GREENVILLE, S.C.-Michelin North America may have ``broken a barrier'' in scrap tire recycling, according to one industry observer, with a new technology that could enable new tires to incorporate up to 10 percent recycled rubber content without sacrificing performance. Michelin announced its technological breakthrough May 17 following lab testing of passenger tires made with fine crumb rubber from waste tires.
The research program was initiated 18 months ago at the urging of Ford Motor Co., which has been encouraging its suppliers to explore the use of recycled materials in their manufacturing processes.
Michelin's research ``clearly has broken a barrier'' for the recycling industry, according to Michael Blumenthal, executive director of the Scrap Tire Management Council. A major limitation to using recycled rubber in new tires, he said, was the adverse impact it would have on tire mileage.
Michelin said its technology permits the use of up to 10 percent recycled rubber content without sacrificing tire durability or driving performance.
Prototype tires have been tested in laboratories and on the road and next will be evaluated on a fleet of Ford luxury vehicles. Michelin anticipates the technology could be used in original equipment tires for Ford vehicles in about five years.
Both Ford and Michelin estimated that such a program could divert about 30 million scrap tires annually from landfills.
Incorporating old tire rubber into new tires isn't a new idea-most tire companies have investigated the possibilities, Mr. Blumenthal said, and some manu-facturers use a minimal amount in their tire production, usually with a maximum content of about 1.5 percent.
``Michelin has broken a barrier, not only in quantity but in application, that is in OE tires,'' Mr. Blumenthal said.
Michelin incorporated refined crumb rubber as a filler to replace some carbon black. The crumb was combined with elastomers, new rubber, new filler material and other chemicals in all parts of a tire, according to Clarence Hermann, Michelin's vice president of product engineering.
So far, results show there is no change in production costs, he added, but that could change if the technology is adapted to larger scale production.
Michelin said it will work to refine the tire formulation, plan manufacturing processes and begin long-term durability and quality testing with a fleet of Ford vehicles.
Last year Ford worked with Syntene Co. to patent a process of converting scrap tire rubber into a thermoplastic rubber for use in brake pedals on Ford vehicles. On the heels of this project, Ford asked Michelin to investigate a similar process to create reusable rubber compounds.
Bridgestone/Firestone Inc. said it also is researching the use of recycled material in new-tire production at Ford's request. ``Our tests and past experience show this is possible but that considerable testing is still required,'' a BFS spokesman said.
In 1990, BFS developed a farm tire made with scrap tire components, but the process was prohibitively expensive and the project was shelved.
In a statement issued in response to Michelin's announcement, Goodyear said it has developed compounds containing recycled tire rubber ``well beyond laboratory applications,'' but is aware of their limitations.
The company said it sees the expanding use of scrap tires as a supplemental fuel as the most viable current solution to the scrap tire disposal problem.
Michelin's results could be considered a testament to the developing scrap tire processing industry. Michelin's Mr. Hermann said the tire maker's current research project was possible in part due to improvements in processing scrap tires into a finer crumb.
Michael Rouse of Rouse Rubber Industries Inc., a supplier of ultra-fine rubber powder, praised Ford and Michelin, calling their research a major movement forward.
``What Michelin has done is a quantum leap in the marketplace.'' But, he added, recycled rubber suppliers will have ``a lot of work to do if it becomes reality.'' The crumb rubber industry will have to prove itself, he said, and meet the standards of the tire industry by producing consistent, high quality recycled material.