As the COVID-19 pandemic rapidly spread across the globe in 2020, the demand for N95 facial masks soon outpaced supply. Global supply chains evaporated. And countries that had previously imported most of their masks soon learned they did not have sufficient domestic manufacturing capacity to address the needs of the medical community.
Meltblown nonwoven material is a critical component of N95 facial masks, as well as filtration materials. Made from polypropylene, the high-performance material is designed to meet stringent filtration specifications.
“One of our areas of expertise is nonwoven converting, including meltblown production lines,” said Michael Pappas, president, Catbridge Machinery. “Our company quickly set to work to package a solution that could help address material shortages.”
Headquartered in Montville, New Jersey, Catbridge Machinery is a leading global supplier of web converting machinery and unique turnkey solutions. Currently, the company is the only supplier of turnkey meltblown production lines based in North America.
Putting Expertise to Work
Long before the pandemic hit, Catbridge Machinery had both compact and multi-beam meltblown equipment in their portfolio. In addition, they had developed a small-scale pilot line for tradeshows that included the key elements of the process.
“There’s always some degree of customization in our solutions,” said Pappas. “In this case, we leveraged our previous work to package a line specifically for N95 mask material.”
To meet typical filtration material standards, the company packaged a solution with a web width of 1.6 meters (5.2 feet). The turnkey production line features both mezzanine and plant-level equipment – and includes extrusion, the meltblown forming system, web handling equipment, all mechanical connections, a controls package and electrical panels.
The process begins in the mezzanine level where polypropylene pellets are fed into the extruder, which heats the material to about 240°C (470°F). A single “beam” of liquified polymer is pumped through a die assembly, which features a series of minuscule holes.
At the same time, high velocity hot air is blown on either side of the hole exit points to stretch or attenuate the fibers. As the filaments cool, they are drawn toward a vacuum table and web handling equipment on the lower level.
“We continuously spray extremely thin strands of polymer on the vacuum table to create a web,” Pappas explained. “This creates a filter material that allows air to pass through, but can also capture a lot of particulates.”
“To optimize filtration, the web is also statically charged,” Pappas added. “As a result, the material will have a ‘static cling’ to trap even more particles.”
The material is finally conveyed, slit and wound for shipment.
Powerful Control – at the Source
The meltblown line runs on a Rockwell Automation control platform featuring Allen-Bradley GuardLogix® safety controllers and Allen-Bradley Kinetix® servo drives and motors. The system is integrated on an EtherNet/IP™ network.
“Typically, we have used graphic terminals for our machine HMI,” said Pappas. “But in this case, we chose Allen-Bradley VersaView® industrial PCs and monitors.”
Rugged VersaView products provide more computing power at the source of the application – and more flexibility in what can be accessed and managed from a screen. In this case, the system runs FactoryTalk® View Site Edition (SE) HMI software, which meets the demands of multiple stakeholders.
Operators can easily access display screens, alarms and system-wide diagnostics. And maintenance and engineering can quickly develop applications and easily maintain the system.
The Beauty of Modularity – and Agility
In addition to packaging a turnkey production line that could support the immediate need for N95 mask material, Catbridge focused on easy expansion and machine flexibility.
“The entire beam assembly at the mezzanine level was built to be independent, modular – and easy to expand,” said Pappas. “Our customers can simply add polymer beams and forming tables to increase capacity or produce unique blends.”
In fact, the customer who purchased the first N95 mask production line has already asked how they can add a second beam to increase output.
The meltblown line is also built for easy changeover.
“Many of the people we’ve worked with in the past don’t produce one product exclusively,” said Pappas. “They might be working on automotive air filtration material, absorbent wipes and masks – and each of these products have specific fiber requirements.”
Running another product usually involves changing the die configuration. Typically, the only mechanical change is removing and replacing the die tip. All other adjustments are driven by changing the recipe from the operator interface.
“The COVID-19 pandemic has been a roller coaster ride for many of us,” said Pappas. “N95 masks are still in short supply, but what will become the norm? We simply don’t know. In these uncertain times, machine flexibility is as important as performance.”