EoW July 2013

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News
Technology
July 2013 26
With six lines now in production, BWE’s
SheathEx™ process is becoming the
new alternative to seamless aluminium
sheathing of high voltage cables.
A further line will be installed and
commissioned in Europe during the
second quarter of this year.
The SheathEx process is an extension
of the well established Conform™
and Conklad™ continuous extrusion
technology. The SheathEx machine
extrudes a continuous and seamless
aluminium tube from two 12mm
diameter rods around a high voltage
cable core. BWE collaborated with high
voltage power cable producers in China
to develop the product and process
specifications for this new and unique
technology.
The SheathEx machine incorporates a
large crosshead to accommodate the
large diameter dies required for cable
sheathing. The aluminium sheath is
seamless, with no weld line or bead. The
twin groove mode of operation ensures
the aluminium sheath is concentric.
BWE’s patented induction heating
system provides a very even temperature
distribution around the tooling, leading
to very stable running conditions, and
consistent properties in the aluminium
tube. The feedstock material is standard
CCR aluminium rod, which is readily
available and cheap, compared to other
materials (such as flat aluminium sheets
used in a welding line).
The cable core passes continuously
through the crosshead. A cooled insertion
tube protects the cable core on entry to
the crosshead, and rapid quench of the
aluminium tube immediately after the
die, prevents thermal damage to the core.
Downstream from the SheathEx machine
the cable sheath is corrugated in-line
and coiled onto large drums. The
SheathEx process is a continuous (no
stop marks), reliable (no weld) and cost
effective (cheap materials, low energy
etc) method of sheathing high voltage
power cables.
SheathEx, Conform and Conklad are
registered trade marks of BWE Ltd.
International patents have been filed
for the SheathEx process, SheathEx
tooling system, machine arrangement,
control method and induction heating
technology that is employed.
BWE Ltd – UK
Website:
Seamless aluminium sheathing of high voltage
cables
▲ ▲ A BWE SheathEx production line
Matt TPU for wire and cable
Huntsman Polyurethanes has developed a non-blooming, matt, polyester-based
solution for the wire and cable market. Irogran® A 85 C 5024 DP is a new material to
eliminate the risk of blooming (when additives migrate to the surface of a material
and become visible).
Blooming has no effect on the mechanical performance of cable, but it is unsightly
and is an issue that cable manufacturers have looked to resolve. Irogran A 85 C 5024
DP is a halogen-free TPU that offers a consistent matt finish and stable extrusion
qualities.
Easy to process, the product is thought well suited to wire and cable applications
such as jacketing, spiral and data cables.
A number of customers have already trialled the product, which has passed third
party RoHS and halogen-free tests. The compound is targeted for use in China, but
the company anticipates interest from elsewhere.
Henry Yao, market development manager for greater China at Huntsman
Polyurethanes, said: “Irogran A 85 C 5024 DP is an important addition to our wire and
cable portfolio. There are other matt technologies available on the market, but this is
unique in terms of the formulation and its non-blooming properties.”
Huntsman Polyurethanes – USA
Website :