UM project aims to locally manufacture N95 respirators

Jul 06, 2023

A University of Michigan-led project aims to fill medical N95 respirator needs after a shortage early in the COVID-19 pandemic and could lead to a "platform of innovations" in materials and designs of the masks.

The project, co-led by Albert Shih, a professor in the mechanical engineering department, looks to create two modular U.S.-made machines to manufacture the masks locally.

A middle layer of N95 masks is made of a melt-blown nonwoven, plastic filtration material that is electrostatically charged and can stop virus-size aerosol particles. The layer was in short supply during the pandemic and the world's supply is manufactured by large machines mostly made in China and Germany, Shih said.

"Only two countries can make these large machines now," Shih said. "We emphasize ... local production, so our machines are smaller and more modular in design."

The resins needed to produce the filters for the masks are not made in the United States, said Brian Love, a professor in the UM Department of Materials Science and Engineering and Biomedical Engineering.

"We make a lot of nonwovens collectively in the U.S., Love said. "There's a range of these resins that are produced but many of them do not have the additive to be able to function as an attractive charge-based filter. If we have the machine capacity here, we can formulate our own resins to make nonwoven layers that replicate what's being used in the masks right now."

The pandemic spurred innovations in mask design and materials but they must have manufacturing capabilities in order to have an impact on people's health, Shih said. His lab is working with U.S.-based machine companies to design and build the N95-making machines.

"We are essentially using the existing material existing design to prove we can do that in a small machine for localized production," Shih said.

Surgical N95 respirators, a subset of N95s, initially were sought by health care workers to limit exposure to COVID-19, according to the Centers for Disease Control and Prevention. The United States found critical shortages of personal protective equipment, or PPE, including the respirators, in the beginning of the pandemic. The Food and Drug Administration announced last summer that demand in health care settings no longer exceeded demand.

Once the machine is built Shih's lab first will test it to see if it can create N95 masks using the current melt-blown material and design. They can then begin experimenting with new mask designs and materials that may allow for better filtration, comfort and sealing around the face, Shih said.

The machines could be “a platform for innovations” in new materials and designs of N95 masks, particularly for health care workers, Shih said.

"Phase two is where the innovations of the new materials and the new designs will come together to be competitive,” he said.

Changing the filtration in N95 masks is expensive with the large machines currently used, Shih said. It is still unclear how much it will cost to make N95 masks with the new machine but the goal is to be cost-competitive, Shih said.

The project could be a pre-emptive safety measure in the event of future pandemics involving airborne viruses when N95 masks likely will be needed, Love said.

"Just having a single producer alone within the U.S. that was making appropriate mask materials would go a long ways towards basically minimizing the amplification problems that might come from disruptions in the supply chain,” Love said.

The project received $3 million in funding from the American Rescue Plan Act, and two Florida-based manufacturers are working on building the machines. Hills Inc. is constructing the melt-blown machine while DemeTECH corporation is building the N95 assembly machine. The assembly machine will integrate Hill’s melt-blown machine by this summer and Shih expects to transfer and set up the N95 production system in Michigan by the end of 2023.

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