Optimising High-Speed Shrink Wrapping of Frozen Pizzas
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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 www.foodmagazine.eu.com issue three | 2013 processing & packaging 35 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 www.foodmagazine.eu.com issue three | 2013 36 processing & packaging 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.