Printing and its Types in Textile Industry | Texhour.com

^Printing

• The formation of a specific colored decorative design on a fabric, with sharply defined edges.

• A print will normally NOT penetrate completely to the reverse of the fabric – unless the fabric is very sheer.

• Most classes of dyes such as reactive, vat, naphthol and disperse can produce prints with requisite color brightness and fastness.

• Pigment colors are the most used in the printing industry. They come in a powder form and adhere to the fibers with the help of resins, which provide adequate adhesion to withstand laundering and dry-cleaning.

• Pigments, especially in light and medium shades and low coverage, are colorfast to most external influences.

• In deep colors and large coverage, the crocking (rubbing) results will be poor. Because of the resin used, pigment printed fabrics will have a stiff hand-feel, and be less permeable - making for uncomfortable wear.

^{Types of Printing}

There are 3 basic approaches to printing a color on a fabric,

1. Direct printing 

2. Discharge printing

3. Resist printing

^{Direct Printing}

• Direct Printing is the most common approach. It can be done with both white and colored fabric. If it is done on colored fabric, it is called overprinting.

• Water-based prints use water-soluble dyes which are imprinted on the fabric in a paste form by dissolving in water to which a thickening agent has been added e.g. gums or seaweed alginates.

• Pigment printing is done without special thickeners, as the pigment itself is a powder, and resins and solvents are also being added which make the mixture viscous.

^{Discharge printing}

• It has the ability to make bright, opaque colors with a soft hand on dark dyed grounds. This cannot be achieved with any direct printing method.

• The fabric is the first piece dyed in the requisite ground color with reactive dyestuffs which are dischargeable.

• This fabric is then printed with the discharging ink when the bleaching agent destroys (removes) the body color, and the added pigment gives the printed area a new color.

• The discharging ink has a short shelf life and has to be used within a few hours of its preparation.

^{Requirements for Discharge Printing:}

* The fabric or garment should be made from cellulosic fibers. If blended, the cotton content should be at least 80%.

* Some dyes resist the discharge reaction and take on a tint of the original fabric color – eg kelly green, purple and royal blue.

* The fabric or garment should not have been over-dyed, as phantom colors may surface once the top color is cut.

^{Resist Printing}

• In resist dyeing which a wax or other substance is printed onto fabric which is subsequently dyed. The waxed areas do not accept the dye, leaving uncolored patterns against a colored ground.

• Batik and tie-dyeing are examples of resist printing.