Borschevska N. Improvement of the technology for manufacturing of leather products using laser equipment.

The Production of footwear and leather goods technologies with the use of laser equipment is improved. The aim of improvement to increase automation and economic efficiency of production, expand the range of products by creating a unique design and improving aesthetic properties, ensuring product competitiveness. The influence of laser treatment (depth and area of ablation) on the physical-mechanical, hygienic and aesthetic properties of leather for uppers and leather goods is determined. Increasing the depth of ablation to 50-52% of the thickness of the skin adversely affects its physical and mechanical properties was found. As well deteriorating the performance of footwear and leather goods was found too. Area increasing of engraved elements to 50% of the total product part area is not recommended for use on critical parts of footwear that are subjected to the greatest load during molding and operation. The tensile strength decreases when the ablation area increasing up to 50% of the total sample area, and depth – up to 0,7 mm. The tensile strength for «Nappi» is decreases in 1,5–2 times, for «Krast» – in 1,1 times, and for «Flotar» – in 0,65 times. The leather dermis structure in the area of laser ablation has been studied. The electron microscopy results are confirm that the dermis structure has not undergone morphological changes under the action of laser radiation. That confirms the correct choice of the operation of laser engraving technological parameters. Laser treatment does not have a negative effect on the dermis structure and opens the capillary-porous structure of the skin, thereby increasing its vapor permeability are installed. The main technological parameters of the finishing process (engraving and perforation) and cutting of shoe parts with the use of laser equipment are established. The beam power for engraving of skins with a polished or polished surface, is regulated in the range from 11 to 40 W at a laser head speed of 270 to 300 mm / s. For engraving of decorative elements by laser with a high degree of image detail, to use mainly a 1.5-inch lens is recommended. The interval (focal length) between it and the surface will be 3.81 cm. The natural leather and various materials manufacturing cutting is performed with a laser head speed in the range from 15 to 80 mm/s, and the power can increase up to 120 watts. Requirements for the preparation of decorative elements models for laser engraving are developed and the coefficients of adjustment of their linear dimensions for the technological process of molding are obtained. The engraved element or perforation with a complex composition reproduction on the surface of a part is displayed in a graphic layout using a color scheme, where each colors corresponds to certain technological laser equipment parameters. The graphic layout must meet the following requirements: vector objects only; all elements must be converted into closed-loop curves, the thickness of which is "0" or "Hair line"; overlapping objects and their crossing are not allowed; the contours should form one layer. The contour application of decorative elements technology with the use of surface laser engraving has been improved. To use laser engraving surface with an ablation depth of 0.1 mm, followed by painting the decorative element with acrylic paints is proposed. The quality of the product finishing by contouring evaluation was showed: eight layers of acrylic paint provide an aesthetic appearance of the product and high resistance of the coating to repeated bending (4 points, which corresponds to the maximum value according to DSTU 2726-94) and dry friction (with stands 200 revolutions without damage coating). The women's bags assortment group was developed to test the technology of contour application of decorative elements with the use of laser engraving. The footwear and leather goods design and construction with the use of laser equipment at different stages of production have been developed. New models were developed and existing ones are improved with using laser perforation in order to increase the production economic efficiency, the introduction of resource-saving technologies and search for alternative ways to form the range of footwear at the company "Primeshoes". Complex schemes on model parts are created. Leather goods and accessories have a unique author's design due to laser engraving of decorative elements and logos. The range of leather goods development results been introduced into the production of "Your Tailor".