Video: How Does Selective Laser Sintering (SLS) 3D Printing Work?

Selective laser sintering(SLS) is a laser powder bed fusion process that uses a high-power laser to center small particles of polymer powder, primarily nylon. A thin layer of the powder is distributed on top of the build platform from a supply container. The build chamber and bed plate are heated to just below the plastics melting temperature. This makes it easier for the laser to solidify the part.

The laser directs its beam to the scanner system, which consists of a mirror control by a galvo-motor system. The beam traces out the first layer of the past cross-section and heats the powder to the material's melting point; the particles are then sintered together. The build platform moves down by one layer into the build chamber, typically about 200 microns.

The process repeats until the parts are complete. During printing, the unmelted powder supports the solidified parts, which eliminates the need for dedicated support structures. Once the printing process is complete, the build chamber needs to cool down to ensure optimal mechanical properties and prevent the warping of the parts. The finished parts are separated from the build chamber, and any excess powder is cleaned off them. SLS printed come out grainy; if necessary, they can be post-processed using vapor smoothing and media tumbling.