Abstract

The non-pickling tanning for cattle hide upper leather was carried out with chrome-less process based on zirconium-aluminum-titanium tanning (DMT-II) in this paper. The best material offers of DMTII and chrome tanning agent were selected through preliminary experiments. The operating parameters in the tanning process, including the pretreatment, the temperature after basification and the final pH, were optimized using the orthogonal testing method. The chrome content of wastewater was chosen as an evaluation index. The evaluation indexes of the optimum scheme were compared with those of the conventional chrome tanning method. The shrinkage temperature of the crust leather (Ts), the chrome content of wastewater BOD5/COD and the gross mechanical property and the histological sections were evaluated. The results showed that the shrinkage temperature of the crust leather could be up to 90°C when the tanning temperature was 35°C and the pHafter tanning was 4.5, the chrome content of the wastewater was less than 50mgL-1. The BOD5/COD was much higher than those of the conventional chrome tanning method. Moreover, the shrinkage temperature, mechanical properties, crust leather fibres tighter density were comparable to those of conventional chrome tanning.