Удосконалення технології виробництва еластичних шкір при ензимній пластифікації структурованого напівфабрикату

We have developed a technology of enzymatic plasticizing of chrome­tanned semi­finished leather with using protosubtilin G3x in the production of leather. To develop the enzymatic plasticizing technology, the used material was a semi­finished product of the method of chrome tanning after a neutralization process; it had been derived from large pig hides with an average area of 180 dm2 (a weight of 6.8 kg) and cattle (heifers) with an average heavy weight of 24.3 kg. The average area of the finished leather material was 133.0 dm2 and 316.0 dm2. Enzymatic plasticizing was produced by applying protosubtilin G3x at a temperature of 54 oС. Enzymatic plasticizing of semi­finished leather compared with the control technology ensures the formation of the material structure with deformation and plastic properties increased by 28.0–44.0 % and 26.0–43.0 %, respectively from hides of pigs and heavy heifers.The process of enzymatic plasticizing of chrome­tanned semi­finished leather is enabled by the destruction of hydrogen and natural links between the lateral radicals of collagen macromolecules as a result of forming temporary enzyme­collagen complexes, followed by blocking released functional groups with fat emulsion particles. This twice reduces the duration of mechanical plasticizing after the processes of drying and moisturizing.The current technology used by the PJSC “Chinbar”, which includes enzymatic plasticizing by enzymaz 10TD, provides an increased output area of the leather material from semi­finished hides of pigs and heavy heifers compared with the control technology, respectively by 3.5 % and 4.0 %, and an opportunity to get an economic benefit of 1.2 thousand UAH and 3.3 thousand UAH per 100 m2 of the finished material.The use of protosubtilin G3x in the developed technology of enzymatic plasticizing in optimal conditions helps reduce the duration of mechanical plasticizing two times and increase the output area by 6.3 % and 5.4 %, respectively for leather obtained from hides of pigs and cattle, which can provide an economic benefit of 1.86 thousand UAH and 4.45 thousand UAH per 100 m2 of the finished material compared with the control technology.The developed energy­efficient and more cost effective technology of enzymatic plasticizing of chrome­tanned semi­finished leather from cattle hides and large pig hides can be considered rather promising for introduction into the manufacturing of supple leather materials.Разработан процесс энзимной пластификации полуфабриката хромового дубления в технологии производства эластичных кож. Технологии энзимной пластификации полуфабриката обеспечивают формирование кож с повышенными деформационно-пластическими показателями, увеличением их площади на 5,4–6,3 % и повышением экономической эффективности на 1,20–1,86 и 3,35–4,45 тыс. грн соответственно для кожи с сырья крупного рогатого скота и крупных шкур свиней.Розроблено процес ензимної пластифікації напівфабрикату хромового дублення в технології виробництва еластичних шкір. Технології ензимної пластифікації напівфабрикату забезпечують формування шкір з підвищеними деформаційно-пластичними показниками, збільшення їх виходу за площею на 5,4–6,3 % та підвищення економічної ефективності на 1,20–1,86 і 3,35–4,45 тис. грн відповідно для шкіри з сировини великої рогатої худоби та крупних шкур свиней

Удосконалення процесу фарбування шкіряного напівфабрикату сполуками титану

We developed technology of dyeing a leather semi-finished product of chrome tanning based on research into the processes of interaction in the system of dermis collagen-azo dye-titanium compounds. Physical and chemical properties of the working solutions of azo dyes, modified by titanium compounds of different chemical composition, were explored. A more energetic interaction was established between the brown azo dye 345, the molecules of which contain phenolic group, and titanium compounds with possible formation of chelate compounds.A study of kinetics of the sorption of azo dyes by collagen fibers, structured by the compounds of chromium, revealed a significant dependence of sorption of the dye, the molecules of which contain less auxochrome –SO3Na-groups, on temperature in the presence of titanyl oxalic acid. In this case, absolute values of the sorption of a dye at temperature of 20 oС are two times lower compared to the brown dye 345. With increasing concentration of the dye with a lower molecular weight, acidic blue-black, modified by ammonium sulfate titanylate, its diffusion capacity into the gel of gelatin is reduced by two times with an increase in the concentration to 80 g/dm3. An increase in the concentration of a dye in the system is symbatic to an increase in the activity of its interaction with collagen, accompanied by reduced diffusion capacity into the gel of gelatin. It was found that filling a semi-finished product of chrome tanning with acrylic polymers contributes to the increase in chemisorption of azo dye when using ammonium sulfate titanylate by 1.5 times.The effect of the composition of dyeing solution on the coloristic properties of a filled semi-finished product was demonstrated when fixating the dye on its surface by ammonium sulfate titanylate. We determined optimal ratio of ammonium sulfate titanylate and a dye, which ensures the formation of leather material with a higher saturation of coloration of the surface of a semi-finished product by 2.1–2.9 %, maximum resistance to wear and light fastness in comparison with the control technology. The designed technology of comprehensive filling-dyeing-greasing makes it possible to reduce the consumption of azo dye, exclude at the final stage of dyeing additional consumption of a dye and environmentally harmful compounds of chromium by the use of ammonium sulfate tytanilate as a fixative of dye with a 5-fold saving of reagent. Исследован процесс сорбции азокрасителей на модифицированных коллагеновых волокнах и кожевенном полуфабрикате хромового дубления в зависимости от концентрации соединений титана различного химического состава. Разработана технология крашения кожевенного полуфабриката, предусматривающая использование сульфатотитанилата аммония на заключительной стадии наполнения-крашения-жирования, обеспечивающая существенное уменьшение расхода экологически вредных соединений хрома и получение сертифицированного кожевенного материалаДосліджено процес сорбції азобарвників на модифікованих колагенових волокнах і шкіряному напівфабрикаті хромового дублення залежно від концентрації сполук титану різного хімічного складу. Розроблена технологія фарбування шкіряного напівфабрикату, яка передбачає використання сульфатотитанілату амонію на заключній стадії наповнювання-фарбування-жирування, забезпечує суттєве зменшення витрат екологічно шкідливих сполук хрому та одержання сертифікованого шкіряного матеріал

Resource-saving technologies for the production of elastic leather materials

This monograph contains a collection of recent research papers focusing on advancing existing technologies and developing new technologies to improve the environmentally friendliness and save resources during the production of elastic leather materials. The papers are organized based on the type of technological process used to preserve raw hides. A lot of attention is devoted to mathematical planning, simulations, and multicriteria optimization of the technological processes using newly developed chemical reagents. The monograph contains a complex study of physicochemical properties and characteristics of the resulting leather materials. The developed technologies were tested by the private joint-stock company Chinbar (Kyiv, Ukraine) and implemented at Ukrainian tanneries. Total number of figures – 58, tables – 95, and references – 491

Photoacoustic characterization of nanowire arrays formed by metal-assisted chemical etching of crystalline silicon substrates with different doping level

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