48172926 Dyeing and Printing Defects

7/31/2019 48172926 Dyeing and Printing Defects

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Dyeing And Printing

DefectsAnalysis

Submitted by:-

Yash Vyas

A.P-V


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Classification Of Defects

Minor Defect

A defect is defined as minor

defect that is not likely to reduce the

usability of the product, but neverthelessmay negatively influence the sales.

The minor defects can be untrimmed

thread-ends, slight dirt in a non-noticeablezone which can be removed, etc.


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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.


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Dyeing Defects


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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.


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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.


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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 thedifferences in tension of

either the filling or warp

yarns.


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Bleeding

Its a loss of color when the dyedfabric is wetted or emerged inwater.

The water here, becomes coloredand may cause discoloration ofother fabrics.

This is usually due to eitherimproper dye selection or poordye fastness.


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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


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Shading

It is a variation in color

tone either

horizontally or

vertically.

It is generally due to

uneven tension on the

fabric.


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Stained

It indicates a

discoloration caused

by a foreign substance,dirt, grease, oil or

sizing residue on the

fabric being dyed.


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Hole in sulfur

dyed 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.


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Printing Defects


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Methods of Printing

1. Block

2. Stencil

3. Screen

4. Flat Press

5. Roller


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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 shadowing

effect around the outline of the

pattern design.


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Bleeding

Caused due to Low viscosity of

print paste

It is major defect as it happens

throughout the fabric unless

the viscosity is corrected.


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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.


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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.


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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 relaxedstate.


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Banding

Defect created by the print heads movement over the substrate.

Use of scanning print head, or a print head that moves back andforth 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.


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Unwanted pigment

marking on fabric

Caused due to screen has holes

in it that should have beencovered. This could be because

of ageing of the screen and

eventual damage or just

improper exposure to light.


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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.


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Color Out

The result of color running low in reservoir on printing

machine

Mottled

Color applied unevenly during printing


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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.


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Finishing Defects


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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


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FABRIC FINISHING

The most simple form of finishing is theironing 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(wetfinishing) are used.


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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


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Unwanted marks on

fabric.

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.


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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.


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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.


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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.


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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.


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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.


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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.


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Cuts or Nicks

Caused by indifferent handling of scissors. snips or

mechanical trimmers.

Seam Tears

Frequently caused by the turning equipment used to

reverse garments in finishing.


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Soil

Caused by oil, grease or dirt. Often times originating

from a dirty work area or machinery not properly

cleaned

Streaks

Markings caused by some types of turn boards ordefectively finished trimming.


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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 ofpressing surface.


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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


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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.


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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


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Thank You.

48172926 Dyeing and Printing Defects

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