Circular Economy Implementation for Plastic Products in SMEs: Framework Development and Practical Application in Case Studies

Plastics are of key importance for numerous technical applications due to their functional properties and cost efficiency. However, their production from fossil raw materials and disposal pose major environmental problems. The transition to a circular economy (CE) is supposed to address these problems and is particularly difficult for small and medium enterprises (SMEs). A framework is developed that illustrates circular economy (CE) strategies in the plastics industry, focussing on the practical implementation in the product life cycle and the actual contribution to a CE. Case studies of a polypropylene desk equipment and a polyurethane foam insulation element illustrate the practical application of the developed framework in two German SMEs and indicate further need for support. The developed CE concepts for both product systems were evaluated based on their environmental impacts using Life Cycle Assessment (LCA). The results show that CE strategies must be product-specific to be effective. Strategies such as the use of post-industrial recyclates and the use of biobased materials offer advantages but are not sufficient on their own to close material cycles. Closed-loop recycling and the reuse of products require customised collection systems but can contribute to truly closed material cycles. Overall, this framework serves as a starting point for identification of CE concepts for plastic products by companies and thereby promotes the transition to a more circular plastics economy. Future research should focus on evaluation of technical compatibility and long-term consequences as well as scalability of CE strategies and on alternative evaluation approaches.