WCA March 2009

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and
Wire & Cable ASIA – March/April 2009 67
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.
Sikora AG – Germany
Fax: +49 421 489 0090
Email:
Website:
CSS 2 detects contamination in XLPE-materials ❍ ❍