| 摘要 |
<p>A polyester film roll having a core and a polyester film wound around the roll, characterized in that when the diameter of the roll is measured successively at various points in the direction of the width thereof, the difference of the maximum and minimum measured values is 2 [the width (m) of the roll] 10-3 or less and [the length of a wound film] 10-7 or less, or the maximum length of the straight line drawn perpendicularly from a curve representing the fluctuation or change of the diameter of the roll which is obtained by the above measurement to the straight line connecting the both ends of the curve is 500 ν µm or less in the convex side (the maximum convex) and 300 ν µm or less in the concave side (the maximum concave). The film roll can be employed for manufacturing a polyester film roll which is free from wrinkle or slack which has occurred conventionally with the elapse of time and has a good appearance of shape, without changing properties of the film.</p> |
