| Abstract [eng] |
Taking into account the daily increasing consumerism and growing scale of production, environmental challenges are faced. These problems do not escape the leather industry either, because lime unhairing and chromium tanning are processes, which pollutes the environment and the treatment of generated wastewater is an expensive and complex process One of the solutions to these problems is the usage of enzymatic preparations into the hide treatment. The aim of integrating the enzyme preparation into the pickling process is to reduce the amount of chemicals used in the further stages of the leather semi-finished product processing. Also, the replacement of chromium compounds with vegetable tannins can be one of the alternatives to create a sustainable productsand maintain the qualitative indicators, which would satisfy the needs of market.. During the work, studies were done in order to evaluate the influence of enzymatic treatment on pickling, chroming, tanning and the wet finishing process. During the work, the caseinolytic and collagenolytic activity of the enzyme preparations Lithudac L and Oropon WB was investigated. The enzyme preparation Lithudac L was used during the pickling process. The influence of the enzyme preparation on the properties of the treated skin, such as the amount of collagen proteins removed during pickling, the porosity of the skin, the shrinkage temperature, the penetration and consumption of tannins, was determined. The influence of the enzymatic preparation on the pH of skin extracts and tanning process solutions was also evaluated. After the chroming process, the amount of chromium compounds in the leather and the amount of substances soluble in dichloromethane, as well as the mechanical and physical properties after fatliquoring, were evaluated. Infrared spectroscopy and thermogravimetric analysis were performed to evaluate the influence of enzymatic treatment on the changes in the structure of the pelt and the leather semifinished product. In this work, it was found that enzymatic processing after pickling makes skin processes more efficient and improves the quality indicators of the leather. More non-collagen proteins are removed from the skin, tannins penetrate faster, the shrinkage temperature is higher, absorption of fatty substances are better, thermal destruction slows down. |
