| 摘要 |
PURPOSE:To efficiently form a tubular film having excellent transparancy by using a cooling mandrel with a specific surface roughness in the manufacture of the tubular film by an inflation method. CONSTITUTION:In a manufacturing method for a resin film in which a molten resin bulb extruded from a circular die is cooled by a mandrel provided inside the die, the mandrel used for cooling has a surface roughness of 3.5-8mu Rmax (where Rmax is value measured by JIS-B 0601). The method is particularly effective for the manufacture of the film of thermoplastic resin of low melt viscosity (e.g., polyamide resins, polyester resins, etc.). |
