AMGTA
The Additive Manufacturer Green Trade Association (AMGTA) has issued a report outlining the requirements to passivate metal powder bed fusion condensate waste for transport and recycling.
Developed by AMGTA members Sintavia and KBM Advanced Materials, the new process mixes powder condensate with a removable resin to render the waste non-hazardous and shippable to a recycling plant. The removable resin is provided by KBM.
Metal condensate – the term used for the excess soot and powder that is blown off of a build plate during the powder bed fusion 3D printing process – is considered a hazardous materials and is therefore costly to dispose of. Currently, Sintavia passivates its condensate waste by mixing it with silicon oil and sand, which makes the transportation possible without risk of ignitability, but the metal powder cannot be economically recovered. Through its work with KBM, Sintavia is testing alternatives to passivate powder condensate and enable the re-use and/or recycling of metal powder.
During trials of the condensate passivation process that uses KBM resin, the powder condensate was mixed with the resin using a plastic spoon to form a paste, before being left to dry on an aluminium tray with parchment paper to prevent it from sticking. Using EOS RFS 1.0 H282 and EOS RFS 2.0 IN718, the following three scenarios were evaluated:
250g RFS 1.0 H282 + 5g KBM resin + 80ml solvent
1kg RFS 1.0 H282 + 15g KBM resin + 150ml solvent
237g RFS 2.0 IN718 + 5g resin + 40ml solvent
While all scenarios formed a dense paste that dried after a few hours, scenarios #1 and #2 were not completely solid and became crumbs after a little pressure was applied, while scenario #3 was completely solid. No hazardous situations were reported and the air quality remained within acceptable limits. Sintavia and KBM are set to perform additional trials with different types of powder condensate, but have taken confidence from the initial trials that the procedure works.
“Today’s report is a must-read for any company involved in laser powder bed fusion metal additive manufacturing,” commented Sherri Monroe, Executive Director of the AMGTA. “Not only does this new process reduce transportation costs, but it is also reversible, meaning that metal recycling companies can have unsoiled access to the underlying powder once it is received – thus allowing for the potential to recycle waste material that previously had to be put in a hazardous waste landfill.”
“I hope that other companies adopt this new process as it will reduce their transportation costs since the underlying material is no longer hazardous,” added Brian Neff, AMGTA Board Chair and Sintavia CEO. “This report is an excellent example of the AMGTA taking a leadership role in developing sustainable use practices for additive manufacturing.”
