Chrome-Free Tanning: Effect of a Combination Tannage Based on Mimosa and Biogenic Silica from Rice Husk

Abstract

Chromium (III) sulfate is a popular tanning agent for producing leather. However, chrome tanning wastewater is one of the problems in the leather tanning industry. To prevent this, tanning using vegetable materials can be used in the leather tanning process. One of the natural ingredients that can be used is mimosa. However, mimosa is relatively expensive, so a substitute/combination tanning agent is needed to make tanning costs cheaper. This research aims to determine the effect of using a combination of mimosa and silicic acid from rice husk (RHSA) tanners on the quality of the tanned leather produced. This research uses a completely randomized factorial design with mimosa and RHSA as factors. The analysis shows that the best treatments were 20% mimosa and 20% RHSA. In addition, the analysis shows that the treatment met the standard. The resulting shrinkage temperature was 84 °C, tear strength was 39.98 N mm-1, tensile strength was 26.42 N mm-2 and elongation at break was 41%. Combination tanning also shows no significant difference from conventional tanning and reduces mimosa without decreasing leather quality.