Bulk Molding Compound

BMC is a combination of chopped glass strands and resin in the form of a bulk pre-preg. BMC is suitable for either compression or injection molding. Injection molding of BMC is used to produce complex components such as electrical equipment, car components, housings for electrical appliances and tools, in large industrial volumes.

Unlike SMC, it is not necessary to include a maturation stage. Consequently, BMC pre-preg formulations contain higher filler contents.

The chopped glass strands vary in length depending on the level of performance required. Reinforcement content generally ranges between 15 and 20 percent; however, it may reach 25 percent for the highest performance. BMC uses a lower reinforcement content than SMC and permits higher filler loadings with lower costs.