The scientists are now publishing a 3D print file so that as many institutions and individuals as possible can contribute to better protection against the coronavirus. The first visors are already being used by medical staff at a clinic in Essen.

During the coronavirus crisis, protective equipment that covers the entire face (so-called "medical shields" or face visors) is becoming increasingly scarce. Doctors and nursing staff in particular urgently need these to protect themselves from the virus. Researchers at Fraunhofer IML have now developed a way to produce parts for face visors quickly and efficiently using a 3D printer. In order to produce headbands, which are one of the components of a visor alongside the elastic band and lens, they optimized the open source design for the printer manufacturer Prusa's headbands.

"The original file was designed for smaller 3D printers and did not fully utilize the significantly larger installation space of our printer. Thanks to the flexibility of the plastic, it was possible not to print the headbands already curved as before, but to shape them after printing. This allowed us to increase production from 60 to up to 500 parts per printing process. At 24 grams, the printed parts are also very light," explains Mathias Rotgeri, research associate in the Machines and Systems department at Fraunhofer IML.

The Fraunhofer scientists are now making this optimized file available so that all research institutions and companies that have 3D printers with laser sintering processes and want to help can make optimal use of their build space. "The potential of 3D printing is particularly evident in the current crisis: anyone who owns a 3D printer can help their local hospitals and care facilities. The maker scene is already very active here. Private individuals and inventors everywhere are printing parts for medical devices and equipment. We are now deliberately targeting owners of larger printers who can produce larger quantities more quickly," adds Christian Prasse, Head of Strategic Development at Fraunhofer IML.

Fraunhofer IML delivers the manufactured parts after printing to ensure rapid supply. The institute focuses on local demand. For example, the lung clinic at the university hospital in Essen and care and support facilities in Dortmund have already received components for visors. These consisted of parts from the Fraunhofer IML, Dortmund University of Applied Sciences and Arts and a number of manufacturers who produce for small-scale requirements. The parts are assembled by the users on site. Initial feedback has been very good: the visors are very comfortable to wear thanks to their low weight, relatively soft surface and the high flexibility of the plastic.

As materials such as Plexiglas are also currently in short supply, the scientists are also testing unusual solutions for the visor panes: For example, laminating film can be used laminated in two layers on top of each other. This makes the lens very light and it can still be cut with a laser.

The scientists are currently working on how the surface of the 3D printed parts can be optimized so that it can be disinfected even better. The use of so-called used powder is also being tested. This powder is a by-product of all 3D printing anyway, is usually not completely reused and is therefore available to most owners of 3D printers with laser sintering processes.

Fraunhofer IML makes the print file available to interested parties: https://www.iml.fraunhofer.de/de/medical-shield-3d-druck.html