7 Types of 3D printing technologies Explained
In Korea, 3D printers are widely used in universities, elementary, middle, and high schools, and education is being conducted. In addition, there are 3D printing operation technicians and 3D printer development industrial engineers in the national technical qualifications. It is expected that 3D printing technology will be applied in a wider range of industrial fields in the future.
For those who have heard of 3D printing but are confused about the specifics, I would like to summarize the basics of 3D printing.
First, let’s get the terminology right: what is 3D printing?
According to the International Organization for Standardization (ISO), 3D printing is a technology for manufacturing objects by stacking them layer by layer based on 3D model data. In formal terms, it is defined as additive manufacturing (AM). (International Organization for Standardization, Additive manufacturing-General principles)
The opposite of additive manufacturing is subtractive manufacturing, or (injection) molding, or formative manufacturing. For example, cutting processing using a CNC lathe to make a mold and injection molding using a mold to mass produce, and currently, most commonly produced items are released through mass production.
In Korea, the ‘3D Printing Industry Promotion Act’ was enacted on December 22, 2015, and has been in effect since December 23, 2016. It defines ‘three-dimensional printing’ as “the activity of three-dimensionalizing electronic information (hereinafter referred to as ‘three-dimensional drawings’) to realize three-dimensional shapes through an automated output device.”
While “additive manufacturing” is the official term, the term “3D printing” is also frequently used in the marketplace, and it’s important to recognize that these terms refer to the same technology, rather than making a clear distinction.
Next up is the terminology for the different types of 3D printing technologies.
According to the International Standard Organization (ISO), there are seven different types of 3D printing technologies.
- MEX, Material extrusion
- VPP, Vat photopolymerization
- MJT, Material jetting
- BJT, Binder jetting
- PBF, Powder bed fusion
- DED, Directed energy deposition
- SHL, Sheet lamination
If you’re not familiar with standardized technology classification terminology, you’re probably familiar with FDM, FFF, SLA, DLP, Polyjet, SLS, EBM, etc. These terms are defined by individual companies and developers. For example, FDM is the name given to the technology by Scott Crump (founder of Stratasys), who first developed it, and FFF was defined by the Reprap project, which open-sourced the same technology as FDM.
As the 3D printing industry evolves, companies introduce different technologies and define nomenclature to characterize them. However, for consumers, it can be confusing to see the same or similar technologies referred to by different names.
In response, the International Organization for Standardization has identified seven technology classifications based on core technical principles and methods. (The International Organization for Standardization works on a wide range of standardization efforts, including materials, data, processes, and services, as well as terminology definitions.)
In some cases, the materials, applications, and methods used are not well described or are ambiguous within the seven classifications. For example, bio 3D printing or architectural 3D printing can be considered MEX methods in the broader context, but may be better categorized separately due to the specialized materials used in these narrow applications.
To summarize the terms and product families that are included in the seven 3D printing technologies according to the International Organization for Standardization, they are
*Standardization is an essential part of any industry’s development. For example, RGB colors, bolts and nuts, and Phillips and flathead screwdrivers are all examples of standardization that make it easier to use around the world. On the other hand, standardization can be a barrier to entry because it sets new standards, so many countries around the world are making efforts to lead standardization efforts.
- MEX, Material Extrusion
Material extrusion methods, including those commonly referred to as FDM or FFF.
- VPP, Vat Photopolymerization
A method of manufacturing liquid photocurable resins by curing them with UV light. Includes SLA, DLP, and LED methods.
- PBF, Powder Bed Fusion
This is a method of manufacturing by melting powdered materials with a high energy source (laser, electron beam, etc.). It is mainly used for metal 3D printing, and is the most industrialized and developed technology.
- DED, Directed Energy Deposition
Similar to PBF, DED is utilized in metal 3D printing applications and uses powdered materials, but differs in that it is fed and manufactured in real-time.
- BJT, Binder Jetting
This is a method of manufacturing by jetting an adhesive (binder) onto a powdered material. The adhesive can be mixed with ink to achieve full color, and sand or metal powder can be applied to produce metal parts. In the case of sand, a mold is made and then traditional metal fabrication methods are added, and in the case of metal powder, the material is sintered. However, the sintering process involves heating the powder in a loose molecular structure and has an average shrinkage rate error of 2-8%.
- MJT, Material Jetting
This is a method of manufacturing liquid photocurable resin by jetting it in real time. The advantage is that full color can be realized by mixing ink with the light-curable resin, and the surface finish is very good. However, it has the disadvantages of weak strength and high material cost.
- SHL, Sheet Lamination
This is a method of manufacturing by stacking sheets in the form of thin plates. Laser cutting is used to create layer-by-layer shapes, and a heating process is used to bond the sheets together. It was expected to be prominent in the education sector because it can use paper, but the high cost of equipment and materials limits its application.
Now that you know the terminology of additive manufacturing and the classification of the seven technologies, let’s take a closer look at the features of each technology.