MJF vs SLS: Which 3D printing technology should you choose?

When choosing a 3D printing technology, it is sometimes difficult to understand the differences and advantages of each technology you are considering. It might be the case with Multi Jet Fusion (MJF) and Selective Laser Sintering (SLS) 3D printing technologies.

Indeed, MJF and SLS are quite similar; they are both part of the bed powder technologies. But there are some differences regarding the printing process, materials available, surface finish options, and mechanical properties. Let’s dive into this technology comparison! MJF vs. SLS: Which one of these 3D printing technologies will be the most suitable for your project?

How do SLS and MJF work?

The main difference between these two technologies is their heat source. SLS uses a laser to scan and sinter across each cross-section. MJF, on the other hand, dispenses an ink (fusing agent) on the powder to absorb infrared light. Let’s get a bit more into details. 

• Multi Jet Fusion (MJF)

Multi Jet Fusion is an additive manufacturing technique developed by the company HP. It creates parts additively thanks to a multi-agent printing process. During this process, a fusing agent is applied to a material layer, fusing the particles where they need to. Then a detailing agent is used to modify fusing and create fine details and smooth surfaces. The area exposed to the energy leads to reactions between the agents and the material to make the part.

The build box is removed from the printer when the printing process is complete. Like any powder-bed technology, n operator carefully extracts the parts from the build box and removes the remaining powder thanks to brushes and air blowers.

• Selective Laser Sintering (SLS)

SLS is an additive manufacturing method creating parts additively by sintering fine polymer powder particles to fuse them locally.

During the 3D printing process, the SLS machine preheats the bulk powder material in the powder bed somewhat below its melting point. Then, a roller will apply a layer of polymer powder, the laser will sinter the powder according to the 3D file, and the build platform will lower before applying a new layer of powder. The process will then be repeated until the desired part is created. 

Here are the similarities between these two additive manufacturing processes: 

• They are deposited on the fusion of powdery material and implement a sintering process requiring a heat source.
• Neither 3D printing technique needs support structures during the printing process, allowing the creation of complex geometries.
• They are mainly used with thermoplastics or elastomers.
• They can both be used to boost your product development but also your production. Both produce durable parts for functional testing and end use. 
• They create objects layers by layers according to a 3D model (or STL file).

What is the dimensional accuracy and layer thickness of SLS and MJF?

SLS and MJF are both industrial technologies that offer high dimensional accuracy for your 3D printed parts. 

• PA12 with SLS

Standard layer thickness: 100 – 120µm
Accuracy: ± 0.3% (minimum of ± 0.3 mm)

• PA12 with MJF

Standard layer thickness: 80µm

Accuracy X/Y : ± 0.3% (minimum of ± 0.3 mm)
Accuracy Z : ± 0.5% (minimum of ± 0.5 mm)

The mechanical properties of MJF vs SLS

SLS and MJF are comparable in the strength of the part. However, MJF emerges slightly ahead because it is more isotropic. The mechanical properties and performances of the technology also depend on the material you choose. But let’s stick with comparing the PA 12 available with these two technologies to understand the different properties they might offer!

• MJF

Elongation at break: 20%

Tensile strength: 48 MPa

Tensile Modulus: 1700 MPa

• SLS

Elongation at break: 20 ± 5%

Tensile Strength: 45 ± 3 MPa

Tensile Modulus: 1700 ± 150 MPa

SLS and MJF: Plenty of 3D printing materials available

SLS technology is used to offer more materials and finishing options, as Multi Jet Fusion initially only offered Nylon PA12. But HP evolved quite quickly and had to adapt to the needs of 3D printing users. 

Selective Laser Sintering options available with Sculpteo:

• Nylon PA12: A versatile and resistant 3D printing material.
• Ultrasint® PA11: A sustainable option, similar to PA12.
• PA12 (grey): A durable fabric from a delicate grey polyamide powder.
• Nylon 3200 Glass-Filled: A mix of polyamide powder and glass fibers.
• Alumide: A blend of polyamide powder and fine aluminum particles.
• Ultrasint® PA11 CF: A material combining high ductility, impact performance, and rigidity.
• Ultrasint® PA11 ESD: A powder material with electrostatic discharging properties for increased process safety in advanced applications.
• Ultrasint® PA6 MF: A material combining superior thermal resistance with high isotropic rigidity thanks to in-particle reinforcement technology.
• Ultrasint® TPU 88A: A resistant, flexible, and rubbery material.

HP Multi Jet Fusion options available with Sculpteo:

• PA12: A material is characterized by good elasticity and high impact resistance.
• PA11: A 3D printing option based on 100% renewable biomass sources.
• PP: Highly used in industrial manufacturing due to its good mechanical properties
• Ultrasint® TPU01: This material offers durable, strong, and flexible parts.

Surface finish: What are your options?

3D printing parts with either SLS or MJF technology leads to grainy surface finishes that can be post-processed to a high standard. The fusing agent used during the HP Jet Fusion printing process is black, enhancing infrared rays’ absorption. Because of this, parts printed with MJF usually have a grey appearance, making it easier to dye them black.

Finishing options will depend on the material you choose for your project. 

PA12 SLS: 

• Dye
• Paint
• Polish
• Color Touch
• Color Resist
• Chemical Smoothing

PA12 MJF:

• Paint
• Polish
• Color Touch
• Color Resist
• Chemical Smoothing

What applications for SLS and MJF ?

SLS and MJF are two versatile technologies, mainly thanks to their wide range of materials. 

When 3D printing with the Selective Laser Sintering or Multi Jet Fusion process, you must choose the material properties that will fit your project. These 3D printing processes are consumer products, architectural models, drones, robotics, luxury, automotive, medical, ioT devices, sports equipments, footwear, orthopedic technology, education, sculptures, jigs and fixtures, promotional items, and more. All parts you need, from functional prototyping to production, can be manufactured using this additive manufacturing technology.

This additive manufacturing technique allows you to create concept models and parts for functional tests. You can even add surface finishes on your parts to get great final products. It is possible to prototype complex designs with this additive manufacturing technology. You can do as many iterations as you want to improve your product design; you must modify your 3D file.

Cost and Lead times of MJF and SLS with Sculpteo

These two aspects depend on many different factors; that is why we encourage you to make the test using our online 3D printing platform. You can upload a 3D file of your choice and compare these two technologies’ costs and lead times. A quote will be generated automatically, as well as the lead times, depending on the production mode you are willing to choose.

We offer three production modes: Economy(+/- 15 days), Standard (2 to 15 days), and Express (2 days)! These production modes are all available with Selective Laser Sintering and HP Multi Jet Fusion.

The price of your order is calculated thanks to four factors, the dimensions, the volume, the number of parts, and the production mode selected. 

Make the test: Upload your 3D design! If you have any questions, feel free to contact our team of 3D printing experts.

Are you looking for a manufacturing partner?

Using an online service bureau such as Sculpteo, there is no minimum order quantity, from a single object to 10 000+ parts, you can 3D print the exact amount of parts you need.  With 10+ years of expertise in additive manufacturing for production and prototyping, Sculpteo is also offering rigorous quality control. 

Sculpteo offers a wide selection of high-performance materials developed by BASF and dedicated to demanding applications. From automotive to consumer goods, including robotics or medical. Sculpteo provides adapted manufacturing tools and support to all businesses, helping them to reach the next level.  We’ll take care of your orders in our industrial ISO 9001 factory!