05-12-2012, 04:37 PM
Stereolithography (SLA) - The Process
Stereolithography.docx (Size: 83.13 KB / Downloads: 33)
ABSTRACT
The Stereolithography Apparatus consists of a vat of liquid resin and an ultra violet laser arrangement. Using proprietary software, a 3D CAD file is sliced into a series of 2D cross section layers. Each sliced section is drawn individually onto the surface of a vat of photosensitive liquid resin. The resin cures on exposure to the UV light and after each layer is drawn, the machine platform moves down into the vat, a new layer of resin is applied to the surface and the laser traces out the next section of the required model. The process is repeated many times until the model is fully 'grown' layer by layer in the vat.
Elements of the object are secured by a supporting structure, which is made by the same process, and at the same time as the main object. When the object is built, the base plate is then raised to lift the object. The part is then drained, washed and the support structure broken away. The result is a solid resin model, accurate to within 0.1mm of the original CAD data.