View
117
Download
2
Category
Preview:
Citation preview
04th Februray 2010
Dr Sanjiv Kamat
Pigment PrintingPigment Printing Of Of TextilesTextiles
Dr. Sanjiv KamatPidilite Industries Limited
04th Februray 2010
Dr Sanjiv Kamat
04th Februray 2010
Dr Sanjiv Kamat
04th Februray 2010
Dr Sanjiv Kamat
04th Februray 2010
Dr Sanjiv Kamat
Pigment Dispersions – Pigment Dispersions – Historical DevelopmentsHistorical Developments
As old as 3000 years with mineral pigments and natural As old as 3000 years with mineral pigments and natural polymers as binder and thickeners(starch,glue)polymers as binder and thickeners(starch,glue)
1920’s- Organic Pigment dispersions1920’s- Organic Pigment dispersions 1930’s –Emulsion copolymerisation techniques.1930’s –Emulsion copolymerisation techniques. 1937 –Pigment paste based on water in oil emulsion1937 –Pigment paste based on water in oil emulsion 1950 – Oil in water systems.1950 – Oil in water systems. 1960- Aqueous self crosslinking dispersions as binders1960- Aqueous self crosslinking dispersions as binders Early 60’s - Pidilite introduced pigment Early 60’s - Pidilite introduced pigment
dispersion in India.dispersion in India. 1990s Ecological improvements(emmission)1990s Ecological improvements(emmission)
Digital printingDigital printing
04th Februray 2010
Dr Sanjiv Kamat
Why Pigment Printing ?Why Pigment Printing ?
Versatile-Suitable for all substrates and Versatile-Suitable for all substrates and machinesmachines
Low impact on waste waterLow impact on waste water Low consumption of water, no washing Low consumption of water, no washing
after printingafter printing Short process cycle –faster output , Print, Short process cycle –faster output , Print,
dry,fixdry,fix Best light fastnessBest light fastness Very High Reliability Very High Reliability Zero printing defects possibleZero printing defects possible
04th Februray 2010
Dr Sanjiv Kamat
Relative properties of Printing Relative properties of Printing stylesstyles
PropertiesProperties Pigment Pigment Substantive Substantive
LightLight
WashingWashing
RubbingRubbing
WeatheringWeathering
HandleHandle
ExcellentExcellent
AcceptableAcceptable
GoodGood
Very GoodVery Good
AcceptableAcceptable
GoodGood
Very GoodVery Good
Very GoodVery Good
PoorPoor
ExcellentExcellent
04th Februray 2010
Dr Sanjiv Kamat
• Colour pigment• Binding agent• Fixer• Thickener• Auxiliaries- emulsifiers- softeners
Components of Pigment Printing System
04th Februray 2010
Dr Sanjiv Kamat
• Pigment (25-45 %) • Water• Auxiliaries- emulsifiers / dispersing agents- Co solvent / glycols (few)- preservative
Composition of the Pigment Dispersion
04th Februray 2010
Dr Sanjiv Kamat
Factors influencing Selection of PigmentFactors influencing Selection of Pigment
Fastness to Fastness to WashingWashing LightLight SolventSolvent PerspirationPerspiration ChlorineChlorine
HeatHeat SalivaSaliva
LegislationsLegislations
04th Februray 2010
Dr Sanjiv Kamat
Influence of Particle Size of PigmentInfluence of Particle Size of Pigment
FlocculationFlocculation Hue/Tint StrengthHue/Tint Strength Hiding/TransparencyHiding/Transparency Gloss/Flatting and Film appearanceGloss/Flatting and Film appearance ViscosityViscosity StabilityStability Weather ResistanceWeather Resistance
04th Februray 2010
Dr Sanjiv Kamat
PigmentsPigments
Primary Particles0.01-5mu
Aggregates0.05-50mu
Agglomerate0.1-1000mu
04th Februray 2010
Dr Sanjiv Kamat
Pigment dispersionPigment dispersion
Large number of Large number of aggregatesaggregates and and agglomerates agglomerates formed during drying and pulverizing process of formed during drying and pulverizing process of pigment press cakepigment press cake
To obtain better To obtain better gloss, rheological properties gloss, rheological properties and color strengthand color strength pigment applications need pigment applications need pigment in disperse formpigment in disperse form
Size of aggregates and agglomerates is reduced Size of aggregates and agglomerates is reduced from from 10-60 micron10-60 micron to below to below 1 micron1 micron
04th Februray 2010
Dr Sanjiv Kamat
Dispersion ProcessDispersion Process
Size Reduction:Size Reduction: Breaking of larger aggregates Breaking of larger aggregates and agglomerates into smaller primary particles and agglomerates into smaller primary particles by impact and shear forceby impact and shear force
Wetting Process:Wetting Process: Uniform spreading of liquid Uniform spreading of liquid medium on the pigment surface making a medium on the pigment surface making a contact angle of zero degree. Proper wetting contact angle of zero degree. Proper wetting improves glossimproves gloss
Stabilization:Stabilization: Dispersed particles are Dispersed particles are prevented to come togetherprevented to come together
04th Februray 2010
Dr Sanjiv Kamat
Dispersion Properties Depend uponDispersion Properties Depend upon
Suitability of pigmentSuitability of pigment Particle sizeParticle size Particle size distributionParticle size distribution Degree of dispersionDegree of dispersion Electrical chargeElectrical charge Specific gravitySpecific gravity Crystal structure & stabilityCrystal structure & stability
04th Februray 2010
Dr Sanjiv Kamat
TextureTexture
Feel and appearance of surface especially how Feel and appearance of surface especially how rough or smooth it is .rough or smooth it is .
Decided by the Decided by the degree of aggregationdegree of aggregation of the of the primary particlesprimary particles
Soft textureSoft texture have have large agglomerateslarge agglomerates and few and few aggregatesaggregates
Large number of aggregatesLarge number of aggregates give give hard texturehard texture Various surface treatments used to improve Various surface treatments used to improve
texturetexture
04th Februray 2010
Dr Sanjiv Kamat
Texture is affected byTexture is affected by
pH(fluctuation in the process)pH(fluctuation in the process) TemperatureTemperature Solvent in condensationSolvent in condensation Process slow or fast(Rate of addition)Process slow or fast(Rate of addition) Drying process(Convection,IR,Air suction)Drying process(Convection,IR,Air suction)
04th Februray 2010
Dr Sanjiv Kamat
Texture and structureTexture and structure
SOFTSOFT
<<Bisazo < Phthalocyanine < Bisazo < Phthalocyanine < monoazo < betanaphthol < monoazo < betanaphthol < Benzimidazolone < Quinacridones Benzimidazolone < Quinacridones < DPP < Perylene < Carbazole< DPP < Perylene < Carbazole < <
HARDHARD
04th Februray 2010
Dr Sanjiv Kamat
Dispersing EquipmentDispersing Equipment
04th Februray 2010
Dr Sanjiv Kamat
Size ReductionSize Reduction
Commonly used EquipmentsCommonly used Equipments
Type Of Action
Ball Mill ImpactSand Mill Sheer+Impact
Impact+SheerBead Mill Sheer+ImpactThree Roller MillSheer Kneader Sheer Extruder Sheer
Equiptment
Attritors
04th Februray 2010
Dr Sanjiv Kamat
Influence of pigment dispersion particle size Influence of pigment dispersion particle size on printingon printing
Small particle size may cause a low colour yield besides clogging of Small particle size may cause a low colour yield besides clogging of screens and may also entail thixotropic propensity of print pastes. screens and may also entail thixotropic propensity of print pastes. Wash fastness may be inferior since the pigment particles may not Wash fastness may be inferior since the pigment particles may not be held properly in the layer of binder film. be held properly in the layer of binder film.
For instance, 40g/kg shade using a pigment dispersion having a For instance, 40g/kg shade using a pigment dispersion having a particle size of 0.1 micron and binder of 0.3 micron, since these particle size of 0.1 micron and binder of 0.3 micron, since these particles are not held appropriately in the binder film, the wash particles are not held appropriately in the binder film, the wash fastness may be affected. , since with very fine particle size; the fastness may be affected. , since with very fine particle size; the pigments are liable to bleed on washing e.g. Pigment Red 2 with a pigments are liable to bleed on washing e.g. Pigment Red 2 with a lower particle size. Red and Bordeaux pigments have a tendency to lower particle size. Red and Bordeaux pigments have a tendency to bleed on washing . bleed on washing .
Large particle size may entail dull prints.Large particle size may entail dull prints. High viscosity of pigment dispersions may not only lead to thicker High viscosity of pigment dispersions may not only lead to thicker
print pastes but also cause inadequate penetration during printing print pastes but also cause inadequate penetration during printing on the substrate.on the substrate.
04th Februray 2010
Dr Sanjiv Kamat
Recent Development in Emulsifiers
No clear technical trend visible- combination products
- emulsifier/rheolog. additive- emulsifier/rheolog. additive/fixing agent
- pure emulsifier• APEO-free• Non-ionic
04th Februray 2010
Dr Sanjiv Kamat
Pigment Printing BindersPigment Printing Binders should should Have good adhesion but no tackHave good adhesion but no tack Be resistant to chemical and mechanical Be resistant to chemical and mechanical
stressstress Be flexibleBe flexible Be non yellowingBe non yellowing Be removable from screensBe removable from screens Be shear stableBe shear stable Resistance to agingResistance to aging
04th Februray 2010
Dr Sanjiv Kamat
Binder Properties Influenced byBinder Properties Influenced by
NEGATIVE
POSITIVE
AN
NBA
Soft Tacky
Softer More Tacky
Softest Most Tacky
Hardest
Harder
Hard
Lowest Fastness
Best Fastness
NBA
EA
B
Styrene
MA
04th Februray 2010
Dr Sanjiv Kamat
BindersBinders
Monomer Monomer Tg (°C)Tg (°C)Ethylene Ethylene -125-125
ButadieneButadiene -78-78
Butyl AcrylateButyl Acrylate -52-52
Ethyl AcrylateEthyl Acrylate -22-22
Vinyl AcetateVinyl Acetate +30+30
Vinyl Chloride Vinyl Chloride +80+80
Methyl MethacrylateMethyl Methacrylate +105+105
Styrene/AcrylonitrileStyrene/Acrylonitrile +105/130+105/130
04th Februray 2010
Dr Sanjiv Kamat
1. not self-cross linking2. self-cross linking (reactive side groups)
Parameters influencing crosslinking• Type and number of reactive groups• Temperature• Duration• pH valueCrosslinking results in improved1. Fastnesses 2. Stability to temperature 3. Permanency of effects
Type of Binders
04th Februray 2010
Dr Sanjiv Kamat
Binders Functional GroupsBinders Functional Groups Carboxyl functionality –Binders contain acrylic Carboxyl functionality –Binders contain acrylic
acid or methacrylic acid as co-polymers. acid or methacrylic acid as co-polymers. Provides sites for cross-linking reactionsProvides sites for cross-linking reactions
Amide Functionality – Acrylamide as a part of Amide Functionality – Acrylamide as a part of the functional group .Binders having the functional group .Binders having substituted acrylamide groups have self cross substituted acrylamide groups have self cross linking propertieslinking properties
SBR Binders-Butadiene monomer provides SBR Binders-Butadiene monomer provides elasticity ,while styrene and acrylonitrile give elasticity ,while styrene and acrylonitrile give oil and solvent resistance Disadvantages are oil and solvent resistance Disadvantages are oxidation and discoloration due to residual oxidation and discoloration due to residual double bonds double bonds
04th Februray 2010
Dr Sanjiv Kamat
Binder Particle SizeBinder Particle Size
Smaller the particle size of the binder Smaller the particle size of the binder results in brighter prints as total results in brighter prints as total internal reflection increases.internal reflection increases.
Bigger particle size binder may increase Bigger particle size binder may increase coverage but prints may look duller coverage but prints may look duller
Very small particle size will lead of Very small particle size will lead of clogging of screens because of clogging of screens because of agglomeration agglomeration
04th Februray 2010
Dr Sanjiv Kamat
Recent Development in Binders
• Increasingly softer handle
• Fastnesses improved
• Running properties were improved
• Reduction in residual free monomer content
04th Februray 2010
Dr Sanjiv Kamat
NormalCH2=CH-CO-NH-CH2-OH N - methylol acrylamide
detaching formaldehydereaction partners: - sec. amino groups
- N-methylol groups / N-methylol ether groups- amide groups- melamine groups- dicyan diamide groups- related groups
AlternativeCH2 - CH- epoxy components (e.g. epichlorhydrin
O formaldehyde-freereaction partners: - hydroxylic / carboxylic groups
- amino groups, react. methylene groups
Binders Components for self cross linking
04th Februray 2010
Dr Sanjiv Kamat
••
Synthetic Thickeners
-CH2 -CH - CH2 - CH CH2 -CH - CH2 - CH -
COOH COOHCOO - COO - n
first synth. thickeners in 1969• mechanism: n - addition of alkali (NH4OH) causes an electrostatic repellency- formation of a three-dimensional network = increase in viscosity• molecular weights in the range of 1000000 • partially crosslinked
n
OH-
04th Februray 2010
Dr Sanjiv Kamat
Thickener propertiesThickener properties
Molecular Molecular WeightWeight
High / LowHigh / Low ViscosityViscosity High/LowHigh/Low
Polymer Polymer ContentContent
High /LowHigh /Low ViscosityViscosity High/LowHigh/Low
Same Same Polymer Polymer content content
High High Molecular Molecular WeightWeight
Low Low Molecular Molecular WeightWeight
Low DosageLow Dosage
Low CoverageLow Coverage
Low FastnessLow Fastness
High DosageHigh Dosage
High High CoverageCoverage
High FastnessHigh Fastness
04th Februray 2010
Dr Sanjiv Kamat
Pidicryl SHRP - Rheology Pidicryl SHRP - Rheology modifiermodifier
0
20
40
60
80
100
AQA +SHRP
TimeSec
Viscosity
Rheology change under Shear ( Squeegee Pressure)
Shear force
Shear force released
04th Februray 2010
Dr Sanjiv Kamat
Rheology Modifier - Pidicryl SHRPRheology Modifier - Pidicryl SHRP
Reduces Flushing tendency on different Reduces Flushing tendency on different fabricsfabrics
Improves colour yieldImproves colour yield Improves brightnessImproves brightness Improves leveling highly recommended Improves leveling highly recommended
in full blotch printingin full blotch printing Lower penetrationLower penetration Higher coverage Mts/Kg of print pasteHigher coverage Mts/Kg of print paste Best results at pH > 8Best results at pH > 8
04th Februray 2010
Dr Sanjiv Kamat
04th Februray 2010
Dr Sanjiv Kamat
Two trends:a) higher efficiency / price optimizationb) improved technology / multifunctional
• pasty• lower hydrocarbon content• non-fuming• high purity / good and quick swelling behaviour• good storage stability / little settling
Recent Development in Thickeners
04th Februray 2010
Dr Sanjiv Kamat
Two trends:a) higher efficiency / price optimizationb) improved technology / multifunctional
• pasty• lower hydrocarbon content• non-fuming• high purity / good and quick swelling behaviour• good storage stability / little settling
Recent Development in Thickeners
04th Februray 2010
Dr Sanjiv Kamat38
Developments in Fixing AgentsDevelopments in Fixing Agents
• Melamine resin fixing agent / contains HCHOhigher etherification, thus:- reduced HCHO content- less HCHO emission during drying and fixation- reduced HCHO content on the fabric- less reactivity
• Isocyanate fixing agent / HCHO-free-cold fixing / not blocked / shelf life /
high reactivity- hot fixing / blocked
04th Februray 2010
Dr Sanjiv Kamat
Ecological IssuesEcological Issues
Air• hydrocarbons (white spirit/thickener/antifoam)• HCHO (fixing agent/binders/preservative)• monomers (binding agent/fixing agent/thickener)• fume (thickener/softener/urea/glycols)
Water• hydrocarbons (white spirit/thickener/softener/antifoam)• heavy metals (Pigments)• APEO (emulsifiers/binders/softener)Fabric• HCHO (fixing agent/binders/preservative)• fastnesses (binding agent/fixing agent/pigments)• MAK amines (colour pigments (some in the red range))• APEO (colour pigments,binders),
04th Februray 2010
Dr Sanjiv Kamat
Influencing Factors – Pigment PrintingInfluencing Factors – Pigment Printing
Viscosity: Design, machineViscosity: Design, machine Water HardnessWater Hardness Screen MeshScreen Mesh Drying TemperatureDrying Temperature Fabric typeFabric type pH of printing pastepH of printing paste Particle size of Pigment dispersion and BinderParticle size of Pigment dispersion and Binder
04th Februray 2010
Dr Sanjiv Kamat
Fastness not achieved !Fastness not achieved !
Light Light Depth of ShadeDepth of Shade
PerchPerch Pigment selectionPigment selection
High TempHigh Temp Pigment Selection Pigment Selection
CrockingCrocking Depth of ShadeDepth of ShadeBinder TypeBinder TypeBinder ConcentrationBinder ConcentrationCuring conditionsCuring conditionsFabric Type and GeometryFabric Type and Geometry
04th Februray 2010
Dr Sanjiv Kamat
Colour Textile interactions in Ink Jet PrintingColour Textile interactions in Ink Jet Printing
Print Head TechnologiesPerformanceDrop performanceInk/Material compatibilityNozzle cloggingNozzle crustingBiological growthContaminationLong-term operability
Textile/Ink InteractionDrying time Colour value/yieldChroma (colour quality) Spreading/wickingRub fastness Water fastness Light fastness
Colour /Ink Formulation
PropertySurface tension ViscositySpecific gravity pHConductivity Dye purityDye purity/solubilityToxicological propertiesParticle size StabilityAccoustic properties Shelf life
Textile
04th Februray 2010
Dr Sanjiv Kamat
Printhead TechnologyPrinthead Technology•Thermal Drop on Demand(DOD)
•Piezo Drop on Demand
•Binary Continuous inkjet heads
•Multi-deflection continuous heads
•Air jet deflection
• Valve Jet
04th Februray 2010
Dr Sanjiv Kamat
04th Februray 2010
Dr Sanjiv KamatMarch 2007GAP Delhi
Dr Sanjiv Kamat 45
Thank you
Recommended