Leather and Footwear Journal

Volume 17, no 1

Contents
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The Effects of Backpacks of Different Structures with Different Loads on Shoulder to Back Pressure in Primary School Students
- Pages 3-8
  Nan ZHOU^1,2, Wuyong CHEN¹*, Jin ZHOU¹, Luming YANG¹, Xiaoyan ZHANG²
  - ¹National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu 610065, China
  - ²Guangzhou Shiling Leather & Leather Products Investigation Center Co. Ltd, Guangzhou, 510850, China
  ABSTRACT. The main purpose of this study was to evaluate the difference between soft and hard backpacks in pressure transmission effect and decompression with increased load weight. mFLEX was used to measure shoulder to back pressure on 100 primary school students (malefemale ratio 4:6) wearing different bag loads (equivalent to 5%, 10%, 15%, 20% and 25% of their body weights). Meanwhile, a comparative analysis test was done between backpacks of different structures (red backpack A with shoulder and back cushion design and regular yellow backpack B without shoulder and back cushion design). The conclusion is, along with the increase of backpack load, shoulder to back pressure value increased significantly, among them shoulder pressure value increased linearly, and back pressure value increased exponentially. Pressure values of the cushion bag (A) in three areas were all significantly larger than those of control bag (B). The results of the study are contrary to our hypothesis. Instead of effectively alleviating the concentration of pressure in three stress areas, left shoulder, right shoulder and lower back (LS, RS and LB), the buffer structure increases the pressure values. Therefore, in main pressure areas, we cannot simply rely on adding buffer structure to reduce the pressure generated by loading.
  
  KEY WORDS: backpack, load, structure, shoulder-back pressure, primary school students
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The Influence of New Preservation Products on Vegetable Tanned Leather for Heritage Object Restoration
- Pages 9-16
  Claudiu SENDREA*, Lucretia MIU, Marian CRUDU, Elena BADEA
  - INCDTP - Division: Leather and Footwear Research Institute, 93 Ion Minulescu, 031215 Bucharest, Romania, claudiusendrea@yahoo.com
  ABSTRACT. The paper studied the effect of four materials for the preservation of collagen-based heritage objects. The products developed were applied to new leather samples tanned with vegetable tanning agents such as quebracho and mimosa, which were then subjected to accelerated ageing for 24, 48 and 72 hours, at the temperature of 50℃. The effects of the new environmentally-friendly materials applied to leather were assessed according to a characterisation protocol specific for preservation and restoration of collagen-based heritage objects. The effects of the new formulations on vegetable tanned leather were assessed using the characterisation protocol that includes physicalchemical and organoleptic analyses in terms of colour change, handle, uniform spread, hydrophobisation (resistance to water drop and penetration time). Colour change was determined and assessed using Datacolor CHECK II portable spectrophotometer, and CIEL*a*b* and CIEL*C*h software, obtaining chromatic coordinates for each leather sample treated with the studied formulations. Treatments have caused some changes in leather characteristics, depending on the product applied.
  
  KEY WORDS: vegetable tanned leather, preservation, restoration
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Supplier Involvement in New Product Development: A Study in the Brazilian Footwear Industry
- Pages 17-30
  Diego Castro FETTERMANN¹*, Marcia Elisa Soares ECHEVESTE², Andre SAIDEL², Guilherme Luz TORTORELLA¹
  - ¹Federal University of Santa Catarina, Department of Industrial Engineering and Systems, Florianopolis, Brazil, d.fettermann@ufsc.br, gluztortorella@gmail.com
  - ²Federal University of Rio Grande do Sul, Department of Industrial Engineering and Statistics, Porto Alegre, Brazil, echeveste@producao.ufrgs.br, aseidel@masterskills.com.br
  ABSTRACT. The supplier involvement in the New Product Development (NPD) has become an important contribution to the solution of problems, which causes the process to be faster and more productive. However, it is still difficult to manage the supplier involvement during the NPD process. This study evaluates benefits and success factors of the supplier involvement during the process of NPD among three companies from the footwear industry in Sinos Valley/Brazil. The method developed indicates which items must be implemented as common objectives between company and supplier, as well as the most influential points for the success of the partnership. The results present an array of opportunities for the improvement of the partnership between company and suppliers.
  
  KEY WORDS: success factors, Sinos Valley, supply chain management
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Finishing Product for Improving Antifungal Properties of Leather
- Pages 31-38
  Olga NICULESCU¹*, Dana Corina DESELNICU², Mihai GEORGESCU¹, Mihaela NITUICA¹
  - ¹INCDTP - Division Leather and Footwear Research Institute, 93 Ion Minulescu St., Sector 3, Bucharest, Romania
  - ²Politehnica University of Bucharest, 313 Splaiul Independentei, 060042, Bucharest, Romania
  ABSTRACT. Some biocides used in the leather industry have a certain toxicity and are prohibited by the directives in force. A product with antifungal properties containing coriander essential oil was tested as finishing auxiliary for bovine shoe upper leather. The paper presents the results obtained in leather finishing using the new product AF-C and evaluation of its antifungal activity against Aspergillus niger strain. For maximum efficiency, the concentration of AF-C antifungal product must not decrease below 65% in the final dressing for leather finishing.
  
  KEY WORDS: leather, finishing, coriander essential oil, antifungal product
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Antibacterial Nanocompound Based on Silicone Rubber. Part I - Obtaining and Characterisation
- Pages 39-44
  Mihaela NITUICA (VILSAN)*, Maria SONMEZ, Mihai GEORGESCU, Dana GURAU, Olga NICULESCU
  - INCDTP - Division Leather and Footwear Research Institute, 93 Ion Minulescu St., sector 3, Bucharest, mihaela.nituica@icpi.ro, mihaelavilsan@yahoo.com
  ABSTRACT. The purpose of this paper is to develop an antibacterial polymer nanocompound based on silicone rubber reinforced with TiO2 nanoparticles and with added crosslinkers - dicumyl peroxide. The antibacterial nanocompound polymer was developed by vulcanization on a laboratory roll mill, so as to be further processed by means of molding using the electric press, with preset parameters for optimum processing. The antibacterial polymer nanocompound obtained was characterized in terms of physical-mechanical properties in normal condition and after accelerated aging at 70℃ for 168 hours; it was also characterized in terms of immersion in specific environments for the food and pharmaceutical industries according to standards in force, and structurally by FT-IR. The new advanced material based on silicone elastomer (silicone rubber) helps to improve product quality, protects human health, sterilizes products against bacteria and microbes and last but not least protects the environment, but also increases the turnover of domestic and international companies. Following physical-mechanical and chemical characterization of polymer nanocompounds, two variants were selected (P5 and P6) which have potential applications in food and pharmaceutical industries.
  
  KEY WORDS: silicone rubber, polymer nanocompound, vulcanization, antibacterial nanocompound
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Characteristics of Chrome Complexes in Neutralizing Effluent
- Pages 45-50
  Jinwei ZHANG^1,2, Yanping GAO¹, Wuyong CHEN^1,2*
  - ¹National Engineering Laboratory for Clean Technology of Leather Manufacture, Chengdu, 610065, China
  - ²Key Laboratory for Leather Chemistry and Engineering of the Education Ministry, Chengdu, 610065, China
  ABSTRACT. In order to explain the reason of chromium released from chrome tanned leather to effluent in neutralizing, the chromium complex composition, structure and property in neutralizing effluent were characterized. Hide powder was tanned by chromium sulfate liquor with 33% basicity (BCS), and then the tanned hide powder was treated by conventional neutralizing to prepare neutralizing effluent (NE). Ion exchange chromatography (IEC) and gel filtration chromatography (GFC) were used to separate NE to study its chromium composition firstly; then ultraviolet-visible absorption spectroscopy (UV) and Fourier Transform Infrared Spectroscopy (FT-IR) were combined to analyze the structure of chrome complexes in NE; at last, chromium from NE was used for tanning and the thermal properties of the tanned hide powder were measured by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The results indicated that NE mainly consisted of anionic-zero valent, monovalent and bivalent chrome complexes and the molecular volume was small also. The Cr(III) complexes in NE were mainly combined with ligands like SO₄^2- and HCOO^- through single point coordination. Compared with the control, higher weightlessness rate but lower maximum thermal decomposition temperature (T_max), thermal denaturation temperature (T_d) and enthalpy (ΔH) of NE chrome tanned hide powder demonstrated poor tanning ability of the chromium. In short, the characteristics of chromium complexes released from neutralizing process were: anionic-zero valent and low positive charge composition, small molecular volume, mainly combined with ligands through single point coordination and poor tanning ability. The study would provide foundation and reference for developing chromium solidifying methods in neutralizing.
  
  KEY WORDS: neutralizing effluent, chromium complex, composition, structure, tanning property
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The Influence of Compatibiliser on the Properties of Polymer Composites
- Pages 51-58
  Mihai GEORGESCU*, Laurentia ALEXANDRESCU, Maria SONMEZ, Mihaela NITUICA, Olga NICULESCU, Dana GURAU
  - INCDTP - Division: Leather and Footwear Research Institute, 93 Ion Minulescu, sector 3, Bucharest, Romania, mihai.georgescu@icpi.com, mihai.georgesku@yahoo.com
  ABSTRACT. Thermoplastic polymers are materials of the future, with special properties, depending on the type of elastomer, the degree of reinforcement, the type of reinforcement material, the functionalization of the reinforcing material, the type of functionalization agent, the elastomer-compatibiliser-reinforcing agent ratio, etc. Polycarbonate (PC) and polyamide (PA) are two elastomers with high hardness, immiscible due to differences in polarity, processing temperature, and solubility. These factors lead to a poor dispersion of PC in the PA matrix and vice versa. Mechanical and physical properties of these polymer blends come not only from the combination of polymeric compounds, but also from the developed morphological forms (interface). Therefore, an additive is required to act as a compatibiliser able to effectively reduce elastomer viscosity. In order to observe the influence of the selected compatibiliser on the properties of polymer composites, the latter were characterized physico-mechanically and morphologically. Thus, compatibilisers chosen for this study were polycaprolactone and polyalkyloxazoline. These compatibilisers, with specific surface and free energy, intervene in polymer-polymer interactions, increasing compatibility, forming polymer-compatibiliser-polymer bonds. Considering these properties formulations of polymercompounds were established (P1-P13) based on polyamide/compatibiliser/polycarbonate/fibreglass. Tested polymer composites contain different percentages of polyamide and polycarbonate (90, 70, 50, 30, 10), compatibiliser (caprolactone and oxazoline) 3-7%, and 10-30% fibreglass.
  
  KEY WORDS: composites, polymers, polyamide, polycarbonate, compatibilisers
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Regulations for the Prescription of Footwear as Medical Device
- Pages 59-66
  DANIEL PETCU*, VIORICA ROSCULET
  - INCDTP - Division: Leather and Footwear Research Institute, 93 Ion Minulescu St., Bucharest, Romania, email: crispinian.ro@gmail.com, icpi@icpi.ro
  ABSTRACT. Orthopedic footwear is part of the category of medical devices used in the conservative treatment of foot and lower limbs pathomechanics. For the custom-made medical device the manufacturer has to perform the design based on the prescription of a duly qualified medical practitioner that sets the specific design characteristics of the device. Quality management standards in the field of medical devices govern the entire process (or parts thereof) from design and development to delivery and provide technical support for their implementation. In this respect, the prescription is constituted as an input, respectively an essential requirement of the design process and must be complete and unambiguous. This paper aims to analyse aspects of medical prescription as an essential requirement of the design and manufacturing process of custom-made orthopedic footwear.
  
  KEY WORDS: orthopedic footwear, medical device, prescription, quality management
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Leather Finishing with New Pigment Paste
- Pages 67-74
  Olga NICULESCU¹*, Dana Corina DESELNICU², Mihai GEORGESCU¹, Mihaela NITUICA¹
  - ¹INCDTP - Division: Leather and Footwear Research Institute, 93 Ion Minulescu St., Sector 3, Bucharest, Romania
  - ²Politehnica University of Bucharest, 313 Splaiul Independentei, 060042, Bucharest, Romania
  ABSTRACT. The paper presents obtaining and characterisation of full grain bovine shoe upper leather finished with new pigment pastes containing flax seed oil (brown colour) and poppy seed oil (yellow colour) as plasticizer instead of castor oil (reference). Nitrocellulose, polyurethane or acrylic dressing were used as final dressing. Finished leathers were characterized by physical-mechanical analysis and colorimetric method before and after aging. The leathers finished with polyurethane or acrylic final dressing had the highest resistance to light after aging under the influence of artificial light in comparison with those finished with nitrocellulose dressing. Flax and poppy seed oils used as plasticizers improved resistance to ageing of coating.
  
  KEY WORDS: pigment paste, plasticizer, castor oil, flax seed oil, poppy seed oil
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