Author : Rajan Kumar Raha, Md. Tarikul Islam, PradiptaSarkar and Md. Shahidul Islam

Most of the leathers produced worldwide are chromium tanned. The negative environmental impact of chromium pressurizes the tanners to find out alternative tanning technologies. In this research as an alternative to the conventional chrome tanning a wet white leather was produced by commercial grade sodium Hexa Meta phosphate (SHMP) tanning in wet condition at room temperature. The quality deficiencies of the wet white leather were improved by a modified method of syntan (Basyntan DLE) assisted SHMP tanning. The optimum SHMP tanning conditions were identified as pH of the tanning bath (3), offer of the SHMP (12% based on pelt weight) and tanning time (6 hours). Shrinkage temperature and tensile strength of the SHMP tanned wet white leather were 84 °C and 19.15N/mm2 respectively. In the modified system 8% offer of Basyntan DLE along with 12% SHMP was identified as best combination. In this condition shrinkage temperature of the wet white leather enhanced 6.02% from 84 °C to 89 °C. Other physical properties were also found to be increased significantly. Due to the improvement of leather quality and generation of chromium free wastewater, this syntan assisted SHMP tanning may be the potential cleaner technology as a substitute of the most practiced wet blue technology in the tanning industry.

Keywords: Wet white leather,Tanning, Cleaner technology, Polyphosphate, Syntan.

Article published in International Journal of Advance Industrial Engineering , Vol.5, No.1 (March-2017)