Composites: Bulk molding compound
A composite whose composition isn’t strictly defined, bulk molding compound (BMC) is typically made from a mixture of glass fibers, thermoplastic resins, and other materials such as styrene and certain fillers. Other fibers can be used – such as carbon, certain polymers, or even asbestos – but glass is the most common material, often in the form of short, chopped fibers. BMC is also called dough molding compound, because it mixed in a dough like form, rather than a sheet like form (a similar material produced in sheets is known as sheet molding compound (SMC)).
These composites are lighter in weight than materials with similar strengths and are considered high strength themselves. The raw material, after mixing, has excellent flow characteristics, allowing for fine control of detail on parts produced as well as highly accurate dimensions. Depending on the materials used they can be resistant to corrosion as well. The fillers used mean that BMC can be produced in a variety of colors as well, and the composite is an insulator
The mixture used to create BMC is typically extruded, after which the final product is usually created through methods such as compression or injection molding. Common applications include electrical and automotive applications.