Study on the recycling of PA12 powder waste for sustainable 3D printing

voxeljet AG, Dressler Group and Fraunhofer IPA have completed a material study looking at the reuse of PA12 waste powder from laser-based 3D printing systems. In this study, the excess powder from selective laser sintering systems was recycled by Dressler Group and tested on voxeljet’s VX200 HSS 3D printer.

The results show that the recycled PA12 powder can be successfully processed with High Speed Sintering (HSS) technology and enables cost-efficient and sustainable production. The material properties of the parts produced with recycled powder are comparable to those made from virgin powder – in some cases even better.

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

PA12 powder, which is not consumed in selective laser sintering (SLS) systems, loses its flowability due to the high temperature in the printing process and is difficult to reuse. To avoid this, a large amount of fresh powder is usually added, resulting in high costs and waste. voxeljet’s HSS technology, which uses infrared energy and an inkjet-based print head instead of lasers, enables gentler processing and makes the recycled powder reusable. This technology can significantly reduce the cost of materials and offers a more environmentally friendly approach to additive manufacturing.

Dressler Group homogenized the used powder and ensured that key properties such as flowability and moisture were optimized for HSS technology.

“The VX200 HSS is an open-source system that allows us to quickly change the process parameters and adapt to any powder,” says Jan Kemnitzer, head of the research team at Fraunhofer IPA, adding: ”This allowed us to quickly adapt the 3D printer to the material and achieve consistent or improved results in part properties.”

This study highlights the importance of the circular economy in the field of additive manufacturing and offers a potential solution to the problem of excess powder waste. The first results of the study will be presented at the Formnext 2024 trade fair in Frankfurt, where voxeljet and Fraunhofer will showcase the potential of this technology.

“The results of this study are particularly interesting for ink- and printhead-based technologies such as HSS technology. The ability to process this recycled powder on production platforms such as the VX1000HSS will bring immense cost savings,” says Tobias Grün, Global Product Management at voxeljet. “Typically, powder costs account for 50% of operating costs. Therefore, this development offers a huge impact on cost efficiency while promoting a circular material flow and reducing waste.”