Lighter, Recyclable Body Seal from Cooper Standard Wins SAA Award

Among the benefits of FlexiCore’s lighter weight is less weight lifted per shift for assembly line workers, the company says.

March 1, 2025

Chris Clonts

Cooper Standard says its new product is so flexible that it is easier to install than traditional body seals. (Cooper Standard)

A lighter, colorable and fully recyclable thermoplastic body seal from Cooper Standard won the annual Innovations in Lightweighting Award given by the Society for Automotive Analysts.

The standard in the industry has been EDPM seals, represented on the left. Cooper’s new seal is made of thermoplastic vulcanizate. (Cooper Standard)

At the society’s December meeting, Jay Murdock, senior product development engineer for Cooper Standard, accepted the award and said its FlexiCore product was designed with an eye on strong trends in what OEMs want from suppliers: sustainability, carbon neutrality, lightweighting, and recyclability.

Traditional body seals around door openings, which have been around since the 1970s, are made of a metal carrier with an ethylene propylene diene monomer (EPDM) seal formed around it. EPDM is a versatile material used for everything from rubber roofing to coolant hoses and wiper blades.

“We’ve made improvements over the years, gone to micro-dense EPDM and moved to different types of lightweighting there, but it's just small, incremental improvements and you still didn't get to recyclability,” Murdock said. FlexiCore is made of 100% thermoplastic vulcanizate (TPV) and polypropylene materials. TPVs are a category of thermoplastic elastomer made of a rubber and plastic polymer mixture.

He said that the product carries such significant weight savings that in one study, the product shaved 44% of the weight of traditional seals when used on a four-door vehicle.

He said that in addition to being 100% recyclable and meeting strength and performance needs, it can be made in colors. Just as molded thermoplastic can be colored, so can FlexiCore, which can be molded or extruded. He said the new setup represented a 50% reduction in the weight of the carrier alone.

The material is not only more flexible than previous standards but stays in place better due to its greater extraction force. (Cooper Standard)

“We actually saved 44% weight savings on a four-door vehicle. That's taking that metal EPDM and replacing it with our thermoplastic FlexiCore,” Murdock said. “And by the time you look at all that, that was about a 50% weight savings just in the carrier alone. And then going to the TPV materials, we're able to really realize a total of 44% weight savings over the current EPDM metal carrier.

“So we have a low-density material. We have less energy-intensive extrusion process because we've gone from a thermal set EPDM, we've gone to 100% TPV, it's all thermal plastic. You shorten up your extrusion line, and you actually take 20% less energy to produce the part, and it reduces our carbon footprint.”

He said the material can be installed 20% faster and the lighter weight means a significant reduction in operator fatigue over the average 200-vehicle-per-shift assembly line. “We’ve got the person assembling the seals lifting a quarter-ton less during that shift,” he said.

Cooper Standard also said the product is also lower on VOCs and odors because much of the off-gassing occurs during the manufacturing process. Murdock said the product is currently being used on Tesla vehicles and a few vehicles in Europe.

Before announcing the winner, SAA judges Dave Andrea, a supplier-relations partner at Plante Moran and SAE International board member, and Abhay Vadhavkar, a consultant for Envorso, relayed the awards criteria.

Technical complexity. For instance, was it a reuse of an existing material or existing process and it just has a new home, or was it truly innovative?
Total savings of the product, quantified in cost, weight and overall number of parts.
Scalability. Can the whole industry benefit from it or is it a one-time thing?
Serviceability. For instance, a gigacasting solves complexity, but is generally more difficult to service. The entire lifecycle is considered.