What is Vat Photopolymerization Process?
One of the first 3D printing technologies, developed in 1986, was stereolithography (SLA), which is based on the polymerization of a photosensitive curable resin due to exposure to ultraviolet light. 3D Systems was the first company to introduce a commercialized 3D printer to the world. The basis of this technology is similar to the powder bed as shown in Fig. 1, but instead of a powder bed, a liquid polymer is consecutively solidified by a concentrated ray of UV light.
Fig. 1. Stereolithography (SLA) technology for manufacturing Polymeric parts using photosensitive resin. The system consists of Liquid photopolymers, laser, focusing tools, build platform, polymer supply system, and leveling system. (image from additively.com)
The process is comprised of the layer-upon-layer exposure of the thin layer of the photosensitive polymer while the light scans the cross-section. When it is finished, the platform moves down, new material pours into it, and the process continues. This technology also has been used for manufacturing ceramic. However, this newly developed technology bears more resemblance to binder jetting although it uses UV and polymer sensitive liquid for binding ceramic to fabricate the green part.
This technology is capable of bottom-up and top-down manufacturing and primarily is limited to photopolymers. However, effort has been made to introduce nanoceramic particles to the resin and print ceramic parts as well.
Vat Polymerization or Stereolithography (SLA), Source: 3dsystems.com
Vat Polymerization or Stereolithography (SLA), Source: FormLabs.com