For the BSH washing machine production plant located in Łódź, Poland, the change to a new generation of appliances led to a new production strategy. Injection-molded parts, which had long been outsourced from external contractors, are now manufactured in-house. The injection molding partner WITTMANN supported the new injection molding facility’s development by delivering large MacroPower machines – each equipped with an extensive automation package.
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They are proud of the “Project of the Year” award: Adam Sobczynski, Process Engineer, and Andrzej Pirek, Head of Manufacturing Engineering, at BSH, together with Bogdan Zabrzewski, Managing Director of WITTMANN BATTENFELD Polska (from left to right) |
“With the development of our new appliances, we have responded to current customer demand”, explains Dr. Andrzej Pirek, Head of Department of Manufacturing Engineering, during our visit to BSH Sprzȩt Gospodarsrwa Domowego Sp. Z o.o. in Łódź. “All our washing machines now come with the highest energy efficiency class A. They also consume less water and run at a lower noise level.” The lion’s share of the washing machines manufactured in Łódź are destined for European markets. Mainly the global brands of Bosch and Siemens are made at this location.
Andrzej Pirek always keeps a close watch on the behavior and wishes of the consumers. Energy savings and more sustainability are the order of the day, and this is where households and production plants are in a very similar position. “Our aim is to make top-quality products with a long service life and maximum efficiency”, says Pirek. “Here, the injection molding technology from WITTMANN makes a significant contribution. Both the MacroPower injection molding machines’ process stability and their low energy consumption have a very positive effect.”
As the factory grew, new platforms and new processes emerged. This year, the site is celebrating its 30th anniversary. Aligned with appliance development, all processes were analyzed. “We realized that we could tap a great savings potential by making the injection-molded parts ourselves”, Pirek reports.
Number of good parts exceeds target
On the day of our visit, several MacroPower injection molding machines – all with 900 tons clamping force – are standing in a row in the new injection molding hall. No less impressive are the components the linear robots are removing from the molds and stacking on pallets placed directly beside the machines. There are two different types of round parts, both very large and complex with many connection and assembly elements, destined to enclose the washing drum later on in the end product, after they have been joined together. Both housing halves are injection-molded from fiberglass-reinforced polypropylene, each with the remarkable shot weight of just under 4 kilograms.
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Trimmed for efficiency: the new injection molding facility achieves a high automation level. |
On the pallets, the freshly molded parts are first brought to an RFID-controlled FIFO storage facility, until they have reached their final geometry. From there, they are passed on directly to an assembly line in the neighboring production hall. There, the two housing halves are welded together using vibration welding. “For the quality of the weld seam, there is zero tolerance. The drum must be absolutely watertight to prevent leaks in the washing machine”, explains Pirek. The prerequisite here is extremely precise forming of the geometrically complex parts by injection molding.
Here, the MacroPower injection molding machines bring their strengths into play with highly accurate servo-hydraulic movements and a reliably constant injection molding process. “Our scrap rate is below our original target”, comments Pirek with pleasure.
Systematic development of injection molding expertise
With its own injection molding facility, BSH has significantly increased the vertical range of manufacture at its Polish washing machine plant. All the important value creation stages now take place in-house, which has a positive effect on unit costs and consequently competitiveness. The new strategy is now paying off, but a number of obstacles had to be overcome to get there.
For the workforce in Łódź, injection molding was a completely new technology. Here, WITTMANN BATTENFELD Polska supported the project with an extensive, tailor-made training program. “We not only trained the machine operators, but also the maintenance and security staff, and the process engineers, too”, says Bogdan Zabrzewski, Managing Director of the WITTMANN subsidiary in Poland, located in Grodzisk Mazowiecki, only 100 km east of Łódź. “The short distances are a definite advantage. Whenever we are needed, we are always quickly on site”, Zabrzewski comments.
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First in, first out. The FIFO storage area serves exclusively as the space for the time of material ageing following injection molding. From the storage area, the housing halves pass on directly to the neighboring assembly lines. |
The location also benefited from the global production network of the BSH Group. The same washing machine models are produced in other countries, too, and certain injection-molded parts were already manufactured in-house there for earlier generations of appliances. “We cooperated very closely with our colleagues from other countries, and were thus able to learn a lot for our new injection molding shop”, Pirek reports. ‘Network of Experts’ is the designation of this concept at BSH, which functions for all technologies being used within the Group. All locations are part of a digital network. “Industrie 4.0 makes cooperation beyond the boundaries of individual locations very simple”, says Pirek.
Automation made to measure
The housing geometry of the new washing machine generation, however, presented all production sites with a new challenge. “We had to completely re-design our automation concept”, says Zabrzewski. Starting with the grippers and all the way to stacking the molded parts on pallets for transport to FIFO storage.
The W863 pro robots with a maximum load capacity of 75 kilograms perform several different functions. They insert the bearing bushes into the mold to be over-molded, demold the housing halves and stack these on the pallets according to a preprogrammed storage pattern. To handle the pallets, WITTMANN has developed a multi-level conveyor system. The pallet exchange is carried out fully automatically. The pallets are prepared for collection on the upper level of the conveyor while an empty pallet is moving up from the lower level.
Another special feature is the integration of the robot’s control system in the production cell. The robot program is downloaded via the injection molding machine’s control system, with an RFID code to ensure that the correct gripper has been attached.
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Washing machines are manufactured at the plant in Łódź primarily for the European markets. |
“The success of this project is the result of extremely close cooperation between the process experts at BSH, the automation specialists at WITTMANN in Germany and our local technical lab at WITTMANN BATTENFELD Polska”, says Zabrzewski. BSH benefits from the fact that the injection molding machines and the automation equipment have all come from a single source. “That was our target from the very beginning”, says Pirek. “We had only one central contact partner for the entire project and are convinced that this was why we were able to start up the system so quickly and smoothly.”
The availability of the machines is vital. They must be “ready for production” at any time, as Bogdan Zabrzewski emphasizes. For there is no production of goods to be kept in stock. If the injection molding production came to a halt, this would also immediately bring the assembly line to a standstill. So, reliability in service was another decisive argument in favor of choosing WITTMANN as injection molding partner. In any case of trouble, the WITTMANN service engineers are very quickly on site. Particularly critical spare parts are kept in stock.
“Within the walls of our plant, we have built up a completely new factory. Without WITTMANN, we would not have been so successful in this project”, emphasizes Pirek, and praises above all the very open communication as an essential success factor. “Here, the right people are working together. People with a lot of knowledge and experience communicating openly with each other at any time. The plant in Łódź has now become the benchmark within our production network.”
A wonderful confirmation of this success story came in the form of a special award. Project Leader, Michał Zimowski and his team had submitted an entry for an internal BSH award contest. From a total of 50 projects submitted, the foundation of the injection molding facility in Łódź was chosen as Project of the Year 2024.
