In 1995, Phoenix-based The Dial Corp. reshaped the primary packaging operation at its London, OH, plant during a transition from a roll-fed to a sheeted format for cartons of its dryer sheet product. At the same time, management seized the opportunity to also automate its palletizing methods.
Limited floor space and the variety of cases that must be handled made Dial's engineers favor a robotic solution to palletizing
"Our Toss 'N' Soft line consists of seven different package sizes, from 20-count to 200-count," says operations supervisor Tina McGillivray. "That means seven different case sizes requiring different palletizing patterns."
McGillivray worked closely with Fanuc Robotics (Auburn Hills, MI) to develop a "work cell" solution that helps Dial meet its aggressive production schedule. It consists of a close-coupled Fanuc M-400 robot and a stretch wrapper from Orion (Memphis, TN).
No pallets are used. The robot begins each palletizing cycle by placing a slipsheet on the turntable of the stretch wrapper. Cases of Toss 'N' Soft are conveyed to the robotic palletizer, which uses vacuum pick-up cups to grab cases and place them on the slipsheet in whatever pattern is appropriate for that case and that layer.
Upon load completion, the robot signals the stretch wrapper to wrap the full loads, which range from 130 to 240 cases. Wrapped loads are then conveyed out of the work cell on the stretch wrapper's powered roller discharge conveyor to a pick-up point. There fork lifts use gripping devices to pull the lip of the slipsheet onto their forks.
Changeovers can be programmed into the machine in about five minutes. Using a hand-held controller, an operator calls up the appropriate pallet pattern from memory. Also required is a minor adjustment to the gripping tools.
Runs around the clock
"The new line is running around the clock," says McGillivray. "In fact, only two operators per shift are required to maintain the palletizing operation. Doing it manually in the past required four people. And these two today produce about 25 percent more per shift than when we had four people in the picture."
McGillivray says it was Fanuc's reputation and its willingness to put together the whole cell, palletizer plus stretch wrapper, that influenced her and her colleagues in selecting equipment. While the M-400 is a standard unit, the "end-of-arm" tooling that does the gripping was customized for Dial's specific requirements.
In addition to the savings gained by reducing labor costs, McGillivray points to other advantages Dial now enjoys. Pallets, for instance, have been eliminated. Product damage has been reduced as well.
"The whole cell cost about $186κ― ," says McGillivray. "That's pretty inexpensive when you consider what we gained."
Dial's first robotic palletizer has prompted the company to consider automating other product lines as well. "We're impressed with the robot's operation and the support our vendors have provided throughout the entire project," says McGillivray.
