Stereolithography is the primary technology behind all resin 3d prints. It is the most widely used technique for producing quality 3D prints. First, the printer roller spreads out a thin layer of polymer. Because this layer is in liquid form, it will naturally spread out over the platform making sure that all layers receive a consistent thickness.
Most resin 3d printers use UV sensitive liquid polymers. When struck by a programmed computerized UV laser, the resin will start changing from a liquid to a solid state. Essentially, the laser draws various outlines of the print onto the layer of the resin and hardens the touched parts. Similarly, the parts not touched by the laser will remain in the liquid form.
The printer repeats these two steps over and over again. Next, the printer uses a fraction to lower the model, and the roller of the printer spreads out a new layer. Then, the laser solidifies some specific areas of that layer, which will essentially become parts of the 3d print. This procedure is repeated until the creation of the model is finished.
After the completion of the printing process as well as the printing of the entire object, the print is successfully raised out of the resin tank. Similarly, the excessive liquid will flow away. It is important to note that this liquid can be used again for other prints. Moreover, the prints need to be removed carefully and finished manually, for instance, removing structures, smoothing the surfaces, and spraying the paint surfaces etc.
This technology also uses more than one material. In fact, some companies offer four types of Stereolithography-based resins, which come with their own respective characteristics. Nonetheless, such resins share some common attributes as they feature shiny smooth surfaces and are best for post-processing.
The mammoth resin is used on the biggest 3d printers. Previously, the mammoth resin was known as paintable resin. 3D printers can print very large parts, for example, the size of up to 2100x700x800 mm that can be spray-painted in various colors.
The transparent resin can be ordered in various colors. It is currently the only transparent material that most companies offer. You can order it for parts of a large size, for instance, 2100x700x800 mm.
Moreover, a gray resin is used for a variety of purposes. It comes with a unique and great level of detail. It is suitable for small and medium size models, as well as features a gray smooth surface. The gray color is perfect for spray painting jobs. This is the reason gray resin is so popular among the modeling community.
Furthermore, a standard resin is a low-budget resin that provides very detailed results. In order to save money, it is recommended to use standard resin with some support structures, such as less time in post processing.
Another technology that is used resin is PolyJet. It usually works by jetting the resin in thin layers onto a build tray in the process of completion of the model. All layers are cured by using UV light after being jetted, which likewise produce fully-cured models that can be used immediately.