APPLYING PROTEASES TO CONFER IMPROVED SHRINK-RESISTANCE TO WOOL

The activity of an alkaline bacterial protease in conferring shrink-re sistance to wool tops and woven cloth has been enhanced by pretreatmen t of the wool with sodium sulphite at pH 8.5-9.0. Among 16 proteases w hose activities were compared, Esperase was found to be the most activ e, while causing the least damage when applied after sulphite treatmen t. None was found to confer adequate shrink-resistance to tops under t hese conditions without causing excessive damage. For some examples of woven cloth, sodium sulphite applied alone caused a significant reduc tion in shrinkage, and subsequent application of Esperase then afforde d good washability. Excellent washability was obtained if the cloth wa s first oxidised with peroxymonosulphuric or monoperoxyphthalic acid b efore treating with Esperase.