Michelin reports it has successfully validated the use of Carbios’ enzymatic recycling technology for PET plastic waste in its tires. Carbios confirms the potential of its recycled PET to address all types of applications – from bottles to clothing fibers and now technical fibers.

The validation of Carbios’ technology in Michelin’s tests, marks a new step towards 100% sustainable tires.

PET (PolyEthylene Terephthalate) is a petroleum-based plastic wherein the monomers used, ethylene glycol and terephthalic acid, come from the transformation of petroleum. PET is the raw material for one of the main textile fibers used in tire reinforcements.

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 taken a major step towards developing 100% sustainable tires. Michelin has successfully tested and applied Carbios’ enzymatic recycling process for PET plastic waste, in order to create a high tenacity tire fiber that meets the tire-giant’s technical requirements.

Enzymatic recycling – PET to new tires

Carbios’ enzymatic recycling process uses an enzyme capable of depolymerizing the PET contained in various plastics or textiles (bottles, trays, polyester clothing, etc.). This innovation, reportedly, allows infinite recycling of all types of PET waste. It also allows the production of 100% recycled and 100% recyclable PET products, with the same quality as if they were produced with virgin PET.

The application of PET enzymatic recycling in car tires: a pioneer

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 colored and opaque plastic waste such as bottles, once repolymerized in PET, made it possible to obtain a high tenacity fiber meeting Michelin’s tire requirements.

The technical fiber 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 tires, due to its breakage resistance, toughness, and thermal stability.

“We are very proud to be the first to have produced and tested recycled technical fibers for tires. These reinforcements were made from colored 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 tires into a true circular economy. Michelin is committed to achieving 40% sustainable materials (of renewable or recycled origin) by 2030 and 100% by 2050.

The potential of Carbios’ process confirmed

According to Michelin, this event constitutes a very significant step in the global tire manufacturing 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 tires are sold worldwide (by all tire manufacturers combined). The PET fibers used in these tires represent 800,000 tons of PET per year.

When applied to Michelin – this represents nearly 3 billion plastic bottles per year that could be recycled into technical fibers for use in the company’s tires.

“In 2019, Carbios announced it had produced the first PET bottles with 100% 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 fibers, such as those used in Michelin’s tires,” said Alain Marty, Carbios’ Chief Scientific Officer.

Original press release by Michelin.