Inside the Furnace

Send us Fan MailIn this episode of the AM Insider podcast, hosts Justin Hopkins and Dustin Kloempken sit down with Stefan Joens, a second-generation business owner of Elnik Systems. The conversation explores the critical but often misunderstood role of thermal processing in metal additive manufacturing, particularly for binder jetting and other sinter-based technologies.Key Discussion PointsRedefining Sintering: Stefan argues that sintering should be viewed as an in-process step rather than "post-processing" because a metal part is not truly complete until it has undergone this thermal cycle.The Science of the Furnace: The episode explains how furnaces vaporize polymer binders at low temperatures before heating metal particles just below their melting point to fuse them together. This process involves a significant shrinkage of 10% to 20%.Batch vs. Continuous Furnaces: For companies deciding on equipment, Stefan notes that batch furnaces offer high flexibility for various alloys and runs under 200,000 parts, while continuous furnaces are the "unbeatable" choice for high-volume, consistent production.The "Glass Box" Approach: Stefan shares his mission to turn the "black box" of furnace technology into a "glass box," focusing on educating users so they understand the metallurgy and physics happening inside the chamber.Industry Evolution: The group discusses moving past the initial industry "hype" toward a more mature phase focused on alloy development—such as titanium, copper, and Inconel—and actual production-ready parts.Expert RecommendationsStefan strongly advises that before making a major capital investment, companies should benchmark their parts. He encourages sending full loads of printed parts to experts, such as his sister company DSH Technologies, to prove the process works before buying a furnace. He also recommends resources like the Metal Injection Molding Association (MIMA) and the Formnext and Rapid + TCT trade shows for continued learning.