The question is valid because special conditions need to be considered here. Why vacuuming is necessary at all can be quickly explained: because every "printed" metal part is created in a powder bed. One or more lasers target exactly those areas that will ultimately become the printed product and harden the powder. What remains is the large amount of unhardened powder. It needs to be vacuumed up, and two basic principles must be considered.
Double Challenge: Explosion Protection and Material Cost Efficiency
First: Like other metal dusts, metal powders for additive manufacturing are explosive. If you were to vacuum them from the workspace using a conventional industrial vacuum cleaner, the risk of an actual explosion would be significant. The powder must therefore be made "harmless" or "inert" – that is: inertized. For such tasks (originally in machining), Ruwac has developed compact wet separators.
Second: Metal powders for additive manufacturing are really expensive. For special alloys or metals (such as titanium), costs can be several hundred euros per kilogram. Since a large portion of the material still exists as powder, these are significant quantities that should definitely be reused. Otherwise, additive manufacturing cannot be economically viable.
These requirements are met by vacuuming with the wet separator. The powder is first directed into a liquid container – then it is no longer explosive. To be able to reuse it, it only needs to be dried. This way, the property profile remains intact.
Proven Solution and Look into the Future
This principle has proven itself. Leading manufacturers of systems for additive manufacturing with metals have had Ruwac wet separators in their (accessory) program for many years.
In the near future, the extraction and recycling of metal powders in 3D printing will be simplified even further. Then, inertization will not take place in a liquid but under protective gas, and drying can be eliminated. Ruwac has developed this process to series production readiness and presented it at the Formnext trade show in November 2024 – the central platform for industrial 3D printing experts.
Further information about extraction in additive manufacturing