Brigitte Diekhaus, Ralf Mickley, Dr. Henning Stieglitz, Heinrich Dohmann, Dr. Markus Bornemann
Papers # 2016 Berlin
The paper offers an overview of systems and components for efficient pipe extrusion, particularly for larger and thick-walled pipes. It introduces several possibilities for lower melt temperatures and internal pipe cooling. Together these systems can significantly reduce sagging and cooling length needed in the line. Furthermore, a look is taken at a system for inline product change that allows fast color and pipe dimension changes during the production of larger (diameters above 250 mm), thick-walled pipes. The main components are the pipe head including the adjustable melt gap, the calibration sleeve and the pipe support in the vacuum bath and the end sealing.
In the past years, the cost pressure faced by manufacturers in pipe extrusion has been rising continuously. For example: In the production of highly standardized products that need little production know-how, the price at which raw material has been bought is a deciding factor, along with the overweight and the tolerances that need to be considered in the calculation of production cost.
In addition, delivery times are shortening continuously, even for more specialized products of which there are usually lesser amounts in stock. Production batches are also becoming smaller and smaller.
Therefore, the economic efficiency of a pipe extrusion line is determined essentially by four factors:
- Output / line speed
- Energy consumption per kg of output
- Wall thickness tolerance
- Flexibility in (dimension) change processes
Taking these topics into consideration, manifold new developments addressing these challenges were made in the past months and tried in the field. These will now be introduced one by one.