APPLICATIONS OF DIELECTRIC ANALYSIS FOR CURE MONITORING AND CONTROL IN THE POLYESTER SMC/BMC MOLDING INDUSTRY

摘要

Dielectric Analysis is routinely used for monitoring the cure of thermosetting resins. Implantable, disposable sensors allow measurements of the curing process to be made in various locations throughout a part. Permanent, reusable sensors hush mounted in the mold allow the measurements to be made automatically during each molding cycle. This paper discusses process development, QA/QC, and production control in the polyester SMC/BMC industry. The curing rate through the cross-section of SMC parts of thicknesses up to 3/4 of an inch is examined. The effect of aging temperature on the reactivity of BMC demonstrates the use of Dielectric Analysis as a QA/QC test. Finally, it is shown that overall cycle times can be reduced by real time identification of the part-to-part variability in cure times during production molding. This allows closed-loop feedback to the press controller as to the proper time to demold each part. [References: 8]