| 摘要 |
PURPOSE:To produce the subject product having a bulging part and a three-dimensional irregular bend and free of seam by supplying a tubular blank material to a long cavity having a bulging part while adjusting an extrusion speed, to form a parison, and thereafter blow moding the parison. CONSTITUTION:A tubular synthetic resin material is extruded through the extruding port 5' of the die head 5 of an extruding machine 1 into a long cavity having a bulging part 7a provided in a laterally split metal mold 6' and motors 14 and 17 of a cross slide 4 and a lifting and lowering device 8 mounted on a cylindrical member 9 provided at the leading end of a cylinder 3 are operated to shift the extruding port 5' along the axis of the cavity 7. In the bulging part 7a, the extrusion speed is accelerated and its thickness is increased, and thereafter the extruding machine 1 is stopped. Then, the tubular raw material is cut by means of a cutter 18, and the tube diameters at respective parts are made equal, the bulging part 7a obtaining a thick parison (a). Then, a rotary plate 20 is half rotated by means of a motor 23 to shift the metal mold 6 into a clamping device 24. Then, a movable plate 26 is caused to descend, to perform the mold registering of the metal mold 6' on the metal mold 6. Air is blown in the parison (a) through an air inlet port 27 to perform blow forming of the resin. |
