Continuous monitoring of setting and hardening of epoxy resin

Abstract

A problem in the manufacturing of composite materials is the monitoring of the curing process in order to distinguish the different stages of the structural formation and to provide adequate conditions for proper epoxy impregnation. The method used to monitor the setting and hardening of epoxy in this study is based on ultrasonic propagation. A wave generator was connected to a sensitive broadband acoustic emission transducer in order to transmit elastic waves through the thickness of setting and hardening epoxy. The acquisition was conducted by another sensor of the same type acting as receiver. Different parameters like the wave velocity and attenuation are monitored in order to examine the rate of hardening. The changes in viscosity and elastic modulus with time can be monitored by the changes in the wave parameters. The effect of temperature is also discussed. © RILEM 2013.