Transcript DYEING: DEFINITIONS - Prof. Rbchavan @BDU-Home

DYEING: DEFINITIONS
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DYEING
UNIFORM COLOURATION OF TEXTILE MATERIAL
IN FIBRE, YARN OR FABRIC FORM.
THE COLOUR PRODUCED SHOULD WITHSTAND
EXTERNAL AGENCIES SUCH AS WASHING, LIGHT,
RUBBING etc TO WHICH TEXTILE MATERIAL IS
SUBJECTED DURING USE.
THE COLOURATION SHOULD NOT RESTRICT ONLY
TO THE FIBRE SURFACE BUT SHOULD PENETRATE
THE FIBRE CROSS SECTION.
THE SURFACE COLOURATION IS KNOWN AS RING
DYEING.
DYEING: DEFINITIONS
PAINTING
• APPLICATION OF COLOUR TO ANY SURFACE WITH
THE HELP OF SUITABLE ADHESIVE. IT IS
BASICALLY SURFACE COLOURATION. HAS
FASTNESS PROPERTY TO SOME EXTERNAL
AGENCIES DEPENDING ADHESIVE FORCES
BETWEEN (FIBRE) SURFACE AND COLOURING
COMPOUND.
TINTING
• SURFACE COLURATION. NO FASTNESS PROPERTY
TO EXTERNAL AGENCIES. THE PROCESS IS USED
FOR FIBRE IDENTIFICATION OF DIFFERENT
VARIETIES DURING SPINNING
PRINTING
• LOCALIZED COLOURATION IN THE FORM OF
DESIGN. DYE PENETRATION IN THE FIBRE CROSS
SECTION
DYES AND PIGMENTS
DYES
• COLOUR COMPOUND
• SOLUBLE IN WATER OR CAN BE MADE SOLUBLE IN
WATER
• POSSESSES AFFINITY TO FIBRE TO BE DYED
• PENETRATION OF DYE IN FIBRE CROSS-SECTION
UNDER DYEING CONDITIONS
• INTERACT WITH FIBRE WITH SUITBLE DYE-FIBRE
INTERACTIVE FORCES DEPENDING ON THE NATURE
OF FIBRE AND NATURE OF DYE
• NATURE OF DYE-FIBRE INTERACTION DETERMINES
THE FASTNESS PROPERTY OF DYE TO EXTERNAL
AGENCIES. THERE SOME EXCEPTIONS TO THIS
RULE.
DYES AND PIGMENTS
TINTING COLOURS
• DYES HAVING NO AFFINITY TO FIBRE.
• EASILY REMOVED DURING WASHING
PIGMENTS
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COLOURING COMPOUND
INSOLUBLE IN WATER
NO AFFINITY TO FIBRE
NO INTERACTION WITH FIBRE
AFFINITY OR SUBSTANTIVITY
• ATTRACTION BETWEEN DYE AND FIBRE UNDER
GIVEN DYEING CONDITIONS.
• ABILITY OF DYE TO MOVE FROM SOLUTION PHASE
TO FIBRE PHASE DURING THE DYEING OPERATION
• THIS MEANS REDUCTION IN DYE CONCENTRATION
IN SOLUTION PHASE AND CORRESPONDING
INCREASE OF DYE CONCENTRATION IN FIBRE
PHASE WITH DYEING TIME.
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DYES HAVE AFFINITY TO FIBRE
• PIGMENT AND TINTING COLOURS HAVE NO
AFFINITY TOWARDS FIBRE.
CLASSIFICATION OF FIBRES
NATURAL
VEGETABLE
COTTON
JUTE
RAMIE
LINEN
ANIMAL
WOOL
SILK
REGENERATED
VISCOSE
CELLULOSE ACETATE
SYNTHETIC
POLYESTER, NYLON, ACRYLIC
CLASSIFICATION OF DYES
WATER SOLUBLE
SUITABILITY TO FIBRE
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DIRECT
ACID
BASIC OR CATIONIC
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REACTIVE
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SOLUBILIZED VAT
COTTON, WOOL, SILK, NYLON
WOOL, SILK, NYLON
MAINLY ACRYLIC, LIMITED WOOL,
SILK
MAINLY COTTON, LIMITED WOOL,
SILK
COTTON
WATER INSOLUBLE
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VAT
SULPHUR
DISPERSE
COTTON
COTTON
MAINLY POLYESTER, LIMITED
NYLON, ACRYLIC
IN-SITU COLOUR FORMATION
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AZOIC
OXIDATION COLOURS
COTTON
COTTON
PIGMENT COLOURS
ALL FIBRES DEPENDING ON
BINDER
THEORETICAL CONCEPT
DYEING PROCESS
• FIBRE
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DYE BATH: DYE, WATER, DYEING
AUXILIARY
INTRODUCTION OF FIBRE IN DYE BATH
DYEING UNDER SUITABLE CONDITIONS FOR
SUITABLE LENGTH OF TIME
ZERO TIME
ALL DYE IN DYE BATH
WITH PASSAGE OF TIME
INCREASE IN DYE
CONCENTRATION ON FIBRE
CORRESPONDING DECREASE IN DYE
CONCENTRTION IN DYE BATH
THIS PHENOMENON IS KNOWN AS DYE
EXHAUSTION AND OCCURS DUE TO AFFINITY OF
DYE FOR FIBRE
DYEING MECHANISM
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DIVISION OF DYE SYSTEM IN THREE PHASES
DYE IN SOLUTION
FIBRE SURFACE
INTERIOR OF FIBRE
DURING DYEING THREE TYPES OF EQUILIBRIA EXIST
DYE IN SOLUTION  DYE ON FIBRE SURFACE  DYE IN THE
INTERIOR OF FIBRE
FIRST EQUILIBRIA TRANSFER OF DYE FROM SOLUTION TO
FIBRE SURFACE
SECOND EQUILIBRIA
PENETRATION OF DYE FROM FIBRE
SURFACE TO FIBRE INTERIOR
DISTURBANCE IN FIRST EQUILIBRIA
PROCESS CONTINUE TILL THREE PHASES ARE IN EQUILIBRIUM
DYE FIBRE INTERACTION
CLASSIFICATION OF ATTRACTIVE
FORCES
ATTRACTIVE FORCES BETWEEN DYE AND FIBRE
1.
VAN DER WAAL’S FORCES OR DISPERSION FORCES
2.
HYDROGEN BONDS
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ELECTROSTATIC ATTRACTION
4.
CO-VALENT BOND
DYE-FIBRE INTERCTION
FORCES OF ATTRACTION
DYE CLASS
FORCE OF ATTRACTION
CELLULOSIC (COTTON, JUTE, VISCOSE)
DIRECT, VAT, SULPHUR VANDER WAAL, H-BOND
SOLUBILIZED VAT
REACTIVE
CO-VALENT BOND
WOOL, SILK, NYLON
DIRECT, ACID, METAL
COMPLEX
REACTIVE
IONIC OR ELECTROSTATIC
IONIC/COVALENT
POLYESTER
DISPERSE
VANDER WAAL, H-BOND
ACRYLIC
CATIONIC
INONIC OR ELECTROSTTIC
FORCE OF ATTRACTION AND WASH
FASTNESS
• DYED FIBRE MUST MEET CERTAIN FASTNESS REQUIREMENT
TO VARIOUS AGENCIES LIKE WASHING, LIGHT, RUBBING
• FASTNESS PROPERTY DEPENDS ON SEVERAL FACTORS
• WASH FASTNESS DEPENDS ON
• FORCE OF ATTRACTION BETWEEN DYE AND FIBRE
• PHYSICAL STATE OF DYE INSIDE THE FIBRE
• PHYSICAL STRUCTURE OF FIBRE
• BOND ENERGY
• COVALENT BOND > ELECTROSTATIC BOND > H-BOND >
VANDER WAAL FORCE
• WASH FASTNESS
• REACTIVE DYE > ACID, METAL COMPLEX, CATIONIC >
DIRECT, VAT, SULPHUR, DISPERSE
EXCEPTIONS
• VAT DYES ON COTTON
• EXCELLENT WASH FASTNESS PROPERTY
REASONS
• DYE INSIDE FIBRE WATER INSOLUBLE FORM
• STATE OF DYE INSIDE FIBRE AGGREGATED (VERY HIGH
MOLECULAR WEIGHT)
• BOTH THESE FACTORS LEAD TO VERY HIGH WASH FASTNESS
ON COTTON THOUGH WEAK FORCES OF DYE-FIBRE
INTERACTION
DISPERSE DYES ON POLYESTER
• DYE INSIDE FIBRE WATER INSOLUBLE FORM
• VERY COMPACT PHYSICAL STRUCTURE OF FIBRE
• DYE UNABLE TO DIFFUSE OUT UNDER WASHING CONDITIONS
BRIEF HISTORY OF DYEING
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PRACTICED AS EARLY AS
3000 B C IN CHINA
2500 B C IN INDIA
DYED GARMENTS FOUND IN EGYPTIAN TOMBS
KNOWLEDGE OF DYEING WENT TO EGYPT THROUGH INDIA
DYES USED WERE OF NATURAL ORIGIN,
EXTRACTION FROM PLANTS OR INSECTS
PLANT DYES
INDIGO, MADDER
INSECT DYES
LAC, COCHENEAL, KERMES
MAJORITY OF NATURAL DYES ARE FIXED ONTO FIBRE WITH
THE HELP OF METAL SALTS KNOWN AS MORDANTS
IMPORTANT MORDANTS
ALUM, FeSO4, CuSO4, SnCl2, K2CR2O7
SYNTHETIC DYES
• 1856 FIRST SYNTHETIC DYE. WILLIAM PERKIN, ENGLAND
• CHANCE DISCOVERY
• AT THE AGE OF 14, ASSOCIATED WITH FAMOUS GERMAN
CHEMIST HOFFMAN
• FASCINATED BY EXPERIMENTS IN ORGANIC CHEMISTRY
• SET UP HIS OWN LABORATORY AT RESIDENCE
• EXPLORED EXPERIMENTS IN CHEMISTRY IN HIS
LABORATORY AFTER OFFICE HOURS AND ON HOLIDAYS
• IN THE COURSE OF EXPERIMENTS OXIDIZED ANILINE WITH
K2Cr2O7, OBTAINED BLACK PRECIPITATE
• BLACK PRECIPITATE EXTRACTED WIT ETHYL ALCOHOL
GAVE BRILL. PURPLE SOLUTION WHICH COLULD USED FOR
COLORATION OF SILK
• FIRST SYNTHETIC DYE MAUVE
• AT THE AGE OF 18 PERKIN SET UP HIS OWN FACTORY FOR
MANUFACTURE OF DYES ON INDUSTRIAL SCALE
• MANY CHEMIST IN EUROPE STARTED WORKING ON DYE
SYNTHESIS
100 YEARS OF CHRONOLOGICAL DEVELOPMENTS OF
SYNTHEIC DYES
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1856
1858
FIRST SYNTHETIC DYE (PURPLE ), PERKIN
DISCOVERY OF THE PROCESS OF DIAZOTIZATION
AND COUPLING, PETER GREISS
1859
MAGENTA DYE, FRENCH CHEMIST VERGUIN
1862
FIRST SULPHONATED DYE
1863
ANILINE BLACK, NICHOLSON
1880
IN SITU AZOIC COLOUR FORMATION, READ
HOLLIDAY
1884
FIRST DIRECT DYE, CONGO RED, BOTTIGER
1893
FIRST SULPHUR DYE
1897
SYNTHETIC INDIGO
1890
METAL COMPLEX DYE
1901
VAT DYE
1922
DISPERSE DYE
1956
REACTIVE DYE
NATURAL DYES BEFORE 1856 ABOUT 100
SYNTHETIC DYES TODAY
2000-3000
NOMENCLATURE OF DYES
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SYNTHETIC DYES KNOWN BY THEIR TRADE NAMES
USUALLY INDICATE THE TRADE NAME OF COMPANY, SHADE OBTAINED, HUE
OR TONE OF THE SHADE e.g.
CHLORAZOL BROWN R (DIRECT DYE)
INDANTHRENE BLUE 2R (VAT DYE)
• CHLORAZOL TRADE NAME OF ICI
• BROWN
SHADE
• R
REDDISH HUE OF BROWN
• FOR HUE LETTERS LIKE B, R, Y, OR BB, RR OR 2B, 3R, 4R ETC ARE USED
• SOMETIMES OTHER LETTERS INDICATES SUB CLASS WITHIN THE MAIN
CLASS e.g.
• PROCION RED M5B (COLD BRAND REACTIVE DYE)
• PROCION RED H5B (HOT BRAND REACTIVE DYE)
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COLOUR INDEX
DOCUMENTATION OF ALL DYES
JOINT PUBLICATION OF SOCIETY OF DYERS AND COLOURISTS (SDC), ENGLAND
AND AMERICAN ASSOCIATION OF TEXTILE CHEMISTS AND COLOURISTS
(AATCC) , USA
• INFORMATION ON TRADE NAMES, CHEMICAL STRUCTIRE, PROPERTDIES etc.
• EACH DYE IS IDENTIFIED BY CI NUMBER (COLOIUR INDEX NUMBER)
FIBRE FORM
• FIBRE
• YARN
• FABRIC
FABRIC FORM
• WOVEN
• KNITTED
• NON-WOVEN
DYEING METHODS
BATCHWISE OR EXHAUST DYEING
• FIBRE
• YARN
• FABRIC
SEMI-CONTINUOUS DYEING
• FABRIC
CONTINUOUS DYEING
• FABRIC
• YARN IN WARP SHEET FORM (INDIGO DYEING FOR
DENIM)
EXHAUST DYEING
MATERIAL TO LIQUOR RATIO (M:L RATIO)
• VOLUME OF WATER TAKEN IN RELATION TO WEIGHT OF
MATERIAL (FIBRE, YARN OR FABRIC)
e.g. M:L :: 1:10 MEANS FOR 1 kg OF TEXTILE MATERIAL 10
LITRES OF WATER TAKEN FOR DYEING
% DYEBATH EXHAUSTION
• AMOUNT OF DYE GONE FROM SOLUTION PHASE TO FIBRE
PHASE AT THE END OF DYEING PERIOD EXPRESSED IN TERMS
OF %. IT IS A MEASURE OF DYE SUBSTANTIVITY. THE TERM IS
MAINLY APPLICABLE TO BATCHWISE DYEING.
• % FIXATION: AMOUNT OF DYE FIXED (INTERACTED) WITH
FIBRE AFTER WASHING/SOAPING.
% SHADE
• AMOUNT OF DYE TAKEN FOR DYEING ON THE BASIS OF
WEIGHT OF MATERIAL
• e.g. 2% SHADE MEANS 2 gm DYE TAKEN FOR DYEING 100 gm
MATERIAL i.e TEXTILE FIBRE, YARN OR FABRIC.
BATCHWISE DYEING
• DYEING IN SMALL BATCHES, 100-300 kg FABRIC
FABRIC DYEING EQUIPMENTS
DESIGNED ON THREE PRINCIPLES
FABRIC MOVING, DYE LIQUOR STATIONARY
• JIGGER (FABRIC IN OPEN WIDTH FORM)
• WINCH (FABRIC IN ROPE FORM)
FABRIC STATIONARY, DYE LIQUOR MOVING
• BEAM DYEING MACHINE FOR DYEING POLYESTER OR
POLYESTER/COTTON BLENDS (FABRIC IN OPEN WIDTH)
BOTH FABRIC AND DYE LIQUOR MOVING
JET DYEING MACHINE (FABRIC IN ROPE FORM)
CONTINUOUS DYEING
PADDING
• SATURATION OF FABRIC BY DYE SOLUTION AND SQUEEZING
THE EXCESS LIQUOR BY PRESSING BETWEEN SQUEEZ
ROLLERS
• MACHINE: PADDING MANGLE
• TERMS COMMON FOR CONTINUOUS DYEING OF FABRIC.
EXPRESSION
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%INCREASE IN WEIGHT OF DRY FABRIC AFTER PADDING e.g.
DRY FABRIC WEIGHT 1kg
FABRIC WEIGHT AFTER PADDING 1.8 kg
INCREASE IN DRY FABRIC WEIGHT 0.8 kg
% INCREASE IN WEIGHT 80%
EXPRESSION 80%
HIGHER THE VALUE OF % EXPRESSION LESS IS LIQUOR
SQUEEZING BY PADDING MANGLE AND VICE VERSA