DOI: 10.36347/sjet.2019.v07i08.006

Pages: 238-244

The retanning process is considered as one of the most important processes in leather making, and it plays an important role in the modern leather industry. The fibre structure of hide or skin is not uniform and the retanning agent improves the properties of leather by filling the empty part of wet-blue leather. It could contribute to further stabilization of collagen fibres and give better handle properties to leather such as fullness and elasticity. In a conventional leather retanning process, retanning materials used include both inorganic salt like basic chromium salt, zirconium salt and aluminum salt and organic materials such as vegetable tanning agent, synthetic tanning agent, resin retanning and aldehyde tanning agent. Extract from the barks of Acacia seyal (Talh bark), widely distributed in Sudan, has been evaluated for its utilization in the retanning of the leather and presented in this paper. Barks of talh have been extracted for 1 hour with distilled water (1:10 w/v) at temperature above 80˚C. The talh extract prepared has been used for the retanning of wet blue leathers. The effectiveness of talh extract in retanning of wet blue leathers has been compared with mimosa retanning. The organoleptic properties of the leathers viz. softness, fullness, grain smoothness, grain tightness (break), general appearance, uniformity of dyeing of talh retanned leather have been evaluated in comparison with mimosa retanned leathers. Talh retanning resulted in leathers with good grain tightness. Dyeing characteristics of talh retanned leathers have been found to be better than mimosa retanned leathers. Also physical strength characteristic and shrinkage temperature and economic viability were noted. The effluent arising from this retanning system has been analyzed for its environmental impact.