WCA September 2012

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Technology news
Wire & Cable ASIA – September/October 2012 46
For many years it has been popular to shield MV, HV and
EHV cables with lead or aluminium or with longitudinal
applied glued Al/PE tapes. Based on the growing market
demand for alternative solutions for these, Rosendahl
Austria has entered this segment of power cable
manufacturing equipment.
Rosendahl’s metal tape forming and welding line RN-W
gives the possibility to produce cables with better
properties like increased mechanical stability, water and/or
gas tightness, high-pressure resistance, lower weights,
smaller dimensions and short current resistance. At the
same time this technology is more environmentally friendly
and more flexible.
The metal sheathing process starts with a tape out of
copper, aluminium or stainless steel, which will be applied
around a cable core. These tapes will be formed,
longitudinal welded and sized. Depending on the requested
product design a corrugation process can follow.
An advantage of this solution is the possibility to fulfil
plenty of different demands (cable designs) with high
productivity. In addition to this it is possible to have an
“offline” or an “inline” (combination with the jacketing
process) configuration.
Metal tape forming with longitudinal welding gives cable
designers and makers the possibility to serve solutions to
the market, especially in the field of renewable power
generation and transport.
The target is to serve lighter cables, which fulfil all
requirements and specifications.
At the same time these cables offer increased flexibility and
cross pressure resistance. In the field of land-cables
Rosendahl’s RN-W presents an innovative alternative to the
commonly known “combined layer technology” where, for
example, screen wires and tapes are used.
Rosendahl Maschinen GmbH – Austria
Website:
Metal tape forming
and welding line
RN-W for MV, HV &
EHV power cables
❍ ❍ Increased flexibility from Rosendahl
Highest quality wire
Wire drawing is one of the major bulk deformation
processes to produce high quality wire in a wide
cross-section dimension range.
During this manufacturing process the cross-section of a
wire or rod is reduced by pulling it through a die, located
in a special die holder tool. In the multi-pass wire drawing
machines the wire goes through several stages of such
forming tools. The drawing force for the deformation
process is mainly influenced by the geometry of the die.
For the evaluation of the die geometry the delta factor is
used to predict the optimum approach angle. For the
reduction of wear and friction and to achieve high surface
quality, optimal hydrodynamic lubrication is important.
The Linnox drawing machine by CPA is designed as a
wet drawing machine for fine high-strength steel wire and
operates on the principle of the so-called slip drawing
process. Implementation of modern technological
aspects ensures the production of highest wire quality.
High pressure cooling lubricant jets in the deformation
zones protect against metal dust, provide an intense heat
removal directly at the forming area and guarantee an
optimum lubrication of the drawing tools. Another
advantage is the high operating comfort with an
integrated control system.
CPA – Austria Website: