MPC, Inc. (Walworth, WI) is molding a complex multifunction distribution port for the new Nissan Altima that combines sequencing, precision timing, multi-slide actions, scientific molding, and robotics.
The metal-to-plastic conversion combines two parts into one assembly that acts as a manifold for the car’s cooling system. Use of thermoplastics, specifically glass-filled Amodel polyphthalamide (PPA), reduces component weight about one pound. Simplification of the assembly cut costs 25%.
The real engineering feat in the project was the incorporation of 10 ports into one tool for a part made with high glass (33%_ PPA.
The seamless barb ports feed coolant to and from the transmission cooler, throttle cooler, heater core, oil cooler, and also provide coolant to the radiator. The component, also described as a water outlet assembly, includes a press-in-place seal, sealed threaded insert, a wire harness bracket, and oil drip rail, and houses the thermostat.
The ten male ports are manufactured without use of a parting line in the tool. The processs works because of precision timing of multiple valve gates and multiple side actions. The tool was manufactured by the Industrial Molds Group (Rockford, IL). All of the shut-offs are nonplanar.
The PPA assembly eliminated 18 machining operations and two leak paths. According to Chip Robers, director of engineering at MPC, the part achieves machined metal tolerances out of the mold without secondary processes required. Annual volumes are projected at 800,000 pieces.
Amodel PPA-GF33 was chosen due to its long-term dimensional stability and higher elongation at demolding temperature. Amodel is a specialty polyamide (nylon) that has higher thermal capabilities and is stronger, stiffer and less hygroscopic. According to Solvay Specialty Polymers (Alpharetta, GA), it retains its excellent mechanical properties–including fatigue and creep resistance–over a broad temperature range in humid and chemically aggressive environments.
Miniature Precision Components (MPC), which was founded in 1972, specializes in complex under the hood components.
The water outlet assembly is a finalist in the Society of Plastics Engineers Automotive Innovation Awards program. Winners will be announced at a banquet in Livonia, Mich. Nov. 7.
