Researchers from Northwestern University recently demonstrated the ability of a single 3D printer to produce 1,000 face shield parts each day. Considered as a delicate piece of personal protective equipment (PPE), face shields protect a health worker from the infection of COVID-19 as he treats patients. When David Walker and Chad Mirkin, researchers from Northwestern heard about the shortage of PPE in hospitals, they immediately sprang into action.
In October last year, Mirkin, together with his research team, via a breakthrough article which journal, Science published, uncovered the new 3D technique named HARP or high-area rapid printing. This is a printer, 13-foot tall with a print bed, 2.5 square-foot with the ability to print about half-a-yard in just 60 minutes, a record quantity for the 3D printing field. According to Mirkin, even the 3D printers' fleets are going through some difficulties in meeting the demand for PPEs, specifically the face shields as there is a massive need at present because of the widespread COVID-19.
1,000 Face Shield Parts per Day
Parts are being produced at a rate of 1,000 each day by having operated the printer 24/7. With this, volunteer members of the teamwork in six-hour shifts to maintain the production cycle going unceasingly. Face shields composed of three parts: one durable plastic headband, an elastic band, and a clear plastic sheet. The last-mentioned component is clipped into the headband, which is then secured to the head of the wearer with a very flexible elastic band.
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Meanwhile, a team called the Azul 3D is leading the printing of the headbands. It has collaborated with a local manufacturing firm to provide the laser-cut clear plastic face shields. Another partner, the third, is responsible for the face shield parts' sanitizing and packaging into easy-to-assemble packages, which will, later on, be supplied to various area hospitals. The team noted, as well, that the face shields are washable and reusable, and now, it is working on the regulatory requirements to put the said face shields into use.
HARP's Functionality
HARP depends on a new, patent-pending edition of the so-called stereolithography, a kind of 3D printing that's converting a liquid plastic into a solid object. Additionally, HARP is printing vertically and using a projected ultraviolet light functioning to cure the liquid resins into solid plastic. This said procedure can print hard, ceramic or elastic pieces. These continuously printed components are mechanically strong or durable in contrast to the laminated structures that are common to the other 3-D printing techs. Incidentally, these products can be used for airplanes, cars, fashion, orthotics, and dentistry, among others.
A major restricting factor for the present 3D printers is in-demand. Each resin-based 3D printer produces a lot of heat while operating at fast speeds, sometimes going beyond 180°C. Moreover, this doesn't just result in hazardously hot surface temperatures. It can crack and deform the printed parts, as well. Essentially, the Northwestern technology bypassed this issue with a nonstick liquid behaving as if it was liquid Teflon. HARP is projecting light via a window to make a resin solid atop a vertically moving plate. As a result, the liquid Teflon flows above the window to eliminate the heat and circulates it through a cooling unit.
Below is a video of how HARP works:
