EPDM Foam vs TPO Foam
Polymer · grade comparison
EPDM Foam and TPO Foam are both polymer grades. EPDM Foam is the stronger of the two: tensile strength 0.55 MPa (0.0798 ksi) against 0.35 MPa (0.0508 ksi) for TPO Foam, about 57% more. TPO Foam is lighter (0.05 g/cm³ vs 0.1 g/cm³ for EPDM Foam) and EPDM Foam is stiffer (0 GPa vs 0 GPa). On the shop floor, EPDM Foam machines more easily (excellent vs good) and TPO Foam welds better (very good vs poor).
EPDM FoamChoose it when strength drives the design, or when the part sees heat.
TPO FoamChoose it when weight is the constraint, or when it will be welded.
EPDM Foam vs TPO Foam: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Shear Strength
Hardness, Shore A
Tear Strength
Compression Set (22 h, 70 °C)
Compressive Modulus
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Melting Temperature (Tm)
Thermal
How each material carries heat and how hot it can run.
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Thermal Conductivity 0.04 W/m·K0.02 BTU/hr·ft·°F · Specific Heat Capacity 1,900 J/kg·K0.45 BTU/lb·°F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Volume Resistivity
Dissipation Factor (1 MHz)
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
UV / Weathering Resistance
Same in both: Corrosion Resistance 88 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Same in both: Embodied Carbon (primary production) 3.6 kg CO₂/kg · Typical Recycled Content 5%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Thermal Diffusivity
Same in both: Specific Stiffness (E / density) 0 MN·m/kg · Thermal Shock Resistance Index 0
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.
Manufacturing and finishing
| Capability | EPDM Foam | TPO Foam |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | — | — |
| Best machined surface | — | — |
EPDM Foam vs TPO Foam — frequently asked
Is EPDM Foam stronger than TPO Foam?
Yes. EPDM Foam has a typical tensile strength of 0.55 MPa (0.0798 ksi) against 0.35 MPa (0.0508 ksi) for TPO Foam — about 57% more.
Which is cheaper, EPDM Foam or TPO Foam?
Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, EPDM Foam or TPO Foam?
EPDM Foam. Its machinability rates excellent (85/100) against good (60/100) for TPO Foam; for welding the order is TPO Foam first (very good, 70/100) then EPDM Foam (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in EPDM Foam and TPO Foam 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.