ExxonMobil has developed a sustainable alternative to EPDM-based glass-run-channel (GRC) weatherseals, the company has announced.
The new systems solutions consist of two new TPV grades that are used together: SantopreneTM R2 TPV, which includes post-consumer recycled (PCR) material and SantopreneTM High Resilience (HR) TPV, which offers elastic recovery performance comparable to EPDM. The former offers an optimized balance of performance and cost-effectiveness for the foot element of the GRC, while the latter provides the enhanced resilience, elastic recovery, and UV resistance needed for the lips and skins of the glass-run channels.
Due to its performance properties, Santoprene HR TPV is a viable replacement for EPDM rubber currently used for semi-dynamic weatherseal applications, plus technical and commercial tests are in progress for use in dynamic weatherseals.
"In the automotive weatherseals 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.
According to ExxonMobil, the use of TPVs can provide potential sustainability benefits such as reduced weight, more sustainable manufacturing and recycling versus other polymeric materials like thermoset rubber or EPDM rubber, which is difficult to recycle.
Santoprene TPV scrap generated during weatherseal manufacture can be melted and remolded, reducing the amount of waste. And, when a vehicle reaches its end-of-life, components made with the TPV can potentially be recovered and recycled, further contributing to the customer's circular economy model. Moreover, the new systems solutions also offer a reduction in weight by replacing the traditional metal reinforcement with PP.
"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," said Dan Moore, vice president specialty elastomers and butyl for ExxonMobil.