| 摘要 |
PURPOSE:To obtain a stretching device for an annular film, which can establish comparatively easily a longitudinal and lateral draw ratios and perform simply and easily simultaneous and biaxial stretching, by a method wherein a plurality of sets of pairs of holding tools are arranged by widening gradually spaces among pairs of the holding tools and each pair of the holding tools move the annular film at a fast speed in order along a moving route. CONSTITUTION:When an annular film 1 approaches a heating unit 3, a pair of holding tools 2, 2 are moved under a state where the surface of the heating unit 3 is covered by holding the annular film 1. While the annular film 1 is heated at an appropriate temperature by the heating unit 3 during movement, the annular film 1 is stretched laterally gradually by the holding tools 2, 2. When the annular film 1 stretched laterally is handed over to the next pair of the holding tools 2, 2 and the pair of the holding tools 2, 2 move the annular film 1 at a higher speed than that of the previous holding tools 2, 2. Therefore, the annular film 1 is stretched in the direction of vertical and horizontal axes at the same time. |
