BMC | Bulk Moulding Compound

BMC (Bulk Moulding Compound) can be moulded both in injection or compression process for large-scale production of medium-size or small complex parts.

BMC is, like SMC, a polymeric composite material, which consists primarily of a thermosetting resin, mineral fillers and glass fibre reinforcement. The resin used is generally unsaturated polyester (UP) or vinyl-ester (VE). Additional ingredients such as thermoplastic components, catalysts, inhibitors, mould release agents, thickeners and colour pigments are used to enhance the performance and moulding process of the final product.

Our Verkid® BMC products come in bulk, supplied in ≈900 kg boxes with ≈15 kg bags.

The transformation or moulding process is carried out by compression in a hot mould at temperatures between 130 – 170ºC and under pressure (typically 20 – 100 bar), or in injection machines (mould temperature between 145 – 175ºC, pressure 80 – 160 bar) specially designed for this process.

BMC applications are wide-ranging in the Automotive & Transportation, Electrical & Energy, Building & Construction, Industrial, Service, Sanitary, Domestic and Medical markets.

What is BMC?

BMC (Bulk Moulding Compound) is a fibre reinforced compound, in a thermoset resin matrix, with mineral fillers and different additives. Generally thermoset unsaturated polyester or vynil-ester resins are used as organic matrix.

With the aim of enhance its characteristics and improve its transformation, other components are added: catalysts, inhibitors, thermoplastic additives, demoulding agents, thickeners and pigments.


Resins, fillers and additives are automatically weighted and mixed together to form the mother paste. In a second mixer, more fillers, colour pigments and chopped glass fibre are automatically weighted and mixed together within a computer-controlled process to ensure a perfect impregnation or wet out of the glass fibre.

The resulting mix is then sent to an extruder, which compacts the BMC material and packs it into bags. At the end of the process, after BMC bags pass through a metal detector to prevent material from having any metallic foreign object, BMC bags are packed into boxes.


BMC must mature before it reaches optimal conditions for moulding. Typically the required maturation time is between 2 and 4 days, depending on the specific formulation.

Even after the material has matured, it continues to thicken at a speed dependant on the storage temperature. Therefore there is an optimal utilisation period of typically, between 1 and 6 months, dependant mainly on the specific formulation and storage temperature, which is recommended to be between 15 and 25ºC. Higher storage temperatures can significantly reduce the usability time of BMC.


BMC can be moulded both in injection or compression processes for large scale production of medium-size or small complex parts. Although moulding activities are carried out by our customers, Astar assists during moulding trials and offers complete technical assistance everytime is required.

+ Moulding Processes

BMC Product Overview

Our Verkid® BMC products are adaptable to your specific needs. We design formulations according to your requirements.

Markets: A&T: Automotive & Transportation | E&E: Electrical & Energy | B&C: Building & Construction | SAO: Sanitary, Appliances & Others

Abrasion  Formulations with enhanced abrasion resistance
Acoustic Applications requiring better acoustic damping properties
Antibacterial   Formulations that prevent the growth of new bacteria and eliminate existing bacteria
Antistatic   Conductive materials with antistatic properties for explosion proof parts
Arc Resistance   Applications requiring arc resistance
Carbon Fiber   Materials with chopped carbon fibers for light weight structural parts with high mechanical properties
ChemicalFormulations with an increased resistance to most chemical agents
Class A   Excellent surface quality for painted body panels
Dielectric   Materials with specific dielectrical properties
Finish  Special appearance effects: granite, marble, stone, etc.
Flame Resistant  Formulations designed to meet your required flame retardancy. UL “Yellow Cards” available.
FlowBetter flow properties during the moulding process to fill intricate parts
Food Contact  Food contact applications
High TemperatureHigh temperature stability for applications requiring high service temperature
Hydrophobe  Applications requiring an increased resistance to water absorption
Low Density   Low density formulations to reduce weight of parts
Low Emission   Formulations with low emission of volatile organic components
Low Shrink ✓ ✓ ✓Parts requiring precise tolerances for mounting of various components
Low Profile   Parts requiring very precise tolerances for mounting of various components
Low Pressure Applications requiring moulding at low press tonnage
Low Smoke Emission Formulations designed to meet low smoke emission requirements
PaintableMaterials adapted to all painting processes
PIMC  Materials adapted to Powder In-Mould Coating process
ReactiveHigh reactivity formulations to reduce curing time
Scratch Resistance  Formulations with an enhanced scratch resistance
StrengthApplications requiring high mechanical performance
SurfaceApplications requiring excellent surface quality
UnidirectionalHigh strength materials with unidirectional reinforcement to strengthen especially the fibre direction
UV stableFormulations with an enhanced UV resistance
OtherTell us your required key properties and we will design the specific formulation to meet them