TECHNOLOGY

Stereolithography is an additive manufacturing process using a vat of liquid UV-curable photopolymer “resin” and a UV laser to build parts a layer at a time. On each layer, the laser beam traces a part cross-section pattern on the surface of the liquid resin. Exposure to the UV laser light cures, solidiies the pattern traced on the resin and adheres it to the layer below.

After a pattern has been traced, the SLA’s elevator platform descends by a single layer thickness, typically 0.05 mm to 0.15 mm (0.002” to 0.006”). Then, a resin-illed blade sweeps across the part cross section, re-coating it with fresh material. On this new liquid surface, the subsequent layer pattern is traced, adhering to the previous layer. A complete 3-D part is formed by this process. After building, parts are cleaned of excess resin by immersion in a chemical bath and then cured in a UV oven.