PC-Foam vs PC-Si
Polymer · grade comparison
PC-Foam and PC-Si are both polymer grades. PC-Si is the stronger of the two: yield strength 58 MPa (8.41 ksi) against 43 MPa (6.24 ksi) for PC-Foam, about 35% more; tensile strength follows at 60 MPa (8.7 ksi) vs 45 MPa (6.53 ksi). PC-Si is the more ductile: elongation 120% versus 18% for PC-Foam. PC-Foam is lighter (1 g/cm³ vs 1.19 g/cm³ for PC-Si) and PC-Si is stiffer (2.2 GPa vs 1.8 GPa). On the shop floor, PC-Si welds better (very good vs fair) and PC-Foam sits in a lower cost tier (standard, $$) than PC-Si (premium, $$$).
PC-FoamChoose it when weight is the constraint, or when cost is the deciding factor.
PC-SiChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
PC-Foam vs PC-Si: 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
Shear Modulus
Bulk 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)
Izod Impact, Notched
Hardness, Rockwell M
Hardness, Rockwell R
Hardness, Shore D
Same in both: Poisson's Ratio 0.38
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Specific Heat Capacity 1,200 J/kg·K0.29 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 68 µm/m·K37.8 µin/in·°F · Max Service Temperature (continuous) 115°C239 °F
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 250 V
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)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 250 L/kg30 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Same in both: Specific Stiffness (E / density) 1.8 MN·m/kg · Thermal Diffusivity 0.1 mm²/s · 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 | PC-Foam | PC-Si |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$$ Premium |
| Min. machined wall | — | — |
| Best machined surface | — | — |
PC-Foam vs PC-Si — frequently asked
Is PC-Si stronger than PC-Foam?
Yes. PC-Si has a typical yield strength of 58 MPa (8.41 ksi) against 43 MPa (6.24 ksi) for PC-Foam — about 35% more. Tensile strength is 60 MPa (8.7 ksi) vs 45 MPa (6.53 ksi).
Which is cheaper, PC-Foam or PC-Si?
PC-Foam is the lower-cost material: it sits in the standard tier ($$) while PC-Si is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which welds better, PC-Foam or PC-Si?
PC-Si. Its weldability rates very good (70/100) against fair (50/100) for PC-Foam.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PC-Foam and PC-Si 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.