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EPP Foam · grade

EPP Foam EPP-90

Properties of the EPP-90 condition, compared with the other EPP Foam grades.

Use where crush strength and stiffness matter more than weight: seat structures, tool trays, load-bearing inserts.

What is EPP Foam EPP-90?

EPP Foam EPP-90 is EPP Foam in the EPP-90 grade — use where crush strength and stiffness matter more than weight: seat structures, tool trays, load-bearing inserts. EPP Foam EPP-90 has a tensile strength of 0.95 MPa (0.138 ksi), weaker than 85% of polymer grades. Elongation at break is 16% and the elastic modulus is 0.02 GPa (0.0029 Msi). EPP Foam EPP-90 has a density of 0.09 g/cm³ (0.0033 lb/in³), lighter than 86% of polymer grades. Its glass-transition temperature is -10°C (14 °F). Closed Cell is the default condition FabDigit quotes; EPP-90 is available on request or by drawing note.

Advantages

  • Lightweight — 0.09 g/cm³ (0.0033 lb/in³), better than 86% of polymer grades
  • Good corrosion resistance — 90/100, better than 81% of polymer grades

Limitations

  • Hard to polish — 5/100, worse than 99% of polymer grades
  • Poor heat conductor — 0.05 W/m·K (0.026 BTU/hr·ft·°F), worse than 85% of polymer grades
  • High mold shrinkage — 2%, worse than 81% of polymer grades
  • Low stiffness — 0.02 GPa (0.0029 Msi), worse than 76% of polymer grades
  • Absorbs moisture — dry before molding — 0.6%, worse than 76% of polymer grades

EPP Foam EPP-90 properties

Typical room-temperature values for EPP Foam EPP-90 — 12 properties are specific to this condition; the rest are grade-level values shared by every EPP Foam grade. Each bar shows where the value sits among the polymer grades in FabDigit's library — further right is higher.

Physical5

EPP Foam EPP-90 has a density of 0.09 g/cm³ (0.0033 lb/in³), lighter than 86% of polymer grades. Its glass-transition temperature is -10°C (14 °F).

Density0.09 g/cm³0 lb/in³
Melting Temperature (Tm)162°C324 °F
Glass Transition (Tg)-10°C14 °F
Water Absorption (24 h)0.6%
Water Absorption (Saturation)2.5%

Mechanical11

EPP Foam EPP-90 has a tensile strength of 0.95 MPa (0.138 ksi), weaker than 85% of polymer grades. Elongation at break is 16% and the elastic modulus is 0.02 GPa (0.0029 Msi).

Elastic (Young's) Modulus0.02 GPa0 Msi
Poisson's Ratio0.1
Tensile Strength (Ultimate)0.95 MPa0.14 ksi
Elongation at Break16%
Compressive Strength0.78 MPa0.11 ksi
Compressive Modulus0.01 GPa7.25×10⁻⁴ Msi
Flexural Strength1 MPa0.17 ksi
Flexural Modulus0.02 GPa0 Msi
Shear Strength0.48 MPa0.07 ksi
Tear Strength0.9 kN/m5.1 lbf/in
Compression Set (22 h, 70 °C)6%

Thermal8

EPP Foam EPP-90 is rated for continuous service to 105°C (221 °F). It conducts heat at 0.05 W/m·K (0.026 BTU/hr·ft·°F), worse than 85% of polymer grades. Thermal expansion is 90 µm/m·K (50 µin/in·°F).

Thermal Conductivity0.05 W/m·K0.03 BTU/hr·ft·°F
Specific Heat Capacity1,900 J/kg·K0.45 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)90 µm/m·K50 µin/in·°F
Max Service Temperature (continuous)105°C221 °F
Min Service Temperature-40°C-40 °F
Flammability (UL 94)HB
Limiting Oxygen Index18%
Max Service Temperature (short-term)120°C248 °F

Electrical4

EPP Foam EPP-90 has an electrical resistivity of 1×10¹³ Ω·m.

Electrical Resistivity1×10¹³ Ω·m3.94×10²⁰ µΩ·in
Dielectric Constant (1 MHz)1.06
Volume Resistivity1×10¹⁵ Ω·cm
Surface Resistivity1×10¹⁴ Ω

Chemical & Environmental3

Corrosion resistance is excellent (90/100), better than 81% of polymer grades. UV resistance is poor.

Corrosion ResistanceExcellent90/100
UV / Weathering ResistancePoor30/100
Chemical Resistance SummaryGood against water, dilute acids and alkalis, salt solutions, alcohols and most detergents; swells or softens in aromatic/chlorinated solvents, gasoline and hot oils; poor UV resistance unless carbon-black or HALS stabilized.

Sustainability4

Producing a kilogram of EPP Foam EPP-90 takes about 105 MJ of energy and emits 3.6 kg of CO₂ — more than 54% of polymer grades. Typical recycled content is 5%.

Embodied Energy (primary production)105 MJ/kg45,142 BTU/lb
Embodied Carbon (primary production)3.6 kg CO₂/kg
Embodied Water130 L/kg15.6 gal/lb
Typical Recycled Content5%

Manufacturability6

EPP Foam EPP-90's machinability is good (65/100, better than 66% of polymer grades); weldability fair (45/100); formability poor (30/100).

MachinabilityGood65/100
WeldabilityFair45/100
Formability (cold)Poor30/100
PolishabilityNot recommended5/100
Mold Shrinkage2%
Mold Temperature (typ.)145°C293 °F

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Other EPP Foam grades and fills

EPP Foam is also supplied in 10 other conditions. The full side-by-side table is on the EPP Foam overview.

Working with EPP Foam EPP-90

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.

ElementSpec limit (wt %)Nominal
blowing agent residue (pentane / CO2 / alargely diffused out after aging; cells finally air-filled0 – 20.5
nucleating agent, stabilizers, pigmentantioxidant/HALS, talc nucleant, carbon black or color masterbatch0.3 – 21
antistatic / FR / conductive additiveonly in ESD, COND and FR variants0 – 80
polypropylene (random copolymer base resPP-R / PP block copolymer bead matrix≥ 95 (balance)

EPP Foam EPP-90 — frequently asked

What is EPP Foam EPP-90 used for?

EPP Foam EPP-90 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 EPP-90?

EPP Foam EPP-90 has a typical tensile strength of 0.95 MPa (0.138 ksi) — weaker than 85% of polymer grades. Strength varies by condition: see the 11 listed tempers.

Is EPP Foam EPP-90 easy to machine?

Reasonably — machinability is rated good (65/100, better than 66% 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 EPP-90 be welded?

With care — weldability is rated fair (45/100). 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 EPP-90?

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 EPP-90 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 EPP-90?

EPP Foam EPP-90 is rated for continuous use to about 105°C (221 °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 EPP-90?

Yes — EPP Foam EPP-90 is available for CNC machining, sheet metal and injection molding with instant online pricing. Upload a STEP file to get a price and a DFM check.

Sources

  1. ARPRO expanded polypropylene grade data (density series)JSP (2023)
  2. Neopolen P particle foam product rangeBASF (2022)
  3. Eperan-PP expanded polypropylene technical dataKaneka (2022)
  4. ISO 844 — Rigid cellular plastics, compression testISO (2021)
  5. ISO 1798 — Flexible cellular polymeric materials, tensile strength and elongationISO (2008)
  6. 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.