it only occurs where a card wire tip becomes entangled in a yarn and, when suddenly released, draws a loosened fibre end with it. The noise associated with this action is the characteristic hiss of the raising process, which is not heard at the neutral point.

Only a small proportion of the wire tips make effective contact with the fabric at any instant, and of these contacts only some will actually withdraw fibres, but the overall effect of the interaction between card wire and fabric is that the fabric is alternately under tension and relaxed between counterpile and pile rollers. This interaction demonstrates the benefit of the double-action system, namely that significant local tension changes may be developed within the process without any appreciable overall change of fabric tension.

It is apparent from this description that the fabric is in contact with the card wire over a somewhat longer arc under raising conditions. Over this arc the ‘effective’ wires bend backwards and spring out suddenly at the point of release. It follows that the overall fabric tension has two potentially opposed effects: in the first place higher tension will tend to increase the number of contacts between fabric and wire, but on the roller it will tend to pull the fabric free after a shorter contact arc.

It follows that the choice of optimum tension settings remains a matter that can really only be resolved by experience. Because the raised effect results only if a card wire tip becomes embedded in the fabric, the plucking-out of fibres occurs almost entirely from the weft yarns in a woven fabric. A wire tip that enters a warp yarn is likely to slip along it without becoming entangled.

The weft yarns will inevitably suffer an appreciable loss in strength and some length reduction as a result of raising; they should initially be of sufficient strength to allow for this. Ease of raising is facilitated by incorporation in the fabric of short-staple weft yarns of relatively low twist and by the presence of a suitable lubricant. The raising of woven fabric proceeds by lifting individual fibre ends from the weft yarns.

To achieve a uniform nap it is therefore essential to build it up gradually, with a gentle raising action. It is normal practice therefore to give the fabric several raising passes, either repeatedly through the same machine or by operating several machines in sequence. If both faces of the fabric are to be raised it is usual to give no more than two or three passes on one face before changing to the other, in order to keep the two faces

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more or less in balance. As raising proceeds, a given action (as measured by roller speed settings) will tend to have a reduced effect as the card wire is increasingly impeded by the nap already produced. At any single setting there is likely to be a limiting condition beyond which little further raising will take place.

The action of the card wire on the fabric is balanced by reaction on the card wire rollers. Various techniques have been developed to quantify the raising action by measuring the force transmitted back to the roller drives. However, the effect of a given raising force depends intimately on the fabric characteristics. Hence measurements of this sort can only really be of value in assessing the relative rate of raising on a given fabric; they can make a useful contribution to control of the process provided this limitation is appreciated.

The same proviso applies to measurements on raised fabric. The simplest measure of the amount of nap is the increase in thickness under low load or, a little more accurately, the increase of apparent specific volume (the reciprocal of overall density), which allows for width loss on raising. It will be apparent that the same thickness increase may be recorded from one fabric with a short, dense nap and another where the nap is longer but sparser. Here again the measurement is really only useful for following the progress of raising on a particular fabric or for assessing repeat runs under nominally identical conditions.

CalenderingIn this process dry fabric is passed in open width between rollers under pressure in order to alter its handle, surface texture and appearance (Figure 7.2). The machinery is similar in some respects to mangling, although the bowls are harder and the loads generally higher. The important similarity is that the nip through which the fabric passes is formed between two bowls, of which one at least is relatively soft, so that the area of contact is determined primarily by the indentation of this bowl. This protects thick regions in the fabric, and even creases, from severe damage. Modern calenders commonly have two or three bowls in a vertical arrangement. Some sixty or more years ago, when calendering was employed for a very wide

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variety of effects, stacks of six or seven bowls could be encountered, but a three-bowl arrangement is capable of providing the following processes, still regularly in use:

(a) Ordinary calendering (swissing)

(b) Schreinering

(c) Moire effect calendering

(d) Embossing

(e) Friction calendering.

The following is a summary of the important features of a typical machine. The top and bottom bowls are of chilled iron or steel, the middle bowl being the relatively soft one, comprising a central shaft with a substantial thickness of compressed cotton or compressed discs of woollen paper or impregnated synthetic fibre. The top bowl is fixed in its bearings and is directly driven, the other two bowls being raised into contact by pneumatic or, more often, hydraulic cylinders supplying loads up to about 800 kg per cm length of nip. The bottom bowl is normally driven through a slipping clutch to ensure that the bowls are rotating as the load is applied. The top bowl is heated, usually internally by gas flame or circulating oil, possibly externally by radiant elements. The surface temperature of this bowl may be set at 150°C or more.It is important to note that filled calender bowls suffer from the same defect as filled mangle bowls, namely their resistance to bending resides solely in the metal shaft, the filling making no contribution. These bowls are therefore much more prone to deflection than a metal bowl of the same overall diameter.

If the filled bowl is in the central position in a three-bowl calender this problem is unimportant, but if it is the bottom bowl care must be taken to ensure that the effects of

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bowl deflection are not serious, either by limiting the applied load or by applying a suitable camber. This situation will obviously arise in a two-bowl calender, but also in a three-bowl machine if it is required to provide a filled-bowl/filled-bowl lower nip.

SwissingIn this, the simplest, calendering process, the fabric is passed through one or both of the calender nips in order to reduce its thickness somewhat and to provide what might in general be called a ‘crisper’ handle. The calendered effect is most pronounced if the fabric is slightly damp entering the machine and drier leaving it. A moisture content somewhat above the normal air-dry regain is useful, perhaps up to 12-15% for cotton. A top-bowl temperature of 100°C will readily supply the heat needed to evaporate this excess after the nip.

Even in plain calendering the fabric face in contact with a metal bowl will always have a slightly glazed appearance. This may well be an additional advantage, but if it must be avoided the solution is to use filled bowls in bottom and middle positions and apply only the lower nip.

SchreineringThis process is essentially similar to plain calendering using a top bowl engraved with fine parallel lines. These lines should be at an angle that is as near as possible to the apparent lines caused by the twist of the warp yarns.

To meet this requirement it is usual to have a variety of engraved bowls available. A fabric passed through such a nip will have this pattern impressed on its upper surface, resulting in a sheen possessed naturally only by fabrics woven from exceptionally regular yarns. Before the widespread availability of filament synthetic fabrics, the target appearance was that of silk, and schreinering was more widely used, with a variety of types of engraved line. At the present time the choice is likely to be much more restricted.Nevertheless, the process can still be most effective in appropriate circumstances.

Moiré effectThe characteristic moiré patterns may be produced by an engraved roller in a manner analogous to the schreinering process, but the result will show a warpway repeat at a pitch equal to the circumference of the engraved bowl. A truly random moiré effect is obtained by passing two lengths of the same fabric face-to-face through the calender. Each fabric generates a moiré pattern on the other as a result of the inevitable small variations in yarn spacing.

As in plain calendering, if the fabrics are passed through a nip between metal and filled bowls, then one side will be glazed while the other is not. Normally this will not be a problem, but if identical sides are required then two similar filled bowls must be used in the calender.

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EmbossingEmbossing has some similarity to schreinering, but whereas schreinering is essentially a surface effect, the embossing process employs larger and deeper patterns, carried by both bowls. This requires a two-bowl calender in which the bowls are positively geared together.

It is still necessary to have one relatively soft bowl, so that the fabric is not crushed in the contact between metal bowls. The pattern engraved in the metal bowl may be gradually run into the filled bowl, the positive gearing ensuring that the two bowls stay in synchronism.

Friction calenderingThis process can be operated on a three-bowl calender in which both top and bottom bowls are positively driven in such a way that the top bowl has an appreciably higher surface speed, commonly by a factor of about two. In older calenders the speed differential is provided by a gear chain between the top and bottom bowl shafts.

Certain modern designs incorporate separate drives to the two bowls, an arrangementthat facilitates alteration of the friction ratio. When the top and bottom bowls are running at different speeds, the middle filled bowl takes up the speed of the bottom one. The reason for this is that the load on the lower nip is greater than that on the upper, because of the weight of the middle bowl.

With similar coefficients of friction, the frictional force at the lower nip is the greater, and this determines the speed of the middle bowl. (That the speed differential is dependent on the coefficient of friction may readily be demonstrated on an empty machine by wiping a damp cloth across the face of the middle bowl, which will then be seen to accelerate briefly as the damp strip passes through the lower nip.)

The friction calendering action takes place at the upper nip, where the fabric follows the middle bowl speed, and its upper surface is vigorously polished by the top bowl. The application of high nip pressure and high temperature to a fabric impregnated with starch or a synthetic alternative can, on repeated frictioning, produce a material that is quite transparent, having had virtually all the internal air spaces (and hence light-reflecting surfaces) eliminated. At one time friction calendaring in this extreme form was important in the manufacture of tracing cloth and the process is still widely used for bookcloths and similar specialised fabrics.

Reducing stiffnessOccasions may arise when it would be convenient to produce some modest improvement in fabric softness by mechanical means. Machines designed specifically for this purpose, such as the button breaker, may be encountered only very rarely, but simple makeshift arrangements will frequently prove quite effective. What is required, in essence, is to pass the fabric, under controllable tension, over a series of relatively sharp edges. An assembly of square-section bars or scrimp rails will normally suffice.

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Chemical finishing

INTRODUCTION

A dyed, washed-off and dried fabric is seldom an immediately saleable product. Additional processing is required to give the fabric and the garment made from it customer appeal. A well known company coined the phrase: ‘It is the finish that fits the fabric for its purpose’.

Finishing of textiles falls into two categories:

(a) Mechanical finishing

(b) Chemical finishing, the subject of this chapter.

In order to obtain a desired finishing effect the fabric is frequently given severalfinishing steps, and these can be either mechanical or chemical in nature.

OBJECTIVES OF CHEMICAL FINISHINGThe purpose of finishing textiles is to impart the special properties that they must possess to meet appropriate in-service requirements and secure customer satisfaction. Dress goods, shirtings and leisurewear must have an acceptable handle, should not crease in wear and should display good easy-care properties. Workwear must be resistant to hazards encountered by the wearer, e.g. boiler suits worn by garage mechanics must have adequate oil and stain repellency, firemen’s uniforms must be flame-retardant and outdoor workwear must be water-repellent.

Dimensional stabilityFabrics and garments made from cotton or viscose have to withstand washing, laundering or dry cleaning, part of the usual wash and wear cycle. If not chemically finished, cotton and viscose fabrics are dimensionally unstable when washed. Cellulosic fibres, when immersed in a wash liquor, readily absorb water and swell in a lateral direction. Cotton absorbs about 50-60% of its own weight in water, viscose up to 90-100%. The aim of a chemical finish is to reduce the water uptake or ‘imbibition’ of the cellulosic fibres, thereby rendering the treated fibres resistant to swelling and therefore shrink resistant. Good dimensional stability is a prerequisite for cotton and viscose fabrics regularly washed or laundered, such as shirtings, apparel, leisurewear, bed linens, etc.

Easy-care finishingSince the 1950s there has been a marked trend towards automated domestic chores and more leisure time. One facet of this has been the need to develop apparel fabrics and household textiles that are easily washable and require no ironing, or only a minimum of ironing. The introduction of nylon and, particularly, polyester fabrics, with their inbuilt tability to deformation and creasing during wear, and their ‘smooth drying’ properties when washed or laundered, created new demands for higher standards of performance

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also from cellulosic fabrics. From the mid 1950s to the early 1970s a great deal of effort was devoted by the chemical manufacturers to developing new finishing agents that imparted the desired easy-care properties to cotton and, to a lesser extent, viscose fabrics.

Chemical finishing of cellulosic fabrics was given fresh impetus by the availability of a host of new chemicals. The textile finishing industry responded by introducing new or improved application techniques, which imparted easy-care, wash-wear and minimum-iron properties demanded by the consumer. Easy-care finishing is still widely used on cotton, viscose and polyester/cotton fabrics. The extravagant claims made in the 1960s for superlative performance of easy-care-finished 100% cotton fabrics have long since been discounted, but easy-care finishing of certain types of cotton and polyester/cotton fabrics is here to stay.

Crease recovery of finished fabricsEasy-care finishing results in fabrics that resist creasing during wash and wear, yet a fabric’s resistance to and recovery from deformation due to creasing is a property that is frequently evaluated subjectively and assessed incorrectly. A chemically finished cotton or viscose fabric may have excellent recovery (snap-back) properties when creased by hand (clenched fist test) yet the same fabric may crease badly in wear (e.g. during prolonged sitting), or may have lost all its crease recovery after washing. It is clear therefore that two distinct processes exist: dry creasing and wet creasing. An in-between stage, creasing at high relative humidity and elevated temperature (as in sitting) is well known and difficult to overcome by chemical finishing

Test methods exist to evaluate all forms of creasing, including creasing in wear and creasing during travel (box creasing). In evaluating creasing behaviour and crease recovery of a fabric, it is important to specify the type of creasing a fabric may be subjected to in use, so that the correct test method is applied. Thus to evaluate resistance to creasing in wear, samples cut from the fabric are creased under standard conditions of applied load and time. After removal of the load, the specimens are allowed to recover and the angular recovery is measured. The greater the recovery angle, the better will be the resistance of the fabric to creasing in wear.

Polymeric and crosslinking finishesIn order to impart easy-care properties to cellulosic and blend fabrics a chemical finish has to be applied. The original crease-resist process, developed by Tootal Broadhurst Lee Co. in the late 1920s and early 1930s, entailed padding viscose fabric in a solution of a water-soluble precondensate of urea and formaldehyde with an acid catalyst, followed by drying and finally curing the resin-impregnated fabric at 130°C. Treated fabrics had greatly improved dry crease recovery attributable to deposition of urea-formaldehyde (U/F) polymer in the interstices of the fibres. Chemical finishing agents that react mainly by self-crosslinking to form threedimensiona polymer lattices in the fibres include those based on U/F and melamine/ formaldehyde (M/F). Commercially available U/F and M/F products include dimethylolurea (DMU) and trimethylolmelamine (TMM).

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These and similar resin products are still widely used by the finishing industry. Their main attractions are excellent dry crease recovery, simple application and low cost. The demand for cotton and viscose fabrics with good easy-care properties was met by the development of the so-called crosslinking reactants. These condense with the reactive hydroxy groups of the cellulosic fibres to form crosslinks durable to washing and laundering. In the past the chemical manufacturers devoted considerable effort to developing new N-methylol derivatives of ethyleneurea, propyleneurea, triazones and carbamates, to mention just some of the more important types. Of these the following have assumed special significance and are still used today:

- Dimethylolethyleneurea (DMEU)- Dimethyloldihydroxyethyleneurea (DMDHEU), the most widely used reactant- Dimethylolpropyleneurea (DMPU)- Dimethylol-4-methoxy-5,5-dimethylpropyleneurea.

In comparison with the traditional U/F and M/F self-crosslinking resin finishes, these and other cellulose reactants provide finishes that not only impart good easy-care properties, but may enhance or suppress other fabric properties according to the crosslinking reactant chosen.

These include:

- Enhance resistance to hydrolysis during laundering

- Reduce chlorine retention during hypochlorite treatment

- Suppress release of formaldehyde during storage, making-up and wear

- Reduce change of shade of dyed or printed fabrics that can occur as a result of- chemical finishing

- Suppress formation of fishy odours during storage.

Pad-dry-cure methodsThe conventional pad-dry-cure method is the process most widely used to impart easy-care properties to cellulosic fabrics. It is relatively simple and yields fabric with the properties outlined in the table 8.1

It is a characteristic feature of the classical pad-dry-cure method that an improvement in dry crease recovery is accompanied by a corresponding deterioration in physical properties. In fact a direct relationship exists between increase in dry crease recovery angle and loss in strength or abrasion resistance. Many modifications have been proposed to the basic method to obtain an optimum balance between improved easy-care performance and loss in strength. Some of these variants found commercial application, at least for a time.

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Variables at the disposal of the finisher include:

(a) Composition and concentrations of the pad liquor: self-crosslinking resinprecursors or crosslinking reactants, catalysts and auxiliaries

All these variables have a significant effect on the final outcome. Amongst them, catalysts deserve special mention. The self-crosslinking U/F and M/F resins are best catalysed with ammonium salts, e.g. ammonium chloride or mono- or di-ammonium hydrogen phosphate, which at elevated temperature dissociate to liberate the free acid. Undesirable side effects associated with these catalysts include the development of fishy odours and degradation of the resin finish by absorption of chlorine during laundering and subsequent drying.

The crosslinking reactants are best catalysed by metal salts of strong acids, e.g. magnesium chloride or zinc nitrate. Mixtures of metal salts with a-hydroxycarboxylic acids, e.g. tartaric or citric acids, are sometimes used. The chemical manufacturers provide detailed information about suitable resin and catalyst systems and application conditions.

The classical resin finishing process consists of a minimum of three distinct processing steps, afterwashing sometimes being omitted on cost grounds.

(a) Impregnation Fabrics are padded in an aqueous solution containing the crosslinking agent, catalyst and auxiliaries on a two- or three-bowl padding mangle. For cotton an expression or liquor pick-up of 60-70%, calculated on the dry weight of the fabric (o.w.f), is usual; for viscose the expression is generally 90-100% o.w.f.

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(b) Drying Impregnated fabrics are dried at temperatures between 105 and 120°C, depending on availability of machinery. It is frequently desirable to dry fabrics to a known moisture content rather than to complete dryness.

(c)Curing Dried fabrics are cured at elevated temperatures (130-180°C) to effect condensation/polymerisation or crosslinking with the fibre. Under these anhydrous conditions the cellulosic fibres are crosslinked in the unswollen state.

(d) Afterwashing It is desirable to wash the cured fabric in hot detergent solution to remove surface resin deposits, uncured resin and catalyst residues. Washed fabrics are less prone to develop fishy odours or to release as much formaldehyde as the unwashed material.

Moist-cure processesThe disadvantages of conventional resin finishing, i.e. loss of tensile strength, tear strength and abrasion resistance, led to the development of new methods of curing. By curing fabrics with the fibres in a partially swollen state, satisfactory wet and dry crease recovery levels were obtained with less physical damage, thereby achieving a better balance of fabric properties.

Moist crosslinking is carried out on partially swollen cellulosic materials having a residual moisture content of 5-8% in the case of cotton and 1.0-1.6% for viscose. After impregnation with a crosslinking reactant and catalyst, the fabrics are carefully dried to a predetermined moisture content, batched on an A-frame, wrapped in polythene sheeting and slowly rotated for 16-24 h. After completion of the reaction the fabrics are washed-off continuously, i.e. rinsed hot and cold, neutralised and dried.

Crosslinking reactants and catalysts have to be carefully selected to guarantee reproducible results, e.g. DMDHEU or dimethylol-4-methoxy5,5-dimethylpropyleneurea give excellent finishes. The acid catalyst can be sulphuric acid or a mixture of inorganic salts and organic acids. The pH of the impregnating liquor must be between 1 and 2.

In traditional dry curing processes the cellulosic fibres are in an unswollen state during crosslinking, which leads to relatively short crosslinks between cellulose chains, a relatively rigid crosslinked network and therefore relatively large losses in tear strength and abrasion resistance.

In moist crosslinking processes the cellulosic fibres are in a partially swollen state and longer crosslinks are formed between cellulose chains, resulting in a more flexible or elastic network that can better accommodate to deformation during tearing or abrasion. This leads to an improved recovery/strength relationship. Using a traditional dry curing process a 10o rise of angular dry crease recovery produces a loss of tear strength of 5-9%. With a moist crosslinking process the loss of tear strength is reduced to 3.5-6.0% for the same rise in angular dry crease recovery.

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Wet crosslinking is a method designed to give wet crease recovery with little or no dry crease recovery, required for minimum-iron finishes. The method is a modification of moist crosslinking, insofar as the pH of the impregnation liquor is less than 1 and the padded fabric is not dried but is squeezed to a residual moisture content of 70-80%. In all other aspects processing is as for a moist-cure finish. Great care is required when working with a strongly acid impregnation liquor to prevent damage by spillage to operatives, machinery and fabric.

Combined chemical and mechanical finishesCombined finishes generally use a calender to produce the desired mechanical effect. Three types of calendered finishes are generally recognised:

(a) Schreiner, silk or moire finish using a metal roller with finely engraved lines

(b) Chintz or glazed finish using a highly polished smooth metal roller

(c) Embossed finish using an engraved metal roller.

Schreiner finishing imparts a silk-like lustre an d handle; moire finishing gives a rippled appearance and imitates an irregular ‘watered’ effect. Chintz or glazed finishing confers a high gloss and is obtained by friction calendering. Embossed finishing imprints a design in relief consisting of three-dimensional raised (sculptured) and flat areas,

Fabric construction is important in achieving a calendered effect. Moreover, fabrics to be calendered must have adequate strength to withstand the effect of the heated metal roller, often applied to fabrics with considerable pressure, as well as losses resulting from the chemical finish.

To obtain washable mechanical effects, cellulosic fabrics have to be pretreated or sensitised with N-methylol derivatives, and curing must be delayed until after the calendering operation. For cotton fabrics a crosslinking reactant of the DMDHEU type is preferred; for viscose fabrics a combination of a crosslinking reactant with a self-crosslinking resin precondensate is usually selected. The choice of catalyst is equally important: for cotton mono- or di-ammonium phosphate or magnesium chloride is used, whereas for viscose ammonium chloride or ammonium sulphate is recommended.

The pad liquor may contain up to five or six components, e.g. crosslinking reactant and/or self-crosslinking resin, catalyst, softening agent, additive to improve tear strength, hydrophobic agent to enhance resistance to water spotting, and dispersing agent.

Cotton fabrics are padded to 70-80% expression; viscose fabrics to 90400% expression. Careful drying at temperatures of 100-l 20°C is essential to yield fabrics with a residual moisture content of 8-10% for cotton and 10-12% for viscose. As a general guide, an increase in residual moisture content yields a better mechanical effect with better wash

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resistance, but a harsher/stiffer handle and a higher loss in tear strength and abrasion resistance.Schreiner and chintz finishes require a pressure of 25-30 tonne across the face of the roller, the metal bowl being heated to 160-200°C. For embossed finishes the pressure is usually reduced to 15-20 tonne. After calendering the fabric is cured as previously escribed.

The insertion of durable pleats represents another combined chemical and mechanical finish. To produce washable effects a highly reactive reactant or selfcrosslinking precondesate, e.g. DMEU or DMU, is selected. Fabrics are sensitized and dried as previously described, followed by insertion of pleats by a heated knife. Curing or condensation is limited to 1 min at 180°C by the design of the pleating machine.

Flocked finishes are the adherence of tiny fibers or fine particles to create a pile effect on a fabric through one of two methods: Additives for crosslinking finishesAdditives, when added to a chemical finishing liquor, bring about changes in physical or chemical properties of the treated fabrics. Additives are also used to enhance the stability and smooth running properties of the finishing liquors. Wetting, dispersing and antifoam agents

These auxiliaries are usually added in small quantities (I-5 g/l) to finishing liquors. Wetting agents enhance the wetting-out properties and thus the absorptive capacity of fabrics to be treated. Both anionic and nonionic wetting agents can be used.

Dispersing agents ensure stability and compatibility of the various components of a chemical finishing bath for prolonged periods (6-8 h). Nonionic dispersing agents are widely used, but cationic agents can find use in special cases when substantivity is required, i.e. when applying chemical finishes by exhaustion. Antifoam agents prevent foaming of the liquor in the pad trough or at the nip formed by the padding rollers. They act by modifying surface tension and many different products are available, several of them silicones.

SoftenersSofteners are used to improve the handle and smoothness of treated fabrics. Resilience (i.e. the ability to resist and recover from stretching, deformation and creasing) can also be improved. Softening agents are classified according to their ionic properties.

Anionic agents are based on:

- Sulphated oils or fatty acid esters

- Alkyl sulphates

- Fatty acid condensation products.

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Anionic softening agents impart a full handle to treated fabrics, but their softening effect is inferior to that obtainable from cationic or nonionic agents. Products based on (b) or (c) do not discolour under normal curing conditions, but their stability is limited below pH 7.

Nonionic agents are based on:

- Polyglycol ethers and esters

- Ethoxylated phenols

- Silicone products.

Although the softening effect from products based on (a) or (b) is not as good as that given by cationic agents, the nonionic softening agents are universally applicable, as they are unaffected by pH and water hardness. Their resistance to discoloration is good, which is of importance in chemical finishing.

Cationic agents are based on:

- Quaternary ammonium or pyridinium derivatives

- Aminoesters and amides.

The softening effect is excellent on all fibres without affecting the fullness of handle. Cationic agents are widely used in chemical finishing as they are compatible with self-crosslinking U/F and M/F resins and crosslinking reactants.

Reactive softeners are based on N-methylol derivatives of long-chain acylamides or of long-chain acyl-substituted ureas. These softeners are capable of reacting with cellulosic fibres and thus provide softening effects more durable to laundering. They can also impart a mild water-repellent effect to treated fabrics.

Needle lubricantsNeedle lubricants improve the sewing properties, i.e. reduce needle cutting, of easycare cellulosic fabrics. They help to reduce losses in tear strength and abrasion resistance. These products function by lubricating the crosslinked fibre matrix. By making it more flexible, the fibre is better able to accommodate stresses imposed on the fabric structure during sewing, cutting and wear. In general three types of products are employed, outlined below.

(a) Primary and secondary dispersions of polyethylene These products give excellent effects and are widely used. They do not materially affect handle or soiling and because of their excellent stability are almost universally applicable in chemical finishing liquors.

(b) Silicic acid ester dispersions These agents impart similar effects to those obtained from polyethylene dispersions and give a smooth, silk-like handle to treated fabrics.

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(c) Silicone dispersions These are of considerable commercial importance and are discussed below.

Handle modifiersHandle modifiers serve a multitude of functions. Firstly they enable the handle of fabrics to be varied from soft to firm according to demand. Secondly they restore bulk and firmness to fabrics that have become limp during preparation and dyeing processes. Thirdly they enable fabrics to be stiffened if necessary to facilitate making-up procedures. Finally a stiffening finish is required for end uses such as interlinings, workwear, table linen, bed linen, mattress covers, tapes and ribbons.

The chemicals employed are similar to those used as handle modifiers and stiffening agents, but their effect depends on the amount of product applied to the fabrics. They can be natural or synthetic polymers, and finishes can have various degrees of durability, depending on their resistance to washing and laundering.

Natural starches and their derivatives find wide application. Unless used in conjunction with polymeric or crosslinking reactants, the stiffening effects are not durable. Many synthetic polymers give washable effects. These products are usually based on polyacrylic acid and its derivatives, polystyrene, poly(vinyl alcohol), poly(vinyl acetate) and poly(vinyl propionate). Commercial products are frequently made from different monomers to give tailor-made copolymers with known chain lengths and degrees of polymerisation. Many washable stiff finishes are based on the self-crosslinking U/F and M/F derivatives.

Polyacrylate and polysiloxane dispersionsCommercial polyacrylate products are usually copolymers derived from alkylacrylates containing small amounts of reactive comonomers able to crosslink with both:

(a) N-Methylol reactants or polymer-forming precondensates

(b) Cellulosic fibres.

The pH stability of these dispersions is good and reactive polyacrylate dispersions are widely used in easy-care finishing because of their beneficial effect on both 100% cellulosic and cellulosic blend fabrics. When added to the chemical finishing liquor they bring about a remarkable increase in crease recovery without adversely affecting tear strength and abrasion resistance. For any level of easy-care properties it is thus possible to substitute a given amount of crosslinking agent with a reactive polyacrylate dispersion, thereby obtaining a better balance of easy-care properties with a reduced loss of physical properties. Such products do not materially affect handle or soiling of easy-care finished fabrics. Reference has already been made to polyacrylate dispersions as handle modifiers.

Commercial products known as silicones have been available since the 1950s. The early products were either solvent-based or aqueous emulsions and have found wide

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application as durable water-repellents for all classes of textiles. Silicones proved to be good lubricants and are extensively used in making-up to reduce needle cutting. However, their use as softeners has undergone many changes in the last two decades.

From the inert polydimethylsiloxane softeners of the 1950s and 1960s, which did not penetrate the fibre structure and gave only surface lubrication, the 1970s saw the development of reactive polysiloxanes with hydroxy groups at the ends of the polymer chains, making crosslinking possible. In the 1980s aminosiloxane polymers with built-in crosslinking groups and catalysts were developed.

These elastomeric reactive silicones are capable of crosslinking with themselves or with hydroxy groups in cellulosic chains. By penetrating into the fibre matrix to form a three-dimensionalnetwork, they provide internal lubrication and therefore superior softening to easycare finished fabrics. It is believed that 65% of all easy-care formulations nowadayscontain elastomeric reactive silicone softeners.

Amongst the latest developments in this field are the amine-functional silicone microemulsions. These are colourless silicone fluids emulsified by special techniquesto reduce particle size to only one-hundredth of that of a conventional polysiloxane emulsion. Microemulsions, when applied to cellulosic fabrics as part of a crosslinking formulation, produce ‘inner softening’ by building a three-dimensional network or lattice inside the fibre. Such easy-care finished fabrics have a durable, soft and springy handle coupled with excellent physical properties. Silicone microemulsions do not affect the soiling behaviour of the treated fabrics

In general the term chemical finishing is somewhat of a misnomer when applied to finishing of 100% synthetic fabrics. The lack of chemical reactivity of synthetic fabrics, particularly those based on polyester fibres, precludes chemical reaction between fibre and finishing agent. In fact chemical finishing processes devised for cellulosic fabrics (to impart dimensional stability, crease recovery, easy-care properties) are unnecessary for synthetic fabrics, as these desirable properties are already inherent in the fibre.

Most finishing processes for synthetic fabrics are of a mechanical nature. When chemical finishes are applied to obtain certain specialized effects, the chemicals are generally deposited on the fibre surface without penetrating the structure. The durability of such finishes to washing and laundering is therefore only limited.

Heat settingA heat setting treatment is often used to impart desirable properties to synthetic fabrics; his relaxes and stabilises the fibre structure and provides dimensional stability. Setting treatments require high temperatures and are generally carried out prior to dyeing, so as to present the dyer with a dimensionally stable and crease-free fabric during wet processing. Another advantage of presetting is that dyes cannot be adversely affected, or even decomposed, subsequently by the high temperatures used in postsetting.

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Nevertheless, heat fixation can be carried out as the final fixation step for disperse dyes or fluorescent brightening agents, and results in fabrics with excellent dimensional stability.

Conditions for heat setting or dye fixation are:

- Polyester fabrics: 20-30 s at 180-220°C

- Nylon 6 fabrics: 15-20 s at 190-200°C

- Nylon 6.6 fabrics: 15-20 s at 190-230°C.

With nylon fabrics the lower temperature is used to obtain dimensional the higher temperature is required to impart freedom from creasing. stability and the higher temperature is required to impart freedim from creasing.

Hydrosetting and steam settingHydrosetting, usually confined to nylon fabrics, imparts a fuller and softer handle than dry heat setting in hot air. Fabrics are treated in an autoclave for 20-30 min with water at 125-l 35°C.

Steam setting gives results intermediate between those obtainable from dry heat setting in hot air and hydrosetting. Using saturated steam, fabrics are steamed in autoclaves for 20-30 min at steam pressures of 180-200 kPa (1.8-2.0 atm) at 130- 132°C. The results are similar to those obtained from hydrosetting. With superheated steam, setting is carried out on a pin stenter, giving results similar to those obtained from thermofixation, except that steam, being a better heat-transfer medium than air, enables the treatment time to be cut down by 25% to I0-15 s. Moreover, in the absence of air superheated steam setting causes less yellowing of nylon fabrics.

AdditivesMany additives are available for use on 100% synthetic fabrics, to impart the special effects described below. As previously stated, these finishes have only limited durability to washing and laundering on synthetic fabrics.

Filling and stiffening finishesPolyester and nylon fabrics used for interlinings, lace, nets, etc. are frequently stiffened with U/F and M/F resin precondensates; these adhere relatively well to the smooth fibre surface. Dispersions of acrylate copolymers can be used in combination with these resins to impart better elastic recovery from deformation.

SoftenersMany anionic, nonionic and cationic softening agents are on the market and the choice depends mainly on method of application, type of handle required and cost Some of these

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products, besides conferring a soft and silk-like handle, also impart hydrophilic properties and improved sewing/cutting properties.

Frequently used finishes

Hydrophilic finishesSynthetic fabrics have low regain values. Nylon takes up 5% moisture at equilibrium, polyester only 0.5%. To improve comfort in wear, particularly for underwear in contact with the skin, it is desirable to impart a hydrophilic finish. Fatty acid adducts and modified polyamide dispersions are widely used.

Antistatic finishesPractically all chemical antistats, both temporary and permanent, function by providing a hydrophilic surface on the fibre, attracting a film of moisture from the atmosphere. The fibre surface thus becomes conducting and dissipates the charge.

An elegant method is to apply a hydrophilic polymer, e.g. a polyether or polyglycol derivative, to the fibre and attach it permanently by a heat treatment. The polymer chain is thus fused into the fibre surface, whilst the hydrophilic groups make the surface conducting. Permalose TM (Zeneca) is an example, but other chemical manufacturers offer alternative products.

Anti pilling finishesWear of synthetic fabrics may cause undesirable ‘pilling’ by loose or broken fibres migrating to the fabric surface, where they form little knots or pills that are tenaciously held. Chemical finishing represents only one possible solution to the problem and it is not always fully satisfactory, Chemical finishing agents, e.g. polyacrylates and silicone elastomers, function by bonding loose fibres together at contact points, restricting their migration to the fibre surface.

Anti slip finishesSlippage of warp and weft yarns is a well known defect of loosely woven filament fabrics arising from the smoothness of synthetic yarns. The problem can be overcome by reducing fibre surface smoothness, thereby increasing interfibre friction, by applying silicic acid esters, sometimes in combination with polyacrylates. The most popular blends are those of polyester with cellulosic fibres, either cotton or viscose, combining the excellent easy-care and hard-wearing properties of polyester with the comfort and freedom from static or soiling of cellulosic fibres.

Easy-care finishingThe outstanding properties of polyester/cellulosic fabrics are widely recognised, with blend ratios varying from 50:50 to 70:30 . Cotton-rich blends have also been evaluated, but for such blends to be of technical importance a minimum of 35-40% polyester has to be present. As polyester has a price advantage over cotton, the 50:50 blend has been widely adopted.

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It has already been shown in section 8.3.4 that chemical finishing of 100% cellulosic fabrics represents a compromise between improvements in easy-care behaviour and losses in physical durability. Easy-care finishing of polyester/ cellulosic blends requires an even more difficult compromise, because the two constituent fibre types have diametrically opposite finishing requirements. Polyester fibres demand setting at high temperatures and no chemical finishing, whereascellulosic fibres need to be chemically finished, but without exposure to such high temperatures.

Although it might be thought necessary to resort to two distinct finishing steps, i.e. setting of the synthetic fibre followed by chemical finishing of the cellulosic component,simpler sequences are used in practice. Polyester/cellulosic fabrics are often heat set prior to dyeing to give dimensional stability during wet processing, or as part of the Thermosol process in the fixation of disperse dyes. In subsequent chemical finishing care is required to ensure that resins, catalysts and additives, as well as curing conditions, do not adversely affect the colour fastness of the dyed polyester fibres.

Depending on the end use and the handle required, crosslinking reactants or U/F resin precondensates can be used. Reactant resins are often used on polyester/ cotton fabrics, where good easy-care properties coupled with good durability to laundering at 60°C are required. U/F resins may be preferred with polyester/viscose blends, where a resilient, springy handle is required with only moderate wash fastness.

In calculating resin add-on to blend fabrics, it is important to base the calculation on the weight of the cellulosic portion in the blend and not on the total weight of fabric.

In chemical finishing of polyester/cellulosic blends the weaker component, i.e. the cellulosic fibre, is further weakened. This is acceptable as long as the polyester portion of the blend compensates for the losses of tear strength and tensile strength. Likewise loss of abrasion resistance is tolerable in this way for white goods. With dyeings suitable additions must be made to the finishing liquors to minimise the change of shade that occurs when cellulosic fibre is lost by abrasion during wear.

Durable pressDurable press is a generic term for a finishing process in which chemical or physical stabilisation of a fabric takes place after making-up in garment form. By delaying the final finishing step until making-up is completed, it is possible to stabilise the shape of a garment in its final saleable form. In durable press finishing a distinction is normally made between precure and postcure methods.

PrecureThis method is applicable only if the polyester content is at least 60% of the total fabric weight. Before making-up, the cellulosic component is chemically finished in fabric form, in the usual way. The polyester component is heat set after making-up, thereby

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imparting the desired shape to last the life of the garment. Figure 8.1 is a schematic representation of the precure method.

Step 1 representsa conventional pad-dry-cure process using a crosslinking reactant with appropriate catalyst and additives.

Step 2 represents making-up and hot-head pressing; as a result of the applied heat and pressure, the polyester component of the already resinfinished fabric is plasticised and moulded into the required shape. Hot-head pressing at 160°C is therefore the vital step which gives shape retention to the garment.

PostcureIn this method blend fabrics are carefully impregnated with crosslinking reactant, catalyst and additives, but reaction between cellulosic fibres and crosslinking agent is prevented by appropriate selection of chemicals and close attention to working conditions. The chemically sensitised fabric is subsequently made up into garments, the required final shape of which is obtained by prolonged curing in an oven.

Figure 8.2 is a schematic representation of the postcure process. In step 1 the blend fabric is treated with either a stabilised/buffered crosslinking reactant and a reactive catalyst or a reactive crosslinking agent with a stabilised/buffered catalyst.Fabric is dried after impregnation, at a sufficiently low temperature to prevent reaction between the cellulosicfibres and the crosslinking agent.

In step 2 sensitised fabrics are made-up, the garments are pressed and then cured at elevated temperature in a specially constructed oven. In this final operation crosslinking of the cellulosic component and setting of the polyester take place simultaneously, givingthe garment the shape that it retains for life.

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The postcure process removed the responsibility for curing or setting (albeit of garments and not fabrics) from the finisher to the garment maker, and this departure from normal practice caused considerable problems in the trade. It also took time to realise that all accessories used in garment making, i.e. linings, pocketings, waistbands and even sewing threads, had to have a similar response to the fabric panels so that the finished garments did not distort or pucker during hot-head pressing and oven curing. Garments finished to durable press specifications have to be dimensionally stable to washing and have good easy-care properties. The precure method has found acceptance as Fixaform and the postcure method is recognised under the Koratron trade mark.

Soil-release finishesThe popularity of synthetics in blends with cellulosic fibres created a need for more effective washing methods. Blends, particularly those containing polyester or nylon, show considerable soiling that is difficult to remove even under the rigorous washing conditions used for cotton fabrics. This created a demand for finishes that facilitated the removal of soiling from blend fabrics.

Two main types of finish are available to minimise soiling, as outlined below.

(a) Stain- or soil-repellent finishes work by forming a barrier between fibre and soil. Such finishes are based on fluorocarbons that impart an oleophobic and hydrophobic character to the fabric surface.

(b) Soil-release finishes decrease but do not prevent soiling from taking place. They facilitate soil removal during washing and laundering due to the presence of hydrophilic groups in the soil-release agent attached to the fibre surface. Certain soil-release agents function by preventing redeposition of the dispersed or emulsified soil from the wash liquor back onto the fabric.

Hence the purpose of a durable soil-release finish is to facilitate the removal of soiling from polyester/cellulosic fabrics at moderate washing temperatures (40-60°C). This is achieved by combining the soil-release agent, usually an acrylate copolymer, with a crosslinking reactant, catalyst and other additives. In formulating recipes care is taken

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that all other chemicals are compatible with the soil-release agent and do not interfere with its effect on the substrate. Application is by the usual pad-dry-cure process

SPECIALITY FINISHES

Water-repellent finishesWaterproofing is one of the oldest established finishing processes. In the early days waterproofing meant coating fabrics with linseed oil, glue and other materials, yielding stiff and tacky garments impervious to both water and air. Such fabrics were most uncomfortable to wear. Nowadays the rainwear trade produces water-repellent and shower-resistant garments that are no longer purely functional, but also satisfy consumer demands in respect of comfort and fashion. Rubberised waterproofs were discarded long ago and the consumer now requires water-repellent outerwear, i.e.rainwear, leisurewear and workwear, that not only offers protection from the elements, but also has an attractive appearance, a pleasing handle and is comfortable to wear.

Several classes of chemical finishing agents are available to produce finishes that are water-repellent and yet permeable to water vapour and air, and the trade distinguishes between durable and non-durable water repellency. One of the early finishes (still used on canvas for tarpaulins and tentage and for reproofing after dry cleaning) is based on wax dispersions containing aluminium salts. On padding and drying the wax particles are deposited on the fabric surface and, together with the aluminium salts, form a water-repellent layer that penetrates to some extent into the fibre. The resultant finish shows good water repellency, is air permeable, but is removed on washing.

The replacement of aluminium by zirconium salts, which complex more effectively with wax emulsions, results in an improved water-repellent effect with much better durability. Moreover, it is possible to combine paraffin wax/zirconium emulsions with easy-care finishing agents, based on either polymer-forming or crosslinking reactant resins. In fact simultaneous application of easy-care and water-repellent finishing agents provides enhanced water repellency and better durability to washing. Paraffin wax/zirconium salt emulsions are widely used because of their ease of application (pad and dry at 90-130°C), good technical effect, compatibility with other finishes and low cost.

The availability of new compounds since 1940 heralded further developments in the field of water repellency. All these finishes had functional groups able to react with themselves, with other crosslinking agents and with cellulosic fibres. The waterrepellent effects were at least as durable to washing as those from paraffin wax/ zirconium finishes, but most of these new products were more costly and have since been replaced; therefore they will be mentioned only briefly.

A water-repellent finish based on stearamidomethylpyridinium chloride was formerly used to proof cotton rainwear. Application was by the pad-dry-cure method, but processing had to be carefully controlled so that the hydrochloric acid liberated during curing did not degrade the cotton fabric. Another traditional type of water-repellent agent was a water-soluble organochromium complex. This gave good effects, but treated

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fabrics were discoloured as the chromium compound was itself green, so it was restricted to fabrics dyed to medium and dark shades.

Other reactive water-repellent agents still used include products based on polymer-forming or crosslinking reactant resins. Typical commercial products are those based on fatty acyl-substituted methylolmelamines or monomethylolurea, an example of which is shown in Figure 8.3. This fatty acyl-substituted monomethylol-

urea compound is known to give excellent water-repellent effects on cotton and regenerated cellulosic fibres with good resistance to washing. Treated fabrics also have a soft handle. Such agents are particularly suitable for adding to an easy-care finish based on polymer-forming or crosslinking reactant resins; the combined finish reinforces the water-repellent effect and enhances resistance to laundering.

A further development of this concept was Phobotex FT (CGY), a mixture of a hydrophobic agent and an aminoplast. It is applied by the usual pad-dry-cure sequence and is readily combined with polymer-forming or crosslinking reactant resins to impart both crease recovery and water repellency to treated fabrics. The development of siliconesin the 1950s represented the most important addition to the range of water repellents available to the textile finisher. Silicones have assumed considerable importance as the most effective and durable water repellent for natural, synthetic and blend fabrics. Moreover, they impart a smooth, silk-like feel to treated fabrics and garments, the so-called silicone handle.

Commercial water-repellent silicones are based on polymerised siloxanes, primarily copolymers of hydrogenmethyl- and dimethyl-siloxanes, and are marketed as aqueous emulsions. Considerable expertise is required in formulating and manufacturing silicone emulsions. Early drawbacks included inadequate storage stability and emulsion breakdown caused by shear stress at the nip of a pad mangle. The choice of silicone catalyst affects:

- Rate of crosslinking of polysiloxane chains

- Water-repellent effect obtained

- Resultant handle.

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Several catalysts are effective in crosslinking polysiloxane chains, but nowadays organometallic compounds, such as zinc alkylcarboxylates, zinc octoate, zirconium fatty acid derivatives and epoxy-amides or -amines, are mainly used. Zirconium catalysts can be incorporated in commercial silicone emulsions and additional zirconium or zinc salts are often added to the padding liquor. Organometallic compounds, such as fatty acid zinc salts, tend to impart a firm, full handle, with little risk of changes in shade of dyeings or yellowing in the case of white goods. The epoxy-amide or -amine catalysts are noted for their soft and supple handle and impart the highest water repellency with optimum wash fastness, but slight changes in shade may occur, depending on the dyes used.

The mode of action of the catalyst is to orient the polysiloxane chains along the fibre surface. The hydrophobic methyl groups face away from the fibres and repel water molecules, whilst the silicone groups are anchored to the fibre surface by the organometallic compounds (Figure 8.4). A prerequisite for successful silicone finishing is for the fabric to be free from size and surfactants used in preparation and dyeing, such as wetting agents, detergents and softeners. All traces of hydrophilic agents must be removed as they mask the water-repellent effect. Cleanliness is vital in silicone finishing, and this applies to all equipment used.

The general method of applying a silicone finish is to pad the silicone emulsion containing catalyst at room temperature, dry at 100-120°C and cure for 3-4 min at 150-155°C. This procedure is applicable to any fabric irrespective of fibre type.

Cellulosic fabrics and blends show a marked improvement in water repellency and wash fastness if the silicone finish is combined with polymer-forming or crosslinking reactant resins to impart previously described.

A combined easy-care and water repellent finish as :

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Oil- and soil-repellent finishesFinishes imparting oil, stain and soil repellency are less important than the related water-repellent finishes. Their relatively high cost has militated against their adoption. Fields of application include workwear, military and carpets, primary upholstery and loose covers, table linen, etc. automotive fabrics,

Typical products are based on fluorinated hydrocarbons, fluorinated acrylate esters, chromium complexes of perfluorocarboxylic acids and others. Considerable effort has been devoted to developing and extending the range of these chemicals. Their mode of action is similar to that of silicones, in so far as they form a hydrophobic and oleophobic film around fibres that is anchored to the fibre surface, the oil-repellent groups preventing ingress of oil, stains and soil into the fibre. A further water- and oil-repellent finish, using a fatty acylated methylolurea as a water repellent, has been developed for outerwear. The combined finish enhances the hydrophobic and oleophobic effects.

Flame-retardant finishesEarly work on flame retardancy, mainly for military purposes, was primarily concerned with limiting flame propagation. More recently greater emphasis has been given to analyzing the smoke and toxic gases evolved during burning. Processes for making cellulosic fabrics temporarily flame-repellent, based on ammonium phosphate and other inorganic salts, were soon established, but for apparel uses durable finishes were required that met well defined standards.

Flame-retardant finishing of cotton and blends, to impart self-extinguishing behaviour in normal wear and after repeated launderings, creates problems far more complex than those encountered in any other finishing process.

Firstly the amount of add-on, considerably more than required for any other functional finish, tends to impair handle and other desirable fabric characteristics, such as easy-care properties.

Secondly process control has to be rigorous to ensure uniformity and reproducibility of finish, coupled with stringent laboratory testing to exacting standards. This is an expensive finishing process that depends on careful quality control.

The most important group of flame-retardant compounds contain phosphorus; they function by decomposing into chemical species that alter the thermal degradation reactions of the substrate, decreasing the concentration of combustible products and increasing the amount of char produced. Phosphorus-based flame retardants only function effectively if the fibre structure is capable of undergoing transformation to char; melt dripping tends to prevent such transformation in synthetic fibres.

It has also been shown that phosphorus-containing flame retardants function more effectively in conjunction with nitrogen-containing compounds. Nitrogen actually has an additive or a synergistic effect on the performance of phosphorus-containing compounds. Nitrogen-phosphorus systems are thought to act mainly in the solid phase by a

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mechanism of dehydration of the cellulosic fibre, modifying the pyrolysis so that only small amounts of combustible volatiles are formed.

The second most important group of flame retardants are those containing halogens, notably chlorine and bromine. These are thought to operate mainly in the vapour phase by releasing hydrogen halide gas (HCI or HBr) and free radicals that suppress the flame reactions. The efficiency of these retardants is enhanced by the presence of either phosphorus or antimony (as antimony oxide). Both antimonyhalogen and phosphorus-halogen systems are reported to be synergistic.

Table 8.2 summarises commercially available forms of durable flame retardants.

Tetrakis (hydroxymethyl) phosphonium chloride (THPC) Phosphonium derivatives are one of the most important groups of durable flame retardants currently used, in particular on cotton. These agents are based on phosphonium salts having the general formula [(CH2OH)4P+Xn-, where Xn- can be Cl- or OH-.

Commercially the most important agent is tetrakis(hydroxymethyl) phosphonium chloride (THPC). The early technique for making cotton flame retardant was based on THPC applied by a pad-dry-cure process. The fabric was padded with an aqueous solution containing:

(a) THPC and triethanolamine (to absorb any liberated hydrogen chloride)

(b) Trimethylolmelamine and urea; after drying, curing took place at 140°C for4-5 min.

Disadvantages included release of formaldehyde, fabric stiffening and tendering. Fabric tendering was overcome by development of an ammonia-diffusion process, which

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suffered from low processing speeds and the need for a separate large ammonia curing unit. In the 1970s the Proban company developed an ammonia cure unit that was ompact, of simple construction, cheap and capable of efficient curing at speeds of 60 m/min. The processing sequence of the present Proban process is: pad-dry-cure-oxidise-finish.

The Proban padding composition is commercially available as a precondensate of THPC and urea, probably in a 2:1 molar ratio with a P:N ratio of 1 :1. The precondensate is padded, dried and then passed through an ammonia gas curing reactor, which exothermically forms a highly crosslinked phosphorus-nitrogen polymer within the fibre structure. To achieve satisfactory flame retardancy, the weight percentages of phosphorus and nitrogen in the polymer structure should be greater than 2%, depending on fabric density and construction. The ammonia-cured fabric is oxidised with hydrogen peroxide or sodium perborate to enhance the durability of the finish to commercial laundering, UV radiation and weathering.

Further improvements in handle can be made using a softening agent in the final finish followed by compressive shrinkage. THPC or THPOH flame-retardant finishes are degraded by sodium hypochlorite, so Proban-treated fabrics or garments must not be bleached with chlorine-containing bleaching agents. N-methyloldiakylphosphonopropionamides

Research carried out in the United States in the late 1960s showed that the hydrolytic stability of the phosphorus-carbon bond was greater than that of the phosphorusnitrogen bond. This led to the rapid development of the amido derivatives of methyland chloromethyl-phosphonic acids as flame retardants for cotton.Ciba-Geigy showed that effective flame retardants could be based on N-methyloldialkylphosphonopropionamides, and N-methyloldimethylphosphonopropionamide was chosen as the commercial flame retardant, marketed under the trade namePyrovatex CP (CGY).

The reaction with cotton can be represented

Pyrovatex CP is applied with a methylolated melamine resin in the presence of phosphoric acid as a catalyst by a pad-dry-cure technique. To achieve the high levels of phosphorus (2-3%) required for durable flame retardancy, some fabric stiffening (depending on fabric weight and construction) may occur. Furthermore, to avoid an unacceptable loss in strength, efficient neutralisation using an alkaline aftertreatment is essential. This flame retardant functions as a condensed-phase retardant and promotes char formation in an analogous way to Proban. Antimony-chlorine systems

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Flame-retardant industrial fabrics must be able to prevent flame propagation and afterglow even if exposed for prolonged periods to weathering or to severe industrial environments. Handle is of lesser importance, but excessive fabric stiffness must be avoided. Processes developed in the 1950s and 1960s were based on antimony oxide and a halogen donor such as chlorinated paraffin, poly(vinyl chloride) or poly(vinylidene chloride). Afterglow was eliminated by incorporation of a phosphate or borate in the recipe. The finish was applied by a simple pad-dry procedure. It was never suitable for apparel fabrics because of the high add-on required.

Flame-retardant finishes for polyesterNo success has yet been achieved in developing a flame-retardant finish for polyester fabrics that compares with those used for cellulosics. This is due to the difficulty of achieving high levels of finish add-on, and problems caused by softening and melting. Although polyester fibres have inherent flame retardancy, as shown by their ability to shrink away from an igniting source and to melt drip with consequent removal of energy from the flaming textile, this may cause an additional hazard by transferring flame and heat to another site, e.g. to adjacent or underlying fabric layers as well as to the skin of the wearer.

Consequently, an effective flame-retardant finishfor polyester fabrics should:

(a) Promote char formation by catalysing pyrolysis

(b) Enhance melt shrinkage but minimise the drip phenomenon.

At present no satisfactory commercial finish exists, despite considerable research effort. In the 1970s considerable success was achieved with ‘tris’ or tris(2,3- dibromopropyl) phosphate. Tries had to be withdrawn when toxicological testing showed that it was carcinogenic.

Flame-retardant treatments for polyester/cotton blendsThe problem of finding a suitable flame retardant for polyester/cotton blends is even more difficult, because synthetic fibres (polyester) blended with char-promoting cellulosic fibres (cotton) create an increased hazard, the so-called ‘scaffolding effect’, where the molten component wicks onto the char of the cellulosic fibres and fuels combustion. To date satisfactory flame-retardant finishes can only be obtained on ‘cotton-rich’ blends, i.e. blends where the polyester component does not exceed 30% of the total fibre weight.

Bactericidal and fungicidal finishesFinishes that impart resistance to micro-organisms (bacteria and fungi) can be classified into three groups.

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Firstly the cellulosic fibre may be chemically modified to resist attack, e.g. by acetylation or cyanoethylation, but this approach is not within the competence of the finisher and can therefore be discounted.

Secondly a resin that forms an impermeable barrier to micro-organisms may be applied to the fabric. This approach is used with industrial fabrics, e.g. tarpaulins and tentage, where appearance, permeability and porosity are secondary factors. More important are resin precondensates, e.g. halogen-substituted phenol-formaldehyde or N-methylolmelamine derivatives, followed by polymerisation inside the fibre structure. Cotton treated in this way has excellent resistance to micro-organisms.

Thirdly an active antimicrobial finish can be deposited in the cellulosic fibres that is effective both as a bactericide and a fungicide. The finish must be effective, nondiscolouring, durable to washing and non-toxic to humans. Reagents such as coppernaphthenate are effective but impart a green colour to treated fabrics. Tin compounds are colourless but exhibit varying degrees of toxicity. Mercury compounds have been ruled out essentially on environmental grounds, though phenyl mercuric acetate is most effective, even if applied at very low concentration (0.01%). Products established until recently included halogenated phenols, e.g. pentachlorophenol, copper-8-quinolinolate, N-(tributylplumbyl)imidazole, 4,4'-dihydroxyoctachlorodiphenyl diacetate and quaternary ammonium compounds.

METHODS OF APPLICATION

Conventional paddingThe general method of applying finishing agents to fabrics is by padding in open width.

The padding operation consists of two steps:

(a) Impregnation, i.e. guiding the fabric in open width in and out of the finishing liquor contained in a trough

(b) Squeezing, i.e. passing the impregnated fabric through the nip formed by two bowls of the pad to leave a specific quantity of liquor on the fabric.

Although padding is basically a simple operation, for it to be successful attention should be given to the following:

(a) Fabrics must be uniformly wettable, free from creases, knots and foreign objects, e.g. pins, to prevent damage to the bowls

(b) Fabrics must be batched with controlled tension and threaded correctly through the padder; slack or tight lengths of fabric lead to uneven running and cause problems at the nip

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(c) Pad mangles must be in good mechanical working order; pressure rams must be frequently checked for sticking and must deliver a uniform and reproducible pressure across the width of the bowls

(d) Wear of bowls must be recognised and remedied; if the squeezing effect across the width of the bowls is not uniform, the pick-up by the fabric will vary, leading to lack of uniformity of the finished effect, requiring repair of the bowls.

The pick-up of finishing liquor retained by the fabric in padding is referred to as the ‘expression’. It is the weight of liquid retained by a textile material after mangling, calculated as a percentage of either the air-dry or the oven-dry weight of the goods.

Depending on construction, density and other fabric properties, as well as the speed of padding, hardness of the bowls, the pressure applied, etc., an average expression for a 100% cotton fabric is of the order of 60-75%, a 100% viscose fabric 80-95%, and a 70:30 polyester/cotton fabric 50-60%.

Although in the following section alternative techniques are described, it should be borne in mind that an overwhelming number of finishers still use pad mangles because of their simple design, robustness and uncomplicated operation.

Low wet pick-up processingThe initial objectives of low wet pick-up processing were to:

(a) Seek improvements in the control of resin finishing

(b) Promote distribution of resin precondensates or crosslinking agents in the fabric

(c) Achieve better balance between easy-care and loss in wear properties.

More recently other aspects of low wet pick-up processing, such as water and energy conservation, have assumed considerable importance.

Investigations carried out by Triatex International showed that the relationship between easy-care performance and loss in wear properties could be beneficially influenced at the application stage of the easy-care treatment. By applying resin precondensates or crosslinking agents at higher concentration, migration of nonsubstantive finishing agents could be drastically curtailed. Triatex found that buildup of finishing agent on the fibres and embrittlement could be minimsed by reducing the liquor in the system to below 40% on the weight of the cotton.

Further to this improved ratio of easy-care to wear properties, low wet pick-up processing allowed savings of chemicals and water, making it possible to streamline the drying and curing steps into one operation on the stenter.

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In the following sections various novel application methods are briefly described, but it should be noted that each system has advantages and disadvantages. The advantages claimed for low wet pick-up systems are summarised in Table 8.3.

Kiss or lick roll applicationThe first commercial low wet pick-up system was developed by Triatex International of Zürich and is known as the Triatex MA (minimum add-on) system. It is based on the well known technique of applying liquors by means of a lick or kiss roller. The novelty is that the speed of the lick roller and the fabric are controlled independently and this difference in speed enables the wet pick-up level to be carefully adjusted and controlled.

Much background work had to be carried out by Triatex and auxiliary manufacturers in screening softeners, handle modifiers, etc. to develop non-foaming formulations capable of producing a liquor film of uniform thickness across the width of a lick roller. The major problem faced by Triatex was variation of the wet pick-up value. It was solved by incorporating P-particle gauges that continuously monitor the mass of textile material both before and after liquor application. The mechanism involved in transferring the liquor film from the lick roller to the fabric is fairly complex. In essence, when the fabric makes contact with the roller, the liquor film breaks up into small droplets. For uniform application these droplets of liquor must distribute themselves

evenly throughout the thickness and plane of the fabric. The lowest wet pick-up value at which an apparent uniform distribution of finishing liquor is obtained is known as the critical application value (CAV), and for MA and other low wet pick-up systems a CAV of 35-40% is recommended.

Extremely thorough preparation is required for cotton and blend fabrics destined for MA treatment. Mercerising leads to an increase in the CAV. Fabric construction affects the rate at which the droplets distribute themselves by capillary wicking. Closely woven

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fabrics made from fine regular yarns such as shittings have an excellent capillary network and therefore low CAVs, whereas more loosely woven fabrics made from less regular or coarse yarns have an inferior capillary network and tend to have higher CAVs.

Curved-blade applicatorLow wet pick-up application from a curved blade is represented by the West Point CBA system. The CBA (curved-blade applicator) system was developed by West Point Pepperell and the procedure is as follows. The finishing liquor is pumped to a distribution manifold and made to form a uniform film on an accurately machined curved blade. The liquor film flows down the curved blade and transfers to the fabric at the blade/fabric interface. The rate of application is regulated by a process control computer; this monitors fabric speed and regulates liquor pump speed so as to produce and maintain the desired wet pick-up level.

Engraved or spiralled rollersEngraved-roller application systems have been adopted where long runs of identical or similar fabrics are available for finishing. The wet pick-up is controlled by the depth of engraving on the application roller and the type of doctor system in use.

Machinery manufacturer Johannes Zimmer uses a spirally engraved metering or doctor roller to regulate the thickness of the liquor film on the applicator roll. The liquor film is subsequently transferred from the applicator roll to the fabric by contact. The transfer and distribution of the liquor within the fabric is controlled by magnetic rollers.

Another machinery manufacturer, Max Goller, whose low wet pick-up system is marketed under the name Mini-Fluid, uses a magnetic device to control the metering roller, followed by a pneumatic nip to assist transfer and distribution of the liquor within the fabric.

Vacuum applicatorsVacuum systems maintain precise control over the volume of chemical liquor that remains in contact with the fabric. The vacuum slot pulls the finishing liquor into the fibres and removes the excess liquor to be recirculated. Commercially available vacuum systems include:

(a) Vacuum Pad Applicator (Textile Vacuum Extractor, USA)

(b) Evac Vacuum Applicator (Evac, USA)

(c) Aqua-Vat (Babcock Engineering, UK).

Spray applicatorsApplication of finishing liquors by spraying is another approach to low wet pick-up processing. Commercially available spray units include:

(a) SD applicator (Farmer Norton)

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(b) Weko minimal applicator (Weitmann & Konrad)

(c) Spraymiser (Burlington Textile Machinery)

(d) Rotajet (Bruckner).

In the Farmer Norton and Weko units the spray is generated by pumping the finishingliquor to the centres of rapidly revolving discs or rotors, the direction of spray beingcontrolled by baffles.

With precise adjustment of all variables, e.g. rate of delivery of finishing liquor by metering pumps, angular velocity of revolving discs and fabric speed, a uniform distribution of fine droplets of finishing liquor over the full fabric width results.Application can be either single- or two-sided.

Foam applicationIn the minimum add-on (MA) process, droplets of finishing liquor are distributed evenly throughout the fabric by capillary wicking. It was later realised that by using air to increase the volume of applied liquor, a more even application and therefore a better final distribution of finishing liquor would result. Although spraying was a step in the right direction, in the event foam finishing proved to be a moreversatile method.

Foam is an emulsion of air in liquid. To produce a stable foam a surface-active agent must be present that reduces surface tension. Foam finishing is probably the easiest of the various low wet pick-up techniques to install and operate in conjunction with existing machinery. The basic equipment includes a foam generator and a foam applicator. In a foam generator flows of air and liquid are metered and the foam is produced by high-speed rotors. In applying foam to fabric it is necessary to control the rate of application, as for a given blow ratio (i.e. amount of air in the foam) the volume of foam applied determines the pick-up. Several techniques exist by which foam can be applied to a fabric.

Direct method using pressurised foamThe foam, contained under pressure in a distribution box or manifold, is applied directly to the substrate. With Gaston County’s FFT unit the fabric picks up the foam by passing over a slot of variable size. In the Stork RSF system the foam is applied through a rotary screen with the fabric pressed against a backing roller. A microprocessor monitors and controls blow ratio and metering of the foam.

Direct method using non-pressurised foamThe foam reservoir is not maintained under pressure, but pressure is used to apply and to destroy the foam. The Texicon Autofoam unit is a refined version of a knifeon- air unit, the foam generator being of a special design. Once the required details of fabric weight and foam pick-up are fed into the computer, foam delivery is automatically controlled so as to compensate for changes in stenter speed. Resin finishes have been successfully

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applied to furnishings and fashion fabrics using an Autofoam unit. The knife-over-roller applicator developed by United Merchants and Manufacturers (USA) is widely used. It requires fairly stable foams that have to be destroyed after the application stage. The same company has also developed a foam applicator using a horizontal pad technique.

Indirect methodThe principle of indirect metering of foam onto a carrier roller or belt was adopted by several machinery manufacturers, notably Küsters, Monforts and Babcock. In the Küsters Janus machine the foam is doctored onto a drum and transferred to the fabric by contact. The Monforts Vacu-Foam machine uses a knife-over-roller to meter a foam layer onto a rubber blanket. Transfer of the foam onto and into the fabric is assisted by vacuum as the fabric passes round a perforated drum.

Major advantages of foam finishing are:

(a) Even application leading to uniform distribution of finishing agents: with easycare finishes an improved balance of fabric properties may be obtained

(b) Maximum utilisation of chemicals

(c) Minimum add-on: pick-up is reduced from 65 to 15%

(d) Greater productivity: increases from 25 to 50% are possible

(e) Energy savings: less water has to be evaporated and lower temperatures are possible in drying

(f) Wet-on-wet application: possibility of multiple applications without intermediate drying.

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Practical data and analysis

I, ADNAN MUKHTAR and QAISER RAZZAQ carried out several experiments relating to our project of SPECIAL FINISHES, at various textiles dyeing houses. Most of the research work was done at KOHINOOR MILLS, BEBEJAN MILLS, and NISHAT DYEING AND FINISHING.

We are especially thankful to the research and development departments of each of these units, because they helped us a lot in the experimentation and data collection. Similarly we are grateful to the relating persons that assisted us in the collection of results, formulation of conclusion. May it be the R&D Managers, the Finishing Managers, the Lab and Quality Control Managers or the junior workers each of them helped us a lot in whatever way we asked for.

Due to the acute shortage of time, we were unable to cover many of the other important aspects of the projects for which we ask apologies form our respected teacher Mr. KASHIF MUNIR.

However we have tried our best to provide as much of the information as possible. Be it the literature of the finishing auxiliaries used in different dyeing and finishing houses, the application methods, the recipes, the application parameters, or the procedures, we have tried to go through each of them as much as possible, within the limited span of time that was provided to us.

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Softeners

Basosoft SWK All-purpose softener for all types of fibres

Nature Nonionic-emulsified, slightly cationic fatty acid polycondensation product.

Physical form Pale yellowish, aqueous dispersion.Storage If it is kept in the original sealed containers at temperatures

between 5 °C and 30 °C, Basosoft SWK has a shelf life of at least 12 months. Once the drums have been opened, their contents should be used up as quickly as possible. They should be tightly closed again after each withdrawal.

PropertiespH approx. 4 – 5 in a 10 % solutionDensity approx. 1.0 g/cm3 at 20 °CSolubility Miscible with cold water in all proportions.Compatibility Compatible with most finishing agents. If several products are mixedtogether, it is advisable to verify their mutual compatibility by priorexperiment.

Typical recipesShirting (cotton fabric)40 – 60 g/l Fixapret® CL10 – 12 g/l magnesium chloride cryst.10 – 20 g/l Siligen® VN10 – 20 g/l Basosoft SWK

Liquor pick-up: approx. 70%Dry as usualCure for about 3 min at 150 °C

Blouse material (rayon fabric)70 –100 g/l Fixapret CNR Conc.15 – 20 g/l magnesium chloride cryst.10 g/l Condensol® FB10 – 20 g/l Basosoft SWK10 – 20 g/l Siligen SILiquor pick-up: approx. 80%Dry as usualCure for about 1 min at 170 °C

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Outerwear and knitgoods (cotton)30 – 50 g/l Fixapret CL10 g/l magnesium chloride cryst.20 – 30 g/l Siligen VN10 – 20 g/l Basosoft SWK10 g/l Siligen SIELiquor pick-up: approx. 70%Dry as usualCure for about 30 s at 170 °C

Siligen_ SIA Silicone-based softener and additive for the finishing of textiles

Chemical nature Polysiloxane containing amino groupsPhysical form White, slightly opaque emulsionShelf life Siligen SIA can be kept in the original sealed containers at temperaturesbetween 5 °C and 30 °C for at least 9 months. Once containers have beenopened, the contents should be used up quickly. Containers should beclosed tightly after use

PropertiesIonicity NonionicProduct specifications Tolerances for test criteria are given in the product specificationSolubility Miscible with cold water in all proportionsCompatibility Compatible with most finishing agents. When several products are to bemixed together, their compatibility should first be tested

Guideline recipesShirting fabric (cotton)30 – 50 g/l Fixapret® AP8 – 10 g/l magnesium chloride cryst.10 – 20 g/l Siligen VN10 – 20 g/l Siligen SIALiquor pickup: 70%Drying: as usualCuring: 3 min at 150 °C

Blouse fabric (viscose)70 – 100 g/l Fixapret CV14 – 20 g/l magnesium chloride cryst.10 g/l Condensol® FB20 – 30 g/l Basosoft® D15 – 30 g/l Siligen SIA

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Liquor pickup: 90%Drying: as usualCuring: 1 min at 170 °CKnitted fabric (cotton)30 – 50 g/l Fixapret CL8 – 10 g/l magnesium chloride cryst.20 – 30 g/l Siligen VN10 – 20 g/l Siligen SIALiquor pickup: 70%Drying: as usualCuring: 30 s at 170 °C

Knitted fabric (cotton)30 – 50 g/l Fixapret CL8 – 10 g/l magnesium chloride cryst.20 – 30 g/l Siligen VN10 – 20 g/l Siligen SIALiquor pickup: 70%Drying: as usualCuring: 30 s at 170 °C

Siligen SID Softener and additive for finishing textiles, silicone microemulsion

Nature Microemulsion of a polysiloxane with amino groups.Physical form Colourless, slightly opalescent liquid.Shelf life In the original sealed containers at temperatures between 5 °C and 30 °C,Siligen SID has a shelf life of at least 9 months. Once containers havebeen opened, the contents should be used up quickly. Containers shouldbe closed tightly after use.

PropertiesIonicity Nonionic.Product specification Tolerances for test criteria are given in the product specification.Solubility Miscible with cold water in all proportions.Compatibility Compatible with most finishing agents. When several products are to bemixed together, their compatibility should first be tested.

Guideline recipesShirting fabric (cotton)30 – 50 g/l Fixapret® ECO8 – 10 g/l magnesium chloride cryst.10 – 20 g/l Siligen VN10 – 30 g/l Siligen SIDLiquor pickup: 70%Drying: as usualCuring: 3 min at 150 °C

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Blouse fabric (viscose rayon)70 –100 g/l Fixapret CV14 – 20 g/l magnesium chloride cryst.10 g/l Condensol® FB20 – 30 g/l Basosoft® SWK15 – 30 g/l Siligen SIDLiquor pickup: 90%Drying: as usualCuring: 1 min at 170 °C

Outerwear, knit goods (cotton)30 – 50 g/l Fixapret CL8 – 10 g/l magnesium chloride cryst.20 – 30 g/l Siligen VN10 – 20 g/l Siligen SIDLiquor pickup: 70%Drying: as usualCuring: 30 s at 170 °C

Siligen_ SIE Silicone softener for finishing textilesNature Aminofunctional polysiloxanePhysical form White, slightly opaque emulsionShelf life Siligen® SIE can be kept in the original sealed containers at temperaturesbetween 5 and 30 °C for at least 9 months. Partly used containers shouldbe kept tightly closed and used up as soon as possible.

PropertiesIonicity NonionicProduct specification Tolerances for test characteristics are given in the product specificationSolubility Miscible with cold water in all proportionsCompatibility Siligen® SIE is compatible with most finishing agents. When several productsare to be mixed together, their compatibility should first be tested.

Guideline recipesShirting fabric (cotton)30-60 g/l Fixapret® AP10-18 g/l Condensol® LF20-30 g/l Siligen® PEW15-30 g/l Siligen® SIEPick-up: 70 %Drying: as usual

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Curing: 4 min at 150 °C

Blouse fabric (viscose rayon)60-90 g/l Fixapret® ECO15-23 g/l magnesium chloride cryst.20-30 g/l Basosoft® SMS20-40 g/l Siligen® SIEPick-up: 80 %Drying: as usualCuring: 30 s at 180 °C

Outerwear, knitgoods (cotton)30-60 g/l Fixapret® PC10-30 g/l Siligen® SIE20-30 g/l Siligen® PEW20-30 g/l Basosoft® SMSPick-up: 80 %Drying: as usualCuring: 30 s at 170 °C

Ciba® ALCAMINE® CWS Softening agent and processing aid for natural and synthetic fibers

PropertiesCream colored pastillesCationicStable to hard waterStable to acids but should not be used above pH 8Not recommended for application from basic dye baths where sodium sulphate is used. Wherever anionic products are present it is advisable to first check theircompatibility with Alcamine CWS in laboratoryReadily diluted by adding to hot waterGood softener and antistatic agent for all fibersGood non-yellowing properties and will minimize scorching of bleached cotton during heat setting up to 200C

DissolvingThe normal dilution is 1 part Alcamine CWS to 9 parts water, giving a 10% active solution which ispourable. Higher concentrations will give a solution of higher viscosity.Alcamine CWS should be added to the required quantity of water at 60-65C and stirredapproximately 1 hour until completely dissolved. Stirring must be continued during cooling in order

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to avoid the formation of a surface skin which may contaminate the final product. At temperature above 70C the emulsion can develop into a viscous gel which is difficult to stir.The finished product should always be filtered to remove undissolved particles.

Application levelsThe amount of liquid product needed will obviously depend on strength of the product but 0.2 –0.4 % solids on weight of goods are recommend. (2% - 4% 0f 10% dilution)

Application methodsBeing Cationic Alcamine CWS will have affinity for fibers and can therefore be applied by exhaustmethods. A pH of 6.0 to 7.0 is recommended for maximum exhaustion. It is also pplicable by pad or immersion/squeeze techniques, the bath being continuously recharged during process.

Areas of Application As softener As an antistatic agent As a processing aid. The low fibre to metal friction and low of medium fibre to

fibre imparted to acrylic fibers have proved ideal for the conversion of fibre and tow into yarns

Ciba® AVIVAN® LNS Textile softener

Characteristics Benefits- Soft handle with a natural surface - Gives fabrics a warm luxurious handle

- Virtually no temperature yellowing - Allows production of fabrics and garments with a high whiteness

- Stable to metal salts - Can be used in resin finish baths for full easy care finishing

- Antistatic properties synthetics - Reduced static cling of garments

- Increases fiber lubrification - Improved crease recovery, tear strength and abrasion resistance

- Compatible with most optical brighteners - One-bath application with FWAs is possible

- Clear improvement of hydrophilic properties on Fabric - Increased comfort during wear

through moisture transportation. Assists mechanical shrinkage of

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knitwear. Easier fabric printing and reprocessing

- Low affinity to fiber - No tailing in discontinuous application processes

PropertiesChemical constitution: substituted fatty acid amideIonic character: non-ionicpH: 7.5 - 8.5 (1 % formulation)Bulk density (20 °C): 0.6 g/cm3Physical form: cream colored liquid

ApplicationAVIVAN LNS is normally applied by padding

Required amount5 - 50 g/l AVIVAN LNS

ApplicationPadding with a liquor pick-up of 60 - 80 %Bath temperature approx. 20 ºCDrying at 100 - 130 ºC

AVIVAN® RA Softener for cellulosic fibres and their blends with synthetic fibres

USESSoftening woven and knitted fabrics, especially in combination with resin finishes.

CHARACTERISTICS- Imparts supple, soft handle with good surface smoothness- Has very good resistance to sublimation- Hardly no effect whiteness- May impair the rubbing fastness of dyeings and prints produced with naphtholor disperse dyes- Improves tear and abrasion resistance- Increases dry and wet crease recovery- Improves sewability- Hardly no impact on soil retention- Good wash fastness

PROPERTIESChemical constitution: reactive fatty acid amideIonic character: nonionic/cationicpH: 3.0 - 4.5

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Specific gravity at 20 °C: 1.000 - 1.010 g/cm3Physical form: white to slighty yellowish emulsionGeneral stability: Stable in hard water, and to salts, dilute acids andbases, and in both acid and alkaline bleach liquors.Can be used together with fluorescent whiteningagents and most products commonly encounteredin finishing.

APPLICATIONAVIVAN RA is applied mainly by padding together with the products commonlyused in resin finishing.It can also be applied by exhaustion in a weakly acid medium.

Dissolving/dilutingMiscible with cold water in all proportions. Can be added undiluted to the bath.

Required amountpadding 10 - 50 g/l AVIVAN RAexhaustion 1 - 3 % AVIVAN RA

ApplicationPaddingPadding with a pick-up of approx. 60 - 80 %Drying at 110 - 130 °CIf combined with cellulose crosslinking agents the details described in therespective circulars are valid.Exhaustion(Jigger, winch, package, wound package machine, etc.)liquor ratio: 1:5 - 1:20bath temperature: 30 - 40 °Ctime: 14 - 20 minpH: 4.5 - 5.5

Suggested recipes1) Wash-wear finish on cotton woven fabrics20 - 60 g/l KNITTEX FPC conc., FLC conc. or FEL6 - 18 g/l KNITTEX CATALYST MO1 ml/l acetic acid 60 % (not in case of KNITTEX FEL)20 - 40 g/l AVIVAN RA2) Easy-care finish on polyester/cotton shirting and blouse fabric20 - 40 g/l KNITTEX FPC conc., FLC conc. or FEL6 - 12 g/l KNITTEX CATALYST MO1 ml/l acetic acid 60 % (not in case of KNITTEX FEL)20 - 40 g/l AVIVAN RA0 - 20 g/l AVIVAN SO new3) Softening cotton knitted fabric

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After dyeing1 - 3 % AVIVAN RACiba® ULTRATEX® UM New silicone textile softenerPolysiloxane emulsion for the softening finish of all fibers

UsesSoftening of natural and regenerated cellulose fibers and their blends with synthetic fibers, and allsynthetic and animal fibersFacilitating raising for synthetic fibersAdditive for non-felting finishes on woolSoftening of crease-resist, shrink-resist and no-iron finishes on fabrics of natural and regeneratedcellulose and their blends with synthetic fibersULTRATEX UM New can be applied by padding or by low add-on method, e. g. by the TriatexMethod

CharacteristicsULTRATEX UM New forms a film that is highly stable to most detergents and solvents. The product is noted for

- Extremely soft, smooth hand- Low sublimation- Very high degree of whiteness- Durable to washing and dry cleaning- Increases fabric resilience- Increases fiber lubrication- Improved sewability- Minimal effect on thermomigration

Benefits- Gives fabrics a rich silky touch- Reduced contamination of machinery parts and condensation spots on the fabric- Allows production of fabrics and garments with a high whiteness and minimal

shade change on colored fabrics- Fabric performance is maintained through multiple cleaning cycles- Enhances easy care finish effects that help fabrics to keep that freshly pressed

look during use and helps make ironing easier or unnecessary- Improved tear strength, bursting strength and abrasion resistance of finished

fabrics. (Excellent napping)- Reduced risk of needle damage to fabric and hole formation during garment

construction and use. Reduced risk of needle and fabric damage due to fused synthetic fiber.

- Minimal effect on wet fastness and crocking fastness of fabrics containing disperse dyes

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PropertiesChemical constitution: emulsion of functional polydimethylsiloxane

Ionic character: non-ionic/cationic

pH: 4.5 - 6.5

Specific gravity at 20 °C: 0.990 - 1.010 g/cm3

Physical form: white emulsion

General stability: stable to hard water and weak acids

Storage stability: ULTRATEX UM New is stable for 1 year when properly stored in closed containers at 20 °C. The product is sensitive to temperatures below 0 °C and above 40 °C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

ApplicationThe product is generally applied by padding or kiss roll application (especially the Triatex low add-on method).

Dissolving/dilutingULTRATEX UM New is dilutable with cold water. Dilute ULTRATEX UM New with cold water by stirring thoroughly, then add it to the bath. If used together with cellulose crosslinking agents, fillers, additives, etc., these products must be prediluted; ULTRATEX UM New should be added last.

Required amountDepending on the required effect:Padding: 10 - 50 g/l ULTRATEX UM NewTriatex process (low add-on:) 30 - 100 g/l ULTRATEX UM New

ApplicationPadding: liquor pick-up: 60 - 80 %Triatex process (low add-on): liquor pick-up: 30 - 40 % depending on the substrate usedbath temperature: approx. 20 °Cdrying: 90 - 120 °C

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Ultraviolet Absorber

CIBAFAST® PEX UV absorber for PES fibers

UsesDyeing polyester and modified polyester fibers and their blends intended for outlets entailing high exposure to light, particularly car upholstery and interior trim fabrics.

Characteristics Improves the light fastness of dyeings with selected disperse dyes.

Reduces fiber damage due to

Photochemical degradation.

Has high affinity for polyester.

Dispersion has very good bath stability.

Non-foaming

High stability when diluted.

Low viscosity and good storage stability.

BenefitsLonger lasting colors and fabrics,particularly those exposed to light at high ambient temperature.

Increased fiber stability. Fiber degradation due to light and weathering distinctly to considerably reduced, depending on fiber type and denier.

In HT dyeing, exhausts almost completely onto the polyester fiber, thus highly effective.

Stable, including in high-performance dyeing systems with high shear. No sediments or filter deposits on densely wound packages or tightly packed material. Uniform dispersion, even at high bath heating rates and under unfavorable dyeing conditions. Fully compatible with our recommended disperse dyes in conjunction with UNIVADINE TOP or UNIVADINE DP/ UNIVADINE LEV.

Can be used in all state-of-the-art jets, ensures smooth running of the textile material.

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Good dye liquor stability

Pumpable and easy to handle. Suitable for container transport and storage.PropertiesChemical constitution Dispersant-containing preparation of triazine derivatives

Ionic character Anionic

pH of 5% solution 7.0 - 9.0

Physical form White dispersion with low viscosity

Specific gravity (at 20 0C) about 1.04

Viscosity (D= 100) 20°C about 150 mPa.s

Storage stability Stable for 1 year at 20°C in closed containers; not sensitive to freezing or heat

General stability: Stable in hard water and to acids, alkalis inthe pH values between 4 and 10.

Compatibility Can be used together with anionic and nonionic products.

Ecology/toxicology The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The products must not be swallowed.

ApplicationCIBAFAST HLF is added to the liquor at the start of the dyeing cycle and applied by the HT exhaust or pad-thermosol method.

Dissolving/dilutingThe product must be thoroughly stirred before removal from the container.

Required amount

Exhaust method1.5 - 6 % CIBAFAST? HLF (calculated on the weight of the goods)

Continuous pad-thermosol method15 - 60 g/l CIBAFAST? HLF, liquor pick-up 50%

Direct printing

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15 - 60 g/kg CIBAFAST? HLF per kg print paste

Suggested recipes

Exhaust methodx % Ciba TERATOP dye0.5 g/l CIBAFLOW? CIR or CIBAFLOW? SF PLUS1 g/l ammonium sulfatey g/l Ciba UNIVADINE TOP or Ciba UNIVADINE? DP/ Ciba UNIVADINE LEV1.5 - 6 % CIBAFAST HLFpH 5 with formic acid liquor ratio 10:1 - 20:1

Continuous pad-thermosol method1x g/l Ciba TERATOP or Ciba TERASIL X dye5-15 g/l Ciba IRGAPADOL? MP1-2 g/l CIBAFLOW PAD15-60 g/l CIBAFAST? HLFpH 6 with acetic acidliquor pick-up: 50%dry: at 100-140°C, depending on drying equipmentthermosol: at 210 - 230°C for 90 - 30 s

Direct printingx g soft water5 - 10 g Ciba LYOPRINT? AIR15 - 60 g CIBAFAST HLFx g Ciba? TERASIL X or PX dyes30 - 50 g Ciba? ALCOPRINT DT-CS 1000 gdry : at 90°Cfix : at 180°C for 8 min, superheated steam reduction clear

The suggested recipes for padding and printing are also suitable for the newly developed H.W. dyeing-discharge or displacement printing process, which allows dyeing, printing and fixation of automotive fabric in one fabric passage.

The process consists of a pad, wet-in-wet direct print, dry-thermosol step and is carried out on a also newly invented compact padding-printing-thermosoling range, built by Zimmer, Klagenfurt, invented by H. Wöll, Klagenfurt, Austria. Patent is pending (No. A 468/95).

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CIBATEX® APS UV absorber for PES fibers

UsesDyeing polyester and modified polyester fibers and their blends intended for outlets entailing high exposure to light, particularly car upholstery and interior trim fabrics.

CharacteristicsImproves the light fastness of dyeings with selected disperse dyes

Reduces fiber damage due to photochemical degradation.

Has high affinity for polyester.

Dispersion has very good bath stability.

Has remarkable leveling and migration Properties

Non-foamingHigh stability when diluted

Low viscosity and good storage stability

BenefitsLonger lasting colors and fabrics, particularly those exposed to light at high ambient temperature.

Increased fiber stability. Fiber degradation due to light and weathering distinctly to considerably reduced, depending on fiber type and denier.

In HT dyeing, exhausts almost completely onto the polyester fiber, thus highly effective.

Stable, including in high-performance dyeing systems with high shear. No sediments or filter deposits on densely wound packages or tightly packed material.

Uniform dispersion, even at high bath heating rates and under unfavorable dyeing conditions. Fully compatible with our recommended disperse dyes in conjunction with UNIVADINE TOP or UNIVADINE DP/ UNIVADINE LEV.

Can be used in all state-of-the-art jets, ensures smooth running of the textile material.

Good dye liquor stability.

No sedimentation in liquors during padthermosol processes.

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Pumpable and easy to handle. Suitable for container transport and storage.

Pumpable and easy to handle. Suitable for container transport and storage.PropertiesChemical constitution Dispersant-containing preparation of a

benzotriazole derivative.

Ionic character Anionic

pH of 5% solution 6-7

Physical form White, viscous emulsion

Specific gravity (at 20 0C) about 1.2

Storage stability Stable for 1 year at 20°C in closed containers; not sensitive to freezing.

Compatibility Can be used together with anionic and nonionic products. Stable in hard water and to acids, alkalis and electrolytes in the usual amounts.

Ecology/toxicology The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The products must not be swallowed.

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TINOFAST® CEL Reactive UV absorber to improve the Ultraviolet Protection Factor UPFof cellulosic textiles

USESDyeing and printing of textiles for sun protective clothing. To improve the sun screening properties of items such as children's and baby wear, open-air sportswear (e. g. jogging, football, tennis, golf, sailing, etc.), beach, swim and leisure wear (T-shirts, shirts, blouses, hats, etc.), agricultural workwear, and uniforms (military, post office, police, school, etc.). To improve the sun screening properties and stability to light of technical textiles such as tenting, roofing, awning and parasol fabrics, other fabrics used to provide shade as well as household textiles such as blinds.

CHARACTERISTICS- Small amounts applied on cellulosic textiles give maximum and durable protection against ultraviolet radiation- Reactive product- Outstanding exhaustion and fixation- Weak absorption in the long-wave UV A-II region- Strong absorption in the short-wave UV A-I region- Maximum absorption in the UV B region- No finish or coating required

PROPERTIESChemical constitution: reactive UV absorber based on an oxalanilideIonic character: anionicpH (2 % solution): 5.0Specific gravity at 20 °C: 0.770 kg/lPhysical form: powderGeneral stability highly stable in hard water and to electrolytes in the

usual concentrationsStorage stability: TINOFAST CEL is stable for 1 year when properly

stored in closed containers at 20 °C. The product is sensitive to temperatures below 0 °C and above 40°C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

Compatibility: TINOFAST CEL can safely be used together with anionic and non-ionic substances

APPLICATION

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TINOFAST CEL is applied by exhaustion in the dyebath together with reactive or direct dyes. With reactive dyes, TINOFAST CEL can also be applied by the cold pad-batch process. In both cases, the application conditions are the same as those for the respective dyes. In printing, TINOFAST CEL can be applied either before or together with the reactive dyes.

Required amountThe required amount depends on application routine and textile, but will lie within the limits given below. Preliminary trials are recommended.

Exhaust application together with reactive or direct dyes:1.0 - 4.0 % TINOFAST CEL o. w. f.2.0Cold pad-batch application together with reactive dyes:15 - 50 g TINOFAST CEL per litre padding liquor

Printing with reactive dyes:15 - 50 g TINOFAST CEL per kg print paste

CIBACRON F dyes (isothermal at 60 °C) for pale to medium shadesLiquor ratio below 10 : 1A 0.1 - 0.5 g/l CIBAFLOW JET (penetration accelerant)A 0.5 g/l CIBACEL DBC (dyebath conditioner)A 1 - 3 g/l LYOPRINT RG Gran. (reduction inhibitor)A 0.5 - 2 g/l CIBAFLUID C (lubricant)B 1.0 - 4.0 % TINOFAST CEL (UV absorber)B x % CIBACRON F (reactive dye)C 10 - 20 g/l saltD 5 g/l soda ash

CIBACRON LS dyes (isothermal at 70 °C) for pale to medium shadesLiquor ratio below 10 : 1A 0.1 - 0.5 g/l CIBAFLOW JET (penetration accelerant)A 0.5 g/l CIBACEL DBC (dyebath conditioner)A 1 - 3 g/l LYOPRINT RG Gran. (reduction inhibitor)A 0.5 - 2 g/l CIBAFLUID C (lubricant)B 15 g/l saltC 1.0 - 4.0 % TINOFAST CEL (UV absorber)C x % CIBACRON LS (reactive dye)D 3 g/l soda ashE 7 g/l soda ash

CIBACRON C dyes cold pad-batchMethod C1 (requires alkali mixing device)Padding15 - 50 g/l TINOFAST CEL (UV absorber)

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x g/l CIBACRON C (reactive dye)0 - 2 g/l CIBAFLOW PAD70 ml/l sodium silicate (37 - 40 °Bé)15 - 33 ml/l caustic soda 30 % (36 °Bé)5 g/l saltliquor temperature: 30 °Cliquor pick-up: CO 60 - 80 %CV 70 - 90 %Fixation 5 - 8 h at 25 °C

Method for SOLOPHENYL dyesLiquor ratio below 10 : 1A 0.1 - 0.5 g/l CIBAFLOW JET (penetration accelerant)A 0.5 g/l CIBACEL DBC (dyebath conditioner)A 0.5 - 2 g/l CIBAFLUID C (lubricant)B 1.0 - 4.0 % TINOFAST CEL (UV absorber)B x % SOLOPHENYL (direct dye)C 10 - 20 g/l Glauber’s salt in 2 portions (1/5 and 4/5)

Aftertreatment (exhaust)3 % TINOFIX ECO or TINOFIX FRD (fixative, wet fastness improver)pH 6 - 7liquor temperature: 40 °Ctime: 30 min

Method for full-white bleachFull-white bleached material requires:1. usual procedure for full-white bleach2. application of TINOFAST CEL by the method recommended for CIBACRON For CIBACRON LS

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Odor Control

Ciba® CIBATEX® OC-CLD Odor control agent

UsesOdor control treatment of textile products containing cellulosic fibers such as:

Sports- and workwear Intimate apparel Shirt, blouse and dresses Towels Suiting fabrics Knit fabrics Bed linen and covers

Characteristics Confinement of malodors Liquid formulation Based on natural regenerative ingredients Excellent compatibility Dual performance

Benefits Proven odor reduction for sweat and nicotine Easy handling Safe for consumers The odor control treatment is compatible with other finishing treatments Combination of odor control with easy care effect

PropertiesChemical constitution: oligosaccharidesIonic character: slightly amphotericpH at 20°C: 5.0–8.0Specific gravity at 20oC: approx 1.1 g/cm3Viscosity at 20°C: <100 mPasPhysical form: clear solutionStorage stability: CIBATEX OC-CLD is stable for 12 months when

properly stored in closed containers at 20oC. Please avoid storage at temperatures below 0°C and above 40°C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

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Compatibility: CIBATEX OC-CLD can be used together with most chemicals encountered in textile finishing.

ApplicationCIBATEX OC-CLD is normally applied by padding in conjunction with resins.

Dissolving/dilutingCIBATEX OC-CLD can be diluted with cold water.

Required amountDepending on article and required effect: 60–100 g/l CIBATEX OC-CLD ApplicationPadding with a pick-up of approx. 60–80%Bath temperature approx. 20°CDrying at 110–130°CCuring as described in the respective technical data sheets of our crosslinking agents.

Suggested recipes1) Cotton woven fabrics, e.g. shirts

30–60 g/l CIBATEX® RS-FS 9–18 g/l CIBATEX® RC-MH 20–40 g/l CIBATEX® HM-PE 20–40 g/l CIBATEX® HM-UP 10 g/l CIBATEX® HM-FCS 0–1 ml/l acetic acid 60% 60–100 g/l CIBATEX® OC-CLD

2) Cotton knitgoods, e.g. T-shirts

30–40 g/l CIBATEX® RS-FS 9–12 g/l CIBATEX® RC-MH 20–40 g/l CIBATEX® HM-FE 0–40 g/l CIBATEX® HM-EA 0–1 ml/l acetic acid 60% 60–100 g/l CIBATEX® OC-CLD

3) Cotton knitgoods, e.g. intimate apparel

30–40 g/l CIBATEX® RS-FS 9–12 g/l CIBATEX® RC-MH 20–40 g/l CIBATEX® MM-DEH 0–1 ml/l acetic acid 60% 60–100 g/l CIBATEX® OC-CLD

4) Polycotton fabrics, e.g. shirts

30–40 g/l CIBATEX® RS-FS

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9–12 g/l CIBATEX® RC-MH 0–1 ml/l acetic acid 60% 10–20 g/l CIBATEX® HM-PE 10–20 g/l CIBATEX® HM-UP 60–100 g/l CIBATEX® OC-CLD

ApplicationPadding: liquor pick-up approx. 60–90%Bath temperature: approx. 20°CDrying: 110–130°CCuring: 4–5 min at 150 °C (hotflue) or drying and curing on stenter

zone 1 approx. 110°C zone 2 approx. 130°C zones 3, etc. 150–180°C

Total treatment time 40–70 sec

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Elastomer

DICRYLAN® WK new Crosslinking silicone elastomer for the finishing of all kinds of fibres additive for easy-care finishing

USESFor all synthetic and cellulosic fibres and their blends, as well as wool and silk. Also suitable for woven fabrics and knitwear alone or in combination with products used in easy-care finishing with cellulose crosslinking agents. Preferred for textured polyamide and polyester garments and bathing suits, woven and knitted goods of all kinds of fibres.

CHARACTERISTICSDICRYLAN WK new greatly improves the handle and the elastic properties. For optimal crosslinking and best crease recovery and resilience the addition of 10 % PHOBOTONE WS conc. referring to the used amount of DICRYLAN WK new is recommended. With this process the following effects can be achieved:

- Smooth, slightly full handle- Outstanding resilience- Greatly improved crease resistance, particularly under humid conditions- Improved wash-and-wear-effects of synthetics and their blends with wool and regenerated cellulose- Improved elastic recovery of knitwear- Improved stretch and shape recovery of knitgoods- Slighty water-repellent (which can be clearly improved by increasing the amount of PHOBOTONE WS conc.)- Does not impair the textile character- Good durability to washing and dry cleaning- Hardly any influence on fastness properties of dyed and printed fabrics.

The rubbing fastness may be impaired with disperse dyeings or prints.Preliminary trials are advisable

PROPERTIESChemical constitution: emulsion of functional polydimethyl siloxaneIonic character: nonionicpH: 5.5 - 7.0Specific gravity at 20 °C: 0.990 - 1.010 g/cm3Physical form: white to yellowish, low-viscosity emulsionStorage stability: DICRYLAN WK new is stable for 1 year when

properly stored in closed containers at 20 °C. The

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product is sensitive to temperatures below 0 °C and above 40 °C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

HOBOTONE WS conc.

Chemical constitution: emulsion on the basis of polysiloxaneIonic character: nonionicpH: 2.0 - 3.0Specific gravity at 20 °C: 1.000 - 1.020 g/cm3Physical form: white to yellowish, liquid emulsionStability: In the amounts recommended, stable to water

hardness and metal salts, weak acids. Sensitive to alkali. The influence of alkali and acids on the undiluted product causes strong splitting off of hydrogen.

Storage stability: PHOBOTONE WS conc. is stable for 1 year when properly stored in closed containers at 20 °C. The product is sensitive to temperatures below -20 °C and above 30 °C. Slight splitting off of hydrogen (hydrogen gas).

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

APPLICATIONThe product is normally applied by padding.

Dissolving/dilutingStir DICRYLAN WK new thoroughly before use, dilute it with the equal weight of water and add it to the bath. If used together with cellulose crosslinking agents, fillers, additives, etc., these products must be prediluted. PHOBOTONE WS conc. also diluted with the equal weight of water is then added last.

Required amountsynthetic fibres 20 - 60 g/l DICRYLAN WK newcellulosics and blends 30 - 60 g/l DICRYLAN WK newwool 20 - 60 g/l DICRYLAN WK newsynthetic/wool blends 10 - 40 g/l DICRYLAN WK newIf crosslinking is required we would recommend 10 % of weight of PHOBOTONE WS conc. referring to DICRYLAN WK new.ApplicationPadding with a pick-up of aprox. 60 - 90 %Bath temperature approx. 20 °C

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pH-value of the prepared liquor between 4.0 and 6.0Drying at 110 - 130 °C

Curing is carried out as follows:a) 4 - 5 min at 150 °C on curing ovenb) 70 - 30 s at 150 - 170 °C on stenterc) rapid curingzone 1 approx. 110 °Czone 2 approx. 130 °Czones 3, etc. 150 - 180 °CTotal treatment time 40 - 70 sSuggested recipes1) PA and PES knitted and woven fabric

0 - 5 g/l LYOFIX CHN 0 - 4 ml/l KNITTEX CATALYST ZH 0.5 - 1 ml/l acetic acid 60 % 20 - 60 g/l DICRYLAN WK new 2 - 6 g/l PHOBOTONE WS conc. 2 - 6 g/l PHOBOTONE CATALYST EZL

2) Synthetic/cotton knitted and woven fabric

20 - 40 g/l KNITTEX FLC conc. or FPC conc. 6 - 12 g/l KNITTEX CATALYST MO 0.5 - 1 ml/l acetic acid 60 % 40 - 60 g/l DICRYLAN WK new 4 - 6 g/l PHOBOTONE WS conc. 4 - 6 g/l PHOBOTONE CATALYST EZL

3) 100 % wool and wool/synthetic blends

0 - 10 g/l LYOFIX CHN or MLF new 0 - 3 ml/l KNITTEX CATALYST ZH 0.5 - 1 ml/l acetic 60 % 10 - 60 g/l DICRYLAN WK new 1 - 6 g/l PHOBOTONE WS conc. 1 - 6 g/l PHOBOTONE CATALYST EZL 5 - 15 g/l PHOBOL RL

4) Water repellent and resilient finishing of polyester/cotton andpolyester/viscose blends

0 - 40 g/l KNITTEX FPC conc. 0 - 8 ml/l KNITTEX CATALYST ZH 1 ml/l acetic acid 60 % 20 - 60 g/l DICRYLAN WK new 20 - 40 g/l PHOBOTONE WS conc. 20 - 40 g/l PHOBOTONE CATALYST EZL

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20 - 40 g/l PHOBOTONE BC newCiba® ALCOPRINT®PA-NS Antifoam

UsesAntifoam for pigment and disperse printing applications.

Characteristics Self dispersing in cold water. Excellent shear stability. Low viscosity liquid.

Benefits1. Can be added directly to formulations. Not necessary to pre-dilute.2. Stable during and mixing and subsequent printing operations without any

loss of efficiency. Will not break out under shear so minimising tendency to cause spots or screen blockages during printing.

3. Easy handling. Suitable for dispensing in automatic make up units. Can be transported and stored in bulk containers.

PropertiesChemical constitution: Blend of hydrophobes in a highly refined mineral

oil.Ionic character: Non-ionicPhysical form: Opaque light brown liquidSpecific gravity at 25°C: Approx. 0.88General stability: Stable in hard water and to pH values between 4

and 10. Efficiency may be reduced by high concentrations of salts. See further notes under Application.

Storage stability: May be stored for more than one year at 20°C in closed containers. Stirring before use is recommended after prolonged storage. Should not be exposed to temperatures below -10 C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

Compatibility: Compatible with all anionic and non-ionic auxiliaries that are normally used in pigment and disperse printing.

ApplicationALCOPRINT PA-NS is an oil based antifoam which unlike most traditional antifoams is particularly effective at the cold temperatures normally associated with print paste preparation. It posseses outstanding stability to the prolonged high shear forces normally associated with paste preparation and subsequent printing operations, particularly on Rotary ALCOPRINT PA-NS is suitable for use in pigment and disperse printing

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operations however the high electrolyte levels present in reactive and discharge formulations can cause a significant reduction in the efficiency of ALCOPRINT PA-NSand in such cases LYOPRINT AP or LYOPRINT AIR is the prefered choice.

In most situations a concentration of 2.0 - 4.0 g/kg ALCOPRINT PA-NS will be sufficient to prevent foaming and subsequent entrapment of of air into printing pastes. For maximum effect ALCOPRINT PA-NS should be dispersed in water before the addition of any other auxiliaries.Screen machines.

FUMEXOL® AS Antifoam for use in textile processing operations

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USESPreventing foam formation in all textile processing operations in aqueous or nonaqueousmedia which could be adversely affected by foaming

CHARACTERISTICS Easy to dispense Easy to use Best effect at temperatures below 100 °C (212 °F) Volatilizes completely during drying or steaming operations

PROPERTIESChemical constitution: Silicone-free, high boiling organic solventsSpecific gravity at 20 °C: about 0.8 g/cm3Physical form: clear, colourless liquid with characteristic odourStorage stability: FUMEXOL AS is stable for 1 year when properly

stored in closed containers at 20 °C. Flammable.Ecology/toxicology: The usual hygiene and safety rules for handling

chemicals should be observed in storage, handling and use. The product must not be swallowed.

APPLICATION

Dissolving/dilutingFUMEXOL AS is almost insoluble in water, but can be mixed with a large number of organic solvents such as hydrocarbons, alcohols, esters, ketones, etc.

Required amountIn dyeing, sizing and finishing liquors0.2 - 2 ml/lIn print colours, pastes, coating compounds, etc.10 - 20 ml/kg

ProcedureFUMEXOL AS is generally added to the other ingredients, though it may also be sprayed onto the liquor surface. FUMEXOL® is a registered trademark of Ciba Specialty Chemicals Holding Inc.

Ciba® DICRYLAN® AC acrylate dispersionAcrylate dispersion for finishing, coating and printing of textiles and non-wovens

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Uses Apparel Home textiles collar interlinings upholstery fabrics lining fabrics mattress ticking underwear shower curtains knitwear ironing cloths fur imitations Technical textiles Binders for pigment dyeings bonding of non-wovens glass fiber fabrics book covers umbrella fabrics Apparel Home textiles collar interlinings upholstery fabrics lining fabrics mattress ticking underwear shower curtains knitwear ironing cloths fur imitations Technical textiles Binders for pigment dyeings bonding of non-wovens glass fiber fabrics book covers umbrella fabrics

Characteristics Soft, elastic, slightly tacky handle Good fastness to washing and dry cleaning Excellent pigment binding capacity Good stability to light, weathering, hydrolysis and ageing Stock liquors are possible without crosslinking agents, they remain usable after

several days Good running properties on all knife and screen-printing equipments Good dimensional stability, pile anchorage, slip and seam resistance Paste or foam application Excellent shear stability and re-dispersibility

Benefits The material retains its textile character The high-quality effects are not reduced by continuous use and care

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Versatile application possibilities and price reduction by using pigments/filling agents

Versatile application possibilities and price reduction by using pigments/filling agents

Even extreme conditions in use do not reduce the protection by the coating Saving of time and costs No limitation of application methods The performance properties are possible only by coating in the case of certain

articles Multi-purpose High process stability and reproducability; minimum tendency to block screens

PropertiesChemical constitution: aqueous emulsion of an acryl copolymerIonic character: anionicSolid content: 50 %pH (1 g/l): 5.0 - 7.0Viscosity: < 500 cP Brookfield RVT,spindle no. 1 at 20 rpmDensity (25 °C): approx. 1.035 g/cm³Physical form: white emulsionTg: - 24 °CStorage stability: DICRYLAN AC is stable for 1 year whenproperly stored in closed containers at 20 °C.The product is sensitive to temperatures below0 °C and above 40 °C.Ecology/toxicology: The usual hygiene and safety rules for handlingchemicals should be observed in storage,handling and use. The product must not beswallowed.

Ciba® KNITTEX® 7636 Cross linking agent

Uses

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Crease-resistant and easy-care finishes of cellulose articles and their blends with other fibres fast to washing at the boil, according to the requirements of current eco-standards, e.g.1. Eco-Tex-Standard 1002. MST (label for textile tested with regard to harmful substances standard)

Characteristics Pre-catalysed Extremely low content of free and releasable formaldehyde High reactivity Good degree of whiteness Good resistance to hydrolysis Suitable for mill application (padding) and garment finishing

Benefits No seperate addition of catalyst Required Mistakes when preparing the bath can be avoided giving more consistent fabric

Performance Increased productivity due to higher speed of curing machine Increased

productivity due to higher speed of curing machine High flexibility in application

PropertiesChemical constitution: aqueous formulation of a reactant crosslinking agent

based on a modified dimethylol dihydroxy ethylene urea with inorganic magnesium salt

pH: 1.5 - 3.0Specific gravity at 20 °C: 1.225 - 1.245 g/cm3Physical form: clear, colourless to yellowish liquidStorage stability: KNITTEX 7636 is stable for 1 year when properly

stored in closed containers at 20 °C. The product is sensitive to cold below -10 °C and sensitive to heat above 60 °C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

ApplicationThe product is normally applied by padding.KNITTEX 7636 can also be used for garment finishing. KNITTEX 7636 is especially recommended for finishing of cotton trousers (with or without durable crease).

Dissolving/dilutingKNITTEX 7636 is diluted with cold water

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1.Fabric FinishingPadding: liquor pick-up approx. 60 - 90 %Bath temperature: approx. 20 °CDrying: 110 - 130 °CCuring: 4 - 5 min at 150 °C (Hot-Flue) or drying and curing

on stenter zone 1 approx. 110 °C zone 2 approx. 130 °C zones 3, etc. 150 - 180 °C

Total treatment time 40 - 70 s

2. Garment Finishing of cotton trousers (Dip Spin Process)This is intended as a general guide and conditions will vary depending on fabrics, machinery etc.Apply liquor: Treat with liquor in washing machine for 2-5 min.Application is done either by dip spin process or by spray application in a washing machineWet pick up: Spray or spin after dipping to achieve a wet pick up

of 80 - 100 %.(pumping excess liquor back to the mixing tank in the dip spin process). Rotate for a further 3-5 minutes to ensure even application Drying: Tumble dry to approximately 10% residual moisture. Blow out small creases using a topper process and follow by steam pressing if durable crease is required.

Curing: Cure in garment oven for approximately 8 minutes at 145 °C

Suggested recipes1. No-iron or wash-and-wear finish of cotton and synthetic/cotton fabrics forshirts, blouses and dresses

30 - 50 g/l Ciba® KNITTEX® 7636 10 - 30 g/l Ciba® MEGASOFT® FMG new 15 - 30 g/l Ciba® SAPAMINE® FPS

It is advisable to bleach and pretreat the fabrics in full width prior to a no-iron or wash-andwearfinish (in order to avoid rope creases).

2. Durable embossing, schreinering, chintzing and pleating of cotton blouse, dress anddecorative fabrics

30 - 60 g/l Ciba® KNITTEX® 7636 10 - 40 g/l Ciba® MEGASOFT® FMG new 10 - 30 g/l Ciba® SAPAMINE® FPS

3. Printed viscose fabrics for women's outerwear 70 - 100 g/l Ciba® KNITTEX® 7636 15 - 30 g/l Ciba® SAPAMINE® FPS

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15 - 30 g/l Ciba® AVIVAN® MS 0 - 40 g/l Ciba® FORNAX® W 0 - 15 g/l Ciba® FORNAX® K conc.

4. Garment finishing - Dip-spin process on cotton slacks 20 - 50 g/l Ciba® KNITTEX® 7636 15 - 40 g/l Ciba® MEGASOFT® FMG new 15 - 40 g/l Ciba® SAPAMINE® FPS

Ciba® DICRYLAN® FN foam coating products

Ciba® DICRYLAN® FPCiba® DICRYLAN® FVCiba® DICRYLAN® STABILIZER FOFoam coating products on the basis of chemically/thermally crosslinking acrylic acid ester copolymerisates for the textile industry

Uses- Curtain fabrics, e. g. black out articles- Fabrics for shower curtains- Tablecloths- Apparel- Awning fabrics- Mattress fabrics- Roller blinds and black-out vertical blinds- Film screens- Filters for hot gas filtration- Book cloths

CharacteristicsAqueous, mechanically foamable 2-component systems. The polyacrylate dispersions DICRYLAN FN, -FP and -FV need for all foam coatings DICRYLAN STABILIZER FO as foam stabilizers and as crosslinking components or DICRYLAN STABILIZER FL/-7665 in combination with cellulose crosslinking agents containing melamine. For instable foams, an amount of 0,5 - 4 % is required, for stable foams 7,5 - 10 %, based on the zolyacrylate dispersion

DICRYLAN FN soft handlefree of pigmentsfilm transparent

- transparent foams- lamination- electrostatic flocking

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slightly stickyTg: - 9 °C

DICRYLAN FP

soft handlecontaining fillersfilm milky, dryTg: - 11 °C

- pigmented coating- electrostatic flocking

DICRYLAN FV

hard handlefree of pigmentsfilm transparent, dryTg: + 32 °C

- stiff coating- highly abrasion resistantcoatings- mixing component forDICRYLAN FN / -FP

PropertiesChem. constitution: aqueous polyacrylate dispersions

DICRYLAN FN FP FVSTABILIZER FO

Ionic character Anionic Anionic Anionic anionic

pH 2.0 - 4.0 7.0 - 7.5 2.0 - 5.5 10.0 - 12.0

Density (20 °C) g/cm³

1.040 - 1.070 1.000 - 1.200 1.000 - 1.100 1.000 - 1.100

Solid content 50 ± 1 % 47 ± 1,5 % 50 ± 1,5 % 34 ± 3 %

Viscosity mPa.s:(Brookfield DV II)

max. 300spindle 210 rpm, 20 °C

500 - 1500spindle 450 rpm, 20 °C

max. 300spindle 210 rpm, 25 °C

max. 100spindle 210 rpm, 25 °Cz

Physical formwhitedispersion

milky, white tolight graydispersion

whitedispersion

white dispersion

Ecology/toxicology

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The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The products must not be swallowed.

Application

Thickening / DilutingThe viscosity of the paste can be increased by adding a thickener (e. g. DICRYLAN THICKENER R or -X) res. decreased by adding water.

FoamingFor preparation of the foam, dynamic foaming agents are usually used; the compound is mixed with air to a viscous, fine-pored and cream-like foam under pressure. The amount of air is essential for the concentration of the foam, its viscosity and the handle of the coated article. The foam density for DICRYLAN FN, -FP and FV-foams is usually at 0.150 - 0.300 g/cm³ (according to a foam weight of 150 - 300 g/l).

CoatingThe foam is applied by a cylinder coating knife or a knife-over-table; the width of the gap regulates the thickness of the coating film and so the solid add-on. Another application possibility is the rotary screen whereas the floating knife is only possible for thin coatings. The floating knife may only be used exceptionally.

After drying, the foam should have temperature of max.100 °C and a residual moisture of 10 % in order to make certain that the polymer rests un-crosslinked. Drying temperature, air circulation, speed and foam application must be suited to each other. Afterwards, the foam is cooled down and pressed (steel/cotton, steel/paper, steel/plastics or steel/ebonite) with a variable pressure (20 - 70 daN/cm) and temperature (cold to 170 °C).

Curing / PosttreatmentThe compressed foam has to be cured in a separate process. Depending on the end article, the fastness to washing and dry curing of the coating should be optimized by a finishing with cellulose crosslinking agents which can be supplemented with water repellents for water repellent and water tight articles.

With pigmented foams, treatment immediately after caledering is possible by full bath impregnation on the padder or kiss roll on one side with drying and curing afterwards. Transparent foam coatings have to be cured before padding afterwards. The ftertreatment is then effected by drying and curing which can be carried out by a rapid curing process. Instead of or additionally to padding or kiss roll, in many cases a top coat with solid add- ons of 4 - 15 g/m² on the basis of silicone elastomer, PUR or acrylate is carried out. The handle of the foam coating may be influenced by the aftertreatment by padding or top coat.

FastnessFoam coatings with DICRYLAN FN, -FP and FV are fast to several fine launderings and dry curings. It is essential that the application process is carried out correctly.

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1) Black out curtainFabric: CO, CO/PES, PES, CEL Foam coating in three coats, knife-over-roller or rotary screen

1st coat 2nd coat 3rd coat

1000 1000 1000 Pbw DICRYLAN FP

100 100 100 PbwDICRYLAN STABILIZER FO

100 - 100 Pbw

white pigment suspension,e. g. HELIZARIN White RTN(BASF)

- 80 - Pbw

black pigment suspension, e.g. HELIZARIN Black HDT(BASF)

ca. 190 ca. 210 ca. 210 g/l Foaming

35 50 75 g/m² Solid add-on

- Drying 90 - 120 °C, increasing- Pressing between ebonite cylinders after every coat

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- after the 3rd coat calendering steel/cotton roller at 40 °C, pressure ca. 50 daN/cm- if necessary curing at 150 °C

Posttreatment/Padding 15 ml/l INVADIN PBN 20 g/l KNITTEX FEL 6 g/l KNITTEX CATALYST MO 1 ml/l acetic acid 60 % 20 g/l ULTRATEX FMK 6 g/l ethylene urea Drying/Curing 120 - 150 °C, increasing

2) Transparent foam (wax-like handle)Fabric: CO, CO/PES, PAFor handle reasons possibly pretreatment of the fabric with10 g/l OLEOPHOBOL PFOnly drying at max. 120 °C - no curing!

Foam coating, 1 coat knife-over-roller or rotary screen Solid add-on: 30 - 40 g/m² 1000 pbw DICRYLAN FN 100 pbw DICRYLAN STABILIZER FO 50 - 100 pbw water Foaming to 200 g/l Drying at 90 - 120 °C, increasing Calendering at 170 °C, pressure approx. 65 daN/cm, steel/cotton roller top coat,

floating knife

Solid add-on: approx. 5 g/m² 1000 pbw DICRYLAN SAW 10 pbw DICRYLAN DEFOAMER D 20 pbw ammonia 25 % approx. 25 pbw DICRYLAN THICKENER R / water 1:1 Drying/Curing at 130 - 150 °C, increasing

3) Stiff coating for canvas, roller blinds etc.Fabric: CO; PESFoam coating, 1 coat knife-over-roller or rotary screenSolid add-on 80 - 120 g/m²

400 pbw DICRYLAN FP 600 pbw DICRYLAN FV 20 pbw ammonia 25 % 100 pbw DICRYLAN STABILIZER FL 100 pbw white pigment suspension, e. g. HELIZARIN White

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RTN 100 pbw DICRYLAN THICKENER R / water 1:1 Foaming to 200 g/l Drying at 90 - 120 °C, increasing Calendering at 60 °C, pressure ca. 50 daN/cm steel/cotton cylinder Postpadding with 200 pbw VIBATEX KN new

Drying/Curing at 120 - 150 °C

Ciba® PHOBOTONE® WS conc. hydrophobic agentFor durable water-repellent finishing of textile materials on silicone basis

UsesWater repellent finishing of all fibers and their blends

CharacteristicsPHOBOTONE WS conc. has to be combined with PHOBOTONE BC new or PHOBOTONECATALYST EZL. The remarkable features of this product combination are:

- High yield and effectiveness- Excellent water repellent effects, even at- relatively low application amounts- Smooth, soft, subtle handle- Enhanced crease recovery- Improved gloss and luster of pile fabrics

PropertiesChemical constitution: emulsion on the basis of polysiloxane

Ionic character: non-ionic

pH: 2.0 - 3.0

Specific gravity at 20 °C: 1.000 - 1.020 g/cm3

Physical form: white to yellowish, liquid emulsion

General stability: In the amounts recommended, stable in hard water and to metal salts and weak acids. Affected by alkali. Alkali and acids contacting the undiluted product cause considerable splitting off of hydrogen.

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Storage stability: PHOBOTONE WS conc. is stable for 1 year when properly stored in closed containers at 20 °C. The product is sensitive to temperatures below -20 °C and to temperatures above 30 °C. Slight splitting off of hydrogen (hydrogen gas). PHOBOTONE WS conc. becomes a high viscosity paste below temperatures below 0 °C despite the stability to frost. This change of the state of aggregation, however, is completely reversible after slow warming up to room temperature. The product must be brought to room temperature before use and be stirred thoroughly before taking out of the drums.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

Compatibility: PHOBOTONE WS conc. can be combined with most products normally encountered in resin finishing, as long as it is not combined with anionic products in one bath. It can also be used together with cellulose crosslinking agents.

ApplicationApplication is applied by padding only.

Dissolving/diluting- Liquor preparation- adjust pad liquor with acetic acid to pH 4 - 5- dilute PHOBOTONE WS conc. 1:1 with cold hard water, and stir into the pad

liquor- add PHOBOTONE CATALYST diluted 1:1- bulk with cold water

Dissolve thermosetting cellulose crosslinker (KNITTEX and LYOFIX products) according to instructions at first, thencool to about 20 °C and make up to about ¾ of the total liquor volumeadd KNITTEX CATALYST and acetic acidPHOBOTONE WS conc., and last of all PHOBOTONE CATALYST as above.

Preparation of goods and machineryThe goods must be free from size, lubricants and other processing aids, wetting agents,detergents and dyeing auxiliaries. The fabric pH must be weakly acid. Troughs and bowls of pad mangles should be thoroughly cleaned before working with silicone liquors.

Required amount- SYN 20 - 30 g/l PHOBOTONE WS conc.

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- PES/CO 20 - 30 g/l PHOBOTONE WS conc.- PES/CV 20 - 30 g/l PHOBOTONE WS conc.- CEL 25 - 30 g/l PHOBOTONE WS conc.- WO 25 - 30 g/l PHOBOTONE WS conc

CatalysisPHOBOTONE WS conc. should be applied together with PHOBOTONE CATALYST EZL or PHOBOTONE BC new. The choice of PHOBOTONE CATALYSTS dependson the effects desired (see table below):

Effect required PHOBOTONE BC newPHOBOTONECATALYST EZL

max. water repellency onCEL

SYN/CELSYN

×××

extremely soft, subtle handle

×

Velvet

minimum loss of rubbingfastness

×

compatibility with metal saltcatalysts

×

Procedure- Padding at 20 - 25 °C

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- Crying at 110 - 130 °C- Curing in view of fastness of dyestuffs in dry heat- on the stenter 30 - 50 sec at 180 °C- or on the curing machine 4 - 5 min at 155 °C

Suggested recipes1. CO

- 20 - 30 g/l Ciba® KNITTEX® FLC conc.- 5 - 6 ml/l Ciba® KNITTEX® CATALYST ZH or- 6 - 8 g/l Ciba® KNITTEX® CATALYST MO- 1 - 2 ml/l acetic acid 60 %- 30 g/l Ciba® PHOBOTONE® WS conc.- 25 g/l Ciba® PHOBOTONE® CATALYST EZL

2. PES/CO- 15 - 20 g/l Ciba® KNITTEX® FLC conc.- 4 - 5 ml/l Ciba® KNITTEX® CATALYST ZH or- 4 - 6 g/l Ciba® KNITTEX® CATALYST MO- 1 - 2 ml/l acetic acid 60 %- 25 - 30 g/l Ciba® PHOBOTONE® WS conc.- 20 - 25 g/l Ciba® PHOBOTONE® BC new

3. SYN- 0 - 5 ml/l Ciba® INVADINE® PBN- 1 - 2 ml/l acetic acid 60 %- 15 - 20 g/l Ciba® PHOBOTONE® WS conc.- 10 - 15 g/l Ciba® PHOBOTONE® BC new- 0 - 20 g/l Ciba® FORNAX® W or K conc.

4. WO and PES/WO- 0 - 5 ml/l Ciba® INVADINE® PBN- 1 - 2 ml/l acetic acid 60 %- 30 g/l Ciba® PHOBOTONE® WS conc.- 25 g/l Ciba® PHOBOTONE® BC new

Spray application (not product specific)After many years of analysis of epidemiological studies we suspect that aerosols are generated through the spraying technique that potentially may be hazardous to health.For this reason spray application can only be safely conducted if sufficient ventilation equipment is installed at the product application site which will prevent spreading of the aerosols into the workplace. A further possibility would be to carry out the spraying application in a closed system

PHOBOTEX® FMX Water, oil and stain repellent finish

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USESOil, water and stain repellent finish of articles of synthetic fibres and their blendswhich are not aimed at the TEFLON trademark

CHARACTERISTICS- Good water and oil repellent effects- Good resistance to washing and dry cleaning- Compatibility with many other finishing products

PROPERTIESChemical constitution: dispersion of fluoropolymers containing extendersIonic Character: cationic

pH: 2.3 - 4.5

Specific gravity at 20 °C: 1.030 - 1.070 g/cm3

Physical form: white to beige, cloudy dispersion

Storage stability: PHOBOTEX FMX is stable for 1 year when properly stored in closed containers at 20 °C. The product is sensitive to temperatures below 0 °C and above 40 °C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

APPLICATIONPHOBOTEX FMX is normally applied by padding.

Dissolving/dilutingPHOBOTEX FMX is diluted with an equal weight of cold water and added to the bath presharpened with acetic acid.

Required amount20 - 80 g/l PHOBOTEX FMX

ProcedurepH-value of the prepared liquor between 5.0 and 7.0padding with a pick-up of 50 - 70 %bath temperature about 20 °Cdrying at 110 - 130 °Cseparate curing for 5 min at 150 °C on the curing machineor Rapid Curing Process on the stenter at 110 - 170 °C, 45 - 60 sSuggested recipes1. PES/CO raincoat fabric

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- 5 - 10 ml/l INVADINE PBN- 1 ml/l acetic acid 60 %- 10 - 20 g/l KNITTEX FLC conc.- 3 - 6 g/l KNITTEX CAT. MO- 40 - 60 g/l PHOBOTEX FMX- 2. 100 % PES leisure blousons- 5 - 10 ml/l INVADINE PBN- 1 ml/l acetic acid 60 %- 30 - 50 g/l PHOBOTEX FMX

Spray application (not product specific)After many years of analysis of epidemiological studies we suspect that aerosols are generated through the spraying technique that potentially may be hazardous to health.

For this reason spray application can only be safely conducted if sufficient ventilation equipment is installed at the product application site which will prevent spreading of the aerosols into the workplace. A further possibility would be to carry out the spraying application in a closed system.

PHOBOTEX® FLX Water and oil repellent finish

USESWater and oil repellent finish of articles of synthetic fibres and their blends which are not aimed at the TEFLON trademark

CHARACTERISTICS- Good water and oil repellent effects- Good resistance to washing and dry cleaning

PROPERTIESChemical constitution: dispersion of a fluoropolymer containing extenders

Ionic Character: cationic

pH: 2.2 - 4.5

Specific gravity at 20 °C: 1.030 - 1.070 g/cm3

Physical form: white to beige dispersion

Storage stability: PHOBOTEX FLX is stable for 1 year when properly stored in closed containers at 20 °C. The product issensitive to temperatures below 0 °C and above 40°C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

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APPLICATIONPHOBOTEX FLX is normally applied by padding.

Dissolving/dilutingPHOBOTEX FLX is diluted with an equal weight of cold water and added to the bath presharpened with acetic acid.

Required amount30 - 50 g/l PHOBOTEX FLX

ProcedurepH-value of the prepared liquor between 5.0 and 7.0padding with a pick-up of 50 - 70 %bath temperature about 20 °Cdrying at 110 - 130 °Cseparate curing for 5 min at 150 °C on the curing machineor Rapid Curing Process on the stenter at 110 - 170 °C, 45 - 60 s

Suggested recipesPA leisure wear

- 5 - 10 ml/l INVADINE PBN- 1 ml/l acetic acid 60 %- 40 g/l PHOBOTEX FLX

Spray application (not product specific)After many years of analysis of epidemiological studies we suspect that aerosols are generated through the spraying technique that potentially may be hazardous to health.

For this reason spray application can only be safely conducted if sufficient ventilation equipment is installed at the product application site which will prevent spreading of the aerosols into the workplace. A further possibility would be to carry out the spraying application in a closed system.

Ciba® VIBATEX® HKN Poly vinyl acetateAqueous polymer dispersion for stiff finishing and coating of textiles, glass fiber fabrics and nonwovens

Uses- Apparel- Collar interlinings- Lining fabrics- Outerwear- Shoe linings- Home furnishing textiles- Vertical blinds- Roller blinds- Lampshades- Technical textiles

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- Strengthening of nonwovens- Glass fiber fabrics- Book binding fabrics

Characteristics- Formation of a slightly elastic, dry, clear- polymer film- Hard, full handle- Very good pigment binding capacity- Good adhesion, and high resistance to light,- weathering and hydrolysis- Sufficient resistance to washing and dry cleaning- No plasticizers- Thermoplastic properties- Finely dispersed polymer parts, no- sedimentation, also suitable for rotary screens- Easy preparation and good storage stabilityof the coating pastes (pot life)- HF- and heat-sealable in the case of- sufficient polymer add-on

PropertiesChemical constitution: dispersion of a polyvinyl acetateIonic character: non-ionicpH: 3.0 – 5.0Specific gravity at 20 °C: 1.18 - 1.22 g/cm3Viscosity (20 °C) mPa.s: 20000-40000mPa.s @ 23CPhysical form: white viscous dispersionStorage stability: VIBATEX HKN is stable for 2 years when

properly stored in closed containers at 20°C.The product is sensitive to temperatures below 0 °C but not sensitive to heat.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

Application

COATING APPLICATIONS

Dissolving/diluting

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VIBATEX HKN can be diluted with cold water. Stir the product thoroughly before use, and sieve.

ThickeningVIBATEX HKN must be thickened for the preparation of coating pastes. The following products are suitable: DICRYLAN Thickener X (cellulose derivative soluble in water) or DICRYLAN Thickener R (polyacrylic acid derivative) in alkaline medium. The application of DICRYLAN Thickener TFC (without addition of alkali) is also possible.

Paste stabilityThe pastes are stable for several weeks in closed containers at a cool place. Stir before use.

CompatibilityOther polymer dispersionsCombinations with dispersions based on polyacrylate, polyproprionate, polyethylene vinyl acetate, polyvinyl chloride, polyurethane, and butadiene styrene are possible in principle. But the compatibility should be tested in preliminary trials at any rate. VIBATEX JM is preferably applied in case of roller blinds to obtain the desired hardness of the article; each mixture ratio is possible.

Defoaming agentsIn order to prevent excessive foam tendencies in paste coating a defoaming agent such as DICRYLAN DEFOAMER D can be added to the coating recipe, up to 3 % on weight, based on VIBATEX HKN

FillersVIBATEX HKN stands out due to a high absorption and binding capacity for pigments and inorganic fillers such as china clay, talc, calcium carbonate, and titanium dioxide. Coating compounds containing fillers should be homogenized by grinding on a roll mill. Alternatively the fillers and pigments can be predispersed in water with the aid of a pigment dispersant.

Flame retardantsThe coating can be rendered flame retardant by the addition of suitable products. The burning properties of the coated product are partly determined by the flammability of the supporting fabric.

Recommendations for specific items to be supplied on request.AntimicrobialsAntimicrobic effects can be obtained by adding fungicidal products (e. g. FUNGITEX OP, ROP).

Thermoplasticity / Crosslinking

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VIBATEX HKN is a thermoplastic polymer which becomes soft after warming. This can be disadvantageous in use (e. g. lampshades, sun blinds). By adding a cellulose crosslinking agent (e. g. LYOFIX CHN) to the coating paste this can be prevented, the heat sealing property, however, is reduced. If a cellulose crosslinking agent is applied in the pre-impregnation liquor, the thermoplasticity of the coating is retained.

CoatingVIBATEX HKN can be applied by various techniques:

- knife systems (floating knife and knife-over-rubber blanket)- roll coating systems (kiss roll, reverse roll coater)- printing methods (rotary screen, screen roller)

For area coating and partial printing by rotary screen the pastes must be sieved over a vacuum filter. The choice of the coating method depends on the substrate, the required effects and the desired article with solid add-ons between 20 and 250 g/m2. In many cases the coating can be carried out in one passage only, often on both sides. In case of thick films and too high initial temperatures at drying there is a risk of blistering. Dryingis generally performed at temperatures between 110 and 160 °C.

Suggested recipes1. Coating of fabrics for vertical blinds, floating knife on both sides

- 1000 pbw Ciba® VIBATEX® HKN- 0 - 500 pbw Water- 10 pbw Ciba® DICRYLAN® DEFOAMER D- 10 - 15 pbw Ciba® DICRYLAN® THICKENER X- 10 pbw ammonia 25 %

2. Coating of fabrics for roller blinds, floating knife on both sides- 500 pbw Ciba® VIBATEX® JM- 500 pbw Ciba® VIBATEX® HKN- 10 pbw Ciba® DICRYLAN® DEFOAMER D- 10 pbw Ciba® DICRYLAN® THICKENER X- 50 pbw Water- 10 pbw ammonia 25 %

PADDING

Dissolving/dilutingVIBATEX HKN is pasted with cold water, diluted and added to the bath through a strainer. Avoid warming up during a longer period. It is advantageous to stir the product thoroughly before use.

Required amountDepending on the desired handle5 - 500 g/l Ciba® VIBATEX® HKN

Application

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Padding with a liquor pick-up of 60 - 80 %Bath temperature: 20 - 30 °CDrying: 110 - 130 °C

Suggested recipes1. Stiffening of 100 % polyester net fabric

- 200 - 400 g/l Ciba® VIBATEX® HKN- 2. Handle finishing of 100 % cotton fabric- 30 - 50 g/l Ciba® KNITTEX® FLC conc.- 9 - 15 g/l Ciba® KNITTEX® CATALYST MO- 1 ml/l acetic acid 60 %- 5 - 20 g/l Ciba® VIBATEX® HKN- 10 - 30 g/l Ciba® AVIVAN® SO new

3. Finish of a glass fiber bitumen reinforcement fabric- 50 g/l Starch- 175 - 250 g/l Ciba® VIBATEX® HKN- 50 g/l Ciba® HYDROPHOBOL® APK

Ciba ®UVITEX ® EBF 250 % textile whitener

UsesFluorescent whitening agent with bluish white shade for polyester, acetate, triacetate, polyvinylchloride, propylene fibers and their blends in all stages of processing. Versatile application by exhaust and continuous processes.

Characteristics- Liquid, pumpable formulation, miscible with water in all proportions. - Very good build-up.- Development and fixation already at low temperatures.- Good stability to acids. Compatible with most finishing components and catalysts

suitable for white goods.- Very good stability to sodium chlorite.- High stability to alkali and peroxide.- Slightly yellow intrinsic color of the suspension.- Excellent fastness properties. Very high light fastness.- APEO and formaldehyde free.

Benefits- Simple handling, suitable for automatic dispensing equipment.- Brilliant white maximum.- Wide spectrum of applications. Also suitable for exhaust method at the boil.- Slight variations in temperature do not cause differences in the degree of white.- In the pad-bake process, low dry heat fixation temperatures reduce the yellowing

of CEL fibers in PES/CEL blends.- Applicable in finishing with crosslinking agents (PES/CEL blends).

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- Suitable for simultaneous application in chlorite bleaching.- Suitable for discontinuous and continuous bleaching systems with hydrogen

peroxide (PES/CEL blends).- Low soiling of secondary fibers (e.g. cellulose in PES/CEL blends).- Meets the current requirements.- Environment friendly Improved biological degradability.

PropertiesChemical constitution: Benzoxazole derivativeIonic character: Non-ionicPhysical form: Slightly yellow, fine aqueous suspensionpH (10 g/l): About 7Specific gravity (25 °C): 1.07 g/cm³Viscosity (D = 100/s, 25°C): 40 mPa.sConductivity (25 °C): 200 μS/cmStorage stability: UVITEX EBF 250 % is stable for 1 year

when properly stored in closed containers at 20°C. The product is sensitive to cold below 0°C and sensitive to heat above 40 °C.The sediment usually developing with dispersions can be homogenized by stirring.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

StabilityWater hardness GoodPeroxide bleach Very goodChlorite bleach Very goodReduction bleach(based on sodium dithionite) Very goodAlkali Very goodAcid Good

ApplicationThe product can be applied by the exhaust process from acid, neutral or alkaline baths as well as in the sodium chlorite and hydrogen peroxide bleach. UVITEX EBF 250 % can be applied continuously by the pad-bake process and pad-steam systems suitable for printing and bleaching.

PolyesterUVITEX EBF 250 % exhausts well onto polyester at the boil. Suitable carriers promote bath exhaustion and particularly development of the FWA on the fiber. Preliminary trials are necessary, as carriers may impair the light fastness. The highest white effects are obtained under HT conditions (110 - 130 °C).

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The ideal developing temperature in the pad-bake process is between 180 and 190 °C at afixation time of about 30 s. UVITEX EBH, EDR or ERH, which are more stable to sublimation, are recommended for longer baking times and temperatures above 190 - 195 °C.

Polyester blendsUVITEX EBF 250 % can be applied on polyester/cellulose by a one-stage or a multi-stage

method.Polyester/wool is preferably fluorescent whitened by a multi-stage process.

Acetate, TriacetateIn exhaust (with or without bleach) or in pad-bake process.

Polyvinylchloride, PolypropyleneIn exhaust process.

Dissolving/dilutingThe product must be carefully stirred before removal from the container and it is advisable to dilute it before use with about 10 times its weight of cold soft water or preferably warm soft water at 40 - 50 °C. To preserve its stability, the dispersion must not be boiled up. Stock solutions can be prepared, but must be stirred before use. Stock solutions should be kept away from the light; also substrates treated with the whiteningagent as long as it is not fixed.

Required amount Ciba® UVITEX® EBF 250 %PESExhaustion 0.2 - 0.8 %Pad-bake, pad-steamprocessliquor pick-up 40 - 90 %4 - 16 g/l

PES/CELExhaustion 0.1 – 0.5 %Pad-bake, pad-steamprocessliquor pick-up 40 - 90 %2 - 10 g/l

CA, CTAExhaustion 0.4 – 0.8 %Pad-bake, pad-steamprocess

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liquor pick-up 40 - 90 %4 - 16 g/lCLFExhaustion 0.4 – 0.8 %PPExhaustion 0.2 – 0.4 %

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Suggested recipes – polyester

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polyester/cellulose

Suggested recipes –The polyester component should be optically brightened by the methods recommended for polyester. The cellulose component is usually whitened separately afterwards, e.g. in the peroxide bleach or more often in combination with finishing.

Besides multi-stage methods, one-stage processes are also used in which both fibers are optically brightened at the same time, e.g. during bleaching and finishing.

Ciba® PYROVATIM® SB FR pigmentFlame retardant for permanent finishing and coating of textiles

Uses- Aqueous paste and foam coatings for flame-retardant finish of black out furnishing fabrics, vertical window blinds and roller blinds

- Flame-retardant backing of upholstery fabrics and long pile articles- Technical articles with permanent flame retardancy- Finishing on the padder of CO, PES/CO and 100 % PES, for example for vertical

window blinds, roller blind fabrics, special protective clothing

Characteristics- Free from halogen and antimony- Finely dispersed powder

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- Flame-retardant effects fast to mild washing and dry cleaning (dependent on the binder system)

- No hygroscopicity- Thermal degradation > 300 °C (ammonia, no other toxic gases)- Low masking of the shade- Good siftability- No or negligible impairment of the viscosity of polymer dispersions

PropertiesChemical constitution: polyammonium phosphate with parts of melamine/formaldehyde condensatesSpecific gravity at 20 °C: 0.75 - 0.90 kg/lPhysical form: fine-grained white powderStorage stability: PYROVATIM SB is stable for 1 year when properlystored in closed containers at20 °C. The product isnot sensitive to cold or heat.Ecology/toxicology: The usual hygiene and safety rules for handlingchemicals should be observed in storage, handlingand use. The product must not be swallowed

Application- For the fixation on the textile material PYROVATIM SB requires a binding agent whoseproperties determine essentially the handle and the durability of the finish. DICRYLAN PCF ispreferably used for finishing.

- Coatings are normally carried out with polymer dispersions.The following binders are possible for PYROVATIM SB:

- polyacrylic acid ester (DICRYLAN AS, AHS, AM, APS, FN, FP, FV)- polyurethanes (DICRYLAN PCF, PMC)- polyvinyl acetates (VIBATEX KN new)- ethylene vinylacetate copolymers (VIBATEX JM)

ProcessingPYROVATIM SB can be mixed with water to improve its processing qualities. An appropriatesuction stirrer should be used to avoid dust formation. Suspensions of PYROVATIM SB should bestirred or pumped in order to prevent solids from settling out

Required amountBlack-out coatings on cotton, viscose, and flame-retardant synthetic fibers can reach theclassification DIN 4102 B2, in many cases also DIN 4102 B1, if the dosage is appropriate.ApplicationFabric weight, weaving, yarn twist and pretreatment influence the flame-retardant effect.

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Preliminary trials are necessary on each fabric to determine the suitable recipe.If higher quantities of PYROVATIM SB are used in foam coatings, a pigment-free acrylate typesuch as DICRYLAN FN must be chosen to avoid overpigmentation which could impair theelasticity and stability of the film.

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Suggested recipes - polyester/woolTo match the whiteness of the wool component as closely as possible to that of polyester, athree-stage process is advisable. Heat-setting of the PES component should be carried outbefore bleaching. In such a way, the yellowing of wool can be compensated during subsequentbleaching.

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Ciba® FUNGITEX® OP anti-mildew agentProduct for mildewproof finishes

UsesFungicidal finish of

- PAN awnings- PES and CO shower curtains

Characteristics- Distinctly effective against mold fungi- Resistant to weathering and suitable for mild wash- High resistance to sublimation- Only slight reduction of the water repellent effects- No discoloration of the finished fabrics

Benefits- Longer life cycle of the article- The effect is retained after exposure to weathering- FUNGITEX OP can be combined with products which require curing- Combination with water repellent agents is possible- After the finishing it is not necessary to correct the shade

PropertiesChemical constitution: aqueous dispersion of a benzimide azole derivativeIonic character: non-ionic

pH: 6.5 - 7.5

Specific gravity at 20 °C: 1.000 - 1.020 g/cm3

Active content: about 22 %

Physical form: viscous, white to pink dispersion

Storage stability: FUNGITEX OP is stable for 2 years when properly stored in closed containers at 20°C. The product is sensitive to cold below 0 °C and to heat above 40 °C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

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ApplicationFUNGITEX OP is normally applied by padding.

Dissolving/dilutingDilute FUNGITEX OP with water at 30 - 40 °C, with constant stirring; add the product to the bath at a temperature below 30 °C.

Required amountPAN awnings 40 - 60 g/l FUNGITEX OPPES shower curtains 60 -100 g/l FUNGITEX OPCO shower curtains 80 -120 g/l FUNGITEX OP

ApplicationPadding: liquor pick-up about 60 %Bath temperature: 20 - 30 °CDrying: 110 - 150 °CPossibly curing: in combination with OLEOPHOBOL S or

crosslinking agents 4 - 5 min at 150 - 140 °C (curing machine)

Suggested recipes1) PAN awning

- 5 ml/l Ciba® INVADINE® PBN- 40 g/l Ciba® LYOFIX® MMA- 8 g/l Ciba® KNITTEX® CATALYST MO- 1 ml/l acetic acid 60 %- 30 g/l Ciba® OLEOPHOBOL® S- 40 g/l Ciba® FUNGITEX® OP

2) Pretreatment of PES shower curtains- 5 ml/l Ciba® INVADINE® PBN- 1 ml/l acetic acid 60 %- 40 g/l Ciba® OLEOPHOBOL® S- 80 -100 g/l Ciba® FUNGITEX® OP

followed by a coating with DICRYLAN AS and additional products (see technical data sheet of DICRYLAN AS).

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FORNAX® AN conc. Anti-slipping agent

USESImproving resistance to thread slippage of lining fabrics of generated and synthetic fibres and other slippage-prone fabrics. Particularly suitable for white goods due to good compatability with fluorescent whitening agents (FWAs).

- CHARACTERISTICS- Greatly improves resistance to thread slippage and seam strength- Reduces pilling- Minimal effect on handle for this type of product- Can be used in combination only with other anionic products, e. g. FWAs

PROPERTIESChemical constitution: colloidal polysilicic acid

Ionic character: anionic

pH: 8.5 - 11.0

Specific gravity at 20 °C: 1.090 - 1.350 g/cm3

Physical form: opalescent liquid

Storage stability: FORNAX AN conc. is stable for 1 ½ years when properly stored in closed containers at 20 °C. The product is sensitive to temperatures below 0 °C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

Compatibility: FORNAX AN conc. can safely be applied together with anionic substance such as FWAs, polyacrylates dispersions, cellulose glycolates, starch ether carboxylic acids, etc.It cannot be used in conjunction with cationic and some nonionic substances (preliminary trials are therefore advisable). In those cases as well as for a one-bath application with KNITTEX, HYDROPHOBOL, and PHOBOTONE products we recommend FORNAX K conc

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APPLICATIONFORANX AN conc. is normally applied by padding.

Dissolving/dilutingFORNAX AN conc. can be added undiluted to the bath; a solvation is not necesssary.

Required amount (padding)5 - 40 g/l FORNAX AN conc.depending on fabric's slipping tendency.

ApplicationPadding with a pick-up of 60 - 90 %Bath temperature approx. 20 °CDrying 110 - 130 °CIf combined with cellulose crosslinking agents, the details decribed in the respective circulars are valid.

Suggested recipes1) 100 % polyester (filament yarn),

- optically whitened for anorak and blouse fabrics- 5 - 10 g/l LYOFIX CHN- 3 - 5 ml/l KNITTEX CATALYST ZH- 10 - 30 g/l FORNAX AN conc.- 1 ml/l acetic acid 60 %

2) Finishing of synthetic goods to reduce the pilling and snagging tendency- 10 - 20 g/l FORNAX AN conc.- 0 - 30 g/l DICRYLAN AS

Spray application (not product specific)After many years of analysis of epidemiological studies we suspect that aerosols are generated through the spraying technique that potentially may be hazardous to health.

For this reason spray application can only be safely conducted if sufficient ventilation equipment is installed at the product application site which will prevent spreading of the aerosols into the workplace. A further possibility would be to carry out the spraying application in a closed system.

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ZEROSTAT® AT Non-durable antistatic agent

USESTreating of synthetic fibres and their blends with natural fibres at all stages of processing to overcome electrostatic-related problems in processing and use and reduce the impairment of rubbing fastness of disperse dyeings to a minimum. The product is normally applied by padding. One-bath application with lubricants and softening agents. Finishes in combination with crease resist agents and handle modifiers. Well-established in combination with fluorochemicals such as products of the OLEOPHOBOL range.

CHARACTERISTICS- Prevents static build-up- Hardly no yellowing of whites- Hardly no tendency to dry soiling- Very low impairment of rubbing fastness on disperse dyed articles- Hardly no impairment of handle- Helps to avoid corrosion of production machinery

PROPERTIESChemical constitution: organic phosphorous compoundIonic Character: anionicpH: 6.0 - 7.5Specific gravity at 20 °C: about 1.200 g/cm3Physical form: clear liquidGeneral stability: stable in hard water and to acids, alkalis and

resin catalystsStorage stability: ZEROSTAT AT is stable for 1 year when

properly stored in closed containers at 20 °C. ZEROSTAT AT is not sensitive to hot and cold storage conditions.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed

APPLICATIONZEROSTAT AT is usually applied by padding.Dissolving/dilutingZEROSTAT AT can be diluted with cold water in all proportions.Required amountPA, PAN, PES 5 - 20 g/l ZEROSTAT ATApplicationPadding with a pick-up of 60 - 80 %Bath temperature approx. 20 °C

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Drying at 110 - 130 °CIf combined with cellulose crosslinking agents the details described in therespective circulars are valid

LYOFIX® MLFO NEW Low-formaldehyde melamine resin for dimensional stabilisation and handle modification

USES- Crease resist and shrink resist on cellulosic goods- Washfast calendered effects- Handle and stiff finishes on synthetic goods- Resin component for- water-repellent finishes- flame-retardant finishes with PYROVATEX CP new

CHARACTERISTICS- Lower formaldehyde content than conventional melamine resins of this type e.g.

LYOFIX CHN- Good resistance to shrinkage during washing and ironing- Good dry and wet crease resistance and wash-wear properties with minimum

impairment of tensile strength- Very good resistance to washing and dry cleaning- Handle and stiff finishes on synthetic goods- High buffering action, therefore particularly suited for finishes on goods dyed - with sulphur dyes, and for addition to non-buffering resins for finishing goods

dyed or printed with reactive dyes- Optimisation of oil and water repellency- Advantages for the finish of reactive dyeings and prints regarding stability to- hydrolysis in connection with KNITTEX FPC conc. for example

PROPERTIESChemical constitution: alkyl-modified melamine

formaldehyde derivative

pH: 8.0 - 10.0

Specific gravity at 20 °C: 1.240 - 1.260 g/cm3

Physical form: clear, viscous liquid

Storage stability: LYOFIX MLFO NEW is stable for 1 ½ years when properly stored in closed containers at 20 °C. The

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product is not sensitive to temperatures below 0 °C but to temperatures above 40 °C.

Ecology/toxicology: The usual hygiene and safety rules for handling chemicals should be observed in storage, handling and use. The product must not be swallowed.

Compatibility: LYOFIX MLF can be used together with most chemicals normally encountered in resin finishing. In combination with PHOBOTONE products bath stability may be limited. Effect on shade and light fastness: Finishes with LYOFIX MLFO NEW can affect the shade and light fastness of reactive and substantive dyes. Appropriate dye selection is thus called for.

APPLICATIONThe product is applied by padding.

Dissolving/dilutingDilutable with water in all proportions.

Required amountcellulosic fibres 30 - 140 g/l LYOFIX MLFO NEWsynthetic fibres - slightly full handle 5 - 15 g/l LYOFIX MLFO NEW

- stiff finish 60 - 200 g/l LYOFIX MLFO NEW

ApplicationPadding: liquor pick-up 60 - 90 %Bath temperature: 20 - max. 30 °CDrying: 110 - 130 °CSubsequent curing: 4 - 5 min at 150 °C (Hot-Flue) or drying and curing on stenter

zone 1 approx. 110 °Czone 2 approx. 130 °Czones 3, etc. 150 - 180 °C

Total treatment time 40 - 70 s

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Suggested recipes1) Easy-care, shrink-resist finish on cotton fabric with critical tensile strength

- 30 - 80 g/l LYOFIX MLFO NEW- 6 - 14 g/l KNITTEX CATALYST MO- 15 - 30 g/l TURPEX ACN new- 20 g/l AVIVAN RA, SO new

2) Shrink-resist finish on cotton workwear finish- 80 - 100 g/l LYOFIX MLFO NEW- 12 - 15 g/l KNITTEX CATALYST MO- 5 - 20 g/l polyvinyl alcohol 100 %- 20 - 30 g/l TURPEX ACN new- 30 g/l AVIVAN RA, SO new or SFC

3) Shrink-resist finish on cotton knitgoods10 - 30 g/l KNITTEX FLC conc.10 - 20 g/l LYOFIX MLFO NEW5 - 12 g/l KNITTEX CATALYST MO

- 0.2 g/l sodium fluoroborate20 - 40 g/l ULTRATEX FSA new

4) Handle or stiff finish on synthetic fibres- 5 - 200 g/l LYOFIX MLFO NEW- 3 - 20 ml/l KNITTEX CATALYST ZH- 1 - 50 g/l AVIVAN SO new- 1 - 2 ml/l acetic acid 60 %

5) Chintz finish on all-cotton goods- 30 - 40 g/l KNITTEX FPC conc. or FLC conc.- 30 - 50 g/l LYOFIX MLFO NEW- 18 - 21 g/l KNITTEX CATALYST MO- 30 - 40 g/l ULTRATEX FSA new- 20 - 30 g/l AVIVAN RA

Drying 110 - 130 °C, residual moisture 8 - 12 % (cotton scale)Calendering pressure about 50 - 60 daN/cmfriction 0 - 300 %temperature 140 - 190 °CCuring 5 min at 150 °C (Hot-Flue)

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Working

Different tests were carried out by us, depending on the availability and time. Most of the tests that we carried out, were done at

KONINOOR TEXTILES BEBEJAN TEXTILES NISHAT TEXTILES

We also experimented the softness, properties of different softeners, to compare Tear strength tensile strength G.S.M Hand feel

This is to show that which chemical based softener have better results. The working done by us was a real hard work but interesting

Some of the important results that we got are related to following tests Resin Finishing Soil Release Oil and Water Repellent Flame Retardent Postcure Process Normal Finish Teflon Finish Softener applications Comparisons b/w P.E and Silicone based softeners

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Resin Finishing

Recipe

fixapret Eco 59g/l fixapret Ap 60g/l catalyst(MgCl2) 15-25g/l

Procedure PAD DRY CURE

Time & Temperaturedrying +curing 180degree for 1 min 150degree for 3min

TESTING10% Neoceramine by dropping. The one which will be powerful will give green shade and less powerful will give red shade.

BEFORE AFTER

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Normal Finishing

RecipeSoftener Nec 30g/lSoftener 10g/lLusturing agent 10g/lBinder 40-50g/l(variable)

Procedure PADDRYCURE

Time & TemperatureDrying +curing 180degree for 1min 150degree for 3min

TestingCheck the hand feel and shade fastness and tone variation, if any

BEFORE AFTER

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Post-Cure ProcessThe method of prost-cure process has been explained previously. The main difference that comes is the tone change(slightly).

This is a useful process fir garment manufacturing purposes, in which permanent creases are applied on the garment by hanging the garment in curing chambers with the creases applied on them.

NOTE: the finishing recipe has already been applied on it A sample test carried out by us is as shown

BEFORE AFTER

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Oil & water Repellent Finish

Nova HPC 40-60g/l Nova 3505 40-690g/l

ProcedurePADDRYCURE

Time & Temperature180degree for 1min 150degree for 3min

TestingSpray Test (250ml)

BEFORE AFTER

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Softener application

Softener 40g/lWater ParametersQuality 40*40/100*80Pad pressure 2 barsSpeed 3 m/minDrying 110degreeCuring 165-180degree for 3-1 min

ProcedurePADDRYCURE

BEFORE AFTER

Results Softness increases but body reduces

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Teflon finishing + Post-Cure Process

The details of recipe and application is already provided in the literature of chemicals

Expected ResultsThe fabric should be

Soil release Anti crease Water repellent Oil repellent

BEFORE Drying AFTER Drying

After Curing

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Soil release finish

The details of finishing recipes and method of applied is already explained in the literature

Testing The tests are carried out by dropping

Oil spots Ketchup spots Chocolate

These samples are then washed for 20min each. Normally 10-50 washes are given, depending on the requirement s of the customer.

Chocolate spot Oil Spot

Ketchup Spot

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Flame retardant Fnishing

RecipeAfflament KWB 300-400g/lPhosphoric Acid 22-25g/lMelamine resin ( Quedor DMQ ) 60g/lSoftener 60g/lWetting agent ( Invadin PBN ) 5g/l

Procedure PADDRYCURE

Time & TemperatureDrying at 110 degrees for 1-2 minCuring at 150 degrees for 5 min

After stentering and curing, the fabric is washed with the addition of Soda ash 30g/lH2O2 50%

Temperature50 degrees

Time50 seconds

Sample

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Comparison b/w P.E based softener and silicone based softener

NOTE : ALL THE READINGS ARE IN NEWTON

POLYETHLENE

Fabric type G.S.MTENSILE WARP STRENGTH

TEAR WARP STRENGTH

TENSILE WEFT STRENGTH

TEAR WEFT STRENGTH

PC 114 499.5 18.25 295 16.38

CVC 98 444.6 27.1 250.5 17.5

CT 124 606.3 10.7 242.3 8.5

SILICONE

Fabric type G.S.MTENSILE WARP STRENGTH

TEAR WARP STRENGTH

TENSILE WEFT STRENGTH

TEAR WEFT STRENGTH

PC 119 492.2 21.8 267.3 14.1

CVC 100 456.2 23.7 266.3 17.5

CT 125 728.9 11.6 293.2 7.28

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Comparison b/w macro emulsion, micro emulsion, and nano emulsion softeners

Macro emulsion siligen WAMicro emulsion siligen GWANano emulsion nanosil T4

Test is treated on 100%cotton, fully bleached quality of 16*12/84*26

NOTE : ALL THE READINGS ARE IN NEWTON

TYPEWARP TEAR 1

WARP TEAR 2

WARP TEAR 3

WEFT TEAR 1

WEFT TEAR 2

WEFT TEAR 3

WA62 64.4 64 41.1 39.8 45.2

AVG : 63.4AVG : 42.0

GWA34 37 34 11.6 11.7 11.0

AVG : 23.8AVG : 11.4

T464 63 65 35.4 36.2 38

AVG : 64AVG : 36.5

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Glossary

General Textile Trade Terms/Glossary

A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z

General Textile Trade Terms/Glossary with Initial-A

Absorbency

The ability of a fabric to take in moisture. Absorbency is a very important property, which effects many other

characteristics such as skin comfort, static build-up, shrinkage, stain removal, water repellency, and wrinkle

recovery.

Acetate

A manufactured fiber formed by compound of cellulose, refined from cotton linters and/or wood pulp, and

acedic acid that has been extruded through a spinneret and then hardened

Acrylic

A manufactured fiber derived from polyacrylonitrile. Its major properties include a soft, wool-like hand,

machine washable and dryable, excellent color retention. Solution-dyed versions have excellent resistance

to sunlight and chlorine degradation.

Alpaca

A natural hair fiber obtained from the Alpaca sheep, a domesticated member of the llama family. The fiber is

most commonly used in fabrics made into dresses, suits, coats, and sweaters.

Angora

The hair of Angora rabbit.

Anisotropic

A material which has different physical properties in different directions.

Anti-dumping duty

An extra duty imposed on an imported product by an importing country (or group of countries, as in the case

of the EU) to compensate for the dumping of goods by a foreign supplier.

AOX

Adsorbable organic halogens.

APEO

Alkylphenolethoxilate.

Appliqué

A pattern constructed by applying one fabric on top of another.

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Aramid

The generic name for a special group of synthetic fibres (aromatic polyamide) having high strength;

examples are "Kevlar" and "Twaron".

Arran

A traditional style of fishermen's cable-knit sweaters.

Artificial fibres

- Please see cellulosic fibres.

ASEAN

Association of South East Asian Nations-Brunei, Indonesia, Malaysia, Myanmar, Philippines, Singapore,

Thailand and Vietnam.

Asphalt retention (geotextiles)

A measure of the amount of asphalt cement that can be held within the pores of a paving geotextile.

Astrakhan

A thick woven or knitted cloth with a surface of loops or curls which imitates the coat of an Astrakhan lamb.

Atactic

A type of polymer molecule in which groups of atoms are arranged randomly above and below the backbone

chain of atoms, when the latter are arranged all in one plane.

ATC

The Agreement on Textiles and Clothing, which embodied the results of the negotiations on textiles and

clothing conducted under the Uruguay Round of multilateral trade talks. The ATC provides for the phasing

out of MFA quotas between January 1995 and December 2004.

General Textile Trade Terms/Glossary with Initial-B

Barré

An imperfection, characterized by a ridge or mark running in the crosswise or lengthwise directions of the

fabric. BarrŽs can be caused by tension variations in the knitting process, poor quality yarns, problems

during the finishing process.

Basket Weave

A variation of the plain weave construction, formed by treating two or more warp yarns and/or two or more

filling yarns as one unit in the weaving process.

Batiste

A medium-weight, plain weave fabric, usually made of cotton or cotton blends. End-uses include blouses

and dresses.

Ballotini

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Small glass beads which are normally used in reflective paints but which can also be incorporated into

fabrics.

Bandana

Handkerchief designs in simple colour and white stylised patterns, including spots.

Barrier (geotextiles)

a material which prevents fluid movement across the plane of a geotextile. A nonwoven geotextile saturated

with an impermeable substance (eg bentonite clay) can act as a barrier material.

Bast fibre

Strong, soft, woody fibers, such as flax, jute, hemp, and ramie, which are obtained from the inner bark in the

stems of certain plants.

Batik

A traditional dyeing process in which portions of cloth are coated with wax and therefore resist the dye. Batik

fabrics are characterised by a streaky or mottled appearance.

Batt

Single or multiple sheets of fibre used in the production of nonwoven fabric.

Bayadère

A fabric or design with horizontal plain or patterned stripes.

BCF

Bulked continuous filament(BCF) textured yarn used mainly in the construction of carpets or upholstery.

Bedford cord

A cord cotton-like fabric with raised ridges in the lengthwise direction.

Belt-edge separation (tyres)

Separation of the plies of reinforcing fabric from the rubber matrix of a tyre, at the edge of the belt of

reinforcement.

Bias belted tyres

Tyres reinforced by layers of tyre cord fabric arranged alternately so that the main load bearing yarns lie at

an angle of less than 90° to the plane in which the tyre rotates and yarns of adjacent layers cross each

other.

Bi-component fibres

Fibres spun from two different polymers. The most common types are made from polymers which have

different melting points and are used for thermal bonding. Another variant is produced from polymers which

have differing solubilities. In this case one polymer may later be dissolved out to leave ultra-fine filaments.

An example is the production of suede-like fabrics. This process is also used to create crimping, in order to

provide bulk or stretch.

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Bicomponent yarn

A yarn having two different continuous filament components.

Bilaminate (fabric)

A fabric formed by bonding two separate fabrics together.

Binder

An adhesive material used to hold fibres together in a nonwoven structure.

Biocompatibility

Compatibility with living tissue or a living system by not being toxic or injurious.

Birdseye

A fabric woven to produce a pattern of very small, uniform spots.

Bi-shrinkage yarn

A yarn containing two different types of filament, which have different shrinkages.

Blinding (geotextiles)

A condition in which soil particles block openings on the surface of a geotextile, thereby reducing the

hydraulic conductivity of the geotextile.

Blend

A term applied to a yarn or a fabric that is made up of more than one fiber. In blended yarns, two or more

different types of staple fibers are twisted or spun together to form the yarn. Examples of a typical blended

yarn or fabric is polyester/cotton.

BOD

Biological oxygen demand- A measure of pollution by oxygen-consuming organic materials in an effluent

stream.

Boiling

A process in which a yarn or garment made from staple fibre containing wool or animal hair is left in boiling

water so that the original fabric construction is obscured by the felted surface.

Bonded fabric

A nonwoven fabric in which the fibres are held together by a bonding material. This may be an adhesive or a

bonding fibre with a low melting point. Alternatively, the material may be held together by stitching.

Bonding agent

See binder.

Bouclé

A compound yarn comprising a twisted core with an effect-yarn wrapped around it so as to produce loops on

the surface.

Bouclette

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A small bouclé effect.

Bourette

A silk noil fabric made from short fibre (silk waste) with a textured surface.

Bowl

One of a pair of large rollers forming a nip.

Braided yarn

Intertwined yarn containing two or more strands.

Breaking extension

The percentage extension at maximum load.

Breaking strength (geotextiles)

The ultimate tensile strength of a geotextile per unit width.

Breathability

The ability of a fabric, coating or laminate to transfer water vapour from one of its surfaces through the

material to the other surface. See also moisture vapour transmission rate (MVTR).

Brocade

Usually a jacquard woven fabric in which the figure is developed by floating the warp threads, the weft

threads, or both, and interlacing them in a more or less irregular order.

Broadcloth

A plain weave tightly woven fabric, characterized by a slight ridge effect in one direction, usually the filling.

The most common broadcloth is made from cotton or cotton/polyester blends.

Brocatelle

A heavy figured cloth in which the pattern is created by warp threads in a satin weave.

Burlap

A loosely constructed, heavy weight, plain weave fabric used as a carpet backing, and as inexpensive

packaging for sacks of grain or rice. Also, as fashion dictates, burlap may also appear as a drapery fabric.

Burn-out

A brocade-like pattern effect created on the fabric through the application of a chemical, instead of color,

during the burn-out printing process. (Sulfuric acid, mixed into a colorless print paste, is the most common

chemical used.) Many simulated eyelet effects can be created using this method. In these instances, the

chemical destroys the fiber and creates a hole in the fabric in a specific design, where the chemical comes

in contact with the fabric. The fabric is then over-printed with a simulated embroidery stitch to create the

eyelet effect. However, burn-out effects can also be created on velvets made of blended fibers, in which the

ground fabric is of one fiber like a polyester, and the pile may be of a cellulosic fiber like rayon or acetate. In

this case, when the chemical is printed in a certain pattern, it destroys the pile in those areas where the

chemical comes in contact with the fabric, but leave the ground fabric unharmed

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General Textile Trade Terms/Glossary with Initial-C

Cable

To twist together two or more folded yarns.

Calico

Tightly-woven cotton type fabric with an all-over print, usually a small floral pattern on a contrasting

background color. Common end-uses include dresses, aprons, and quilts.

CAI

Compression strength after impact.

Calendered

The term is used to describe a fabric which has been passed through rollers to smooth and flatten it or

confer surface glaze.

Camel's hair

The hair of the camel or dromedary; also used as a broad description of fawn colour.

Canvas

A plain weave usually made from cotton or linen.

Caprolactam

A chemical intermediate used in the manufacture of polyamide (nylon).

Carded

Description of a continuous web or sliver produced by carding.

Carding

The disentanglement, cleaning and intermixing of fibres to produce a continuous web or sliver suitable for

subsequent processing. This is achieved by passing the fibres between moving pins, wires or teeth.

Cashmere

Hair with a mean diameter of 18.5 microns or less from the downy undercoat of Asiatic or selectively bred

feral goats.

Cavalry twill

A firm warp-faced cloth, woven to produce a steep twill effect.

Cellophane effect

An effect created in a fabric which gives it the iridescent appearance of cellophane.

Cellulosic fibres

Fibres made or chemically derived from a naturally occurring cellulose raw material.

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Cellulosic filament

Filaments made or chemically derived from a naturally occurring cellulose raw material.

Centinewton (cN)

A unit of force used to measure the strength of a textile yarn (see tenacity).

Centipoise

A measure of viscosity, equal to 0.001 newton second per m2.

CFRP

Carbon fibre reinforced plastic.

Chafer fabric

A fabric coated with vulcanised rubber which is wrapped around the bead section of a tyre before

vulcanisation of the complete tyre. Its purpose is to maintain an abrasion-resistant layer of rubber in contact

with the wheel on which the tyre is mounted.

Chainette

A tubular cord produced on a circular knitting machine.

Challis

A lightweight plain-weave fabric, made from cotton or wool, usually with a printed design.

Chambray

A cotton shirting fabric woven with a coloured warp and white weft.

Changeant

See shot.

Cheesecloth

An open lightweight plain-weave fabric, usually made from carded cotton yarns.

Chelate

A chemical compound whose molecules contain a closed ring of atoms, of which one is a metal atom.

Chelating agent

A chemical compound which coordinates with a metal to form a chelate, and which is often used to trap or

remove heavy metal ions.

Chemical bonding

Part of a production route for making nonwovens; binders are applied to a web which, when dried, bond the

individual fibres to form a coherent sheet.

Chenille

A yarn consisting of a cut pile which may be one or more of a variety of fibres helically positioned around

axial threads that secure it. Gives a thick, soft tufty silk or worsted velvet cord or yarn typically used in

embroidery and for trimmings.

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Chiffon

A plain woven lightweight, extremely sheer, airy, and soft silk fabric, containing highly twisted filament yarns.

The fabric, used mainly in evening dresses and scarves, can also be made from rayon and other

manufactured fibers.

Chiné

Textiles with a mottled pattern.

Chinoiserie

Fabric designs which are derived from or which are imitations of Chinese motifs.

Chintz

A glazed, printed, plain-weave fabric, usually made of cotton.

CIF

Cost, insurance and freight.

Circular jersey

Fabric produced on circular knitting machines (see also weft knitting).

Ciré

It is a lightweight performance fabric with a shiny surface made from synthetic fibres for use in outerwear.

Cloqué

Cloqué is a compound or double fabric with a figured blister effect, produced by using yarns of different

character or twist which respond in different ways to finishing treatments.

Color fastness

A term used to describe a dyed fabric's ability to resist fading due to washing, exposure to sunlight, and

other environmental conditions.

Comforter

An over-covering on a bed that is made with a fabric shell filled with an insulating material.

Commingled yarn

A yarn consisting of two or more individual yarns that have been combined, usually by means of air jets.

Composite, composite material

A product formed by intimately combining two or more discrete physical phases-usually a solid matrix, such

as a resin, and a fibrous reinforcing component.

Combing

The combing process is an additional step beyond carding. In this process the fibers are arranged in a highly

parallel form, and additional short fibers are removed, producing high quality yarns with excellent strength,

fineness, and uniformity.

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Conjugate yarns

See bicomponent yarns.

Continuous filament

See filament.

Continuous filament strand (glass)

A fibre bundle composed of many glass filaments.

Convertor

A person or a company which buys grey goods and sells them as finished fabrics. A converter organizes

and manages the process of finishing the fabric to a buyers' specifications, particularly the bleaching,

dyeing, printing, etc.

Copolymer

A polymer in which there are two or more repeat units.

Cord

A term used to describe the way in which textile strands have been twisted, such as in cabled or plied yarns.

Corduroy

A fabric, usually made of cotton, utilizing a cut-pile weave construction. Extra sets of filling yarns are woven

into the fabric to form ridges of yarn on the surface. The ridges are built so that clear lines can be seen when

the pile is cut.

Core-spun yarn

A yarn consisting of an inner core yarn surrounded by staple fibres. A corespun yarn combines the strength

and/or elongation of the core thread and the characteristics of the staple fibres which form the surface.

Core-twisted yarn

A yarn produced by combining one fibre or filament with another during a twisting process.

Count

A measure of linear density (see decitex, denier).

Countervailing duty

An extra duty imposed on an imported product by an importing country (or group of countries, as in the case

of the EU) to compensate for subsidies deemed to be illegal which are given to the manufacturer of the

product in the exporting country.

Courtelle

A brand name for acrylic fibre used by Acordis (formerly Courtaulds).

Cover factor (knitted fabrics)

(tightness factor) A number that indicates the extent to which the area of a knitted fabric is covered by yarn.

It is also an indication of the relative looseness or tightness of the knitting.

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Cover factor (woven fabrics)

A number that indicates the extent to which the area of a fabric is covered by one set of threads. For any

woven fabric, there are two cover factors: a warp cover factor and a weft cover factor. Under the cotton

system, the cover factor is the ratio of the number of threads per inch to the square root of the cotton yarn

count.

Covered yarn

A yarn made by feeding one yarn through one or more revolving spindles carrying the other (wrapping) yarn.

Covered yarn may also be produced using air-jet technology.

Coverstock

A permeable fabric used in hygiene products to cover and contain an absorbent medium.

Covert

A warp-faced fabric, usually of a twill weave, with a characteristic mottled appearance obtained by the use of

a grandrelle (two-colour twisted yarn) or mock grandrelle warp.

Crease-resist finish

A finish, usually applied to fabrics made from cotton or other cellulosic fibres or their blends, which improves

the crease recovery and smooth-drying properties of a fabric. In the process used most commonly, the fabric

is impregnated with a solution of a reagent which penetrates the fibres and, after drying and curing, cross-

links the fibre structure under the influence of a catalyst and heat. The crease-resistant effect is durable to

washing and to normal use.

Crêpe

A fabric characterised by a crinkled or puckered surface.

Crêpe de chine

A lightweight fabric, traditionally of silk, with a crinkly surface.

Crepe-back satin

A satin fabric in which highly twisted yarns are used in the filling direction. The floating yarns are made with

low twist and may be of either high or low luster. If the crepe effect is the right side of the fabric, the fabric is

called satin-back crepe.

Crêpe yarn

A highly twisted yarn which may be used in the production of crêpe fabrics.

Crêpon

A crêpe fabric which is more rugged than the usual crêpe with a fluted or crinkled effect in the warp

direction.

Crimp

The waviness of a fibre or filament.

Crimp contraction

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The contraction in length of a previously textured yarn from the fully extended state (ie where the filaments

are substantially straightened), owing to the formation of crimp in individual filaments under specified

conditions of crimp development.

Crimp stability

The ability of a textured yarn to resist the reduction of its crimp by mechanical or thermal stress.

Crimped yarn

see textured yarn.

Crinoline

A lightweight, plain weave, stiffened fabric with a low yarn count (few yarns to the inch in each direction).

Crocking

The rubbing-off of dye from a fabric. Crocking can be the result of lack of penetration of the dyeing agent,

the use of incorrect dyes or dyeing procedures, or the lack of proper washing procedures and finishing

treatments after the dyeing process.

Cross-dyeing

The dyeing of a yarn or fabric containing a mixture of fibres, at least one of which is coloured separately.

Cross-linking

The creation of chemical bonds between polymer molecules to form a threedimensional polymeric network,

for example in a fibre or pigment binder.

Cupro

A type of cellulosic fibre obtained by the cuprammonium process.

Cuprammonium

A process of producing a type of regenerated rayon fiber. In this process, the wood pulp or cotton liners are

dissolved in an ammoniac copper oxide solution. Bemberg rayon is a type of Cuprammonium rayon.

Curcuma

A fabric with a yellow colour similar to that produced by the curcuma spice.

Cure

see curing.

Curing (chemical finishing)

A process carried out after the application of a finish to a textile fabric in which appropriate conditions are

used to effect a chemical reaction. Usually, the fabric is heat treated for several minutes. However, it may be

subject to higher temperatures for short times (flash curing) or to low temperatures for longer periods and at

higher regain (moist curing).

Cut and sew

A system of manufacturing in which shaped pieces are cut from a layer of fabric and stitched together to

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form garments. In the case of tubular knitted fabric, the cloth is either cut down one side and opened up into

a flat fabric or left as a tube and cut to shape.

General Textile Trade Terms/Glossary with Initial-D

Damask

A figured woven fabric in which the design is created by the use of satin and sateen weaves.

Decitex

A unit of the tex system. A measure of linear density; the weight in grams of 10,000 metres of yarn.

Decitex per filament (dpf)

The average decitex of each filament in a multifilament yarn.

Decortication (flax)

The process of removing woody outer layers from the stem of the flax plant to yield flax fibres.

Délavé

A fabric with a washed effect.

Delocalisation

The geographical move of a production unit to a low cost country. (Note that the term is increasingly being

used to describe all forms of shifts in production, including foreign sourcing and subcontracting.)

Denier

A measure of linear density; the weight in grams of 9,000 metres of yarn.

Denim

A 3/1 warp-faced twill fabric made from a yarn-dyed warp and an undyed weft yarn. Traditionally, the warp

yarn was indigo-dyed. Dent

The space between adjacent wires in a reed. Dents/inch

A unit of measure which denotes the number of reed wires and spaces between adjacent wires in one inch.

Devoré

The production of a pattern on a fabric by printing it with a substance that destroys one or more of the fibre

types present.

Diolen

A high tenacity polyester filament yarn produced by Acordis.

Dip dyeing

A process in which a garment is dipped into a dye bath to achieve dye take-up only in those areas

immersed.

Dip-dyed yarns

Yarns produced by dip dyeing.

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Distribution layer

A layer in a nonwoven hygiene product (such as a diaper) which distributes fluid to a superabsorbent and/or

fluff pulp material, where it is absorbed.

District check

Distinctive woollen checks originally made in different districts of Scotland.

DMT

Dimethyl terephthalate-a chemical intermediate used in the manufacture of polyester.

Dobby machine

A device fitted to a weaving machine which is capable of being programmed to make dobby weaves by

selectively raising some warp threads and selectively depressing others.

Dobby weave

A fabric, often of a complex construction, woven on a dobby machine by selectively raising some warp

threads and selectively depressing others.

Doeskin

Generally applied to a type of fabric finish in which a low nap is brushed in one direction to create a soft

suede-like hand on the fabric surface. End-uses include billiard table surfaces and men's' sportswear.

Dogstooth or houndstooth check

A small colour and weave effect using a 2/2 twill.

Donegal

A tweed yarn or fabric with different colour neps.

Dope

see spinning solution.

Dope-dyeing

see mass coloration.

Dotted Swiss

A lightweight, sheer cotton or cotton blend fabric with a small dot flock-like pattern either printed on the

surface of the fabric, or woven into the fabric. End-uses for this fabric include blouses, dresses, baby

clothes, and curtains.

Doupion

A fabric made of irregular, raw, rough silk reeled from double cocoons, or a man-made fibre substitute

designed to imitate the silk equivalent.

Double Cloth

A fabric construction, in which two fabrics are woven on the loom at the same time, one on top of the other.

In the weaving process, the two layers of woven fabric are held together using binder threads. The woven

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patterns in each layer of fabric can be similar or completely different.

Double Knit

A weft knit fabric in which two layers of loops are formed that cannot be separated. A double knit machine,

which has two complete sets of needles, is required for this construction.

Double Weave

A woven fabric construction made by interlacing two or more sets of warp yarns with two or more sets of

filling yarns. The most common double weave fabrics are made using a total of either four or five sets of

yarns.

Dowtherm

The brand name for a special liquid with a high boiling point. Godets and heaters heated by Dowtherm

vapour can be maintained at constant temperatures.

Dpf

see decitex per filament.

Drafting

A process which reduces the linear density of an assembly of fibres. Drafting typically occurs in the early

stages of producing yarns from staple fibres.

Drainage (geotextiles)

The ability of a geotextile to collect and transport fluids. Liquids or gases are transmitted within the plane of

the geotextile and this involves flow across the geotextile. For example, geotextiles are used to capture and

transmit gases (eg methane) beneath the geomembrane in a landfill capping system.

Draw spinning

A process for spinning partially or highly oriented filaments in which the orientation is introduced after melt

spinning but prior to the first forwarding or collecting device.

Draw texturing

A process in which the drawing stage of synthetic yarn manufacture is combined with the texturing process.

Draw twist

A process of orienting a filament yarn by drawing it and then twisting it in integrated sequential stages.

Drill

A twill fabric, usually piece-dyed, similar in construction to a denim.

Dry spinning

In the dry spinning process, polymer is dissolved in a solvent before being spun into warm air where the

solvent evaporates. This leaves the fibrous polymer ready for drawing.

Dry spun

A fibre or filament produced by the dry spinning process.

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Dry-laid

Part of a production route for making nonwovens, in which a web of fibres is produced either by carding or

by blowing the fibres on to an endless belt.

Drylaying

A process for forming a web or batt of staple fibres by carding and/or airlaying.

Duck

A tightly woven, heavy, plain-weave, bottom-weight fabric with a hard, durable finish. The fabric is usually

made of cotton, and is widely used in men's and women's slacks, and children's playclothes.

Dumping

The offer for sale of large quantities of goods in a foreign market at low prices, usually in order to gain

market share, while maintaining higher prices in the home market. Dumping may be deemed to have taken

place when a product is sold in a foreign market at a price which is less than the cost of production plus a

normal profit margin.

Durability

The ability of a fabric to resist wear through continual use.

Durable press

A treatment applied to the fabric in the finishing process in which it maintains a smooth attractive

appearance, resists wrinkling, and retains creases or pleats during laundering.

DWR (fabrics)

durable water repellent. DWR fabrics retain their ability to repel water after washing, dry cleaning or heavy

wear

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