BMC VE (Vinyl ester matrix BMC)
Grade
Pick when the part sees acids, chlorides, hot water or steam that would hydrolyse standard orthophthalic polyester BMC.
Values for the VE condition
Other BMC grades and fills
BMC is listed in 8 conditions; see the grade overview at BMC.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Thermally conductive mineral/ceramic-filled BMC | Use for LED heat-sink housings and encapsulations that need 1–3 W/m·K while staying electrically insulating. | — | 30 | — | — |
Low-profile / Class-A surface BMC | Choose for visible pigmented or painted parts (automotive lamp bezels, appliance fronts) needing near-zero shrink and smooth surface. | — | 35 | 0.5 | 98 HRM |
Carbon/graphite-filled conductive BMC | Use where ESD dissipation or bulk electrical conduction is required (fuel-cell bipolar plates, static-safe housings) rather than insulation. | — | 35 | — | — |
Flame-retardant BMC, UL 94 V-0 / 5VA | Pick when a UL 94 V-0 or 5VA rating and glow-wire performance are mandatory (breakers, contactors, EV connectors). | — | 38 | 0.4 | 105 HRM |
High-whiteness reflector BMC | Choose for LED reflectors and lamp cups needing high initial reflectance with minimal yellowing after thermal/UV ageing. | — | 38 | 0.4 | 105 HRM |
Heat-resistant / high-CTI arc-resistant BMC | Specify for motor commutators, arc chambers and lamp bases running above 160 °C with arc/track exposure. | — | 40 | — | — |
VEThis page Vinyl ester matrix BMC | Pick when the part sees acids, chlorides, hot water or steam that would hydrolyse standard orthophthalic polyester BMC. | — | 50 | 0.7 | 105 HRM |
High-strength BMC, 22–30% longer glass fiber | Use for load-bearing or pressure-containing mouldings (pump housings, structural brackets) where impact and flexural strength dominate. | — | 60 | 0.8 | — |
What is BMC VE?
BMC VE is BMC in the VE grade — pick when the part sees acids, chlorides, hot water or steam that would hydrolyse standard orthophthalic polyester BMC. BMC VE has a tensile strength of 50 MPa (7.25 ksi), stronger than 54% of polymer grades. Elongation at break is 0.7% and the elastic modulus is 12 GPa (1.74 Msi). BMC VE has a density of 1.8 g/cm³ (0.065 lb/in³), heavier than 95% of polymer grades. Its glass-transition temperature is 120°C (248 °F).
Advantages
- Conducts heat well — 0.55 W/m·K (0.318 BTU/hr·ft·°F), better than 99% of polymer grades
- Stiff — 12 GPa (1.74 Msi), better than 98% of polymer grades
- Low, predictable mold shrinkage — 0.15%, better than 97% of polymer grades
- Low embodied carbon — 3 kg CO₂/kg, better than 83% of polymer grades
- Good UV / weathering resistance — 60/100, better than 80% of polymer grades
Limitations
- Limited ductility — 0.7%, worse than 99% of polymer grades
- Limited formability — 3/100, worse than 99% of polymer grades
- Heavy — 1.8 g/cm³ (0.065 lb/in³), worse than 95% of polymer grades
- Difficult to weld — 3/100, worse than 95% of polymer grades
- Difficult to machine — 38/100, worse than 83% of polymer grades
BMC VE properties
Typical room-temperature values for BMC VE; 23 are specific to this condition. Other listed values are BMC reference data and may not represent this condition. Bars are the position among polymer grades.
Physical4
BMC VE has a density of 1.8 g/cm³ (0.065 lb/in³), heavier than 95% of polymer grades. Its glass-transition temperature is 120°C (248 °F).
Mechanical12
BMC VE has a tensile strength of 50 MPa (7.25 ksi), stronger than 54% of polymer grades. Elongation at break is 0.7% and the elastic modulus is 12 GPa (1.74 Msi).
Thermal10
BMC VE is rated for continuous service to 150°C (302 °F). It conducts heat at 0.55 W/m·K (0.318 BTU/hr·ft·°F), better than 99% of polymer grades. Thermal expansion is 25 µm/m·K (13.9 µin/in·°F).
Electrical7
BMC VE is an electrical insulator with a dielectric strength of 14 kV/mm (355.6 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 65% of polymer grades. UV resistance is good.
Sustainability4
Producing a kilogram of BMC VE takes about 55 MJ of energy and emits 3 kg of CO₂ — less than 98% of polymer grades. Typical recycled content is 0%.
Manufacturability7
BMC VE's machinability is fair (38/100, worse than 83% of polymer grades); weldability not recommended (3/100); formability not recommended (3/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BMC VE
Is BMC easy to machine?
Cured BMC is abrasive and brittle — use PCD or diamond-coated tooling, high speed / low feed, support the part and vacuum the dust; drill from the moulded side to avoid chip-out.
Can BMC be welded?
Thermoset: cannot be welded; join by mechanical fasteners, moulded-in inserts, or epoxy/MMA adhesives after light abrasion and solvent wipe.
Can BMC be formed, bent or molded?
Injection, injection-compression or compression mould with stuffer-feed screws at 20–45 °C barrel and 140–180 °C tool, ~30–60 s/mm cure; vent well for styrene and avoid fibre-degrading high shear gates.
What surface finishes work on BMC?
As-moulded surfaces take flash removal by tumbling or media blast; low-profile grades accept primer and 2K polyurethane paint, and vacuum-metallizing after a UV base coat for reflectors.
BMC chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| unsaturated polyester resin (in styrene)ortho/iso-phthalic UP; vinyl ester in VE grades | 18 – 32 | 25 |
| glass fiber (chopped, 3–12 mm)higher in HS-GF25 structural grades | 10 – 30 | 18 |
| low-profile thermoplastic additivePS/PVAc shrink-control additive | 0 – 6 | 3 |
| internal mould release (zinc stearate) | 1 – 3 | 2 |
| peroxide initiator (TBPB/BPO) | 0.5 – 1.5 | 1 |
| thickener (MgO/Ca(OH)2), pigment, additi | 0.5 – 3 | 1 |
| calcium carbonate / mineral fillerreplaced partly by ATH in FR grades, by Al2O3/BN in TC grades | ≥ 35 (balance) | — |
BMC VE — frequently asked
What is BMC VE used for?
BMC VE is typically used for circuit breaker housings, appliance components, automotive under-hood parts and electrical insulators. In short: net-shape thermoset insulator; stable to 150 °C; V-0 flame-retardant grades.
What is the tensile strength of BMC VE?
BMC VE has a typical tensile strength of 50 MPa (7.25 ksi) — stronger than 54% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is BMC VE easy to machine?
Not especially — machinability is rated fair (38/100, worse than 83% of polymer grades). Cured BMC is abrasive and brittle — use PCD or diamond-coated tooling, high speed / low feed, support the part and vacuum the dust; drill from the moulded side to avoid chip-out.
Can BMC VE be welded?
Not readily — weldability is rated not recommended (3/100). Thermoset: cannot be welded; join by mechanical fasteners, moulded-in inserts, or epoxy/MMA adhesives after light abrasion and solvent wipe.
What surface finishes work on BMC VE?
As-moulded surfaces take flash removal by tumbling or media blast; low-profile grades accept primer and 2K polyurethane paint, and vacuum-metallizing after a UV base coat for reflectors.
Can BMC VE be formed, bent or molded?
Injection, injection-compression or compression mould with stuffer-feed screws at 20–45 °C barrel and 140–180 °C tool, ~30–60 s/mm cure; vent well for styrene and avoid fibre-degrading high shear gates.
What is the maximum service temperature of BMC VE?
BMC VE is rated for continuous use to about 150°C (302 °F), and briefly to 200°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D1201 — Thermosetting Polyester Molding Compounds — ASTM International (2019)
- ISO 14526 / ISO 12114 — SMC and BMC compounds, cure and test methods — ISO (2018)
- Engineered Materials Handbook Vol.2: Engineering Plastics (thermoset molding compounds) — ASM International (1988)
- BMC / TMC compound datasheets (IDI Composites, Menzolit, Polynt-Reichhold, Bulk Molding Compounds Inc.) — various (2023)
- UL Yellow Card / Prospector data for thermoset polyester molding compounds — UL Solutions (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.