CLERMONT-FERRAND, France — Group Michelin and French biochemicals company Carbios S.A. have advanced tire sustainability efforts with the development of polyester tire fibers from polyethylene terephthalate (PET) plastic waste.
Michelin said it had "successfully tested and applied" Carbios' enzymatic recycling process for PET plastic waste, in order to create a "high tenacity tire fiber that meets its technical requirements."
Carbios' recycling process uses an enzyme capable of depolymerizing the PET contained in various plastics or textiles, including bottles, trays and polyester clothing.
Unlike mechanically recycled PET, the monomers resulting from Carbios' process can be repolymerized to achieve the high-performance grade required for pneumatic applications, Michelin added.
"The technical fiber obtained is of the same quality as the one from virgin PET, processed with the same prototype installations," it said.
The high-tenacity polyester is particularly suitable for tires, due to its breakage resistance, toughness, and thermal stability, Michelin noted.
"We are very proud to be the first to have produced and tested recycled technical fibers for tires," Nicolas Seeboth, director of polymer research at Michelin, said.
The reinforcement materials, he said, were made from colored bottles and "provide performance identical to those from the oil industry."
Michelin did not elaborate on how or to what extent it has tested fibers produced with Carbios' materials or how it will proceed with their production.
The "world-first" tire application for the materials brings Michelin one step closer to its sustainable ambitions.
The French group aims to source 40% of its tire materials sustainably (from renewable or recycled origin) by 2030 and 100% by 2050.
According to Michelin, 1.6 billion car tires are sold worldwide annually, consuming 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," it added.
Alain Marty, Carbios' chief scientific officer, noted: "In 2019, Carbios announced it had produced the first PET bottles with 100% purified terephthalic acid, 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."