Abstract

Salt curing is a method that is widely used for the preservation of raw hides/skins worldwide and this leads to the enhanced pollution load of tannery by chlorides. The application of alternative short term preservation methods can lead to a substantial decrease in materials consumption. Unfortunately, the application of new methods of short term preservation has not proceeded due to two main reasons: the complication of the proposed preservation method used and unfamiliarity with new chemicals.

In this study, attempts have been made to show some peculiarities which occur when processing hide subjected to short term preservation by sprinkling with a dry mixture containing 5% NaCl and 1% Na2SiF6 (salt-less method). Dehydration and rehydration of the short term preserved hides was investigated, and it was established that simple washing for 2 hours is appropriate to re-hydrate preserved hide qualitatively and to remove surplus sodium chloride.

Short term preserved hide is more susceptible to the action of the unhairing-liming process, and collagen and non-collagen proteins of short term preserved hide are affected more during liming than are proteins of a conventionally salted one. The preservation method has an influence on chromed leather area yield. Wet-blue leather processed from short term preserved hides has 1.4% higher area yield than that produced from salted hide. The shoe upper leather produced from short term preserved hide contained slightly more chromium and fatliquor but the method of preservation had no influence on strength and organoleptic properties of the shoe upper leather produced.