Stereolithography (SLA) is often considered the pioneer of the additive manufacturing processes, with the first production systems introduced in 1988 and patented by 3D systems founder Charles (Chuck) W. Hull. The SLA process utilizes a vat of liquid photopolymer resin cured by ultraviolet laser to solidify the pattern layer by layer to create or “print” a solid 3D model.
An Ultra Violet (UV) laser beam is directed by a computer guided mirror onto the surface of the UV photopolymer resin. The model is built one layer at a time from supplied 3D CAD data.
The laser beam traces the boundaries and fills in a two-dimensional cross section of the model, solidifying the resin wherever it touches. Each successive layer is applied by submersion of the build platform into the resin as the part gradually develops and the platform descends into the liquid resin.
Once the model is complete, the platform rises out of the vat and the excess resin is drained. The model is then removed from the platform, washed of excess resin, and then placed in a UV oven for a final curing. After curing SLA parts are then ready for post processing as required by the specific application.