| 摘要 |
<p>PURPOSE:To obtain the flow molding product with uniform section by controlling the thickness of a parison, while sliding the insert facing a slit along the groove of a flow pin by an actuator, and enlarging or minimizing a part of the slit. CONSTITUTION:During the extrusion of molten resin, when a cylinder 11 is operated and a movable ring 9 is pulled up, an insert 12 elevated along the groove 8 of a flow pin 7. Therefore, the taper part 13 of the insert 12 is moved upward in parallel, whereby the slit 17 at the portion with the piece is partially enlarged. The flow speed of the molten resin passing through the slit 17 of the enlarged portion becomes larger. The molten resin is extruded in the atmosphere, while it has elastic strain larger than that of the molten resin passing through the slit 17 of outer portion. Because the swell ratio of the extruded parison 22 is varies with the difference of elastic strain, the swell of the molten resin passing through the slit of the enlarged portion becomes larger, thereby molding the part 23 with large thickness. When the cylinder 11 is operated and the insert 12 is restored to its original position, the thickness of the parison 22 becomes uniform.</p> |
