But there's another advancement that Shepherd is particularly proud of.
"Coming up with sustainable synthetic rubber, for me, that is the really cool thing," Shepherd said.
Michelin is tapping into technology that uses recycled styrene and bio-butadiene to create more sustainable synthetic rubber. That rubber, Shepherd said, was used in the 53-percent sustainable tire, so it's already proving that it could be a viable component for future tires.
"We are doing quite a bit of research to find solutions for not just producing tires in a conscious and sustainable fashion, but that synthetic rubber, which is typically a combination of styrene and butadiene, is sustainable," Russell said. "Now we can take waste products and turn that into bio-butadiene and recycled styrene cups—yogurt cups—and turn that into styrene for rubber."
Like others across the industry, Continental has added silicate from the ashes of rice husks and plant-based oils to its sustainable materials portfolio. But one of the company's crowning sustainable materials achievements is Cokoon, a sustainable adhesive technology.
Cokoon, Petschick said, is a "textile dip that replaces resorcinol and formaldehyde" in bonding applications between textile reinforcing materials and rubber compounds. Developed in partnership with Kordsa, the "open source" material science has been used in Continental's tire reinforcements since 2019. It will remain an important factor for the next-generation of sustainable tires.
And when it comes to recycled plastics, the German tire maker has found some success there, too.
"Continental is the first tire manufacturer who has started volume production of recycled polyester yarn, which is obtained from recycled polyethylene plastic bottles in a new process," Petschick said. "A set of standard passenger car tires uses the material from around 40 recycled PET bottles."
The recycled plastics technology, dubbed ContiRe.Tex, is used in three tire lines available in Europe—the EcoContact 6, PremiumContact6 and AllSeasonContact.