【3D Printing Application】Three Key Points to Win: Laser Sintering VS. Multi Jet Fusion
Among the three common 3D printing technologies, the movable structures, one-piece molding, and support-free features of powder printing always deliver astonishing results. However, there is more than one type of powder 3D printing, and each material effect has its own strengths!
Taking HP's renowned MJF technology (Multi Jet Fusion) and Sinterit's SLS technology (Selective Laser Sintering) as examples, both are powder-based 3D printing, with the main difference being the heating method.
MJF can be seen as a combination of SLS and inkjet technology. Below, we will compare the 3D printing process, molding effect, material characteristics, cost, and speed:
I. 3D Printing Process
The first layer of powder is spread on the print bed and heated to a temperature close to sintering. A printhead then sprays a fusing agent from above, while a detailing agent is sprayed in non-forming areas to prevent edge sintering. Subsequently, an infrared lamp illuminates the powder, and the areas sprayed with fusing agent absorb the heat and fuse into shape. A new layer of powder is then applied, and the process repeats until 3D printing is complete. After printing, it also requires cooling before removal.
II. Molding Effect
MJF and SLS are both high-precision industrial technologies that do not require support structures and are suitable for one-time 3D printing of complex movable prototypes. However, MJF has a better overall appearance because the MJF printhead sprays solvent at 1200 DPI resolution (approximately 0.022mm per unit), while the SLS laser spot is about 0.3-0.4mm.
Additionally, the detailing agent used by MJF in non-forming areas helps enhance the features and sharp edges of 3D printing. However, MJF is more prone to warping compared to SLS technology.
(MJF is suitable for producing delicate structures, such as the sharp protrusions on gear edges, which can be accurately rendered.)
III. Material Characteristics
HP's MJF currently only offers PA materials, and important engineering properties such as high impact resistance and deformation resistance are not yet fully developed. With rapid technological advancements, it is believed that more material options will be available in the future.
IV. Cost and Speed
In addition, MJF technology can print even when the powder is not fully filled, whereas SLS equipment requires the powder space to be completely filled for each print. The printing time depends on the number of powder layers, which is the main reason for the speed difference. Therefore, for SLS, accumulating multiple objects and filling the print space as much as possible at once is the most cost-effective approach.
(Taking the bracket model in the figure as an example, with a volume of 23.8 cm3 and dimensions of 101.9 x 45.0 x 18.0 mm, price comparisons are provided for 1 unit, 10 units, and a small production run of 100 units.)
As shown in the table below, due to MJF's dedicated post-processing and simplified cooling process, the 3D printing cost for a single object is lower than SLS. However, as the quantity increases, the prices of the two technologies become very close, because printing multiple SLS parts at once reduces the average cost. 
Key Takeaways:
．SLS powder sintering uses laser targeting, while MJF sprays fusing agent and then forms with infrared light.
．Both MJF and SLS technologies can 3D print high-precision, matte-textured, complex movable parts without support structures.
．Currently, SLS offers a diverse range of materials and mature technology, while MJF is slightly faster and has more even mechanical stress.
．The cost of small-batch production for both technologies is similar, but MJF is cheaper for single objects.
Through this sharing, do you have a better understanding of powder 3D printing? 3DMart not only provides 3D printing services, but also offers more equipment and application examples of SLS powder sintering and MJF multi-jet fusion technology. Contact us now to learn more.
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