In the additive manufacturing process, leftover powder is often recycled for the next job. Do the raw materials degrade with time and exposure?

During last week’s live presentation, “Advancing Thermal Management with 3D Printing,” a Tech Briefs reader asked Andrew Carter, Engineer at the Eden Prairie, MN-based manufacturing company Stratasys:

Is there a difference in properties between parts made from completely virgin powder and parts made from completely recycled powder, after the maximum number of reruns?

Andrew Carter, Manufacturing Engineer, Stratasys Direct Manufacturing

Carter: In our study, we saw a level of consistency regardless of the number of times recycled; that was rather surprising. We are not seeing any difference in room-temperature tensile properties, material properties, or even chemical composition.

We do have to remember that we're applying subsequent heat treatments. We have to specify when we're asking this question. In the finally delivered state, in which the customer is concerned with, we're seeing no degradation.

Concerning the “as-built” materials, we know the feedstock changes to some degree. The particle size generally just drifts to the larger end of the distribution, but we're not seeing that manifest itself in the final delivered component.

What do you think? Have you used recycled raw materials in your 3D printing processes? Have a question of your own? Share your thoughts below.