PEEK (Polyetheretherketone)
PEEK (Polyetheretherketone) is a semi-crystalline, high-performance plastic belonging to the polyaryletherketone group. The material is characterized by very high temperature resistance, high mechanical strength, and excellent chemical resistance.
Due to its stable property profile, PEEK is used for technically demanding components that must operate continuously under high mechanical, thermal, or chemical stress.
Features at a Glance
Typical properties of PEEK include:
- very high continuous operating temperature
- high mechanical strength and stiffness
- very good creep resistance
- Excellent wear and sliding properties
- excellent chemical resistance
- good hydrolysis resistance
- very good dimensional stability
- good electrical insulation properties
Due to its semi-crystalline structure, PEEK retains its mechanical properties even at elevated temperatures over long periods of time.
Typical Applications
Due to its high temperature resistance, mechanical strength, and chemical stability, PEEK is used for technically demanding components.
Typical applications include:
- Machinery and Plant Engineering
- Medical Technology
- Aerospace Engineering
- Automotive and Vehicle Engineering
- Chemical Processing Industry
- Semiconductor and Electronics Industry
Typical Components
PEEK is often used for components that are continuously exposed to mechanical and thermal stress.
Typical components include:
- Plain Bearings and Bearing Bushings
- Gaskets
- Valve seats
- Pump Components
- High-Load Precision Components
- Insulators and insulating components
Technical Specifications
The following values are typical guidelines and may vary depending on the type of material and the manufacturer.
| Property | Value |
|---|---|
| Max. operating temperature | ca. 250–260 °C |
| Melting temperature | ca. 343 °C |
| Tensile strength | ca. 90–100 MPa |
| Elastic modulus | ca. 3.600–4.000 MPa |
| Density | ca. 1,30–1,32 g/cm³ |
| Water absorption | very low |
Chemical Resistance
PEEK exhibits very high resistance to many chemical substances.
Particularly resistant to
- Acids and alkalis
- Oils and greases
- Fuels
- Many organic solvents
- Hot water and steam
- Hydrolytic exposure
Limited resistance to
- Strongly oxidizing media
- Concentrated sulfuric acid
Machining and Manufacturing
PEEK is easy to machine and is suitable for precise CNC manufacturing processes.
Typical characteristics during machining:
- Well-suited for CNC milling and CNC turning
- high dimensional accuracy of the components
- Tight tolerances can be achieved
- High-quality finishes can be achieved
- Suitable for prototypes, individual parts, and small-batch and mass production
The selection of the appropriate material should be made on a project-by-project basis, taking into account load, temperature range, contact with media, and economic factors.
Comparison with Other Materials
| Property | PEEK | PPS | PEI |
|---|---|---|---|
| Operating temperature | very high | high | high |
| Mechanical strength | very high | high | high |
| Chemical resistance | very high | very high | good |
| Hydrolysis resistance | very good | good | good |
| Stiffness | high | high | high |
PEEK is often used when both high mechanical strength and chemical resistance are required.
Possible alternative materials
Depending on the application, other engineering plastics may also be considered:
- PPS – good chemical resistance at lower material costs
- PEI – high temperature resistance and good mechanical properties
- PTFE – excellent chemical resistance and very good sliding properties
Frequently asked questions about Polyetheretherketone
What kind of plastic is PEEK?
PEEK (polyetheretherketone) is a semi-crystalline, high-performance plastic belonging to the polyaryletherketone family. The material is characterized by very high temperature resistance, high mechanical strength, and excellent chemical resistance.
What temperature can PEEK withstand?
PEEK can be used continuously at temperatures of approximately 250 °C. Higher temperatures are also possible for short periods, depending on the component geometry and load.
What is the melting point of PEEK?
The melting point of PEEK is approximately 343 °C. This ensures that the material remains mechanically stable even at high operating temperatures.
Is PEEK chemical-resistant?
PEEK has very high chemical resistance to many acids, alkalis, oils, fats, and organic solvents. Limitations exist, among other things, with highly oxidizing media and concentrated sulfuric acid.
Is PEEK resistant to hydrolysis?
Yes. PEEK exhibits very good resistance to hot water and steam. This makes the material suitable for applications involving hydrolytic stress.
What are the mechanical properties of PEEK?
PEEK has high tensile strength, high stiffness, and excellent creep resistance. This makes the material suitable for components subjected to mechanical stress that must retain their shape over the long term.
What components are typically made from PEEK?
Typical PEEK components include plain bearings, gears, seals, valve seats, pump components, and high-load precision components used in mechanical and plant engineering.
Can PEEK be machined?
PEEK is very easy to machine and is suitable for CNC milling and CNC turning.
When is PEEK preferred over other engineering plastics?
PEEK is often used when very high temperatures, mechanical stresses, or aggressive media must be taken into account and other plastics do not sufficiently meet the required properties.