Essentium Takes PEEK to the Next Level

PEEK is a high-performance, semi-crystalline thermoplastic polymer used extensively in the aerospace, oil and gas, medical device, and chemical process industries. It has excellent mechanical and chemical resistance properties that are retained at elevated temperatures, with some grades having a continuous-use operating temperature of up to 500° F (260° C). PEEK is highly resistant to thermal degradation and exposure to solvents, acids, and bases, and offers superior wear and friction resistance.

PEEK is part of a larger family of polymers known as polyaryl ether ketone (PAEK). On a molecular level, the ketone bonds are rigid while the ether bonds are more pliable. It is this balance of stiffness and flexibility that gives PEEK its versatility. On an atomic level, both the ether and ketone bonds are very strong, providing the heat and chemical resistance required for use in harsh environments.

Because it is so robust, PEEK is used to make items for very demanding applications such as bearings, piston parts, pumps, HPLC columns, compressor plate valves, and cable insulation. PEEK is one of the few plastics compatible with ultra-high vacuum applications. Although not biodegradable, it is recyclable, halogen-free, and safe enough to be used in food processing equipment.

PEEK is an inherently flame-retardant polymer. It carries a V-O flammability rating and exhibits very low smoke and toxic gas emission when exposed to flame, making it excellent for air-worthy parts in aerospace applications. PEEK has excellent hydrolytic stability, which makes it ideal for autoclaving, a process common to healthcare-related industries in which products are sterilized using high pressure steam. PEEK absorbs almost no moisture and has low outgassing properties, making it suitable for semiconductor processing and space applications.

Variations in the processing conditions used to mold or print PEEK, such as speed and temperature, can influence the crystallinity, and hence the mechanical properties of the finished piece, so proper monitoring is required. PEEK has a glass transition temperature of about 289° F (143° C) and melts at approximately 662° F (343° C). Due to its high crystallinity, typically around 35%, PEEK can perform at temperatures well past its glass transition temperature. When reinforced with glass or carbon fibers, it can support mechanical loads at temperatures very close to its melting point.

With all of its versatility, PEEK is not without its drawbacks. It can be very expensive (recycling is encouraged), and requires a tightly controlled operating environment. 3D printing with PEEK is challenging. The thermal history of printed parts must be precisely controlled due to rapid crystallization rates, and the stress that builds up during the printing process.

To overcome these challenges, Essentium has partnered with the experts at Lehmann & Voss and Company to develop a better PEEK formula designed specifically for 3D printing. Indeed, it is the highest performance material in our broad materials portfolio. Essentium’s proprietary PEEK formula crystallizes over a longer period and with lower residual stresses than standard-grade PEEK materials for greater printing flexibility and more consistent quality. Essentium PEEK filament is therefore a better choice for applications where tight tolerances are critical, maximum interlayer bonding is desired, and for printing high aspect ratio geometries that tend to warp with other grades of PEEK. Available in a natural beige color in 1.75 mm or 2.85 mm filament diameter, Essentium PEEK spools are offered in 750 g or 2.5 kg sizes.

A high-temperature, high-speed extrusion printer like the Essentium HSE 180•S HT will still be required for the effective utilization of PEEK, but customers will realize much higher success rates when printing complex parts with Essentium PEEK thanks to its unique properties.

If you would like to learn more about Essentium’s high performance PEEK filament and other industrial-grade polymers, please visit our materials page.

Essentium, Inc. provides industrial 3D printing solutions that are disrupting traditional manufacturing processes by bringing product strength and production speed together, at scale, with an open ecosystem and material set. Essentium manufactures and delivers innovative industrial 3D printers and materials enabling the world’s top manufacturers to bridge the gap between 3D printing and machining to embrace the future of additive manufacturing.