Shoe Uppers Research Articles

Analysis of Shoe Upper Product Defect with the Seven Tools and Failure Mode and Effect Analysis (FMEA) Methods in PT. XYZ

PT XYZ is a company engaged in the manufacturing industry with the production of shoe uppers. In the shoe upper production process, defects such as broken pulltab, mudguard crack, tilted backtab, and false collbar are still found which affect quality. The purpose of this study is to determine the level of defects that most often occur so that it can provide suggestions for improvement to reduce the defects of upper shoe products. The methods used are Seven Tools and Failure Mode and Effect Analysis (FMEA). Seven Tools include check sheets, statistics, histograms, pareto charts, pareto diagrams, scatter diagrams, control diagrams, and fishbone diagrams. Then proceed with FMEA analysis to get suggestions for corrective action. Based on the results of research on Seven Tools, it is known that the most dominant defect in shoe uppers is broken pulltab (38.4%), then mudguard crack (30.64%), tilted backtab (16.49%) and false collbar (14.47%). Based on the results of Failure Mode and Effect Analysis (FMEA) research, it is known that the cause of the highest problem at RPN 288 is unbalanced thread setting. The proposed improvement suggestion is to balance the upper thread tension and lower thread tension of the sewing machine.

Eco-friendly production of leather-like material from bacterial cellulose and waste resources

In recent years, resource optimization has been recognized as a top priority among many challenges. Studies have indicated that valuable products can be created by combining natural or discarded resources with cutting-edge biosynthesis techniques. This approach is considered foundational for establishing a “zero-waste” socio-economic structure. This research focuses on optimizing resources and minimizing environmental impacts, especially within the manufacturing and fashion sectors. An innovative leather-like material named BC-BioLeath (Bacterial Cellulose-Based Bio Leather) has been introduced. BC was produced by the fermentation of coconut water, a byproduct of the food industry. Traditional leather-like processing, including tanning, was applied to BC using food waste such as oxidized edible oil and coffee grounds, along with timber industry by-products like vegetable tannins. Studies involving SEM observation, mechanical, style, and dyeing performance testing revealed that the product, BC-BioLeath, exhibited superior mechanical properties. For instance, BC crosslinked with oxidized edible oil showed a tensile strength of 82.14 MPa, surpassing traditional cowhide used in shoe uppers by 2.08 times. When plasticized with glycerol, the tensile strength reached 56.19 MPa, with breaking elongation of 36%. Beyond its mechanical prowess, the product also achieved economic and environmental benefits through waste repurposing, contributing to a natural energy cycle. BC-BioLeath was identified as a more humane and eco-friendly leather alternative. This method showcased not just efficient waste repurposing but also introduced a novel, microbe-focused sustainable production approach. Such a model offered a genuine circular economy solution for high-polluting sectors, such as the leather fashion industry. A cost analysis showed that BC-BioLeath's production cost of $97.92/m2 (excluding labor and operating costs: $7.52/m2) was within the commercial leather range of $39.7 to $220.8/m2. This indicated its sustainability as a competitive alternative.

Analysis of Working Time Measurement and Incentives Work to Increase Shoe Upper Production at CV. Esa Kalen Jaya

As time goes by, competition in the industrial world is increasing, every company is required to be able to compete with other companies. CV.Esa Kalen Jaya is a company that produces semi-finished goods, namely shoe uppers. Where there are obstacles in the form of not being able to fulfill the production targets that have been determined by the company which results in the company's productivity not being optimal. This research was conducted to calculate standard production time through direct observation using a stopwatch time study as well as improving the regulation of the number of working hours and providing work incentives using the piecework plan method. as an effort to increase company productivity.. Results obtained. The standard output obtained is 4588.48 units/month. And after increasing the number of production working hours to 8 working hours, the results were 5,234 units/month, which means the production target has been achieved. And based on the calculation of incentives that the company will provide in standard hourly wages, namely IDR 7,051.41/hour. It can be concluded that by determining the standard production time and determining the number of working hours, the production results have achieved the set production targets.

Enhanced mechanical properties of poly(butylene succinate)/silk sericin composite monofilaments with silane coupling agent KH570

Biodegradable Poly (butylene succinate) (PBS) composites with natural polymers have been widely developed, the compatibility of PBS and natural polymers is often the first consideration in terms of performance. In this work, PBS/silk sericin composite monofilaments (content of silk sericin is 6 wt%) with γ-methacryloxypropyltrimethoxysilane (KH570) as the coupling agent were fabricated by reactive melt-mixing, spinning, and stretching. The effect of KH570 content (1–3 wt%) on the morphology, mechanical property and biodegradation was studied. The reaction between the hydroxyl groups of silk sericin and -Si-OH of KH570 was analyzed by Fourier transform infrared spectroscopy. The cross-section morphology of the monofilaments obtained from SEM and EDS images indicates that the dispersion of silk sericin is improved with the increase of KH570 content. Compared with unmodified composite monofilaments, the composite monofilament with 2 wt% KH 570 shows the best mechanical performance (102% and 80% improvement in tensile strength and elongation at break respectively). The incorporation of silk sericin, which possesses skin-friendly properties, imparts composite monofilaments with advantages in the fields of clothing, headgear, shoe uppers and other related applications. Otherwise, the silk sericin can enhance the biodegradability velocity of PBS/silk sericin composite monofilaments. And the weight loss of the composite monofilaments buried in soil can be adjusted by the synergistic effect of silk sericin and KH570.

Eco-Friendly Leather: Durable and Crack-Resistant Shoe Uppers By IJISRT

Today in this developing world we always want something new or an advanced product and technology. In this daily life we use shoes everyday as office wear, formalwear, casualwear, nightwear etc. It should be comfortable from inside even from outside too, it will have significant work efficiency of the product. This invention is related to development of new crack free leather for shoe upper. It may upgrade the quality of leather and also helps to resolve the finishing operation to make leather more pliable, durable, breathable and comfortable for a long time. Aqueous finishing ageing time and its durability will be increased; it could sustain the leather for a longer period. It will provide a brilliant texture as well as smooth and uniform grain structure. Also it has a tendency till a certain level to protect leather from UV rays. It will have high thermal resistance. Zinc Oxide (ZnO), the element of the bottom layer of leather serves protection from UV rays, also gives shine to the leather which can perform better bondage with collagen (protein peptide). Cowhides last very long due to their greater strength properties and it is widely available in the market due to its constant demand in the market. Cowhide a bovine leather is mostly used for shoe upper and outsole of the shoe as per its high air permeability and water permeability as well as its comfort and durability. It also maintains its shape with chrome tanned. This invention may change the quality of leather and also helps to become environmentally friendly.

МОДЕЛИРОВАНИЕ ПРОЦЕССА РАССЛАИВАНИЯ КЛЕЕВОГО СОЕДИНЕНИЯ ДЕТАЛЕЙ ВЕРХА ОБУВИ ИЗ ВОЙЛОКА

Increasing interest in environmental protection leads to a search new technologies and attempts to revive old technologies for obtaining and processing materials. Environmentally friendly technologies have become more than popular. Currently produced shoes with uppers made of felt and felt satisfy the consumer in design, internal shape, appearance, and some other indicators, however, the issue of increasing the heat-shielding properties of the seams connecting the upper parts is still relevant. One of the disadvantages of the thread method of assembling a shoe upper blank from felt is heat loss through the seams, insufficient strength, and water permeability. Thread-free methods for connecting parts of shoe uppers can eliminate these disadvantages. The object of study was the technological process of gluing parts of shoe uppers made of felt. The subjects of the study are finished shoes and external parts of felt shoe uppers. The advantages of adhesive assembly of felt shoe upper blanks are considered. It is hypothesized that the adhesive assembly method will preserve the heat-protective and strength properties of felt shoes. To assess the bonding strength of parts, felt samples were glued together with a polychloroprene adhesive solution and examined for delamination. To evaluate the modeling of the delamination process, the theory of crack formation and the adhesive separation model were applied. The finite element method was used to simulate the dynamics of separation of one surface from another. The conducted studies and calculations have proven that when felt samples delaminate, the stress is concentrated in the vicinity of the tear-off point, and then gradually decreases in sections of the tear-off length, where the adhesive resistance force ceases to act. The results of modeling the delamination process were used to predict the behavior of adhesives during the operation of felt shoes under different conditions.

Research on the path extraction method of shoe upper grinding based on 3D vision

Shoe upper grinding is a crucial step in the shoe manufacturing process, impacting both the bonding quality between the sole and the upper and the overall appearance of the shoe. Presently, many shoe companies rely on manual or semi-automated grinding methods for shoe uppers, resulting in low production efficiency and subpar grinding quality. This study proposes a 3D vision-based shoe upper grinding path extraction method for guiding a robotic arm to polish the shoe upper and address this issue. Initially, the RGB-D camera was used to obtain the point cloud data of the shoe surface, which was then preprocessed using point cloud filtering, smoothing and registration methods. Second, by combining RGB images with 3D point clouds, we propose a point-cloud region of interest (ROI) extraction method based on RGB information to obtain the feature point cloud of the shoe upper grinding line. Finally, we slice the feature point cloud of the shoe upper grinding line, extract the grinding points using an intersection algorithm, and fit them with a non-uniform rational B-spline curve (NURBS) to obtain the shoe’s upper grinding path. The research demonstrates that this method can effectively extract the shoe upper grinding trajectory curve, significantly reduce the time required to obtain the shoe upper grinding trajectory, and achieve good accuracy, with promising application prospects.

Optimum design of the geometry of boots and socks with the aim of minimum weight and preventing frostbite.

In order to design shoes suitable for cold environments, knowledge of the thermal conditions inside the shoes and the variables affecting those conditions is necessary. A two-dimensional model of a boot and sock was developed to investigate the effect of the materials and dimensions of various parts of shoes and to design geometry for them to prevent foot frostbite. The optimization algorithm was used to optimize the dimensions of the boots to maximize the minimum foot temperature with the lowest boot weight. Two types of shoe soles and two kinds of shoe uppers were used to design suitable shoes. The results show the following: (1) In the design boots, the thermal insulation of the toe area plays an essential role in preventing frostbite. Two variables of the thickness of the toe cap and the length of the shoe sole had the greatest impact on the design of shoes with the least weight and the most protection against frostbite. So that to increase minimum foot temperature from 7°C to 15°C, 16°C, or 17°C, only the amounts of these variables should increase. (2) In designing the suitable boot, choosing the proper shoe sole had a significant effect on increasing the thermal insulation in the shoe and reducing its weight. So, for the boot with a minimum foot temperature of 20°C, by changing the shoe sole from EVA08 to EVA12, the weight is reduced by 42%. (3) To maximize the minimum foot temperature, it is necessary to use thick socks.

Hest, hjort, ku eller geit! Hvilke typer lær ble brukt til sko i Borgund på Sunnmøre i sen vikingtid og tidlig middelalder?

Leather types and tanning technique used on shoes during the late Viking Age / early Medieval Periods in Norway, are addressed with 139 shoes from the deserted town Borgund in Sunnmøre, western Norway, as a case. Shoe-leather is species identified through hair follicle pattern interpretation and ZooMS analysis. Tanning technique is assessed visually. The study shows that the Borgund-shoes were made of leather from domesticated animals, predominantly from cow (Bos taurus), but also horse (Equus caballus), goat- (Capra circus) and tentatively sheep (Ovis aries) was used. Furthermore, raw tanned leather was used for both soles and shoe uppers in Borgund. Borgund’s strong preference for leather made of cattle has parallels in both Danish and English contemporary urban contexts, whereas horse leather is not previously identified as shoe-leather in contemporary Norse-sphere urban contexts. For future research an atlas of Viking Age / Medieval hair follicle patterns based on archaeological leather finds is presented.

Physical and Mechanical Properties of Cotton/Polyester Based Fibers for Shoe Uppers and Lining Products

Abstract The purpose of the study was to evaluate the physical and mechanical properties of various textile materials based on polyester and cotton for shoe uppers and lining. For that purpose, the influence of the ratio of a mixture of cotton and polyester fibers on the quality of the fabric was investigated. As a result, fabrics with the same composition but different yarn numbers differed from each other in specified properties. With an increase in the content of polyester, all specified properties increase except for vapor permeability, which makes it possible to correctly select the composition of fabrics for shoes.

FORMATION OF LEATHER FILLED WITH MODIFIED SYNTAN AND TANIDE COMPOSITION

The technology of manufacturing leather material for the upper of shoes from semi-finished chrome tanning obtained from raw cow hides been has been developed. The technology at the filling-plasticization stage involves the use of a syntane-tanide composition modified with alkylcarboxyethanolamine of aliphatic acids of fraction C7–9. The filling and plasticizing composition includes syntanе BNS TU 17-06-165-89 and mimosa extract tanids with a content of the main substance of 81.7%. The semi-finished product is plasticized with Fosfol L-1301 emulsion of Cromogenia Units, S.A., Spain. Chemical reagents in the structure of the material are fixed by potassium alum modified with sodium formate. All previous and subsequent processes and operations are performed according to the industrial technology of the enterprise “Chinbar”. The resulting semi-finished product is characterized by a volumetric yield of 256 cm3/100 g of protein, a specific surface area of 71 m2/g, which are 8.0 and 11.0% higher than the industrial sample. Deformation properties of topographic areas and coefficients of uniformity of topographic areas of leather materials at loads of 10.0 MPa and rupture were calculated. At the same time, a more effective characteristic of the homogeneity of the material structure is the uniformity factor at a load of 10.0 MPa. The leather material obtained by the experimental technology has a uniformly oriented structure with an arithmetic average coefficient of uniformity of 1.0, and the industrial material has a transversely oriented structure with an arithmetic average coefficient of uniformity of 0.83. The advantage of the experimental material over the industrial one in terms of the complex of physico-chemical and technological properties and the coefficient of uniformity increases the efficiency of its use for the manufacture of leather products. The obtained leather material meets the requirements of DSTU 2726-94 “Leathers for shoe uppers. Specifications”.

FORMATION OF SHOE LEATHER FROM SPLIT PIG HIDES

The technology of forming patent leather has been developed from highly porous semi-finished chrome-tanned pig hides, obtained after their doubling according to the method of public JSC “Chynbar” Ukraine, Kyiv. Finishing of the tanned semi-finished product TU-U 00302391-03-98 is performed using acrylic priming compositions and polyurethanes (PU) of different chemical composition. Acrylic pigmented performer is applied to the surface of the semi-finished product after its absorption properties are equalized by double application of acrylic non-pigmented primer. The priming PU composition has a chemical composition, %, – wt.: pigment concentrate, 40% – 20.0; PU latex, 20% – 80.0; water – up to a density of 1.07. PU solutions of different chemical composition are used for both options for forming the coating on a leather semi-finished product. In particular, PU linear structure PPE-201 based on ether and PU reactive composition (RZK). The investigated film-forming reagents form highly elastic films of high strength. The use of pigmented aqueous polyurethane latex made it possible to reduce the duration of the priming stage and the consumption of the priming composition compared to the previous acrylic leveling and pigmented priming by two times, and to increase the adhesion of the coating to the semi-finished product by 18–21%. It was established that the use of polyurethane latex and the reactive polyurethane composition contributes to the formation of lacquer leather with increased resistance to wet friction by 27% and somewhat higher hygienic properties. According to the complex of physical and chemical properties, the investigated patent leathers meet the requirements of DSTU 2726-94 “Leathers for shoe uppers. Technical requirements” and industrial samples prevail and can be used for the production of model shoes.

APPLICATION OF ACACIA TANNINS IN ELASTIC LEATHER MATERIALS PRODUCTION TECHNOLOGY

An IR-spectroscopic study of the interaction of collagen with blackwood acacia (acacia melanoxylon) tannins and its use for tanning and filling semi-finished leather products in the production of elastic leathers for shoe uppers was conducted. The analysis of IR spectra of the interaction of the chrome tanning collagen products dermis with the acacia extract tannins can indicate the intermolecular ionic bonds formation and a hydrogen bonds dense network building-up with the amino groups of collagen and phenolic and carbonyl groups of the plant extract tannins. The following reagents were used for the semi-finished product tanning: sodium chloride TU 9192-069-00200009527-98, formic and sulfuric acids according to DSTU GOST 1706-78 and DSTU GOST 2184:2018, and sodium carbonate ISO 6353-2-83. Blackwood acacia extract together with the synthesis product of 2-naphtholsulfonic acid with dioxydiphenylsulfone as synthetic tanning agent BNS TU 17-06-165-89 were used to fill the tanned semi-finished product. The application of BNS TU 17-06-165-89 syntan in the process of finishing and filling of chrome tanned semi-finished leather product after catting it into thin slices with a thickness of 1.4 mm together with acacia extract tannins ensures an increase in its diffusion into the structure and provides a process duration reduction. The use of acacia extract tannins in the production technology of elastic hides makes it possible to obtain a filled-greased semi-finished product with increased physical and chemical properties: porosity, volumetric yield, air permeability by 21, 37, 86%, respectively, compared to the chrome tanning semi-finished product. The obtained results give the grounds for recommendation the use of acacia extract tannins in the wide range of elastic leathers production technologies.

The effect of upper panel stiffness on biomechanical performance in athletic footwear

Athletic footwear can improve performance through targeted design features to improve biomechanical mechanisms of performance. The alteration of athletic shoe uppers can impact athletic performance and biomechanics in both males and females; moreover, the impact may differ between males and females due to anatomical differences between sexes. Therefore, assessment of sex-specific impacts of footwear modification on athletic performance is essential when determining how to modify footwear. The purpose of this research was to determine the impact of upper panel stiffness on biomechanical performance during agility tasks and determine if the optimal upper stiffness depends on the sex of the athlete. It was hypothesized that stiffening the upper panel, quantified through uniaxial tension testing, would result in decreased contact time and increased force production during jumping and change of direction tasks. Forty participants (20 males, 20 females) were recruited and completed eight lateral skater jumps, eight counter movement jumps, three triangle drop step drills and six anterior-posterior drills in three footwear conditions that varied in upper panel stiffness. 3D motion capture and embedded force plates were used to measure biomechanical outcomes that were compared between stiffness conditions using a linear mixed effect model. Upper panel stiffness significantly affected contact time during the lateral skater jump with the stiffest shoe resulting in the shortest contact time compared to the two other conditions (p = .02–.046, η2 = 0.18). No sex-related interactions were found for any outcome variable. Taken together, upper panel stiffness is important to consider when developing both male and female footwear.

USE OF NATURAL LEATHER IN SHOE PRODUCTION

In the work, the formation of leather material from semi-finished cattle was carried out – medium chrome-tanned beef at the stage of filling and fattening after it is planed to thickness 0,9–1,1 mm. In this case, the product of the interaction of 2-naphtholsulfonic acid with dioxydiphenylsulfone was used – BNS synthetic tanner (ТУ 17-06-165-89), mimosa extract with a tannin content of 79.0% and an emulsion of a fattening preparation Fosfol L-1301 by company «Cromogenia Units, S.A.» (Spain). Preliminary greasing of the semi-finished product and final fixation of reagents diffused into the structure of the semi-finished product with alumokalium alum gives the leather material a complex of hygienic, physical-mechanical and technological characteristics that meet the requirements for materials for sewing products. The resulting leather material exceeds industrial samples by 13.6% and 11.0%, respectively, in terms of hygroscopicity and vapor permeability. Compared to natural leather, synthetic leather is characterized by significantly lower hygienic properties, and in terms of specific surface area and sorption capacity, they are inferior to natural leather materials by at least 32.0 and 17.0 times, respectively. Accordingly, their vapor permeability and hygroscopicity are 7.0–8.0 and 5.5–6.0 times lower than natural leather. At the same time, to a greater extent, this also applies to a complex of physical and mechanical indicators, including increased defectability and reduced formability during the operation of footwear products. At the same time, their initial aesthetics are relatively quickly lost. The natural leather material obtained by the developed technology can be considered promising due to its advantages compared to synthetic leathers and compliance (ДСТУ 2726-94) for the production of high-quality shoe uppers.

ECOLOGICAL FEATURES OF SOAKING AND ASH PROCESSES IN THE PRODUCTION OF LEATHER

Ecological and colloid-chemical features of soaking-ash processes in processing of raw cattle leather materials at production of elastic leather for uppers of footwear according to operating and developed resource-saving technologies are investigated. To evaluate the effectiveness of the technological processes used a set of physic-chemical and operational properties of leather semi-finished products at different stages of its formation to the finished material. Resource-saving ecologically oriented technology of soaking and ash processes in leather production for shoe uppers from raw salted conserved materials – bull skins has been developed. Physicochemical, technological and ecological features of existing and developed technologies are studied. The developed technology due to the increase of process temperature provides more efficient use of chemical reagents, reduction of concentrations of environmentally hazardous reagents, process duration and energy consumption per unit of output. At the same time, the total consumption of chemical reagents is reduced by 2.2 times, and in the waste technological solutions the concentration of sodium sulfide and calcium hydroxide – by 2.9 and 4.4 times, respectively. However, the developed resource-saving environmentally friendly technology is characterized by a reduction in biological and chemical oxygen demand for the destruction of organic and inorganic substances in the waste soaking-ash solution after treatment of 1 ton of raw materials by 30.0 and 21.0%, respectively. By reducing the duration of the technological process by 2.3 times, the new technology can be considered as energy efficient. The developed resource-saving technology provides the formation of leather material for shoe uppers with an increased yield of 3.9%, and its performance properties meet the requirements of DSTU 3115-95. The results obtained in the development of environmentally friendly resource-saving technology of soaking ash processes for footwear leather uppers from raw cattle leather materials can be effectively used in the development of new innovative technologies for the manufacture of leather materials from a wide range of other raw materials.

Comparison and assessment of selected parameters of chrome-free and chrome-tanned leather

In the leather tanning industry, decision-makers act resolutely to eliminate chrome as a tanning agent due to its negative effect on human health and the natural environment. Considering this, it makes sense to research opportunities to use chrome-free leather as a substitute for chrome-tanned leather. This paper demonstrates research on the mechanical and hygienic properties of leather tanned with glutaraldehyde as well as chrome-tanned leather, intended for shoe uppers. The results of the tensile strength and percentage extension measurements made by the Instron tensile machine, and the results of water vapour permeability measurements made by a moisture analyser, have been analysed using Statistica. The statistical data analysis has been performed using the following tests: Kolmogorov-Smirnov with Lilliefors correction, Shapiro-Wilk, T, Levene, Brown and Forsythe, Fisher-Snedecor, and Cochran-Cox. Regarding mechanical parameters, no statistically significant difference has been observed between chrome-free and chrome-tanned leather in dry conditions. However, such differences have been observed in wet samples. The tests showed higher stability of mechanical parameters of leather tanned with modified glutaraldehyde compared to chrome-tanned leather. Leather tanned with a chrome tanning agent, tested in both dry and wet conditions, showed significant differences between them, considering their tensile strength and percentage extension. The hygienic properties of both types of leather being researched are more or less similar – the research has not found any statistically significant differences for water vapour permeability.

Charaterizations of 3D printed re-entrant pattern/aramid knit composite prepared by various tilting angles

This study intended to compare and analyze the Poisson's ratio and mechanical properties of aramid knit (ARNT), 3D printed auxetic re-entrant pattern (3DP-RE), and 2 types of composite fabrics manufactured with ARNT and 3DP-RE. Specimens were manufactured by 3D printing the re-entrant pattern with a CFDM (conveyor fused deposition modeling) 3D printer and TPU (thermoplastic polyurethane) filament, combining with aramid knit in 2 ways. Then, Poisson's ratio, bending, compression, and tensile properties were tested. As a result of Poisson's ratio, 3DP-RE and its 2 types of composite fabric showed negative Poisson's ratio at all angles and deformed stable at 0° and 90° than the bias direction. The bending strength confirmed that the composite fabric showed a lower value. But, the strain at max bending strength was greater than a substrate fabric. At the compression properties, it has been confirmed that compression strength and toughness are improved when manufacturing composite fabrics. As a result of tensile properties, 3DP-RE and composite fabrics were significantly more initial modulus, elongation and toughness than ARNT and were shown to be the largest in gradient 90°. Therefore, it is confirmed that the performance is excellent when fabricated as a 3DP-RE/ARNT composite fabric, and based on the results of studies, we intend to use it as the basic data for composite fabrics of auxetic structure suitable for shoe uppers.

ВИЗНАЧЕННЯ ВПЛИВУ ЛАЗЕРНОГО ГРАВІРУВАННЯ НА ГІГІЄНІЧНІ ВЛАСТИВОСТІ НАТУРАЛЬНИХ ШКІР ДЛЯ ВЕРХУ ВЗУТТЯ ТА ШКІРГАЛАНТЕРЕЙНИХ ВИРОБІВ

Purpose. Investigation of the effect of laser engraving on the hygienic properties of nature leather for uppers and leather goods, namely leather Krast, Flotar and Nappa. Methodology. To achieve this goal, the method of scanning electron microscopy (SEM) was used. Hygienic properties of Krast, Flotar and Nappa hides was studied in accordance with ISO 14268: 2008 by determining vapor permeability. Findings. According to the results of the study of the effect of laser radiation on the hygienic properties of nature leather for uppers and leather goods, the nature of changes in the micro- and macrostructure of the dermis under laser engraving and allowable depth and area of laser ablation that do not impair the hygienic properties of these skins and products. With increasing ablation depth to 0,7 mm (50% of the total thickness of the sample), the relative vapor permeability increases in all samples of the studied skins, while the relative vapor permeability for the skin of Krast increased by 5%, Flotar by 13,5% and 9,5% for Nappa. The optimal value of the depth of laser ablation, which does not impair the operational and hygienic characteristics of the products is 25–30% of the skin thickness. On the front surface revealed features of the structure, which are characteristic only for the area of direct action of the laser beam, namely the skin samples Flotar and Nappa have obvious signs of welding collagen fibers. In the area of laser ablation, an increase in the interstructural distances between the bundles of collagen fibers was also detected, which was the result of thermophysical processes of laser radiation. Originality. The determined effect affects the depths and flat laser ablations on the morphological structure of the dermis and the hygienic properties of natural leather for shoe uppers and leather goods. Practical value. The vapor permeability of genuine leather for the uppers of shoes and leather goods under the action of laser radiation was determined. The value of the depth and area of laser ablation for finishing leather products, taking into account the impact on the hygienic properties of products in general.

Influence of solar radiation insolation precipitation on hydrophobized leather for shoe uppers

The influence of solar radiation and precipitation on leather samples for the upper part of footwear, treated with water-repellent compounds, was determined and the process of their destruction in natural atmospheric conditions was determined. The study of the effect of solar radiation on natural skin has not been sufficiently studied. In connection with the above, the test was carried out on experimental hydrophobized and initial (control) leather samples in an open area to determine the insolation of solar radiation and precipitation on the skin for the upper shoes. During the tests, a systematic examination of the exposed samples was carried out for 1-6 months, sampling for physico-mechanical and other tests was recorded by meteorological conditions. After that, the samples were subjected to organoleptic evaluation, physical-mechanical and chemical-analytical analyses, as well as structural studies. It was visually determined that, depending on the variant of hydrophobization used, fibrillar collagen formations change in different ways. After atmospheric insolation acts on the control sample, its fibrillar structure changes sharply, numerous micro cracks appear, located mainly perpendicular to the fiber axis, and clearly defined dark zones are found between the fibrils. Fibril outlines become indistinct, numerous torn ends are observed. However, such changes are not observed for hydrophobized samples. Significant changes in physical and mechanical properties are observed in the first and fourth months of natural aging. In the hydrophobized sample, the rate of change in hydrothermal destruction and the appearance of cracks in the face layer subjected to aging in an open area, is always lower compared to the control sample.