**3.2 Selective laser sintering**

The next AM technology considered in the chapter is selective laser sintering, which with the advent of cheaper 3D printer systems allows the application not only for industrial purposes but also for research. The material used in this technology is available in the form of powder that is laser-sintered to create a designed geometry. The powder delivery mechanism consists of two chambers, in the first, there is construction powder that is delivered to the second chamber through rollers and a piston in form of a powder layer. In the second chamber, a layer is precisely sintered to the desired shape utilising laser beams. This technology does not require a support structure, as the unsintered powder provides support to the object under construction. This allows the production of parts of more complex geometry from different types of materials, and it is possible to produce prefabricated assemblies with movable joints. After the production process, further

**Figure 6.** *The principle of operation of SLS technology.*

processing of the part or assembly is required to achieve certain mechanical properties of the finishing quality. In this chapter, the SLS system is discussed, which consists of the SLS 3D printer Sinterit Lisa Pro and the associated equipment for the preparation of powder materials (nylon 11, nylon 12, TPU, TPE, and polypropylene) and processing of parts and assemblies. **Figure 6** shows the working principle of the SLS.
