Trelleborg, Celanese develop CR-free automotive sealing boots

Dusseldorf, Germany – Celanese Corp. and Trelleborg Group have developed a new generation of ball joint sealing boots using thermoplastic elastomers.

The partnership introduces a shift from traditional chloroprene rubber (CR) to Celanese’s Hytrel-branded thermoplastic copolyesters (TPCs), Celanese announced during the K rubber & plastics show held in Dusseldorf earlier this month.

The switch to the materials, said Celanese, enables “a complete redesign of the sealing boot.”

For instance, manufacturers may eliminate the need for metal clamping rings, further reducing complexity and weight.

This, said the materials major, can unlock “significant advantages” in manufacturing efficiency, part performance, and environmental impact.

Ball joint sealing boots are essential components in steering and suspension systems.

Their use is increasing, particularly in electric vehicles equipped with double wishbone suspensions.

According to Celanese, the transition to Hytrel offers benefits such as cost efficiency, as the “multi-cavity” injection moulding of the elastomer reduces part costs by at least 10% compared to CR.

Furthermore, the materials can help with weight reduction as the TPC provides higher stiffness compared to CR, but allowing for thinner wall designs.

This, according to Celanese, results in parts that are 10–20% lighter overall.

The TPC material also eliminates the need for post-curing or cross-linking, and thereby simplifying the manufacturing workflow.

Scrap material from the TPC can also be reground and reused, supporting circular production practices.