PEEK vs Polytetrafluoroethylene
PEEK and Polytetrafluoroethylene are genuine alternatives to one another — a choice somebody actually makes — and differ on 2 measured properties, density most clearly.
PEEK vs Polytetrafluoroethylene
PEEK
The plastic that behaves like a metal — 250 °C continuous service, near-total chemical resistance, and a price to match.
Polytetrafluoroethylene
Carbon wrapped in fluorine, which almost nothing sticks to and almost nothing attacks — the non-stick pan, the plumber's tape and the seal in the chemical plant.
| Property | PEEK | Polytetrafluoroethylene |
|---|---|---|
| Density | 1.3–1.32 g/cm³ | 2.15–2.2 g/cm³ higher |
| Melting point | 343 °C higher | 327 °C |
| Tensile strength Only one of the two has a figure we can stand behind, so there is nothing to compare. | 90–100 MPa | Not known |
| Young's modulus Only one of the two has a figure we can stand behind, so there is nothing to compare. | 3.6–4 GPa | Not known |
Choosing between them
PEEK is recorded as a substitute for Polytetrafluoroethylene — stronger, better at temperature.
What it gives up: Not as chemically inert — PTFE resists things PEEK does not — and both are expensive enough that the choice is rarely about cost.
In this application, on the evidence cited above.