High-rate, Circular Composites for Automotive Applications
Topic(s) : Manufacturing
Co-authors :
Hannah SWINBOURNE (UNITED KINGDOM), Susie MORTON (UNITED KINGDOM)Abstract :
The automotive industry are the largest users of composites, however over 90% of these are glass fibre composites which have limited cost-effective, value retaining end of life processes. High-rate processes are also required, with 69% of automotive composites manufactured using injection moulding and 16% with compression moulding. This project aimed to demonstrate two routes for circularity for high-rate composite materials in automotive, optimising a high value manufacturing process for each. This was verified using mechanical and environmental testing and a low-level Life Cycle Assessment (LCA).
The first method of circularity used was the biological cycle, where materials are bio-derived and return to the biosphere after use. It can often be seen in studies similar to this one where natural fibres are used in composites alongside a non-bio-derived or non-compostable polymer, limiting the end of life options. Flax fibre/PLA was selected as a bio-derived and theoretically compostable material to address this. Secondly, an industry-representative, legacy material was selected for future demonstration of recycling: glass fibre/polypropylene.
Both materials were used to manufacture a demonstrator part using the injection overmoulding process. Injection overmoulding is a thermoplastic process which combines compression moulding and injection moulding, allowing the production of complex geometries with the structural performance of continuous fibres. Inserts and fasteners may also be integrated during manufacture, making it a suitable process for high-rate automotive applications with the potential to reduce process steps. The case study in question was, to the best of the authors’ knowledge, a UK first for injection overmoulding of flax/PLA. Through this key process parameters and handling methods for producing high quality flax/PLA parts were highlighted, these will be described in the publication.
Environmental testing was completed to the automotive standard PV1200 alongside tensile and flexural mechanical testing. To verify sustainability credentials, a cradle to gate LCA highlighted material hotspots in greenhouse gas emissions and demonstrated the importance of considering other environmental impact categories, such as eutrophication potential. The results of this LCA posed an interesting case analysis for weighing up the pros and cons of bio-derived materials, as well as the impact of boundary conditions when considering the growing of materials.
The National Composites Centre engaged with both industry and academia through conferences and workshops to begin to understand the supply chain gaps and barriers to adoption of these materials.
The presentation will show the results of these manufacturing trials, tests, and LCA. The broader opportunities and challenges for biocomposites will also be discussed, and the next steps for closing the loop and demonstrating the end of life of both materials.
The first method of circularity used was the biological cycle, where materials are bio-derived and return to the biosphere after use. It can often be seen in studies similar to this one where natural fibres are used in composites alongside a non-bio-derived or non-compostable polymer, limiting the end of life options. Flax fibre/PLA was selected as a bio-derived and theoretically compostable material to address this. Secondly, an industry-representative, legacy material was selected for future demonstration of recycling: glass fibre/polypropylene.
Both materials were used to manufacture a demonstrator part using the injection overmoulding process. Injection overmoulding is a thermoplastic process which combines compression moulding and injection moulding, allowing the production of complex geometries with the structural performance of continuous fibres. Inserts and fasteners may also be integrated during manufacture, making it a suitable process for high-rate automotive applications with the potential to reduce process steps. The case study in question was, to the best of the authors’ knowledge, a UK first for injection overmoulding of flax/PLA. Through this key process parameters and handling methods for producing high quality flax/PLA parts were highlighted, these will be described in the publication.
Environmental testing was completed to the automotive standard PV1200 alongside tensile and flexural mechanical testing. To verify sustainability credentials, a cradle to gate LCA highlighted material hotspots in greenhouse gas emissions and demonstrated the importance of considering other environmental impact categories, such as eutrophication potential. The results of this LCA posed an interesting case analysis for weighing up the pros and cons of bio-derived materials, as well as the impact of boundary conditions when considering the growing of materials.
The National Composites Centre engaged with both industry and academia through conferences and workshops to begin to understand the supply chain gaps and barriers to adoption of these materials.
The presentation will show the results of these manufacturing trials, tests, and LCA. The broader opportunities and challenges for biocomposites will also be discussed, and the next steps for closing the loop and demonstrating the end of life of both materials.