| 摘要 |
PURPOSE:To enable to adhere reliably a tube pulled into a tube to the inside of the tube without causing accumulation of air between the tube and a tube wall, by substituting gradually steam introduced through one end side of the tube for the air to be discharged through the other end side of the tube under a pressurized state. CONSTITUTION:Air A whose pressure is low to such an extent as to enable to inflate a tube 2 into a circular cross section is enclosed into the tube 2, to begin with, and then steam is sent into the tube through an inlet 7 by opening a valve 6 while the pressure is being kept on. The air A is discharged slowly while the pressure, through which an information state of the tube can be kept on, is being kept on by opening a valve 9. When steam B is substituted for the air A like this, the steam in the inside of the tube advances to an outlet side gradually as the steam is interrupted by the low-pressure air. Heating also of the tube progresses slowly from an inlet side of the steam, the tube is inflated in order from an inlet side wherein mechanical strength has been deteriorated due to softening of the tube and adheres closely to a wall of the tube even if the pressure in the inside of the tube is kept balanced and the air which has sojourned between the wall of the tube and the tube is discharged without being left behind. |
