Repairing of recycled hybrid carbon fiber laminates

Compression molded hybrid laminates have been manufactured by stacking 10 recycled epoxy-based carbon fiber plies with interlaminar polyamide film of 50 μm thickness. At first, carbon fiber (CF) reinforced composites underwent thermo-mechanical disassembly to obtain single composite CF plies. These plies, still impregnated with the waste cured resin, have been re-assembled by interposing one or two sheets of the thermoplastic film in the lamination sequence. Neat laminates have been used for comparison. Samples of size 85 × 30 mm2 have been tested under bending load, and materials repairability has been evaluated under 2 consecutive repairing cycles that have been carried out by applying pressure and heat along the composite failure line. Even though the neat composite showed the best mechanical properties, after the first repairing cycle a drastic drop has been recorded with a reduction of the elastic modulus of 92.4%. On the other hand, the elastic modulus of the hybrid composites has been reduced of only 24% on average. Highlights: Thermo-mechanical disassembly is used to recycle epoxy carbon fiber composite. Hybrid laminates are obtained by placing polyamide film between recycled plies. Pressure and heat are applied along the composite failure line for repairing. Hybrid composites repairing is carried out in comparison with neat materials. Repaired hybrid laminates have a higher elastic modulus than neat once.