Structural ribs for hot fillable containers

Abstract

A plastic container includes an upper portion having a mouth defining an opening into the container. A shoulder region extends from the upper portion. A sidewall portion extends from the shoulder region to a base portion. The base portion closes off an end of the container. The sidewall portion is defined in part by at least one arcuately formed rib having a body portion and opposite ends. The body portion curves from a central portion toward the base portion at each of the opposite ends.

1 . A plastic container comprising:
 an upper portion having a mouth defining an opening into said container;   a shoulder region extending from said upper portion;   a sidewall portion extending from said shoulder region to a base portion, said base portion closing off an end of said container, said sidewall portion defined in part by at least one arcuately formed rib having a body portion and opposite ends; and   wherein said body portion of said at least one arcuately formed rib curves from a central portion toward the base portion at each of said opposite ends.   
   
   
       2 . The plastic container of  claim 1  wherein said at least one arcuately formed rib defines an inboard depression along said sidewall portion. 
   
   
       3 . The plastic container of  claim 2  wherein the container defines a first pair of opposing sidewalls and a second pair of opposing sidewalls, wherein said first pair of opposing sidewalls are longer in length than said second pair of opposing sidewalls. 
   
   
       4 . The plastic container of  claim 3  wherein said at least one arcuately formed rib defines a series of ribs. 
   
   
       5 . The plastic container of  claim 4  wherein said series of ribs are defined on said first pair of opposing sidewalls. 
   
   
       6 . The plastic container of  claim 5  wherein said series of ribs each define a length that is about 50% to about 90% of a width of said first pair of opposing sidewalls. 
   
   
       7 . The plastic container of  claim 6  wherein said sidewall portion is defined in part by at least two vacuum panels formed therein, said vacuum panels being movable to accommodate vacuum forces generated within the container resulting from heating and cooling of its contents. 
   
   
       8 . The plastic container of  claim 7  wherein said series of ribs are defined on said vacuum panels. 
   
   
       9 . The plastic container of  claim 8  wherein said sidewall portion defines a label panel area on an area across said vacuum panels, said label panel area adapted to accept a label covering said series of ribs. 
   
   
       10 . A plastic container comprising:
 an upper portion having a mouth defining an opening into said container;   a shoulder region extending from said upper portion;   a sidewall portion extending from said shoulder region to a base portion, said base portion closing off an end of said container, said sidewall portion defined in part by at least one arcuately formed rib having a body portion and opposite ends, wherein said at least one arcuately formed rib curves away from said mouth toward each of said opposite ends; and   wherein said sidewall portion is further defined in part by at least two vacuum panels formed therein, said vacuum panels being movable to accommodate vacuum forces generated within the container resulting from heating and cooling of its contents.   
   
   
       11 . The plastic container of  claim 10  wherein said at least one arcuately formed rib defines an inboard depression along said sidewall portion. 
   
   
       12 . The plastic container of  claim 11  wherein the container defines a first pair of opposing sidewalls and a second pair of opposing sidewalls, wherein said first pair of opposing sidewalls are longer in length than said second pair of opposing sidewalls. 
   
   
       13 . The plastic container of  claim 12  wherein said at least one arcuately formed rib defines a series of ribs. 
   
   
       14 . The plastic container of  claim 13  wherein said series of ribs are defined on said first pair of opposing sidewalls. 
   
   
       15 . The plastic container of  claim 14  wherein said sidewall portion defines a label panel area on an area across said vacuum panels, said label panel area adapted to accept a label covering said series of ribs. 
   
   
       16 . A method of making a blow-molded PET plastic container, said method comprising the steps of:
 disposing a preform into a mold cavity having a surface defining a shoulder forming region, a sidewall forming region and a base forming region, the sidewall forming region defining at least one arcuately formed extension rib having a body portion and opposite ends, the opposite ends of said at least one arcuately formed extension rib curves from a central portion toward the base forming region at each of said opposite ends;   blowing the preform against the mold surface to form a resultant container having a shoulder, a sidewall and a base, the sidewall defining at least one arcuate depression rib corresponding to the at least one arcuately formed extension rib of the mold cavity; and   removing the resultant container from the mold cavity.   
   
   
       17 . The method of  claim 16  wherein the sidewall forming region defines a series of arcuately formed extension ribs each having a body portion and opposite ends. 
   
   
       18 . The method of  claim 17  wherein the step of blowing the preform further includes blowing material comprising the preform around the series of arcuately formed extension ribs, the material generally flowing from the body portion of each extension rib at an upstream area toward the opposite ends of each extension rib at a downstream area. 
   
   
       19 . The method of  claim 18  wherein the step of blowing further includes forming at least two vacuum panels at the sidewall. 
   
   
       20 . The method of  claim 19  wherein forming at least two vacuum panels includes forming the at least two vacuum panels along a surface encompassing the at least one arcuate depression rib.