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Checkweighers solve a sticky bagging problem

Article-Checkweighers solve a sticky bagging problem

Versatility is American Foods' raison d'être. At its take-on-all-comers operation in Methuen, MA, this private-label confections repacker prides itself on the range of its packaging capabilities.

It has even more reason to crow these days. Since installation of a fast, highly accurate packaging line in December, the company is stylishly showing how to optimally organize the movement of bulk to retail quantities in presentations that clearly tempt consumers.

These transparent, oriented polypropylene pouches, fully decorated and die-cut online for hang-alone or header display, are the best the company has ever put out in terms of quality, safety, exact weight and appearance, American Foods' plant manager Jim Gilet tells PD. "There are no underweights, and giveaway is now minimal for the pouches sold under the labels of supermarket and drug chains and some others," he says.

Gilet is especially impressed by equipment performance, since a large part of the products aren't just unit-wrapped pieces but also gummies, which tend to stick together under pressure and the least bit of elevated humidity.

The problem's solution is only feet from the new twin-tube vertical form/fill/seal machine handling these products: a pair of Lock Inspection Systems' newest ultra-sensitive CE 500 checkweighers that the supplier set up in combination with its metal detectors to screen out contaminants. Checkweigher accuracy to a single gram is maintained, even when the f/f/s machine, Barry-Wehmiller's Hayssen Ultima® ST, is feeding pouches into a conveyor at a combined 130/min rate.

With this level of accuracy, gummies that stick to each other because of pressure in the feeder cups and stay together through the pouching process are detected and rejected when they gain too much weight for the 2?-oz quantity that forms the bulk of line output. Gummies that get hung up in the feeder cups and bring about underweights also result in pouch rejection.

Posted immediately beyond a twin-tube f/f/s machine, the metal detector and checkweigher combination handles pouches at a 130/min rate.

Product movement through the f/f/s machine is tightly monitored by an Allen-Bradley 5/04 programmable logic controller, with consistent performance maintained by the Ultima's maintenance alert and prevention system. As the product is automatically staged for flow into either tube, the film is decorated by a pair of Markem 2i/100 SmartDate® thermal-transfer coders with a 4.2 x 2.8-in. print area and a more than adequate 650-print/min rated output.

Also simplifying the packaging process is a universal film, a transparent adhesive lamination combining two 1-mil layers of OPP, produced by Ultra Flex. The film is resistance-sealed and hole-punched by the Ultima machine. One advantage of the film and sealing choices is that they allow consumers to open the pouches without random tearing.

Close proximity to checkweighing
As the pouches feed out of the f/f/s machine onto a conveyor, they are checked for metallic contaminants by Lock's MET 30+ detector. In close proximity–less than 3 ft downstream–is its CE 500 checkweigher.

This newest-model machine not only reduces giveaway and underweights, but it also maintains a wide range of production statistics to monitor and improve efficiency. Each motor is variable-frequency-controlled, enabling setup of up to 100 different line rates to be stored for instant recall–necessary with the wide range of pouch sizes up to 24 oz.

Built to NEMA 12 standards on a 316 stainless-steel frame, the checkweigher uses a pair of Motorola 32-bit processors for real-time, rapid and accurate operation during the two-shift days the line presently functions. And, it maintains its 1-g accuracy at a rated 300/min output. It is supplied network-ready for connection to the host PLC.

Following checkweighing, the approved pouches convey onto an accumulating table for manual loading into shippers. These are RSC corrugated boxes made to a variety of specifications by Key Container. They are erected at a 42/min rate by a pair of Loveshaw's Little David Model 540 machines that work in conjunction with a FoxJet Marksman® with an UltraJet® printhead, acquired through Hill Packaging.

This system, engineered with a Windows interface and including BoxWriter™ text editor software, gives the company tremendous flexibility in fully identifying products in the shippers while carrying customer identities into retail environments.

Completing the packaging operation, filled and identified shippers are taped by a 3M taper and are manually packed off for palletization. "The total procedure is very clean, neat and free of problems," Gilet says. "And, it's very satisfying to see the line working the way it does."

The decision to buy the new packaging line, he adds, was very much based on favorable experiences with machines installed in Methuen earlier. "Our plant is only seven years old," he explains, "so we have earlier versions of Lock metal detectors and checkweighers working off three other single-tube Ultimas, including one that's servo-driven. We appreciate the fact that our equipment suppliers only make changes that will improve specific functions without a lot of nonsense."

And, with the newest installation, it keeps getting sweeter at American Foods.

More information is available:

Metal detector/checkweigher: Lock Inspection Systems, 978/343-3716. Circle No. 224.

F/f/s equipment: Barry-Wehmiller Cos., 314/862-8000. Circle No. 225.

PLC: Allen-Bradley, 414/382-2000. Circle No. 226.

Coders: Markem Corp.,800/421-9698. Circle No. 227.

Film: Ultra Flex, 401/783-6935. Circle No. 228.

Shippers: Key Container, 401/723-2000. Circle No. 229.

Box erectors: Loveshaw, 800/572-3434. Circle No. 230.

Printers: Foxjet, 800/369-5384. Circle No. 231.

Printer representative: Hill Packaging, 603/898-4750. Circle No. 232.

Taper: 3M Co., 800/328-1681. Circle No. 233.

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