| 摘要 |
A tape or label for sealing a container that provides visual evidence if the seal is forced open or cooled below a breakdown temperature. The tape includes a plastic strip (20), a layer of ink (22) printed on a surface of the plastic strip, and a layer of pressure-sensitive adhesive (24). The tape can be incorporated into a bag (10) for sealing the bag closed. The tape includes an ink layer that is sandwiched between the plastic strip and the adhesive layer. The adhesive can be secured to portions of a bag to seal it closed. If the seal is forced open, the ink layer visibly delaminates from the plastic strip. The adhesive layer and the plastic strip are chosen to have different rates of shrinking when cooled, so that when the tape is cooled below its breakdown temperature, the ink layer delaminates. In an alternative embodiment of the tap, two layers of ink are printed onto the plastic strip. The first layer of ink is clear and is printed onto the untreated plastic strip in a pattern. The second layer of ink is opaque and is printed uniformly over the plastic strip and the clear ink after the plastic strip is treated.
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