Volume 15, no 4

  • Contents
    • Contents PDF
    Full issue
    • Full issue
    Effect of UV Irradiation on Vegetable Tanned Leather
    • Pages 219-228
      Yanping GAO1,2, Shuang YANG1,2, Xiaoyun JIAN1,2, Lucreția MIU3, Carmen GAIDĂU3, Wuyong CHEN1,2*
      • 1Key Laboratory of Leather Chemistry and Engineering of the Ministry of Education, Sichuan University, Chengdu, 610065, P. R. China, wuyong.chen@163.com
      • 2National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu 610065, P. R. China
      • 3INCDTP - Leather and Footwear Research Institute, 93 Ion Minulescu St, sector 3, 031215, Bucharest, Romania

      ABSTRACT. This article aims at studying the influence of UV irradiation on vegetable tanned leather. Vegetable tanned leather was treated in QUV chamber (T = 50°C, irradiance = 1.77 W/mm2nm, ëUVA=340 nm) for 0, 30, 60, 90, 120 and 150 hours. Then, these samples were evaluated by different analytical methods to get a whole picture of the leather during the irradiation. Micro hot table (MHT), differential scanning calorimetry (DSC) and thermogravimetry (TG) were used to evaluate the influences of UV irradiation on thermal behaviors. Damages to mechanical properties were also analyzed by a standard method. Fourier transform infrared spectroscopy (FT-IR) and optical microscopy were used to investigate the changes of structural and histological properties during aging process. With the extension of aging time, thermal stability was gradually reduced to lower values, including shrinkage temperature, thermal denaturation temperature, associated enthalpy and temperature for maximum decomposition rate. In addition, mechanical properties such as tensile strength, tear strength and elongation at break also gradually decreased. The FT-IR results showed that, during the aging process, amide I and amide II band of the tanned collagen gradually shifted to lower numbers, indicating an increasingly serious damage to the structure of the peptide chain, that corresponds to obvious fibril breakages which are also detected through optical microscopy.

      KEY WORDS: UV irradiation, vegetable tanned leather, aging
      Read article
    Parameters Optimization of PID Controllers for Leather Manufacturing Process by Using Genetic Algorithms
    • Pages 229-238
      Adrian-Bogdan HANCHEVICI1, 2*, Sergiu-Adrian GUȚĂ1
      • 1INCDTP - Division Leather and Footwear Research Institute, Bucharest, Romania, email: guta.sergiu@icpi.ro
      • 2Politehnica University of Bucharest, Faculty of Automatic Control and Computers, Romania, email: adrian.hanchevici@upb.ro

      ABSTRACT. In this paper is proposed a control strategy for leather manufacturing process. This control strategy makes use of conventional PID control algorithms in combination with an evolutionary optimization technique, namely genetic algorithms. In order to find the parameters for the PID controllers, different performance indexes are provided to the genetic algorithms. In this study the proposed control strategy is used to control one process parameter, namely the pH value. Simulation results are presented. The results show performance improvement which proves that the proposed control strategy is able to make the closed-loop system behave as expected according to different given performance indexes.

      KEY WORDS: PID, genetic algorithms, leather manufacturing process
      Read article
    Reliability Analysis of Footscan Plate System in Measurement of Plantar Pressure of Spastic Diplegia Children
    • Pages 239-248
      Ting LI1, Binqian LI1, Wuyong CHEN1, Jianxin WU2, Bo XU1, Jin ZHOU1,2*
      • 1National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University; Chengdu, P. R. China, zj_scu@qq.com
      • 2Science Lab, Zhejiang Red Dragonfly Footwear Co., LTD., Zhejiang Province, Wenzhou 325100, P. R. China

      ABSTRACT. This study was aimed at evaluating the reliability of Footscan plate system when measuring pressure in spastic diplegia children (CP). Eighteen CP and 36 typical developed counterparts (TD) with similar age, height and weight were recruited and their plantar pressure was measured in at least five trials. Three-mask model was applied and plantar regions were divided into: forefoot, mid foot and hind foot, under which peak pressure (PP) (N/cm2), relative pressure time integral (PTIrel) (%) and relative contact area (CArel) (%) were calculated. Coefficient of variance (CoV) and intra class coefficient (ICC) were explored for each variable and region. Our outcomes show that in terms of CP, with the increasing of test times, ICC of PP increased, while those of PTIrel and CArel were lowered; additionally, ICC of TD of each pressure variable successively improved. A similar tendency was found for CoV. Considering entire feet of CP and five measurements, reliability of CArel was the best in the three areas; whereas PP and PTIrel were demonstrated to be less reliable, except for the midfoot area. In contrast, reliabilities of TD were shown to be good for all pressure variables under all three regions. Overall, reliability of Footscan plate system in the study of CP was moderate in most variables and under most plantar regions. Thereby, by increasing the test times to no less than five, this protocol could be applied in the clinical and scientific investigation of CP children.

      KEY WORDS: spastic diplegia children, plantar pressure, reliability, intra class coefficient, coefficient of variance
      Read article
    Collagen-Albumin-Gentamicin Hydrogels Usable for Infected Wound Healing
    • Pages 249-256
      Georgeta PĂUNICĂ-PANEA1,2, Mihaela Violeta GHICA3, Ştefania MARIN4, Ana-Maria ENE5, Maria Minodora MARIN4, Elena DĂNILĂ4, Cornelia NIȚIPIR1,6, Mădălina Georgiana ALBU4, Ioan CRISTESCU1
      • 1Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Dionisie Lupu 37, 020022, Bucharest, Romania, paunica_laura@yahoo.com
      • 2Surgery Department, Sfantul Pantelimon Emergency Clinical Hospital, 340-342 Soseaua Pantelimon, 021659, Bucharest, Romania, paunica_laura@yahoo.com
      • 3Department of Physical and Colloidal Chemistry, Faculty of Pharmacy, Carol Davila, University of Medicine and Pharmacy 6, Traian Vuia Str., 020956, Bucharest, Romania, mihaelaghica@yahoo.com
      • 4Collagen Department, Leather and Footwear Research Institute, 93 Ion Minulescu Str., 031215, Bucharest, Romania, icpi@icpi.ro
      • 5Faculty of Applied Chemistry and Material Science, Politehnica University of Bucharest, 1-7 Polizu Str., 011061 Bucharest, Romania, anamariaene92@gmail.com
      • 6Elias Emergency University Hospital, 17, Marasti, Blv. 011461, Bucharest, Romania, nitipir2003@yahoo.com

      ABSTRACT. The aim of this study was to develop new hydrogels for infected wound treatment. The main components of hydrogels were two proteins, one fibrous (type I collagen in the form of gel) and one globular (albumin) in different ratios (10, 20 and 30%), and gentamicin was selected as an antibiotic drug model. The properties of the obtained hydrogels were estimated by rheological measurements and the corresponding lyophilized forms by water up-take capacity. The results showed that the promising hydrogels which can provide good absorbance and antimicrobial properties at the same time are the ones with maximum 20% albumin and 0.2% gentamicin and the in vitro tests are further recommended.

      KEY WORDS: hydrogels, collagen, rheology, albumin
      Read article
    Effect of Ultrasound on the Dry Heat Behaviors of Cattlehide Collagen Fibers
    • Pages 257-275
      Keyong TANG1*, Wei TIAN1, Fang WANG1, Pengxiang JIA1, Jinglong LIU1, Mădălina Georgiana ALBU2
      • 1College of Materials Science & Engineering, Zhengzhou University, Zhengzhou 450001, China, keyongtangzzu@yahoo.com
      • 2INCDTP - Division Leather and Footwear Research Institute, Collagen Department, 93 Ion Minulescu St., 031215, Bucharest, Romania

      ABSTRACT. In this paper, the dry heat behaviors of different cattlehide collagen fiber samples with and without power ultrasound process are studied, and such instruments as Thermal Platform Microscope, Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) are employed in the study. It is indicated that the dry heat behavior of the samples is slightly decreased because of the power ultrasound process. The reason why it is the case may be that part of the crystalline structure in the samples is destroyed by the power ultrasound process.

      KEY WORDS: ultrasound, dry heat behavior, cattlehide collagen fibers, tanning, retanning
      Read article


Menu

  • Homepage
  • Publication Ethics
  • Open Access, Copyright and Licensing
  • Plagiarism Policy
  • Indexing
  • Editorial board
  • Instructions for authors
  • Peer Review Policy
  • Fees and Subscriptions
  • Issues
  • Contact

© 2022 All rights reserved.

Leather and Footwear Journal