• Construction employees at de Man
03.09.20

Compact cell with high performance

Modular robotcell MRZ at Stockmeier Chemie

de Man delivers MRZ to STOCKMEIER Chemie: 15 different types of cardboard with anti-freeze washer, which differ in height, width, length and weight, should be stacked on Euro pallets at STOCKMEIER Chemie. The company decided on the modular MRZ robot cell from de Man Automation + Service GmbH & Co. KG. Advantages of the MRZ: The flexible and compact robot cell is available in various basic modules, from which the customer only has to choose the right variant plus additional options. This results in shorter planning and delivery times as well as lower costs compared to individual solutions.

STOCKMEIER Chemie GmbH & Co. KG is one of the largest chemical distributors in Europe. The company offers a comprehensive range of industrial and specialty chemicals for numerous industries and applications and has also specialized in the development, manufacture and sale of cleaning agents for industrial and commercial use. At the main location in Bielefeld, the window antifreeze, packed in cardboard boxes, was to be automatically palletized. Stockmeier opted for the MRZ version 2.1 with one palletizing station and pallet conveyor technology within the cell plus an optional intermediate and pallet magazine. It achieves an output of 175 to 500 boxes per hour.

Continuous pallet supply
The item to be palletized is selected by the system operator on the HMI PC. Each article is assigned a specific packing scheme in which the packing sequence is stored. First of all, the pallet magazine, which is located above a pallet translator, dispenses an empty pallet (Euro pallet). For filling, the pallets are placed on a feed conveyor belt by a forklift and transported by this into the magazine. The requested pallet is lowered onto the pallet translator from above and is then placed separately under the magazine. It now drives over the chain conveyor to the empty pallet space and is aligned on the left. If necessary, the conveyor technology transports the pallet to the palletizing station, where it is stopped by a stopper and aligned in the direction of travel. The empty pallet space is immediately occupied again so that a smooth palletizing process is guaranteed. While the empty pallet to be palletized arrives, the robot fetches a bottom / intermediate layer - if stored in the packing scheme. These layers consist of rigid cardboard and are stored in an interlayer magazine that is filled by hand. The robot gripper moves to a position above the interlayer magazine and then slowly down onto the magazine. Sensors recognize when the gripper has reached the top cardboard. The robot saves this position so that it can drive straight to the destination when the next layer is fetched. The search height is reset when the door is opened, as there is a possibility that the magazine has been refilled.

Create new packing schemes yourself
The cardboards now enter the cell via a light conveyor system with an 800 mm tunnel as protection against interference and are palletized on Euro pallets by the robot - a Kawasaki CP 180L with four axes was used. de Man placed the robot on a pedestal in order to easily reach the maximum height of the packed pallet of 1650 mm. Since the cardboard boxes cannot be vacuumed, they are gripped individually or in pairs with a fork gripper and placed on the pallet according to the packing scheme. The gripper can handle boxes of flexible size up to a maximum of 400x300x350 mm. So all different product sizes are covered. While the robot is packing the boxes onto the pallet, the next ones are already entering the cell. For the boxes with the highest production rate, the fastest cycle time of the robot is six seconds per box. If the packing scheme provides for it, an intermediate layer is placed between the individual layers. The full pallets are finally conveyed out of the cell, transferred to a conveyor system from WST and transported directly to the warehouse. While the pallet is running out, the next empty pallet is already moving into the cell in order to ensure the shortest possible pallet change time. The system is delivered with 15 pre-installed packing schemes. Further packing schemes can be created by the customer himself in the de Man packing scheme generator after appropriate training.

Intuitive user interface
An S7 1510SP-F is used as the central controller. It controls the field bus system (Profinet) and supplies the robot controller with data. For its part, the PLC receives product data and control data from the HMI, a PC with an SQL server as a database. The proven and clear de Man visualization is used as the user interface. Special feature of the system for Stockmeier: The touch screen measures a full 24 inches and makes it easier for the operator to see all the details of the system layout and to select the functions. All relevant control elements are located directly on the main screen, the operator can get a quick overview of the status of all system parts and have complex components displayed in more detail. Operation is intuitive and, as usual with smartphones, with a "click". Of course, the view is customized in each case. For safety reasons, the entire system is surrounded by a protective fence; access is via a protective door, which must be requested. The safety interlock with guard locking only allows the protective door to be opened when the dangerous movements have been safely stopped. Trapped people can leave the cell thanks to an emergency release. A light grid enables the full pallets to be conveyed out in automatic mode, but prevents unauthorized access to the system.

Standard and yet individual
The modular MRZ robot cell used is part of the “M-series” from de Man. The automation specialist offers its customers a range of pre-planned modular robot cells for various applications: the MKA for erecting cardboards, the MPZ for packing goods in cardboards, the MRZ for palletizing and the MEZ for labeling. All cells are controlled by the MFR material flow computer. The "M-Series" is characterized by a compact footprint, great flexibility and high precision and speed. All cells can be individually adapted to the specific requirements and expanded with options such as camera technology or additional conveyor lines. All products in the series can also be combined with one another to form a complete packaging line. The advantages of the standard cells are obvious: Customers benefit from a faster planning phase and delivery time as well as lower costs compared to individual solutions.