Industry sector: Body Panel Exterior

Part design:

Bodywork parts made from plastic are all the rage. By and large, they are far lighter than their metal counterparts. Plastic also opens up greater design possibilities, enhanced by cost-saving modular construction. Finally, plastics can be penetrated by antenna signals.
Glass-fiber or mineral-reinforced thermosets and thermoplastics are normally used to produce structural components for the bodywork. Reinforcement is necessary to ensure sufficient strength. However, Class A surfaces can only be obtained with considerable outlay, mainly because of the high proportion of filler. This problem has been resolved in stateof-the-art designs using thermoformable plastic films.
These are used as covering material or as a support for the coating and are back-injected or back-filled during the production process. We have devised customized film systems for designs of this type which are already used in series production and development projects.

The polycarbonate-based films Makrofol® DE and Makrofol® DP 1231 are intended for horizontal, temperature-stressed components. Makrofol® DP 1231 is a twin-layer film, made from PC on one side and a PC/ABS blend on the other. Bayfol® DF-A (ABS film) is suitable for vertical, less thermally stressed components.
Our films can be undercoated or coated with an appropriate paint film (paint film technology). For automotive manufacturers, this opens up a cost-effective alternative to bodywork or off-line coating of individual components, which is costlier and makes greater demands on environmental technology. A coating system with a color basecoat and a clear topcoat, which often has two layers, is used for undercoated films, and is not finally hardened until after the film is thermoformed.

Films can either be back-injected by the Film Insert Molding (FIM) process using thermoplastics or back-filled with long fiber-reinforced polyurethane systems or structural reaction molding (S-RIM) polyurethane systems. Makrofol® DP 1231 is particularly suitable for back-injection technology as the twin-layer structure ensures excellent adhesion to the paint and the polyurethane substrate.

We help our customers to develop bodywork parts through our comprehensive service – for instance, with simulation tools for designing components and Technical Service Center facilities for back-injection and back-filling. When it comes to materials, our partners benefit from the know-how that Bayer MaterialScience offers as one of the world’s leading manufacturers of polyurethane systems, polyurethane coating raw materials, and thermoplastics.