voxeljet Breathes New Life into Used PA12 Powder for High Speed 3D Printing

Recycling nylon PA12 powder waste has become a major step toward making 3D printing more affordable and sustainable. Now, voxeljet has joined this growing movement toward sustainable practices in 3D printing, developing a new process that turns discarded powder from selective laser sintering (SLS) systems back into reusable material, extending the life of the powder and reducing waste.

For companies facing high material expenses, this solution means fewer wasted resources and more affordable production. The company’s first 3D printed parts using reconditioned PA12 powder made on its High Speed Sintering (HSS) technology will be shown at Formnext 2024 in Frankfurt, Germany, from November 19th. through the 22nd, where attendees will have the opportunity to examine these parts firsthand.

Game-Changer

A major hurdle in additive manufacturing has been the degradation of PA12 powder, commonly used in SLS printing. Over time, PA12 powder exposed to high temperatures in SLS machines loses its ability to be reused due to changes in its molecular structure, making it challenging to print with again.

Traditionally, manufacturers must continuously refresh the powder to ensure consistent quality, resulting in high material costs and considerable waste. Recycling this material is an essential step toward a circular economy in the industry.

To make this happen, voxeljet collaborated with Dressler Group, a specialist in powder design and manufacturing; the Fraunhofer Institute for Manufacturing Engineering and Automation (Fraunhofer IPA); and the University of Bayreuth in Germany. Together, they developed a process to recondition the used PA12 powder, making it suitable for reuse in voxeljet’s high-speed sintering (HSS) technology.

While voxeljet primarily focuses on high-speed 3D printing systems rather than powder production, it works closely with material experts to develop and optimize materials compatible with HSS applications. HSS, which utilizes inkjet-based printheads and infrared heating, offers a gentler, more gradual sintering process than traditional laser systems. This unique approach allows the recycled powder to retain—or even improve—its material properties. The reconditioning process was then rigorously tested through a material study, demonstrating that the recycled powder performs as well as, or even better than, fresh powder in HSS applications.

Dressler led the reprocessing phase, restoring essential powder characteristics like flowability and moisture content to the material. Voxeljet’s VX200HSS platform, a flexible and open-source system, then printed the reconditioned powder. This adaptability let Fraunhofer IPA’s team customize the printing process for the recycled powder.

“The VX200HSS technology is an open-source system, allowing us to quickly change and adapt process parameters to any powder,” explained Jan Kemnitzer, Research Team Lead at Fraunhofer IPA. “We were therefore able to quickly adapt the 3D printer to the material with consistent or improved results in part properties.”

voxeljet’s VX200 HSS. Image courtesy of voxeljet.

Circular Economy+

The findings of this collaborative study are promising not only for voxeljet’s VX200 HSS but also for the company’s larger production platforms, like the VX1000 HSS.

According to Tobias Grün, Global Product Management at voxeljet, “The results of this study are especially interesting for ink and printhead based technologies such as the HSS technology. The future possibility of processing this recycled powder on production platforms like the VX1000 HSS will bring immense cost savings. Typically, 50 % of the running costs are attributable to powder costs. Thus, this development provides a huge effect on cost effectiveness while boosting a circular material flow, reducing waste.”

voxeljet’s VX1000 HSS. Image courtesy of voxeljet.

Voxeljet isn’t alone in the push to recycle PA12 powder in 3D printing. Companies like Materialise have developed solutions such as Bluesint PA12, allowing 3D printing with up to 100% reused PA12 powder. At the same time, Stratasys recently launched the SAF ReLife solution to repurpose PA12 waste from various powder bed fusion printers. Rapid Powders also introduced a process for upcycling waste nylon PA12 powder, contributing to a broader industry trend toward cost-saving practices and sustainability.

In a parallel development, voxeljet has expanded its HSS network by partnering with one of Europe’s leading AM service bureaus, FKM Sintertechnik GmbH, as a production partner. As part of the collaboration, the VX1000 HSS—the largest ink-based polymer 3D printer—has undergone significant enhancements to meet industrial demands for mechanical strength, homogeneity, and reproducibility. These improvements position the printer as an industry leader, capable of producing both large components and numerous smaller parts with exceptional speed and precision.

The partnership has also marked an important milestone for voxeljet’s HSS Polymer Network, shifting its focus from R&D to production. FKM, a trusted supplier across industries such as aerospace and automotive, is now offering PA12 components produced with the VX1000 HSS to customers. This collaboration exemplifies voxeljet’s commitment to delivering sustainable and efficient solutions while expanding the capabilities of HSS technology.

According to Dr. Alfred Grießer, voxeljet’s Director of Research and Development, “By combining our development with FKM’s expertise as a powder bed specialist, we have been able to ensure that our VX1000 HSS meets the high standards of these industries.”

At Formnext 2024, voxeljet will feature parts produced using the reconditioned PA12 powder at its booth (E08 in hall 12.1), while additional insights into the recycling process will be available at Fraunhofer’s booth (C71 in hall 12.1). As 3D printing moves forward, practical solutions like these show how the industry can balance costs and sustainability without compromising material quality.