SLS or Selective Laser Sintering, is a 3D printing technology, that relies on a laser to melt and solidify layers of plastic, metal, ceramic, glass or other materials into layers, in a 3D dimensional structure. As any other 3D printing technology, the object is being build from the bottom up, as the laser traces the pattern of each cross section of the object onto a bed of powder. Once the layer is built, the platform lowers so that the next layer can be created. However unlike most other technologies, SLS does not require supporting structures. When using SLS, there is no chance of the object falling apart. While the platform, holding the object moves down to make space for another layer, the bed of powder goes up, where the next layer will appear and this bed of powder itself, provides for the stability of the printed object. Atop the the first layer, another layer of powder is spread by a roller. The ability, to create new layers without the possibility of damaging the whole object, allows this technology to build much complex 3D objects than any other machine such as complex interior components and complete parts. This 3D technology is also saving a lot of time, because there is no need to clean the tools or the object from any supporting materials, which is the case with other technologies.
SLS is probably the best out there, when it comes to durable plastic parts. This technology is capable of producing highly durable parts for testing and creating molds, while other 3D printing technologies are not capable of achieving such perfection. Industrial 3D printing is still what SLS is mostly used for, but the first desktop versions of it have already appeared and even more are being worked on and the main goal is to make it mainstream among the 3D printing enthusiasts. SLS parts are so robust, that some of them are used in end-use applications like automotive and aerospace industries. Especially for small-run parts, that usually would require way more work with traditional manufacturing, SLS can be far more price and time efficient.The SLS is the perfect combination of strength, complexity and functionality. It can produce parts faster and cut down on the time required to put them together. The SLS 3D printer itself is great, because it's wearing out ratio is very low and it holds better against other problems, that 3D technologies encounter. SLS is not a stranger to impact-resistant engineering plastic, which are used in many industries today.
The SLS technology is in the process of making it's way to the normal consumer and this is where another technology like FDM beats it. FDM is quite simpler and a lot cheaper than SLS, but this might change in the coming years. If you do not need object of very high complexity and at cheaper price the FDM is the way to go. However if you are in need of a very detailed object SLS definitely beats it.