Circular economy marks major milestone: recycling nylon waste powder in 3D printing, addressing up to 50% of running costs

November 13th, 2024 – Friedberg near Munich, Germany – voxeljet AG, Dressler Group GmbH, and Fraunhofer IPA have announced the successful completion of a material study for waste PA12 powder from laser-based 3D printing systems. In the study, waste powder from Selective Laser Sintering systems was successfully recycled by Dressler Group and 3D printed by Fraunhofer IPA at the University of Bayreuth, using a VX200 HSS platform from voxeljet. The initial results demonstrate that reconditioned PA12 waste powder can be processed effectively using ink- and printhead-based High Speed Sintering (HSS) technology enabling sustainable and cost-efficient production. The preliminary test results indicate that the material properties are equal or may even exceed those of comparable prints with fresh powder.

In SLS systems, unprinted PA12 powder loses its ability to be reused due to high temperature exposure in the build area, which causes the polyamide chains to lengthen after condensation, negatively affecting powder flowability and melt viscosity. This makes the material difficult to process again via laser-based technologies, as the energy input from lasers is too short to process longer molecule chains accordingly. Therefore, comparably high powder refresh rates are necessary, accumulating waste and associated high disposal costs.

The collaborative study aimed to reclaim this used powder by processing it through voxeljet’s VX200 HSS platform. HSS technology, using an inkjet-based printhead and infrared (IR) heating, offers selective and thermally gentler energy input, allowing the polyamide to sinter gradually, enabling the reuse of this powder. This means a real tribute to circular economy in Additive Manufacturing.

Dressler Group, experts in powder design and manufacturing, processed the used PA12 powder to homogenize and recover key powder properties such as flowability and moisture, making it suitable for reuse in HSS.

“Recycling used PA12 powder can effectively reduce costs and support sustainability efforts in AM.” says Dr. Ing. Holger Leonards, Head of R&D at Dressler Group. “Our expertise in regenerating powder properties and handling of large powder volumes enables companies to reclaim this valuable material.”

“The VX200 HSS technology is an open-source system, allowing us to quickly change and adapt process parameters to any powder.” says Jan Kemnitzer, Research Team Lead at Fraunhofer IPA and adds “We were therefore able to quickly adapt the 3D printer to the material with consistent or improved results in part properties.”

“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 VX1000HSS will bring immense cost savings.” says Tobias Grün, Global Product Management at voxeljet. “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.”

This study highlights the growing issue of excess PA12 waste powder within the additive manufacturing industry. By reclaiming this material for use in voxeljet’s HSS technology, companies can reduce waste, lower operational costs, and improve sustainability in their additive manufacturing processes.

First parts of this collaboration will be shown at the formnext trade show in Frankfurt, Germany from November 19^th to 22^nd   and can be seen at the voxeljet booth E08 or the Fraunhofer booth C71 in hall 12.1.