Materials / Compare
Plastic PETG vs. Plastic Polypropylene
Compare Plastic PETG vs. Plastic Polypropylene strength, stiffness, weight and thermal properties.
| Try it on a partA bracket to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | 46.2MPasourcetypical | 33MPasourcetypical, tensile stress at yield ISO 527 |
| Ultimate tensile strength | 46.2MPasourcetypical, peak stress (= stress at yield) | not sourced |
| Flexural strength | 78.9MPasourcetypical | not sourced |
| Elongation at break | 7.6%sourcetypical | not sourced |
| Young's modulus (stiffness) | 1.94GPasourcetypical | 1.45GPasourcetypical, tensile modulus ISO 527 |
| Density | 1,270kg/m³sourcetypical | 900kg/m³sourcetypical, 23 °C ISO 1183-1 |
| Strength to weight | 36.4kN·m/kg | 36.7kN·m/kg |
| Stiffness to weight | 1.53MN·m/kg | 1.61MN·m/kg6% higher |
| Poisson's ratio | not sourced | 0.42sourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene) |
| Shear modulus | not sourced | 0.511GPa |
| Bulk modulus | not sourced | 3.02GPa |
| Speed of sound | 1,236m/s | 1,269m/s |
| Thermal | ||
| Thermal conductivity | 0.21W/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical | 0.17–0.22W/m·Ksourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene) |
| Thermal expansion | 51µm/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical | 80–100µm/m·Ksourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene) |
| 100 mm part over a 50 °C swing | 255µm growth1.76x less | 450µm growth |
| Specific heat | 1,300J/kg·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), DSC at 60 °C (lowest temperature listed) | not sourced |
| Heats up and cools (diffusivity) | 0.127mm²/s | not sourced |
| Thermal shock resistance | not sourced | 28.6W/m |
| Glass transition | 77.4°Csourcetypical | not sourced |
| Max service temperature | 76.2°CsourceHDT 0.455 MPa (printed specimens) | 90°CsourceHDT 0.45 MPa (ISO 75B), unannealed |
| Values for | Ultimaker PETG, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS v1.00, April 29, 2022. | LyondellBasell Moplen HP501H polypropylene homopolymer (general purpose), typical ISO values |
Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Plastic PETG is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is Plastic PETG stronger than Plastic Polypropylene?
Plastic PETG is stronger: its yield strength is 46.2 MPa against 33 MPa for Plastic Polypropylene (40%).
Which is lighter, Plastic PETG or Plastic Polypropylene?
Plastic Polypropylene is lighter: 900 kg/m³ against 1,270 kg/m³ for Plastic PETG.
Which is stiffer, Plastic PETG or Plastic Polypropylene?
Plastic PETG is stiffer: Young's modulus 1.94 GPa against 1.45 GPa for Plastic Polypropylene, so the same part in Plastic PETG deflects less under the same load.
Which is lighter for the same job, Plastic PETG or Plastic Polypropylene?
For the same stiffness or strength: Plastic Polypropylene is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong beam, strong panel or plate.
| Part that must be | Plastic PETG | Plastic Polypropylene |
|---|---|---|
| Stiff rod or tie (tension) | 6% heavier | lighter |
| Stiff beam (bending) | 22% heavier | lighter |
| Stiff panel or plate | 28% heavier | lighter |
| Strong rod or tie | about equal | about equal |
| Strong beam | 13% heavier | lighter |
| Strong panel or plate | 19% heavier | lighter |
For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).
Which conducts heat better, Plastic PETG or Plastic Polypropylene?
Plastic PETG conducts heat better: 0.21 W/m·K against 0.195 W/m·K for Plastic Polypropylene.
Which expands less with temperature?
Plastic PETG expands less: 51 µm/m·K against 90 µm/m·K for Plastic Polypropylene.