Silicon Innovation Consortium for Leather Eco-friendly – SICLE2

Used since prehistoric times, leather is the oldest material invented by man to protect himself from external conditions. It has now become a popular aesthetic material for fashion and luxury. Today, more than two billion square meters are produced worldwide every year. Organised around a sector ranging from tannery to leather goods, footwear and furniture, the French leather industry employs more than 130,000 people in 100 different professions.

However, the leather industry must face societal, environmental and regulatory challenges that could trigger its decline if nothing is done.

A major and undeniable advantage is that leather is a natural material recycled from a waste product: animal skin from the food industry. However, the transformation of putrescible hide into rot-proof leather requires the use of chemicals. Metals, mainly chromium, are among the chemicals used. Although not dangerous, chromium III used for tanning (84% of tanned leathers) can oxidize to chromium VI creating a risk of skin allergy. Since 2015, REACh Regulation No. 1907/2006 has imposed a threshold of 3ppm for chromium VI in leather. Already low, this threshold could, in the coming years, even increase its value to 1ppm, making the manufacture of chrome leathers difficult to maintain.

Alternatives have already been offered to tanners. Tanning agents such as zeolite (aluminum silicate) give convincing results. However, aluminum, just like chromium and metals in general, suffers from a bad image in the eyes of consumers. In addition, leathers tanned with vegetable tannins do not meet the specifications of chrome-tanned leathers. Aldehydic tannins and other organic compounds are still struggling to find their place between regulatory constraints and market expectations.

As a CPDE, CTC's objectives are to support the leather industries in their search for technical, innovative, environmentally friendly and economically viable solutions to meet these challenges. The Objectives and Performance Contract, signed between CTC and its supervisory authority, the Directorate General for Enterprise (DGE), demonstrates this.

The SICLE2 Industrial Chair is an integral part of this approach. CTC, the University of Montpellier and BioWooEB CIRAD laboratory wish to combine their skills and obtain unique expertise in the chemistry of biomolecules, materials, agronomy and leather trades to unlock the technical barriers and enable the leather industry to be more sustainable and sustainable.

Structured around two axis of research, SICLE2 is based on a novel silicon-based tanning process (non-toxic) patented jointly by CTC and the University of Montpellier. The first axis concerns the development of efficient and environmentally friendly tanning methods as well as the development of new leathers with innovative functionalities. Silicon tanning also paves the way for easier recovery of tanning by-products, effluents, and the development of new materials. These aspects are the subject of the Chair's second major research axis, which may be of interest to other industrial sectors such as agriculture, agri-food and construction. These two lines of research will be nourished by a detailed understanding at the molecular level that will make it possible to unlock the obstacles encountered.

Twelve young researchers will be trained as part of SICLE2, thus consolidating a partnership with two engineering schools. Through dedicated training, SICLE2 will support the sector's players in changing industrial practice. Bringing together both economic and environmental issues, SICLE2 is positioned as a national reference to meet the expectations of the leather industry.