- Visible part: engine cover made from PU foam with the one-shot process
- Resistant to thermal aging up to 150°C
- Integration of acoustic and mechanical properties in one part
BASF has developed a flexible polyurethane integral foam that can be used to produce lightweight engine covers with the one-shot process, i.e. with one material in one process step. The so called soft cover, made from Elastofoam I 4603, is manufactured by the Austrian company Polytec Car Styling and fitted as standard in various car models with petrol engines of the Swedish automobile manufacturer Volvo.
Resistant to thermal aging up to 150°C
The sound-absorbing material for the flexible visible part is characterized by a low component density of 140 kg/m³, is dimensionally stable, media-resistant as well as resistant to thermal aging up to 150°C.
While the part has an open-cell foam structure on the bottom surface, the material on the front side forms a coherent skin with an attractive surface appearance. The surface is accurate in every detail and is printable. The part can absorb a lot of energy on account of the open-cell foam structure, thus increasing passive safety for pedestrians in the event of impact against the hood.
Integration of acoustic and mechanical properties in one part
Volvo currently uses the engine cover, which weighs from approximately 1.3 to 1.7 kilograms depending on the automobile model, in four different versions. The important thing is that the engine cover is light, shows good acoustic damping properties and has a high-quality surface. In comparison to conventional engine covers made of two materials, the elastic soft cover foamed in the cost effective one-shot process is able to integrate acoustic and mechanical properties in one part. This saves process steps during production, and better use can be made of the available space around the engine.