THREE-DIMENSIONAL DYE MIGRATION TIME INDICATOR

摘要

The present invention provides a time indicator and method of use for determining and visually displaying the passage of a predetermined period of time. The time indicator of the present invention comprises a top portion and a bottom portion. The top portion is a multi-layer segment comprising a dye support layer coated with a masking layer, which containing a viewing window therethrough, and a non-curing ink or dye permeable polymer layer containing a migrating agent. The bottom portion is a multi-layer segment comprising a base support layer and a migrating ink or dye printed on the top surface of the base segment. The time indicator apparatus further comprises a removable impervious film or middle layer, which can be removed allowing the top and bottom portions to come into contact with one another, thereby activating the time indicator. The time indicator of the present invention allows one to follow the uniform directional visual dye migration through the viewing window.