Materials / Compare
Plastic HDPE vs. Plastic PETG
Compare Plastic HDPE vs. Plastic PETG 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 | 24MPasourcetypical, tensile stress at yield 23 °C, 50 mm/min ISO 527 | 46.2MPasourcetypical |
| Ultimate tensile strength | not sourced | 46.2MPasourcetypical, peak stress (= stress at yield) |
| Flexural strength | not sourced | 78.9MPasourcetypical |
| Elongation at break | not sourced | 7.6%sourcetypical |
| Young's modulus (stiffness) | 0.9GPasourcetypical, tensile modulus 23 °C ISO 527 | 1.94GPasourcetypical |
| Density | 950kg/m³sourcetypical, ISO 1183 | 1,270kg/m³sourcetypical |
| Strength to weight | 25.3kN·m/kg | 36.4kN·m/kg44% higher |
| Stiffness to weight | 0.947MN·m/kg | 1.53MN·m/kg1.61x higher |
| Poisson's ratio | 0.4–0.45sourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | not sourced |
| Shear modulus | 0.316GPa | not sourced |
| Bulk modulus | 2GPa | not sourced |
| Speed of sound | 973m/s | 1,236m/s |
| Thermal | ||
| Thermal conductivity | 0.4–0.49W/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 0.21W/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical |
| Thermal expansion | 120µm/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 51µm/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical |
| 100 mm part over a 50 °C swing | 600µm growth | 255µm growth2.35x less |
| Specific heat | 2,250J/kg·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 1,300J/kg·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), DSC at 60 °C (lowest temperature listed) |
| Heats up and cools (diffusivity) | 0.208mm²/s1.64x faster | 0.127mm²/s |
| Thermal shock resistance | 56.9W/m | not sourced |
| Glass transition | not sourced | 77.4°Csourcetypical |
| Max service temperature | not sourced | 76.2°CsourceHDT 0.455 MPa (printed specimens) |
| Values for | LyondellBasell Hostalen 23050 B high density polyethylene, typical ISO values | 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. |
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 HDPE stronger than Plastic PETG?
Plastic PETG is stronger: its yield strength is 46.2 MPa against 24 MPa for Plastic HDPE (1.93x).
Which is lighter, Plastic HDPE or Plastic PETG?
Plastic HDPE is lighter: 950 kg/m³ against 1,270 kg/m³ for Plastic PETG.
Which is stiffer, Plastic HDPE or Plastic PETG?
Plastic PETG is stiffer: Young's modulus 1.94 GPa against 0.9 GPa for Plastic HDPE, so the same part in Plastic PETG deflects less under the same load.
Which is lighter for the same job, Plastic HDPE or Plastic PETG?
For the same stiffness or strength: Plastic HDPE is lighter for a stiff panel or plate; Plastic PETG is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Plastic HDPE | Plastic PETG |
|---|---|---|
| Stiff rod or tie (tension) | 1.61x heavier | lighter |
| Stiff beam (bending) | 10% heavier | lighter |
| Stiff panel or plate | lighter | 4% heavier |
| Strong rod or tie | 44% heavier | lighter |
| Strong beam | 16% heavier | lighter |
| Strong panel or plate | 4% 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 HDPE or Plastic PETG?
Plastic HDPE conducts heat better: 0.445 W/m·K against 0.21 W/m·K for Plastic PETG.
Which expands less with temperature?
Plastic PETG expands less: 51 µm/m·K against 120 µm/m·K for Plastic HDPE.