garment dyeing with pigments
TRANSCRIPT
Garment Dyeing with Pigments
History of Garment Dyeing Mid 1800’s Overdyieng articles to extend their life.
Specialist laundries.
Late 1800-early 1900 Dyeing of silk stockings and socks
1940’s Nylon was introduced to replace silk in socks which led to development of machinery 1980s Fashion change to casuals and increased usage of cotton. Washes for denim became popular 1990s- Worn look becomes fashionable 2000- Garment dyeing with pigment dispersions
Why Pigment Dyeing
Wash down effect which is not possible otherwise
•Reactives not possible, dyes chemically reacted
• Sulphur dyes difficult to handle. Enzyme time required is double
• Indigo/Vat similar to Sulphurs
• Direct fastness to light is poor and shade change after fixing
• Possible to eliminate/reduce post enzyme treatment
Why Pigment Dyeing
Clean and Level Dyeing
• Robust system which takes care of minor variations in preparation
•On tone shade build up
Good all round fastness
•Light Fastness 6-7
•Staining on cotton 4-5
•Dry Rub 4
Why Pigment Dyeing
Economical process • Short dyeing cycle, resulting in
• lower energy consumption • water conservation • reduced machine time
as when compared to the other class of colorants
Why Pigment Dyeing
Easy on the environment
• No dusting
• No smell in the department as sodium sulfide/hydrosulphate
is not used.
• High bath Exhaustion
• Low salt in the effluent
• Treatment of effluent is simple as pigments are insoluble in
water
• Lower BOD/COD
Routes to apply pigment by Dyeing
•“Reactive” Pigment
• Substrate receptive to pigment
Problems associated with “Reactive Pigment” • Unlevel Dyeing • Additional levelling agent •Temperature sensitive • Excessive tinting of Machine • Expensive
Multi-layered “surface” structure of pigment dyed fibre
1. Cationic polymers form a layer of cationic charges when applied to fiber surfaces.
2. Reactants modify the fibre by forming covalent bonds with
the cellulosic fibre.
CATIONIC PRETREATMENT
Cationizing Chemicals
• polyamino cationic ammonium polymer with azetidinium reactivity • polyamino cationic polyamino cyanoguanidine sulphate • polyamino chlorohydrin quaternary ammonium polymer with epoxide reactivity • amino chlorohydrin quaternary ammonium salt with epoxide reactivity • polyamino quaternary ammonium polymer
Processing
method
Quart. Ammon.Salt Processing conditions
Process Auxiliary Washing
Application sequence
CATIONISATION
Cationisation-Influencing Factors
System for
Pigment Dyeing • Pretreat with
cationising chemical
• Pigmentation with
Pigment dispersion
• Fixation with
Binder
Fixer
Finish with
Softeners
100o
90o
80o
Drain Salt
70o 1gpl
60o
50o
Run m/c for 2min &
allow standing bath
40o treatment for 10min Drain
TempoC30o Pidicron
RMG SPL Texcron Pidicryl Pigment wash wash Binder BGD
pH=4.5-5 XDG +
20o Pidifix SFC
10o
0 10 20 30 40 50 60 70 80 90 100 110 120 130
Duration in Minutes * Hydroextract the goods & tumble dry for 1 hr.
* Biopolishing & softener treatment can be subsequently given .
Textreat Pigmentation Fixation>--->
90c
80c
70c
60c
50c
40c
30c
20c
10c
0c 10 20 30 40 50 60 70 80 90
Duration in Minutes
Wash
Cold Texcron
XDG
solution
10 min 10 min
Drain
20 min
Pidicron
GD804
pH=4.5
(acetic
acid)
Drain
Binder
GD888
4gpl
10 min
Hydroextract
25 min
Wash Cold
The NEW ONE STAGE PROCESS
Comparison of Pidicron RMG SPL and Pidicron GD 804
A B
A: SPENT LIQUOR AFTER PIGMENTATION
B: SPENT LIQUOR AFTER BINDER
RMG SPL GD 804
A B
Forest Green Shade
Rub Fastness Properties
RMG SPL
A B
A: AFTER PIGMENTATION BATH
B : AFTER BINDER TREATMENT
DRY WET DRY WET
A B
DRY WET DRY WET
GD 804
One Step Process
•Pidicron GD 804 •Pidicryl Binder GD 888 •No Fixer
Savings in Water by 25% Time by 25% Steam by 40%
Less fuzz Less enzyme More depth
Pigment Particle Size Distribution
Conventional • Minimum Penetration • Runnability(difficult curing) • High Emulsifier content • 0.5-0.7 microns
• High Exhaustion • Low curing/self polymerising • Low emulsifier content • Acidic • 0.1 microns
Binder Properties
Problems faced and their Causes
Patchy, Un-level Dyeing
• Improper pretreatment • Insufficient Liquor ratio • “Hot spots” on the garment • Improper “Colorant” distribution • pH of Textreat bath • Soft Hydroextraction • Pre-wetting of garments • History and Geometry of Fibre • “Add-on” of contrast colour • Prolonged waiting between textreat and Pigmentation
Dark Spots • Unclean Machine • Pigment dispersion not stabilised • Distribution of Cationising Chemical • Incompatible finishing Chemical
White Patches
• Improper washing off in the pretreatment (alkali retention)
• Abrasion in the machine • Hydro-extraction between textreat and
pigmentation(perforation marks)
Reproducibility of Shade
• Concentration of Cationising Chemical • Particle size distribution of Colorant • Binder formulation • Colour Recipe
Uniformity in a trichromat
• Type of Cationising Chemical • Compatibility of Colorants (Particle size/distribution)
Variation at Seams/Patches • Compact structure • Material compared to body • Lower particle size of Colorant • Proper use of Lubricant/penetrating agent
Crease Marks • Overloading of Machine • Liquor ratio • Liquor Circulation • Temperature gradient • Quantity and method of addition of Lubricating agent
Poor Colour Yield
• Pretreatment/Liquor ratio / Agitation • Excessive rinsing • Concentration of Cationising Chemical
Inadequate Fastness
• Particle size and distribution of Pigment • Quantity of Cationizing Chemical • Quantity of Binder and Fixer • No intermediate drying before finishing
Colour Build-up
• Temperature variation in bath • Heating rate • Quantity of Cationising chemical • Low concentration of Colorant
Tinting of Machine
• Improper dispersion of Colorant • Hot spots on machine walls • Duration of the process • Compatibility of Chemicals • Impurities on Garment
Holes in Garment
• Improper pretreatment • Abrasion in machine • Excessive processing time
Colour in Effluent
• Quantity of Cationising Chemical • pH of application • Particle size distribution of Colorant • Temperature and duration of the process • Binder with high/strong emulsifier
Systems offered in India
• Pidilite • Zydex • Clariant • Dystar • Blue chip (Sanyo)
Selection • system that yields high pigment exhaustion and is reproducible.
• Other important considerations are color range, fastness, cost, and desired results.
• The choice of fabric substrate is also critical to achieving the desired look. It is important to choose fabrics such as twills, single knit, or other types of fabric with a textured surface to achieve the best look with the pigment-dyeing process.
• Rotary drum machine capable of being programmed with a variable drum speed during the dyeing cycle. However, other types of equipment, such as paddle machines, can also be used