EOW May 2007

equipment for wire treatment

Heat and surface treatment systems

reliably annealed in a two-zone circuit without any additional supply of energy. The RM series annealers from Niehoff are able to switch automatically between two and three-zone annealing according to the wire diameter, thus avoiding energy wastage.

as wire made of various copper alloys. This kind of wire is very difficult to anneal in resistance continuous annealers designed for copper. The RI annealers create wire with a fine grained, homogeneous microstructure that gives it very good processing and forming properties. RI annealers can be combined with rolling systems and drawing systems, and are suitable for round, flat and profile wires with a simple cross-section made of brass, bronze and German silver, as well as nickel and nickel alloys such as heating conductor and resistance alloys. The process for plating copper alloy wires realised in continuously working galvanic plating lines must generate a tight plating with homogeneous physical properties and a high surface quality along the whole wire length. Modern plating lines for copper alloys must meet demanding technical, ecological and economical requirements. Maschinenfabrik Niehoff and Steuler Anlagenbau, a manufacturer of surface treatment plants, combined their experience to develop the Niehoff-Steuler WPT wire plating technology and to manufacture galvanic wire plating lines for tin plating, tin-lead plating, nickel plating, silver plating, and zinc plating of non-ferrous metal wires. Advantages of WPT lines include complete solutions without interface problems, minimised consumption of energy, water and chemicals, up to 100% usage of anode materials, and automatic dosing of additive and supply of water. Maschinenfabrik Niehoff GmbH & Co KG – Germany

For physical reasons, wire must be annealed during the drawing process. For certain applications a surface treatment is also necessary. Maschinenfabrik Niehoff GmbH & Co KG, Germany offers a range of continuous annealers and galvanic plating lines for wire made of copper, aluminium and other non-ferrous metals and their alloys. Wire made of copper and copper alloys is normally continuously annealed immediately following the drawing process, in an annealer which is integrated into the drawing line. The wire is fed over contact pulleys, which induce an electrical voltage. A defined current flows as a result of the inherent resistance of the wire material causing the wire to heat up. Niehoff has developed annealers for various applications. The product line incudes systems that process between 1 and 42 wires with diameters ranging from 0.05mm to 8mm. In practice, heat treatment during continuous annealing of copper wire consists of a pre-heating, the main annealing, and sometimes post- heating. As a result, the annealing sections in the annealers are designed as a three- zone circuit. After the wire has passed through the main annealing section, it is cooled using a coolant, which is then removed with forced air emitted by air jets. In order to remove any moisture residue on the wire surface, the wire is heated again in the third zone. However, if the wire diameter is greater than 0.20mm, the residual heat in the wire is sufficient to evaporate the moisture. Consequently, this wire can be

Anode basket with anode material

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The company has also developed an inline annealer for use in the production of wire made of EC aluminium and numerous aluminium alloys. Because aluminium has a strong tendency to oxidise, continuous resistance annealers for aluminium wire must be designed so that no oxygen can enter during the heating process. The Niehoff Bühler NBM joint venture company has developed RI type inductive continuous annealers. These operate on the basis of the induction principle, and are suitable for wire with low electrical and heat conduction characteristics, such

Fax : +49 9122 977 155 Email : info@niehoff.de Website : www.niehoff.de

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EuroWire – May 2007