Influence of Different Products on Wet Finishing for Leather Properties and Waste Generation

Abstract

Leather is widely used for various applications. The processing involves a series of steps in which chemical processes and mechanical operations are carried out, with the addition of a series of products. Among the performance and quality parameters of the leather produced are the chemical and physical properties. The quality of the leather and the product obtained is influenced by its processing and the products used. Several studies are found in the literature on the effect of processing on leather properties. The present study brings the results of the influence of different products used in retanning, dyeing and fatliquoring (wet finishing) on the final properties of the leather. Physical tests of resistance to tearing, cracking and distension of the grain, the functional groups present in its structure, the thermal stability by DSC and TGA tests, dye uptake rate percentage and the remaining concentration of dye in the solution were used to evaluate the influence of different products on leather properties. It was observed that the parameter that influenced the applied force and the distension of the grain of the leather was the type of retanning agent used; the greater resistance to distension was obtained by Tara retanned leathers. As for the degree of dye uptake rate and remaining concentration of dye in the effluent, they were not affected by the studied parameters and all hides showed similar dye uptake. Regarding tear resistance, the type of grease was the parameter that had a significant effect on leather, higher resistance values were observed for leather greased with Coripol. The novelty of the work is in measuring how different dyeing, retanning and greasing products influence the properties of the final product, which is an advance towards greater cost-benefit in the choice of products to be used in the process.