Quality assurance, one pizza at a time

Great Kitchens, one of the largest private-label manufacturers of frozen pizzas in the U.S., specializes in the growing “take-and-bake” pizza market where product quality sets them apart from the competition. To ensure that only the highest quality product reaches customers, Great Kitchens relies on PowerPhasePLUS metal detectors from Mettler-Toledo Safeline (http://www.mt.com/safelineus) on each of its packaging lines.

PowerPhasePLUS metal detectors incorporate an advanced coil design for enhanced sensitivity to zero in on all types of contamination, from common ferrous and nonferrous tramp metal to the most difficult-to-detect stainless-steel fragments. If metal is detected, the system automatically rejects the “bad” product without slowing or stopping the line production line. Operating two production shifts and one sanitation shift per day, five days a week, Great Kitchens produces between 32,000 and 50,000 pizzas per day on each of four production lines. The throughput depends on the size of the pizzas—smaller pizzas are produced more quickly. The pizzas are manufactured fresh and cryogenically frozen. Then they are shrink wrapped and passed through the metal detector before being packed in retail cartons.

During the production shifts, Great Kitchens keeps the room at 45 to 48 deg F. During the sanitation shift, the high-temperature, high-pressure washdowns cause the temperature and the humidity in the room to soar. To operate reliably, the metal detectors must handle both temperature extremes. They must also be water-tight so the electronics are not compromised during the washdowns. Featuring an IP69K-rated control panel, the PowerPhasePLUS metal detectors exceed NEMA 4X specifications.

To maximize detection sensitivity while virtually eliminating false rejects, Safeline developed a “Faraday Screen” that is placed between a detector coil system and the product being inspected. This screen filters out certain signals and unwanted frequencies that can interfere with normal plant operations, such as two-way radio communication.

“We measure the success of our metal detectors based on the consistent verification of detection sensitivity as well as equipment uptime,” notes Jim LaRocco, vice president of operations at Great Kitchens. “We are very happy with the reliability of the Safeline metal detectors to operate dependably in our cold environment and to handle our hot water washdowns.”

“I've been working in the food industry for fifteen years, and I've used many different metal detectors during that time,” notes Roberto Giuliano, quality assurance director at Great Kitchens. “Nothing compares to Safeline metal detectors—especially in a challenging environment like ours. The PowerPhasePLUS is a workhorse.”

With the growing popularity of take-and-bake pizzas and Great Kitchens' success in winning and continually satisfying major national accounts, the company is experiencing double-digit growth. “The Safeline metal detectors give us the versatility to continue to increase our production throughput while maintaining high quality assurance,” says LaRocco. “From a maintenance standpoint, they are easy to keep up. From a reliability standpoint, you couldn't ask for more.”

Great Kitchens currently manufactures pizzas in three different sizes—12, 14 and 16 in.—and the production lines are changed over to handle the various products. Changing over the metal detectors is achieved in minutes by recalling the preprogrammed setting via a touchpad; no mechanical adjustments or change parts are needed.

To maximize production flexibility, the metal detectors are designed to operate at multiple frequencies.

To maximize production flexibility, Safeline designed the PowerPhasePLUS metal detectors to operate at multiple frequencies to automatically accommodate variations in product specifications. “With multiple frequencies, Great Kitchens can inspect either fresh or frozen product,” noted Steve Stark, sales representative for Westlake, Inc., who introduced the Safeline detectors to Great Kitchens. “Currently, they are inspecting only frozen product, but the multiple frequencies give them the flexibility to do both in the future.”

“The metal detectors are one of the critical control points in our Hazard Analysis and Critical Control Points plan. To ensure that the detectors are performing to our high standards, we test each one every fifteen minutes to verify sensitivity,” notes LaRocco. “An additional layer of security exists with these detectors because they require an access code that prevents unauthorized adjustments.” The operator code permits line operators to change the product category used during a product changeover. The supervisor code permits complete adjustment of setup parameters such as the setting of sensitivity. The engineer's level provides complete access to all technical parameters.

“We are so confident with Safeline, that we've recommended them to our raw-material suppliers to ensure we collectively maintain the highest levels of quality and food safety,” concludes LaRocco.

More information is available:

Mettler-Toledo Safeline, 813/889-9500. http://www.mt.com/safelineus