- Outer diameter regulation by means of vacuum control
- Control intervenes if pre-set value deviate by >5mbar
The control unit VR-3 produces a consistent vacuum in the calibration bath of an extrusion line – automatically. When in mode “Maintain Constant Vacuum“, the fully automatic vacuum control unit VR-3, equipped with Siemens PLC (Programmable Logic Controller) and developed by Extrudex Kunststoffmaschinen, Germany, ensures that the pre-set vacuum value is consistently maintained throughout the entire production period.
Outer diameter regulation by means of vacuum control
The VR-3 is operated via a touch display. Its PLC automatically ensures a vacuum generation via Venturi systems, a fully automatic vacuum constancy and an outer diameter regulation by means of vacuum control. Process water temperature regulation and generation/retrieval of important process data are also ensured.
Control intervenes if pre-set value deviate by >5mbar
The control permanently compares the set value with the actual value, measured precisely via the digital vacuum sensor. Should the pre-set value deviate by >5mbar, the control intervenes immediately and automatically adjusts the actual reading to the set value via the VR-3. The available vacuum actual values for the individual product, together with the actual values of the cooling water can be stored in the primary PLC control. Consequently, this provides a reliable process control by obtaining continuous stabilising control measurements combined with a complete process data acquisition and registration. When in mode “outer diameter control”, it ensures that the tube diameters can be maintained within pre-set tolerances, engaging a laser measuring head.
Siemens PLC with vacuum control VR-3 (photo: Extrudex)
