Weber extrusion presented an extrusion line for 5-layer PE-RT pipes
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The new extrusion line was augmented by an innovative 5-layer coextrusion tool by ETA Kunststofftechnologie GmbH based in Troisdorf. Outstanding surface quality, low individual layer thicknesses and high output were the focus of the tool development here. The production speed of 70 m/min that could be achieved with the new high-performance extrusion line is well above the usual speeds available on the market.
A total of 20 plastics processing companies had the opportunity to gain detailed insights into the various line components and the performance of the entire system at six demonstration events.
During the six presentation days, sample pipes with an outer diameter of 18 mm and a wall thickness of 2 mm were produced. Hostalen 4731B PE-RT material was used for the inner and outer layers. The quality of the pipes produced was assessed on site in terms of surface quality and layer distribution and convinced all who were there.
The total output of approx. 420 kg/h was the sum of the outputs of five WEBER single-screw extruders. All extruders were linked to form an easy-to-operate system together with the higher-level NEXXT365 line control. This made it possible to implement and demonstrate starting, ramping up to maximum speed and shutting down the line in an impressively simple way.
The newly developed coextrusion tool by ETA facilitates a maximum total throughput of 500 kg/h and the production of pipes with a diameter range between 8 mm and 32 mm.
The tool uses circular distributors – a special type of helix mandrels - for distributing the melt of all five plastic layers. These circular distributors ensure short holding times of the polymer melts in the tool, fast colour and material changes, as well as a very even distribution around the entire circumference.
This allows for reduced layer thicknesses and a pipe wall without mechanical or visual weak points.
Thanks to the special geometric design of the flow channels, the extrusion tool has a long service life and is easy to operate. It also offers the possibility of making adjustments regarding the number of layers and the layer structure. The modular concept allows the integration of various options such as a colour striping module, different coatings for the flow channel surfaces and an electromechanical centring device.
