Time/temperature indicators
Abstract
Abstract A DEVICE FOR DETECTION AND INDICATION OF THAWING OF A FROZEN OBJECT. THE DEVICE IS ATTACHED TO THE FROZEN FOOD AND INCLUDES AN INDICATOR AND A SENSOR WHICH UNDERGOES COLOR CHANGE UPON THAWING TO A PRESELECTED TEMPERATURE BELOW 100*F. IN PARTICULAR, A SMALL TRANSPARENT CONTAINER OF SENSING MATERIAL, COMPRISING AN ORGANIC GEL EXHIBITING SYNERESIS, IN COMBINATION WITH AN INORGANIC SALT HYDRATE, IS COVERTED TO THE FROZEN STATE IN PROXIMITY TO A PH INDICATOR, AND THE ENTIRE COMBINATION ATTACHED TO THE FROZEN FOOD PACKAGE OR OTHER FROZEN OBJECT. WHEN THE PACKAGE OR OTHER OBJECT IS EXPOSED FOR A PREDETERMINED TIME TO TEMPERATURES ABOVE THAT AT WHICH THE SENSING MATERIAL MELTS, THE LATTER BECOMES LIQUID AND REACTS WITH THE PH INDICATOR TO PRODUCE A COLOR CHANGE THEREIN WHICH IS READILY VISIBLE THROUGH THE TRANSPARENT CONTAINER. REFREEZING HAS NO EFFECT ON THE COLOR CHANGE.
Inventors
- 👤 Maria Telkes
- 👤 Henry Hahn
Bibliographic Details
Claims Analysis
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