Stereolithography (SL or SLA from Stereolithography Aparatus ) is an additive manufacturing technology for producing models, prototypes, patterns, and in some cases, production parts.
Stereolithography is an additive manufacturing process using a vat of liquid UV-curable photopolymer "resin" and a UV laser to build parts a layer at a time. On each layer, the laser beam traces a part cross-section pattern on the surface of the liquid resin. Exposure to the UV laser light cures, solidifies the pattern traced on the resin and adheres it to the layer below.
After a pattern has been traced, the SLA's elevator platform descends by a single layer thickness, typically 0.05 mm to 0.15 mm (0.002" to 0.006"). Then, a resin-filled blade sweeps across the part cross section, re-coating it with fresh material. On this new liquid surface, the subsequent layer pattern is traced, adhering to the previous layer. A complete 3-D part is formed by this process. After building, parts are cleaned of excess resin by immersion in a chemical bath and then cured in a UV oven.
Stereolithography requires the use of support structures to attach the part to the elevator platform and to prevent certain geometry from not only deflecting due to gravity, but to also accurately hold the 2-D cross sections in place such that they resist lateral pressure from the re-coater blade. Supports are generated automatically during the preparation of 3-D CAD models for use on the stereolithography machine, although they may be manipulated manually. Supports must be removed from the finished product manually; this is not true for all rapid prototyping technologies.
Advantages and disadvantages
Stereolithography has many common names such as: 3D printing, optical fabrication, photo-solidification, solid free-form fabrication and solid imaging. One of the appealing aspects about SL is that a functional part can be created within one day. The length of time it takes to produce any one part depends on the size and complexity of the project and can take anywhere from a few hours to more than a day. Most SL machines can produce parts with a maximum size of approximately 50 cm x 50 cm x 60 cm (20" x 20" x 24"). Prototypes made by stereolithography can be very beneficial as they are strong enough to be machined and can be used as master patterns for injection molding, thermoforming, blow molding, and also in various metal casting processes. Although stereolithography can produce a wide variety of shapes, the process is often expensive - the photo-curable resin costs anywhere from $80 to $210 per litre. A stereolithography machine can cost from about $100,000 to more than $500,000. 1
Machine, 3D printing, Additive manufacturing, Desktop manufacturing, Digital fabricator, Direct digital manufacturing, Direct metal laser sintering, Disruptive technology, Fab lab, Fused deposition modeling, Instant manufacturing, Direct manufacturing, On-demand manufacturing, Lithography, MakerBot Industries (Cupcake CNC), Objet Geometries, Open design, Rapid manufacturing, Rapid prototyping, RepRap Project, Selective laser sintering, Self-replicating machine, Solid freeform fabrication, Stereolithography in medicine
- Stereolithography.com - Rapid Prototyping Services include SLA ...
- Stereolithography - Wikipedia, the free encyclopedia
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- Rapid Manufacturing, Rapid Prototyping, Stereolithography | MetroRP
- HowStuffWorks "How Stereolithography (3-D Layering) Works"