Dyeing And Printing Defects Analysis

Submitted by:-Yash Vyas

A.P-V

Classification Of Defects

• Minor Defect –• A defect is defined as minor

defect that is not likely to reduce theusability of the product, but neverthelessmay negatively influence the sales.

• The minor defects can be untrimmedthread-ends, slight dirt in a non-noticeable zone which can be removed, etc.

Classification Of Defects

• Major Defect: • A defect that, if conspicuous on the

finished product, would cause the item to be a second. (A "second" is a garment with a conspicuous defect that affects the salability or serviceability of the item.

Dyeing Defects

Causes Of Dyeing Defects

Due to Material:– Material having dead fibers or other defective fibers.

– Left over of Chemicals after bleaching etc.

– Material not properly desized.

– Material not properly mercerized.

– Absorbency of the fabric not proper.

– Sticking of insoluble material on the fibers.

– Impurities are not removed properly.

– Uneven heat treatment.

Causes Of Dyeing Defects

Due to Water Quality:– More Hardness of water

– Water has metal ions such as iron.

– pH of water not proper

– Water having more chlorine

Due to Improper Dye Solution:– Improper weight ratio of colors, material and chemicals.

– Improper material to water ratio

– Improper filtering of concentrated colors.

Barre

• Its horizontal shaded band across the width of the fabric.

• It may be caused by variation in the size of the filling yarn and by the differences in tension of either the filling or warp yarns.

Bleeding

• It’s a loss of color when the dyed fabric is wetted or emerged in water.

• The water here, becomes colored and may cause discoloration of other fabrics.

• This is usually due to either improper dye selection or poor dye fastness.

Crocking

• It is the rubbing off of the color.

• It may rub onto another fabric.

• This may be due to inadequate scoring subsequent to dyeing.

Shade Bar

• It is a horizontal band of a different hue running across the fabric.

• It may be caused by a change of filling bobbin in the loom or a loom stop and start up

Shading

• It is a variation in color tone either horizontally or vertically.

• It is generally due to uneven tension on the fabric.

Stained

• It indicates a discoloration caused by a foreign substance, dirt, grease, oil or sizing residue on the fabric being dyed.

Color variationin yarn

• Caused due to lack of agitation in

the dye bath.

• This is a major defect. The yarn

was supposed to be uniformly

blue in color.

Hole in sulfurdyed fabric

• Caused due to tendering which

takes place because sulphur is

converted into sulphuric acid

after oxidation which is harmful

for the cellulosic fibers.

• This is a major defect. The defect

occurred after washing the garment.

Creasing

• Causes unleveled penetration of dyes which in turn results into unleveled dyeing, which causes colour variation.

• Differs from crease streak in that streak will probably appear for entire roll.

• On napped fabric, final pressing may not be able to restore fabric or original condition. Often discoloration is a problem.

Off Shade

• It refers to color that doesn't exactly match the standard or the prepared sample.

• This may be due to faulty dye foundation or application or may be due to variation in dye lot.

Streaked

• This type of defect on the fabric indicates either a stain or uneven dyeing caused by folds in the fabric during the dyed process.

Printing Defects

Methods of Printing1. Block

2. Stencil

3. Screen

4. Flat Press

5. Roller

Flushing/Wicking

• Caused due to Low viscosity of print paste.

• It occurs when the printed area

bleeds out into the unprinted

area. The result is a ‘haloing’ or

shadowing effect around the

outline of the pattern design.

Bleeding

• Caused due to Low viscosity of

print paste

• It is major defect as it happens

throughout the fabric unless

the viscosity is corrected.

Misfits

• A misfit is a print defect caused by improper alignment of the

screens. Also known as “out of registration, misfits leave

unprinted areas in the design.

• For example, a green leaf may overlap its black outline or

print over another color.

Stick-ins

• A stick-in occurs when a small fiber or piece of lint gets stuck

in the screen opening.

• The result is a small unprinted circle in the design. A stick-in is

very difficult to see and often goes unnoticed during a long

run.

Scrimps

• A scrimp defect occurs when the fabric creases underneath

one of the screens during the printing process.

• The pattern is then printed on top of the crease, leaving a

large unprinted area when the fabric returns to its relaxed

state.

Banding

• Defect created by the print head’s movement over the substrate.

• Use of scanning print head, or a print head that moves back and

forth across the substrate in straight line placing drops of ink at

precise locations along the line.

• If the head is not properly aligned, or if the substrate advances

unevenly, the result is a slight horizontal “band” or line of

unprinted area.

Unwanted pigmentmarking on fabric

• Caused due to screen has holes

in it that should have been

covered. This could be because

of ageing of the screen and

eventual damage or just

improper exposure to light.

Back Fabric Seam Impression

• Backing fabric is often used to cushion fabric being printed. If

there is a joining seam in the backing fabric, an impression

will result on printed fabric.

Color Smear

• The result of color being smeared during printing.

Color Out

• The result of color running low in reservoir on printing

machine

Mottled

• Color applied unevenly during printing

Crack or miss alignment in transfer printed fabric.

• Incomplete transfer of design

from paper to fabric on transfer

printing due to removal of

transfer of paper while the

fabric was still hot.

Finishing Defects

FABRIC FINISHING• A series of processing operations applied to

gray fabrics to enhance their appearance and

hand, properties and possible applications.

• Play a fundamental role for the commercial

excellence of the results of textiles

FABRIC FINISHING• The most simple form of finishing is the

ironing or pressing on the fabric.

• In finishing , the fabric is subjected to mechanical and chemical treatment in which its quality and appearance are improved and its commercial value enhanced.

• Physical finishing techniques(dry finishing processes) or chemical finishing methods(wet finishing) are used.

FABRIC FINISHING

• Functional finish:

– Wearability, Hand, Mechanical resistance,

Easy care, Wettability, Washability,

Deformability, Anti bacterial, Anti fungal,

Soil-proof and Fire-proof ability

• Aesthetic finishes:

– Aesthetic looks

Unwanted marks onfabric.

• Oily stains with dust adhered to

surface which makes the stains

more prominent and difficult to

remove, due to contact with oil

or grease covered exposed

machine parts, careless handling

could be another cause.

Decolorized patch on fabric

• Caused due to

– chemical spillage on fabric.

– Localized excess bleaching.

– Localized excess enzyme wash.

• Can be result into weakening of

the fabric.

Pin Holes

• Holes along selvage caused by pins holding fabric while it

processes through tenter frame.

• Major defect if pin holes extend into body of fabric far enough

to be visible in the finished product.

Sanforize Pucker

• Results from uneven wetting out on sanforize.

• usually caused by defective spray heads.

• Fabric will appear wavy or puckering when spread on cutting

table.

• Difficult to detect during inspection on inspection machine

with fabric under roller tension.

Bowing

• Usually caused by finishing.

• Woven filling yarns lie in an arc across fabric width; in knits

the course lines lie an arc across width of goods.

• Establish standards of acceptance. Critical on stripes or

patterns; not as critical on solid color fabrics.

Pilling

• Pilling is a common fabric defect occurring on knitted and woven fabrics.

• In producing a yarn, long fibers tightly-twisted produce a serviceable yarn. When short stable fibers are mixed into the yarn the result is a yarn that will not hold together. The short staple fibers will separate from the yarn and curl up in a ball, forming what is referred to as a pill.

• Pilling is accentuated by the friction of normal wear, washing and routine dry cleaning.

Water Spots

• Usually caused by wet fabric being allowed to remain too long

before drying; color migrates leaving blotchy spots.

Selvage Torn

• Usually caused by excessive tension while processing through tenter frames.

Cuts or Nicks

• Caused by indifferent handling of scissors. snips ormechanical trimmers.

Seam Tears

• Frequently caused by the turning equipment used to reverse garments in finishing.

Soil

• Caused by oil, grease or dirt. Often times originatingfrom a dirty work area or machinery not properlycleaned

Streaks

• Markings caused by some types of turn boards or defectively finished trimming.

Inadequate Pressing

• Caused by excessive heat or pressure resulting in poor pleating, fullness or twisting of a seam on garment surface.

Pressing Producing Shine on Fabric

• Usually caused by excessive heat or incorrect type of pressing surface.

Loose threads

• Loose threads will get wound on guide rollers forming ridges in the processing machines and cause creases at these places.

• Also loose threads can cause problems of Dye /Print transfer in a padding / Printing application

Askewed or Bias

• Condition where filling yarns are not square with wrap yarns

on woven fabrics or where courses are not square with wale

lines on knits.

Folding Defects

• Garment not Folded to Specifications

• Garment not Folded with proper Materials:Cardboard, tissue or other specified packaging materials

omitted

• Garments not Buttoned, Flys not Closed, IncorrectNumber of Pins

Thank You.