New HSS 3D Printing Process Can Print a Chair in Minutes – Interview with Neil Hopkinson of Sheffield Univ.

A little under a year ago we covered a project at the University of Sheffield which promised to change the way manufacturers viewed 3D printing as a tool for mass production. Professor of Manufacturing Engineering, Neil Hopkinson, was leading the charge in the development of a technology called High Speed Sintering (HSS), which was able to fabricate objects at production-level speeds, in mass quantities.

When it comes to tinkerers and hobbyists like myself, we can mainly deal with the sluggish nature of our own 3D printers, at least for the time being. However, in order for manufacturers to take the technology seriously, away from prototyping and small batch production, 3D printing systems must be on par with other mass manufacturing techniques.

This is just what Hopkinson and his team are looking to accomplish, and since our article last August, they have made tremendous progress on all fronts. In fact, earlier this week, numerous publications picked up on the magnitude of this work at the University of Sheffield, on what will be a £1 million 3D printer when all is said and done. Here at 3DPrint.com we wanted to dive a bit deeper into the details this technology, the forthcoming printer, and the future of HSS, therefore we reached out directly to Hopkinson himself for more clues.

The technology is rather ingenious. Unlike most sintering machines which use a laser to slowly melt a layer of powder-based material before raking another layer of powder over top, the HSS process is able to sinter an entire layer of material in an instant. Sound impossible? It’s not! The HSS process includes an additional step; an inkjet printer. After each layer of powder is spread among the build platform, the inkjet nozzles then spray a carbon black ink onto the powder in the shape of the particular object being printed. Immediately following this step, an infra-red lamp is passed over top the carbon black (an infra-red radiation absorbing material) and rapidly heats it while leaving the surrounding material as is. This allows an entire layer of an object to be printed in under 20 seconds.

So just how faster will this machine be when compared to other laser sintering machines on the market today?

Neil Hopkinson

“Speed (production rate) depends on bed area, the bigger the faster,” Hopkinson explained to us. “We are building a 1 meter cubed machine which, depending on part geometry, will be ~10-100 times quicker than laser sintering – the chunkier the part the higher the increase over laser sintering.  It is best suited to thermoplastics, from elastomers to engineering polymers, but in the long term it could apply to metals and/or ceramics.”

These rapid speeds could transform the way in which manufacturers utilize additive manufacturing technology, not only speeding up the production process, but also providing manufacturers the ability to quickly re-purpose a machine without lengthy and expensive retooling.

“A (finger) ring on a 1 square meter bed would be less than 1 second [to print] per part,” Hopkinson explained to 3DPrint.com. “A tennis ball might be a couple of minutes per part and a fully assembled chair would take a few hours unless chairs could be stacked in the build. A flat pack chair would probably take minutes per assembly, depending on the ability to pack parts in the bed. Please note these are production RATES; it will not be a case of pressing “play” and then having a tennis ball appears after 2 minutes, it will be more like 100 tennis balls will appear in ~3 hours.”

The HSS process is a perfect example of ‘economies of scale’ at play.  As more items are packed onto the build platform the average production time it takes per item rapidly decreases. Because of this, Hopkinson believes that the technology will accelerate the adoption of additive manufacturing substantially.

“The cost and time points offered by this will see AM apply to high volume production, allowing affordable functionally personalized footwear through to lighter parts in high volume automotive,” explains Hopkinson.

The University of Sheffield, nor Hopkinson plan to sell these machines, instead opting to license the technology to larger corporations who can do the leg work for them. In fact, German-based 3D printer manufacturer voxeljet is already on board. The very first HSS printer will officially be launched sometime in 2017 if all goes as planned. This also happens to be only a matter of months after HP is expected to launch their high-speed 3D printers, which certainly has some of the larger players within the industry a bit nervous. With all this in play, one has to wonder if perhaps Stratasys or 3D Systems may look toward HSS as a way to compete. Hopkinson wouldn’t divulge which companies they were in discussion with but did have the following to say:

“My colleagues at Loughborough University (who own the base patents as that it where I worked when we first filed) are working with a number of organisations to license and commercialise the technology. The versatility of the process lends itself to multiple vendors supplying to different target markets; some will make very large machines, some will make small machines, some will specialize in certain material types etc. With UK government (EPSRC) funding, we are making a large machine that will also enable embedding of electrical functionality in parts.”

We are about to enter a very exciting time within the industry. With numerous rapid printing technologies in the works, many large corporations about to enter the space, and investment dollars continuing to flow in, the next two to three years are going to see exponential change. So when can we expect to see an HSS printer sitting on our own desktop at home? Perhaps sooner than you would have imagined. When I asked Hopkinson if such a printer could be scaled down to work on the desktop his reply was quite optimistic:

“Yes, the beauty of inkjet printing is that it is scalable from small to very large in the 2D printing world, I see it doing the same in the 3D printing/AM world.”

What are your thoughts regarding the future of this technology within both the manufacturing and hobbyist spaces? Discuss in the HSS 3D Printer forum thread on 3DPB.com.  Check out the video below describing the HSS process: