Author : M.H Abdella, A.E Musa and S.B Ali

The retanning process is a very important step in leather manufacturing because it overcomes some of the disadvantages of chrome tannage and it can contributes to further stabilization of collagen fibers and good handle of leather, such as fullness, softness, elasticity and so on. In order to meet customers’ requirements, a wide variety of retanning agents are used in retanning process viz. vegetable tan and phenolic synthetic/organic tanning materials. Sunt bark, widely distributed in Sudan, has been evaluated for its utilization in the retanning of the leathers. In the present investigation, sunt bark powder has been used for the retanning of wet blue leathers. The effectiveness sunt bark in retanning of wet blue leathers has been compared with wattle retanning. The organoleptic properties of the leathers viz. softness, fullness, grain smoothness, grain tightness (break), general appearance, uniformity of dyeing of sunt bark retanned leather have been evaluated in comparison with wattle retanned leathers. Sunt retanning resulted in leathers with good grain tightness. Physical strength characteristic and shrinkage temperature were noted. Dyeing characteristics of sunt retanned leathers have been found to be better than wattle retanned leathers.

Keywords: Sunt bark, Retanning, Garad bark, Acacia nilotica, Shoe upper leather