| 摘要 |
A method and an apparatus for orienting amorphous plastic material causes the material to be displaced through a gap with a smallest gap width less than the material thickness of the plastic material. During such displacement, the material is oriented, under the formation of a transition zone (18) between as yet unoriented (thicker) material (16b) and oriented (thinner) material (16a). The material is displaced at a speed entailing that crystallization energy released on orientation reaches the defining surfaces (14, 17) of the plastic material at a point in time when the material has already assumed its reduced thickness. The apparatus includes a drawing ring (50) and a mandrel (60), between which the gap is formed. When the plastic material enters into the gap, the gap is of a width which substantially corresponds to the material thickness of the amorphous material. In the direction of displacement of the plastic material, the gap width is reduced so as to be less than the material thickness of the amorphous material, but exceeds the material thickness of the oriented material. |
