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

Paula Antunes, British School of Leather Technology, looks at methods of crosslinking solubilised collagen to give it the strength and stability required to make it suitable for long term medical applications

Investigations carried out by French leather and footwear research centre CTC have looked at discrete methods of branding leather and leather products. The research was carried out to monitor traceability of an item in order to reduce counterfeiting of luxury goods

Leather is not a readily burnable substance. However, to provide a margin of safety to allow time for evacuation of vehicles or buildings, additional fire-resistant protection is necessary. By Dr Campbell Page and Kurt Becker, TFL Leather Technology Ltd, Basel, Switzerland

The Problem

Sheep scab is a highly infectious condition caused by the small mite Psoroptes ovis and is estimated to cost UK sheep farmers £3 to £4 million a year in lost income1. The infection causes immense distress to the sheep and results in damage to the leather and to the fleece caused by the animal chewing its skin and rubbing itself to relieve the itching.

Introduction

REACh lays new obligations on the industry and defines a new approach to chemicals control. Enterprises which manufacture or import more than one ton of a substance per year will be required to register these chemicals. Evidence demonstrating the safe use of the substance needs to be submitted in a registration dossier to the new European Chemicals Agency in Helsinki, Finland. Those established outside the EU who manufacture a substance on its own, in preparations or in articles, formulate a preparation or produce an article that is imported into the EU, must appoint someone in the EU as their only representative for registration or mandate the importer.

METHOD

Thanks to their previous experience with Spanish leather industries, INESCOP carried out several Initial Environmental Reviews in Tunisian tanneries as a starting point of the environmental analysis. A questionnaire was then prepared to gather information on the most important environmental problems and CNCC technicians visited 17 Tunisian tanneries in order to assist them in filling in the questionnaire.

There is room for improvement on the way to sustainable leather manufacturing. Institutes and scientists worldwide work on improvements for curing, dehairing, liming, pickling and tanning. Local developments, such as the application of Reverse Osmosis in Tamil Nadu, try to find ways to spare precious drinking water. China is forcing its tanning industry to switch from raw/salted hides to wet-blue, wet-white or crust in order to avoid the water pollution and/or consumption.

Introduction

With the recently developed 'link-lock'1 theory the 'link' part of the reaction concerns the primary reactant, the main component that reacts directly with the collagen. All tanning reactions exhibit this part of the mechanism, which may involve any or all types of reaction: hydrogen bonding, hydrophobic bonding, electrostatic interaction and covalent bonding. The effects are twofold:

1. Introduction

The term 'ageing' refers to the combination of manifestations, both physical and organoleptic, that occur in leather after manufacture, particularly over time. R Segura1 found that one of these manifestations is yellowing, which may arise from the fatliquors used and/or synthetic retanning agents. In the case of fatliquors, the best test is that of temperature, while retanning agents are more likely to be affected by ultraviolet light.

Introduction

Since the early 1900s, soaking was regarded as an equilibrium process. Practitioners and scientists1,2,3,4 of the time recognized the importance of a thorough soak for the proper rehydration of hides and skins and soaking for two to three days was the norm. During the eighties, new insight provided improvements that promised faster and more effective soaking. In particular, Bienkiewicz5 and Alexander6 et al began to unravel the biochemistry of the non-collagen impurities that inhibit isolation of collagen for tanning. Identification of the glycosaminoglycans that retard the opening up process has led to a more direct approach to removal of these impurities.

The Problem

Barbed wire fencing is the most common cause of the thin scratches and scars affecting the grain surface of many cattle hides around the world. It is possibly the single most common cause of downgrading in the leather industry.

Introduction

About 60% of Indian tanning occurs in Tamil Nadu where there is a discharge limit for TDS of 2,100mg/l. In 2006 the TDS situation in Tamil Nadu (TN) became even more critical for the tanning industry than it was in 2005.

At Tanning Tech in Bologna Alpe Spak were featuring their Divididora Suprema splitting machine which is available for wet-blue/dry hides. There was a lot of interest shown in the machine which Alpe Spak say is entirely designed with the latest technologies and with high quality materials, with high performance, reliability and strict adherence to the latest health and safety regulations.

Also, requirements may vary around the world: for some 'eco-friendly' footwear is important. All these attributes have to be taken into consideration by retailers, footwear designers and leather manufacturers alike. The consumer's expectations are constantly moving upwards so, if want to make footwear that sells, innovation is crucial. In this article we look at how the leather industry is moving ahead with new and novel ideas for footwear leather.

The problem

Farmers need a method of permanently identifying their cattle. In fact it is compulsory in many countries and branding has been the tradition method of use for centuries. Ear tags are too easily lost and, like tattoos, can only be read at close quarters. Branding provides a quick, cheap and very permanent mark that is easy to read at a distance. But, whilst branding helps the farmer, it certainly does not help the leather which is left with scars and grain disfigurement.

It has been estimated that in Australia alone, 12 million cow pats1 hit the ground every hour! Multiply that to account for the world's cattle population and that's an awful lot of dung! But how does all this poo affect the leather industry? Well, it is difficult to know where to start because dung contamination of hides and skins causes so many problems for the tanner.

According to Maier, the chemical industry has by no means exhausted its potential. The latest developments even show that it is possible to improve fastness properties without sacrificing the natural qualities of the leather.

Hide defects and imperfections have always been problematic for tanneries seeking to maximise the usable area of leather crust. Surface defects influence the profitability of leather-making and present one of the biggest challenges to the tanners.

Introduction

TCIM are operating a state of the art primary treatment. The daily effluent volume of 150 m3 is screened, aerated and mixed in a balancing tank. This follows physical/chemical separation of solids involving coagulation, flocculation and sludge settlement. In this treatment step, coarse solids are removed and suspended solids as well as colloidal fractions are settled. The soluble organic fractions of the effluent are then treated in a sequence of seven horizontal reed beds with a total surface area of 450 m2.

Ringworm

Despite its name, ringworm is not caused by a worm at all. It is in fact a fungal infection that can be caused by three different types of fungi: Microsporum, Trichophyton and Epidermophyton. Collectively they are called Dermatophytes.

By obtaining the average moisture content of a pile of wet leather it is possible to better define the quantities of reactive chemicals needed. The Nuclear Magnetic Resonance has been improved as a promising solution to determine the moisture of the piled material.

Chrome tanned leathers contain chromium in valence state III (Cr III). The amount of chrome in the leather varies due to variations in production processes but for a shoe upper leather the chromium content is typically 4%.

Thema will be present in Tanning Tech where they will highlight their Dry-Flat continuous conditioning machine, the result of Thema System's long experience in the field of drying and natural conditioning of leather. The Dry-Flat line meets market requirements for a machine to dry or simply condition skins or hides which have varying moisture content at delivery and which, after conditioning, will have precisely controlled, uniform humidity and perfect flatness. This has been achieved by removing the moisture in a natural, unforced manner, with temperature and relative humidity parameters under constant control and management by PLC.

What are VOCs?

VOCs are carbon-based compounds that easily evaporate into the atmosphere. There are several forms of VOCs, some examples being:

* acetone

* trichloroethylene

* isopropyl alcohol

* methylethyl ketone

* white spirit

VOCs are commonly used in many industries for processes such as degreasing, thinning and dissolving. They can also be found in certain materials, such as paint, inks and adhesives.