How to use SLS to 3D print face shields

There has been a large-scale response by the 3D printing community to the COVID-19 pandemic, with a giant effort to close the gap between supply and demand for PPE for front-line NHS workers. In recent weeks, some really clever and innovative designs have been released for people to produce but all have been designed and optimized for FFF printers.

Nick Allen, MD at 3DPRINTUK says, “One thing we noticed was that many of the face shield related designs were perfectly suited for FFF machines, but didn’t work well with the SLS process. As a company, we are intimately associated with SLS, and so we began to look at how we could optimize designs for the 3D printing technology that we use every day.”

What the team at 3DPRINTUK noticed when they looked, for example, at the amazingly well-designed and ground-breaking Prusa face shield design was that only 14 individual headbands could be printed on the EOS FORMIGA P110 SLS machine at a time. The team focused on a design that the P110 could accommodate in 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.

Allen continues, “That is 6 minutes per shield. The design that we created clips together in 10 seconds, uses silicone straps for adjustment, can take an acetate sheet with 3 holes, is lightweight at only 42 g, and is sterilizable 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 looked for partners to scale up production. In recent weeks, the engineering team 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.

From the get-go, there was a great connection between the 3DPRINTUK and AUB teams, with AUB producing the initial batch of 5000 units and more thereafter. 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 said: “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 honored 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 maximizing PPE production through design and collaboration.”

Allen concludes, “We would invite anyone else with 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.”

3DPRINTUK
3dprint-uk.com

AUB
www.aub.ac.uk/PPE