Leather is an animal skin having undergone a complex transformation process, namely via tanning, in order to make it rot proof. Materials which are not made from animal skin can therefore not be referred to as leather.
Key data
Nature of the fabric: : tanned animal skin
Global annual production : approximately 7 million megatonnes
Main producer countries :China, Italy, Vietnam (per order of production)
Source : Preferred Fiber & Materials Market Report 2021 - Textile Exchange
Properties of leather and application examples
The properties of leather vary according to the origin of the skin, the type of tanning employed and the finishings applied. Nevertheless, leather can have the following properties: Resistance - Suppleness - Thickness - Breathability.
Leather is used in:
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furnishings owing to its resistance.
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footwear for its resistance and breathability.
Can leather be recycled? Numerous projects are in progress to succeed in recycling leather. Nevertheless, for the moment, no veritable industrial solutions exist.
LEATHER WORKING GROUP (LWG)
This 400 member group has developed an environmental audit protocol for tanneries.
he tanneries audited by LWG are responsible for 16% of global leather production.
Choosing leather produced by the tanneries audited by LWG offers organisations a guarantee that the leather produced is more environmentally-friendly.
Source : Leather Working Group
ENVIRONMENTAL WATCH POINTS
Animal well-being
Pay attention to the origin of skin; animal welfare standards vary according to geographical zone.
Pollution of soils, water and air
Owing to the chemical products used for tanning.
Health risks
Pay attention to production and working conditions.
Significant water consumption
Pay attention to geographical origin as water management regulations vary.
Numerous stages are necessary to transform skin to leather
- Preservation of the skin (namely via salting).
- River work" to eliminate the epidermis, hair and fatty tissues as well as to clean the skins.
- Skins are sorted according to species / races, weight and quality.
- Tanning to transform the skin into leather thanks to tannins which are plant, mineral or combined substances used to transform putrescible skins into a rot-proof material, leather.
- Wrought ironing / Finishing : to transform tanned leather into finished leather, ready to be used
Source : Dossier Découverte Qu'est-ce que le cuir ? - Conseil National du Cuir
LEATHER PRODUCTION DIAGRAM
PLANT TANNING
Generally speaking, leather is tanned (transformation of skin into leather) thanks to mineral tannins, namely chrome. Nevertheless, other tanning processes exist such as plant tanning which is the oldest method. This process consists in using plant tannins, extracts of leaves or bark, to transform the skin into leather.
Plant tanning is complementary to mineral tanning. In effect, the finish of the material, both visually and when touched, can differ according to the type of tanning used.
Beware of the term "plant" however; this term does not mean that the environmental impact of the material is lower. As in all eco-design approaches, it is essential to analyse the environmental impact of the entire life cycle of a product and to compare the various scenarios in order to identify which scenario is the most environmentally-friendly (it is therefore not relevant to only compare two different materials, mineral versus plant).
"ALTERNATIVE" MATERIALS TO LEATHER
By definition, leather is animal matter. All of the materials known as "vegan" leather are therefore artificial and should be referred to as imitation leather. These materials are presented as alternatives to leather, although there is no certainty as to their durability - it is therefore inappropriate to compare their characteristics with those of leather. Care must be taken when choosing materials.
In effect, new materials of vegetal origin are emerging, namely: mushrooms, cork, hemp, pineapple, eucalyptus, apple …
It is frequently the "by-products" of these materials which are used in manufacturing: apple skins, pineapple leaves or hemp fibre residues.
These manufacturing processes therefore use a raw material which is basically waste from the food industry (like leather) or agriculture; the use of the vegetal product is therefore optimised.
Although these materials are of vegetal origin, it should be noted that they frequently use oil-based binders.
Source : Preferred Fiber & Materials Market Report 2020 - Textile Exchange
LEATHER-BASED RECYCLED MATERIALS
Leather-based recycled materials also exist, namely from tannery waste and production off-cuts. Examples:
- ELeather, an English company, which produces a material from tannery shavings /waste (tanned using chrome) to bind them (hydroentanglement) with an unwoven textile core. The material is then coated with polyurethane.Bonded leather, a material obtained from tannery shavings /waste (plant tanning) which is shredded and mixed with 40/50% of latex.
To find out more about leather-based recycled materials, consult the report: Recycled Leather - A primer for industrials to better understand alternative materials to virgin leather
