BMC Molding

BMC, or Bulk Molding Compound, is a type of thermoset composite molding material. BMCs are unsaturated polyesters or vinyl esters, and can be injection or compression molded with thermoset molding machines. The properties of BMC molded parts include exceptional dielectric strength, electrical insulation, heat resistance, and chemical resistance. These end properties lend BMC to be molded for a variety of safety-critical components in Electrical, Automotive, and Industrial markets. In its raw state, BMC resembles a play-dough like form usually filled with glass fibers and or minerals dispersed within the resin system. Molding wise, BMCs are generally injection molded, but can also be compression molded. Injection molding BMCs require the use of a molding machine stuffer or ram to help injection material into the screw and barrel.

Electrical components such as terminal blocks, connectors and circuit breakers are molded from thermoset BMCs due to these desirable electrical properties, keeping the product assembly and components safe, even under a potential product failure. Automotive transmission and powertrain components utilize heat resistance and chemical resistance properties of BMC for parts exposed to automotive fluids, oils, and grease. Likewise the high temperature resistance allows BMC parts to remain strong and durable even within applications experiencing high operating temperatures.