AKRON (Sept. 13)—Michelin North America Inc.´s polyurethanes business group and Dow Chemical Co. have signed an agreement to develop ring technology that is lightweight, strong, and cost-effective to use in the tire maker´s PAX System. The ring, an internal device used to support a deflated run-flat tire, likely will be made of polyurethane, according to Don Baldwin, Michelin Automotive Industry Division manager of new business. Dow will provide its materials processing, polyurethane and manufacturing expertise in the alliance while Michelin will handle design and test support, he said at the International Tire Exhibition and Conference, held Sept. 12-14 in Akron. Calling the integrated tire/wheel system a "novel approach to addressing the needs of auto makers and the driving public," Dow´s Peder Danielsen said the pact should accelerate development of the PAX System. The key for Dow will be to come up with a support ring that´s half the mass of the rubber ring presently in the tire, he said at the conference. Michelin "knows rubber inside and out; we know polyurethane inside and out," Danielsen said. "They´re helping to steer our technology in the right direction."