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Science and Technology in the Leather Industry

Contributions towards sustainable development by European tanners


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What Is The Tanning Industry?

Tanning hides and skins is one of mankind’s oldest trades.
It began when primitive man realised there was more value to an animal than food. Our prehistoric predecessors used the hides and skins of large mammals for clothing that protected them from adverse weather conditions. However, left untreated, the hide or skin of an animal quickly begins to rot, putrefy and smell. So our ancestors found ways to stop this natural process so their clothing didn’t become unwearable, if not unbearable. Just think how those early discoveries happened. After a hide lay out in the sun for a few days, it became stiff and hard, but the offensive smell disappeared.

Picture: Heritage Museum

An important prehistoric advancement was smoke tanning. Hides and skins were used as building material for tents and huts. The smoke from the fireplace preserved (tanned) the hides and increased their resistance to the elements. This method was utilized extensively by Native Americans for their teepees and wigwams, and remains popular today in some parts of China.

Another successful invention was vegetable tanning. It probably started when hides were placed in a pool of water surrounded by trees. Pieces of wood, bark and leaves floated in the pond which contained natural “agents,” or chemicals, that tanned the hide. This type of treatment dominated the leather industry until the 19th century when the chrome tanning process for leather emerged.

 During the Middle Ages, tanneries became well-organised. They gathered in special areas where raw materials (hides and skins, access to water) were present in large quantities. Many tanneries have been located in the same areas in Europe for more than 500 years.

There weren’t many changes in leather manufacturing from the Middle Ages through the end of the 17th century. But advancements in chemistry in the 19th century were vital to the development of the industry, especially chrome tanning, which utilizes salts of chromium to tan the animal skins and hides, as well as the use of enzymes and many other discoveries.

At first, the science of leather tanning was accidental. Yesterday, tanning harnessed the best practices of an agrarian craft and transformed it into a modern industry. Today, research and development is a systematic process that maximises the benefits of animal hides and skins as an important natural resource while minimising stress on the environment.

Tomorrow, the European leather industry will continue to develop innovative clean technologies that bring sustainable solutions to complex ecological, safety, aesthetic and performance challenges.

Picture: LGR

The European Leather Industry

The leather industry in the European Union (EU) consists of approximately 3,000 tanneries that directly employ some 50,000 people. It embraces primarily small and medium-sized tanneries. The tannery industrial sector in Europe is present in all the European countries except Luxembourg, although the majority is concentrated in Southern European countries. Certain regions and municipalities within the EU member states retain characteristic concentrations of tanneries, whose socio-economic life heavily depends on this sector's activity.

Europe is an important player in the international leather trade, providing 25 percent of the world’s leather production and one of the largest and most dynamic consumer markets for leather articles.

With revenues of nearly 8 billion Euros, the tanners in Europe are very competitive in the global leather market. EU tanneries have a long tradition of producing a wide variety of leather, from bovine and calf leather to sheep and goat leather, from sole and exotic specialities to double-face garment leather. Centuries of experience and the outstanding know-how of European tanners and dressers create continuously strong demand for their products.   

For a comprehensive explanation on the manufacturing of leather, check out our special page.

Environmental Advancements in the Leather Industry

Cleaner water, better environment
Leather is usually tanned with chromium, or “chrome”: the chemical element used to coat other metals with a shiny finish that does not tarnish. Tanning hides with chromium salts produces soft, supple leather that can be dyed in a wide range of colours. By reducing the quantity of these salts to the precise amount required to maintain the quality consumers expect in a leather product, the discharge of chromium into the water used to process hides has been reduced by more than 90%.

Water worth waiting for
Large amount of water were once a significant part of many leather tanning processes. However, since water has become a scarce resource in some parts of Europe, the leather industry has done its part to re-engineer its once-wasteful ways.
For the past few decades, science has helped the leather industry reduce its water consumption by more than 60 percent. This has been achieved by the development of new cleaning techniques, the use of batch processes instead of rinsing, and better water management.

An energetic alternative to waste byproducts
Only 20% of the mass of an animal’s hide is converted into leather. Today, the excess fat and tissue left over from the tanning process is converted in “biogas” plants that utilize a fermentation process to change these effluents into an alternative source of fuel. Technologies have also been developed to convert untanned hide and skin trimmings into organic byproducts like gelatine, glue and other protein products.

Air that cares
Unfortunately, the leather industry can be a factor in less-than-desirable air quality near local tanneries. One of the problems for the industry has been the use of organic solvents in the finishing stage of the manufacturing operations.
Science has helped the leather lower the emission of organic solvents to the air by 90 percent for most leather types. This has been achieved by the introduction of improved systems combined with new environmentally friendly finishes.

Hair today, organic fertiliser tomorrow
In leather manufacturing, one of the first steps is the removal of hair from the hides using a disintegration agent such as sulfide. This organic waste accumulates in the wastewater sent to the local purification plant.
Science has developed a new process that reduces the residue from unhairing by 50%. Instead of dissolving the hairs from the hides, they are kept intact so they can be used as fertiliser by farmers, thereby reducing the use of synthetic alternatives for helping crops grow.

Scientific Advancements Add New Qualities To Leather

Leather is a natural material with unique properties that make it the preferred choice for crafting thousands of products in addition to traditional applications in upholstery, shoes, garments and luggage.

The main difference between leather and synthetic materials is that leather can "breathe" and shape itself over time to the wearer.  High-quality leather also offers the ability to absorb moisture without feeling wet.  For example, the human foot produces between three and five centilitres of sweat every day.  Forty percent of the sweat will disappear, while the remaining moisture should be absorbed by the shoe so the foot doesn’t feel wet.  Leather is the best material for this purpose.
Leather also resists a nearly infinite amount of bending and delivers excellent elasticity.  This is an important comfort factor for the top part, or “upper,” of a shoe since the foot swells during the day.

The quality of finished leather depends on a combination of the original properties in the natural hide, and the chemical and physical components added during the manufacturing process.  New technologies are being invented every year that make leather more versatile, more colourful and more appealing as an alternative to woven fabrics and plastic.

Hot stuff
Special chemical treatments can enhance the fireproof qualities of leather to supplement its natural heat resistance properties.  This increases the safety of using leather in applications where fire resistance is important like movie theatres, salons, cars, aeroplanes and upholstery.  Fireproof leather can even be used for common products like potholders that adhere to any surface for a better grip.

A rainbow of choices
Purple leather?  Advancements in the finishing processes make it possible to produce leather in any colour you can imagine in addition to traditional shades of brown and black.  Many internationally recognised designers are choosing leather to replace synthetic and dyed fabrics in stunning new designs.  From futuristic chic to natural glamour, leather is fast becoming the first choice for apparel that’s soft, stunning and sexy.  Even protective clothing made from leather has become stylish, with a fit and finish that’s as appropriate on a Parisian fashion runway as an airport runway.

Designers are also using leather for their latest products, working closely with tanneries to develop leather with unique new properties like water resistance, not to mention a rainbow of colours, textures and finishes that look and feel right in any room.

A new kick
When it comes to sports equipment, nothing can match the strength, abrasion resistance, durability and flexibility of leather for footballs, equestrian harnesses, sport gloves, baseball mitts and the safety equipment worn by athletes everywhere from the jogging track to the ski slopes.  It’s no accident that motorcycle enthusiasts rely on leather for their outerwear…it’s the ultimate in protection from the elements, not to mention the asphalt.

Just like mom

When babies are born, the infants are often laid on a blanket made of…leather!  The soft, warm qualities of leather are far superior to other materials for the critical moment when the child is first separated from its mother.  This particular kind of leather must be “baby-proof” through careful selection and processing to make it soft, safe and comfortable.

Picture: The Celtic Sheepskin Company

The Future Of The Leather Industry

To prosper in the future, European tanneries must remain at the forefront of technological development. It is imperative that they establish co-operation within the EU and continue to participate in future R&D activities. The European leather industry and scientists working for the industry are committed to reducing the environmental impact from the tanning process, and also to improve the quality of the product.

The Tanweek brochure provides some examples of the benefits of science on this ancient craft. There are many more tanning technologies that have been substantially improved in recent years; the leather research institutes in all European countries can provide more information about these breakthroughs.

Over the course of the last two decades, the European
leather industry has developed innovative clean technologies bringing sustainable solutions to complex problems, in accordance with the guidelines established by the Rio Conference in 1992. European tanners will move ahead with sustainable development efforts after the UN World Summit for Sustainable Development held in 2002.

The combination of science and the leather industry will continue to improve the environmental performance of the industry, and thereby improve the quality of life for European citizens.

Wet and wild
Today, most leather clothing has to be dry cleaned by professionals. In the future, scientific advancements will allow you to wash some kinds of leather in an ordinary washing machine.  Some kinds of leather are so water-friendly, you can even relax in leather swimwear at the beach.

Picture: Nasa
To infinity and beyond

Leather has played an important role in man’s conquest of space.  Its superior breathability, flexibility and corrosion resistance makes it ideal for gloves, boots, helmets and other mission-critical spacesuit applications.  Other surprising new uses for
leather are being invented every day, thus assuring that nature’s finest fabric will continue its remarkable history well into the future.

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