Patent Publication Number: US-9896254-B2

Title: Multi-serve hot fill type container having improved grippability

Description:
BACKGROUND OF THE INVENTION 
     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. 
     SUMMARY OF THE INVENTION 
     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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a plastic container that is constructed according to a preferred embodiment of the invention; 
         FIG. 2  is a front elevational view of the plastic container that is shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along lines  3 - 3  in  FIG. 1 ; 
         FIG. 4  is a cross-sectional view taken along lines  4 - 4  in  FIG. 2 ; 
         FIG. 5  is a cross-sectional view taken along lines  5 - 5  in  FIG. 2 ; 
         FIG. 6  is a cross-sectional view taken along lines  6 - 6  in  FIG. 2 ; 
         FIG. 7  is a cross-sectional view taken along lines  7 - 7  in  FIG. 2 ; 
         FIG. 8  is a perspective view of a container assembly including the plastic container that is shown in  FIG. 1 ; and 
         FIG. 9  is an enlargement of a portion within  FIG. 2 , depicting a vacuum panel in a container that is constructed according to the preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to  FIG. 1 , a round, hot fillable plastic container  10  that is constructed according to a preferred embodiment of the invention includes a container body  12  having a main body portion  14 , an upper portion  16  and a bottom  22 . In the preferred embodiment, the upper portion  16  includes a finish portion  18  having an external thread  20 . A rounded dome portion  58  is preferably provided between the main body portion  14  and the upper portion  16 . 
     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  FIGS. 1 and 2 , the main body portion  14  has a plurality of vacuum panels  46 ,  50  defined therein and is constructed to have generally hourglass shape with a central portion  26  that is narrower, as measured transversely to the longitudinal axis  54  of the container  10 , than either an upper portion  28  or a lower portion  30  of the main body portion  14 . The hourglass shape optimizes grippability of the container  10 . 
     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 R 1 , and the lower gripping portion  40  preferably has a concave outer surface  44  that defines a second average radius of curvature R 2 . In the preferred embodiment, the second average radius of curvature R 2  is substantially the same as the first average radius of curvature R 1 , 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 D MAX , shown in  FIG. 2 , located immediately above the first groove  32 . A portion of the container  10  that is immediately beneath the second groove  34  in the preferred embodiment is substantially equal to a maximum outer diameter D MAX . These two locations on the container body  12  form dimensionally stable points of contact, which enable the container  10  to be efficiently handled using conventional conveyance technology in a packaging facility. The provision of the first and second grooves  32 ,  34  immediately adjacent to the dimensionally stable points of contact enhances the dimensional stability of those portions of the container body  12 . A plastic container  10  is what is termed in the industry a round container, meaning that it has a substantially circular transverse cross-section in the areas of its maximum outer diameter D MAX . 
     Preferably, a ratio R 1 /D MAX  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 R 1 , R 2  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&#39;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 .  FIG. 9  is an enlarged portion of  FIG. 2  depicting one of the vacuum panels  50  within the lower gripping portion  40 . Each of the vacuum panels  50  also has a maximum width W V1  at a lower end thereof that is greater than a maximum width W V2  at an upper end thereof. 
     Referring to  FIG. 6 , the outwardly extending pillow portion  48  of each of the pillows  50  preferably has a convex shape facing outwardly as viewed in transverse cross-section, and has an average radius of curvature R 3 . A ratio R 3 /D MAX  of the average radius of curvature R 3  to the maximum outer diameter of the container  10  is preferably substantially within a range of about 0.15 to about 0.65, more preferably substantially within a range of about 0.2 to about 0.5 and most preferably substantially within a range of about 0.25 to about 0.45. The convex shape of the pillows  50  promotes label support. 
     As  FIG. 4  best shows, each of the outwardly extending pillow portions  48  also preferably is convex facing outwardly as viewed in vertical or longitudinal cross-section, and has an average radius of curvature R 4 . A ratio R 4 /R 1  of the average radius of curvature R 4  to the first average radius of curvature R 1  is preferably substantially within a range of about 0.3 to about 1.4, more preferably substantially within a range of about 0.35 to about 1.2 and most preferably substantially within a range of about 0.4 to about 1.1. 
     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  FIG. 9  shows, the pillow  52  includes a maximum width W P1  at a lower end thereof that is greater than a maximum width W P2  at an upper end thereof. 
       FIG. 8  shows a container assembly  60  that is constructed according to the preferred embodiment of the invention. The container assembly  60  includes the container  10  described above, which has been filled with product such as fruit juice, and has been wrapped in a shrink fit label  62  that conforms to the hourglass shape of the container body  12 . Container assembly  60  further includes a conventional closure cap  64  and a tamper evident seal in order to keep the product sealed within the container  10 . 
     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.