Pigment printing

Hafeezullah Memon

Zhejiang Sci-Tech University

Hangzhou, China

Pigment printing:

Pigment printing has gained much importance today and for some fibers (e.g.

cellulose fibers) is by far the most commonly applied technique. Pigments can be used on

almost all types of textile substrates and, thanks to increased performance of modern dyeing

auxiliaries; it is now possible to obtain high-quality printing using this technique. The term

"pigment print" is used generally for any type of printed image that uses strictly pigments.

Pigment printing processes have been utilized since the middle of the 19th century. The

image stability of pigment printing is superior to that of any other method of printing,

including traditional silver-halide or metal-based. Pigment is a substance in particulate from

that is substantially insoluble in a medium but which can be mechanically dispersed in this

medium to modify its color and light – scattering properties. In other words, Pigments are

insoluble coloring matter mostly mineral origin; those have been used for the coloration of

metal wood, stone, and textile material.

Pigments are colors which do not dissolve and penetrate into the fibers. They have not

to be applied together with a film forming binder. More than 50% of all printing colors are

pigment types. It represents an alternative to direct printing. In this system there is no need to

carry out a steaming process, as steaming is replaced by polymerization (generally carried out

simultaneously with drying).

Fig: Pigment printing

This type of printing process is very simple, low-cost and can be carried out easily on

all types of fabrics, particularly on blends, since pigments can adhere to all fibers; there is no

need to use dyes of different color classes. On the other hand, the adhesives, which bind the

pigment to the fabric, can give serious problems when the fabric hand varies. For prints with

a low coverage ratio, the hand variation can be acceptable but it is not when the coverage

ratio is high or at least for all uses. Furthermore, the pigment lies on the surface and has low

fastness to friction (this depends mainly upon the type and quantity of binding agent and

upon the polymerization degree). Some valid alternatives to this type of printing can give

special effects such as printing with swelling agents (generally synthetic polyurethane-base

pastes are used), with covering pigments and glitter (metal powders or particles of plastic

materials) etc.

Fig: Pigment Printing Recipe

Pigment Printing Process:

Fig: Pigment Printing Process flow

Pigment Printing RecipePigmentsBinder Fixer Na alginate White spirit Pre-Treatments Singeing, Desizing, Scouring, Bleaching, Mercerization (depend on customer requirements)PrintingWith binder and fixerDrying90-100%/110-120°CCuringCotton 140-160°C/110-120°C 3-5 minPolyester 160-220°C 30-60sWashingSometimes it is omitted

Fig: Pigment Printing Machine flow

Advantages of Pigment Printing:

Applicable to natural and synthetic fiber.

Wide range of color can be produced.

Can be used for dope dyeing for filament yarn.

Easily applicable.

Less expensive.

Maximum output of goods because of the elimination of washing-off, quick sampling

and high printing speed.

It presents the fewest problems for the printer of all the coloration processes, with

regard to labor costs, equipment and reliability of production.

Properly produced pigment prints, using selected products, have an unsurpassed

fastness to light and good general fastness properties.

Extremely well suited for color resist effects, for example, under azoic and reactive

dyes.

From the economical point of view, pigment printing, using pastes free from white

spirit, is more acceptable than any other systems, excepting transfer printing methods.

Disadvantages of Pigment Printing:

Not controllable for the binder film.

Use of solvent like kerosene, spirit etc can produce problems like flammability, odor,

pollution etc.

The jamming up of equipment and air and water pollution is observed.

Wet and rubbing fastness is average.

The handle of the printed goods is often unduly hard because of the large amounts of

external cross linking agents.

Pre-Treatments machinesRoller or Rotary printingDryerStenterWashing machine

Are sensitive to crushing during roller printing and pigment printing needs shallow

engravings on screen printing.

The original surface of the textile material is covered by the binder film. This is

occasionally aesthetically effective but usually undesirable.

Application of Pigment Printing:

Uses of Pigment printing is wide range. The garments of the women which are made

by cotton, polyester or viscose blends are printed by pigments if the medium color depths are

needed. Decorative curtain, towels are printed by pigments. Pigment printing also used in bed

linen, aprons, children’s garments, night wear dresses, various cottons and cellulose

materials.