Stereolithography (SLA) is an additive process that uses a vat of liquid UV-curable photopolymer resin and a computer controlled UV laser to build parts one thin layer at a time. The UV laser cures, or, solidifies the part layer and adheres it to each additional layer.
After each layer has been cured, the SLA machine lowers the platform by a single layer thickness, typically 0.002″ to 0.006″. A resin filled sweeper blade then moves across the cured layer recoating it with another layer of uncured resin. Each layer is cured by the laser, curing it and adhering it to the previous layer. This process repeats until the 3-D part is completed. Once complete, the SLA machine raises the platform from the vat of resin and the part can be removed, cleaned and final cured in a UV “oven”.
One advantage of stereolithography is that a functional part can be built in a relatively short period of time. The amount of time required depends on the size, complexity and layer thickness the part will be built with. Parts can take anywhere from a few short hours to a day or more. Parts built with an SLA machine can be used as master patterns for RTV molding, finished and painted or simply lightly sanded and may be used for shape studies or final presentation models.
The Stereolithography process can help you decrease costly mistakes by detecting design flaws before the manufacturing process. It can be a cost-effective option for low-volume production and also provides quick lead times.
To learn more, check out this great resource for Stereolithography.