Materials / Compare
Plastic PLA vs. Plastic Polypropylene
Compare Plastic PLA 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 | 52.5MPasourcetypical | 33MPasourcetypical, tensile stress at yield ISO 527 |
| Ultimate tensile strength | 52.5MPasourcetypical, peak stress (= stress at yield) | not sourced |
| Flexural strength | 96.8MPasourcetypical | not sourced |
| Elongation at break | 7.8%sourcetypical | not sourced |
| Young's modulus (stiffness) | 3.25GPasourcetypical | 1.45GPasourcetypical, tensile modulus ISO 527 |
| Density | 1,240kg/m³sourcetypical | 900kg/m³sourcetypical, 23 °C ISO 1183-1 |
| Strength to weight | 42.3kN·m/kg15% higher | 36.7kN·m/kg |
| Stiffness to weight | 2.62MN·m/kg1.63x higher | 1.61MN·m/kg |
| 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 | 1,619m/s | 1,269m/s |
| Thermal | ||
| Thermal conductivity | 0.13W/m·Ksourcebase material: NatureWorks Ingeo biopolymer, amorphous sheet, 25 °C | 0.17–0.22W/m·Ksourcebase material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene) |
| Thermal expansion | not sourced | 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 | not sourced | 450µm growth |
| Specific heat | 1,200J/kg·Ksourcebase material: NatureWorks Ingeo biopolymer, amorphous sheet, 25 °C | not sourced |
| Heats up and cools (diffusivity) | 0.0874mm²/s | not sourced |
| Thermal shock resistance | not sourced | 28.6W/m |
| Melting point | 152°Csourcetypical | not sourced |
| Glass transition | 59.1°Csourcetypical | not sourced |
| Max service temperature | 58.8°CsourceHDT 0.455 MPa (printed specimens) | 90°CsourceHDT 0.45 MPa (ISO 75B), unannealed |
| Values for | 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. | 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 PLA is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is Plastic PLA stronger than Plastic Polypropylene?
Plastic PLA is stronger: its yield strength is 52.5 MPa against 33 MPa for Plastic Polypropylene (1.59x).
Which is lighter, Plastic PLA or Plastic Polypropylene?
Plastic Polypropylene is lighter: 900 kg/m³ against 1,240 kg/m³ for Plastic PLA.
Which is stiffer, Plastic PLA or Plastic Polypropylene?
Plastic PLA is stiffer: Young's modulus 3.25 GPa against 1.45 GPa for Plastic Polypropylene, so the same part in Plastic PLA deflects less under the same load.
Which is lighter for the same job, Plastic PLA or Plastic Polypropylene?
For the same stiffness or strength: Plastic PLA is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie; Plastic Polypropylene is lighter for a stiff panel or plate, strong beam, strong panel or plate.
| Part that must be | Plastic PLA | Plastic Polypropylene |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 1.63x heavier |
| Stiff beam (bending) | lighter | 9% heavier |
| Stiff panel or plate | 5% heavier | lighter |
| Strong rod or tie | lighter | 15% heavier |
| Strong beam | 1% heavier | lighter |
| Strong panel or plate | 9% 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 PLA or Plastic Polypropylene?
Plastic Polypropylene conducts heat better: 0.195 W/m·K against 0.13 W/m·K for Plastic PLA.