Patent Application
20070062907
1. Field of the Invention
The present invention relates generally to containers, and more particularly, to plastic containers having an improved, multi-functional waist design.
2. Related Art
Containers, and particularly plastic containers, are subjected to varying forces during filling, sealing, and storage of the container. For example, hot-filled containers often experience an internal vacuum that occurs as a result of shrinkage of the contents as they cool. This can result in distortion of the container, for example, ovalization of a round container. In order to withstand these kinds of forces, containers are typically provided with a reduced-diameter “waist” structure that extends around the sidewall of the container in a direction perpendicular to the central axis of the container. The waist structure increases the hoop strength of the container. Prior art waist structures normally include a tightly radiused indentation when viewed from the side of the container. This type of known waist structure can be undesirable from a design standpoint. In addition, the known waist structure can occupy a relatively large portion of the container that could otherwise be used for aesthetic purposes, for example, branding. Therefore, there remains a need in the art for a container having an improved waist structure that overcomes the shortcomings of conventional designs.
The present invention relates to a container. According to one exemplary embodiment, the container defines a central axis and comprises a finish and a base located at opposite ends of the central axis, a sidewall located between the finish and the base, a dome located between the finish and the base, and a waist located between the dome and the sidewall, wherein the waist includes a substantially flat wall portion that extends substantially parallel to the central axis.
According to one aspect of the invention, the substantially flat wall portion can define a substantially vertical ring that extends around the central axis.
According to another aspect of the invention, the container can further include a bumper, with the waist located between the bumper and the dome.
According to another aspect of the invention, the dome can define a first height substantially parallel to the central axis, the substantially flat wall portion can define a second height substantially parallel to the central axis, and the second height can be at least about 20% of the first height. Preferably, the second height can be at least about 30% of the first height. More preferably, the second height can be at least about 40% of the first height.
According to another aspect of the invention, the container can further include branding located on the substantially flat wall portion. For example, the branding can be embossed on the substantially flat wall portion. Additionally or alternatively, the branding can be located on a film located on the substantially flat wall portion.
According to another aspect of the invention, the substantially flat wall portion can provide a gripping surface.
According to a second exemplary embodiment of the invention, the container comprises a finish and a base located at opposite ends of the container, a sidewall extending from the base, a dome extending from the finish, and a waist located between the sidewall and the dome, wherein the waist includes a substantially flat wall portion having branding located thereon.
According to a third exemplary embodiment of the invention, the container comprises a finish and a base located at opposite ends of the container, a sidewall extending from the base, a dome extending from the finish, and a waist located between the sidewall and the dome, wherein the waist includes a substantially flat wall portion that provides a gripping surface.
Further objectives and advantages, as well as the structure and function of preferred embodiments, will become apparent from a consideration of the description, drawings, and examples.
The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.
Embodiments of the invention are discussed in detail below. In describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. While specific exemplary embodiments are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations can be used without parting from the spirit and scope of the invention. All references cited herein are incorporated by reference as if each had been individually incorporated.
Referring to
Container 10 generally includes a base 12, a sidewall 14, a dome 16, and a finish 18. Container 10 defines a central axis A that extends along the center of the container between the base 12 and the finish 18, as shown in
The sidewall 14, as shown, is substantially tubular and has a substantially circular cross-sectional shape in a plane perpendicular to the central axis A, although other cross-sectional shapes are possible. Alternative cross-sectional shapes can include, for example, an oval transverse cross-section; a substantially square transverse cross-section; other substantially polygonal transverse cross-sectional shapes such as triangular, pentagonal, etc.; or combinations of curved and arced shapes with linear shapes. As will be understood by one of ordinary skill in the art, when the container has a substantially polygonal transverse cross-sectional shape, the corners of the polygon are typically rounded or chamfered. The sidewall 14 can include various structural and/or aesthetic elements, such as vacuum panels 22 and 24, and ribs 26, as will be understood by one of ordinary skill in the art.
Container 10 can also include a recessed waist 28 located between the dome 16 and the sidewall 14. Waist 28 can increase the hoop-strength of container 10, and thus help prevent ovalization or other deformation of container 10 that may occur, for example, as the result of internal vacuum forces that occur when the container's contents cool after hot filling. As shown in
In contrast to the waist 28 of the present invention, the tightly radiuses waists of the prior art can result in disadvantages, particularly in larger containers. For example, as the height of the container increases, the portion of the container occupied by the dome increases. The dome, however, can create a weak spot in the container with respect to top load. Methods to reduce the height of the container dome can include, for example, increasing the height of the sidewall below the dome. Other techniques that have been used to improve top-load strength in large containers have included creating larger vertical portions in the dome, use of structural elements such as vertical or horizontal ridges or additional circumferential rings or hoops and various other modifications of the dome design. These modifications have provided varying success and are not acceptable in some cases, for example, for aesthetic reasons. The present invention overcomes some of these drawbacks. For example, use of the present invention allows extension of the container height below the dome without extending the height of the sidewall. As a result, known dome designs with acceptable top-loading capacity can be used in taller containers.
Referring to
In addition to reinforcing the container 10, the wall portion 30 can serve other functions. For example, branding can be provided on the wall portion 30. As shown in
Container 10 can have a one-piece construction and can be prepared from a monolayer plastic material, such as a polyamide, for example, nylon; a polyolefin such as polyethylene, for example, low density polyethylene (LDPE) or high density polyethylene (HDPE), or polypropylene; a polyester, for example polyethylene terephthalate (PET), polyethylene naphtalate (PEN); or others, which can also include additives to vary the physical or chemical properties of the material. For example, some plastic resins can be modified to improve the oxygen permeability. Alternatively, the container can be prepared from a multilayer plastic material. The layers can be any plastic material, including virgin, recycled and reground material, and can include plastics or other materials with additives to improve physical properties of the container. In addition to the above-mentioned materials, other materials often used in multilayer plastic containers include, for example, ethylvinyl alcohol (EVOH) and tie layers or binders to hold together materials that are subject to delamination when used in adjacent layers. A coating may be applied over the monolayer or multilayer material, for example to introduce oxygen barrier properties. In an exemplary embodiment, the present container is prepared from PET. Container 10 can be made by conventional blow molding processes including, for example, extrusion blow molding, stretch blow molding and injection blow molding.
The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. All examples presented are representative and non-limiting. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.
