Printing

PRINTING

TEXTILE PRINTING

KWM: Printing

Textile printing is used to signify the production, by various means of colored patterns on designs upon all sorts of textile fiber. Textile printing is the most important and versatile of the techniques used to add design, color, and specialty to textile fabrics.

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STEPS OF PRINTING 

The basic steps in the printing process are as

follows: 

Preparation of the fabric

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Preparation of the print paste.

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Printing the fabric.

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Drying the printed fabric.

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Fixation of the printed dye or pigment.

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Afterwashing.

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PRINT PASTE AND ITS INGREDIENTS Print

paste is a viscous solution of printing ingredients referred below that is used for textile printing. The main three printing ingredients are: •

Dyestuff or pigments

•

Thickeners: Thickener can be defined as a substance used to increase the viscosity of a print paste or other fluid, in order to control its flow properties.

•

Chemicals and waters: The main types of chemicals used for textile printing are wetting agents, solvents, solution acids, dispersing agents, hygroscopic agents, oxidizing & reducing agents, defoamers, acids, alkalis, catalyst & carriers, swelling agents etc.

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PLASTISOL VS. WATER-BASED INK 

There are two main types of ink that are used for textile printing.

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Water-based ink utilizes either dyes or pigments in a suspension with water as the solvent. The evaporation of the water is necessary to set or cure the ink. Plastisol ink is a PVC based system that essentially contains no solvent at all.

Usage Recommendations T-Shirts/light colors T-Shirts/dark colored Nylon Jackets Towels Yard goods Sporting Goods

Plastisol Excellent Good Good Poor Poor Excellent

Water-base Excellent Poor Poor Excellent Excellent Poor

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STYLE OF PRINTING 

Metal style of printing: In the metal style of printing fabric is printed with silver or gold solution or nonremovable resins.

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Resist Printing: In this method, the fabric is first printed in a design with a chemical that resists dye. The fabric is then dyed. The resist will leave the fabric white or some other color in the print areas. One of the advantages of this method is that dyes with very high colorfastness can be used.

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Flock Printing: Flock printing is a process in which a ‘flock’ is fixed on to a cloth by means of adhesive to form printed pattern. It produces a pile or velvety effect on the fabric similar to form a printed pattern.

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STYLE OF PRINTING (CONTD.) 

Discharge Printing: ‘Discharge’ means removal and ‘Discharge style’ refers process which can produce a white or colored effects on a dyed ground by printing paste containing a chemical capable of removing the ground color called ‘discharging agents.’ It could be of two types

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White Discharge: the printed part remains white after destroying the dyed color Color Discharge: With a dye incorporated in the print paste which is resistant to discharging agents. When printed the discharging agents removes the ground color and at the same time deposit color on the dyed ground.

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METHOD OF PRINTING 

Block printing: In this method the wooden or metal block with a negative and raised design (i.e. in relief) is first stamped on the print paste and then on the cloth and an impression of positive design is made on the cloth.

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Screen printing: In hand screen printing the fabric is stretched out on a long table. The screens are moved methodically along the fabric. When a screen is in position the dye paste is pressed through the open mesh with a squeegee blade.

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Transfer printing: Transfer printing is defined as any process by which a design is transferred from paper to another substrate. Selected disperse dyes transfer in vapor form to thermoplastic fibers when the printed paper and fabric are brought into close contact in a transfer press at 170°-220°C.

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FLAT BED SCREEN PRINTING

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FLAT BED SCREEN PRINTING

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ROTARY SCREEN PRINTING

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ROTARY SCREEN PRINTING

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PIGMENT PRINTING 

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In pigment printing, insoluble pigments, which have no affinity for the fiber, are fixed on to the textile with binding agents in the pattern required. Importance of pigment printing Pigments, of course, are used for the production of plain-colored fabrics, but are of much greater importance in printing. The pigment can be applied to all fibers potentially and it is the only coloration to glass fiber, fabric and polyester No wet treatment is required, so drying and curing is applicable to all fiber. Extensive color range of highly light fast colors Possible to produce good combination shades on blended fiber in one padding operation Application procedure is simple Less expensive

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FOIL PRINTING This printing method is based on

aluminum or copper one. A foil layer is affixed to a certain

KWM: Printing

the use of metallic foil paper of

material by a heating process.

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WATER BASED GEL PRINT A rapidly drying aqueous

printing ink containing a gel forming polymer soluble in

the ink but which rapidly gels upon application of the ink to a substrate during a

printing process. Gel ink gives high gloss ‘wet looking’ prints that have a

three-dimensional feel to 15

SPRAY PRINTING A spray gun forces the color through a screen

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HIGH DENSITY PRINTING 

High Density printing is the

specially formulated ink through a very thick stencil

KWM: Printing

process of printing a

to achieve a raised, glossy smooth print with very sharp edges.

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