28010401 textile auxiliaries non surfactant auxiliaries 01

7/29/2019 28010401 Textile Auxiliaries Non Surfactant Auxiliaries 01

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Non-surfactant

auxilaries andapplications

Wirote Sarakarnkosol


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Non-surfactant auxiliaries

: Classification Electrolyte pH control

Enzyme Reducing and Oxidising agents Sequestering agent Thickener and Migration inhibitor Hydrotropic agents Fastness improving agents


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Electrolyte


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Electrolyte

NaCl and Na2SO4 are commonly used.

Increase the adsorption of Reactive and

Direct dyes on cellulose. (Also for leuco Vat

and Sulphur dyes)

Promote aggregation of soluble dyes.

NaCl gave stronger effect than Na2SO4.


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Electrolyte

Decrease the adsorption of Anionic dyes

on PA and WO.

Kosmotropes increase hydrophobic increase dye adsorption

Chaotropes decrease hydrophobic decrease dye adsorption

NaCl gave more decreasing

the adsorption of anionic dyes

on PA than Na2SO4 !!


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Electrolyte:: Equilibrium adsorption isotherm at 34oC and rate of dyeing at 40oC for CI Direct Blue 1 on viscose in

the presence of electrolyte singly and binary mixture


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Electrolyte:: Fixation of CI Reactive Red 180 with various concentrations of Group IA chlorides


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Electrolyte:: Fixation of CI Reactive Red 180 with various concentrations of potassium salts of dicarboxylic acids

K oxalate

K tartrate

K phthalate


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Electrolyte

: Ecological approach High salt loading is indesirable in waste-

water.

Na2SO

4causes corrosion of concrete

pipes.


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pH control :


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pH control :

3 differents technique1. Maintenance of a high degree of acidity or alkalinity

2. Control pH within fairly narrow tolerance mainly in the

near-neutral region (pH 4-9)3. Gradual shifting of the pH as dyeing proceeds


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pH control

: Maintenance of a high degree of acidity or alkalinity Easy to control

Acid region use in application oflevelling

acid and 1:1 metal complex dyes to PAand WO.

Alkali region use in reactive, sulphurorvat

dyes to CEL.


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pH control:pH value of some common acid in distilled water.

Normality 2 N 1 N 0.1 N x N 0.01 N 0.001 N

Material

Hydrochloric acid g/l - 36.5 3.65 1 g/l 0.37 0.037

HCl pH - 0.11 1.08 1.61 2.00 3.00

Sulphuric acid g/l - 49.0 4.9 1 g/l 0.49 0.049

H2SO

4pH - 0.24 1.17 1.79 2.05 3.00

Formic acid g/l 92.0 46.0 4.60 1 g/l 0.46 0.046

HCOOH pH 1.61 1.79 2.32 2.76 2.85 3.42

Lactic acid g/l 180.0 90.0 9.00 1 g/l 0.90 0.090

C3H

6O

3pH 1.78 1.97 2.43 2.94 2.95 3.50

Acetic acid g/l 120.0 60.0 6.00 1 g/l 0.60 0.060

CH3COOH pH 2.18 2.40 2.87 3.27 3.37 3.89


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pH control:pH value of some common base with concentration.

Normality 2 N 1 N 0.1 N x N 0.01 N 0.001 N

Material

T.S.P.P. g/l - 83.0 8.30 1 g/l 0.83 0.083

Na4

P4

O7

pH - 10.50 10.15 9.35 9.25 9.01

Sodium carbonate g/l 106.0 53.0 5.30 1 g/l 0.53 0.053

Na2CO

3pH 11.60 11.50 11.00 10.30 10.00 9.80

Ammonia g/l 34.0 17.0 1.70 1 g/l 0.17 0.017

NH4OH pH 11.72 11.59 11.16 11.00 10.64 10.15

Sodium phosphate g/l 98.6 49.3 4.93 1 g/l 0.49 0.049

Na3PO

4pH 12.8 12.30 11.40 11.20 11.10 10.95

Sodium hydroxide g/l - 40.0 4.00 1 g/l 0.40 0.040

NaOH pH - 13.93 12.98 12.38 12.00 11.00


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pH control : Near-neutral region (pH 4-9)

Very difficult to control.

pH of pure water7.47 at 0oC, 7.00 at 24oC and

6.13 at 100oC. Use in Milling acid and 1:2 metal complex dyes

on PA and WO., Basic dyes on PAN and

Disperse dyes on PES, PA, PAN.

Precise control with buffer.


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pH control : Buffer

Buffers are generally based on

combinations ofweak acid + its base salt

orweak base + its acid salt Most common buffer is acetic acid/sodium

acetate (pH range 3.8 5.8) Low cost


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Buffer : Phosphate buffer

More cost than acetate

buffer

More resistant totemperature induced

change

Buffering region at pH

2.5-3.5, pH 6-8 and pH10.5-11


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Buffer : Others

Pyrophosphoric acid (H4P

2O

7) and its salts

(pH 39)

Orthoboric acid (H3BO3), sodium tetraborate(borax Na

2B

4O

7) and sodium hydroxide

(pH 8.110.1) Citric acid and sodium hydroxide (pH 2.16.4) Sodium carbonate and sodium bicarbonate

(pH 9.311.3).


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pH control : Shifting of the pH

Acid shift region use fornon-migrating anionic

dyes on WO or PA.

Ammonium salts is the conventional system foracid shifting.

Alkali shift region use forreactive dyes on CEL.

Sodium salts of volatile acid is the conventionalsystem foralkaline shifting.


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Acid shifting : Ammonium salts

Ammonium sulfate generally used for

dyeing milling acid dyes on PA and WO.

Can be used only open system.

Acid liberate

Volatile to atmosphere


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Acid shifting : Hydrolysable ester

Can be used alone or mix with alkali for

higher starting pH.

Can be used in closed system

High cost

Such as Ethylactate

Lactic acid


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Acid shifting : Hydrolysable ester

Diethyl tatrate 2-Hydroxyethyl chloroacetate

Acid part

Acid part

Alcohol part

Alcohol part


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Acid shifting : Lactone

-butyrolactone


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Alkaline shifting :

Salt of weak acid

Alkali liberate

Sodium formate and Sodium bicarbonate are also used

forreactive dyes on CEL printing.

Sodium acetate


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Enzyme :


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Enzyme :

Biocatalyst foraccelerating the reaction

-amylase use fordesizing process

Catalase forremoving residual H2O

2after

bleaching

Cellulase forbiofinishing of denim

Etc.


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Amylase enzyme for desizing

Convert starch to water-soluble product

Non-ionic wetting agent should be combine used

Temperature range cover 20 115

o

C:Prefer > 70oC (gelatinous point of starch)

pH range cover 5.5 9 : Prefer pH 7 8 (conditionfor degraded product solubilisation)

Salt and Hardness maybe require. Detect residual starch with Iodine solution


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Mode of action of enzymatic degradation : by SDC


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Optimum conditions for enzymatic desizing : by SDC


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Amylase enzyme for desizingTest for degree of desizing (TEGEWA scale) : by SDC

TEKEWA Rating 1 TEKEWA Rating 7


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Catalase :

Remove residual H2O

2to water and

oxygen.

Activity range pH about 5-9

Activity range temperature 50-55oC

Do not destroy the dye molecules.


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Catalase :Hydrogenperoxide removal efficiencyLiquor condition 0.1 g/l 50% Hydrogenperoxide

0.1 g/l Organic stabilizing agent

X g/l Product test

Procedure : Keep the dye liquor at XC for 10 min. and follow dyeing with H2O2 sensitive reactive dyes

Further dyeing : 1 % Sensitive Reactive Blue dye.

40 g/l Common salt

20 g/l Soda Ash60 min at 60C LR 10:1

Material: knitted cotton


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Cellulase

Can convert Cellulose to soluble product

Partially or wholly replacement of Pumice stone

abrasion on cotton denim fabric. Saving in time and labour, much less fabric

abrasion and no debris.

Devided to Neutral andAcid cellulase

Contain endocellulase, exocellulase orbeta-

glucanases


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Cellulase :Dissolution of the cellulose


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Cellulase : Denim finishing

Denim is cotton twill-weave fabric with a dyedwarp with INDIGO and raw white weft.

Acid cellulases (pH 4.55.5 ; 4555oC) give high

aggressive action on cotton which use shortertime but backstaining.

Neutral cellulases (pH 68 ; 5060oC)have lessaggressive action but less or no backstaining.

Terminated with inactivating, by raising the pH to10 or by increasing the temperature to75oC for1015 minutes.


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Reducing agent & Oxidising agent


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Reducing agent & Oxidising agent

Decoloration of material- Bleaching- Stripping

Redox inhibitor- Reduction inhibitor- Antioxidant

Coloration assistance- Reducing agent for Vat & Sulphur dyes- Re-oxidising agent for Vat & Sulphur dyes

3 ACTIONS


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Reduction of Vat dyes


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Reducing agent : Vat dyes assistantReduction potentials of various reducing agents measured as 5 g/l solutions in

15 ml/l caustic soda 38o

B at 60o

C

- Vat dyes have reduction potentials in aqueous media from770 to 1000 mV

the majority 900 to 950.


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Reduction of Sulphur dyes

Sulphur dyes


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Reducing agent : Sulphur dyes assistantReduction potentials of various reducing agents measured as 5 g/l solutions in

15 ml/l caustic soda 38o

B at 50o

C

Sulphur dyes have average only about600 mV


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Reduction clearing of Disperse azo

dyes

CI Disperse Orange 5

Example

N N

Cl

Cl

O2N N

CH3

CH2CH2OH

4H

NH2

Cl

Cl

O2N H2N N

CH3

CH2CH2OH

+


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Reducing agent :Fastness of black polyester dyeings after various reduction clearing

treatments


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Reducing agent : Sodium dithionite

/Hydros/Sodium hydrosulphite Most important reducing system for the batchwise application of vat

dyes in a solution of sodium hydroxide.

Forsulphur dyes, the process is difficult to control and may bedestroyed through OVER-REDUCTION.

But effective with CI Solubilised Sulphurand sulphurised vat dyes.

Reduction clearing forDisperse dyes.


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/Hydros/Sodium hydrosulphiteReduction reaction of hydros with Vat dyes

Reduction reaction of hydros with atmosphere


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Environmental problems Can produce sulphite and sulphate.

Sulphite can be oxidised easily to sulphate

High concentrations of sulphate can cause

damage to unprotected concrete pipes.


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Reducing agent : Sodium sulphide

and Sodium hydrogen sulphide Most widely used for Sulphur dyes

At least 12 g/l sodium sulphide is required to

dissolve the water-insoluble CI Sulphur dyes Sodium hydrogen sulphide is use 0.6 times of

sodium sulphide but necessary to add alkali (10

g sodium hydroxide or 5 g sodium carbonate per

7 g sodium hydrogen sulphide)


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Reducing agent : Sulphide

Environmental problems. Toxicity ofhydrogen sulphide. Odour threshold being 0.035 0.14 mg/m3

Unpleasant odours (pH < 9) Neutralisation or acidification can occurgaseous

hydrogen sulphide. Corrosion of the effluent drainage system.

Damage to the treatment works and the oftenassociated high pH.


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Reducing agent :Thiourea dioxide/

Formamidine sulphinic acid Powerful reducing agent for vat dyes.

Lower MW than sodium dithionite.

Lower sulphite and sulphate load. More stable than sodium dithionite.

Cause over-reduction of indanthrone vat dyes.

Glucose or sodium nitrite cant stabilise. Very good for reductive colorant stripping.


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Reducing agent :Thiourea dioxide/

Formamidine sulphinic acid Formamidine-sulphinate in alkaline media

is more readily oxidised than dithionite.

Low water solubility. Not suitable for continuous process.

Thiourea dioxide Sodium formamidinesulphinate Sodium hydrogen sulphoxylate


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Reducing agent : Sodium

formaldehyde-sulphoxylate Know as Rongalite C orFormulsol G

Produce from Sodium dithionite with

formaldehyde More stable than dithionite at lower

temperatures


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Reducing agent : Sodium

formaldehyde-sulphoxylate Can be used to prepare stable pad liquors

and print pastes.

At higher temperatures, they are capableofrapid reduction of vat dyes.

Used first in conventional steam fixation of

vat prints.


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Reducing agent :

Other sulphoxylates Sodium acetaldehyde is suitable for flash-ageing

process.

Zinc formaldehyde sulphoxylate :- Mono zinc : Water soluble

- Di zinc : Water insoluble

Calcium formaldehyde sulphoxylate is insolublein water which low tendency to haloing

Mono Zinc formaldehyde sulfoxylateSod. acetaldehyde sulfoxylate Calcium formaldehyde sulfoxylate


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Reducing agent : Hydroxyacetone

Sulphur-free and biodegradable

Used for vat, sulphur and indigo dyes with

high concentrations of NaOH Does not over-reduction of indanthrone.

Give different shades with carbazole dyes,

compared with sodium dithionite


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Reducing agent : Glucose

Characteristic odour preferable than odour ofalkaline sulphide bath.

High alkali concentration is required. Minimum dyeing temperature of 9095oC being

necessary. High COD level in the effluent. A lot of by-product ; losing its reducing action. Should mix with Hydros forhigher efficiency


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Reducing agent :

Dithionite/glucose system


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Reducing agent :

Dithionite/glucose system Potential slightly lower than that of dithionite

alone, although glucose has the lowest potential.

Without the risk of over-reduction. Optimal colour yield and good reproducibility

Other glucose binary systems, including

hydroxyacetone or sodium formaldehyde-

sulphoxylate as stabiliser gave similar results.


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Reducing agent : Others

2-Mercaptoethanol

Sodium hydrogen sulphite

Iron Triethanolamine complex

Iron Gluconic acid complex

etc.


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Reducing agent : Summary of advantages anddisadvantages of the three most important types reducing

agent for indigo, vat or sulphur dyeingSodium dithionite

Advantages

(1) Sufficient reduction potential for vat, sulphur or indigo dyeing(2) Good stability of leuco vat dyebaths

Disadvantages

(1) Waste water loading; inhibits biological degradation and leads

to a greater oxygen demand

(2) Can cause over-reduction at higher temperatures

(3) Special safe storage facility required


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agent for indigo, vat or sulphur dyeingSulphinic acid derivatives

Advantages

(1) Sufficient reduction potential for vat, sulphur or indigo dyeing.(2) Especially suitable for high-temperature dyeing methods.

(3) Good resistance to oxidation by air.

Disadvantages

(1)As fordithionite disadvantage (1)

(2) Potentially temperature-dependent.


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agent for indigo, vat or sulphur dyeingHydroxyacetone

Advantages

(1) Biologically degradable(2) Ease of dosing in liquid form

(3) Very good stability to storage

Disadvantages

(1) Does not reach full reduction potential and thus mainly

suitable for indigo and sulphur dyes

(2) Persistent odour

(3) Limited commercial production


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Oxidising agents : H2O2

Use forbleaching on Cotton and other CELs.

Can use as re-oxidising agent for vat dye and

sulphur dyes (easy but low washing fastness) Environmentally friendly (Very low AOX values)

Peroxide bath do not corrosive

Can be used both exhaustion and continuous

Give a good whiteness even without prior

scouring


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Fiberdamage (occur by free radical formation

especially in the present iron or copper)

Quality of whiteness (Less attractive tone) Cost-effectiveness (AOX-containing effuent are

omitted)

- 2 times of hypochlorite bleaching in batchwise process

- 6 times of hypochlorite bleaching in continuous process


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:Effect of pH in bleaching

Optimum


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Oxidising agents for bleaching :

H2O

2:Mechanism of bleaching and fibre damage


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:Effect of Fe(III) concentration on rate of decomposition

2.9 g/l H2O2, Sodium Silicate 5 g/l, Magnesium Sulphate 0.2 g/l 95o

C, pH 12 (Absence of substrate)


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Schematic diagram of catalytic

damage occurrence


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: Desizing of PVA


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Oxidising agent :

Sodium hypochlorite Most environmentally damaging of all bleaching agent

with regard to AOX values. May even be banned insome countries.

Bleached goods are prone to subsequent yellowing onstorage. Substrate must be scoured before bleaching. Stock solutions of sodium hypochlorite are unstable and

must always be chemically analysed before use. Hypochlorite bleaching can not combine with some

FWAs and dyestuff.


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Oxidising agent :

Sodium hypochlorite Economical attractiveness

Lower risk of catalytic fibre damage,

although some chemical damage canoccur depending on temperature and pH

Powerful bleaching action.

High attractive whiteness (Bluish white)


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Oxidising agent :

Sodium hypochloriteEffect of pH on the composition of sodium hypochlorite solutions


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Oxidising agent :

Sodium hypochloriteAfter bleaching with hypochlorite it is

always necessary to remove residual

chlorine present call Antichlor Bisulphite and hydrogen peroxide are

generally used for antichlor


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Oxidising agent : Sodium chlorite

Lower AOX values than hypochlorite. Generally carried out underacidic conditions. (different

from peroxide and hypochlorite)

Risk of chemical damage is low. Minimal scouring action in acidic bleach results in lower

weight losses hence good sewability Least sensitive to accelerated damage by metallic

contamination useful for synthetic fibres and particularly important foracrylic fibres.


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Toxic and unpleasant chlorine dioxide vapour

can be liberated.

Highly corrosive. No rapid chlorite bleaching process is available.

Bleached goods gave lower absorbency.

Some dyes and FBAs are destroyed by chlorite

bleaching


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:Effect of pH on the composition of sodium chlorite solutions


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Oxidising agent : Peracetic acid

Peracetic acids can be effective oxidative

bleaching agents and, at least potentially,

offer an alternative to the environmentallysensitive chlorine bleaches.


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Oxidising agent : Dichromate and

chromate salts.

Sodium and Potassium salts are generally used.

Use combine with acetic acid (pH 4.5-5.5) for re-

oxidising sulphur dyes Gave the harsher handle and less hydrophilic of

dyed fabric

Can not use in yarn dyes because its decrease

the winding property of yarn.


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Oxidising agent : Dichromate and

chromate salts.

Ifcombine with Coppersalt, Light fastness is

improved

Provide high washing and rubbing fastness. Environmental problem due to Cr3+

Low cost

Sometimes use as antireduction for disperse

dyes on T/C.


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Oxidising agent : Iodate salts

Potassium iodate is generally used.

For re-oxidise of sulphur dyes, no harsherhandle and

high rubbing fastness.

Use combine with Lactic or Acetic acid (pH 3.5-5)

Not Formic acid!!

Very high cost.

Maybe use as anti-reduction for disperse dyes on T/C.

O


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Oxidising agent :

Sodium m-nitrobenzene sulphonate

Use as anti-reduction for reactive, direct

and acid dyes.

Protect the reduction of azo group via heatorunfavorite condition.

Can re-oxidise Vat and Sulphur dyes.

NO2

SO3Na

2H

NH2

SO3Na


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28010401 textile auxiliaries non surfactant auxiliaries 01

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