Creating an object with Powder Bed Fusion technology and polymer powder is generally known as Selective Laser Sintering (SLS). As industrial patents expire, these types of 3D printing technology are becoming increasingly common and lower cost.
First, a bin of polymer powder is heated to a temperature just below the polymer’s melting point. Next, a recoating blade or wiper deposits a very thin layer of the powdered material — typically 0.1 mm thick — onto a build platform.
A CO2 laser beam then begins to scan the surface. The laser will selectively sinter the powder and solidify a cross-section of the object. Just like SLA, the laser is focused on to the correct location by a pair of galvos.
When the entire cross-section is scanned, the build platform will move down one layer thickness in height. The recoating blade deposits a fresh layer of powder on top of the recently scanned layer, and the laser will sinter the next cross-section of the object onto the previously solidified cross-sections.
These steps are repeated until all objects are fully manufactured. Powder which hasn’t been sintered remains in place to support the object that has, which eliminates the need for support structures.