Abstract

The influence of the system containing NaOH, N7Sa and a salt such as NaC1, N,4a,S0 HCOONa or N4a,HPO on the properties of hair in the process of unhairing was investigated. The influence of alkaline process conditions such as concentration ofNaOH and salt, temperature and duration of the process on the degradation of collagen and non-collagen proteins, the swelling and the quality of unhairing was also studied.

It was established that addition of various salts influences the degree of opening up of the dermal structure. This is observed when the amounts of additional salts are not less than 4—5% of NaC1,SN,47Oa HCOONa and 1—2% of N4.a,HPO The unhairing efficiency decreased when these amounts of salts were used with the exception of NaC1. The temperature is of great importance. It must be no more than 30°C. The tendency towards swelling does not follow the tendency to destruction of the collagen. Under certain conditions of the alkaline treatment, the swelling decreases and degradation of collagen increases.

The addition of various salts during alkaline treatment widens the range of possibilities of using NaOH for unhairing hides.