Sara her  question:

HOW DO BLEACHES WORK?

Bleaching is the way to turn cloth and yarn white by removing the natural coloring. Industrial bleaching calls for several special kinds of machines.

Manufacturers usually use hydrogen peroxide or sodium hypochlorite to bleach linen and cotton cloth. They soak the material in a chemical bleaching bin for two to 12 hours, depending on the texture of the cloth and the strength of the bleaching chemical.

A solution of sulfuric acid washes the chemicals out of the material to prevent the bleaching chemicals from harming the fabric.

Sulfurous acid or hydrogen peroxide is used to bleach wool or silk. Sulfuric acid is used to remove color from feathers and straw while chlorine bleaches wood pulp and the rags from which paper is made.