Wire drawing and coating using a combined geometry hydrodynamic unit: Theory and experiment

In conventional drawing, the diameter of the wire is reduced by pulling it through a reduction die. By plasto-hydrodynamic technique, the wire diameter can be reduced by a limited amount without using any conventional reduction die. In this process, the wire is pulled through a tubular orifice of certain bore which is filled with a viscous fluid (polymer). The smallest bore size of the orifice is always greater than the diameter of the undeformed wire and hence it is possible to avoid metal-to-metal contact. During the past few years, plasto-hydrodynamic wire drawing has been investigated by different researchers using either stepped parallel or tapered bore pressure unit. In this paper, wire drawing and coating using a combined parallel and tapered bore hydrodynamic unit has been modelled considering that the polymer is a non-Newtonian fluid and results are obtained for different wire speeds in terms of the changes in viscosity, shear stress, percentage reduction in area, pressure distribution and coating thickness. (c) 2006 Published by Elsevier B.V.