MJF

MJF – Multi Jet Fusion

Multi Jet Fusion (MJF) is the new type of SLS fabrication.

MJF offers a finer level of detail and better resolution than corresponding methods using thermoplastics. The level of detail exceeds that of e.g. selective laser sintering.

Advantages: Quick, with high level of detail

With its amazing speed and resolution, the printer sets a new standard for what is possible in 3D printing. The machine is ideal for prototypes as well as series production in quantities that have not previously been associated with additive manufacturing.

Technical information

Just like SLS technology, MJF lays down material in powder form with a thickness of 0.08 mm. But there the similarity ends.
In the next steps of the process, two different liquid agents are applied via the print head with a resolution of 1200 dpi. A “fusing agent” is applied where the material is to be fused and a “detailing agent” is applied on areas which are not intended for fusion.
Then energy in the form of heat is added, which makes the powder fuse where the fusing agent has been applied. The process is subsequently repeated with a new layer of powder. Once the process is complete, the parts are removed from the build surface, brushed down and blown clean of powder. Finally, the agreed post-processing is carried out, e.g. polishing, dying or lacquering.

Tolerances for MJF: min ± 0.2 mm and ± 0.25% of dimension. Finer tolerances by special arrangement. Minimum wall thickness in x/y/z is 0.5 mm. Level of detail down to 0.1 mm.
There is a risk of increased tolerances in the case of split and glued parts.

Digital Manufacturing Network Partner

As a proud member of HP’s digital manufacturing network (DMN Network Partner), we have been qualified by HP and approved for the quality of our 3D printing and quality processes.

Guidelines

Flat top surfaces can sag slightly.
Grainy surface.
Risk of warping on large flat areas.
Uneven wall thickness can affect accuracy in the form of non-linear shrinkage.
Threads of less than M10 are not recommended directly in the plastic. For smaller threads and strengthening purposes, HeliCoil or Trisert thread repair inserts are a good idea. In the case of HeliCoil, please inform us before we manufacture the parts so that we can enter the threads directly in the CAD model and fit the thread inserts later on. External threads of less than M10 are not recommended. These are machined into the finished part.
For surfaces with an angle of less than 20° to the X/Y plane, distortion due to the layer effect (stepping) can be marked. The steeper the angle, the better the surfaces.
To obtain a press fit, ensure a gap of 0.1 mm (average particle size X2). This fit will be slightly looser on wear (particles work loose over time).
To obtain moveable parts printed in a workpiece, ensure a gap of 0.4 mm in X/Y/Z. It is also important that loose powder in the gap can be removed.
Working hinges can be easily achieved in polypropylene. However, it is important that one takes care when first opening the item to which they are attached, so as to ensure longer service life of the hinge. Hinges can also be made from PA2200, but their service life tends to be shorter.

Customer case - Bondtech

Bondtech uses 3D printing for volume production

Bondtech AB is the market leader in filament extruders for 3D printers in the FDM segment. Recently they launched their new extruder, the BONDTECH LGX Extruder.
Each extruder contains a number of components manufactured by Protocol AB in series production using MJF technology from HP 3D printing.
This is a shining example of how 3D printing technology is used in a full production setting.