Machine module provides software-supported product changeovers
A machine builder embedded a high-speed linear motor transport system in a machine, adding speed and flexibility and saving space with the new design. Koch Pac-Systeme GmbH, headquartered in Pfalzgrafenweiler, Germany, specializes in building customer-specific blister packaging machines and systems. With extensive line design experience, the company’s engineers are able to stay flexible and implement each customer’s requirements. The packaging experts recently demonstrated their expertise with a complex new packaging line for toothbrushes.
The transport system from Beckhoff Automation is designed to replace mechanical systems with software functionalities that make the line more compact and more flexible for faster product changeovers.
Koch achieved a seamless, integrated and efficiently executed packaging process with customized equipment ranging from blister machines to product infeed and blister grouping modules to end-of-line packers. Customers received solutions that meet industry-specific requirements and are matched to the size and shape of the respective products. A line for packaging toothbrushes is controlled via automation software and processes up to 320 toothbrushes or 240 blisters per minute, showing off the packaging line’s flexibility.
Project manager Gert Müller explained the functional scope and complexity of the line with a total length of 28 m.
“At first, the line will be operated with two different formats for which the customer uses two different foil thicknesses,” he said. “What makes the line so attractive is its superior flexibility, because an automatic foil width adjustment feature allows the customer to use different foil sizes to produce additional blister sizes in the future. After the blisters have been formed, the toothbrushes are supplied via a high-speed pick-and-place (HSPP) system that uses a camera to control their position.
“Next, another HSPP places the cardboard backing and uses ultrasonic spot sealing to keep it in place for the actual sealing process. A laser system applies a code to the back of the card that is verified downstream via a camera system. After the blisters have been separated in a punch station, they are transferred via a two-axis portal to the central labeling and grouping unit before another HSPP system groups and transfers them to a cartoning machine. The packaged blister packs are then transferred to the customer’s downstream packaging steps.”
Transport system increases labeling and grouping unit efficiency
Müller explained how the labeling and grouping unit is an example of Koch’s expertise in developing innovative solutions.
“We installed a circuit that is 11-m long and equipped with 24 movers with special carriers for single and twin blisters. When the product changes, only the carriers have to be switched out,” he said.
Since this is a very quick and easy process, setup changeover times are reduced considerably, added global account manager Wolfgang Braun. “The end customer wants to produce different formats with our packaging line, and therefore very fast and flexible format changeovers are required.”
Jürgen Welker, director automation and technology at Koch, said there were two specific factors that convinced the company to use transport technology: The high throughput rate and the ability to adapt to various labeling speeds
Welker also noted machine design-related benefits from the transport system. “The labeling and grouping unit – and therefore the entire line – would have been 2 m longer and much more complex due to the additional mechanical components that would have been required. It also would have been much less accessible for the operators to execute format changes.”
Braun considered the flexibility and the ability to convert the line very quickly to be key benefits from the end customer’s perspective.
“The original plan called for a conventional solution based on a so-called bucket chain. While it was designed to be width-adjustable, it quickly encountered limitations because of the constantly expanding product spectrum. One – much more expensive – solution would have been to add a second bucket chain or even a split line with two separate packaging machines,” he said.
Transport system ensures high flexibility with advanced software functionality
The labeling and grouping unit integrates flexible motion sequences, according to Müller. “Depending on the format, the two-axis system transfers eight or 12 blister packs to four or six movers. These movers then travel to the labeling station. Another HSPP system places the blister packs in multiple layers into the cartoning machine’s product chain in accordance with the outer packaging type. The system stands still for loading and unloading while the labeling process runs continuously,” Müller said.
The software functionality also answers the requirement for rapid product changeovers, because each blister format has its own recipe, including the precise processing positions that can be selected with a mouse click. In addition, the machine module has two labeling devices. Depending on the format, the software tells the transport system which of these it needs to travel to.
PC- and EtherCAT-based control technology benefits
An industrial PC was able to control the 24 movers precisely. The control cabinet PC was able to control two HSPP systems by handling the systems as additional TwinCAT NC tasks. Both HSPP systems also were equipped with servo drive technology.
“TwinCAT software provides all necessary functionalities,” Welker said. “The fact that each mover is mapped as a separate servo axis in TwinCAT is hugely advantageous for us. That way, we can monitor and adjust each mover separately, which is convenient and safe due to integrated higher-level functions like collision avoidance. And to top it all off, there is the exceptional performance of EtherCAT. The controller makes full use of EtherCAT’s extreme speed, particularly where the communication with the many servo drives in the system is concerned.”
Keywords: mobile machinery, system integration
Koch Pac-Systeme designed a labeling and grouping unit in a toothbrush packaging line with a transport system.
PC and EtherCAT-based technology helped the machine could operate efficiently without any challenges.
The software functionality also answers the requirement for rapid product changeovers.
What benefits could your plant derive from a transport system?