Although there are many different printers available, only nine basic types of 3D printing technology currently exist: Fused Deposition Modeling (FDM), Stereolithography (SLA), Digital Light Processing (DLP), Selective Laser Sintering (SLS), Selective Laser Melting (SLM), Electron Beam Melting (EMB), Laminated Object Manufacturing (LOM), Binder Jetting (BJ), and Material Jetting/Wax Casting. The three most common are SLA, FDM, SLS. These technologies have significantly impacted the way businesses, professionals, consumers and educational institutions function due to their adoption of 3D printing.
SLA – Stereolithography
The oldest additive printing technology is SLA. This form of 3D printing works by exposing a layer of photosensitive liquid resin to a UV-laser beam. The resin hardens in the desired pattern, and the object is built one layer at a time. DLP printing mimics the functions of an SLA printer with the main difference being it cures resin using a digital projector and light. A downfall of SLA printing is that the object must be rinsed with a solvent after the printing completes, and even at times has to bake in a UV light to finish the curing process.
FDM – Fused Deposition Modeling
FDM is the most common form of desktop 3D printing in the consumer market. The FDM system consists of a platform extrusion nozzle and a control system that provides a quick and straightforward solution to 3D printing. The thermoplastic filament is heated and deposited in x and y coordinates as the object is built layer-by-layer in a z-direction. FDM printers build objects from the bottom up and typically need support structures if the object has overhanging parts more than a 45° angle. This form of 3D printing is the most cost-effective way for individuals and small businesses to create parts quickly and efficiently. The printers have evolved from bulky, expensive machines to smaller, faster, economical ones that have become the key components for engineering and design departments.
SLS – Selective Laser Sintering
SLS printing is when a laser is used to solidify and bond grains of plastic, ceramic, glass, metal or other materials into layers to produce a 3D object. It works like other additive manufacturing technologies in that it provides a print by building layers-upon-layers until the object is complete. Once the laser traces the pattern of each layer slice into the bed of powder, the bed lowers and another layer is traced and bonded on top of the previous. A major benefit of SLS printing is that it does not require a support structure to produce intricate designs.