A high-flow heat-stabilized glass-fiber-reinforced nylon is being applied in a commercial production vehicle’s oil-pan module for the first time. Daimler’s Mercedes-Benz C Class utilizes DuPont’s Zytel 70G35 HSLR nylon for the lower shell of the oil pan, with the thermoplastic allowing added functionality through an integrated oil deflector to calm oil stirred by the crankshaft, as well as high ribs in the sump that act as baffles, settling oil and directing it toward the sump. The lower Zytel shell is paired with a die-cast aluminum upper shell by automotive supplier Bruss, with the hybrid design saving 1.1 kg in weight compared to a fully aluminum system.
In addition, the material’s high level of flow reportedly allowed long flow distances, short injection times, and consistency in thin-walled sections. The processor adds that the material’s suitability for vibration welding boosts productivity. The pan’s rear section forms a sump for approximately 6 liters of oil and is rigid in shape, while the front is flatter, so that its resistance to bending is relatively low and it required design features to minimize warpage and eliminate the potential for oil leaks at the joint with the aluminum upper shell.
Zytel 70G35 HSLR’s high melt flow meant a single, central gate completely fills the mold cavity, allowing fast cycles, reduced tool costs, and simplified process control, while also minimizing the number of weld lines and risk of air entrapments.
At DuPont’s Technical Centre in Geneva, the pan endured test that simulated the combined engine and transmission being dropped by a fork-lift. Prototype component testing at Bruss showed that even after 1000 hours of aging in hot oil at 150°C, the pan withstood test conditions without critical damage.
Given the success of this program and the functionality of the plastic involved, DuPont posits that future oil pan models could include the oil pick-up pipe, oil level switch, oil filter, other oil return components, or oil pumps. In addition to being nominated for the Society of Plastics Engineers Most Innovative Use of Plastics Award in the powertrain category of its annual automotive awards, the Part was featured in Friedrichshafen, Germany at the Fakuma event. DuPont; www.dupont.com.