3D printing or additive manufacturing (AM) is the capability of printing three dimensional objects, which can take any shape, form or size.
To create the objects, a printer runs an additive process, which essentially lays down several 0.1mm layers of a given material (such as plastic, elasto plastic, PLA, acrylate, food and in the future, even human tissue) on top of each other’s until the product takes full shape.
The process usually starts with the digital version of the object designed on a 3D printing software such as CAD, SketchUp or Solidworks.
However, 3D printing is much more than this and has several different technologies under its umbrella. The most used ones are selective laser sintering (SLS), fused deposition modelling (FDM) and stereolithography (SLA).
According to the Standard Terminology for Additive Manufacturing Technologies, developed by the American Society for Testing and Materials (ASTM), there are seven categories for 3D printing processes.
These are vat photopolymerisation, material jetting, binder jetting, material extrusion, powder bed fusion, sheet lamination, and directed energy deposition.
Vat photopolymerisation, for example, uses mostly the stereolithography technology. A printer working on vat photopolymerisation has a container filled with photopolymer resin which becomes solid has it is exposed to UV light.
With the material jetting method, printing material is applied in droplets through a small diameter nozzle. The material is again injected layer by lawyer and becomes hard as UV light is applied.
The binder jetting process uses powder and liquid glue to create the three-dimensional object. When printing, powder is applied in equal layers and binder is injected through jet nozzles to glue the powder particles.