Moisture Retention Seal

Abstract

Various moisture retention seals are disclosed, in the contexts of canisters and corresponding closures forming packages for avoiding moisture evaporation and in retaining liquid or moisture contained in the packages.

What is claimed is: 
     
         1 . A package, comprising:
 a closure having an interior surface; and   a canister having a flexible top portion in contact with the interior surface of the closure, the interior surface of the closure normally applying a generally downward contact force to at least part of the flexible top portion to form a top seal between the closure and the canister, the interior surface of the canister deflecting the at least part of the flexible top portion generally downward from a rest position; wherein:   the at least part of the flexible top portion of the canister is in the rest position when not in contact with the closure; and   the interior surface of the closure deflects the at least part of the flexible top portion of the canister by a deflection angle from the rest position when in contact with the canister, the deflection angle being less than about ninety degrees.   
     
     
         2 . A package according to  claim 1 , wherein the interior surface of the closure is generally planar. 
     
     
         3 . A package according to  claim 1 , wherein the interior surface of the closure is generally frustoconical. 
     
     
         4 . A package according to  claim 1 , wherein the flexible top portion of the canister is in contact with the interior surface of the closure at other than a protrusion extending from the interior surface of the closure. 
     
     
         5 . A package according to  claim 1 , wherein the flexible top portion of the canister has, in vertical cross section, a serpentine shape. 
     
     
         6 . A package according to  claim 1 , wherein the flexible top portion of the canister has a generally annular shape when in the rest position and a generally frustoconical shape when deflected from the rest position. 
     
     
         7 . A package according to  claim 1 , wherein the closure includes a locking skirt and the canister has a complimentary locking feature, the locking skirt and the complementary locking feature cooperating to secure the closure to the canister and provide a second seal between the closure and the canister. 
     
     
         8 . A package according to  claim 1 , wherein:
 the flexible top portion of the canister has a generally serpentine vertical cross section defining at least one radially outwardly convex portion;   the closure defines a generally vertical inside circumferential wall; and   the flexible top portion and the closure are configured such that, when the closure is when in contact with the canister, the at least one radially outwardly convex portion contacts the generally vertical inside circumferential wall of the closure, thereby forming at least a second seal between the closure and the canister.