EoW November 2011

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EuroWire – November 2011 38
technology news
British company PWM, which designs
and manufactures high-performance
cold welding equipment, is stepping up
production of its custom-made dies for
welding two different sizes of non-ferrous
wire and rod.
According to PWM’s managing director,
Steve Mepsted, more wire manufacturers
are looking for cold welding dies capable
of bonding different sizes of wire during
the wire drawing process.
“We custom make dies specifically for
this application, enabling manufacturers
to weld different wire sizes together
extremely quickly when changing spools,”
said Mr Mepsted.
“Manufacturers can, for example, weld
2.5mm diameter wire to 2.7mm diameter
wire without disrupting production,
which has considerable cost benefits.”
PWM’s double cavity dies are hand-made
by skilled engineers in the company’s
own workshops to stringent quality
standards using top quality tool steel.
Although most of the recent demand is
for dies to weld wire sizes with diameters
within the range 0.3mm to 1.8mm (0.011"
to 0.071"), PWM has made dies to bond
materials with larger diameters, for
example 8mm rod to 9.5mm rod.
PWM offers manufacturers a
fast turnaround and can provide
custom-made dies within two weeks from
receipt of order. Standard sizes of die can
be supplied within 24 hours.
PWM Ltd – UK
Fax: +44 1233 820 591
Email:
Website:
Custom-made cold
weld dies facilitate
continuous production
▲ ▲ Custommade dies from PWM
As North America prepares to rebuild the crumbling infrastructure and increase the
quantity of power transmission lines, decisions need to be made about how to get the
power from the generation plants to the places it is required.
Overhead transmission lines of 400kV have significant environmental impact. Therefore
underground power lines are a preferred option. Underground transmission lines –
Milliken cables – are used in high voltage underground transmission when servicing
highly populated areas around cities, airports, power generations plants, etc.
These conductors’ large cross sections are obtained with a composition of sectors. The
pre-spiralled sectors are made separately on rigid stranders, and in a second phase
are composed into one large cross section with a drum twisting line. The Milliken
conductor is composed with four to seven pre-spiralled compacted sectors. Each sector
is separated from the adjacent with insulating or semi-conductive tapes. Frequently,
a central round conductor is used and a water blocking tape is placed between the
sectors’ layers.
Cortinovis has developed rotating machines specifically designed to handle these large
conductors: the Cortinovis rigid cage strander with rotating compacting heads, and the
Cortinovis drum twister with rotating pay-offs for sector assembly.
Cortinovis Machinery America, Inc – USA Fax : +1 908 479 1644
Email: Website:
Rebuilding the North American power
transmission infrastructure