Bakeries that have capitalized on technological advancements in production equipment, particularly those associated with pan handling systems, are surely reaping their rewards. Automated pan handling systems efficiently handle multiple product changeovers, reduce downtime and increase throughput. Units can be customized to fit a variety of space requirements and production needs. Pan handling systems also are designed to maximize pan life.
“The robotic pan handling systems are faster, more consistent, quieter and able to handle a larger array of pan types and weights versus the conventional stackers/unstackers, which helps reduce maintenance and sanitation issues,” says Ken Mentch, sales engineer, Workhorse Automation Inc., Oxford, Pa.
Some of the most significant benefits associated with automated pan systems are those afforded to line operators. Workers sustain fewer injuries by not having to manually push pan trucks around the plant. In addition, automated units provide operators with a system interface for managing pan stacking, unstacking, pan storage retrieval, product changeovers, depanning, maintenance and sanitation.
Efficiency engineering
Improvements in pan handling systems give bakers the flexibility to run multiple types of products without incurring downtime. Pan handling systems that have the capability of handling changeovers with fewer line stoppages improve throughput.Charles Gales, manager, automation sales, Weldon Solutions, York, Pa., explains how increased throughput can be achieved:
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Robotic pan stackers move more smoothly than fixed path pan stackers and unstackers by handling multiple pans at one time. This gentle handling results in fewer jams.
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Robotic systems can be designed with potential jam points at waist height rather than overhead.
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Automatic pan changeovers ensure the least amount of time is spent between production runs.
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Continuous improvement in the programming and operation of automated pan handling systems results in fewer faults and reduced downtime due to maintenance.
Machines equipped with computer-based vision systems contribute to improved process efficiencies. “Our latest Automatic Pan Storage & Retrieval Systems (AS/RS) have been improved for speed with the use of lasers for distance measuring,” Mentch says. “The new speeds achieved on the AS/RS allow one system to handle a simultaneous changeover of lids and pans on two separate production lines.”
Maximizing space
Some bakers may avoid investing in mechanized equipment because of limitations posed by their processing area's footprint. Fortunately, designers of pan handling systems have taken space availability into consideration by creating units that vary not only in the width of pans that can be moved at one time, but also in stacking height.
For instance, Capway Systems offers a range of robotic units, from a single-arm robot with a 3-ft. wide mechanical gripper to those that can handle up to 30 ft. of pans at one time. All are specifically engineered for production rate, pan size and variety of products, notes Frank Achterberg, president of the York, Pa.-based company. The small, single-arm robot is basically a replacement for the conventional magnetic stackers and unstackers where pans are manually stacked on or off a truck, or onto a secondary system.
Achterberg estimates the space required for a small system at about 25 ft. by 14 ft., which is comparable to the area used for a standard stacker/unstacker. A large system that holds a variety of pan styles in higher stack heights may require a footprint that is 35 ft. wide by 100 ft. long.
A robotic system with mechanical grippers can actually pick up an entire horizontal row of pans and stack them vertically. “It's all done within a confined area,” Achterberg explains. “Once the pans are placed within a unit, they don't have to be moved again, so there's no secondary equipment or personnel required. You can also safely stack higher. For instance, the stacks could be up to 96 in. high instead of 40 in.”
Emphasis also has been placed on the use of multi-level storage and retrieval systems, which capitalizes on the availability of vertical cube space within bakeries, Mentch notes. Maximizing unused vertical space allows bakeries to better use valuable production floor space.
Pan care
Included among the benefits of vertical stacking is the improvement not only in the life of the glazing, but on the pan itself. The glazing “rub off” is minimized when pans are placed in an aligned vertical stack. With conventional stacking, pans are normally stacked directly on their bottoms, which over time causes crushing and damage from the weight of the pans, especially with roll pans. On the other hand, a robotic system is so precise, pans can be stacked on the bar band so no weight is on the actual pan, Achterberg notes.
Stacking robots and automated pan storage systems can not only extend pan life, but also reduce the frequency of pan glazing and straightening, Gales says. “The controlled, gentle motion of these units, along with equal usage of the entire pan inventory, maximizes the life of the pans,” he adds.
Keeping pans clean and free of foreign debris is critical to any baking operation. Capway Systems has received numerous patents on its mechanical gripper design, which as Achterberg suggests, has certain benefits over the more traditional magnets or even vacuums. “A vacuum can get clogged, or magnets can attract all kinds of metal particles, which could possibly get into the pan.”
Some bakeries request that their pans be stacked upside down to avoid the potential for contamination to exposed pans. Initially, this process seems beneficial for pan handling systems that use magnets to pick up pans because if the pans are stored upside down, the magnets will contact the outside of the pan versus the inside. But, technically, the outside of one pan becomes the inside of the pan on the next higher layer, which still has the potential for contamination, Achterberg notes.
Lids are used on pans going through the oven to achieve the “square” shape, as with sandwich breads. For lidded product, Weldon Solutions offers a lid-stacking robot that is designed to work alongside the lid return conveyor. “The robot picks up multiple lids at one time and gently stacks them next to the conveyor, putting them back onto the line as needed,” Gales says. “A single robot can often handle sufficient lids for changeover between lid types. This eliminates the need for two fixed path stacking units.”
Hands-free operation
Automated pan handling systems give line operators the freedom and flexibility to focus on other production-related tasks and product quality. For instance, “robots can be programmed to pick up different sized pans with no need for adjustment of conveyor side guides or other devices,” Gales says.
Robotic systems eliminate the risk of injury that could potentially result from the physical labor required to move pan trucks — a task necessitated by conventional units where pans must be stacked or unstacked manually. Computerized integrated controls also simplify maintenance issues that could otherwise negatively impact productivity.
“The robotic pan stacker, robotic pan unstacker and the automatic AS/RS all have been improved for speed and changeover ease with automatic pan setup features and interlocked controls so that an operator can initiate a pan changeover from a remote location, such as the divider,” Mentch explains. “Our latest pan system software packages were developed with maintenance issues in mind, so we provide an abundant amount of technical information at the system interface about the specific system fault to help reduce troubleshooting time for line operators.”
Integrated, easy-to-read screen prompts give operators the option to change system parameters with just the “touch of a button,” says Todd Frandsen, operations manager, Benda Mfg., Tinley Park, Ill. The company's system interface includes a user-friendly menu with options that enable operators to change conveyor speeds rapidly for faster product changeovers and increased throughput. Listed among Benda's system controls are options for maintenance and washdown modes, the latter of which controls certain conveyors for sanitation.
“Benda also has implemented the use of an Ethernet network in its pan system controls to provide multiple points of communication that can be gathered and displayed for operator information,” Frandsen adds. “If problems are detected, they can be instantly displayed at multiple locations indicating where and what the problem is, so it can be rectified quickly to reduce downtime.”
Although the cost of automated pan handling systems may be one challenge bakers need to overcome, the benefits associated with increased throughput, reduced downtime, less labor, fewer lost-time injuries and increased pan life certainly makes these robotic systems well worth consideration. Bakers also producing various types of bread products requiring multiple changeovers will appreciate the ease with which an operator can effect the transformation from one product to another.
