Abstract

An attempt has been made to develop a method for processing leathers in a narrow range of pH viz., 4.0.8.0. A process for dehairing at a pH of around 8.0 has been explored. This has been achieved by employing a commerical enzyme in combination with small quantities of sodium suiphide. A method for applying the dehairing formulation on the grain side was established. Hair removal was shown to be complete using scanning electron microscopy (SEM) and cystine content analysis. Potential grain damage by the enzyme formulation was avoided through process control measures and the effectiveness of such methods was established by investigation by scanning electron micrographs. Strength and bulk properties of the experimental leathers appear to show some improvement as compared to the leathers made using conventional processes. The process enjoys an environmental benefit by significantly reducing the COD load in the effluent. Improved chrome content in the grain surface of the butt region adds an additional benefit to the dehairing process developed.