Bulk Molding Compound (BMC) is a Thermosetting molding material which comprises a resin matrix containing thermoplastic polymer as Unsaturated Polyester Resin, Styrene Monomer, filler and fiber reinforcement. This is a one kind of Polymer.

Various types of BMC are available depending on the combination of resin matrix and reinforcement. Normally, unsaturated polyester resin is used as the resin matrix, and glass fiber is used as the reinforcement.

The main features of BMC are excellent dimensional accuracy, high rigidity, and excellent heat resistance. Owing to these features, BMC is widely used in precision parts, heavy electric machinery, automotive parts, Circuit Breaker, Motor Encapsulation, etc.

BMC is molded either by compression molding, transfer molding, or injection molding.