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PVC Foam (Rigid, Structural Core) vs Syntactic Foam (Epoxy)

Polymer · grade comparison

PVC Foam (Rigid, Structural Core) 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 3 MPa (0.363 ksi) for PVC Foam (Rigid, Structural Core), about 4.8 times as much. In exchange, PVC Foam (Rigid, Structural Core) is the more ductile: elongation 10% versus 1.5% for Syntactic Foam (Epoxy). PVC Foam (Rigid, Structural Core) 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 0.1 GPa). On the shop floor, PVC Foam (Rigid, Structural Core) machines more easily (excellent vs good) and PVC Foam (Rigid, Structural Core) welds better (poor vs not recommended).

PVC Foam (Rigid, Structural Core)Choose 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, or when the part sees heat.

PVC Foam (Rigid, Structural Core) vs Syntactic Foam (Epoxy): properties

PVC Foam (Rigid, Structural Core)Syntactic Foam (Epoxy)

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.1 GPa0.01 Msi
2.4 GPa0.35 Msi

Shear Modulus

0.03 GPa0 Msi
0.9 GPa0.13 Msi

Tensile Strength (Ultimate)

3 MPa0.36 ksi
12 MPa1.7 ksi

Yield Strength (0.2% offset)

1 MPa0.17 ksi
—

Elongation at Break

10%
1.5%

Compressive Strength

1 MPa0.2 ksi
48 MPa7 ksi

Compressive Modulus

0.09 GPa0.01 Msi
2.4 GPa0.35 Msi

Flexural Strength

2 MPa0.29 ksi
22 MPa3.2 ksi

Flexural Modulus

0.08 GPa0.01 Msi
2.2 GPa0.32 Msi

Shear Strength

1 MPa0.17 ksi
15 MPa2.2 ksi

Fracture Toughness (K_IC)

0.12 MPa·√m0.11 ksi·√in
0.7 MPa·√m0.64 ksi·√in

Bulk Modulus

—
2 GPa0.29 Msi

Izod Impact, Notched

—
20 J/m0.37 ft·lbf/in

Hardness, Shore D

—
80 Shore D

Hardness, Rockwell M

—
80 HRM

Same in both: Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Density

0.08 g/cm³0 lb/in³
0.45 g/cm³0.02 lb/in³

Glass Transition (Tg)

80°C176 °F
100°C212 °F

Water Absorption (24 h)

—
0.1%

Water Absorption (Saturation)

—
1.2%

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.03 W/m·K0.02 BTU/hr·ft·°F
0.12 W/m·K0.07 BTU/hr·ft·°F

Specific Heat Capacity

1,400 J/kg·K0.33 BTU/lb·°F
1,100 J/kg·K0.26 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

40 µm/m·K22.2 µin/in·°F
32 µm/m·K17.8 µin/in·°F

Max Service Temperature (continuous)

70°C158 °F
80°C176 °F

Min Service Temperature

-200°C-328 °F
-60°C-76 °F

Heat Deflection Temp. @ 0.45 MPa

75°C167 °F
98°C208 °F

Limiting Oxygen Index

27%
23%

Max Service Temperature (short-term)

90°C194 °F
105°C221 °F

Heat Deflection Temp. @ 1.8 MPa

—
85°C185 °F

Electrical

Conductivity and insulation.

Dielectric Constant (1 MHz)

1.12
2

Dielectric Strength

—
9 kV/mm229 V/mil

Dissipation Factor (1 MHz)

—
0.008

Volume Resistivity

—
1×10¹⁴ Ω·cm

Same in both: Electrical Resistivity 1×10¹² Ω·m3.94×10¹⁹ µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

80 / 100
85 / 100

UV / Weathering Resistance

30 / 100
35 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

90 / 100
60 / 100

Weldability

15 / 100
0 / 100

Formability (cold)

25 / 100
0 / 100

Polishability

—
20 / 100

Mold Shrinkage

—
0.2%

Mold Temperature (typ.)

—
70°C158 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

95 MJ/kg40,843 BTU/lb
105 MJ/kg45,142 BTU/lb

Embodied Carbon (primary production)

4.5 kg CO₂/kg
6 kg CO₂/kg

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

31 kN·m/kg
27 kN·m/kg

Specific Stiffness (E / density)

1.2 MN·m/kg
5.3 MN·m/kg

Thermal Diffusivity

0.3 mm²/s
0.2 mm²/s

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.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scalePVC Foam (Rigid, Structural Core)

Manufacturing and finishing

CapabilityPVC Foam (Rigid, Structural Core)Syntactic Foam (Epoxy)
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

PVC Foam (Rigid, Structural Core) vs Syntactic Foam (Epoxy) — frequently asked

Is Syntactic Foam (Epoxy) stronger than PVC Foam (Rigid, Structural Core)?

Yes. Syntactic Foam (Epoxy) has a typical tensile strength of 12 MPa (1.74 ksi) against 3 MPa (0.363 ksi) for PVC Foam (Rigid, Structural Core) — about 4.8 times as much.

Which is cheaper, PVC Foam (Rigid, Structural Core) 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, PVC Foam (Rigid, Structural Core) or Syntactic Foam (Epoxy)?

PVC Foam (Rigid, Structural Core). Its machinability rates excellent (90/100) against good (60/100) for Syntactic Foam (Epoxy); for welding the order is PVC Foam (Rigid, Structural Core) first (poor, 15/100) then Syntactic Foam (Epoxy) (not recommended, 0/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in PVC Foam (Rigid, Structural Core) 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.