Asahi Kasei Plastics North America, Fowlerville, Mich., developed the Tenac-C ZSeries low-emission acetal copolymer for the seat-adjuster comfort mat in the lumbar support (pictured) for the 2011 Jeep Grand Cherokee. Injection molded by Brose Group, the component uses the new material to improve the vehicle’s interior air quality, and it shaved 400 g/0.88 lb off the weight of the lumbar-support mechanism. The new resin exceeded the new VDA 275 performance targets for low VOCs and provided natural lubricity so as to eliminate need for any grease or other lubricants.
Another new low-emission acetal is DuPont Delrin 300TE from DuPont Performance Polymers, Wilmington, Del. It’s said to be the company’s first impact-modified acetal to meet the most stringent VOC specs for automotive interiors. Independent testing reportedly showed formaldehyde emissions at least 50% below the limit set by leading German OEMs. With MFI of 6 g/10 min, the new grade bridges the gap between Delrin 100T (2 MFI), which combines high viscosity with very high impact resistance, and the medium-viscosity, stiffer Delrin 500T (112 MFI). Its high flow is suitable for thick-wall parts with long flows, such as struts for headrests—a key application target.
Delrin 300TE is said to be considerably tougher than Delrin 300PE, an existing low-emission grade. The new product has a notched Charpy impact strength of 18 kJ/m2 at room temperature (vs. 11 for 300PE) and 10 kJ/m2 at -30 C (vs. 8 for 300PE).