3D printing refers to the technology making prototypes of an object with a 3D printer. In this technology, the printing material is fused or hardened under the control of a computer software and creates 3D prototypes. This technology is essentially used in the rapid prototyping or additive manufacturing. Additive manufacturing technology makes 3D objects from a computer-aided model by adding material, layer by layer. In a 3D printer, the binder material is usually deposited onto a powder with injecting printer layer by layer.
Types of 3D printing
Currently, different technologies have been used in 3D printers, and below describe the most popular ones.
Stereolithography is the oldest method in the history of the 3D printing by which three-dimensional objects can be created. Charles Hull was the first to patent this method back in1986.
Stereolithography is used in the 3D printing machine called Stereolithographic apparatus (SLA). In this technology, liquid plastic is converted into solid 3D objects. SLA works with a computer-aided (CAD) file to process the objects. This CAD file has all the necessary information such as the dimensions, shapes etc. of the required object for the printing. This is the additive manufacturing technique.
2.Digital Light Processing (DLP)
The technique used in DLP is similar to stereolithography. This technology was first created by Larry Hornbeck in 1987. In this technology, a digital micro-mirror is laid out on a chip. This 3D printer is also equipped with an LCD display. DLP’s printing material is the liquid plastic resin which is placed in a transparent resin container. As compared to some other 3D printers such as SLA, DLP has a quicker print time for most parts, and so is regarded as a better printer.
3.Fused Deposition Modeling (FDM)
Fused deposition modeling or FDM was developed by Scott Crump in the 1980s. In FDM, production-grade thermal plastic is used as the printing material. Due to its accurate and reliable process as well as its low cost, FDM printing is one of the most extensively used 3D printers. It is used for such applications as making functional prototypes, concept models, manufacturing aids, and creating 3D objects with accurate details. Also, considering the fact that in this technology the injected resin is poured in appropriate locations, it has the highest strength to weight ratio as compared to other methods.
4.Selective Laser Sintering (SLS) Technology
SLS makes printing particles are fused together by high-power CO2 lasers. In addition to the laser sinters powder, it also uses other materials such as white nylon powder, ceramics, and even glass. This printer was first developed and patented in the mid-1980s by Dr. Carl Deckard.
5.Selective Laser Melting (SLM) Technology
SLM uses high-power laser beams to form 3D printed parts. In this technology, the laser beam melts and fuses various metallic powders together. The process of printing is divided into basic parts such as
Heat + Powdered material + layered structure + precision= complete 3D object
6.Electron Beam Melting (EBM) Technology
EBM technique is similar to SLM but it uses powerful electron beam in a vacuum for the fusion and melting of metallic powders instead of the laser beam. One of its main features is its ability to make objects with complex geometries with the freedom of design. EBM produces parts that are incredibly strong and dense in their makeup.
7.Laminated Object Manufacturing (LOM) Technology
Laminated object manufacturing technology is the rapid prototyping that uses both heat and pressure to fuse or laminate the layers of plastic or paper. Laser or computer-controlled blade cuts the object to the desired shape.
8.Binder Jetting (BJ) Technology
Binder jetting technology is the 3D printing process that uses powder based material and bonding agents to build objects. Bonding agent acts as a strong adhesive to attach the powder layers together.
The following table displays some of the major differences among different 3D printing technologies.