Plastic aerosol container assembly and method of making

Abstract

A plastic aerosol container assembly includes a plastic container that has a main body portion defining an interior space and a finish portion that defines an opening. A pressurized aerosol mixture is maintained within the interior space. The finish portion has an inner surface that has an undercut defined therein. An aerosol valve assembly is mounted to the plastic container so that a portion thereof engages the inner surface of the finish portion so as to be retained by the undercut. The plastic container is preferably fabricated from material including polyethylene terephthalate. At least one location in the finish portion may be crystallized in order to provide enhanced resistance to stress cracking.

What is claimed is: 
     
         1 . A plastic aerosol container assembly, comprising:
 a plastic container having a main body portion defining an interior space and a finish portion defining an opening, the finish portion having an inner surface that has an undercut defined therein; and   an aerosol valve assembly mounted to the plastic container, the aerosol valve assembly having a portion that engages the inner surface of the finish portion so as to be retained by the undercut.   
     
     
         2 . A plastic aerosol container assembly according to  claim 1 , wherein the aerosol valve assembly is seated against the undercut. 
     
     
         3 . A plastic aerosol container assembly according to  claim 1 , wherein the plastic container is fabricated from a material comprising polyethylene terephthalate. 
     
     
         4 . A plastic aerosol container assembly according to  claim 3 , wherein the material comprising polyethylene terephthalate is crystallized at least one location within the finish portion. 
     
     
         5 . A plastic aerosol container assembly according to  claim 1 , wherein the finish portion has a longitudinal axis, and wherein the undercut is oriented within a transverse plane that is substantially perpendicular to the longitudinal axis. 
     
     
         6 . A plastic aerosol container assembly according to  claim 1 , wherein the undercut extends substantially along an entire inner circumference of the inner surface of the finish portion. 
     
     
         7 . A plastic aerosol container assembly according to  claim 1 , wherein the aerosol valve assembly is not directly secured to an outer surface of the finish portion. 
     
     
         8 . A plastic aerosol container assembly according to  claim 1 , further comprising a pressurized aerosol mixture within the plastic container. 
     
     
         9 . A plastic aerosol container, comprising:
 a main body portion defining an interior space; and   a finish portion that is unitary with the main body portion and has an inner surface that has an undercut defined therein.   
     
     
         10 . A plastic aerosol container according to  claim 9 , wherein the main body portion and a finish portion are fabricated from a material comprising polyethylene terephthalate. 
     
     
         11 . A plastic aerosol container according to  claim 10 , wherein the material comprising polyethylene terephthalate is crystallized at least one location within the finish portion. 
     
     
         12 . A plastic aerosol container according to  claim 9 , wherein the finish portion has a longitudinal axis, and wherein the undercut is oriented within a transverse plane that is substantially perpendicular to the longitudinal axis. 
     
     
         13 . A plastic aerosol container assembly according to  claim 9 , wherein the undercut extends substantially along an entire inner circumference of the inner surface of the finish portion. 
     
     
         14 . A plastic aerosol container, comprising:
 a main body portion defining an interior space; and   a finish portion that is unitary with the main body portion, and wherein the main body portion and the finish portion are fabricated from a material comprising polyethylene terephthalate, and wherein at least a portion of the finish portion is crystallized.   
     
     
         15 . A plastic aerosol container according to  claim 14 , wherein the finish portion has an inner surface that has an undercut defined therein. 
     
     
         16 . A plastic aerosol container according to  claim 15 , wherein the finish portion has a longitudinal axis, and wherein the undercut is oriented within a transverse plane that is substantially perpendicular to the longitudinal axis. 
     
     
         17 . A plastic aerosol container according to  claim 15 , wherein the undercut extends substantially along an entire inner circumference of the inner surface of the finish portion. 
     
     
         18 . A method of forming a plastic aerosol container, comprising steps of:
 (a) providing a preform having a finish portion;   (b) blow molding a plastic container from the preform; and   (c) reforming the finish portion so that an inner surface thereof has an undercut defined therein, and wherein step (c) is performed at some point after step (a).   
     
     
         19 . A method of forming a plastic aerosol container according to  claim 18 , wherein step (c) is performed after step (b). 
     
     
         20 . A method of forming a plastic aerosol container according to  claim 18 , wherein the preform having the finish portion is formed by injection molding, and wherein step (c) is performed by reheating the finish portion and reshaping the finish portion using a mechanical tool. 
     
     
         21 . A method of forming a plastic aerosol container according to  claim 18 , wherein step (c) is performed by shaping the undercut so that it is oriented within a transverse plane that is substantially perpendicular to a longitudinal axis of the finish portion. 
     
     
         22 . A method of forming a plastic aerosol container according to  claim 18 , wherein step (c) is performed by shaping the undercut so that the undercut extends substantially along an entire circumference of the inner surface of the finish portion. 
     
     
         23 . A method of forming a plastic aerosol container according to  claim 18 , wherein the preform is fabricated from a material comprising polyethylene terephthalate.