Patent ID: 11565459

Abstract:
The invention provides a heat-shrinkable polyester-based film roll obtained by winding a heat-shrinkable polyester-based film with a shrinkage ratio of 30% or more in a film main shrinkage direction in hot water at 90° C. for 10 seconds. The film roll has a winding length of 2000-25000 m and a width of 400-2500 mm. The film has a thickness of 5-40 μm. In thickness unevenness in a width direction of the film on a surface layer of the film roll, there are positions having concave thickness patterns, and in a concave portion that has a maximum thickness difference (maximum concave portion), thickness unevenness in the maximum concave portion, which is obtained from the maximum thickness difference in the maximum concave portion and an average thickness of the film is 10% or less. The winding hardness of the surface layer of the film roll is 400-800.