| 摘要 |
PURPOSE:To prepare a dense and high-strength polyacetal hollow body, by drawing the polyacetal hollow body into more than 3 times of the draw ratio while being pressed from the inside and the outside through a fluid and being heated below the softening temp. CONSTITUTION:The end of the long hollow body A wound on a supplying drum 2 is connected to a pressure pump 7 and the end of the drawn hollow body A' wound on a winding machine 6 is closed. The hollow part of the hollow bodies A, A' are pressed by a pressing fluid C. The drawing apparatus B, B' are constituted of cylindrical vessels 21, 22 having pressure keeping members 11, 12 and 15, 16 on their both ends, the supplying holes and the taking-out holes, and fluid outlets 17, 18 and inlets 19, 20 respectively. The long hollow body A is drawn during passing the drawing apparatus B, B' while being pressed under a required pressure from the outside through pressing fluids C, C' and being heated by steam pipes 23, 24 which are located at the outside of the cylindrical vessel and have double pipe structure, through the fluids C, C'. The drawing of high draw ratio can be thereby achieved with inhibiting void generation and fibrilation. |
