EoW September 2007

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EuroWire – September 2007 87
dies & die shops
Temsa Diamond Die Division
SA, Spain, specialises in the
manufacture of diamond
dies and tools for the cable
and wire industries.
The company’s manu-
facturing programme covers
natural diamond (ND),
synthetic monocrystalline
(MCD), and synthetic
polycrystalline (PCD) wire
drawing dies, extrusion dies
and cable guides for cable
coating, and special dies in PCD for pipe
calibration and cable compacting.
There is a common discrepancy between
the actual possibilities of PCD blanks and
the so called ‘maximum recommended
bore size’ proposed by the PCD blank
manufacturers, particularly in the design
of sets of dies for the Cu and Al rod
breakdown machines.
Estimates are usually calculated
assuming that the dies will operate
on the mid range of percentage of
elongation/reduction per draft.
As the elongation/reduction percentages
are high in the rod breakdown process,
the dimensions of the PCD blanks
required must be carefully considered,
in order to build a suitable geometry on
the die.
It is advisable to perform a careful study
of each dies geometry, based on the
machine’s cinematic sequence, and
then decide which PCD blank will suit
the process. The contact point of the
rod (or wires) on the reduction cone
should be approximately at 50% of the
cone’s length. In most cases, this involves
adjusting the angle of the reduction
cone, adapting its aperture
to the particular elongation/
reduction percentages of
the machines.
As the rod does not always
go perfectly straight into
the die, a PCD blank must be
used that is big enough to
allow a wide open entrance
angle, to prevent scratches
on the rod and excessive
generation of metal dust
due to lack of appropriate
flow of the lubricant emulsion. Users
should also beware using ‘standard’
calculations for non-standard processes,
and should check with their diamond die
supplier that the proposed PCD blanks
are suitable for extraordinary elongation/
reduction percentages, and that a logical
geometry will be built into the dies when
rod breakdown machines are involved.
Temsa Diamond Die Division SA
– Spain
Fax: +34 93 660 0473
Email:
Website:
The right PCD dies for Cu and Al rod breakdown machines
Temsa Diamond Die Division specialises in the manufacture of diamond dies ▲