SLA is a fast prototyping process. Those who use this technology are serious about accuracy and precision. It can produce objects from 3D CAD data (computer-generated) files in just a few hours. This is a 3D printing process that’s popular for its fine details and exactness. Machines that use this technology produce unique models, patterns, prototypes, and various production parts. They do this by converting liquid photopolymers (a special type of plastic) into solid 3D objects, one layer at a time. The plastic is first heated to turn it into a semi-liquid form, and then it hardens on contact. The printer constructs each of these layers using an ultra violet laser, directed by X and Y scanning mirrors. Just before each print cycle, a recoater blade moves across the surface to ensure each thin layer of resin spreads evenly across the object. The print cycle continues in this way, building 3D objects from the bottom up.
Once completed, someone takes the 3D object from the printer and detaches it carefully from the platform. The 3D part will usually have a chemical bath to remove any excess resin. It’s also common practice to post-cure the object in an ultra violet oven. What this does is render the finished item stronger and more stable. Depending on the part, it may then go through a hand sanding process and have some professional painting done. SLA printing has become a favored economical choice for a wide variety of industries. Some of these include automotive, medical, aerospace, entertainment, and also to create various consumer products.
For 3D printing DLP as well as SLA  works with photopolymers. But what makes SLA and DLP processes unalike is a different source of light. For DLP 3D amateurs generally use more conventional sources of lights such as  arc lamps. The other important piece of process is a liquid crystal display panel, that is being applied to the whole surface of building material during single run of DLP process. The material to be used for printing is liquid plastic resin that is placed in the transparent resin container. The resin hardens quickly when affected by large amount of light.The printing speed is pretty impressive. The layer of hardened material can be created with such printer in few seconds. When the layer is finished, it’s moved up and the next layer is started to be worked on.
