A Comprehensive Analysis of Consumer Properties of Nutria Velour Hydrophobicized with Alkenmalein-acrylsyntane Composition

A set of consumer properties of hydrophobicized nutria fur velour obtained with the use of alkenmalein-acrylsyntane composition has been studied. Components of this composition included alkenmalein polymer, polyacrylic polymer and synthetic tanner. The process of filling and hydrophobicizing nutria fur velour was carried out at pH of the working solution of 6.8‒7.0, temperature of 40‒43 °С during three hours and completed at a pH of 3.8‒4.0.Hydrofobicized nutria fur velour was obtained from raw materials with low hair quality, heterogeneous structure in different topographical areas and low density but with satisfactory physical and mechanical properties of the skin tissue.Influence of the component ratio of the filling and hydrophobicizing composition on the physicochemical properties of fur velour was established. Specifically, the following characteristics have been studied: total thermal resistance, dynamic water wetting, water drop absorption, wetting angle, wetting, vapor permeability, air permeability, etc.Optimal component ratio of the alkenmalein-acrylsyntane composition has also been established which ensures formation of a modified nutria fur velour with a set of improved consumer properties compared with the sheepskin velour. In particular, reduction of the total thermal resistance and vapor permeability of the hydrophobicized nutria fur velour observed during hydroprocessing was less: 9.7 and 1.7 times, respectively, than that of the sheepskin velour. At the same time, aesthetic indicators of the nutria velour (coloristic design and quality of leather dressing were also higher (by 39‒41%) than those of the sheepskin velour.The obtained results from hydrophobicizing fur velour with a set of required consumer properties indicate the possibility of expanding the range of products made from fur raw materials with poor-quality hair but satisfactory physical and mechanical indicators of skin tissue. Fur products manufactured from hydrofobicized nutria velour will be suitable for wearing under conditions of high humidity

Improvement of the Filling and Plasticization Processes of Forming Multifunctional Leather Materials

The study concerns the filling and plasticizing processes in the final stages of forming multifunctional leathers from various raw materials on the basis of using new composite systems. The structure of a tannin-containing composition was found to affect the process of its diffusion throughout the structure of the topographic areas of the semifinished chrome-tanned product. In particular, we have determined that the depth of diffusion of the filling composition in loose areas was close to 100 % with a 5 % use of the mass of the intermediate product; in dense areas even with a bigger use of the mass, it was only 80 % of the thickness of the intermediate product.The structure of the filling and plasticizing composition was developed to form various leathers from hides of cattle and sheep. A protein hydrolysate and a highly dispersive modified aluminosilicate have proved to influence the process of forming and the physicochemical properties of semifinished leathers. If the filling and plasticizing composition contains optimal amounts of montmorillonite and protein hydrolysate at 4–2 % of the semifinished leather mass, the obtained leather materials have respective tensile strengths of sheepskin and bovine hides of 15–16 MPa and 20–22 MPa, and their stiffness is 15–16 and 21-22 SN.The use of montmorillonite in the filling and plasticizing compositions in processing semifinished chrome-tanned products proved to ensure stability of the dispersed structure in further processing and its mobility in the cyclic deformation of the products. The complex study of the process of filling and plasticizing semifinished chrome-tanned products was the basis for developing effective technologies to produce elastic materials for footwear leather uppers and apparel and haberdashery articles with the necessary physical and mechanical properties as well as bigger volume and area outputs by 270–310 сm3/100 g of protein substance and by 5–6 %, respectively, in comparison with the outputs of the industrial technology

Optimization of Leather Material Filling-plasticizing Process Using Disperse System

The second­order mathematical model is obtained on the basis of experimental data at the PJSC Chinbar (Ukraine) using experimental design techniques. The model describes the semi­finished leather filling­ plasticizing process adequately. The filling­plasticizing leather material is obtained from cattle raw material using chrome tanning method and slicing the material to 1.5–1.6 mm thickness. The dispersing mixture of natural fats and oils: beef tallow, sunflower oil, and fish oil in a ratio of 1:1.75:2.25 % was used for plasticizing the semi­finished material. The nonionic surface active agent was used to emulsify the fats. The diagrams of single­factor dependencies for simulation models are obtained, and the influence of disperse system ingredients on basic technological properties of the leather material are analysed. The studied ingredients were plasticizer, modified filler, nonionic surfactant. The studied quality parameters were the output area of the semi­finished product, the total content of fatty substances in the tanning material and the hardness of material.The software calculation module in the Visual basic for Application environment is developed to automate the calculation of the optimal dispersed system composition. The module allows converting multi­criteria task into single­ criterion task using maximin convolution and Hooke­Jeeves method to solve the optimization task. As a result, the optimum values of the factors that influence the semi­finished leather filling­plasticizing process conditions are found. The optimum values of the concentration parameters of disperse system ingredients using multi­criteria constrained optimization task of the filling­ plasticizing process are found. The output area of the leather material with a minimum hardness of 19.0 sN is increased as compared to the control technology by 7.0 % with 115.3, 22.5, 23.9 concentrations in the solution of plasticizer, modified filler and a nonionic surfactant, respectively. In addition, the fatty substances content in the finished material is 7.6 %, that complies with DSTU 3115­95 “Leather for Garments. General Specifications”. The developed software module can be applied for the optimization of technological processes of composite materials formation