| 摘要 |
PURPOSE:To produce film having uniform thickness by a method wherein the widthwise temperature distribution of the film is made uniform by improving the shape of the air outlet of plenum ducts at the preheating part of a stretching machine. CONSTITUTION:In a film stretching machine consisting of plenum ducts 16a and 16b, which are arranged opposite to each other on both sides of film and from which hot air or cold air is jetted, and clip main bodies 1, which grasp the end parts of the film and move for stretching, the amount of hot air or cold air jetted from the plenum ducts 16a and 16b against the end parts of the film is set to be larger than the amount of hot air or cold air jetted against the central part of the film. |
