3D printers

3D printers are increasingly common devices in today’s world. They both enable major companies to develop and implement new technologies and products, and also make it possible to create everyday objects at home. The rapid development and falling price of this technology has made it accessible to virtually everyone.

However, the device itself is not everything. When deciding to produce an object based on this technology, one must consider its subsequent use. The conditions in which it will operate, the loads it will have to carry, whether it is to be resistant to weather conditions and chemical agents, and many other factors determine the material and the printing technique in which it will be made. Current technology makes it possible to adapt 3D printing material to practically any task: from common plastics through wood-like and flexible materials to powdered metals and composites.

At home, printers using plastic filaments (such as PLA, ABS or PET-G) using the FDM technique are mainly used. This is based on the fact that, through an extruder, a material in the form of a filament (made of thermoplastic material) is introduced into a heated head, from which, according to a pre-programmed code, the liquid material is then introduced in successive layers onto a work table, on which it solidifies. The application of successive layers of material ‘builds’ the workpiece. This is the opposite process to traditional CNC machining, as the material is not subtracted from the workpiece but added to it (additive manufacturing).

Another 3D printing method worth mentioning is SLA (stereolithography), a technique that uses beam-cured resins as the feedstock. The liquid resin is located at the bottom of the machine in a tank, while the work table is immersed in it from above. As with the FDM technique, in SLA the object is created layer by layer, but in this case by photochemically curing successive layers of the workpiece until it is completely formed. Such prints are characterised by the highest print accuracy and enable faithful reproduction of even the smallest details.

The printing technique used in industry is SLS, which involves sintering thin layers of build-up powder (usually polymer or metal) with a laser. Unlike earlier technologies, SLS already requires a professional infrastructure for the production of parts as well as specialised equipment for their subsequent processing. Unlike the FDM technique, we will not see characteristic layers on sintered models. They are characterised by a uniform, slightly rough surface. Due to the properties of the prints, this technology is used by industry for the rapid creation of prototypes or short production runs.