What are BMC Polymers?

Block Molding Compound (BMC) represents a glass fiber-reinforced polymer material, available in bulk bag and block forms. It comprises a polymer resin, inert fillers, fiber reinforcements, catalysts, stabilizers, and pigments, creating a viscous mass rich in short fibers. BMC injection molding is a specialized process used for manufacturing thermoset plastic parts.

While the plastic component of BMC typically employs polypropylene, alternative types can also be utilized. The fiber component, commonly glass but adaptable to carbon or aramid fibers, results in a versatile substance that can be molded into various shapes and sizes.

Tailoring BMC formulations to specific needs enables the achievement of outstanding mechanical properties, precise dimensional control, flame retardancy, high dielectric strength, corrosion resistance, and remarkable strength. The fluidity of block molding compounds makes them suitable for diverse applications, and they are available in a spectrum of colors.

Applications of BMC:

Major appliance parts
Small appliance components
HVAC components
Industrial light covers
Automotive applications like valve covers, headlight liners, ignition components
Motor mounts, brush cards, brush holders, starter housings, and circuit breaker housings
Recessed lighting baffles

Why Choose BMC?

When seeking a composite material to replace metal, especially for intricately shaped parts impractical for traditional composite sheet or tape manufacturing, block molding compounds emerge as a viable solution. BMC offers several advantages over metal.

Lightweight:
BMC parts weigh 40% less than aluminum, possess higher tensile strength, and are simpler to manufacture than continuous fiber composites.

High Strength:
Compression molding of BMC into complex parts allows customization with integrated ribs and reinforcements, enabling them to withstand structural loads that often surpass the carrying capacity of metal.

Corrosion Resistance:
Toray’s block molding compounds exhibit solvent and corrosion resistance. Substrates include epoxy and thermoplastic resins such as PEEK, PEKK, PEI, and PPS.