Колоїдно-хімічні аспекти відмочувально-зольних процесів виготовлення еластичних шкір

The colloid-chemical aspects of soaking and liming processes of raw hides processing in the elastic leather production for shoe uppers have been studied. The comparative ecological analysis of soaking and liming processes in the elastic leather materials production is carried out. It is shown that low-waste soaking and liming technology in terms of the physical and chemical properties of the semi-finished leather materials provides lower consumption of environmentally damaging reagents compared to the current technology, namely sodium sulfides and calcium hydroxide by 2.9 and 4.2 times and reducing the total processing time by 2.3 times and electricity costs by 1.7 times. The obtained limed semi-finished product on a set of structurally sensitive indicators is instantiated by higher structure stability. According to the study of the extracted organic unstructured components oxidation degree of the dermis in working solutions and plumping of the limed semi-finished product, deeper structural changes of the skin obtained by the current technology were established due to higher calcium hydroxide consumption and processing time of the semi-finished product. Developed environmentally friendly low-waste technology provides leather for the shoe uppers with increased yield by 3.9%, which meet the requirements of DSTU 3115-95. The obtained elastic leather is characterized by higher strength, absence of loose grain defect and break of leather. Gentle plumping of the limed semi-finished product provides the leather formation with a higher yield area and, accordingly, raw hides efficient use. It is established that according to the complex of ecological and technological indicators the low-waste technology of soaking and liming processes has significant advantages over the current technology in the elastic leather for shoe uppers manufacturing.