3D printers have become more and more popular in recent years. They can be used, for example, to reprint small and large spare parts at home without having to buy them separately. But professional 3D printers are also used in industry. But how do the devices actually work? Over time, three methods have established themselves, which we are introducing to you here.
This is how a 3D printer works in general
The technology of the 3D printer was developed in the 1980s and has been used in industry since then, for example for the production of complex auto parts. In the last ten years, however, the technology has also been adapted for private use at home and has been continuously improved. After the printers cost a few hundred euros a few years ago, you can get your own printer for significantly less money today.
Basically, the functionality of a 3D printer is similar to that of normal printers: Instead of a text or image file, a model is first created with 3D software before printing. This later tells the printer where to apply the material or where to cure it. Then the model is sent to the printer, which starts 3D printing. How exactly the print works and how long it takes depends on the technique and material chosen. However, 3D printing in the private sector often takes several hours, depending on the size of the model. In the following sections you will learn how 3D printers work for private purposes as well as for industry..
For private users: Fused Deposition Modeling
Since the printers and materials used in Fused Deposition Modeling are somewhat cheaper than the other methods, they are most often used in private settings. The process uses materials that become liquid when heated slightly and can be shaped. These are, for example, plastics such as PET, but in theory chocolate can also be used for it.
The material is heated in a printer head and then applied in thin layers to a plate using a gland. The model is printed in layers from the bottom up. The printer head can move flexibly in any direction in order to get to any point in the printing area.
Since the material takes some time to harden and a new layer can only be applied when the layer underneath is at least slightly hardened, the printing process takes a relatively long time. In addition, support structures may have to be planned so that the structure does not collapse as long as it is not completely solid.
Industrial processes: stereolithography and laser sintering
There are also other 3D printing methods that are more commonly used in industry. Theoretically, you could of course also use them privately, but due to their size and functionality, they are actually only suitable if a large number of the models are printed at once.
The stereo is the oldest 3D printing process. A basin is filled with synthetic resin that hardens under UV radiation. A device that can specifically emit UV rays hangs above the pool . There is also a platform in the pool that can move up and down. At the beginning of the printing process, the platform is just high enough to be very lightly covered with the resin. UV rays are then emitted from above in such a way that the synthetic resin hardens in certain places. Once a level is solid, the platform is lowered a little, the synthetic resin runs over the hardened layer and the next level is hardened with the UV rays. So the model is built layer by layer from bottom to top. Each layer is just a fraction of a millimeter thick. The great advantage of this method compared to the other methods is that the edges of the model are smooth and not rough at the end.
When Laser Sintering there are two areas: on the one hand, a container in which the Print material lies. This can be a powdered plastic or even metal, for example. On the other hand, there is again a platform on which the model is printed. The printer initially uses a roller to pick up material from the first container and apply it thinly on the platform. A laser hangs above the platform , which, as in stereolithography, can harden certain areas of the material. The platform then moves down a little, the roller applies new material and the laser hardens certain areas of the material again. The advantage of laser sintering is that the material hardens immediately and no complex support structures have to be planned..