TINE Meieriet Øst decided to introduce greater automation in order to achieve a significant increase in palletizing capacity. The company, a subsidiary of TINE BA, Norway’s largest producer of dairy products, thus wanted to move away from manual palletizing downstream of a TetraPak filling machine. In addition to this, older systems were also earmarked for replacement. Another reason for greater automation was the lack of space available. The solution considered was jointed-arm robots with short cycle times, long reach, repeatability, flexibility, high payload capacity and gentle handling.
Implementation / Solution
Palletizing of dairy products TINE invested in three KUKA KR 180 PA palletizing robots, which can load a combined total of 1,000 to 1,200 pallets a week. This corresponds to ten pallets an hour. The robot grippers can each be controlled as two additional robot axes. The resulting adjustability of the end-effectors means that all of the products in the filling lines can be handled. The jointed-arm robots palletize milk-based soft drinks, UHT and fresh milk, and desserts.
The goods arrive from the production area on six roller conveyors. Each of the robotic cells is fed by two of the conveyors. The KR 180 PAs take the loaded trays from their respective pair of conveyors by reaching between the rollers with their forks. They then stack the products by type up to 1.3 meters high on europallets. These are kept ready under the corresponding product conveyors on a floor-level roller conveyor. In order to achieve high stability, the robots change the stacking pattern from layer to layer. They also insert slipsheets as required.
The KR 180 PA used in robotic cell 1 is equipped with a servoelectric gripper which can extend its fork to varying lengths. This makes it possible to set down trays in a defined position, even if they have different widths and depths. The forks of the two other grippers are only capable of moving out to a single, defined end position. All three end-effectors move their forks downwards and away from the load after setting it down. In this process they use a hold-down device to press down on the goods so that none of the cardboard sheets inserted vertically between the products sticks out, for example. The grippers must be able to operate the hold-down devices with variable pressure. Otherwise additional articles, such as spoons and drinking straws, which are included with some products, would be pressed by the robots into the packages, damaging them.