The bottling plant of Coca Cola FEMSA in Montevideo is one of the few in the world that uses refillable PET bottles, which allows for the returned bottles to be refilled in an eco-friendly way. But not all bottles are returned and not all returned bottles are in condition to be refilled. Because of this, new bottles need to be entered into the filling production line to compensate those that are lost.
The first challenge in this is ergonomy, as the pallets of new bottles that must be sent into the filling production line are more than 2 meters tall, with 6 layers of bottles and 121 bottles in each level, which made the unloading of the bottles manually a complicated task. Secondly, matching the required maximum speed of 16.000 bottles per hour meant that many operators needed to be working on this task.
Automating the depalletizing process was proposed to supply the production line while needing less manpower.
The solution designed by Pensur consists of a Kuka KR120 R3200 PA palletizing robot using a custom gripper designed and manufactured by Pensur for this application. This gripper allows the robot to grab a whole layer of 121 empty bottles at once using pneumatic actuators and pick the interlayer cardboard using a vacuum system. Aditionally, it uses the same gripper to manipulate the empty pallets and pile them for a forklift to take out.
The system operates automatically in coordination with the filling line, which dictates if new bottles need to be entered. A pallet conveyor system is responsible for entering the pallets into the cell and leaving a new pallet available for depalletizing whenever available. The intervention of an operator is only required when, after a pallet of containers is loaded on the entry transport, they must remove the film wrapper and give the order for the pallet to be entered into the cell.
The depalletizer has a control panel to give commands to the system, make configurations and view statistics and events. Additionally, the communication of statistics and status of the system to the plant SCADA was implemented.
For the design and implementation of the depalletizer, a risk assessment was carried out and the most demanding safety regulations were followed. All cell entrance doors have safety interlocks, multiple emergency buttons, and the pallet entrance has a laser safety barrier with muting. In addition, best security practices for the programming of the system were followed, especially in the events that there are entrances to the cell to guarantee the safety of the operators.
During the whole design, installation and commisioning process, we worked closely with the client to adapt every aspect of the project to their needs and workflow.
The implemented depalletizer system meets all the desired requierements and has the capacity to increase production. The gripper designed and manufactured by Pensur enabled the robot to have the perfect tool for the job without compromising in other aspects. Finally, the depalletized allowed to decrease the amount of personnel occupied with the task of entering new bottles into the REFPET line.