Mastering Multi‑Jet Fusion (MJF): A Comprehensive Guide to 3D Printing Excellence

MJF, which is an abbreviation for multi-jet fusion, is a much-beloved type of 3D printing that comes packed with some pretty impressive benefits, like the fact its parts can be up to 98% isotropic, the powder is reusable (up to 80% of unused material), it’s fast, and its parts are very detailed. MJF printers also come with removable build volumes, allowing you to remove a completed part and cool it while you install another part and carry on with the printing process, making it excellent for high-volume production. Another bonus is that no support structures are required during printing. So, with all these benefits in mind, what exactly is MJF, and how does it work? Let’s see.

What is Multi Jet Fusion 3D Printing?

Multi-jet fusion creates 3D-printed parts using nylon, polypropylene, or TPU (thermoplastic polyurethane), all in powdered form. It was developed by HP Additive and commercially released in 2016. Compared to other more established methods of 3D printing, MJF is a relatively new kid on the block but has gained popularity because of how good it is.

It works by applying a fusing and detailing agent to a thin layer of powder that’s been placed in the shape of the part’s cross-section at a pre-set height. The fusing agent is good for absorbing heat and the detailing agent helps the edges be crisper and sharper, as well as prevents the molten plastic from bleeding past the edges of the part. An infrared heat source then bonds the powder into the final part by sintering the particles together wherever the fusing agent is applied, which is followed by the print bed moving down by the thickness of one layer (usually around 80 microns), and the process repeats itself. The following image shows a part made using this process: