90—APPLICATION OF THE DESCALING TECHNIQUE TO THE THEORY OF SHRINKPROOFING OF WOOL

Abstract

Lincoln 36s fibres, shrinkproofed by various methods, were examined microscopically, frictional measurements were carried out and whole fibre and cuticle-rich material were analysed for amino acids and amide-nitrogen. In all treatments, except alcoholic NaOH, fission of disulphide bonds is the primary chemical reaction which produces the necessary change of physical properties to effect shrinkproofing, although there are other secondary reactions in at least two treatments.

Shrinkproofing by degradative chemical methods is considered to be a function of modification of surface properties and of whole fibre properties. It is found that the efficacy of shrinkproofing parallels the severity of surface modification observed by microscopy for all treatments in which there is little or no attack on the whole fibre. The other properties measured, viz., loss of cystine in cuticle or whole fibre and frictional properties, show no correlation with the degree of shrinkproofing.