Process Development and Characterization of a Locally Reinforced Thermoplastic Sheet Molding Compound

Composite materials are well established for lightweight applications in the automotive industry, with Sheet Molding Compound (SMC) being one of the most widely used composite types. However, the thermosetting resin system makes recycling difficult, which proves to be detrimental when facing the current trend towards sustainability and resource efficiency. The new acrylic ELIUM reactive thermoplastic resin system allows processing in SMC, providing a sustainable and resource-efficient alternative for SMC applications. Regarding part design, further weight reductions may be achieved by hybridization and functional integration. By co-molding continuously fiber-reinforced thermoplastics (Co-FRTP) with discontinuously fiber-reinforced thermoplastic (DiCo-FRTP) SMC, the benefits of the different material classes can be combined in a synergistic way. In this work, a process approach for the production of locally reinforced Elium SMC parts was investigated. Pultruded profiles and wet compression molded plates were co-molded with Elium-based SMC, respectively. The interfacial shear strength of those specimens was evaluated using the edge shear test, and a bench-scale fuel fire test was conducted to assess flame resistance. Potential applications in battery electric vehicles are discussed.