Bleaching of yarn using cabinet and cheese/package processing machine:

Bleaching of cotton yarn can be carried out using cabinet or cheese/package processing machine. In the cheese/package processing machine, the yarn are wound onto perforated stainless-steel cone or cheese. Now-a-days spiral spring type of cheese as shown in the figure, is mainly used. Before winding yarn on it, it is covered with a sheet of porous paper to make manupulation during winding and the removl of any residue of unwound yarn, easier. The soft winding of yarn on cheese is preferred. The cheese or cone are loaded onto the perforated vertical tubes (Spindles) of the carrier and this carrier is drop in the dye vessel. In the dye vessel, when the processing is started, the liquor move either from inside to out side or out side to inside. The    direction of movement of liquor is reversed periodically for uniform treatment. 

                                                           Yarn wound on Spring

                                                                              Spindle

The selection of bleaching receipe depends upon the requirement of whiteness. Following chemicals may be used:

1. Hydrogen peroxide
2. Sodium hydroxide
3.tablizer (Sodium silicate)
4. Wetting agent