Project SuMa focuses on product development of sustainable composite materials on different levels (biobased, natural fibres, reclaimed fibres) for the additive manufacturing technology. The objective of the project is to develop these new types of materials, related to an aerospace, an automotive, and a sporting goods use case. The study is rounded-off with a life cycle analysis of dedicated benchmark applications.

SuMa experimentally investigated the development of short fibre reinforced 3D printing filament with various reclaimed carbon fibre content, as well as the development of a continuous tape filament with reclaimed carbon fibre. The engineering plastic material (PA11-CF, Tg=42°C, Tm= 180°C) [6] and a high-performance plastic material (PEI-CF, Tg=145°C, Tm= 320°C) were enabled for additive manufacturing. In combination with reclaimed carbon fibre, short and high oriented composite materials were developed, characterized and used in the three end user applications.

Quasi-static tensile tests demonstrated that an increase in fibre content leads to an increase in tensile strength and stiffness, see Figure 2. The 3D printing process helps the re-alignment of short fibres, resulting in a 10% increase in tensile strength. Thereby the recycled carbon fibres showed nearly the same properties as their virgin counterpart. Compounds with 35w% carbon fibre were possible.

The project broadened the scientific understanding of discontinuous fibre topology (natural fibre or rCF) related to additive manufacturing. Process related parameters could be related to the mechanical performance of the final component. The findings of this project promote the holistic design-for-circularity approach and a shift towards carbon neutral production of composites.