Recycling Technique of Carbon Fiber Laminate Using Hydrolysis Near Critical Region

Abstract

This paper aimed to maximize resin removal from CFRP in the near-critical region. A near-critical water process was performed in a batch reactor to recycle CFRP for temperatures ranging from 543K to 573K and reaction times up to 30 minutes. The removal percentages of weight were between 53.9% and 9731% and the yield of the process was significantly increased up to 97.1%, when operating in 573K temperature and immediately removing the near-critical water after reaction. The microscopic images showed that a clean surface of recycled carbon fibers was confirmed. For preventing re-solidification of epoxy resin, a circulating system of the near-critical water dissolving epoxy resin is needed and the use of a flow reactor is recommended for better mass transfer. Due to the importance of recycling of CFRP during the next few years, a new low cost recycling system is essential to deal with the tons of waste composite materials. This study will be helpful to design a commercial scale recycling system in the further direction.