DiDe4Rec

Digital Design 4 Recycling process for fiber-reinforced lightweight structures

The amended End-of-Life Vehicle Directive of the EU significantly increases the requirements for a higher use of recycled materials in new vehicles. Particularly for fiber-reinforced thermoplastics, raising the recyclate share poses considerable challenges, since volatile material streams and fluctuating material properties make the reliable design of structural components more difficult. A contribution to addressing these challenges was made by the BMWE research project DiDe4Rec, which was successfully completed at the end of 2025. The objective was to develop a holistic design approach for circular lightweight products made of fiber-reinforced thermoplastics that considers not only technical and economic but also ecological aspects of circularity throughout the development process. ILK focused on the material reuse of mechanically recycled short-fiber-reinforced injection-molded components. In this context, a prediction model was developed that captures the influence of different recyclate qualities and contents on the properties of short-glass-fiber-reinforced injection molding compounds. This makes it possible to estimate material properties as early as the initial stages of the development process. These results feed into the BMFTR project Pro-gRec, which started at the end of 2025 and aims to make property prediction applicable to unknown recyclate streams in the future. Within ProgRec, ILK is developing an AI-based prediction tool that quickly and efficiently derives rheological and mechanical material cards for process and structural simulation, even under batch-to-batch variations of recyclates.