Thermoplastic composites in structural lightweight applications: Potential of unidirectional fiber reinforcement and sandwich structures

Thermoplastic fiber composites are suited to a wide range of application areas due to their broad property profile, which ranges from standard to high-performance polymers combined with highly technological and automated production processes such as injection molding. By incorporating discontinuous fiber reinforcements into the polymer matrix, all areas of the part are nearly equally reinforced. With local continuous reinforcements it is possible to reduce fiber use to the most highly loaded areas of the components. This method, which draws on principles applied in nature, strengthens the parts with only a slight weight or even no weight increase compared to non-reinforced parts. The combination of injection molding as a process for large-scale production with the excellent mechanical properties resulting from continuous-fiber-reinforcements enables the production of high-strength components at reasonable cost. This paper presents the investigations of process developme nts with injection molded components in combination with wound and planar fiber structures. Fundamental experiments are presented with tensile loaded structures in the first case and flexural loaded structures in the second. The results lead to a better understanding of the influence of local continuous-fiber reinforcements and their applicability in structural components