BMW sports car features DuPont Zytel polyamide
March 31, 2016 - United States Of America
The BMW i8 plug-in hybrid sports car features a resonator made of glass-fibre reinforced DuPont Zytel PLUS 95G35, tuned to reduce the typical high-frequency air intake sound to a lower level, so improving driving experience.
Zytel PLUS is a high-performance polyamide, produced with DuPont’s proprietary SHIELD technology which provides superior long-term resistance to high temperatures and aggressive fluids typical of under-the-hood applications. Due to its function, the resonator has a relatively large volume. With an optimised design in terms of wall thicknesses and the use of this high stiffness and high strength grade of Zytel PLUS, it weighs just 1.5 kg. Installed between the air filter and turbo charger in the rear of the i8, it is part of the air management system of the sports car’s compact 1.5 litre 3-cylinder petrol engine.
The resonator was developed by close collaboration between BMW Group, DuPont Performance Materials, and MANN+HUMMEL. The Tier-1 supplier makes use of its experience in hot-gas welding to assemble two injection moulded parts – the perforated interior tube as well as an outer tube measuring about 40 cm in length with integrated fittings for fuel tank ventilation and blow-by inlet – to create the broad-band resonator. An additional air duct including an elastic bellows segment, made of an unreinforced soft
nylon grade, is then mounted to connect the resonator to the air intake filter, while the system’s opposite end fits to the intake side of the turbo charger, according to a press release.
Florian Janiak, polymer specialist / global production strategy, MANN+HUMMEL said, “Zytel PLUS 95G35 performs well in such a hot and confined operating environment and what’s more, it retains most of its weld strength even after extended exposure to very high temperatures, where traditional materials would drop significantly. We also found it very easy to mould and weld in our hot gas process.”
Thomas Werner, global key account manager, DuPont Performance Polymers said, “Our collaboration with BMW Group and MANN+HUMMEL is another illustration of DuPont’s materials and developmental capabilities in partnership with automotive OEMs and Tier-1 suppliers demonstrating, as the resonator for the futuristic BMW i8 hybrid shows, leadership in advanced polymers such as Zytel PLUS for demanding under-the-hood applications.” (GK)