Time Temperature Monitor

A time-temperature indicator comprising:

• an indicator liquid reservoir;
• a migration medium;
• and
• a trigger;
• wherein the trigger is operable to release an indicator liquid from the reservoir upon activation of the trigger into an entrance of a channel defined within the migration medium, wherein the extent of migration of indicator liquid from the trigger area through the channel can be determined by a change in color or brightness of the migration medium and is an indication of one or both of differences in temperature and a passage of time;
• wherein the migration medium comprises a planar medium, having first and second major surfaces, which can absorb the indicator liquid;
• wherein the channel is defined within the migration medium by a rapidly cured de-wicking ink and is defined at the surface of the first and second major planes of the migration medium by first and second impermeable lamination media;
• and
• wherein at least one of the impermeable media is transparent such that a change in colour or brightness can be determined, as between a trigger area of the migration path and a distal portion of the migration channel.

A process for manufacturing a time-temperature indicator, the process comprising the steps of:

• (a) selecting a planar migration medium having first and second major planes;
• (b) applying a de-wicking agent to define a migration path within the migration medium;
• (c) allowing the de-wicking agent to cure;
• (d) applying first and second impermeable media upon the first and second major planes whereby to define a migration channel closed to the upper face, lower face and sides and having an entry portion defined at one end of the migration path;
• (e) providing a trigger about an area of one of the impermeable media adjacent said entry portion, which trigger is operable to allow a transfer of indicator fluid therethrough upon activation;
• and
• (f) providing a liquid reservoir adjacent said trigger portion being positioned on an opposite side of said one of the impermeable media.

An apparatus for manufacturing a time-temperature indicator, the time-temperature indicator comprising an indicator liquid reservoir, a migration medium and a trigger;

• wherein the trigger is operable to release an indicator liquid from the reservoir upon activation of the trigger into an entrance of a channel defined within the migration medium, wherein the extent of migration of indicator liquid from the trigger area through the channel can be determined by a change in colour or brightness of the migration medium and is an indication of one or both of differences in temperature and a passage of time, the apparatus comprising:
• a printing means, operable to print an ink upon a planar migration medium having first and second major planes, the ink being applied to define multiple units of time-temperature indicators, wherein the migration paths are defined;
• a curing station, operable to cure the de-wicking ink;
• first and second impermeable media lamination stations, operable to place first and second impermeable media upon the first and second major planes whereby to define a migration channel closed to the upper, lower and sides and having an entry portion defined at one end of the migration path;
• a trigger defining station wherein a trigger is defined within an area of the one of the impermeable lamina;
• and
• a liquid reservoir defining station operable to place a sachet of indicator fluid adjacent said trigger portion on a side of the impermeable lamina opposite said migration channel.