A new electronic connector gasket molded from ethylene acrylic elastomer and polyamide in a multi-shot process reduces  assembly time by 30-40% and component cost by 25-40% compared with conventional gaskets and separate wiring harnesses.

The 2K technology employed is licensed exclusively to DuPont (Wilmington, DE) by Evonik Degussa GmbH (Hanau-Wolfgang, Germany) and allows direct bonding of elastomer and plastics to simplify assembly by eliminating the need for primer or anchoring. The new electronic connector gasket is molded by Dana Corp. (Neu-Ulm, Germany) from DuPont's Vamac ethylene acrylic elastomer (AEM) and Zytel polyamide resin. The combination reportedly offers enhanced part quality and reliability, even after heat and automotive fluid aging.

The seal of the integrated connector gasket, which includes both a wiring harness and power connectors, is made of Vamac AEM permanently bonded to the gasket body of Zytel nylon to provide long-term heat and oil resistance and to eliminate leaks. The particular grade of Zytel nylon 66 specified for the gasket body combines excellent mechanical properties with enhanced heat aging performance, hydrolysis resistance and improved oil resistance. Vamac AEM provides high sealing performance, low permeability and excellent resistance to oil and grease. Moreover, seals made of Vamac AEM are highly resistant to compression set and maintain long-term sealing force, so the gasket can be disassembled and reassembled for reuse.

"The greatest challenge was to seal metals, thermoplastics and rubber materials at the open window connector point. We worked closely with DuPont to modify the polymers and develop new process technology to create optimal adhesion between Zytel nylon and Vamac AEM throughout the gasket," says Berthold Schiele, sales engineer and project manager for plastic systems at Dana. "The adhesion of Vamac AEM to Zytel nylon exceeded our expectations. We subjected the bonded materials to a special pull force test, but the extra force necessary to separate the two far exceeded the actual operating conditions the gasket will meet in long-term service. Consequently, we can see considerable potential application for this technology and materials combination in the future."

The Dana gasket is the first to integrate the wiring harness and all fuel injector, plug, sensor and actuator/solenoid power connections. The result is a highly integrated unit, complete with pre-assembled wiring harness that can reduce assembly time by 30-40%, and eliminates the need to machine cylinder head holes, feed cables or control wiring direction. Accurate positioning of all power connections is assured, while yielding a 25-40% component cost saving compared with conventional gaskets and separate wiring harnesses.

In addition to undergoing a 150,000 mile in-vehicle endurance trial, the electronic connector gasket has met or exceeded all industry standard tests, including heat aging, and exposure to internal engine heat, oil and dynamic operating conditions. Its subsequent adoption by major players in the off-highway, construction, agricultural, stationary and marine diesel engine markets has been rapid. The first commercial installations in Europe took place from early 2010 in large diesel engines manufactured by MTU (Friedrichshafen, Germany), Deutz (Cologne, Germany), and Liebherr (Bulle, Switzerland), following exhaustive validation and field trials.-[email protected]