WCA March 2009

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Cleanliness in compounds Absolute cleanliness is essential in high-voltage cable production. With the CSS 2 for real time control and detection of contamination in the polymer melt, Sikora believes it can offer the technology to guarantee process stability and product quality at the production line. The CSS 2 camera system detects contamination particles in XLPE-materials. With super clean PE-material, higher voltage insulation strength with identifiable wall thicknesses and no defect charges can be achieved. Contamination can be caused by material handling. Shavings can be created by wear of the extruder screw or the cleaning of the extruder screw can leave dust particles that bring tiny pores or inclusions into the material. Contamination in the form of combustion particles such as amber and scorches, which occur during the long-term operation of the line, are also a risk. The CSS 2 system ensures continuous real-time and online quality assurance, removing the need for time-delaying laboratory analysis. 100% inspection of the XLPE-melt in the flow channel allows an immediate intervention in the production process. The flow channel between the extruder and the crosshead includes sight glasses and an optical CCD-camera system, which transilluminates the insulation material. The high-resolution CCD-colour camera detects particles of 20µm in the PE-melt and the identified constituents are classified with regard to their size. Particles that exceed the specified tolerance value are analysed and their colour, situation, vertical and horizontal dimensions and the light absorption are displayed. The measuring data of contamination is stored on a hard disk for subsequent inspections. Besides the graphical display of the detected particles, monitor pictures show a live image of the complete material flow – even if the selected tolerance level is not exceeded – and a trend curve of particles per litre. After data analysis the results are presented in a histogram according to size and quantity. The system informs the operator when production can start and shows when contaminations exceed the tolerance value and operator intervention is needed. In contrast to granulate control, the system actually detects contamination in the material before the cable is produced.

CSS 2 detects contamination in XLPE-materials ❍ ❍

Sikora AG – Germany Fax : +49 421 489 0090 Email : sales@sikora.net Website : www.sikora.net

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Wire & Cable ASIA – March/April 2009