Abstract
Experimentally, it has been observed that when a solid rod is pulled through a stepped or conical passage, which is filled with viscous fluid (like polymer melt) then the pressure generated is so high, that the outer casing may rupture if the wall thickness is not large enough. Furthermore, if the casing is very strong, the rod may suffer permanent deformation if it is not made of a very hard material. In this paper an experimental study of the die-less wire drawing process is carried out in which the conventional reduction die is replaced by a die-less reduction unit. The unit consists of a parallel bore section and a tapered bore size greater than the incoming wire diameter such that metal to metal contact is totally eliminated. This technique of wire drawing eliminates the problem of wear and breakage during start-up. Furthermore, due to ease of the wire insertion through the unit, the leader wire is no longer a necessity. The reduction of the wire diameter is induced by the hydro-dynamic action of polymer within the die-less unit. The experimental work was under taken with borosiloxane polymer as pressure medium. The results of this study should be useful in optimizing the design of the die-less reduction unit for plasto-hydrodynamic die-less drawing and coating of wires, tubes and wire ropes.