Time-temperature exposure indicator with delayed threshold response

An ascending time-temperature exposure indicator device, comprising:

• a substrate;
• a transport element supported by the substrate;
• and
• a thermally sensitive indicator element supported by the substrate, the indicator element comprising a solid indicator material, the indicator material configured to move along the transport element when melted, wherein
• the indicator material is configured to be a solid below a predetermined threshold temperature of about 10° C.,
• the indicator material is configured to melt and move along the transport element in response to exposure to a temperature at or above the predetermined threshold temperature,
• the transport element and the indicator element are configured so that exposure to at least the predetermined threshold temperature for a predetermined exposure time in a range of about 4-8 hours results in at least a predetermined amount of movement of the indicator material along the transport element, and exposure of the melted indicator material to a temperature at or below a stop temperature in a range of 6-8° C. causes the indicator material to stop moving along the transport element.

A time-temperature exposure indicator label for monitoring time exposure of a host product to a predetermined threshold temperature, the time-temperature exposure indicator label comprising:

• a substrate;
• a human or machine-readable dataform on the substrate;
• a transport element supported by the substrate;
• and
• a thermally sensitive indicator element supported by the substrate, the indicator element comprising a solid indicator material, the indicator material configured to move along the transport element when melted, wherein
• the indicator material is configured to melt in response to exposure to a temperature at or above the predetermined threshold temperature,
• the predetermined threshold temperature is in a range of from about −10° C. to about 70° C.,
• the indicator material further comprises a mixture of a synthetic polymeric material and a wax material,
• the transport element and the indicator element are configured so that exposure of the host product to the predetermined threshold temperature for the predetermined exposure time results in at least a predetermined amount of movement of the melted indicator material along the transport element.

A batch of ascending time-temperature exposure indicators, comprising:

• a unifying container,
• a plurality of at least 50 time-temperature exposures indicators physically coupled to the unifying container, wherein each time-temperature exposure indicator comprises, respectively:
• a substrate;
• a transport element supported by the substrate;
• and
• a thermally sensitive indicator element supported by the substrate, the indicator element comprising a solid indicator material, the indicator material configured to move along the transport element when melted, wherein
• the indicator material is configured to melt and move along the transport element in response to exposure to the predetermined threshold temperature,
• the transport element and the indicator element are configured so that exposure to the predetermined threshold temperature for the predetermined exposure time results in a change of indicator state by exhibiting a predetermined amount of movement of the indicator material along the transport element,
• wherein in response to exposure at the predetermined temperature, at least 90% of the plurality of indicators change indicator state at the predetermined exposure time.

A method of manufacturing time-temperature exposure indicators, comprising:

• producing a batch of 50 indicators, by
• providing a substrate for each indicator,
• providing a transport element on the substrate, and
• providing an indicator element on the substrate, the indicator element comprising an indicator material in solid form, configured to melt and move along the transport element in response to exposure to a temperature at or above a predetermined threshold temperature, wherein the transport element and the indicator element are configured so that exposure to the predetermined threshold temperature for a predetermined exposure time ranging from 4 to 8 hours results in a change of indicator state by exhibiting a predetermined amount of movement of the indicator material along the transport element,
• wherein for each batch of time-temperature exposure indicators, at least 90% of the time-temperature exposure indicators change indicator state during the predetermined exposure time range when exposed to the predetermined threshold temperature.