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A brief introduction to how 3D printers work – Part 1
One of the most elementary questions about 3D printing is: How exactly do 3D printers actually work? Therefore, we would like to offer you a brief introduction to how 3D printers work.
Which 3D printing technologies are there?
First of all, we have to make it clear that there is not “one” 3D printing technology, but a variety of 3D printing technologies. We should therefore first get an overview of this variety of additive technologies.
The first thing to do is to differentiate between the different groups of 3D printing technologies.
Laser vs. powder bed based processes
An important differentiation between different 3D printing processes lies in the distinction between the processes that use a laser beam and those that melt powder. However, even this rough distinction by no means covers all additive processes and how they work. This is how stereolithography works, after all the oldest 3D printing process, neither with powder nor with a laser beam.
So how do 3D printing processes work in detail?
So let’s take a look at the individual 3D printing processes and how they work.
stereolithography
This oldest 3D printing process works with a liquid photopolymer, which is hardened under UV light. The 3D printer pulls the printing plate down and builds up the model layer by layer. As soon as this process is completed, the component is post-exposed in an exposure chamber until it is completely cured.
Transparent epoxy models from stereolithography.
The laser-based 3D printing process
Selective laser sintering
Probably the most widespread 3D printing process is selective laser sintering (also known as SLS printing). The 3D printer fuses a powdered, sintered plastic locally. This means that the laser beam draws the pattern defined in the 3D files in the powder and builds this into an unbreakable model.
Selective laser melting
Basically, selective laser melting (also called SLM printing) works in the same way as selective laser sintering. The difference, however, is that the powder is not sintered. In addition, SLM printing is practically only used for the 3D printing of metal.
Metal part made from SLM printing.
The powder bed based 3D printing process
Fused deposition modelling
This 3D printing process is usually known by the abbreviation FDM printing. A plastic in the form of rolls or sticks is melted in the extruder and transferred through the nozzle onto a printing bed. There, the 3D printer shapes the liquid material according to the structure specified in the 3D files.
ColorJet Printing
With ColorJet Printing (CJP printing), the 3D printer builds the desired component piece by piece by simultaneously binding the respective layers of powder. This is done from the bottom up and without support geometries.
In addition, there are of course other, much less well-known 3D printing processes, which we will get to know in a second part.
Learn more about 3D printing materials and processes and visit our website.
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