DETERMINATION OF THE INFLUENCE OF LASER ENGRAVING ON THE HYGIENIC PROPERTIES OF NATURAL LEATHER FOR SHOE UPPERS AND LEATHER GOODS

Abstract

Purpose. Investigation of the effect of laser engraving on the hygienic properties of nature leather for uppers and leather goods, namely leather Krast, Flotar and Nappa. Methodology. To achieve this goal, the method of scanning electron microscopy (SEM) was used. Hygienic properties of Krast, Flotar and Nappa hides was studied in accordance with ISO 14268: 2008 by
determining vapor permeability. Findings. According to the results of the study of the effect of laser radiation on the hygienic properties of nature leather for uppers and leather goods, the nature of changes in the micro- and macrostructure of the dermis under laser engraving and allowable depth and area of laser ablation that do not impair the hygienic properties of these skins and products. With increasing ablation depth to 0,7 mm (50% of the total thickness of the sample), the relative vapor permeability increases in all samples of the studied skins, while the relative vapor permeability for the skin of Krast increased by 5%, Flotar by 13,5% and 9,5% for Nappa. The optimal value of the depth of laser ablation, which does not impair the operational and hygienic characteristics of the
products is 25–30% of the skin thickness. On the front surface revealed features of the structure, which are characteristic only for the area of direct action of the laser beam, namely the skin samples Flotar and Nappa
have obvious signs of welding collagen fibers. In the area of laser ablation, an increase in the interstructural distances between the bundles of collagen fibers was also detected, which was the result of thermophysical
processes of laser radiation. Originality. The determined effect affects the depths and flat laser ablations on the morphological structure of the dermis and the hygienic properties of natural leather for shoe uppers and leather goods. Practical value. The vapor permeability of genuine leather for the uppers of shoes and leather goods under the action of laser radiation was determined. The value of the depth and area of laser ablation for
finishing leather products, taking into account the impact on the hygienic properties of products in general.