PEEK plastics: properties, applications & processing
PEEK plastic: high temperature resistance, chemical resistance and dimensional stability. Properties, areas of application and processing for precise industrial components.
PEEK (polyether ether ketone) is one of the most capable high-performance plastics and is used wherever temperature resistance, dimensional stability, chemical resistance and mechanical strength are required simultaneously. For precise components, PEEK is frequently machined from PEEK sheets or rods and then cut via plastic machining. These properties make PEEK a key material in mechanical engineering, medical technology, aerospace, the automotive environment and in safety-critical applications such as plastic in the defence industry.
Material definition and structure
PEEK is a semi-crystalline thermoplastic with a high melting temperature and pronounced structural stability. The combination of low water absorption, very good creep resistance and exceptional dimensional stability enables permanently precise components even under extreme conditions.
Further characteristics and material data can be found on the PEEK material page.
Mechanical properties
The mechanical performance of PEEK includes:
– high stiffness and strength – very good impact strength – outstanding abrasion and wear resistance – low creep tendency under continuous load
This makes PEEK suitable for functional components, sliding guides, bearing components and constructions that must function precisely over years.
Thermal properties
PEEK remains permanently functional up to approx. 250 °C. Thanks to low thermal expansion and the stable crystalline structure, the material remains dimensionally stable even in cyclic temperature ranges.
Advantages at a glance: – high heat deflection resistance – low expansion under temperature changes – reliable behaviour under continuous heat
Chemical resistance
PEEK resists: – oils and greases – fuels – numerous solvents – hot steam / hydrothermal conditions
Since PEEK does not corrode, the material replaces metallic components with higher maintenance requirements in many plants.
Electrical properties & tribological performance
PEEK offers outstanding electrical insulation, even in moisture. The tribological properties enable long-lasting, low-friction sliding and guide elements.
Semi-finished products: sheets, rods and cut pieces
PEEK is usually offered as: – sheet – rod – dimensionally accurate cut piece
Semi-finished products form the basis for precise CNC components. Cut pieces and available formats can be found under the PEEK sheets.
Via plastic machining, dimensionally accurate individual parts and series can be produced from them.
Application areas
Typical fields of use: – mechanical engineering – medical technology – aerospace – automotive – pump and valve systems – electrical engineering – safety-critical systems in defence & military technology
The defence article will later link PEEK with other high-performance plastics in security applications.
Comparison table: PEEK vs. PA / POM / PET / PTFE / PEEK GF30 / PEEK CF30
| Material | Temperature resistance | Chemical resistance | Mechanical strength | Creep tendency | Special features |
|---|---|---|---|---|---|
| PEEK | up to approx. 250 °C | very high | very high | very low | universal high-performance plastic |
| PA6 / PA66 | medium | low-medium | good | higher | moisture-sensitive |
| POM | medium | medium | good | medium | very good machinability |
| PET | medium | good | good | low-medium | hard, dimensionally stable |
| PTFE | low-medium | very high | very low | very high | extremely low coefficient of friction |
| PEEK GF30 | up to 250 °C | very high | very high | very low | glass-fibre reinforced, higher stiffness |
| PEEK CF30 | up to 250 °C | very high | very high | very low | carbon-fibre reinforced, optimum stiffness & thermal conductivity |
Key technical characteristics (overview)
| Property | Typical value |
|---|---|
| Density | approx. 1.30 g/cm³ |
| Continuous service temperature | ~250 °C |
| Thermal conductivity | ~0.25 W/mK |
| Tensile strength | ~90–100 MPa |
| E-modulus | ~3,600–4,000 MPa |
| Water absorption | very low |
| Insulation capability | high |
Values depend on the manufacturing process and modification.
Processing and CNC machining
PEEK can be machined extremely precisely. The following requirements apply to milling and turning processes:
– low thermal conductivity → controlled cooling required – sharp tool geometries for smooth surfaces – moderate feed rates, stable clamping technology – process planning for tight tolerance ranges
Processes and machining options can be found under: – milled parts – turned parts – plastic machining
These areas will later form the direct cluster link to the specialised article "PEEK machining".
Why PEEK is preferred in safety-critical applications
PEEK offers: – reliable function under heat, cold and rapid load changes – high material fatigue limits – dimensionally stable geometries even under continuous load – no stress cracks from media contact
This means the material meets typical requirements of the aerospace, medical technology and defence industries.
Future & further development
Modified PEEK types (glass-fibre reinforced, carbon-fibre reinforced, tribologically optimised) continuously expand the application possibilities. PEEK is also gaining importance in 3D printing.
FAQ
Can PEEK be used permanently at high temperatures? Yes, PEEK remains stable and dimensionally stable up to about 250 °C.
Is PEEK chemical-resistant? Yes, the material resists many acids, bases, fuels and solvents.
Can PEEK be milled and turned well? Yes, with controlled cutting values and suitable tool geometry, very precise components are produced.
When is PEEK worthwhile compared with POM or PA? Whenever temperature, wear, media contact or dimensional stability are critical factors.
Are there reinforced variants? Yes – GF30 and CF30 for higher stiffness, better thermal conductivity and optimised tribological properties.
High-performance plastic for high demands
PEEK is one of the most important high-performance plastics for demanding constructions. Its combination of temperature stability, chemical resistance, dimensional stability and mechanical strength enables long-lasting components that function reliably even under extreme conditions. In conjunction with precise processing via plastic machining, milled parts and turned parts, the material forms a high-performance basis for technical functional components in industry, engineering and defence.
