With 3D printing, it is possible to change a virtual object into a physical one, almost instantly. Along with improving manufacturing, 3D printing makes it possible to create highly customized products for users. Product designers are now designing and printing 3D product prototypes quickly and inexpensively as it makes it possible to identify design flaws and fix them earlier in the manufacturing process, thus saving money and preventing issues that might impact negatively on the customer experience.
Different Types of 3D Printing
Fused Deposition Modeling (FDM)
Also Known as Fused Filament Fabrication, FDM is a kind of 3D printing technology that uses Material Extrusion process. Since Material Extrusion devices are inexpensive and widely available – and inexpensive, this type of 3D technology is being used by several industries to achieve long-term business objectives. FDM deploys a process wherein a spool of filament of solid thermoplastic material (PLA, ABS, PET) is loaded into the 3D printer. Then, it is pushed by a motor through a heated nozzle, where it melts. The printer’s extrusion head then moves along specific coordinates, depositing the 3D printing material on a build platform where the printer filament cools and solidifies, forming a solid object. The advantage of this type of 3D printers is that it offers the best surface finish along with complete colour.
Stereolithography (SLA)
Stereolithography is considered to be world’s first 3D printing technology. It employs Vat Polymerization wherein photopolymer resin (Standard, Castable, Transparent, High Temperature) in a vat is selectively preserved by a light source. An SLA printer uses mirrors, called galvanometers or galvos, where one is positioned on the X-axis, the other on the Y-axis. These galvos aim the point of a laser beam across the vat of resin, selectively curing and solidifying a cross-section of the object in the build area, building it up layer by layer.
Digital Light Processing (DLP)
One of the main types of 3D printing, this one is quite similar to SLA, the only difference being that DLP uses a digital light projector that flashes a single image of each layer all at one time, or does multiple flashes for larger parts. Also, DLP has faster print times when compared to SLA. This is because, in the former, each layer is exposed all at once Common applications for SLA and DLP are injection mould-type polymer prototypes, jewellery, hearing aids, and dental applications.
Selective Laser Sintering (SLS)
SLS uses a 3D printing process called Power Bed Fusion. Since SLS parts are made from real thermoplastic material, they are durable, suitable for functional testing, and can support living hinges and snap-fits. Common applications for SLS are the manufacturing of functional parts, complex ducting requiring hollow designs, and low-run production. Its strengths are in the creation of functional parts, parts with good mechanical properties, and with complex geometries.
Material Jetting (MJ)
MJ 3D printing technology uses photopolymer resin (standard, castable, transparent, high temperature) and works in a way similar to the common inkjet printer. MJ differs from other types of 3D printing technologies that deposit, sinter, or cure build material with point-wise deposition. Also, instead of using a single point to follow a path which outlines the cross-sectional layer, MJ machines deposit build material in a fast, line-wise manner. The advantage of MJ 3D technology is that ir can fabricate multiple objects in a single line without affecting build speed. As long as the models are arranged correctly with optimal spacing, MJ can produce parts faster than other types of 3D printer.
Drop On Demand (DOD)
DOD also uses the Material Jetting process. It uses a pair of inkjets. One deposits the wax-like build material, the second deposits the dissolvable support material. Like other typical kinds of 3D printing technology, a DOD printer follows a predetermined path for jetting material in a point-wise deposition, creating the cross-sectional area of an object layer by layer. DOD printers also a ‘fly-cutter’, which is known to skim the build area after each layer is created, thus making sure that there is a perfectly flat surface before starting the next layer. Common applications for MJ and DOD are full-coloru product prototypes, prototypes similar to injection molding, low-run injection molds, and medical models.
Direct Metal Laser Sintering (DMLS) & Selective Laser Melting (SLM)
These are the two types of 3D printing technologies that practice Metal Powder Bed Fusion, the process where a heat source is utilized to fuse metal particles one layer at a time. Both these printing technologies are used to create metal parts, including aluminum, stainless steel, and titanium. DMLS 3D printing technology is used to create parts from metal alloys. Rather than melting it, DMLS heats the metal powder with a laser to a temperature where it fuses together on a molecular level. SLM, on the other hand, uses the laser to completely melt the metal powder to form a homogeneous part.
Electron Beam Melting (EBM)
This Type of 3D printing uses the Metal Powder Bed Fusion process. Also, unlike DMLS and SLM, EBM uses a high energy beam of electrons for inducing fusion between metal particles in a powder. Applications of the aforementioned 3D printers are constructing functional metal parts for the aerospace, automotive, medical, and dental industries.
