3D printing is often referred to as additive manufacturing. It is used for many applications, with one of the most popular being producing rapid prototype models. This method of manufacture uses only the material that is needed to produce the part, whereas more traditional methods of manufacture such as CNC machining often uses a whole block of material to produce the part, which can produce a considerable amount of waste, which is costly.
When using the process of 3D printing, only the material used to produce the part is charged for. The 3D printer interpolates files from computer aided design (CAD).using .stl file format. Fine horizontal layer sections are produced by the printer software, these sections can be printed in an ultra fine resolution at 16 microns thick or 28 microns, The layers are printed by a series of heads using technology similar to that of inkjet printing, spraying the layer sections down onto the print bed using a pre-heated photo cured acrylic resin liquid, one on top of the next, the resin is cured on the fly with strong ultra violet light, eventually forming a solid.
Two materials are used during the construction of a part, Model material and a soft support material; this provides support for overhanging features during construction (picture right). The support material is easily removed with water jetting, removal of the support reveals the hard cured model part, as a last stage the model is immersed in an ultra sonic bath containing sodium hydroxide solution, the part is then rinsed with water and air dried ready for shipping.
Simple print head diagram
The print head moves across the x & y axis of the printer table depositing very thin layers of model and support material, one layer at a time. As each new layer is sprayed on top of the last the print table moves downwards by a fraction of a millimetre so that the printing plane stays level with the printer heads, this repeats until all the layers have been printed and the model is complete.