RIM PU Foam FR (Flame-retardant RIM system)
Flame-retardant grade
Specify for rail, transit, medical and electrical enclosures needing UL 94 V-0 / EN 45545 or FMVSS 302 compliance.
Values for the FR condition
Other RIM PU Foam grades and fills
RIM PU Foam is listed in 7 conditions; see the grade overview at RIM PU Foam.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Flexible integral-skin RIM foam, ~0.35–0.5 g/cm³ | Pick for soft-touch, energy-absorbing parts: steering wheels, armrests, headrests, handles, gym/medical padding with a tough skin. | — | 4 | 200 | 62 Shore A |
MC-0.6Default Unfilled semi-rigid microcellular RIM, integral skin, ~0.6 g/cm³ | Default all-round RIM foam: paintable integral skin, good impact and stiffness balance for housings, panels and trim. | 8 | 12 | 130 | 45 Shore D |
FRThis page Flame-retardant RIM system | Specify for rail, transit, medical and electrical enclosures needing UL 94 V-0 / EN 45545 or FMVSS 302 compliance. | 8 | 10 | 80 | 50 Shore D |
Rigid RIM structural foam, ~0.25–0.35 g/cm³ | Lowest-cost stiff lightweight shells (medical equipment covers, machine enclosures, furniture cores) where thick ribbed walls replace sheet metal. | — | 9 | 6 | 60 Shore D |
High-density microcellular RIM elastomer, ~0.9–1.05 g/cm³ | Choose for tough painted exterior body panels/fascias and bumpers needing high tear, impact and cold ductility at near-solid density. | — | 26 | 200 | 65 Shore D |
Reinforced RIM, 12–20 % milled glass fiber / glass flake | Use when CTE must be cut and stiffness/HDT raised for on-line painted exterior panels and larger flat surfaces. | — | 26 | 25 | 75 Shore D |
Structural RIM over 30–45 % continuous glass mat preform | Highest stiffness/strength route — resin is injected into a glass-mat preform in the mold; for load-bearing panels, floor pans and bumper beams. | — | 85 | 2 | — |
What is RIM PU Foam FR?
RIM PU Foam FR is RIM PU Foam in the FR grade — specify for rail, transit, medical and electrical enclosures needing UL 94 V-0 / EN 45545 or FMVSS 302 compliance. RIM PU Foam FR has a yield strength of 8 MPa (1.16 ksi) and a tensile strength of 10 MPa (1.45 ksi) — weaker than 93% of polymer grades. Elongation at break is 80% and the elastic modulus is 0.27 GPa (0.0392 Msi). RIM PU Foam FR has a density of 0.68 g/cm³ (0.0246 lb/in³), lighter than 83% of polymer grades. Its glass-transition temperature is 80°C (176 °F). MC-0.6 is the default condition FabDigit quotes; FR is available on request or by drawing note.
Advantages
- Lightweight — 0.68 g/cm³ (0.0246 lb/in³), better than 83% of polymer grades
Limitations
- Low strength — 8 MPa (1.16 ksi), worse than 93% of polymer grades
- Poor heat conductor — 0.09 W/m·K (0.052 BTU/hr·ft·°F), worse than 83% of polymer grades
- Difficult to weld — 10/100, worse than 82% of polymer grades
- Needs corrosion protection — 70/100, worse than 78% of polymer grades
- Absorbs moisture — dry before molding — 0.6%, worse than 75% of polymer grades
RIM PU Foam FR properties
Typical room-temperature values for RIM PU Foam FR; 26 are specific to this condition. Other listed values are RIM PU Foam reference data and may not represent this condition. Bars are the position among polymer grades.
Physical4
RIM PU Foam FR has a density of 0.68 g/cm³ (0.0246 lb/in³), lighter than 83% of polymer grades. Its glass-transition temperature is 80°C (176 °F).
Mechanical15
RIM PU Foam FR has a yield strength of 8 MPa (1.16 ksi) and a tensile strength of 10 MPa (1.45 ksi) — weaker than 93% of polymer grades. Elongation at break is 80% and the elastic modulus is 0.27 GPa (0.0392 Msi).
Thermal10
RIM PU Foam FR is rated for continuous service to 90°C (194 °F). It conducts heat at 0.09 W/m·K (0.052 BTU/hr·ft·°F), worse than 83% of polymer grades. Thermal expansion is 120 µm/m·K (66.7 µin/in·°F).
Electrical7
RIM PU Foam FR is an electrical insulator with a dielectric strength of 12 kV/mm (304.8 V/mil) and a resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 78% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of RIM PU Foam FR takes about 105 MJ of energy and emits 4.6 kg of CO₂ — more than 54% of polymer grades. Typical recycled content is 3%.
Manufacturability7
RIM PU Foam FR's machinability is fair (50/100, worse than 73% of polymer grades); weldability not recommended (10/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with RIM PU Foam FR
Is RIM PU Foam easy to machine?
Trim flash and drill with sharp carbide or router bits at high speed and low feed; the cellular core cuts easily but glass-filled RRIM/SRIM is abrasive and dust must be extracted.
Can RIM PU Foam be welded?
Thermoset — cannot be melt-welded; join with two-part PU/epoxy adhesive, moulded-in inserts or self-tapping screws into ribbed bosses.
Can RIM PU Foam be formed, bent or molded?
High-pressure impingement mixing at 12–20 MPa, component temperatures 30–50 °C, mould 45–80 °C, demould in 30–120 s; design uniform 3–8 mm walls (thicker allowed than thermoplastics), 1–3° draft, vented low-cost aluminium or nickel-shell moulds.
What surface finishes work on RIM PU Foam?
In-mould release residue must be washed or power-washed off before painting; integral skin accepts PU primer and 2K PU topcoat directly, and conductive primers allow electrostatic on-line painting of RRIM body panels.
RIM PU Foam 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 |
|---|---|---|
| polymeric/modified MDI (isocyanate compoA-side; index typically 100–110 | 35 – 55 | 45 |
| chain extender (1,4-butanediol / ethylensets hard-segment content and modulus | 2 – 8 | 5 |
| blowing agent (water and/or HFO-1233zd /controls core density | 0.2 – 2.5 | 1 |
| amine + tin catalyst packagecream/gel time control for fast demold | 0.3 – 2 | 1 |
| silicone surfactant / cell regulator | 0.3 – 1.5 | 0.8 |
| internal mould release + pigment | 0.5 – 2.5 | 1.2 |
| milled glass fiber / glass flake (RRIM v | 0 – 25 | 15 |
| polyether polyol (polyol blend base)B-side; polyester polyol used where oil/abrasion resistance outweighs hydrolysis risk | ≥ 35 (balance) | — |
RIM PU Foam FR — frequently asked
What is RIM PU Foam FR used for?
RIM PU Foam FR is typically used for automotive fascias and body panels, structural furniture components, equipment housings and agricultural equipment shrouds. In short: one-step integral-skin parts; low-cost tooling, large panels; thermoset, not weldable.
What is the yield strength of RIM PU Foam FR?
RIM PU Foam FR has a typical yield strength of 8 MPa (1.16 ksi) and a tensile strength of 10 MPa (1.45 ksi) — weaker than 93% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is RIM PU Foam FR easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 73% of polymer grades). Trim flash and drill with sharp carbide or router bits at high speed and low feed; the cellular core cuts easily but glass-filled RRIM/SRIM is abrasive and dust must be extracted.
Can RIM PU Foam FR be welded?
Not readily — weldability is rated not recommended (10/100). Thermoset — cannot be melt-welded; join with two-part PU/epoxy adhesive, moulded-in inserts or self-tapping screws into ribbed bosses.
What surface finishes work on RIM PU Foam FR?
In-mould release residue must be washed or power-washed off before painting; integral skin accepts PU primer and 2K PU topcoat directly, and conductive primers allow electrostatic on-line painting of RRIM body panels.
Can RIM PU Foam FR be formed, bent or molded?
High-pressure impingement mixing at 12–20 MPa, component temperatures 30–50 °C, mould 45–80 °C, demould in 30–120 s; design uniform 3–8 mm walls (thicker allowed than thermoplastics), 1–3° draft, vented low-cost aluminium or nickel-shell moulds.
What is the maximum service temperature of RIM PU Foam FR?
RIM PU Foam FR is rated for continuous use to about 90°C (194 °F), and briefly to 130°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between RIM PU Foam MC-0.6 and RIM PU Foam FR?
MC-0.6 is the default condition — default all-round RIM foam: paintable integral skin, good impact and stiffness balance for housings, panels and trim. FR: specify for rail, transit, medical and electrical enclosures needing UL 94 V-0 / EN 45545 or FMVSS 302 compliance. Yield strength is 8 MPa in MC-0.6 versus 8 MPa in FR.
Sources
- Bayflex / Baydur RIM system technical data — Covestro (formerly Bayer MaterialScience) (2022)
- Elastoflex / Elastolit RIM and integral-skin systems — BASF Polyurethanes (2021)
- RIMLINE / polyurethane RIM system data sheets — Huntsman Polyurethanes (2020)
- Engineered Materials Handbook Vol. 2: Engineering Plastics (RIM section) — ASM International (1988)
- Polyurethane Handbook, 2nd ed. (Oertel) — Hanser (1994)
- CES/Granta EduPack polymer & foam eco-property data — Ansys Granta (2023)
- ASTM D3489 / D1621 / D3574 — microcellular and cellular PU test methods — ASTM (2019)
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.