Leather and Footwear Journal

Volume 11, no 2

Contents
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Leather Dyeing: Can The Process Overcome Water Quality Restrictions?
- Pages 79-90
  Govindan DEVIKAVATHI*, Victor JOHN SUNDAR, Chellappa MURALIDHARAN
  - Leather Process Technology Division, Central Leather Research Institute, Council of Scientific & Industrial Research, Chennai, India, email: devikavathi@gmail.com, fax: 0091-44-24430267
  ABSTRACT. Dyeing is a process carried out to impart the required colour to the leather. Dyeing of leather plays an important role in the final appearance and aesthetics of leather. Water is the medium currently employed by the leather industry for the conversion of raw hides and skins to leather, including dyeing. Water quality, particularly in the places of tannery clusters in Tamil Nadu, India, was assessed. Many clusters are identified with water hardness in the range of 20000-35000 ppm. Dyeing is carried out by sourcing out the water in these areas. An attempt has been made to study the effect of hardness on the dyeing of leather using different classes of present day dyestuffs. Some interesting results have emerged based on the study carried out. The influence of water quality associated with the physico-chemical characteristics of the dyed leather is also reported in this paper. Apart from the need for significant quantity of water for dyeing, the quality of water plays an important role in leather making.
  
  KEY WORDS: dyeing, dyes, hard water, colour, softness
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The Influence of High Density Polyethylene Added to Ionic Thermoplastic Elastomer Compounds Based on Maleinized Ethylene-Propylene Terpolymer Rubber
- Pages 91-108
  Maria Daniela STELESCU*, Daniela BERECHET, Dana GURAU
  - INCDTP Division: Leather and Footwear Research Institute, 93 Ion Minulescu St., Bucharest, Romania, email: dmstelescu@yahoo.com
  ABSTRACT. This paper studies the influence of high-density polyethylene on the characteristics of ionic thermoplastic elastomers based on maleinized ethylene-propylene terpolymer rubber (EPDM-g-MA). Ionic thermoplastic elastomers were obtained by processing elastomers containing ionisable groups, namely EPDM-g-MA, by introducing metal salts or polyvalent metal oxides which can react with functional groups of ionisable molecules forming ionic fields, as well as introducing fillers, ionic plasticizers, polyolefins, antioxidants etc. From the results obtained it was noticed that upon increasing the amount of high-density polyethylene (HDPE) introduced in EPDM-g-MA blends, hardness, modulus and tear strength increase and elasticity and residual elongation decrease. These effects prove that the properties of polymer blends depend on the characteristics of component polymers and on their molar ratios. The blend containing 80 phr polyethylene was selected, as it had the optimum values of hardness, modulus, tear strength and good values for tensile strength, elongation at break and elasticity. This blend was used to make ionic thermoplastic elastomer granules in the laboratory extruder-granulator. The new types of granules were characterized and their functionality and the reproducibility of the technology by means of which they were obtained were demonstrated. They can be used to obtain new types of soles and toplifts for footwear, to make protection equipment, to obtain gaskets, hoses, conveyor belts which are resistant to concentrated acids and bases etc.
  
  KEY WORDS: maleinized ethylene-propylene terpolymer, high-density polyethylene, ionic thermoplastic elastomers
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CRISPIN Dynamics 3D New Solution for Shoemakers, Creating and Modifying the Shoe Last
- Pages 109-120
  Mariana DRISCU*, Mariana PASTINA
  - Faculty of Textile, Leather and Industrial Management, Gh. Asachi Technical University, 53 D. Mangeron Blvd., 700050, Iasi, Romania, e-mail: mcocea@tex.tuiasi.ro, mariana.pastina@yahoo.com
  ABSTRACT. This paper presents the basic functions for creating and modifying the shoe last using CRISPIN Dynamics 3D system Last Maker and Shoe Design modules, useful in obtaining a shoe last data base. There is a brief presentation of CRISPIN Dynamics 3D which is a CAD/CAM system for footwear which offers new and enhanced solutions for shoemakers. CRISPIN Dynamics have developed a range of quality software products to give the shoemaker a major advantage over its competition. With the specific instruments of CRISPIN Dynamics CAD Suite software, Model Tracer and Shoe Design modules, a database of shoe lasts has been developed. This database can be used in viewing, article by article, graphics of the last and their main geometrical parameters and in searching for a last, after one or more parameters, depending on user options. The created database is useful for footwear manufacturers who can always find the shoe last that fits their product.
  
  KEY WORDS: last, parameter, grading, flattening, database
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Polymeric Flocculants Based on Acrylamide and Acrylic Acid Obtained by Electron Beam Irradiation
- Pages 121-132
  Gabriela CRACIUN*, Elena MANAILA, Daniel IGHIGEANU
  - National Institute for Laser, Plasma and Radiation Physics, Electron Accelerators Laboratory, 409 Atomistilor St., 077125 Magurele, Romania, e-mail: gabriela.craciun@inflpr.ro
  ABSTRACT. This paper presents the physical-chemical characteristics of environmentally friendly polymeric materials for waste water treatment, obtained by electron beam irradiation. These polymeric flocculant materials are obtained by copolymerization of acrylamide and acrylic acid, and have the following characteristics: conversion coefficient Cc>90%, low residual monomer concentration Mr<0.05%, high intrinsic viscosity Î·intr>6 dl/g, a low linearity coefficient kH<1 and good solubility in water. Establishing these physical-chemical parameters leads to obtaining polyelectrolytes with minimal toxicity and a high flocculation or coagulation aid capacity.
  
  KEY WORDS: flocculant, copolymerization, acrylamide, acrylic acid, electron beam
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The Study of Pretanning Bovine Skins with Oligomeric Benzenesulfonic Melamine-Formaldehyde Resin
- Pages 133-148
  Melinda PRUNEANU¹*, Stelian Sergiu MAIER¹, Vasilica MAIER¹, Viorica DESELNICU²
  - ¹Gh. Asachi Technical University of Iasi, 71 Dimitrie Mangeron Blvd., 700050, Iasi, Romania, email: pruneanu_melinda@yahoo.com
  - ²INCDTP Division Leather and Footwear Research Institute, 93 Ion Minulescu St., Sector 3, Bucharest, Romania
  ABSTRACT. This paper presents the study of pretanning bovine hides using a tanning oligomer based on benzenesulfonic melamineformaldehyde resin (RMFBS) in the presence or absence of resorcinol as crosslinking agent. In order to test the penetration and retention capacity, as well as the tanning power of the resin, pre-tanning treatments are applied, according to framework formulations, on bovine pelt samples, processed according to a classical process. The applied RMFBS treatment implies testing the ability of syntan to fix into the dermis and its ability to increase shrinkage temperature of pelt, upon individual application, or in combination with resorcinol. Leather samples thus treated are subjected to physical-chemical analyses by FTIR-ATR spectroscopy, fluorescence spectroscopy and SEM electron microscopy, in order to highlight both the structural changes in the collagen matrix and the ability of the resin to combine with functional groups of dermis proteins. The experimental data obtained confirm the pre-tanning capacity of the RMFBS oligomer, reaching the highest performances for an offer of 15% RMFBS dry substance in relation to the dermal substance.
  
  KEY WORDS: pelt, pre-tanning, benzenesulfonic melamine-formaldehyde resin, resorcinol, shrinkage temperature
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Designing and Creating a Support Infrastructure for Quick and Semi-Customized Footwear Manufacturing
- Pages 149-162
  Ana Maria VASILESCU¹*, Constantin PETRESCU², Cristinel MOVILA²
  - ¹INCDTP Division: Leather and Footwear Research Institute, Bucharest, email: icpi@icpi.ro
  - ²SC Rialto Prod SRL, Bucharest, email: contact@rialto.ro
  ABSTRACT. The proposed research has focused on optimizing the tools of the organization system, taking into consideration the fact that suppliers of components, equipment and the main features of shoe companies are located in various places in the country or abroad. To their support, a software system supporting the flow of information across the GLA (supply group management) supply chain was designed and developed. The aim is to reduce the design-industrialization cycle so that the footwear industry would be competitive in the market, facilitating the creation of leading fashion models, as a result of the electronic exchange of information in the footwear sector. Also, defining the architecture and functions of the SIFAST software platform allows semi-customization of shoes for EU beneficiaries and efficient data exchange throughout the supply chain to satisfy delivery time requirements. The technology used in the logistics of the entire footwear-making process follows the manufacturing process step-by-step. By means of a simple and friendly interface it helps customers choose the footwear design process, the real manufacturing flow of this type of product and the necessary raw materials. Each raw material is selected from a complex database according to the features requested by the customer.
  
  KEY WORDS: footwear, semi-products, supplies, database
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