Structuring of Collagen of the Dermis during Rawhide Formation

Abstract

Abstract. 1 The research has been carried out to study colloid-chemical characteristics of stagewise formation of structured leather semi-finished product. It is established that the activity of basic chromium sulfate complexes increases significantly while transition from anion form to cation one. During plastication of dermis structure by alkyl carboxy ethanolamine tannins, diffusion of basic chromium sulfate complexes into dermis accelerates and therefore provides a high level of chemical structuring of collagen of the dermis. Environmentally-effective technologies were designed for chrome tanning in production of leather rawhide Wet-blue and non-chrome tanning for producing leather semi-finished products of polyfunctional application.

Fast high-pressure tanning of animal skins by accelerated chromium sulphate complexation

“…Depending on the pH value, ageing and types of available ligands, many different metal complex structures exist in parallel (Indubala and Ramaswamy 1973;Takenouchi 1981). However, at pH 3 the conditions are not in favour to form oligo-nuclear complexes of sufficient size to cross-link fibrils with a distance of 10 to 16 angstrom between each other (Danylkovych et al 2017;Imar and Vernali 2000). Consequently, the chromium complexes penetrate fully inside the acidified cross section of the collagen.…”

“…If only the hexaaquachromium ion resulted, the dissolved sulphate and hydroxide would remain in the free tanning solution and the hydroxide would lead to an increase in the pH value. Since the pH value decreases, it is assumed that water held by the chromium ion is exchanged by the sulphate and hydroxide ion (Danylkovych et al 2017). Figure 2 shows a possible structure of a hydrated chromium cation that is formed in the tanning solution.…”

Investigation on Polymer-Mineral Tanned Leather Properties

“…Given that mineral tanning is one of the most important processes in leather production, an actual problem is a further improvement of tanning process with both chrome compounds and alternative ones, such as titanium, applying modern, non-toxic chemical materials, which are diffusible and which can ensure even spreading and maximum fixation of a tanning agent into the derma. This helps to develop the structure and potential properties of leather, as well as decrease harmful environmental impact [5][6][7][8].…”