Leather and Footwear Journal

Volume 20, no 2

Contents
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COMPARISON OF FOOT MORPHOLOGY BETWEEN CHINESE AND MONGOLIAN CHILDREN
- Pages 97-108
  Shiya RAN¹, Hao LIU², Shiyang YAN^{1, 2}, Ruoyi LI^{1, 2}, Jitka BADUROVA³, Luming YANG^{1, 2}*
  - ¹National Engineering Laboratory for Clean Technology Leather Manufacture, Sichuan University, Chengdu 610065, China
  - ²Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China
  - ³Tomas Bata University, Zlin, 76001, Czech Republic
  ABSTRACT. Knowledge of foot morphology is fundamental to optimize children’s footwear design. The aim of this study is to compare the foot morphology of Chinese and Mongolian children from 7 to 14 years old. Relative data of 339 Mongolian children and another matched 379 Chinese children were collected using 3D foot scanner. The findings of this study are as follows: i) the absolute foot length of Chinese children is significantly greater than that of Mongolian children of the same age; ii) Mongolian children show significantly greater heel width, toe thickness, lateral malleolus height, instep height and ball girth compared to Chinese children of the same age. The foot width of Chinese children is significantly greater than that of Mongolian children of the same age; iii) Chinese children have a higher risk of hallux valgus than Mongolian children of both sexes. Small variations in foot morphology discussed in this paper could be useful when considering the shoes design for Mongolian and Chinese children.
  
  KEY WORDS: foot morphology, Mongolian children, Chinese children, footwear design
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CHARACTERIZATION OF SILICA/SILVER-BASED ANTIBACTERIAL LEATHER
- Pages 109-118
  Nur Mutia ROSIATI¹, Fitrilia SILVIANTI², Mustafidah UDKHIYATI¹
  - ¹Department of Leather Processing Technology, Politeknik ATK Yogyakarta, Sewon, Bantul 55281, Yogyakarta, Indonesia, mutia.rosiati92@gmail.com
  - ²Department of Rubber and Plastic Processing Technology, Politeknik ATK Yogyakarta, Sewon, Bantul 55281, Yogyakarta, Indonesia
  ABSTRACT. The hydrophilic character of vegetable tanned leather is potentially a medium for bacterial growth. A treatment using an antibacterial agent applies to prevent bacterial growth on it. The vegetable tanned leather in this study was obtained from the tanning of goat skin using mimosa as a tanning agent. The utilization of silica from volcanic ash modified with silver was employed in this study as an antibacterial agent. The functional groups of materials were analysed using FTIR spectrophotometer and evaluated. The results of thermal studies using TG/DTA show that vegetable tanned leather coated with silica (leather@SiO₂ ) and vegetable tanned leather coated with silica/silver (leather@SiO₂/Ag) are thermally stable materials. The inhibition zones of Staphylococcus aureus for leather@SiO₂ and leather@SiO₂/Ag were larger compared to vegetable tanned leather with inhibition area of 21.25 ± 0.50 mm, 24.80 ± 1.64 mm and 11.40 ± 0.55 mm, respectively. This confirmed the effectiveness of utilization of silica-based volcanic ash and silver as an antibacterial agent.
  
  KEY WORDS: leather, silica, silver, antibacterial agent
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DEVELOPMENT OF A DEGREASING PROCESS FOR PAICHE SKINS (Arapaima gigas) FOR TANNING PRESERVING THE NATURAL PATTERN AND COLOR
- Pages 119-132
  Abdón SEGUNDO ESPADA, Liliana MARRUFO SALDAÑA*, Julio BARRA HINOJOSA, Rosa CONTRERAS PANIZO
  - Productive Innovation and Technological Transfer Center of Leather, Footwear and related industries (CITEccal Lima), Technological Institute of Production (ITP), Caquetá Ave. 1300, Rímac, 15094, Lima, Perú, asegundo@itp.gob.pe, lmarrufo@itp.gob.pe, julio.barra.h@uni.pe, rcontreras@itp.gob.pe
  ABSTRACT. The utilization of Amazonian fish skins, like paiche, to obtain leather, has been gaining importance in Peru. The beauty of the pattern of this fish skin comes from its light beige color and the black strip that runs through its back. This research aimed to develop a degreasing process for the tanning of paiche skin, that allows to preserve its natural pattern and color in the finished leather. For this purpose, a mixture of degreasers, diesel oil, lipases, and surfactants was used. In tanned skins, physical-mechanical properties, such as tear strength, tensile strength, elongation percentage, and shrinkage temperature, were evaluated. The presence of fishy smell in tanned paiche skins was evaluated through an analysis of fat content, fatty acid profiles, and sensorial tests. Besides, wastewater of the process was characterized to determine BOD5, COD, TSS, oils, and greases, TPH, phenols, and pH. This wastewater was treated by a laboratory-scale system, based on sedimentation, sifting, and flocculation-coagulation. As a result, a degreasing process using 8% of diesel oil, 18% of surfactants and 1.2% of lipidic enzymes, applied in cycles before and after the pickling process, was established. This process allowed the conservation of pattern and color of skin and the reduction of polyunsaturated fatty acids that cause the fishy smell in the leather, which complied with physicalmechanical standards for making footwear, bags, and clothing. Thus, a reduction in the pollutant charge in wastewater was achieved to acceptable environmental levels.
  
  KEY WORDS: paiche, Arapaima gigas, fishskin, tanning process, degreasing
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ANTIFUNGAL ACTIVITY OF LEATHER TREATED WITH Anethum graveolens AND Melaleuca alternifolia ESSENTIAL OILS AGAINST Trichophyton interdigitale
- Pages 133-144
  Mariana Daniela BERECHET¹, Corina CHIRILĂ¹, Demetra SIMION¹, Olga NICULESCU¹, Maria STANCA¹, Cosmin-Andrei ALEXE¹, Ciprian CHELARU¹, Maria RÂPĂ², Dana Florentina GURĂU¹
  - ¹Division: Leather and Footwear Research Institute (ICPI), Bucharest, 031215, Romania, marianadanielaberechet@yahoo.co.uk
  - ²Polytechnic University of Bucharest
  ABSTRACT. Trichophyton interdigitale is a common fungus causing onychomycosis of the nail in humans. Plants are a rich source of bioactive compounds with antifungal properties used in various compositions in pharmaceuticals, cosmetics or various industrial products. In the present paper, the antifungal activity of two kinds of leathers was tested: ecologically processed sheepskin leather lining (Eco) and sheepskin leather lining processed with basic chromium salts (Cr), treated with Anethum graveolens and Melaleuca alternifolia essential oils. Dill (Anethum graveolens) essential oil rich in o-cymene (30.71%) and α -phellandrene (23.21%) and tea tree (Melaleuca alternifolia) essential oil rich in terpinene-4-ol (23.06%) were used. The results obtained in this study show that the essential oil of Anethum graveolens and Melaleuca alternifolia had a high antifungal effect against Trichophyton interdigitale. Tea tree and dill essential oils offer a much safer alternative protection against fungi as compared to synthetic compounds with adverse reactions to body and environment. The results of this study may have potential for use in developing applications for cosmetics, pharmaceuticals, obtaining leathers and textiles with selective bioproperties.
  
  KEY WORDS: Anethum graveolens and Melaleuca alternifolia essential oil, antifungal activity, Trichophyton interdigitale, sheepskin leather lining
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NOVEL USE OF THE INTEL REALSENSE SR300 CAMERA FOR FOOT 3D RECONSTRUCTION
- Pages 145-152
  Fangchuan LI¹, Shuangjia LIU¹, Luyu JIANG¹, Weihua ZHANG², Jin ZHOU^{3, *}
  - ¹College of Software Engineering, Sichuan University; Chengdu 610065, P. R. China
  - ²College of Computer Science, Sichuan University; Chengdu 610065, P. R. China
  - ³The Key Laboratory of Leather Chemistry and Engineering Ministry of Education, Sichuan University; Chengdu 610065, P. R. China
  ABSTRACT. Foot three-dimensional (3D) reconstruction is increasingly used in real life at present; however, current 3D measuring devices are usually expensive and have a large volume. So they are limited used in a specific domain and feasible method for accurate, fast and low-cost foot 3D reconstruction are required. Since the Intel RealSense SR300 camera has advantages on 3D scanning, such as high efficiency, portable, low-cost and simple operation, this camera has been widely applied in multi-scenario, such as gaming. But its performance on foot scanning is still unknown. Thereby this study first aimed to design and develop a foot 3D scanning protocol based on the Intel RealSense SR300 camera and then to contrast this new method with a traditional one in terms of accuracy. Fifteen healthy adults without any foot deformity or foot disease participated and their feet were measured by our simulated measurements (SM) and manual measurements (MM). 13 variables were calculated and contrasted and their significant differences were assessed by Single-Sample T Test with significant level of 0.05 and confident interval of 95%. The results show that the SR300 presented a precise foot 3D reconstruction on the mean differences ranged from -1.3 mm to 5.2 mm; meanwhile eight of the thirteen foot parameters exhibited no significant differences between the two methods. Overall, these findings above demonstrate that the SR300 is a valid tool for foot 3D scanning and it can be widely applied in the both medical and commercial fields.
  
  KEY WORDS: Intel RealSense SR300, foot 3D scanning, foot measurement, footwear customization
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DEVELOPMENT OF PROCESSES IN THE USE OF PEROXIDE AS AN INGREDIENT TO REDUCE FREE FORMALDEHYDE LEVELS IN THE SKIN
- Pages 153-160
  Emiliana ANGGRIYANI*, Laili RACHMAWATI, Nais Pinta ADETYA
  - Department of Leather Processing Technology, Politeknik ATK Yogyakarta, Sewon, Bantul, 55281 Yogyakarta, Indonesia, emiliana.anggry@gmail.com
  ABSTRACT. This study aims to reduce the levels of free formaldehyde in the skin. The material used is goat skin. The process is carried out by formaldehyde (formalin) tanning on pickled goat skin. Furthermore, skin that has been tanned with formalin is washed with peroxide (H₂O₂) 0.5%, 1% and 2%. The formalin tanned skin produced was tested for formalin levels contained in the skin, then the data obtained was analysed by One Way ANOVA test. In addition, physical tests were carried out for the average value of tear strength and softness. The results showed that the higher the level of H₂O₂ used, the smaller the formalin content in the skin. The best results were obtained using 1% H₂O₂ which was 0.12 ± 0.005 % (p <0.05) taking into account the safety aspects of H₂O₂ . Furthermore, free formaldehyde levels of 0.045 mg/kg were obtained at 1% H₂O₂ . The value of tear strength with formaldehyde is higher than that of chrome tanning while the softness value is still below that of chrome tanning. Therefore, the use of H₂O₂ can be considered in an effort to reduce the levels of formaldehyde contained in formaldehyde as an alternative tanner substitute for chrome minerals.
  
  KEY WORDS: reduce, formaldehyde, peroxide, skin
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LOAD TRANSFERENCE WITH RUNNING SPEED IN NATURAL REAR-FOOT STRIKE MALE RUNNERS
- Pages 161-172
  Ruoyi LI^{1, 2}, Hao LIU¹, Xuecan CHEN³, Jitka BADUROVA⁴, Haojun FAN², Luming YANG^{1, 2}
  - ¹National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu, 610065, China
  - ²Key Laboratory of Leather Chemistry and Engineering, Sichuan University, Chengdu, 610065, China
  - ³Fuzhou Customs District P.R. China, Fuzhou, 350000, China
  - ⁴Tomas Bata University, Zlin, 76001, Czech Republic
  ABSTRACT. The purpose of this study was to identify the influence of running speed on plantar pressure, and to use a load transfer algorithm to investigate the load transference in healthy recreational male runners who had a natural rear-foot strike pattern. Totally, 49 healthy males participated in this study, 39 of them (age 22.8 ± 1.8 years, weight 65.6 ± 7.9 kg, height 171.9 ± 4.0 cm) were identified as rear-foot strike runners. Data of pressure parameters, including maximum force, peak pressure, contact area and force-time integral (FTI) was recorded by Pedar-X insole plantar pressure measurement system at 8 different speeds (5, 6, 7, 8, 9, 10, 11, 12 km/h). The results indicated that with the increase of running speed, plantar pressure significantly increased under all foot regions except for the big toe. Faster running speeds resulted in significant lower FTI in all foot regions except for lateral midfoot and heel. Medial metatarsal, central metatarsal, and big toe were the main loading regions for rear-foot strike male runners during running. Load transferred from medial foot to lateral foot in transverse direction, and from toes to metatarsal, midfoot and heel in the longitudinal direction with increasing speeds. As a component of the spring mechanism, the arch played a key role in supporting and transferring loads.
  
  KEY WORDS: running, speed, load transfer, rear-foot strike, plantar pressure
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ANTIBACTERIAL COMPOUND BASED ON SILICONE RUBBER AND ZnO AND TiO₂ NANOPARTICLES FOR THE FOOD AND PHARMACEUTIC INDUSTRIES. PART I – OBTAINING AND CHARACTERISATION
- Pages 173-182
  Mihaela NIȚUICĂ (VÎLSAN)^{1, *}, Maria SÖNMEZ¹, Mihai GEORGESCU¹, Maria Daniela STELESCU¹, Laurenția ALEXANDRESCU¹, Dana GURĂU¹, Carmen CURUȚIU^{2, 3}, Lia Maria DIȚU^{2, 3}
  - ¹INCDTP - Division Leather and Footwear Research Institute, 93 Ion Minulescu St., sector 3, Bucharest, mihaela.nituica@icpi.ro, mihaelavilsan@yahoo.com
  - ²University of Bucharest, Faculty of Biology, 1-3 Portocalelor St., 6th district, 060101, Bucharest, Romania
  - ³Research Institute of University of Bucharest, 36-46 M. Kogalniceanu St., 5th district, 050107, Bucharest, Romania
  ABSTRACT. Taking into account the progress in science and technology, it has been and is still necessary to develop new innovative and high-performance materials. Globally, obtaining new advanced polymeric structures based on nanopowder-reinforced elastomers, with highperformance properties, offers possibilities for developing new materials and expanding their field of application. At present, polymeric materials occupy a very important place in all areas of human activity, being part more and more of everyday life. The need to develop new materials with high-performance properties led to this paper, which describes the obtaining and characterization of a compound with antibacterial properties based on silicone rubber (silicone elastomer - ELASTOSIL) reinforced with nanoparticles with antifungal, antibacterial and antimicrobial properties (ZnO and TiO₂). The dispersion of nanoparticles in the mass of the elastomeric compound has a decisive role in influencing its antimicrobial and antibacterial sterilization properties. The elastomeric compound based on silicone rubber with antibacterial and antimicrobial properties is obtained by vulcanization, and is characterized from a physical-mechanical, chemical and structural point of view, according to the standards in force. The antibacterial elastomeric compound reinforced with nanoparticles has potential uses in the food and pharmaceutical fields.
  
  KEY WORDS: antibacterial compound, curing, silicone rubber, TiO₂, ZnO
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MULTICRITERIA COMPROMISE OPTIMIZATION FOR LEATHER AND FUR SKIN MATERIALS TANNING TECHNOLOGY
- Pages 183-196
  Halyna YEFIMCHUK^{1, *}, Vladyslava SKIDAN², Mariya NAZARCHUK³, Eduard SELEZNOV¹, Anzhelika YANOVETS¹
  - ¹Lutsk National Technical University, Lvivska Str., build.75, Lutsk, Ukraine, 43018, email: gefimchuk@gmail.com
  - ²Kyiv National University of Technology and Design, Nemyrovych-Danchenko Str., build.2, Kyiv, Ukraine, 01011
  - ³Lesya Ukrainka Eastern European National University, Voli Prosp., build.13, Lutsk, Ukraine, 43025
  ABSTRACT. The work is devoted to the study of the influence of electro-activated aqueous solutions on the technological cycle of leather and fur skin materials production and footwear made of them. The influence of electro-activated aqueous solutions on the physicochemical transformations of the structure of skin tissue collagen is exemplified by rabbit fur skins used for shoe production. The spectral characteristics of changes in the structure and chemical composition of dermal collagen are determined and optimal modes of tanning process of leather and fur skin materials based on multicriteria compromise optimization are determined.
  
  KEY WORDS: electro-activated aqueous solutions, anolyte, catholyte, leather and fur skin materials, footwear
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CHARACTERIZATION OF NEW AND ARTIFICIALLY AGED PARCHMENTS
- Pages 197-204
  Lucreţia MIU^{1, *}, Elena BADEA^{1, 2}, Claudiu ŞENDREA¹,
  - ¹INCDTP – Division: Leather and Footwear Research Institute, 93 Ion Minulescu st., 030215 Bucharest, Romania, lucretia.miu@icpi.ro
  - ²Department of Chemistry, Faculty of Sciences, University of Craiova, Calea Bucureşti 107 I, 200585 Craiova, Romania
  ABSTRACT. This study aims to characterize new and artificially aged parchments. Parchment samples of calf, sheep, goat and pig were exposed to artificial ageing at 70°C in 3 cycles: first cycle for 7 days, second cycle for 14 days and 21 days for the 3^rd cycle. Thus, a treatment temperature of 70°C was selected to avoid sudden structural changes and rapid collagen denaturation. To evaluate the deterioration degree of parchments, the samples exposed to the first cycle were subjected to physical-mechanical, chemical tests and shrinkage temperature while the samples exposed to the second and 3^rd cycle to physical-mechanical test. Depending on the ageing cycles significant changes were reported. The accelerated ageing of parchments degraded the physical-mechanical properties and lowered the shrinkage temperature. The behavior of sheep and goat parchment samples to accelerated ageing suggests a rather high deterioration in the hydrothermal stability.
  
  KEY WORDS: physical-mechanical properties, shrinkage temperature, parchment, collagen, accelerated ageing
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