Printing and its Types in Textile Industry | Texhour.com
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.
• 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 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.
• 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.
• 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.