Abstract

The influence of the system containing NaOH, Na2S and a salt such as NaCI. Na2SO4,HCOONa or Na2HPO4on the properties of pelt in the unhairing process was investigated.

The process of unhairing was separated into two stages: (i) degradation of the hair and (ii) opening up the dermal structure. The opening up stage was carried out in the liquor from the hair degradation after dilution with water.

It was established that the above salts added to the solution for opening up the dermal structure influence the kinetics of the removed collagen and non-collagen proteins and also swelling of the hide. The supplementary use of salts is not convenient because it is more convenient to regulate the properties of the pelt by using a suitable quantity of water in the opening up stage.

The technology of lime-free production of pelt was developed based on the results of these investigations. Application of this technology showed that the quality indexes of the garment leather produced using this method meet the manufacturer’s requirements.