b'Look-AheadREUSABLE RESPIRATORST he ExOne Co. in North Hunting- then fine-tune it during the high- of filters. Ansys Inc. in Canonsburg, don, Pennsylvania, and the Uni- temperature densification or sin- Pennsylvania, is providing additional versity of Pittsburgh have partneredtering process to achieve optimumcomputer simulation support to ana-to develop reusable metal filters thatfiltering and airflow performance,lyze and optimize filter performance.fit into a specially designed respira- said Markus Chmielus, associateSince ancient times, copper has tor cartridge for sustainable, long- professor of mechanical engineer- been known to possess antibacte-term protection from contaminants. ing and materials science at Pitt. rial properties. The first recorded ExOnes binder jetting technol-ogy is a high-speed form of 3D printing that can produce metal parts with specific porosity levels that effectively can filter out con-taminants while allowing airflow.The company has 3D-printed res-pirator filters using two metalscopper and 316L stainless steeland a range of porosity levels for use inside a unique cartridge de-signed by the Department of Me-chanical Engineering and Materials Science at Pitts Swanson School of Engineering. Initial testing for air-flow and filtration efficiency is un-derway, and the filters are being op-timized with the goal of adhering to an N95 respirator standard.Our team has been working ur-gently to expedite this promising and reusable solution for medicalExOnepersonnel on the front lines of fight- A reusable, sterilizable copper filter has been 3D-printed.ing the COVID-19 pandemic, said CEO John Hartner of ExOne. OurExOnes binder jetting technol- use of copper to kill germs was in customers routinely print porousogy uses an industrial print head tothe Edwin Smith Papyrus, the old-metal filters for a variety of purposes,selectively deposit a liquid binderest known medical document,ac-and we are confident that well haveonto a thin layer of powdered mate- cording to the Smithsonian Institu-a solution soon that can enablerial, layer by layer, until a final objecttion. Many studies have proven the medical personnel to sterilize metalforms. After 3D printing powdereddisinfecting powers of copper. A filters for repeated reuse, eliminatingmetals, the object then is sintered instudy funded by the U.S. Depart-waste. Once approved, we can printa furnace to dial in a specific level ofment of Defense in 2015 revealed these filters in a variety of sizes forporosity. While binder-jetted metalthat copper alloys contributed to a respirators, ventilators, anesthesiatypically is sintered to full density,58% reduction in infections. COVID-masks or other equipment. some applications, such as filters,19 research suggests that the virus The advantage of binder jet 3Drequire a particular level of porosity. dies faster on copper than on other printing over other additive manu- To test filters using different met- surfaces.CTEfacturing methods for this filter ap- als and porosities, Chmielus re- For more information about ExOne, plication is the ability to utilize thesearch group uses CT scanners to an- call877-773-9663orvisitwww.porosity of the printed part andalyze the microstructure and porosityexone.com.52SEPTEMBER 2020LookAhead.indd 52 8/17/20 11:15 AM'