In this blog post, we will compare the two most popular powder-based techniques: Selective Laser Sintering (SLS) and Multi Jet Fusion (MJF). We will describe the different techniques and what they are best suited for.
SLS – Selective Laser Sintering
SLS is a 3D printing method that uses a high-precision laser to melt and bind polymer powder, such as nylon or polyamide, in thin layers to create a solid model. The laser melts the polymer powder in a cross-section of the components in one layer and then the build plate is lowered and the next layer of powder is placed on top. This is repeated until the entire object is complete.
SLS is a very popular technology in 3D printing thanks to its large build volume, wide range of materials and ability to create complex geometries and functional prototypes and parts. It can be used to create both large and small objects with high precision and strength, and the materials used are often both durable and flexible. SLS is particularly suitable for manufacturing components that require high strength, high accuracy and good chemical resistance. Examples of applications include the automotive industry, the aerospace industry and medical technology.
MJF - Multi Jet Fusion
Multi Jet Fusion, developed by HP, is another 3D printing technology that, like SLS, builds objects in layers of molten powder. Instead of using a laser to melt powdered material, MJF uses a printhead technology that applies two agents to cross-sections of the components like a traditional paper printer, then melts those areas using a heat light source. The process is repeated layer by layer until the entire construction is complete. When the construction box containing components and powder has cooled, the powder is removed from the components, which are then blasted. The remaining powder can be reused to a very high degree.
One of the most prominent advantages of the MJF is its high print speed, which makes it ideal for large series production. MJF can create objects with very fine details and surfaces, and it can also handle complex geometries. However, the build volume is smaller than for SLS, which can be limiting in some cases when manufacturing larger parts.
Visual difference
Prints made with SLS and MJF have many similarities and it is not always obvious which technology to use and both MJF and SLS are very suitable for small and large series. MJF usually produces details with a core that is black or dark gray and a surface that is grainy gray while SLS usually results in white grainy details. If it is desired that the details are colored, details made with MJF can usually only be colored to black or gray while details made with SLS can often be colored to any color. The advantage of colored black or gray MJF details is that any scratches become black and therefore not as visible when compared to SLS where these scratches would have become white.
Conclusion
Ultimately, the choice between SLS and MJF will depend on the specific requirements and applications of the project. Due to the differences in how the technologies work, the pricing is slightly different but is often very similar. Therefore, it is often a good idea to explore the capabilities and prices of both technologies in parallel. Both technologies offer impressive opportunities to create complex and functional objects, and they continue to drive innovation and growth in the 3D printing industry. Both SLS and MJF are constantly being improved and adapted to meet new needs and requirements. As these technologies develop and refine, we are sure to see even more materials, applications and exciting opportunities in additive manufacturing and the manufacturing of primarily end products.
