Patent Application
20120097635
1. Field of the Invention
This invention relates generally to the field of plastic containers, and more particularly to plastic containers that are designed to accommodate volumetric expansion and contraction such as that inherent to the hot-fill packaging process or to packaging applications where internal pressurization is anticipated.
2. Description of the Related Technology
Many products that were previously packaged using glass containers are now being supplied in plastic containers, such as containers that are fabricated from polyesters such as polyethylene terephthalate (PET).
PET containers are typically manufactured using the stretch blow molding process. This involves the use of a preform that is injection molded into a shape that facilitates distribution of the plastic material within the preform into the desired final shape of the container. The preform is first heated and then is longitudinally stretched and subsequently inflated within a mold cavity so that it assumes the desired final shape of the container. As the preform is inflated, it takes on the shape of the mold cavity. The polymer solidifies upon contacting the cooler surface of the mold, and the finished hollow container is subsequently ejected from the mold.
Hot fill containers are designed to be used with the conventional hot fill process in which a liquid or semi-solid product such as fruit juice, sauce, salsa, jelly or fruit salad is introduced into the container while warm or hot, as appropriate, for sanitary packaging of the product. After filling, such containers undergo significant volumetric shrinkage as a result of the cooling of the product within the sealed container. Hot fill type containers accordingly must be designed to have the capability of accommodating such shrinkage. Typically this has been done by incorporating one or more vacuum panels into the side wall of the container that are designed to flex inwardly as the volume of the product within the container decreases as a result of cooling. Several vacuum panels are typically provided, with integral column structures interposed between the respective vacuum panels. The vacuum panel regions of conventional hot fill containers are usually recessed with respect to the adjacent columns. Hot fill containers are typically fabricated using PET, but alternatively can be fabricated using a material such as polypropylene using an extrusion blow molding process.
In many cases, the needs of a manufacturer require that a label be secured to the container over the vacuum panels. In order to avoid excessive crinkling or deformation of the label when the container is squeezed or when volumetric expansion or contraction occurs within the container, it is important that the vacuum panels and the container as a whole be designed to provide as much support for the label as possible. In some cases, one or more raised areas are provided within the vacuum panel for improved label support. These are typically referred to as pillows or islands.
Smaller hot fill containers, typically those under 32 ounces in volume, are commonly referred to as single serve containers in the industry as the entire contents of the container can be consumed by a user at one time. Containers that are 32 ounces and larger are typically referred to as multi-serve containers. These include large juice containers, with common volumetric sizes being 32 ounces, 48 ounces, 64 ounces, 96 ounces, and even a gallon. Design considerations that are present in the engineering of larger, multi-serve containers can be substantially different than those that are taken into account for smaller, single serve containers.
Grippability is an important design consideration in the engineering of such containers. In larger, multi-serve containers grippability has often been enhanced by providing a pair of deep vacuum panels that can also serve as gripping points for a consumer when picking the container up and handling the container during pouring. However, when a product manufacturer desires a large, multi-serve container to which a shrink fit label will be applied, the use of such deep vacuum panels is impractical because the label will bridge the recesses that are defined by the vacuum panels and render them inaccessible for gripping the container. In addition, certain product manufacturers prefer round containers, i.e. containers that are substantially circular in transverse cross-section at their widest dimensions, and it is difficult to implement certain types of gripping recesses in a circular container. Accordingly, designing a large, multi-serve container that is simultaneously suitable for use with a shrink fit label and that possesses adequate grippability for a consumer has been problematic, particularly in a round container.
A need exists for an improved round, multi-serve hot fillable container that provides superior grippability and that is suitable for use with shrink fit labeling.
Accordingly, it is an object of the invention to provide an improved round, multi-serve hot fillable container to provide superior grippability and that is suitable for use with shrink fit labeling.
In order to achieve the above and other objects of the invention, a round, hot fillable plastic container according to a first aspect of the invention includes an upper portion defining an opening and a bottom portion. The container further includes a main body portion having a plastic sidewall that has a plurality of vacuum panels defined therein. The main body portion has a generally hourglass shape with a central portion that is narrower than upper and lower portions thereof. The main body portion further has a first groove defined in the upper portion thereof, a second groove defined in the lower portion thereof and a third groove that is defined in the central portion thereof, whereby dimensional stability of the container is retained during handling and when the main body portion is gripped by a consumer.
A round, hot fillable plastic container according to a second aspect of the invention includes a plastic sidewall defining an interior space and defining an internal volume of the container that is at least about 32 ounces. The sidewall defines a main body portion having a generally hourglass shape with a central portion that is narrower than upper and lower portions thereof. The main body portion further has a first groove defined in the upper portion of the main body portion, a second groove defined in the lower portion of the main body portion and a third groove that is defined in the central portion of the main body portion. An upper gripping surface having a first plurality of vacuum panels is defined between the first groove and the third groove and a lower gripping surface having a second plurality of vacuum panels is defined between the second groove and the third groove. A label is mounted on the plastic sidewall so as to conform to the main body portion.
These and various other advantages and features of novelty that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to
In this embodiment, the entire container 10 is preferably fabricated from a material such as polyethylene terephthalate, commonly known by the acronym PET, from a plastic preform using the well-known reheat stretch blow molding process. Alternatively, the container 10 can be fabricated from a material such as polypropylene, and could be manufactured using a conventional extrusion blow molding process, the details of which are well known in this area of technology.
The main body portion 14 and the rest of the container 10 is fabricated as a single, unitary piece having a thin plastic sidewall 24. As is best shown in
The main body portion 14 preferably has a first groove 32 that is defined in the upper portion 28, and a second groove 34 that is defined in the lower portion 30. In the preferred embodiment, both the first and second grooves 32, 34 extend circumferentially within a transverse plane about an entire circumference of the container body 12. The main body portion 14 additionally preferably includes a third groove 36 that is located in the central portion 26 of the main body portion 14. The third groove 36 also preferably is configured so as to extend circumferentially within a transverse plane about an entire circumference of the container body 12. Each of the grooves 32, 34, 36 is preferably constructed so as to be of constant depth in shape throughout their circumference. In other words, each of the grooves 32, 34, 36 preferably has a substantially annular shape that is symmetrical about the longitudinal axis 54 of the container body 12.
The container 10 is preferably a multi-serve container, preferably defining an internal volume that is at least about 32 ounces, more preferably at least about 48 ounces and most preferably at least about 64 ounces.
The main body portion 14 has an upper gripping portion 38 defined between the first groove 32 and the third groove 36, and a plurality of vacuum panels 46 are preferably defined in the upper gripping portion 38. Similarly, the main body portion 14 has a lower gripping portion 40 that is positioned between the second groove 34 and the third groove 36. The lower gripping portion 40 preferably includes a plurality of vacuum panels 50.
In the preferred embodiment, the upper gripping portion 38 as a shape that is substantially symmetrical to the shape of the lower gripping portion 40 about a transverse plane that contains the third groove.
The upper gripping portion 38 preferably has a concave outer surface 42 that defines a first average radius of curvature R1, and the lower gripping portion 40 preferably has a concave outer surface 44 that defines a second average radius of curvature R2. In the preferred embodiment, the second average radius of curvature R2 is substantially the same as the first average radius of curvature R1, and the respective concave outer surfaces 42, 44 together form a single curved shape that defines the hourglass shape of the container body 12 in the main body portion 14. In the preferred embodiment, the radius of curvature of each of the concave outer surfaces 42, 44 is substantially constant, but in alternative embodiments could have some variability.
The plastic container 10 defines a maximum outer transverse dimension, which in the preferred embodiment is a maximum outer diameter DMAX, shown in
Preferably, a ratio R1/DMAX of the first average radius of curvature to the maximum outer diameter of the container 10 is substantially within a range of about 1.0 to about 20.0, more preferably substantially within a range of about 1.5 to about 8 and most preferably substantially within a range of about 1.75 to about 5.
Each of the average radii of curvature R1, R2 is preferably substantially within a range of about 100 mm to about 1000 mm, more preferably substantially within a range of about 150 mm to about 700 mm and most preferably substantially within a range of about 200 mm to about 500 mm. In the most preferred embodiment, the two concave outer surfaces 42, 44 define a single radius of curvature that preferably falls within the ranges specified above.
In the most preferred embodiment, the upper gripping portion 38 includes six vacuum panels 46 that are spaced evenly about the circumference of the container body 12 and that are respectively separated from each other by columns 56. Each of the vacuum panels 46 preferably includes an outwardly extending pillow portion 48 in order to provide label support, as will be discussed in greater detail below. In the preferred embodiment, the vacuum panels 46 are substantially identical to each other in size and shape.
The hourglass shape optimizes grippability of the container 10. Grippability is optimized further by the presence of the indentations that are formed between the columns 56 and the pillow portions 48, which permit a consumer to gain finger traction and purchase with respect to the container body 12, even when a label is positioned between the container body 12 and the user's fingers.
Similarly, the lower gripping portion 40 in the most preferred embodiment includes six vacuum panels 50 that are evenly spaced about the circumference of the container body 12 and that are respectively separated from each other by columns 58. Each of the vacuum panels 50 preferably includes an outwardly extending pillow portion 52 in order to provide label support. In the preferred embodiment, the vacuum panels 50 are substantially identical to each other in size and in shape, and are also shape to be substantially symmetrical in size and in shape, about a transverse plane that includes the third groove 36, with the vacuum panels 46 that are provided in the upper gripping portion 38.
Preferably, at least one vacuum panel 46, 50 is tapered so that is wider at an end that is distal to the third groove 36 that it is at an end that is proximate to the third groove 36. In the most preferred embodiment, all of the vacuum panels 46, 50 are so tapered, and the extent of the tapering is proportional to the increased surface area that is created as a result of the hourglass shape of the main body portion 14 near the upper and lower portions 28, 30.
Referring to
As
In addition, each of the pillows 52 is also preferably tapered in shape so that it is wider at an end that is distal to the third groove 36 than it is at an end that is proximate to the third groove 36. As
The aforementioned structure provides a round, multi-serve hot fillable container that possesses superior grippability and that is suitable for use with shrink fit labeling.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
