 Adhesion and leather finishing [premium content]
Over and above the choice of binders, pigments and other finishing auxiliaries, the integrity of the finish is highly dependent upon the adhesion of the finish to the substrate, the coalescence of each finishing application within that film, and the inter-coat adhesion. Various mechanisms are involved in creating good adhesion at these critical stages, and these are described in detail in the following paper.
World Leather - 01 - Feb/Mar 2008
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Adhesion and leather finishing [premium content]
Over and above the choice of binders, pigments and other finishing auxiliaries, the integrity of the finish is highly dependent upon the adhesion of the finish to the substrate, the coalescence of each finishing application within that film, and the inter-coat adhesion. Various mechanisms are involved in creating good adhesion at these critical stages, and these are described in detail in the following paper.
World Leather - 01 - Feb/Mar 2008
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The manufacture and control of water-resistant leather [premium content]
Many factors must be taken into account when manufacturing water-resistant leathers. This includes both the raw materials selection, and the processing to the finished state. Care must be taken to ensure that the achievements gained by careful materials procurement and leather manufacturing techniques are not diminished by inappropriate works practices.
World Leather - 01 - Feb/Mar 2008
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Companies act to keep chromium VI out [premium content]
Chrome tanned leathers have been used in footwear and clothing for almost a century, and might thus be considered as fit for use. The properties of chromium compounds in both the trivalent and hexavalent forms are known, and, as the trivalent form is used in tannage the process has been considered safe.
It was first recognised in the late 1990s that under certain conditions small amounts of Cr(III) could be oxidised to Cr(VI) in leather manufacture and during storage. This was mainly due to oxygen provided by certain fatliquors, and accordingly these products were identified. Moreover, it was found that many vegetable tanning agents and scavenging products were effective in addressing these effects. The problem was no longer
a technical issue. But, the problem of chromium VI does not appear to go away, and is being taken very seriously by fashion groups, especially those selling children's footwear. Some of the issues raised – such as Cr(VI) being 5% above a limit of 3 ppm as determined by one laboratory (+0.15 mg/l) with three other laboratories suggesting the
level was acceptable – are playing with determinations on the fringe of detection. However, when health matters – and especially children's health – are considerations, any concerns of the consumer will be driven by what is perceived as opposed to any technical debate.
This article is based on a presentation given in World Footwear Jan/’Feb 2008, and is a timely reminder to the industry that vigilance remains of extreme importance.
World Leather - 03 - May 2008
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Preserving agents in the leather production process [premium content]
Due to extended times in transport and storage, leathers in the wet blue and wet white condition need protection against bacterial and fungal contamination. This is provided by synthetic preserving agents. However, triggered by new regulations, these agents and their use in the leather production process have become the focus of a number of chemical safety and consumer health issues.
This paper provides an overview of basic leather preservation, the most common
ingredients, and the current situation regarding use of these products.
World Leather - 08 - Dec/Jan 2008
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Back to Basics: A Framework for Leather Manufacture - Essay 19 [premium content]
Leather drying and conditioning
World Leather - 05 - Aug/Sept 2007
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Solar Reflective (Cool) leather [premium content]
A new technology for leather has been developed to reduce the build up of solar heat and provide the level of comfort consumers expect from a natural product.
World Leather - 01 - Feb/Mar 2007
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The hydrophobing of chrome-free leather [premium content]
Nowadays, hydrophobic qualities in high quality leather
are demanded for many fields of application. These
properties range from the so-called ‘pearl’ effect through
to ‘waterproofness’, as given by classical impregnation.
However, requirements for good waterproofing include water
resistance throughout the whole leather cross-section and
reduced water uptake. These characteristics have to remain
durable under static and dynamic conditions whilst at the same time the leathers should show reasonable water vapour
permeability. This is to ensure a high wearing comfort for shoe upper leathers and sitting comfort for upholstery leather.
World Leather - Dec/Jan 2006
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Automobile leather manufacture: Part 2 [premium content]
Practical considerations for the production of wet white.
World Leather - Oct 2006
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Technologies to improve the useful area of leather [premium content]
The manufacturing of leather is facing diverse challenges nowadays including pressure from the eco-toxicity point of view, in the form of stringent new regulations. The measures necessary to deal with these issues add to the cost pressure that tanners are experiencing.
World Leather - Aug/Sep 2006
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