WCN Spring 2011

Drive concept Slip reduction for long wire drawing machines

Lubrication of drawing materials

Slip reduction by using 3-motor technique - Less abrasion of tin and nickel - Less wear of drawing capstans - Reduced noise - Smaller motor sizes, AC-technique becomes more reasonable

- Control of flow rate - Control of temperature - Spraying of capstans and dies - Cleaning of lubricant - Separate lubricant supply for final die holders

downstream processes. They must be simply made ‘Triple A’ − Advanced, Accessible and Adjustable and, of course, attractive in price. The market offers machines with various annealing principles. 2-zone

The increasing demand for reduced cross section reduction on the fine wire drawing lines requires an increase in the number of drafts. A high number of drafts in gearbox machines results in high cumulative slip towards the wire inlet side of the line. High slip has a negative effect on the lifetime of the drawing capstans, on the quality of plated wires, on the noise level of the lines and on the frequency of wire breaks. Drawing machines with three drives reduce the slip at the passages to about 5% and the maximum slip at the wire inlet of standard lines from around 45% to 15%. Power splitting from two to three motors results in the reduced performance of the single motors which makes the application of AC drives cheaper – another advantage of this concept. The advantage arising from the application of AC drive technology is self-explanatory.

As mentioned before, drawing line speeds are increasing and thus we must turn our attention to wire lubrication in order to provide sufficient amount of emulsion at an adequate temperature and pressure at each critical point of the line.

2-Zone annealing

K2 (+)

Drawing lubricant supply Fine die holder

K1 (-)

K3 (-)

• Less energy consumption • Higher efficiency • Diameter range > 0.25mm

3-Zone annealing

K2 (+)

Annealing

The importance of final die spraying is often underestimated.

3.2 Annealing

K1/K4

Triple A Advanced Accessible Adjustable and Attractive in price

At the final die the wire reaches its minimum diameter and the wire speed is the highest within the line. Due to the fact that the final die is located last in the drawing lubricant supply line, neither the pressure nor the quantity of the emulsion are adequate for proper lubrication and rinsing of the final die. For a sufficient grade of lubrication here, a separate line from the lubricant supply system with adjustable spraying is absolutely crucial.

K3 (-)

• Higher energy consumption • Better drying due to reheating zone • Diameter range < 0.25mm

Up-to-date multiwire annealers have to treat multiple wires individually but equally throughout the annealing path to ensure equal electrical and physical properties of the wires for the

annealers with preheating and main annealing zone or 3-zone annealers

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WCN Issue N° 44 www.iwma.org