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Large-Scale AM for Manufacturing PPE during COVID-19
in 2002 – 2004 and can be transmitted through mass manufacturing techniques such as injection
[6]
an airborne droplet and contact transmission . molding when increased demand makes the
[7]
It has also been established that people are able production of tooling and moulds a cost-effective
to transmit the infection despite not obviously option.
displaying symptoms (asymptomatic) . Due to the prevalence of desktop FFF 3D
[8]
For these reasons, the wearing of personal printers, most of the designs being manufactured
protective equipment (PPE) has become a vital by these global communities are optimized for
requirement for frontline medical staff, those with common 3D printer formats, such as build plates
critical caring responsibilities and key workers of approximately 200 × 200 mm and 0.4 mm
facing increased potential exposure to SARS- (sub-mm) extrusion nozzles . These limitations
[16]
Cov-2. The WHO has recommended that PPE generally mean that the main components of
also includes eye protection to safeguard against face shields can take 1 – 2 h to produce, which
droplet and airborne transmission . Droplet presents a significant issue for producing larger
[9]
transmission (as happens with influenza) occurs volumes of components. Typical thermoplastic
when droplets from an infected individual that deposition rates on desktop 3D printers are
is generated during coughing, sneezing, or even usually on the order of 10 mm /s . Large-scale
3
[17]
talking pass through the air and land on the eyes, additive manufacturing (LSAM) systems have
nose, and mouth of another individual leading to built volumes with dimensions of 1 m or greater
infection . and typically use nozzles with diameters of
[10]
With this increased global demand for PPE, 1 mm or greater, allowing for significantly higher
governments and organizations have struggled deposition rates on the order of 100 mm /s. LSAM
3
to source enough for millions of regular PPE has been used previously to manufacture tooling
users, let alone for non-typical users such as for various applications [18-20] , as well as being used
pharmacies and general practitioners who are for direct manufacture of large single objects
[21]
now at increased risk of infection during their such as furniture and bike frames .
[22]
[23]
daily activities. These supply chain issues have The ability to deposit thermoplastic materials
arisen due to a global shortage of PPE items such at rates of up to 100 mm /s with LSAM means that
3
as eye protection/face shields and the inability to bridge manufacturing rates for PPE components
manufacture enough items quick enough . In can be significantly increased addressing
[11]
response to this unprecedented demand, many immediate requirements in advance of an eventual
companies, academic institutions, and individuals increase in production capacity using techniques
have sought to use democratized manufacturing such as injection molding. In this paper, we
facilities and equipment such as three-dimensional report the design and development of face shield
(3D) printers (generally fused filament fabrication components optimized for production using
[FFF] systems) to produce components for much LSAM technology such that a component that
needed PPE items such as face shields [12,13] . would normally take 1 – 2 h to produce can be
This manufacturing effort has seen members of made in under 5 min. The development of process
the international 3D printing community come parameters to ensure continued part quality with
together in vast, rapidly formed collaborative larger part volumes per production run is also
networks to address the PPE shortfall in a way presented.
reminiscent of the often-proposed concept of
localized microfactories [14,15] . In the context of a 2 Materials and methods
traditional product development cycle, this type of
activity can be likened to bridge manufacturing, The headbands were printed on a 3D Platform 300
where the use of additive manufacturing techniques Series Workbench Pro (3D Platform, USA) with
is used to bridge the gap between small volume, High Flow Extruder 300 3D Printer Extruder,
time-intensive manufacturing processes, and other fitted with a 1.8 mm nozzle. The material used
52 International Journal of Bioprinting (2020)–Volume 6, Issue 4
