3D Printing What is it and how does it work

3d printing, how does it work and what is it used for?

As we discussed in one our other blog post, “Types of 3d Printers”

We currently use FDM and SLA technology in our business.

How Do SLA 3D Printers Work?

Stereolithography (SLA)

Stereolithography (SLA) is the original industrial 3D printing process. SLA cures liquid resin using UV light. SLA printers excels at producing parts with high levels of detail, smooth surface finishes, and tight tolerances. The quality surface finishes on SLA parts, not only look nice, but can aid in the part’s function—testing the fit of an assembly, for example. It’s widely used in the medical industry and common applications include anatomical models and microfluidics.

How Do FDM 3D Printers Work?

Fused Deposition Modeling (FDM) or Fused Filament Fabrication (FFF)

Fused deposition modeling (FDM) is a common desktop 3D printing technology for plastic parts. An FDM printer functions by extruding a plastic filament layer-by-layer onto the build platform. It’s a cost-effective and quick method for producing physical models. There are some instances when FDM can be used for functional testing, but the technology is limited due to parts having relatively rough surface finishes and lacking strength.


3D Modeling Software

The first step of any 3D printing process is 3D modeling. To maximize precision (and because 3D printers can’t magically guess what you want to print), all objects have to be designed in a 3D modeling software. Some designs are too intricate and detailed for traditional manufacturing methods. That’s where this CAD software comes in. Modeling allows printers to customize their product down to the tiniest detail. The 3D modeling software’s ability to allow for precision designs is why 3D printing is being hailed as a true game changer in many industries. This modeling software is especially important to an industry, like dentistry, where labs are using three-dimensional software to design teeth aligners that precisely fit to the individual. It’s also vital to the space industry, where they use the software to design some of the most intricate parts of a rocketship.


The 3D Printing Process

When the modeling and slicing of a 3D object is completed, it’s time for the 3D printer to finally take over. The printer acts generally the same as a traditional inkjet printer in the direct 3D printing process, where a nozzle moves back and forth while dispensing a wax or plastic-like polymer layer-by-layer, waiting for that layer to dry, then adding the next level. It essentially adds hundreds or thousands of 2D prints on top of one another to make a three-dimensional object.

In SLA printing, an ultraviolet laser traces the shape of the object to be printed, layer by layer, on a UV-sensitive resin (aka photopolymer, or photopolymer resin) housed in a tray or vat, and the resin exposed to the laser hardens to form the printed object. The resins come in 500-milliliter and 1-liter bottles, with prices from printer manufacturers starting at about $100 per liter. Some manufacturers have formulated resins for strength, flexibility, rigidity, and other qualities, and such resins tend to sell at a premium. Resins have suffered from a limited color palette, and have tended to be confined to black, gray, white, and clear, though some brighter-colored and metallic resins have become available of late.



What can you use a 3D printer for? It's a bit like asking "How many ways can you use a photocopier?" In theory, the only limit is your imagination. In practice, the limits are the accuracy of the model from which you print, the precision of your printer, and the materials you print with. Modern 3D printing was invented about 25 years ago, but it's only really started to take off in the last decade. Much of the technology is still relatively new; even so, the range of uses for 3D printing is pretty astonishing.


Life's a one-way journey; fallible, aging humans with creasing, crumbling bodies naturally see great promise in a technology that has the potential to create replacement body parts and tissue. That's why doctors were among the earliest people to explore 3D printing. Already, we've seen 3D printed ears (from Indian company Novabeans), arms and legs (from Limbitless Solutions, Biomechanical Robotics Group, and Bespoke), and muscles (from Cornell University). 3D printers have also been used to produce artificial tissue (Organovo), cells (Samsara Sciences), and skin (in a partnership between cosmetics giant L'Oreal and Organovo). Although we're some way away from having complete 3D printed replacement organs (such as hearts and livers), things are rapidly moving in that direction. One project, known as the Body on a Chip, run by the Wake Forest Institute for Regenerative Medicine in North Carolina, prints miniature human hearts, lungs, and blood vessels, places them on a microchip, and tests them out with a kind of artificial blood.

Apart from replacement body parts, 3D printing is increasingly being used for medical education and training. At Nicklaus Children's Hospital in Miami, Florida, surgeons practise surgery on 3D-printed replicas of children's hearts. Elsewhere, the same technique is used to rehearse brain surgery.


Aerospace and defense

Designing and testing airplanes is a complex and expensive business: a Boeing Dreamliner has about 2.3 million components inside it! Although computer models can be used to test quite a few aspects of how planes behave, accurate prototypes still need to be made for things like wind-tunnel testing. And 3D printing is a simple and effective way to do that. While commercial airplanes are built in quantity, military planes are more likely to be highly customized—and 3D printing makes it possible to design, test, and manufacture low-volume or one-off parts both quickly and cost-effectively.


Making prototypes of airplanes or space rockets is an example of a much broader use for 3D printing: visualizing how new designs will look in three dimensions. We can use things like virtual reality for that, of course, but people often prefer things they can see and touch. Increasingly, 3D printers are being used for rapid, accurate architectural modeling. Although we can't (yet) 3D print in materials such as brick and concrete, there's a wide range of plastics available and they can be painted to look like realistic building finishes. In the same way, 3D printing is also now widely used for prototyping and testing industrial and consumer products. Since many everyday things are molded from plastic, a 3D printed model can look very similar to the finished product—perfect for focus-group testing or market research.

Personalized products

From plastic toothbrushes to candy wrappers, modern life is here-today, gone-tomorrow—convenient, inexpensive, and disposable. Not everyone appreciates off-the-shelf mass production, however, which is why expensive "designer labels" are so popular. In the future, more of us are going to be able to enjoy the benefits of affordable, highly personalized products custom-made to our exact specification. Jewelry and fashion accessories are already being 3D printed. Just as the Etsy website created a worldwide community of artisan crafters , so Zazzy has now replicated that using 3D printing technology. Thanks to simple online services like Shapeways, anyone can make their own 3D printed nick-nacks, either for themselves or to sell to other people without the expense and hassle of using their own 3D printer (even Staples is now offering 3D printing services in some of its stores).


The future of 3D printing

Many people believe 3D printing will herald not merely a tidal wave of brash, plastic gimmicks but a revolution in manufacturing industry and the world economy that it drives. Although 3D printing will certainly make it possible for us to make our own things, there's a limit to what you can achieve by yourself with a cheap printer and a tube of plastic. The real economic benefits are likely to arrive when 3D printing is universally adopted by big companies as a central pillar of manufacturing industry. First, that will enable manufacturers to offer much more customization of existing products, so the affordability of off-the-shelf mass-production will be combined with the attractiveness of one-off, bespoke artisan craft. Second, 3D printing is essentially a robotic technology, so it will lower the cost of manufacturing to the point where it will, once again, be cost-effective to manufacture items in North America and Europe that are currently being cheaply assembled (by poorly paid humans) in such places as China and India. Finally, 3D printing will increase productivity (since fewer people will be needed to make the same things), lowering production costs overall, which should lead to lower prices and greater demand—and that's always a good thing, for consumers, for manufacturers, and the economy.