The science behind HP’s new full-colour 3D printers

Jet Fusion 500 science behind it

They can produce production-quality prototypes faster, better, and more affordably than any other 3D printers, but behind HP’s new Jet Fusion 500 series is breakthrough thinking on light, heat and speed.

The new HP Jet Fusion 500 printers are an industry first: capable of creating production-quality prototypes quickly, accurately and affordably — making advanced 3D technology accessible to a wider swath of digital innovators. And this huge leap forward in 3D printing began as HP explored a surprising realm of light — one that we’re unable to see.

Cheryl MacLeod, HP’s Global Head of 3D Fusion Science, leads the team of scientists and engineers at HP’s 3D Open Materials and Applications Lab in Corvallis, Oregon who are charged with developing the science behind the company’s portfolio of 3D printing materials. “We ultimately think of printing as a way to convey information,” says MacLeod. “And with 3D colour printing, we now have an entirely new language.” 

Seeing the light

In developing the new Jet Fusion technology, HP’s 3D R&D teams called on the company’s deep expertise in the science of ink to create black fusing agents able to absorb heat at greater speeds, as is needed for 3D printing. But printing colour with exclusively black agents isn’t possible, so a new solution needed to be found.

HP’s scientists realized that they needed a primer coat of white on the outer layers of the black parts being produced so that colour could be applied and fused. But how could you create a layer of white when all available fusing agents were black? A new kind of fusing agent was needed, so that the surface of the fused part remained white, but absorbed heat as well as black. And they found the answer in an unexpected realm of light — one that we’re unable to see.

“That was a huge breakthrough for us and the entire 3D printing community,” says HP’s Matt Shepherd, Project Technical Lead, Systems Engineering for 3D Printing. “The light that we’re able to see with the human eye — the whole spectrum of the rainbow — if you absorb any of that light you can see colour. We needed to find a way to absorb the light we can’t see: the infra-red light that gives us heat. The invisible light. We knew that was the key to cracking the code.”

To do so, engineers experimented to find the exact spectrum of energy-absorption that a clear agent would need to successfully fuse colour. Once that was accomplished, they were able to identify new kind of clear additive that could absorb invisible infrared light to heat and enable a complex fusion of printing materials, heating agents, and colours with microscopic precision. But this discovery was just one part of a larger colour puzzle.

The earth as a prototype

The next challenge was to print colours on three-dimensional objects as precisely and evenly as HP’s 2D printers print on paper. HP’s 3D R&D engineering teams went back to their whiteboards and developed an approach that took its inspiration from the shape and surface of the earth.

They started with a new black fusing agent that, as it melts, resembles the molten layer of earth’s core. Outside of that core, they printed the mantle — in this case a clear 3D fusing layer that left a white surface to enable colour. That mantle then became a colourful crust, not unlike the surface of the earth.

With this model established, engineers were able to learn how colour could be applied evenly and precisely across any solid surface, because each layer could be controlled at the “voxel” level — a.k.a. the tiny three-dimensional pixels that form the DNA of Multi Jet Fusion.

It’s that level of control, laying down 340 million voxels per second, each only 25 microns in diameter (¼ the width of a single human hair), that has given HP’s newest 3D solution its unique ability to print three-dimensional objects with such precise colour, shape and detail.

The next breakthrough? It starts with accessibility 

These remarkable new printers allow users to produce engineering-grade, functional parts or prototypes in colour, black or white in a fraction of the time of other methods. And with more affordable pricing than other systems, it democratizes advanced 3D printing technology by making it accessible for smaller businesses, universities, entrepreneurs, and other types of innovators.

A heart surgeon, for example, can custom-create a true-colour replica of a patient’s heart, with its complex network of veins and valves, in three dimensions instead of relying on a flat X-ray, and print it within steps of the operating room. In fact, the Phoenix Children’s Hospital is currently exploring new ways to create personalized experiences that benefit the long-term well-being of its patients by using HP’s colour 3D printing technology.

“We’ve been advancing, reinventing, and setting the gold standard for digital printing in all its forms for 35 years,” says Paul Benning, HP’s Chief Technologist for 3D Printing. “HP’s decades of experience, proprietary technology, global reach, and legacy of industry-changing innovation — from 2D to 3D to whatever the future holds — are the things that have allowed us to continue making the world better for everyone, everywhere, in so many amazing ways.”

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