Three dimensional printing is an additive manufacturing process which involves the production of tangible objects from an input digital file. Additive manufacturing method is the production of solid items by adding successive layers of the material until the object is produced. Each of the added layers are usually sheets of the material which takes the shape required by the designer.
3D printing typically starts with the production of a virtual design usually done with the help of a Computer Aided Design (CAD). Experts in designing objects with CAD can do the initial design on their computer before uploading the print file to the 3D printer. For those who want to print an existing object, a 3D scanner can be used to make a digital copy of the object before putting it into the 3D modeling program. 3D printers use different kinds of technologies to realize their objects and some of these technologies are discussed below.
Selective Laser Sintering (SLS)
The SLS technology makes use of a powerful laser to fuse little particles of the desired materials together. Some popularly used materials are plastic, ceramic, glass and metals. These materials are usually fed to the printer in powdered form after which it fuses them by scanning the layers generated by the 3D modeled program. After the layer is scanned, the powder bed adds one layer of thickness to the object being produced in order to move a step further in the production. This process is repeated times and times again until the whole object is completed. One advantage of the SLS method is that excess powders in the production of an object can be recycled and used for another production.
This method is similar to the photo polymerization method where solids are produced from liquids. The Stereolithography technology involves the use of a vat of liquid ultraviolet curable photopolymer resin and an ultraviolet laser to build successive layers of the object. In order to produce a layer, the laser beam picks out a cross-section of the design on the surface of the liquid resin and exposes it to ultraviolet light thereby curing and solidifying it, before adding it to the previous layer.
Fused Deposit Modeling (FDM)
This technology involves the use of a metal wire or plastic filament usually unwound from a coil and used to supply the required material to an extrusion nozzle capable of turning the flow on or off. The extrusion nozzle is heated in order to melt the input material and it has the ability to move either horizontally or vertically depending on the instruction it gets from a Computer-Aided Manufacturing (CAM) software package. As the heated material is extruded through the nozzle to form successive layers, it immediately hardens thereby sticking to the previous layer produced.
In conclusion, the 3 technologies mentioned above are the most popular technologies employed these days by 3D printers manufacturing companies. All three of them employs different 3D printing software but can be easily understood and operated perfectly with time.