Summary
The application
Packing and palletizing of frozen burger products for dispatch to retail stores.
The challenge
Speed up the packing of frozen packaged burgers while also preventing possible injury to staff and automating the packing and palletizing.
The solution
Several ABB robots are used to pick up packs of frozen products, place them in cases and then stack the cases on pallets ready for dispatch.
A leading US manufacturer of frozen burgers has used ABB robots to streamline its production and avoid injury to its employees.
Starting as a fast-food chain, White Castle now has an extensive retail operation, selling its popular range of frozen mini burgers, or ‘sliders’, to stores across the USA.
One of the company’s major facilities is its frozen food plant in Louisville, Kentucky. Here, pre-cooked hamburger meat arrives as logs and is sliced into individual patties. The patties are manually placed on bun bottoms, and then topped with grilled onions and cheese and the upper bun. The completed sliders are then flow wrapped two-to-a-package and transferred into a blast freezer.
From here, the packages are placed onto a conveyor that leads to three separate packaging lines - two parallel lines for 12-count cartons sold at general retail locations, and one separate line for 16-count cartons sold at wholesale clubs.
As production of sliders increased, the company noticed several bottlenecks in the process, in particular the packing of slider two-packs into the retail cartons, a highly repetitive task that involved the handling of frozen product.
To speed up this process and move employees into less physically stressful jobs, in 1998 the company installed one IRB 340 FlexPicker® on each of the lines. Equipped with vacuum grippers and sophisticated motion control, each IRB 340 robot on the 12-count carton lines picks six two-slider-packs at a time, while a newer IRB 360 FlexPicker on the 16-count 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.
Each of the original IRB 340 models are still in operation at the Louisville plant, over twenty years later.
“The ABB delta robots are the best investment we ever made,” says Plant Manager Tony 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.”
Optimizing designs with ABB RobotStudio
White Castle also later installed additional robotic cells on two other areas of the parallel lines – one to pack the retail cartons into 12-count shipper cases, and one to palletize the shipper cases onto 96-case pallets. These original robots served their purpose for many years, but eventually approached obsolescence.
White Castle called in CIM SYSTEMS INC., an authorized ABB robotic systems integrator, to find replacement solutions for the carton packing and palletizing area.
The new palletizing system presented some design challenges. The first was a tight palletizing area which needed to fit two full lines. The solution was to position the end of the conveyor from each line perpendicular to the front of the robot, one just beyond the other, with a pallet station along the right side of the robot.
White Castle also wanted the robot to pick empty 45-pound pallets off a stack and place them in the build station once a previous pallet had been built and moved to the stretch wrap station. This required a more complex end effector design and intricate robot motion.
To develop the solution design, CIM used RobotStudio®, ABB’s offline programming software, to simulate the palletizing cell, including the specialized end effector, and determine the optimal robot position and motion. Using the software also helped to identify any bottlenecks as well as calculate accurate space requirements and cycle time.
CIM needed to coordinate the robot motion and pallet pattern, making sure the load would clear the first pallet, no matter its height, to safely reach the second pallet.
The end effector was bigger than most because of the need to pick up both cases and pallets. It features vacuum cups that pick three eight-pound cases at a time for the palletizing operation, along with four pneumatically operated hooks positioned on each corner to securely handle each empty pallet. This combination enables the robot to execute both functions without requiring a tool change.
RobotStudio helped CIM design and prove the performance of the system while accommodating all the variables. The palletizing robot used in this system is an ABB, 4-axis IRB 660 with a 3.15 meter reach and a 180 kilogram payload. This configuration provides enough length and strength to reach and clear all points in the palletizing cell from a stationary position, both horizontally and vertically.
New robots for case packing station
White Castle’s latest automation installation features two-ABB IRB 1200 robots that pack the retail cartons into twelve-count shipper cases – this station is sited after the packaging line and before the palletizing robots. Mounted on a common pedestal between the two packaging lines, the two lower-payload robots use vacuum end effectors to pick two retail cartons at a time and place them into the cases.
The new 5 kg case-packing ABB robots, one dedicated to each line, replace a single, larger robot that served both lines with dwindling efficiency as production volumes increased. Manual operators, who were previously required to assist the process, have been moved to more rewarding jobs in the facility.
CIM again used RobotStudio to identify the optimal positioning of the robots based on their footprint, reach and payload, and to validate the requisite system performance in relation to the existing components of the packaging line.
“The tremendous experience we have had with the ABB FlexPickers over the years caused us to look closely at ABB when it was time to replace our other robots. We were introduced to CIM SYSTEMS and we couldn’t be happier,” says McGraw. “The palletizing robot and the case packing robots have really increased the efficiency of our operation. They are truly plug and play systems that require minimal manual support.”
