Resin infusion process monitoring using graphene coated glass fabric sensors and infusible thermoplastic and thermoset matrices

In this study, an online process monitoring system based on rGO coated glass fabric sensors was developed to monitor different stages of the resin infusion process. The developed sensors were able to monitor reinforcement compaction response, resin flow, race tracking, and resin cure when using thermoset resin and a novel low viscosity thermoplastic resin (i.e., Elium (R)). The coated glass fabric patches and strips were embedded at different locations within the laminate. The electrical resistance changes occurring within the embedded sensors during different stages of the manufacturing process were continuously monitored. The relative drop in overall resistance of the sensors upon contact with the resin systems was different for epoxy resin and Elium (R) resin due to differences in their electrical conductivity. It was found that the coating quality, dimensions, and spatial position of the sensors within the laminate and the type of resin system affected the performance of the sensors.