| 摘要 |
PURPOSE:To prevent expansion of a cylindrical body, by a method wherein the cylindrical body is pulled out through a liquid sealing device of an end part of a cooling liquid tank after the extruded cylindrical material has been solidified by leading the same within a depressurized cooling liquid tank through a sizer to cool the circumference of the same. CONSTITUTION:Resin melted by heating by an extruding machine 1 is extruded through a die 3 by making the same into a cylindrical body 6, led within a cooling liquid tank 7a, which is filled with a cooling liquid and depressurized into negative pressure, through a sizer 9, further led within a liquid feeding cylinder 13, the cooling liquid is jetted in the form of a jet flow through a slit 15 provided on the circumference of an inner wall of the liquid feeding cylinder 13 by sending the cooling liquid into the liquid feeding cylinder through a pressing-in port 14 at predetermined pressure and the cylindrical body 6 is cooled by flowing the cooling liquid within a gap 16 at high speed. Then the cylindrical body 6 is led within a cooling liquid tank 7b through a liquid sealing device 19, taken off further by a take-off device 28 through the liquid sealing devices 19, 19 and the transparent cylindrical body 6 is obtained. |
