Fabrication and properties of composites utilizing reclaimed woven carbon fiber by sub-critical and supercritical water recycling

Abstract

Supercritical fluid recycling has emerged as an appealing method for recycling carbon fiber reinforced plastics (CFRP). Under supercritical conditions, the high reactivity, low viscosity and high diffusivity of water greatly facilitate the efficient degradation of the polymer matrix to allow the harvesting of clean and mostly undamaged fibers. We previously reported the successful use of supercritical water recycling to recover carbon fibers from high-performance single-layer composites and possibly multi-layered composites. The fibers are reclaimed in the original woven architecture, which is beneficial for direct use for reclaimed-fiber composites. In this study, the fabrication of reclaimed-fiber composites (RFC) was investigated using fibers recycled from aerospace-grade IM7/8552 (Hexcel) 12-layer composites. Two fabrication methods – hand lay-up and vacuum infusion – were attempted. The recycled matrix materials were also combined with fresh resin and cured. The reclaimed-fiber composites exhibited 80–95% of flexural strength of virgin carbon fiber composites. This paper also discusses the manufacturing issues associated with the reuse of reclaimed materials.