Abstract:
A plastic container includes an upper portion having a mouth defining an opening into the container. A shoulder region extends from the upper portion. A sidewall portion extends between the shoulder region and a base portion. The base portion closes off an end of the container. A vacuum panel region defined in part by at least two vacuum panels. Each of the vacuum panels are movable to accommodate vacuum forces generated within the container resulting from heating and cooling of its contents. The vacuum panel region occupies an area outboard of the sidewall portion.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure generally relates to plastic containers for retaining a commodity, and in particular a liquid commodity. More specifically, this disclosure relates to a plastic container having a vacuum panel region defined on the plastic container in an area distinct from a sidewall having a label panel area. 
       BACKGROUND 
       [0002]    As a result of environmental and other concerns, plastic containers, more specifically polyester and even more specifically polyethylene terephthalate (PET) containers are now being used more than ever to package numerous commodities previously supplied in glass containers. Manufacturers and fillers, as well as consumers, have recognized that PET containers are lightweight, inexpensive, recyclable and manufacturable in large quantities. 
         [0003]    Blow-molded plastic containers have become commonplace in packaging numerous commodities. PET is a crystallizable polymer, meaning that it is available in an amorphous form or a semi-crystalline form. The ability of a PET container to maintain its material integrity relates to the percentage of the PET container in crystalline form, also known as the “crystallinity” of the PET container. The following equation defines the percentage of crystallinity as a volume fraction: 
         [0000]    
       
         
           
             
               % 
                
               
                   
               
                
               Crystallinity 
             
             = 
             
               
                 ( 
                 
                   
                     ρ 
                     - 
                     
                       ρ 
                       a 
                     
                   
                   
                     
                       ρ 
                       c 
                     
                     - 
                     
                       ρ 
                       a 
                     
                   
                 
                 ) 
               
               × 
               100 
             
           
         
       
     
         [0000]    where ρ is the density of the PET material; ρ a  is the density of pure amorphous PET material (1.333 g/cc); and ρ c  is the density of pure crystalline material (1.455 g/cc). 
         [0004]    Container manufacturers use mechanical processing and thermal processing to increase the PET polymer crystallinity of a container. Mechanical processing involves orienting the amorphous material to achieve strain hardening. This processing commonly involves stretching an injection molded PET preform along a longitudinal axis and expanding the PET preform along a transverse or radial axis to form a PET container. The combination promotes what manufacturers define as biaxial orientation of the molecular structure in the container. Manufacturers of PET containers currently use mechanical processing to produce PET containers having approximately 20% crystallinity in the container&#39;s sidewall. 
         [0005]    Thermal processing involves heating the material (either amorphous or semi-crystalline) to promote crystal growth. On amorphous material, thermal processing of PET material results in a spherulitic morphology that interferes with the transmission of light. In other words, the resulting crystalline material is opaque, and thus, generally undesirable. Used after mechanical processing, however, thermal processing results in higher crystallinity and excellent clarity for those portions of the container having biaxial molecular orientation. The thermal processing of an oriented PET container, which is known as heat setting, typically includes blow molding a PET preform against a mold heated to a temperature of approximately 250° F.-350° F. (approximately 121° C.-177° C.), and holding the blown container against the heated mold for approximately two (2) to five (5) seconds. Manufacturers of PET juice bottles, which must be hot-filled at approximately 185° F. (85° C.), currently use heat setting to produce PET bottles having an overall crystallinity in the range of approximately 25%-35%. 
         [0006]    After being hot-filled, the heat-set containers may be capped and allowed to reside at generally the filling temperature for approximately five (5) minutes at which point the container, along with the product, is then actively cooled prior to transferring to labeling, packaging, and shipping operations. The cooling reduces the volume of the liquid in the container. This product shrinkage phenomenon results in the creation of a vacuum within the container. Generally, vacuum pressures within the container range from 1-380 mm Hg less than atmospheric pressure (i.e., 759 mm Hg-380 mm Hg). If not controlled or otherwise accommodated, these vacuum pressures result in deformation of the container, which leads to either an aesthetically unacceptable container or one that is unstable. Hot-fillable plastic containers must provide sufficient flexure to compensate for the changes of pressure and temperature, while maintaining structural integrity and aesthetic appearance. Typically, the industry accommodates vacuum related pressures with sidewall structures or vacuum panels formed within the sidewall of the container. Such vacuum panels generally distort inwardly under vacuum pressures in a controlled manner to eliminate undesirable deformation. 
         [0007]    While such vacuum panels allow containers to withstand the rigors of a hot-fill procedure, the panels have limitations and drawbacks. First, such panels formed within the sidewall of a container do not create a generally smooth glass-like appearance. Second, packagers often apply a wrap-around or sleeve label to the container over these panels. The appearance of these labels over the vacuum panels is such that the label often becomes wrinkled and not smooth. Additionally, one grasping the container generally feels the vacuum panels beneath the label and often pushes the label into various panel crevasses and recesses. 
       SUMMARY 
       [0008]    A plastic container includes an upper portion having a mouth defining an opening into the container. A shoulder region extends from the upper portion. A sidewall portion extends between the shoulder region and a base portion. The base portion closes off an end of the container. A vacuum panel region is defined in part by at least two vacuum panels. Each of the vacuum panels are movable to accommodate vacuum forces generated within the container resulting from heating and cooling of its contents. The vacuum panel region occupies an area outboard of the sidewall portion. 
         [0009]    According to additional features, the vacuum panels each define a plane that is substantially parallel to a longitudinal axis of the plastic container. The vacuum panels can be generally rectangular shaped. In one example, the vacuum panels include three pair of vacuum panels. Each vacuum panel opposes a corresponding vacuum panel. The sidewall portion includes a series of horizontal ribs that substantially circumscribe a perimeter of the sidewall portion. 
         [0010]    According to another example, the vacuum panel region can comprise a first vacuum panel region and a second vacuum panel region. The sidewall portion is formed intermediate of the first and second vacuum panel regions. Both of the first and second vacuum panel regions define three pair of vacuum panels. 
         [0011]    Additional benefits and advantages of the present disclosure will become apparent to those skilled in the art to which the present disclosure relates from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of a plastic container constructed in accordance with the teachings of the present disclosure. 
           [0013]      FIG. 2  is a side elevational view of the plastic container of  FIG. 1 . 
           [0014]      FIG. 3  is a top view of the plastic container of  FIG. 1 . 
           [0015]      FIG. 4  is a cross-sectional view of the plastic container taken along line  4 - 4  of  FIG. 1 . 
           [0016]      FIG. 5  is a perspective view of a plastic container constructed in accordance with additional teachings of the present disclosure. 
           [0017]      FIG. 6  is a side elevational view of the plastic container of  FIG. 5 . 
           [0018]      FIG. 7  is a top view of the plastic container of  FIG. 5 ; and 
           [0019]      FIG. 8  is a cross-sectional view of the plastic container taken along line  8 - 8  of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The following description is merely exemplary in nature, and is in no way intended to limit the disclosure or its application or uses. 
         [0021]    With reference to  FIGS. 1-4 , a plastic, e.g. polyethylene terephthalate (PET), hot-fillable container according to the present teachings is shown and generally identified at reference number  10 . As shown in  FIG. 2 , the plastic container  10  has an overall height H 1  of about 190.3 mm (7.49 inches). The height H 1  may be selected so that the plastic container  10  fits on the shelves of a supermarket or store. In this particular embodiment, the plastic container  10  has a volume capacity of about 20 fl. oz. (591 cc). Those of ordinary skill in the art would appreciate that the following teachings are applicable to other containers, such as containers having different shapes, which may have different dimensions and volume capacities. It is also contemplated that other modifications can be made depending on the specific application and environmental requirements. 
         [0022]    The plastic container  10  according to the present teachings defines a body  12  and includes an upper portion  14  having a finish  16 . Integrally formed with the finish  16  and extending downward therefrom is a shoulder region  20 . The shoulder region  20  merges into and provides a transition between the finish  16  and a sidewall portion  22 . The sidewall portion  22  extends downward from the shoulder region  20  to a vacuum panel region  26 . The vacuum panel region  26  merges into a base portion  28  having a base  30 . A neck  32  may also be included having an extremely short height, that is, becoming a short extension from the finish  16 , or an elongated height, extending between the finish  16  and the shoulder region  20 . The plastic container  10  has been designed to retain a commodity. The commodity may be in any form such as a solid or liquid product. In one example, a liquid commodity may be introduced into the plastic container  10  during a thermal process, typically a hot-fill process. For hot-fill bottling applications, bottlers generally fill the plastic container  10  with a liquid or product at an elevated temperature between approximately 155° F. to 205° F. (approximately 68° C. to 96° C.) and seal the plastic container  10  with a cap (not illustrated) before cooling. In addition, the plastic container  10  may be suitable for other high-temperature pasteurization or retort filling processes or other thermal processes as well. In another example, the commodity may be introduced into the plastic container  10  under ambient temperatures. 
         [0023]    The finish  16  of the plastic container  10  includes a portion defining an aperture or mouth  36 , and a threaded region  38  having threads  40 . The finish  16  can also define a support ring  42 . The support ring  42  may be used to carry or orient a preform (the precursor to the plastic container  10 , not illustrated) through and at various stages of manufacture. For example, the preform may be carried by the support ring  42 , the support ring  42  may be used to aid in positioning the preform in the mold, or an end consumer may use the support ring  42  to carry the plastic container  10  once manufactured. 
         [0024]    The aperture  36  allows the plastic container  10  to receive a commodity while the threaded region  38  provides a means for attachment of a similarly threaded closure or cap (not illustrated). Alternatives may include other suitable devices that engage the finish  16  of the plastic container  10 . Accordingly, the closure or cap (not illustrated) engages the finish  16  to preferably provide a hermetical seal of the plastic container  10 . The closure or cap (not illustrated) is preferably of a plastic or metal material conventional to the closure industry and suitable for subsequent thermal processing, including high temperature pasteurization and retort. 
         [0025]    The sidewall portion  22  includes a series of horizontal ribs  44 . The horizontal ribs  44  substantially circumscribe the entire perimeter of the sidewall portion  22  of the plastic container  10 . The horizontal ribs  44  extend continuously in a longitudinal direction from the shoulder region  20  to the vacuum panel region  26 . According to one example, the sidewall portion  22  can define a width W 5 . The width W 5  can be approximately 60 mm (2.36 inches). The base  30  functions to close off the base portion  28  of the plastic container  10  and, together with the finish  16 , the shoulder region  20 , the sidewall portion  22 , and the vacuum panel region  26 , to retain the commodity. The base portion  28  generally defines an outer surface having a thread detail  48  formed therearound. The thread detail  48  can assist in providing structural integrity to the base portion  28  as well as provide an ornamental appeal to the plastic container  10 . Additionally, the thread detail  48  may facilitate attachment of a secondary container or closure. 
         [0026]    The vacuum panel region  26  is generally defined between lateral surfaces  50  at a stepped-out portion  52  of the plastic container  10 . The vacuum panel region  26  defines a plurality of vacuum panels  56  generally extending on respective planes that are parallel to a central longitudinal axis  60  of the plastic container  10 . According to one example, the stepped-out portion  52  can define a width W 1  between opposing vacuum panels  56 . The width W 1  can be approximately 85 mm (3.35 inches). Preferably, the width W 1  may be at least 10% greater than the width W 5 . More preferably, the width W 1  may be about 20%-40% greater than the width W 5 . 
         [0027]    As illustrated in  FIGS. 1-4 , the vacuum panels  56  may be generally rectangular in shape. It is appreciated that the vacuum panels  56  may define other geometrical configurations as well. Accordingly, the plastic container  10  illustrated in the  FIGS. 1-4  has six (6) vacuum panels  56 . The inventors however equally contemplate that more than or less than six (6) vacuum panels  56  can be provided. By way of example, the vacuum panel region  26  can also be formed on the plastic container  10  having two (2), three (3), four (4), five (5), seven (7) or eight (8) vacuum panels. As illustrated, the present teachings facilitate the orientation of vacuum panels  56  in a horizontal direction relative to the central longitudinal axis  60  of the plastic container  10 . Surrounding the vacuum panels  56  are horizontal and vertical connecting walls  62  and  64 , respectively. Each horizontal connecting wall  62  is generally defined between the vacuum panel  56  and respective lateral surfaces  50 . The horizontal connecting walls  62  define a generally arcuate profile in horizontal cross-section (see  FIG. 4 ). Each vertical connecting wall  64  is defined between adjacent vacuum panels  56 . 
         [0028]    Optionally, each horizontal connecting wall  62  may define a distinctly identifiable structure between the lateral surfaces  50  and an underlying surface  66  of vacuum panels  56 . The horizontal connecting walls  62  provide strength to the transition between the lateral surfaces  50  and the underlying surface  66  of the vacuum panels  56 . The resulting localized strength increases the resistance to creasing and denting in the vacuum panel region  26  and the plastic container  10  as a whole. 
         [0029]    A label panel area  70  is defined at the sidewall portion  22 . The label panel area  70  therefore occupies a distinct portion of the plastic container  10  relative to the vacuum panel region  26 . As is commonly known and understood by container manufacturers skilled in the art, a label (not shown) may be applied to the sidewall portion  22  (label panel area  70 ) using methods that are well known to those skilled in the art, including shrink-wrap labeling and adhesive methods. As applied, the label may extend around the entire body  12  or be limited to a partial circumference of the sidewall portion  22 . 
         [0030]    Upon filling, capping, sealing and cooling, as illustrated in  FIG. 4  in phantom, the horizontal connecting walls  62  each act as a hinge that aids in the allowance of the underlying surface  66  of vacuum panels  56  to be pulled radially inward, toward the central longitudinal axis  60  of the plastic container  10 , displacing volume, as a result of vacuum forces. In this position, the underlying surface  66  of vacuum panels  56 , in cross section, illustrated in  FIG. 4  in phantom, forms a generally concave surface  66 ′. The configuration of the sidewall portion  22  and the vacuum panel region  26 , allow the vacuum reaction to be absorbed in a controlled manner by the vacuum panels  56  without substantial disruption to the label panel area  70  or a remainder of the plastic container  10 . 
         [0031]    As illustrated in  FIG. 2 , the vacuum panels  56  have a width W 2 . In one example, for the plastic container  10  having a nominal capacity of approximately 16.9 fl. oz. (500 cc), the width W 2  may be about 43.81 mm (1.72 inches). A height H 2  defined at an outermost edge of the vacuum panels  56  may be about 27.16 mm (1.07 inches). The height H 2  may vary slightly across the width W 2  of the vacuum panels  56 . A height H 3  defined from the shoulder region  20  to a transition between the sidewall portion  22  and the vacuum panel region  26  may be about 74.33 mm (2.93 inches). A height H 4  of the finish  16  may be about 19.71 mm (0.76 inch). A height H 5  of the base portion  28  may be about 48.08 mm (1.89 inches). 
         [0032]    With reference to  FIGS. 5-8 , a plastic, e.g. polyethylene terephthalate (PET), hot-fillable container according to the present teachings is shown and generally identified at reference number  110 . As shown in  FIG. 6 , the plastic container  110  has an overall height H 6  of about 262.92 mm (10.35 inches). The height H 6  may be selected so that the plastic container  110  fits on the shelves of a supermarket or store. Again, it is contemplated that other modifications can be made depending on the specific application. 
         [0033]    The plastic container  110  according to the present teachings defines a body  112  and includes an upper portion  114  having a finish  116 . Integrally formed with the finish  116  and extending downward therefrom is a shoulder region  120 . The shoulder region  120  merges into and provides a transition between the finish  116  and a first vacuum panel region  118 . The first vacuum panel region  118  merges into a sidewall portion  122 . The sidewall portion  122  extends downward from the first vacuum panel region  118  to a second vacuum panel region  126 . The second vacuum panel region  126  can transition into a base portion  128  having a base  130 . A neck  132  may also be included having an extremely short height, that is, becoming a short extension from the finish  116 , or an elongated height, extending between the finish  116  and the shoulder region  120 . The plastic container  110  has been designed to retain a commodity. The commodity may be in any form such as a solid or liquid product. In one example, a liquid commodity may be introduced into the plastic container  110  during a thermal process, typically a hot-fill process, such as described above. In another example, the commodity may be introduced into the plastic container  110  under ambient temperatures. 
         [0034]    The finish  116  of the plastic container  110  includes a portion defining an aperture or mouth  136 , and a threaded region  138  having threads  140 . The finish  116  can also define a support ring  142 . The support ring  142  may be used to carry or orient a preform (the precursor to the plastic container  110 , not illustrated) through and at various stages of manufacture. For example, the preform may be carried by the support ring  142 , the support ring  142  may be used to aid in positioning the preform in the mold, or an end consumer may use the support ring  142  to carry the plastic container  110  once manufactured. 
         [0035]    The aperture  136  allows the plastic container  110  to receive a commodity while the threaded region  138  provides a means for attachment of a similarly threaded closure or cap (not illustrated). Accordingly, the closure or cap (not illustrated) engages the finish  116  to preferably provide a hermetical seal of the plastic container  110 . The closure or cap (not illustrated) is preferably of a plastic or metal material conventional to the closure industry and suitable for subsequent thermal processing, including high temperature pasteurization and retort. 
         [0036]    The sidewall portion  122  includes a series of horizontal ribs  144 . The horizontal ribs  144  circumscribe the entire perimeter of the sidewall portion  122  of the plastic container  110 . The horizontal ribs  144  extend continuously in a longitudinal direction from the first vacuum panel region  118  to the second vacuum panel region  126 . According to one example, the sidewall portion  122  can define a width W 6 . The width W 6  can be approximately 50.8 mm (2.0 inches). The base  130  functions to close off the base portion  128  of the plastic container  110  and, together with the finish  116 , the shoulder region  120 , the sidewall portion  122 , and the first and second vacuum panel regions  118  and  126 , respectively, to retain the commodity. 
         [0037]    The first and second vacuum panel regions  118  and  126  are generally defined at first and second stepped-out portions  152  and  154 , respectively, of the plastic container  110 . The figures and the following description are directed toward first and second vacuum panel regions that are substantially equivalent in formation, however, they may be formed differently from each other. The first and second vacuum panel regions  118  and  126  each define a plurality of vacuum panels  156  and  158 , respectively, generally extending on respective planes that are parallel to a central longitudinal axis  160  of the plastic container  110 . According to one example, the stepped-out portions  152  and  154  can define a width W 3  between opposing vacuum panels  156  (and likewise, opposing vacuum panels  158 ). The width W 3  can be approximately 67.06 mm (2.64 inches). As in the previous example, preferably, the width W 3  may be at least 10% greater than the width W 6 . More preferably, the width W 3  may be about 20%-40% greater than the width W 6 . 
         [0038]    As illustrated in  FIGS. 5-8 , the vacuum panels  156  and  158  may be generally rectangular in shape. It is appreciated that the vacuum panels  156  and  158  may define other geometrical configurations as well. Accordingly, the plastic container  110  illustrated in the  FIGS. 5-8  has six (6) vacuum panels  156  defined on the first vacuum panel region  118 , and six (6) vacuum panels  158  defined on the second vacuum panel region  126 . The inventors however equally contemplate that more than or less than six (6) vacuum panels  156  and  158  can be provided. By way of example, one or both of the first and second vacuum panel regions  118  and  126  can also be formed on the plastic container  110  having two (2), three (3), four (4), five (5), seven (7) or eight (8) vacuum panels. As illustrated, the present teachings facilitate the orientation of vacuum panels  156  and  158  in a horizontal direction relative to the central longitudinal axis  160  of the plastic container  110 . 
         [0039]    Surrounding the vacuum panels  156  are horizontal and vertical connecting walls  162  and  164 , respectively. Each horizontal connecting wall  162  is generally defined between the vacuum panel  156  and an adjacent radial surface  165 . The horizontal connecting walls  162  define a generally arcuate profile in horizontal cross-section (see  FIG. 8 ). Each vertical connecting wall  164  is defined between adjacent vacuum panels  156 . 
         [0040]    Surrounding the vacuum panels  158  are horizontal and vertical connecting walls  167  and  168 , respectively. Each horizontal connecting wall  167  is generally defined between the vacuum panel  158  and an adjacent radial surface  169 . The horizontal connecting walls  167  define a generally arcuate profile in horizontal cross-section (see  FIG. 8 ). Each vertical connecting wall  168  is defined between adjacent vacuum panels  158 . 
         [0041]    Optionally, each horizontal connecting wall  162  and  167  may define a distinctly identifiable structure between the adjacent radial surfaces  165  and  169  and an underlying surface  171  and  172  of vacuum panels  156  and  158 , respectively. The horizontal connecting walls  162  and  167  provide strength to the transition between the adjacent radial surfaces  165  and  169  and the underlying surfaces  171  and  172 . The resulting localized strength increases the resistance to creasing and denting in the first and second vacuum panel regions  118  and  126 , and the plastic container  110  as a whole. 
         [0042]    A label panel area  180  is defined at the sidewall portion  122 . The label panel area  180  therefore occupies a distinct portion of the plastic container  110  relative to the first and second vacuum panel regions  118  and  126 . In this example, the label panel area  180  is defined between the first and second vacuum panel regions  118  and  126 . As is commonly known and understood by container manufacturers skilled in the art, a label (not shown) may be applied to the sidewall portion  122  (label panel area  180 ) using methods that are well known to those skilled in the art, including shrink-wrap labeling and adhesive methods. As applied, the label may extend around the entire body  112  or be limited to a partial circumference of the sidewall portion  122 . 
         [0043]    Upon filling, capping, sealing and cooling, as illustrated in  FIG. 8  in phantom, the horizontal connecting walls  162  and  167  each act as a hinge that aids in the allowance of the underlying surface  171  and  172  of vacuum panels  156  and  158  to be pulled radially inward, toward the central longitudinal axis  160  of the plastic container  110 , displacing volume, as a result of vacuum forces. In this position, the underlying surface  171  and  172  of vacuum panels  156  and  158 , in cross section, illustrated in  FIG. 8  in phantom, form a generally concave surface  171 ′ and  172 ′, respectively. The configuration of the sidewall portion  122  and the first and second vacuum panel regions  118  and  126 , allow the vacuum reaction to be absorbed in a controlled manner by the vacuum panels  156  and  158  without substantial disruption to the label panel area  180  or a remainder of the plastic container  110 . 
         [0044]    As illustrated in  FIG. 6 , the vacuum panels  156  and  158  have a width W 4 . In one example, for the plastic container  110  having a nominal capacity of approximately 16.9 fl. oz. (500 cc), the width W 4  may be about 34.63 mm (1.36 inches). A height H 7  defined at an outermost edge of vacuum panels  156  and  158  may be about 21.16 mm (0.83 inch). The height H 7  may vary slightly across the width W 4  of the vacuum panels  156  and  158 . A height H 8  defined by the sidewall portion  122  (label panel area  180 ) may be about 76.29 mm (3.00 inches). A height H 9  of the finish  116  may be about 18.62 mm (0.73 inch). A height H 10  of the second vacuum panel region  126  and the base portion  128  may be about 74.81 mm (2.95 inches). 
         [0045]    While the above description constitutes the present disclosure, it will be appreciated that the disclosure is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.