In contrast to much of the 3D-printing PPE effort, this latest initiative is focused on SLS technology, not FDM. Explains Nick Allen, MD at 3DPRINTUK: “From the very beginning of the Covid-19 crisis, in common with numerous other 3D printing companies, we analysed ways in which we could make useful interventions and help the efforts of the NHS.

“One thing we noticed was that many of the face shield-related designs were perfectly suited for FDM machines but didn’t work well with the SLS process. As a company, we are intimately associate with SLS, and have printed over two million SLS prints, so we began to look at how we could optimise designs for the 3D printing technology that we use every day.”

For the ground-breaking Prusa face shield design, only 14 individual head bands could be printed on the EOS FORMIGA P110 SLS machine at a time, for example. The team focused on a design that the P110 could accommodate in much larger numbers. By nesting the main peak component inside one another they were able to create one that allowed for 260 to be printed in a single print with a 27-hour build time.

Continues Allen: “That is six minutes per shield, which is a game-changer. The design that we created clips together in 10 seconds, uses silicone straps for adjustment, can take an acetate sheet with three holes, is lightweight at only 42 g, and is sterilisable with IPA, autoclave or ethylene oxide (Et0). All in all, we believe that this is the most efficient visor design to produce via 3D printing available today.”

Additional design benefits include a closed peak design for extra protection, the material used (PA2200/Nylon 12) is biologically safe, and the shape has been designed so that it can be flat packed into an A4 envelope for cheap postage and storage.

Once the design was proved and validated, 3DPRINTUK had to look for partners to scale up production. In recent weeks, it has been directly involved with the UK Cabinet and manufacturers working on a number of large ventilator projects, which has taken up their own printing capacity. Information relating to the design was released and the first facility to take on the manufacturing role was the Arts University Bournemouth (AUB), which had access to the P110 machine and also had laser cutting capabilities.

AUB produced an initial batch of 5,000 units and more thereafter, with these shields will be distributed for free to front line key workers.

The arts university has been spearheading an effort by educational institutions to manufacture and create vital protective equipment for the healthcare sector. Since its campus closure in March, the university’s facilities have become a production line for visors, facemasks, scrubs and gowns, which are being distributed across a range of public healthcare settings, including doctors’ surgeries, care homes, and volunteers providing door-to-door services for the elderly.

AUB vice chancellor Professor Paul Gough says: “We’re delighted to be involved with this vital project. Many AUB staff members have been involved, from our cutting-edge technical teams to our Innovation and Campus Services teams. AUB is honoured to play a part in the national drive to create and distribute life-saving apparatus, it’s so important that we’re all able to play our part during this global pandemic.

“As a specialist university, we firmly believe in the ways in which research and creativity can greatly improve productivity. In times like these, we’re challenged to rapidly innovate, and at such a crucial time, it’s hugely heartening to see those from across the creative industries maximising PPE production through design and collaboration.”

Allen concludes: “We would invite anyone else with the SLS capacity to make the face shield to contact us and we will share the design data with them. This has been a monumental effort from all involved, and I would personally like to thank Tom Preston, Fred Holdsworth, Eden Franham, Rhiannon Evens, Alex Greatwich, Lucy Devall, Paul Johnson, and Tom Marshall from the Arts University Bournemouth, and my colleagues at 3DPRINTUK, Jason Pereira, Joshua Wells, Chris Owen and Kirby Downey.

“We’re sad that we will not be able to manufacture many of them in house, but to see the project come to fruition and with such gracious and dedicated work from so many people is truly humbling.”