| 摘要 |
PURPOSE:To enable manufacturing of heat-shrinkable pipe having the inside diameters different from each other, by a method wherein a heat-shrinkable pipe expanded after a form of the outside diameter of an expanded mold tube is cooled rapidly, its shape is held, the mold tube is deaerated, restored to a state before expansion and pulled out from the heat-shrinkable pipe. CONSTITUTION:A mold tube 1a is passed through within a heat-shrinkable pipe 2a and the heat-shrinkable pipe 2a is heated and softened. Then when pressurized air A is blown into the mold tube 1a and the mold tube 1a is expanded to the desired outside diameter, the heat-shrinkable pipe is expanded to a shape after the outside diameter D of the mold tube 1a. The expanded heat- shrinkable pipe 2b is cooled rapidly. The mold tube 1b is restored to a state before expansion by deaerating the same and pulled out from the heat-shrinkable pipe 2b. A shape of the heat-shrinkable pipe 2b manufactured in this manner is fixed as it is and the shape is held until the same is reheated. Therefore, even in the case where the same mold tube 1a is used for the heat-shrinkable pipe 2b having the same inside diameter and the time of extruding, the inside diameter can be changed easily by changing only pressure of the pressurized air A to be applied to the mold tube 1a. |
