Kevin Smith and Julien Soosaipillai discuss collaborative process of creating PPE in fight against Covid-19

Kent School of Architecture and Planning (KSAP), along with colleagues from School of Computing and the School of Engineering and Digital Arts (EDA), have collaborated to design and supply 300 sets of personal protective equipment (PPE) for East Kent’s largest hospice charity, Pilgrims Hospice.

KSAP’s Workshop Manager, Kevin Smith, along with 3D CAD Technician, Julien Soosaipillai worked on the project from inception. They documented the pitfalls and progress of the project to date, “We experimented with several designs which were sent to NHS facilities; they preferred the PRUSA 3D V3 printed frame design which is designed to hold a clear plastic screen, bent around the head secured on a radial arrangement of forward-facing location studs. These are sized to just fit through a standard paper hole-punch hole, the idea being that anyone with a hole-punch could make the clear plastic shield front screen.

The original design called for 0.5mm PETG but this is in very short supply due to the unprecedented global demand. We experimented with the 1mm PETG we use for laser cutting but found it to be too stiff; i.e. it kept popping off the frame. PETG is preferred as it is fairly tough and reasonably resistant to solvents (often used for machine guards etc.).

We wanted the shields to be as sterile as possible. The 3D parts can withstand being soaked in Isopropanol to achieve this, so the screens needed to be similarly treatable. We also needed something that was available in paper sizes in case a hole-punch was to be used and preferably available in easily accessible large numbers. We had a stock of 0.24mm PVC A4 Binder covers and experimented with these. Although unable to withstand any significant heat they proved to be completely safe with Isopropanol so we cut a few samples and sent them to a local GP practice and the Pilgrims Hospice for trials. The feedback was good but said they would prefer a more wrapped around design.

3D CAD Technician, Julien Soosaipillai, redesigned the frame using Fusion 360, pulling the side arms in whilst retaining the hole-spacing. The modified sets were duly dispatched and approved. The University of Kent’s Design and Print Centre made 2000 PVC sheets available and the Schools of Engineering and Digital Arts and Computing supplemented our dwindling supplies of filament with everything that they had.

We have now set up a 3D printing Hub in the Digital Crit space using all the KSAP printers together with those from EDA, The School of Computing and School of Physical Sciences. Currently we are running eight Ultimakers, along with four Prusa printers, all printing a mixture of PLA and PETG.  Jigs were duly designed to drill and trim 100 screens at a time and a rotary winder is used to wind on elastic at a predetermined length, speeding up the cutting.”

The visors are supplied flat packed, each pack consists of 10 frames, 10 screens, and 10 lengths of elastic with some printed instructions. Kevin Smith, Workshop Manager, estimates that the team can make and pack 280 – 300 visors per day. Kent Innovation and Enterprise has been co-ordinating enquiries from the start and are currently arranging funding to order more materials to maximise production.