RPU FOAM-40 vs RPU GF30
Polyurethane · RPU grade comparison
RPU FOAM-40 and RPU GF30 are two grades of the same polyurethane grade, RPU: FOAM-40 (rigid closed-cell insulation foam, 30–45 kg/m³) versus GF30 (30% glass-fiber / milled-glass reinforced RIM-SRIM). The chemistry is identical, so every difference below comes from the condition. RPU GF30 is the stronger of the two: tensile strength 70 MPa (10.2 ksi) against 0.28 MPa (0.0406 ksi) for RPU FOAM-40, about 250 times as much. In exchange, RPU FOAM-40 is the more ductile: elongation 6% versus 2% for RPU GF30. RPU FOAM-40 is lighter (0.04 g/cm³ vs 1.38 g/cm³ for RPU GF30) and RPU GF30 is stiffer (6 GPa vs 0.01 GPa). On the shop floor, RPU FOAM-40 machines more easily (excellent vs good).
RPU FOAM-40Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
RPU GF30Choose it when strength drives the design, or when the part sees heat.
RPU FOAM-40 vs RPU GF30: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polyurethane 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 polyurethane 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
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Izod Impact, Notched
Same in both: Shear Modulus 0.87 GPa0.13 Msi · Bulk Modulus 3 GPa0.48 Msi · Poisson's Ratio 0.38 · Shear Strength 40 MPa5.8 ksi · Fracture Toughness (K_IC) 1.3 MPa·√m1.2 ksi·√in · Hardness, Shore D 80 Shore D · Hardness, Rockwell M 75 HRM · Hardness, Rockwell R 110 HRR
Physical
Density and transition temperatures.
Density
Water Absorption (24 h)
Same in both: Glass Transition (Tg) 95°C203 °F · Water Absorption (Saturation) 1.2%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Heat Deflection Temp. @ 1.8 MPa
Limiting Oxygen Index
Same in both: Specific Heat Capacity 1,600 J/kg·K0.38 BTU/lb·°F · Heat Deflection Temp. @ 0.45 MPa 85°C185 °F · Max Service Temperature (short-term) 130°C266 °F
Electrical
Conductivity and insulation.
Dielectric Constant (1 MHz)
Same in both: Electrical Resistivity 1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in · Dielectric Strength 18 kV/mm457 V/mil · Dissipation Factor (1 MHz) 0.04 · Volume Resistivity 1×10¹³ Ω·cm · Surface Resistivity 1×10¹³ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 70 / 100 · UV / Weathering Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Same in both: Weldability 5 / 100 · Formability (cold) 5 / 100 · Polishability 60 / 100 · Mold Shrinkage 0.3% · Processing Melt Temperature (typ.) 35°C95 °F · Mold Temperature (typ.) 55°C131 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 103 MJ/kg44,282 BTU/lb · Embodied Carbon (primary production) 4.6 kg CO₂/kg · Embodied Water 230 L/kg27.6 gal/lb · Typical Recycled Content 3%
Strength versus weight
Yield strength against density for every polyurethane grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
RPU FOAM-40 vs RPU GF30 — frequently asked
Is RPU GF30 stronger than RPU FOAM-40?
Yes. RPU GF30 has a typical tensile strength of 70 MPa (10.2 ksi) against 0.28 MPa (0.0406 ksi) for RPU FOAM-40 — about 250 times as much.
Which grade does FabDigit quote by default, FOAM-40 or GF30?
Cast is the default RPU condition in the FabDigit quote flow (neither FOAM-40 nor GF30). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which is easier to machine, RPU FOAM-40 or RPU GF30?
RPU FOAM-40. Its machinability rates excellent (90/100) against good (55/100) for RPU GF30.
Ready to make it?
Upload a CAD file and FabDigit prices the part in RPU FOAM-40 and RPU GF30 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.