Dr Lakshmi Muthusubramanian1* CLRI, Chennai, and Rajat B Mitra2, National Chemical Laboratory, Pune, discuss an eco-friendly approach to the synthesis of methylene
bisthiocyanate as a fungicide in leather processing

Dr Victoria Addy, technical director, BLC Leather Technology Centre, reviews the latest developments in enzyme technology for the leather industry

Following on from the article, ‘Soil resistant leather comes of age’ by Dietrich Tegtmeyer, Tillmann Hassel, Juergen Reiners, Stefan Wildbrett and Michael Franken of LANXESS, published in Leather International, April 09, page 22, the authors provide an update on the advantages of anti-soiling products for the tanner and consumer

Dutch tanners, Wendel Leather Group (Gebr. Wendel Leder-fabriek en Handelmij) have recently installed the final phase of their automated dye drum unloading system at their plant in Tilburg.
The project, which was managed and installed by Intermedia Holland from Dongen, was installed to improve worker health and safety as well as increase productivity at the tannery. The Wendel Leather Group have three tanneries located throughout Holland in Waalwijk, Rijen and Tilburg with the Waalwijk plant being the company headquarters.

By BLC - Leather Technology Centre

Operation of a direct recycling plant for final liquors in chrome tanning by Juan Manuel Salazar, Americana de Curtidos Ltda. Y CIA SCA, Colombia. This paper was presented at the 2008 FLAQTIC Congress in Rio de Janeiro.

Introduction

Azo dyes used to be among the leading colouring agents in the textile industry, especially in developing countries. Since the 1990s, when legislation was introduced restricting certain azo dyes, there has been much confusion and misunderstandings concerning azo dyes. This article aims to clear these up.

Introduction

Formaldehyde is a chemical compound (also known as methanal) that is widely used in many industries. It is the simplest aldehyde chemically with the formula H2CO. Formaldehyde is a gas at room temperature but it is also readily soluble in water (and is often sold as an aqueous solution).

The appearance of a product has a great deal of influence on the consumer's decision to purchase. A consumer or professional buyer will expect the article and its different components to be homogeneous in their overall appearance. Colour management is a delicate process and requires reliable tools and constants in order to meet the quality levels demanded. In a strong position due to their expertise in vision technology, CTC studied the best performing colorimetric measurement systems for leather and have developed a mechanism/device to automate the batching of pieces of leather for leathergoods.

These are the references to the article published in the November/ December 2008 edition of Leather International on 'Recycling chrome liquors by Juan Manuel Salazar of Americana de Curtidos.

Introduction

Recently, the climate surrounding restricted substances has grown quite confusing for many suppliers and manufacturers of leathergoods. What is the difference between statutory and non-statutory requirements? Which substances are harmful and which are not?

In response to the need for further improvements in the performance, safety and environmental impact of fungicidal agents, Zenith have developed a new fungicide specifically for application in the leather industry.

Fungicides are an essential component of leather manufacture to prevent the occurrence of mould on part processed and finished leather. If used correctly and sourced from a reputable supplier, fungicides used within the leather making process present no risk to the consumer. This article by BLC Leather Technology Centre Ltd discusses the typical fungicides used in leather processing.

Antimony is a chemical element in the periodic table that has the symbol Sb (Latin: stibium, meaning ‘mark') and atomic number 51. Metalloid antimony has four allotropic forms. The stable form of antimony is a white metalloid. Yellow and black antimony are unstable non-metals. Antimony is used in flame proofing, paints, ceramics, enamels, and a wide variety of alloys, electronics and rubber.

In the third part of their review of the effects of syntans on the properties of leather, Dr Ramón Palop, Joan Parareda and Olga Ballús, from the tanning laboratory at Cromogenia-Units SA, highlight the physical and organoleptic properties imparted by synthetic tannins.

Introduction

The European Commission has recently imposed a restriction in Directive 2006/112, a follow up from Directive 76/769/EEC, which relate to the marketing and use of dangerous substances and preparations. The aim of this legislation is to restrict the use of perfluoroctane sulphonates in order to limit health and environmental risks.

Also under investigation is the use of perfluoroctanoic acid, as the USA's EPA (Environmental Protection Agency) is looking to phase out emissions of this chemical over the next few years.

In our November/December edition we published details of an IULTCS presentation: Alternatives to sulfide dehairing: use of oxidative agents by William N Marmer and Robert L Dudley, Eastern Regional Research Center, USDA Agricultural Research Service. They also provided a related visual display: Oxidative dehairing: to relime or not to relime.

Part 2 of an experimental study - colorimetric testing - by Dr Ramón Palop, Joan Parareda and Olga Ballús of the tanning laboratory of Cromogenia-Units SA, Barcelona, Spain.

Part I of an experimental study - ageing resistance - by Dr Ramón Palop, Joan Parareda and Olga Ballús of the tanning laboratory of Cromogenia-Units SA, Barcelona, Spain.

The Problem

An earlier article in this series discussed the problems of butcher's strain; small tears resulting from extremes of force during the removal of the skin from the carcase. This article is a natural progression from that and discusses flay cuts.

What is cadmium?

Cadmium is a transition metal which occurs naturally in the form of greenockite. It is rare and nearly always associated with sphalerite (a sulfide ore of zinc). Hence, cadmium is largely produced as a byproduct from the mining of zinc. The name of the element was derived from the Latin ‘cadmia' and the Greek ‘kadmeia,' both ancient names for calamine (zinc carbonate). Cadmium and several cadmium containing-compounds are known carcinogens and can induce many types of cancer.

V Sivakumar, K Jeyaraj, R Chandrasekar, and G Swaminathan from the Central Leather Research Institute, Adyar, Chennai, India discuss the advantages of adding titanium to chrome leathers.

Veinous defects on the surface of the leather have been familiar to tanners for many years. CTC has evaluated which stages of processing a box-calf leather offer opportunities to alleviate these defects whilst conserving the functionalities required from this type of leather.

Farrukh Nazir, from PCSIR Leather Research Centre, Karachi, Pakistan, reviews the use of mangrove as an ecologically friendly tanning material.

An awareness of restricted substances is critical for all involved in the leather supply chain. Many substances are restricted either through legislation or through the brands and eco-labels. Although the leather industry is becoming more aware of the substances that are restricted, it is of interest to consider the background to their listing and some of the reasons behind their restriction. This article provides an overview of the element lead (Pb).

Eser Eke Bayramoglu, Faculty of Engineering, Department of Leather Engineering, Ege University, Türkiye, highlights the use of essential oils as potential biocides for the leather industry

In recent years the consumer market has moved towards requiring an enhanced level of responsibility from brands and retailers for their products. To keep leather brands and retailers up-to-date on hot topics regarding restricted substances, BLC will be writing a series of articles for this publication.

Purchasing decisions are based on factors such as quality and, increasingly, on social, ethical, safety and environmental grounds. Restricted substances are an important issue for both manufacturers and consumers due to extensive and complex legislation. Whether it is potentially harmful to the environment or to the user, everything should be checked in order to demonstrate due diligence and corporate social responsibility.

In each issue, one substance will be looked at in detail, including subjects such as legislation, toxicity and safe limits. This overview article is the first in the series and covers frequently asked questions by manufacturers and retailers.

The Heidemann lecture at last year's Washington IULTCS Congress was presented by Lorenz Siggel of BASF. Collagen is the most abundant protein in mammals and has been studied for more than a century with the aim of improving the tanning, dyeing and finishing processes.

Introduction

Chrome tannage has been recognized as one of the most effective tanning agents and has been widely employed in the leather industry since its discovery more than 100 years ago. However, due to its environmental impact, the practice of tanning with chromium (Cr) compounds has been restricted or prohibited in developed areas such as the United States and Europe and certain goods made with chrome tanned leathers are no longer allowed to be manufactured or sold within these countries.

My train rolled along tracks winding though a landscape dotted with farms and the steady rattle was punctuated by the assault of raindrops and gusting wind against the windows. We had just pulled out of a station and the new passengers, with a cold dampness clinging to them, fled into our car. 

A novel wet-end technology based on expandable microspheres has been developed by LANXESS in order to upgrade lower quality hides and skins. Dietrich Tegtmeyer presented the work at the IULTCS Congress in Washington. His co-authors were Otto Vorlaender, Werner Zeyen, Frank Silberkuhl and Christopher Tysoe.

Work on alternatives to sulfide dehairing through the use of oxidative agents was presented at the XXIX congress of the IULTCS/103rd annual meeting of ALCA in Washington DC earlier this year. The authors are William N Marmer and Robert L Dudley of the Eastern Regional Research Center, USDA Agricultural Research Service. This is an abridged version and the copyright of the full paper rests with ALCA.

White shoes gain a pinkish hue before they have been worn. Leather brief cases can become sticky during storage. The phenomena of migration and bleeding are the enemies of the shoe and leathergoods industries. This article explores this issue and identifies methods of prevention. Tanners and suppliers should be equally interested because the solution to this problem lies in their hands