The SLA process uses a vat of UV-curable liquid resin which is cured by a laser to build parts one thin layer at a time. The laser ‘draws’ a single layer cross-section of the part on the top surface of the liquid resin, curing and solidifying it whilst joining it to the layer below.
Once a layer has been drawn and cured, the SLA machine’s platform is lowered by an amount equal to the depth of one layer. This then allows the re-coater blade to sweep across the vat, spreading another layer of fresh resin, ready for the laser to draw on. In this way a whole three-dimensional part is built up. Once completed, the build is drained, washed in a chemical bath to remove the excess resin, and then finished to the customer’s specifications.