DIE DRAWING OF TUBULAR THERMOPLASTICS

摘要

A process for the deformation of a hollow workpiece comprising orientable, thermoplastic polymer by passage in the solid phase through a die having both an entry side and an exit side, which process comprises providing the hollow workpiece at the entry side of the die; applying to the hollow workpiece from the exit side of the die a tension insufficient to cause tensile failure of the workpiece but sufficient to deform the hollow workpiece by drawing it with reduction in its bulk cross-sectional area in the solid phase simultaneously through the die and over an internally positioned former having a cross-sectional area greater than the initial internal cross-sectional area of the hollow workpiece; and collecting the deformed hollow workpiece from the exit side of the die.