​PEEK Material

PEEK Material: Comprehensive Technical Overview

1. Introduction to PEEK

Polyether ether ketone (PEEK) is a High-performance thermoplastic polymer belonging to the polyaryletherketone (PAEK) family. This semi-crystalline material is renowned for its exceptional combination of mechanical, thermal, and chemical properties, making it suitable for demanding engineering applications across various industries.

2. Key Characteristics of PEEK

2.1 Mechanical Properties

PEEK exhibits outstanding mechanical strength with a tensile strength of 90-100 MPa and flexural strength of 170 MPa. Its modulus of elasticity ranges between 3.6-4.0 GPa, providing excellent stiffness. The material maintains these properties even at elevated temperatures, with only 15% reduction in tensile strength at 150°C compared to room temperature.

2.2 Thermal Properties

PEEK has a glass transition temperature (Tg) of 143°C and melting point of 343°C. Its continuous service temperature reaches 250°C in air, with short-term exposure capability up to 300°C. The coefficient of thermal expansion is relatively low at 47 × 10-6/K (parallel to flow) and 67 × 10-6/K (perpendicular to flow).

2.3 Chemical Resistance

PEEK demonstrates remarkable chemical resistance, withstanding most organic and inorganic chemicals except concentrated sulfuric acid and nitric acid. It shows less than 1% weight gain after 24 hours immersion in water at 23°C and maintains dimensional stability in high humidity environments.

2.4 Electrical Properties

The dielectric strength of PEEK is 19 kV/mm, with volume resistivity of 1016 Ω·cm. Its dielectric constant remains stable (3.2-3.3) across a wide frequency range (50 Hz to 1 MHz) and temperature spectrum.

2.5 Tribological Properties

Unfilled PEEK has a coefficient of friction of 0.3-0.4 against steel. When reinforced with carbon fibers, the wear rate can be reduced to 1 × 10-6 mm3/Nm, making it suitable for bearing applications.

3. PEEK Material Grades

• Unfilled PEEK: Virgin material with balanced properties

• 30% Glass-filled PEEK: Increased stiffness (E = 9.7 GPa) and dimensional stability

• 30% Carbon-filled PEEK: Enhanced thermal conductivity (0.9 W/mK) and wear resistance

• PTFE-filled PEEK: Improved lubricity (μ = 0.15-0.2) for bearing applications

• Electrostatic Dissipative (ESD) PEEK: Surface resistivity of 106-109 Ω/sq

4. Applications of PEEK Material

4.1 Aerospace Industry

PEEK is extensively used in aircraft components due to its excellent strength-to-weight ratio and flame retardancy (UL94 V-0 rating). Applications include:

• Structural brackets and clips

• Cable insulation and conduit systems

• Fuel system components

• Bearings and bushings in auxiliary power units

4.2 Medical Applications

The biocompatibility (ISO 10993 compliant) and sterilization capability (autoclavable up to 134°C) make PEEK ideal for:

• Spinal fusion cages and trauma fixation devices

• Dental instrument components

• Surgical tool handles

• Prosthetic joint components

4.3 Oil and Gas Industry

PEEK's chemical resistance and high-temperature performance enable its use in:

• Downhole electrical connectors

• Seal rings and backup rings

• Valve seats and wear rings

• Subsea equipment components

4.4 Semiconductor Manufacturing

In cleanroom environments, PEEK is preferred for:

• Wafer carriers and handling components

• Plasma-resistant chamber parts

• Chemical delivery system components

• Vacuum system seals and gaskets

4.5 Automotive Applications

PEEK is increasingly used in vehicles for:

• Transmission components (gears, thrust washers)

• Turbocharger components

• Electrical connectors in high-temperature zones

• Sensor housings

5. Maintenance and Care of PEEK Components

5.1 Cleaning Procedures

For general cleaning:

• Use mild detergents or isopropyl alcohol (IPA)

• Avoid strong acids (pH < 2) and strong bases (pH > 11)

• Ultrasonic cleaning is acceptable at temperatures below 80°C

• For medical applications, follow autoclave sterilization protocols (121-134°C, 15-30 minutes)

5.2 Storage Conditions

Optimal storage parameters:

• Temperature: < 40°C

• Relative humidity: < 60%

• Protect from UV exposure

• Store away from strong oxidizing agents

5.3 Handling Precautions

• Use clean, powder-free gloves to prevent contamination

• Avoid sharp impacts that could cause surface scratches

• For precision components, maintain in controlled environments (cleanrooms when applicable)

• When machining, use sharp tools to prevent material degradation

5.4 Inspection and Maintenance Schedule

Recommended inspection intervals:

• Mechanical components: Every 6 months or 5,000 operating hours

• Seals and gaskets: Annually or per system maintenance schedule

• Electrical components: Before each commissioning cycle

• Medical implants: Per manufacturer's guidelines (typically pre-sterilization)