By Melissa Hillebrand
When selecting a pan handling system, bakers should consider how pan life is preserved, as well as flexibility, reliability and efficiency.
Depanners are an important part of the pan handling system. Most depanners feature vacuum cups to remove bread and buns from their pans.
PHOTO COURTESY OF STEWART SYSTEMS
Pan handling is one of the most important functions in a bakery, yet also one of the most overlooked. It is easy for bakers to take for granted how their pans are stored and handled, given their concerns about ingredients, mixing and baking. However, pan handling is central to running an efficient plant and producing bakery foods.
The pan handling system is composed of pan stackers and unstackers, pan storage retrieval, depanners and washers and dryers. Preserving pan life is one factor bakers must consider before purchasing pan handling equipment. Bakers must ensure that pans are handled gently from unstacking to depanning to stacking. Other factors to consider include flexibility, reliability and efficiency.
A gentle depanning system is one way to ensure pan life. Given new premium pan bread varieties, it is important for depanners to preserve the quality of the bread and not damage the bread's toppings and structure.
Most depanners use a vacuum-based system to remove bread from pans. One manufacturer says it is important for the system to place a tight vacuum seal over the products, because if there is a tight seal, air does not blow into the pan and disturb the toppings. The manufacturer also recommends that bakers specify the size of pans they use, so the vacuum cups are properly sized.
Another pan handling manufacturer offers an innovative depanning system that is ideal for par-baked or soft breads, he says. In most vacuum systems, air is sucked in through the breads as they are being depanned, which can damage the bread. To prevent this type of damage, the manufacturer's system features a valve that opens in the vacuum chamber while the vacuum cups are turned on. Air is then drawn from this valve, instead of through the bread.
Pan stacking, unstacking
The beginning and end of a pan handling system is the unstacking and stacking systems. These systems must quickly and efficiently place pans on conveyors at the beginning of the line, and also remove the pans and gently place them in stacks for pan storage. These systems also efficiently handle automatic pan changeovers, and multiple pan sizes.
One manufacturer offers a stacking and unstacking system that accomplishes all these requirements. The system accommodates bread pans as large as 42 ins. long, 18 ins. wide and 5 ins. high. Bread pans are stacked as high as 60 ins. Bun pans must not be larger than 42 ins. long, 23 ins. wide and 2 ins. high. These pans are stacked at heights as high as 40 ins. The system also keeps noise below 85 decibels.
In this system, pans are fed, through the easy way (short dimension leading) or hard way (long dimension leading), from an infeed conveyor. The pans are then transferred to a magnetic rail, which allows for accumulation and pan control, the manufacturer says. On this rail is an electromagnetic thruster. This is a pneumatic cylinder with an attached electromagnet. The electromagnet, controlling the pans while they move off the magnetic rail, turns off within half of an inch from the stacks and places the pans on the stacks.
The electromagnetic thruster is quiet, gentle and accurate, the manufacturer says. As the stacks build, the system has an elevator system that lowers as the stack height increases. At about half of the stack height, the manufacturer says an A lift conveyor handles the weight of the stacks, instead of the elevator. The A lift continues to lower the pans as the height builds, and once the stack is at its full height, the A lift lowers to the bottom of the machine and discharges the stack to an exit conveyor. The stack then moves to a pan storage system or is stored on a conveyor for future use.
"The advantage of the A lift is that it allows the elevators to cycle around and be ready to create a new stack as soon as the full stack is finished," the manufacturer says. "They almost simultaneously lower that stack out of the way and start building a new stack right on top. That way we don't have any changeover time or delays."
The manufacturer says this system is easy to operate and reliable. The electromagnetic thruster rarely fails, he says, and the system has a photoelectric sensor that prevents pan or machine damage. The photo eye senses if a pan is off track and shuts down the machine, preventing further damage.
Another manufacturer offers a different option for pan stacking and unstacking. This system features a gantry-style robot. After pans are conveyed into the system, the machine performs a right-angle transfer to align pans the hard way. If the pans are already aligned, no adjustments are made. Pans continue to move into the system until the conveyor fills with pans. Once this happens, the robot picks up the pans and deposits them in stacks. The manufacturer says the robot can pick up as many as 28 pans at one time.
The gantry-style robot features mechanical fingers that pick and stack pans. There are four pneumatically operated fingers per pan. The fingers are mounted on sliding rods and close around the bar bands of the pans to lift and stack them. The manufacturer says the system handles any size of bread and bun pans.
An automated storage retrieval system is ideal for storing pans from the stacker and retrieving pans for the unstacker. This system generally can be programmed in conjunction with pan stacking and unstacking software, retrieving and storing pans when necessary. Most importantly, an automated storage retrieval system allows for continuous pan handling.
One pan storage retrieval manufacturer offers an automated system that features a shuttle system. When called, the shuttle, containing a pick up and deposit vehicle (PDV), moves to the stacker. The PDV groups together stacks of pans and places them on the shuttle. The shuttle them moves to a storage facility and deposits the pans. Pans can be grouped in a single-level of multi-level system.
Washing, drying pans
After bakery foods are removed from their pans, it is necessary to wash these pans before the pan handling cycle repeats. A washing and drying system must sanitize, yet be efficient and provide cost savings. For high-volume bakers, an inline washing and drying system is ideal.
An inline washing and drying system is a conveyorized tunnel washer that contains various sections to wash, rinse, sanitize and dry pans as they move through the tunnel.
One manufacturer offers bakers a washing and drying system that offers cost savings. Bakers will find these cost savings in the equipment's recirculating wash tank. "We're unique because our system uses about one-fifth of the water consumption of a standard tunnel washer," one pan washing and drying system manufacturer says.
The first section of this washing and drying system is a recirculating detergent wash, where the water temperature is between 150°F to 160°F degrees. This is followed by a recirculating rinse at the same temperature. This rinse is pump driven and removes loose soils and detergent from the pans. It is followed by a sanitizing rinse, where the water temperature is between 180°F and 190°F. After this rinse, the pans are dried. Then the pans are used immediately or they proceed to the pan stackers.
The water from the sanitizing rinse is routed back to the recirculating rinse, which constantly is freshened with the sanitizing rinse. "The sanitizing section only has to sanitize something instead of rinse and sanitize with fresh water," the manufacturer says, "and this cuts down the consumption of the water."
Any low-sudsing aluminum-safe detergent is ideal for this pan washing and drying system, the manufacturer says. The water in the recirculating detergent wash is pumped at 40 psi to 60 psi.
Multiple options exist for bakers' pan handling needs. These options include innovative solutions to pan stacking and unstacking, depanning, washing and drying. Bakers will find that these solutions promote flexibility and help preserve the life of their pans.