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38 May 2016
T E CHNOLOG Y
Tube Düsseldorf: Innovations go global. Take advantage
of the highest calibre expertise of the No. 1 international
fair as the show goes global. Draw on international syn-
ergies from these leading trade fairs. A cycle of regional
events, staged in successionaround theglobe, responding
to local market and customer needs. Detailed informa-
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Messe Düsseldorf GmbH
P.O. Box 101006
40001 Düsseldorf_Germany
Tel. +49(0)211/4560-01
Fax +49(0)211/4560-668
Tube_WW_87x260_Text EN.indd 1 23.12.14 14:01
Quality assurance
during extrusion of
large tubes
SIKORA’S new Centerwave 6000 features several
transceivers arranged around the circumference of a tube,
to send and receive continuous frequency modulated
millimetre waves for non-contact and µm-precise online
measurement of diameter, ovality and wall thickness, for
larger plastic tubes during extrusion.
In recent years, successes regarding measuring
accuracy have been achieved by researching metrological
applications with frequencies in the millimetre waves range.
However, the results could not be used for the coating
thickness measurement of cylindrical products. With the
Centerwave 6000 measuring system, Sikora has created
new preconditions for the reliable measurement of the
nominal size as well as the outer diameter, ovality and wall
thickness of all kinds of extruded DIN tubes.
Even without knowledge of the properties of the extruded
material and its temperatures, the Centerwave 6000
measures the outer contour as well as the wall thicknesses
simultaneously at several points of the circumference, for
increased precision. Layer thicknesses of multi-layer tubes
can also be measured precisely.
The transceivers continuously send and receive frequency
modulated millimetre waves. Boundary layers, for example
each front and back site of a plastic, reflect these waves,
which are detected and demodulated by the receiving unit
of the relevant transceiver. These received signals contain
information regarding the distance between boundary layers
of the different materials.
After an algorithmic processing of the received signals of
each sensor, the requested measuring values are ready for
visualisation in just a few milliseconds. The values can also
be used for the control of the different dimensions of a tube
in the extrusion line.
For the development of the technology on the basis
of a CW-millimetre wave chip, the goal of creating a
non-contact measuring device at the extrusion of tubes
that is maintenance-free and durable was decisive. By
independently identifying the characteristic values of the
material, the Centerwave 6000 generates measuring values
with high precision, without the need for specifications
regarding the material parameters.
The Centerwave 6000 can provide precise measuring
values at different positions of the production line, even in the
hot area, as no coupling mediums are required, temperatures
are not decisive, and calibrations are not necessary. Two
stand-alone gauge heads have been created, for different
tube diameters – 120 to 400mm, and 250 to 1,000mm.
The Ecocontrol 6000 industrial PC offers numeric
presentation of the measuring values, as well as graphic
visualisation and extensive trend and statistic data features.
Sikora AG – Germany
Email:
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