Figure 1. Using a Rexroth automation system, the Perfecta can fill and produce bags at a rate of 400 per minute with thread and label, or with an outside paper protection. A highlight of the automation system is Rexroth’s integrated safety technology.
Safety up to date
With motion control from Rexroth, Teepack pursues a clearly defined goal.
“We can activate the additional modules and necessary servo drives on the respective machine via the user interface. This reduces the variety of the software and allows for quick, subsequent integration of additional modules,” says Meyering, explaining a decisive advantage.
The motion control synchronizes the individual modules with the cycle of the Perfecta, and it automatically takes over format and recipe changes from the main control without any necessary additional control intervention.
A particular highlight of the automation is Rexroth’s integrated safety technology, Safety on Board. It’s comprised of several certified safety functions, such as safe stop/operation stop and safe movements in the form of reduced speed, maximum torque or turning direction. The safety functions directly in the drive shorten the reaction times to below two milliseconds. With other safety solutions, a machine cycle has to be interrupted for a coercive dynamization of up to eight hours in order to detect “dormant bugs.” Now, the tests automatically run online in the background during processing with Rexroth Safety on Board, and without any required intervention by the user. This creates the prerequisites for a continuous 24/7 operation.
Figure 2. With the two machines Perfecta and Zenobia, Teepack counts on the Rexroth automation solution IndraMotion for Packaging.
Different machine – same automation
Teepack has also extended its product range with the newly developed, vertical tubular bag machine, Zenobia. The new machine fills block-bottom bags with little air inside. For automation, it uses IndraMotion for Packaging in the controller-based version IndraMotion MLC, which is able to control up to 64 servo drives. With compact hardware, users can even use robotics functions via the motion control and PLC functions.
“The Zenobia is designed for continuous, as well as intermittent operation,” says Myering.
In both operation modes, the machine can produce “Air Free” bags with little air inside in one step, and thus replaces a second machine that had been necessary to utilize until now. Thanks to the continuous process, the machine achieves a performance increase of up to 20 percent. Additionally, the products are filled in a more gentle way so the bags have a better quality and the machine runs more smoothly. This machine is not only designed for tea packers but also for users who pack frozen food, pasta and fresh goods, leguminous plants or other food and non-food products. These capabilities are new for Teepack.
In comparison to the Perfecta, Teepack only changes the hardware platform of the automation system in order to control a larger number of servo axes. Engineering tools, the run time system and the motion modules remain the same and reduce the time required for the implementation of new concepts.
“With the Zenobia, we mainly use the driving along the motion curves, as well as pressure mark and dancer controls of the IndraMotion,” says Meyering.
With this, the software developers can even copy program modules that have been written between the individual machine ranges, since the Rexroth system solution uses the same software for all hardware versions. Teepack modularly includes additional units and modules in the open automation architecture, as is the case with the tea bag machines.
Figure 3. The drive-based IndraMotion MLD controls up to eight servo axes in real time via SERCOS III without any necessary additional hardware.
Open interfaces
All of the system solutions from Rexroth support connection to the most diverse control communications and automation environments with open interfaces. With the Zenobia, the user only enters the thickness and length of the bag when it is time to weld, and then the PC control uses these as a basis to calculate the optimum motion profiles of the individual axes, and sends the data to the motion control via TCP/IP. The motion controller controls the overall machine cycle with a capacity of up to 200 bags per minute. Also, Teepack uses leading, state-of-the-art safety with Safety on Board from Rexroth.
The folding parts of the tubular bag machine adapt to the individual filling level of the bags, and thus consider variations of the filling height. The scanning of the filling height takes place during the welding of the head and/or bottom seam. The head seam, which is made by the transverse sealing jaws, is also the bottom seal of the following bag so that no projecting packaging material occurs.
With the new vertical tubular bag machine, Teepack addresses the world market as they already have with the tea bag machines. “An imp