Materials / Compare
Plastic HDPE vs. Plastic PLA
Compare Plastic HDPE vs. Plastic PLA 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 | 52.5MPasourcetypical |
| Ultimate tensile strength | not sourced | 52.5MPasourcetypical, peak stress (= stress at yield) |
| Flexural strength | not sourced | 96.8MPasourcetypical |
| Elongation at break | not sourced | 7.8%sourcetypical |
| Young's modulus (stiffness) | 0.9GPasourcetypical, tensile modulus 23 °C ISO 527 | 3.25GPasourcetypical |
| Density | 950kg/m³sourcetypical, ISO 1183 | 1,240kg/m³sourcetypical |
| Strength to weight | 25.3kN·m/kg | 42.3kN·m/kg1.68x higher |
| Stiffness to weight | 0.947MN·m/kg | 2.62MN·m/kg2.77x 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 | 1,619m/s |
| Thermal | ||
| Thermal conductivity | 0.4–0.49W/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 0.13W/m·Ksourcebase material: NatureWorks Ingeo biopolymer, amorphous sheet, 25 °C |
| Thermal expansion | 120µm/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | not sourced |
| 100 mm part over a 50 °C swing | 600µm growth | not sourced |
| Specific heat | 2,250J/kg·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 1,200J/kg·Ksourcebase material: NatureWorks Ingeo biopolymer, amorphous sheet, 25 °C |
| Heats up and cools (diffusivity) | 0.208mm²/s2.38x faster | 0.0874mm²/s |
| Thermal shock resistance | 56.9W/m | not sourced |
| Melting point | not sourced | 152°Csourcetypical |
| Glass transition | not sourced | 59.1°Csourcetypical |
| Max service temperature | not sourced | 58.8°CsourceHDT 0.455 MPa (printed specimens) |
| Values for | LyondellBasell Hostalen 23050 B high density polyethylene, typical ISO values | Ultimaker PLA, 3D-printed specimens, XY (flat) orientation; 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 dated April 20, 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 PLA is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is Plastic HDPE stronger than Plastic PLA?
Plastic PLA is stronger: its yield strength is 52.5 MPa against 24 MPa for Plastic HDPE (2.19x).
Which is lighter, Plastic HDPE or Plastic PLA?
Plastic HDPE is lighter: 950 kg/m³ against 1,240 kg/m³ for Plastic PLA.
Which is stiffer, Plastic HDPE or Plastic PLA?
Plastic PLA is stiffer: Young's modulus 3.25 GPa against 0.9 GPa for Plastic HDPE, so the same part in Plastic PLA deflects less under the same load.
Which is lighter for the same job, Plastic HDPE or Plastic PLA?
For the same stiffness or strength: Plastic PLA is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | Plastic HDPE | Plastic PLA |
|---|---|---|
| Stiff rod or tie (tension) | 2.77x heavier | lighter |
| Stiff beam (bending) | 46% heavier | lighter |
| Stiff panel or plate | 18% heavier | lighter |
| Strong rod or tie | 1.68x heavier | lighter |
| Strong beam | 29% heavier | lighter |
| Strong panel or plate | 13% 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 PLA?
Plastic HDPE conducts heat better: 0.445 W/m·K against 0.13 W/m·K for Plastic PLA.