| 摘要 |
PURPOSE:To form stripe pattern of concave type or protruded type on a trunk of a sleeve while a extrusion forming, by a method wherein concaved type or protruded type forms are formed, the extruded sleeve being made contact to a cooling core by a vacuum attracting means. CONSTITUTION:By extracting the sleeve type resin 22 extracted from the point of a die 10 by a take-off unit at larger speed than the flow speed in a flow channel 13, the wall thickness of resin is thinly extended as well as its diameter is narrowed, and resin is cooled being contacted to the outer surface of the cooling core 15, thus the sleeve 23 is formed. At the same time, since the sucking force works through a sucking hole 18 from the vacuum means to the resin 22 passing on the concaved part 17 of the core 15, the resin 22 is contacted to the wall surface of the concaved part 17, and the stripe form 24 of concaved type corresponding to the shape of the concaved part is formed. |
