A continuous mixer feeds Pretzels Inc.'s newest production line, commissioned in fall 2011. Die changes for different snacks stop throughput, just as they do on batch-fed lines, however. Photo: Northeast Indiana Regional Partnership
"Because of the flexibility we need to have, we have found that it doesn't make sense to automate casepacking," he explains. "It would just be another machine that has to be changed four times a day, when we change packaging films. And we like having the operator look at the bags. It allows that final opportunity to detect any deficiencies."
Riding the rails
Lean manufacturing principles have been front and center in many food companies' continuous improvement efforts, and some lean adherents denounce accumulation zones on packaging lines "as a crutch," notes Stellar's Kolodziej. He is not among them: "You have to build in accumulation or you're shooting yourself in the foot."
Mike Weikert concurs. As director of applications engineering at Nercon Engineering and Manufacturing Inc., Oshkosh, Wis., Weikert recommends various packaging line accumulation options, including Nercon's buffering solution that incorporates a movable carriage attachment to expand container travel paths as needed. "People often have a wish list of what they want accumulation to accomplish," he says, "but if they want to buffer 10 minutes of production, we listen but then show them they don't have the floor space to sustain that."
Inevitably, the conversation turns to minimizing changeover time, and that provokes an examination of alternatives to guardrail adjustments. From slotted brackets with carriage bolts requiring tools to fully automated, one-button solutions that activate pneumatic air cylinders or electric actuated cylinders, manufacturers crunch the numbers for time required, labor costs and changeover frequency. If extended changeover times result in upstream production interruptions, "the cost justification is a lot lower," Weikert understates.
Red Gold employs a quick set-point method that uses color-coded spacers to position railing for the next run. "The simpler you can make it, the fewer mistakes you're going to have," says Rick Jones, director of quality. If fine tuning is needed, operators are empowered to tweak the set-up when the line is running.
Cooked batches can flow to multiple packaging lines, lowering the likelihood of a processing interruption. While three changeovers in an hour constitute "an extreme event, it can happen and it does happen," says Jones.
To minimize downtime, the types of products being manufactured determine equipment selections. For example, PD pumps drive CIP systems in the Elwood plant, where ketchup is produced, while progressive cavity pumps are used in the Geneva, Ind., facility, because they shorten CIP cycles to evacuate products with particulates.
Both Red Gold and Pretzels Inc. underwent upgrades to their data management systems in recent years, an often painful but necessary process if manufacturing flexibility is to be maintained. "Supervisory control software enforces the production rules that give you flexibility," Invensys' Schiel suggests. The accuracy and accessibility of the information it yields determines how productive shift change meetings will be, he says.
Rules enforcement is important, Jones allows, but off-the-shelf software must be modified to meet the specific requirements for a plant's line flexibility. "The integrator or the software company can't define the problems you're trying to solve; you must do it," he emphasizes. "Because of our continuous improvement focus, we've become a lot better at narrowing the gap between what the system delivers and what we need."
Thanks to Red Gold's focus on lean, managers have become more adept at querying the database about the true impact of changeovers and other metrics beyond turns and line efficiency, adds Crooks.
Pretzel's legacy ERP no longer was supported, forcing a new installation. "It's always a challenge to go through that process, but I'm very confident in the numbers we're getting now," says Huggins. "We're always looking to increase the amount of usable information that we get, and the new systems give you much more information."
Production scheduling has become more complex in the past 20 years as manufacturers have sought to minimize inventories while meeting more diverse customer needs. "We're always responding to customers' needs to be slightly different than the leading brand," says Red Gold's Crooks. Besides managing a growing selection of package formats, his colleagues must respond to requests for "a special twist" to help customers' products stand out.
Allergens add another layer of complexity, and the conventional approach is to run those products at the end of the schedule. Dedicated lines would add flexibility, though most reject that as an unattainable extravagance. However, Pretzel Inc.'s purchase in 2011 of the Philly Soft Pretzel factory in Canonsburg, Pa., effectively is adding that flexibility.
Acquiring sales and customers drove the original purchase, but recently a process for peanut butter-filled pretzels was perfected. The new item did well in market tests, and the Pennsylvania plant is being dedicated to its production. "We wouldn't do that product (in Bluffton) because all are other products' packaging would have to say, 'Made in a bakery that uses tree nuts,'" Huggins explains. If additional allergen-bearing products are developed, Canonsburg is the logical production point.
Managing multiple facilities adds complexity, but added flexibility is an attractive offset. And whether a food company is dedicated to its own brands or processes for multiple clients, more flexibility is a good thing.
This article originally appeared in the June 2013 issue of Food Processing Magazine.