Bumper in thin-wall technology: an update regarding materials, processes, and technology innovations

摘要

There has been continuous further development in the integration of functions and thus the demands made of bumper fascias. From an independent system for preventing minor damage they have grown into a form-integrated styling element with expanded demands made of aerodynamics, passive safety and sensors. This has also meant that the number of components to be integrated has steadily increased. System weight has risen significantly, especially in the case of so-called 'soft nose' models which have taken over parts of the bonnet and fenders. The present contribution deals with the subject of how worthwhile weight reductions can be achieved through the wall thickness reductions made possible by new, improved types of polypropylene (PP) with greater flowability and stiffness. Paint specifications and the quality requirements of a Class A surface must, of course, be satisfied with no compromises. Accordingly, the applicability of new developments in ultrasonic welding to series production was specifically investigated and further development work carried out until series production readiness.