137 Analysis of Debris Generated During the Process of Cutting and Grinding of Carbon Fibers-Reinforced Plastics

Abstract Carbon fiber reinforced plastics (CFRP) is a leading functional material with superior strength and low mass density compared to metal. Recently, due to its excellent property, it has spread to a wide range of fields from sporting goods, such as golf clubs and fishing rods, to aerospace products. However, there is concern that debris (microparticles) is easily released in the processing process of CFRP. The present study investigated the ambient level, size, and shape of particles generated from CFRP during various machining processes in an occupational setting. The size and shape of particles were observed using scanning electron microscopy (SEM) and their chemical compositions were also analyzed using energy dispersive spectroscopy (EDS). The majority of debris from CFRP was cylindrical with a diameter comparable to the diameter of the original carbon fiber, suggesting transversally split carbon fiber. However, some of the debris was fibrous, length >5 μm, width 3, suggesting longitudinally split carbon fiber. These fibrous fragments were morphologically compatible with the WHO definition of respirable fibers. The particles in the working environment were also monitored with a real-time monitoring device, NanoScan SMPS Model 3910. Measurement by real-time monitoring device showed that not only microparticles but also smaller particles were released in the processing process of CFRP. These particles are probably breakdown elements of the epoxy thermoset polymer (resin) in CFRP. The potential hazard of debris from CFRP in the processing process in an occupational setting and risk assessment is needed for the safe handling of CFRP.