PEEK — Polyether Ether Ketone
Polyether Ether Ketone
PEEK (polyetheretherketone) is a high-performance semi-crystalline thermoplastic offering exceptional chemical, wear and hydrolysis resistance, a continuous service temperature of about 250 °C and naturally flame-retardant behavior. It equips the most demanding parts: aerospace, medical implants, semiconductors, oil and gas, high-performance bearings.
- Mold temperature: 160-200°C
- Melt temperature: 370-400°C
- Shrinkage: 1.0-1.5%
- Density: 1.30-1.32
- Manufacturer grades: Victrex PEEK 450G (Victrex), KetaSpire PEEK XT (Solvay), Vestakeep 2000G (Evonik)
Processing
PEEK is hygroscopic: drying for about 3 h at 150 °C before molding is required. Its temperatures are extreme: melt between 370 and 400 °C, which calls for a high-temperature press with a suitable nozzle and runners. The mold must be hot, regulated between 160 and 200 °C, to drive crystallization: a mold that is too cold yields an amorphous, brittle and under-performing part. Limit residence time to avoid thermal degradation.
Advantages
- Exceptional continuous service temperature (~250 °C)
- Remarkable chemical, wear and hydrolysis resistance
- Excellent mechanical properties and controlled hot creep
- Naturally flame-retardant, low smoke emission
Limitations
- Very high material cost
- Extreme temperatures: high-temperature press and tooling required
- Hot mold (160-200 °C) mandatory for correct crystallization
- Hygroscopic: drying at 150 °C required before molding
Common injection molding defects
- Amorphous, brittle part — Mold too cold: regulate the mold between 160 and 200 °C to achieve correct crystallization
- Sink marks — On thick sections: increase holding pressure and time
- Burns / degradation — Excessive residence time or temperature at 370-400 °C: reduce residence time and purge regularly
Typical applications
Aerospace, medical, semiconductors, high-temperature parts