WARREN, Mich. – There's loud humming and sounds of soft metal stamping as you walk into a bright white area of a decades-old transmission plant owned by General Motors just outside of Detroit. But the sounds, almost white noise, aren't of auto parts being produced, they're large reels of fabric running through machines and employees using laser welders to make medical face masks. In less than a week, GM converted 31,000 square feet of the 2.7 million-square-foot plant, which was decommissioned last year, from producing transmissions to the personal protection equipment for first responders and health care workers on the frontlines of combating the coronavirus pandemic. "I never thought I'd be a mask maker but there's a lot of stuff we're doing that we'd never thought we'd do," Robert Portugaise, a lead GM production engineer, said Thursday standing in the middle of the operations. "We continue to work and try to make improvements." GM initially aimed to make 20,000 masks in the first days of production, which started April 6. It quickly doubled that number and, as of Wednesday, had produced more than 620,000 masks. A second shift also was added this week to assist in producing masks, include some for GM employees in preparation of auto production eventually reopening.

General Motors is beginning to produce N95 masks at a former transmission plant outside Detroit. The manikin head is being used to test the fit of the masks prior to production for distribution beginning. Michael Wayland / CNBC

Engineers on Thursday afternoon also were preparing a new production line to begin making much-needed N95 masks, which still need to be tested and certified. "There's quite a bit to it. N95 masks are a little bit more complicated," Portugaise said, adding there's more welding, fabric layers and a folding process that needs to be done. "We're still in the debug phase." Once fully operational, the machine should be able to produce 12,000 masks a day, according to Portugaise, whose day job is executive director of manufacturing engineering for propulsion systems at GM.

'They're inspired'

Making medical-grade level 1 face masks isn't as simple as it may seem. It's particularly challenging to do in a week, which the automaker did. More than 30 engineers, designers, buyers and members of the manufacturing team were asked to help with product development, sourcing materials and equipment as well as planning the production process.

In less than a week, GM converted 31,000 square feet of the 2.7 million-square-foot plant, which was decommissioned last year, from producing transmissions to face masks for first responders and health care workers on the frontlines of combating the coronavirus pandemic. Michael Wayland / CNBC

The needed materials included metal nose pieces, elastic straps and blown, non-woven fabric filter material. Simultaneously, GM collaborated with Michigan-based companies JR Automation and Esys Automation to design and build the custom machinery needed to assemble the masks. For the project, the team also built an ISO Class 8-equivalent cleanroom at the plant. The team cleared the area and crews then installed new electrical service lines to power the production equipment and assembly stations, according to GM. "The team out there, they're inspired in how they're engineering and how they're engaging with the work teams out there to increase production, and ramp-up, and scale up, and install," Gerald Johnson, GM executive vice president of global manufacturing, said in an interview at the facility Thursday afternoon.

General Motors Executive Vice President Global Manufacturing and Labor Relations Gerald Johnson (middle) watches as engineers and technicians set-up and test the machines that will be used to manufacture Level 1 face masks at a plant in Warren, Michigan. Photo by John F. Martin for General Motors

The mask production is being done by paid volunteers, including hourly workers with the United Auto Workers union as well as salaried employees, in two 10-hour shifts a day. Some of the process uses repurposed materials and machines that the automaker utilizes in auto production, including the material from an insulation supplier, a line-feeding and cutting machine and scanners used for quality control.

Making the masks

The face mask production process begins with the thin material on large spools being fed into a machine that welds three layers of the product into one; crimps the front of the masks; and inserts its metal line, or nose wire. The machine then cuts the fabric and spits the masks out faster than an ATM machine dispensing bills.

Face masks are cut by a machine and spit out faster than an ATM machine dispensing bills. The machine ultrasonic welds three layers of the material into one, crimps the front of the masks and inserts the metal line, or nose wire, in the mask. Michael Wayland | CNBC

A worker at the end of the line does a quick product check, followed by a more in-depth inspection at another workstation. At full speed, the machine can produce 40,000 per shift, according to Portugaise. From there, the masks are lined in small plastic bins and workers laser weld the ear loops onto the masks, which is one of the most labor-intensive parts of the process. Currently, employees have to spot weld all four corners individually by hitting a foot pedal, somewhat like a sewing machine operates, on the floor. A light indicates when each weld is done. Soon, the company hopes to be able to do two welds at once with new machines that are still being tested.

A GM worker laser welds the ear loops onto the face masks, which is one of the most labor-intensive parts of the process. Michael Wayland | CNBC

To encourage employees to work quickly, each person receives a metal cog for every 100 masks the complete on a shift. Portugaise said the double welding machines should significantly increase welding production. Some workers can produce as many as 300 masks in one hour, he said. There's another quality check for each batch of 100 masks, which are then stored in sterilization boxes or rooms. Some of the sterilization units were donated by the Philadelphia Flyers, Chicago Blackhawks and an equipment manager for the Detroit Red Wings. The machines are typically used to sterilize equipment in hockey. Once sterilized, 10 masks are placed in a bagging machine that also puts instructions and precautions with GM's logo on the bags for shipping.

Once the face masks are sterilized, they are placed placed in groups of 10 into a bagging machine that also puts instructions, precautions and the GM logo on the bags for shipment. Michael Wayland | CNBC

The face mask production is one of the efforts GM has committed to during the coronavirus pandemic, which has shutdown its U.S. manufacturing operations since mid-March. GM is manufacturing other personal protective equipment, including latex-free face shields, protective gowns and aerosol boxes. It's also producing critical care ventilators, in partnership with Washington-based Ventec Life Systems at a plant in Kokomo, Indiana. The automaker expects to produce about 600 ventilators by the end of this week, according to GM's Johnson. He said the company is on track to deliver 30,000 ventilators for the national stockpile by the end of August. "There's a mixed emotion. Obviously no one's happy about Covid-19 virus and many lives are being affected by it and were concerned about everybody's health and well-being," Johnson said. "Similarly though, I am extremely proud of what I see the teams pull together here in amazing timeframes … That's been inspiring."