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