PEEK/PEKK – Polyether Ether Ketone / Polyether Ketone Ketone Copolymer

🧩 PEEK/PEKK – Polyether Ether Ketone / Polyether Ketone Ketone Copolymer

PEEK/PEKK is a next-generation, ultra-high-performance material resulting from the combination of PEEK and PEKK. It offers exceptional thermal stability, complete chemical resistance, superior processability, and constant mechanical behavior up to 300 °C. It is used in automotive, aerospace, medical, and industrial technical parts where reliability and precision at extreme temperatures are critical.

🔹 What is PEEK/PEKK PEEK/PEKK is a semi-crystalline aromatic copolymer resulting from the blend of two related polyketones:

PEEK — more flexible, with stable melting properties.
PEKK — more rigid, with a higher melting point. By adjusting the PEEK/PEKK ratio, a material is obtained that is more processable than pure PEEK but maintains identical thermal and chemical resistance, often used as an alternative in extreme applications (EGR, turbines, braking, pumps, pressure sensors).

🔧 Composition and Properties

Composition: 60–70% PEEK, 30–40% PEKK.
Density: 1.32–1.37 g/cm³.
Melting Point: 355–370 °C.
Continuous Thermal Resistance: 280–310 °C.
Chemical Resistance: Exceptional.

🚗 Automotive Applications

Engine / Thermal: Turbine covers, pumps, valves, EGR sensors (stability at 300 °C, chemically inert).
Transmission / Braking: Bushings, bearings, pistons, spacers (resistance to friction and thermal shock).
Electrical / Sensor Systems: ECU housings, fittings, sensor covers (excellent insulation, fire stability).
Technical Structures: Frames, clips, load-bearing parts (high rigidity, low weight).

🔧 Welding Temperature and Methods

Hot Air: 390 – 410 °C (slow melting, homogeneous and stable flow).
Heat Plate: 380 – 400 °C (clean joint, no oxidation).
Manual Extrusion: 380 – 410 °C (compatible PEEK or PEEK/PEKK rod).

🔩 Welding Compatibility

✅ Excellent Compatibility: PEEK, PEK, PEEK+GF, PEEK+CF, PPS, PPSU, PES, PEI, PSU.
✅ Good Compatibility: PEEK+HT, PEEK+PEI, PPA, PPS+CF.
❌ Incompatible: PP, PE, PS, ABS, PMMA, PVC, PET, PC.

💡 ReplastMD Recommendation: Use PEEK or PEEK/PEKK rod at 400 °C. Heat uniformly to avoid internal stresses between copolymer phases. Slow cooling is essential to maintain optimal crystallinity and maximum strength.