WCA September 2015

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Wire & Cable ASIA – September/October 2015
Technologynews
Degreasing of stranded wires and ropes
ROPE and strand making often requires the individual wires
to be properly lubricated before stranding. During stranding
the individual wires also work-harden, which makes the
strand lose its straightness and causes individual wires to
“flower” when the strand is cut.
Often the strands and ropes have to be cleaned and/or
stress relieved before they are suitable for further
processing or packing. This is common in many
applications, for example in strands and ropes for the
medical, jewellery, architectural and decorative sectors.
Plasmait has been working with wire manufacturers in these
sectors to design an effective solution for heat treatment of
stranded products and ropes. The plasma machine allows
for an accurate distribution of heat/temperature throughout
the cross-section of the stranded construction.
Individual wires are annealed or stress relieved to equal
temper/softness, which straightens the strands and
prevents the “flowering” of strand ends. Accurate control of
heat transfer and thereby resulting mechanical properties
can be achieved on a wide range of stranded constructions
and materials such as copper, aluminium, stainless steel,
plated wire wires and many other materials and their alloys.
The annealing/stress relieving process is conducted in a
controlled inert atmosphere in low vacuum, which facilitates
effective degreasing inside the stranded construction during
the annealing process. This is a result of a distinct feature of
plasma discharge that is the strongest in the small cavities
between the individual wires in the stranded construction.
Surface activation can be achieved if extra coating adhesion
is necessary in-line with subsequent polymer coating.
Plasma machines can be used on a wide range of diameters
and materials. They are compact machines that use little
floor space. Plasma machines can cold start in a few
minutes and can be stopped immediately. This avoids the
lengthy heating-up and cooling-down times and associated
energy costs that are symptomatic of a conventional tube
furnace.
Plasmait GmbH – Austria
Website:
❍ The plasma machine allows for an accurate distribution of heat/
temperature throughout the cross-section of the stranded
construction