The number of unfilled U.S. manufacturing jobs will swell to 2.4 million in a decade unless aggressive recruiting and training begin now.

That was the message Monday from industry leaders who stopped at Protolabs' factories in Plymouth and Brooklyn Park and Graco in Minneapolis as part of a 25-city State of Manufacturing Tour spearheaded by the National Association of Manufacturers (NAM).

"We are kind of on a recruiting mission," Jay Timmons, CEO of NAM, told forum guests at the new Protolabs factory in Brooklyn Park. "Today we have about 428,000 open jobs in this country. That's a lot of openings [and] we can't find enough people to fill those jobs."

The numbers will worsen if nothing is done to interest more young people in skilled manufacturing jobs, said officials. NAM represents 14,000 manufacturing operations.

"Manufacturing is obviously a huge part of the economy in the U.S.," said Carolyn Lee, executive director of the Washington-based Manufacturing Institute and a panel member. "But there is no place we go where we don't hear that companies are desperate for skilled workers. A baby boomer retires every 10 seconds."

Timmons and the rest of the traveling group are trying to highlight "the next frontier" of manufacturing as they travel the country.

Factories today offer great pay, training, career advancement and the chance to work with technology, robots and sophisticated machine programs that produce quality goods efficiently, Timmons said.

"Protolabs deploys the type of advanced technologies that define modern manufacturing," he said.

But getting that message across to the public will take more work, he said. It will require factories to educate younger students about job opportunities and working conditions. And they will need to offer more internships and apprenticeships like Protolabs does.

And the industry still has work to educate the public on the type of jobs offered in today's factories. Many parents and young people still view factories as the grimy jobshops of decades ago, panelists said.

That misperception, Lee said, has parents pushing college-age students away from technical-college degrees that can give graduates multiple job offerings and salaries spanning $50,000 to $75,000 a year.

To showcase that reality, Protolabs CEO Vicki Holt, who also is NAM's regional vice chairwoman, gave a tour of the new Brooklyn Park facility to congressional aides and politicians, Dunwoody College of Technology students and Chamber of Commerce officials.

"We're excited to be part of this event to provide an up-close view of what manufacturing looks like today, how this digital evolution benefits product developers and how this tech-enabled manufacturing landscape is creating new opportunities for workers," Holt said.

She led the group, which included Minneapolis Mayor Jacob Frey, through the pristine operation with 270 CNC (computer numeric control) milling machines grinding steel, aluminum or plastic into parts for customers around the globe. Each of the machines, she said, cost about $100,000 and is tended to by 225 employees.

"Protolabs is a pioneer in digital manufacturing," and is growing dramatically, Holt said. "Five years ago, we had 750 employees. Today we have 2,700."

The company will add another 650 workers in 2019, she said.

The group of national manufacturing officials last week toured Protolabs' 3-D printing plant in Raleigh, N.C. In coming weeks, the group will be in Arizona, California, Iowa and Ohio.

"We are excited to tell [the industry's] story and the positive impact" it has on communities, Timmons said.

That message is needed, said E.J. Daigle, robotics and manufacturing dean at Dunwoody College. More firms must reach out to young people and let them know about the training, paid internships and tuition assistance that is available, he said.

"I'd prefer seeing these young folks working in apprenticeships and internships at Protolabs [and Graco] than at McDonald's and other retail and fast-food places," Daigle said.