HR Foam vs Viscoelastic PU Foam
Polymer · grade comparison
HR Foam and Viscoelastic PU Foam are both polymer grades. HR Foam is the stronger of the two: tensile strength 0.13 MPa (0.0189 ksi) against 0.1 MPa (0.0145 ksi) for Viscoelastic PU Foam, about 30% more. In exchange, Viscoelastic PU Foam is the more ductile: elongation 150% versus 130% for HR Foam. HR Foam is lighter (0.05 g/cm³ vs 0.05 g/cm³ for Viscoelastic PU Foam) and Viscoelastic PU Foam is stiffer (2.5×10⁻⁴ GPa vs 2×10⁻⁵ GPa). On the shop floor, HR Foam machines more easily (excellent vs good), HR Foam welds better (fair vs poor), and HR Foam sits in a lower cost tier (standard, $$) than Viscoelastic PU Foam (premium, $$$).
HR FoamChoose it when strength drives the design, or when weight is the constraint.
Viscoelastic PU FoamChoose it when the part is bent, formed or impact-loaded.
HR Foam vs Viscoelastic PU 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
Compressive Modulus
Tear Strength
Compression Set (22 h, 70 °C)
Shear Strength
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Max Service Temperature (continuous)
Min Service Temperature
Limiting Oxygen Index
Same in both: Max Service Temperature (short-term) 120°C248 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in · Volume Resistivity 1×10¹² Ω·cm
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Mold Shrinkage
Mold Temperature (typ.)
Same in both: Formability (cold) 90 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 103 MJ/kg44,282 BTU/lb
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
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 | HR Foam | Viscoelastic PU Foam |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$$ Premium |
| Min. machined wall | — | — |
| Best machined surface | — | — |
HR Foam vs Viscoelastic PU Foam — frequently asked
Is HR Foam stronger than Viscoelastic PU Foam?
Yes. HR Foam has a typical tensile strength of 0.13 MPa (0.0189 ksi) against 0.1 MPa (0.0145 ksi) for Viscoelastic PU Foam — about 30% more.
Which is cheaper, HR Foam or Viscoelastic PU Foam?
HR Foam is the lower-cost material: it sits in the standard tier ($$) while Viscoelastic PU Foam is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, HR Foam or Viscoelastic PU Foam?
HR Foam. Its machinability rates excellent (85/100) against good (60/100) for Viscoelastic PU Foam; for welding the order is HR Foam first (fair, 40/100) then Viscoelastic PU Foam (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in HR Foam and Viscoelastic PU 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.