dyeing final

8/6/2019 Dyeing Final

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Dyeing Process of Acrylic Fiber

Submitted by:-

Nitin

Shubhda Gupta

MFT 2ND Sem

Submitted to:-

Mr. Vasant Kothari


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Acrylic: entirely synthetic material

=>not hold on to the dyes

Basic dye works best for acrylics

Dyes Effect on acrylic fiber

All-purpose dye, such as Rit

Tint

Do not produce acceptable

results

PROsperse Disperse Dyes produce only light colors

fiber reactive dyes wash out, leaving temporary

stain.

Acrylic dyes exhaustion is slow, not good

build up for darker shades

Basic dyes produce more intense colors,but are more toxic


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Basic dyes are water-soluble

They are mostly used with a mordant.

A mordant is a chemical agent which is used to

set dyes on fabrics by forming an insolublecompound with the dye.

Reeds, raffia, grasses, and barks, acts as a

mordant for basic dyes.

Basic dyes are said to be very bright, andparticularly washfast on acrylic.


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Basic dyes are cationic,

Basic dyes appear to be easy to use

Result in brilliant colours

They dye everything permanently.

They may be much more hazardous than

the other dye classes


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Dye names containing : Manufactured by:

SANDOCRYL Clariant Sandoz

ORCOZINE Orco

Acrylene Dyes.co.uk, sold only to industry

Clariant's Sandocryl Modified

Basic Dyes

Batik Oetoro

Mauvein, the first of all synthetic dyes, is a basic

dye, also known as aniline purple;


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Be aware that it can be damaged by

sudden cooling.

Allow the acrylic to cool only quite

gradually.

Raise the temperature only gradually

between 60 and 70 degrees c.

Getting the dye level is a challenge. Therefore, chemical agents that retard dye

striking is used to produce smoother solid

colours.


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Preparingthe

material

desiring scouring bleaching

Combined desiring and scouring are often

possible

Polyvinyl alcohol is normally used.


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Process Material used

Scouring weakly alkaline solutions of ammonia or

presidium pyrophosphate (Na3HP207)

leaching sodium chlorite (Na I 2) and formic acid

brightening a fluorescent whitening agent

Stabilizing (to control

chlorine dioxideemission )

borax or polyphosphates


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The dye powder is pasted with aceticacid and mixed with boiling wate

Cationic dyes are coloured (avoiddust escaping from the powders)

Solid forms of dyes are not easy to dissolve

because of their tendency to form gummy

material.

Preparation of a paste with methanol and

addition of warm or hot water is sometimes a

useful alternative

D e+ a + HO- a = D e-OH s


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Instructions for basic dyes:

For 1 lb dry fabric, medium intensity:

1 tsp dye [**NOTE: 1 tsp = 5 ml; 1 tbs = 15

ml**]

1 tbs acetic acid (equivalent to 11 tbs or

165 ml vinegar at 5% strength)

2.5 - 3 gal water (10 - 12 liters)


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Acrylic fibers may contain a variety of

different anionic groups.

The dye solution is often prepared by

pasting with acetic acid, and a stable Phof 4.5-5.5 can be obtained by addition of

sodium acetate to buffer the solution.

An addition of up to 2.5 g of anhydrous

sodium sulphate helps to offset the

negative surface charge and sodium ions

weakly block anionic sites in the fibre.


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If dye additions are needed to give the

correct shade, the bath temperature is

first slowly reduced to below 80 c

After dyeing is complete, the bath isslowly cooled to 50-60 C

The material is finally rinsed and possibly

given a mild scour with a non-ionic

detergent and a little acetic acid plus a

softening agent.


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At A AddAuxili ri s & AceticAcid

At B dd is erse es ( re-

dis ersed)


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Loose Fibre DyeingMachine

The machine issuitable for dyeing

loose fibre materialsof cotton, wool,acrylic, cashmere,etc.

Complete process ofscouring, bleaching,dyeing and softeningcan be done in asingle operation


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Low Ratio of 1:8

Direct and indirect steam heating meets

different requirements.

Max. Working Temperature: 100C

Heating rate: Approx. 5C/minute

(According to steam pressure of

6kg/cm2)Cooling rate: Approx. 2C/minute

(According to steam pressure of 3kg/cm2)


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Cationic dyes rapidly adsorb on all available

surface of the acrylic fibres

Addition of sodium sulphate to the dyebath

suppresses the rapid strike Above the dyeing transition temperature

(TD) under the actual dyeing conditions,

cationic dyes tend to exhaust very rapidly

over a small range in temperature.


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Users of basic dyes should Buy dyes in liquid or paste form when possible;

Mix powders inside glove box, hood, or wear

respirator;

Wear gloves;

Install canopy hood over dye bath.

A glove box may be constructed

A canopy hood contains fans to exhaust air tothe outside

Do not breathe any of the dye powder

Be sure to request a separate MSDS sheet for

each dye colour.


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use dye weighing 1% to 3% of the weight ofthe acrylic, to be dyed

Add . l of 3 % acetic acid er litre of

water and gallons of water er ound ofacrylic

Dissolve dye and acid in cold water

Add acrylic fiber to the cold dyebath beforebringing it to a boil

Boil acrylic in the dyebath for an hour, andallow it to cool off, referably overnight


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Acrylic is sold under names such as Orlon,Courtelle, Dralon, Leacryl, Acrilan, and

Nitron.

It is composed of poly (propenonitrile)(polyacrylonitrile) with small amounts of

a co-monomer.

dyeing final

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