Practical Guide to Understanding 3D Printing Technology; An Academic Review
Advancing at well over Mach III, breaking news events reporting never-before-seen innovative 3D printing technology seems to be a common occurrence, every 30 minutes or so. If you type in any search engine “3D printing” or “new 3D printing technology” you will be confronted with almost 80 million hits, good luck trying to sort your way through that mess. Unless you are intimately connected with developing 3D technology, which I happen to be, then scant chance you will have the technical chops to distinguish hype from reality. I have encountered countless interactions with people asking me about the newly reported 3D printed car, organ, or genetic twin brother. If you are truly a 3D printing enthusiast and want to be able to distinguish the ever-emerging technologies that are going to “disrupt” the 3D printing industry, then you should carve out some time in between prints to read up on the polymers and customized additive manufacturing market.
In a format that is detailed, yet succinct, this Chemical Review article (click here for link) lays a strong foundation for the current 3D printing technologies, especially regarding some of the core methods and companies behind them. If you own a 3D printing shop, or use a 3D printer, or if you are thinking about launching a new 3D printing startup, then you absolutely need to read this review in its entirety.
For me, and I am a little biased considering I am involved in the formulation of 3D polymers, I like how thorough the authors were with the section on current and past photoinitiators and monomers. What is your favorite monomer diluent? Is it dipropylene glycol diacrylate (DPGDA) because it is claimed to undergo less shrinkage during polymerization? This section was rather impressive considering there is no real database for this type of information, it certainly hits all the major compounds used for resin formulations. I also really enjoyed the Powder Bed Fusion Process section. I am delighted that the authors highlighted the process and importance of controlling the morphology of the particles. This is likely the most important factor in producing high quality and reproducible printed parts from powders and certainly one of the major challenges that was conquered early on. Maybe you, the reader, can be the one that figures out a way to recycle SLS material taking the amorphous none-spherical agglomerates and converting them back into the small spherical semi-crystalline particles everyone loves and needs. Or maybe you will be the one to invent the next 3D technology that has no post-cure processing, toxic powders, or messy cleanup?
That said, don’t be fooled by the classic “hockey stick” graphs that convey the 3D printing growth and market value. You typically see these “hockey stick” exponential growth plots from the business development team at your friendly large corporation. Don’t heed to my ominous warnings though, I do believe that the market is growing at warp speed, but one should always keep in mind that ultimately it comes down to where the most impact will be. Areas like tissue manufacturing, industrial manufacturing, commercial supply, and advanced prototype materials are all mega-industries that, for the currently available 3D printing technology, need a great deal of improvement. For example, and I am getting off track here a little, but there was some news, and a lot of hype, that you will soon be able to purchase a 3D printed car. Did you hear about this? Well if you didn’t the first thing you should do is search around because several companies and prototypes are being released. One of the companies, Divergent, used metal sintering (metal 3D printing) to complete their high-end sports car. This should cause you to be skeptical, I mean how many different materials are in a car? Why are there so many different materials in a car? Isn’t 3D printing expensive compared to injection molded production parts? How much is this car? Isn’t metal 3D printing quite labor intensive, one needs to remove support material, polish the surface, and the build trays are not the size of a car, are they? So many unanswered questions but, I digress, you can read the articles and form your own opinions. Ultimately, to evaluate ideas and emerging technologies you need to have a solid background of information. I am happy to report that you don’t need to devote most of your life, like me, to working in the 3D printing industry to have that knowledge. You can pretty much get most of the hard-fought information industry guys obtain with some reading, and I recommend starting with the Chemical Review article linked to this M2 Materials blog post.
I hope you enjoy the article as much as we did and that it will impart the ammunition necessity to decipher the emerging 3D printing technologies. See below for a link to the article