Exactly your chemistry
ITMA Munich2007 TextileBusiness PM Pretreatment September2007
Desizing
Clariant Pretreatment
Pretreatment Handbook
Pretreatment
Definition The purpose of desizing desizing is to elimina m inate sizing products in order order to ensure ensure the success of scour scour boiling i ng and bleaching and the production o n of faultlessdyeings faultlessdyeings.. Before Before starting i ng this process it is advisabl advisable to determi determine n e thetype of thesizes so as to facilitate t ate their their removal. Clariant Clariant’s ’s MINILAB MINILAB can easily be made made available available for rapid identif identification i cation of the sizing sizing products such as starch starch and PVA (polyvinyl alcohol). For a precise precise qualitative ive and and quantitative analysis, extraction in the the Soxhlet together with infrared curves and chromatogramsa chromatogramsa re required.
DESIZING of fabrics of cellulosic cellulosic fibres fibres and thei theirr blend blends s with with synthe synthetic tic fibre fibres s using using the the BACTOSOL enzymes and the Hostapal wetting agents/detergents agents/detergents
The Minilab fromClariant: this mobile laboratory laboratory is indispensable indispensable for monitoring ng thegood qualityof qualityof thepretreatmen m ent of textiles. It is possibl possible not onlyto identify the sizeso n thegoods but also to analyse the the residuesof alkali, acid, acid, peroxide, peroxide, iron, iron, the pH of the the fabric fabric and many many otherparameter otherparameters. s. It is accompan accompanied by a comprehensive comprehensive manualdescribing its use.
Back to sizing Main Main characteristics of sizes Requirements Requirements in sizing sizing and subsequentprocess steps
Sizing requirements:
Thanks Thanks to their complet complete e range range of chemic chemical al product products s for the textil textile e indust industry ry and the synergi synergism sm between between sizing sizing products products and the pretreatment pretreatment of textiles, textiles, Claria Clariant nt present presents s here here a compreh comprehensi ensive ve survey survey of the techniques techniques for desizing desizing fabrics fabrics with the most suitable suitable products products for total total eliminati elimination on of natural natural and synthetic synthetic sizes sizes to the benefit benefit of all who handle handle textil textiles. es.
Needs of subsequent processes:
reductionof friction
high weavingefficiency
goodfilm formation formation
stabilityto electrolytesand alkaline solutions
no skin formation watersolubility (cold or hot water, hard water) non-foaming non-foaming (in the bath or on rollers) lowcosts
readily removable (desizing) compatibility compatibility witho therprocess steps (e.g. singeing/ thermofixation) ecologicalcompatibility
The preparation o n of threads for weaving weaving involves v es coverin covering g thewarp threads threads with a s iz e w it h s pe pe ci ci fifi c p ro ro pe rt rt ie s ( s se ee table). e ). A fibre b re is easier easier to weave weave if its pilosity o sity is reduced: uced: its resist resistance a nce to rubbing is significantly significantly improved. Sizing therefor refore e impro improves ves the weava weavabil bility i ty of warp threads by reducing thread-thread thread-thread and thread-metalfriction.
identifiable identifiable on the fibre
The efficie efficiency ncy of a size size is measured measured by the weaving weaving yield. d . Clariant a riant offers a compl complete e te range of of sizes sizes under the designations g nations ARKOFIL, VINAROL and TYLOSE.
2
For high high quality t y desizing z ing itis essentia essentiall to know thechemical c al and physicalpropert physicalpropertiesof iesof thesizes in orderto apply a process process which c h willensure willensure theirtotal elimination. ion.
3
The chemica chemicall identit identity y of sizes sizes The The products ducts for for sizing sizing are generally erally natura u ral polyme y mers (starc (starch) h) as is or modified (CMS) as well as synthetic polymers and copolymers copolymers (PVA, PAC, PES, etc.). etc.). It goes goes withoutsayingthat thefabriccan contain a in a single size or a mixture of different ferent sizes depending on the he type and and structure of the the textile substrate, substrate, alongside waxes, fats and lubricatingparaffin.
Starch:
Carboxymethylcellulose:
Abbreviations of sizes: CMS = CMC = PVA = PAC = PES =
CarboxyM arboxyMethylS ethyl Starch CarboxyM arboxyMethylC ethyl Cellulose PolyV olyVinyl Alcohol Alcohol Poly A crylate PolyE olyEster
Cellulose
• linear linear chain • -1,4-gly -1,4-glycosidic linkage linkage • 100 - 1,500 repeating ng units
• linear chain, no branching branching • -1,4-glycosidiclinkage linkage • 1,000 - 7,000 repeating ng units
To obtain CMC, a well swollen l en cellulose cellulose is alkalized i zed and then etherif etherified ied with sodium sodium chloroac chloroacetat etate. e. CMCs are identifiable indirectly with uranyl nitrate or with with acridine orange orange and eliminable either either enzymati enzymaticall c ally with with cellulase u lases such as Bactosol CA or by hot washing washing in the presenceof Hostapal or Imerol or Imerol surfactants.
thetwo components components of starch starch - amylopectin opectin and amylose ose
• branchedchains chedchains amylopectin • -1,4-glycosidic linkages linkages -1,6-glycosidic -1,6-glycosidic branchingpoints • 1,000 to 7,000 repeatingunits (or evenmore)
CMC - a derivative derivative of cellulose cellulose
amylose
Polyacrylates:
PAC - a product product of acrylic acrylic synthesis synthesis
There are several several PACs prepared from acrylic i c acids, acids, methacrylic ic acidsor acrylic esters. The mostcommonly mostcommonly used acrylate a te salts salts are: ammonium, um, sodium, potassium potassium and calcium. PACs PACs are strong electrolytes electrolytes and are are therefore therefore readily soluble in a neutral or alkaline medium medium.. PACs are indirectly indirectly identifiable w itit h n in hy hy dr dr in a nd nd eliminable by wash washing ing in the h e presen presence of Hostapal or Imerol surfactants.
The most widely use d che mica l modification is carboxym carboxymeth ethylat ylation ion to i mp mp ro ro ve ve e li mi mi na na titi on on o f th e s ta ta rc rc h (CMS)
Starch is a macromolecular macromolecular polysaccharide polysaccharide which is identifiable by its bluish violet colouration on with theiodinereactant theiodinereactant in theMinilab a b and is eliminable withalpha-amyla withalpha-amylase enzymes enzymes such as Bactosol MTN or HTN. or HTN.
Polyester:
PVA is identifiable by its deep bluish s h violet e t colouration with the iodine n e reactant and the boric reactant. a nt. It is eliminable, eliminable, after after swelling, i ng, with the Hostapal or Imerol or Imerol surfactants. surfactants. This syntheticsize is highlysensitive to alkalis, alkalis, electrolytesand ectrolytesand aboveall to theheat treatment treatment of singeing. singeing.
Other sizes: fatty substances and additives
4
X = COOM, CN, OH, COMH2, COOR M = H+, Na+, NH4+, K+, Ca2+ , Mg2+
PES - synthesis by polycondensation
Polyvinyl Polyvinyl alcohol: alcohol: PVA - partially ally or totally totally hydrolized hydrolized Polymerisati s ation o n of the vinyl monomer monomer, through synthesis h esis of polyvinyl polyvinyl acetate can producepartially or totally hydrolizedPVAs. PVA PVA exists sts in two spatial forms: orms: isotactic isotactic or syndiotacticconformations. syndiotacticconformatio ns.
Y = H, CH3
To improve improve sliding sliding of the fibres fibres and reduce reduce abrasion oils, s , fats and paraf paraffins fins as well as other other products such as antistatic agents, fungicides, fungicides, etc. are applied during sizing. These substances are generally generally hydrophobic hydrophobic and insoluble nsoluble in water. er. Theycan be eliminated eliminated duringdesizing thanksto the emulsifying ying power of the the Imerol or Hostapal or Hostapal surfactants.
PES is obtained by thepolycondensation of polyglycols with with aliphati aliphatic or aromatic i c acids contai containin n ing hydro hydrophili philic groups such such as sulphate, phosphate, carboxylate, etc. Their main main disad disadvan vantag tage is their sensitivi sitivity t y to alkalis is and electrolyt electrolytes. e s. They They are identifiable with Astrazon Astrazon Red F-3BL and eliminable by the Imerol or Hostapal surfactants as well well as our Sirrix sequestrants.
5
Elimination Elimination - sensitivity sensitivity of sizes sizes en zymatic elimination
A desizing recipe can be optimized zed for a s ingle known size (ideal case) or or for a mixture mixture of unknow unknown n sizes sizes (frequent case). The golden rule rule in case of doubt doubt as to the natur nature e of the the size size is to adapt adapt a desizi desizing n g recip recipe e capab capable le of of elimi i minatin n ating g the the most most diffi f icult c ult size; size; if necessary, enzymatic enzymatic desizing for bioconversion of the insoluble starchinto water-soluble glucose.
-amylases
washing > 80°C
cellulases
Starch
–
CMS
–
CMC
–
PVA
–
–
PAC
–
–
PES
–
–
–
( )
Iodine test for starch starch - TEGEWA TEGEWA Violet Violet Scale Scale
sensitivity to pH alkaline
acid
–
–
–
–
–
–
Grey cotton
Desizedwith Bactosol MTN
– – –
A systematic, ic, progressive procedure makes it possible to identifystarch, polyvinylacetate, PVA and CMC sizeswith 5 d if fe fe re re nt nt r ea ea ct ct an ts ts . T he he m et et ho ho d i s n ot ot d ir ec ec t a nd nd intermediate ate extractions are necessary. It goes goes withoutsayingthat withoutsayingthat in cases cases of doubtit doubtit is possible b le to use more more sophisti histicated c ated analy analytical tical methods h ods such such as extraction in the Soxhlet, infrared, chromatography, chromatography, as well as theinformation in the Minilabmanual fromClariant.
Standard solutions: Solution 1.3 g iodine + 2.4 g potassium iodide in 1 l water Solution 0.13 g iodine + 2.6 g potassium iodide + 4 g boric acid in 100 ml water Solution 11.88 g potassium dichromate in 50 ml water + 25 ml sulphuric acid conc. Solution 30 g sodium hydroxide in 70 ml water Solution uranyl nitrate 4% (aqueous solution)
To tal
Optimu m
d esizing
Rat i ng 1
Rat i n g 9
Thanks to theblue scale it is easyto identify f y and quant quantify ify residues of starch starch on thefabric. The The iodine n e reactant(Minil reactant(Minilab) a b) producesa producesa more or less intense bluish violet colourationdepending colourationdepending on the residualquantity of starchysizes. A quantitative quantitative approximation approximation isassociated: rating rating 9 represents represents a quantityof starchless than 0.04%, rating 1 more than2.5% starch. Rating 5, 5, less than0.2%, is acceptable for dyeing. dyeing. PVA can also be identified identified by a touchof boricacid in an iodinemedium. Colourationis dark blue.
Caution Caution -problems -problems : To ensure ensure the success success of all the operations ations followin o wing desizing z ing suchas bleaching, n g, dyeing dyeing or printing, printing, it is important ortant that the materialis materialis complete completely clear of sizes. sizes. The most significant significant results of poor desizing are are lower lower degrees of whiteness, whiteness, insufficientabsorbency, insufficientabsorbency, spots, reserves, unlevelness, unlevelness, moiré of dyeings, dyeings, too harshhandle leadingto breaks. The originscan be classifiedin 2 groups: groups: Group 1; pretreatm pretreatment ent probems: overdrying of sizedwarp threads, high gh content of of waxes and lubricants lubricants whicha re difficult to emulsify, emulsify, high content content of sizes. Group 2; process process problems: problems: poor wetting out and low pickup, too short swelling swelling of the he sizes, bath containing containing enzyme poisons, insufficient insufficient final washing.
6
7
The “Cross-Country” alpha-amylase
Bactosol PHC liq. hc
Thanks to its wide pH and temperature action range, the perfectly removes starch with each desizing process.
Internal, Eric Argast, PG Pretreatment
2006
Bactosol PHC Pad Batch Desizing
Injecta
Hostapal MRZ liq. conc Bactosol PHC liquid hc Sirrix ANTOX liq.
4 ml/l 1-2 ml/l 2-3 ml/l
Bath pH
5-6 20-30°C (cold) or 60-80°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.
Hostapal MRZ liq. Sirrix ANTOX liq. Bactosol PHC liquid hc
4 ml/l 1 ml/l 1 ml/l
Bath pH Bath temperature
5-6 80°C
steaming
Recipe
Recipe
Batching time
2006
Bactosol PHC Injecta desizing (Benninger)
Impregnation temperature
Internal, Eric Argast, PG Pretreatment
Injecta desizing
washing
Impacta
washing
Cold Pad Batch bleaching
impregnation
impregnation Internal, Eric Argast, PG Pretreatment
2006
Internal, Eric Argast, PG Pretreatment
2006
Bactosol PHC Pad Steam desizing singeing
impregnation
Grey fabric steaming
Recipe
Hostapal MRZ liq. Bactosol PHC liquid hc Sirrix ANTOX liq.
4 ml/l 1 ml/l 2 ml/l
Bath pH Bath temperature Steaming time Steaming temperature
5-6 60-80°C 1-3 min 100°C
Internal, Eric Argast, PG Pretreatment
Fast swelling of sizes with the high temperature Bioconversion of starch into watersoluble sugars
2006
Pinholes: consequence of Catalytic damages
Your umbrella against iron
A strong final washing eliminates sugars from the fabric
A short guide to Sirrix 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).
Better protection against pinholes
Result strongly positive: molecular and ionic iron are strongly present on the fabric
Extraction and complexation of Iron, Calcium and Magnesium, destruction of pigments from the raw cotton during the enzymatic desizing and the bleaching processes.
in desizing Better whiteness in bleaching
Complexing Science Complexing behaviour
Without protection
Classic sequestrant
0 g/l
The fabric is soaked in the solution at room emperature, e.g. in a petri dish, for 10-15 minutes, rinsed with demineralized water and dried : Blue staining on the fabric, according to the 1g potassiumhexa-cyanoferrate (II) trihydrate = reaction below: K4[Fe(CN)6], 3H2O to dissolve in 100 ml 1N HCl. 3 K4[Fe(CN)6] + 4 FeCl3 = K4[Fe(CN)6] 3 + 12 KCl Then add 50ml ethanol absolute. (Prussian Blue)
2 g/l
Catalytic damages – Prevention Application
ANTOX Process With Sirrix ANTOX ANTOX-Desizing ANTOX-Scouring ANTOX-Bleaching Mechanism Iron passivation/ Complexation
Acidic process With 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 Mechanism Iron ionization / complexation Fe + 3H+ Fe3+ Insoluble
soluble
3-4 ml/kg Hostapal MRZ liq. 1-2 ml/kg Bactosol PHC liq. hc 1-4 ml/kg Sirrix ANTOX liq. Few seconds at 70-80°C
2 ml/kg 4 ml/kg 20 ml/kg 30 ml/kg 1-4ml/kg
Hostapal MRZliq. Stabilizer FCB liq. NaOH48°Bé H2O2 50% Sirrix ANTOX liq.
Steaming: 15 min at 100°C
1 ml/kg Sirrix NEliq. 1 ml/kg Acetic Acid 0.5 ml/kg Bactosol SAP liq. conc. Washboxat 40°C
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ANTOX -MATRIX
Scour Boiling
0
2
4
0
2
4
Pretreatment Handbook
ml/l
Pretreatment
ml/l
Definition
Composition of cotton and other cellulosic fibres
Alkalinescour boilingis a cleaningprocess for cellulosic fibres usinglarge quantitieso f caustics oda at hightemperatureas well as special chemicalproductsto removethe natural impuritie s in cotton and other cellulosic fibres, free them from troubling substances and make them absorbent. At the same time vegetable conta mination swells perfectly and is softened for rapid decoloration durin g bleaching. Alkali ne scour boili ng is an intermediate process after enzymatic desizing and before peroxidebleaching. Even if the quantity of impuritie s is not so high it is essential to eliminate thembecause of their negativeeffect in subsequent finishingprocesses. Fats and waxes prevent penetration of the watersoluble dye and min eral substances can cause precipitation of the dye or during bleaching in the presence of iron annoying catalytic damage. It is also essential to elimin ate vegetable residues as wella s the proteinsand other substances presentin thefibre.
The tables below show the chemicalcomposition of these naturalfibres for bettertargeting of thesubstances and impurities to beremoved.
Percentage of Cellulose Pectin Waxes Proteins Minerals Other organic compounds
Thequality of scourboilingis measured above allby theabsorbency; withoutabsorbencythereis no dyeingand no print.
Hydrophobic:
Whole fibre 88.0 – 96.0 0.7 – 1.2 0.4 – 1.0 1.1 – 1.9 0.7 – 1.6 0.5 – 1.0
propertyof a greyfabricto repel water because ti conta insthe natural cottonwaxes andfats which have to be saponified.
Apart from cotton (Gossypium), the Liberian fibres such as linen, hemp and ramie also require intensive scour boilingto achieve goodabsorbency. Hydrophil ic:
Mature cotton bloom
Primary wall 52 12 7 12 3 14
propertyof a scourboile dfabricto absorbwater. The causticsoda saponifies the hydrophobic fats to soap. The textile materialcan be dyed.
2
fibres substances cellulose hemicellulose pectins lignins solubles substances fats
cotton
linen
hemp
ramie
jute
82.7 5.0 0.7 0 1.0
62.4 17.2 2.3 2.5 3.9
67.0 16.1 0.8 3.3 2.1
68.8 13.1 1.9 0.6 5.3
64.4 12.0 0.3 11.8 1.2
0.6
1.7
0.7
0.3
0.3
3
Otherproperties of surfactants
The minerals
- Stabilityto caustic soda and scope of application Dependin g on thegeographicaloriginof thecottonits mineralcomposit ion can vary considerably. The tables below show some values of residuala sh of different cottonsas well as thedetailed composition of 2 cottons.
Analysi s of two different qualiti es of cotto n
Ash content of thedry fibre: Ash content o f differen t qualities of cotto n Dharwar
: 4.16 %
Dhollerah
: 6.22 %
Sea Islands : 1.25 %
Broach
: 3.14 %
Domrawottee : 2 .52 % Egypt
: 1.73 %
Peru
: 1.68 %
Pernambuco
: 1.60 %
Bengal
: 3.98 %
USA
: 1.52 %
The resid ual ash conte nt gives a good indic atio n of the degree of mineral contamination in the naturalfibre and it is also interesting to know the ppm content of calcium, magnesium and iron (seetable). Theearth alkalis Ca and Mg cause problems in dyeing, while iron is extremely dangerous in bleaching. Itgoes withoutsayingthatgood scourboiling drasticallyreduces the amountsof theseminerals.
Composition of the ash: SiO2 Al2O3 CaO MgO K2O Na2O Fe2O3 SO3 P2O5 CO2 Cl others
: : : : : : : : : : : :
Bombay % 3.99
Punjab % 1.85
15.56 10.80 9.75 1.87 27.32 4.51 5.89 1.96 3.26 12.19 6.55 0.34
14.40 12.87 10.65 4.36 26.03 8.40 1.92 2.52 4.46 8.03 3.84 2.52
0 - 2°Bé NaOH
:
0 -8°Bé NaOH
:
0 - 18°Bé NaOH
:
18 -32°Bé NaOH
:
surfa cta nts for discontin uousprocessesor desizin g; anionicor nonionic. surfa cta nts for contin uousand dis contin uous processes, desizing, scour boilingand b leaching; anionicor nonionic. surfactants for concentratedscourboil ing with all- in reinforcement bath;anionic. surfactants for mercerizin gand causti cizin g; anionic
- Wettingout The wettingout properties are the ability to eliminate surface tensions very rapid ly enabling the water or aqueous soluti on to penetrate rapidly to the heart of the fibre. The wett ing effect depends on the pH as well as the temperatureof thebath. It is measuredin seconds withround swatches of grey cotton(hydrophobic) and a progressive concentration of wetting agent. Below: Wetting test PM 7101.
100
Wetting time in seconds
Mineral composition of cellulosic textile fibres in ppm Cotton Egypt Cotton Turkey Cotton China Cotton Pakistan Cotton India Cotton Brazil (GO) Cotton Brazil (MS) Cotton USA Linen from Normandy
Ca 425 910 514 550 625 1024 2425 728 3412
Mg 352 485 502 480 580 625 1085 352 328
Fe 29 63 68 65 55 238 208 71 92
10 bad wetting agent
Very good wetting agent
1
4
1
2
4
8
10 g/l product
5
A good detergent also enables the removal of mineral oils, theiremulsions as well as their oil/water dispersions. An exampleof contamination of a fabric by mineral weavingoils and their removalwith HostapalMRN liq. conc. is shown below.
Wetting test Tampex T he w et ti ng p ow er ca n a ls o b e d em on st ra te d w it h t he Tampex test which shows the abilityof the wettingagent (in a coloured solution) to penetrate a pile of round swatches of grey cotton in 60 seconds contact. The more swatches are wetout (coloured), the more efficient is the wettingagent.
Example: Removalof mineral oil with Hostapal MRN liq. conc.
low surfactant
fair surfactant
goodsurfactant
Hostapal MRN
- Detergent power The detergent power is the abil ity to remove a standard fatty contamination on an EMPA standardized reference wool fabric. The Wool washing test PM 7102 is carrie d out in a neutr al and a weakly alkali ne (carbonate ) medium with progressive concentrations of surfactant and with mechanical action.
Oil/Water not miscible
Oil/Water emulsified
without
with Humectol LYS
All types of mineral oils and other lubricating agents can be emulsified perfectly thanks to the surfactant qualitiesof HumectolLYS. This is particularly advantageous when scouring fabrics containin g elastomeric fibres (Lycra, Dorlastan, etc.).
low surfactant
fair surfactant HostapalMRN
6
7
no absorbency
good absorbency
verygood absorbency
Capillarity test with SolarTurquoise Blue GLL-160%
- Foamfor mation One of the intrinsic propertie s of surfacta nts is the formation of foam in aqueous solution. Dependin g on the chemical composition of the surfactant, its concentration, the pH and temperature of the bath, this foam can be more or less abundant. As a rule this surface foam causes considerable problemsin textile applications, e.g. in jets or in impregnation baths. Theaddition of an antifoam or deaeratingagent avoids these problems. Itgoes withoutsayingthatthe antifoam used must be free from silicone (risk of spots) or a rubber solvent (attackon therollers).
on cotton yarn
severe foaming
weak foaming
on fabric 0
40
80 mm
medium absorbency
good absorbency
Penetrating drop test - Absorb ency
low absorbency
Absorbency is the most important parameter of the pretreatment of cellulosic fibres, withoutwhich it would be impossible to dye or print.
low absorbency
good absorbency
verygood absorbency
Thes urfactant in combinationwith causticsoda makesit possible to obtain a certain absorbency whichdepends on several factors: – thec oncentration of caustics oda – scour boilingtemperature – scour boilingtime – type of textile material 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 troublesomefor fabricswhich are to receivefluorocarbon or water-repellentfinishes. Thec apillarity test or drop test are easy methods of visualizing good or poorabsorbency. >180 sec .
8 4
18
46
-n
- Chemistryof sequestrants During alkalin e scour boil ing it is essentia l to remove the natu ral mineralsin the cottonat thesame time as thewaxes to ensuregood bleaching effects. Theonly way to remove these metallic salts and oxides is to use organic sequestrants. One speaks of complexing, sequestering, chelating or maskingthe metals.
L
The oldest sequestrants used for processing textiles are EDTA, DTPA, gluconic and glucoheptonic acids. The new modern sequestrants are based on methylene phosphonic (MP) acid s such as EDTMP, DTPMP, HEDP, AMP, HMDTMP, which are more stable and more active in an alkaline and oxidizingmedium.
M
m
m -n
ML
-n
K
L
M
Diethylene triamine pentamethyl phosphonic acid (DTPMP)
ML
Gluconic acid Glucoheptonic acid DTPA EDTA NTA ATMP EDTMP DTPMP STP DTPA = EDTA = NTA = ATMP = DTPMP= EDTMP= STP =
Nitrilotrimethylene phosphonicacid (AMP)
1-hydroxyethane 1-1 diphosphonic acid (HEDP)
L = L ig an d M = Metallic cation K = dissociation consta nt of the metal - Sirrix DNA complex pK = - log K
m
m- n
Example of pK
Hexamethylene diamine tetramethyl phosphonicacid (HMDTMP)
1 sec.
9
- Dissociation constant (pK) of a complex
Organic sequestrants
Ethylene diamine tetramethyl phosphonic acid (EDTMP)
25 sec .
mm
Ca
Mg
Fe
Cu
1.2 1.2 10.9 10.7 6.41 6.68 9.33 7.11 5.36
0.7 0.7 9.3 8.7 5.41 6.49 8.63 6.40 5.81
37.2 37.2 27.5 25.1 15.87 26.9 19.6 – –
39 39 – 18.7 12.7 13 18.95 19.47 8.70
dieth ylenetriamin epentaceticacid ethylene diaminetetraceticacid nitri lo-tria ceticacid amino-trimethylene phosphonic acid diethylenetriaminepenta (methylenephosphonic) acid ethylene diamine tetra (methylenephosphonic) acid sodium tripolyphosphate
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.
In order to obtain an idea of theprofile of a sequestrant there are vario us tests to show specificproperties of thesespecial chemicals. Opposite the demineralizing action of Sirrix DNA durin g alkali ne scour boiling.
Example: Scourboiling of cottonwool for pharmacopoeia. Recip e:
10
40 g/l NaOH soli d 1 g/l Hosta palMRN liq. conc. 2 g/l Sirrix DNA liq. 2 h at130°C
Results: Mineralcontent before and after scourboiling
11
0 - Antip recipit ant effect
1
2
g/l sequestrant
- 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.
The organic sequestrant can avoid any insolu ble precip itation by chelating (masking) metalliccations. Avoiding the precipitation of copper hydroxide Cu(OH)2 when addin g caustic soda to the cupricsolution containing Sirrix DNA is illustrated here.
Poor sequestration of iron
- Inhibitingeffecton calcium Goodsequestrationof iron with Sirrix DNA liq.
Test: Add a complexing agent to a bath containing 25°e calcium, 25°e magnesium, 20 g/l sodium 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 procipitatesis very high in an alkaline medium at 100°C.
0
1
2
without sequestrant
g/l sequestrant
with Sirrix DNA
0
Test with black filter paper
- Dispersing effectof sequestrants
Poor sequestration of calcium
Certain mineral substances and others in the fibre or the bath can disturb dyeing and precipitate dyes such as Indanthrene® Blue BC.
1
2
g/l sequestrant
Poor dispersing effect
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.
Goodsequestrationof calcium with Sirrix DNA liq.
Gooddispersing effectof Sirrix DNA liq.
12
13
Exactly your chemistry
Bleaching
- Threshold effect
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 between the cation and the precipitating anion. For example, for a stoechiometric ratio of 1:1 for CaCO 3, 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.
0
1
2
Pretreatment Handbook
g/l sequestrant
- Demetallizing effecton a dye Certain brilliant dyes (e.g. phthalocyanines) conta in meta ls in their chemical composition. The meta l is bound by semipola r bonds to the organic mole cule. Thebrillianceof thedye can disappear if a sequestrant complexes the b ou nd m eta l. T he s ha de c an c ha ng e complete ly by demeta llization. Special sequestrants are used in dyein g whichdo not change themetallic constitution of the dye.
Destructive effecton the dye
No effect on the dye
14
Pretreatment
Definition
Theperoxo-anion formed can react in 3 possible waysd uringbleaching: - oxidation of thenatural dyesin thecotton; thechromophoric group is oxidizedand becomescolourless
The last phase of purification of cotton, bleaching, is themost visib le. Afterthis treatm ent thenaturalyellowis h and brownishpigments and the vegetableimpurities in the cotton disappear. The bleaching reactiontakes place as follows: a strong oxidizingagent, hydrogen peroxide, destroys the chromophoricgroups of thenatural dyes in the cotton. Decolorationtakes place and the material looks whiter. This bleaching of cotton is made more difficult by the presenceof seeds and vegetable residues which are darker in colouration than the cottonitself; intensive bleaching would stil l be necessary to eliminate these disturbing vegetable fragments. Comparedto the other bleachingagents used (sodium hypochlorite, sodium chlorite, sodium permanganate, etc.) hydrogenperoxide is themostefficie nt and,at thesametime, theonewhich pollu testheenvironmentleast.
-
O2H
C
-O H 2
S 1. Thesymmetric almolecule ofhydrogen peroxideH-O-O-H isactivate dby theadditionof causticsoda which causesheteroly ticsplittingwithformatio n of the peroxo-anion -O2H responsible for bleaching :
-O H + H O 2 2
Eisenhut factor S 0.01 - 0.2 0.21 - 0.3 0.31 - 0.5 0.51 - 0.75 > 0.75
Hydrogenperoxidecan bedefinedas a weakacid characterizedby thedissocia tio n constant Ka
H+ + H-O-O-
Acid constant K a = 2.5 . 10-12 The peroxo-anion formedcan producean oxidizing or reducingreaction dependingon the medium. 3.
O xi di zi ng r e a ct io n :
H2 O2 + -OH
4.
R ed uc in g r ea ct io n :
H2 O2
HO- + 1/2 O 2
- oxidation of the cellulose, loss in the degree of polymerisation (DP). This oxidation is identifiable with the Fehlingreagent. The alcohol function of the cellulose (-CH2OH) oxidizes into aldehyde(-CHO), acid (-COOH), monoketone(=CO), etc. and ends with rupture of the cellulosic cycle. The degradation 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.
Mechanisms
H-O-O-H
C
HO OH (colourless)
- formatio n of mole cular oxygen; this is a loss of oxidiz ing agent resulti ng in a reduction in the degree of white ness obtained by the bleaching process
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.
2.
C
(coloured)
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.
H-O-O-H + -OH
C
1 2000 log log 2 DP f
2000 DPi
1
Comment very good, undamaged good, very carefully bleached satisfactory slightly damaged badly damaged
targetbleachedcotton
S<0.4
O 2 + H2 O + e- (E = -0.08 V) -
O2 + 2H+ + 2 e (E = +0.7 V)
2
Stabilization of hydrogen peroxide Stabilizer SIFA
3
Act ion pro fil e of Stab ili zer SIFA
Perfectstabilization of H2O2 Even in a strongly reinforced bath Stabilizer SIFA prevents premature uncontrolled decomposition of thehydrogen peroxide. The bleaching process is a complex reaction mechanism because hydrogen peroxide has to be activ ated and stabilized at the same time. Caustic soda activ ates H2O2 and favours the formatio n of hydroxoperoxide ions. The stabilizer orients the peroxo-anions towards oxidation of the naturalcoloured pigments in thec ottonand at the same time avoids or limitsside reacti onssuch as the formation of mole cular oxygen (lossof whiteness) or theoxidation of thecellulose (loss of DP). Stabilizer SIFA, a unique, totally organic macromolecule, achieves perfect stabilization of the hydrogenperoxide withoutany significative damage.
Higherand progressive degreesof whiteness More than 95% of theperoxo-anions are directedtowards oxidationof thepigments ensuring superoxidation of the naturaldyes in the cotton. Extremewhitenessis ther esult. Theh igherthe quantityof stabilizer, themore peroxo-anions there willb e in the reactionmedium and the higher will bethe whit eness. Synergismwith fluorescent brighteners Duringsimultaneousbleaching and brightening, Stabilizer SIFA increases theabsorption of UV radiation by the fibre leadingto a synergism of whitenessunattainableby otherstabilizers. High degreesof whiteness are ensured in this manner. Thetemperature, a positive medium for Stabilizer SIFA Thewhitening effectof Stabilizer SIFA is greatlyincreased if bleaching takesp lace at high temperature (90-100°C) with prolongedsteaming. The more extreme the bleachingconditions are, themore unique Stabilizer SIFA will be: •Cold pad batch technique • P ad st ea m, sh or t st ea mi ng , 1 -2 m n i • C om bi -St ea m, s te am in g fo r 7 -1 2 mi n •Combi-Steam, J-Box, U-Box 20-40 min
: : : :
lowperformance, identi calto others i de nt ic al t o ot her s t ab ili ze rs d is ti nc tl y b ett er t ha n ot her s unique and superiorstabili zer
Replaces sodium silicate Allthe resultsshow clearly thatthe mineralmolecule of sodium silicate is inferiorto the effectsand advantages of Stabilizer SIFA. Furthermore depositsand precipitations are completelya voidedwith Stabilizer SIFA. Prevents catalytic damage Thanksto itsspecial macromolecular chainand itspoles whichattract the poisons, all harmfulcatalysts such as Fe, Cu and Mn cations are emprisonned and inactivated in thetrap-like structure of Stabilizer SIFA. Bleaching can be carried out in completesecurity.
Hydrogen peroxide is a realdanger for the textile substrate. If the oxidizing molecule is wrongly oriented and inspite of the formation of an inoffensive molecule of water in th e final phase, the texti le substrate can suffe r irreversible damage: loss of DP, no resis tance to tearin g, catalytic perforation due to heavy metals, rust spots, poor and heterogenic degrees of whiteness. A single molecule, Stabilizer SIFA is able to conquer the undesirableeffects of H2O2 and ensure a superiorquality of bleaching. The followingshows themain propertiesof Stabilizer SIFA .
4
5
Stabilizer SIFA - Advantages Synergetic effect with fluorescent brighteners Increase in thedegree of whiteness Example: Pad steambleach Material: Co wovenfabric, desizedand scourboiled Hot peroxidebleach
Degreeof whiteness with fluorescent brightener
Degreeof whiteness without fluorescent brightener
Perfect stabilizing action in peroxidebleaching liquors Test: Bleaching liquorreinforced 4 times
Excellent anticatalytic action Peroxidebleaching liquorcontains 100 mg Fe III ions Residualperoxide content in % after 6 h
Conventional stabilizer
Without
With SIFA
Conventional stabilizer
SIFA
SIFA
6
7
Sirrix DNA against ir iron on contamination
Fighting th e catalysts
In 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 p retreated with the protonic complex Sirrix DNA to provide maximum security in peroxide bleaching.
This table clearly shows the elements which can cause catalytic degradation of hydrogenperoxide.
Prussian Blue test
In the texil e industry the following metal catalystsare the main ones encountered: • iron (mostimportant damagingelement) • copper (fromviscose manufacture) •manganese(oftentogetherwith iron) Only traces of other metalsare found.
Identification of iron on the substrate
It is possible to check the presenceof iron on textile fabricswith the PrussianBlue test.
Without protection Classic sequestrant
Solution:
1g potassium hexa-cyanoferrate (II) trihydrate= K4[Fe(CN)6], 3H2O to dissolve in 100 ml 1N HCl. Then add 50 ml ethanol absolute. The fabric is soaked in the solution at room temperature, e.g. in a petri dish, for 10-15 minutes, rinsed with demineralizedwater and dried Fe positive:Blue staining on the fabric, according to the reaction below: 3 K4[Fe(CN)6] + 4 FeCl 3 = K4[Fe(CN)6 ] 3 + 12 KCl (Prussian Blue) Method:
Sirrix DNA
Test: Add Sirrix DNA 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. Sirrix DNA quantitatively complexes the iron ions in a hot alkaline medium. In this way the iron is sequestered and inactivated completely.
Iron complexation
Ant icat alyt ic effect and bl eachin g assi stant
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 oxycellulosecombined 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.
8
A free catalytic cation like Fe3+ in the bleach liquor causes exothermic decomposition Without protection Classic sequestrant which increases the temperature of the bath, forms considerable foam and finally precipitates insoluble ferric hydroxide. Sirrix DNA imprisons the destructive Fe 3+ 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.
Sirrix DNA
9
Stabilizer Trilogy Stabilizer Trilogy
An an tic orr osi ve effec t 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:
Formation of rust
Fe + 1/2 O2 FeO 2Fe + 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 surface which 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 g radually d issolves.
The range of sta bili zers for hydrogen peroxide consis ts of 3 basic products: Stabilizer SIFA , Stabilizer SOF and Stabilizer 2000. I t g oe s w it ho ut s ay in g t ha t a l 3 s ta bi li ze rs f un ct io n perfectly under all conditions and in all bleaching processes, h ow ev er s el ec ti on a cc or di ng t o th e c ri te ri a Efficiency, Economy and Ecology is preferable.
The"iron rod" test A piece of bleached cotton jersey is rolled round an iron rod a nd 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.
Preferredapplication Bleaching processes:
Pad Batch demineralization
Sirrix DNA
Other sequestrant
Material:
• cold pad batch • discontinuous • immersion • p ad sh or t s te am , 1- 2 m in • C ombi -St eam, 5-2 0 mi n •U-Box, J-Box, L-Box, 20-90 min • pad roll • c o mb in ed w i th b r i gh te ne re s • e col ogi ca l con st rai nts
Without protection
Linenand cotto ncontamin edwith Fe, Cu, Znand againstCa, Mg
Chemicals : 5-15 ml/l Sirrix DNA liquid 3-6 ml/l HostapalMRN liquid conc. Procedure:
- pad cold - batch 4-6 h atroom temperature - scour thoroughly
10
11
Penetration power (Tampex test)
Surfactant Trilogy • HostapalMRN liquid conc. • HostapalMRZ liquid • ImerolPCJ
The surfa ctants for bleaching must be good wetting agents s o t ha t th e f ab ri c p ic ks u p th e m ax im um amount of chemicalliquoras wellas good detergents in order to confer good absorbency to ensure perfect subsequent dyeing. The basic range contain s three surfactants which are suitable for bleaching cellulosic fibres:
: : :
nonionic, stable to 9°Bé, biodegradable nonionic, stable to 9°Bé, biodegradable nonionic, stable to 9°Bé, biodegradable
Foam formation (Ross-Miles test)
Scope of application : HostapalMRN
• cold pad batch bleaching • pad steambleaching withs eparate metering pumps • pad steambleaching with maximumpickup and separate meteringpumps • discontinuous bleachingon thejet and overflowwith highturbulence
HostapalMRN or HostapalMRZ HostapalMRZ ImerolPCJ
MRN
Comparative propertiesof the 3 surfactants: 90
84
70
Hostapal MRZ
60
Imerol PCJ
neutral
10
2 Surfactant (g/l)
Hostapal MRZ
14
18
10 7
6
0
Detergent power (EMPA test )
28
20
11
10
MRZ
34
30
24
1
Imerol PCJ
40
20
0
60
50
30 20
Hostapal MRZ
alkaline
44
40
70
Imerol PCJ
Hostapal MRN
74
60
54
50
PCJ
PCJ
79
80
Hostapal MRN
54
MRZ
neutral and alkalinewetting out with 2°Bé NaOH 90
Wettingtime in seconds
80
Stabilizer SOF Stabilizer SOF Stabilizer SOF St ab ili ze r SO F St abi liz er SI FA Stabilizer SIFA Stabilizer SIFA S ta bi li ze r S IF A St abi liz er 200 0
3
4
0
1
2 Surfactant (g/l)
Hostapal MRN
5
0 3
4 12
MRN
13 0.1
0.2
0.4
0.8
ml/l
The different bleaching processes (1) Singeing
Desizing
Impregnation
Steaming
Washing
Drying
Continuous bleaching processes: There are different types of continuousbleachingranges 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. Oneof the mostmodern ranges isas follows: • singeing at theentrance to themachine • desizing • intermediatescouring • wet-on-wet impregnation withmaximum 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 thesteamer • drying on heated cylinders.
— Singeing module: this must be adapted and synchronized with the resto f therange; this demandshigh fabric speed to avoid burning — Desizing module: after rapid impregnation the fabric passes, in the case of Benninger, into the Injecta module for rapid swelling of the PVA and other synthetic sizes as well as for rapid enzymatic bioconversion of thestarchby Bactosol HTN. — Impregnation module: afte r brie f inte rmediate scourin g on the Extracta, the material is impregnated wet-on-wet with maximum pic kup on the way to the Impacta module. The bath is fedby metering pumps and a computer ensures the exact amounts (in ml/kg) of the chemical products
— Prescouring module: at theexit of the steamer thisspecial Fortracta module ensures rapid extraction of the degradedimpurities carried by the fabric. The aim is to reduce the degree of contamination rapidly before proper scouring. — Scouring module: thanks to the speciall y designed passage of the fabric in the Extracta as well as theuse of countercurrent and a reduced consumption of water per kilo of fabric, itis possible to obtain a very high degreeof scouringwhile economizing in water and energy. — Drying module: the fabric passes over a battery of drying cylinders which ensure low resid ual humid ity. Overdrying is not recommended as this canlead to yellowingof the fabric and a reduction in its absorbency.
— Steaming module: in the Reacta compartment at100°C, thehydrogen peroxide is activ ated by the caustic soda and stabilized by Stabilizer SIFA to removenatural pigments and bleach the cottonwithout degrading it. 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 superiorfinal qualityo f bleaching.
14
15
Maximal add-on technique : Continuous bleaching with maximum pickup
Classic al wet- on-wet impregnatio n avoids inte rmedia te drying and the major risks involved such as lower a bs or be nc y, lo we r d egr ee of whiteness and insolubility of residual contamination. To e ns ure g oo d u nif or mit y o f bleaching and good reproducib ility strict control of the concentrations of the chemic als such as caustic soda, h yd ro ge n p er ox id e a nd t h e o th er chemic als is essential. With large volume impregnatio n troughs (5002000 litr es) it is not possib le to maintain all the concentratio ns of the p ro du ct s c on st an t in s pi te o f intermediate tit ration with out using highly concentrated reinforcing baths w hi ch a re o n th e t hr es ho ld o f instability.
Thanks to the new wet-on-wet impregnation modules with a maximum pickup of 150% and a bath volume reduced to 10-100 litres fed by separate mete ring pumps it is easie r to achieve homogeneity and consistency of th e qualit y of bleaching. This application by addition of the bath repla ces the old technique of repla cingthe bath with its many variables and imprecisio n. There are other advantages of this technique such as titration not required, less risk of breaks and markingin thesteamer thanksto thehigh pickup.
All the new continuous bleaching ranges today are equipped with an impregnation module for maxim um pickup with separatemeterin g pumps; a monitoring computer allows adaptation within seconds for each recipe and each fabric. The products are metered in mg/kg fabric. Titration is superfluous. This new technique has the advantages of efficiency (no scour boilin g required, one single stage), ecology (less chemic al load in the wastewate r) and high reliability.
16
17
Maximal add-on modules :
Maximal add-on modules :
BEN-IMPACTA (Benninger )
Flex-Nip (Küsters)
Better impregnation with controlled liquor pick-up
Fabric entry Pick-up:500-600g water
Fabric exit Pick-u p:900-1200gliquorwith chemicals
1 Fabric 2 Replenishing liquor 3 Flow / cleaning 4 Addi tion liquor (10 l) 5 Metal chassis 6 Compress ible pipe (air) 7 Water-tight lip Water within the fabric is replaced by chemicals
• Controlledliquor application • Penetration insteadof addition • Exact quantity of chemicalson the fabric
Chemicals metering station 1. 2. 3. 4. 5. 6.
Input Fabric weight Recipe
2-roller nip; adjustable 0.3-3 kN Divider insert Circulation pump Horizontal liquor flow Vertical liquor flow Chemical feed
Optimax (Menzel)
5 kN
1 Desized fabric, hot 2 Rowatex rollers 3 Liqu or feed line 4 Guid ed bath return 5 Precise regulation of pick-up 6 Liquor held in nip (8 l) 1. 2. 3. 4. 5. 7.
Feed pump Flow meter Control valve Level measurement Speed measurement BEN-IMPACTA
18
19
Dip-Sat Vario (Goller)
Steamers have different profiles dependingon the quality of the material to be treated, the size of production, the length of steaming according to the chemicalp rocess applied, etc. On a modular basis these steamers can be combined à la carte accordingto thedesired application.
three different methods for saturation of the fabric equal chemical distribution over the whole fabric width through overflow cascade equalizing roller to support even chemical pick-up driven fabric transport roller to minimize tension extremely low bath content no filtration required no reinforcement up of the bath required
Rapid steamer; 25-200 m capacity
Dosing system GOLLER-EXTRACTA
The REACTA Combi-Steam: Steamer withsi mple roller bed; 3-40 min dwell time
preselection of recipe on the PLC process controlled forced dosing of the chemicals promotional to fabric weight automatic adjustment to speed and pick-up of the fabric automatic supervision of chemical flow
Combi-steamer with simple roller bed; 3-40 min dwell time
20
To avoid breaks and irreversible folds durin g steamingthe fabric enters thesteamer in rope form specia lly for sensitive articles. The optimum passage for each type of article is automatically adjustedat the touchof a button. The rolle rs have a larger diameter to protect the material bett er again st fold s. The rolle rs are veryc lose in the Roller-Belt. The steamer is guaranteed withoutair with saturatedsteam.
21 Combi-steamer with double roller bed; 5-50 min dwell time
Open width washers:
Examplesof continuous bleaching ranges
The purpose of washing is to eliminate the maximum of the impuritiesas quickly as possible with as ilttle water as possible. Vertical passage of the fabricin the waterc an be single or double with or withouta pressing roller. Thelength of the passage of the material in an open width washer canvary between 30 and 15 meters. Atthe exit of thewashera squeezingroller elim inatesthe majo rity of the water. The addition of 3-4 Extracta washing compartments is enough to eliminate difficult substances such as caustic soda. The washingcapacity of a washercan be measuredby itssuitabilityfor eliminatingcaustic soda. Residualcaustic soda is measuredon the fabricbut also in thewashbath. In certain cases wheretreatment has been stronglyalkaline itis advisableto apply a final neutralization treatmentwith Sirrix DNA.
DA-6C withoutintermediatesqueezing 30 m capacity
D-6C withoutintermediatesqueezing 30 m capacity
DA-4 withintermediatesqueezing 18 m capacity
D-4 withintermediatesqueezing 18 m capacity
EA-7C withoutintermediatesqueezing 21 m capacity
E-7C withoutintermediatesqueezing 21 m capacity
EA-5 withintermediatesqueezing 15 m capacity
Thereare many combinations of steamers froma simple steamer for shock bleachingfor one minute up to scour boiling/bleaching in a single stage for 60 minutes. The choice of machine depends on the specificc onditions of the textile processor: thetype of articles, productio n, available budget, destinati on of the fabric and the availa ble space, etc. Complete ranges can easilyexceed 100 metersin length.
E-5 withintermediatesqueezing 15 m capacity
22
23
Küsters ranges
Benninger ranges
Pretreatment Ranges with FLEXNIP-Application System
Steaming
INJECTA
IMPACTA
safer : higher liquor quantity and subsequent lowered chemical concentration
more uniform : pure liquor addition without any liquor exchange and therefore constant chemical concentration
more protective : single-step process by dispensing a separate scouring stage and therefore less fibredamage
less pollution : less caustic soda use in contrast to a usual scouring step and far less residual draining liquor
more stable : reinforcement factors : FLE XNIP 1:1,2 - 1:1,5 vat 1:3 - 1:5
more savings : less investment in machinery, lower energyc onsumption; easy operation (omission of titration)
Single-step Bleaching range with Mäander-Washing Machines
Desizing
Washing
Impregnation
Washingaftersteaming
Neutralizing
PREYET-module Reagents/water
fabric
steam
Vacuum-module washing/ desizing
PREYETmodule
Vacuum-module short steamer
dry-vacuum (lint)
washing
singeing
24
Steamer
washing/ EVAC- washing desizing module
Flexnipimpregnation
washing EVACmodule
25
Babcockrange Goller range
CombiSteam
Desizing
DIP-SAT Impregnation
Bleaching
Washing after bleaching
Brugmanrange Liquortemperature:
Chemical treatment
SUPER-SAT Impregnating
Rinsing
60°C / 40°C Neutralizing afterwashing
Goller range Brubo-Sat : Single stage bleaching
Brubo-Sat Pretreatments : Enzymatic desizing (washing range) 2-4 ml/l Bactosol ® HTN 1-2 ml/l Hostapal ® MRZ temp: 70-90°C time : 0,5-2 min
Bleaching
Washing
DIP-SAT Impregnation
Washinga fterbleaching
26
MENZEL - single-step bleaching range with Optimax add-on system
UsualWashes (washing range) 1-2 ml/l Hostapal MRZ 1-2 ml/l Plexophor ECO pH : 7 -1 0 temp: 70-90°C time : 0,5-2 min
Protonic demineralization (washing range) 2-4 ml/l Sirrix ® DNA 1-2 ml/l Plexophor ® ECO 1-2 ml/l HostapalMRZ temp: 50-70°C time : 0,5-2 min
Alkalin e scour ing (steamrange) 1-2 ml/l Hostapal MRZ 4-8 ml/l Sirrix CRC 20-60 g/l NaOH solid steam: 1-20 min
Peroxidebleaching (steamrange) 6-8 ml/l Stabilizer SIFA 1-2 ml/l Hostapal MRZ 20-60 ml/l NaOH 50% 20-60 ml/l H2O2 50% steam: 1-20 min Final neutralization 2-4 ml/l Sirrix NE 1-3 ml/l Bactosol SAP temp: 20-50°C time : 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
27
Bleaching ranges for cotton tubular knits
This Brückner range ensures demineralizationof contaminatedcottons at the entrance to themachine evenbefore bleaching. This treatment with Sirrix DNA for 15 min at 75°C drastically reduces the calciu m, magnesiumand particula rly the iron content. The fabric is thenscoured and impregnated for pad steam bleachin g for 20 min at 100°C. The range can be used for whites for subsequent dyein g in which case the resid ual peroxide must be removed with Bactosol ARL during the washing/n eutr aliz atio n operatio n. The same range can be used for full whitesin which case a fluorescent brightener such as Leucophor BMF is added to thebleaching liquor. Attheend of the washingrange a softenercanbe appli ed.
1 Hot fabric 2 High hydro extracting with Rowatex-Cylinders 3 Liquor supply (preadjusted) 4 Guide for surplus-liquor 5 Exact and reproducible Pick-Up by pressure-adjustment for maximal Add-On 6 Liquor tank with minimal volume
Bleaching at 150% with Clariant recipe : Fabric : 100% Cotton Steaming time : 20 min Optimax-impregnation with : 6 ml/l HostapalMRZ li quid 8 ml/l Stabiliz er SIFA liquid 2 ml/l Sir rix AK liquid 40 ml/l NaOH 36°Bé 4 0 m l/l H2O2 50%
I mp reg nat io n
OPTIMAX : A one-stage bleaching system with high liquor application • Higher operating reliability thanks to more stable, concentrated feed liquors; no titrating necessary. • Higher absorbency and maximum whiteness along with very minimal cellulosic fibre damage. • Expansion of article assortment through higher uniformity of the liquor application. • Less danger of crosswise creases in the s teamer 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.
St or ag e U- Bo x
Protonic treatment 4-8 ml/l Sirrix DNAliq. 3-4 ml/l ImerolPCJ liq. 0.5 ml/l HostapalNAN liq. 15 min at75°C
28
R in si ng Im pr eg na ti on
St eam in g
Peroxidebleaching 4-8 ml/l Stabil izer SIF A li q. 15-25 ml/l NaOH 36°Bé 25-35 ml/ l H2O2 50% 6-8 ml/ l Leucophor BMF liq. 0.5 ml/ l HostapalNAN liq . Steaming: 20 min at 100°C
Ri ns in g 9 0/9 0/9 0/9 0/60 /60 /40 ° C
Neutralizing/Peroxidekiller 0.8% Sirrix NE li q. 0.5% Bacto sol ARL liq. WashboxNo. 5 at 60°C
Softening at40°C 2% CeralubeSVN liq.
29
Complete pretreatment with the WR system from MCS:
Bleaching ranges in ropeform (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.
1 = Entrance to the machine 2 = Impregnation saturator - eitherfor a hypochlorite bleach 2 g/l activ e chlorine 4 ml/l HostapalMRZ liquid - or for demineralization with Sirrix DNA 10 ml/l Sirrix DNA liquid 4 ml/l HostapalMRZ liquid 3 = J-Box, dwellcold for 10-15 minutes 4 = WR 4 tubes for scourin g 5 = WR 12 tubes for pretreatment tubes 1 to 2:
wetti ngout wit h 2 ml/l HostapalMRZ liquid
tubes 3 to 6:
peroxidebleach: 20 minutes at 90°C 1 ml/l HostapalMRZ liquid 4 ml/l Stabilizer SOF liquid 15 ml/l NaOH 36°Bé 25 ml/l H 2O2 35%
tubes 7 to 10: hot washin goff tubes 11 to 12:neutralizationwith 1-3 ml/l Sirrix NE liquid 1-3 ml/l Bactosol ARL liquid or softeningwith CeralubeSVN liquid
30
31
Influencing parameters: see table
The different bleaching processes (2)
The table shows theinfluence ofeach productin therecipe and the effectof varyingits concentration, weak-medium-strong.
Semi-continuous bleaching processes: Concentrations: weak-medium-strong
In these mi-continuous technique we differentiate between cold pad batch and hot pad roll processes. The difference between these two processes is the temperature and the type of batching. In the pad batch process the roll ed materia l is rotated at room temperature carefully covered with plastic film to avoid drying. In the pad roll process the impregnated and padded material is rolled in a hot chamber (90-100°C) for 1-2 hours. The quality of rinsing/washing off after bleaching is decisive for highdegreesof whitenessand good absorbency.
Product Stabilizer SOF
Cold pad batch bleaching Cold bleachingis oftencarried out in thetextile industrybecause itoffers the followinginterestingadvantages: — simple, inexpensiveinstallation — reducedconsumption of energy, reaction at room temperature — direct application on greyfabric straight aftersingeing — adequatedegree of whiteness and absorbencyfor various dyeing processes.
factor (ml/l) 3
6
Influence
degree of whiteness
positive
unchanged
absorbency
negative
DP values
neutral
residual size content
9
Hostapal MRN liq.
2
4
8
Sodium Silicate 38°Bé
5
10
20
NaOH 36°Bé
40
80
120
H2O 2 35%
20
50
100
Sodium Persulphate (g/l)
2
4
8
Batching (h)
12
24
48
Example of application : Theapplication itself is simple : singeing
grey fabric
impregnation
Example of a classical recipe Hostapal MRN liquid conc. Stabilizer SOF liquid Sodium silicate 38°Bé Sirrix AK liquid NaOH 36°Bé H2O2 35% Sodium persulphate Sandozin NAN liquid
batching without silicate / without persulph ate 5 ml/l 7 ml/l 80 ml/l 70 ml/l 1 ml/l
washing with silicate / with persulphate 5 ml/l 5 ml/l 10 ml/l 3 ml/l 80 ml/l 70 ml/l 4 g/l 1 ml/l
— singeing — cold impregnation — paddingat 80-100% pickup — rollingo n rollers, a plastic film protects againstdrying — batchingat room temperature for 16-24 hours with continuousrotation — intensive washingon an open-widthwasher.
Stabilizer SOF
:
Ho st ap al M RN c on c.
:
S od i um s i li c at e 38 °B é
:
Cau sti c so da 36°Bé
:
Hydrogenperoxide35% : So di um p er su lp hat e : — Cold impregnation, pickup ca.80%, batching at room temperature for 16-24 h — Intensive washing: 1st and 2nd bath with 1 ml/l HostapalMRN + 1 ml/l Sirrix AK at95°C, then washingoff and, if necessary, neutralizationwith Sirrix NE in the final bath.
32
toolow a concentratio n doesnotstabiliz eH 2 O2 sufficiently, too high a concentration blocks thebleaching reaction optimum : 6 ml/l thehighertheconcentration, thebetter willbe theefficie ncyof extraction optimum : 4 ml/l withoutsodium silicate a lowerdegree of bleaching must beexpectedas well as visible vegetable residues optimum : 10 ml/l toolow a concentration doesnot activ atethe H2O2 sufficientlyand the degreeof whiteness is lower; withtoo higha concentration there is a risk of loweringthe degreeof polymerization(DP) optimum : 80 ml/l above 80 ml/l thedegreeofwhiteness does notincreasesignificantly thisoxidizerimproves thedesizin g effectand thedegreeof whiteness optimum : 4 g/l
The optimum batching time is ca. 24 hours. At theend of the reaction spotting with titanyl chloride must remain yello wish which indic ates good stabilization of ther esidualhydrogen peroxide. HostapalNAN, a highly activ e deaerating agent, canbe added if excessive foamis formed due to the highspeed of the fabric fromsingeing to impregnation.
33
Cold pad batch bleaching with previous desizing on thesame range In the cold bleaching process rotation of the roll throughout batching is highly important. A certain amount of fo am formatio n can be observed at the edges of the roll. This foam shows that activation of the hydrogen peroxide by the caustic soda is takin g place and that theb leachingprocess is progressing as desired. If the foamdisappears afteronly 2-3 hours, this indicatesthat s ta bi li za ti on i s n ot o pt im al a n d t ha t t he b le ac hi ng r es ul t w il l b e unsatisfa ctory. In the ideal case, the controll ed formatio n of foam remains until the end of batching. This, of course, only applieswhen no antifoamshave been added. Whichever the case, the residual peroxide is determin edat theend of batchingby means of the titanylchloridetest. A positive result, yellowish colouration, shows that, thanks to the good stabilization, the fabric still conta ins hydrogen peroxide which will be beneficialduring subsequentwashing off.
Module 1 : Injecta desizing and wet-on-wetimpregnationfor bleaching Injecta desizing
grey fabric
washing
w/w-impregnation for CPB bleaching
impregnation
batching
Module 2 : Injecta desizing and Impacta for cold wet-on-wetbleaching INJECTA desizing
IMPACTA CPB bleaching
grey fabric
washing
Practicalremarks
Cold pad batch bleaching is often onlythe first stage because after the 24 h batching the prebleached fabric canbe given a pad steam scour boilready for dyein g or given a CombiSteam reble ach for high whites.
batching
impregnation
Recipes
enzymatic shock desizing
cold pad batch bleaching
Hostapal MRZ liquid Plexophor ECO liquid Bactosol HTN liq.conc. Stabilizer SOF liquid NaOH 36°Bé H2 O2 35%
4 ml/l 1 ml/l 1 ml/l – – –
4 ml/l – – 6 ml/l 60 ml/l 60 ml/l
Bath temperature Batching time
80°C –
20°C 16-24 h
Pad Batch/Pad Steam combination:
Enzymaticshock desizing eliminates sizes whichare sensitive to alkali (PVA) and makes it possible to greatlyreduce thea mountsof bleachingagents which ensuresa higher final quality.
53 35
34
The different bleaching processes (3) A versatile pro duct 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.
Discontinuous bleaching processes or treatment in a full bath: Discontinuous bleaching means that a certain quantity of material is submitted to an oxidizing chemical process for a certain length of time at a well defined liquor ratio (volume of water in relation to theweight of the material); long liquor ratio (20:1 - 50:1), short liquor ratio (2:1 - 6:1). As regards the transport or circulation, either the material moves (the bath stands still) or the bath circulates (the material stands still). As a rule, bleaching is foll owed immediately by dyeing on the same machine, after intermedia te 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.
Imerol PCJ Liquid ... removes contaminants from textile good - for good !
Contaminants sent into orbite Imerol PCJ
Thefollowingmachines canbe used (seealsodiagrams and photos): Jet/Overflow: short liquor ratio where thematerial circulates at highspeed. The chemicalproducts applie d must notproduce anyfoamat allotherwisetransport of themateria lwill be hindered. Jig: short liquorratio. The materialis rolle d up and thenunrolled whilepassin g through thechemical bath. In this way it passes throughthe bath many times. Part of the material remains in the air (cooling). Today, the new jigs are equip pedwith vacuum or submerged suctionto obtain bette r leveln ess of the effects. It goes withoutsaying thatthis type of machine is not ideal for final washing. Beam dyeing machine: herethe mate rialstands still andthe bath circulate s throughthe materialfrom theinside to the outside. Perfectwettingout guaranteesgood levelnessof theeffects. Package dyeing machine: the bath circulates fromthe insid e to theoutside of the bobbin as wellas fromthe outside to the inside. The alternati on frequency is defin ed. Perfect wetti ng out guaranteesgood levelness of the effects. Winch: long il quor ratio (20:1 - 50:1). The mate rial circula tes slowly in this machine. Foamis not particula rly disturbing. In somecases the formation offoam makesi t possible to use shorterliquor ratios (Sancowadprocess).
36
... and offers these major advantages : 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, protonic treatments, 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.
37
Humectol LYS Stabilizer SOF liquid
Elimination of oiling agents from textiles containing elastomericfibres before or after thermofixation. The different types of elastomericfibres
A specific stabilizer for silicate-free, alkaline peroxide bleaching of cotton and its component in fibre blends.
Oil/Water not miscible
Oil/Water emulsified
Properties of HumectolLYS : Stabilizer SOF liquid with its excellent properties is suitable for use in the silicate-free, alkaline peroxide bleaching of cellulosic fibresand their blends. Stabilizer SOF liquid is distinguished by its exceptional efficacy at low application amounts.
Extraction of oils, anti-redeposition, avoids spots and stripiness, improves handle and lustre, reproducible results, ecological profile, suitable for all techniques. simple covering
c or es pu n
c or etwisted
"Inf luence of pH"
20 min
10 min
80 2. Bleaching 3. Rinsing
The most important advantages are: 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-foaming universally applicable for continuous and discontinuous processes as well as the cold pad batch process is biodegradable
60
1. Protonic treatment
5. Dyeing 10 min
40 Hydrogen peroxide
with HumectolLYS
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 (2060°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.
" Inf luence of Temperatu re"
4. Enzymatic anti-peroxide treatment
Stabilizer SOF Liquid
20
without
Bactosol ARL
100 kg cotton jersey, liquor ratio 9:1 °C 100
tangled byAir Jet
Caustic soda
without enzyme
Bactosol ARL Liquid
with Bactosol CA (pH 5, 60°C, 30 min)
Sirrix 2UD Liquid Imerol* PCJ Liquid
0 0
20
40
60
80
100
120
Bactosol CA
140 min
Waterconsumption: 27 l/kg
38
Stabilizer SOF liquid provides all the advantages for efficient, economic peroxide bleaching
Différents Jets / Overflow
biopolishtest: fibrils recovery after treatment
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 peachskin effects on Tencel as a better handle on cellulosic textiles without damaging the fibre in any way.
39
Example : AirJ et-2000 (LAIP)
Example : SATURNO (Brazzoli )
1 Overflow 2 Turbo 3 Turbo and overflow pump 4 Overfl ow regulation valve 5 Turb o regulation valve 6 R eel with big diameter 7 Basket
Brazzoli S.p.A . has designed and manufactured the Saturno HTF, 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 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, Polynosicsand similar substrates. Special softwares enables programming of all the machine and dyeing cycle parameters.
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.
8 Filter with high filtering surface
Therefore, the processing of today's fashionable articles such as cotton/lycraand polyest er/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 f or 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.
40
Temperatur e : Pr essure : Liquor ratio : Max im um sp eed : Maximum capacity :
140°C 3 bar 2:1 - 3:1 600 m/mi n 200 kg per tube - base 300 gr/m tlin
41
Example : Bleachstar (Scholl)
Example : Rapid Suau-2000 FLB (ATYC)
Bleachstar ®
Following the history of new machinery developments, ATYC are once again on the forefront of the new technology in launching the F-FL series with Intelligent regulation and the following advantages.
The most economical way to produce high quality whites The 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%.
Dyeing after bleaching
Versatility Using the double Overflow/booster system 1 (patented), independantly adjustable, giving the facility to process all kinds of fabrics.
Fabric relaxation The storage chamber 2 is longitudinally inclined avoiding compacting of the fabric.
Example : TurboFlow (Brazzoli) Functional diagram of the machine working with Overflow and Turbo principle simultaneously
Rapid dye cycles and maximum loads also on lightweight fabrics Due to the double transport tubes 5, fabric speeds, up to 600 mts/min 3, 8 liquor exchanges per minute 4 and inclined storgechamber 2.
A Overflow B Turbo C Overfl ow pump
Low liquor ratio Because of its inclined storage chamber 2 and a rapid transfer of dye liquor back to the pump 4.
D Turbo pump
Simple operation Loading/unloading at floor level without using platforms and circulation of the fabric can be seen through the inspection window 7.
E Turbo regulation servodrived valve F R eel with big diameter G Basket
Trouble free operating conditions The 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.
Long life The machine is constructed entirely in stainless steel AISI316.
H Filter with high filtering surface I By-pass valve
42
IntelligentRegulation is patented by ATYC
°C
43
100
High Speed (HS)-Process; Mega-Combi
30 80
10
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, DrimareneHF dyes. The advantages are: rapid process, savings of water and energy, high degree of safety and total reproducibility of the shades.
Standard scouring process
60
Dyeing! 20 40
°C
100
Overflow
20
2 g/l Soda Ash
pH 5 withSirrix 2UD
20
1.0 g/l ImerolPCJ Liquid 2.0 g/l Sirrix 2UD Liquid
0.1-0.4 g/l Sirrix NE (pH 6.5-7)
0 0
80
20
40
60
80
100
Bactosol CA B ac tos ol AR L
120
140
min
Dosing
Soda ash °C
Migration
100
30
One bath-two stage peroxidebleaching process (for normal soiled goods)
Alkali
D ri ma re n HF
Peroxide
60
Salt
40
Ladiquest 1097
ImerolPCJ Sirrix 2UD
80
10 20 60
20
0.1-0.4 g/l Sirrix NE (pH 6.5-7)
5
40
2.0 ml/l HydrogenPeroxide50%
Dyeing! 0
5
0
20
1.2 g/l NaOH Flakes
15
30
45
1.0 g/l ImerolPCJ Liquid 2.0 g/l Sirrix 2UD Liquid 20
0.15 g/l Bactosol ARL conc.
40
75
90
105
min
°C 100 45
0 0
60
Two bath bleaching/brightening process for maximum degree of whiteness
20
60
80
100
120
140
160
min 80
°C
100
0.75 g/l ImerolPCJ 2.0 g/l Sirrix DNA Liquid (5 g/l ArostitBLN gran)
30
Two bath peroxide bleaching process (for heavily soiledg oods)
80
10
0.75 g/l ImerolPCJ Liq. 2.0 g/l Sirrix DNA Liquid
Dyeing!
60
0.1-0.4 g/l Sirrix NE (pH 6.5-7)
20
60
20
10 5 0.15 g/l Bactosol ARL conc.
1.2 g/l NaOH Flakes
0 20
40
60
80
100
20
120
140
160
44 min
5
20
0.5 ml/l Imerol PCJ Liquid 5.0 ml/l HydrogenPeroxide50% 0.6% Leucophor BSB 1.2 g/l NOH Flakes 0.5 ml/l Stabilizer SOF
20
0.5 ml/l Imerol PCJ Liquid 0.5 ml/l Stabilizer SOF Liquid 2.0 ml/l HydrogenPeroxide50%
20
0
0.1-0.4 ml/l Sirrix NE (pH 6.5-7)
40
40
5
10
2-3% DestofilLC or CeralubeJW
45
0 0
20
40
60
80
100
120
140
160
180
200
min
Different jigs
Different package machines
Example: Turbo-Jigg (TVE-ESCALE) with submerged suction
Example: Beam dyeing machine (ICBT)
Traditionally, jigs base their working system on passing the fabric through a chemical bath. TurboJigg® 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. 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 the impregnation process.
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 machi ne (ICBT) Example: Vacu-Jigger (Henriksen)
Pretreatment/bleaching of cross-wound packages, complete cycle: bobbinsof cotton Demineralizationwith Sirrix DNA 2 ml/ l Sirrix DNA li q. 3 ml/ l HostapalMRZ liq. 20 min at70°C rinse, then Alkalinescour boiling 20 ml/l NaOH 36°Bé 1 ml/ l HostapalMRZ liq. 1 ml/ l Sirrix DNA li q. 40 min at110°C rinse, then Peroxidebleaching 6 ml/l H2 O2 35% 3 ml/l NaOH 36°Bé 1 ml/ l Stabiliz er SOF li q. 1 ml/ l HostapalMRZ liq. 40 min at110°C, rinse, then antiperoxide treatment withBactosol ARL
P re tr e at m en t /b l ea c hi n g completecycle: grey cottonfabric
46
TwinJig (Küsters)
on
the
Enzymaticdesizing 3 ml/l Bactosol MTN liq. 3 ml/l HostapalMRZ liq . pH 6 withSirrix 2UD 4-6 passages at 65°C rinse, then Alkalinescour boiling 15-30 ml/l NaOH 36°Bé 2 ml/l HostapalMRZ liq . 1 ml/ l Sir rix DNAliq. 4-6 passages at90-95°C rinse, then Peroxidebleaching 8- 15 ml /l H2O2 35% 4 -8 m l/ l N aO H 3 6° Bé 1 ml/l Stabili zer SOF li q. 1 ml/l HostapalMRZ liq . 4-6 passages at90-95°C rinse thenantiperoxide treatment withBactosol ARL
j i g,
Vacuum suction and elimination of the contaminated water Rinsing ramp Spraying with water 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.
47
Winch
Processing Centre for Pretreatment, Dyeing and Special Treatments
Bleaching/optical brightening of 100% cottonknit goodson thewinch: Protonictreatment 2 ml/ l HostapalMRZ liq. 1 ml/ l Sir rix DNAliq. 15 min at 60°C rinse, then Bleaching/opticalbrightening 6 ml/l H2 O2 35% 3 ml/l NaOH 36°Bé 1 ml/ l HostapalMRZ liq. 0.5 ml/l Stabilizer SOF liq. 0.8% Leucophor BSB liq. 50 min at 90°C rinse, soften
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.
48
Winch HaspelflowB (Brückner)
49
Definition
Exactly your chemistry
Mercerizing
Mercerizationis a strongly alkalineprocesswith irreversible alteration of the physicalcharacteristics and appearance of cellulosic fibres by swelling. During mercerization or causticizing the cottonfabric, knit or thread is submitted to a treatment with concentrated caustic soda between 18 and 32°Bé NaOH. The interactio n between the caustic soda and cell ulose creates a serie s of physico-chemical modifications to the cellulosic fibre and modifies itsproperties entirely. Themain modifications are: – destruction of thecuticle – increaseof the internalsurface of thefibre – the microscopic cross-section shows swelling of thecellulose – increasein the reactivityof the cellulose – thelumen disappears – bettersuitability for finishing treatments – the fibres twist intospiral coils – betterresistance to chemical products, microorganisms, sunlight, etc. – thefibres are shortenedby 20-25% – significant increasein dyeing affinity by upto 25% – the macromolecularstructure of thecellulose ismodified – bettertensile strength – thec rystallinezones of thecellulose are orientedalong the axis of the fibre – betterdimensionalstability
Pretreatment Handbook
Mechanisms Depending on the concentration of thea lkali we differentiate an additive reaction (formula 1) and a substitutive reaction (formula 2) withformation of sodium cellulosate. (1)
CEL-OH
+
NaOH
CEL-OH , NaOH
addition
(2)
CEL-OH
+
NaOH
CEL-ONa + H2O
s ubs titu tion
Durin gcaustizingthe twoformulaecoexist: (3)
untreated
treated
CEL-OH , NaOH
CEL-ONa + H 2O
The baryta index indicates the degree of mercerization. This index expresses the ratio between the absorption of Ba(OH)2 (bariu m or baryta hydroxide) by a mercerizedcotton and that absorbedby an unmercerized cotton. The index of a mercerizedcotton sample can vary from115 to 165 dependingon thedegree of mercerization. A barytaindex above150 indicates thatmercerization is complete.
Pretreatment
2
Advan tag es of mercerizing tages mercerizing Example of titrationof Ba(OH) 2 and determination of thebaryta index:
• Dyeing affinity
– 10 ml Ba(OH)2 solution, reference solution requires 24.3 ml HCl0.1 N for neutralisation – 10 ml Ba(OH)2 solution, an unknownsample requires19.58 ml HCl0.1 N – 10 ml Ba(OH)2 solution, a standard unmercerized cottonrequires 21.20 ml HCl0.1 N
Dyeing / Printing
Thebarytaindex is calculatedfor theunknown sampleas follows:
24.30 19.58 100 152 24.30 21.20
• Brilliant colours • Tinctorial strength • More homogeneous tone-in-tone shades • Dimensional stability
it is essentia l to repeat the measurements 3 timesto obtain a meanbarytaindex
Mercerization
Finishing
• Dynamometric resistance • Tensile strength • Suitability for finishing
• Brilliance • Handle
Appearance
• Coverageof dead/immature cotton • Regular geometryof the structure
Example:
3
Dyeingaffinity
4
Example:
Comparisonof theeffects withcold and hot mercerizing
• betterdimensional stability • better stabilityto washing • betterappearance
Influencing parameters
Mercerizing
cold
hot
DP
Effects
grey fabric bleached fabric
idem idem
idem idem
Tensile strength
grey fabric bleached fabric
idem idem
idem idem
Dyeing affinity
grey fabric bleached fabric
< >
> <
Br ill iance
gr ey fabr ic bleached fabric
< <
> >
Dimensional stability
grey fabric bleached fabric
< <
> >
Handle
grey fabric bleached fabric
> idem
< idem
Suitability for resin finishing
grey fabric bleached fabric
< idem
> idem
Influencing parameters are:
— Theoriginof thecotton. Dependingon the originof thecotton themercerizing effectsmay be more or e l ss pronounced. — The concentration of caustics oda or alkali. The best effectsare obtainedwith a caustic soda concentration of 28 to 32°Bé or 270 to 330 g/l NaOH solid. — The temperature. The lower the temperatu re, the greater the bril li ance because maximum swelling of the cellulose takes place between 12 and 15°C. A coolin g syste m is adaptedto keepthe alkalinebath at a lowtemperature. Modern machines are equipped with impregnation between 50 and 60°C. The cellulose swell s more rapidly than at 15°C and thedyeingaffinity is ata maxim um. On the old machines for cold mercerization (15°C) the fabric speed was 20-30 m/min comparedto 100 m/min on the new hot mercerizing machines.
When to mercerize ?
Mercerizingcan be carried out at variouspoints duringthe pretreatment cycle of thec ottonfabric:
— Thetime. Complete swellingof the cellulose takes place in 30-60 s withNaOH. Withliquid ammonia the time is reducedto between15 and 20 s. On principle, the more rapid ly the cellu lose is impregnated with lye, the more rapid will be the swell ing, which is the reason for addin g a mercerizin g wetting agent such as MERCEROL QW-LF. The relationship betweentime and temperature is decisive for swelling. — Thetension overthe width and lengthof thefabric. Stabilizatio n is essential to obtain the maxim um effect and rinsing must be carrie d out under tension. In this way the reorientation of the molecular chains makes it possible to obtainmaximum dimensional stabilityand brilliance.
5
— On grey material. The only advantage is thatthe fabric is dry on entering the lye which avoid s the varia tions in concentration of the wet-on-wet technique. On theother hand thedisadvantagesare considerable: contamination of the lye by the desizing agents, singeing dust, natural impurities in the cotton, etc. This lye is no longer suitable for recycling. Danger in thecase of sizing with PVA. Cotton knit goods and yarncan be mercerizedin the grey state. — On desizedmaterial. The situation is better thanon greyfabric as far as contamination of the lye is concerned. It is essential thatall sizes, particularly PVA sizes, are removed. In time this lye is also contaminatedby the naturalimpurities in thecotton. — On scour boiled material. This is a suit able point for merceriz ing. It is necessary to rinse the fabric well to eliminate the alkali so as to avoid differences in the NaOH concentration during mercerizing. By mercerizingscour boiledc ottonit is possible to avoid the problemsof mercerizing bleached fabricsuch as loss of the degreeof whiteness and reductionof absorbency. — On bleachedmaterial. Todaythisis thebestpoint for mercerizing cotto n fabric s. Thedyeingaffinity andbrilliancewill beat a maximum. The lye will be veryclean forproblem-freerecycli ng.Mercerizing bleachedgoodsallowsbettercoverageof breaks, folds andphysicalfaultscausedby passageon the Roller-Belt duringpad steamperoxide bleaching. — On dyed material. Thepurpose is to increase thetensilestrength of thefabricand make it more suita ble for fi nishingprocesses inclu dingsynthetic resin finishing. It is obviousthat the dye must be stable to concentrated caustic soda.
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Shrinking burette 50 ml / Test
MERCEROL QWQW-LF: th e mercerizing mercerizing wetting agent
Shrinkage action Apparatus :
Ther ole of the wettingagent is extremely important duringmercerizing in a stronglyalkaline medium. It increasesthe speed of penetration of the lye into the deep layers of thetextile substrateto allowrapid swellingof thecellulose. Withoutthe wettingagent mercerization is only superficialand peripheral(researched for fabrics intendedfor washed out fabricsand denim).
Material : Concentration of lye :
Theperformance of the wettingagent isjudged by:
Additives :
– thew ettingpower between18 and 32°Bé NaOH – thes hrinkingeffect of thefibre between18 and 32°Bé NaHO – the foaming behaviour between 18 and 32°Bé NaHO – theb iodegradability – thee cologicalprofile: absence of solvent, cresol and other toxic substances
Temperature :
– increasesthe brilliance – confersa supple, full handle – causes high initial and final shrinkage – ensuresa regular appearance of thematerial – promotesabsorption of dye – guaranteesimpeccable results both on hightwist yarns and tightly woven fabrics thanks to the penetrated wettingout of the material.
7
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 mmdivision 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 mm should be read aft er 5 - 10 - 15 - 30 - 45 - 60 - 90 seconds. Evaluation : The shrinking values read in mm should be converted into a percentage of the total length of yarn by the following formula : shrinking in mm 2 % shrinkage 10 into a percentage of the total length of yarneight 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) 8 • 90 seconds (final shrinkage). Procedure :
Thanks to its goodsolubil ity, itsstronganionic character and its wideregion of activity between18 and 32°Bé NaOH, Mercerol QW-LF is suitablefor mercerizing because of the following properties
Shrinking burette with a cooling jacket and rotating thermostat. Steel weight with hole, =8 mm, l=30 mm, weight approx. 11g Stop-watch
Shrinkage test
Foaming behaviour
shrinkage in sec. (for 50% shrink) at 26°Bé NaOH
shrinkage in sec. (for 50% shrink) at 30°Bé NaOH 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 NaOH Concentration of surfactant : 5 g/l Test temperature : 18°C Foaming behaviour and foam stability should be written down in the test report : Productdoes not foam foams a little foams moderately foams strongly foams very strongly Foam persists slowly subsides quickly subsides
— Mercerol QW-LF — Competitor 1 — Competitor 2
wetting time in sec. at 26°Bé NaOH
foam in cm at 26°Bé NaOH
MERCEROL QW-LF
Wetting test
Comp etitor 1
Competitor 2
Comp etitor 1
Competitor 2
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. Overflow Material :
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.
Procedure :
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.
Evaluation :
wetting time in sec. at 30°Bé NaOH Foam Liquor
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.
9
Gas washing bottle with integrated filter plate Volume: 500 ml
The profile of a mercerizing machine is directly connected to the formof the substrate, i.e. woven, knit(tubular or knit) or yarn. Themachine is built for true mercerizing with 250-350 g/l NaOH solid for better brilliance and dimensional stabil ity or for simple improvement of dyeing affin ity with concentrations of 170-200 g/l NaOH solid by causticizing.
Step 1 : Intensive impregnation in hot lye
Automatic s trong lye contr ol 1. Feed of fresh lye in any concentration (raw lye, lye from the condensation unit) 2. Feed of diluent(wate r, weak lye in any concentration) 3. Process lye 4. Control for lye concentration 5. Control for lye amount 6. Control for lye temperature
Thec lassicalfunctionalparts and zones of a mercerizing machine for wovenfabric are: — the impregnationz one with concentrated lye for wet-on-wetor wet-on-dry application — the reactionzone where swellingof the cellulose starts — the stabilization zone under tension where thelye is dilutedby countercurrent from28°Bé to 8°Bé — the washingzone and theneutralizationzone.
Installation for light woven fabrics which are easy to impregnate React ion
Stabili zat ion
10
BEN-Dimensa advantages : four tuned steps guarantee optimum results
Profile of a mercerizing machine for woven fabric; type DIMENSA (Benninger)
Impregnat io n
MERCEROL QW-LF
Filter plate
Machines and mercerizing technology The first merceriz ing trials were carriedout in 1850 by John Mercer who had noticed the change in chemical properties of cotton submitted to high concentrations of caustic soda of about 300 g/l NaOH solid; in particular, swell ing of the cellu lose, considerable shrin king of the textile substrate and the release of heatas well as better dyeingaffinity, better dimensional stabilityand greater brilliance.
foam in cm at 30°Bé NaOH
Neutralization and washing
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 of over 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 at lye extraction. The versatility of the BEN-DIMENSA permits every textile result concerning the mercerizing effect. This is achieved by objective selection of the process parameters such as : — Lye temperature — Lye concentration — Lye reaction time — Fabric lengthwise and crosswise tension
Chainless prin ciple
Double Impregnation
Chai n princip le
Stabilization
A Processor B Impregnation C Stock tank D Heating E Measuring vessel concentration F Temperature feeler G Level measuring sonde
Chainlessprinciple
Neutralization and washing
11
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.
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Step 2 : The reaction t akes place during the dwell ti me
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.
Step 3 : The BEN-DIMENSA memorizes the fabric dimension s The uniformly applied lye is now to be removed. On the BEN-DIMENSA MS and the BENMINI 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.
On the BEN-MINI MERC there is no reaction compartment and the fabric is pinned to the stenter frame immediately after impregnating. At the speeds usual with this type of machine the dwelling time in the stenterzone suffices.
No selvedge to middle differences occur with the BEN-DIMENSA The reaction takes place in the entire zone from impregnation to the stenterframe. The proven Benningerchainless 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 ML the dwelling zone consists only of the chainless impregnation and reaction compartments.
Lye extraction on the stenterf rame 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 stenterframe. 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.
On the BEN-DIMENSA MC the fabric is pinned to the integrated stenter frame at the end of the reaction compartment.
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.
Mahlo system for "on line" measuring of the pH after washing off after mercerizing The CHEMCON CMC rap id measuring method for the pH value and conductivity in continuous washing processes • Continuous recordi ng of the pH value and conductivity on the running goods • No impairment of the substrate • Improvement of the finishing quality
water-steam mix
• Optimization of process flow
Lye extraction begins in the stenter frame
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Core-neutralizing of the fibres with Sirrix NE
pH
For 1 Liter solution 10 ml/l Sirrix NE li q.
1414
Auto mation of m easuri ng and con tro l syst ems Extract
Calculation unit
pH... . . . S / cm
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Profit f rom the advantages of BEN-DIMENSA Width gain and hig h dimensional stabil ity are compatible on the BEN-DIMENSA You 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
With Acetic Acid 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 to neutralize the textile material to a pH between 7 and 8.
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.
Neutralized surface
Constant warp density over the whole fabric width An increase number of ends in the selvedge zone leads to pa ttern distortion 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.
NaOH Acetate blocking buffer zone
The BEN-DIMENSA fulf ils textile producers' wishes
With Sirrix NE liq.
13
1212
Traditional mercerizing results with selvedge thickening and deviations in weight per unit area.
Neutralized core
11
BEN-DIMENSA corrects irregularities caused processing and increases the stabilized fabric width.
by
Mercerizing and Neutralizing on Dimensa-Machine
1010 9
88
Sirrix NE liq.
7
66
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.
5
44 3
22 1
0 00 0
50 5 0
100 1 0 0
150 Volume NaOH 1N (ml) 1 5 0
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Mercerizing machine EcoMerce (Kuesters) BEN-DIMENSA MS 4
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 Ecomerceprocess. 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 d well 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.
Combination of chainless system and stenter frame 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
Balance concentration (~300g NaOH / L) t c e f f e g n i z i r e c r e M
Add-on mercerizing EcoMerce (60-70°C) Hot mercerizing (60-70°C) Cold mercerizing (15-20°C)
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)
BEN-DIMENSA MS 1 Combination of chainless system and stenter frame for speeds of 20-100 m/min • washing and neutralizing of a separate washing machine
ECOMERCE
Time (sec)
EcoMerce versus conventional mercerizing
New mercerizing technology with caustic soda addition and a defined extension in width and l ength BEN-DIMENSA KNIT Small machine for knit goods for speeds of 2-20 m/min
Technical Data : Useful width UW (increments 200 mm) 1600-3400 Overall width UW +1850 mm M ax im um he ig ht (f ab ri c i nf ee d) 3 00 0 m m
1. Flexnip (addition of caustic soda) 2. Diffusion compartment 3. Squeezing rollers 4. Length stretching zone 5. Width stretching zone 6. Stabilization compartment
Speeds : - B e n- Di me ns a M S 4 - B e n- Di me ns a M L 3 - B en -D im en sa M S - B e n- Dim en sa K ni t
2 0- 10 0 m /m in 2 0- 15 0 m /m in 2 0- 10 0 m /mi n 2 -2 0 m /mi n
Fabric content of modules : - I m pr eg na ti on com pa rt me nt - R eactio nc ompar tment - Stabilizing compa rtment
7 .5 m 5.8- 8.5 m 8.5 m
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18
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
Ecomerceco ntinuous chainless mercerizing rangewithroll er stretching unit
Roller stretching unit
Actual value
T e ns i o n c on t o rl
Technical Data
T a r ge t v a l u e
Pin wheel stretching unit
Differential drive
Working width
900 ... 3400 mm
Fabric speed
max. 120 m/min
A Stretching process inwarp direction
Widthafterstretchingzone
EcoMerce mercerizing machine
Stretchingproc ess i n w e f t dri e ct i o n
Diffusioncompartment (2modules); high efficiency squeezing units
B Stretc hing process inweftdirection
F a br i c w d i th
High efficiencysqueezing units
EcoMerce; Stabilizing Section
Initial width
• Intensive stabilization: meander shaped liquor feed in cross and counter flow • subdivision in individual baths with rinsing liquor circuit • Cascade-type arrangement of the s ections • 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
Initial width Stretchingproc ess inwarp direction
Lengthafter stretchingzone Fabric length
Widthafterstretchingzone
Initiallength
Technical Data
19 Ecomerceco ntinuous chainlessmercerizing range with pinwheel stretching unit
St ab il izi ng mo dule
Hi gh ef fic ie nc ys qu ee zin g u nit s
Working width
900 ... 3400 mm
Fabric speed
max. 120 m/min
20
Mercerizing with liquid ammonia
EcoMerce Pin Wheel Stretching Unit For defined warp and weft stretching
Theliquidammoniaprocess is a unique processusingthe NH3 moleculeat -33°C. This process has become irreplaceable for 100% cotton for non-iron shirts. Summerclothing of 100% cellulo sic fibres is appreciated for its wearing comfo rt and easy care. The same appli es to home wear. Workwear of 100% cott on treated with liquid ammoniais becoming increasinglypopular for demanding end uses (hospitals, kitchens, ships) and the easier care offered (reduced wear and tear, drying tunnel with out ironing). Combined with a flameretardantfinish, liquidammonia treatment is suitablefor protectiveclothing.
• Combined length and width stretching zone between diffusion and stabilization • 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.
Processes Technical Data working width
In the SANFOR-SET processthe NH3 is appli edcontinuously to thecottonand theammonia is eliminate d by evaporation durin g passage overa hot cylin der. This process is calle d the dry NH3 process. In the recent BEAU-FIXE process fromVERAMTEX, theNH 3 is removed from the fabric by washing. The totallysealed machine recovers and recycles the ammonia. There is no risk of ppmof NH3 in thesurrounding air. Swelling of the cellulose takes place in 10-15 seconds in the Beau-Fixe process.
900 ... 3400 mm
max stretch in width direction
150 mm
max. st ret ch i n war p di re ct o in
dep endi ng on cl ot h t ensi on and mat er ial Theimportant parameters of theBeau-Fixe process: – a constant temperatureof -33°C; theboiling temperature of NH3 – a stable concentration of 100% NH3 liquid – demineralized waterwithout additives – complete reactionwithin a fewseconds
Stretchingprocess inwarp direction
Stretchingprocess inweft direction
Initialwidth
Width after stretchingzone
21
The Beau-Fixe process advantages
22
Processe and Machine
Natural and practical The particular qualities of natural fibres are emphasized. 100% natural fibres can be employed without their traditional drawbacks.
Luxury Products are lustrous and have a more luxurious appearance. The handle is softer and more lively.
Dimensional stability Dimensional stability is greatly improved (*)
Machine washing Fabrics are stronger and easier to care for. They dry more quickly. Machine washing of linen has become possible.
Dry crease recovery All the advantage of clothing which does not crease during wear (*)
Colour fastness Dye affinity is increased and colour fastness to light and washing is improved
A Dipping in liquid ammonia at 33°C B Rinsing in pure water C Drying D Recovery,purificationand recycling the ammonia 1 Liquid ammonia at -33°C 2 Ammonia vapor 3 Pure water 4 Ammonia solution 5 Water recovered and recycled • A quint essentially eco logic al process A 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.
Easy-care or no n-iron The crease recovery obtained enables workwear garments to be processed in tunnel finishing. It eliminates or greatly reduces the need for home ironing (*)
• A versatil e process Cotton, linen, ramie, regenerated cellulose. Beau-Fixe is the only process for treatment of both knitted and woven fabrics. Better quality The 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.
•Quick service Collection and return of goods in 7 days within 1.000 km of Brussel
23
•an experienced team Our team can advise you on adapting your finishing processing to the new fibre properties.
An efficient process that transforms the fibre in less than 10 seconds.
24
Appl icati ons Cotton 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 creaserecovery results. Without ammonia treatment, the fabric would tear or wear very quickly. Dyed or undyedfabric ? 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. Workwear Here, 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. Velvet The fabric keeps its beauty longer and washing does not flatten the nap.
Linen
Lyocell
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-towear natural fibre with an ecolo gical maintenance treatment opens up new horizons. The fabric's handle is particularly improved with Beau-Fixe.
Denim
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 trousers below were washed 20 time. The difference in treated/untreated appearance is clear: the treated-fabric leg is smoother, less discolouredand longer than the untreated fabric.
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.
Beau-Fixe is a treatment that replaces mercerization to advantage, with effects that surpass those obtained with mercerization.
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)
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 !
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
25
26
Mercerizing cotton cotton knit goods goods Others Mercerizin gwoven fabrics doesnot pose to o many technicalproble msbut thisis nottrue for knitgoods. In the mid-70s mercerized cotton knit goods were produced almost exclu sively with mercerized yarns. Therapiddevelopmentof highquality cotton jersey clothingmade an adaptation of the mercerizing method essential. Mercerized yarns produce a highly brilliant cotton which is readil y dyeable but it is extremely expensive and poses certain technic al problems, such as the differences in tension between the insid e and outsid e yarns when drawing out the hanks during mercerization which in turncause unlevelness. Furth ermore, mercerizationof theyarns doesnot improvethe dimensionalstability of the finishedpiece of jersey.
Knitwear When 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. Jersey Jersey must be tube-treated to avoid having the selvedges roll. Heavier knits, such as interlock and rib fabric, may be treated open width.
In contr ast to the relatively stable woven fabrics, ela stic cotton knit goods shrink far more durin g swell ingin the caustic soda and cannotbe keptunder constant tension on the guide rollers of the machine. The materialshrinks more in the crosswisedirection atthe edges than in the middle and the resulting mercerizin g differences automatic ally cause proble ms in dyein g. For tubular knitgoods special mercerizin g machines were developed to reduce the technicalproblems to a minimum.
Other plant fibres, such as hemp and ramie The 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.
Major problem when mercerizing cotton knit goods
Technical fabrics Thanks 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.
Selvedge densification
New developments for wool and aramids Preliminary 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.)
Selvedge densification
27
caustification compartment
stabilization compartment
28
DORNIER - Mercerizing range for tubular knit goo ds The numerous continuously operating DORNIER mercerizing machines all 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.
DORNIER - Mercerizing range for tubular knit goods 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 everydiameter. • 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.
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 a pplied to the fabric has been substantially increased by recycling. This increases the stabilizing effect.
• Heat exchangers guarantee uniform, exact temperatures in 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
A =
NaOH - impregnating and rea cting section
B=
stabiliz ing section
C =
washing section
D=
neutrali zin g section
A B C D F G H I K L M P R S
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Lye preparation tank Agitator Filte r box (NaOH) Filt er box (H2O) Tank, upper Tank, lower Washing tower Coolin g section Metering pump Density and liquid level control Washing trough Automatic temperature control Pump (NaOH) 1 Pump (NaOH) 2
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DORNIER -T he 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.
Bleaching machine for tubular knit goods with impregnating-p reheatingand dwelling zone as well as washing sections.
Standstill times in mercerizing can thus be utilized for bleaching. This concept guarantees full exploration of the machine in an extremely economic manner.
Combin ed mercerizingand 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.
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 8 ml/l 30 ml/l 40 ml/l
Combin ed mercerizingand bleaching range in compact layout, consisting of: impregnating, reaction and washing sections for mercerizing or, impregnating section, heatingand dwelling zone as well as washing sections for bleaching.
Hostapal MRZ liq. Stabilizer SIFA liq. NaOH 48°Bé H2O2 50%
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