Collaboration Developing 3-D Printed Reusable Filters for PPE

ExOne and the University of Pittsburgh along with other collaborators are testing a filter designed for reusable, sterilizable personal protection equipment (PPE).

Currently being 3-D printed in copper and stainless steel, the filter would enable long-term PPE use that medical personnel and even everyday consumers could use, ExOne said. This sustainable, reusable solution can meet current safety needs while addressing the environmental challenges of disposable PPE as well, according to the company.

“From the beginning of the COVID-19 crisis the ExOne team knew that we might have a special solution to offer in this crisis with our porous 3-D printed metal filters. That’s because we have customers who’ve been using our binder jet 3-D printers to manufacture metal filters with very specific levels of porosity for years, usually for industrial use,” said John F. Harner, ExOne chief executive officer.

“While our R&D teams have largely been focused on 3-D printing high-density metal parts without porosity, printing porous metal objects is something we’ve done since we first began binder jetting metal in the mid-1990s. It’s how we got our start,” said Harner. “Binder jet 3-D printing is uniquely suited to print porous metal that can filter our contaminants while allowing the level of airflow required.”

ExOne’s technology uses an industrial printhead to selectively deposit a liquid binder onto a thin layer of finely powdered material, layer by layer, until a final object is formed. After 3-D printing powdered metals, the object is then sintered in a furnace to dial in a specific level of porosity. While binder jetting metal is typically sintered to full or high density, some applications require a specific level of porosity such as filters.

Dr. Markus Chmelius, associate professor of mechanical engineering and materials science at the University of Pittsburgh Swanson School of Engineering, has been optimizing and analyzing the microstructure and porosity of the filters. Also, Ansys has been providing additional computer simulation to optimize the performance of the filters.

ExOne now is partnering with several makers of plastic respirator masks such as Open Health Solutions on a completely sterilizable and reusable solution. Also, customers can scan their face with a free smart phone app, Bellus3D FaceApp, to have a custom-designed facemask 3-D printed in a biocompatible and autoclavable surgical resin. The mask will feature a reusable metal filter 3-D printed by ExOne, which fits into a cartridge on the front of the mask and also can be sterilized and reused.

The Open Health mask design has been submitted to the National Institutes of Health for approval, and ExOne says it is moving as quickly as possible with its partners to bring these solutions to market.