Abstract:
A blister package having a shaped blister flange and a correspondingly shaped backing. The flange and backing are non-planar, thereby permitting the width of the blister pocket while maintaining the area of contact between the blister flange and backing. The blister package is manufactured by the general steps of (a) producing a blister with a shaped flange, (b) locating the blister in a correspondingly shaped die, (c) producing a backing with a layer of heat activated adhesive, (d) locating the backing over the blister, and (e) applying heat and pressure to the backing and blister with a correspondingly shaped heated press.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to packaging, and more particularly to blister packages and a method for manufacturing the same.  
           [0002]    Blister packages are widely used in the industry to package articles for display during sale. Blister packages are desirable because they are relatively inexpensive to manufacture and to fill, and they allow the packaged article or articles to be viewed by the customer at the point of sale. Blister packages are available in a variety of styles. A conventional “face-seal” blister package  80  is shown in FIG. 1. A face-seal blister package typically includes a transparent (or translucent) blister  82  that is secured to a backing material  84 , such as a paperboard panel. The blister is typically manufactured from PVC or PET, and is shaped to hold the article(s) to be packaged. For small articles, such as tacks or brads, the blister may define a simple rectangular void, while for larger articles, the blister may be shaped to match the contours of the article being packaged. In a conventional “face-seal” blister package construction, the blister  82  includes a pocket  86  and a peripheral flange  88 . The flange  88  extends outwardly in a single plane to define a mounting surface for securing the blister  82  to the backing  84 . The flange  88  is typically secured to the backing  84  by conventional methods, such a heat activated adhesive. In a common blister pack construction, the blister flange  88  is approximately one quarter of an inch in width. This will provide sufficient attachment between the blister  82  and backing  84  for many standard applications. The size of the flange  88  will, however, vary from application to application depending in large part on the size and weight of the article(s) being packaged, the type of adhesive used to secured the blister and backing, and the materials used to manufacture the backing and blister.  
           [0003]    A second conventional package  80 ′ is shown in cross-section in FIGS. 2 and 3. This type of package is referred to as a “mock clamshell” construction because it is designed to provide the appearance of a conventional clamshell package. The mock clamshell package  80 ′ includes a blister  82 ′ that is secured to a planar backing  84 ′. The blister  82 ′ includes a planar major surface  92 , a pocket  86 ′ extending forwardly from the major surface  92 , and a platform  90  that extends rearwardly from the periphery of the major surface  92 . The major surface  92  is substantially coextensive with and secured to a paperboard backing  84 ′. The platform  90  extends rearwardly to emulate the appearance of a more expensive clamshell package.  
           [0004]    These conventional blister package constructions suffers from a number of significant disadvantages. As best shown in FIGS. 1 and 2, the flanges  88  and  88 ′ decrease the width of the pocket  86  and  86 ′ for packages  80  and  80 ′ of a given width, thereby reducing the volume of products that can be displayed in a given display area. For example, a conventional two and one half inch wide package includes a two-inch pocket and a quarter-inch flange. Because the flange extends along both sides of the package, the flange decreases the maximum width of the pocket by a total of one half of an inch. As a result, the pocket can be only 80 percent of the overall width of the blister package to incorporate the flange. This means that, in the lateral direction, twenty percent of the display area is for the most part wasted. In addition, the planar flange of a conventional blister package severely limits package design and is visually unappealing in many applications.  
         SUMMARY OF THE INVENTION  
         [0005]    The aforementioned problems are overcome by the present invention wherein a blister package is provided with a shaped blister flange and a correspondingly shaped backing. The flange and backing are non-planar and are intersecured by corresponding non-planar tooling.  
           [0006]    In a preferred embodiment, the present invention includes an angled blister flange and a correspondingly angled backing. The package is manufactured by providing a planar backing and a blister with an angled flange. The backing and blister are intersecured with conventional adhesives using a special die and heated press. The die and heated press are shaped to correspond with the angled blister flange. As the die and heated press are closed, the backing is pressed into the shape of the blister, giving the backing a peripheral margin that extends along an angle with the blister flange. Simultaneously, the heat from the heated press activates the adhesive coating on the backing thereby securing the backing to the blister along the blister flange. If desired, the shaping and sealing steps can be performed separately.  
           [0007]    The present invention provides a simple and inexpensive blister package with reduced dimensions and an improved visual appearance. The shaped blister flange provides the ability to increase the size of the blister pocket available in a given amount of space. The size of the blister pocket can be increased over conventional planar blister packages without increasing the overall size of the package and without compromising the attachment area between the blister and backing. Further, the shaped blister flange provides for significant variety in the design and appearance of the package. Also, the contours or bends in the blister and in the backing significantly strengthen the overall construction of the package. This allows the thickness of both the blister and the backing to be reduced, thereby reducing the overall cost of the package.  
           [0008]    These and other objects, advantages, and features of the invention will be readily understood and appreciated by reference to the detailed description of the preferred embodiment and the drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a perspective view of a first prior art blister package;  
         [0010]    [0010]FIG. 2 is a front elevational view of a second prior art blister package;  
         [0011]    [0011]FIG. 3 is a side elevational view of the second prior art blister package;  
         [0012]    [0012]FIG. 4 is a perspective view of a blister package according to the present invention;  
         [0013]    [0013]FIG. 5 is a front elevational view of the package;  
         [0014]    [0014]FIG. 6 is a side elevational view of the package;  
         [0015]    [0015]FIG. 7 is a sectional view of the package taken along line VII-VII of FIG. 5;  
         [0016]    [0016]FIG. 8 is perspective view of an alterative blister package;  
         [0017]    [0017]FIG. 9 is sectional view of the alternative blister package taken along line IX-IX of FIG. 8;  
         [0018]    [0018]FIG. 10 is perspective view of a second alterative blister package;  
         [0019]    [0019]FIG. 11 is sectional view of the second alternative blister package taken along line XI-XI of FIG. 10;  
         [0020]    [0020]FIG. 12 is a flow chart of the general steps involved in manufacturing the blister package;  
         [0021]    [0021]FIG. 13 is a sectional view of the blister and backing in an open die and heated press assembly;  
         [0022]    [0022]FIG. 14 is a sectional view of the blister and backing in a closed die and heated press assembly;  
         [0023]    [0023]FIG. 15 is a top plan view of the backing showing the score lines;  
         [0024]    [0024]FIG. 16 is perspective view of a third alterative blister package;  
         [0025]    [0025]FIG. 17 is sectional view of the third alternative blister package taken along line XVII-XVII of FIG. 16; and  
         [0026]    [0026]FIG. 18 is a bottom plan view of the third alternative blister package.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     The Blister Package  
       [0027]    A blister package according to a preferred embodiment of the present invention is shown in FIG. 4, and generally designated  10 . The blister package  10  is designed to hold articles at the point of sale, and is typically discarded by the consumer after the article is removed. In some applications, the blister package will, however, be used as a storage container until the articles are exhausted (e.g. tacks or brads). The blister package  10  generally includes a blister  12  and a backing  14  (see FIG. 7). The blister  12  and backing  14  are intersecured to define an enclosed space  17  for holding the desired article or articles. For purposes of this disclosure, the terms “front,” “back,” “forward” and “rearward” are used herein to denote the corresponding directions with respect to the blister package when it is hanging for display at the point of sale. For example, the front surface of the blister package is the surface of the package facing the consumer when the package is on display. Further, the term “display plane” is used herein to denote a plane extending along the height and width of the blister when the package is on display. Typically, the display plane is a substantially vertical plane extending parallel to the shelf or rack that supports the package. Additionally, the term “shaped” is used herein to describe a non-planar or contoured component, whether including curved and/or differently angled portions.  
         [0028]    The present invention will first be described in connection with a relatively simple blister package shown in FIGS.  4 - 7 . The blister  12  is typically manufactured from a transparent or translucent polymer, such as polyvinyl chloride (PVC) or polyethylene terephthalate (PET). The blister  12  generally includes a major surface  16 , a pocket  18  extending forwardly from surface  16  and a flange  20  extending rearwardly at an angle from the periphery of surface  16 . The major surface  16  is typically planar and defines a hanging hole  22  for hanging the blister package  10  from virtually any standard display hook at the point of sale. In some applications, the major surface  16  may be eliminated and the flange  20  may extend directly and solely from the periphery of the pocket  18  (See FIG. 10). The hanging hole  22  is preferably located at the top center of the major surface  16 . The size, shape and location of the hanging hole  22  will vary from application to application.  
         [0029]    As noted above, the pocket  18  extends forwardly from the major surface  16  and, in the illustrated embodiment, is generally rectangular in shape. The pocket  18  can, however, be of virtually any desired size and shape (e.g. FIGS. 8 and 10) to define an appropriate space for containing the article or articles to be packaged. The pocket  18  is configured to display the article or articles on a display plane, which generally extends substantially vertically and substantially perpendicularly to the line of sight of consumers when the package is displayed during normal use.  
         [0030]    The flange  20  extends at an angle rearwardly from the periphery of the surface  16 . The angle of the flange  20  will vary from application, but in the preferred embodiment, the angle is approximately 60 degrees from the plane defined by the major surface  16 . As described below in connection with various alternative embodiments, the flange  20  may be shaped or contoured to provide more complex package designs. The major surface  16  may be non-planar or may be eliminated in some applications. In such applications, the angle of the flange  20  is measured from the display plane (not shown). As will be readily apparent to one skilled in the art, the overall width of the package will vary with changes in the angle and width of the flange  20 . The overall width of the package can be determined by the formula: [2×(F×COS A)]+W, where F is the width of the flange  20 , A is the angle of the flange  20  with respect to the major surface  16 , and W is the width of the major surface  16 . The angle formed in the blister  12  significantly improves the strength and rigidity of the blister  12  and of the assembled blister package  10 . Accordingly, the angled flange  20  permits the use lighter weight materials than would be required for similar packages with a planar flange. For standard applications, the blister  12  is approximately 0.012, 0.015 or 0.018 of an inch in thickness (12, 15 or 18 gauge).  
         [0031]    The backing  14  is a generally planar sheet of stock material that is secured to the rear of the blister  12  to enclose the article or articles within the blister pocket  18 . The backing  14  includes a front surface  32 , a back surface  34  and, preferably, a hanging hole  38 . The hanging hole  38  is aligned and typically corresponds in shape with the hanging hole  22  of the blister  12 . The backing is preferably manufactured from any of a variety of paperboard materials readily available in the industry. As described in more detail below, the backing  14  will be shaped to conform to the blister flange  20  during the manufacturing process. In the illustrated embodiment, the backing  14  includes a peripheral margin  30  surrounding a major portion  31 . The peripheral margin  30  is bent backward during manufacture to correspond with the shape of the blister flange  20  (See FIG. 7). The width and height dimensions of the backing  14  are selected to match the dimensions that the blister  12  would have had if the blister flange  20  was not angled (e.g. width of the blister pocket plus actual width of the flanges). This will allow the backing  14  to be substantially coextensive with the blister flange  20  after the backing  14  has been shaped to conform to the angled blister flange  20 . The angle or bend introduced into the backing  14  during manufacture will significantly improve the strength and rigidity of the backing  14  and of the assembled blister package  10 . In the preferred embodiment, the backing  14  is approximately 0.014 of an inch in thickness (14 point). It should be noted that conventional constructions using a planar backing might typically require a thickness of 0.021 of an inch thick (21 point) for similar applications. The backing  14  further includes a layer of adhesive (not shown) extending over its front surface  32 . The adhesive (not shown) is preferably a conventional heat activated adhesive, such as ______, that is selected for its ability to adhere to the backing  14  and the blister  12 . If desired, the adhesive coating can be applied only to the peripheral portion  30  of the backing  14  where the blister flange  20  and the backing  14  are in contact. This will typically provide a sufficient attachment between the backing  14  and blister  12 .  
         [0032]    In the preferred embodiment, the backing  14  is provided with score lines that facilitate shaping of the backing  14 . For example, referring now to FIG. 15, the backing  14  can include radial score lines  50  in the corners to facilitate bending of the corners. Similarly, the backing  14  can include score lines  52  to facilitate bending of the peripheral margin  30  rearwardly from the major portion  31 . The location and arrangement of score lines will vary from application to application.  
       Manufacture and Assembly  
       [0033]    The blister package  10  is manufactured and assembled using a die and heated press specially  50  adapted to function with an angled blister flange  20 . As shown in FIGS. 13 and 14, the die and heated press assembly  50  includes a die  52  and a heated press  54  (platen). The die  52  defines an opening  58  designed to receive the blister  12 . The periphery  56  of the opening  58  is angled to correspond with the angle of the blister flange  20 . The heated press  54  is mounted upon an actuation mechanism (not shown) for moving the heated press  54  with respect to the die  52 . The heated press  54  includes a bottom surface  56  that is shaped and dimensioned to match with the opening  58  of the die  52 , taking into account the thickness of the blister  12  and backing  14 . The heated press  52  is heated to the appropriate temperature for activating the specific adhesive applied to the backing  14 . The temperature as well as the pressure and dwell time of the press will vary from application to application.  
         [0034]    The manufacturing process will be described with reference to the flow chart of FIG. 12. The blister  12  is manufactured  100  using conventional techniques and apparatus. For example, the blister  12  can be manufactured using conventional vacuum forming techniques and apparatus. In the preferred embodiment, the blister  12  is manufactured from  12  gauge PVC sheet stock. Typically, a sheet of the appropriate stock material is vacuum formed into an array of blisters. The sheet is the is then cut to separate the array into individual blisters.  
         [0035]    The backing  14  is also manufactured  102  using conventional techniques and apparatus, such as printing, coating and diecutting presses. In the preferred embodiment, the backing  14  is manufactured from  14  point paperboard stock. The adhesive  36  is applied  104  to the backing  14  with a conventional applicator, such a roller, and allowed to dry. The adhesive is typically applied around the periphery of the backing  14 , for example, around the peripheral one-quarter inch of the backing  14 . The disposition and type of adhesive will vary from application to application as desired. Typically, the layer of adhesive is applied to a sheet of stock material and then the sheet is cut into a plurality of individual backings. Any desired score lines, such as score lines  50  and  52 , can be formed in the backing  14  during the die cutting step.  
         [0036]    As shown in FIG. 13, the blister  12  is inserted  106  upside down into the opening  58  with its flange  20  engaging the angled periphery  56  of the opening  54 . This step can be performed manually or it may be automated using conventional machinery. Once the blister  12  is positioned, the article or articles to be packaged are inserted  108  into the pocket  18 . This step is typically automated through the use of conventional product feeding machinery (not shown), but may also be performed manually. The backing  14  is then placed  110  on top of the die  52  over the blister  12  with its front surface  32  down. The backing  14  is preferably registered using conventional apparatus, such as stationary or retractable locating pins  90   a - c  protruding from the die  52 .  
         [0037]    Once the backing  14  is properly registered with respect to the blister  12 , the heated press  54  is lowered  112  into the die opening  54  (See FIG. 14). The heated press  54  reshapes the backing  14  forcing it down into the die opening  54 . Typically, the heated press  54  may cause the corners of the backing  14  to wrinkle and or crease slightly as it conforms to the shape of the die opening  54 . The heated press  54  applies heat and pressure to the blister  12  and backing  14 , thereby activating the adhesive  36  and sealing the blister  12  to the backing  14 . The heated press  54  is then raised  114  to provide access to the finished package. For mass production, the die may include multiple die openings so that multiple packages can be formed and sealed in a single actuation of the heated press assembly.  
       Alternative Embodiments  
       [0038]    A variety of alternative blister packages in accordance with the present invention are shown in FIGS.  8 - 11  and  15 - 16 . These alternative embodiments illustrate the flexibility of the present invention by showing variously shaped packages that provide increased pocket width and improved aesthetic appearance while maintaining the required surface area of contact between the blister and the backing. FIGS. 8 and 9 show a blister package  10 ′ in which the blister  12 ′ includes a hemispherical pocket. In this embodiment, a backing  14 ′ with a curved bottom edge is secured to the blister  12 ′. As perhaps best shown in FIG. 9, the pocket flows smoothly and continuously into the flange  20 ′. The blister flange  20 ′ tapers off to provide the package  10 ′ with a substantially planar upper portion  56 .  
         [0039]    [0039]FIGS. 10 and 11 show a blister package  10 ″ including a blister pocket  18  “that extends to all four outer edges of the package”. The blister pocket  18 ″ includes four sides that are inclined at the same angle as the flange  20 ″. In this embodiment, a rectangular backing  14 ″ is secured to the blister  12 ″. The backing  14 ″ conforms to the shape of the flange  20 ″ during manufacture.  
         [0040]    FIGS.  16 - 18  show yet another alternative blister package  10 ′’‘ including a curved blister  12 ′’‘ and backing  14 ‘’‘. Although the blister  12 ′’‘ and backing  14 ′’‘ are curved, they terminate in a horizontal plane at the bottom of the package  10 ′’‘. As a result, the blister  12 ′’‘ and backing  14 ′’‘ function as a pedestal to provide a free-standing package. The blister pocket  18 ′’‘ is substantially hemispherical in the illustrations, but may obviously be shaped or contoured as desired. The curve in the blister  12 ′’‘ and backing  14 ′’‘ may be produced during the heat press stage of manufacture by pressing the blister  12 ′’‘ and backing  14 ′’‘ into the desired shape and then intersecuring them. Additionally or alternatively, depending on the application, the blister  12 ′’‘ can be formed (e.g. blow molded) with a certain degree of curvature. In some applications, it may be desirable to form the blister  12 ′’‘ with the degree of curvature desired in the completed package  10 ′’‘ while in other applications, it may be desirable to form the blister  12 ′’‘ with a lesser degree of curvature. The blister  12 ′’‘ and backing  14 ′’‘ are typically sealed together using heat activated adhesive (not shown) around the periphery of the package  10 ′’‘, for example, along a peripheral one-quarter inch of the blister  12 ′’‘ and backing  14 ′’‘. Obviously, the disposition and type of adhesive will vary from application to application as desired. For example, additional adhesive (not shown) may be disposed between the blister  12 ′’‘ and backing  14 ′’‘ in a line surrounding the pocket  18 ′’‘. This additional adhesive will help to resist separation of the blister  12 ′’‘ and backing around the pocket  18 ′’‘ and to retain small articles in the pocket  18 ′’‘.  
         [0041]    The above description is that of a preferred embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.