Materials / Compare
Plastic HDPE vs. Plastic UHMWPE
Compare Plastic HDPE vs. Plastic UHMWPE 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 | 20MPasourcetypical, tensile stress at yield ISO 527, 50 mm/min |
| Ultimate tensile strength | not sourced | 43MPasourcetypical, tensile stress at break ISO 527, 50 mm/min |
| Elongation at break | not sourced | 465%sourcetypical, nominal elongation at break ISO 527 |
| Young's modulus (stiffness) | 0.9GPasourcetypical, tensile modulus 23 °C ISO 527 | 0.66GPasourcetypical, tensile modulus ISO 527, 1 mm/min |
| Density | 950kg/m³sourcetypical, ISO 1183 | 930kg/m³sourcetypical |
| Strength to weight | 25.3kN·m/kg17% higher | 21.5kN·m/kg |
| Stiffness to weight | 0.947MN·m/kg33% higher | 0.71MN·m/kg |
| 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 | 842m/s |
| Thermal | ||
| Thermal conductivity | 0.4–0.49W/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 0.4W/m·Ksourcetypical, unfilled (narrative value, generic Celanese UHMWPE) |
| Thermal expansion | 120µm/m·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | 200µm/m·Ksourcetypical, 20 to 100 °C (generic Celanese UHMWPE) |
| 100 mm part over a 50 °C swing | 600µm growth1.67x less | 1,000µm growth |
| Specific heat | 2,250J/kg·Ksourcebase material: high-density polyethylene family (INEOS Olefins & Polymers USA, Typical Engineering Properties of HDPE) | not sourced |
| Heats up and cools (diffusivity) | 0.208mm²/s | not sourced |
| Thermal shock resistance | 56.9W/m | not sourced |
| Melting point | not sourced | 130–138°CsourceDSC 10 K/min |
| Max service temperature | not sourced | 80°Csourcerecommended max constant operating temperature |
| Values for | LyondellBasell Hostalen 23050 B high density polyethylene, typical ISO values | Celanese GUR 4120 (avg. molecular weight 4.7x10^6 g/mol), typical values on compression-molded specimens; CTE and thermal conductivity from Celanese's generic UHMWPE guide (grade not named) |
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.
Questions
Is Plastic HDPE stronger than Plastic UHMWPE?
Plastic HDPE is stronger: its yield strength is 24 MPa against 20 MPa for Plastic UHMWPE (20%).
Which is lighter, Plastic HDPE or Plastic UHMWPE?
Plastic UHMWPE is lighter: 930 kg/m³ against 950 kg/m³ for Plastic HDPE.
Which is stiffer, Plastic HDPE or Plastic UHMWPE?
Plastic HDPE is stiffer: Young's modulus 0.9 GPa against 0.66 GPa for Plastic UHMWPE, so the same part in Plastic HDPE deflects less under the same load.
Which is lighter for the same job, Plastic HDPE or Plastic UHMWPE?
For the same stiffness or strength: Plastic HDPE 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 UHMWPE |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 33% heavier |
| Stiff beam (bending) | lighter | 14% heavier |
| Stiff panel or plate | lighter | 9% heavier |
| Strong rod or tie | lighter | 17% heavier |
| Strong beam | lighter | 11% heavier |
| Strong panel or plate | lighter | 7% heavier |
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 UHMWPE?
Plastic HDPE conducts heat better: 0.445 W/m·K against 0.4 W/m·K for Plastic UHMWPE.
Which expands less with temperature?
Plastic HDPE expands less: 120 µm/m·K against 200 µm/m·K for Plastic UHMWPE.