Plastic container having a ring-shaped reinforcement and method of making same

Abstract

A plastic container comprises an upper portion including a finish adapted to receive a closure, a lower portion including a base, a sidewall extending between the upper portion and the lower portion, the sidewall having an interior surface and an exterior surface, and a substantially planar reinforcing ring extending substantially perpendicularly from the interior surface of the sidewall. A method of making a plastic container is also disclosed.

1 . A plastic container comprising: 
 an upper portion including a finish adapted to receive a closure;    a lower portion including a base;    a sidewall extending between the upper portion and the lower portion, the sidewall having an interior surface and an exterior surface; and    a substantially planar reinforcing ring extending substantially perpendicularly from the interior surface of the sidewall.    
   
   
       2 . The plastic container of  claim 1 , wherein the exterior surface of the sidewall immediately opposite the reinforcing ring is substantially free of indentations.  
   
   
       3 . The plastic container of  claim 2 , wherein the exterior surface of the sidewall immediately opposite the reinforcing ring includes a seam.  
   
   
       4 . The plastic container of  claim 1 , wherein the reinforcing ring comprises a crease in the sidewall.  
   
   
       5 . The plastic container of  claim 1 , wherein the reinforcing ring comprises a first portion of the sidewall and a second portion of the sidewall that are folded over one another.  
   
   
       6 . The plastic container of  claim 1 , wherein the reinforcing ring defines a nominal height and a nominal width, and the nominal width is at least about three times the nominal height.  
   
   
       7 . A method of blow molding a plastic container, comprising: 
 inserting a preform into a mold, the preform comprising an upper portion, a lower portion, and a sidewall extending between the upper portion and the lower portion;    stretching the preform with a stretch rod;    contacting the stretch rod with a portion of the sidewall to form a ring of material around the stretch rod; and    inflating the preform into a container, wherein the ring of material forms a reinforcing ring on the container.    
   
   
       8 . The method of  claim 7 , wherein the step of stretching the preform with the stretch rod causes the portion of the sidewall to contract around the stretch rod to form the ring of material.  
   
   
       9 . The method of  claim 8 , further comprising the step of selectively forming a reduced-temperature region on the sidewall, wherein the reduced-temperature region substantially coincides with the portion of the sidewall that contracts around the stretch rod.  
   
   
       10 . The method of  claim 7 , further comprising the step of preheating the preform to a first temperature.  
   
   
       11 . The method of  claim 10 , further comprising the step of cooling a portion of the sidewall to a second temperature less than the first temperature.  
   
   
       12 . The method of  claim 7 , wherein the ring of material defines an upper section of the sidewall and a lower section of the sidewall, and during the step of inflating the preform into the container, a portion of the upper section and a portion of the lower section fold over one another.  
   
   
       13 . The method of  claim 7 , wherein the container includes a container sidewall having an interior surface and an exterior surface, and the reinforcing rings extends from the interior surface.  
   
   
       14 . The reinforcing ring of  claim 13 , wherein the reinforcing ring is substantially planar and substantially perpendicular to the sidewall.  
   
   
       15 . The method of  claim 7 , wherein the upper portion defines an opening in the preform, and the lower portion is closed, and the step of stretching the preform with the stretch rod includes inserting the stretch rod through the opening and contacting the closed lower portion.