Fingerprinting resin cure with dielectric analysis

Resin cure has been studied in a variety of viscometers and cure meters¹ in an attempt to control product uniformity. Most of the conventional tests detect the state of cure as a function of the fiscosity of the material which is determined either by a rotating spindle which senses the resistance to flow or by the distance that the resin flows in a standard die within a test mold. Such procedures are, of necessity, limited to inspection and quality control testing, and they do not aid the resin formulator in making adjustments in the final forming operation. There are many time and temperature effects which can sufficiently alter the resin character such that its behavior in a final forming operation is not totally predictable.