CONTAINER HAVING VACUUM COMPENSATION ELEMENTS

Abstract

A lightweight container includes an enclosed base, an upper portion that extends upwardly to a finish; and a body located between the base and the upper portion. The sidewall includes vacuum compensation elements having a series of arches that are arranged to resemble water ripples formed by a water droplet.

Description

BACKGROUND

This invention relates to containers, and more particularly to plastic containers capable of flexing in response to changes in internal pressure.

Plastic containers for perishable products are often filled at an elevated temperature in a process generally known as hot-filling, which includes filling the product at about 185 degrees F. and immediately sealing the container. After sealing, the contents of the container contract upon cooling, which creates a vacuum condition inside the container.

Many conventional cylindrical containers would deform or collapse under the internal vacuum conditions without some structure to prevent it. To prevent collapse, some containers have panels, referred to as “vacuum panels,” located in the panel sidewall. The vacuum panels are configured to inwardly and easily flex in response to internal vacuum such that the remainder of the container body remains cylindrical. The structure between the vacuum panels, such as vertical posts, is stiff relative to the vacuum panels. Often, the vacuum panels are located about the circumference of the body of the container and then covered by a label that wraps around the circumference to hide the vacuum panels and posts.

Other hot-fill containers have a pair of opposing vacuum panels that incorporate handgrips, which usually are not covered with a label panel to enable gripping. Rather, other portions of the container, such as the cylindrical segments between the handgrips, provide a label surface.

The vacuum panels of many bottles are generally rectangular. Often, deformation of a generally rectangular vacuum panel causes high stress areas at the corners and in the areas outside the vacuum panels near the corner.

There is a need for improved containers that are lightweight and capable of withstanding hot-filling conditions.

SUMMARY OF THE INVENTION

A container is provided that includes an enclosed base, an upper portion that extends upwardly to a finish; and a body located between the base and the upper portion. The body includes a sidewall having at least one vacuum compensation element. In one embodiment, the element comprises an intermediate, closed-curve structure; first and second upper arches located above the intermediate structure; and first, second, and third lower arches located below the intermediate structure. Preferably, the first and second upper arches are respectively spaced apart vertically from the intermediate structure by a first and second dimension, and the first, second, and third lower arches are respectively spaced apart vertically from the intermediate structure by a third, fourth, and fifth dimension. The second dimension is greater than the first dimension, and the fifth dimension is greater than the fourth dimension, which is greater than the third dimension. Accordingly, each element produces an image of a water droplet landing in a pool of water. Each arch represents a segment of a ring or wave radiating from the center. A longitudinal cross section of each arch also has the cross sectional shape of a wave radiating from the point of impact. Because the image may be represented as viewed from an angle, the dimensions between the arches may vary accordingly.

A label panel is provided that is spaced apart from the elements. Preferably, the container has an even number of circumferentially spaced, vacuum compensation elements, which may provide enhanced support of the sidewall.

The inventors have found that container shown in the figures can be made lightweight. The body of the container may optionally function as a gripping surface that is label-less the label panel provides a surface for receiving the label. The gripping surface is enhanced by the field geometry.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an elevational view of a container illustrating aspects of the present invention;

FIG. 2 is another elevational view of the container shown in FIG. 1;

FIG. 3 is a perspective view of the container shown in FIG. 1;

FIG. 4 is a transverse cross section taken through lines I-I shown in FIG. 1;

FIG. 5 is an enlarged view of a portion of FIG. 4; and

FIG. 6 is a plot of calculated deformation of the container after hot filling.

BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS

Container 10 is capable of being hot filled and includes an enclosed base 12, an upper portion 14, a label panel 16, and a body 18. Base 12 preferably is circular and includes a circumferential heel 20, a standing ring 22, and a reentrant portion 24. Heel 20 extends downwardly from body 18 to the circular standing ring 22. Preferably, body 18 smoothly yields to heel 20, and the present invention encompasses additional structure (not shown in the figures, between body 18 and heel 20. Reentrant portion 24 may be of any type. For example, reentrant portion 24 may include conventional, radial reinforcing ribs, may be rigid or configured to deform in response to internal vacuum and function with the vacuum compensation features of container 10, or may comprise other structure.

Upper portion 14 includes an upper label bumper 30, a cylindrical portion 32, a dome 34, a neck 36, and a finish 38 that includes threads 40. Upper label bumper 30 defines the boundary of label panel 16. Cylindrical portion 32 preferably is short relative to the vertical length of dome 34, which extends upwardly and inwardly to neck 36. The present invention also encompasses containers having a large mouth (not shown in the figures). Threads 40 receive corresponding threads of a closure (not shown in the figures) upon hot-filling.

As shown in FIG. 1, label panel 16 extends from upper bumper 30 to a lower bumper (described below) and preferably is cylindrical to enable a label to be applied around its circumference. Label panel 16 may optionally includes ribs 46, which are shown in the Figures, to enhance the hoop strength and ovality.

Body 18 includes a sidewall 48, the lower label bumper 50 at its upper end, at least two vacuum compensation elements 54, which each includes a group of arches, and preferably at least two panels 49, which preferably are decorative. Container 10 has an even number of elements 54 and panels 49 that are evenly spaced around the sidewall 48 of the body 18 so that each element 54 is diametrically opposed by another element 54 and each panel 49 is diametrically opposed by another panel 49. The panels 49 disposed between the elements 54 preferably have an inwardly concave surface as shown in FIG. 1.

As shown in FIGS. 1-3, the element 54 includes arches that are arranged to product an image of segments water ripples formed by a water droplet. Element 54 may include an intermediate curved structure 110; first 113 and second 114 upper arches; first 115, second 116, and third 117 lower arches; and a simulated water droplet 118. The intermediate structure 110 has a curved upper 111 and lower 112 portion. Preferably, the intermediate structure 110 is an oval, but may be a circle or other shape having a curved upper 111 and lower 112 portion. More preferably, the intermediate structure is a pair of concentric ovals.

The element 54 may further include first 113 and second 114 arches located above the intermediate structure 110, and first 115, second 116, and third 117 lower arches located below the intermediate structure 110. Preferably, the first upper arch 113 is spaced from the intermediate structure 110 by a first dimension, and the second upper arch 114 is spaced from the intermediate structure 110 by a second dimension that is greater than the first dimension. Further, the first lower arch 115 is spaced from the intermediate structure 110 by a third dimension, the second lower arch 116 is spaced from the intermediate structure 110 by a fourth dimension that is greater than the third dimension, and the third lower arch 117 is spaced apart from the intermediate structure 110 by a fifth dimension that is greater than the fourth dimension. Also, as shown in the figures, first lower arch 115 is spaced apart from intermediate structure 110 (either by the horizontal centerline of structure 110 or to its closest edge) by a distance that is greater than the spacing distance between first upper arch 113 and intermediate structure 110—that is, the third dimension is greater than the first dimension. And the second lower arch 116 is spaced apart from intermediate structure 110 by a distance that is greater than the spacing distance between second upper arch 114 and intermediate structure 110—that is, the fourth dimension is greater than the second dimension. Accordingly, the configuration of the arches relative to intermediate structure 110 and each other provides a section of a perspective view of concentric ripples.

The upper arches 113 and 114 preferably curve downward toward the intermediate structure 110 and the lower arches 115, 116, and 117 preferably curve upward toward the intermediate structure 110, such that the intermediate structure 110, upper arches 113 and 114, and lower arches 115, 116, and 117 resemble the concentric ring pattern of a water ripple. Also, the element 54 may include a water droplet 118 located above the upper arches 113 and 114. Accordingly, each element produces an image of a water droplet landing in a pool of water. Each arch represents a segment of a ring or wave radiating from the center. A longitudinal cross section of each arch also has the cross sectional shape of a wave radiating from the point of impact. Because the image may be represented as viewed from an angle, the dimensions between the arches may vary accordingly.

FIG. 4 illustrates a preferred configuration of the intermediate structure 110, upper arches 113 and 114, lower arches 115, 116, and 117, and water droplet 118 in a longitudinal cross section of the sidewall 48 taken along the reference line I-I of FIG. 1. As shown, the upper arches 113 and 114 are inclined upwardly and outwardly away from the intermediate structure 110 and the lower arches 115, 116, and 117 are inclined downwardly and outwardly away from the intermediate structure 110. Each arch may have a configuration that is designated by reference numeral 120 and may apply to each arch 113, 114, 115, 116, and 117. FIG. 5 schematically shows the arch 120 in longitudinal cross section, which includes a surface 122, a peak 124, and a transition 126. The surface portion 122 is the sloped portion of the arch that is upwardly and outwardly inclined for the upper arches and downwardly and outwardly inclined for the lower arches. Accordingly, FIG. 5 illustrates the orientation of lower arches 115, 166, and 117. The orientation of upper arches 113 and 114 would be opposite that shown in FIG. 5. The peak 124, for each arch, is located radially at the most distal location from the bottle longitudinal centerline. The transition 126 is an inwardly sloped segment that connects the peak 124 of one arch 120 to the surface 122 of an adjacent arch 120. Thus, in cross section, the arches resemble water ripples moving away from the intermediate structure. The present invention encompasses any inclination of the arches relative to a vertical axis.

In operation, container 10 is capable of receiving a product at an elevated hot-fill temperature, such as approximately 185 degrees F. Preferably, container 10 is formed of a plastic having an intrinsic viscosity in the range typical for hot fill containers. Container 10 may be formed by any blow molding process, such as a two stage, stretch blow molding process with a heat setting stage. The present invention is not limited to this two stage process, but rather encompasses any process for making a container and any container that employs the general technology described herein. For example, the present invention encompasses any container having one or more vacuum compensation elements, or its equivalent, as described herein.

FIG. 6 illustrates the deformation of container 10 after conventional hot-filling, in which the maximum deformation is roughly centered on the upper arches 113 and 114 and lower arches 115, 116, and 117, and roughly located on the longitudinal centerline of element 54.

Upon capping during the hot-filling process, elements 54 are pulled inwardly in response to internal vacuum. Intermediate portions 64 after hot filling have an upright, straight shape to form posts. FIG. 9 indicates very little deformation in the posts. Because the face of elements 54 are roughly flat (in transverse cross section) after hot-filling, container 10 has a roughly box-like configuration in the center of body 18 while label panel 16 remains cylindrical.

Claims

1. A plastic hot-fill bottle comprising: an enclosed base;an upper portion that extends upwardly to neck and a finish; anda body located between the base and the upper portion, the body including a sidewall comprising alternating panels and posts, at least one panel including: an intermediate curved structure having an upper portion and a lower portion;a first upper arch and a second upper arch located above the intermediate structure, the first upper arch being vertically spaced apart from the upper portion of the intermediate structure by a first dimension, the second upper arch being vertically spaced apart from the first upper arch by a second dimension that is greater than the first dimension; anda first lower arch and a second lower arch located below the intermediate structure, the first lower arch being vertically spaced apart from the lower portion of the intermediate structure by a third dimension, the second lower arch being vertically spaced apart from the first lower arch by a fourth dimension that is greater than the third dimension.

2. The bottle of claim 1 wherein the intermediate structure is an oval.

3. The bottle of claim 2 further comprising an inner oval located inside of the intermediate structure.

4. The bottle of claim 2 further comprising a third lower arch that is vertically spaced apart from the second lower arch by a fifth dimension that is greater than the fourth dimension.

5. The bottle of claim 2 wherein the third dimension is greater than the first dimension and the fourth dimension is greater than the second dimension such that the lower arches are spaced apart from each other and from the intermediate structure by a larger distance than the first arches are spaced apart from each other and the intermediate structure.

6. The bottle of claim 5 wherein the arches simulate a section of a perspective view of ripples in the surface of water.

7. The bottle of claim 1 further comprising a droplet located above the second upper arch.

8. The bottle of claim 1 wherein the upper arches have a positive curvature and the lower arches have a negative curvature.

9. The bottle of claim 8 wherein the intermediate structure and upper arches form at least a portion of a concentric ring pattern and the lower arches from at least a portion of another concentric ring pattern.

10. The bottle of claim 1 wherein the sidewall further comprises an upper portion and a lower portion that are substantially circular in transverse cross section.

11. The bottle of claim 10 wherein the posts have approximately the same diameter in transverse cross section as the upper and lower portions before filling.