MINIMIZING THE IMPAIRMENT OF THE PHYSICAL-PROPERTIES OF WOOL DURING DYEING BY RESTRICTING THE LEVEL OF PERMANENT SET

If permanent setting of the wool fibre, which occurs during dyeing, can be restricted, the impairment of physical properties is reduced. This can be achieved by adding an oxidising agent, such as potassium bromate or hydrogen peroxide, to the dyebath. Oxidising agents also restrict the extent to which hygral expansion increases as a result of piece dyeing. When used in the presence of dyes, oxidants may cause differences in the colour of the dyed wool.