Making automotive composites more sustainable is not only about changing the material. The new material must also be strong, formable and scalable, while enabling the production of large, complex geometries required by vehicle body components.

This demonstrator explores several routes built around flax-fibre composites, combining the natural-fibre reinforcement with polypropylene, a self-healing Elium® - based resin system and LIST-developed vitrimer systems. Different manufacturing approaches, including prepreg production, thermoforming and resin transfer moulding, are being assessed to determine how these material systems can be processed into automotive body panels.

The work has already demonstrated the complete processing route for flax/polypropylene, from prepreg manufacturing to the thermoforming of curved components. The vitrimer route adds another dimension: tests have demonstrated fibre and resin recovery, reprocessing into a new composite, thermoformability and even substantial recovery of mechanical properties through thermal healing. 

Rather than proposing a single material solution, the technology demonstrates how different sustainable material and manufacturing combinations can be matched to demanding automotive geometries and performance requirements and thus offers manufacturers more routes towards lighter, more circular composite body components.