Wire Drawing Machines

After having reduced the diameter as much as possible by hot rolling (smallest diameter approximately 5.5 mm), smaller diameters must be produced by cold drawing (see Golis et al., 1999; Schruff, 2004). Tension is applied to draw the hot rolled wire in several pulls down to a final required diameter between 1 and 2 mm. Calcium and sodium stearate are usually applied as a drawing lubricant. These soaps are particularly suitable at high drawing speeds because the lubricant film remains intact. Due to friction, temperatures above 150 °C and as high as 400 °C develop, which cannot be reduced by the cooling effect of the lubricant and air alone. Thus the dies are cooled with water and the wire with compressed air. Compared with earlier machines, modern dry wire drawing machines are more efficient with regard to the consumption of cooling water and lubricant as well as the filtration of stearate dust emissions. Dry aluminum wire drawing machine are machines that pull in the forward direction (Ruge and Wohlfahrt, 2001; Schimpke et al., 1977). They pull the wire as many as 14 times, i.e. a series of 14 drawing dies which are usually powered separately using rotational speed regulators. Typical technical data may be found in Table 22.4.