| 摘要 |
PURPOSE:To manufacture polyester oriented film having few uneven thickness at a high efficiency by providing polyester containing at least one of alkaline metal, alkaline earth metal, zinc, manganese and a compound of them, preparing a sheet constituting low specific resistance polyester bonded or laminated with both ends of high specific resistance, out of which electrostatic charge is separated, cooling down and solidifying same with a moving cooling material and orienting. CONSTITUTION:0.005-1wt% of at least one of alkaline metal, alkaline earth metal, zinc, manganese and a compound of them is contained in polyester. A compound of them is contained in polyester. Polyester A making specific resistance 2X10<8>-5X10<9>OMEGA.cm at 285 deg.C, and polyester B whose specific resistance is set at 1/100-1/5 of polyester A at 285 deg.C, are melted respectively into a sheet made by bonding or laminating polyester B to both ends of polyester A. Electrostatic charge is separated, cooled and solidified by a moving cooling material, and then the sheet is oriented to manufacture a polyester oriented film. |
