Study of the Biodegradability of Leather Tanned with Sodium Aluminosilicate

Abstract

The leather industry transforms raw hides into leather by mechanical and chemical processes. The main chemical process is the tanning in which the fibers are stabilized and cannot putrefy. To this end, different chemicals can be used that are capable of forming crosslinkages between collagen molecules. In this sense, the most used products are: chromium salts, aluminum, vegetable tannins, synthetics, aldehydes, resins and silicates. In this work, a new biodegradable tanning process based on zeolites was studied in two steps. In the first one, a tanning process for sheepskins and cow hides was developed. In the second one, three types of retanning process to obtain shoe upper, vegetable and leather goods were studied. This new system allows to obtain leather that can decompose naturally in a relative short period of time. Leather tanned with this system shows similar values to the biodegradability of pure collagen.Specifically, with the retanning system used for shoe upper allows to obtain a 74.4% relative biodegradability compared to pure collagen.