In addition to gypsum-based printing, there are many other powder-based technologies that use a similar process for printing and require no support structure, such as laser sintering (SLS). The interior of the printer is heated to just above the melting point of the powder you choose, then the part is printed layer by layer. The parts are then sintered together with a laser beam, which only fuses the areas that touch. The resulting parts have an inner porosity that needs to be filled, and are often grainy with surface finish.
Selective laser sintering (SLS) is a popular choice for plastic printing because of its versatility in materials and its ability to create complex geometries without the need for supports. A key feature of SLS is that it is a fully functional, production-grade technology, which means you can produce parts with high performance and quality comparable to injection molding. This includes impact resistance, durability and strength, as well as excellent surface finish and dimensional accuracy.
Metal-based SLS printing includes direct metal laser sintering (DMLS) and selective laser melting (SLM). Both processes are able to produce metal parts with good physical properties, including strength, and great surface finishes - often better than the original metal itself. This is a highly customizable process ideal for tackling challenging designs, such as intricate internal channels, complex surface textures or incorporating ceramics.
A newer, faster and scalable version of SLS is called binder jetting. This reflects the way conventional 2D printers work: a roller evenly distributes metal powder over the print bed, then a jetting head much like that of a 2D printer quickly jets binding polymer into the shape of each cross section. This bonds to the powder, which is then melted with a laser.
