ABSTRACT
The art of bleaching has been practiced since the beginning of civilization. White fabrics made of wool and of linen were found in archeological excavations, and bleaching operations are mentioned and described in old texts. The bleaching process can be carried out at several stages of the fiber-to-fabric production sequence. The processes for bleaching based on hypochlorite vary with the kind of the fabric, the amounts to be bleached, and the machines to be used. The slow rate of bleaching, the excess of active chlorine needed in the bleach liquors, and the need for strict control of the chlorine concentration of the liquor and of the fluidity of the fabric during bleaching triggered a series of attempts to accelerate the hypochlorite processes. Regenerated cellulosic fibers, normal viscose rayon, or high-wet-modulus fibers are more vulnerable than cotton to chemical damage, this being particularly so with normal viscose rayon.
