Stereolithography(SLA) Printing Technology| Definition, Types, Features, Working
Stereolithography also known as vat photopolymerization or resin 3D printing, is a type of additive manufacturing that is used to produce 3D objects by using Ultraviolet(UV) laser to cure the liquid resin into solidified object. In other words, this technique can also be defined as that 3D printing technique in which liquid resin upon interactions with certain wave-length of light become solid plastic.
It is the first-ever 3D printing technology that was introduced by Chuck Hull in 1986. This technology is considered one of the best to make prototypes, dental models, medical devices, jewelry designs and engineering components, because of its ability of providing high product detail, excellent surface finishes, and tight tolerance to water and air.
Key Features of Stereolithography
Following are some key features of stereolithography.
VAT Photopolymerization
Stereolithography is best for producing products with accurate dimensions that have reliable adhesion to the layer, because the printing process is based on the VAT Photopolymerization process. This process uses ultraviolet laser beam to cure thin layers of photosensitive liquid resin into solid object. Actually, the laser beam traces each cross-section of 3D model and then directly draw onto the resin surface by following the bottom-up approach.
High Resolution and Precision
The ability to build the models of high-resolution and perfect precision is one of the biggest feature of Stereolithography to give fine details of functional prototypes, intricate patterns in jewellery, and microfluidic devices. As this printing technique can produce very low layer thickness of around 25-50 microns (0.025-0.05 mm), so it is highly used for fabricating thin walls, sharp corners, and tiny cavities.
Smooth Surface Finishes
One of the key feature of Stereolithography is to give smooth surface finishes to products whose requirements are aesthetics and tactile feel, because it can produce objects having very thin layers joint together very closely and strongly. This printing technique ensures the smoothest surface, so end-product does not need samding or polishing. This feature makes the printing technique best for producing consumer-facing prototypes, dental models, and jewelry masters.
Material Versatility
This printing technique supports different types of resins to attain rigidness, flexibility, resistance to high-temperatures, biocompatibility, castability, according to the product requirements. For example, biocompatible resins are necessary for making dental and medical models, while rubber-like resins are necessary for inducing flexibility/elasticity in the object. Similarly, castable resins are necessary for attaining desired molding. The ability of making object by using different materials make this technique best for using across different industries, ranging Healthcare and aerospace to art and consumer electronics.