Multi-layer bottle

Abstract

A multi-layer beverage container includes a multi-layer wall having an outer layer, a middle layer, and an inner layer. At least the inner layer is configured to flex inwards to accommodate a change in the sealed internal volume of the beverage container after a hot-filled beverage is filled inside the container and allowed to cool. The outer layer and inner layer delaminate from each other to accommodate this volume change, which allows the outer layer to retain its original shape. The middle layer functions to encourage delamination of the layers with respect to each other. A space corresponding to the volume change of the interior volume of the container is formed between the wall layers.

What is claimed is: 
     
         1 . A method of filling a beverage into a beverage bottle, the method comprising:
 applying a negative pressure relative to ambient pressure to an interior of the beverage bottle before filling the beverage bottle to initiate delamination between an intermediate layer and an outer layer of the beverage bottle;   filling the beverage bottle with a beverage;   sealing the beverage bottle; and   cooling the beverage such that the beverage reduces in volume, wherein the intermediate layer contracts to adapt to the reduced volume and the outer layer maintains its original shape.   
     
     
         2 . The method of  claim 1 , wherein applying the negative pressure draws air into a volume between the outer layer and the intermediate layer through a vent hole in the outer layer, and
 wherein the volume is equal to the reduction in volume after the beverage has been cooled.   
     
     
         3 . The method of  claim 1 , wherein the intermediate layer comprises a different material than the outer layer, the different material configured to promote delamination between the intermediate layer and the outer layer. 
     
     
         4 . The method of  claim 3 , wherein the outer layer and an inner layer of the beverage bottle comprise PET. 
     
     
         5 . The method of  claim 1 , wherein the outer layer is between 2 and 5 times a thickness of an inner layer of the beverage bottle. 
     
     
         6 . The method of  claim 1 , wherein the intermediate layer does not extend into a base or a neck of the beverage bottle. 
     
     
         7 . The method of  claim 1 , wherein the outer layer comprises a horizontal rib disposed about a circumference of a body of the beverage bottle, wherein the horizontal rib is configured to stiffen the outer layer. 
     
     
         8 . The method of  claim 1 , wherein the beverage is a hot beverage. 
     
     
         9 . The method of  claim 1 , wherein the vent hole is elliptical. 
     
     
         10 . A method of filling a beverage into a beverage bottle, the method comprising:
 filling the beverage bottle with a beverage;   sealing the beverage bottle;   cooling the beverage such that the beverage reduces in volume; and   equalizing a pressure in a space formed between an outer layer of the beverage bottle and an intermediate layer of the beverage bottle through an elliptical vent hole formed in the outer layer,   wherein an intermediate layer of the beverage bottle contracts to adapt to the reduced volume and the outer layer maintains its original shape.   
     
     
         11 . The method of  claim 10 , wherein the equalizing is accomplished through a plurality of elliptical vent holes formed in the outer layer, the plurality of elliptical vent holes including the elliptical vent hole. 
     
     
         12 . The method of  claim 11 , wherein the plurality of elliptical vent holes are disposed in a lower third of the beverage bottle. 
     
     
         13 . The method of  claim 10 , wherein the intermediate layer comprises a different material than the outer layer, the different material configured to promote delamination between the intermediate layer and the outer layer. 
     
     
         14 . The method of  claim 10 , wherein the outer layer is between 2 and 5 times a thickness of an inner layer of the beverage bottle. 
     
     
         15 . The method of  claim 10 , wherein the intermediate layer does not extend into a base or a neck of the beverage bottle. 
     
     
         16 . A method of filling a beverage into a beverage bottle, the method comprising:
 filling the beverage bottle with a beverage;   sealing the beverage bottle;   cooling the beverage such that the beverage reduces in volume; and   concentrating a stress induced on the beverage bottle by the cooling of the beverage using a stress concentrator formed in a least an outer layer of a wall of the beverage bottle,   wherein an intermediate layer of the wall contracts to adapt to the reduced volume and the outer layer maintains its original shape.   
     
     
         17 . The method of  claim 16 , wherein the stress concentrator is formed as a circumferential indentation in a layered wall of the beverage bottle. 
     
     
         18 . The method of  claim 16 , further comprising equalizing a pressure in a space formed between the outer layer and the intermediate layer through a vent hole formed in the outer layer. 
     
     
         19 . The method of  claim 16 , wherein the outer layer is between 2 and 5 times a thickness of an inner layer of the beverage bottle. 
     
     
         20 . The method of  claim 16 , wherein the intermediate layer does not extend into a base or a neck of the beverage bottle.