stereolitografi

Stereolithography, often abbreviated SLA and known in Swedish as stereolitografi, is a vat photopolymerization additive manufacturing process for producing three-dimensional parts from liquid photosensitive resin. A computerized light source selectively cures resin layer by layer to form the object. In a typical system, a build platform starts near the top of a resin-filled vat and, after each cured layer, moves downward by a layer thickness. A laser or a digital light projector traces a cross-section of the part on the liquid surface, solidifying the resin where exposed. The process repeats until the model is complete; supports may be added to overhangs and later removed.

Materials are photosensitive polymers—resins with varying stiffness, toughness, temperature resistance, and biocompatibility. Post-processing usually involves rinsing in a solvent to remove uncured resin and a post-curing step under UV light to achieve final properties.

SLA offers high dimensional accuracy and smooth surface finishes, making it suitable for prototypes, dental and jewelry molds, medical devices, and detailed parts. Drawbacks include relatively slow build speeds compared with some other methods, resin cost, equipment and maintenance, and the need for careful post-processing and handling due to chemical hazards.

History and variants: The technology was developed in the early 1980s by Chuck Hull, who founded 3D Systems to commercialize it. Variants using a projector instead of a laser are sometimes referred to as DLP-based stereolithography or vat photopolymerization.

See also: Digital light processing, vat photopolymerization, 3D printing, rapid prototyping.