34 processing & packaging

Optimising high-speed shrink wrapping of frozen pizzas

Palermo’s Pizza’s high-speed shrink wrapping line is capable of side-sealing 150 frozen pizzas per minute with consistent high quality seals and near zero defect rate – 50% faster throughput than conventional side-seal frozen pizza shrink wrap lines.

Frozen pizza remains one of the intact during wrapping. These method is that pizza toppings will most ubiquitous foods in the ingredients tend to shift around frequently fall underneath where typical American household. and fall to the bottom of the shrink the seal is being made, and Convenience, low price and a bag before sealing. compromise the integrity of the continually growing assortment of Additionally, frozen pizza being a seal. When the wrapped pizza options have made frozen pizza a low profile product has a high comes out of the tunnel, the lap favourite heat-and-serve choice capability for shingling while seal can be loose or open, but it is for households constrained by time travelling back-to-back on the very hard to detect. Usually it is and budgets. infeed conveyor before entering the customer who discovers that the pizza According to the American Frozen the wrapper. Shingling prompts they purchased has not been secu Food Institute, 66% of households poor infeed registration, resulting rely sealed. in the United States consumed in missed flights, double product To achieve a better quality seal on frozen pizza in 2010. With total bagging and broken crust. When frozen pizzas, food processors sales reaching US$3.2 billion running at high speeds, such as have utilised continuous motion (USD) in that year, this accounts 100 pizzas per minute, most infeed side-seal shrink wrappers. These for almost 10% of US mass-market systems cannot consistently systems allow a continuous frozen food sales. The US is the maintain accurate indexing with incoming stream of pizzas through largest frozen pizza market in the the shrink wrapper. the wrapper while a side-seal is world, representing approximately generated, followed by an end seal 43% of global market value. which separates each package Consequently, many Shrink wrapping challenge before entering the shrink tunnel. frozen pizza producers Because the seal is being formed Keeping up with the demand for have opted for lap seal on the edge of the pizza, rather this very popular consumer wrappers to achieve the than across the bottom, the product can be a challenge for higher throughput, danger of loose toppings food processors. Not only contaminating the seal area is because of the high throughputs despite the loss in seal eliminated, resulting in a much required, but because frozen pizza quality more reliably sealed package. can be a difficult product to package. Few frozen food Conventional continuous side-seal wrappers, however, have a limited products require more careful The conventional machinery speed range. They are useful up handling through the packaging employed for high-speed shrink to about 100 pizzas per minute process than pizza. And nowhere wrapping of frozen pizzas – at the throughput, above that and their in the packaging cycle is this more rate of 100 to 150 pizzas per quality output diminishes. critical than in shrink wrapping. minute – typically uses lap seal Consequently, many frozen pizza technology for sealing the shrink Automated shrink wrapping of producers have opted for lap seal bag. The lap seal method wraps frozen pizzas has long presented wrappers to achieve the higher the film around the pizza as it goes significant challenges for food throughput, despite the loss in through a forming shoe, then it processors. Delicate handling of seal quality. these frozen pizza pies is required overlaps the film on the bottom of Palermo’s Pizza’s high-speed, to keep the sauce and loose the pizza, static sealing it before side-seal wrapper line toppings like pepperoni, going into the shrink tunnel. A mushrooms, sausage and cheese key problem with this sealing Now, a new generation of

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continuous motion side- seal shrink wrapper for frozen pizzas provides the benefits of a secure seal combined with a high- Palermo’s is an throughput capability. innovator in the frozen Palermo’s Pizza is one frozen pizza pizza category, creating manufacturer that is utilising this the industry’s first self- shrink latest continuous side-sealing wrapper technology. rising frozen pizza and and shrink Based in Milwaukee, Wisconsin, its first ultra-thin crust tunnel, then on to Palermo’s Pizza was started by product labeling and cartoning. The Sicilian immigrants Gaspare and product is then cased, palletised Zina Fallucca who opened an and sent off to shipping or deep Italian bakery on Milwaukee’s east The popularity of these brands has freeze storage. side in 1964. The bakery expanded made Palermo’s one of the fastest “We have been experiencing into a full-service restaurant known growing manufacturers of frozen continued growth at a double-digit for its pizza, and by 1979 they pizzas in the United States. To rate every year,” says Mike Walz, began to manufacture and sell meet the demand for its products, Vice President of Operations for frozen pizzas based on their the company recently expanded its Palermo’s Pizza. “As we grew and family’s traditional Sicilian recipes. headquarters and manufacturing the demand for product went up, it facility. Opened in 2011, its new Palermo’s is an innovator in the generated a need for us to operate 250,000 square foot state-of-the- frozen pizza category, creating the at a higher level of speed to meet art USDA manufacturing plant is a industry’s first self-rising frozen the demand.” showpiece of packaging pizza and its first ultra-thin crust “The challenge that we were technology, operating four product. It manufacturers a family facing as we tried to push our line packaging lines for handling its of frozen pizzas under the speeds up was the ability of our frozen pizzas. But, central to Palermo’s brand including products existing lap seal wrappers to run at Palermo’s packaging operation is such as Primo Thin™, Naturally the higher rate of speed, and its main packaging line, for Rising™, Stone Baked™ and provide a reliable seal,” continues handling its top-selling 12-inch Classics by Palermo’s™. The Walz. “The lap sealers use a static frozen pizzas. company continues to research and sealing process. It is an overlap develop new products and flavours Prior to reaching that packaging on the bottom of the pizza. that cater to consumer needs, such line, sauce and toppings are Sometimes we would lose that as its recent introduction, deposited onto dough to form the seal, and in the shrink tunnel that Palermo’s Hand Tossed Style™, pizzas which are then put through would open up. That tended to be which features ‘family-favourite an ammonia-based spiral freezer. limiting factor when running at flavours’ on a middle-thickness Exiting the freezer, the now frozen higher speeds.” pizzas are conveyed through the crust. “On our main packaging line we

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were using a lap sealer that was operating at less than 90 12-inch pizzas per minute,” explains Walz. So, we embarked on a project to increase the line rate on that line first. After reviewing several shrink wrap designs, we settled on one system that could be custom configured to meet our specific needs, instead of adapting to an existing format.” Texwrap The system that Palermo’s selected is a high-speed, continuous motion, servo- controlled side-seal shrink wrapper, from Texwrap, a leading designer and manufacturer of fully- automatic shrink wrapping systems. What makes this system so unique is its utilisation of multiple technologies which are integrated into one system architecture, enabling high-speed throughput of up to 150 frozen pizzas per minute with consistent high-quality seals and without damage to the fragile pizza products. The throughput speed of the wrapper is achieved by the sealing head, which is a patented servo orbital-motion technology. It eliminates the need for the head to move with the product while the seal is being made. The sealing head moves in an ellipse, without the back and forth motion of typical sealing heads, which dramatically increases the throughput speed of the wrapper. with a product protection system The side-seal on this which ensures that the orbital The orbital head is controlled by system uses the head will not close down on any very fast and precise servo patented Green pizza. A sensor maps the position motors, as is the entire wrapper of each pizza as it enters the Machine technology and infeed. The system is built orbital head operating space, and invented by Shrink with Generation 3 servo knows when a pizza is misplaced, Packaging Systems technology, meaning that it was skipping that seal cycle. designed from the ground up to Corp integrate servo technology, PLC “We tested the wrapper at 180 control and the mechanical pizzas per minute,” Walz says. elements of the system. The faster than the maximum 90 pizzas “This is very fast throughput. But system’s 10-axis servo controls per minute with our prior lap it performed as expected, with provide extremely accurate sealer.” accurate registration and secure registration, minimi ze the amount Side-seal design seals, and no product damage. On of film used for wrapping, and a continual basis, we normally Sealing film securely at such reduce the need for maintenance. operate the system at 120 –140 extreme speeds requires a very Palermo’s wrapper is equipped pizzas per minute, considerably special side-seal design. The side-

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seal on this system uses the convection tunnel, equipped with that not only met our design patented Green Machine digital temperature controls, high specifications, but exceeded it,” technology invented by Shrink velocity fans, individual top and continues Walz. Packaging Systems Corp. During bottom controls for air direction, In the highly competitive frozen sealing, belts grip the film securely and variable-speed conveyors. pizza market, high volume over a long distance allowing the These features control the right production with near zero defect seal to be made on the pizza and amount of heat to be put in the rates in packaging is critical to the trim to be cleanly separated. A right places, over the correct profitability. Those manufacturers special heating element seals and amount of time to produce that embrace advanced shrink separates the film between them. consistent shrink results. wrapping technology to streamline The system is self-compensating. packaging throughput will be in a As wrapper speed increases, the What began as a small better position to run efficient film stays in contact with the ethnic bakery in 1964 manufacturing plants and reduce heating element longer, eliminating operating costs. the need for constant adjustment. featuring authentic About Palermo’s Pizza Because the film-gripping belts Italian pizza has allow the tension on the film to be Palermo’s Pizza is a brand of become a leading name frozen pizza manufactured by isolated from the sealing process, in the frozen pizza the result is consistent seals using Palermo Villa Inc. of Milwaukee, the absolute minimum film width. industry Wisconsin. The company has been In addition to superior control of making quality, Italian style frozen the elements needed for great pizzas since 1979. What began as a small ethnic bakery in 1964 seals at speed, the other The heat tunnel incorporates a featuring authentic Italian pizza advantage of Green Machine feature called Seams Down, which has become a leading name in the technology is that its simplicity ensures that the side-seal seams frozen pizza industry. virtually eliminates the do not position over the printed maintenance associated with most circular label on top of the pizza. Palermo’s frozen pizzas are side-seal designs. When shrink wrapping pizza, the available at grocery stores and big The infeed is optimised, as well, for seam can potentially climb up past box retailers in almost every state. maximised throughput and careful the center top of the pizza and The company also distributes its product handling. A Texwrap- obscure the label on the top. By pizza products in Canada. designed lane-combining system directing the air inside of the About Texwrap Packaging takes three lanes of pizzas exiting tunnel to make the film on the Systems the freezer and consolidates them bottom of the pizza shrink before Texwrap is the leader in the design into one lane. Then, a servo-driven the film on top, this condition is and manufacture of fully-automatic flying nose bar is programmed to avoided. shrink wrap systems for many not only place the pizzas inline at a Palermo’s entire infeed and shrink industries including food and set spacing without touching each wrap system is designed to be beverage, pharmaceuticals and other, but also to automatically sanitary-friendly. Rated for heavy printing. An industry innovator, adjust the speed of the entire line wash down, the corrosion- Texwrap holds patents on some of to match incoming production. resistant, welded stainless steel the most significant breakthrough This ensures that pizzas do not design eliminates crevices and technologies in the shrink shingle, keeping toppings and areas where food could collect. wrapping industry. Its full line of crusts intact, which is critically The conveyors incorporate quick- standard wrappers include L-bar important at throughput rates of disconnect removable sections for sealers, continuous-motion side- 150 pizzas per minute. Following, easy cleaning, and fall-through sealers, intermittent-motion a lug conveyor automatically design so food debris will not get side-sealers and lapsealers, as inserts a cardboard circle trapped. well as tunnels, conveyors and underneath the pizzas, and indexes Performance infeeds. I the product into the wrapper. “Knowing the inherent design of The wrapper’s infeed is a totally both the static lap seal and the integrated system that self-adjusts continuous motion side-seal, the to incoming production. As the speed and the quality of the seal pizzas slow down or speed up, so is tremendously improved with the Jim McMahon does the entire wrapping system. continuous system,” explains Director To support the shrink wrapper, Walz. Zebra Communications www.zebracom.net Palermo’s installed a Texwrap “We were able to get a shrink triple-chamber forced air wrap system on our primary line

www.foodmagazine.eu.com issue three | 2013