How It Works
(SLA or SL; also known as stereolithography apparatus, optical fabrication, photo-solidification, or resin printing)
Stereolithography is an additive manufacturing process that works by focusing an ultraviolet (UV) laser on to a vat of photopolymer resin.[12] With the help of computer aided manufacturing or computer aided design software (CAM/CAD),[13] the UV laser is used to draw a pre-programmed design or shape on to the surface of the photopolymer vat. Because photopolymers are photosensitive under ultraviolet light, the resin is solidified and forms a single layer of the desired 3D object.[14] This process is repeated for each layer of the design until the 3D object is complete.
In models featuring an elevator apparatus, [15] an elevator platform descends a distance equal to the thickness of a single layer of the design (typically 0.05 mm to 0.15 mm[citation needed]) into the photopolymer vat. Then, a resin-filled blade sweeps across a cross section of the layer, re-coating it with fresh material.[15] The subsequent layer is traced, joining the previous layer. A complete 3D object can be formed using this process. Designs are then immersed in a chemical bath in order to remove any excess resin and cured in an ultraviolet oven.[15]