Start Date: Jun 25, 2004
End Date: Jun 24, 2009
Oxidative chemicals will be evaluated for dehairing activity. Following dehairing, fleshing and splitting, the grain split will be further dehaired if necessary to remove remaining hair stubble. Further processing would complete the conversion of hide to crust leather. Enzymes (keratinases, dispase, acidic or alkaline proteases, and type IV collagenases will be evaluated as alternatives to chemical dehairing. Processes will be developed for partial or total removal, from limed hides, of proteoglycans (such as decorin) and glycans (such as dermatan sulfate) by first 'opening-up' the hides thoroughly to the entrance of chemicals and then treating the hides in the presence of concentrated salts with chymotrypsin, trypsin, pancreatic bate, halophile protease and/or glycanases (during bating). Both the decorin core-protein and the sulfated glycan content will be measured before and after application of the novel treatment, and mechanical and physical changes in the resultant leather will be evaluated. The effect of treatments on the physical and mechanical properties of leather ultimately made from the treated hides will be assessed. A mathematical, predictive drying model for chrome-free leather will be established and compared to the earlier one developed for chrome-tanned leather. Based on the new model, the optimal drying conditions for chrome-free leather will be identified. A finishing process will be developed that will improve the UV- and heat resistance of automobile upholstery leather. Alpha-tocopherol (Vitamin E) will be added during wet processing or added to the finishes and applied to the grain layer of the leather during the finishing process. In-line nondestructive testing technology by acoustic emission (AE) will be developed to assess the mechanical properties of leather following drying, staking, buffing, drum milling, and finishing. The additional funding will be used to evaluate processes for expediting the diffusion of salt into the hide. The ability of acoustic/mechanical energy or alternative salt formulations to shorten the time of brining and possibly decrease the salt requirement will be assessed.