5. Printing

Printing is a process of reception on a material of color patterns. The technology of printing includes four basic stages: drawing of a printing paint; drying by hot air; steaming for achievement of dye in deep layers of a fiber and washing for removal of thickener and not fixed dye.

There are three kinds of the printing: the direct printing at which on a white background put a color pattern; the corrosive printing at which on the painted material receive a white or color pattern by means of corrosive structure; the reserve printing at which on a cloth at first put printing structure, and then paint, thus in places of drawing of printing structure of coloring does not occur.

Feature of printing in comparison with dyeing consists that dye passes in a fiber not from a water solution and from a dry film of thickener to fiber surfaces. In process of steaming dye moves from the bulked up film of a thickener in a fiber also enters interaction with the reactionary centers of polymer.

5.1. Reactive dyes printing

Reactive dyes are widely used for cotton, flax, rayon staple fabric and cotton and rayon knitwear printing. Various methods and all kinds of equipment can be used in printing, fixing and rinsing fabrics and knitwear.

Table 5.1. Printing Ink Composition and Fixation Conditions

Printing Ink Composition, g/kg and Fixation Conditions	Reactive Dyes
	With index „Kh"		Non-Indexes
	Steaming at T
	102-105	140-150	102-105	140-150
Dye	10—60	10—60	10—60	10—60
Urea	50—150	200	50—150	200
Ludigol	10	10	10	10
Sodium Bicarbonate	15	15	15—20	15—20
or Soda Ash	-	-	15—20	15—20
Thickener	a	a	a	a
Water	The rest to 1 kg
Fixation Time, min.	2—3	1—2	6—8	1—2

Thickener amount (a) depends on the needed printing ink viscosity.

5.2. Pigments printing

The pigmentary press covers 70-80 % of all stuffed textile materials owing to the simplicity, universality and ecological is pure. It is allows to receive drawings of any complexity and color scale on cotton and mixed textile materials (a fabric, jersey, nonwoven cloths, etc.). Pigments — not soluble in water painting substances of a mineral or organic origin. They have not an affinity for textile fibers and are fixed on them in the film of binding substance which provides high adhesion to a substratum. The given way of the textile printing is universal, differs technological simplicity (printing — drying — heat treatment), is safe in ecological from carrying, as relation as does not include operations steaming and washings of the printed fabrics. Pigments printing it is often combined with various kinds of final furnish.

The structure of pigmentary printing compositions includes the following components:

- The binding (film-forming) substance capable to formation of a film thin, elastic, colorless and steady against ageing, a keeping particle of a pigment on a fiber thanks to high adhesive durability for-fastening. As binding substances polymers of the various structures may be used.

- The sewing agent — precondensates of thermojet pitches (PTRS) which is intended for strengthening of fastening of a film of binding substance with pigment particles on a fiber at the expense of formation (at 140 160 °С in the presence of potentially sour catalyst) of additional cross-section communications between this film and a substratum on polycondensation reaction of polycondensation CH₂OH PTRS with active groups (-СООН, — ОН, — NH₂, etc.) polymers of the film and a fiber. As PTRS may be used Metazins, Carbamols, Glikazins and other similar products.

- The catalyst (salt or acid), easily forming protons at thermal decomposition and hydrolysis in the course of thermal processing and promoting to course of the polycondensation specified above reaction ((NH₄C1, (NH₄)₂S₂O₃, MgCl₂, Zn(N0₃)₂, (COOH)₂, wine, dairy and other weak organic acids).

- Pigment is entered into a painting paste in the quantity defined behind color and intensity of coloring (it is preferable in the form of paste). Besides mineral and organic pigments (with the average size of the particles 1-2 microns) in the pigments pastes for expansion of possibilities of art-colorist finishing of textiles can be used metal powders, luminous-embossing connections and substances with various factor of refraction of light, allowing to receive "pearl" colorings.

- The thickener is entered into a printing paint for creation necessary viscously-still and clearness of a contour of drawing on a fabric. For the pigmentary press application of natural and synthetic thickeners is possible. Recently thickeners on a basis acrylic the copolymers sharply raising the viscosity in the sour environment, owing to ionization and mutual pushing away carboxyl groups of the specified copolymers are most extended.

Besides the specified basic components the pigmentary paint can contain softener (for decrease in rigidity of a signature stamp) and the substances preventing clogging engravings of a shaft or a sieve of a template pigmentary dye at great volume of the press.

Rapid growth of manufacture of the mixed fabrics has caused sharp increase in consumption of painting pigments in колорировании textile materials (more than 50% of all printed fabrics in the world). Advantage of the pigmentary press is its big ecological compatibility: an exception of operation of washing, smaller теплозатраты, comparative simplicity of hardware registration, sharp reduction of all kinds of emissions in environment thanks to reduction of a work cycle of processing of a textile material. At the pigmentary press 100% use of painting substances with achievement of high brightness and light resistance of colorings are carried out practically at lower compared with other classes of dyes the expense (on 15-20 %).

Last years ecological questions from outside the buyer get the increasing value. It is taken into consideration both in questions of the legislation and at marks of textile products by ecological labels. The label of the international society of check in the field of textile ecology EkO-teks-100 is for example used. The basic danger is connected with the maintenance in paints of substances of type of formaldehyde and hydrocarbons.

Ecologically improved compounding of pigmentary printing paints not containing hydrocarbons and containing a little or completely not containing formaldehyde, offers ф. СНТ (Germany):

Table 5.2. Ecologically improved compounding of the pigmentary press

Component of a printing paint	The Compounding 1	The Compounding 2
Water	Х г	Х g
SnT-foamextinguish BS	2 g	2 g
tubigat 0 18	10-20 g	10-20 g
tubifastAF 85 -	90 g	90 g
tubivis SNP 110 S -10 g or	10 g
tubivis14	18 g	18 g
tubisoft SEM	6 g	6 g
tubifix ML 50	5 g
tubifix 3220/3	5 g
	In total 1000g	1000 g
The formaldehyde maintenance	near. 73prm	Less than 20prm

F.Klariant (Austria) offers painting pigments of Printofiks Н, the textile products printed with them, can be noted a sign "Eko-teks".

Printing composition for cotton fabrics, gm/kg:

Pigment TP. . . . . . . . . . . . . . . . X

Binder "Emultex 5BN . . .150-190

Fixing agent SI. . . . . . . . . . . .0-10

Thickening agent SI. . . . . . . . . 30

Softened water condensate to 1000 gm

For synthetic fabrics:

Pigment TP. . . . . . . . . . . . . . . . .X

Binder Emultex 5BN. . . . 150-190

Fixing agent SI. . . . . . . . . . . . . .15

Thickening agent SI. . . . . . . . . .30

Softened water condensate to 1000 gm

Drying of printed substrate at 100-110°C, thermo fixation 150°C 5 min.

Emultex 5BN, Fixing agent SI, Thickening agent SI are original products of Co "Pigment".

Pigments TP are well compatible with all up-date components used in compositions for pigment printing on natural, artificial land, synthetic fibers.