Title awarding university: Leibniz University Hannover

Cooperation: AUDI AG

Title of the doctoral project: Systematic investigation of the recyclability of combinations of different plastics

Short description of the doctoral project: Plastic components often consist not just of one type of plastic, but of a combination of several. In the automotive industry in particular, different plastics are used together due to their individual suitability for certain applications. Interior parts, for example, often consist of a hard carrier plastic and a softer, haptically appealing plastic on top. Common joining techniques such as gluing or back-injection lead to a permanent material composite that cannot be separated again, or only with disproportionately high effort. It is often no longer possible to recover the plastic types from the affected old components by dismantling or using post-shredder technologies. These composites are only used for low-grade downcycling applications or for thermal recycling. In contrast, the possibility of recycling inseparable plastic composites together in order to feed them into the circular economy has been little investigated. The compatibility of the plastics plays a central role here. The reuse of compatible plastic combinations holds great potential for OEMs, who are additionally motivated by the End-of-Life Vehicle Ordinance to establish a higher proportion of recyclate in plastic components.

The main objective of the doctoral project is therefore to investigate the recyclability of prominent plastic combinations from the automotive sector. The results generated will be used to make recommendations for the “Design for Recycling” of compatible and critical material combinations, as well as for recycling-friendly joining techniques. The doctoral project is embedded in a project in cooperation with Audi AG.