Submitted to: Journal of American Leather Chemists Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 1, 2005
Publication Date: November 10, 2005
Citation: Marmer, W.N., Dudley, R.L. 2005. Oxidative dehairing by sodium percarbonate. Journal of American Leather Chemists Association. 100(11):427-431. Interpretive Summary: The United States produces in excess of 35 million cattlehides annually. Before these hides can be converted to leather they need to undergo a dehairing step. The conventional dehairing agent has been sodium sulfide, but safer, benign alternatives are needed. To that end we examined a common laundry detergent additive, sodium percarbonate, as a potential dehairing agent. It readily removed hair from cattlehides without any damage to the hide. The results will lead to commercial scale trials, and the results of those trials should demonstrate a benign alternative to sulfide for the American tanning industry.
Technical Abstract: The dehairing of cattle hides generates large quantities of waste that are of environmental concern as they have a large biological and chemical oxygen demand. We had demonstrated that the traditional dehairing agent, sodium sulfide, can be replaced by an oxidative dehairing agent, sodium perborate, thereby reducing the amount of hazardous chemical in the waste stream. The by-product of perborate is borate, however, which is suspected to accelerate the degradation of wooden dehairing drums. In this paper we report the results of a study that uses sodium percarbonate, another oxidative agent, as the dehairing agent. Although oxidatively dehaired hides exhibit a slight resistance to acid dye uptake, leather produced from percarbonate-dehaired hides in all other studied aspects -- shrinkage temperature, chromium uptake, elongation at break, toughness index -- compared favorably to leather from sulfide-dehaired hides.