BASF has now developed a flexible polyurethane (PU) integral foam that can be used to produce lightweight engine coverings using a single-shot process. The so-called soft cover, made from Elastofoam I 4603, is manufactured by Austrian company Polytec Car Styling and fitted as standard in various car models with petrol engines made by Volvo.
|Foam PU with integral skin forms one-piece, sound-damping engine cover.|
The tailor-made PU foam Elastofoam I makes it possible to produce engine covers that are characterized by good sound absorption and thermal engine encapsulation says BASF. 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 said to be accurate in every detail and is printable. The part can also 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.
"Together with BASF, we have developed the part in such a way that material, production and functionality are optimally adjusted to one another. Moreover, we have achieved this in an unbelievably small amount of time. We can thus manufacture various geometries for different engine models and still simplify our logistics", says Christian Schobesberger, responsible for technical development at Polytec.
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.