Up-Cycling Recycled GF/PA6 into Hybrid Sandwich Panels
BEng Final Year Project, University of Edinburgh, 2026
Glass-fibre-reinforced polyamide-6 (GF/PA6) composites are everywhere in structural automotive parts, but when they reach end-of-life, there's no good way to recycle them without wrecking their value. The shredded granules have too high a fibre content to run through standard injection moulding, so industry "down-cycles" them — diluting with virgin PA6 until they're just filler for non-structural parts.
I explored a route to use the recycled pellets as both the core and the matrix source of a sandwich panel — compression moulding them between two continuous glass-fibre face sheets, so the excess polymer in the recycled pellets migrates outward to impregnate the skins during the same cycle. I built and tested panels across five core thicknesses (2–8 mm) to see how bending stiffness scaled with core thickness, and where manufacturing quality started to break down.
Asides from the soft and hard skills of working in a lab -including recording an experiment, I learned how much test-rig artefacts can render results unusable; considering the limitations and recommendations sections was the most educational part of the process.