Parkway-Kew Corp. is a full service supplier of
hardsurfaced wire drawing blocks or capstans and
is recognized as the world leader in this field.
The cutting edge HVOF, plasma, metallizing and
submerged arc coating technologies are used to
improve the wear and corrosion resistance of
many process parts. Tuner rolls, sheaves, step
cones and various guide devices are prime
candidates for hard coating to minimize the down
time associated with frequent change out.
In the 1950's Parkway-Kew Corp. pioneered
the use of submerged arc welding for the
rebuilding and hardsurfacing of wire drawing
blocks. Submerged arc welding is still
considered the premier method and most cost
effective method for hardsurfacing wire drawing
blocks. PK-503 with its characteristic cracked
appearance caused by heat checking of the super
hard alloy. In some cases, the cracked surface
may be detrimental to the quality of the wire.
In these instances, PK-200 which is a sub arc
alloy of the same hardness, but lesser chemistry
is used on steel sleeves or steel blocks because
it will deposit virtually crack free.
Later, Parkway-Kew Corp. introduced the use
of fuse welding for wire drawing rings used to
draw copper and aluminum. PK-920, PK-700, and
PK-800 are the industry standards in this field.
They offer a viable lower cost alternative to
solid ceramics without the potential breakage or
slippage problems inherent in solid ceramics.
In the early 80's, Parkway-Kew Corp. added
the metallizing capability at the request of
some of its customers. The primary alloys used
with this method of hardsurfacing are PK-400 and
PK-475. Both alloys are very forgiving and
provide the highest quality surface finish to
the wire being drawn. These alloys are not the
most wear-resistant alloys, but can be the most
practical and in the case of very large wire,
they are the only successful type of
hardsurfacing.
In 1989, Parkway-Kew Corp. introduced the
first HVOF (high velocity oxygen fuel) coating
for a wire drawing block. HVOF is a
hardsurfacing process where the alloy powder is
expelled from a spray gun at speeds that can
exceed Mach 6 and the powder impinges on the
substrate and then builds up on itself. It forms
a hard dense coating, which is imperfection free
that then can be ground to specifications. A
wide variety of alloys can be applied with the
HVOF system; the two primary alloys for wire
drawing blocks are PK-700 and PK-920. PK-700 is
a tungsten carbide alloy and PK-920 is a nickel,
chrome, and boron alloy.
In the late 90's, Parkway-Kew Corp.
introduced the plasma sprayed ceramic coated
block. This method has proven very cost
effective for high speed and high slip, ferrous
wire drawing applications, especially for small
high quality or plated wires. PK-1500 is the
most wear resistant ceramic utilized for wire
drawing blocks.
14" Vaughn intermediate block
hardsurfaced with PK-503 |
22" Macbee stripper block
hardsurfaced with PK-503 |
|
