Generally regarded as the world’s first fast-food hamburger chain, White Castle, founded in 1921, has over 350 locations in 15 states, mostly in the Midwest and metro-New York City. On the surface, that leaves a good portion of the U.S. without access to the indulgent palate pleasure of iconic square sliders, loaded with grilled onions and perhaps a slice of cheese.
That was the case until 1987, when White Castle opened a retail division, which supplies merchants large and small across the U.S. with frozen, packaged sliders made at three U.S. factories. The factories mimic the way the sliders are made in restaurants but leave the final microwave preparation to the consumer.
The retail sales model has been quite a success. At the end of 2021 White Castle sold its six-billionth retail slider, with over 20% of that total having come in the previous three years.
Demand has been so high that White Castle’s Louisville, Ky. factory—one of the first White Castle frozen food plants opened in 1997—now operates three shifts, six days a week. It also serves approximately half of the U.S. retail volume, processing tens of thousands of pounds of meat in making 800,000 sliders per day. 
White Castle’s Louisville, Ky. factory operates three shifts, six days a week. It serves about half of the U.S. retail volume, processing tens of thousands of pounds of meat in making 800,000 sliders per day.
Pre-cooked hamburger meat comes into the facility in log form and is sliced into individual patties. The patties are manually placed on bun bottoms, and then topped with grilled onions, (plus cheese during the shifts cheeseburgers are made), and the upper bun. The burgers are then flow wrapped two-to-a-package on equipment from Campbell Wrapper Corporation, and transferred into a blast freezer operating at 35°F below zero.
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Recently upgraded articulated-arm robots
CIM used RobotStudio, ABB’s offline programming software, to experiment with highly realistic simulations of the palletizing cell while designing the EOAT and determining the optimal robot position and motion.
Pre-Y2K Adopter of Delta-Style Robots
During the first several years of operation at White Castle’s retail facility, most of the packaging processes were handled manually. As the frozen sliders gained popularity and production volumes increased, Plant Manager Tony McGraw and his staff noticed certain areas of the packaging line that were causing backups.
One in particular was the packing of slider two-packs into the retail cartons, a highly repetitive task that involved the handling of frozen product. In effort to speed up this process and move employees into less physically stressful jobs, McGraw began to investigate a range of potential automation enhancements to the line. If a viable solution did exist, it had to be fast and accurate, and work in the existing space, which was very tight. The option that showed the most promise was a delta-style robot, a new technology that had been in development since the mid-1980s but had only recently been commercially available. 
White Castle became an early adopter of delta-style robots, installing one IRB 340 FlexPicker on each of its packaging lines way back in 1998. Two are still in operation today.
The key design feature of a delta robot is three arms, connected to universal joints at the base, which move in a constant parallelogram motion that maintains the orientation of the end-of-arm tool that handles the product. Delta robots can execute precise and fast motions because, unlike articulated-arm robots that have motors in each arm, delta robot motors are located in the main body above the work area. All movement comes from the extremely light robot arms, allowing for low inertia and fast acceleration for incredibly fast pick-and-place motion of lighter items. In 1998, not long before McGraw began looking for carton-packing automation, ABB introduced the IRB 340 FlexPicker, one of the first commercially available delta robots. This robot was capable of 10G acceleration, and exponentially faster than human operators in handling smaller items.
White Castle became an early adopter, installing one IRB 340 FlexPicker on each of the lines. Equipped with vacuum grippers and sophisticated motion control, each IRB 340 robot on the 12-ct carton lines picks six two-slider-packs at a time, while a newer IRB 360 FlexPicker on the 16-ct line picks eight two-packs at a time. In every cycle the robots pack a layer of two cartons simultaneously, with two pick-and-place iterations completing two cartons at a time.
While ABB’s delta robot portfolio has since been significantly upgraded and expanded with greater capabilities, longer reaches and higher payloads, each of the original IRB 340 models are still in operation today at the White Castle Louisville plant, some twenty-plus years later. “The ABB delta robots are the best investment we ever made,” says McGraw. “Their speed and accuracy keep the lines moving and they are highly reliable. We have taken great care to maintain them, and we will continue to do so. I think they will last a good while longer.” PW
