PEEK Processing: Techniques and Applications Polyetheretherketone (PEEK) is a high-performance thermoplastic renowned for its exceptional mechanical properties, chemical resistance, and thermal stability. Processing PEEK requires specialized techniques to fully leverage its unique characteristics while overcoming challenges such as high melting temperatures (343°C) and stringent processing conditions. Processing Methods 1. Injection Molding: PEEK is commonly processed via injection molding, which demands precise temperature control (380–400°C for the melt) and high-pressure tooling. The material’s low melt viscosity facilitates complex part geometries, but mold temperatures (160–200°C) must be maintained to prevent internal stresses and ensure dimensional stability. 2. Extrusion: PEEK extrusion is used for producing rods, tubes, and films. The process involves melting PEEK pellets and forcing them through a die. Cooling rates must be carefully controlled to avoid crystallization defects, as rapid cooling can lead to amorphous structures with reduced mechanical strength. 3. Compression Molding: For large or thick components, compression molding is preferred. PEEK powder or pellets are heated in a mold under high pressure, ensuring uniform density and minimal voids. This method is ideal for high-load applications like aerospace or medical implants. 4. Additive Manufacturing (3D Printing): Selective Laser Sintering (SLS) and Fused Filament Fabrication (FFF) are emerging techniques for PEEK. Challenges include warping due to thermal gradients and the need for high-temperature printers (>370°C). Post-processing (e.g., annealing) is often required to enhance crystallinity and mechanical performance. Key Considerations - Material Handling: PEEK must be dried (2–4 hours at 150°C) before processing to prevent hydrolysis. - Tooling: Wear-resistant molds (e.g., hardened steel) are essential due to PEEK’s abrasive nature. - Post-Processing: Machining PEEK requires carbide tools, and annealing (200–250°C) improves part stability. Applications PEEK’s biocompatibility makes it suitable for spinal implants and dental devices, while its lightweight, high-strength properties are valued in aerospace (brackets, seals) and automotive (sensor housings, bearings). In electronics, PEEK’s dielectric strength supports insulating components. Conclusion Mastering PEEK processing demands expertise in thermal management, tooling design, and post-treatment. Its versatility across industries underscores its status as a premier engineering polymer, though optimal performance hinges on meticulous processing protocols.