EPP
A bead-foam form of PP offering high energy-absorption, multiple-impact recovery and chemical resistance combined with very low density; used in reusable packaging and automotive energy-management parts.
Reference datasheet — EPP is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the EPP30 condition
EPP grades and fills
EPP is supplied in 8 conditions, soft to hard. EPP30 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
EPP 20 g/L | Lightest standard grade for low-mass void fill and light protective packaging where loads are small. | 0.18 | 0.25 | 15 | 15 Shore A |
Flame-retardant EPP | Specify where transport, rail-interior or appliance fire requirements demand better than plain HB behaviour. | 0.26 | 0.35 | 14 | 18 Shore A |
Cold drawn | Use for ESD-protective trays and shielding-class dunnage needing permanent, humidity-independent conductivity. | 0.36 | 15 | ||
EPP30Default EPP 30 g/L | The general-purpose density for reusable packaging, dunnage and automotive trim energy absorbers. | 0.4 | 18 | ||
EPP 45 g/L | Choose when heavier parts or higher crush loads must be carried with still-good multi-impact recovery. | 0.45 | 0.6 | 20 | 25 Shore A |
EPP 60 g/L | Used for bumper cores, knee bolsters and heavy-duty returnable containers needing higher plateau stress. | 0.65 | 0.85 | 22 | 30 Shore A |
EPP 90 g/L | For load-bearing cores, tool trays and crash structures where stiffness matters more than mass saving. | 1 | 1 | 24 | 40 Shore A |
EPP 120 g/L | Highest standard density, for severe repeated impact and semi-structural inserts where crush stress must be maximised. | 1 | 2 | 25 | 46 Shore A |
Supply forms, finishes and certifications
Ways EPP is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
AS | Antistatic (dissipative) EPP | Coating |
FG | Food-contact / medical grade EPP | Certification |
UV | UV-stabilized / black weatherable EPP | Grade option |
What is EPP?
A bead-foam form of PP offering high energy-absorption, multiple-impact recovery and chemical resistance combined with very low density; used in reusable packaging and automotive energy-management parts. EPP has a density of 0.03 g/cm³ (0.0011 lb/in³), lighter than 94% of polymer grades. Its glass-transition temperature is -12°C (10 °F). EPP has a tensile strength of 0.4 MPa (0.058 ksi), weaker than 91% of polymer grades. Elongation at break is 18% and the elastic modulus is 0 GPa (5.8×10⁻⁴ Msi).
What is EPP used for?
- Automotive bumper energy absorbers
- Reusable protective packaging
- Sound/vibration insulation
- Sports protective gear
- Returnable dunnage trays
Advantages
- Lightweight — 0.03 g/cm³ (0.0011 lb/in³), better than 94% of polymer grades
- Good corrosion resistance — 90/100, better than 82% of polymer grades
Limitations
- High mold shrinkage — 2.5%, worse than 93% of polymer grades
- Poor heat conductor — 0.04 W/m·K (0.0208 BTU/hr·ft·°F), worse than 92% of polymer grades
- Low stiffness — 0 GPa (5.8×10⁻⁴ Msi), worse than 91% of polymer grades
- Degrades in UV without stabilisers — 25/100, worse than 76% of polymer grades
- Absorbs moisture — dry before molding — 0.6%, worse than 75% of polymer grades
EPP properties
Typical room-temperature values for EPP-EPP30; bars are the position among polymer grades.
Physical5
EPP has a density of 0.03 g/cm³ (0.0011 lb/in³), lighter than 94% of polymer grades. Its glass-transition temperature is -12°C (10 °F).
Mechanical10
EPP has a tensile strength of 0.4 MPa (0.058 ksi), weaker than 91% of polymer grades. Elongation at break is 18% and the elastic modulus is 0 GPa (5.8×10⁻⁴ Msi).
Thermal8
EPP is rated for continuous service to 100°C (212 °F). It conducts heat at 0.04 W/m·K (0.0208 BTU/hr·ft·°F), worse than 92% of polymer grades. Thermal expansion is 90 µm/m·K (50 µin/in·°F).
Electrical5
EPP has an electrical resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), better than 82% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of EPP takes about 100 MJ of energy and emits 3.8 kg of CO₂ — less than 61% of polymer grades. Typical recycled content is 10%.
Manufacturability4
EPP's machinability is good (60/100, better than 51% of polymer grades); weldability good (55/100); formability fair (35/100).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. EPP is highlighted; hover a dot for its name, or open the interactive family chart.
Working with EPP
Is EPP easy to machine?
Blocks cut cleanly with hot wire, band knife or CNC router at high feed; avoid slow, high-friction tooling that melts and smears the skin.
Can EPP be welded?
Beads fuse to each other by saturated steam in the mould; parts can be joined by hot-air/hot-plate welding, ultrasonic staking or PP-compatible hot-melt and double-sided tape—solvent glues do not bond PP.
Can EPP be formed, bent or molded?
Made by steam-chest bead moulding (typ. 0.20–0.40 MPa steam, ~130–145 °C) after bead pre-expansion; allow 1.5–3.5% shrink plus post-mould stabilization/drying, and design generous draft and steam-hole layout.
EPP 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 |
|---|---|---|
| ethylene comonomerin random-copolymer EPP beads, lowers fusion temperature | 0 – 8 | 4 |
| blowing agent residue (CO2 / pentane / acell gas largely replaced by air after ageing | 0 – 1 | 0.3 |
| stabilizers / nucleants / pigmentsantioxidant, talc nucleant, colour; carbon black in conductive grades | 0.1 – 3 | 1 |
| propylene (PP repeat unit)high-melt-strength homopolymer or random copolymer base resin | ≥ 92 (balance) |
What surface finishes work on EPP?
Surfaces accept flame or corona pre-treatment then PP-compatible primer/water-based paint, in-mould films and skins; no plating or anodizing, and printing needs low-tack, low-solvent inks.
How much does EPP cost?
EPP is a premium-cost polymer ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
EPP — frequently asked
What is EPP used for?
EPP is typically used for automotive bumper energy absorbers, reusable protective packaging, sound/vibration insulation, sports protective gear and returnable dunnage trays. In short: lightest structural PP form; multi-impact energy absorber; reusable packaging foam.
What is the tensile strength of EPP?
EPP has a typical tensile strength of 0.4 MPa (0.058 ksi) — weaker than 91% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is EPP easy to machine?
Reasonably — machinability is rated good (60/100, better than 51% of polymer grades). Blocks cut cleanly with hot wire, band knife or CNC router at high feed; avoid slow, high-friction tooling that melts and smears the skin.
Can EPP be welded?
Yes — weldability is rated good (55/100). Beads fuse to each other by saturated steam in the mould; parts can be joined by hot-air/hot-plate welding, ultrasonic staking or PP-compatible hot-melt and double-sided tape—solvent glues do not bond PP.
What surface finishes work on EPP?
Surfaces accept flame or corona pre-treatment then PP-compatible primer/water-based paint, in-mould films and skins; no plating or anodizing, and printing needs low-tack, low-solvent inks.
Can EPP be formed, bent or molded?
Made by steam-chest bead moulding (typ. 0.20–0.40 MPa steam, ~130–145 °C) after bead pre-expansion; allow 1.5–3.5% shrink plus post-mould stabilization/drying, and design generous draft and steam-hole layout.
What is the maximum service temperature of EPP?
EPP is rated for continuous use to about 100°C (212 °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 EPP30 and EPP120?
EPP30 is the default condition — the general-purpose density for reusable packaging, dunnage and automotive trim energy absorbers. EPP120: highest standard density, for severe repeated impact and semi-structural inserts where crush stress must be maximised.
How much does EPP cost?
EPP is a premium-cost polymer ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ARPRO Expanded Polypropylene technical data (density range 20–120 g/L) — JSP (2023)
- Neopolen P particle foam product information — BASF (2022)
- Eperan-PP expanded polypropylene data sheets — Kaneka (2022)
- Engineered Materials Handbook Vol. 2: Engineering Plastics (polypropylene) — ASM International (1988)
- Cellular Solids: Structure and Properties — Cambridge University Press (Gibson & Ashby) (1997)
- Polypropylene foam property records — CAMPUS / UL Prospector (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.