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PBAT vs PET

Polymer · grade comparison

PBAT and PET are both polymer grades. PET is the stronger of the two: yield strength 80 MPa (11.6 ksi) against 10 MPa (1.45 ksi) for PBAT, about 8.0 times as much; tensile strength follows at 82 MPa (11.9 ksi) vs 30 MPa (4.35 ksi). In exchange, PBAT is the more ductile: elongation 650% versus 20% for PET, and PET is harder (85 Shore D vs 32 Shore D). PBAT is lighter (1.26 g/cm³ vs 1.39 g/cm³ for PET) and PET is stiffer (3.1 GPa vs 0.09 GPa). On the shop floor, PET machines more easily (very good vs poor) and PBAT welds better (excellent vs fair).

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

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

PBAT vs PET: properties

PBATPET

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

0.09 GPa0.01 Msi
3.1 GPa0.45 Msi

Poisson's Ratio

0.45
0.4

Tensile Strength (Ultimate)

30 MPa4.4 ksi
82 MPa11.9 ksi

Yield Strength (0.2% offset)

10 MPa1.5 ksi
80 MPa11.6 ksi

Elongation at Break

650%
20%

Flexural Modulus

0.09 GPa0.01 Msi
3.1 GPa0.45 Msi

Hardness, Shore A

90 Shore A
—

Hardness, Shore D

32 Shore D
85 Shore D

Tear Strength

120 kN/m685 lbf/in
—

Shear Modulus

—
1.1 GPa0.16 Msi

Bulk Modulus

—
5 GPa0.65 Msi

Compressive Strength

—
100 MPa14.5 ksi

Compressive Modulus

—
3 GPa0.44 Msi

Flexural Strength

—
120 MPa17.4 ksi

Shear Strength

—
55 MPa8 ksi

Fracture Toughness (K_IC)

—
4 MPa·√m3.6 ksi·√in

Izod Impact, Notched

—
40 J/m0.75 ft·lbf/in

Hardness, Rockwell M

—
94 HRM

Hardness, Rockwell R

—
120 HRR

Physical

Density and transition temperatures.

Density

1.26 g/cm³0.05 lb/in³
1.39 g/cm³0.05 lb/in³

Melting Temperature (Tm)

115°C239 °F
255°C491 °F

Glass Transition (Tg)

-30°C-22 °F
79°C174 °F

Water Absorption (24 h)

0.4%
0.11%

Light Transmission

80%
88%

Water Absorption (Saturation)

—
0.5%

Refractive Index

—
1.575

Thermal

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

Thermal Conductivity

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

Specific Heat Capacity

1,800 J/kg·K0.43 BTU/lb·°F
1,150 J/kg·K0.27 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

170 µm/m·K94.4 µin/in·°F
65 µm/m·K36.1 µin/in·°F

Max Service Temperature (continuous)

55°C131 °F
100°C212 °F

Min Service Temperature

-30°C-22 °F
-20°C-4 °F

Heat Deflection Temp. @ 0.45 MPa

60°C140 °F
115°C239 °F

Vicat Softening Point (B50)

80°C176 °F
180°C356 °F

Limiting Oxygen Index

21%
22%

Max Service Temperature (short-term)

90°C194 °F
150°C302 °F

Heat Deflection Temp. @ 1.8 MPa

—
80°C176 °F

Electrical

Conductivity and insulation.

Volume Resistivity

1×10¹⁴ Ω·cm
1×10¹⁶ Ω·cm

Electrical Resistivity

—
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in

Dielectric Strength

—
22 kV/mm559 V/mil

Dissipation Factor (1 MHz)

—
0.018

Surface Resistivity

—
1×10¹⁵ Ω

Comparative Tracking Index (CTI)

—
600 V

Same in both: Dielectric Constant (1 MHz) 3.2

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

60 / 100
70 / 100

UV / Weathering Resistance

25 / 100
30 / 100

Manufacturability

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

Machinability

25 / 100
78 / 100

Weldability

88 / 100
45 / 100

Formability (cold)

92 / 100
50 / 100

Mold Shrinkage

1.6%
2%

Melt Flow Rate

3.5 g/10 min
—

Processing Melt Temperature (typ.)

170°C338 °F
280°C536 °F

Mold Temperature (typ.)

30°C86 °F
135°C275 °F

Polishability

—
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

75 MJ/kg32,244 BTU/lb
82 MJ/kg35,254 BTU/lb

Embodied Carbon (primary production)

4 kg CO₂/kg
2.8 kg CO₂/kg

Typical Recycled Content

0%
25%

Embodied Water

—
120 L/kg14.4 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

24 kN·m/kg
59 kN·m/kg

Specific Stiffness (E / density)

0.1 MN·m/kg
2.2 MN·m/kg

Modulus of Resilience

556 kJ/m³
1,032 kJ/m³

Thermal Diffusivity

0.1 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 scalePETPBAT

Manufacturing and finishing

CapabilityPBATPET
CNC machining—Yes
Sheet metal—Yes
Injection molding—Yes
Default condition—Unfilled
Relative cost$$ Standard$$ Standard
Min. machined wall—0.5 mm
Best machined surface—Ra 0.8 µm
Chrome Plating (Plastic)—Yes
EMI Shielding Coating—Yes
Painting—Yes
Soft Touch Coating—Yes
Spray Painting—Yes
UV Coating—Yes

PBAT vs PET — frequently asked

Is PET stronger than PBAT?

Yes. PET has a typical yield strength of 80 MPa (11.6 ksi) against 10 MPa (1.45 ksi) for PBAT — about 8.0 times as much. Tensile strength is 82 MPa (11.9 ksi) vs 30 MPa (4.35 ksi).

Which is cheaper, PBAT or PET?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, PBAT or PET?

PET. Its machinability rates very good (78/100) against poor (25/100) for PBAT; for welding the order is PBAT first (excellent, 88/100) then PET (fair, 45/100).

Ready to make it?

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