Michelin successfully tested and applied Carbios’ enzymatic recycling process for end-of-life polyethylene terephthalate (PET) to create a high-tenacity tire fiber that meets its technical requirements.
Carbios’ enzymatic recycling process uses an enzyme capable of depolymerizing the PET in various plastics or textiles (bottles, trays, polyester clothing, etc.), allowing the production of 100-percent-recycled products with the same quality as if they were produced with virgin PET. Additionally, these products would be fully recyclable, according to a news release from the companies.
They say conventional thermomechanical recycling processes for complex plastics do not achieve the high-performance PET grade required for pneumatic applications. However, the monomers resulting from Carbios’ process, which used colored and opaque postuse plastic, once repolymerized into PET, made it possible to obtain a high-tenacity fiber that meets Michelin’s tire requirements.
The technical fiber obtained is of the same quality as the one from virgin PET and is suitable for tires because of 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,” says Nicolas Seeboth, director of Polymer Research at Michelin. “These reinforcements were made from colored bottles and recycled using the enzymatic technology of our partner, Carbios. 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 of achieving 40 percent sustainable materials (of renewable or recycled origin) by 2030 and 100 percent by 2050.
According to the companies, 1.6 billion car tires are sold worldwide (by all tire manufacturers combined) annually. The PET fibers used in these tires represent 800,000 metric 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 percent purified terephthalic acid made from the enzymatic recycling of postconsumer PET waste,” says Alain Marty, Carbios chief scientific officer. “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.”