ZERO-AOX SHRINKPROOFING TREATMENT FOR WOOL TOP AND FABRIC .1. GLOW-DISCHARGE TREATMENT

The glow discharge treatment of wool in nonpolymerizing gases like air, oxygen, and nitrogen is presented as a new zero-AOX pretreatment for shrinkproofing wool top and fabric. Modification of the wool fibers is restricted to the outer 30-50 nm, and consists of plasma etching and surface oxidation. The former is responsible for the abrasion of the fatty acid layer from-the cuticle and parts of the exocuticle-A; the latter introduces new anionic groups, i.e., sulphonate and carboxylate functions. Carboxyl groups derive from a backbone oxidation of the protein chains in the cuticle cells. Sulphonate groups are generated by oxidation of disulphide functions. Surface modification applicable to both wool top and fabric results in an increased hydrophilicity of the fiber surface and has an excellent shrinkproofing effect in combination with a new shrinkproofing resin.