A Clever Concept Ensures Success

Color accentuated metal and plastic bottle caps sporting the logos and striking brand names of the drinks manufacturers have become an important part of the packing industry. They also ensure safe, hygienic handling of the bottles and guarantee that the contents are not impaired during transport and storage. Millions of these caps with easy-grip shapes and advertising slogans are produced on the machines of the subsidiary of the Swiss PackSys Global Group (PSG) in Thailand.
PSG is the only machine manufacturer worldwide to produce complete lines for the production of extra long aluminum caps for wine and spirits bottles. These are punched from pre-printed aluminum sheets, deep-drawn in several steps, cut to the exact length and fed to the decoration line. In the next work step, a gas or electric oven removes the residue lubricant and oil from the deep-drawing process by heating. Then the caps are primed, dried and printed by the offset technique. After applying a clear varnish they are finally dried in a second oven. Another machine then rolls edges, beading and nominal breaking points into the decorated caps. Special plastic discs or sealing discs are inserted in the final step.

 

Quick change

 

PSG has relied on Siemens automation technology for many years in the construction of their production systems. The key elements of the new decoration line are the Simotion motion control system in the drive-based D435 version for the mid performance range and adapted drive technology from the modular Sinamics S120 converter series.
A drive assembly is made up of a separate infeed/feedback unit, Simotion regulation modules and optionally single or double-axis motor modules. The structure in the so-called booksize format is compact and service-friendly because all the components can be changed independently of each other. A digital system bus (Drive-Cliq) and electronic rating plates save tiresome parameterization in first-time commissioning as well as in the replacement of a drive component. There are 1FK7 servo motors on all main axes of the production line. The machine is operated by a 10-inch touch panel with a Simatic WinCC flexible user interface.

 

Modular and service-friendly

 

The basic difference of the Simotion solution from the previous solution is the integration of PLC, motion control and technology functions into one device. These are integrated directly into the Sinamics drive assembly here. The merging reduces the hardware scope and lowers the costs. It also does away with interfaces and the associated adaptations of PLC and motion control. This, in turn, leads to shorter engineering and cycle times which are necessary to print the required 250 caps per minute (15,000 pieces per hour).
The production system is driven basically by eight servo motors. Six of these ensure precisely adapted processes during the caps' journey through the printing machine. Motors are installed respectively at the entrance to and exit from the drying oven. A Simotion D435 hardware platform and two Sinamics CU320 control units co-ordinate the interaction of all 16 servo axes. A total of approximately 150 digital input signals and 130 output signals must be processed.
Two PT100 temperature sensors on the drying oven are also connected to the motion control system. In addition, the “fast cam” option is used in order to be able to respond faster to process signals. This way, a cycle time of 240 ms is ultimately achieved.

 

Expectations totally satisfied

 

The time available for the pilot project was extremely tight. The metal cap decoration line was accepted by the customer just four months after the presentation of the concept. The mechanical engineering company's mid-term goal is a uniform automation concept for all machine types as well as the one-stop shopping at an equipper. Those responsible at PSG are convinced that they will have further service and cost advantages as a result which will ultimately benefit the end customer.

 

 

Advantages of Simotion and Sinamics: