Selective Laser Sintering
SLS is an additive manufacturing process that uses a laser-based technology. A computer guided laser beam selectively creates parts by sintering polymer powder particles to bind them together. During the 3D printing process, the SLS machine preheats the powder material that is in the printer bed to just below its melting point and then the laser further raises the temperature of the selected regions to melt and fuse the powder together.
First a roller will apply a layer of polymer powder on the build platform, then the laser will sinter the powder according to the 3D model. The printer's build platform will lower itself after a layer is completed and apply a new layer of powder. The process is repeated till the part is created. Once the 3D print is complete the object then needs to cool down before it can be taken out of the printer.
Where 3D printing processes such as FDM and SLA require support structures to build complex overhanging parts, SLS process does not need to create any supports as the parts are surrounded by unsintered powder at all times. This allows for more design freedom to create intricate geometries such as interlocking parts, moving parts, hinges etc.