A Necessary Filter

The Nonwovens Institute (NWI) at North Carolina State University is proactively responding to the COVID-19 pandemic. Our aim is to fully leverage and fortify our facilities to produce facemasks that are desperately needed in the coronavirus fight. Thus, with the full support of NC State, NWI is dedicating its meltblown and spunbond nonwoven making facilities and expertise to produce specially designed fabrics that can be delivered to USA manufacturers to assemble facemasks. Photo by Marc Hall

Nonwovens Institute ramps up to create mask filters – and masks – for health care workers.

By Mick Kulikowski

There’s no shortage of NC State ingenuity when it comes to combatting shortages of personal protective equipment used by health care workers and first responders.

NC State’s Nonwovens Institute (NWI) is using its two research and training pilot production lines to produce face mask materials that will be used to protect medical workers on the front lines of fighting the effects of COVID-19.

Surgical face masks are made with nonwoven materials, says Behnam Pourdeyhimi, executive director of NWI, Wilson College of Textiles associate dean for industry research and extension and William A. Klopman Distinguished Professor.

N95 respirators and surgical masks are generally a sandwich of one or two common nonwoven layers — so-called spunbond layers that provide mask shape and protect the inner filtration layer — combined with a layer of nonwoven meltblown material that serves as the filtration layer and captures microscopic unwanted particles like viruses and bacteria.

But because of the current critical need for masks caused by COVID-19, Pourdeyhimi and his NWI team created a new spunbond material that can serve as an effective filter without the need for a meltblown filtration layer. The unique fabric is composed of two different polymer materials that are combined to make a single fiber with significant strength and bulk — and that shows effectiveness in filtration similar to current materials used.

“Because of the COVID-19 crisis, we took the spunbond technology and created a new generation of unique filters that have excellent filtering capability and can potentially be reused after cleaning with peroxide, or potentially alcohol solution,” Pourdeyhimi said. “Because these materials are strong, unlike classical meltblown filters, they can also be cut and sewn by traditional techniques.”

Typically, one meter of spunbond material provides enough material for about 20 to 25 masks when using the current designs, Pourdeyhimi said. One of the NWI’s production lines started producing 2,000 meters of spunbond material per hour, with the potential to create some 20,000 meters of spunbond material in a day. NC State is currently in discussion with industrial partners to make masks with the material.

NWI’s other production line is a state-of-the-art meltblowing pilot line that will make the classical meltblown material for N95 masks and surgical masks.

“We created a recipe for the production of classical N95 respirator materials and will ship those materials out for industrial partners to convert these into respirators,” Pourdeyhimi said.

The meltblown material takes a bit more time to produce; Pourdeyhimi estimates that his production line can make about 12,000 meters of material in one work shift.

Thanks to support from across the university, Pourdeyhimi says that NC State has ordered machines that will allow the NWI to make surgical masks in its Centennial Campus facilities. Those machines should arrive in the next month.

“We will set these machines up and take our own materials and convert them into masks and provide them to local communities,” Pourdeyhimi said.

Pourdeyhimi said the outpouring of support offered internally by units such as the Office of Research and Innovation, the Office of Finance and Administration, the Office of the Provost, the Wilson College of Textiles and The Kenan Institute, as well as externally by industry partners, has been overwhelming.

Photograph by Marc Hall

ExxonMobil, for example, offered polymer materials to the university at no cost. Mask material production eats up approximately 25,000 pounds of polymer per week. Chemical manufacturing company NatureWorks has also offered polylactic acid (PLA) polymer for this effort. PLA is in short supply, but NatureWorks has secured the supply for NWI to ensure continuous production.

“North Carolina has the largest number of nonwoven companies in the nation, so we are reaching out to them to see if they would also invest in converting machines (that would turn mask materials into masks),” Pourdeyhimi said.

He added that, in order to increase the capacity of meltblown fabrics, “We are looking at possibly changing the way companies are producing things so that we might be able to produce filters that would be useful during this crisis. We are putting a lot of partnerships in place to be able to expand the amount of materials that are available both locally and nationwide.

“I’ve never seen the community come together the way it has.”

Mick Kulikowski is the assistant director for News and National Media Coordinator for University Relations, a unit of University Communications and Marketing at North Carolina State University, Raleigh, N.C.

Source: NC State University