PMI Foam vs Syntactic Foam (Epoxy)
Polymer · grade comparison
PMI Foam and Syntactic Foam (Epoxy) are both polymer grades. Syntactic Foam (Epoxy) is the stronger of the two: tensile strength 12 MPa (1.74 ksi) against 2 MPa (0.319 ksi) for PMI Foam, about 5.5 times as much. In exchange, PMI Foam is the more ductile: elongation 3% versus 1.5% for Syntactic Foam (Epoxy). PMI Foam is lighter (0.08 g/cm³ vs 0.45 g/cm³ for Syntactic Foam (Epoxy)) and Syntactic Foam (Epoxy) is stiffer (2.4 GPa vs 0.09 GPa). On the shop floor, PMI Foam machines more easily (excellent vs good).
PMI FoamChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
Syntactic Foam (Epoxy)Choose it when strength drives the design.
PMI Foam vs Syntactic Foam (Epoxy): 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.
PMI FoamSyntactic Foam (Epoxy)
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Shear Strength
Bulk Modulus
Flexural Modulus
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Same in both: Poisson's Ratio 0.3
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Limiting Oxygen Index
Max Service Temperature (short-term)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Electrical
Conductivity and insulation.
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Electrical Resistivity
Dielectric Strength
Volume Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 35 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Polishability
Weldability
Mold Shrinkage
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Same in both: Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
Same in both: 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 | PMI Foam | Syntactic Foam (Epoxy) |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
PMI Foam vs Syntactic Foam (Epoxy) — frequently asked
Is Syntactic Foam (Epoxy) stronger than PMI Foam?
Yes. Syntactic Foam (Epoxy) has a typical tensile strength of 12 MPa (1.74 ksi) against 2 MPa (0.319 ksi) for PMI Foam — about 5.5 times as much.
Which is cheaper, PMI Foam or Syntactic Foam (Epoxy)?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PMI Foam or Syntactic Foam (Epoxy)?
PMI Foam. Its machinability rates excellent (85/100) against good (60/100) for Syntactic Foam (Epoxy).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PMI Foam and Syntactic Foam (Epoxy) 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.