WCA January 2015

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60 Wire & Cable ASIA – January/February 2015
Sikora AG
Bruchweide 2
28307 Bremen
Germany
Tel : +49 421 489 000
Email:
Website:
The system is installed after the XLPE transport box
(ie octabin or bag), and a hopper, before the hopper of the
extruder, whereas the compound is fed by gravity.
Green technology for higher productivity
of the production line
As explained at the start, green technologies have to
provide both an environmental and financial benefit to the
market. The following gives an example of how the green
system also increases the productivity of the line.
A very important aspect is always the cable joint,
specifically with regard to power cables for offshore
applications. The joints where the cables are connected
together are critical as each joint contains a potential risk
for breakdowns.
Therefore, energy suppliers expect cable manufacturers
to deliver large cable lengths in one piece with a minimum
amount of joints. Consequently, the aim is to produce
energy cables with long lengths with only a few joints while
using highly pure raw material.
One solution is to omit the screens. However, this is
not a suitable alternative for all cable manufacturers.
But, even with the screens remaining in the production,
the application of the newly developed inspection and
sorting system will give manufacturers the benefit of
keeping the screens clean for decisive longer production
runs.
In order to catch possible impurities in the XLPE
compound before they get into the cable, manufacturers
use screens, which are positioned directly in the melt
flow after the extruder, before the crosshead, and thus
prevent contamination from entering the product.
But degraded XLPE, ie scorches or excessive amounts
of contaminants after a certain run time, can clog these
screens. Then the melt pressure in the extruder may
increase significantly.
Finally, production has to be stopped in order to change
the screens, which in turn means that later a joint is
required at that position.
Therefore, the system supports cable manufacturers to
produce long cable lengths in one piece to avoid cable
joints which are the weakest link of the cable. It assures
that contamination that would clog the screens is detected
and separated before it enters the production process.
As a result, longer production cycles can be run and fewer
cable joints are required. Thus, there is a minimised risk of
breakdown as only pure material is used for the insulation.
Conclusion
The introduced system for online inspection and sorting
of material represents an innovative solution of green
technology for power cables.
By assuring clean material for the production process,
plastic material and thus crude oil can be saved, the
productivity of the production line improved and the
lifetime of the cable extended. The short payback period
of the technology also positively contributes towards
consolidated earnings for the company. With this system
the quality and functionality of end products in the cable
industry is increased significantly.