The two technologies are similar in many ways. For example, they use and melt powder materials, both require a heat source for sintering, and both work by layering. They also don’t require object support during printing, which makes building complex geometric shapes possible (and a lot easier). The main materials used for both technologies are pretty much the same, too – thermoplastics and elastomers.

Okay, we got the similarities between SLS and MJF. There are some major differences, though, which will be key when you decide which one to use.

Materials
SLS has been around for much longer and was originally patented in 1997. The technology has undergone several advancements, making it possible to use different materials (allowing for more flexibility of choice), such as PA 11, PA 12, PEBA 2301 3D, Alumide, TPU, etc.
MJF, on the other hand, is a new technology, made commercially available in 2017. It can work with a lot less materials such as PA 11, PA 12, and TPU.

Feature resolution and accuracy
Both SLS and MJF provide high dimensional accuracy. However, when comparing both technologies, the functional resolution of SLS parts is slightly better than that of MJF. However, since both techniques are prone to warping, you should definitely avoid large flat areas when 3D printing.

Print times for SLS and MJF production parts are pretty much the same. Still, the time required for the entire process, including machine setup, printing and cooling, MJF takes less time. This is because MJF printers have a removable build platform that allows printed parts to cool outside the machine. MJF is also faster when producing multiple parts because the technology can print dozens of parts simultaneously.

As for recyclability – about 80% of the powder recovered from MJF printed parts is recyclable, while SLS is only 30-50% recyclable. So if you’re really concerned about your environmental footprint and plan to print large quantities, there’s a clear winner in this category.

Surface Finish
Both technologies provide grainy surface finish, but the MJF parts’ finish is just a little bit smoother. However, SLS parts allow for easier coloring, because they are usually white or grey, while the fusing agent used in MJF is black in order to absorb infrared rays better. This is the reason MJF parts are darker and they’re usually dyed black.

Part Sizes
If you’re planning on producing larger parts, you should definitely go with SLS. This technology can print parts up to 60 x 35 x 56 cm, while MJF can print about 40% smaller parts. MJF, however, is a tad better at printing really small parts – 0.5 mm compared to SLS which goes as small as 0.8 mm.

Cost
Cost is often a deciding factor that can change your plans drastically. Luckily, the cost of production of MJF and SLS parts is roughly the same. MJF parts, however, get cheaper at scale because MJF printers can print multiple parts at once.
SolidFill offers both kinds of technologies, so if you want great quality at a very reasonable price – look no further. No machine time fee here!