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The Multi Carrier System was first deployed at Dr. Kurt Wolff GmbH & Co.KG in an Optima filling machine from the Moduline series © Optima

Digitalization in machine building

Individuals in the swarm

How can frequently changing (and in extreme cases single) products in a line be filled, sealed, labeled, and packaged in a flexible and cost-effective manner? With their new Multi-Carrier-System, Siemens and Festo offer an innovative response to current and future trends in the packaging industry and beyond.

Individualized products – for example, products that are “personalized” via online configurators –  and thus packaging in very small quantities, in batch sizes as small as one, will be the rule rather than the exception in more and more sectors in the future. Producers of cosmetics and pharmaceutical products are traditionally among the trendsetters in the packaging industry. But in other areas as well, product and/or packaging variations changing seasonally or for special campaigns, and ever­-shorter product lifecycles in general, are placing increasingly higher demands on the flexibility of production systems.

Of paramount importance in this process is a production and material flow in the plants that can support the increasing number of variations, although the focus is not so much on very high throughput rates but rather on high flexibility and dynamism between the stations as well as on process safety. Many operators would like a continuous material flow with optimized (i.e., small, or preferably no) buffers in between in order to be able to design future generations of machines that are even more compact. In the face of increasing numbers of different product formats, minimized set-up times are also a stated aim.

Modules for an optimized material flow

With their joint development of what they call the Multi-Carrier-System (MCS), Siemens and Festo have created an innovative solution for the changing transport tasks within plants. The solution is a new and modular linear drive system that allows for more flexible and dynamic transport of multiformat-capable goods or workpiece carriers. At the core are primary components available in varying lengths, with which transport distances of any length can theoretically be set up. The associated secondary components are integrated into the carriers.

To avoid bottlenecks, the carriers run synchronously with the process – optionally singly or in groups – within the machine according to the rules of swarm behavior, exactly as required by flexible processes. Individual carriers can be easily moved into and out of the plant. In addition, the entire MCS is easy to integrate into existing transport routes, so that the machine can be quickly changed to accommodate different formats, other product types, or seasonal requirements.

The primary and secondary components of the linear motors by Festo are completely sealed and have a high degree of protection, safeguarding them from contamination by leaking product and making them easy to clean. This is critical in the cosmetics and pharmaceutical industries, but also in the food and beverage industry. The carriers are placed on the secondary elements and can be designed individually, enabling, for example, easy adaptation to various guide systems or particular properties for special hygiene requirements.

The MCS development was substantially driven by Optima Consumer GmbH. The packaging-machine specialist is now successfully using the system for the first time in a packaging line of the Moduline machine series at Dr. Kurt Wolff GmbH & Co. KG in Bielefeld, Germany. The Bielefeld-based company fills, seals, labels, and boxes just under 20 bottle formats of its shampoo series Plantur 21, Plantur 39, and Alpecin in constant alternation and in various groupings.

The key to achieving the required output of at least 120 bottles per minute was a detailed material flow analysis; simulation in the Mechatronics Concept Designer based on that analysis; and perfect ­teamwork between Optima, Siemens, Festo, and Dr. Wolff, the partners involved in the project. The MCS implemented in the packaging line of the Moduline machine series includes more than 100 MCS linear motors in the drive-based motion control system and more than 60 additional, synchronized (servo) axes at a total of nine stations.

Within the machine, the individually controllable carriers move synchronously with the process, either singly or in groups © Optima/Marion Stephan Photographie

Proven drive performance

Siemens implemented the high-performance drive and control system for the MCS within just a few months. The existing standards played a decisive role in this. They include the Simotion motion control system, proven in many industrial applications, as well as the matching modular Sinamics S120 drive system and a software solution previously patented for high-end applications for precise control across motor segments (closed-loop operation with transmitter) or automatic control (open-loop operation without transmitter) of the carriers. This allows for speeds of up to 4 m/s and accelerations of up to 50 m/s2. The levels actually achieved depend on the type and volume of the given product. The motion control can be optimized using standard Sinamics and Simotion tools. The combination with special drive functions such as VIBX (for vibration extinction) is also possible. This allows sophisticated control algorithms to actively counteract even the spilling-over of liquid media during fast acceleration and braking.

The MCS is format-compatible with established workpiece carrier systems, meaning it can be combined with them as needed; subsequently expanding existing systems is also easy. For instance, carriers can also be (re-)equipped outside the line and easily moved in and out as required, significantly speeding up production changes.

The carriers are equipped with noncontact readable and writable RFID (radio-frequency identification) transponders for an optimized production flow and seamless traceability. It is also possible to record and analyze the individual performance data of each carrier. Using a condition monitoring system, imminent problems of individual carriers or of a transport route can be identified and eliminated quickly and the plant availability maintained at the highest level.

Because the MCS builds on the standards mentioned above, it can be electronically linked with the (Sinamics) drive axes of the core processes and of the auxiliary units, with all the options offered by Simotion. As each carrier technically corresponds to a virtual axis in the drive system, perfectly matched interpolated processes – for instance, also synchronized via disk cams – can be realized. And, ideally, this can be done without an additional controller, although in principle it is also possible to distribute the tasks onto several “shoulders.” In any case, the fast communication via Profinet with IRT (isochronous real time), also across controllers, means shorter cycle times and thus maximum (drive) performance.

Topology of the Multi-Carrier-System © Siemens AG

Highest flexibility for diverse applications

With the MCS, Siemens and Festo not only anticipated current trends in the packaging industry; other applications with frequent product changes, particularly in assembly automation, also benefit from the high flexibility and dynamism.

Picture credits: Siemens AG