PU-FR-V0 V0-FLEX
Hardness band
V0-FLEX = flexible flame-retardant elastomeric grade
Pick for FR gaskets, cable grommets, keypads and over-moulded soft-touch parts on electrical prototypes.
Values for the V0-FLEX condition
Other PU-FR-V0 grades and fills
PU-FR-V0 is listed in 7 conditions; see the grade overview at PU-FR-V0.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
V0-FLEXThis page Flexible flame-retardant elastomeric grade | Pick for FR gaskets, cable grommets, keypads and over-moulded soft-touch parts on electrical prototypes. | — | 12 | 250 | 30 Shore D |
Impact-modified / tough flame-retardant grade | Use for snap-fits, drop-tested enclosures and battery covers where V-0 must be combined with ductility. | 36 | 40 | 18 | 76 Shore D |
Halogen-free FR grade | Specify when halogen-free / low-smoke compliance is required alongside V-0 (rail, telecom, EU appliance programmes). | 42 | 44 | 5 | 84 Shore D |
Black pigmented FR grade | Pick when the part must be black out of the mould (no paint) — e.g. connector housings, power-tool shells. | 44 | 46 | 6 | 82 Shore D |
V0-STDDefault Standard rigid ABS-like FR casting grade | Default choice for electrical enclosures and appliance housings needing V-0 at 1.5–3 mm with ABS-like stiffness. | — | 48 | 6 | 82 Shore D |
Mineral / glass-filled flame-retardant grade | Choose for stiff, dimensionally stable FR housings and brackets where higher density and lower impact are acceptable. | — | 50 | 2 | 87 Shore D |
High-heat flame-retardant casting grade | Use when the FR part sees 100–120 °C (lamp bases, power supplies, under-hood electrical prototypes); needs long oven post-cure. | — | 55 | 3.5 | 85 Shore D |
What is PU-FR-V0 V0-FLEX?
PU-FR-V0 V0-FLEX is PU-FR-V0 heat treated to V0-FLEX — pick for FR gaskets, cable grommets, keypads and over-moulded soft-touch parts on electrical prototypes. PU-FR-V0 V0-FLEX has a tensile strength of 12 MPa (1.74 ksi), weaker than 81% of polyurethane grades. Elongation at break is 250% and the elastic modulus is 0.02 GPa (0.0029 Msi). PU-FR-V0 V0-FLEX has a density of 1.35 g/cm³ (0.0488 lb/in³), heavier than 90% of polyurethane grades. Its glass-transition temperature is 85°C (185 °F). V0-STD is the default condition FabDigit quotes; V0-FLEX is available on request or by drawing note.
Advantages
- Low moisture uptake — 0.25%, better than 93% of polyurethane grades
- Ductile — tolerates forming and impact — 250%, better than 86% of polyurethane grades
- Forms and bends easily — 60/100, better than 75% of polyurethane grades
Limitations
- Heavy — 1.35 g/cm³ (0.0488 lb/in³), worse than 90% of polyurethane grades
- Difficult to machine — 25/100, worse than 90% of polyurethane grades
- High mold shrinkage — 0.8%, worse than 83% of polyurethane grades
- Low stiffness — 0.02 GPa (0.0029 Msi), worse than 81% of polyurethane grades
PU-FR-V0 V0-FLEX properties
Typical room-temperature values for PU-FR-V0 V0-FLEX; 20 are specific to this condition. Other listed values are PU-FR-V0 reference data and may not represent this condition. Bars are the position among polyurethane grades.
Physical4
PU-FR-V0 V0-FLEX has a density of 1.35 g/cm³ (0.0488 lb/in³), heavier than 90% of polyurethane grades. Its glass-transition temperature is 85°C (185 °F).
Mechanical10
PU-FR-V0 V0-FLEX has a tensile strength of 12 MPa (1.74 ksi), weaker than 81% of polyurethane grades. Elongation at break is 250% and the elastic modulus is 0.02 GPa (0.0029 Msi).
Thermal10
PU-FR-V0 V0-FLEX is rated for continuous service to 75°C (167 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 83% of polyurethane grades. Thermal expansion is 80 µm/m·K (44.4 µin/in·°F).
Electrical7
PU-FR-V0 V0-FLEX is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (68/100), worse than 92% of polyurethane grades. UV resistance is poor.
Sustainability4
Producing a kilogram of PU-FR-V0 V0-FLEX takes about 100 MJ of energy and emits 5.2 kg of CO₂ — less than 83% of polyurethane grades. Typical recycled content is 0%.
Manufacturability6
PU-FR-V0 V0-FLEX's machinability is poor (25/100, worse than 90% of polyurethane grades); weldability not recommended (0/100); formability good (60/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with PU-FR-V0 V0-FLEX
Is PU-FR-V0 easy to machine?
Machines and drills easily with sharp carbide tools and vacuum extraction, but ATH filler is abrasive and the dust must be captured; avoid heat build-up which softens the surface.
Can PU-FR-V0 be welded?
Thermoset — cannot be welded; join with two-part PU or epoxy adhesive, or cast-in inserts.
Can PU-FR-V0 be formed, bent or molded?
Degas both components, mix and pour under vacuum into silicone moulds at 40–50 °C; short pot life (2–5 min) and high filler viscosity demand fast pouring and 60–70 °C oven post-cure for full FR and HDT properties.
What surface finishes work on PU-FR-V0?
Sands and primes well; paint or soft-touch coat for colour and UV protection, since aromatic MDI systems yellow in sunlight; texture is replicated directly from the silicone mould.
PU-FR-V0 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 |
|---|---|---|
| polyol (polyether/polyester blend, B-sidresin side incl. catalyst, defoamer, pigment | 35 – 55 | 45 |
| aluminium trihydrate (ATH) flame retardaprimary halogen-free FR/smoke suppressant | 10 – 30 | 18 |
| phosphorus flame retardant (phosphate/phgas- and condensed-phase synergist | 2 – 8 | 4 |
| mineral filler / pigmentTiO₂, talc, carbon black depending on colour | 0 – 5 | 2 |
| MDI-based polyisocyanate prepolymer (A-saromatic MDI; yellowing under UV | ≥ 25 (balance) | — |
PU-FR-V0 V0-FLEX — frequently asked
What is PU-FR-V0 V0-FLEX used for?
PU-FR-V0 V0-FLEX is typically used for electrical enclosure prototypes, appliance housings, connector housings and safety-critical casings. In short: UL94 V0 cast PU; flame-retardant enclosure prototypes; filled, higher-density PU.
What is the tensile strength of PU-FR-V0 V0-FLEX?
PU-FR-V0 V0-FLEX has a typical tensile strength of 12 MPa (1.74 ksi) — weaker than 81% of polyurethane grades. Strength varies by condition: see the 7 listed tempers.
Is PU-FR-V0 V0-FLEX easy to machine?
Not especially — machinability is rated poor (25/100, worse than 90% of polyurethane grades). Machines and drills easily with sharp carbide tools and vacuum extraction, but ATH filler is abrasive and the dust must be captured; avoid heat build-up which softens the surface.
Can PU-FR-V0 V0-FLEX be welded?
Not readily — weldability is rated not recommended (0/100). Thermoset — cannot be welded; join with two-part PU or epoxy adhesive, or cast-in inserts.
What surface finishes work on PU-FR-V0 V0-FLEX?
Sands and primes well; paint or soft-touch coat for colour and UV protection, since aromatic MDI systems yellow in sunlight; texture is replicated directly from the silicone mould.
Can PU-FR-V0 V0-FLEX be formed, bent or molded?
Degas both components, mix and pour under vacuum into silicone moulds at 40–50 °C; short pot life (2–5 min) and high filler viscosity demand fast pouring and 60–70 °C oven post-cure for full FR and HDT properties.
What is the maximum service temperature of PU-FR-V0 V0-FLEX?
PU-FR-V0 V0-FLEX is rated for continuous use to about 75°C (167 °F), and briefly to 110°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between PU-FR-V0 V0-STD and PU-FR-V0 V0-BK?
V0-STD is the default condition — default choice for electrical enclosures and appliance housings needing V-0 at 1.5–3 mm with ABS-like stiffness. V0-BK: pick when the part must be black out of the mould (no paint) — e.g. connector housings, power-tool shells.
Sources
- PX5620 flame-retardant polyurethane casting system TDS — Axson Technologies / Sika (2021)
- F-series FR vacuum casting resins technical data — Axson Technologies (2020)
- UL 94 — Tests for Flammability of Plastic Materials for Parts in Devices and Appliances — UL Solutions (2023)
- ISO 527 / ISO 178 / ISO 75 plastics test methods — ISO (2019)
- Engineered Materials Handbook Vol. 2: Engineering Plastics (polyurethane thermosets) — ASM International (1988)
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.