Between Grimma and Döbeln and between Oschatz and Colditz, strawberries, cherries, currants and raspberries as well as plums, apples and pears ripen in large quantities in Saxony's 'fruit country' under favorable climatic conditions. In the middle of this fertile region, a sweet must and fruit wine press was built in 1936, just outside the town of Döbeln. It is the origin of today's Sachsenobst winery.

Back in the 1980s, plant manufacturer Bayer, which still works for Sachsenobst today, developed a handling system for the hot-filled liquids to reduce the workload of the winery employees. "Fruit juices are filled to the brim at 90 °C, fruit wines at 60 °C. They are then cooled down to around 35 °C so that the aroma and vitamins are retained," explains production manager Luise Hoppe. After all systems and transport equipment were comprehensively modernized in 1997 at a cost of more than 11 million euros and equipped with drives from the manufacturer SEW-Eurodrive, among other things, something happened five years later that went down in the history of the Sachsenobst winery as 'Black Tuesday': The flood of the century in the Freiberg Mulde flooded all the buildings on August 13, 2002, destroying the entire bottling technology. The next flood came in 2013. After that, an extensive renovation of important plant components was necessary, which ultimately resulted in the tender for a new multifunctional palletizing system.

"Our requirements were high," says Johannes Zimmermann, Technical Manager of the Sachsenobst winery, looking back and adds: "The system to be built was to take over the entire conveying and handling processes of the incoming empties, the pallets and the handling of the crates and cartons. We didn't have much space available, as the system had to be installed at the front of our bottling hall. There was only a space of 15 m wide, 10 m deep and 6.50 m high available." Against this background, the decision was made together with the contracted plant manufacturer Bayer to install the palletizing system on two levels. In addition, an automatic pusher had to be installed in this limited space to feed the new glass into production. The system can transport a total of 8000 one-liter bottles per hour.

How the material flow works

The material flow in the newly constructed plant is as follows: The filled and cooled bottles are automatically packed into crates by a bottle packer. A spiral conveyor transports these crates to the upper level of the palletizing system. There they first meet the grouping station and the row pusher, which create the layer pattern. A synchronous servo motor drives the row pusher via toothed belts. Specifically, this is a highly dynamic servomotor in a compact design from SEW's CMPZ series. Another four of these servomotors are installed to move the gantry. They drive the rotary axis A as well as the linear axes in the X, Y and Z directions and are equipped with absolute encoders for fail-safe positioning.

Once a layer has been provided, a clamping jaw gripper picks up the entire layer and places it on a Euro pallet. But the palletizer also performs other tasks. To ensure that there are always enough pallets, crates and bottles available, pallets with empties are continuously fed in on a feed conveyor. The palletizer unloads the empties pallets layer by layer and transfers the empties containers to an unloading table. From there, the separated crates automatically reach the bottle unpacker and are then transported to the unscrambler, while the empty returnable crates are conveyed to the crate washer. The empty pallets are stored in a pallet magazine.

View of the palletizing system with the empty goods infeed (top), the pallet magazine (middle) and the outfeed section for the full goods (left)

© SEW-Eurodrive

The disposable bottles are packed in cartons or trays, which are also palletized. Beyer Maschinenbau built a second gripper for this purpose, which is called a louver gripper in accordance with its mode of operation. The special feature here is that after a product layer has been lifted, a blind is moved under the product in order to be able to transport the product safely. This shutter gripper rests on a table in the machine's operating area until it is used. The palletizing system places the jaw gripper on this table and automatically releases the mechanical connection. The system operators then disconnect the gripper from the power and compressed air lines. The gantry then picks up the gripper in two steps. The mechanical connection is made automatically, while the electrical and compressed air lines are connected manually.