PRINTING OF WOOL

R.B.CHAVANDEPARTMENT OF TEXTILE TECHNOLOGY

INDIAN INSTITUTE OF TECHNOLOGY

HASU-KHAS, NEW DELHI 110016

INTRODUCTION

• PROPORTION OF WOOL PRINTING IS VERY LOW

COMPARED TO COTTON

• COMMERCIAL REASONS THAN TECHNICAL

REASONS

• BASI FABRIC COST, COST OF SAMPLES, SHORTER

RUN LENGTH , MAKE PRINTED WOOL EXPENSIVE

• THERE IS RENEWED INTEREST IN THE PRINTED

WOOL DUE TO ENVIRONMENT FRIENDLINESS AND

NON-FLAMMABILITY.

PREPARATION FOR PRINTING

• EMPHASIS ON EFFICIENT FABRIC PREPARATION TO GET LEVELNESS, GOOD COLOUR YIELD AND BRIGHTNESS OF PRINT.

SETTING• NECESSARY TO RELAX AND STABILIZE CLOTH

BEFORE SCOURING.

• CARRIED OUT BY CRABBING EITHER CONTINUOUSLY OR DISCONTINUOUSLY

• PLAIN WEAVE CHALLIS AND WORSTED TWILL WIDLY USED FOR PRINTING REQUIRE SETTING BEFORE SCOURING

SCOURING

• TO REMOVE NATURAL WAXES, PROCESSING OILS, DIRT

• SIZE IN CASE OF LIGHT WEIGHT FABRICS

• CONTINUOUS AND BATCHWISE SCOPURING METHODS ARE USED.

MILLING

• LIGHT MILLING IS SOME TIMES EMPLOYED TO IMPART DESIRED FINISH TO CLOTH.

OXIDATIVE PROCESSES

• CHLORINATION- THE TRADITIONAL METHOD FOR PREPARING WOOL FOR PRINTING.

• REACTION OF WOOL WITH CHLORINE IS pH DEPENDENT

• STRONG ACID pH: RAPID REACTION, LITTLE YELLOWING

• ALKALINE pH SLOW REACTION, SIGNIFICANT YELLOWING

CHLORINATION

• REACTIONS• CYSTENE OXIDATION• RAPID OXIDATION OF CYSTENE RESIDUES TO CYSTEIC ACID• PEPTIDE BOND CLEAVAGE• CHLORINE TENDS TO CLEAVE PEPTIDE AND PROTEINS AT

THE TYROSENE RESIDUE• ACID CHLORINATION: TWO FUNCTIONS• CREATES NUMBER OF STROGLY ANIONIC GROUPS SUCH AS

RSO3-, RCOO-

• BREAKS DISULPHIDE AND PEPTIDE CROSSLINKS MAKING WOOL MORE READILY ACCESSIBLE.

• EASY SWELLING BY WATER• MUCH MORE HYDROPHILIC FIBRE SURFACE• EASY ABSORPTION AND EVEN DISTRIBUTION OF PRINT

PASTE

CHLORINATION METHODS

• SODIUM HYPOCLORITE: TRADITIONAL METHOD

• pH 1.5-2

• CONTINUOUS METERING OF HCl OR H2SO4

• NOW SELDOM USED

• DICHLOROISOCYNURIC ACID

• COMMONLY KNOWN AS DCCA

• COMMERCIAL PRODUCTS

• BASOLAN DC (BASF)

• Fi-CHLOR CLEARON (CHLORCHEM Ltd)

• SOLUBLE SALT CONTAINING 60% AVAILABLE CHLORINE

• HYDROLYSIS OF DCCA IN WATER RESULTS FORMATION OF HYPOCLOROUS ACID (SCHEME 10.3 PAGE 335)

DCCA APPLICATION

• BATCHWISE APPLICATION• 3-4% owf • pH 3.5-4.5 WITH ACID• Temp. 20-250C • TIME 30 MIN• ANTICHLOR WITH REDUCING AGENT• BLEACH• MACHINES: WING, JIGGER, JET DYEING MACHINE• CONTINUOUS APPLICATION• PAD 35-50 gpl• WETTING AGENT 2 gpl• DWELL IN CHUTE 2-5 MIN.• RINSE, ANTI-CHLOR• BATCHWISE METHOD MOST COMMON

KROY TECHNOLOGY• USE OF CHLORINE GAS

• CONTINUOUS METHOD FOR FABRIC TREATMENT IN OPEN WIDTH

• CHLORINE GAS FROM CYLINDER AND WATER ARE PRECISELY METERED INTO CHAMBER

• CHLORINE GAS DISSOLVES IN WATER WITH THE FORMATION OF HYPOCLOROUS AND HCl ACIDS

Cl2 + H2O HOCl + HCl

• THIS ACID SOLUTION (pH 2) ALONG WITH WETTING/ANTIFOAM AGENT ADDED

• SPRAY ON FABRIC IN SPECIALLY DESIGNED CHAMBER

• CHLORINATING SPECIES REACT RAPIDLY WITH WOOL

• CHLORINE DDOSAGE IS ABOUT 4% owf

• SPEED OF FABRIC 10-15 m/min

• RINSING, ANTICHLORINATION AND NEUTRALIZATION IS DONE IN SUBSEQUENT CHAMBERS.

• SINCE THE INTRODUCTION OF KROY TECHNOLOGY THE PROBLEMS ASSOCIATED WITH THE PREPARATION OF WOOL FOR PRINTING APPEAR TO HAVE BECOME A THING OF THE PAST.

PRINTING RECIPE

ACID/METAL REACTIVE

COMPLEX DYE DYE

DYE X X

UREA 50-100 50

THIDIGLYCOL 50 -

WETTING AGENT 5-10 5-10

ANTIFOAM 1-5 1-5

ACID OR ACID DONOR 10-30 10-30

THICKENER(10-12%)500 500

WATER TO BULK 1000 1000

PRINTING RECIPE• UREA: AIDS DYE DISSOLUTIUON

HUMECTANT, PROMOTE WOOL SWELLING, DYE PENETRATION DURING

STEAMING• THIODDIGLYCOL: DYE SOLVENT• WETTING AGENT: NECESSARY IN CASE OF

INADEQUATE CHLORINATION

• ANTIFOAM: IN CASE OF MACHINE PRINTING• ACID COMPOUND: CITRIC ACID OR AMM.

TARTARATE OR SULPHATE• REMAZOLS ARE FIXED UNDER NEUTRAL OR SLIGHT ALKALINE

CONDITIONS USING SOD. ACETATE 40g/kg• SOD. CHLORATE OXIDIZING AGENT TO COUNTERACT THE

REDUCING EFFECT OF THICKENER AND WOOL ON DYE (Acid conditions)

• SOD. META NITRO BENZENE SULPHONATE IN CASE OF REMAZOL (alkaline conditions)

STEAMING

• DYE IN AGGREGATED FORM ON FIBRE SURFACE WITHIN THICKENER FILM AT PRINTING AND DRYING STAGE

• STEAMING: THICKENER FILM SWELLING• DYE DISSOLUTION• WOOL FIBRE SWELLING• DYE PENETRATION• DYE FIXATION• STEAMING FOR 10-15 MIN FOR REACTIVE DYES

30-45 MIN FOR METAL COMPLEX AND ACID DYES

• SATURATED STEAM AT 1020C • STAR AGER MOST SUITABLE FOR BATCH

STEAMING

YELLOWING

• CHLORINATED WOOL YELLOWS TWICE AS FAST AS UNTREATED WOOL

• YELLOWNESS INDEX OF STEAMED WOOL REACHES MAX. IN 15-20 MIN.

• WOOL PREPARED BY NON-CHLORINATION METHOS IS LESS PRONE TO YELLOWING.

WASHING AND AFTER TREATMENT• TO REMOVE THICKENER, CHEMICALS AND UNFIXED DYE. • TO ATTAIN DESIRED LEVEL OF WET FASTNESS• CARE SHOULD BE TAKEN TO PREVENT STAINING OF UNPRINTED

PORTIONS OF FABRIC. • WASHING CONDITIONS• PRINTS WITH ACID MILLING AND METAL COMPLEX DYES ARE ARE

WASHED AT ABOUT 30-400C AND REACTIVE DYES AT 70-800C WITH AMMONIA

• INCOMPLETE REMOVAL OF THICKENER WILL GIVE RISE TO FASTNESS AND HANDLE PROBLEMS

• THE USE OF OPTIMUM STEAMING CONDITIONS ENSURES A HIGH DEGREE OF FIXATION AND LEAVES A MINIMUM OF UNFIXED DYE TO BE WASHED OUT.

• WOOL FELTING DURING WASHING SHOULD NOT TAKE PLACE. THIS IS ENSURED BY PROPER PRETREATMENT PROCESSES

• WASHING IS DONE ON WING OR CONTINUOUS OPEN SOAPER.• HIGHEST POSSIBLE LIQUOR RATIO DURING WASHING NESSARY TO

PREVENT STAINING OF UNPRINTED PORTIONS.

MACHINE WASHABLE PRINTS

• REACTIVE DYES GIVE MACHINE WASHABLE PRINTS

• WASHING MUST BE CARRIED OUT AT 800C IN PRESENCE OF AMMONIA.

• WITH NON REACTIVE DYES WASHING DONE AT 30-400C

• FOR MACHINE WASH FASTNESS, WASHING IS DONE AT 50-60C IN PRESENCE OF AMMONIA AND APPROPRIATE AUXILIARY., AND THEN TREAT WITH CATIONIC DYE FIXING AGENT.

• CATIONIC DYE FIXING AGENT IMPROVES WET FASTNESS AND PERSPIRATION FASTNESS

• THEY SHOULD BE USED AFTER A THOROUGH WASH OTHERWISE DETERIORATION WITH RUB FSTNESS OCCURS.

• PRODUCTS MAAINLY BASED ON CONDENSATES OF FORMALDEHYDE AND DYCYANDIAMIDE.

• MANY NON-FORMALDEHYDE BASED PRODUCTS ARE NOW AVAILABLE.

DISCHARGE PRINTING

• DISCHARGE PRINTS ARE CONSTANTLY IN DEMAND

• PREDYED FABRIC IS DYED WITH A STRONG REDUCING AGENT WHICH DESTROYS THE GROUND SHADE TO GET WHITE DISCHARGE PRINT

• IN COLOUR DISCHARGE, ILLUMINATING COLOUR RESISTANT TO DISCHARGING AGENT IS INCLUDED IN THE PRINT PASTE.

GROUND SHADES

• DISCHARGE PRINTING INVOLVES THE CHEMICAL DESTRUCTION OF DYED AT THE PRINTED PORTIONS

• THE GROUND SHADE DYES ARE INVARIABLY AZO DYES.

• DISCHARGEABILITY RATING SHOULD BE 4-5

• MANY ACID. METAL COMPLEX AND REACTIVE DYES ARE DISCHARGEABLE.

• LABORATORY TEST FOR DISCHARGEABILITY IS ESSENTIAL PARTICULARLY FOR MIX SHADES WHERE ALL DYES IN A MIXTURE MAY NOT DISCHARGE AT THE SAME RATE.

DISCHARGING AGENT

• REDUCING AGENT FOR DISCHARGE PRINTING

REDUCING AGENT TRADE NAME• SODIUM FORMALDEHYDE

SULPHOXYLATE

DIRECT PRINTING

• MOST SIMPLE STYLE

• PRINTING ON PREPARED GROUND

• OFTEN BLEACHED IN CASE OF LARGE UNPRINTED AREAS

• SOMETIMES DYED IN PALE SHADES

• DYED IN MEDIUM SHADES AND OVER PRINTED WITH DARK COLOURS TO OBTAIN SHADOW EFFECTS

PRINTING MACHINES

• ROTARY SCREEN PRINTING MACHINE

• NOT SUITABLE FOR SHORT LENGTHS

• SOMETIMES CHOSEN FOR BLOTCH PRINTS OR WARP WAY STRIPE PRINTS

• AUTOMATIC FLAT SCREEN PRINTING MACHINE

• MOST POPULAR FOR SHORT RUN LENGTHS

MANUAL SCREEN PRINTING

• POPULAR IN INDIA.

DYE SELECTION

• CRITERIA

• PRICE

• BRIGHTNESS OF SHADE

• GOOD COVERAGE PROPERTIES

• GOOD SOLUBILITY AND PRINT PASTE STABILITY

• GOOD BUILD UP PROPERTIES

• GOOD WASHING OFF PROPERTIES

• SATISFACTORY WET AND LIGHT FASTNESS

NON-REACTIVE DYES

• ACID MILLING DYES

• METAL COMPLEX DYES

COMMERCIAL DYES

• ACIDOL, ACIDOL M (BASF)

• SUPRANOL, ALIZARIN, ISOLAN (BAYER)

• POLAR, IRGANOL, LANASET (Ciba-geigy)

• COOMASSIE, CARBOLAN (ICI)

• SANDOLAN, LANASYN (SANDOZ)

REACTIVE DYES

• USED FOR HIGH WET FASTNESS STANDARDS

• MACHINE WASHABLE WOOL: PRESENT TREND

• GOOD WATER SOLUBILITY

• SHORTER STEAMING TIME ADVANTAGE IN CONTINUOUS STEAMING

• REACTIVE DYES SUITABLE FOR WOOL PRINTING

DYE NAME REACTIVE GROUPMANUFAC.

• LEVAFIX E-A MONOCHLORO BAYER

DIFLUORO PYRIMIDINE

• DRIMARINE R, K -DO- SANDOZ

• LANASOL BROMOACRYLAMIDO CGY

• REMAZOL VINYL SULPHONE HOECHST

• PROCION P, H-E MONOCHLOROTRIAZINE ICI

REDUCING AGENTS

CHEMICAL NAME TRADE NAME• SODIUM SULPHOXYLATE FORMALDEHYDE RONGALIT C (BASF)

• ZINC SULPHOXYLATE FORMALDEHYDEDECROLIN (BASF)

• CALCIUM FORMALDEHYDE SULPHOXYLATE RONGALIT H (BASF)

• THIOUREA DIOXIDE REDUCING AGENT F

• STANNOUS CHLORIDE

• MOST COMMON FORMALDEHYDE SULPHOXYLATES

HOCH2SO2NA HCHO + HSO2 + Na HSO3 + 2H

Ar-N=N-Ar’ + 4h ArNH2 + ArNH2’

SOD. FORMALDEHYDE SULPHOXYLATE

• WATER SOLUBLE PRODUCT

• GIVES GOOD WHITE DISCHARGE

• DEVELOPS FULL REDUCTION POTENTIAL IN THE

ALKALINE pH RANGE

• GREAT CAR NECESSARY TO PREVENT FIBRE

DAMAGE AND SHRINKAGE

• RARELY USED FOR WOOLON ITS OWN

• pH ADJUSTMENT RESULTS IN REDUCED STABILITY

CALCIUM FORMALDEHYDE SULPHOXYLATE

• WATER INSOLUBLE, STABLE

• CAN LEAD TO PROBLEMS OF SCREEN CHOKING AND UNSATISFACTORY PENETRATION OF THE DISCHARGE

• BASF HAS DEVELOPED 30% DISPERSION OF GREATER STABILITY

• LESS FIBRE DAMAGE AND LESS SHRINKAGE THAN SODIUM SALT

• Ca SALT IS COMMONLY USED IN COMBINATION WITH Na SALT

ZINC FORMALDEHYDE SULPHOXYLATE

• FUNCTIONS IN THE WEAKLY ACID pH

• NO FIBRE DAMAGE AND SHRINKAGE THERE CAN BE PROBLEMS IN WASHING OUT THE DECOMPOSITION PRODUCTS OF SOME REDUCED DYES LEADING TO AFTER YELLOWING OF THE DISCHARGE ON EXPOSURE TO LIGHT AND AIR.

• ALSO GIVES RISE TO EFFLUENT PROBLEMS

THIOUREA DIOXIDE

• THIOUREA DIOXIDE

H2N

=SO2 H2N OH H2O

H2N S - H2N

HN O = O + H2SO2

H2N

• ATTRACTIVE ALTERNATIVE TO FORMALDEHYDE SULPHOXYLATES

• RARELY USED DUE TO ITS LOW SOLUBILITY (37 g/l)

•

STANNOUS CHLORIDE

Ar-N=N-Ar’ + SNCL4 + 4H2O ArNH2 + Ar’NH2 + 2SnO2 + 4HCl

• NOT COMMON FOR WOOL DISCHAGE PRINTING• LOW REDOX POTENTIAL PERMITS THE USE OF

WIDER RANGE OF ILLUMINATING DYES• AT THE SAME TIME LIMITS THE NUMBER OF

GROUND SHADES WHICH ARE DISCHARGEABLE• AFTER BROWNING OF WHITTE DISCHARGE IS

ALSO A PROBLEM• PROBLEM OF EFFLUENT DISPOSAL• CORROSION OF STEAMER DUE LIBERATION OF

HCl• IN PRESENCE OF THIDIGLYCOL MOST

UNDESIRABLE MUSTARD GAS IS PRODUCED.

ILLUMINATING DYES

• REAL PROBLEM: SELECTION OF DYES RESISTANT TO REDUCING AGENT FOR COLOUR DISCHARGE

• SUITABLE DYES• CI DIRECT YELLOW 28

• CI ACID YELLOW 3

• CI ACID RED 52, 315

• CI DIRECT BLUE 106

• CI BASIC YELLOW 3

• CI ACID VIOLET 90

• CI ACID BLUE 61:1

• THREE COLOUR MIXTURE IS MADE UP OF

• CI ACID YELLOW 3

• CI ACID VIOLET 90

• CI ACID BLUE 61:1

PRINTING AND FIXATION

• VARIOUS PRINT PASTE RECIPES BASED ON PRINTER’S KNOW-HOW AND EXPERIENCE, LOCAL WORK CONDITIONS

• TYPICAL RECIPE• DYE X

• UREA 30-50

• THIDIETHYLENE GLYCOL 30-50

• WATER Y

• Na/Zn/Ca FORMALDEHYDE

SULPHOXYLATE 30-180

• THICKENING 500

• MILD OXIDIZING AGENT 5-20

• AMMONIUM CHLORIDE 5-20

• ZINC OXIDE 1:1 20-50

• WATER TO BULK 1000

PRINT RECIPE

• REUCING AGENT MUST BE USED TO MINIMUM LEVEL DEPENDING UPON DISCHARGABILITY OF GROUND SHADE

• HIGHER LEVELS WILL LEAD TO BOTH HALOING OVER REDUCTION OF ILLUMINATING COLOUR

• MILD OXIDIZING AGENT (NITROBENZENE SULPHONIC ACID) USED TO PREVENT UNWANTED REDUCTION OF ILLUMINATING DYE

• USE OF TOO HIGH LEVEL AFFECT THE DISCHARGEABILITY OF GROUND SHADE, STORAGE STABILITY OF PRINT AND REPRODUCIBILITY OF REULTS

DRYING

• DRY PRINTS AS QUICKLY AS POSSIBLE AT NOT TOO HIGH A TEMPERATURE

• LONG STORAGE AFTER DRYING SHOULD BE AVOIDED

• STORAGE UNDER MOIST CONDITIONS LEAD TO DECOMPOSITION OF REDUCING AGENT AFFECTING DISCHARGEABILITY

RESIST PRINTING

• END RESULTS OF RESIST PRINTING ARE SIMILAR TO DISCHARGE PRINTING

• PROCESSING ROUTE IS DIFFERENT

• PRINT RESIST AGENT DYE APPLICATION (USUALLY NIP PADDING) REIST AND DYE FIXATION WASH DRY

• COLOURED RESIST: INCORPORATION OF ILLUMINATING COLUR IN RESIST PRINT PASTE ABLE TO FIX IN PRESENCE OF RESIST AGENT

• RESIST TECHNIQUES : TWO CLASSES• REACTIVE RESIST FOLLOWED BY PIECE DYEING FROM

LONG LIQUOR

• MECHANICAL/CHEMICAL RESIST: PRINT RESIST AGENT, APPLY GROUND SHADE BY WET-ON WET PRINTING WITH A BLANK SCREEN

CHEMICAL RESIST PROCESSES

• REACTIVE RESIST AGENT (SANDOSPACE R (SANDOZ)

• REACTIVE RESIT AGENT RESEMBLING TO COLURLESS REACTIVE DYE

• HIGHLY REACTIVE WATER-SOLUBLE ANIONIC PRODUCT

SANDOSPACE R

• THE COMPOUND IS ABLE TO REACT WITH AMINO GROUPS IN WOOL

• THE RESIST PRINT TAKES PALCE DUE TO BLOCKING OF REACTIVE AMINO SITES ON FIBRE AND BY ANIONIC REPULSION.

• THE PRODUCT USED FOR RESIST PRINTING OF WOOL AND NYLON

• APPLICATION• EXHAUST DYEING OR PAD APPLICATION• 10-12% ADD ON• 80-90% RESIST EFFECT WHEN DYED IN 2% SHADE• AT PALE SHADE COMPLETE WHITE RESIST• TONE ON TONE EFFECT IN DARK SHADES

SULPHAMIC ACID RESIST

• THE MOST PROBABLE REACTIVE SITES ON WOOL FOR SULPHAMIC ACID ARE

• BASIC AMINO GROUPS

• SERINE HYDROXY GROUPS AND CYSTENE LINKAGES

• THE REACTIONS ARE COMPLEX

SULPHAMIC ACID RESIST• UREA IS ESSENTIL FOR MAX. UPTAKE OF

SULPHAMIC ACID• RECIPE FOR WHITE RESIST• SULPHAMIC ACID 150-200 • UREA 150-200• THICKENER 500• NON IONIC WETTING AGENT 2• ANTIFOAM 1• WATER TO BULK TO 1000• PRINT, DRY, CURE 150-1600C FOR 4-5 MIN

• COLOURF RESIST: INCORPORATE ILLUMINATING DYE IN PRINT PASTE

• TWO STAGE FIXATION• CURING FOR SULPHAMIC ACID• STEAMING FOR 30 MIN AT 100-1020 C TO FIX ILLUMINATING

COLOUR

SULPHAMIC ACID RESIST• STEAMING AND BAKING STEPS ARE NOT INTERCHANGEABLE

• SULPHAMIC ACID HYDROLYSIS IF STEAMING IS DONE FIRST AFFECTIGN RESIST EFFECT

• THOROUGH WASHING OFF INCLUDING AMMONIA WASH AT 700C IS NECESSARY TO REMOVE UNFIXED DYE AND TO PREVENT CROSS-STAINING OF UNPRINTED AREAS DDURING SUBSEQENT DYEING.

• DYEING

• CARRIED OUT FROM LONG LIQUOR WITH REACTIVE DYESREACTIVE DYES ARE USED BOTH FOR COLOURED RESIST AND GROUND SHADE DYEING, FASTNESS PROPERTIES OF PRINTS ARE GOOD.

• THERE IS CERTAIN AMOUNT OF FIBRE DAMAGE BUT NOT AS HIGH AS IN DISCHARGE PRINTING

STEAMING• CARRIED OUT FOR 10-20 MIN AT 100-1020C • AIR FREE STEAM IS AESSENTIAL• ADDITION OF SMALL AMOUNT OF HYDRAZINE TO

THE BOILER WATER IS BENEFICIAL IN BINDING FREE OXYGEN IN STEAM

• REQUIRED STEAMING TEMPERATURE IS ATTAINED AS QUICKLY AS POSSIBLE SINCE FORMALDEHYDE SULPHOXYLATE BEGINS TO BREAKDOWN AT ABOUT 50-600C

WASHING OFF• MILD CONDITIONS AS THE DYES USED FOR

COLOUR DISCHARGE GENERALLY POSSESS POOR WET FASTNESS.

MECHANICAL/CHEMICAL RESIST PROCESS

• BATIK AND TIE-DYE ARE EXAMPLES OF MECHANICAL RESIST

• THIOTAN WS (SANDOZ)• CATIONIC AGENT FORMS COMPLEX WITH ANIONIC DYE

PREVENT DYE FIXATION• CONCENTRATION 600-700 g/kg OF PRINT PASTE FOR WHITE

RESIST• 600 g/kg FOR COLOUR RESIST• PRINT WITH THIOTAN WS• WET ON WET PRINT WITH DYE• DRY• STEAM• WASH

• DRAWBACK• HIGH CONCENTRATION OF REIST AGENT

REACTIVE UNDER REACTIVE RESIST

• MONOCHLORO TRIAZINE REACTIVE DYE AS ILLUMINATING COLOUR

• PRINT FROM MILD ALKALINE (pH 7.6 WITH SODIUM ACETATE)

• ADD SODIUM SULPHITE IN PRINT PASTE• PRINT GROUND SHADE WET ON WET WITH VINYL

SULPHONE DYES (MILD AKLINITY)• DRY• STEAM FOR 20 MIN AT 1020 C • WASH OFF IN AMMONIA AT 60-700C • GROUND SHADE PRINT IS RESISTED AT THE

PRINTED AREAS DUE TO PREENCE OF SODIUM SULPHITE WHICH REACTS RAPIDLY WITH VINYL SULPHONE GROUP, PREVENTING DYE FIXATION.

COLD PRINT BATCH• THE METHOD IS BASED ON USE OF SOD. METABISULPHITE AND HIGH

LEVELS OF UREA TO ACCELERATE COLD FIXATION OF HIGHLY REACTIVE DYES OF DICHLOROTRIZINE TYPE (PROCION MX) AND MONOCHLRODIFLUROPYRIMIDINE (LEVAFIX E-A) TYPES.

• PROCESS

• PRINT

• INTERLEAVE WET WITH POLYTHENE FOIL,

• BATCH FOR 24 HOURS.

• FIXATION LEVEL UPTO 80%

• STEAMING NOT ESSENTIAL.

• AMMONIA WASH TO REMOVE UNFIXED DYE

• METHOD MOST SUITABLE FOR SMALL SCALE PRINTERS IN INDIA

• CONTINUOS LENGTHS ARE DIFFICULT MAINTAIN IN MOIST CONDITION DURING BATCHING

• METHOD MOST SUITABLE FOR PRINTING GARMENT CUT PANELS

• PRINTED PANELS ARE STACKED OVER EACH OTHER WITH SEPARATION BY POLYTHENE FILM.

TRANSFER PRINTING

• SUBLIMATION TRANSFER PRINTING BASED ON SUBLIMATION PROPERTY OF DISPERSE DYE

• MOST SUITABLE FOR POLYESTER HAVING GOOD AFFINITY OF DISPERSE DYE VAPOURS.

• WOOL HAS NO AFFINITY TO DISPERSE DYES

• MODIFICATION OF FIBRE OR DYE OR BOTH IS ESSENTIAL

• FIBRE MODIFICATION

• PRETREAT WITH POLAR COMPOUNDS LIKE UREA, THIDIGLYCOL OR LACTIC ACID

• USE OF TERTIARY AND QUATERNARY ORGANIC BASES AND SLTS TO CLEAVE S-S BONDS THEREBY OPENING WOOL STRUCTURE

• PAD APPLICATION OF SURFACTANTS AND ACRYLIC MONOMERS

• ABOVE METHODS COMMERCIALLY NOT SUCCESSFUL

CSIRO AND IWS METHOD

• CONSIST OF PRETREATMENT WITH ANIONIC SURFACTANT AND CHROMIUM SALT.

• THE USE OF SPECIALLY SYNTHESIZED METALLIZABLE DISPERSE DYES e.g.

KERATRAN PROCESS• PAD WOOL WITH• SOD. DI-ISO-OCTYL SULPHO SUCCINATE 50 g/l• UREA 50 g/l• LACTIC ACID 20 g/l• CHROMIUM (III) CHLORIDE 7.5 g/l

• SURFACTANT IMPART AFFINITY TO DISPERSE DYES• CHROMUMIUM SALT PROMOTES THE FORMATION

CHROMIUM-DYE COMPLEX DURING TRANSFER PRINTING• LACTIC ACID IMPROVES PAD LIQUOR STABILITY• TRNSFER TEMP 195-2000C FOR 30 SEC.• STEAM FOR 30 MIN AT 1000 C FOR FULL COLOUR

DEVELOPMENT AND WASH FASTNESS(UREA PALY IMP. ROLE IN DYE FIXATION)

• DRABACK• LIMITED SHADE RANGE• NECESSITY OF SEPARATE STEAMING STEP AND AFTER WASH

WET OR MIGRATION TRNSFER PRINTING

• USE OF LANASOL REACTIVE DYES ON PAPER

• PADDING OF WOOL WITH THICKENED LIQUOR, UREA AT ACID pH

• CONTACT BETWEEN WET WOOL AND PRINTED PAPER FOR 30-6- SEC AT 1060C WITH THE APPLICATION OF HIGH PRESSURE

• STEAMING

• WASHING OFF TO REMOVE UNFIXED DYE

• COMMERCIALLY NOT SUCCESSFUL

NOVEL EFFECTS

• BURN OUT PRINTING

• SUITABLE FOR PRINTING OF BLENDS

• PRINT WITH A CHEMICAL/AUXILIARY WHICH DESTROYS ONE COMPONENT OF THE BLEND IN THE PRINTED AREAS

• EFFECT OBTAINED ON WOOL/POLYESTER

• PRINT WITH SOD. HYDROXIDE

• PRESSURE STEAMING AT 1200 C FOR 15 MIN.

• WOOL COMPONENT IS DESTROYED IN THE PRINTED REAS

• WASH OFF.

SCULP[TURED EFFECTS

• FELTING PROPERTY OF FWOOL IS EXPLOITED IN THIS TECHNIQUE

• PRINT ON UNTREATED UNFINISHED WOOL WITH A PRINT PASTE CONTAINING A SHRINK RESIST POLYMER IN PRESENCE OF SOD. BICARBONTATE.

• DRY• BAKE AT 1500C TO CURE THE RESIN. • SCOUR AND MILL• PRINTED PORTIONS DO NOT SHRINK PRODUCING

SCULPTURE PRINT EFFECT.• PIGMENT COLOUR MAY BE INCLUDED IN THE

PRINT PASTE• THE RESIN ACTS AS PIGMENT BINDER.