| 摘要 |
PURPOSE:To obtain highly productively said tube of smooth surface and good secondary workability, by passing the cylindrical film through the inside of the die head and covering it by the molten parison extruded from the die head at the specified condition. CONSTITUTION:The cylindrical film 5 which is made by rounding the laminate film 1 containing the metal layer and overlapping its edge is passed through the inside of the die head 8 at the condition in which the outside air pressure of the cylindrical film 5 is lowered by aspirating air in the die head space 9 and die head tip space 10. The inside of the cylindrical film 5 is kept at the atmospheric pressure by the air hole, the cylindrical fiml 5 is covered by the molten parison in the expanded state due to the air pressure difference. The cylindrical film is cooled, being kept at the desired shape by applying decompression of the aspirating room 19 through the hole 18 of the cooling jacket. |
