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An effort by :

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Block printing

Roller printingScreen printing

Flat bed

RotaryHeat transfer

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Roller printing ,also called cylinder printing ormachine printing, on fabrics is a textileprinting process patented by Thomas Bell in1783 in an attempt to reduce the cost of the

earlier copperplate printing.

It is used to reproduce small monochromepatterns characterized by striped motifs and

tiny dotted patterns called "machinegrounds".

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Roller printing is the most economical andfastest way of printing. It can print over 6000

yards of fabric in an hour.

The outputs of this machine cannot besurpassed by any other method of printing.

Designs with upto 16 colors present noproblem in roller printing.

This method is also known as machineprinting

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Central pressure bowlwrapped with lappings

Endless wollen blanket

A back grey

Cloth to be printed

Engrave copper roller

Color box

color doctor Lint doctor

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The engraved roller is first supplied with theprinting paste by the furnishing roller( it is socalled because it supplies the paste to theengraved roller).

The paste is applied in the engraving as wellas the non-engraved portions.

When this engraved roller comes in contactwith the color doctor, it scrapes out theexcess paste from the non-engraved portion.

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During further rotation it meets the lintdoctor which is placed at an angle against therotation of the rollers.

The engraved roller continues the rotation,picks up the paste and the cycle repeats.

A number of engraved rollers provided withseparate furnishers , color boxes and colorand lint doctors are placed around the central

pressure bowl , so that by a single passage ofthe cloth through the machine all the colorsrequired in the design are printed, each rollersupplying a part of the design.

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In order to get an accurate impression on thecloth, it is important that the engraved rolleris capable of lateral and up and downadjustment thus it should be capable of

independent motion.

The pressure of the printing roller on theprinting bowl is obtained by a spring.

Screws allow the independent movement ofthe printing rollers.

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The color doctor is made up of steel.

It consists of a sharp steel blade 1/32 to 1/16thick and has a razor like edge, which rests on anengraved roller.

The other edge is clamped tightly between twobrass plates and screwed together.

It is provided at each end with a supporting

pivot.

It is given a to and fro motion parallel to thedirection of the roller axis to prevent unequalwear and tear of the blade edge.

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The lint doctor differs from the color doctorin the way that It is made up of brass. No transverse motion is imparted to it.

Its purpose is to pick up loose cotton fibresattached to the engraved roller. Which if notcleared would pollute the printing paste inthe color box.

The lint doctor edge should be sharp enoughto remove this fibre but it is less sharp thanthat of the doctor blade.

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Its inclination against the roller should beproper otherwise it can damage theengraving.

The lint doctor also scrapes away the printingpaste that may be present on the non-engraved portion of the roller so that it doesnot contaminate the printing paste of the

next roller printing the subsequent design incase where a multicolored design is beingprinted.

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This is a covering of the central pressure bowland is made up of special fabric of linen wrapand worsted weft.

It resists the pressure to which it is subjected

during actual printing. 8-12 layers of fabric are wound on the bowl

free from creases.

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It consists of 30-50 yards of thick woollen clothtightly woven and then felted. It is of eventhickness ,texture and elasticity.

It increases the effect of elasticity of the lapping

and it circulates continuously round the pressurebowl between the lapping and the cloth to beprinted.

Its ends are sewn together with strong silk thread

to make it endless travelling blanket.

After continuous use, the blanket becomes hardand soiled by the paste penetrating into it andthus should be replaced or turned.

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Another blanket (washable) takes the form ofendless rubber covered cloth and serves tocarry away the paste passing through thecloth being printed.

On leaving the printing machine the blanket

runs over steel rollers into a washer providedwith three brushes arranged round a stainlesssteel cylinder. The first brush scrubs the surface of the blanket,

removing most of the contaminating paste, which isthen removed by warm water spray.

The second completes the cleaning process.

Third prepares the blanket for drying.

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When the woollen blanket is used, unbleached

cotton cloth is run between the blanket and thecloth to be printed to protect the blanket fromthe paste passing through the cloth.

When the washing blanket is employed the back

grey is not necessary.

Back grey is wound on a roller at the back of theprinting machine and after printing, it leaves themachine and is again wound on another roller,

again at the back.

After use it is taken for bleaching and may beused for printing ( this time as bleached cloth tobe printed.)

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A furnisher partly dips into the printing paste andworks in contact with the engraved roller towhich it furnishes the printing paste and hencethe name.

A furnisher roller may be provided with bristles.Which in addition to supplying the paste alsowork as a scrub to scrape out any solid materialdeposited in the engravings.

Color boxes are long, narrow and shallowtroughs carried on a check of iron attached to theadjustable bearing of the printing rollers andmoving backwards and forward with them.

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Solid and shell engraved rollers are available,

both varying in length from 32-80.

Solid rollers have a diameter of 5-12 whileshells have outer diameter of 5-30.

The hollow cylinder of copper(1/2 to 1-1/4thick walls) has a tab extending throughout theentire length on the inside of the shell, which fitsinto a slot cut into its mandrel.

When the copper engraved rollers are chromiumor nickel plated their lives can be considerablylengthened.

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These are long steel shafts serving as axels for

the engraved rollers when the latter are placed inthe printing machine.

These are about a yard longer than the printingroller and project at about 18 at each end of the

roller.

These projecting portions are cylindrical for adistance of 6-8 to work smoothly in the brasssteps of adjustable bearings in which they turn.

Then it tapers off to facilitate the slipping of therollers. The middle part of the mandrel uponwhich the engraved roller is forced, correspondsto the inner diameter of the engraved roller.

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The design on the roller is stamped by usinga suitable mill.

One repeat of the design is first transferredto a small roller called die of soft steel withpolished surface.

The dimensions of the die should be suchthat the circumference of the printing roller is

an exact multiple of that of the die so that anexact number of whole repeats can betransferred on the printing rollers.

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The die with the polished surface is dipped in asolution of copper sulphate till an even depositof copper is formed in the die.

Fe + CuSO4 = Cu + FeSO4

In the meantime a design is drawn on a paperwith sodium sulphide solution. The paper is thendraped around the moistened surface of thecopper die

A thick canvas piece is tied around it tightly for1-2 hrs and the design is transferred to the diein lines of copper sulphide. It is then engraved

with hand. Kriti Sharma

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When the die is fully engraved it is hardened bydipping in bone ash and a little charcoal.

It is then heated to cherry red, plunged into cold

water for tempering to required hardness.

The design thus obtained is called INTAGLIO

The hardened die is now placed in a machine inclose contact with another roller of mild steel andis set in motion.

The die and the mill are constantly revolved atincreasing pressure wherein the design of theintaglio is transferred in relief.

The mill is then hardened and is used to embossthe design on the printing rollers using sufficient

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The mill then is moved by a distance equal tothe width of the repeat design and therotation is started again.

This is repeated several times in order totransfer the design to the entire length of theroller.

In order to print a multicolored design,

separate separate dies are prepared for eachcolor.

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Sharp and fine vertical lines can be printed veryeasily.

Uniform texture is produced.

Photo engraved designs such as flowers etc. withtonal gradation and light and shadow effect canbe produced.

It produces sharp, crisp and uniform designs.

It is very cheap and fast thus economical.

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Number of colors that can be used are limited.

Embossing new rollers for new designs is time consuming.

The purity of color is not maintained.

A limited width of cloth can be printed.

The size of the repeat design is limited due to thecircumference and the length of the roller.

Damage due to back grey like stitch impressions, backgrey creases etc. is more.

Handling heavy engraved roller makes change of designmore time consuming.

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