A new vegetable tanning material for leather industry: Acacia nilotica L.

Tanning is the most important stage giving the required characteristics to raw materials used in leather industry. Chromium salt is still the most preferred tanning material due to the leather properties of the final products. However, ecological awareness, restrictions and legislations have led the tanners and researchers to seek alternatives to chromium tanning system. Numerous alternatives such as vegetable tannins, titanium, zirconium, aluminum, oxazolidine, starch, silica, polymers, syntans etc. have been investigated to overcome the arising ecological problems. Although there was no fully replacement of chromium salt yet, the tendency is still towards to chromium-less production and the production of metal free leathers. In this study, a new vegetable tanning material extracted from the fruit of Acacia nilotica L. was used in the tanning process of the leather industry. The tannin content, the influence on especially the shrinkage temperature, and final physical properties of leathers such as tensile strength, elongation %, tear strength and color measurements have been investigated. Comparable results with commonly used vegetable tannins were obtained from the extract of Acacia nilotica L. The results showed that the extract of Acacia nilotica L. could be the potential new vegetable tanning material also alternative to metal tanning and other tanning systems for leather industry.