Introduction to 3D Printing: History, Processes, and Market Growth
Today's 3D printers had their start in the rapid prototyping technologies of the 1980s and found their use in the industrial market. As patents expire, 3D printing technology is becoming more available to consumers.
Today's 3D printers had their start in the rapid prototyping (RP) technologies of the 1980s and found their use in the industrial market. As patents expire, 3D printing technology is becoming more available to consumers.
Beginning of an Industry
At the time of their invention in the 1980s, 3D printers focused on creating scale models using computer-aided design (CAD). The first patent for a 3D printer was issued to Charles Hull for "Apparatus for Production of Three-dimensional Objects by Stereolithography" in 1986. Hull went on to start the first 3D printing company, 3D Systems Corporation.
With this background in industrial manufacturing, most 3D printing technology was protected by patents held by companies in the industrial market. As patents expired, 3D printers geared for the consumer began to appear.
Dr. Bryony Core, a Technology Analyst at IDTechEx, explains: "3D Printing technologies have existed since the 1980s; however, it was not until the expiration of Stratasys' patent in 2009 protecting their ownership of the fused deposition modeling (FDM) process that affordable consumer thermoplastic extrusion printers proliferated. The expiration of subsequent patents covering alternative additive manufacturing processes has further fuelled this growth."
The 3D Printing Process
3D printers build objects using a process known as additive manufacturing. Material is put down in layers; each layer adds to the previous layer and in turn becomes a base for the next layer. Most 3D printers in the consumer market use thermoplastic inks in the printing process. These polymers become soft and pliable within a temperature range and then re-solidify when allowed to cool.
A functional diagram of a 3D printer
Referring to the diagram above, the print bed is where the object is printed. It's usually covered with an adhesive material, and with some inks it also needs to be heated in order to minimize distortion in the printed object. The extruder temperature may be set manually, depending on the model; the nozzle position is controlled by the microcontroller, which is directed by commands in the print file.
Some printers incorporate USB ports to read files from USB drives; other printers interface to external computers, which may be running 3D print monitor and control applications. The microcontroller positions the nozzle at the X, Y, and Z coordinates needed and a specific amount of ink is set. High-precision 3D printers produce minimal wasted material.
3D Printer Inks
The photo below shows a variety of filaments, the most common form of ink used by 3D printers. Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) filaments are usually used in consumer 3D printers. Filaments are categorized by diameter, extruder temperature required, print bed temperature needed, and what the print bed should be coated or covered with for best adhesion.
Print File Formats
Directions for positioning the nozzle and controlling the ink(s) are received from a print file. There are many file formats in use. While CAD programs have been the traditional way to produce files, today newer design tools, as well as scanners and cameras, are used.
These tools can generate and capture data not needed for a 3D print of the object, and their output may be in a proprietary format. As shown in the block diagram below, a file may need to be translated to an accepted format for 3D printing. This may involve taking out extra data, modifying the file format, and slicing (layering) the data. Software programs such as Blender, an open source 3D creation suite, will accept and translate many file formats.
Generating 3D print files
Table 1 lists a few of the 3D print file formats in use. The *.STL format was created to support Chuck Hull's original printer. It supports a layering process for one extruder. As printers developed, other formats, both open-source and proprietary, were developed. In 2015, the 3D Manufacturing Format (*.3MF) was announced. Developed and supported by the 3MF Consortium, the aim is to standardize 3D print files.
|*.STL||Stereolithography; 3D single color (one extruder ~1980s)|
|*.WRL||Vermal; multi-color (supports more than one extruder)|
|*.OBJ||Open source 3D geometric format|
|*.3MF||3D manufacturing format - 3MF Consortium specification (introduced in 2015, and still in use)|
An Exciting Future
Industries using 3D printing have grown with improvements in capturing 3D data, control accuracy, and available materials. The 3D Printing Conference & Expo, held in New York City in March 2017, offered sessions in bioprinting, automotive, aerospace, consumer products, medical, oil and gas, hobbyist/maker, dental, education, and jewelry.
As patents expire, new inks and print technologies are being offered. An exciting development for electrical engineers is the availability of conductive inks, which make it possible to print objects that can conveniently incorporate electronic components such as sensors or LEDs. Magnetic filaments are also available, so prints will stick to magnets!
With composite materials available in filament, liquid, metal, and powder forms, 3D printed objects are moving beyond prototyping to functional and even manufactured areas. Printers with more than 3 axes are printing objects suitable for high-end components. Other techniques allow printing outside the printer frame.
The photo below shows spool holders printed in PLA and carbon fiber inks. Both took 4 hours to print. The cost for the PLA was about $3.00, and for the carbon fiber, about $5.00; however, the carbon fiber clogged the nozzle, which had to be replaced (apparently some finesse is required if you want to use carbon fiber without nozzle issues). When working with materials other than PLA and ABS, check extruder temperatures and whether premium nozzles are recommended.
3D-printed spool holders (Photo credit: Robinson Cruz)
The 3D printer market was $2,200 million in 2012; all reports and forecasts point to a huge growth cycle. The market is expected to hit $7,240 million by 2019, with global forecasts calling for $30.19 billion by 2022.
Dr. Core notes: "Even after significant media hype, some market sectors are reporting huge growth rates. Growth in the market will partly arise from the increasing use of 3D printers amongst existing users, in addition to the adoption of 3D printing by new users in industries where mass customization is required as standard and design complexity no longer adds cost. Aerospace and oil & gas have the top two rates of growth of end-user industries."
In aerospace, companies are using the technology to produce airplane components and entire wing structures. In gas and oil industries, 3D printed components allow replacement parts to be printed on an "as needed" basis in field operations. If a 3D printer and digitized-component files are included in a parts-management system, many components could be printed instead of ordered.
Advances in 3D printing are being announced daily. The technology is being used for all kinds of applications from building hearts, to building houses! Even NASA has a 3D printer on the International Space Station (for that just-in-case moment).
Within the context of industrial manufacturing, 3D printers face limits in what can be manufactured as well as uncertainty within the legal framework surrounding print files and printed objects. Unlike traditional manufacturing technologies that turn out hundreds of components per hour, 3D printing is a slow process.
Beyond the printer technology, providing the file for a 3D-printed object requires expertise in both modeling and software. After printing is completed, a certain amount of handling is required to remove the printed object and finish it. Currently, materials are limited and some printing technologies may end up not being a good fit for all markets.
3D-printed objects can have variable levels of complexity and require variable levels of handling
Questions surround liability of parts when there's a failure, as well as how to handle the intellectual property involved. If a part is printed in a truck outside your house, as an Amazon patent hints at, is the liability the same as a part shipped from a vendor's manufacturing facility? As these issues get sorted out, there is an exciting future for 3D printing, well beyond what was imagined when Chuck Hull filed his patent.
In industrial markets, the economics of 3D printing has to fit into traditional business management: What is the cost to produce components? What will be the return on investment? How is intellectual property protected? What liability does the business face should components fail? Can components be delivered in the timeframes needed?
The consumer market has a wide range of 3D printers available, with corresponding variations in price; the Quintessential Universal Building Device is available for less than $200, whereas MakerBot's Replicator Z18 model costs over $6000. With 3D printers becoming more affordable, it's not surprising to find libraries providing 3D printing stations, like the one shown below, for their patrons. For a small fee, uploaded files can be printed and picked up when ready.
3D printer station, Summit Free Public Library, Summit, NJ.
Finally, It's Fun!
For engineers, makers, and creators, it's a fun time to get into 3D printing. Many sites offer files for download, and there are options to utilize 3D printers even if purchasing one isn't in your near future. As 3D printers become more commonplace, more and more uses will become available.
Regardless of your market, if you are considering the purchase of a 3D printer, Dr. Core advises: "With such a diverse range of options available, examine the market carefully for the printer process, materials, and software that will best suit your needs to ensure you leverage this disruptive technology efficiently."