Stereolithography: 3D Printing by Laser solidyfing Liquid-Resin

Stereolithography (SLA) is a resin 3D printing or additive manufacturing process that uses a vat of photopolymer resin that can be cured. The build plate moves down in small increments and the liquid polymer is exposed to light where the UV laser draws a cross section layer by layer. The process repeats until a model has been created. The object is 3D printed by pulling the object out of the resin (bottom up) which creates space for the uncured resin at the bottom of the container and can then form the next layer of the object. Another way is to 3D print the object by pulling it downward into the tank with the next layer being cured on the top.

These photopolymer parts do not have the strength of SLS or FDM parts, but can typically achieve much higher levels of detail. As the photopolymer is UV sensitive, these products are susceptible to deforming and changing colors in sunlight.

SLA is commonly used to generate highly detailed artwork, non-functional prototypes, and can be used to make molds in investment casting applications.