PVC Foam (Rigid, Structural Core) vs Silicone Foam (Sponge Rubber)
Polymer · grade comparison
PVC Foam (Rigid, Structural Core) and Silicone Foam (Sponge Rubber) are both polymer grades. PVC Foam (Rigid, Structural Core) is the stronger of the two: tensile strength 3 MPa (0.363 ksi) against 1 MPa (0.174 ksi) for Silicone Foam (Sponge Rubber), about 108% more. In exchange, Silicone Foam (Sponge Rubber) is the more ductile: elongation 160% versus 10% for PVC Foam (Rigid, Structural Core). PVC Foam (Rigid, Structural Core) is lighter (0.08 g/cm³ vs 0.32 g/cm³ for Silicone Foam (Sponge Rubber)) and PVC Foam (Rigid, Structural Core) is stiffer (0.1 GPa vs 0 GPa). On the shop floor, PVC Foam (Rigid, Structural Core) machines more easily (excellent vs very good).
PVC Foam (Rigid, Structural Core)Choose it when strength drives the design, or when weight is the constraint.
Silicone Foam (Sponge Rubber)Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
PVC Foam (Rigid, Structural Core) 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 (Rigid, Structural Core)Silicone Foam (Sponge Rubber)
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
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)
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
Heat Deflection Temp. @ 0.45 MPa
Limiting Oxygen Index
Max Service Temperature (short-term)
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Constant (1 MHz)
Dielectric Strength
Dissipation Factor (1 MHz)
Volume Resistivity
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)
Mold Shrinkage
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
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 | PVC Foam (Rigid, Structural Core) | Silicone Foam (Sponge Rubber) |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
PVC Foam (Rigid, Structural Core) vs Silicone Foam (Sponge Rubber) — frequently asked
Is PVC Foam (Rigid, Structural Core) stronger than Silicone Foam (Sponge Rubber)?
Yes. PVC Foam (Rigid, Structural Core) has a typical tensile strength of 3 MPa (0.363 ksi) against 1 MPa (0.174 ksi) for Silicone Foam (Sponge Rubber) — about 108% more.
Which is cheaper, PVC Foam (Rigid, Structural Core) or Silicone Foam (Sponge Rubber)?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PVC Foam (Rigid, Structural Core) or Silicone Foam (Sponge Rubber)?
PVC Foam (Rigid, Structural Core). Its machinability rates excellent (90/100) against very good (80/100) for Silicone Foam (Sponge Rubber).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PVC Foam (Rigid, Structural Core) 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.