ENHANCING THE UNIFORMITY OF ELASTIC LEATHER FROM EQUINE HIDES

Abstract

The objective of this work is to enhance the uniformity of elastic leather made from equine hides by using a syntan-tannin composition with С7–9 aliphatic acid alkylcarboxyethanolamines in the wet-finishing processes. For this study, we used samples of chrome-tanned semi-finished leather (wet-blue) from equine hides, each measuring 25 dm², taken from various topographical areas, including the back, neck, and belly, which are characterised by significant non-uniformity. Control samples were symmetrically taken along the spine line. The study investigated the complex of physicochemical properties of leather from equine hides using the syntan-tannin composition with alkylcarboxyethanolamines of С7–9 aliphatic acids during the wet-finishing stage of the chrome-tanned semi-finished product. Simultaneously, the uniformity of the resulting material was evaluated using the coefficient of uniformity. Determining the chemical composition of the leather across the topographical areas allowed us to establish an increase in the content of organic tanning agents in regions with lower density. A slight increase in thickness was also observed in these same areas. The effective filling of the volume of the leather semi-finished product, achieved by employing a syntan-tannin composition with alkylcarboxyethanolamines, results in a 3.4% increase in the material's area yield. Based on the coefficient of uniformity, the produced leathers are characterised by high uniformity of deformation properties across all topographical areas. This facilitates the efficient cutting of components for shoe uppers in the manufacture of a wide range of products. Compared to industrial technology, the resulting leathers have a 21.0% higher coefficient of uniformity for deformation properties. This provides a basis for recommending the syntan-tannin composition for industrial trials at the wet-finishing stage.