Developed by Hewlett-Packard, Multi Jet Fusion (MJF) is an additive industrial 3D printing method that creates parts additively. The final parts exhibit fine feature resolution, quality surface finishes, and many more mechanical properties than selective laser sintering. Multi Jet Fusion or MJF 3D printing service, like Laser sintering, is a powder-based technology. However, the only difference is that the former does not use lasers. The machine's powder bed is heated uniformly. However, a fusing agent is jetted instead of a laser, where the elements have to be selectively fused. A detailing agent will be jetted after completing the fusing process to improvise the print's resolution. When the infrared lights are passed over the powder bed surface, the jetted materials will capture the heat and evenly distribute it.
The polyamide MJF material is a coarse white powder that has a grey colour and sandy look. The grey colour is because of the usage of black ink as the fusing agent with the white polyamide powder. This is the reason why the final grey colour has different shades depending on the print. For an even look, the best way is to use black to dye the printed models. Polymide (MJF) can be used for models that require surface details, crisp textures, or labels. The material can be good for extremely complex parts with hinges and lattices.
For polyamide (MJF), the recommended wall thickness is 1mm minimum. If the parts are huge, then thicker walls are recommended or added ribs or fillets for reinforcement.
Hollow Models And Holes
The best way is to use hollow solid models, if possible, to prevent any sink marks and thus save the material. The wall thickness for hollowed models are 2-3 mm, and to remove the excess powder, it must have two holes minimum with a 2mm diameter.
Interlocking parts can be printed with Polyamide ( MJF) if the parts have 0.5 mm as minimum clearance.
Surface Details And Engraved Text
Polyamide (MJF) can be used for detailed surfaces. For letters, the embossed textures should have a minimum thickness of .25mm or .55mm.
Because of the cooling down procedure, flat plains such as A4 can get deformed during the 3D printing service. For optimal results, it is better to avoid this kind of surfaces. Size 340x256x360mm is the maximum size for Multi Jet Fusion prints. However, you are allowed to print as many subparts or components as needed for your final design.Also read: Stages of 3D metal Printing
Both polyamide (MJF) and Polyamide (SLS) are quite alike, and they can accomplish slightly different results with 3D printing technologies. Both the polyamides can help in similar applications; however, the advantages provided by MJF is a bit more when compared to SLS.
Polyamide (MJF) is a good material for detailed surface resolution, and the prints will have higher isotropy and less porosity. Polyamide (MJF) allows designs with thinner walls.
Another advantage of using Multi Jet Fusion 3D printing is that it is much quicker than printing with laser sintering technology. In MJF 3D print technology, the fusing is done at once for each layer. In SLS, a laser scan is used to contour the model. Another reason for the faster production is that less cool-down time is required for MJF than SLS.
The expert opinion from the plastic molding manufacturer in India is that MJF 3D printing is the best technology if you require shorter lead times. However, for colourful finishes, SLS is the right choice as MJF is always black or grey.