FabDigit

EPP Foam vs Poron and 2 more: properties

EPP FoamPoronPU FoamEVA Foam

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.01 GPa0 Msi
0 GPa2.18×10⁻⁴ Msi
2×10⁻⁴ GPa2.9×10⁻⁵ Msi
0.01 GPa7.25×10⁻⁴ Msi

Poisson's Ratio

0.1
0.3
0.3
0.3

Tensile Strength (Ultimate)

0.5 MPa0.07 ksi
1 MPa0.15 ksi
0.13 MPa0.02 ksi
1 MPa0.15 ksi

Elongation at Break

15%
150%
150%
200%

Compressive Strength

0.3 MPa0.04 ksi
0.07 MPa0.01 ksi
0.01 MPa7.25×10⁻⁴ ksi
0.1 MPa0.01 ksi

Compressive Modulus

0.01 GPa7.25×10⁻⁴ Msi
8×10⁻⁴ GPa1.16×10⁻⁴ Msi
0 GPa5.8×10⁻⁴ Msi

Flexural Strength

0.6 MPa0.09 ksi

Flexural Modulus

0.01 GPa0 Msi

Shear Strength

0.25 MPa0.04 ksi
0.35 MPa0.05 ksi

Tear Strength

0.9 kN/m5.1 lbf/in
2 kN/m8.6 lbf/in
0.3 kN/m1.7 lbf/in
2 kN/m8.6 lbf/in

Compression Set (22 h, 70 °C)

8%
5%
5%
15%

Hardness, Shore A

20 Shore A
30 Shore A

Physical

Density and transition temperatures.

Density

0.05 g/cm³0 lb/in³
0.32 g/cm³0.01 lb/in³
0.03 g/cm³0 lb/in³
0.06 g/cm³0 lb/in³

Melting Temperature (Tm)

162°C324 °F
85°C185 °F

Glass Transition (Tg)

-10°C14 °F
-35°C-31 °F
-50°C-58 °F
-30°C-22 °F

Water Absorption (24 h)

0.6%
3%
0.5%

Water Absorption (Saturation)

2.5%
800%
2%

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.04 W/m·K0.02 BTU/hr·ft·°F
0.06 W/m·K0.03 BTU/hr·ft·°F
0.04 W/m·K0.02 BTU/hr·ft·°F
0.04 W/m·K0.02 BTU/hr·ft·°F

Specific Heat Capacity

1,900 J/kg·K0.45 BTU/lb·°F
1,700 J/kg·K0.41 BTU/lb·°F
1,500 J/kg·K0.36 BTU/lb·°F
2,100 J/kg·K0.5 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

90 µm/m·K50 µin/in·°F
70 µm/m·K38.9 µin/in·°F
180 µm/m·K100 µin/in·°F

Max Service Temperature (continuous)

100°C212 °F
90°C194 °F
90°C194 °F
70°C158 °F

Min Service Temperature

-40°C-40 °F
-40°C-40 °F
-40°C-40 °F
-50°C-58 °F

Limiting Oxygen Index

18%
19%
18%

Max Service Temperature (short-term)

120°C248 °F
120°C248 °F
120°C248 °F
90°C194 °F

Vicat Softening Point (B50)

55°C131 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in

Dielectric Constant (1 MHz)

1.06
1.7
1.1
1.4

Volume Resistivity

1×10¹⁵ Ω·cm
1×10¹³ Ω·cm
1×10¹² Ω·cm
1×10¹⁴ Ω·cm

Surface Resistivity

1×10¹⁴ Ω
1×10¹³ Ω

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

90 / 100
70 / 100
90 / 100

UV / Weathering Resistance

30 / 100
40 / 100
25 / 100
35 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

60 / 100
80 / 100
90 / 100
85 / 100

Weldability

45 / 100
30 / 100
70 / 100

Formability (cold)

30 / 100
90 / 100
90 / 100
90 / 100

Polishability

5 / 100
5 / 100
10 / 100

Mold Shrinkage

2%
1.5%
2.5%

Mold Temperature (typ.)

145°C293 °F
50°C122 °F
165°C329 °F

Melt Flow Rate

2.5 g/10 min

Processing Melt Temperature (typ.)

160°C320 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

105 MJ/kg45,142 BTU/lb
100 MJ/kg42,992 BTU/lb
102 MJ/kg43,852 BTU/lb
75 MJ/kg32,244 BTU/lb

Embodied Carbon (primary production)

3.6 kg CO₂/kg
5 kg CO₂/kg
4.6 kg CO₂/kg
3.4 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
220 L/kg26.4 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

5%
0%
10%
15%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

11 kN·m/kg
3 kN·m/kg
4 kN·m/kg
17 kN·m/kg

Specific Stiffness (E / density)

0.2 MN·m/kg
0 MN·m/kg
0 MN·m/kg
0.1 MN·m/kg

Thermal Diffusivity

0.5 mm²/s
0.1 mm²/s
0.8 mm²/s
0.3 mm²/s

Strength versus weight

Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scalePU FoamEPP FoamPoronEVA Foam

Manufacturing and finishing

CapabilityEPP FoamPoronPU FoamEVA Foam
Default conditionClosed CellStandardOpen CellClosed Cell
Relative cost$$ Standard$$ Standard$ Budget$$ Standard
Min. machined wall
Best machined surface

Both are offered for Injection molding. Both take the same 5 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Soft Touch Coating, Spray Painting, UV Coating.

Ready to make it?

Upload a CAD file and FabDigit prices the part in EPP Foam and Poron side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.