| 摘要 |
<p>ASTRACT OF THE DISCLOSURE A method for the deformation of a hollow workpiece comprising an orientable, thermoplastic polymer by passage in the solid phase through a die having both an entry side and an exit side is provided herein. The novel process comprises the first step of providing the hollow workpiece at the entry side of the die. Then a tension, which is insufficient to cause tensile failure of the workpiece but which is 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, is applied to the hollow workpiece from the exist side of the die. Finally, the deformed hollow workpiece from the exit side of the die is collected. This oriented tubular material has improved mechanial properties, especially in directions other than the machine directions.</p> |
