SLA is an acronym that stands for StereoLithography Apparatus.Stereolithography is the heart of ProtoCAM's rapid prototyping service, turning your 3D CAD drawing into a solid object. Most stereolithography prototyping can be completed in as little as 1 to 2 days, with larger projects typically completed in under 5 days.
To create an SLA rapid prototype, first a three-dimensional CAD part is "sliced" horizontally into cross-sections between 0.002" and 0.006" thick. The slices are fed to 3D Systems' Stereolithography Apparatus. Inside the stereolithography chamber of the apparatus, an ultraviolet laser traces the first layer of the part on a metal platen, submerged just below the surface of a vat of photo-sensitive polymer. Wherever the laser touches the liquid, it solidifies. Once the layer is traced, the platen sinks the thickness of a layer below the level of the liquid. A sweeper bar moves across the surface of the last layer, making sure there is the exact amount of resin on top. The next layer is then built upon the previous layer. In this manner the entire part is built from the bottom up, with the completed sections of the part remaining submerged.
The resins used in our SLA machines are photosensitive epoxy polymers.The standard epoxy resin has a heat deflection temperature of 144°F and high temperature epoxy resin has a heat deflection temperature of 392°F.
Advantages of SLA prototyping:
1. Cost effective (Development costs reduced).
2. Assists to identify any problems with the efficacy of earlier design, requirements analysis and coding activities
3. Process is simple: There are no milling or masking steps required.
4. No milling step so accuracy in z can suffer.
Disadvantages of SLA prototyping：
1. Long-term curing can lead to warping.
2. Support structures are typically required.