Leather and Footwear Journal

Volume 21, no 4

Contents
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THE IMPROVED APPROACH TO THE DEVELOPMENT OF PARAMETERS FOR THE INNER SHAPE OF MILITARY BOOTS
- Pages 205-216
  Liliia CHERTENKO, Viktoriia KERNESH, Nataliia PERVAIA*, Tymofii LYPSKYI
  - Kyiv National University of Technologies and Design, 2 Nemyrovycha-Danchenka Str., 01011, Kyiv, Ukraine, email: nataliiapervaia@gmail.com
  ABSTRACT. In the work, anthropometric studies of the feet were performed by means of 3D scanning. The results of scanning have been used for two main purposes. Firstly, the features and morphological structure of the feet of young men aged 20-30 were studied, who are the representatives of the Ukrainian population that are subject to mobilization into the ranks of the Armed Forces. Apart from this, the quantitative distribution of the main morphological features of the feet of the sample population was analyzed. During measurements, it was noticed that a large number of men had hypertrophy of the heads of the 1st and 5th metatarsal bones. In order to rationalize the range of lasts with different sizes and fullness, while trying to fully satisfy the requirements of compliance with the anthropometric parameters of the feet of consumers, the parameters of the feet with the hypertrophy of the heads of the 1st and 5th metatarsal bones must be taken into account in the lasts with increased width. Furthermore, the results of scanning constitute the basis for calculating and developing basic parameters of lasts. For this, the work suggested the method of designing a last shape based on such types of input data as a digital foot model, dimensional foot parameters, and a foot print obtained as a result of mass 3D scanning of the feet.
  
  KEY WORDS: footwear last, shoe last design, footwear inner shape, military boots, 3D scanning, foot parameters
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FUNCTIONAL FOOTWEAR DESIGN FOR PREVENTING FALLS IN THE ELDERLY: A SYSTEMATIC RESEARCH BASED ON FAULT TREE ANALYSIS
- Pages 217-228
  Jingwen LI
  - Yunnan University of Business Management, Innovation and Entrepreneurship College, Kunming 650000, Yunnan, China, jingwenli21@163.com
  ABSTRACT. The purpose of this research is to improve the elderly’s footwear for preventing falls in walking. The design method of the footwear for the elderly was proposed based on fault tree analysis (FTA). There were four phases for improving the footwear. At first, the fault tree diagram was built by determining the causes of the elderly falling, literature review and user interview were applied at this phase. Then, both qualitative and quantitative analyses were conducted. The minimal cut sets of the elderly falls were identified. Besides, seven core risk factors were proven as strong or moderate influences for the falling issues, and which are related directly or indirectly to the elderly’s footwear. Finally, the footwear optimizations were made, and the seven core risk factors were mainly considered in the design process. The proposed design method provided a series of specific steps to help to define the practical causes of the elderly falling. The improvements of the footwear were made reasonable in that way, as well as enabled an improved experience for the elderly users.
  
  KEY WORDS: elderly, functional footwear, falls prevention
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BIODEGRADABLE POLYMER COMPOSITE BASED ON NBR RUBBER AND PROTEIN WASTE
- Pages 229-236
  MIHAELA NIŢUICĂ (VÎLSAN)*, MARIA SÖNMEZ, MIHAI GEORGESCU, MARIA DANIELA STELESCU, LAURENȚIA ALEXANDRESCU, DANA GURĂU
  - INCDTP - Division Leather and Footwear Research Institute, 93 Ion Minulescu St., sector 3, Bucharest, mihaela.nituica@icpi.ro, mihaelavilsan@yahoo.com
  ABSTRACT. The aim of this work is to characterize a biodegradable polymer composite based on butadiene-co-acrylonitrile rubber (NBR) and protein waste (ground leather). The biodegradable polymer composite was obtained by the mixing technique on a Brabender Plasti-Corder mixer and then on an electric roller (without heating), between its rollers, with sulfur vulcanization activators and Th accelerator, relative to 100 parts plasticized elastomer, obtaining 3-4 mm thick sheets, with strict observance of the technological recipe, but also of the established mode of operation. The obtained mixtures are then subjected to rheological characterization to determine the vulcanization time using the Monsanto rheometer (to determine the optimum temperature and vulcanization times in the laboratory electric press in specific molds for obtaining specimens to be subjected to subsequent characterization). Biodegradable polymeric composites based on butadiene-co-acrylonitrile rubber (NBR) and protein waste (leather waste from the footwear and leather goods industry) were made at optimal working parameters, and the characterization was performed on equipment specific to elastomers and according to standards in force for the footwear and consumer goods industry such as: plates for general purpose footwear soles as well as for water and mud environments, but also for the food industry, car mats, gaskets and components used under normal working conditions, technical plates, insoles, etc.
  
  KEY WORDS: NBR rubber, protein waste, biodegradable, vulcanized, composite
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TECHNOLOGY DEVELOPMENT OF LIQUID FINISHING OF CHROME-TANNED GOATSKIN
- Pages 237-246
  Nataliia PERVAIA*, Olga ANDREYEVA
  - Kyiv National University of Technologies and Design, 2 Nemyrovych-Danchenkо Str., 01011, Kyiv, Ukraine, nataliiapervaia@gmail.com
  ABSTRACT. There has been developed resource-saving environmentally friendly technology for producing chrome-tanned goatskin for shoe upper using new synthetic materials, which involves neutralization in the presence of Politan BN – syntan-neutralizer based on naphthalene sulfonic acid (Codyeco S.p.a., Italy) in the amount of 3.6% (in terms of dry residue), fatliquoring with a mixture of drugs Sulphirol C – a fatliquoring drug based on sulfonated fish oil, resistant to electrolytes (Smit & Zoon, Netherlands) and SMX 473 – a semi-synthetic composition based on sulfonated and sulphated fats (Shebekinsky industrial chemistry, Russia) in the ratio of 70:30 with a total fat consumption of 5.0% (in terms of 100% fat), retanning-filling Retanal LMV 100 – retanning agent based on melamine (Cromogenia Units, Spain) in the amount of 4.5% (in terms of dry residue). This allows to expand the range of chemical materials for liquid finishing and increase production efficiency (conditional economic benefit is UAH 9.22 per 1 m² of finished products due to more rational use of raw and material resources), while increasing the uniformity of distribution of tensile strength in different areas of the skin, strength of surface, elongation at strain 10 MPa in 1.2-1.4 times, the skin yield by area increases by 1.8%, and its grade – by 0.7%; improve the physical, mechanical and hygienic properties of the skin; reduce the harmful load on the environment. The technology has passed production tests at PJSC “Chinbar” (Kyiv, Ukraine) and is ready for implementation at tanneries.
  
  KEY WORDS: resource-saving technology, liquid finishing, leather for shoe upper
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OPTIMIZATION OF VALUES OF TECHNOLOGICAL PARAMETERS FOR OBTAINING THERMOPLASTIC POLYMER COMPOSITION FOR BOTTOM SHOES
- Pages 247-256
  SAYFULLO SAFOYEVICH MUSAYEV, GULNOZ OLIMOVNA SAMIYEVA*
  - Bukhara Institute of Engineering and Technology, 200100, K. Murtazaev street 15, Bukhara, Republic of Uzbekistan
  ABSTRACT. This work reveals the dependence of the composition and production parameters on the properties of a thermoplastic polymer composition based on a copolymer of ethylene with vinyl acetate and suspension polyvinyl chloride (EVA / PVC-S), as well as the choice of the optimal composition of the mixture and finding the optimal technological parameters for its production. Thermoplastic polymer-sole compositions were obtained by the method of thermomechanical mixing. To describe the properties of polymer - plantar compositions, depending on the ratio of components and technological parameters of obtaining, the method of mathematical planning – “Full factorial experiment” of type № = 2^k was chosen, which allows to obtain separate estimates of linear effects and two-, three-factor interactions. In this work, to build a mathematical model, the following factors were selected: the content of EVA in the composition, the temperature and mixing rate, and regression equations were used when obtaining a new type of shoe bottom material using a full factorial experimental method. Optimal results were obtained when the EVA content of the polymer composition was 15%, the mixing temperature was 185°C, and the mixing speed was 25 rpm. The strength and operational-technological indicators of the quality of a thermoplastic polymer composition for the bottom of footwear based on a copolymer of ethylene with vinyl acetate and suspension polyvinyl chloride have been determined. Regression equations for the dependence of the deformation-strength properties on the technological factors of the creation of polymer sole compositions are constructed. It has been proved that by selecting the optimal values of technological parameters it is possible to obtain a sole material with high deformation-strength and operational-technological characteristics.
  
  KEY WORDS: copolymer of ethylene with vinyl acetate, suspension polyvinyl chloride, mathematical planning of the experiment, generalized quality indicator, desirability function
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DESIGNING OF THE SHOE UPPER USING FOOT NUMERICAL CHARACTERISTICS AND MODERN COMPUTER TECHNOLOGIES
- Pages 257-266
  Vladyslava SKIDAN^{1, *}, Halyna YEFIMCHUK², Olena MYTELSKA¹, Volodymyr PAVLENKO¹, Kateryna SMYKALO³
  - ¹Kyiv National University of Technology and Design, Nemyrovych-Danchenko Str., build.2, Kyiv, Ukraine, 01011, v.v_skidan@ukr.net
  - ²Lutsk National Technical University, Lvivska Str., build.75, Lutsk, Ukraine, 43018, gefimchuk@gmail.com
  - ³Lesya Ukrainka Volyn National University, 13 Voli Ave., Lutsk, Ukraine, 43025, smykalo.kateryna@vnu.edu.ua
  ABSTRACT. The article presents the process of designing the details of shoe upper for schoolchildren using the numerical characteristics of the feet and modern computer technology. A software module for processing the obtained data in the MathCad Education program has been developed, which allows to create parametric models of the foot and longitudinal-vertical section of the internal shape with a deviation of not more than 5%. It is established that developing parametric aspects of shoe upper design is advantageous in the age range from 11 to 13 years. Patterns between different parameters of schoolchildren’s feet are also determined. On the basis of the developed parametric models and the proposed principles of modular transformation the construction of low shoes (half-boots) is designed and made.
  
  KEY WORDS: foot, design, shoe design, computer technology
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BIOMECHANICAL FOOT ANALYSIS IN CASE OF FOUR TYPOLOGIES: NORMAL FOOT, PES CAVUS, PES PLANUS AND HALLUX VALGUS
- Pages 267-280
  Mariana COSTEA, Arina SEUL, Aura MIHAI*
  - “Gheorghe Asachi” Technical University of Iasi, Faculty of Industrial Design and Business Management, 28 Mangeron, 700050, Iasi, Romania, mariana.costea@academic.tuiasi.ro, arina.seul@academic.tuiasi.ro, aura.mihai@academic.tuiasi.ro
  ABSTRACT. As each person is different in terms of conformation of the foot and temporal and spatial peculiarities of the individual gait pattern, an extended biomechanical analysis was performed for four categories of foot identified by the authors in a previous research study, namely normal, pes cavus (high arched), pes planus (flat) and hallux-valgus foot, in the case of young people aged 20-30 years. A representative case study was selected and the plantar pressures obtained in dynamics were analysed, following the next sequence: framing the subject in the appropriate category, simultaneous visualisation of the footprint for the left and right foot, impulse analysis, recording the variation of plantar pressures and the forces exerted on the foot as a function of time, calculating the percentage values of balance on the rear-foot, heel and medial areas, positioning of the foot axis according to the direction of movement, identification of individual characteristics of walking phases and their temporal / spatial characterisation parameters, highlighting the hysteresis for heel and rear-foot areas, recommendations for the application of orthotic devices. These results are significant in the modelling and design of the bottom shoe assembly, thus proposing solutions for balancing the pressures on the plantar surface by choosing the appropriate dimensional and shape characteristics of the components of this assembly.
  
  KEY WORDS: foot biomechanics, gait analysis, customized footwear
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