Photo Gallery Chattanooga firm to help U.S. Navy figure out how to 3-D print explosives View 5 Photos

The U.S. Navy wants to be able to buy an off-the-shelf 3-D printer and use it to print explosives.

A huge coffee facility in New Orleans used to overfill coffee cans by about 8 percent, which wasted money. But since the plant's process was hard to predict, the coffeemaker didn't want to shortchange customers.

Pharmaceutical companies need just the right amount of active ingredient mixed with filler in the pills they produce — or face drug recalls.

So who are they going to call?

E&G Associates, Inc., a Chattanooga consulting business with five engineers (including a father and his two sons) and two laboratories jam-packed with $2 million worth of measuring equipment — much of which the engineers built themselves. It's on the third floor of the INCubator, the Hamilton County Business Development Center at 100 Cherokee Blvd., on Chattanooga's North Shore.

E&G's expertise is handling bulk solids — think coffee beans — and powders, such as those used to make pills.

That's lost knowledge to many chemical engineers, said Bryan J. Ennis, the "E" of E&G Associates. He's the company's president and a retired civil and chemical engineering professor at the University of Tennessee at Chattanooga.

U.S. engineers are schooled in liquids and gases — but not solids, even though 60 percent of all U.S. manufacturing involves solids handling — he said, because of the oil and gas industry's dominance here.

"Europe's different; they're driven by coal," Ennis said.

Solid knowledge

So E&G's consultants fill the niche.

They know that you can't just get a sledgehammer and bang on the side of a hopper to get the coffee beans flowing again.

"One of the rules is, you never vibrate a solid — unless it's moving," Ennis said.

E&G's engineers measure such things as friction between coffee beans (which varies depending on the beans' oil content). E&G's labs can take more esoteric measurements, too, such as determining particle size through laser diffraction, finding a particle's "skeletal density," and measuring a powder's surface area.

Once E&G's engineers learn the properties of a particle or powder, it can tell a client like the New Orleans coffee plant how to angle the funnels that empty the six-story-high hoppers that hold coffee beans. E&G also can say what material the hoppers should be built from, such as stainless or carbon steel.

"There is no perfect hopper that will handle every material," said Brandon Ennis, a project engineer at E&G who works alongside his father, Bryan, and his brother, Benjamin Ennis, another project engineer.

E&G was founded decades ago, but wasn't doing much until two years ago, when Brandon and Benjamin revived it as a startup company.

The firm's other two project engineers are Michael Winn and Nasseem Jibrin. E&G's four young engineers are recent graduates of UTC's engineering program.

E&G says it helped the New Orleans coffee plant reach 1 percent accuracy filling its coffee cans, and E&G works with the coffeemaker on an ongoing basis.

Hourglass tells the story

To help clients visualize solids handling, the engineers at E&G Associates use hourglasses that contain a mix of salt and poppy seeds.

Hold up one end of the hourglass and the salt and poppy seeds separate.

That's called "funnel flow" — and it's what you don't want if you're a coffee maker that wants a consistent blend of ground coffee. Separation of ingredients also is bad if you're a pharmaceutical company looking for pills with consistent amounts of active ingredient.

Flip over the hourglass, and the salt and poppy seeds blend together in what's called "mass flow." That's good for making a consistent coffee or medicine.

The angle of the funnel walls inside the hourglass walls mean the difference between funnel flow and mass flow.

E&G recently won a $150,000 federal grant to help the Navy figure out how to turn plastic explosives into a nylon powder that can be fed into an off-the-shelf Hewlett Packard 3-D printer to make explosives charges of varying shapes.

No explosives are being tested in Chattanooga. That's being handled in partnership with the mining and explosives program at the Missouri University of Science and Technology in Rolla, Mo.

While the INCubator is home to other startup companies focused on 3-D printing, such as Branch Technology and Collider, E&G Associates, Inc. is different in that it doesn't need outside investors.

It has "bootstrapped" itself and pays the bills through its consulting work.

Now, the company gets all the work its five employees can handle. The Ennises are happy with that and don't have immediate plans to expand.

Contact staff writer Tim Omarzu at tomarzu@timesfreepress.com or www.facebook.com/MeetsForBusiness or on Twitter @meetforbusiness or 423-757-6651.