FFF (Fused Filament Fabrication) aka FDM (Fused Deposition Modeling)
Extruding 3D-printers extrude printable materials through a heated extruder. The 3D-printer forms objects by extruding thin layers of print material on it’s program route. As a layer is finished, either the platform is lowered or the extruder is raised a pre-set layer height, usually this value is between 0.1 – 0.5 mm. Layer height effects on the printing resolution.
Materials used in 3D-printers that use this technology are usually PLA (Polytactic acid) and ABS (Acrylonitrile butadiene styrene). But there are many other materials, like: Nylon, HDPE, PCL, Polycarbonate. Mostly these materials are available in variety of colours.
Powder-based 3D printers work in the same principle as FDM 3D-printers, since they add printing material layer by layer forming the object. A thin layer of powder is laid on the bed, then for example an inkjet head adds binding liquid to desired locations. This binding can also be done with a laser, which melts the powder into a more solid substance.
After the extrusion head has done it’s job for that layer, the bed is lowered and covered with powder again. This is repeated until the print is done. When the print is done, the excess powder can be removed and the final print is revealed.
No support material is needed, because the powder themselves work as support.
Laminated object manufacturing
It’s based on the principle of adding sheets of material on top of another, and then binding them with glue. First the printer cuts the desired shape with a knife, and then it adds glue on top of the cut area, and lays another sheet of material. Thus creating layers.
No support material is needed, because the sheets themselves work as support.
Materials vary from paper, metal and plastic.
In stereolithography the object is created from a photo-reactive resin. The way stereolithography works, is so that there’s an liquid tank, which is filled with the resin, and then a laser or a projector lights the bed inside the liquid tank. Thus creating the very first layer, then the bed is risen or lowered, depending on the way the 3D-printer prints. With this technique can layer resolutions of up to 16 µm achieved.