Small packages have become big business for Severance Foods, a
manufacturer of private-label tortilla chips in Hartford, CT.
“One-ounce bags are new for us, and our previous machines couldn’t
handle that size,” says Severance Foods president Richard Stevens. The
company needed a vertical form/fill/seal machine capable of higher line
speeds to handle a range of sizes from 1-oz to 2-lb bags.
Stevens also needed a machine that could produce consistent
seals—something he had experienced problems with in the past.
“Sometimes the seal wasn’t strong enough, or there might be a ripple or
tear in it,” he explains. “Also, if the package wasn’t tracked
correctly, the graphics weren’t centered on the bag.”
Double time
Severance Foods purchased a robag 3-RSJ 320 from tna (www.tnarobag.com)
as part of an investment in a new 1,500- lb/hr chip line. The new line
plus the company’s existing production line and bagger doubled capacity
to 3,000 lb/hr.
Severance Foods chose the robag primarily for its flexibility, says tna
regional sales manager Toby Steward. “As a contract packager, they need
to run a wide range of packages,” he says, “and they never know what
they may need to do in the future as they get new customers.”
The machine fills the new 1-oz bags with ease using partial tube
technology. “When you run a small bag, you’re generally running the
same size corn chip, so it’s harder to get it into the small bag,”
explains Steward. Typically, a bagging machine’s forming collar shapes
the film into a round tube, and a solid metal tube is used inside the
forming tube to convey the product to the bag. However, the metal tube
can eliminate 15% to 20% of the space available for product to fall
through, he says. The robag foregoes the solid metal tube, thereby
creating a larger opening in the forming device that allows the chips
to fall into the smaller bags more efficiently without blocking the
tube.
The robag runs larger bags at 15 to 20 bags/min and 1- to 2-oz bags at
70 bags/min. “Before, we had a top speed of about 40 bags per minute on
the previous bagger, no matter what size the bag was,” says Stevens.
In addition to sufficient line speeds, Stevens wanted a machine that
was simple to operate. “We wanted something that was gong to be easy
for us to train additional operators on so that when it came time to
add additional machines, the learning curve would be shorter,” he says.
“The training takes about a quarter of the time it would take to train
a person to run the previous machine.”
Better seals, less waste
The robag’s rotary jaws and built-in controls for functions such as
film tracking and sealing temperatures produce a more attractive
package with consistent seals, says Stevens. As a result, the company’s
reject level is much lower than it was on previous bagging machines.
Stevens estimates that waste has been reduced from about 4% or 5% on
previous machines to 1% or 2% using the robag. “There were a number of
issues that affected the quality of the bag itself,” he says. “Some
loss was due to roll changeover, or the film going off track, or a
change in seal temperature resulting in an improper seal.”
The robag also has gas-flushing capabilities to increase shelf life—a
new requirement from some of Severance Foods’ customers. “As the chips
go into the bag, nitrogen is blown into the bag to displace oxygen,”
explains Stevens. “The environment in the bag is about 2 percent oxygen
to reduce the rancidity of the oil and provide a longer shelf life.”
Severance was so pleased with the robag’s performance that the company
bought a second unit to replace the bagger on its older production
line. The new machines also required the installation of a conveyor
system from PPM Technologies (www.ppmtech.com) to transport chips from
the production line to the baggers.
As more customers request smaller and smaller bag sizes, Severance
Foods is strongly considering buying a third robag with higher line
speeds and a scale system that has smaller buckets. “We’ve seen minimal
breakdowns, and downtime has been reduced,” says Stevens of the robags.
“Another
benefit is a reduction in scrap of 2 percent to 3 percent. It makes for
a nicer-looking package. Other machines require more human intervention
to keep temperature and alignment correct. The robag takes a lot of the
human factor out of that.”
