New Santoprene integrated thermoplastic vulcanizate (TPV) systems from ExxonMobil have the potential to improve performance and recyclability while optimizing costs for glass run channel (GRC) weather seals. The systems are enabled by two new TPV grades that, when used together, are designed to replace EPDM rubber. Santoprene R² TPV includes post-consumer recycled (PCR) material and Santoprene High Resilience (HR) TPV offers elastic recovery performance comparable to EPDM, which can be difficult to recycle. For other mechanical properties, both grades deliver a similar performance to EPDM, said ExxonMobil.

Made with PCR material, Santoprene R² TPV can help improve the life-cycle impact compared with regular Santoprene TPV, while offering an optimized balance of performance and cost-effectiveness for the foot element of the GRC. Santoprene TPV scrap generated during weather-seal manufacture can be melted and remolded, reducing the amount of waste. When a vehicle reaches its end of life, components made with Santoprene TPV can potentially be recovered and recycled, further contributing to the customer’s circular economy model.

“Initiatives like the EU Green Deal and China VI are driving the automotive value chain to constantly consider how new sustainability objectives can be achieved. We are proud to build on our history of innovative solutions for the automotive value chain — working with Santoprene TPV, sustainability can now be instilled throughout the entire lifecycle of your vehicle,” said Dan Moore, Vice President, Specialty Elastomers and Butyl, ExxonMobil.

Santoprene HR TPV provides enhanced resilience, elastic recovery, and UV resistance for the lips and skins of the GRC. Frame-under-glass GRCs, which are popular in Europe and becoming increasingly so in Asia Pacific, are typically made with a metal frame and EPDM (ethylene propylene diene monomer) rubber. Now, the EPDM can be replaced with Santoprene TPV. Due to its performance properties, Santoprene HR TPV is a viable replacement for EPDM rubber currently used for semi-dynamic weather-seal applications; technical and commercial tests are in progress for use in dynamic weather seals.

“In the automotive weather-seals market, Santoprene TPV is acknowledged by the industry as being successful for static and less demanding semi-dynamic applications, while EPDM has been the material of choice for highly demanding semi-dynamic and dynamic seals. That is until now,” said Leslie Chan, Global SE&B Market Development Manager, ExxonMobil. “The improved performance properties of Santoprene HR TPV, including resilience and elastic recovery, unleash the potential use of TPV as an EPDM alternative for more-demanding dynamic applications.”

“In addition to the recycling potential, these system solutions support a reduction in weight for all types of vehicles by replacing metal reinforcement with PP and design flexibility,” said Jessica Vasquez, Global SE&B Product Technology Manager. “Material-related vehicle weight constraints remain one of the challenges to achieving even greater energy savings.”

“Appreciating these changes in the mobility market, ExxonMobil recognizes an opportunity for smart innovation, acknowledging that it takes many years of collaboration across the value chain to deliver shared value,” said Stephen Chan, Global SE Auto Market Development Manager. “Working with OEMs and Tier 1 suppliers, commercial tests are proving very successful, confirming that Santoprene HR TPV meets OEM specifications for highly demanding semi-dynamic weather-seal applications in a range of vehicles.”