PVC Foam (Flexible, Closed-Cell) vs Silicone Foam (Sponge Rubber)
Polymer · grade comparison
PVC Foam (Flexible, Closed-Cell) and Silicone Foam (Sponge Rubber) are both polymer grades. Silicone Foam (Sponge Rubber) is the stronger of the two: tensile strength 1 MPa (0.174 ksi) against 0.55 MPa (0.0798 ksi) for PVC Foam (Flexible, Closed-Cell), about 118% more. PVC Foam (Flexible, Closed-Cell) is lighter (0.1 g/cm³ vs 0.32 g/cm³ for Silicone Foam (Sponge Rubber)) and PVC Foam (Flexible, Closed-Cell) is stiffer (0 GPa vs 0 GPa). On the shop floor, PVC Foam (Flexible, Closed-Cell) sits in a lower cost tier (standard, $$) than Silicone Foam (Sponge Rubber) (high, $$$$).
PVC Foam (Flexible, Closed-Cell)Choose it when weight is the constraint, or when cost is the deciding factor.
Silicone Foam (Sponge Rubber)Choose it when strength drives the design, or when the part sees heat.
PVC Foam (Flexible, Closed-Cell) vs Silicone Foam (Sponge Rubber): 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.
PVC Foam (Flexible, Closed-Cell)Silicone Foam (Sponge Rubber)
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Compressive Modulus
Shear Strength
Hardness, Shore A
Tear Strength
Compression Set (22 h, 70 °C)
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)
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Constant (1 MHz)
Volume Resistivity
Dielectric Strength
Dissipation Factor (1 MHz)
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
Formability (cold)
Processing Melt Temperature (typ.)
Mold Shrinkage
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
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 | PVC Foam (Flexible, Closed-Cell) | Silicone Foam (Sponge Rubber) |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
PVC Foam (Flexible, Closed-Cell) vs Silicone Foam (Sponge Rubber) — frequently asked
Is Silicone Foam (Sponge Rubber) stronger than PVC Foam (Flexible, Closed-Cell)?
Yes. Silicone Foam (Sponge Rubber) has a typical tensile strength of 1 MPa (0.174 ksi) against 0.55 MPa (0.0798 ksi) for PVC Foam (Flexible, Closed-Cell) — about 118% more.
Which is cheaper, PVC Foam (Flexible, Closed-Cell) or Silicone Foam (Sponge Rubber)?
PVC Foam (Flexible, Closed-Cell) is the lower-cost material: it sits in the standard tier ($$) while Silicone Foam (Sponge Rubber) is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
When should I choose PVC Foam (Flexible, Closed-Cell) over Silicone Foam (Sponge Rubber)?
Pick PVC Foam (Flexible, Closed-Cell) when weight is the constraint, or when cost is the deciding factor. Pick Silicone Foam (Sponge Rubber) when strength drives the design, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PVC Foam (Flexible, Closed-Cell) and Silicone Foam (Sponge Rubber) 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.