Stereolithography (SLA) is a 3D printing technique for producing very precise plastic parts with excellent surface quality. Therefore, the stereolithography is ideal for prototyping, mold making and mass production of final parts. It is also used to make visual pieces (models, trophies, etc.).

Stereolithography apparatus (SLA) is the first 3D printing technique invented by Richard 'Chuck' Hull in 1977. His invention will then be followed by the commercialization of his technology, then of the first stereolithography machine installed in 1983 in the United States.

The stereolithography technique is based on the principle of photo-polymerization of resin (plastic in liquid form) UV-sensitive. For example, pour this resin in a glass, place it in daylight and your resin will solidify in a few minutes.

In parallel, the principle of 3D printing is to digitally slice a 3D file into very thin layers, which will then be solidified and then superimposed. And this for the vast majority of 3D printing technologies to date.

Therefore, in stereolithographic 3D printing, a light source will photo-cure each layer of the 3D file in a resin bath.

In addition, there are different light sources: the laser source and the LED source. The first is certainly more expensive, but it offers the great advantage of obtaining very precise and very fine results. Conversely, the second is more affordable but the accuracy is less good.
If you want to print only parts where precision is not important (figurines, statues, trophies, foundry dies, etc.), SLA technology with LED will suffice (such as RapidX machines). On the other hand, if the precision must be high or if your parts have very thin walls, you will opt for an SLA solution with a laser such as SystemX machines.

In addition, the choice of material can impact your result. Indeed, a rather low-end resin will give you less precise parts, and could cause misfires during 3D printing. It is therefore important to identify the right resin for your application. For this, the technical sheets already list a lot of data from numerous tests.

Finally, stereolithography has solved the problem of prototyping, thus eliminating the mold. Since then, this technique is still widely used for prototyping needs and now used in the production of final parts in small and medium series.

Benefits of stereolithography

  • This technique makes it possible to produce parts with very high precision ;

  • Very fine details can therefore be easily printed ;

  • The pieces come out with a very soft surface quality (no visible lines) ;

  • They are waterproof, and the surfaces are easy to use (sanding, drilling, painting, etc.) ;

  • They can also be dyed using the 3DColor coloring machine ;

  • The SLA technique is ideal for making functional technical parts (clips, connectors, etc.) ;

  • Stereolithography is also perfect for making visual models (models, prototypes, dental models, etc.);

Laser-based SLA technology

LED-based SLA technology