Pushing the Fundamentals of Mechanical Composite Recycling

There are many materials and composites which are difficult to recycle and therefore have a negative impact on the environment if not disposed of properly. One example of this is fiber-reinforced composites consisting of a resin matrix and layers of reinforcement fibers such as glass or carbon fibers. International agreements such as the Sustainable Development Goals (SDGs) of the United Nations aim not only at humanitarian aspects but also, in the context, at ecological and sustainable approaches. SDG 7 (affordable and clean energy), 9 (industry, innovation and infrastructure) and 12 (responsible consumption and production), include action points in which the handling of materials plays an essential role. In the hierarchy of sustainability, the recycling of raw materials is second only to primary waste prevention and thus essential for sustainable production. An example of the need for an early recycling strategy for composite materials is the EU Commission’s draft on the future handling of end-of-life vehicles and recyclates in new vehicles (circularity requirements for vehicle design and on management of end-of-life vehicles) [1]. Nowadays, many specifications have only mentioned the demonstrability of closed-loop recycling, but have not required actual implementation. This means that many composite materials have been sent for thermal recycling, but this is not a long-term solution. Therefore, an “honest” assessment of the recyclability of such complex materials is only possible if an understanding of material behavior, degradation, and micro-level interactions is created. The approach presented in this proposal is to generate knowledge about fundamental material behavior and multi-scale interactions during mechanical recycling in order to evaluate the applicability of mechanical recycling to fiber reinforced composites. The overall goal of the underlying cooperation between the participating institutions is a holistic consideration of the recycling process of composites.