It wasn’t too difficult to use a 3D printing machine to produce face shields in response to the coronavirus. The real trick was using 100 machines to make 25,000 of them.
Raytheon Technologies launched a rapid-response effort to produce that many face shields for first responders in response to the coronavirus pandemic. Given the demand and urgency, the company employed additive manufacturing machines from operations all over the world.
“It was unprecedented to bring the entire corporation together to print one single file across multiple processes and materials using somewhere around 100 machines in less than two weeks,” said Jesse Boyer, fellow for additive manufacturing at Raytheon Technologies. “To ramp up to that volume that quickly is something that’s touted using additive manufacturing, but rarely demonstrated. The opportunity was a great learning experience.”
Additive manufacturing works differently from traditional fabrication. In its simplest form, the difference is like that between addition and subtraction. A metal component would traditionally be made by machining a solid block of material, subtracting what’s not needed to create the desired part. On the other hand, 3D printing builds a part layer-by-layer, generally using lasers or other thermal-mechanical, or chemical, processes to bond materials that come in various forms, including powder (which can look and feel like sand), wire, filament, liquid.
That means additive manufacturing is well suited for designs that would be difficult to make using traditional methods, such as shapes that are less prismatic and more organic. Take, for example, a heat exchanger for a jet engine. Traditional methods have produced block-like components that take up a certain amount of space and weight. Additive manufacturing could weave organic shapes that fit into tighter spaces, said Boyer.
“The wild side is to continue to do that, to make very complex, yet optimized structures for areas we couldn’t normally do in a jet engine,” he said. “We explore methods like bio-mimicry, by looking at the best nature has produced. Additive then reduces the constraints of conventional manufacturing and substantially increases our ability to optimize what we can manufacture going forward.”
Yet the technology is still evolving rapidly. To date, different machines can produce inconsistent results, depending on such factors as the material used and the process involved, according to Paula Hay of Collins Aerospace, one of four businesses that form Raytheon Technologies. Hay helped coordinate the effort to produce the face shields.
“One of the big complaints about additive is, if you do something on two different machines, you get two different answers,” Hay said, adding that the experience with face shields showed that “when you have a good design and a good file, you get a repeatable product. They looked alike; they were alike.”
That is a good sign for the near future of 3D printing. Although traditional manufacturing is still often preferable for mass production (it can be more cost-effective in most cases), the fact that 3D printing is moving toward a more repeatable result points to a future where it is more competitive with traditional methods, a future that will unleash less conventional designs for a wide variety of products.
“If you step back and look at additive manufacturing, the 3D printing industry, there was a significant amount of hype 10 years ago,” said Venkat Vedula, executive director of the Raytheon Technologies Additive Manufacturing Process and Capability Center, part of the company’s Technology & Global Engineering team. “It was almost treated like a panacea that would replace all the traditional manufacturing. Now we have a better understanding of the technology and a more realistic understanding of where it will add a benefit.”
There are four areas in which additive manufacturing adds the most value now, according to Vedula:
- Optimized design. “There are novel, generative designs that can’t be made with conventional manufacturing, and even if you could, it would be (prohibitively expensive),” he said.
- Part unitization. Vedula offers the example of a fuel nozzle that can be 3D-printed in a single piece. “We can reduce the lead time by several months to five or six weeks,” he said.
- Part substitution. Additive manufacturing can reduce the lead time or cost for low-volume parts.
- Aftermarket. Additive manufacturing can produce products at the point of use. “If we have an aircraft on the ground and can’t repair the parts, if you have the CAD (computer-assisted design) model, you can print it right there,” he said.
3D printing is a tool in the toolbox for the future of manufacturing, according to Vedula.
“Additive is not going to replace cheap metal parts, and it shouldn’t because there is a technology that has been matured over centuries,” he said. “One of the major breakthroughs was a little over 10 years ago in the medical industry, with products like titanium implants. That’s where we started to see a better quality product, better machines, higher-power lasers.”
Today, according to Vedula, as they use 3D printing to make products from engines to components, companies like Raytheon Technologies are well-positioned to advance the technology: “Aerospace and defense is certainly in the forefront.”