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Covid-19 powder bed fusion sterilizable face shield

The last few weeks has seen a cornucopia of COVID-19 face shield designs optimized for desktop 3D printers. This is absolutely fantastic!

To increase the possibilities, we have adapted the popular Prusa design for powder bed fusion (PBF). We made the arms of the frame foldable, like on a pair of sun glasses.

One of the challenges with shields designed for desktop printers is that they can be inefficient to print on PBF printers (SLS, MJF). This is because PBF machines want as many parts as possible nested in the machine at once. On the little EOS Formiga SLS machine I have, for example, I can only fit 30 Prusa frames in a print. In contrast, with the foldable design, we can fit 108 sets into a single print which, if we start at lunch time, will be finished the next morning.

The other advantage of printing with PBF is that the products can be more easily sterilized than when printed using material extrusion, which is very porous. laser sintered nylon parts can be sterilized with a steam autoclave, EtO (Ethylene Oxide), plasma, chemical, or gamma sterilization. Note however that,as nylon is hygroscopic, considerations should be given to moisture absorption.

The prototypes were kindly printed by Jonny Nyman and Axel Nordin, from Lund University in Sweden, on a Formiga P110 in nylon.

There are 2 versions of this design. The first version sees the 'headband' component of the face shield frame also printed in the powder bed fusion machines. The files for that version can be downloaded HERE

The second version sees the headband strap laser cut out of 0.5mm PET (0r 0.75mm). The files for that version are available HERE.

Please note: My lab has been shut-down during the COVID-19 crisis so I have not been able to personally test the design myself. So although colleagues have, very kindly, printed test parts for me, I have not held them in my own hands, so I cannot guarantee how well it will work. But, as soon as I have access to my machines again, I will print it and review the design to perfect it. This should, however, work for others who may want to continue developing the shield.

Screenshot of assembled face shield frame

If you come up with any further improvements, please email them to us at olaf.diegel@auckland.ac.nz and we'll update the downloadable files on the site.

 

 

Above is a picture of the prototypes printed by my colleagues at Lund University, and below is a screenshot of a build setup to print 108 sets of frames in an EOS Formiga P110 selective laser sintering machine.

 

copyright 2020, olaf diegel