Polyimide Prepreg — Production Monitoring
The molding of a polyimide/graphite prepreg in a production press was automated using the ion viscosity to initiate processing steps.
Pressure was applied when the ion viscosity detected the viscosity minimum of the material, the critical time when the resin would flow properly but the excess volatiles would not be trapped. An additional critical point was employed to trigger de-mold when the part was sufficiently cured, thus reducing cycle times and increasing throughput. This is reflected in a much lower price for the molding. (measurement with DEA 288)