STUDIES ON THE STIFFNESS OF SILK FIBRES

(9) SOFTNING OF RAW SILK BY THE MIXTURE OF UREA AND OTHER AGENTS

Abstract

Mainly the mixture of urea and other agents were tested for the purpose of finding the agents which have strong softening effects upon raw silk.
1) The mixture of urea and higher alcohol (emulsified with sulfuric ester of higher alcohol) had a coparativelystrong effect.
2) In the case of the mixture of urea and higher alcohol, when the temperature of the treatment had reached 70°C the weight-increase ratio and also the effect became higher and stronger.
The influence of numbers of C of higher alcohol and that of pH the solution were not clear.
3) The nature of the raw silk which is treated with the mixed solution of urea and higher alcohol approaches gradually to that of untreated one as time elapses.
4) Raw silk is not especially softened by such a method in which the raw silk is first treated with urea solution and then treated with the solution of other agents.
5) The mixture of urea and sodium cyclohexylsulfamate showes a fairly strong softening effect upon raw silk. The effect become stronger when higher alcohol is added to it. The mixture of urea and KCNS also has a comparatively strong softening effect.