EPP Foam FR (Flame-retardant EPP)
Flame-retardant grade
Choose where rail/transport or appliance fire specs (e.g. FMVSS 302, UL 94 HF-1) must be met.
Values for the FR condition
Other EPP Foam grades and fills
EPP Foam is listed in 9 conditions; see the grade overview at EPP Foam.
Compare all 9 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
EPP 20 g/L | Pick for lightest-weight void fill and light-goods packaging where load is very low. | — | 0.2 | 14 | — |
EPP 30 g/L | Common packaging / RC-model and drone-airframe density: light, still resilient after repeated impacts. | — | 0.33 | 15 | — |
Conductive EPP | Use for ESD-safe trays needing true dissipative/conductive path; also improves UV resistance from carbon black. | — | 0.44 | 11 | 31 Shore A |
FRThis page Flame-retardant EPP | Choose where rail/transport or appliance fire specs (e.g. FMVSS 302, UL 94 HF-1) must be met. | — | 0.45 | 12 | 30 Shore A |
ESD / antistatic EPP | Pick for electronics returnable packaging where charge build-up on the foam must be limited. | — | 0.47 | 13 | 30 Shore A |
Closed CellDefault standard steam-molded EPP bead foam (≈45 g/L) | Default all-round EPP for automotive energy absorbers, returnable packaging and cushioning; best strength/weight compromise. | — | 0.5 | 15 | — |
EPP 60 g/L | Choose for higher-energy automotive bumper cores and returnable dunnage needing more crush strength. | — | 0.66 | 16 | — |
EPP 90 g/L | Use where crush strength and stiffness matter more than weight: seat structures, tool trays, load-bearing inserts. | — | 0.95 | 16 | — |
EPP 120 g/L | Top of the density range for structural/semi-load-bearing foam cores and heavy-duty pallet or fixture bodies. | — | 1 | 16 | — |
What is EPP Foam FR?
EPP Foam FR is EPP Foam in the FR grade — choose where rail/transport or appliance fire specs (e.g. FMVSS 302, UL 94 HF-1) must be met. EPP Foam FR has a tensile strength of 0.45 MPa (0.0653 ksi), weaker than 90% of polymer grades. Elongation at break is 12% and the elastic modulus is 0.01 GPa (0.0011 Msi). EPP Foam FR has a density of 0.05 g/cm³ (0.0016 lb/in³), lighter than 90% of polymer grades. Its glass-transition temperature is -10°C (14 °F). Closed Cell is the default condition FabDigit quotes; FR is available on request or by drawing note.
Advantages
- Lightweight — 0.05 g/cm³ (0.0016 lb/in³), better than 90% of polymer grades
Limitations
- Hard to polish — 5/100, worse than 99% of polymer grades
- Poor heat conductor — 0.04 W/m·K (0.0225 BTU/hr·ft·°F), worse than 88% of polymer grades
- Low stiffness — 0.01 GPa (0.0011 Msi), worse than 83% of polymer grades
- High mold shrinkage — 2%, worse than 81% of polymer grades
- Absorbs moisture — dry before molding — 0.6%, worse than 75% of polymer grades
EPP Foam FR properties
Typical room-temperature values for EPP Foam FR; 20 are specific to this condition. Other listed values are EPP Foam reference data and may not represent this condition. Bars are the position among polymer grades.
Physical5
EPP Foam FR has a density of 0.05 g/cm³ (0.0016 lb/in³), lighter than 90% of polymer grades. Its glass-transition temperature is -10°C (14 °F).
Mechanical11
EPP Foam FR has a tensile strength of 0.45 MPa (0.0653 ksi), weaker than 90% of polymer grades. Elongation at break is 12% and the elastic modulus is 0.01 GPa (0.0011 Msi).
Thermal8
EPP Foam FR is rated for continuous service to 100°C (212 °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 90 µm/m·K (50 µin/in·°F).
Electrical4
EPP Foam FR has an electrical resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 74% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of EPP Foam FR takes about 105 MJ of energy and emits 3.6 kg of CO₂ — more than 54% of polymer grades. Typical recycled content is 5%.
Manufacturability6
EPP Foam FR's machinability is good (60/100, better than 51% of polymer grades); weldability fair (42/100); formability poor (28/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with EPP Foam FR
Is EPP Foam easy to machine?
Cuts easily with hot wire, band saw, oscillating knife, CNC router (sharp single-flute, high feed) or waterjet; expect fuzzy bead-fracture edges and static-clinging debris.
Can EPP Foam be welded?
Blocks and skins can be joined by hot-plate/hot-air fusion or PP-compatible hot-melt; solvent bonding does not work, and most PSA tapes need corona/flame treatment or primer.
Can EPP Foam be formed, bent or molded?
Shaped by steam-chest molding of pre-expanded beads (saturated steam ≈0.15–0.40 MPa); allow ~1.2–3% shrinkage plus post-mold shrink/aging, and design draft, vent-pin layout and uniform wall thickness.
What surface finishes work on EPP Foam?
Cannot be polished or plated; use in-mold film/skin, flocking, water-based PP-adhesion-promoter paint or laser-marked labels, and use molded-in inserts rather than tapped threads.
EPP 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 |
|---|---|---|
| blowing agent residue (pentane / CO2 / alargely diffused out after aging; cells finally air-filled | 0 – 2 | 0.5 |
| nucleating agent, stabilizers, pigmentantioxidant/HALS, talc nucleant, carbon black or color masterbatch | 0.3 – 2 | 1 |
| antistatic / FR / conductive additiveonly in ESD, COND and FR variants | 0 – 8 | 0 |
| polypropylene (random copolymer base resPP-R / PP block copolymer bead matrix | ≥ 95 (balance) | — |
EPP Foam FR — frequently asked
What is EPP Foam FR used for?
EPP Foam FR is typically used for car bumper energy-absorbing inserts, seat cores and headrests, protective packaging foam, returnable shipping containers, robot and drone bumpers and automotive interior trim padding. In short: lightweight closed-cell EPP.
What is the tensile strength of EPP Foam FR?
EPP Foam FR has a typical tensile strength of 0.45 MPa (0.0653 ksi) — weaker than 90% of polymer grades. Strength varies by condition: see the 9 listed tempers.
Is EPP Foam FR easy to machine?
Reasonably — machinability is rated good (60/100, better than 51% of polymer grades). Cuts easily with hot wire, band saw, oscillating knife, CNC router (sharp single-flute, high feed) or waterjet; expect fuzzy bead-fracture edges and static-clinging debris.
Can EPP Foam FR be welded?
With care — weldability is rated fair (42/100). Blocks and skins can be joined by hot-plate/hot-air fusion or PP-compatible hot-melt; solvent bonding does not work, and most PSA tapes need corona/flame treatment or primer.
What surface finishes work on EPP Foam FR?
Cannot be polished or plated; use in-mold film/skin, flocking, water-based PP-adhesion-promoter paint or laser-marked labels, and use molded-in inserts rather than tapped threads.
Can EPP Foam FR be formed, bent or molded?
Shaped by steam-chest molding of pre-expanded beads (saturated steam ≈0.15–0.40 MPa); allow ~1.2–3% shrinkage plus post-mold shrink/aging, and design draft, vent-pin layout and uniform wall thickness.
What is the maximum service temperature of EPP Foam FR?
EPP Foam FR is rated for continuous use to about 100°C (212 °F), and briefly to 120°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in EPP Foam FR?
Yes — EPP Foam FR is available for injection molding; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ARPRO expanded polypropylene grade data (density series) — JSP (2023)
- Neopolen P particle foam product range — BASF (2022)
- Eperan-PP expanded polypropylene technical data — Kaneka (2022)
- ISO 844 — Rigid cellular plastics, compression test — ISO (2021)
- ISO 1798 — Flexible cellular polymeric materials, tensile strength and elongation — ISO (2008)
- Engineered Materials Handbook Vol. 2: Engineering Plastics (polypropylene data) — 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.