Compared to conventional die-cast or sheet-metal alternative materials, Arnite housings occupy less space, require fewer parts and assembly operations, and permit a wider range of design options to fit sculpted, space-constrained vehicle design. Further, in addition to reducing moulding cycle time, Arnite PBT’s lower density results in 10-13 percent less material consumption compared with other thermoplastics.
“Arnite provides excellent stiffness and notched impact strength,” said Richard Frissen, Application Development Manager, Automotive, DSM Engineering Plastics. “Overall cost reductions are possible, even on small details, such as moulded-in electrical contacts, not feasible in metal.”
Wiper assemblies encased in Arnite TV8 260 pass fatigue, creep, snow block and endurance tests. The material, specially designed for rear wiper motor housings and seat adjustment gear housings, has been adopted by automotive supplier Valeo for a range of Ford vehicles. Arnite TV8 260 has been formulated to optimise production, with viscosity, cycle times, weldability (especially hot-plate and vibration), compatibility with other resins, and weight, all tailored for maximum manufacturing throughput.
The new material joins six other Arnite PBT grades suitable for gear housings (with primary strengths parenthetically): in 30-percent glass-filled Arnite TV4 660 (low warpage, laser- weldable), Arnite TV4 261 (high flow; ultrasonic and vibration-weldable), Arnite TV4 261 CCT (cost competitive technology, ultrasonic and laser-weldable); in 20-percent glass-filled Arnite TV4 640 (low warpage, laser-weldable), Arnite TV4 240 (high flow; ultrasonic and vibration-weldable), and Arnite TV6 241 T (high toughness, acoustic properties). In polyethylene terephthalate (PET), DSM offers Arnite AV2 372 (dimensional stability, stiffness) and Arnite AV2 390 (high stiffness).
Arnite thermoplastic polyesters (PBT and PET) are a focused line of materials with exceptional mechanical, electrical, and thermal properties with very good chemical resistance and dimensional stability. The Arnite family includes unreinforced and glass-fibre-reinforced grades, as well as special grades designed to minimise warpage and maximise impact strength or optimise surface quality. In addition to gear and motor housings, automotive applications include fuse boxes, sensors, lamp reflectors, grilles, door handles and roof racks; in lighting Arnite is employed in lamp bases and connectors; and for compressor components and electronic part housings.
