A process by which the natural colors of textile fiber are removed to achieve whiteness for development of true color is known as bleaching. This is the last pretreatment process of textile goods.
This is an oxidation process where the natural color of the fabric destroyed. For any type of dull shade this process is not necessary but for the brilliant shade this process must be used and for the medium shade light bleaching process is used.
Precaution: Most of bleaching agent create some adverse impact on fiber thus the process should be accomplished with minimum of damage to the fiber being bleached strong and uncontrolled bleaching action can degrade the cotton fiber. Thus the process must be regulating carefully.
In the bleaching process 20-30 GSM of the grey fabric must be damage. Finally will get the required GSM of the fabric.
Bleaching process: The following processes are suitable for textile processing.
  1. Hydrogen peroxide (H2O2) bleaching.
  2. Sodium hypochlorite (NaOCl) bleaching.
  3. Sodium chlorite (NaClO2) bleaching.
  4. Bleaching powder (Ca(OCl)Cl) bleaching.