Impedance cure and flow monitoring in the processing of advanced composites.

摘要

The paper presents recent developments in the area of impedance cure and flowmonitoring of thermosetting matrix/continuous reinforcement composites.Impedance cure monitoring is a variation of dielectric cure monitoring whichfollows the progress of the curing reaction and the accompanying structuralphenomena by means of the impedance spectrum response of the curing material.Currently, a good correlation between specific features of the imaginaryimpedance spectrum and the progress of the reaction has been found to hold underisothermal conditions. In this paper the correlation between the impedance andthe progress of the reaction is extended to dynamic cure conditions. Impedanceflow monitoring of the filling stage of liquid moulding of glass composites,based on lineal sensors, has been developed and reported recently. Here, thistechnique is extended to the case of conductive reinforcements with thedevelopment of a new sensing system. The system performance is tested againstvisual observation of the flow front position during resin transfer moulding.