Infrared Technology Helps Researchers Define Temperature & Settings Issues Causing 3D Printing Problems

I don’t think I’ll ever become desensitized to the magic of 3D printing. Whether enjoying from the desktop as a medieval castle or a Star Wars battleship is plucked off the build plate displaying incredibly fine resolution, or learning about what researchers are doing in the lab, from 3D printing skin in the near future to creating new jaw and gum cells in dentristy, it is a constant education—and a source of wonder. As the applications—and the innovations—just continue to grow, so does the urge in aspiring to greater perfection.

Although this is hardly a new industry, created in the late 80s most notably by 3D Systems co-founder Chuck Hull, 3D printing hurtled into the mainstream at an accelerated pace, to say the least. And the technology has experienced some growing pains, from sudden overcrowding in the marketplace to a range of issues that users encounter on a daily basis, depending on their hardware. As these growing pains have continued to throb, resulting in some consequences with faulty products and unhappy consumers, researchers and manufacturers alike have continued to work on refining the process of 3D printing, this fledgling, expanding at a rather terrifying rate, some might say.

Now, researchers are putting the focus on the primary issue: heat. While it’s a fundamental part of 3D printing, obviously there are many things that can go wrong—and no one likes to come back to the print job to find a hunk of melted (um, what was that supposed to be again?) filament in their possession. Aside from epic fails, many other issues can arise as well. In attempting to solve much of this inconvenience and potential mess, teams such as those at Oak Ridge National Laboratory have been working with another technology in the form of infrared (IR) cameras, hoping that an innovative new system will help identify problems more expediently for users.

The ultimate goal is to take control of the process of 3D printing more fully, and to stop the problems before they escalate—as well as learning to eliminate them from happening altogether. We’ve seen numerous companies engaged in new quality assurance techniques too, mainly in the larger industrial scenes with 3D printing in metal, from Sigma Labs to EOS. The bottom line is important, and avoiding errors in manufacturing is logically, key.

And the fact is that computers and machines most likely are going to do exactly what we tell them to, forging ahead exactly as we have set them up to. And therein lies the rub. Operator error is of course responsible for many quality issues in regards to settings (emphasis on temperature here, again) and material usage.

Ralph Dinwiddie, ORNL

With infrared cameras, everything can be monitored, and temperature settings can be measured. This has been proving quite effective at Oak Ridge National Laboratory (ORNL) in Knoxville, a company we’ve written about recently in regards to a robotics project they are involved in with Transcend Robotics. In this capacity, however, they are examining IR cameras extensively for use with 3D printing. According to Ralph Dinwiddie, an AM researcher there, the lab is able to measure temperatures in many different areas and stages as products are being manufactured.

Infrared technology offers a non-contact, high speed tool that’s also very precise. Able to detect settings with issues, the IR camera can pinpoint the source of a problem, to include:

• Poor surface finish
• Delamination of layers
• Shrinkage
• Part porosity
• Dimensional errors
• Thermal distortion
• Stresses

FLIR SC8202 MWIR camera monitors a stage of the AM process.

Cameras that many researchers use today lean toward lower resolution, longwave infrared (LWIR) uncooled cameras, such as the FLIR A65sc and the FLIR X6900sc, which is a high speed, midwave infrared (MWIR) cooled camera. Some of these models are easily mounted right onto the 3D printers, allowing for fast sensing of developing issues regarding temperature.

“We need the ability to record temperatures at high speeds and to calibrate these cameras with our own black-body source,” says Dinwiddie, making it clear that what they need in their research is a camera capable of windowing capabilities.

An IR camera that can read smaller subgroups of pixels is more efficient. Fewer pixels are needed on each frame, and more data is transmitted at a faster pace.

Thermal image of an AM extruder laying material at high temperatures.

“My work also demands a lot of flexibility in terms of lenses,” says Dinwiddie. “For example, I’ve used telephoto lenses, wide angle lenses, standard 50-mm lenses, as well as microscope lenses, and a macro lens. I’ve also used extension rings so I can focus much closer than I’d normally be able to do.”

Porosity is also an issue that’s being delved into much more often these days, as we also saw in following a recent study by LLNL regarding porosity in 3D printing with metal. With IR technology, the cameras are able to help with settings that keep porosity from developing.

IR cameras should prove to continue to be helpful in 3D printing technology in the future as they allow for materials scientists to continue refining settings and parameters, as well as studying issues in temperature and porosity. It’s predicted that tools such as these will indeed contribute to the industry as a whole.