Supported by the European Space Agency, Polish 3D printer company Zortrax has developed a way to co-print two forms of the super-tough polymer PEEK – one insulating and one conductive.

Zortrax-composite-PEEK

“After nearly a year of research and development efforts, we have reached a major milestone,” according to Zortrax. “The first prototype composite parts made out of standard PEEK and experimental electrically conductive PEEK developed by ESA have been fabricated.”

Replacing metals with polymers, and getting structures to do more than one thing, are tw ways to save weight in aerospace.

Zortrax-3D-printed-PEEK-with-black-conductive-PEEK“In a standard airplane or spacecraft, you need to include both structural elements and wiring responsible for transferring energy or data between various systems,” said Zortrax R&D head Michał Siemaszko. “That is what we aim to solve with 3D printing PEEK components with electrically conductive paths. This way, the structural parts can at the same time perform electricity or data transfer functions without weight penalty incurred for additional wires. Imagine casting a solid steel slab that also works as a USB connector.”

That said, PEEK is not as strong as steel, but challenges some aluminium alloys.

PEEK (polyether ether ketone) is an expensive physically strong chemical-resistant vacuum-resistant polymer originally invented by ICI (now Victrex) over 30 years ago, that has been developed into different forms, some of which can operate up to 250°C. It is notoriously difficult to print as, amongst other things, it warps and shrinks unless processed at carefully-controlled high temperatures.

The printer used was Zortrax’ Endureal, a dual-extrusion printer that has traditionally been used to co-print an object and, in a different polymer, support structures to maintain the object’s integrity until the object is complete.

For the proof-of-concept, a standard Endureal printer was modified to increase the rigidity of the extrusion system for better dimensional accuracy, its maximum extrusion temperature was increased to 480°C, it printing chamber to 200 °C and the build platform to 220°C. Changes in both firmware and software were also required to print the two-PEEK composite.

“We expect solutions developed in projects like this one to trickle down to our production level 3D printers,” said Zortrax CEO Rafał Tomasiak.

And this is already happening to Endureal machines, which are getting the hardware upgrades for PEEK + PEEK. “Customers can rest assured that the printers they ordered will come ready to print composite models after a simple software update when the technology reaches production level,” according to the company.

Endureal 3D printer:

400 x 300 x 300mm build volume
480°C extrusion
220°C build platform
200°C chamber
Prints materials including PEEK and Z-PEI 9085 (polyetherimide)

The research was discussed today at the FabAddComp scientific conference held in Lorient, France.