EOW May 2007

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EuroWire – May 2007 117
Sirio Wire is an Italian company
that supplies equipment for the
chemical and electrochemical
treatment of wire, including
ultrasonic and electrolytic cleaning,
chemical and electrochemical
pickling, coating, and electro-
deposition. The company’s
bronzing lines for the production
of tyre bead wire combines many
of these elements.
The bead wire is a bronze coated
wire used for the reinforcement of
all types of tyre. A bronzing line can
be divided into three main sections:
a stress relieving lead bath, a
cleaning and pickling section,
and a bronzing section. The lines
operate at very high speed (up
to 500m/min) with wire diameter
between 0.8mm and 1.8mm.
As the speed of the wire is very high in this
type of line, special care has to be taken
for all rising and air wiping steps, and Sirio
Wire has designed an efficient solution to
reduce the liquid drag out from one bath
to another.
The line consists of a set of polypropylene
or stainless steel working basins, and
a set of tanks made of polypropylene
welded plates.
Collecting pipes feed the working basins,
and the bath is pumped from the storage
tank located below, by vertical pumps.
The alignment of all working basins
allows straight line guiding of the
wire, without any deviation. It is
essential for the wire entering the
bronze plating line to be perfectly
clean, and it is therefore necessary
to remove all residuals of soap
and oxide present on the wire.
Sirio Wire recommends the use
of a combined system, first using
electrolytic cleaning in an alkaline
bath to remove any soap present
on the wire, then an electrolytic
pickling bath to remove oxide and
activate the surface of the wire for
the deposition.
The wire is bronze coated by
chemical displacement in an acid
bath (containing copper sulphate,
tin sulphate and sulphuric acid)
at a controlled temperature. A good
agitation is obtained in the bath in order
to improve the coating process.
SirioWire Srl – Italy
Fax: +39 0362 576 138
Email:
Website:
lBronzing line for tyre bead wire
equipment for wire treatment
General view of a bronzing line ▲