PEKK (polyether ketone ketone) is one of the highest-performance polymer materials available and is manufactured using the process SLS. PEKK, together with PEEK (polyetheretherketone), belongs to the PAEK family — a group of thermoplastics with exceptional mechanical, chemical and thermal properties. Parts made of PEKK combine high stiffness and tensile strength with impressive heat resistance up to ~249 °C, and can withstand continuous exposure to acids, hydrocarbons and industrial chemicals. PEKK parts can replace aluminum in some applications — with up to 40% less weight — and meet industry requirements in aviation and rail thanks to their inherent flame retardancy (UL94-V0) without additives.
Why is PEKK — and not PEEK — used for SLS?
Both PEKK and PEEK are semi-crystalline PAEK polymers, but they differ significantly in their crystallization rate. PEEK crystallizes very quickly, making it susceptible to thermal cracking and difficult to handle in the SLS process where the powder is exposed to repeated heat. PEKK has a significantly lower crystallization rate and behaves more like an amorphous material during the 3D printing process — it provides better powder flow, more controlled sintering properties and, above all, a much higher refresh rate (powder return rate). PEEK powder can handle a refresh rate of only ~20%, while PEKK powder can be reused in a significantly higher proportion, making PEKK the economically and process-related superior alternative to SLS. For this reason, PEKK — and not PEEK — is used exclusively for SLS technology in industrial production. PEEK, on the other hand, is used in FDM applications where powder handling is not an issue.
Mechanically, PEKK is similar to injection-molded polyamide 6 with 35% glass fiber reinforcement, and offers a competitive alternative to metal components in applications where weight and corrosion resistance are crucial. Post-processing in the form of machining and drilling is fully possible. The material is biocompatible and is used in medical technology, but requires certification for implant applications — see information box below.
⚠️ Medical use: PEKK is biocompatible and used in medical technology, but 3D printed parts are not automatically approved for implants or medical technology applications. Certification and validation according to applicable regulations (e.g. MDR, ISO 10993) are required. Contact Us for more information.
PEKK is suitable for: aircraft components (structural parts, fasteners, duct parts), parts within defense industry, motorsport and automotive, oil and gas industry (chemically exposed parts), electrical and electronic applications (E&E), replacement of metal parts for weight reduction purposes, and medical technology applications with certification.
