Rapid Fiber Opening Process for Skins: An Approach for Fail-Safe Chemical-Free Process

Abstract

Conventional beam house operations adopted by the global tanning industry are coming under the close scrutiny of the environmentalists on account of the possible adverse effect on human health and environment. Lime, which is used to the tune of about 10% on the weight of the raw hides and skins, in re-liming stage contribute to generation of large quantities of sludge, the disposal of which is a serious concern. Also the process duration to achieve the required fiber opening in the re-liming process is very long, ranging from 24-72 hrs for different substrates and end products. Enzyme based beam house processes are being advocated to overcome the problems associated with the conventional processes. However, enzyme based methods need greater control over process parameters to achieve satisfactory results in leather processing and avoid damage to the pelt. To overcome the problems associated with the conventional re-liming process, an attempt has been made in the present investigation to utilize cocktail of carbohydrases for fiber opening of hides and skins. Fiber opening at optimized concentration of the above enzyme has been studied for its efficiency on goatskins. A process using optimum quantity of enzyme led to fiber opening in 30 minutes. The efficacy of enzyme on rapid fiber opening of dehaired skin was studied at different experimental conditions of pH, time and enzyme concentration. The performance of the enzyme in the given experimental conditions was assessed by quantifying the removal of carbohydrate and proteoglycan and examining the fiber opening by scanning electron microscopic studies. Effect of enzyme on the final quality of the leather was evaluated by changes in chemical characteristics, physical properties and visual examination.