2. Bleaching in Jigger:

Jigger machine can be used for desizing, scouring, bleaching, dyeing and finishing purposes. In this machine fabric is treated in open width. The jigger machine consists of a relatively small tub and drawing rollers located above the dye/treatment bath. The fabric is wound around one of the rollers. During treatment of fabric in this machine, fabric is passed through the liquor bath and rewind onto the second roller. When all the fabric is passed through the treatment/dye-bath the direction of movement is reversed, and in this way the fabric is passed back and forth throughout the treatment/dye-bath until the treatment is completed. Following receipe may be taken for bleching of cotton fabric with hydrogen peroxide:

1. Hydrogen peroxide (35% concentration) : 2-4%

2. Stablizer: 0.5-1.5%

3. Sodium hydroxide: 0.5-1%

4. Wetting Agent: 0.1%

The above chemicals are added in the jigger bath and temperartue is raised slowly to 85-95oC. The bleaching is continue 1 to 3 hours depending upon the type of fabric.Then fabric is hot wash followed by several cold washes. Finally if needed peroxide killer may be used to remove residual peroxide.

In the jigger bleaching, stabilser can be removed easily as the fabric is treated in open bath. The materila to liquor ratio is also low in jigger processing, therefore saving of water is also expected.