Container assemblies including metal closures and thermoplastic containers and methods of hot-filling food and beverage products

Abstract

Container assemblies are described herein that include a metal closure and a container including a plastic finish. The container assemblies may be characterized by improved performance including reproducibility of force needed to remove the closure. Furthermore, the container assemblies described herein may be compatible for use with hot-fill packaging processes.

What is claimed is: 
     
         1 . A container assembly comprising:
 a plastic container including an opening and a finish, said finish including a plastic material that is softer than glass;   wherein said finish includes one or more threads; and   a metal closure including four lugs;   wherein said lugs are configured to engage said one or more threads when said metal closure is placed and rotated on said plastic container to pull said plastic container and said metal closure together;   wherein one or more of said lugs include a top portion and an inner portion;   wherein at least one of said top portion and said inner portion is flattened.   
     
     
         2 . The container assembly of  claim 1  wherein said top portion has a radius of curvature of between about 2.5 mm and about 3.5 mm. 
     
     
         3 . The container assembly of  claim 1  wherein said inner portion has a radius of curvature of between about 1.5 mm and about 2.5 mm. 
     
     
         4 . The container assembly of  claim 1  wherein said plastic material is a thermoplastic material. 
     
     
         5 . The container assembly of  claim 1  wherein said plastic material is polyethylene terephthalate. 
     
     
         6 . The container assembly of  claim 1  wherein said lugs are evenly spaced about said metal closure. 
     
     
         7 . The container assembly of  claim 1  wherein said metal closure comprises an inner diameter of about 38 mm. 
     
     
         8 . The container assembly of  claim 1  wherein said finish comprises an inner diameter of about 28 mm to about 32 mm. 
     
     
         9 . The container assembly of  claim 1  wherein said finish comprises an outer diameter of about 33 mm to about 37 mm. 
     
     
         10 . The container assembly of  claim 1  wherein said metal closure comprises a cylindrical sidewall. 
     
     
         11 . The container assembly of  claim 1  wherein said metal closure comprises a gasketing material configured for sealing engagement with a top edge of said finish. 
     
     
         12 . A beverage product comprising:
 a beverage sterilized using a hot-fill packaging process; and   a container assembly in which said beverage is disposed and including a metal closure sealingly engaged on a container that includes a thermoplastic finish.   
     
     
         13 . The product of  claim 12  wherein said container includes an opening of about 28 mm to about 32 mm; and
 wherein said metal closure includes four lugs. 
 
     
     
         14 . The product of  claim 13  wherein one or more of said lugs include a top portion and an inner portion;
 wherein at least one of said top portion and said inner portion is flattened. 
 
     
     
         15 . The product of  claim 13  wherein one or more of said lugs include a top portion and an inner portion;
 wherein said top portion has a radius of curvature of between about 2.5 mm and about 3.5 mm. 
 
     
     
         16 . The product of  claim 13  wherein one or more of said lugs include a top portion and an inner portion;
 wherein said inner portion has a radius of curvature of between about 1.5 mm and about 2.5 mm. 
 
     
     
         17 . A method of packaging a food or beverage product comprising:
 treating a food or beverage product to a condition that includes application of an elevated temperature greater than about 50° C.;   partially cooling the food or beverage product;   adding the food or beverage product to a container comprising a thermoplastic finish having at least one thread;   capping the food or beverage product in said container by rotating a metal closure onto said finish, said metal closure comprising four lugs engaged with said at least one thread sufficient to provide an air-vacuum tight seal;   maintaining the food or beverage product and the container at a hold temperature less than said elevated temperature; and   further cooling the food or beverage product and the container.   
     
     
         18 . The method of  claim 17  wherein said elevated temperature is no greater than about 100° C. and wherein said hold temperature is between about 65° C. to about 90° C. 
     
     
         19 . The method of  claim 17  wherein said metal closure comprises a vacuum-indicating top panel. 
     
     
         20 . The method of  claim 17  wherein said capping further comprises engaging said lugs with a sidewall of said finish;
 wherein each of said lugs comprises a top portion and an inner portion; and 
 wherein at least one of said top portion and said inner portion is flattened.