PEEK Polyetheretherketone: High-Performance Polymer Properties & Equivalents
Published: 2026-05-25
Polyetheretherketone (PEEK) is a colorless organic thermoplastic polymer in the polyaryletherketone (PAEK) family, offering an exceptional combination of thermal stability, chemical resistance, and mechanical strength. It is one of the...
Polyetheretherketone (PEEK) is a colorless organic thermoplastic polymer in the polyaryletherketone (PAEK) family, offering an exceptional combination of thermal stability, chemical resistance, and mechanical strength. It is one of the highest-performing engineering thermoplastics and is used in demanding environments like aerospace components, medical implants, semiconductor manufacturing, and oil & gas downhole connectors.
PEEK can be processed by injection molding at melt temperatures of 360-400°C with mold temperatures of 160-200°C. Its semicrystalline nature requires proper mold temperature control to achieve optimal crystallinity and dimensional stability. It has excellent resistance to hydrolysis, steam, and a wide range of chemicals including acids, bases, and organic solvents—outperforming most other thermoplastics in aggressive chemical environments.
Key grades include unfilled PEEK (general purpose), 30% glass-fiber reinforced (increased stiffness and HDT), 30% carbon-fiber reinforced (maximum strength and thermal conductivity), and bearing-grade with PTFE/graphite additives for tribological applications.
Technical Properties
| Density | 1.32 g/cm³ |
|---|---|
| Tensile Strength | 100 MPa |
| Melting Point | 343 °C |
| Shrinkage Rate | 1.2% |
| Flexural Modulus | 4.1 GPa |
| Hdt | 160 °C at 1.82 MPa |
| Continuous Service Temp | 260 °C |
Engineering Tool: Shrinkage & Cost Estimator
Calculate part weight, mold cavity dimensions accounting for shrinkage, and material cost — all locally in your browser.
Equivalents & Cross-References
| Equivalent / Alternate | Action |
|---|---|
| Victrex PEEK | |
| Tecapeek | |
| KetaSpire | |
| Vestakeep |
Frequently Asked Questions
What melt temperature is required for injection molding PEEK?
PEEK requires a melt temperature of 360-400°C and mold temperature of 160-200°C. Standard injection molding machines cannot process PEEK—the machine must be equipped with high-temperature barrels, ceramic heater bands, and oil-heated molds. Most general-purpose machines are limited to ~350°C and are unsuitable for PEEK processing.
How does PEEK compare to PTFE (Teflon) for chemical resistance?
PEEK offers comparable chemical resistance to PTFE against most chemicals, but with vastly superior mechanical properties—PEEK's tensile strength (100 MPa) is approximately 5× higher than PTFE (20-30 MPa). PTFE has a higher continuous service temperature (260°C vs PEEK at 260°C—equivalent) and a lower coefficient of friction. Choose PTFE for unloaded seals and gaskets; choose PEEK for structural components requiring both chemical resistance and mechanical load-bearing capacity.
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References & Industry Standards
- ASTM International. Standard Specifications for Engineering Plastics & Thermoplastics. astm.org
- UL Prospector. Plastics & Elastomers Material Database. ulprospector.com
- MatWeb. Material Property Data for Engineering Thermoplastics. matweb.com
- ISO 1043. Plastics — Symbols and Abbreviated Terms. iso.org