Victrex PEEK 450G (unreinforced, injection moulded), Victrex TDS rev. March 2026; Poisson from Victrex fluid-management flyer (2020-07)
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 PEEK stronger than Plastic PLA?
Plastic PEEK is stronger: its yield strength is 98 MPa against 52.5 MPa for Plastic PLA (1.87x).
Which is lighter, Plastic PEEK or Plastic PLA?
Plastic PLA is lighter: 1,240 kg/m³ against 1,300 kg/m³ for Plastic PEEK.
Which is stiffer, Plastic PEEK or Plastic PLA?
Plastic PEEK is stiffer: Young's modulus 4 GPa against 3.25 GPa for Plastic PLA, so the same part in Plastic PEEK deflects less under the same load.
Which is lighter for the same job, Plastic PEEK or Plastic PLA?
For the same stiffness or strength: Plastic PEEK 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 PEEK
Plastic PLA
Stiff rod or tie (tension)
lighter
17% heavier
Stiff beam (bending)
lighter
6% heavier
Stiff panel or plate
lighter
2% heavier
Strong rod or tie
lighter
1.78x heavier
Strong beam
lighter
45% heavier
Strong panel or plate
lighter
30% 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 PEEK or Plastic PLA?
Plastic PEEK conducts heat better: 0.29 W/m·K against 0.13 W/m·K for Plastic PLA.