| 摘要 |
PURPOSE:To enable preparation of a tubular member having longitudinally uniform size as well as having small diameter, by providing a scaling up path part and a scaling down path part near the tip end part of a resin flow path. CONSTITUTION:Near the tip end part of a resin flow path 13 there are provided a scaling up flow path part 18 whose inner and outer diameters become gradually larger toward the outlet, and a scaling down flow path part 19 whose inner and outer diameters become gradually smaller, and an outlet flow path part 20 is provided following them. In the course where a resin passes through the scaling up flow path part 18, its pressure is lowered. Then in the course passing through the scaling down flow path part 19 the pressure rises; as the outlet is near, the degree of rise is restrained and it is extruded from the outlet. As the result, it is possible to mold by extrusion of the tubular member of stabilized size because of reduced amount of the resin spread to radial direction at the time of extrusion from the outlet, and the resin deposit under bonding to the edge faces of a die 11 and a nipple 12, and because the outlet of a gas supply hole 14 is not closed. As the diameter of the outlet flow path part can be freely set, the molding of the tubular member of small diameter is also possible. |
