EoW November 2010

Compounds & colourings

Placement of the adapter in the extrusion line ▲ ▲

Ultrasonic PE melt temperature measurement systemUltratemp 6000

The ultrasonic PE melt temperature measuring system consists of an adapter, which is placed between extruder screw and extruder crosshead. The adapter includes a high-temperature ultrasonic transmitter and an ultrasonic receiver placed at opposite sides of the flow channel. In this way the ultrasonic signal propagates through the entire cross-section of the PE melt flow (typically 50mm diameter for CV-line insulation extruder) and an averaged PE melt temperature can be determined in real-time. An additional pressure gauge is located at the measurement position to record the melt pressure. This pressure gauge is used to compensate the moderate pressure influence on the ultrasonic velocity. Mounted on the outside of the flow channel the ultrasonic sensors do not penetrate or have any contact with the polyethylene melt and so the extrusion process is not affected by the sensors. The measuring rate of 100Hz allows a fast response time as well as the registration of small temperature variations. During the polyethylene extrusion process an ultrasonic PE melt temperature measurement system ensures a non-contact, non-invasive, online measurement of PE melt temperature in real-time, using the temperature and pressure dependence of the recorded ultrasonic velocity. Within the capturing of material-specific ultrasonic velocity data this system is suitable for various polyethylene materials. The measuring accuracy of the melt temperature is deduced to be less than ±1°C. For the first time it is possible to accurately measure melt temperature of cross-linkable PE in CV-lines without disturbing extrusion. With Ultratemp 6000 it is possible to follow online the most critical variable of CV-line extrusion, thus avoiding premature cross-linking, maintaining process stability and possibly extending the running time. It also offers the possibility of feedback control of melt temperature.

Sikora AG – Germany Fax : +49 421 48900 90 Email : sales@sikora.net Website : www.sikora.net Maillefer Extrusion Oy – Finland Fax : +358 9 886 65 771 Email : info@maillefer.net Website : www.mailleferextrusion.com

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EuroWire – November 2010