Automated deburring: Safe and round

Figure 1
The deburring machine can accommodate multiple parts across its 59-in.-wide opening.

Brian Lone’s description of just what is fabricated at JBT FoodTech’s Sandusky, Ohio, factory might sound familiar to some job shops. For a manufacturing facility dedicated to building food processing equipment, its production lineup still runs the gamut.

One day fabricators could be working on a 40-foot-long fryer. The next day it could be a freezer as large as a garage. JBT FoodTech even builds a machine that uses waterjets to cut food into proper proportions.

No matter the type of equipment made, however, it is all fabricated from stainless steel. Federal food guidelines demand it.

So the company works with a lot of gauge-thickness stainless steel sheet, which is cut on a laser cutting machine.

“We aren’t happy with the sharp square corners that a laser leaves,” Lone said. “It’s not so much of a dross issue, which was an issue at one time. We just don’t want anyone getting cut.”

Eliminating the sharp corners was a simple goal, but one that proved fairly daunting for the shop floor.

Throwing People at Deburring

For several years JBT FoodTech relied on a team of fabricators using pneumatic sanding tools to deburr all of the parts. The skilled hands turned out quality work, but that was not destined to last.

Like many other U.S. manufacturers, the food equipment-maker was hit by a wave of retirements in 2013. Lone said they lost five skilled workers during that year.

Good tidings for the new retirees quickly turned into bad news for the shop floor. The remaining fabricators, which numbered from eight to 10 depending on job assignments, had to balance deburring and machine operation responsibilities. They were needed to push parts through the press brakes, but those laser-cut parts with burrs—which could be as small as 2 by 9 in. and as large as nearly a full sheet—were stacking up in the corner, waiting for someone to grab the portable sander and go to work.

Temporary employees were assigned deburring, but their lack of experience led to rework.

Figure 2
The machine deburrs and rounds the edges but does not mar the parts’ stainless steel surface or tear off the protective sheet found on some parts with critical cosmetic requirements.

“What would happen then is that everybody’s idea of what deburring was would cause problems. It’s so subjective,” Lone said. “We would get parts that were overdeburred and underdeburred.”

The amount of people involved in the deburring operation was getting hard to stomach as well. Six people worked to remove burrs on the first shift, and three people continued the task on the second shift.

Going the Automated Route

Lone said that he investigated machine tools that could automate the deburring, but the search got more serious in the latter part of 2013. Management realized that something had to be done to lighten the load on the Sandusky fabrication department.

Lone’s Internet research took him to a video that showed LISSMAC equipment. What caught his eye was the fact that he could put a part on one side and both the part’s top and bottom would be addressed simultaneously. An operator wouldn’t have to retrieve the part as it exits the machine, walk to the other side of the machine, flip the part over, and feed it through again.

The Sandusky team reached out to LISSMAC and shortly thereafter the machine was installed near the company’s laser cutting machine. The SBM-L deburring and edge-rounding machine was up and running in February 2014 (see Figure 1).

It has an abrasive belt that runs across the parts as they feed into the machine. The belt provides the sanding action that removes any dross that may result from the laser cutting process.

The next stage is two rows of edge-rounding blocks that run across the parts. In this instance, the abrasive blocks round off internal and outside edges.

“The parts are running through a combination of table rollers and feed rollers with openings in between. The cross belts are working through the openings on both the top and bottom,” said Ingo Heiland, LISSMAC vice president.

Lone said that a less experienced individual is now assigned to deburring. He takes the laser-cut parts from a skid and processes them through the machine. He then collects them and places them on skids destined for bending or whatever downstream process comes next.

The rest of the fabricators that used to be tied up with deburring have been reassigned throughout the shop. Two graduated to become full-time assemblers as they had the skills to help there, Lone said.

“We moved them to other areas of the shop in better locations for us,” he said. “They are in locations where they can use their skills.”

The deburring machine’s performance has met expectations as well.

According to the way that JBT FoodTech tracks production efficiency, the deburring area was lucky to hit 40 percent efficiency when it was operating the hand tools. Today they are routinely surpassing original production goals for the department, Lone said.

“In eight hours of work, [a machine operator] is doing about 26 hours’ worth of labor. That’s a fact—day by day,” he said.

While performing the necessary deburring and edge rounding, the machine is not marring the parts’ stainless steel surface (see Figure 2). A majority of the parts have a No. 2B finish, which is reflective but somewhat cloudy, and they maintain that same look after they exit the deburring machine.

The machine also leaves vinyl part identification labels in their place as the parts are processed. The labels are designed to come off with some gentle effort, yet they are able to withstand the machine’s grinding and edge-rounding action.

Looking back on the equipment’s performance, Lone said he wishes that it had not taken so long. It would have saved a lot of hard work that, frankly, no one was really excited to do.

“No one wanted to do it. The poor finisher. Everyone looked at deburring as a sort of punishment for the day,” he said.

That’s a statement any fabricator can relate to, especially if they have had to do the deburring themselves.

JBT FoodTech, 1622 First St., Sandusky, OH 44870, 419-626-0304, www.jbtfoodtech.com

LISSMAC USA Corp., 356 Hudson River Road, Waterford, NY 12188, 518-326-9094, www.lissmac-corpor ation.com