Abstract

The leather industry today is dominated by wet-blue leathers due to its advantages. However, alternatives are being actively sought due to environmental concerns. In this study, an effective combination tanning system based on zirconium and tetrakis (hydroxymethyl) phosphonium sulphate (THPS) has been explored producing wet-pink leathers. The leather properties and physical strength characteristics are on par with conventional chrome tanned leathers. The leathers made using this combination tanning exhibit good light fastness. A shrinkage temperature of 102 ± 0.4°C has been obtained for the Zr-THPS tanning system with sodium tartrate as the ligand. The analysis of spent tan liquor shows that there is an interaction between zirconium and THPS resulting in the pink colour of leathers.