Pedestrian protection is a growing concern, especially as mega-cities around the globe experience population shifts to more walkable communities. Economic research shows people are moving into downtowns and suburban neighborhoods that offer convenient and safe access to shopping and employment opportunities within walking distance.
Couple this trend with regulatory action aimed to make vehicles safer for drivers and passengers, and automakers are responding with new technologies and design features offering better protection for pedestrians.
The automaker Volvo collaborated with Austria-based Polytec Car Styling to achieve these objectives. After multiple tests, they settled on crafting the engine cover using Elastofoam® I, a flexible polyurethane integral foam, by BASF. Not only does it achieve the desired pedestrian protection sought by Volvo, but it is also capable of being processed in a single step, making it a more cost-efficient option than traditional engine covers.
The engine cover’s ability to absorb the energy of an impact is due to its open-cell foam structure. It provides an additional passive safety measure for pedestrians in the event of impact against the vehicle’s hood.
The material on the front side forms a coherent skin with an attractive surface finish. The low density of the flexible visible part also offers good sound absorption and is resistant to temperatures of up to 150 degrees Celsius.
Typical engine covers are made using two materials resulting in a two-step production process. With an integrated lightweight flexible foam core and a rugged, yet compact pore-free skin, an Elastofoam® I engine cover can be made single step. Elastofoam® I also allows for a lighter engine cover, weighing 1.3 to 1.7 kilograms depending upon what model the engine cover is for.
Together, the companies were able to achieve a component with lightweight construction, functional integration and compliance with safety standards to meet Volvo’s objectives.
“When you look at engine acoustics, managing vehicle weight and strength, plastics technology is of great importance as a solution to meeting those demands,” said Andreas Stockheim, segment manager for powertrain and chassis with the Performance Materials Europe business unit at BASF. “It takes a high amount of technical expertise to develop or adjust the recipes to meet the customer requirements and with Polytec we’ve developed a part that optimizes not only the properties of the material, but its production and functionality.”
