Accurate depositors save bakers product, money
Aug. 1, 2015
by Laurie Gorton
No baker profits from product giveaway, and no consumer wants to buy underweight packages. Accurate weights start with accurate depositing. So, how should producers of baked foods and snacks operate these systems to maintain consistent weights day in and day out?
“In the production of wirecut and deposited cookies, with or without inclusions, the largest element of cost control is product accuracy,” said Rick Parrish, director of sales and marketing, Franz Haas Machinery of America, Inc., Richmond, VA. “Accurate weight-control of individual cookies across the width of the line provides consistent production and savings.”
Package labeling regulations require a declaration of the contents’ weight, and manufacturers must ensure that the net weight of food being packaged meets the stated amount. While the Food and Drug Administration (FDA) wrote these rules to prevent skimping on contents, overweights are just as much a concern. Compliance is mandatory for all foods shipped via interstate commerce.
At the bakery, conformity with FDA regulations means packages that contain too much or too little product are usually discarded and result in waste and unnecessary expense.
Some package types have absolutely no margin for error. “For count packages like trays, piece weight accuracy is crucial to making a wirecut line profitable,” said David Kuipers, vice-president, sales and marketing, Reading Bakery Systems, Robesonia, PA. Although not as important for items packaged by weight in bag-in-box or bulk styles, accuracy is still important for good oven band loading and color uniformity.
“A new machine that offers high weight accuracy often gives [the baker] a short payback period,” Mr. Parrish said. He described a new depositor, designed to function as an all-in-one depositor, extruder and wire cutter. It can manage up to three dough masses of various viscosities and a variety of inclusions. The system has very high deposit weight precision, he said.
Evaluate many factors
How the baker maintains accuracy in depositing involves several factors.
First and foremost, maintenance must take priority, and all manufacturers of depositors interviewed for this report noted improvements in design and engineering that facilitate maintenance. Bakers should match those efforts with thorough training of operators, noted John McIsaac, vice-president, strategic business development, Reiser, Canton, MA. “We fully train the operators and the folks who work on the machine when we install it,” he observed.
Accuracy starts with the processes upstream of the depositor, according to Piet Vader, sales manager USA, Tanis Food Tec, Lelystad, The Netherlands, which is represented in North America by Naegele, Inc., Alsip, IL. “Only when you have full control over parameters such as viscosity, pH, density, capacity, temperature and crystal structure, will you be able to deposit within the narrowest bandwidths possible,” he said.
Consistent doughs are an essential aspect. “Deposits will be the same all day long,” said Paul Kean, vice-president, Risco USA Corp., South Easton, MA, “provided the doughs are delivered at consistent temperatures and viscosity.”
Expanding on this idea, Lance Aasness, executive vice-president, Hinds-Bock Corp., Bothell, WA, said, “For our hopper-fed depositors, maintaining a uniform level of product in the hopper is mandatory.” Hopper level controls can be used to automatically start and stop the transfer pump that brings dough or batter into the depositor. This approach requires no operator attention.
It’s important to match the size of the batch to the size of the hopper. “Often, people make the mix too large,” explained Paul Rooijmans, sales manager, Tromp Group Americas, Richmond, VA. Batters can change density over time, which alters the accuracy of volumetric portioning systems like depositors.
“The size of the hopper and fill level are critical as well,” Mr. Rooijmans continued. Because of compression within a hopper filled to the very top edge, the same volume of batter from the bottom will weigh more than batter taken from the top. The result is then more mass per volume and a heavier deposit.
Monitoring deposit parameters during machine operation is essential, too. For depositors that also aerate batters, such as those manufactured by E.T. Oakes Corp., Hauppauge, NY, the machine setup should establish the desired initial and final density requirements. Robert (Bob) Peck, the company’s vice-president, engineering, advised further, “Check sample deposit weights often and adjust the manifold distribution valves when necessary. Document weights and check for trends. Create — and use — statistical quality control charts to validate that the process is in control.”
Ensure consistency across rows
Each part of the depositor and the line it feeds affect piece-weight accuracy, according to Mr. Kuipers, who described the impact on wirecut products. Starting with mixing, he asked, “Are all ingredients blended thoroughly? If block fats are used, is the temperature of each block consistent when added to the dough, and have they been adequately blended into it? Are inclusions distributed evenly?”
Those inclusions can affect a depositor’s accuracy, too. Cesar Zelaya, bakery technology manager for Handtmann, Inc., Lake Forest, IL, described the servo-driven flow divider in the Handtmann depositor. “It achieves consistent flow of the batter and an even distribution of the inclusions during the depositing action,” he said.
Servos allow depositors to operate in a way previously not possible: They enable pistons to fill slowly yet empty quickly. “You can set the speed of loading and unloading pistons at different rates,” Mr. Rooijmans said. For example, the baker can set loading to take place for 0.6 to 0.8 seconds and unloading for 0.2 to 0.3 seconds. “If you reload at the fast 0.2-second rate, you risk loading the pistons unevenly because batter sticks to hopper walls,” he explained. “The outside edge can fill at 5 to 10% less than those in the center by loading too fast.”
Servo-driven systems were noted as well by Neil Anderson, director of business development, Axis Automation LLC, Hartland, WI. “Customers told us they needed to increase production speeds without compromise, and that’s what we have focused on,” he said.
Some doughs may require lay time before depositing. Mr. Kuipers cautioned that doughs must be metered accurately into the depositor’s hopper. Filler blocks between the depositor’s rollers facilitate movement of stiff doughs typical of wirecut goods. “Is the gap between the rolls the minimum it can be?” he continued. “Are filler block bores accurate, and do they match the wirecut die? Is the machine free from any residue? Are the wirecut cups free of nicks and damage? Is the wireframe straight and installed parallel with the bottom of the cups? Is the wire diameter or blade being used?”
Consider seals, sanitation
A good fit between machine parts ensures accurate performance, and that’s where the system seals enter the discussion. Seals wear at different rates depending on batter formulations, according to Mr. Rooijmans. The company’s depositors can be configured with 15 different seals, ranging from soft to hard. “Two or three can be used for 80% of the products made on the depositor, but you have to find the right seal for the system and the products it will make,” he said. The baker may need to work with the equipment company’s field engineers, experimenting to find the best choice.
And the final aspect is — no surprise — to keep the depositor clean. “Proper sanitation and maintenance are required to achieve high accuracy in deposit weights,” Mr. Parrish said. Clean-in-place (CIP) systems offer this reassurance. He noted the company designed its new depositor with a CIP system. The nozzle plates and pump house can be pulled out and reinstalled without tools, and hoppers can be tilted to allow access for cleaning the feed rollers.
Rondo, Inc., Moonachie, NJ, designed its newest depositor for in-situ washdown, noted Jerry Murphy, the company’s president. “This is for full wet cleaning, allowing the whole system to be cleaned as a unit rather than always having to disassemble it,” he explained.
To accomplish this objective, the company took all engineering for its newest depositor back to base construction. The frame was modified to eliminate areas where debris could collect. This included smooth surfaces and readily decoupled hoppers and other devices. “And we made it as tool-less as possible,” Mr. Murphy added. Bakers typically order spare hoppers and complete sets of pistons to speed up changeover; cleaning of these takes place off-line and in off-times.
Reading reengineered its wirecut depositor to make it more sanitary. “For sanitation, we removed all the drive and cutting mechanisms from beneath the cutting area,” Mr. Kuipers said. Another change was to provide side access for removing dies and filler blocks.
Engineers at Baker Perkins, Grand Rapids, MI, turned to sanitary design guidelines published by the Grocery Manufacturers Association. “This calls for sloped surfaces, stainless steel construction, continuous welds and micro-finishes, which means a finely polished surface,” said Sam Pallottini, the company’s die product sales manager, describing the company’s technology. “We decided to make these changes in our equipment to avoid microbial and pest harborages and minimize dust accumulation,” he noted.
Because depositing is a critical stage in preparation of many baked foods and snacks, bakers will gain big advantages from proper choice and maintenance of their depositors. “In light of skyrocketing ingredient prices and increased shipping costs, more than ever before we need to perfect the way we manufacture our bakery products,” said Stewart Macpherson, vice-president, sales and marketing, Unifiller Systems, Delta, BC.
A well-designed bakery depositor should allow the baker to meet three very important goals, he added. First is precise portion control while saving on ingredient costs and reducing waste. Second is increased productivity that will reduce labor costs. Third is the ability to maintain product consistency to meet customer expectations.