Flexible package

An all-in-one automation solution from KEB for a Stickpack machine provides real added value through variable adaptation to customer requirements.

The tubular bag machine SBL-50-M from the Merz company in Lich is a vertical and fully-automatic form, fill and seal unit for the manufacture of small tubular bag packaging, called "Stickpack". Achim Fuchs, Development Manager Software at Merz, describes the concept: "This machine is a multi-channel basic machine for producing bags. It can pack a wide range of products... get more information, such as liquids, powders and creams, in combination with different product feeds and dosages." The main requirement for the control unit concept, namely the flexible ability to respond to customer specifications, was successfully implemented by KEB: "The C6 Compact control unit can be used both as a main and sub-control unit," explains Fuchs.

"As an embedded control unit for this all-in-one solution, communication to the I/Os and axes takes place through EtherCAT. The data exchange between HMI and the control unit takes place via Ethernet, and simultaneously provides the LAN network for remote maintenance." In the event the customer specifies a different control unit, the data exchange to the conventional PLC is implemented via an additional fieldbus interface, such as Profinet, CAN or Ethernet/IP. 

The C6 HMI is another KEB component in this system. "It serves as a scalable machine visualisation with integrated Combivis Connect Runtime for remote maintenance of the equipment," explains Fuchs. The remote maintenance software "Combivis connect" creates a VPN between the office computer and the remote devices, and thus ensures problem-free access to remote sub-networks. "This offers an intelligent, easy and secure solution for the maintenance or analysis of the machine by the customer or service team directly from the workstation." C6 HMI can be adapted to conventional controls thanks for the large number of available software drivers, and thus sets a new standard of flexibility.

At this time, the KEB COMBIVERT F5 servo drive is the executive unit which implements the specified movements of the control unit into the corresponding kinematics, in combination with the related servomotor. It will be replaced with the new Combivert S6 servo drive in the future, in order to ensure even faster cycle times together with the already integrated EtherCAT interface. In addition, the drive also features a two-channel integrated multi sensor interface, in order to analyse an external encoder in addition to the motor position feedback, which depicts the machine cycle in the motion controller.

"KEB always focuses on the system concept," explains Benjamin Schmidt, who works in regional sales and is the contact person for Merz at KEB. "The numerous software modules in the Combivis Studio 6 libraries also ensure that individual components that logically complement each other are easily combined into a functioning unit. They help developers with the simple connection of the power unit and the programming of the movement profiles." In the case of Merz' packaging machine, it is the "CAM Axis Control" module that implements the electronic cam disk, which can be adjusted during operation and thus allows for numerous movement profiles. The machine's movements are supplemented with a cam switch that controls the actuators in real time, with repeatable accuracy. The "Heat Control" module regulates the temperature zones of the sealing tools with the required accuracy, whereby the temperature is recorded with the KEB Remote Analog Inputs (PT 100). Additional power units for volume dosing, pump dosing or handling can be added as part of the axis assembly or independently. Achim Fuchs is pleased: "The easy integration of the power units into the control concept, the flexibility of the system for different customer specifications, and the solution-oriented advisory services finally turned the decision in favour of KEB."