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DYEING OF BLENDS

DYEING ANDPRINTING

SUBMITTED BY:

ABDUL ROLL NO 1

BALARAJ ROLL NO 7

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INTRODUCTION OF DYEING

Dyes are colorants that are applied to, or formed in, a textile substrate

in a molecularly dispersed form

They derive their colour from the conjugated double bonds in their

molecular structure.

Dyes must be soluble or capable of being made soluble in the medium

in which they are applied, or they must themselves be molecularlydispersible into the fibers.

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METHODS OF DYEING

UNION DYEING

Different fibers may require different dyes to obtain the same colour

This may be done by putting the appropriate colour dye that is specificto each type of fiber into one dye bath.

It gives color uniformity and same shade in dyeing

It gives low fastness.

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CROSS DYEING

Cross dyeing produces varied effects.

Either the warp or the filling yarns may be stock-dyed or yarn-dyed, one set of yarns being left undyed.

The fabric is piece-dyed after weaving; thus, colour is given to

the undyed yarn in a second dye bath, and the yarns that were

originally stock-dyed or yarn-dyed acquire some additional

coloring, which blends with the piece-dyed portion of the fabric.

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PIGMENT DYEING

Blends can be dyed in a uniform shade with one operation applicable

to all fibers.

Pigment coloration is economical because of limited number of

processing steps.

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PIGMENT DYEING

Advantages:

It has an extensive color range and high light fastness. It has satisfactory wash fastness.

The possibility of combining dyeing and finishing exists with

pigment coloration.

Products must be selected so that finish and binder react under

same conditions of pH and/or temperature.

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PIGMENT DYEING

DisadvantagesHeavy shades crock badly. Light shades may wet crock.

Pigment adversely affects hand. The large amount of binder required

may stiffen fabric. This is most noticeable on very thin fabrics.

Pigment coloration may have sticking or buildup on pad rolls.

Migration (uneven coloration) may occur if drying is variable or pickup

is high.

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JIGGER DYEING OR BATCH DYEING

In jigger dyeing, fabric is first loaded on the draw rollers of the jigger.

Steam is used to heat the water present in the trough of jigger.Fabric is rinsed and washed and then water is discharged.

Dye solution is mixed in the bath and is heated by the steam.

Fabric runs through this solution till it gets the required degree of dye

fixation and shade matching.

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JIGGER DYEING OR BATCH DYEING

Fabric runs through this solution till it gets the required degree of dye

fixation and shade matching.

After fabric gets dyed, hot dye bath is discharged.

Fabric is then washed to remove unfixed dye.

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JET DYEING-BATCH DYEING

In jet dyeing, jet is filled with water and fabric is supplied in the form of

rope by fabric injector.

Jets are interconnected in series which causes movement of fabric.

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JET DYEING-BATCH DYEING

Dye solution is prepared in separate tanks and pumped into jet at 120-

130 degree Celsius.

Fabric is dipped in rope form in the dye bath till fixation.

Hot dye bath is discharged and washed with cold water to remove

unfixed dye.

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THERMOSOL DYEING-CONTINUOUS

DYEING

Fabric is dipped in dye bath and heated with infrared in infrared

section.

After heating, fabric is dried and cured in curing section at high

temperature.

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THERMOSOL DYEING-CONTINUOUS

DYEING

At this high temperature dyes are fixed to the fiber.

After dyeing, fabric is subjected to hot or cold washing depending uponthe quality of fabric and the type of dye employed.

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IMPORTANT FACTORS IN SELECTING

DYES FOR BLENDS

Dye auxiliariesDye bath temperature

Stress on fabricRetarding agentsDye molecule blockageFibers on which dyes are applied

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DYEING OF POLYESTER AND

COTTON BLEND

Polyester and cotton blend can be dyed by:

1. Vat and Disperse dye.2. Direct and Disperse dye.

3. Reactive and Disperse dye.

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BATCH DYEING METHOD OF

POLYCOT BLEND

TWO BATH METHOD:Polyester is dyed in one bath and then reduction clearing is applied to

remove unfixed disperse dye.Cotton is then dyed with direct dye in one bath.

ONE BATH TWO STEP METHOD:Dye bath is first prepared with disperse dyes and dyeing assistants.

Blended polycot is then dipped in the dye bath which is having boilingtemperature.Dyeing bath is cooled to dyeing temperature of cotton and thenreactive dyes are used.

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BATCH DYEING METHOD OF

POLYCOT BLEND

REVERSE METHOD:It is a two bath dyeing method in which cotton of polycot blend is dyed

with reactive dyes.Polyester of polycot blend is dyed with disperse dye.The process is then reversed.

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CONTINUOUS DYEING OF POLYCOT

BLEND

In continuous method polyester is dyed with disperse dye by thermosol

method

Cotton is dyed with vat dyes by continuous pad dye method.

Dye pad consists of vat dyes and disperse dyes with acetic acid of ph

between 4.5 to 5

Anti migrant, dispersing agent and wetting agent (0-5gm/l) is used.

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DYEING OF POLYESTER WOOL

BLEND

Poly wool blend can be dyed by:

1. Disperse and acid dyes.2. Acid metalized dyes.

3. Selected direct dyes.

4. Selected reactive dyes.

5. Chrome dyes.

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DYEING OF POLYWOOL BLEND BY

TWO BATH METHOD

Polyester is dyed first in dye bath-

1. Disperse dyes with dye carriers are used.

2. Acetic acid and ammonium acetate is used to maintain pH in

between 5-6.

3. Temperature is raised to the boiling or slightly above boiling level

(1050C) for 45 to 60 min4. Reduction clearing carried out with hydrosulphite (3g/l), ammonia

(3g/l), and nonionic detergent (1g/l), at 50- 550C for 20min.

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DYEING OF POLYWOOL BLEND BY

TWO BATH METHODWool is then dyed with acid dyes:

1. Dye bath is prepared at 500 degree Celsius.2. Acid dyes and acid containing 2%H2SO4 is used.

3. Sodium sulphate is used as a leveling agent.

4. It is run for 5 to 10 min

5. Temperature is increased gradually at a rate of10degree Celsius/min

to boil while agitating.

6. The material for 50 to 60 min.

7. Then the yarn is rinsed with cold water and dried.

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DYEING OF POLYWOOL BLEND BY

ONE BATH METHOD

Polywool blend is dyed by one bath method to achieve light to medium

shades.

The dye bath contains the disperse and acid dyes, a dye carrier, a

dispersing agent, ammonium acetate, and acetic acid of pH 5-6.

The temperature is raised slowly to boil over 45 min.

Dyeing is continued at 100-105 degree Celsius for 60 minutes.

After dyeing material is washed with nonionic detergent at 60 degree

Celsius.

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DYEING OF POLYESTER VISCOSE

BLEND

DYEING BY TWO BATH METHOD:In first bath polyester is dyed with disperse dye.

Reduction clearing is done by using Sodium Hydrosulphite, Setamol

WS at 80 degreeCelsius.

Check for Colour Bleeding, if heavy colouraration is occuring then

repeat the reduction clearing process.Overflow wash and drain.

Hydrogen peroxide at 60 0C , drain

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DYEING OF POLYESTER VISCOSE

BLEND

Viscose is dyed in a separate bath using water and pre dissolved

color.

Temperature is raised up to 70 degree Celsius.

Pre dissolved gluabers salt (50gm/l) and soda ash (20gm/l) is added.

Formic acid is added to neutralize.

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DYEING OF COTTON VISCOSE BLEND

Cotton and viscose can be blended by using:1. Direct and Disperse dyes.

2. Reactive and Acid dyes.

3. Direct and Acid dyes.

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DYEING OF COTTON VISCOSE BLEND

Both fibers are dyed with the same dyes

It is normally dyed by Tone on Tone dyeing .

Viscose has higher affinity for dyes and normally dyes deeper than

cotton.

Mercerization of cotton reduces differential shading.

Longer dyeing times favour exhaustion of dye into viscose.

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BIBLIOGRAPHY

www.p2pays.org/ref/12/11959.pdf

CHEMICAL PROCESSING OF TEXTILESBY V.A.SHENAITEXTILES FIBER TO FABRIC BYV.B.COBMANwww.wikipedia.org

http://www.p2pays.org/ref/12/11959.pdfhttp://www.p2pays.org/ref/12/11959.pdf

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THANK YOU