Reinforced plastic containers

Abstract

A plastic container that may be used in hot fill applications includes a finish portion having an opening, a main body portion and a bottom portion. The main body portion includes a vacuum panel area and a circumferentially extending reinforcement groove that has reinforcement structure provided therein positioned substantially adjacent to the vacuum panel area. The bottom portion includes a standing ring, a central interior substantially flat portion that has a plurality of alternating parallel ribs and grooves defined therein and a transitional surface between the standing ring and the substantially flat portion. The parallel ribs and grooves define a complex structure with respect to the transitional surface that provides a stiffening effect, particularly in containers that are fabricated from polypropylene.

What is claimed is: 
     
         1 . An extrusion blow-molded hot fill type plastic container, comprising:
 a finish portion defining an opening; a bottom portion;   a main body portion having a vacuum panel area with at least one vacuum panel defined therein and arranged to accommodate volumetric expansion and contraction, wherein the main body portion further includes a circumferentially extending reinforcement groove having reinforcement structure provided therein, and wherein the circumferentially extending reinforcement groove is positioned substantially adjacent to the vacuum panel area, wherein the reinforcement structure comprises a plurality of flutes within the circumferentially extending reinforcement groove, the plurality of flutes including alternating convex and concave surfaces defining a generally sinusoidal pattern in plan view, whereby dimensional distortion of at least part of the main body portion that is adjacent to the vacuum panel area is minimized during hot fill process.   
     
     
         2 . The extrusion blow-molded hot fill type plastic container according to  claim 1 , wherein the bottom portion is constructed and arranged so as to be substantially flat with a plurality of alternating parallel ribs and grooves defined therein, whereby dimensional distortion of the bottom portion is minimized during the hot fill process and deflection as a result of vacuum uptake is directed toward the vacuum panel area. 
     
     
         3 . The extrusion blow-molded hot fill type plastic container according to  claim 1 , wherein each of the plurality of flutes has a vertical component. 
     
     
         4 . The extrusion blow-molded hot fill type plastic container according to  claim 1 , wherein each of the flutes is oriented so as to be substantially vertical. 
     
     
         5 . The extrusion blow-molded hot fill type plastic container according to  claim 1 , wherein the circumferentially extending reinforcement groove extends about an entire circumference of the main body portion. 
     
     
         6 . The extrusion blow-molded hot fill type plastic container according to  claim 1 , wherein the circumferentially extending reinforcement groove has a minimum depth and a maximum depth, and wherein a ratio of the minimum depth to the maximum depth is substantially within a range of about 0.1 to about 0.9. 
     
     
         7 . The extrusion blow-molded hot fill type plastic container according to  claim 6 , wherein the ratio of the minimum depth to the maximum depth is substantially within a range of about 0.2 to about 0.8. 
     
     
         8 . The extrusion blow-molded hot fill type container according to  claim 7 , wherein the ratio of the minimum depth to the maximum depth is substantially within a range of about 0.35 to about 0.65. 
     
     
         9 . The extrusion blow-molded hot fill type container according to  claim 1 , wherein the circumferentially extending reinforcement groove as viewed in longitudinal cross-section has a first upper groove sidewall that is angled with respect to a groove bottom at a first angle and a second lower groove sidewall that together with the upper groove sidewall defines a wedge that is angled with respect to the groove bottom at a wedge angle that is substantially within a range of about 15° to about 45°. 
     
     
         10 . The extrusion blow-molded hot fill type plastic container according to  claim 9 , wherein the wedge angle is substantially within a range of about 20° to about 40°. 
     
     
         11 . An extrusion blow-molded hot fill type plastic container, comprising:
 a finish portion defining an opening;   a bottom portion that is substantially round when viewed in bottom plan view;   a main body portion having a vacuum panel area with at least one vacuum panel defined therein and arranged to accommodate volumetric expansion and contraction, the main body portion further including a circumferentially extending reinforcement groove having reinforcement structure provided therein, the reinforcement structure comprising a plurality of flutes within the circumferentially extending reinforcement groove, the plurality of flutes including alternating convex and concave surfaces defining a generally sinusoidal pattern in plan view;   wherein the bottom portion is constructed and arranged to include a substantially flat portion having a plurality of alternating parallel ribs and grooves defined therein, whereby dimensional distortion of the bottom portion is minimized during hot fill process and deflection as a result of vacuum uptake is directed toward the vacuum panel area.   
     
     
         12 . The extrusion blow-molded hot fill type plastic container according to  claim 11 , wherein the bottom portion further includes a standing ring, and the substantially flat portion is positioned within the standing ring and elevated with respect to the standing ring. 
     
     
         13 . The extrusion blow-molded hot fill type plastic container according to  claim 12 , wherein the substantially flat portion is substantially centered with respect to the standing ring. 
     
     
         14 . The extrusion blow-molded hot fill type plastic container according to  claim 12 , wherein the substantially flat portion occupies at least 75% of an area defined within the standing ring. 
     
     
         15 . The extrusion blow-molded hot fill type plastic container according to  claim 12 , further comprising a transitional surface between the substantially flat portion and the standing ring, and wherein the alternating parallel ribs and grooves of the substantially flat portion intersect the transitional surface to form a complex shape that stiffens the bottom portion against deformation. 
     
     
         16 . The extrusion blow-molded hot fill type plastic container according to  claim 15 , wherein the transitional surface is shaped so as to be substantially symmetrical about a longitudinal axis of the hot fill type plastic container. 
     
     
         17 . The extrusion blow-molded hot fill type plastic container according to  claim 15 , wherein the bottom portion is fabricated from a material comprising polypropylene. 
     
     
         18 . An extrusion blow-molded polypropylene container, comprising:
 a finish portion defining an opening;   a main body portion having a vacuum panel area defined therein, the main body portion further including a circumferentially extending reinforcement groove having reinforcement structure provided therein, the reinforcement structure comprising a plurality of flutes situated within the circumferentially extending reinforcement groove, the plurality of flutes including alternating convex and concave surfaces defining a generally sinusoidal pattern in plan view; and   a bottom portion fabricated from polypropylene and substantially round when viewed in bottom plan view, the bottom portion including a substantially flat portion having a plurality of alternating parallel ribs and grooves defined therein, whereby dimensional distortion of the bottom portion is minimized.   
     
     
         19 . The extrusion blow-molded polypropylene container according to  claim 18 , wherein the bottom portion further includes a standing ring, and the substantially flat portion is positioned within the standing ring and elevated with respect to the standing ring. 
     
     
         20 . The extrusion blow-molded polypropylene container according to  claim 19 , wherein the substantially flat portion is substantially centered with respect to the standing ring. 
     
     
         21 . The extrusion blow-molded polypropylene container according to  claim 19 , wherein the substantially flat portion occupies at least 75% of that is an area defined within the standing ring. 
     
     
         22 . The extrusion blow-molded polypropylene container according to  claim 19 , further comprising a transitional surface between the substantially flat portion and the standing ring, and wherein the alternating parallel ribs and grooves of the substantially flat portion intersect the transitional surface to form a complex shape that stiffens the bottom portion against deformation. 
     
     
         23 . The extrusion blow-molded polypropylene container according to  claim 22 , wherein the transitional surface is shaped so as to be substantially symmetrical about a longitudinal axis of the container. 
     
     
         24 . The extrusion blow-molded hot fill type plastic container according to  claim 1 , wherein the circumferentially extending reinforcement groove is positioned on the main body portion between the finish portion and the vacuum panel area. 
     
     
         25 . The extrusion blow-molded hot fill type plastic container according to  claim 24 , wherein the circumferentially extending reinforcement groove is positioned no more than 34 millimeters from the vacuum panel area.