TPO Foam FR (Flame-retardant grade)
Flame-retardant grade
Choose where interior/rail/electrical burn tests (FMVSS 302, UL 94 HF-1) must be passed.
Values for the FR condition
Other TPO Foam grades and fills
TPO Foam is listed in 10 conditions; see the grade overview at TPO Foam.
Compare all 10 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
33 kg/m³ | Common roll-goods density for interior trim backing and soft gasketing. | 0.13 | 0.28 | 140 | 16 Shore A |
25 kg/m³ | Pick for light cushion packaging and void-fill where softness matters more than load bearing. | — | 0.2 | 120 | 12 Shore A |
60 kg/m³ | Use when the part must resist thermoforming stretch and carry higher gasket sealing loads. | 0.24 | 0.5 | 170 | 25 Shore A |
Non-crosslinked extruded foam | Lowest-cost route for packaging and protective sheet; coarser cells, higher set, fully re-extrudable scrap. | — | 0.28 | 130 | 18 Shore A |
FRThis page Flame-retardant grade | Choose where interior/rail/electrical burn tests (FMVSS 302, UL 94 HF-1) must be passed. | — | 0.3 | 120 | 24 Shore A |
80 kg/m³ | Choose for repeated-impact pads, deep-draw thermoformed laminates and structural gaskets. | 0.34 | 0.7 | 180 | 30 Shore A |
D45Default 45 kg/m³ | Default all-round density: soft touch with usable load bearing for IP/door-trim laminates and sealing. | — | 0.35 | 150 | 20 Shore A |
Chemically/electron-beam crosslinked sheet | Specify crosslinked TPO foam when fine uniform cells, good thermoformability and low compression set are needed. | — | 0.4 | 170 | 22 Shore A |
100 kg/m³ | Pick for load-bearing spacers, anti-squeak/rattle pads and NVH parts needing firm resilience. | 0.45 | 0.9 | 190 | 35 Shore A |
Moldable expanded TPO bead foam | Use steam-chest molded bead foam for 3D energy-absorbing parts softer and more elastic than EPP. | — | 0.45 | 60 | 28 Shore A |
What is TPO Foam FR?
TPO Foam FR is TPO Foam in the FR grade — choose where interior/rail/electrical burn tests (FMVSS 302, UL 94 HF-1) must be passed. TPO Foam FR has a tensile strength of 0.3 MPa (0.0435 ksi), weaker than 94% of polymer grades. Elongation at break is 120% and the elastic modulus is 0 GPa (1.89×10⁻⁴ Msi). TPO Foam FR has a density of 0.06 g/cm³ (0.002 lb/in³), lighter than 88% of polymer grades. Its glass-transition temperature is -50°C (-58 °F). D45 is the default condition FabDigit quotes; FR is available on request or by drawing note.
Advantages
- Lightweight — 0.06 g/cm³ (0.002 lb/in³), better than 88% of polymer grades
Limitations
- Low stiffness — 0 GPa (1.89×10⁻⁴ Msi), worse than 97% of polymer grades
- Poor heat conductor — 0.04 W/m·K (0.0225 BTU/hr·ft·°F), worse than 88% of polymer grades
TPO Foam FR properties
Typical room-temperature values for TPO Foam FR; 22 are specific to this condition. Other listed values are TPO Foam reference data and may not represent this condition. Bars are the position among polymer grades.
Physical4
TPO Foam FR has a density of 0.06 g/cm³ (0.002 lb/in³), lighter than 88% of polymer grades. Its glass-transition temperature is -50°C (-58 °F).
Mechanical9
TPO Foam FR has a tensile strength of 0.3 MPa (0.0435 ksi), weaker than 94% of polymer grades. Elongation at break is 120% and the elastic modulus is 0 GPa (1.89×10⁻⁴ Msi).
Thermal8
TPO Foam FR is rated for continuous service to 95°C (203 °F). It conducts heat at 0.04 W/m·K (0.0225 BTU/hr·ft·°F), worse than 88% of polymer grades. Thermal expansion is 150 µm/m·K (83.3 µin/in·°F).
Electrical4
TPO Foam FR has an electrical resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (84/100), better than 58% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of TPO Foam FR takes about 95 MJ of energy and emits 3.6 kg of CO₂ — less than 70% of polymer grades. Typical recycled content is 5%.
Manufacturability6
TPO Foam FR's machinability is good (58/100, worse than 55% of polymer grades); weldability good (60/100); formability very good (78/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with TPO Foam FR
Is TPO Foam easy to machine?
Die cutting, kiss-cut, hot-wire, oscillating blade or waterjet all work; avoid conventional milling which smears and melts the cell walls.
Can TPO Foam be welded?
Joins by hot-air/impulse/ultrasonic welding to itself and to TPO skins; adhesives require flame, corona or plasma pretreatment because of the low-energy surface.
Can TPO Foam be formed, bent or molded?
Crosslinked sheet vacuum/press-forms at roughly 140–170 °C surface temperature; bead grades are steam-chest molded, non-crosslinked grades are extruded at about 175–215 °C melt.
What surface finishes work on TPO Foam?
Cannot be painted or plated as a foam; use flame lamination, PSA transfer tape, textile/TPO skin lamination or embossing for the visible surface.
TPO 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 |
|---|---|---|
| polypropylene (PP homo/copolymer)matrix phase | 45 – 75 | 60 |
| olefin elastomer (EPR/EPDM/POE)provides rubber-like softness and low-temperature flexibility | 20 – 50 | 33 |
| chemical blowing agent + crosslinker resomitted in physically (CO2/N2) foamed grades | 1 – 5 | 3 |
| talc / nucleant, antioxidant, UV & proce | 1 – 5 | 2 |
| flame retardant (FR grades only)ATH/phosphorus or brominated systems | 0 – 20 | 0 |
TPO Foam FR — frequently asked
What is TPO Foam FR used for?
TPO Foam FR is typically used for automotive interior soft-touch padding, footwear midsole components, sporting goods cushioning, gasketing and protective sleeves. In short: softer than EPP; rubber-like closed-cell olefin; weldable to TPO skins.
What is the tensile strength of TPO Foam FR?
TPO Foam FR has a typical tensile strength of 0.3 MPa (0.0435 ksi) — weaker than 94% of polymer grades. Strength varies by condition: see the 10 listed tempers.
Is TPO Foam FR easy to machine?
Reasonably — machinability is rated good (58/100, worse than 55% of polymer grades). Die cutting, kiss-cut, hot-wire, oscillating blade or waterjet all work; avoid conventional milling which smears and melts the cell walls.
Can TPO Foam FR be welded?
Yes — weldability is rated good (60/100). Joins by hot-air/impulse/ultrasonic welding to itself and to TPO skins; adhesives require flame, corona or plasma pretreatment because of the low-energy surface.
What surface finishes work on TPO Foam FR?
Cannot be painted or plated as a foam; use flame lamination, PSA transfer tape, textile/TPO skin lamination or embossing for the visible surface.
Can TPO Foam FR be formed, bent or molded?
Crosslinked sheet vacuum/press-forms at roughly 140–170 °C surface temperature; bead grades are steam-chest molded, non-crosslinked grades are extruded at about 175–215 °C melt.
What is the maximum service temperature of TPO Foam FR?
TPO Foam FR is rated for continuous use to about 95°C (203 °F), and briefly to 120°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between TPO Foam D45 and TPO Foam D100?
D45 is the default condition — default all-round density: soft touch with usable load bearing for IP/door-trim laminates and sealing. D100: pick for load-bearing spacers, anti-squeak/rattle pads and NVH parts needing firm resilience.
Sources
- ASTM D3575 — Flexible Cellular Materials Made from Olefin Polymers — ASTM International (2020)
- UL 94 — Tests for Flammability of Plastic Materials (HBF/HF-1 foam categories) — UL (2021)
- Crosslinked polyolefin foam sheet product ranges (Alveolit/Alveolux type) — Sekisui Alveo (2023)
- Azote / Plastazote polyolefin foam technical data — Zotefoams (2023)
- Engineered Materials Handbook Vol. 2: Engineering Plastics (cellular polymers) — ASM International (1988)
- Polyolefin foam and TPO compound property records — CAMPUS / UL Prospector (2024)
- TPO/POE — 1688 / SMM (2025)
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.