Multi Jet Fusion (MJF) is an innovative industrial 3D printing process that is transforming the world of manufacturing. It offers the ability to produce functional nylon prototypes and end-use production parts quickly, often in as fast as a single day. This remarkable technology boasts a range of advantages, including quality surface finishes, fine feature resolution, and consistent mechanical properties, making it stand out from processes like selective laser sintering (SLS).
MJF finds its applications in a variety of industries and is particularly well-suited for:
1. Parts Requiring Consistent Isotropic Mechanical Properties
2. Functional Prototypes and End-Use Parts
3. Complex and Organic Geometries with Fine Features
Design Guidelines for Multi Jet Fusion:
To make the most of MJF technology, it's essential to consider some crucial design guidelines:
- Maximum Part Size: 11.1 in. x 14.9 in. x 14.9 in (284mm x 380mm x 380mm)
- Layer Thickness: 0.00315 in. (80 microns)
- Minimum Feature Size: 0.020 in. (0.5mm)
- Wall Thickness: 0.020 in. (0.5mm)
Tolerances can typically achieve +/- 0.012 in. (0.30mm) plus 0.1% of nominal length for each additional inch, but they may change depending on part geometry. Warpage can be a concern for larger part sizes and thin features, so maintaining a uniform thickness of 0.125 in. (3.175mm) is recommended for stability.
MJF Material Options:
MJF offers a range of materials to suit different requirements. Two notable options are:
1. PA 12 Black: This is a high tensile strength nylon that exhibits near isotropic mechanical properties. It's a cost-effective choice and ideal for designs with living hinges.
2. PA 12 40% Glass-Filled Black: This 40% glass-filled nylon material excels in heat deflection, making it suitable for applications requiring high-temperature resistance.
Multi Jet Fusion Surface Finish:
MJF provides several surface finish options to enhance the cosmetic appearance of parts:
- Standard: A bead blast removes powder and leaves a consistent overall texture. Parts are dyed black for a uniform look.
- Vapor Smoothing: This option significantly reduces surface roughness, transforming the as-printed surface from over 250 μin RA to a smooth 64 – 100 μin RA after smoothing. Available for PA12 Black.
- Custom: Secondary options include applying a primer and adding taps and inserts to the parts.
How Does Multi Jet Fusion Work?
The MJF process involves the encapsulation of parts within a powder bed. Once printing is complete, the bed is moved to a processing station where loose powder is removed using a vacuum. Afterward, parts are bead blasted to eliminate any remaining residual powder. The final step involves dyeing the parts black to improve their cosmetic appearance.
In conclusion, Multi Jet Fusion is a game-changing technology in the field of 3D printing, with a wide range of applications and material options. Designing parts with the specified guidelines in mind and utilizing the available surface finish options can help manufacturers unlock the full potential of MJF for creating functional prototypes and production parts.