Package for indicating heat-seal condition
AssigneeBemis Company, Inc.
InventorsYuan Liu, Xiangke Shi
Life of this patent
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Abstract
Heat-seal condition indicating packages include a first sealing substrate comprising a leuco dye and a second sealing substrate comprising a leuco dye developer. The packages may optionally include a leuco dye sensitizer which dissolves both the leuco dye and the leuco dye developer when melted. The packages further include a heat-seal produced between the first sealing substrate and the second seating substrate. The heat-seal comprises a reaction product of the leuco dye and the leuco dye developer. The reaction product may be colored, which may provide the heat-seal with a detectable optical characteristic. A magnitude of the optical characteristic may be proportion to the strength of the seal between the first and second seating substrates.
Claims20
A heat-seal condition indicating package comprising:
- a first sealing substrate comprising a leuco dye;
- a second sealing substrate comprising a leuco dye developer;
- and
- a heat-seal coupling the first sealing substrate to the second sealing substrate, the heat-seal comprising a colored reaction product of the leuco dye and the leuco dye developer,
- wherein an optical characteristic indicative of the colored reaction product in the heat seal is detectable.
A heat-seal condition indicating package comprising:
- a first sealing substrate comprising a leuco dye;
- a second sealing substrate comprising a leuco dye developer;
- a heat-seal region in which the first sealing substrate is coupled to the second sealing substrate, the heat-seal region comprising a colored reaction product of the leuco dye and the leuco dye developer;
- and
- a non-seal region adjacent to the heat seal region,
- wherein the colored reaction product provides the heat-seal region with an optical characteristic different than the non-seal region.
A method, comprising:
- providing a first sealing substrate comprising a leuco dye;
- providing a second sealing substrate comprising a leuco dye developer;
- and
- heat sealing the first sealing substrate to the second sealing substrate to produce a heat-seal, wherein producing heat-seal results in a change in an optical characteristic at the heat-seal.
Dependencies are inferred from the claim text.