3D PRINTING
How Does It Work?
The first step for a design in digital format to be transferred to a machine to be reproduced autonomously, either in metal (as an engraving) or in wax for micro fusion, was the combination of computer-aided design (CAD-CAM ) with numerical decimal control machines (CNC).
The CAD-CAM design is characterized by:
- Guarantee absolute precision.
- Simplifying the introduction of modifications in a design, making the development of variants quick and easy (introducing new elements or deleting any of the existing ones, resizing or even returning to a previous version is simple).
- Like any digital product, a design in digital format is capable of being stored and shared immediately and safely at a very low cost.
- Minimize the need to incur production costs, since the availability of photorealistic digital images created from a 3D model (rendering) allows the creation of product portfolios in digital format.
What is stereolithography?
Stereolithography is considered the origin of 3D printing processes, with the first equipment patented in 1984 by Charles Hull and the first commercial machine developed by 3D Systems in 1988.
This process, known as SLA (stereolithography), uses the principle of light curing to create 3D models from resins sensitive to UV rays. This is solifed by the passage of a laser layer by layer, thereby providing higher quality models made with this technology.
The SLA 3D printers are characterized by their liquid printing material and by the presence of a UV protection cover (usually orange, green, red or yellow). They offer a relatively small volume of production in comparison with other printing technologies, even some machines such as Materialise's Mammoth can produce pieces of more than 2 meters.
How does 3D printing work with stereolithography?
As with any 3D printing technique, a 3D digital file is required. This can be obtained through CAD software (SolidWorks, Sculpt or Maya, for example). This file, often in STL format, is sent to the machine, where a second software (called a slicer) cuts the model in thin layers of printing of a fixed thickness. And finally the printer is given the order to start printing.
After finishing printing, we go to the cleaning stage with a solvent (usually isopropyl alcohol also known as isopropanol), this is necessary to remove the excess of non-solidified resin.As with FDM technology, stereolithography uses the use of supports when printing complex forms. In the form of scaffolds, which allow to support the parts that fall into the void. These supports are easily removed during post-processing of the models.