Development of a leather processing method in narrow pH profile: Part 1. Standardisation of dehairing process

An attempt has been made to develop a method for processing leathers in a n arrow 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 enz yme in combination with small quantities of sodium sulphide. A method for a pplying the dehairing formulation on the grain side was established. Hair r emoval was shown to be complete using scanning electron microscopy (SEM) an d cystine content analysis. Potential grain damage by the enzyme formulatio n was avoided through process control measures and the effectiveness of suc h 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 proces ses. 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 deve loped.