Additive manufacturing or 3D printing is the process of making 3-dimensional objects (solid) in from a digital file. This creation is achieved using an additive process. This involves creation of an object by laying down layer upon layer of an object until it becomes complete. Each of the layer can be considered as a horizontal slice or cross-section of the final object.
How does it work?
The process all starts by making a 3D virtual design of what you want to make. The virtual design is made in the form of a computer aided file by the help of a 3D modeling program or by a 3D scanner. The 3D scanner copies the original object and creates a virtual copy of the object and places it into the 3d modeling program.
When you want to print the object from the 3D modeling software, it slices the model into several hundreds or even thousands of layers that are horizontal. The file is then uploaded onto the 3D printer and then the printer creates the final object one layer at a time. The 3D printer then reads every slice each layer at a time and then proceeds to lend all the layers together without leaving any sign of blending resulting into a single 3D object.
Technologies and Methods
You should know that just like many tech gadgets in the market, 3D printers do not all make use of similar technology to create the objects. There are several ways in which they realize their goal and they were made available from 2012. They were all additive and differ mainly in the method that they use to build the layers and create the final object some of the methods use softening material or melting to come up with the layers, making use of these kind of technology are fused deposition modeling and selective laser sintering. Another method of 3D printing is to use liquid material that have been cured by varying technologies. The most popular technology that makes use of this method is stereolithography.
Selective Laser Sintering
This technology makes use of a high power laser to fuse/merge small particle of metal, plastic glass powders or ceramic into one three dimensional mass that I desired. The laser fuses selectively the material by scanning every layer produced by the 3D modeling program. After scanning each layer, the powder bed is increased by a single layer. This is done repeatedly until the object is complete.
All the untouched powder after the process will act as the support for the object. There is therefore no need for any additional support. This is one of the advantages that this technology has over the other two that are fore mentioned.
Fused Deposition Modeling (FDM)
This technology uses a metal wire or a plastic filament which is unwound from a given coil and provides the material to a nozzle which has the ability to turn off or on the flow of the material. The nozzle gets heated in order to melt the material and can move vertically or horizontally. This movement is controlled by a CAM software package. The object is formed by the melted material that is extruding from the nozzle. It does this I layers and the material hardens immediately after its extrusion.
Stereolithography (SLA)
This technology uses a vat of ultraviolet liquid curable polymer resin and a UV laser to build up the object layer by layer. For every layer, the UV beam traces out a pattern of the cross-section on the surface of the liquid. The UV light from the beam also solidifies the resin on the layer below it.
