OPTIMIZATION OF A SYNTAN-TANNIN COMPOSITION FOR FILLING ELASTIC LEATHER MATERIAL

Abstract

The goal of this work is to develop an optimal syntan–tannin filling composition for the production of elastic leather material using multicriteria optimization. To achieve this goal, a chrome-tanned leather semi-finished product from heifer hide with an average thickness of 1.1–1.2 mm was used. Based on a priori studies, an optimal syntan–tannin filling composition was developed using mathematical modeling. In the process of multicriteria optimization of the filling composition, an a priori experiment was conducted. An experimental plan was synthesized and implemented using the McLean–Anderson algorithm and a custom-developed multi-threaded program for computing a D-optimal plan. A mathematical model of the syntan–tannin filling composition was obtained. Based on Harrington’s desirability function, the optimal consumption of the filling composition ingredients and the properties of the resulting semi-finished product were determined. The optimal composition of the syntan–tannin mixture was established (in mass %): alkylcarboxyethanolamines of aliphatic acids C7–9 – 7.7; syntan based on naphthol sulfonic acid, dioxydiphenyl sulfone, and formaldehyde – 19.3; mimosa extract – 31.5; quebracho extract – 41.5. This enables a 19.0 % reduction in the consumption of natural tannins, while providing a leather material with an increased volume yield, porosity, and reduced stiffness by 11.8 %, 12.6 %, and 24.0 %, respectively, compared to the current technology. The developed filling technology for leather semi-finished products using a phenol-free syntan and alkylcarboxyethanolamines of aliphatic acids C7–9 can be recommended for the production of leather materials from other types of raw hides.