MX2007006579A

MX2007006579A - Vacuum panel base.

Info

Publication number: MX2007006579A
Application number: MX2007006579A
Authority: MX
Inventors: Gilles Keller; Michel Romand; Gilles Rapet; Gilles Perez
Original assignee: Graham Packaging Co
Priority date: 2004-12-01
Filing date: 2005-12-01
Publication date: 2007-11-22
Also published as: WO2006060365A1; BRPI0518731A2; AU2005312012A1; US20060113274A1

Abstract

A plastic container having a sidewall and a base merging with the sidewall. The base includes an annular bearing surface and an inner portion for accommodating inner forces tending to collapse the sidewall. The inner portion has a hinge for facilitating the inward collapse of the inner portion, a vacuum panel, and a support ring interposed between the hinge and the vacuum panel for facilitating a flexure of the vacuum panel.

Description

"BASE PANEL TO THE EMPTY" FIELD OF THE INVENTION The present invention relates in general terms to a container having a base structure for reinforcing the structural integrity of the container.

BACKGROUND OF THE INVENTION Currently many liquid products are sold to the consuming public in plastic containers that are mostly aesthetically pleasing. Such containers may have smooth, contoured side walls that closely resemble glass. When these containers are filled by the so-called hot filling process, they must be structurally sound to withstand the various forces related to the hot filling process. The hot filling process is the procedure by which the containers are filled with a beverage at high temperature and are plugged immediately afterwards. As the beverage cools within the container, stresses and stresses develop in the container due to changes in volume content. In some cases, the hot fill process can create a vacuum inside the container.

A polyolefin container prepared by a continuous extrusion blow molding process can be used in the hot filling process. Continuous extrusion blow molded polyolefin containers include multiple layer containers that provide the requested structure and barriers for oxygen and oils, for example. These multi-layer containers typically include a polyolefin layer, such as polypropylene or polyethylene, as the main structure supply layer. Other layers may include oxygen barrier layers, moisture barrier layers, and spray coats in order to provide the necessary barrier structures, as well as adhesives between the layers. Those skilled in the art should understand that to form a blow molded plastic container of continuous polyolefin extrusion, a parison can be heated in an extruder, captured by a mold, and blown into the mold. Specifically, to form the cavity of the container, a parison can be extruded into the mold and as the mold is adjusted, a pneumatic blowing pin, for example, can pierce the parison and inflate the parison against the mold walls. The mold typically contains vacuum boiling bags above and below the mold cavity for capture the excess parison above and below the cavity. The person skilled in the art can understand that as the parison is inflated into the mold and captured in the vacuum boiling bags, portions of the parison should adhere together. Once the container is cooled, excess boiling under vacuum can then be stopped from the container after it is ejected from the mold. The desire to provide structural integrity to the containers undergoing the hot filling process has resulted in the development of different techniques and design elements. For example, the introduction of vacuum panels into the side wall of the container is known to improve the structural integrity of the container. Although these structural elements molded into the structure of the side walls can provide structural integrity, they tend not to be aesthetically pleasing. By incorporating such a structure into the base of the container, aesthetically unpleasant structures can be concealed. Although the aforementioned structural elements can function satisfactorily for their intended purposes, there is a need to provide aesthetically pleasing containers that have a base structure that can withstand the forces of the hot filling process. The base structures must be capable of accommodating variations in the volume of the contents of the container and changes in pressure and temperature. In addition, the base structure must be capable of being manufactured in conventional high-speed equipment.

BRIEF DESCRIPTION OF THE INVENTION The embodiments of the invention by way of example provide a plastic container having a tubular side wall and a base that joins the side wall. The base includes an annular support surface having a weak point, and an internal portion for receiving internal forces that have to collapse the side wall. The inner portion has a hinge to facilitate inward collapse of the inner portion, a vacuum panel, and a support ring interposed between the hinge and the vacuum panel to maintain the vacuum panel shape as the panel collapses. internal portion. Additional embodiments of the invention provide a plastic container having a substantially cylindrical side wall and a base that attaches to the side wall. The base includes an annular support surface having a weak point, and an inner portion having an annular hinge, a support ring, and a vacuum panel surrounded by the annular hinge and the annular ring. support for. In such an embodiment, the inner portion extends outwardly under a first state and bends inwardly when a vacuum is generated inside the plastic container. Additional embodiments of the invention provide a plastic container that includes substantially cylindrical and smooth side wall and a base that attaches to the side wall. The base includes an annular support surface having a weak point, and an inner portion having an annular hinge, a support ring, and a vacuum panel surrounded by the annular hinge and the support ring. In such an embodiment, the inner portion extends outwardly under a first state and bends inwardly when a vacuum is generated inside the plastic container without forming at least one of the side wall and the base. The additional objects and advantages, as well as the structure and function of the preferred embodiments will become apparent from a consideration of the description, drawings, and examples.

BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of the invention set forth above and others will become apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings in which like reference numbers generally indicate identical, functionally similar, and / or structurally similar elements. Figure 1 graphically represents a perspective view of an exemplary embodiment of a container base according to the present invention; Figure 2 graphically represents a cross-sectional view of an exemplary embodiment of a base according to the present invention; and Figure 3 graphically depicts a cross-sectional view of an exemplary embodiment of a base according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION The embodiments of the invention are described in detail below. When describing the modalities, a specific terminology is used for the sake of clarity. However, the invention is not intended to be limited to the specific terminology thus selected. Although specific embodiments are described by way of example, it should be understood that this is done for illustrative purposes only. One skilled in the art will recognize that other components and configurations of the spirit and scope of the invention. All references cited herein are incorporated by reference as if each of them had been incorporated individually. Figure 1 is a bottom perspective view of an exemplary embodiment of a container 10 according to the present invention. Figure 1 shows the plastic container 10 for packaging liquids and the like. The container 10 can be made from a plastic such as a nylon, a polyester, such as PET, a polyolefin, such as polyethylene, polypropylene, or the like. The plastic can be in one or more layers of a multi-layer container, or it can be the only component of the container. The container 10 can have a tubular side wall 11 that can be attached to the base 12. In an exemplary embodiment of the invention, the side wall 11 can be a substantially smooth and substantially cylindrical wall. The side wall 11 can be flexible, even resistant to deformation when a vacuum is generated inside the container 10. Figure 2 illustrates a cross-sectional view of an exemplary embodiment of a base 12 according to the present invention . As seen in Figure 2, the base 12 may have an annular support surface 13 for contact with a horizontal surface (not shown). The annular support surface 13 may have a weak point 18 to allow inward flexing of the base 12. The base 12 may also have an inner portion 17 surrounded by the annular support surface 13. The inner portion 17 by including the hinge annular 14, the support ring 15 and the vacuum panel 16. As seen in Figure 2, the annular hinge 14 can have a curved cross section so that it is out in an inward direction of the container 10. The ring 15 can be interposed between the annular hinge 14 and the vacuum panel 16. The support ring 15 can have a curved cross section that is concave in an outward direction of the container 10. During the use of the container 10, the container is filled with a hot liquid and when the liquid is cooled, the inner portion 17 can collapse inwardly to a substantially toothed position as seen in the dashed lines in Figure 3. For example , in one embodiment of the invention, the annular hinge 14 can provide a bending point for the inner portion 17 so as to fold inwardly allowing the vacuum panel 16 to bend toward the position shown in the dashed lines in Figure 3 The support ring 15 provides structural integrity to both the panel at vacuum 16 as to the support surface 13. That is, the support ring 15 helps maintain the shape of the inner portion 17 as the inner portion 17 collapses inwardly due to pressure or volumetric changes to the interior of the container 10. In the illustrated embodiment, the support ring 15 maintains the circular shape of the inner portion 17. The support ring 15 also cooperates with the hinge 14 to isolate the movement of the inner portion 17 of the support surface 13. Consequently , as the inner portion collapses, the shape and integrity of the support surface 13 is maintained. In an exemplary embodiment of the invention, the weak point 18 may allow the annular support surface 13 to bend toward the base of the container for preserving the integrity of the annular support surface 13, as seen by the directional arrow A in Figure 3. In other embodiments of the invention, the vacuum panel 16 is doubled the inward and maintains its convex shape or becomes more flat seen transversally. The bending occurs around the hinge 14. In this embodiment also, the support ring 15 serves to maintain the circular shape of the inner portion 17. Also, alone or in cooperation with the hinge 14, the shape and integrity of the surface are maintained. of support. Still in another modality, the shape of the portion internal 17 does not change as the base is doubled. Rather, the vacuum panel 16 together with the support ring 15 move as a unit in an inward direction to the interior of the container 10. The flexure occurs around the hinge 14. The flexure of the hinge 14 is sufficient to avoid distortion of the support surface 13 as the inner surface 17 moves inward, as seen by the dashed lines in Figure 3. In such an embodiment, the weak point 18 may allow the annular support surface 13 to bend toward the the base of the container in order to preserve the integrity of the annular support surface 13, as seen by the directional arrow A in Figure 3. When the above described inflections of the inner portion 17 occur, the vacuum in the container 10 is relieved. and the substantially cylindrical appearance of the side wall 11 is retained, so that the container 10 remains firm. In addition, the bends provide resistance to kinks and / or deformations in the annular support surface 13 of the base 12. Advantageously, the container 10 will not significantly collapse in the side wall of the container, but rather, the inner portion 17 will moves inside the container to compensate for the vacuum that can be generated inside the container 10.

Consequently, a container with a base as in the exemplary embodiments of the present invention can be formed with smooth side walls. Structural features in the side wall, which may be unattractive to consumers, can be minimized or avoided. Because the base compensates for a significant portion of the vacuum generated during processing, the amount of material in the side wall can be reduced. That is, the side wall does not need to be reinforced with plastic material to avoid distortion. In an exemplary embodiment of a container, this can result in a reduction in weight from the initial 45 grams, for example, to a final weight of 35 grams, for example. Consequently, using the present invention, the weight of the container can be reduced by 5 percent or more, by more than 10 percent, or even by more than 20 percent, for example. The actual weight reduction obtained may depend on the size of the container, the material used to make the container, and whether additional structural features are used to accommodate a vacuum. The modalities illustrated and described in this specification are intended only for those experts in the field to make and use the investment. Nothing in this specification should be considered as limiting the scope of the present invention. All the examples presented are representative and not limiting. The embodiments of the invention described above can be modified or varied, without being isolated from the invention, as will be appreciated by those skilled in the art in light of the above teachings. Therefore, it should be understood that, within the scope of the claims and their equivalents, the invention may be implemented in a manner different from that specifically described.

Claims

- - NOVELTY OF THE INVENTION Having described the invention as antecedent, the content of the following claims is claimed as property: CLAIMS 1. A plastic container characterized in that it comprises: a tubular side wall; a base which is attached to the side wall, the base including an annular support surface comprising a weak point, and an inner portion for receiving the internal forces tending to collapse the side wall, the inner portion having a hinge to facilitate the collapse inward of the inner portion, a vacuum panel, and a support ring interposed between the hinge and the vacuum panel to maintain the vacuum panel shape as the inner portion collapses.
2. The plastic container according to claim 1, characterized in that the vacuum panel extends outwards.
The plastic container according to claim 1, characterized in that at least one of the vacuum panel or the internal portion is bent inwardly when a vacuum is generated inside the container of plastic.
The plastic container according to claim 1, characterized in that the annular support surface is bent inwardly at the weak point in order to further facilitate collapse inwardly of the inner portion.
The plastic container according to claim 3, characterized in that the internal portion is bent an amount sufficient to prevent deformation of the annular support surface when a vacuum is generated inside the container.
6 The plastic container according to claim 4, characterized in that the internal portion is bent without deforming at least one of the side wall and the base.
The plastic container according to claim 1, characterized in that the side wall is substantially cylindrical.
The plastic container according to claim 1, characterized in that the side wall is substantially smooth.
9. The plastic container according to claim 1, characterized in that the plastic container is composed of polyolefin.
10. The plastic container according to claim 9, characterized in that the polyolefin is polyethylene or polypropylene.
11. A plastic container, characterized in that it comprises: a substantially cylindrical side wall; a base joining the side wall, the base including an annular support surface comprising a weak point, and an inner portion having an annular hinge, a support ring, and a vacuum panel surrounded by the annular hinge and the support ring, wherein the inner portion extends outwardly under a first state and bends inwardly when a vacuum is generated inside the plastic container.
The plastic container according to claim 11, characterized in that the internal portion is bent without deforming at least one of the side wall and the base.
The plastic container according to claim 11, characterized in that the side wall is substantially smooth.
14. The plastic container according to claim 11, characterized in that the plastic container comprises a plastic.
15. The plastic container according to claim 14, characterized in that the plastic is a polyolefin.
16. The plastic container according to claim 15, characterized in that the polyolefin is selected from polyethylene and polypropylene.
17. The plastic container according to claim 11, characterized in that the annular support surface is bent inwardly at the weak point in order to further facilitate collapse inwardly of the inner portion.
18. A plastic container, characterized in that it comprises: a substantially cylindrical and smooth side wall; a base joining the side wall, the base including an annular support surface comprising a weak point, and an inner portion having an annular hinge, a support ring, and a vacuum panel surrounded by the annular hinge and the support ring, wherein the inner portion extends outwardly under a first state and bends inwardly when a vacuum is generated inside the plastic container without deforming at least one of the side wall and the base.
19. The plastic container according to claim 18, characterized in that the plastic container is composed of polyolefin.
20. The plastic container according to claim 19, characterized in that the plastic container is composed of polyethylene.
21. The plastic container according to claim 19, characterized in that the plastic container is composed of polypropylene.
22. The plastic container according to claim 18, characterized in that the annular support surface is bent inwardly at the weak point in order to further facilitate collapse inwardly of the inner portion.