DuPont (Wilmington, Del., USA) reports that an oil sump molded from DuPont Zytel nylon resin is helping the Swedish commercial vehicle manufacturer Scania meet new challenges with regard to noise, emissions and weight. The lightweight yet equally robust oil sump — the lower shell of the oil pan module — is among the host of innovative technical solutions incorporated by Scania in its new Euro 6 engines. It has enabled a reduction in the weight of the component by more than 50 percent, or 6 kg/13.2 lb, versus its aluminum predecessor to improve fuel economy and reduce emissions.
The application was produced in Sweden by the Plastal Group AB, a supplier of engineered plastics to the automotive industry, with the material, design and processing support of DuPont representatives in the country and across Europe and the input of prototype specialists Idé-Pro of Skive, Denmark.
The material used is a heat-stabilized, 35 percent glass-fiber reinforced grade of Zytel 66 nylon. The adoption of the DuPont material for this application — a first for the truck market and only the second development for commercial production vehicles worldwide following the launch of the award-winning Daimler oil pan module in 2008 — is expected to dampen engine noise to help meet Euro 6 noise emission standards.
According to the development team at Scania, their main reasons for choosing Zytel nylon were that it meets technical requirements when used in oxidized oil and still provides the necessary level of impact performance. Having settled on the initial design and material, Scania contacted Idé-Pro to undertake the first steps in the part's development.
Beyond material selection, DuPont also assisted Scania in refining the sump's design and the production process, particularly with regard to achieving a consistently tight seal between the sump and the engine. This required precise tolerance control of a large component, measuring 847 mm by 467 mm by 203 mm, achieved by comprehensive mold flow analyses, prototype testing and ongoing optimization of processing parameters.
The pan was tested at the DuPont European Technical Centre in Geneva, where an air cannon was used to fire steel balls at an angle of 45° and at a speed of 80 kph/50 mph at the sump. These tests confirmed that the ribs effectively dissipate the impact energy, becoming damaged in the process, while the structural integrity of the sump remained preserved.