WCA July 2009

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❍ Ultratemp 6000 measures the temperature of polyethylene melts

Ultrasonic temperature measurement for XLPE insulated cables

of the flow channel. In consequence, the sensors do not affect the extrusion process, even if they have to be exchanged. The extremely high mea- suring rate allows a fast response time as well as the registration of small temperature variations. In all production lines Ultratemp 6000 can be combined with the display and control systems Ecocontrol 600, 1000 and 2000 for efficient production control. The processor systems display numeric and graphical process infor- mation with analysis tools, such as trending, and statistical process control analysis. The Ecocontrol models offer con- tinuous monitoring of the measured values. Alternatively, Ultratemp 6000 can be delivered with a Profibus-DP interface.

response time and can influence the melt flow properties that may result in cross-linking. Sikora’s Ultratemp 6000 is a non- contact system based on non-invasive ultrasonic technology, optimising ex- trusion line productivity. It measures the melt temperature during production and does not influence the melt flow properties. Ultratemp 6000 ensures homogeneous melt viscosity for the extrusion pro- cess and helps to avoid premature cross-linking after screens, which may lead to ambers and scorches in the polyethylene material. The measuring technology is based on high-temperature ultrasonic sensors. The adapter of the system, including the ultrasonic sensors, is positioned in the flow channel between extruder and crosshead. In contrast to conventional methods the ultrasonic sensors do not influence the polyethylene melt flow, because the sensors are at the outside

Melt temperature plays a critical role during the production of medium voltage (MV) and high voltage (HV) XLPE insulated power cables; it can affect the quality of the product as well as the productivity of the extrusion process. Polyethylene materials are used with organic peroxides for cross-linking, and here the melt temperature is subject to tight tolerances since proper melting and homogeneity set the lower limit, while avoiding premature cross-linking sets the upper limit. In research cooperation with the machine manufacturer Maillefer Extrusion Oy of Finland, Sikora AG has developed the new, patent pending melt temperature measuring system Ultratemp 6000. Conventional measurement methods, including contact thermocouple sen- sors or hand-held meters, do not offer reliable results – they are contact measurements with a relatively slow

Sikora AG – Germany Fax : +49 421 48900 90 Email : sales@sikora.net Website : www.sikora.net

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Wire & Cable ASIA – July/August 2009