Comparison of the SLS method with other 3D printing methods: what distinguishes selective laser sintering from other AM techniques?

3D printing has revolutionized many industries, offering many different additive methods, such as FDM (Fused Deposition Modeling), SLA (Stereolithography) and Binder Jetting. Among them, selective laser sintering (SLS) of high-performance polymers (in particular polyamide PA12) stands out for its unique features and advantages. The largest company providing services using the SLS method in Poland is Technology Applied which offers most of mentioned above.

Selective Laser Sintering (SLS) involves using a laser beam to selectively sinter layer by layer of powdered polymer material until a three-dimensional object is created. Parts made from PA12 using the SLS technique are known for their high strength, flexibility and precision of detail, making this method ideal for engineering applications and rapid prototyping.

Fused Deposition Modeling (FDM) – the most popular 3D printing method in the world, uses thermoplastic filaments that are melted and applied in layers. Although FDM is more affordable and easy to use, parts produced by this method are often less durable and much less precise compared to SLS. Additionally, in the case of more complex geometries, it is necessary to use support structures made either of the same material or of a support material soluble in water or chemicals. In both cases, it is necessary to remove the supports (manually or chemically), which extends the production time of the parts and has a negative impact on their final aesthetics (fragments built on supports are always visually worse than those built on the 3D printer’s printbed).

Stereolithography (SLA) uses UV light to harden the resin layer by layer. SLA ensures high accuracy and a smooth surface finish, but the products are usually less durable than those made using the SLS method – by default, they have lower temperature and mechanical resistance. Moreover, the resin materials used in the SLA technique may be less resistant to environmental factors compared to PA12. However, the biggest difference is post-processing – elements made of resins must first be bathed in isopropyl alcohol (IPA) to clean them of resin residues, then exposed to additional UV curing in a dedicated device, and finally remove the support structures that are also present here. In the case of SLS, all you need to do is clean them of powder.

Another popular additive method – Binder Jetting – involves applying a binding agent to a layer of powder, which allows for 3D printing complex geometries. Unfortunately, the mechanical strength and durability of elements manufactured using this method are usually lower than in the case of SLS. In the case of metal powders, it is necessary to sinter the finished parts to give them the necessary durability and strength. Unfortunately, during this process, the parts shrink (on average by about 20%) compared to 3D printed parts.

In summary, SLS stands out in 3D printing for its ability to create strong, functional parts with complex geometries and high accuracy, without the need for support structures. It is also a very efficient method in terms of production time, because elements can be stacked in the 3D printer chamber, completely using its working area (in FDM and SLA methods, the user is always limited by the table surface in the XY axes). This combination of features makes SLS the preferred method in applications where high quality and durability are required, outperforming other techniques such as FDM, SLA, and Binder Jetting, especially in demanding industrial applications.

Technology Applied, as the largest provider of 3D printing services in Poland, offers all the above-mentioned additive techniques (except Binder Jetting). Contact the company to learn the key differences and choose the best additive manufacturing method for yourself.

Photos: www.ta.parts