RESEARCH OF THE INFLUENCE OF LASER ENGRAVING ON THE PHYSICAL AND MECHANICAL PROPERTIES OF NATURAL LEATHER FOR SHOE UPPERS AND LEATHER GOODS

Abstract

Research of the influence of laser engraving on the physical and mechanical properties of natural leathers for shoe upper of footwear and leather goods, namely leather crust, Flotar and Nappa. Methodology. The methods of physical and mechanical analysis of leather, mathematical planning (multivariate experiment) and statistical processing of experimental values were used for the study problems. Findings. According to the research influence of laser engraving on the physical and mechanical properties of natural leather for shoe upper and leather goods, it was found that the depth and area of laser ablation affect the tensile strength indicators. There is a certain relationship between them. Based on the
results experiment, it can be stated that an increase in the depth of ablation to 50-52% of the thickness of the leather negatively affects the physical and mechanical properties, can worsen the operational and consumer characteristics of footwear and leather goods. An increase in the area of engraved elements up to 50% of the total  area  of  a  product  part  is  not  recommended  for  use  on  shoe  parts.  The  recommended  power  for engraving  natural  leather  for  shoe  upper  and  leather  goods  is  60-80%  of  the  machine's  power.  For engraving leather with a polished surface, the laser beam power is adjustable from 11 to 40 W at a head speed  of  270  to  300  mm/s.  For  laser  engraving  decorative  elements  with  a  high  degree  of  detail,  it  is recommended to use a 1.5'' lens, where the spacing between it and the surface will be 3.81 cm. Increasing the focal length is advisable when engraving captions and images with low detail requirements. Originality. The regularities of the influence of the depth and area of decorative elements during
laser engraving on the physical and mechanical properties of natural leather for shoe upper of footwear and leather goods have been determined. Practical value. The optimal parameters of laser engraving for finishing shoes and leather goods made of natural leather have been determined.