What is SLS 3D Printing?
Selective Laser Sintering (SLS) is a 3D printing methodology that works by using a laser to melt and fuse powdered raw materials into solid objects.
Printers designed for SLS printing have four major parts – a build platform, a powder delivery piston, a leveling roller, and a laser. The build platform, which starts at the top of its tube, and the powder delivery piston, which begins at the bottom, are situated on either side of a metal column. The powder for printing, which can range from plastic, to metal, to silicates, rests on the powder delivery piston.
To start the printing process, the leveling roller pushes a thin layer of powder onto the build platform. The laser then pulses down on the platform and heats the powder. There are a variety of temperatures the laser is capable of; it either heats the powder above its melting point or below its melting point. Heating the powder causes it to fuse together and form a solid layer. After the laser finishes sintering the powder, the build platform drops by about .1mm, and the powder delivery piston rises slightly. The leveling roller once again pushes the powder onto the build platform, creating a new thin layer. The laser sinters another layer onto the previous layer, and the process repeats. When the object is completed, users must allow it to cool before removing it.
SLS 3D Printing in Practice
Unlike FDM and SLA, SLS uses powdered materials, and the object doesn’t require supports while it’s being printed. Furthermore, SLS has the widest range of materials available for use because it works with powders. Complex geometric shapes are fairly simple to build with SLS, but object may occasionally have extra fused materials that hinder the printer’s accuracy. Another factor affecting the printer’s accuracy is the complexity involved in finding the laser’s proper temperature. The finished product is typically porous and rough, so they often need to be coated or sanded to achieve a smooth finish.
SLS is best used in industries that only need to print a few customized objects in high quality materials. Products like dental retainers, prosthetics, and hearing aids are sometimes produced using SLS. The aerospace industry also uses SLS to create fine, delicate prototypes. Because of the inherently dangerous, messy technique of SLS printing, there are currently no desktop printers available for purchase, but there are plans to bring SLS printing to consumers soon.