PEEK (polyetheretherketone) is a high-performance thermoplastic that is lightweight, strong, resistant to heat degradation, and wear resistant. DoonX Plastics offers a wide variety of Peek products in different sizes, shapes, and colors to meet all of your needs.
When it comes to polyetheretherketone, it is widely recognized that if plastic materials were to be compared to a pyramid, PEEK would sit at the apex. Polyetheretherketone resin (commonly referred to as PEEK resin) is a semi-crystalline, high-performance thermoplastic engineering plastic. PEEK boasts remarkable mechanical properties, chemical corrosion resistance, wear resistance, fatigue resistance, and dimensional stability, withstanding temperatures up to 260°C. It is commonly used in engineering machinery, aerospace and aviation products, among others.
The polymer is made up of repeating units of ether and ketone groups. This structure imparts a high degree of thermal stability, allowing PEEK to withstand high temperatures without degrading. The ether linkages provide flexibility, while the ketone groups contribute to the material’s rigidity and high melting point. This unique combination of flexibility and strength enables PEEK to maintain its mechanical properties in extreme conditions, making it an ideal material for a wide range of high-performance applications.
Key Characteristics and Performance Parameters of PEEK
PEEK is renowned for its remarkable combination of properties, making it highly sought after in industries requiring materials that can withstand extreme conditions. Below, we delve into its main characteristics and list relevant performance parameters for each.
Mechanical Properties
Strength and Durability
- Tensile Strength: PEEK can exhibit a tensile strength up to 100 MPa, showcasing its ability to withstand significant stress before failing.
- Flexural Strength: With a flexural strength of approximately 165 MPa, PEEK demonstrates excellent resistance to bending forces.
Impact Resistance and Hardness
- Impact Strength: The material’s Charpy impact strength can reach 80 kJ/m², indicating good resistance to sudden impacts.
- Hardness: On the Shore D scale, PEEK’s hardness is often rated around 84, reflecting its resistance to surface deformation.
Thermal Properties
High-Temperature Resistance
- Melting Point: PEEK has a high melting point of around 343°C, enabling it to maintain structural integrity in high-temperature applications.
- Continuous Use Temperature: It can continuously operate at temperatures up to 260°C without losing its mechanical properties.
Thermal Expansion and Conductivity
- Coefficient of Thermal Expansion: With a low coefficient of thermal expansion (CTE) of about 47 x 10^-6 /°C, PEEK exhibits minimal dimensional changes with temperature fluctuations.
- Thermal Conductivity: Its thermal conductivity is relatively low, around 0.25 W/(m·K), which is beneficial for insulating components from heat.
Chemical Resistance
Chemical Compatibility: PEEK is resistant to a wide range of chemicals, including hydrocarbons, acids, and solvents, maintaining its integrity in corrosive environments.
Electrical Properties
- Dielectric Strength: PEEK possesses a high dielectric strength of 19 kV/mm, making it an excellent electrical insulator.
- Volume Resistivity: With a volume resistivity of 10^16 ohm·cm, it effectively prevents electrical conduction.
Wear and Fatigue Resistance
- Wear Rate: Exhibiting a low wear rate, PEEK components have a long service life even in applications involving repetitive motion or friction.
- Fatigue Strength: It has a high fatigue strength, allowing it to endure cyclic loading conditions without significant degradation.
The array of properties exhibited by PEEK positions it as a material of choice for high-performance applications across various industries. Its ability to maintain structural and functional integrity under extreme mechanical, thermal, chemical, and electrical stresses makes it unparalleled in the field of engineering plastics.
What is PEEK plastic used for?
The outstanding properties of PEEK, including its high thermal stability, exceptional mechanical strength, superior chemical resistance, and excellent wear and fatigue resistance, make it a preferred material across a wide spectrum of applications. Here are some of the key areas where PEEK’s unique performance parameters have been leveraged:
Aerospace and Aviation
Used in the manufacturing of bushings, seals, and back-up rings that require high strength, lightweight, and resistance to high temperatures and chemicals. PEEK reduces the overall weight of aircraft, contributing to fuel efficiency and performance optimization.
Automotive Industry
In the automotive sector, PEEK is utilized for parts like gears, bearings, pump and compressor components, and electrical connectors. Its ability to withstand harsh environments, coupled with excellent mechanical properties, enhances the durability and reliability of automotive components.
Medical Devices
PEEK finds applications in the production of medical implants, such as spinal fusion devices and dental healing caps, as well as in surgical instruments. The material’s biocompatibility, sterilization resistance, and similar modulus to bone make it ideal for medical applications.
Electronics
In the electronics industry, PEEK is used for connectors, coil bodies, and insulators, where high-temperature resistance and electrical insulation are crucial. Its stability in high-temperature environments ensures the reliability of electronic components.
Oil and Gas Industry
PEEK is used in seals, compressor rings, and valves in the oil and gas sector, where material resistance to harsh chemicals and temperatures is a must. Provides long-term performance in extreme conditions, reducing maintenance and downtime.
Machinery and Equipment
Gears, bearings, and seals in various machinery and equipment benefit from PEEK’s high mechanical strength and wear resistance. Extends the service life of components and machinery, leading to increased efficiency and reduced operational costs.
These applications highlight PEEK’s versatility and ability to meet the demands of industries requiring materials that offer a combination of high-performance properties. Its widespread use in critical and high-value applications underscores PEEK’s role as a material of choice for advancing technology and improving the durability and efficiency of products across various sectors.
Comparison of PEEK with Other Engineering Plastics
PEEK (Polyetheretherketone) is often compared to other high-performance plastics due to its distinctive set of properties. Understanding how PEEK stands out from these materials can highlight why it is chosen for demanding applications over other polymers.
PEEK vs. PTFE (Polytetrafluoroethylene)
- Thermal Stability: While both materials can withstand high temperatures, PEEK’s melting point (around 343°C) is significantly higher than PTFE’s (around 327°C), making PEEK suitable for applications that require exposure to higher temperatures.
- Mechanical Strength: PEEK offers superior tensile and flexural strength compared to PTFE, which is softer and more prone to deformation under load.
- Wear Resistance: PEEK has a lower coefficient of friction and better wear resistance than PTFE, making it ideal for applications involving moving parts.
PEEK vs. PA (Polyamide/Nylon)
- Moisture Absorption: PA can absorb moisture, which may affect its mechanical properties and dimensional stability. In contrast, PEEK exhibits excellent resistance to moisture, maintaining its properties even in wet environments.
- Temperature Resistance: PEEK’s ability to maintain its strength at high temperatures surpasses that of PA, which generally has a lower maximum service temperature.
- Chemical Resistance: PEEK is more resistant to a wide range of chemicals compared to PA, making it suitable for harsh chemical environments.
PEEK vs. PEI (Polyetherimide)
- Temperature Performance: Both materials exhibit good thermal stability, but PEEK can operate at slightly higher temperatures without losing its mechanical properties.
- Flame Retardancy: PEI is inherently flame retardant without the need for additives. PEEK also offers excellent flame resistance, but its performance can be enhanced with flame retardant additives for specific applications.
- Cost and Performance: While PEI is a cost-effective alternative for some high-temperature applications, PEEK is preferred when superior mechanical properties and chemical resistance are required, despite its higher cost.
PEEK vs. PSU (Polysulfone)
- Thermal Resistance: PEEK has a higher thermal resistance compared to PSU, making it more suitable for high-temperature applications.
- Strength and Stiffness: PEEK generally offers better mechanical strength and stiffness than PSU, providing enhanced durability and load-bearing capacity.
- Chemical Compatibility: Both materials have excellent chemical resistance, but PEEK’s resistance to a broader range of chemicals makes it more versatile in harsh chemical environments.