SENSOR SYSTEM FOR MONITORING IMPREGNATION AND CURE DURING RESIN TRANSFER MOLDING

In the resin transfer molding (RTM) fabrication of composites, knowled ge of the position of a moving resin front during impregnation is impo rtant for process optimization. We describe here a simple, inexpensive , multi-point sensor system based on DC conductometry for determinatio n of resin position in an RTM mold. This Resin Position Sensor (RPS) s ystem consists of a matrix of small sensors embedded in the RTM tool, whose combined output can be used to produce a resin flow pattern at a ny given time after the start of impregnation. As it cures, the resin resistance increases and the sensor can then function as a cure monito r. A large, 24-sensor RTM tool was fabricated for demonstration of the RPS. Flow contour maps generated from sensor data during impregnation of both E-glass and carbon fiber preforms are shown.