Fluoroelastomer Solves GM Transmission Warranty Issue

An automotive industry game-changing material that processes like plastic but has the flexibility of an elastomer is now being broadly used for a sealing application in General Motors transmissions.

“In this specific case, there had been thought to be but two choices; conventional plastic or

Fluoroelastomer replaces nylon in transmission sealing application. Phoro: SPE Automotive Division

conventional rubber,” says Rory Pawl, innovation and trend researcher manager for the Americas at the Freudenberg-NOK General Partnership (Plymouth, MI). “The plastics that had been used previously failed to seal and prevent electrical shorts.”  GM sought new material solutions because of warranty issues.

The new material is FluoroXyprene Fluorinated Thermoplastic elastomer that is said to bridge the gap between PTFE and rubber. Two-phase morphology allows for customization by adjusting the ratio of fluoroplastic and fluoroelastomer. Characteristics can also be changed by switching types of plastic and rubber.

As opposed to PTFE, FluroXyprene can be net shape molded. As opposed to rubber it can be molded in seconds as opposed to minutes. Freudenberg-NOK is the processor and the material supplier. Bosch is the system supplier. Molding takes place at the company’s Global Fluid Power Division Automotive Lead Center in Findlay, OH.

The new material is also described as highly chemical resistant, 100% recyclable and highly elastic. Creep resistance is improved compared to traditional thermoplastics. The function of the material is to seal metal leads on a transmission control module. “That design could not be produced without this material,” says Pawl.

FluroXyprene is also being used by other customers as a fuel hose liner. There are pending applications as a tip on a spray gun, O-rings, and coatings. Freudenberg-NOK is conducting internal invetsigatiosn on potential use as a seal on a rotating shaft, and a seal on a reciprocating piston.

“This allows for the first time a thermoplastic elastomer material to be used in demanding applications,” says Pawl. Nineteen US patents have been granted and more are pending.

The part is a finalist for SPE Automotive Innovation Awards. Winners will be announced Wednesday in Livonia, MI.

About Doug Smock

Former Chief Editor at Plastics World and Senior Technical Editor Design News
Automotive, Design, Elastomers, Injection Molding, North America, Polyamides , , , , ,

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