TEMPERATURE INDICATOR FOR THE INDICATION OF TEMPERATURE FLUCTUATIONS OF ITEMS

摘要

The invention refers to a temperature indicator which records exceeding the upper or prescribed temperature level, at which items in a cold chain should be maintained. The indicator is composed of 10 layers that make it possible for an adequate quantity of an indicator material (3) to be deposited on a carrier substrate (1) that is activated by a pull-out tab (6) being pulled out; the indicator material (3) can thus propagate across an absorption layer (9) and any exceeding of temperature becomes visible. A separation ribbon (4) prevents propagation of the indicator material (3) prior to activation, while a protective layer (8) provides for adequate functionality. Individual layers are glued by adhesive layers (2, 5, 7). The indicator is covered by a transparent self-adhesive film (10), on which instructions or any commercial messages can be printed, except on the place of a transparent portion (10a) where an absorption layer (9) should remain transparent. By changing at least one physical property, such as a change in the aggregate state of the indicator material (3), the indicator irreversibly records any exceeding temperature up to maximum cumulative time that depends on the selected materials for the indicator material (3) and the absorption layer (9). The indicator can be completely realized by a combination of methods used in graphics technology. This provides for a precise realization of a conical groove (la) for the indicator material (3) in the carrier substrate (1) and precise dosing of this material; perfect reproducibility of all indicators is herewith ascertained. Flexible substrates are generally used and this is why the temperature indicator is thin and flexible and meets all requirements for a smart label. While activated, the temperature indicator can already be present on an item, so the packaging can be completely prepared separately from product packing and the indicator is activated only when the packed product has entered the cold chain.