Selective Laser Sintering (SLS) and Multi Jet Fusion (MJF) are industrial 3D printing technologies that belong to the powder bed fusion family and share many similarities. Both processes build parts by thermally fusing (or sintering) polymer powder particles layer by layer, don’t require support material and are great for functional applications.
Essentially, the main difference between these two technologies is their heat source. SLS uses a laser to fuse powder into solid parts. MJF, on the other hand, dispenses ink (fusing agent) on the powder then passes an infrared energy source to build the solid part. Essentially, MJF combines SLS and Binder Jetting technologies.
Since SLS and MJF create parts that are very similar, it’s important for industrial designers to understand the differences between the two processes. Why choose SLS over MJF, and vice versa? In this article, we compare the two technologies in terms of material options, quality, cost and more, to narrow down your options.
PA 12 (nylon) is the main material used in SLS and MJF. When printing with nylon, MJF has slight edge in strength and flexibility and has more consistent mechanical properties along all directions of the part’s geometry. However, as SLS has been around longer, you have a wider range of material options including glass-filled Nylon (PA12 GF) and flexible TPU.
3D printing parts with either SLS or MJF technology leads to grainy surface finishes that can be post-processed to a better standard. SLS will provide you with a broader range of colour and surface finishing options, whereas MJF is limited to its natural grey form (and black achieved through dyeing).
While industrial SLS machines offer a larger build size (up to 400 x 400 x 450 mm) than MJF (up to 294 x 211 x 144 mm), allowing for the stacking of more parts, MJF technology has a faster print speed. Given that print time significantly impacts total cost, MJF is generally more cost-effective for producing large volumes of parts.
Due to its large build size, SLS can be more efficient and cost-effective for nested items, provided they fit within the build size and orientation constraints. This makes it well-suited for producing low-volume and small parts.
Available for MJF, SLS, SLA, SLM, FDM
Generally, SLS takes into consideration how much space the part takes in the build, where as MJF is more to do with the amount of material used by the part. For this reason, MJF typically costs less for lower density parts, and SLS is a better option for more solid parts.
The accuracy and quality of your 3D printed part will depend on many factors such as the design itself, and the material you choose. Both SLS and MJF technologies are known to print parts with similar accuracy and part quality. MJF can achieve slightly ‘crisper’ results for small details such as text etc. but both technologies are comparable in general.
| Industrial MJF | Industrial SLS | |
|---|---|---|
| Materials | PA12 | PA12, PA12+GF, TPU |
| PA12 Mechanical Properties | ★★★★ | ★★★☆ |
| Surface Finish | ★☆☆☆ | ★★☆☆ |
| Speed | ★★★★ | ★★☆☆ |
| Accuracy | ★★★★ | ★★★★ |
| Cost | Generally more competitive for higher volume parts Generally cheaper for low density parts | Generally more competitive for low volume production and small parts Generally cheaper for solid parts |
| Applications | Functional rapid prototyping High strength prototypes Lower density parts | Functional rapid prototyping High strength prototypes Solid parts |
| Build Volume | Up to 294 x 211 x 144 mm | Up to 400 x 400 x 450 mm |
Upload CAD and calculate the cost of your part
Certain considerations like part size, cost or material choice, may make the decision for you when deciding between MJF or SLS 3D printing. Refer to the table above when deciding between which process is better suited than the other based on key factors. For more information, view our Full 3D Printing Services.
While the table provides a good overview, every project is treated on a case-by-case basis. If you’re having trouble picking between SLS and MJF, send your CAD drawing to info@hlhrapid.com and our engineers will get back to you with advice.
