Bulk moulding compound
Bulk moulding compound (BMC), bulk moulding composite, or dough moulding compound (DMC),
Manufacturing
BMC is manufactured by mixing strands (Greater than 1/8” and less than 2"
The viscosity of BMC dictates how effectively it can fill a mold. When at high viscosity, the pressure applied to the BMC is not enough for it to flow, and when at low viscosity, the fibers will stay in one place while the rest of the material flows without them. The viscosity constrains the amount of each component that can be used when mixing BMC. Having a large amount of fibers or longer fibers improves mechanical properties but makes the BMC more viscous. Adding fillers can lower the cost of the BMC or improve a certain property, but causes the BMC to become more viscous. Adding more styrene lowers viscosity but causes the moulded BMC to become brittle. When at an optimal viscosity to allow flow, components made using BMC can be up to 16" in their longest dimension before the components of the mixture begin to separate.[2]
See also
References