What is 3D Printing?
In a nutshell, 3D printing could be defined as the process of creating a physical (3-Dimension) object from a digital/electronic design using an additive manufacturing (AM) process. Well, if I could use the KISS (Keep It Simple and Silly) principle, I could further define this term by breaking it down as follows:
3D (3-Dimension): is a term we use to refer to object(s) having 3 dimensions (length, width, and height) that represent any real/physical objects.
Printing: on the other hand, printing is a general term used to define the process of producing a physical copy of an electronic document using a machine (printer).
Additive Manufacturing (AM): is a coined term that gained its popularity in the early 2000s to define the process of adding substances together in layers so as to attain a tangible object. This substance can be molten plastic or selectively chosen metal powder that is selected by laser technology.
3D printing, therefore, is simply the process of producing a real/physical object using an electronic design. This object is printed by adding together of substances in layers to form the physical object.
Drawing from the definitions given, it could be clear that the term “3D Printing” does not explicitly define any single technology of manufacturing/printing. It is rather a term that defines several diverse but fairly related technologies of printing whose history spans just over three decades.
Honestly, researching and packaging together such scattered pieces of history could at times be fairly challenging. Then again, we took on the challenge and did just that. In this edition, we are basically going to examine the in-depth facts about 3D printing technology, highlight how it has been progressing and what we believe is cooking in the “3D printing” industry. And by “basically”, I mean you might consider sticking around as we examine some 1500+ words together. This won’t be long; I promise. Just grab a cup of cappuccino and we will go through this together.
History of 3D Printing
Although 3D printing started gaining much of its popularity in the period after 2010, the technology itself had been around for about 23 years prior to 2010 (Weller, Kleer & Piller, 2015). The earliest researches on Additive Manufacturing can be traced back to 1981 when a Japanese researcher known as Hideo Kodama from Nagoya Municipal Industrial Research Institute invented two additive methods that could fabricate 3D prototypes through hardening a thermoset polymer (Kodama, 1981).
In 1984 July, three French researchers (Alaine Méhauté, Olivier Witte, and Jean André) proposed to research more on stereolithography (a form additive manufacturing). Their application was turned down by the French General Electric Company due to the lack of a good “business perspective” in their proposed invention (Gabor et al., 2017).
In the same year (1984), Chuck Hull of the 3D Systems Corporation coined the term “Stereolithography”. He defined stereolithography as the process and apparatus of manufacturing solid objects by successfully printing thin layers curable UV substance one on top of another. Chuck can be attributed to being the inventor of the principle that runs on most modern day 3D printers. Since then, gradual improvements had been done on the device by the MIT, The Z-Cooperation and the addition of the “dot-on-dot” technique introduced by Solidscape in an attempt to enhance precision in printing (ibid).
The earliest forms of industrial additive manufacturing involved a non-additive process of casting, fabrication, and stamping that involved much of removal than the addition of substance when manufacturing. With continued researching, several interrelated methods of manufacturing were developed that performed better through an additive rather than a non-additive method of manufacturing. These rapid advancements that advocated for alternatives to metal removal created an avenue for the release of consumer 3D printers that were cheaper than the traditional industrial-only 3D printers. As a result, much of the popularity if this technology can be traced to 2010.
Five Main 3D Printing technologies
When thinking about technologies used in 3D printing, we ought to shift our focus to 2 main questions: “how do we 3D print?” and “what do we need in order to do 3D printing?”
Examining the various technologies that have evolved over time, it’s evident that this is the main difference between the different available 3D printers. Even though all 3D printing technologies aim to produce solid objects given an electronic 3D design, their method of achieving this goal is incredibly different. Let’s begin our classification with…
1 – The Fused Deposition Modeling (FDM) 3D printing technology
You can think of FDM as a controlled “pen-like” substance that has a thick solid-ink that is controlled by a 3D printer’s internal component to print solid substances much like writing but with a thick ink repeatedly.
A 3D Printer that employs the use of FDM is composed of a solid string filament that is pulled from a larger reel of solid string-filament and directed to a heated nozzle that melts the string and directs the molten substance over the area to be printed (build platform) using the instructions of a software application. Once the molten layer solidifies, a new layer is again deposited on the older layer selectively until an object is clearly modeled.
FDM is the most popularly known technology for low-cost consumer 3D printing. It is mainly used in rapid prototyping and the printing of circuit boards for microelectronics like prototype drones.
FDM protégé include 3D printers with Fused Filament Fabrication (FFF), Filament Extrusion and Material Deposition
2 – Stereolithography and Digital Light Processing
Stereolithography and Digital Light Processing are mainly used to manufacture 3D substances that require very high precision or highly detailed products like jewelry and sculptors.
These two methods employ the use of light and a liquid photopolymer that solidifies when hit by light to produce a 3D substance. Here, the build platform gets submerged into a lucid tank that is filled with the liquid resin (photopolymer). A ray of light is selectively shot through the tank onto the build platform. This solidifies the resin and it gets uplifted. The uplift leaves a vacuum which gets filled by flowing resin and the process gets repeated until a solid output is achieved.
The Stereolithography is the older form of 3D printing that used laser light whereas the Digital Light processing uses the normal UV light. This method is very popular with 3D printers that emerged in the early 2000s.
The main protégé include 3D printers with Vat Polymerization and Photocuring.
3 – Selective Laser Sintering (SLS)
The SLS technique of 3D printing utilizes a beam of laser light to liquefy and then solidify layers of powdered material into solid objects.
A typical SLS implementing 3D printer has got two adjacent tanks. One holds the build platform and the other holds the powdered material. At the beginning of printing, the powder supplying tank spills part of the powder in onto the build platform tank. A layer of the laser is shot through the powder keenly and controlled by a rotating mirror to solidify a selected region on the building platform. The piston holding the powder material is pushed upwards while letting out the powder that is leveled by a leveling roller. At the same time, the piston holding the build platform is pulled downwards and the laser shot through the new layer of powder selectively and repeatedly until the entire object gets printed.
This method is one of the most popular earliest methods of 3D printing. In the current market, it is used mainly in aerospace ducting when printing plastic.
The main protégé of this method is the Powder Bed Sintering (PBS).
4 – Material Jetting
The idea behind material jetting is much like the operating mechanism of a normal ink-jet printer. The only diversion of the mechanism is that in a material jetting mechanism for a 3D printer, the liquid substance jetted on a build platform gets solidified immediately by a beam of laser jetted by the same metal head shooting the liquid to solidify instantly.
This type of 3D printing allows one to print a model using different colors and a combination of substances that can yield different toughness. Material Jetting allows one to create models with an expression of the finest details and in a rapid speed of creation.
Though the method is unpopular, it is likely to gain more popularity with time as it is a later invention and it is effective for rapid prototyping.
The main protégé for this category are 3D printers with PolyJet and MultiJet Modeling features.
5 – Metal Printing
The technique of metal printing borrows much from the SLS technique already discussed before. The main difference, however, is that unlike SLS that jetted a heating laser on a plastic polymer, metal printing jets its laser on a bed of metal. Since metals have varying melting points, it is always advisable to use a building platform that has a higher melting point than the metal bed or powder being solidified.
Owing to the high temperatures and a high degree of caution when using metal printers, most of them are reserved for industrial usage and they are used to print functional prototypes and final parts that need to be made of metals or alloys of metal.
Here is the final take…
Now, picture this: you are an architect/designer of a new building or a new gadget’s layout in 1982. It is your dream project and thus you are willing to give it all you’ve got. So, what could you do? Where do you start? Well, you will first head to the drawing room, right? You pick some ruler, pencil, paper and an eraser (you can add any other accompaniment you would need in 1982). Then you would meticulously draw your design line-by-line considering the top, bottom, rear, front and any other relevant view of your model. Finally, you would head to a different shop where you would carefully model your prototype while taking into consideration all the details of the design.
Well, all that tedious process is now simplified. Instead of pen and paper, we go to AutoCAD or AutoDESK or Blender or …(name your favorite designing software). And instead of taking time in a separate physical workshop for modeling, 3D printing will help you curve out your prototype at the touch of a button. It does not only eliminate the need for intensive labor in prototyping but also increases accuracy when prototyping. And this is the main reason why I believe 3D printing, though still unpopular, can be perceived as an oncoming wave. In recent years, 3D modeling has been responsible even for the manufacture of actual car prototypes. E.g. the fancy Audi RSQ model prototype was wholly designed by KUKA robotics.
Even so, there are still obstacles to the popularity of 3D printing as currently most of the 3D printers are expensive, limit the choice of material to model substances and most of the prototypes from 3D printing have very limited endurance. Then again, looking at the great progress made within the past 7 years, I am confident that soon most of these obstacles will have been overcome. “Rome”, they say, “was never built in a day.”