Recovery of Carbon Fibers from CFRP and Surface Modification using Superheated Steam

Abstract

The high production cost of carbon fiber has limited the widespread application of carbon fiber reinforced plastics (CFRP) and the increasing quantity of CFRP waste in the future is of concern. The development of a high-efficiency and low-cost recycling process for CFRP waste is therefore required. In this paper, we examine the potential for carbon fiber recovery from CFRP while simultaneously modifying the fiber surface for adequate interfacial adhesion with the resin in new CFRP materials using a superheated steam (SHS) treatment. SHS treatment at over 500 °C enabled the recovery of continuous textile fibers from CFRP with polyamide 66 matrix resin, and the recovered fibers had almost the same tensile strength as the virgin fiber. On the other hand, the addition of N₂ gas to SHS was effective in suppressing degradation of the strength of virgin carbon fibers and improving the interfacial adhesion between fiber and epoxy resin.