Morphology of the Surface of Natural Leather after Laser Exposure

Abstract

The main and leading factor in the world economy is the use of innovation. The development of new and highly intelligent technologies makes it possible to ensure high rates of economic development. In addition, the development of high-level technologies makes it possible to preserve the ecosystem and reduce the number of harmful industries. The article discusses the problems of the development of laser technologies for solving the problems of the leather industry of the Republic of Belarus and the Republic of Uzbekistan according to the research conducted by the authors. The morphology of the surface of the sample was investigated by the methods of optical and scanning electron microscopy, and the elemental analysis of natural leather under the action of laser radiation was carried out. Laser processing was carried out on the Flexsi 600 industrial complex (based on a CO₂ laser source Rofin Synar (Germany), which is designed for high-speed cutting, marking, and engraving of various materials, power P = 135 W, scanning speed V = 600 mm/s, frequencies ν = 5.0; 3.5; 2.5; 1.5; 1 kHz). Laser processing was carried out from the front surface of the shoe blank. The process of leather perforation was investigated. It is shown that, after perforation with a frequency of 5 kHz, the laser impact zone is approximately 330 μm along the entire perimeter of the hole. With a decrease in the frequency of laser action, a continuous combustion zone is not formed and the size of the zone of influence narrows. From the analysis of the results, it follows that the most favorable perforation modes are in the region of 2.5–3 kHz. At an exposure frequency of 1–1.5 kHz, leather perforation does not occur. The scanning electron microscopy method was used to study the surface morphology of a natural leather sample exposed to laser radiation from the front and back sides. It was found that the effect of laser polishing of leather is achieved in the range of input energies of 30–240 J and exposure durations of 30–240 s. The treatment was performed using a LS-2134D yttrium aluminum garnet laser (LOTIS, Belarus) with a wavelength of 1064 nm, generating in a two-pulse mode (pulses are separated by a time interval of 3 μs, pulse duration is 10 ns..