Thermoset plastics are synthetic materials that strengthen during their cure cycle through the use of a chemical reaction activated by heat and pressure.
The molecular crosslinking results in a molded part that maintains its properties at elevated temperatures thus allowing for use in applications such as cookware, appliance handles and knobs, electrical connectors and ashtrays.
Thermosetting plastic products are typically produced by heating liquid or powder and injecting into a mold where under heat and pressure the material goes through its cure cycle resulting in the chemical reaction to attain its physical properties.
Unlike thermoplastic Injection molding, cured thermoset materials cannot be reground or reused after their initial processing. In general thermoset materials are more difficult to process because of their low viscosity and required cure cycle. Cycles times are generally much longer and because of the high pressures outgassing and high mold temperatures needed the part need to be deflashed after molding. Flashing cannot be avoided in thermoset injection molding and the flash must be removed as a standard secondary operation. Many times the deflasing process can be automated in a conventional tumbling operation.
The longer cycle times due to the chemical reaction occurring in the mold and the abrasive nature of thermoset materials make mold construction more critical. Proper mold design and mold steel selection is critical to successful thermoset molding.
Azmex has been molding thermoset material for over 10 years. We currently mold are variety of thermoset material such as Phenolic, DAP, Polyester and Epoxy.