Package for keeping goods in a temperature-deccreased, preservative state and a temperature indicator therefor

Abstract

In a first aspect, the invention relates to a package ( 1 ) for keeping goods in a temperature-decreased, preservative state, in which the temperature should have a certain desired value. According to the invention, the package is connected to a temperature indicator ( 2 ) comprising means, which preserves a certain property when the temperature of the goods is decreased towards and past a predetermined limit value, which is at least somewhat higher than said desired value, but which alters this property in an irreversible way if the temperature during the storage would rise to or above said limit value. Advantageously, the temperature indicator ( 2 ) may be transparent as long as the temperature is lower than said limit value, but become opaque when the limit value is exceeded, e.g. in order to make reading of a bar-code ( 8 ) impossible. In a second aspect, the invention also relates to the temperature indicator as such.

1 . Package for keeping goods in a temperature-decreased, preservative state in which the temperature should have a certain highest desired value, characterized in that a temperature indicator ( 2 ) is connected to the same ( 1 ), which indicator comprises means ( 5 ,  6 ), which has a certain property when the temperature of the article is decreased towards and past a predetermined limit value which is at least somewhat higher than said desired value, but which alters said property in an irreversible way if the temperature during the storage would rise to or above said desired value.  
     
     
         2 . Package according to  claim 1 , characterized in that said means ( 5 ,  6 ) is initially transparent and preserves the transparency thereof during temperature reduction past said limit value and said desired value, but is converted to an irreversible opaque state if the temperature would rise above the limit value.  
     
     
         3 . Package according to  claim 1  or  2 , characterized in that the temperature indicator ( 2 ) is integrated with the package ( 1 ) by being included in an external surface thereof.  
     
     
         4 . Package according to any one of the preceding claims, characterized in that the temperature indicator is in the form of a thin label.  
     
     
         5 . Package according to  claim 2  and  4 , characterized in that the temperature indicator ( 2 ) is applied to the outside of a bar-code ( 8 ) exposed on an external surface of the package ( 1 ) in order to at least partly cover the same and, on one hand, in the transparent state thereof permit reading of the code, but on the other hand in a possibly occurred, opaque state make conventional reading of the code impossible.  
     
     
         6 . Package according to any one of the preceding claims, characterized in that said means in the temperature indicator consists of two liquid mixtures ( 5 ,  6 ) having different chemical compositions, a first one ( 5 ) of which having a lower freezing point than the second one ( 6 ) and being spaced-apart from this via a partition wall ( 4 ) initially being liquid-tight, but which, upon refrigeration to a certain limit temperature above said desired temperature, looses the liquid tightness thereof, the two liquid mixtures ( 5 ,  6 ) preserving their properties in a frozen state, but being altered irreversibly if heating would take place to or above said limit temperature, more precisely by the fact that the second liquid mixture penetrates out into the first one and is mixed therewith while causing a chemical reaction with the ensuing change of state.  
     
     
         7 . Temperature indicator for packages intended for keeping goods in a temperature-decreased, preservative state in which the temperature should have a certain highest desired value, characterized in that the same comprises a means ( 5 ,  6 ), which has a certain property when the ambient temperature is decreased towards and past a predetermined limit value which is at least somewhat higher than said desired value, but which alters this property in an irreversible way if the temperature would rise to or above said limit value.  
     
     
         8 . Temperature indicator according to  claim 7 , characterized in that said means ( 5 ,  6 ) is initially transparent and preserves the transparency thereof during temperature reduction past said limit value and said desired value, but is converted to an irreversibly opaque state if the temperature would rise above said limit value.  
     
     
         9 . Temperature indicator according to  claim 7  or  8 , characterized in that the same is in the form of a thin label ( 2 ).  
     
     
         10 . Temperature indicator according to any one of claims  7 - 9 , characterized in that said means in the temperature indicator consists of two liquid mixtures ( 5 ,  6 ) having different chemical compositions, a first one ( 5 ) of which having a lower freezing point than the second one ( 6 ) and being spaced-apart therefrom via a partition wall ( 4 ) initially being liquid-tight, but which, upon refrigeration to a certain limit temperature above said-desired temperature looses the liquid tightness thereof, the two liquid mixtures ( 5 ,  6 ) preserving their properties in a frozen state, but being altered irreversibly if heating would take place to or above said limit temperature, more precisely by the fact that the second liquid mixture penetrates out into the first one and is mixed therewith while causing a chemical reaction with the ensuing change of state.