French companies Carbios, Michelin move close to sustainable tyres
May 05, 2021 - France
Carbios, a company pioneering new bio-industrial solutions to reinvent the lifecycle of plastic and textile polymers, and Michelin, a leader in sustainable mobility, have moved closer to developing 100 per cent sustainable tyres. Michelin has validated Carbios’ enzymatic recycling process for PET plastic waste, to create a high tenacity tyre fibre.
Carbios’ enzymatic recycling process uses an enzyme capable of depolymerising the PET contained in various plastics or textiles (bottles, trays, polyester clothing, etc). This innovation allows infinite recycling of all types of PET waste. It also allows the production of 100 per cent recycled and 100 per cent recyclable PET products, with the same quality as if they were produced with virgin PET.
Michelin has successfully tested and applied Carbios’ enzymatic recycling process for PET plastic waste, in order to create a high tenacity tyre fibre that meets the tyre-giant’s technical requirements. The application of PET enzymatic recycling in car tyres is a world first.
Conventional thermomechanical recycling processes for complex plastics do not achieve the PET high-performance grade required for pneumatic applications. However, the monomers resulting from Carbios’ process, which used coloured and opaque plastic waste such as bottles, once repolymerised in PET, made it possible to obtain a high tenacity fibre meeting Michelin’s tyre requirements.
The technical fibre obtained is of the same quality as the one from virgin PET, processed with the same prototype installations. This high tenacity polyester is particularly suitable for tyres, due to its breakage resistance, toughness, and thermal stability.
“We are very proud to be the first to have produced and tested recycled technical fibres for tyres. These reinforcements were made from coloured bottles and recycled using the enzymatic technology of our partner, Carbios,” said Nicolas Seeboth, director of Polymer Research at Michelin. “These high-tech reinforcements have demonstrated their ability to provide performance identical to those from the oil industry.”
Carbios’ enzymatic recycling process therefore enables Michelin to get one step closer to its sustainable ambitions, and contributes to the entry of tyres into a true circular economy. Michelin is committed to achieving 40 per cent sustainable materials (of renewable or recycled origin) by 2030 and 100 per cent by 2050.
This major step constitutes a world-first in the tyre sector and confirms the potential of Carbios’ process to engage the industry in a responsible transition towards a sustainable circular economy model.
Every year, 1.6 billion car tyres are sold worldwide (by all tyre manufacturers combined). The PET fibres used in these tyres represent 800,000 tonnes of PET per year. When applied to Michelin – this represents nearly 3 billion plastic bottles per year that could be recycled into technical fibres for use in the company’s tyres.
“In 2019, Carbios announced it had produced the first PET bottles with 100 per cent Purified Terephthalic Acid (rPTA), made from the enzymatic recycling of post-consumer PET waste. Today, with Michelin, we are demonstrating the full extent of our process by obtaining from this same plastic waste, recycled PET that is suitable for highly technical fibres, such as those used in Michelin’s tyres,” said Alain Marty, Carbios’ chief scientific officer.