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PP-R vs TPO

Polymer · grade comparison

PP-R and TPO are both polymer grades. PP-R is the stronger of the two: yield strength 25 MPa (3.63 ksi) against 12 MPa (1.74 ksi) for TPO, about 108% more; tensile strength follows at 26 MPa (3.77 ksi) vs 15 MPa (2.18 ksi). PP-R is the more ductile: elongation 600% versus 400% for TPO, and PP-R is harder (65 Shore D vs 45 Shore D). PP-R is stiffer (0.85 GPa vs 0.6 GPa) and TPO runs hotter in service (90°C vs 70°C continuous). On the shop floor, PP-R machines more easily (good vs fair), PP-R welds better (excellent vs very good), and PP-R sits in a lower cost tier (budget, $) than TPO (standard, $$).

PP-RChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

TPOChoose it when the part sees heat.

PP-R vs TPO: properties

PP-RTPO

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.85 GPa0.12 Msi
0.6 GPa0.09 Msi

Shear Modulus

0.3 GPa0.04 Msi
0.21 GPa0.03 Msi

Bulk Modulus

3 GPa0.42 Msi
—

Poisson's Ratio

0.43
0.42

Tensile Strength (Ultimate)

26 MPa3.8 ksi
15 MPa2.2 ksi

Yield Strength (0.2% offset)

25 MPa3.6 ksi
12 MPa1.7 ksi

Elongation at Break

600%
400%

Compressive Strength

40 MPa5.8 ksi
18 MPa2.6 ksi

Compressive Modulus

0.9 GPa0.13 Msi
—

Flexural Strength

30 MPa4.4 ksi
15 MPa2.2 ksi

Flexural Modulus

0.85 GPa0.12 Msi
0.55 GPa0.08 Msi

Shear Strength

18 MPa2.6 ksi
12 MPa1.7 ksi

Izod Impact, Notched

80 J/m1.5 ft·lbf/in
600 J/m11.2 ft·lbf/in

Hardness, Shore D

65 Shore D
45 Shore D

Hardness, Rockwell R

85 HRR
60 HRR

Hardness, Shore A

—
92 Shore A

Tear Strength

—
60 kN/m343 lbf/in

Compression Set (22 h, 70 °C)

—
55%

Physical

Density and transition temperatures.

Density

0.91 g/cm³0.03 lb/in³
0.89 g/cm³0.03 lb/in³

Melting Temperature (Tm)

148°C298 °F
163°C325 °F

Glass Transition (Tg)

-12°C10 °F
-50°C-58 °F

Water Absorption (Saturation)

0.1%
0.05%

Refractive Index

1.49
—

Same in both: Water Absorption (24 h) 0.02%

Thermal

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

Thermal Conductivity

0.24 W/m·K0.14 BTU/hr·ft·°F
0.2 W/m·K0.12 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

150 µm/m·K83.3 µin/in·°F
110 µm/m·K61.1 µin/in·°F

Max Service Temperature (continuous)

70°C158 °F
90°C194 °F

Min Service Temperature

-10°C14 °F
-40°C-40 °F

Heat Deflection Temp. @ 0.45 MPa

80°C176 °F
75°C167 °F

Heat Deflection Temp. @ 1.8 MPa

52°C126 °F
45°C113 °F

Vicat Softening Point (B50)

80°C176 °F
65°C149 °F

Max Service Temperature (short-term)

95°C203 °F
120°C248 °F

Same in both: Specific Heat Capacity 1,900 J/kg·K0.45 BTU/lb·°F · Limiting Oxygen Index 18%

Electrical

Conductivity and insulation.

Dielectric Strength

27 kV/mm686 V/mil
25 kV/mm635 V/mil

Dissipation Factor (1 MHz)

4×10⁻⁴
6×10⁻⁴

Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dielectric Constant (1 MHz) 2.3 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

UV / Weathering Resistance

20 / 100
45 / 100

Same in both: Corrosion Resistance 90 / 100

Manufacturability

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

Machinability

62 / 100
50 / 100

Weldability

95 / 100
80 / 100

Formability (cold)

70 / 100
80 / 100

Polishability

45 / 100
25 / 100

Mold Shrinkage

1.6%
1.3%

Melt Flow Rate

0.3 g/10 min
10 g/10 min

Same in both: Processing Melt Temperature (typ.) 215°C419 °F · Mold Temperature (typ.) 40°C104 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

78 MJ/kg33,534 BTU/lb
82 MJ/kg35,254 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
110 L/kg13.2 gal/lb

Typical Recycled Content

0%
10%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

29 kN·m/kg
17 kN·m/kg

Specific Stiffness (E / density)

0.9 MN·m/kg
0.7 MN·m/kg

Modulus of Resilience

368 kJ/m³
120 kJ/m³

Same in both: 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.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scalePP-RTPO

Manufacturing and finishing

CapabilityPP-RTPO
Default condition——
Relative cost$ Budget$$ Standard
Min. machined wall——
Best machined surface——

PP-R vs TPO — frequently asked

Is PP-R stronger than TPO?

Yes. PP-R has a typical yield strength of 25 MPa (3.63 ksi) against 12 MPa (1.74 ksi) for TPO — about 108% more. Tensile strength is 26 MPa (3.77 ksi) vs 15 MPa (2.18 ksi).

Which is cheaper, PP-R or TPO?

PP-R is the lower-cost material: it sits in the budget tier ($) while TPO is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, PP-R or TPO?

PP-R. Its machinability rates good (62/100) against fair (50/100) for TPO; for welding the order is PP-R first (excellent, 95/100) then TPO (very good, 80/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in PP-R and TPO 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.