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PET CF30 vs PET rPET

Polymer · PET grade comparison

PET CF30 and PET rPET are two grades of the same polymer grade, PET: CF30 (30% Carbon Fiber) versus rPET (post-consumer recycled PET). The chemistry is identical, so every difference below comes from the condition. PET CF30 is the stronger of the two: yield strength 80 MPa (11.6 ksi) against 55 MPa (7.98 ksi) for PET rPET, about 45% more; tensile strength follows at 200 MPa (29 ksi) vs 60 MPa (8.7 ksi). In exchange, PET rPET is the more ductile: elongation 25% versus 1.8% for PET CF30. PET rPET is lighter (1.38 g/cm³ vs 1.46 g/cm³ for PET CF30) and PET CF30 is stiffer (21 GPa vs 2.8 GPa). On the shop floor, PET rPET machines more easily (very good vs fair) and PET rPET welds better (fair vs poor).

PET CF30Choose it when strength drives the design, or when the part sees heat.

PET rPETChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

PET CF30 vs PET rPET: properties

PET CF30PET rPET

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

21 GPa3 Msi
2.8 GPa0.41 Msi

Poisson's Ratio

0.38
0.4

Tensile Strength (Ultimate)

200 MPa29 ksi
60 MPa8.7 ksi

Yield Strength (0.2% offset)

80 MPa11.6 ksi
55 MPa8 ksi

Elongation at Break

1.8%
25%

Compressive Strength

175 MPa25.4 ksi
80 MPa11.6 ksi

Flexural Strength

265 MPa38.4 ksi
88 MPa12.8 ksi

Flexural Modulus

19 GPa2.8 Msi
2.7 GPa0.39 Msi

Shear Strength

55 MPa8 ksi
45 MPa6.5 ksi

Fracture Toughness (K_IC)

4 MPa·√m3.6 ksi·√in
3.3 MPa·√m3 ksi·√in

Izod Impact, Notched

70 J/m1.3 ft·lbf/in
30 J/m0.56 ft·lbf/in

Hardness, Shore D

85 Shore D
83 Shore D

Hardness, Rockwell M

100 HRM
90 HRM

Hardness, Rockwell R

120 HRR
117 HRR

Same in both: Shear Modulus 1.1 GPa0.16 Msi · Bulk Modulus 5 GPa0.65 Msi · Compressive Modulus 3 GPa0.44 Msi

Physical

Density and transition temperatures.

Density

1.46 g/cm³0.05 lb/in³
1.38 g/cm³0.05 lb/in³

Melting Temperature (Tm)

253°C487 °F
255°C491 °F

Water Absorption (24 h)

0.1%
0.11%

Water Absorption (Saturation)

0.35%
0.5%

Same in both: Glass Transition (Tg) 79°C174 °F · Refractive Index 1.575 · Light Transmission 88%

Thermal

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

Thermal Conductivity

0.6 W/m·K0.35 BTU/hr·ft·°F
0.24 W/m·K0.14 BTU/hr·ft·°F

Specific Heat Capacity

1,050 J/kg·K0.25 BTU/lb·°F
1,150 J/kg·K0.27 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

15 µm/m·K8.3 µin/in·°F
65 µm/m·K36.1 µin/in·°F

Max Service Temperature (continuous)

150°C302 °F
90°C194 °F

Min Service Temperature

-40°C-40 °F
-20°C-4 °F

Heat Deflection Temp. @ 0.45 MPa

245°C473 °F
75°C167 °F

Heat Deflection Temp. @ 1.8 MPa

230°C446 °F
68°C154 °F

Vicat Softening Point (B50)

180°C356 °F
82°C180 °F

Limiting Oxygen Index

24%
21%

Max Service Temperature (short-term)

220°C428 °F
150°C302 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

100 Ω·m3.94×10⁹ µΩ·in
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in

Volume Resistivity

10,000 Ω·cm
1×10¹⁶ Ω·cm

Surface Resistivity

100,000 Ω
1×10¹⁵ Ω

Same in both: Dielectric Strength 22 kV/mm559 V/mil · Dielectric Constant (1 MHz) 3.2 · Dissipation Factor (1 MHz) 0.018 · Comparative Tracking Index (CTI) 600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

70 / 100
62 / 100

UV / Weathering Resistance

45 / 100
30 / 100

Manufacturability

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

Machinability

45 / 100
72 / 100

Weldability

25 / 100
45 / 100

Formability (cold)

10 / 100
45 / 100

Mold Shrinkage

0.15%
0.7%

Processing Melt Temperature (typ.)

285°C545 °F
280°C536 °F

Mold Temperature (typ.)

120°C248 °F
135°C275 °F

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

105 MJ/kg45,142 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

6.5 kg CO₂/kg
1.1 kg CO₂/kg

Typical Recycled Content

0%
100%

Same in both: Embodied Water 120 L/kg14.4 gal/lb

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 scalePET

PET CF30 vs PET rPET — frequently asked

Is PET CF30 stronger than PET rPET?

Yes. PET CF30 has a typical yield strength of 80 MPa (11.6 ksi) against 55 MPa (7.98 ksi) for PET rPET — about 45% more. Tensile strength is 200 MPa (29 ksi) vs 60 MPa (8.7 ksi).

Which grade does FabDigit quote by default, CF30 or rPET?

Specify the condition in the material field or the drawing note; FabDigit prices the quote for the state you call out.

Which is easier to machine, PET CF30 or PET rPET?

PET rPET. Its machinability rates very good (72/100) against fair (45/100) for PET CF30; for welding the order is PET rPET first (fair, 45/100) then PET CF30 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in PET CF30 and PET rPET 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.