CLERMONT-FERRAND, France — Michelin Group is moving to convert more than 80% of the textile reinforcement adhesives it uses in tire manufacturing by 2025 to an in-house developed adhesive that's free of substances considered potentially harmful to humans.
The new adhesive was developed by ResiCare S.a.S., a Michelin subsidiary company that grew out of the tire maker's internal research and development departments.
ResiCare has developed an adhesive that is free of formalin and resorcinol, materials that have been judged to pose both health and environmental risks, Michelin said.
Michelin first disclosed the development of the adhesive in 2018, and its intention to start using it after nine-plus years of research and development.
The new resin adhesive uses undisclosed materials that take the place of resorcinol — an isomer of benzenediol that is used in combination with formaldehyde to create an adhesive. ResiCare has been granted over 40 patents on the technology, Micheln said.
Since 2018 Michelin has produced over 80,000 tires with the new resin.
To jump-start the conversion process, Michelin set up a mobile ResiCare resin production unit earlier this year at its Olsztyn, Poland, tire plant. Based on the Olsztyn model, ResiCare intends to set up other compact production units over the coming months in Europe and Asia, opening the way to an ambitious plan to deploy this textile reinforcement technology for all tire producers.
Michelin isn't alone in researching alternatives to resorcinol-based adhesives.
Continental A.G.'s tire division is collaborating with Turkish textile reinforcement maker Kordsa Tecknik Tekstil A.S. to develop a "sustainable" adhesion system standard for bonding textile materials to rubber-based compounds.
The ultimate goal is to develop a technology that would replace the substances resorcinol and formaldehyde with more eco-friendly chemicals and make the technology accessible to other suppliers and competitors, the companies disclosed in August 2017.
Since then Hanover-based Conti and Kordsa, have developed a plan to offer their development, dubbed "Cokoon" as a license-free, "open source" technology.
In 2020, the companies said the 70 companies that have expressed interest include a mix of tire manufacturers, converters, textile suppliers and mechanical rubber goods producers.
Separately, Michelin dislcosed that ResiCare has developed a non-toxic and bio-sourced glue that's being used to produce a range of "eco-responsible" plywood. The breakthrough is the result of a collaboration that began in 2018 between ResiCare and Arbor Groupe's Allin business unit.
The new product, dubbed R'PLY, uses proprietary technology based on Resi4 FIT glue, which cuts the use of formaldehydes in plywood by 60% versus comparable products, according to Michelin.