Fleece-processing machines
Source: CAN Newsletter Motion Control, 2005
The raw material is a soft white and virtually non-tearable fleece which works extremely well as a filter. Spooled onto two 1-m thick tubes, the material leaves the factory 15 work-stations down the line as ready-made vacuum filter bag. “Vacuum bags made of paper are no longer the trend. The synthetic fleece, which is handled in our machines, is the superior when it comes to technical characteristics,” says Rolf Deerberg, owner of the company Deerberg Maschinenbau in Germany. The company, founded in 1983 as engineering office, has in the meantime specialized in developing, construction and sales of specialized machines for the processing of fleece, paper and cardboard.
Already ten years ago, the engineers switched the drive concept of their production lines to highly dynamic servo drives and replaced mechanical cam disks or upright shafts, used for process synchronizing, with servo motors or networked servo controllers.
“We have very much become servo-fans”, says Rolf Deerberg to emphasize the importance of this step. Twenty-six servo axes are part or the drive concept of the vacuum bag machine. A further seven motors are used as co-drives; their engine speed is controlled by frequency converters. Plant engineering and construction projected the control concept as master/slave configuration. The material feed as master provides the frequency of cycles. “Our goal is 60 bags a minute. At the moment we are just below than number”, explains sales manager Hartmut Ustorf. The machine is configured by a user via a human machine interface. The HMI is connected to a PLC, which in turn transmits the signals of the process control to the controllers.
All servo inverters are networked via the integrated CANopen-based systembus; their processors are synchronized. The machine provides two control shafts. The main control shaft rotates with the number of cycles of the produced bags.
