Patent Publication Number: US-6659300-B2

Title: Container having square and round attributes

Description:
FIELD OF THE INVENTION 
     This invention generally relates to plastic containers for retaining a commodity, and in particular a liquid commodity. More specifically, this invention relates to a plastic container having a square shoulder region tapered into a round foot print. 
     BACKGROUND OF THE INVENTION 
     Numerous commodities previously supplied in glass containers are now being supplied in plastic, more specifically polyester and even more specifically polyethylene terephthalate (PET) containers. The manufacturers and fillers, as well as consumers, have recognized that PET containers are lightweight, inexpensive, recyclable and manufacturable in large quantities. 
     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 is related to the percentage of the PET container in crystalline form, also known as the “crystallinity” of the PET container. Crystallinity is characterized as a volume fraction by the equation:        Crystallinity   =       ρ   -     ρ   a           ρ   c     -     ρ   a                         
     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). 
     The crystallinity of a PET container can be increased by mechanical processing and by thermal processing. Mechanical processing involves orienting the amorphous material to achieve strain hardening. This processing commonly involves stretching a 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 is known as biaxial orientation of the molecular structure in the container. Thermal processing involves heating the material (either amorphous or semi-crystalline) to promote crystal growth. 
     The marketing of beverages, particularly liquor, is strongly driven by the need to create and retain brand identification among consumers. One method of increasing brand recognition is the use of a particular container shape. As part of an overall marketing strategy, many beverage marketers have built brand identification based on container shapes having non-circular, particularly square cross sections. In many instances, the investment and benefit in identifying a product by its container configuration precludes changes in container configuration which would enhance manufacturing capabilities but potentially injure brand recognition. 
     Non-circular shaped containers create several problems during the manufacturing process. For example, square shaped containers must be kept in a particular orientation during filling, labeling and packaging which can significantly decrease production efficiency. Square shaped containers frequently can get caught on machine guides and stack up on the production line. Additionally, square shaped containers require inspection of all four sides in order to locate an appropriate flat surface for labeling. Accordingly, required rotation mechanisms are more complicated. Thus, square shaped containers frequently require re-orientation on the production line, decreasing labeling accuracy, production speed and efficiency. 
     The outer panels or sides of a square shaped plastic container often sink in and deform due to “shrink back”. This phenomenon is magnified under vacuum conditions created by warm fill (i.e., liquid product filled into the container while the liquid product is at an elevated temperature, typically above ambient temperature but below about 54° C. (130° F.)) and cool down. Such sink in and deformation is caused, in part, by a decrease in rigidity found in the outer panels or sides of square shaped plastic containers relative to traditional glass containers. The above described sunken panels cause labeling issues such as rippled labels, poor label adhesion and decreased reliability of automatic processes. One solution to the above described sunken panels has been an attempt to increase panel rigidity by increasing the thickness of the panel through the addition of material. Such an increase in material, however, significantly increases container cost. 
     Traditional circular shaped plastic containers do not exhibit the sunken panel phenomenon. The curvature of the sidewalls found in a circular shaped plastic container tend to resist buckling better than a flat panel surface. Thus, there is a need for an improved plastic container which maintains brand identity by creating the visual perception of a square shaped container while incorporating the material handling, labeling and structural benefits of a circular shaped container. Compound panel curvature greatly reduces potential panel shrink back. 
     SUMMARY OF THE INVENTION 
     It is, therefore, a principal object and purpose of the present invention to provide a plastic container that provides the handling, labeling and structural benefits of a circular shaped container while preserving the brand identification benefits of a square shaped container. 
     It is an additional principal object and purpose of the present invention to provide a plastic container that does not require frequent re-orientation on the production line, thus increasing labeling accuracy, production speed and efficiency. 
     It is another object and purpose of the present invention to provide a plastic container that provides increased rigidity and resists panel shrink back. 
     It is still another object and purpose of the present invention to provide a plastic container having lower resin costs and increased production line efficiencies. 
     It is another object and purpose of the present invention to provide a plastic container that has a square shoulder region which gradually tapers into a round foot print. 
     These and other objectives and advantages are provided by the present invention which is directed to a plastic container that provides the handling, labeling and structural benefits of a circular shaped container while preserving the brand identification benefits of a square shaped container. The plastic container includes a neck having a mouth defining an opening into the container, a shoulder region extending from the neck to a body portion, the body portion extending from the shoulder region to a base, the base closing off an end of the container. The neck, shoulder region, body portion and base cooperating to define a receptacle chamber within the container into which product can be filled. The shoulder region has a substantially square cross section while the base has a substantially circular cross section. Consequently, the plastic container creates the visual perception of a square shaped container while incorporating the material handling, labeling and structural benefits of a circular shaped container. 
     A second embodiment of the invention includes a neck having a mouth defining an opening into the container, a shoulder region having a substantially square cross section, a body portion and a base having a substantially circular cross section. The body portion including pinch grips. 
     Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and accompanying drawings, wherein: 
     FIG. 1 is a front elevational view of a plastic container in accordance with the present invention; 
     FIG. 2 is an elevational view taken from a front left corner of the plastic container in FIG. 1; 
     FIG. 3 is a left elevational view of the plastic container in FIG. 1; 
     FIG. 4 is an elevational view taken from a rear left corner of the plastic container in FIGS. 1 and 3; 
     FIG. 5 is a rear elevational view of the plastic container in FIG. 1; 
     FIG. 6 is a cross sectional view of the plastic container, taken generally along line  6 — 6  of FIG. 1; 
     FIG. 7 is a cross sectional view of the plastic container, taken generally along line  7 — 7  of FIG. 1; 
     FIG. 8 is a rear elevational view of a second embodiment of a plastic container in accordance with the present invention; and 
     FIG. 9 is an elevational view taken from a front left corner of the plastic container in FIG.  8 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following description of the preferred embodiment is merely exemplary in nature, and is in no way intended to limit the invention or its application or uses. 
     As illustrated in FIGS. 1-5, a plastic container  10  of the present invention includes an elongated neck  12 , a shoulder region  14 , a body portion  16  and a base  18 . The neck  12  of the plastic container  10  includes a portion defining an aperture or mouth  20 , a threaded region  22  and a support ring  24 . The aperture  20  allows the plastic container  10  to receive a commodity while the threaded region  22  provides a means for attachment of a similarly threaded closure or cap (not shown), which preferably provides a hermetical seal for the plastic container  10 . The support ring  24  may be used to carry or orient the preform (the precursor to the plastic container  10 ) (not shown) through and at various stages of manufacture. For example, the preform may be carried by the support ring  24 , the support ring  24  may be used to aid in positioning the preform in the mold, or the support ring  24  may be used by an end consumer to carry the plastic container  10 . 
     Integrally formed with the elongated neck  12  and extending downward therefrom is the shoulder region  14 . The shoulder region  14  merges into and provides a transition between the elongated neck  12  and the body portion  16 . The body portion  16  extends downward from the shoulder region  14  and includes sidewalls  26 . Because of the specific construction of the plastic container  10 , the sidewalls  26  may be formed without the inclusion therein of vacuum panels, and if desired, is generally smooth. 
     The base  18  of the plastic container  10 , which generally extends inward from the body portion  16 , includes a chime  28  and an intravenous slot or notch  30  formed therein. The base  18  functions to close off the bottom portion of the plastic container  10  and, together with the elongated neck  12 , the shoulder region  14  and the body portion  16 , to retain the commodity. 
     The plastic container  10  of the present invention is a blow molded, biaxially oriented container with an unitary construction from a single or multi-layer material such as polyethylene terephthalate (PET) resin. Alternatively, the plastic container  10  may be formed by other methods and from other conventional materials. Plastic containers blow molded with an unitary construction from PET materials are known and used in the art of plastic containers, and their general manufacture in the present invention will be readily understood by a person of ordinary skill in the art. 
     With continued reference to FIGS. 1-5, the neck  12  of the plastic container  10  is elongated, enabling the plastic container  10  to accommodate volume requirements. Additionally, as a result of the neck  12  of the plastic container  10  being elongated, the need for three (3) separate labels is eliminated. A rear label of the plastic container  10  is not required as the information contained therein can be added to a larger label which easily fits on the elongated neck  12  of the plastic container  10 . Thus, the elongated neck  12  of the plastic container  10  eliminates the need for a third label thereby reducing label costs and improving production efficiencies. 
     As illustrated in FIG. 6, the shoulder region  14  has a substantially square cross section. Accordingly, the shoulder region  14  of the plastic container  10  includes four sides  32 , all of which are substantially equal in length. Each side  32  is slightly bent inward at a midpoint  34  or, stated differently, each side  32  is an arc of relatively large radius. The dimension between the midpoints  34  of opposing sides  32  defines a shoulder width  36 . Between each side  32  and integrally formed therewith are rounded corners  38 . The rounded corners  38  are arcs of relatively small radius. The dimension between opposite rounded corners  38  defines a diagonal distance  39 . The relative proportions of the radii of the sides  32  and the rounded corners  38  may be adjusted accordingly to balance the visual perception of a square, taking into account productability and structural considerations. 
     As illustrated in FIG. 7, the base  18  of the plastic container  10  has a substantially circular cross section. The dimension of the diameter of the base  18  defines a base width  40 . As described above, and with continued reference to FIGS. 3-5, the base  18  includes the chime  28  and the intravenous slot or notch  30  formed therein. The intravenous slot or notch  30  is located at a rear portion of the base  18  of the plastic container  10  and is generally centered thereon. The intravenous slot or notch  30  is generally polygonal in shape and includes an inclined surface  42 , a rear surface  44  and sides  46 . The inclined surface  42  slopes downward from the rear portion of the plastic container  10  toward a front portion of the plastic container  10 . The rear surface  44  is generally vertical. The intravenous slot or notch  30  acts as an indexing/locating feature and is used to orient the plastic container  10  for labeling without disturbing the aesthetics or negatively affecting the stability of the plastic container  10 . 
     In order to enhance the visual perception of the plastic container  10  as square shaped, the dimension of the shoulder width  36  is substantially equal to the dimension of the base width  40 . Similarly, in order to enhance the visual perception of the plastic container  10  as square shaped, the dimension of the diagonal distance  39  between opposite rounded corners  38  of the shoulder region  14  is greater than the base width  40 . 
     Additionally, in order to enhance the visual perception of the plastic container  10  as square shaped, the sidewalls  26 , which are generally arcuate in shape, having a relatively large radius, gradually (at an angle of 13° or less from a center line  48  as shown in FIGS. 2,  4  and  9 ) taper downward from the shoulder region  14  toward the base  18 . In this regard, the center line  48  on the sidewalls  26 , extending from the midpoint  34  of the shoulder region  14  toward the base  18 , is substantially a straight vertical line. 
     As a result, the sidewalls  26  of the plastic container  10 , when viewed from the front as in a retail display, appear to be relatively flat, similar to the sides  32  of the shoulder region  14 . This effect is created by the customer&#39;s eye focusing on the straight vertical center line  48  on the sidewalls  26  in profile rather than focusing on the increasing curvature of the sidewalls  26  as they descend and gradually taper downward from the shoulder region  14  to the base  18 . 
     The above described visual effect may be further enhanced by the labeling of the bottle. The label can be designed to direct a customer&#39;s visual attention to the square shaped shoulder region  14 . Also, a majority of the label may be located on the substantially flat upper portion of the sidewalls  26 . The label may also use subtle variations of shape or line width to alter the perspective of the customer and give a more square like appearance as is well known in the visual arts. 
     As described above, the sides  32  of the shoulder region  14  and the sidewalls  26  of the plastic container  10  are not actually flat, but rather are generally arcuate in shape. Accordingly, the radii of the generally arcuate shaped sides  32  and the sidewalls  26  decreases progressively from the shoulder region  14  to the base  18 . As a result of the above construction, the structural resistance of the sidewalls  26  to sinking in is greatly improved over traditional square shaped plastic containers having flat sides. The enhanced rigidity of the rounded corners  38  of the shoulder region  14  and the portions of the sidewalls  26  proximate thereto, lends support to the flatter upper portion of the sidwalls  26 . The lower portions of the sidewalls  26  have the typical structural resistance to sinking in normally found in any circular shaped plastic container. 
     Accordingly, the shoulder region  14  of the plastic container  10  having a substantially square shaped cross section preserves the brand identification benefits associated with a square shaped container while the substantially circular cross section attributes of the base  18  increases the structural stability and ease which the plastic container  10  is handled during transfer, filling and labeling operations thus allowing the plastic container  10  to run on a faster production line. 
     FIGS. 8 and 9 illustrate a second general embodiment  100  of a plastic container according to the invention. As noted previously, the second embodiment  100  of the invention includes pinch grips as are well known in the art, but still exhibits the desired brand identification benefits associated with a square shaped container and the handling, structural attributes associated with a circular shaped container. Like reference numerals will be used to describe like components between the two embodiments. As with the previous embodiment  10 , the plastic container  100  includes, but is not limited to, the elongated neck  12 , the shoulder region  14 , the body portion  16  and the base  18 . The plastic container  100  differs primarily from the previous embodiment  10  in that it includes pinch grips. 
     The plastic container  100  includes an opposed pair of indentations  102  formed in two opposing sidewalls  26 , which enables the plastic container  100  to be grasped between a user&#39;s thumb and fingers of one hand. Each of the indentations  102  comprise a large generally rectangular shaped surface  104 . Each of the surfaces  104  include a plurality of generally horizontally spaced anti-slip finger grips  106 , each of which also forms a stiffener rib in the surface  104 . As a result, each of the finger grips  106  is convex in a direction outward of the plastic container  100 . 
     Accordingly, a user of the plastic container  100 , desiring to lift the container, either for transport purposes or for tipping purposes to discharge the contents, will position his/her hands on the sidewalls  26  so that the thumb is engaged with one of the indentations  102  and the fingers are engaged with the opposite indentation  102 . The finger grips  106  facilitate such engagement and ensure against inadvertent slipping. 
     While the above description constitutes the preferred embodiments of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.