Active Packaging Technology
The invention provides active packaging for food, medicine, or other perishable items. The packaging includes at least one active component to capture moisture and/or gas that may otherwise pass through the packaging wall
1 . A packaging wall containing an active component to capture moisture and/or gas that may otherwise pass through the packaging wall, the packaging wall comprising a multi-layer wall that includes at least six layers, the multi-layer wall including a desired sequence of at least three layers, the desired sequence being found at least twice in the packaging wall, the active component being incorporated into the two outermost layers of the desired sequence, such that at least four layers comprising the active component are provided in the multi-layer wall.
2 . The packaging wall of claim 1 wherein at least two of the layers comprising the active component are in direct contact with each other.
3 . The packaging wall of claim 1 wherein two of the layers comprising the active component define exposed outermost layers of the packaging wall.
4 . The packaging wall of claim 3 wherein at least two of the layers comprising the active component are embedded layers of the packaging wall.
5 . The packaging wall of claim 1 wherein the desired sequence comprises at least five layers.
6 . The packaging wall of claim 1 wherein the multi-layer wall includes at least two oxygen barrier layers.
7 . The packaging wall of claim 6 wherein each oxygen barrier layer is separated, by at least one layer, from each layer comprising the active component.
8 . The packaging wall of claim 6 wherein the oxygen barrier layers each comprise EVOH.
9 . The packaging wall of claim 6 wherein the multi-layer wall includes at least four tie layers.
10 . The packaging wall of claim 1 wherein the active component comprises a transition metal salt selected from the group consisting of an iron salt, a nickel salt, a copper salt, a manganese salt, and a cobalt salt.
11 . The packaging wall of claim 1 wherein the multi-layer wall includes the following layers: protective boundary layer/tie layer/oxygen barrier layer/tie layer/protective boundary layer/protective boundary layer/tie layer/oxygen barrier layer/tie layer/protective boundary layer, wherein the protective boundary layers each comprise the active component, and the oxygen barrier layers each comprise a crystalline polymer.
12 . The packaging wall of claim 1 wherein the packaging wall is part of a container in which an oxygen sensitive food item is contained.
13 . A method for producing a packaging wall containing an active component to capture moisture and/or gas that may otherwise pass through the packaging wall, the method comprising forming a multi-layer wall that includes at least six layers, the multi-layer wall being formed so as to comprise a desired sequence of at least three layers, the desired sequence being found at least twice in the packaging wall, the active component being incorporated into the two outermost layers of the desired sequence, such that at least four layers comprising the active component are provided in the multi-layer wall.
14 . The method of claim 13 wherein the multi-layer wall is formed such that two of the layers comprising the active component define exposed outermost layers of the packaging wall.
15 . The method of claim 14 wherein the multi-layer wall is formed such that at least two of the layers comprising the active component are embedded layers of the packaging wall.
16 . The method of claim 13 wherein the multi-layer wall is formed such that at least two of the layers comprising the active component are in direct contact with each other.
17 . The method of claim 13 wherein the multi-layer wall is formed such that the desired sequence comprises at least five layers.
18 . The method of claim 13 wherein the multi-layer wall is formed so as to include at least two oxygen barrier layers.
19 . The method of claim 18 wherein the multi-layer wall is formed such that each oxygen barrier layer is separated, by at least one layer, from each layer comprising the active component.
20 . The method of claim 13 wherein the multi-layer wall is formed so as to include at least four tie layers, each tie layer being directly between an oxygen barrier layer and a layer comprising the active component.
21 . The method of claim 13 wherein the active component incorporated into the packaging wall comprises a transition metal salt selected from the group consisting of an iron salt, a nickel salt, a copper salt, a manganese salt, and a cobalt salt.
22 . The method of claim 13 wherein the multi-layer wall is formed by a process that includes coextruding the desired sequence of layers, wherein a first stream resulting from said coextruding is then divided into at least two substreams, each substream comprising the desired sequence of layers, the substreams thereafter being recombined one on top of another into a second stream that comprises at least two periods of the desired sequence of layers.
23 . The method of claim 13 wherein the multi-layer wall is formed so as to include the following layers: protective boundary layer/tie layer/oxygen barrier layer/tie layer/protective boundary layer/protective boundary layer/tie layer/oxygen barrier layer/tie layer/protective boundary layer, wherein the protective boundary layers each comprise the active component, and the oxygen barrier layers each comprise a crystalline polymer.