September 2007

ITMA Munich 2007

Textile BusinessPM Pretreatment

Clariant Pretreatment

DesizingDesizingPretreatment Handbook

Pretreatment

Exactly your chemistry

2

DESIZING of fabrics of cellulosic fibres and their blends with synthetic fibres using the BACTOSOL enzymes and theHostapal wetting agents/detergents

Thanks to their complete range of chemical productsfor the textile industry and the synergism betweensizing products and the pretreatment of textiles, Clariant presents here a comprehensive survey of thetechniques for desizing fabrics with the most suitableproducts for total elimination of natural and syntheticsizes to the benefit of all who handle textiles.

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DefinitionDefinitionThe purpose of desizing is to eliminate sizing products in order to ensure the success of scour boiling and bleaching and theproduction of faultless dyeings. Before starting this process it is advisable to determine the type of the sizes so as to facilitate theirremoval. Clariant’s MINILAB can easily be made available for rapid identification of the sizing products such as starch and PVA (polyvinyl alcohol). For a precise qualitative and quantitative analysis, extraction in the Soxhlet together with infrared curves and chromatograms are required.

The Minilab from Clariant: this mobile laboratory is indispensable for monitoring the good quality of the pretreatment of textiles. It is possible not only to identifythe sizes on the goods but also to analyse the residues of alkali, acid, peroxide, iron, the pH of the fabric and many other parameters. It is accompanied by a comprehensive manual describing its use.

The preparation of threads for weavinginvolves covering the warp threads witha size with specific properties (seetable). A fibre is easier to weave if itspilosity is reduced: its resistance to rubbing is significantly improved. Sizingtherefore improves the weavability of warp threads by reducing thread-threadand thread-metal friction.

Back to sizingMain characteristics of sizesRequirements in sizing and subsequent process steps

The efficiency of a size is measured by the weaving yield. Clariant offers a complete range of sizes under the designations ARKOFIL, VINAROL and TYLOSE.

For high quality desizing it is essential to know the chemical and physical properties of the sizes in order to apply a process which will ensuretheir total elimination.

Sizing requirements:reduction of friction

good film formation

no skin formation

water solubility (cold or hot water, hard water)

non-foaming (in the bath or on rollers)

low costs

Needs of subsequent processes:high weaving efficiency

stability to electrolytes and alkalinesolutions

readily removable (desizing)

compatibility with other process steps(e.g. singeing / thermofixation)

ecological compatibility

identifiable on the fibre

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The chemical identity of sizesThe products for sizing are generally natural polymers (starch) as is or modified (CMS) as well as synthetic polymers and copolymers (PVA, PAC, PES, etc.). It goes without saying that the fabric can contain a single size or a mixture of different sizes depending on the type and structure of the textile substrate, alongside waxes, fats and lubricating paraffin.

Abbreviations of sizes:

CMS = CarboxyMethylStarchCMC = CarboxyMethylCellulosePVA = PolyVinylAlcoholPAC = PolyAcrylatePES = PolyEster

Polyvinyl alcohol: PVA - partially or totally hydrolized

Polymerisation of the vinyl monomer, through synthesis of polyvinyl acetate canproduce partially or totally hydrolized PVAs. PVA exists in two spatial forms: isotactic or syndiotactic conformations.

PVA is identifiable by its deep bluish violet colouration with the iodine reactant and the boric reactant. It is eliminable, after swelling, with theHostapal or Imerol surfactants. This synthetic size is highly sensitive to alkalis, electrolytes and above all to the heat treatment of singeing.

Starch: the two components of starch - amylopectin and amylose

• branched chains• -1,4-glycosidic linkages

-1,6-glycosidic branching points• 1,000 to 7,000 repeating units (or even more)

amylopectin • linear chain• -1,4-glycosidic linkage• 100 - 1,500 repeating units

amylose

The most widely used chemicalmodification is carboxymethylation to improve elimination of the starch(CMS)

Starch is a macromolecular polysaccharide which is identifiable by its bluish violet colouration withthe iodine reactant in the Minilab and is eliminable with alpha-amylase enzymes such as Bactosol MTN or HTN.

5

Other sizes: fatty substances and additives

To improve sliding of the fibres and reduce abrasion oils, fats and paraffins as well as otherproducts such as antistatic agents, fungicides, etc. are applied during sizing. These substances are generally hydrophobic and insoluble in water. They can be eliminated during desizing thanks to the emulsifying power of the Imerol or Hostapal surfactants.

Carboxymethylcellulose: CMC - a derivative of cellulose

• linear chain, no branching• -1,4-glycosidic linkage• 1,000 - 7,000 repeating units

Cellulose

To obtain CMC, a well swollen cellulose is alkalized and then etherified with sodium chloroacetate. CMCs are identifiable indirectly withuranyl nitrate or with acridine orange and eliminable either enzymatically with cellulases such as Bactosol CA or by hot washing in thepresence of Hostapal or Imerol surfactants.

Y = H, CH3

X = COOM, CN, OH, COMH2, COORM = H+, Na+, NH4

+, K+, Ca2+, Mg2+

Polyacrylates: PAC - a product of acrylic synthesis

There are several PACs prepared from acrylic acids, methacrylicacids or acrylic esters. The most commonly used acrylate salts are: ammonium, sodium, potassium and calcium. PACs are strongelectrolytes and are therefore readily soluble in a neutral or alkalinemedium. PACs are indirectly identifiable with ninhydrin and eliminable by washing in the presence of Hostapal or Imerolsurfactants.

Polyester: PES - synthesis by polycondensation

PES is obtained by the polycondensation of polyglycols with aliphatic or aromatic acidscontaining hydrophilic groups such as sulphate, phosphate, carboxylate, etc. Theirmain disadvantage is their sensitivity to alkalis and electrolytes. They are identifiable with Astrazon Red F-3BL and eliminable by the Imerol or Hostapalsurfactants as well as our Sirrix sequestrants.

6

Standard solutions:Solution 1.3 g iodine

+ 2.4 g potassium iodidein 1 l water

Solution 0.13 g iodine+ 2.6 g potassium iodide+ 4 g boric acidin 100 ml water

Solution 11.88 g potassiumdichromate in 50 ml water+ 25 ml sulphuric acid conc.

Solution 30 g sodium hydroxide in 70ml water

Solution uranyl nitrate 4%(aqueous solution)

Elimination - sensitivity of sizes

A desizing recipe can be optimized for a single knownsize (ideal case) or for a mixture of unknown sizes(frequent case). The golden rule in case of doubt as to the nature of the size is to adapt a desizing recipecapable of eliminating the most difficult size; if necessary, enzymatic desizing for bioconversion of theinsoluble starch into water-soluble glucose.

A systematic, progressive procedure makes it possible to identify starch, polyvinyl acetate, PVA and CMC sizes with 5 different reactants. The method is not direct and intermediate extractions are necessary.It goes without saying that in cases of doubt it is possible to use more sophisticated analytical methods such as extraction in the Soxhlet, infrared, chromatography, as wellas the information in the Minilab manual from Clariant.

enzymatic elimination sensitivity to pH-amylases cellulases

washing > 80°Calkaline acid

Starch – – – –

CMS – ( ) – –

CMC – – –

PVA – – –

PAC – – –

PES – – –

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Iodine test for starch - TEGEWA Violet Scale

Total Optimum desizing

Thanks to the blue scale it is easy to identify and quantify residues of starch on the fabric. The iodine reactant (Minilab) produces a more or lessintense bluish violet colouration depending on the residual quantity of starchy sizes. A quantitative approximation is associated: rating 9 represents a quantity of starch less than 0.04%, rating 1 more than 2.5% starch. Rating 5, less than 0.2%, is acceptable for dyeing. PVA can also be identified by a touch of boric acid in an iodine medium. Colouration is dark blue.

Caution - problems :

To ensure the success of all the operations following desizing such as bleaching, dyeing or printing, it is important that the material is completelyclear of sizes. The most significant results of poor desizing are lower degrees of whiteness, insufficient absorbency, spots, reserves, unlevelness, moiré of dyeings, too harsh handle leading to breaks. The origins can be classified in 2 groups:

Group 1; pretreatment probems: overdrying of sized warp threads, high content of waxes and lubricants which are difficult to emulsify, high content of sizes.

Group 2; process problems: poor wetting out and low pickup, too short swelling of the sizes, bath containing enzyme poisons, insufficient finalwashing.

Grey cottonDesized with

Bactosol MTN

Rating 1 Rating 9

2006Internal, Eric Argast, PG Pretreatment

Bactosol PHC liq. hc

2006Internal, Eric Argast, PG Pretreatment

The “Cross-Country” alpha-amylase

Thanks to its wide pH and temperature action range, the perfectly removes starch with each desizing process.

2006Internal, Eric Argast, PG Pretreatment

Bactosol PHCPad Batch Desizing

Recipe

Hostapal MRZ liq. conc Bactosol PHC liquid hc Sirrix ANTOX liq.

Bath pH Impregnation temperature

Batching time

4 ml/l 1-2 ml/l 2-3 ml/l

5-620-30°C (cold) or60-80°C (warm)

>4 h

Usually, the pad batch desizing is preceded with a singeing.

A very strong and efficient subsequent washing is needed in order to eliminate the degraded sizes.

2006Internal, Eric Argast, PG Pretreatment

Bactosol PHCInjecta desizing (Benninger)

Recipe

Hostapal MRZ liq. Sirrix ANTOX liq. Bactosol PHC liquid hc Bath pH Bath temperature

4 ml/l 1 ml/l 1 ml/l 5-680°C

washing

Injecta Impacta

steaming

impregnation

Injectadesizing

Cold Pad Batchbleaching

impregnationwashing

2006Internal, Eric Argast, PG Pretreatment

Bactosol PHCPad Steam desizing

Recipe

Hostapal MRZ liq. Bactosol PHC liquid hc Sirrix ANTOX liq.

Bath pH Bath temperature Steaming time Steaming temperature

4 ml/l 1 ml/l 2 ml/l

5-660-80°C1-3 min 100°C

Fast swelling of sizes with the high temperatureBioconversion of starch into water-soluble sugarsA strong final washing eliminates sugars from the fabric

impregnation

Grey fabricsteaming

singeing

Your umbrella against iron

Pinholes: consequence ofCatalytic damages

Result strongly positive: molecular and ionic iron are strongly present on the fabric

A short guide toSirrix ANTOX liq.

Anti-Oxycellulose agent which removes iron contamination and destroys natural pigments of cotton for a reliable and better bleaching without catalytical damage risk (pinholes).

Extraction and complexation of Iron, Calcium and Magnesium, destruction of pigments from the raw cotton during the enzymatic desizing and the bleaching processes.

Better protection against pinholesin desizing

Better whitenessin bleaching

Complexing Science

The fabric is soaked in the solution at room temperature, e.g. in a petri dish, for 10-15 minutes, rinsed with demineralized water and driedBlue staining on the fabric, according to the reaction below:3 K4[Fe(CN)6] + 4 FeCl3 = K4[Fe(CN)6] 3 + 12 KCl

(Prussian Blue)

Withoutprotection

Classicsequestrant

:1g potassium hexa-cyanoferrate (II) trihydrate = K4[Fe(CN)6], 3H2O to dissolve in 100 ml 1N HCl. Then add 50 ml ethanol absolute.

Complexing behaviour

0 g/l

2 g/l

Catalytic damages – Prevention

ANTOX ProcessWith Sirrix ANTOX

ANTOX-DesizingANTOX-ScouringANTOX-Bleaching

MechanismIron passivation /Complexation

Acidic processWith Sirrix NE / Sirrix ANTOX

Acid Demineralization- Pad Batch, 4 hours, 20-40°C- J- and U-Box, 5-20 min, 20-60°C- Shock, 1-2 min, 60-80°C

MechanismIron ionization / complexationFe + 3H+ Fe3+

Insoluble soluble

3-4 ml/kg Hostapal MRZ liq.1-2 ml/kg Bactosol PHC liq. hc1-4 ml/kg Sirrix ANTOX liq.

Few seconds at 70-80°C

2 ml/kg Hostapal MRZ liq.4 ml/kg Stabilizer FCB liq.

20 ml/kg NaOH 48°Bé30 ml/kg H2O2 50%

1-4 ml/kg Sirrix ANTOX liq.Steaming: 15 min at 100°C

1 ml/kg Sirrix NE liq.1 ml/kg Acetic Acid

0.5 ml/kg Bactosol SAP liq. conc.Washbox at 40°C

Application

ANTOX -MATRIX

0 2 4

0

2

4

ml/l

ml/l

Scour BoilingScour BoilingPretreatment Handbook

Exactly your chemistry

Pretreatment

2

DefinitionDefinitionAlkaline scour boiling is a cleaning process for cellulosic fibres using large quantities of caustic sodaat high temperature as well as special chemical products to remove the natural impurities in cottonand other cellulosic fibres, free them from troubling substances and make them absorbent. At thesame time vegetable contamination swells perfectly and is softened for rapid decoloration duringbleaching. Alkaline scour boiling is an intermediate process after enzymatic desizing and beforeperoxide bleaching.Even if the quantity of impurities is not so high it is essential to eliminate them because of theirnegative effect in subsequent finishing processes. Fats and waxes prevent penetration of the water-soluble dye and mineral substances can cause precipitation of the dye or during bleaching in thepresence of iron annoying catalytic damage. It is also essential to eliminate vegetable residues as well as the proteins and other substances present in the fibre.

The quality of scour boiling is measured above all by the absorbency; without absorbency there is no dyeing and no print.

Hydrophobic : property of a grey fabric to repel water because itcontains the natural cotton waxes and fats whichhave to be saponified.

Hydrophilic : property of a scour boiled fabric to absorb water. The caustic soda saponifies the hydrophobic fats to soap. The textile material can be dyed.

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fibressubstances

cotton linen hemp ramie jute

cellulose 82.7 62.4 67.0 68.8 64.4hemicellulose 5.0 17.2 16.1 13.1 12.0pectins 0.7 2.3 0.8 1.9 0.3lignins 0 2.5 3.3 0.6 11.8solublessubstances

1.0 3.9 2.1 5.3 1.2

fats 0.6 1.7 0.7 0.3 0.3

Percentage of Whole fibre Primary wallCellulose 88.0 – 96.0 52Pectin 0.7 – 1.2 12Waxes 0.4 – 1.0 7Proteins 1.1 – 1.9 12Minerals 0.7 – 1.6 3Other organic compounds 0.5 – 1.0 14

Mature cotton bloom

Composition of Composition of cottoncottonandand otherother cellulosic fibrescellulosic fibres

The tables below show the chemical composition of these natural fibres for better targeting of the substances and impurities to be removed.

Apart from cotton (Gossypium), the Liberian fibres suchas linen, hemp and ramie also require intensive scourboiling to achieve good absorbency.

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Mineral composition of cellulosic textile fibres

in ppm Ca Mg FeCotton Egypt 425 352 29Cotton Turkey 910 485 63Cotton China 514 502 68Cotton Pakistan 550 480 65Cotton India 625 580 55Cotton Brazil (GO) 1024 625 238Cotton Brazil (MS) 2425 1085 208Cotton USA 728 352 71Linen from Normandy 3412 328 92

Depending on the geographical origin of the cotton its mineral composition can vary considerably. The tables below show some values of residual ashof different cottons as well as the detailed composition of 2 cottons.

The residual ash content gives a good indication of the degree of mineralcontamination in the natural fibre and it is also interesting to know the ppmcontent of calcium, magnesium and iron (see table). The earth alkalis Ca and Mg cause problems in dyeing, while iron is extremely dangerous in bleaching. It goes without saying that good scour boiling drastically reducesthe amounts of these minerals.

The minerals

Ash content of different qualities of cotton

Analysis of two different qualities of cotton

Dharwar : 4.16 % Broach : 3.14 %Dhollerah : 6.22 % Domrawottee : 2.52 %Sea Islands : 1.25 % Egypt : 1.73 %Peru : 1.68 % Pernambuco : 1.60 %Bengal : 3.98 % USA : 1.52 %

Bombay Punjab% %

Ash content of the dry fibre: 3.99 1.85

Composition of the ash:SiO2 : 15.56 14.40Al2O3 : 10.80 12.87CaO : 9.75 10.65MgO : 1.87 4.36K2O : 27.32 26.03Na2O : 4.51 8.40Fe2O3 : 5.89 1.92SO3 : 1.96 2.52P2O5 : 3.26 4.46CO2 : 12.19 8.03Cl : 6.55 3.84others : 0.34 2.52

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- Wetting out

The wetting out properties are the ability to eliminate surface tensions veryrapidly enabling the water or aqueous solution to penetrate rapidly to theheart of the fibre. The wetting effect depends on the pH as well as thetemperature of the bath. It is measured in seconds with round swatches of grey cotton (hydrophobic) and a progressive concentration of wetting agent.

Below: Wetting test PM 7101.

- Stability to caustic soda and scope of application

0 - 2°Bé NaOH : surfactants for discontinuous processes or desizing; anionic or nonionic.

0 - 8°Bé NaOH : surfactants for continuous and discontinuousprocesses, desizing, scour boiling and bleaching; anionic or nonionic.

0 - 18°Bé NaOH : surfactants for concentrated scour boiling with all-inreinforcement bath; anionic.

18 - 32°Bé NaOH : surfactants for mercerizing and causticizing; anionic

Other properties of surfactants

1

10

100

1 102 4 8

Wetting time in seconds

Very goodwetting agent

badwetting agent

g/l product

6

Wetting test Tampex

low surfactant fair surfactant good surfactant Hostapal MRN

- Detergent power

The detergent power is the ability to remove a standard fattycontamination on an EMPA standardized reference woolfabric. The Wool washing test PM 7102 is carried out in a neutral and a weakly alkaline (carbonate) medium withprogressive concentrations of surfactant and with mechanicalaction.

The wetting power can also be demonstrated with theTampex test which shows the ability of the wetting agent (in a coloured solution) to penetrate a pile of round swatches of grey cotton in 60 seconds contact. The more swatches are wet out (coloured), the more efficient is the wetting agent.

low surfactant fair surfactant Hostapal MRN

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Example: Removal of mineral oil with Hostapal MRN liq. conc.

Oil/Waternot miscible

Oil/Wateremulsified

without withHumectol LYS

All types of mineral oils and other lubricating agents can be emulsifiedperfectly thanks to the surfactant qualities of Humectol LYS.This is particularly advantageous when scouring fabrics containingelastomeric fibres (Lycra, Dorlastan, etc.).

A good detergent also enables the removal of mineral oils, their emulsions as well as their oil/water dispersions. An example of contamination of a fabric by mineral weaving oils and their removal with Hostapal MRN liq. conc. is shownbelow.

8

- Absorbency

Absorbency is the most important parameter of the pretreatment of cellulosic fibres, without which it would beimpossible to dye or print.

The surfactant in combination with caustic soda makes it possible to obtaina certain absorbency which depends on several factors:

– the concentration of caustic soda– scour boiling temperature– scour boiling time– type of textile material

- Foam formation

One of the intrinsic properties of surfactants is the formation of foam in aqueous solution. Depending on the chemicalcomposition of the surfactant, its concentration, the pH and temperature of the bath, this foam can be more or lessabundant. As a rule this surface foam causes considerableproblems in textile applications, e.g. in jets or in impregnationbaths. The addition of an antifoam or deaerating agent avoidsthese problems. It goes without saying that the antifoam usedmust be free from silicone (risk of spots) or a rubber solvent(attack on the rollers).

It is necessary to distinguish between ”true absorbency", i.e. quantitative saponification of the hydrophobic waxes/fats and "pseudo-absorbency" when the surfactant remains on the surface of the fibres and provides false absorbency. This pseudo-absorbency can easily disappear in subsequent washing off in cold water of the nonionic residues or during subsequent mercerization. This pseudo-absorbency is extremely troublesome for fabrics which are to receive fluorocarbon or water-repellent finishes.The capillarity test or drop test are easy methods of visualizing good or poor absorbency.

severefoaming

weakfoaming

9

Capillarity test withSolar Turquoise Blue GLL-160%

on cotton yarn

on fabric

noabsorbency

goodabsorbency

very goodabsorbency

lowabsorbency

mediumabsorbency

goodabsorbency low

absorbencygood

absorbencyvery good

absorbency

>180 sec. 25 sec. 1 sec.4 18 46 mm

0 40 80 mmPenetrating drop test

10

1-hydroxyethane 1-1 diphosphonic acid(HEDP)

Hexamethylenediamine tetramethylphosphonic acid(HMDTMP)

Diethylene triaminepentamethyl phosphonicacid (DTPMP)

Ethylene diamine tetramethyl phosphonicacid (EDTMP)

Nitrilotrimethylenephosphonic acid (AMP)

Organic sequestrants

During alkaline scour boiling it is essential to remove the naturalminerals in the cotton at the same time as the waxes to ensure goodbleaching effects. The only way to remove these metallic salts and oxides is to use organic sequestrants. One speaks of complexing, sequestering, chelating or masking the metals.

- Chemistry of sequestrants

The oldest sequestrants used for processing textiles are EDTA, DTPA, gluconic and glucoheptonic acids. The new modern sequestrants are basedon methylene phosphonic (MP) acids such as EDTMP, DTPMP, HEDP, AMP, HMDTMP, which are more stable and more active in an alkaline and oxidizing medium.

11

The word "chelate" comes from the Greek "chele" which means a crab's claw. This describes a spatial structure composed of an organic or inorganic complexing agent and a metal ion imprisoned in this structure. All sequestrants and chelating agents are complexing agents. Sequestration is the ability to form a soluble metal complex. A chelating agent is a chemical entity able to inactivate a metal ion by complexing it and imprisoning it in a closed rigid structure. Ligands are the groups which ensure immediate surrounding of a cation.

The stability of a complex is defined by the pK value (cologarithmic value). If the pK is lower than 2 the complex is not stable. The higher the pK, the more stable the complex is. This is the way Sirrix DNA forms inactive, harmless complexes with the calcium, magnesium, iron and copper ions, thus avoiding all their problems.

n-m

mn-

n-mm-n

MLMLK

MLML

Example of pK Ca Mg Fe Cu

L = LigandM = Metallic cationK = dissociation constant of the

metal - Sirrix DNA complexpK = - log K

Gluconic acidGlucoheptonic acidDTPAEDTANTAATMPEDTMPDTPMPSTP

1.21.2

10.910.7

6.416.689.337.115.36

0.70.79.38.75.416.498.636.405.81

37.237.227.525.115.8726.919.6

––

3939

–18.712.71318.9519.47

8.70

DTPA = diethylene triamine pentacetic acidEDTA = ethylene diamine tetracetic acidNTA = nitrilo-triacetic acidATMP = amino-trimethylene phosphonic acidDTPMP = diethylene triamine penta (methylene phosphonic) acidEDTMP = ethylene diamine tetra (methylene phosphonic) acidSTP = sodium tripolyphosphate

- Dissociation constant (pK) of a complex

In order to obtain an idea of the profile of a sequestrant there are varioustests to show specific properties of these special chemicals.

Opposite the demineralizing action of Sirrix DNA during alkaline scourboiling.

Example: Scour boiling of cotton wool for pharmacopoeia.

Recipe :

40 g/l NaOH solid1 g/l Hostapal MRN liq. conc.2 g/l Sirrix DNA liq.

2 h at 130°C

Results :Mineral content beforeand after scour boiling

12

- Inhibiting effect on calcium

Test: Add a complexing agent to a bath containing 25°e calcium, 25°e magnesium, 20 g/lsodium carbonate, 20 g/l potassium sulphate, 20 g/l potassium chloride. Adjust the bath to pH 11 with NaOH and hold at the boil for 1 hour, then filter off hot. The tendency to form calcium and magnesium procipitates is very high in an alkaline medium at 100°C.

0 1 2 g/l sequestrant

- Antiprecipitant effect

The organic sequestrant can avoid any insoluble precipitation by chelating (masking) metallic cations.Avoiding the precipitation of copper hydroxide Cu(OH)2 when adding caustic soda to thecupric solution containing Sirrix DNA is illustrated here.

without sequestrant

with Sirrix DNA

Poor sequestration of calcium

Good sequestration of calcium with Sirrix DNA liq.

Test with black filter paper

13

- Inhibiting effect on iron

Test: Add a complexing agent to an alkaline bath at pH 11 containing 30 mg/l Fe III chloride and 5 g/l sodium carbonate and hold at the boil for 30 minutes, then filter off hot. The tendency to form insoluble hydroxide and iron carbonate precipitates is very high.

- Dispersing effect of sequestrants

Certain mineral substances and others in the fibre or the bath can disturb dyeing and precipitate dyes such as Indanthrene® Blue BC.

The illustration shows the dispersing power of complexing agents in a bath containing 0.1 g/l Indanthrene Blue BC, 10 g/l sodium hydrosulphite, 50 ml/l NaOH 38°Bé and 2 g/l sodium carbonate after 1 hour at 60°C. The filtration is shown to demonstrate the efficiency of the dispersing power of a sequestrant.

0 1 2 g/l sequestrant

Poor dispersing effect

Good dispersingeffect ofSirrix DNA liq.

0 1 2 g/l sequestrant

Poor sequestration of iron

Good sequestration of iron withSirrix DNA liq.

14

The threshold effect is defined as the ability to avoid a foreseeable insoluble precipitation by a substoichiometric addition of sequestrant. The precipitation-inhibiting effect is quantifiable by the molecular ratio betweenthe cation and the precipitating anion. For example, for a stoechiometricratio of 1:1 for CaCO3, Sirrix DNA makes it possible to avoid precipitation of carbonate even at a ratio of 1000:1. This property is fundamental for avoiding calcium deposits in steamers and keeping bleaching liquors stable. The mechanism is explained by the disturbance and slowing down of the crystal structuring.

- Threshold effect

- Demetallizing effect on a dye

Certain brilliant dyes (e.g. phthalocyanines) contain metals in their chemical composition. The metal is bound by semipolar bonds to theorganic molecule. The brilliance of the dye candisappear if a sequestrant complexes thebound metal. The shade can change completely by demetallization. Specialsequestrants are used in dyeing which do notchange the metallic constitution of the dye.

0 1 2 g/l sequestrant

Destructive effect on the dye

No effecton the dye

BleachingBleachingPretreatment Handbook

Pretreatment

Exactly your chemistry

2

DefinitionDefinitionThe last phase of purification of cotton, bleaching, is the most visible. After this treatment the natural yellowishand brownish pigments and the vegetable impurities in the cotton disappear. The bleaching reaction takes place as follows: a strong oxidizing agent, hydrogen peroxide, destroys the chromophoric groups of the natural dyes in the cotton. Decoloration takes place and the material looks whiter. This bleaching of cotton is made more difficultby the presence of seeds and vegetable residues which are darker in colouration than the cotton itself; intensive bleaching would still be necessary to eliminate these disturbing vegetable fragments. Compared to the otherbleaching agents used (sodium hypochlorite, sodium chlorite, sodium permanganate, etc.) hydrogen peroxide isthe most efficient and, at the same time, the one which pollutes the environment least.

MechanismsMechanisms1. The symmetrical molecule of hydrogen peroxide H-O-O-H is activated by the addition of caustic soda which causes heterolytic splitting with formation of the peroxo-anion -O2H responsible for bleaching :

H-O-O-H + -OH -O2H + H2O2. Hydrogen peroxide can be defined as a weak acid characterized by the dissociation constant Ka

H-O-O-H H+ + H-O-O-

Acid constant Ka = 2.5 . 10-12

The peroxo-anion formed can produce an oxidizing or reducing reaction depending on the medium.

3. Oxidizing reaction : H2O2 + -OH O2 + H2O + e- (E = -0.08 V)

4. Reducing reaction : H2O2 O2 + 2H+ + 2 e- (E = +0.7 V)

Hydrogen peroxide (H2O2) was discovered by Louis-Jacques Thénard in 1818. This symmetrical molecule is shaped like a dihedron with the base composed of two oxygen atoms O-O, to each end of which a hydrogen atom is attached at an angle of 96°. The intramolecular vibrations illustrated here correspond to the oscillations of the atoms around their point of equilibrium, similar to that of a mass hanging from a spring, which is the chemical bond.

This extremely reactive molecule produces carrier types of an unbound electron called free oxygen radicals (HO ; O2

-). This property is utilized for desinfecting purposes (against viruses, bacteria, fungi) as well as for bleaching hair or fibres such as cotton, linen, viscose, wool and silk.

3

The peroxo-anion formed can react in 3 possible ways during bleaching:- oxidation of the natural dyes in the cotton; the chromophoric group is oxidized and becomes colourless

- formation of molecular oxygen; this is a loss of oxidizing agent resulting in a reduction in the degree of whiteness obtained by the bleachingprocess

-O2H HO- + 1/2 O2

-O2HC C C C

HO OH(coloured) (colourless)

- oxidation of the cellulose, loss in the degree of polymerisation (DP). This oxidation is identifiable with the Fehling reagent. The alcohol function of the cellulose (-CH2OH) oxidizes into aldehyde (-CHO), acid (-COOH), monoketone (=CO), etc. and ends with rupture of the cellulosic cycle. Thedegradation is measurable by determining the initial DP (DPi) and the final DP (DPf) by viscometry. The degradation factor “S” (Eisenhut) shows the degree of degradation of the cellulosic chain.

120002000log2log

1

if DPDPS

Eisenhut factor S0.01 - 0.20.21 - 0.30.31 - 0.50.51 - 0.75> 0.75

target bleached cotton S<0.4

Commentvery good, undamagedgood, very carefully bleachedsatisfactoryslightly damagedbadly damaged

4

StabilizationStabilization ofof hydrogenhydrogen peroxideperoxideStabilizer SIFAStabilizer SIFA

The bleaching process is a complex reaction mechanism because hydrogen peroxide has to be activated and stabilized at the same time. Caustic soda activates H2O2 and favours the formation of hydroxo-peroxide ions. The stabilizer orients the peroxo-anions towards oxidationof the natural coloured pigments in the cotton and at the same time avoidsor limits side reactions such as the formation of molecular oxygen (loss of whiteness) or the oxidation of the cellulose (loss of DP). Stabilizer SIFA,a unique, totally organic macromolecule, achieves perfect stabilization of the hydrogen peroxide without any significative damage.

Hydrogen peroxide is a real danger for the textile substrate. If the oxidizingmolecule is wrongly oriented and inspite of the formation of an inoffensive molecule of water in the final phase, the textile substrate can sufferirreversible damage: loss of DP, no resistance to tearing, catalyticperforation due to heavy metals, rust spots, poor and heterogenic degreesof whiteness. A single molecule, Stabilizer SIFA is able to conquer theundesirable effects of H2O2 and ensure a superior quality of bleaching. Thefollowing shows the main properties of Stabilizer SIFA.

5

Perfect stabilization of H2O2Even in a strongly reinforced bath Stabilizer SIFA prevents premature uncontrolled decomposition of the hydrogen peroxide.

Higher and progressive degrees of whitenessMore than 95% of the peroxo-anions are directed towards oxidation of the pigments ensuring superoxidation of the natural dyes in the cotton.Extreme whiteness is the result. The higher the quantity of stabilizer, the more peroxo-anions there will be in the reaction medium and the higherwill be the whiteness.

Synergism with fluorescent brightenersDuring simultaneous bleaching and brightening, Stabilizer SIFA increases the absorption of UV radiation by the fibre leading to a synergism of whiteness unattainable by other stabilizers. High degrees of whiteness are ensured in this manner.

The temperature, a positive medium for Stabilizer SIFAThe whitening effect of Stabilizer SIFA is greatly increased if bleaching takes place at high temperature (90-100°C) with prolonged steaming. Themore extreme the bleaching conditions are, the more unique Stabilizer SIFA will be:

• Cold pad batch technique : low performance, identical to others• Pad steam, short steaming, 1-2 min : identical to other stabilizers• Combi-Steam, steaming for 7-12 min : distinctly better than others• Combi-Steam, J-Box, U-Box 20-40 min : unique and superior stabilizer

Replaces sodium silicate All the results show clearly that the mineral molecule of sodium silicate is inferior to the effects and advantages of Stabilizer SIFA. Furthermoredeposits and precipitations are completely avoided with Stabilizer SIFA.

Prevents catalytic damageThanks to its special macromolecular chain and its poles which attract the poisons, all harmful catalysts such as Fe, Cu and Mn cations are emprisonned and inactivated in the trap-like structure of Stabilizer SIFA. Bleaching can be carried out in complete security.

Action profile of Stabilizer SIFA

6

Stabilizer SIFA - Advantages

Increase in the degree of whitenessExample:Pad steam bleachMaterial:Co woven fabric, desized and scour boiledHot peroxide bleach

Peroxide bleaching liquor contains100 mg Fe III ions

Residual peroxide content in % after 6 h

Excellent anticatalytic action

Perfect stabilizing action in peroxide bleaching liquors

Test:Bleaching liquor reinforced 4 times

With-out

WithSIFA 7

Synergetic effect with fluorescent brighteners

Degree of whiteness without fluorescent brightener Degree of whiteness with fluorescent brightener

Conven-tionalstabi-lizer SIFA

Conven-tionalstabi-lizer SIFA

8

FightingFighting thethe catalystscatalysts

The presence of catalysts in the bleaching bath (metal particles or cations) leads to a rapid exothermic reaction and then a total degradation of the oxidizing agent. These elements are true bleaching poisons and can lead to the severest damage:• Formation of holes where metal particles are enclosed in the fabric.• Formation of oxycellulose combined with severe loss in DP value.• Loss in degree of whiteness due to the loss of hydrogen peroxide.

These catalysts can be sequestered and inactivated with Sirrix DNA in ion form. In metallic form, the metal must first be ionised by a treatment with Sirrix DNA in order to sequester it.Sirrix DNA exhibits an exceptional anti-catalytic behaviour.

This table clearly shows the elements which can cause catalyticdegradation of hydrogen peroxide.

In the texile industry the following metalcatalysts are the main ones encountered:• iron (most important damaging element)• copper (from viscose manufacture)• manganese (often together with iron)Only traces of other metals are found.

It is possible to check the presence of iron on textile fabrics with the Prussian Blue test.

9

Sirrix DNA against iron contaminationSirrix DNA against iron contaminationIn certain areas of the world, cotton contains large quantities of iron which cause considerable problems in hydrogen peroxide bleaching. The iron is very difficult to remove because it is chemically fixed to the fibre. Accidental iron contamination during weaving frequently occurs.To avoid perforation of the textile material by the iron catalyst, the fabric is pretreated with the protonic complex Sirrix DNA to provide maximum security in peroxide bleaching.

Test: Add Sirrix DNA to an alkaline bath at pH 11 containing 30 mg/l Fe III chlorideand 5 g/l sodium carbonate and hold at the boil for 30 minutes, then filter off hot. The tendency to form insoluble hydroxide and iron carbonate precipitates is very high. Sirrix DNA quantitatively complexes the iron ions in a hot alkaline medium. In this way the iron is sequestered and inactivated completely.

Prussian Blue testSolution: 1g potassium hexa-cyanoferrate (II) trihydrate = K4[Fe(CN)6], 3H2O

to dissolve in 100 ml 1N HCl. Then add 50 ml ethanol absolute.Method: The fabric is soaked in the solution at room temperature, e.g. in a

petri dish, for 10-15 minutes, rinsed with demineralized water anddried

Fe positive: Blue staining on the fabric, according to the reaction below:3 K4[Fe(CN)6] + 4 FeCl3 = K4[Fe(CN)6] 3 + 12 KCl

(Prussian Blue)

Identification of iron on the substrate

Without protection Classic sequestrant Sirrix DNA

Iron complexation

Without protection Classic sequestrant Sirrix DNAA free catalytic cation like Fe3+ in the bleach liquor causes exothermic decomposition which increases the temperature of the bath, forms considerable foam and finally precipitates insoluble ferric hydroxide. Sirrix DNA imprisons the destructive Fe3+

cation and inactivates it completely. The bleach liquor is stabilized and maintains its full activity.

If the bath is contaminated with iron ions (from the soda or the water) the decomposition reactions of H2O2 by the radicals is rapid and violent and all the peroxide can disappear within a short time (see graph). The strong anticatalytic effect of Sirrix DNA makes it possible to block, sequester and inactivate the destructive iron ions, thus ensuring a protected bleaching process.

Anticatalytic effect and bleaching assistant

10

An anticorrosive effect

A piece of bleached cotton jersey is rolled round an iron rod and then placed in a beaker containing water with or without sequestrant. The illustration shows the formation of ferric oxide (rust) after 48 h in contact with the water. Thanks to its anticorrosive action Sirrix DNA alone prevents any formation of rust on the fabric, thus avoiding later catalytic damage.

In the lab it is difficult to imitate catalytic damage because rust formation must occur before catalytic attack by iron. The formation of rust takes place according to the following formula:

Pad Batch demineralization

Material: Linen and cotton contamined with Fe, Cu, Zn and against Ca, Mg

Chemicals: 5-15 ml/l Sirrix DNA liquid3-6 ml/l Hostapal MRN liquid conc.

Procedure: - pad cold- batch 4-6 h at room temperature- scour thoroughly

Other sequestrant Without protectionSirrix DNA

The "iron rod" test

Formation of rust

Fe + 1/2 O2 FeO2Fe + 3/2 O2 Fe2O3

This corresponds to an iron pipe which begins to decompose after a few weeks in a damp atmosphere. The rust formation goes through the following phases: adsorption of oxygen from the air on the surface of the metal - migration of the iron atoms with oxide formation on the surfacewhich leads to holes in the crystal grating of the metal - migration of iron atoms from deeper layers - further rust formation on the surface. In this way the original compact crystalline structure gradually dissolves.

11

StabilizerStabilizer TrilogyTrilogy

The range of stabilizers for hydrogen peroxide consists of 3 basic products: Stabilizer SIFA, Stabilizer SOF and Stabilizer 2000. It goes without saying that all 3 stabilizers functionperfectly under all conditions and in all bleaching processes, however selection according to the criteria Efficiency, Economy and Ecology is preferable.

Bleaching processes:

• cold pad batch Stabilizer SOF• discontinuous Stabilizer SOF• immersion Stabilizer SOF• pad short steam, 1-2 min Stabilizer SOF• Combi-Steam, 5-20 min Stabilizer SIFA• U-Box, J-Box, L-Box, 20-90 min Stabilizer SIFA• pad roll Stabilizer SIFA• combined with brighteneres Stabilizer SIFA• ecological constraints Stabilizer 2000

Preferred application

12

28

18

74

7

79

60

5

14

34

0

10

20

30

40

50

60

70

80

90

0 1 2 3 4

Hostapal MRNHostapal MRZImerol PCJ

20

84

11

5454

6

44

24

0

10

20

30

40

50

60

70

80

90

0 1 2 3

10

4

Hostapal MRNHostapal MRZImerol PCJ

SurfactantSurfactant TrilogyTrilogyThe surfactants for bleaching must be good wettingagents so that the fabric picks up the maximum amount of chemical liquor as well as good detergentsin order to confer good absorbency to ensure perfectsubsequent dyeing. The basic range contains threesurfactants which are suitable for bleaching cellulosic fibres:

• Hostapal MRN liquid conc. : nonionic, stable to 9°Bé, biodegradable• Hostapal MRZ liquid : nonionic, stable to 9°Bé, biodegradable• Imerol PCJ : nonionic, stable to 9°Bé, biodegradable

Scope of application :

• cold pad batch bleaching• pad steam bleaching with separate

metering pumps• pad steam bleaching with maximum pickup

and separate metering pumps• discontinuous bleaching on the jet and

overflow with high turbulence

Hostapal MRN

Hostapal MRN or Hostapal MRZ

Hostapal MRZ

Imerol PCJ

Comparative properties of the 3 surfactants:neutral and alkaline wetting out with 2°Bé NaOH

neutral

alkaline

Wetting time in seconds

Surfactant (g/l) Surfactant (g/l)13

Penetration power(Tampex test)

Foam formation(Ross-Miles test)

Detergent power(EMPA test)

Imerol PCJ

HostapalMRZ

HostapalMRN

PCJMRZMRN

0.1 0.2 0.4 0.8 ml/l

PCJ

MRZ

MRN

14

Continuous bleaching processes:

There are different types of continuous bleaching ranges adapted to the textile article to be treated, the volume of production concerned, the desired effects, the available space, the possible treatment combinations and above all with the design and specific mechanical functions of each machine manufacturer.One of the most modern ranges is as follows:• singeing at the entrance to the machine• desizing• intermediate scouring• wet-on-wet impregnation with maximum pickup for bleaching• combi-steam steaming either under tension (1-2 min) or on a Roller-belt for a longer period• open-width washing at the exit of the steamer• drying on heated cylinders.

TheThe differentdifferent bleachingbleaching processesprocesses (1)(1)

15

— Singeing module: this must be adapted and synchronized with therest of the range; this demands high fabric speed to avoid burning— Desizing module: after rapid impregnation the fabric passes, in thecase of Benninger, into the Injecta module for rapid swelling of the PVA and other synthetic sizes as well as for rapid enzymatic bioconversion of the starch by Bactosol HTN.— Impregnation module: after brief intermediate scouring on theExtracta, the material is impregnated wet-on-wet with maximum pickupon the way to the Impacta module. The bath is fed by metering pumpsand a computer ensures the exact amounts (in ml/kg) of the chemicalproducts— Steaming module: in the Reacta compartment at 100°C, the hydrogenperoxide is activated by the caustic soda and stabilized by Stabilizer SIFA to remove natural pigments and bleach the cotton without degradingit. The Combi-Steam comprises a short passage under tension (1-2 min) followed by a passage on Roller-belt for a longer period (up to 60 min). The steaming conditions in saturated steam are constant to ensure a superior final quality of bleaching.

— Prescouring module: at the exit of the steamer this special Fortractamodule ensures rapid extraction of the degraded impurities carried by thefabric. The aim is to reduce the degree of contamination rapidly beforeproper scouring.— Scouring module: thanks to the specially designed passage of thefabric in the Extracta as well as the use of countercurrent and a reducedconsumption of water per kilo of fabric, it is possible to obtain a very highdegree of scouring while economizing in water and energy.— Drying module: the fabric passes over a battery of drying cylinderswhich ensure low residual humidity. Overdrying is not recommended as this can lead to yellowing of the fabric and a reduction in its absorbency.

Singeing Desizing Impre-gnation

Steaming Washing Drying

16

Classical wet-on-wet impregnationavoids intermediate drying and themajor risks involved such as lowerabsorbency, lower degree of whiteness and insolubility of residualcontamination.To ensure good uniformity of bleaching and good reproducibilitystrict control of the concentrations of the chemicals such as caustic soda, hydrogen peroxide and the otherchemicals is essential. With large volume impregnation troughs (500-2000 litres) it is not possible to maintain all the concentrations of theproducts constant in spite of intermediate titration without usinghighly concentrated reinforcing bathswhich are on the threshold of instability.

Thanks to the new wet-on-wet impregnationmodules with a maximum pickup of 150% and a bath volume reduced to 10-100 litres fed by separate metering pumps it is easier to achievehomogeneity and consistency of the quality of bleaching. This application by addition of the bath replaces the old technique of replacing the bath with its many variables and imprecision. Thereare other advantages of this technique such as titration not required, less risk of breaks and marking in the steamer thanks to the high pickup.

All the new continuous bleaching ranges todayare equipped with an impregnation module for maximum pickup with separate metering pumps; a monitoring computer allows adaptation withinseconds for each recipe and each fabric. Theproducts are metered in mg/kg fabric. Titration issuperfluous. This new technique has theadvantages of efficiency (no scour boilingrequired, one single stage), ecology (lesschemical load in the wastewater) and highreliability.

ContinuousContinuous bleachingbleaching withwith maximummaximum pickuppickup

17

Maximal add-on technique :

18

Maximal add-on modules :

Better impregnation with controlled liquor pick-up

BEN-IMPACTA(Benninger)

• Controlled liquor application• Penetration instead of addition• Exact quantity of chemicals on the fabric

Water within the fabricis replaced by chemicals

1. 2-roller nip; adjustable 0.3-3 kN2. Divider insert3. Circulation pump4. Horizontal liquor flow5. Vertical l iquor flow6. Chemical feed

1. Feed pump2. Flow meter3. Control valve4. Level measurement5. Speed measurement7. BEN-IMPACTA

Fabric entryPick-up: 500-600g water

Fabric exitPick-up: 900-1200g liquor withchemicals

Chemicals metering station

InputFabric weightRecipe

5 kN

19

Maximal add-on modules :

1 Fabric2 Replenishing liquor3 Flow / cleaning4 Addition liquor (10 l)5 Metal chassis6 Compressible pipe (air)7 Water-tight lip

1 Desized fabric, hot2 Rowatex rollers3 Liquor feed line4 Guided bath return5 Precise regulation of pick-up6 Liquor held in nip (8 l)

Flex-Nip(Küsters)

Optimax(Menzel)

20

three different methods for saturation of the fabricequal chemical distribution over the whole fabric width

through overflow cascadeequalizing roller to support even chemical pick-up

driven fabric transport roller to minimize tensionextremely low bath contentno filtration requiredno reinforcement up of the bath required

preselection of recipe on the PLCprocess controlled forced dosing of the chemicals promotional to fabric weight

automatic adjustment to speed and pick-up of the fabricautomatic supervision of chemical flow

Dosing system GOLLER-EXTRACTA

Dip-Sat Vario(Goller)

21

Steamers have different profiles depending on the quality of thematerial to be treated, the size of production, the length of steaming according to the chemical process applied, etc. On a modular basis these steamers can be combined à la carte according to the desired application.

To avoid breaks and irreversible folds duringsteaming the fabric enters the steamer in ropeform specially for sensitive articles. Theoptimum passage for each type of article isautomatically adjusted at the touch of a button.The rollers have a larger diameter to protectthe material better against folds. The rollers are very close in the Roller-Belt. The steamer is guaranteed without air with saturated steam.

The REACTA Combi-Steam:

Rapid steamer; 25-200 m capacity

Steamer with simple roller bed; 3-40 min dwell time

Combi-steamer with simple roller bed; 3-40 min dwell time

Combi-steamer with double roller bed; 5-50 min dwell time

22

Open width washers:

The purpose of washing is to eliminate the maximum of the impurities as quickly as possible with as little water as possible. Vertical passage of the fabric in the water can be single or double with or without a pressing roller. The length of the passage of the material in an open width washer can vary between 30 and 15 meters. At the exit of the washer a squeezing roller eliminates the majority of thewater. The addition of 3-4 Extracta washing compartments is enough to eliminate difficult substances such as caustic soda. Thewashing capacity of a washer can be measured by its suitability for eliminating caustic soda. Residual caustic soda is measured on thefabric but also in the washbath. In certain cases where treatment has been strongly alkaline it is advisable to apply a final neutralizationtreatment with Sirrix DNA.

DA-6Cwithout intermediate squeezing30 m capacity

DA-4with intermediate squeezing18 m capacity

EA-7Cwithout intermediate squeezing21 m capacity

EA-5with intermediate squeezing15 m capacity

E-5with intermediate squeezing15 m capacity

E-7Cwithout intermediate squeezing21 m capacity

D-4with intermediate squeezing18 m capacity

D-6Cwithout intermediate squeezing30 m capacity

23

Examples of continuous bleaching ranges

There are many combinations of steamers from a simple steamer for shock bleaching for one minute up to scour boiling/bleaching in a single stage for 60 minutes. The choice of machine depends on the specific conditions of the textile processor: the type of articles, production, available budget, destination of the fabric and the available space, etc. Complete ranges can easily exceed 100 meters in length.

24

Benninger ranges

Reagents/water fabric

steam

PREYET-module

Vacuum-moduleVacuum-moduleshort steamer washing

PREYET-modulewashing/

desizing

INJECTA IMPACTA

Steaming

Desizing Washing Impregnation Washing after steaming Neutralizing

25

Küsters rangesPretreatment Ranges with FLEXNIP-Application System

safer : higher liquor quantity and subsequent lowered chemical concentration

more protective : single-step process by dispensing a separate scouring stage and therefore less fibre damage

more stable : reinforcement factors :FLEXNIP 1:1,2 - 1:1,5vat 1:3 - 1:5

Single-step Bleaching range with Mäander-Washing Machines

more uniform : pure liquor addition without any liquor exchange and therefore constant chemical concentration

less pollution : less caustic soda use in contrast to a usual scouring step and far less residual draining liquor

more savings : less investment in machinery, lower energy consumption;

easy operation (omission of titration)

singeing

dry-vacuum(lint)

washing/desizing

EVAC-module

washing

Flexnip-impregnation

washing

Steamer

EVAC-module

26

Liquor temperature :

Combi-Steam

Chemicaltreatment

SUPER-SATImpregnating

Rinsing 60°C / 40°C

Neutralizingafter washing

Babcock range

Goller range

Washing

Bleaching

Washing after bleachingDIP-SATImpregnation 27

Goller range

Desizing Bleaching Washing after bleaching

Brugman range

Brubo-Sat Pretreatments :

Enzymatic desizing(washing range)2-4 ml/l Bactosol® HTN1-2 ml/l Hostapal® MRZtemp: 70-90°Ctime : 0,5-2 min

Protonic demineralization(washing range)2-4 ml/l Sirrix® DNA1-2 ml/l Plexophor® ECO1-2 ml/l Hostapal MRZtemp: 50-70°Ctime : 0,5-2 min

Usual Washes(washing range)1-2 ml/l Hostapal MRZ1-2 ml/l Plexophor ECOpH : 7-10temp: 70-90°Ctime : 0,5-2 min

Alkaline scouring(steam range)1-2 ml/l Hostapal MRZ4-8 ml/l Sirrix CRC20-60 g/l NaOH solidsteam: 1-20 min

Peroxide bleaching(steam range)6-8 ml/l Stabilizer SIFA1-2 ml/l Hostapal MRZ20-60 ml/l NaOH 50%20-60 ml/l H2O2 50%steam: 1-20 min

Final neutralization2-4 ml/l Sirrix NE1-3 ml/l Bactosol SAPtemp: 20-50°Ctime : few seconds

Brugman's solution to the state of the art processing technology is the Brubo-Sat concept, comprising of the chemical applicator, dosing system and steamer.

Brubo-Matic pre-wash units

Unipad Squeezing unit

Brubo-Sat max add-on system (120-150%)

Brubo-Sat steamer

Brubo-Matic washing units

Brubo-Sat :Single stage bleaching

DIP-SATImpregnation

28

MENZEL - single-step bleaching range with Optimax add-on system

1 Hot fabric2 High hydro extracting with Rowatex-Cylinders3 Liquor supply (preadjusted)4 Guide for surplus-liquor5 Exact and reproducible Pick-Up

by pressure-adjustment for maximal Add-On6 Liquor tank with minimal volume

• Higher operating reliability thanks to more stable, concentrated feed liquors; no titrating necessary.• Higher absorbency and maximum whiteness along with very minimal cellulosic fibredamage.• Expansion of article assortment through higher uniformity of the liquor application.• Less danger of crosswise creases in the steamer thanks to higher liquor application.• Less consumption of energy, water and chemicals and therefore lower costs.• Less processing time by elimination of the scour boiling step.• Minimal residual liquor amounts and therefore less waste-water and environmental pollution.

Bleaching at 150% with Clariant recipe :

Fabric : 100% CottonSteaming time : 20 min

Optimax-impregnation with :6 ml/l Hostapal MRZ liquid8 ml/l Stabilizer SIFA liquid2 ml/l Sirrix AK liquid40 ml/l NaOH 36°Bé40 ml/l H2O2 50%

OPTIMAX : A one-stage bleaching system with high liquor application

29

Bleaching ranges for cotton tubular knits

This Brückner range ensures demineralization of contaminated cottons at the entrance to the machine even beforebleaching. This treatment with Sirrix DNA for 15 min at 75°C drastically reduces the calcium, magnesium and particularly the iron content. The fabric is then scoured and impregnated for pad steam bleaching for 20 min at100°C. The range can be used for whites for subsequent dyeing in which case the residual peroxide must beremoved with Bactosol ARL during the washing/neutralization operation. The same range can be used for full whites in which case a fluorescent brightener such as Leucophor BMF is added to the bleaching liquor. At the end of the washing range a softener can be applied.

Impregnation Storage U-Box Rinsing Impregnation Steaming Rinsing 90/90/90/90/60/60/40 °C

Protonic treatment4-8 ml/l Sirrix DNA liq.3-4 ml/l Imerol PCJ liq.0.5 ml/l Hostapal NAN liq.15 min at 75°C

Peroxide bleaching4-8 ml/l Stabilizer SIFA liq.15-25 ml/l NaOH 36°Bé25-35 ml/l H2O2 50%6-8 ml/l Leucophor BMF liq.0.5 ml/l Hostapal NAN liq.Steaming: 20 min at 100°C

Neutralizing/Peroxide killer0.8% Sirrix NE liq.0.5% Bactosol ARL liq.Washbox No. 5 at 60°C

Softening at 40°C2% Ceralube SVN liq.

30

Bleaching ranges in rope form (MCS)

This range can be used for treating cotton knits in tubular form or open. The WR concept from MCS is modular. The machine can be constructed with 8, 12 or 16 tubes. The WR 12 tubes can be used for wetting out (the first 2 tubes), bleaching (the next 4 tubes), rinsing (4 tubes) and neutralization/softening (the last 2 tubes). For high whites or contaminated fabrics it is possible to prebleach with sodium hypochlorite or carry out demineralization with Sirrix DNA. The WR pretreatment system offers definite advantages with a simple production cycle.

31

Complete pretreatment with the WR system from MCS:

1 = Entrance to the machine

2 = Impregnation saturator- either for a hypochlorite bleach

2 g/l active chlorine4 ml/l Hostapal MRZ liquid

- or for demineralization with Sirrix DNA10 ml/l Sirrix DNA liquid4 ml/l Hostapal MRZ liquid

3 = J-Box, dwell cold for 10-15 minutes

4 = WR 4 tubes for scouring

5 = WR 12 tubes for pretreatment

tubes 1 to 2: wetting out with2 ml/l Hostapal MRZ liquid

tubes 3 to 6: peroxide bleach: 20 minutes at 90°C1 ml/l Hostapal MRZ liquid4 ml/l Stabilizer SOF liquid15 ml/l NaOH 36°Bé25 ml/l H2O2 35%

tubes 7 to 10: hot washing off

tubes 11 to 12: neutralization with1-3 ml/l Sirrix NE liquid1-3 ml/l Bactosol ARL liquid

or softening with Ceralube SVN liquid

32

Semi-continuous bleaching processes:

In the semi-continuous technique we differentiate between cold pad batch and hot pad roll processes. The difference betweenthese two processes is the temperature and the type of batching. In the pad batch process the rolled material is rotated atroom temperature carefully covered with plastic film to avoid drying. In the pad roll process the impregnated and paddedmaterial is rolled in a hot chamber (90-100°C) for 1-2 hours. The quality of rinsing/washing off after bleaching is decisive for high degrees of whiteness and good absorbency.

TheThe differentdifferent bleachingbleaching processesprocesses (2)(2)

Cold pad batch bleachingCold bleaching is often carried out in the textile industry because it offersthe following interesting advantages:

— simple, inexpensive installation — reduced consumption of energy, reaction at room temperature— direct application on grey fabric straight after singeing— adequate degree of whiteness and absorbency for various dyeing

processes.

The application itself is simple :

— singeing— cold impregnation— padding at 80-100% pickup— rolling on rollers, a plastic film protects against drying— batching at room temperature for 16-24 hours with

continuous rotation — intensive washing on an open-width washer.

Example of application :

— Cold impregnation, pickup ca.80%, batchingat room temperature for 16-24 h

— Intensive washing: 1st and 2nd bath with1 ml/l Hostapal MRN + 1 ml/l Sirrix AK at 95°C, then washing off and,if necessary, neutralization with Sirrix NE inthe final bath.

without persulphate with persulphate Example of a classical recipe without silicate / with silicate /

Hostapal MRN liquid conc. Stabilizer SOF liquid Sodium silicate 38°Bé Sirrix AK liquid NaOH 36°Bé H2O2 35% Sodium persulphate Sandozin NAN liquid

5 ml/l 7 ml/l

--

80 ml/l 70 ml/l

-1 ml/l

5 ml/l 5 ml/l

10 ml/l 3 ml/l

80 ml/l 70 ml/l

4 g/l 1 ml/l

grey fabric impregnation washingbatching

singeing

33

Product factor (ml/l)

degree of whiteness

absorbency DP values residual size content

Stabilizer SOF 3 6 9

Hostapal MRN liq. 2 4 8

Sodium Silicate 38°Bé 5 10 20

NaOH 36°Bé 40 80 120

H2O2 35% 20 50 100 Sodium Persulphate (g/l) 2 4 8

Batching (h) 12 24 48

Concentrations:weak-medium-strong Influence positive unchanged negative neutral

Influencing parameters: see table

The table shows the influence of each product in the recipe and the effect of varying itsconcentration, weak-medium-strong.

Stabilizer SOF : too low a concentration does not stabilize H2O2 sufficiently, too high a concentration blocks the bleaching reactionoptimum : 6 ml/l

Hostapal MRN conc. : the higher the concentration, the better will be the efficiency of extractionoptimum : 4 ml/l

Sodium silicate 38°Bé : without sodium silicate a lower degree of bleaching must be expected as well as visible vegetable residuesoptimum : 10 ml/l

Caustic soda 36°Bé : too low a concentration does not activate the H2O2 sufficiently and the degree of whiteness is lower; with too high aconcentration there is a risk of lowering the degree of polymerization (DP)optimum : 80 ml/l

Hydrogen peroxide 35% : above 80 ml/l the degree of whiteness does not increase significantlySodium persulphate : this oxidizer improves the desizing effect and the degree of whiteness

optimum : 4 g/l

The optimum batching time is ca. 24 hours. At the end of the reaction spotting with titanyl chloride must remain yellowish which indicates goodstabilization of the residual hydrogen peroxide.Hostapal NAN, a highly active deaerating agent, can be added if excessive foam is formed due to the high speed of the fabric from singeing to impregnation.

34

Recipes enzymatic shock desizing

cold pad batchbleaching

Hostapal MRZ liquid Plexophor ECO liquid Bactosol HTN liq. conc.Stabilizer SOF liquid NaOH 36°Bé H2O2 35%

Bath temperature Batching time

4 ml/l 1 ml/l 1 ml/l –––

80°C –

4 ml/l ––6 ml/l 60 ml/l 60 ml/l

20°C16-24 h

Cold pad batch bleaching with previous desizing on the same range

Module 1 : Injecta desizing and wet-on-wet impregnation for bleaching

Module 2 : Injecta desizing and Impacta for cold wet-on-wet bleaching

grey fabric impregnationwashing w/w-impregnation

for CPB bleaching batching

Injectadesizing

grey fabricimpregnation

washing batching

IMPACTACPB bleaching

INJECTAdesizing

Enzymatic shock desizing eliminates sizes which are sensitive to alkali (PVA) and makes it possible to greatly reduce the amounts of bleaching agents whichensures a higher final quality.

35

In the cold bleaching process rotation of the roll throughout batching is highly important. A certain amount of foam formation can be observed at theedges of the roll. This foam shows that activation of the hydrogen peroxide by the caustic soda is takingplace and that the bleaching process is progressing

Practical remarks

Pad Batch/Pad Steam combination:

53

Cold pad batch bleachingis often only the first stage because after the 24 h batching the prebleachedfabric can be given a pad steam scour boil ready for dyeing or given a Combi-Steam rebleach for highwhites.

as desired. If the foam disappears after only 2-3 hours, this indicates thatstabilization is not optimal and that the bleaching result will beunsatisfactory. In the ideal case, the controlled formation of foamremains until the end of batching. This, of course, only applies when no antifoams have been added. Whichever the case, the residual peroxideis determined at the end of batching by means of the titanyl chloride test. A positive result, yellowish colouration, shows that, thanks to the goodstabilization, the fabric still contains hydrogen peroxide which will bebeneficial during subsequent washing off.

36

TheThe differentdifferent bleachingbleaching processesprocesses (3)(3)

Discontinuous bleaching processes or treatment in a full bath:

Discontinuous bleaching means that a certain quantity of material is submitted to an oxidizing chemical processfor a certain length of time at a well defined liquor ratio (volume of water in relation to the weight of the material); long liquor ratio (20:1 - 50:1), short liquor ratio (2:1 - 6:1). As regards the transport or circulation, either thematerial moves (the bath stands still) or the bath circulates (the material stands still). As a rule, bleaching isfollowed immediately by dyeing on the same machine, after intermediate washing if necessary. The aim of discontinuous treatment is to pass through the pretreatment/bleaching phase as quickly as possible in order to free the machine for dyeing. One of the certain advantages is that batches of different weights can be treated on small, medium or large machines. A discontinuous machine offers considerable flexibility compared to a continuous machine.

The following machines can be used (see also diagrams and photos):

Jet/Overflow: short liquor ratio where the material circulates at high speed. The chemical products applied must not produce any foam at all otherwise transport of the material will be hindered.

Jig: short liquor ratio. The material is rolled up and then unrolled while passing through the chemical bath. In thisway it passes through the bath many times. Part of the material remains in the air (cooling). Today, the new jigsare equipped with vacuum or submerged suction to obtain better levelness of the effects. It goes without sayingthat this type of machine is not ideal for final washing.

Beam dyeing machine: here the material stands still and the bath circulates through the material from the insideto the outside. Perfect wetting out guarantees good levelness of the effects.

Package dyeing machine: the bath circulates from the inside to the outside of the bobbin as well as from theoutside to the inside. The alternation frequency is defined. Perfect wetting out guarantees good levelness of theeffects.

Winch: long liquor ratio (20:1 - 50:1). The material circulates slowly in this machine. Foam is not particularlydisturbing. In some cases the formation of foam makes it possible to use shorter liquor ratios (Sancowad process). 37

A versatile product

Sirrix 2UD liquid is distinguished by its very strong action over an extremely wide pH spectrum. The product exercises its high, characteristic action under strongly acid to highly alkaline conditions. These properties are reversible, making it a true product with variable geometry.

Imerol PCJ Liquid... removes contaminants from textile good - for good !

excellent scouring agent with rapid wetting action and high cleaning power

removes mineral oil contamination and sizing agents and imparts excellent cleanliness and good absorbency to the material

exhibits good compatibility with all enzymes

good pH stability and therefore a wide application spectrum, e.g. in scour boiling, bleaching, protonictreatments, biowashing, etc.

stable in liquors with up to 40 g/l caustic soda solid (ca. 6°Bé)

minimal foaming

ecological as it is free from APEO, nitrogen and phosphorus

Imerol PCJ liquid offers all the advantages of efficiency, economy and biodegradability.

Contaminants sent into orbite

Imerol PCJ... and offers these major advantages :

38

Stabilizer SOF liquid

A specific stabilizer for silicate-free, alkaline peroxide bleaching of cotton and its component in fibre blends.

Stabilizer SOF liquid with its excellent properties is suitable for use in the silicate-free, alkaline peroxide bleaching of cellulosic fibres and their blends. Stabilizer SOF liquid is distinguished by its exceptional efficacy at low application amounts.

sodium silicate is completely replaced

even with low amounts a high degree of whiteness can be achieved

complexes heavy metal ions and thus prevents catalytic damages

is stable to up to 70 g/l caustic soda (ca. 10°Bé)

is non-foaminguniversally applicable for

continuous and discontinuous processes as well as the cold pad batch process

is biodegradable

Stabilizer SOF liquid provides all the advantages for efficient, economic peroxide bleaching

0

20

40

60

80

100

0 20 40 60 80 100 120 140

20 min

10 min

10 min

Imerol* PCJ LiquidSirrix 2UD Liquid

Caustic soda

Stabilizer SOF Liquid

Hydrogen peroxide

1. Protonictreatment

2. Bleaching3. Rinsing

5. Dyeing

4. Enzymaticanti-peroxidetreatment

Bactosol ARL Liquid

Water consumption: 27 l/kg

min

°C100 kg cotton jersey, liquor ratio 9:1

The most important advantages are:

39

Humectol LYSElimination of oiling agents from textiles containing elastomeric fibres before or after thermofixation.

Properties of Humectol LYS :

Extraction of oils, anti-redeposition, avoids spots and stripiness, improves handle and lustre, reproducible results, ecological profile, suitable for all techniques.

Bactosol ARL

The different types of elastomeric fibres

simplecovering

tangledby Air Jet

corespun core-twisted

without withHumectol LYS

Oil/Waternot miscible

Oil/Wateremulsified

biopolish test:fibrils recovery after treatment

"Influence of pH" "Influence of Temperature"A new hybrid catalase enzyme specifically for removing hydrogen peroxide as water and oxygen with a wide scope of application: flexible pH (4-10), flexible temperature (20-60°C) and flexible application (discontinuous - continuous). This revolutionary treatment is ecofriendly because it avoids using reducing substances (sulfur) without affecting the fibre or dye. The advantage are: better leveling properties and no critical shade changes, rapid kinetics, shorter treatments time, minimal water consumption. Enzymatic treatment with Bactosol ARL unites advantages of economy, ecology, security and rapidity. a modern and innovative product for today's textile industry.

Bactosol CA

Bactosol CA is a biocatalyst based on a selection of enzymes with specific action on cellulosic substrates. Under the highly intense mechanical action in the Air Jet 2000 at very short liquor ratio this enzyme enables the elimination of disturbing surface fibrils on cotton knit goods, the production of peach-skin effects on Tencel as a better handle on cellulosic textiles without damaging the fibre in any way.

with Bactosol CA (pH 5, 60°C, 30 min)without enzyme

40

Différents Jets / Overflow

Example : SATURNO (Brazzoli)

Therefore, the processing of today's fashionable articles such as cotton/lycra and polyester/cotton are particularly suited for Saturno HF.The operating temperatures that can be reached with this sturdy pressure machine design is 140°C.The production of the Saturno HTF can be supplied in several versions from 1 to 6 channels, with a loading capacity of 150 Kg for 1-channel through 900 Kg for 6-channels.Each channel has it own independent internal reel, with a specified speed. Increased loading capacity can be achieved by coupling two machines of the same size.The Saturno HTF model is normally supplied with a filter and an additional tank, in the automatic version it can be integrated with dosing pumps, liter counter, seam detector, level and temperature controls, colour kitchen and controlled automatically by a microprocessor, to give constant high quality dyeing.In the Saturno HTF model, as in the other models, the overflow system can be integrated with a further "turbo" system jet. This increases the circulation speed of the material and increases the dye penetration, especially in close weave cloths.

Brazzoli S.p.A. has designed and manufactured the SaturnoHTF, a high temperature, pressure overflow dyeing machine for processing in the rope from, both woven and knitted fabrics composed of natural, synthetic and blended fibres.

The special section if the internal tank holding the fabrics allows forward feeding of the fabric with no problems or tangles. The pure Overflow Dyeing Principle allows the Saturno HTF to precess the fabric under conditions of no tension and no pilling in the fabric.

1 Overflow2 Turbo3 Turbo and overflow pump4 Overflow regulation valve5 Turbo regulation valve6 Reel with big diameter7 Basket8 Filter with high filtering

surface

41

Example : AirJet-2000 (LAIP)

Temperature : 140°CPressure : 3 barLiquor ratio : 2:1 - 3:1Maximum speed : 600 m/minMaximum capacity : 200 kg per tube - base 300 gr/mtlin

The AirJet 2000 is a machine for dyeing knitted and woven fabric in rope form at a very low liquor ratio. The babric is circulated by air from a special rectangular shaped thrust nozzle which facilitates fabric opening, thus avoiding twisting which leads to creases and crow's feet.A special non-motorized reel presents the fabric at the entrance of the nozzle wihout traction or tension on the fabric itself. This special reel avoids the abrasion and polishing problems generally due to the difference in speed between the reel and the fabric.A plaiter situated at the exit of the nozzle ensures perfect loading inside the holding chamber by eliminating any possible knots. An ideally situated system of sprinklers enables uniform dyeing of the fabric and perfect cleaning of the inside of the machine itself.The AirJet 2000 is the ideal machine for processing highly sensitive fabric where there is a danger of polishing, fibrillation and friction such as Lyocell+, Tencel+, Modal, Microfibres, Cupro, Polynosics and similar substrates.Special softwares enables programming of all the machine and dyeing cycle parameters.

42

Example : Rapid Suau-2000 FLB (ATYC)

Low liquor ratioBecause of its inclined storage chamber 2 and a rapid transfer of dye liquor back to the pump 4.

Trouble free operating conditionsThe design features of the machines allow fabric speeds up to 600 mts/min 3 and its unique Inteligent Regulation device 6(patentd) makes all machine settings totally automatic.

Following the history of new machinery developments, ATYCare once again on the forefront of the new technology in launching the F-FL series with Intelligent regulation and the following advantages.

VersatilityUsing the double Overflow/booster system 1 (patented), independantlyadjustable, giving the facility to process all kinds of fabrics.

Fabric relaxationThe storage chamber 2 islongitudinally inclined avoiding compacting of the fabric.

Rapid dye cycles and maximum loads also on lightweight fabricsDue to the double transport tubes 5,fabric speeds, up to 600 mts/min 3,8 liquor exchanges per minute 4and inclined storge chamber 2.

Simple operationLoading/unloading at floor level without using platforms and circulation of the fabric can be seen through the inspection window 7.

Long lifeThe machine is constructed entirely in stainless steel AISI-316.

Intelligent Regulation is patented by ATYC

Dyeing after bleaching

43

The most economical way to produce high quality whitesThe patented Scholl Bleachstar®

eliminates crease marks and gives consistently better shrinkage values than traditional, continuous bleaching systems. The Bleachstar® is not only a high quality batch bleaching system, but can also be used as a dyeing machine. With the use of the Scholl Counterflow Recycling System, bleaching costs can be reduced up to 40%. The newest advancement in the Bleachstar system is reuse of the bleach bath. Bleach batching liquor can now be reused up to 10 times with no loss in quality. Chemical costs are reduced up to 30%.

Example : Bleachstar (Scholl)

Functional diagram of the machine working with Overflowand Turbo principle simultaneously

Example : TurboFlow (Brazzoli)

Bleachstar®

A OverflowB TurboC Overflow pumpD Turbo pumpE Turbo regulation servodrived valveF Reel with big diameterG BasketH Filter with high filtering surfaceI By-pass valve

440

20

40

60

80

100

0 20 40 60 80 100 120 140 160

0

20

40

60

80

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0 20 40 60 80 100 120 140 160

0

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100

0 20 40 60 80 100 120 140

30

Standard scouring process

20

5

10

5

20

1.0 g/l Imerol PCJ Liquid2.0 g/l Sirrix 2UD Liquid

2 g/l Soda Ash

0.1-0.4 g/l Sirrix NE(pH 6.5-7)

Dyeing !

min

°C

min

°C

20

30

10

20

1.0 g/l Imerol PCJ Liquid2.0 g/l Sirrix 2UD Liquid

1.2 g/l NaOH Flakes

2.0 ml/l Hydrogen Peroxide 50%

0.15 g/l BactosolARL conc.

Dyeing !0.1-0.4 g/l Sirrix NE(pH 6.5-7)

One bath-two stage peroxide bleaching process(for normal soiled goods)

30

20

10

20

min

°C

5 5

0.75 g/l Imerol PCJ Liq.2.0 g/l Sirrix DNA Liquid

0.5 ml/l Imerol PCJ Liquid0.5 ml/l Stabilizer SOF Liquid2.0 ml/l Hydrogen Peroxide 50%

1.2 g/l NaOH Flakes

0.15 g/l BactosolARL conc.

0.1-0.4 g/l Sirrix NE(pH 6.5-7)

Dyeing !Two bath peroxidebleaching process(for heavily soiled goods)

45

0

20

40

60

80

100

0 15 30 45 60 75 90 105

This HS process for ultra-rapid pretreatment/bleaching and dyeing includes protonic demineralization with Sirrix 2UD, biopolishing of the fabric with Bactosol CA, elimination of residual hydrogen peroxide with Bactosol ARL which enables problem-free dyeing with the new class of reactive dyes, Drimarene HF dyes. The advantages are: rapid process, savings of water and energy, high degree of safety and total reproducibility of the shades.

Two bath bleaching/brightening process for maximum degree of whiteness

High Speed (HS)-Process; Mega-Combi

0

20

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0 20 40 60 80 100 120 140 160 180 200

Imerol PCJSirrix 2UD

min

°C

45

20

10

20

0.75 g/l Imerol PCJ2.0 g/l Sirrix DNA Liquid(5 g/l Arostit BLN gran)

min

°C

10 5

Soda ashPeroxide

OverflowpH 5 with Sirrix 2UD

Bactosol CABactosol ARL Drimaren HF

Alkali

Salt Ladiquest 1097

Dosing Migration

0.5 ml/l Imerol PCJ Liquid5.0 ml/l Hydrogen Peroxide 50%0.6% Leucophor BSB

1.2 g/l NOH Flakes0.5 ml/l Stabilizer SOF

0.1-0.4 ml/l Sirrix NE(pH 6.5-7)

2-3% Destofil LCor Ceralube JW

46

Different package machines

Example: Beam dyeing machine (ICBT)

A wide range of beam dyeing machines makes it possible to select the machine suitable for the required production.Width from 800 to 4200 mm.Single or double width.Capacity from 25 to 1200 kg.In beam dyeing machines the bath is circulated through a perforated beam around which is rolled the fabric to be dyed. These machines can be used up to 145°C.

Example: Package dyeing machine (ICBT)

Pretreatment/bleaching of cross-woundpackages, complete cycle:bobbins of cotton

Demineralization with Sirrix DNA2 ml/l Sirrix DNA liq.3 ml/l Hostapal MRZ liq.20 min at 70°C

rinse, thenAlkaline scour boiling

20 ml/l NaOH 36°Bé1 ml/l Hostapal MRZ liq.1 ml/l Sirrix DNA liq.

40 min at 110°Crinse, then

Peroxide bleaching6 ml/l H2O2 35%3 ml/l NaOH 36°Bé1 ml/l Stabilizer SOF liq.1 ml/l Hostapal MRZ liq.

40 min at 110°C,rinse, then antiperoxide treatmentwith Bactosol ARL 47

Different jigsExample: Turbo-Jigg (TVE-ESCALE) with submerged suction

Traditionally, jigs base their working system on passing the fabric through a chemical bath. Turbo-Jigg® uses a new concept that passes the liquid through the fabric. Better penetration of the fabric fibers results in a higher quality product and reduces the number of cycles required to finish the impregnation and rolling-up process.

Example: Vacu-Jigger (Henriksen)Pretreatment/bleaching on the jig, complete cycle:grey cotton fabric

Enzymatic desizing3 ml/l Bactosol MTN liq.3 ml/l Hostapal MRZ liq.

pH 6 with Sirrix 2UD4-6 passages at 65°Crinse, then

Alkaline scour boiling15-30 ml/l NaOH 36°Bé

2 ml/l Hostapal MRZ liq.1 ml/l Sirrix DNA liq.

4-6 passages at 90-95°Crinse, then

Peroxide bleaching8-15 ml/l H2O2 35%4-8 ml/l NaOH 36°Bé

1 ml/l Stabilizer SOF liq.1 ml/l Hostapal MRZ liq.

4-6 passages at 90-95°Crinse then antiperoxide treatmentwith Bactosol ARL

The fabric speed is adjusted in order to obtain a uniform centrifugal acceleration during the treatment period. This constant centrifugal acceleration allows uniform bath transfer onto the fabric.

Vacuum suction and elimination of the

contaminated waterRinsing rampSpraying with water

The Turbo-Jigg® model uses two suction tubes submerged in the washing drum. They are connected to a group of filters and an innovative suction pump which passes the bath through the fabric during theimpregnation process.

48

Twin Jig (Küsters)

Processing Centre for Pretreatment, Dyeing and Special Treatments

The jigger is one of the oldest and most universal machines in textile finishing. Although attempts are constantly being made to improve the machine, the principle of operation has remained unchanged for many years. The persistent tendency towards small lots and the specific qualities of certain fabrics have led to comeback of the Jigger.Küsters set out to develop a Jigger concept which would meet all demands of modern production as regards reproducibility, profitableness and environmental compatibility.

49

Bleaching/optical brightening of 100% cotton knit goods on the winch:

Protonic treatment2 ml/l Hostapal MRZ liq.1 ml/l Sirrix DNA liq.

15 min at 60°Crinse, then

Bleaching/optical brightening6 ml/l H2O2 35%3 ml/l NaOH 36°Bé1 ml/l Hostapal MRZ liq.0.5 ml/l Stabilizer SOF liq.0.8% Leucophor BSB liq.

50 min at 90°Crinse, soften

Winch

WinchHaspelflow B (Brückner)

MercerizingMercerizingPretreatment Handbook

Exactly your chemistry

Pretreatment

untreated treated

2

DefinitionDefinitionMercerization is a strongly alkaline process with irreversible alteration of the physical characteristicsand appearance of cellulosic fibres by swelling. During mercerization or causticizing the cotton fabric, knit or thread is submitted to a treatment with concentrated caustic soda between 18 and 32°Bé NaOH.The interaction between the caustic soda and cellulose creates a series of physico-chemicalmodifications to the cellulosic fibre and modifies its properties entirely.The main modifications are:– destruction of the cuticle– the microscopic cross-section shows swelling of the cellulose– the lumen disappears– the fibres twist into spiral coils– the fibres are shortened by 20-25%– the macromolecular structure of the cellulose is modified– the crystalline zones of the cellulose are oriented along the axis of the fibre

Depending on the concentration of the alkali we differentiate an additive reaction (formula 1) and a substitutive reaction (formula 2)with formation of sodium cellulosate.

– increase of the internal surface of the fibre– increase in the reactivity of the cellulose– better suitability for finishing treatments– better resistance to chemical products, microorganisms, sunlight, etc.– significant increase in dyeing affinity by up to 25%– better tensile strength– better dimensional stability

MechanismsMechanisms

(1) CEL-OH + NaOH CEL-OH , NaOH addition

(2) CEL-OH + NaOH CEL-ONa + H2O substitution

During caustizing the two formulae coexist :

(3) CEL-OH , NaOH CEL-ONa + H2O

The baryta index indicates the degree of mercerization. This index expresses the ratio between the absorption of Ba(OH)2 (barium or baryta hydroxide) by a mercerized cotton and that absorbed by an unmercerized cotton. The index of a mercerized cotton sample canvary from 115 to 165 depending on the degree of mercerization. A baryta index above 150 indicates that mercerization is complete.

3

Example of titration of Ba(OH)2 and determination of the baryta index:

– 10 ml Ba(OH)2 solution, reference solution requires 24.3 ml HCl 0.1 N for neutralisation– 10 ml Ba(OH)2 solution, an unknown sample requires 19.58 ml HCl 0.1 N– 10 ml Ba(OH)2 solution, a standard unmercerized cotton requires 21.20 ml HCl 0.1 N

The baryta index is calculated for the unknown sample as follows :

15210020.2130.2458.1930.24 it is essential to repeat the measurements 3

times to obtain a mean baryta index

4

AdvantagesAdvantages ofof mercerizingmercerizing• Dyeing affinity

• Brilliant colours

• Tinctorial strength

• More homogeneoustone-in-tone shades

• Dimensional stability

• Dynamometric resistance

• Tensile strength

• Suitability for finishing

• Brilliance

• Handle

• Coverage of dead/immature cotton

• Regular geometry of thestructure

Mercerization

Dyeing /Printing

Finishing

Appearance

Example :

Dyeing affinity

5

Influencing parameters

Influencing parameters are:

— The origin of the cotton. Depending on the origin of the cotton the mercerizingeffects may be more or less pronounced.

— The concentration of caustic soda or alkali. The best effects are obtained witha caustic soda concentration of 28 to 32°Bé or 270 to 330 g/l NaOH solid.

— The temperature. The lower the temperature, the greater the brilliancebecause maximum swelling of the cellulose takes place between 12 and 15°C. A cooling system is adapted to keep the alkaline bath at a low temperature. Modernmachines are equipped with impregnation between 50 and 60°C. The cellulose swells more rapidly than at 15°C and the dyeing affinity is at a maximum. On theold machines for cold mercerization (15°C) the fabric speed was 20-30 m/min compared to 100 m/min on the new hot mercerizing machines.

— The time. Complete swelling of the cellulose takes place in 30-60 s with NaOH. With liquid ammonia the time is reduced to between 15 and 20 s. On principle, themore rapidly the cellulose is impregnated with lye, the more rapid will be theswelling, which is the reason for adding a mercerizing wetting agent such as MERCEROL QW-LF. The relationship between time and temperature is decisivefor swelling.

— The tension over the width and length of the fabric. Stabilization is essential to obtain the maximum effect and rinsing must be carried out under tension. In thisway the reorientation of the molecular chains makes it possible to obtain maximum dimensional stability and brilliance.

Example :

• better dimensional stability• better stability to washing• better appearance

6

Comparison of the effects with cold and hot mercerizing

Mercerizing can be carried out at various points during the pretreatment cycle of the cotton fabric:

— On grey material. The only advantage is that the fabric is dry on entering the lye which avoids the variations in concentration of the wet-on-wettechnique. On the other hand the disadvantages are considerable: contamination of the lye by the desizing agents, singeing dust, natural impurities in thecotton, etc. This lye is no longer suitable for recycling. Danger in the case of sizing with PVA. Cotton knit goods and yarn can be mercerized in the greystate.— On desized material. The situation is better than on grey fabric as far as contamination of the lye is concerned. It is essential that all sizes, particularlyPVA sizes, are removed. In time this lye is also contaminated by the natural impurities in the cotton.— On scour boiled material. This is a suitable point for mercerizing. It is necessary to rinse the fabric well to eliminate the alkali so as to avoiddifferences in the NaOH concentration during mercerizing. By mercerizing scour boiled cotton it is possible to avoid the problems of mercerizing bleachedfabric such as loss of the degree of whiteness and reduction of absorbency.— On bleached material. Today this is the best point for mercerizing cotton fabrics. The dyeing affinity and brilliance will be at a maximum. The lye willbe very clean for problem-free recycling. Mercerizing bleached goods allows better coverage of breaks, folds and physical faults caused by passage on the Roller-Belt during pad steam peroxide bleaching.— On dyed material. The purpose is to increase the tensile strength of the fabric and make it more suitable for finishing processes including syntheticresin finishing. It is obvious that the dye must be stable to concentrated caustic soda.

When to mercerize ?

Effects Mercerizing cold hot

DP grey fabricbleached fabric

idemidem

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Tensile strength grey fabricbleached fabric

idemidem

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Dyeing affinity grey fabricbleached fabric

<>

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Brilliance grey fabricbleached fabric

<<

>>

Dimensionalstability

grey fabricbleached fabric

<<

>>

Handle grey fabricbleached fabric

>idem

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Suitability forresin finishing

grey fabricbleached fabric

<idem

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7

MERCEROL QWMERCEROL QW--LF:LF:thethe mercerizingmercerizing wettingwetting agentagent

The role of the wetting agent is extremely important during mercerizing in a strongly alkaline medium. It increases the speed of penetration of the lye intothe deep layers of the textile substrate to allow rapid swelling of the cellulose.Without the wetting agent mercerization is only superficial and peripheral (researched for fabrics intended for washed out fabrics and denim).

The performance of the wetting agent is judged by:

– the wetting power between 18 and 32°Bé NaOH– the shrinking effect of the fibre between 18 and 32°Bé NaHO– the foaming behaviour between 18 and 32°Bé NaHO– the biodegradability– the ecological profile: absence of solvent, cresol and other toxic substances

Thanks to its good solubility, its strong anionic character and its wide region of activity between 18 and 32°Bé NaOH, Mercerol QW-LF is suitable for mercerizing because of the following properties

– increases the brilliance– confers a supple, full handle– causes high initial and final shrinkage– ensures a regular appearance of the material– promotes absorption of dye– guarantees impeccable results both on high twist yarns and tightly woven fabrics thanks to

the penetrated wetting out of the material.

8

Shrinking burette 50 ml / Test

Shrinkage action

Shrinking burette with a cooling jacket and rotating thermostat.Steel weight with hole, =8 mm, l=30 mm, weight approx. 11gStop-watch

shrinkage % 10

2 mm in shrinking

These values should be entered for each concentration as a function of time. From the shrinkage curve thus obtained a strength relation is deducted after :• 15 seconds (initial shrinkage)• 90 seconds (final shrinkage).

Apparatus :

Material :Concentration of lye :

Additives :

Temperature :

Procedure :

Evaluation :

into a percentage of the total length of yarn eight

Grey cotton mixed shock-stable yarn, ungassed

26 and 30°Bé

3 - 5 - 7 g/l wetting agent. These amounts should be varied according to the efficiency of the product.

18°C

The test solutions should be poured into the burette and the thermostat set for 5 minutes. Should any error occur in the volume, this should be corrected by filling up to a mark corresponding to a depth of immersion of 50 cm. Then a sample of yarn approximately 120 cm long should be threaded into the steel weight and both ends of the yarn fixed with a clip in such a way that the lower end of the steel weight stands at 0 on the mm-division of the shrinking scale. Then the steel weight is allowed to fall into the lye and the stop-watch immediately set working. The shrinking values in mmshould be read after 5 - 10 - 15 - 30 - 45 - 60 - 90 seconds.The shrinking values read in mm should be converted into a percentage of the total length of yarn by the following formula :

9

Shrinkage test

Neither of the two methods for testing wetting effect described in TM 7101 can be used in the case of mercerizing wetting agents, since the viscosity of the solution makes the immersion of the fabrics impossible. Testing in this case is by the laying on method.

Raw cotton fabric according to DIN 53 901. As described in TM 7101, circular discs of 3.5 mm diameter to correspond to an area of approximately 10 cm2 should be cut from this fabric.

The solutions used to measure shrinking effect should be poured into a Petri dish. The testing of wetting effect should follow immediately by laying on the fabric-discs. The time that elapses until the liquid level has closed over the fabric should be measured.

The wetting times determined in seconds should be entered on log/log paper, as described in TM 7101. Strength evaluation should be carried out for an average wetting time of 15 seconds.

Material :

Procedure :

Evaluation :

Wetting test

— Mercerol QW-LF— Competitor 1— Competitor 2

shrinkage in sec. (for 50% shrink) at 26°Bé NaOH shrinkage in sec. (for 50% shrink) at 30°Bé NaOH

wetting time in sec. at 26°Bé NaOH

wetting time in sec. at 30°Bé NaOH

10

Foaming behaviour

Testing should be in accordance with TM 7105 in comparison with the products mentioned there, the foaming behaviour of which should be taken as a reference point.Concentration of lye : 26 and 30°Bé NaOHConcentration of surfactant : 5 g/lTest temperature : 18°CFoaming behaviour and foam stability should be written down in the test report :Product does not foam

foams a littlefoams moderatelyfoams stronglyfoams very strongly

Foam persistsslowly subsidesquickly subsides

Gas washing bottle with integrated filter plateVolume: 500 ml

Overflow

Foam

Liquor

Filter plate

foam in cm at 26°Bé NaOH

foam in cm at 30°Bé NaOH

MERCEROL QW-LF Competitor 1 Competitor 2

MERCEROL QW-LF Competitor 1 Competitor 2

11

Impregnation Reaction Stabilization

Stabilization

Neutralization and washing

Neutralization and washing

Chainless principleChainless principle Chain principle

Double Impregnation

The first mercerizing trials were carried out in 1850 by John Mercer whohad noticed the change in chemical properties of cotton submitted to highconcentrations of caustic soda of about 300 g/l NaOH solid; in particular, swelling of the cellulose, considerable shrinking of the textile substrateand the release of heat as well as better dyeing affinity, better dimensionalstability and greater brilliance.

Machines and Machines and mercerizingmercerizing technologytechnologyThe profile of a mercerizing machine is directly connected to the form of the substrate, i.e. woven, knit (tubular or knit) or yarn. The machine is builtfor true mercerizing with 250-350 g/l NaOH solid for better brilliance and dimensional stability or for simple improvement of dyeing affinity withconcentrations of 170-200 g/l NaOH solid by causticizing.

Profile of a mercerizing machine for woven fabric; type DIMENSA (Benninger)The classical functional parts and zones of a mercerizing machine for woven fabric are:— the impregnation zone with concentrated lye for wet-on-wet or wet-on-dry application— the reaction zone where swelling of the cellulose starts— the stabilization zone under tension where the lye is diluted by countercurrent from 28°Bé to 8°Bé— the washing zone and the neutralization zone.

Installation for light woven fabrics which are easy to impregnate

12

Step 1 : Intensive impregnation in hot lye

A small controllable liquor content is used in the intensive impregnation compartment. The process lye is continually circulated and the temperature and concentration monitored. The automatic lye control permits the addition of fresh lye, water or recovered lye of 20 to 40°Bé from recycling.Reaction heat is emitted when mixing the process lye. In hot mercerizing this is utilized, while in cold mercerizing it causes an energy consuming lye cooling process. If difficult blended fabrics are to be mercerized, in which the fibres could be damaged with a longer time at high temperatures, for instance with a PES percentage ofover 50%, cooling rolls can be mounted at the infeed to the reaction zone in order to cool the fabric immediately after impregnation.Squeezing to a lower lye content is possible with hot mercerizing. The lower lye consumption provides savings in water and steam atlye extraction.

BEN-Dimensa advantages :four tuned steps guarantee optimum results

The versatility of the BEN-DIMENSA permits every textile result concerning the mercerizing effect. This is achieved by objectiveselection of the process parameters such as :— Lye temperature— Lye concentration— Lye reaction time— Fabric lengthwise and crosswise tension

The thus optimized process provides the best mercerizing effect with savings in lye, water and steam. In comparison with other mercerizing ranges the small lye volume permits very fast changes in concentration and, therefore, short production interruptions. And no lye losses occur at changes. Changeover to a lower lye concentration for caustification processes therefore does not result in big losses.

Savings of lye, washing water and steam are money for your account.

1. Feed of fresh lye in any concentration (raw lye, lye from the condensation unit)2. Feed of diluent (water, weak lye in any concentration)3. Process lye4. Control for lye concentration5. Control for lye amount6. Control for lye temperature

A ProcessorB ImpregnationC Stock tankD HeatingE Measuring vessel concentrationF Temperature feelerG Level measuring sonde

Automatic strong lye control

13

Step 2 : The reaction takes place during the dwell time

Instead of 45-50 seconds as with cold mercerizing, the same effect can be obtained in only 25-30 seconds with hot mercerizing. In order to keep width contraction as low as possible, the fabric is kept under constant tension during the reaction phase.

No selvedge to middle differences occur with the BEN-DIMENSA

The reaction takes place in the entire zone from impregnation to the stenter frame. The proven Benninger chainless principle with positive cloth guidance is applied in this section of the machine. The cloth is constantly in contact with the rolls. The impregnation compartment only is flooded.

On the BEN-DIMENSA MC the fabric is pinned to the integrated stenterframe at the end of the reaction compartment.

On the BEN-MINI MERC there is no reaction compartment and the fabric is pinned to the stenterframe immediately after impregnating. At the speeds usual with this type of machine the dwelling time in the stenter zone suffices.

Lye extraction begins in the stenter frame

On the BEN-DIMENSA ML the dwelling zone consists only of the chainless impregnation and reaction compartments.

14

Step 3 : The BEN-DIMENSA memorizes the fabric dimensions

The uniformly applied lye is now to be removed. On the BEN-DIMENSA MS and the BEN-MINI MERC hot weak lye is first sprayed onto the fabric. In this manner the shrinking forces are partially decreased. In this condition the fabric can be stretched to the desired width with comparatively little force. Selvedge to middle differences are prevented or compensated by a special selvedge lye extraction process.In the stenter frame an increase in the fabric width can also be achieved very well. Longitudinally the needle chain permits stretching by increasing the speed, or shrinking through fabric overfeed. With knits, an overfeed of up to 20% can be employed, which means that longitudinal stretch is compensated for in the best possible manner. The needle chain leaves no marks in the selvedge and guides the fabric surely, even under the extreme conditions of high width tension and high shrinking forces.

Lye extraction on the stenter frame does not suffice to prevent subsequent shrinkage in the washing machine. When washing with free shrinkage, the opened spiral coils in the cotton fibres are partially closed causing irreversible dimensional changes. In order to suppress this effect and to carry-out further lye extraction before entry into the washing compartment, Benninger has a further zone with permanent positive guidance after the stenter frame.

Only completely opened spiral windings in the cotton fibre lead to the acknowledged improvement in dimensional stability, tenacity, lustre, etc. At the end of the stabilizing operation the caustic soda concentration has been so far reduced that no further permanent changes occur. The molecular changes in the morphological structure in warp and weft at the end of the stabilizing zone are memorized. In subsequent finishing operations such as stentering, dyeing and washing the dimensions are not irreversibly influenced.

Step 4 : Washing and neutralizing with a concentration controlled water supply

Any residual alkali is now washed out in the washing machine. With fabrics and longitudinally stable knitted goods the BEN-EXTRACTA is used. The top roll drive with press rolls prevents longitudinal distortion and width contraction.

Mahlo system for "on line" measuring of the pH after washing off after mercerizing

The CHEMCON CMC rapid measuring method for the pH value and conductivity in continuous washing processes

• Continuous recording of the pH value and conductivity on the running goods• No impairment of the substrate • Improvement of the finishing quality• Optimization of process flow

Steam is blown onto the running goods and suctioned

off. The condensate is analyzed. The measured

values and their relation to each other provide an

indication as to the finishing result.

Automation of measuring and control systems

The amount of washing water is economical and objectively controlled by measuring the weak lye concentration at the fabric infeed in the stabilizing zone (stenter frame or chainless stabilizing compartment). Exact neutralization of the fabric is ensured through automatic pH control.

water-steam mix

Extract

Calculationunit

pH...... S/cm

15

Core-neutralizing of the fibres with Sirrix NE

Most pretreatment processes are carried out in an alkaline medium, e.g. scour boiling, mercerizing and bleaching. Neutralization of the soda by the protonic complex Sirrix NE makes it possible to eliminate all traces of alkali, even those lodged in the core of the fibres. Often the operation is controlled by a ph-METER. In this way the last or last-but-one rinsing bath in a pretreatment range is held at a constant pH of 4 or 5 with Sirrix NE toneutralize the textile material to a pH between 7 and 8.

Strong acids like hydrochloridric or sulfuric acid are not recommended because there is a risk of degradation of the fibre (hydrocellulose) should the machine stop. Weak acids like acetic or formic acid are frequently used and neutralize the caustic soda on the surface, But often traces of alkali are blocked in the core of the fibre. After drying or prolonged batching soda migrates to the surface and causes yellowing of bleached or brightened fibres. Sirrix NE, thanks to its special composition with high ionic mobility, totally dislodges the soda from the microscopic cavities of the fibres and thus preserves the final whiteness of the cotton.

With Acetic Acid

With Sirrix NE liq.

Neutralized surface

NaOH

Acetate blockingbuffer zone

Neutralized core

02468

101214

0 5 0 1 0 0 1 5 0

1413

12111098765432100 50 100 150

Sirrix NE liq.

Volume NaOH 1N (ml)

pH For 1 Liter solution 10 ml/l Sirrix NE liq.

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Profit from the advantages of BEN-DIMENSA

Width gain and high dimensional stability are compatible on the BEN-DIMENSAYou achieve a bigger finished width. In spite of that, the quality standard of the shrinkage value is not impaired. On the contrary, through the width stretching in the stentering frame and the subsequent excellent stabilizing, a distinctly better stabilized width is achieved than on conventional mercerizing machines. The relationship of finished width to shrinkage in the weft direction is clearly improved

Constant warp density over the whole fabric widthAn increase number of ends in the selvedge zone leads to patterndistortion in yarn dyed fabrics, and in dyed fabrics to side-to-centre shading. With the BEN-DIMENSA denser selvedges are avoided. In spite of the gain in width the mas per unit area does not proportionally diminish as mainly the denser selvedge are equalized.

Traditional mercerizing results with selvedge thickening and deviations in weight per unit area.

BEN-DIMENSA corrects irregularities caused by processing and increases the stabilized fabric width.

The BEN-DIMENSA fulfilstextile producers' wishes

Mercerizing and Neutralizing on Dimensa-Machine

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BEN-DIMENSA MS 4

Combination of chainless system and stenterframe for speeds of 20-100 m/min for woven• chainless intensive impregnation compartment• chainless reaction zone• stenter frame• chainless stabilizing compartment• washing and neutralizing zone

BEN-DIMENSA ML 3

Chainless system for speeds of 20-150 m/min• chainless intensive impregnation unit• chainless reaction zone• chainless stabilizing compartment• washing and neutralizing zone

BEN-DIMENSA MS 1

Combination of chainless system and stenterframe for speeds of 20-100 m/min• washing and neutralizing of a separate washing machine

BEN-DIMENSA KNIT

Small machine for knit goods for speeds of 2-20 m/min

Speeds :

- Ben-Dimensa MS 4 20-100 m/min- Ben-Dimensa ML 3 20-150 m/min- Ben-Dimensa MS 20-100 m/min- Ben-Dimensa Knit 2-20 m/min

Fabric content of modules :- Impregnation compartment 7.5 m- Reaction compartment 5.8-8.5 m- Stabilizing compartment 8.5 m

Technical Data :

Useful width UW (increments 200 mm) 1600-3400Overall width UW +1850 mmMaximum height (fabric infeed) 3000 mm

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Mercerizing machine EcoMerce (Kuesters)

EcoMerce is an advanced development of the wet mercerizing process for caustic treatment of cotton blends at various caustic concentrations.Faster diffusion of caustic into the fibres and superior mercerizing results are the main characteristics of the Ecomerce process.Following a prewashing process, the Flexnip application unit, already proven on countless pretreatment and dyeing ranges, is used to apply caustic evenly to the fabric in a specific concentration and quality to ensure the required concentration within the fibres after a short diffusion phase. After only a short dwell in the diffusion zone, a maximum fabric swelling effect is achieved. The fabric is then guided through a stretching zone with length and width stretching units. in the following stabilizing section, the caustic soda is washed out in order to stabilize the new fabric dimensions.

The application of caustic of a higher concentration than usual causes an immediate swelling of the fibres, resulting in less caustic soda requirement per kilo of fabric, compared with existing methods of operations (see Diagram)

ECOMERCE

New mercerizing technology with caustic soda addition and a defined extension in width and length

1. Flexnip (addition of caustic soda)2. Diffusion compartment3. Squeezing rollers4. Length stretching zone5. Width stretching zone6. Stabilization compartment

Balance concentration (~300g NaOH / L)

Add-on mercerizing EcoMerce (60-70°C)

Hot mercerizing (60-70°C)

Cold mercerizing (15-20°C)

Mer

ceriz

ing-

effe

ct

Time (sec)EcoMerce versus conventional mercerizing

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EcoMercemercerizingmachine

Stretching processin weft direct ion Fabric width

Ecomerce continuous chainless mercerizing range with roller s tretching unit

Roller stretching unit Pin wheel stretching unit

A Stretching processin warp direction

B Stretching processin weft direct ion

Width after s tretching zone

Initial width

Ecomerce continuous chainless mercerizing range with pin wheel s tretching unit

Fabric length

Initial width

Width after s tretching zone

Initial length

Length after s tretching zone

Differential drive

Tension control Target valueActual value

Stretching processin warp direction

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EcoMerce; Diffusion Compartment

• Suitable for the Flexnip add-on mercerization process, hot or cold mercerization with additionally flooded caustic troughs• Driven stainless steel bottom roller, with grooved surface, top rolers with soft rubber covering• Caustic soda circuit with mixing trough, circuit pump, heat exchanger,• jet pipes, concentration control• Closed stainless steel housing, modular systems

Technical Data

Working width 900 ... 3400 mm

Fabric speed max. 120 m/min

• Intensive stabilization: meander shaped liquor feed in cross and counter flow• subdivision in individual baths with rinsing liquor circuit• Cascade-type arrangement of the sections• Closed steam-proof housing out of stainless steel with direct heating, modular system• Driven bottom rollers, stainless steel with fine-grooved surface• Top rollers, stainless steel, with soft rubber covering as jockey roller• Rinsing liquor concentration control for connection to caustic recovery unit, optional

Technical Data

Working width 900 ... 3400 mm

Fabric speed max. 120 m/min

Diffusion compartment (2 modules);high efficiency squeezing units

High efficiency squeezing units

Stabilizing module High efficiency squeezing units

EcoMerce; Stabilizing Section

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EcoMerce Pin Wheel Stretching Unit

For defined warp and weft stretching

• Combined length and width stretching zone between diffusion and stabilization

Technical Data

working width 900 ... 3400 mm

max stretch inwidth direction 150 mm

max. stretch in depending on clothwarp direction tension and material

Stretching processin warp direction

Stretching processin weft direction

Initial widthWidth afterstretching zone

• Length stretching zone with drive and web tension measuring unit for reproducible stretching in warp direction

• Width stretching zone with web tension measuring unit, 2 pairs of pin wheels, automatic pinning, fabric width control and monitoring of pin position for reproducible stretching in weft direction• Feeding of low concentrated caustic to initiate the stabilization process on the pinned fabric, caustic circuit with pump and collecting tank.

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Mercerizing with liquid ammonia

The liquid ammonia process is a unique process using the NH3 molecule at -33°C.This process has become irreplaceable for 100% cotton for non-iron shirts. Summer clothingof 100% cellulosic fibres is appreciated for its wearing comfort and easy care. The sameapplies to home wear. Workwear of 100% cotton treated with liquid ammonia is becomingincreasingly popular for demanding end uses (hospitals, kitchens, ships) and the easier care offered (reduced wear and tear, drying tunnel without ironing). Combined with a flame-retardant finish, liquid ammonia treatment is suitable for protective clothing.

Processes

In the SANFOR-SET process the NH3 is applied continuously to the cotton and the ammoniais eliminated by evaporation during passage over a hot cylinder. This process is called thedry NH3 process. In the recent BEAU-FIXE process from VERAMTEX, the NH3 is removedfrom the fabric by washing. The totally sealed machine recovers and recycles the ammonia. There is no risk of ppm of NH3 in the surrounding air. Swelling of the cellulose takes place in 10-15 seconds in the Beau-Fixe process.

The important parameters of the Beau-Fixe process:

– a constant temperature of -33°C; the boiling temperature of NH3– a stable concentration of 100% NH3 liquid– demineralized water without additives– complete reaction within a few seconds

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The Beau-Fixe process advantages

Natural and practicalThe particular qualities of natural fibres are emphasized. 100% natural fibres can be employed without their traditional drawbacks.

Dimensional stabilityDimensional stability is greatly improved (*)

Dry crease recoveryAll the advantage of clothing which does not crease during wear (*)

Colour fastnessDye affinity is increased and colour fastness to light and washing is improved

LuxuryProducts are lustrous and have a more luxurious appearance. The handle is softer and more lively.

Machine washingFabrics are stronger and easier to care for. They dry more quickly. Machine washing of linen has become possible.

Easy-care or non-ironThe crease recovery obtained enables workwear garments to be processed in tunnel finishing. It eliminates or greatly reduces the need for home ironing (*)

Better qualityThe improvement in mechanical properties increases wear life and resistance to abrasion.

(*) Effects reinforced due to synergy between the Beau-Fixe treatment and an appropriate resin treatment.

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Processe and Machine

•A quintessentially ecological processA necessary intermediate in the development of living tissue, ammonia is a product widely preset in nature. It is completely eliminated from the textile material after treatment. It is then recovered, purified and recycled back into processing without causing pollution to either air or water.

•A versatile processCotton, linen, ramie, regenerated cellulose. Beau-Fixe is the only process for treatment of both knitted and woven fabrics.

•Quick serviceCollection and return of goods in 7 days within 1.000 km of Brussel

•an experienced teamOur team can advise you on adapting your finishing processing to the new fibre properties.

A Dipping in liquid ammonia at 33°CB Rinsing in pure waterC DryingD Recovery, purification and recycling the ammonia

1 Liquid ammonia at -33°C2 Ammonia vapor3 Pure water4 Ammonia solution5 Water recovered and recycled

An efficient process that transforms the fibre in less than 10 seconds.

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Applications

Combine the comfort of using natural fabrics with the easy maintenance of synthetics.

Most of our work consists of treating fabric for shirts.

The treatment is generally followed by a resin treatment in order to obtain the best crease-recovery results. Without ammonia treatment, the fabric would tear or wear very quickly.

Dyed or undyed fabric ?The treatment is applied to all fabrics, whether they are yarn dyed, white or white-to-be-dyed. The best phase to the textile production line in which to apply the Beau-Fixe treatment depends on the results desired and on the types of fabric.

WorkwearHere, too, the Beau-Fixe + cross-linking combination yields excellent results. It becomes possible to obtain 100%-cotton articles that can be maintained with tunnel-finish.

VelvetThe fabric keeps its beauty longer and washing does not flatten the nap.

Cotton

Most consumers are very fond of linen but are quickly frustrated by how difficult it is to maintain and by its extreme tendency to crease. This leads some people to claim that "linen is worn creased". And while some consumers are snobbish about their wrinkled linen clothing, most avoid linen because they find it simply creases too much.

With the Beau-Fixe treatment, we obtain linen that is easy to maintain, thus opening up new market opportunities for this fibre. The combination of a locally produced, enjoyable-to-wear natural fibre with an ecological maintenance treatment opens up new horizons. The fabric's handle is particularly improved with Beau-Fixe.

We believe very strongly in the future of this fibre. We are even attempting to involve designers in researching this new material and in improving its image. A whole world of new possibilities for linen !

Linen

26

This new fibre, derived from wood pulp, is also a "green" fibre: the manufacturing process is very clean and the finished product is extremely pleasant to the touch.

The Beau-Fixe treatment has the same effect as on cotton: improvement in strength, in touch, and in crease-resistance. Crease-resistance is further improved by subsequent resin treatment.

The treatment also has effects specific to Lyocell: it eliminates stiffness when the fabric is wet and it stops fibrillation. the first point facilitates the task of the finisher, who often works with wet fabric and who can now avoid crackiness and wrinkles, the bothersome effects of which are well known.

Washing is also more effective; the fabric lasts appreciably longer. We washed a workwear fabric 100 times at 90°C ! The results are available on request (see the web site www.veramtex.com)

Softness in the wet state is equally important for comfort, in places where perspiration could be a problem, for example.

Fibrillation is also a well-known characteristic, which gives fabric a "peach skin" touch.This is sometimes a desired effect, but it is produced in an uncontrolled way. Traditional treatment with enzymes is often very costly

Lyocell

The trousers below were washed 20 time. The difference in treated/untreated appearance is clear: the treated-fabric leg is smoother, less discoloured and longer than the untreated fabric.

Beau-Fixe is a treatment that replaces mercerization to advantage, with effects that surpass those obtained with mercerization.

Denim

27

KnitwearWhen certain precautions are taken (see below), it is also possible to treat knitwear. The result is better elasticity, a more pleasant touch, and reduced snarling.

JerseyJersey must be tube-treated to avoid having the selvedges roll.

Heavier knits, such as interlock and rib fabric,may be treated open width.

Other plant fibres, such as hemp and ramieThe Beau-Fixe treatment invariably results in surprisingly advantageous effects. We have therefore always been interested in testing the use of the treatment for improvement of other plant fibres, such as hemp and ramie.

Technical fabricsThanks to the Beau-Fixe treatment, it is possible to give plant-fibre fabrics unusually high resistance-to-abrasion and quick-drying properties, which in turn make it easier to meet particular requirements.

New developments for wool and aramidsPreliminary tests on wool show an improvement in handle and a reduction in pilling. Recent university studies reveal that ammonia enables further treatment of aramides (glue, dye, etc.)

Others

28

MercerizingMercerizing cottoncotton knitknit goodsgoodsMercerizing woven fabrics does not pose too many technical problems but this is not true for knit goods. In the mid-70s mercerized cotton knit goods were produced almost exclusivelywith mercerized yarns. The rapid development of high quality cotton jersey clothing made an adaptation of the mercerizing method essential. Mercerized yarns produce a highly brilliantcotton which is readily dyeable but it is extremely expensive and poses certain technicalproblems, such as the differences in tension between the inside and outside yarns whendrawing out the hanks during mercerization which in turn cause unlevelness. Furthermore, mercerization of the yarns does not improve the dimensional stability of the finished piece of jersey.

In contrast to the relatively stable woven fabrics, elastic cotton knit goods shrink far more during swelling in the caustic soda and cannot be kept under constant tension on the guide rollers of the machine. The material shrinks more in the crosswise direction at the edges thanin the middle and the resulting mercerizing differences automatically cause problems in dyeing. For tubular knit goods special mercerizing machines were developed to reduce thetechnical problems to a minimum.

Major problem when mercerizing cotton knit goods

Selvedge densification

Selvedge densification

caustificationcompartment

stabilizationcompartment

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DORNIER - Mercerizing range for tubular knit goods

The numerous continuously operating DORNIER mercerizing machinesall fulfill the exacting demands placed on them with regards to quality, output and ease of operation.With this machine all types of knitted fabrics such as single jersey, fine rib and piqué in cotton or cotton blends can be mercerized. A distinct imrpovement in quality is given, not only to high quality goods in fine combed cotton, but also to medium qualities in short staple cotton yarns.High class underwear has joined outwear and sportswear as the main articles for processing.

The DORNIER system - patented ,motorized, automatically adjustable circular expander in the stabilizing-, washing- and reaction sections guarantees economic mercerization of tubular knit fabrics in all these areas.The essential technical features of the circular expander system are:• Reproductible values through controlled tension during the whole treatment.• In the tubular state otpimum length and width control are ensured for every diameter.• Uniformity of stitches and wales over the whole fabric length and width. Thereby prevention of build-ups and selvedge runoffs when dyeing.• Full mercerization, free from selvedge marks and stitch distortion.• Uniform fabric appearance, weight, shrinkage as well as improved dimensional stability and a fast, high lustre.

A = NaOH - impregnating and reacting section

B = stabilizing section

C = washing section

D = neutralizing section30

DORNIER - Mercerizing range for tubular knit goods

Technical details• Circular expander with pressure compensation and rolling friction. Thus a higher spreading tension with almost constant traction force, i.e. longitudinal tension can be achieved.• Drastically reduced setting-up times due to motorical adjustment of circular and flat tube expanders, even during slow run of machine.• Crease-free fabric run through the circular expander in the impregnating and the washing sections.• Self-cleaning filter for lye and washing water.• Constant water consumption, although the amount of water applied to the fabric has been substantially increased by recycling. This increases the stabilizing effect.

A Lye preparation tankB AgitatorC Filter box (NaOH)D Filter box (H2O)F Tank, upperG Tank, lowerH Washing towerI Cooling sectionK Metering pumpL Density and liquid level controlM Washing troughP Automatic temperature controlR Pump (NaOH) 1S Pump (NaOH) 2

• Heat exchangers guarantee uniform, exact temperaturesin the individual washing towers.• Heat recovery system for waste water.• All drives, roller bearings and upper traction rolls located outside of the wet area.• Three-phase current drives guarantee a perfect and controlled fabric run. Modern frequency convectors, controlled by the dancer rolls, ensure careful fabric treatment.• The sealed machine housings, with integrated exhaust flap, are made from lye and acid proof steel.• Provision for mounting a turntable and untwister at the fabric infeed.

Caustic soda

Steam

Wetting agent

Fresh water

Wash water

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DORNIER - The expandable and combinable machine concept

DORNIER supplies compact ranges with all the auxiliaries necessary for automatic operation.

Based on the concept of the tubular mercerizing machine we have now designed a combined mercerizing - bleaching range. This consists basically of the impregnating-, reaction- and washing sections of the mercerizing machine and is complemented with a preheating- and dwelling zone for the bleaching unit. The impregnation and washing sections are used in both processes.The machine sections can be arranged one after the other, or in a compact layout, so that existing mercerizing facilities can be extended to form combined mercerizing-bleaching ranges without any trouble whatsoever.

Standstill times in mercerizing can thus be utilized for bleaching. This concept guarantees full exploration of the machine in an extremely economic manner.

Further expansion to include a circular squeezer and drier in our sales program is under discussion. This project illuminates the fact that DORNIER is striving to create a machine program for tubular knit goods finishing from one and the same supplier.

Recipes for cotton-knitwear

Mercerizing step Bleaching step 26°Bé NaOH 6 ml/l Mercerol QW-LF liq. 2 ml/l Sirrix DNA liq.

6 ml/l Hostapal MRZ liq. 8 ml/l Stabilizer SIFA liq. 30 ml/l NaOH 48°Bé 40 ml/l H2O2 50%

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Bleaching machine for tubular knit goods with impregnating- preheating-and dwelling zone as well as washing sections.

Combined mercerizing- and bleaching range consisting of: impregnating-, reaction- and washing sections for mercerization or, impregnating section, heating and dwelling zone as well as washing sections for bleaching.

Combined mercerizing- and bleaching range in compact layout, consisting of: impregnating, reaction and washing sections for mercerizing or, impregnating section, heating-and dwelling zone as well as washing sections for bleaching.