EOW May 2007

equipment for wire treatment

l Bronzing line for tyre bead wire

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 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.

General view of a bronzing line

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.

SirioWire Srl – Italy Fax : +39 0362 576 138 Email : info@siriowire.it Website : www.siriowire.it

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EuroWire – May 2007