| 摘要 |
PURPOSE: A heat shrinkable polyester film, and particularly to a heat shrinkable polyester film suitable for use in a label is provided. CONSTITUTION: A heat shrinkable polyester film of the present invention has a transverse tear defect percentage of about 20% or less as determined in the following vibration test: the film is rolled into a tubular shape, two of its opposite edges bonded together, and then the tubular film is placed around a vertical stack (total weight: 660 g) of three food container cans each having a diameter of 72 mm and a height of 55 mm; the can stack with the tubular film placed therearound is passed through a shrink tunnel to shrink the tubular film onto the can stack; a total of 18 packs of such can stacks are placed into a cardboard box having a length of 455 mm, a width of 230 mm and a height of 165 mm (6 packs in the length direction by 3 packs in the width direction), and the cardboard box is sealed; the cardboard box is vibrated along the width direction for 30 min by a stroke of 50 mm and at a vibration rate of 180 reciprocations/min, after which the transverse tearage of the tubular film is visually observed; and the transverse tear defect percentage (%) is determined based on the number of defective packs per 18 packs, wherein the defective pack is any pack having a tear flaw of 30 mm or longer along a can periphery. The heat shrinkable polyester film of the present invention has a good shock resistance during shipping especially under low temperatures, with a good finish after shrinkage and a sufficient solvent adhesiveness. Thus, the heat shrinkable polyester film of the present invention is suitable for use in a multi-packaging label for packaging, inter alia, a stack of cans. |
