ABOUT MJF 3D PRINTING
MJF (Multi Jet Fusion) is a method of additive manufacturing that produces highly functional prototypes and end-use parts with an excellent surface using the Powder Bed Fusion process. The process is actually quite similar to (Selective Laser Sintering), however parts offer better feature resolution and improved mechanical and chemical resistance properties.
The process prints exclusively in a Nylon 11 or 12 (PA11 or PA12) material, with the exception of a glass filled variant. Parts are initially printed in a Grey colour, however a dye is used to make parts matt black if required.
Other post processing includes bead-blasting, which will remove any layer lines and leave a light textured finish.
The resulting parts offer great mechanical properties and an excellent surface finish. Although a relatively new process, MJF is quickly becoming the go-to 3D printing process, offering the functional benefits of ABS FDM 3D printing and the surface finish benefits of SLA 3D printing.
MJF 3D PRINTING WORK?
Multi Jet Fusion uses agents to selectively fuse Nylon powder together in a pre-determined shape. Heating elements then turn this powder into a solid layer. Once the first layer is completed, this process repeats on top of the existing layer. until he whole 3D shape has been achieved.
Once completed, loose powder which has not been fused is removed, usually using a vacuum. Finally, parts are post processed with a bead blast and/or black dye to apply a light texture and improve appearance.
Unlike other 3D printing process, the surplus powder can be reused, making MJF one of the most environmentally friendly and efficient 3D printing processes available.
WHEN TO USE MJF 3D PRINTING
MJF (Multi Jet Fusion) 3D printing creates parts to an excellent resolution of 80 microns means intricate shapes can be created with a smooth surface finish. The mechanical properties and dimensional accuracy of MJF 3D printing but limited material and colour choices mean it is usually used for functional and engineering focused components.
Well designed parts will be free from warpage, however it is important to note that some parts may be subject to warpage if design guidelines are not followed.
MJF PRINTING PROS
Dense property profiles and high density parts
Excellent chemical resistance to oil, greases, salts, hydrocarbons and some acids
Great mechanical properties
Good surface finish. No layer lines
High dimension accuracy
Ability to print intricate details
Great layer resolution (80 microns)
MJF PRINTING CONS
Unnecessary for many applications
Badly designed parts can suffer from extensive warpage
Limited colour choices (Grey or Black)
Cannot achieve a gloss surface finish
Only 3 material choices (Nylon 11, Nylon 12 & Glass Filled Nylon)
Read our detailed design guidelines for designing parts for the MJF 3D printing process.