Abstract:
A method for hermetically sealing a bulk article wherein a strip of wrapping material is initially positioned onto an article such that extending ends of the wrapping material strip extend from away from an edge of the article, each end having a different length. The article is rotated to cause the ends of the strip to cover an uncovered side of the article with a fin-like section extending therefrom away from the article which can be sealed without contacting the article. The fin-like section is cooled and folded onto the top of the article so as to form an axial seam. Lateral ends of the wrapping material strip are then sealed to complete the hermetic sealing process.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims priority under 35 USC §119 from provisional application, U.S. Ser. No. 60/372,354, filed Apr. 10, 2002, the entire contents of which are herein incorporated by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates to the field of packaging, and in particular to a method for hermetically wrapping bulk articles, such as confectionaries and pharmaceutical products, among others.  
         BACKGROUND OF THE INVENTION  
         [0003]    Hermetic wraps, such as so-called “pillow” wraps, have been developed to more or less hermetically seal a wrapped bulk article such as candies, gum and the like. To date, these wraps have been performed on horizontal wrapping machines which require a significant footprint and are expensive to maintain and install.  
           [0004]    Rotary cut and wrapping machines, on the other hand, which do not require as significant a footprint as the above horizontal wrapping machines have been used to package confections, chews, bubble gum and the like. These machines utilize sealing methods that have been limited to various die fold end wraps, twist wraps, turned under fold single point wraps and the like. To date, existing rotary wrapping machines have not been able to produce a “pillow type” hermetic seal or wrap at cost-effective speeds exceeding 500 pieces per minute.  
         SUMMARY OF THE INVENTION  
         [0005]    It is a primary object of the present invention to overcome the above-noted deficiencies of the prior art.  
           [0006]    It is another primary object of the present invention to develop a more efficient method for wrapping bulk articles, such as, for example, confectionaries and pharmaceutical products.  
           [0007]    Therefore and according to one aspect of the invention there is disclosed a method of wrapping a bulk article, said method including the steps of:  
           [0008]    placing a bulk article in wrapping material, said wrapping material being defined as a strip having ends extending over respective sides of said article and beyond the edges of the article, each of the extending ends of said strip having different lengths;  
           [0009]    folding each of said extending edges of said strip over one edge of the article, so as to define a fin-like section;  
           [0010]    heat sealing the fin-like section to define an axial seam wherein said fin-like section is sealed away from the wrapped article; and  
           [0011]    sealing the lateral ends of the wrapping strip so as to define a hermetic seal about the article.  
           [0012]    The article can include a variety of items, including but not limited to hard and soft chewy candies, gum, foodstuffs, and pharmaceutical (human and veterinary) products.  
           [0013]    According to another aspect of the invention, there is described an apparatus for wrapping at least one bulk article, said apparatus including a rotary wheel having a plurality of pockets along an outer periphery thereof, said wheel being supported for rotation about a center axis of the wheel. A bulk article is fed into a first pocket of said wheel and into a strip of wrapping material. The strip of wrapping material is sized to be fitted about the periphery of the article and includes a pair of ends of dissimilar length extending from respective sides of the article. The article is then rotated to a second position by the pocket wheel which folds each of the ends of the wrapping material strip over an edge of the article and forms a fin-like section extending away from the article.  
           [0014]    Preferably, a heater is provided adjacent to one of said pockets for heat sealing this fin-like section of wrapping material. This sealing operation does not require contact with the article being wrapped and therefore no heat or pressure is imparted to the article, but only to the fin-like section. In lieu of heat sealing, other sealing means, such as ultrasonic welding and/or pressure sensitive cold seals, can be utilized.  
           [0015]    The formed seal is then cooled at a subsequent operation, such as by means of a water chiller or other appropriate apparatus. The article is then removed from the pocket wheel and the fin-like seal is folded over onto the top of the product which is then conveyed through an end seal apparatus to complete the hermetic seal operation.  
           [0016]    An advantage of the above wrapping method is that a seal is created which extends away from the product permitting heat contact over substantially an entire major dimension (e.g., length, width) of the wrapped product.  
           [0017]    These and other objects, features and advantages will be readily understood from the following Detailed Description which should be read in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 is a pictorial view of a wrapping method for a bulk article in accordance with a preferred embodiment of the invention;  
         [0019]    [0019]FIGS. 2A and 2B are side elevational views of a wrapping apparatus used for carrying out the wrapping method of FIG. 1;  
         [0020]    [0020]FIG. 3 is an enlarged view of a pocket wheel station shown in FIG. 2A, illustrating the heat sealing of a fin section of the bulk article depicted in FIG. 1;  
         [0021]    [0021]FIG. 4 is an enlarged view of a pocket wheel station subsequent to that of FIG. 3, illustrating a cooling operation of the bulk article;  
         [0022]    [0022]FIG. 5 is an enlarged view of a subsequent pocket wheel station which provides an exit for the bulk article;  
         [0023]    [0023]FIG. 6 is a partial top view of the end sealing portion of the apparatus of FIGS. 2A and 2B; and  
         [0024]    [0024]FIG. 7 is a perspective view of a bulk article employing the wrapping method of FIG. 1. 
     
    
     DETAILED DESCRIPTION  
       [0025]    The following description relates to a specific apparatus for performing the present wrapping method. It will be readily apparent from the discussion that follows that other machinery can be used to create wrapped articles as described herein. The example shown herein relates to a rectangularly shaped bulk article, such as candy or gum but the herein defined wrapping method can easily be applied to articles of varying shapes and configurations.  
         [0026]    Referring to FIG. 1, there is shown a pictorial view of the wrapping method in accordance with the present invention. A bulk article  10 , such as a continuous section of chocolate, caramel, or other confectionary or other material of example, such as fudge or dough, is first cut into a rectangular configuration from a feed line  20  through conventional means, such as a cutting blade (not shown). Referring to FIGS. 1 and 2A, the bulk article  10 , after being cutting into its rectilinear shape, is horizontally shuttled to a cut and wrap station, shown generally as  24 , adjacent a rotatable pocket wheel  28 . The cut and wrap station  24  is modified to allow a strip of wrapping material  32  to be fed from a supply of wrapping material (not shown) prior to the article  10  being pushed horizontally into a rotary folding box  36  of the pocket wheel  28 . The wrapping material  32  is composed of polyethylene, mylar, wax paper, foil or other suitable film material and typically includes a heat activated adhesive usually coated on the inside of the material which can include printed material on the outside surface thereof. The herein-described pocket wheel  28  includes a plurality of rotary folding boxes  36  disposed arcuately about the wheel, defining a number of take-up positions for bulk articles  10  as the wheel is caused to rotate through a central mechanism (not shown). As shown in FIG. 1, first and second folds  40 ,  44  of the wrapping material strip  32  are created around the bulk article  10  along respective edges  48  and  52 .  
         [0027]    The strip of wrapping material  32  that is provided is sized such that an additional amount of wrapping material remains outside of the rotary folding box  36  on each of the edges of the bulk article  10  to be wrapped, permitting this material to be folded back upon itself. Preferably, the material  32  is at least half the width of the product shape in a double thickness as required in a subsequent step.  
         [0028]    Each rotary folding box  36  of the pocket wheel  28  of the herein described apparatus is preferably equipped with a pressure block  56  that is attached to the back of each pocket. This block  56  is made sufficiently wide, intentionally exceeding the desired width of the wrapping material and having a radial length sufficient to backup the overlap of material protruding from it when the bulk article  10  and the material are clamped together into contact.  
         [0029]    As shown in FIGS.  1 - 4 , the partially wrapped article  10  is then caused to index with the pocket wheel  28  within the folding box  36  and rotate through a series of consecutive stations of the apparatus. At first station approximately 90 degrees from the original wrap and cut station  24 , a heater  60  heaving a concave contact surface  64  is disposed in relation to the pocket wheel  28 , shown more particularly in FIG. 3. The heater  60  includes a spring loaded mechanism  70  that acts to press onto and heat the overlapped material inside the pressure block  56  it rests upon. This allows the heat seal to occur away from the formed product and more specifically behind and away from the bulk article  10 . The heat seal forms a fin-like section  68 , shown more particularly in FIG. 1, which defines an axial seam as well as respective third and fourth folds  72 ,  76 . In lieu of a heat seal, the seam can be formed using an ultrasonic horn (not shown) and a welding process.  
         [0030]    After a given number of indexing operations, the bulk article  10  is pinched using a similar spring-loaded mechanism  82  similar to that described above relative to a water-chilled concave cooling station  80  having a similar contact surface  86 . This cooling operation sets the long axial adhesive of the seam of the defined fin section as shown in FIG. 4, as the wheel rotates past the contact surface  86  thereof.  
         [0031]    The wrapped package then proceeds incrementally to an exit position or station  90 , shown in FIG. 5, from the rotating folding box  36  of the pocket wheel  28  and dwells horizontally. In this position as conveyed, the axial seam is now turned over 180 degrees from the sealed positions described above, and is “above” the product.  
         [0032]    As the wrapped bulk article  10  is extracted from the rotary folding box of the pocket wheel  28 , the product is passed beneath a heel  84  of the concave surface of the cooling station  80 . Simultaneously, the long seam of the fin-like section  68  is pushed onto the top of the exiting product, thereby creating a final fold.  
         [0033]    As the wrapped bulk article  10  emerges from under the heel  84  of the cooling block and exits the rotatable pocket wheel  28 , the article is placed within a chain lug style conveyor  88  disposed between a shallow track and a spring loaded hold-down bar  94 , which keeps the partially wrapped article  10  in place throughout a plurality of various end seal positions.  
         [0034]    Once located within the chain lug conveyor  88 , the wrapped article  10  is pushed between a pair of package endformers  100 , situated on each lateral side thereof as shown in FIG. 6. These endformers  100  are machined with respective lead-ins  104  that are used to capture the lateral ends of wrapping material  32  and to guide the ends which are closed between a set of narrow slots  108 . This operation, as shown in FIG. 6, flattens and spreads each end of the wrapping material  32  into a bow tie-like shape extending approximately halfway up the ends of the bulk article  10 .  
         [0035]    After the lateral ends of the wrapped product have been flattened and shaped, each bulk article  10  is moved into an end heat portion  112  of the wrapping apparatus. In this portion, the ends of the wrapped bulk article  10  are moved through closely fitted slots  116  that have been machined into a pair of metal blocks  120 ,  124 . These blocks  120 ,  124  are heated, for example, by electrical resistance type heaters (not shown), that are controlled by self-monitoring heat controllers (not shown). The heater blocks  120 ,  124  are preferably contained with temperature sensors in a conventional manner that report the achieved temperature to the control station through a feedback circuit which determines whether more or less heat is required. As the wrapped bulk article  10  passes through the slotted heated portions, the lateral ends of the wrapped bulk article  10  are subjected to a predetermined amount of heat over the length of the heater blocks  120 ,  124 .  
         [0036]    As a result of the above heating operation, the adhesive material on the interior of the ends of the wrapping material of the bulk article  10  is melted and gently pressed together and held in the above preformed bow tie shape. The heater blocks  120 ,  124  are preferably mounted with fasteners through lateral slots that permit adjustment of the distance from the heaters to the actual product in the wrapping apparatus. Significant to the present invention, the above operation allows only the end wrapping material to be pressed against the heaters, and not the actual contained product.  
         [0037]    After a predetermined amount of heater length, the end seal areas of the wrapped article  10  are resented between a pair of counter rotating end crimpers  130 , driven by the control system to a specific surface speed. These crimpers  130  provide the pressure required to set a firm seal with various style impressions being left on the ends. The long seam is tacked down at each end of the bulk article  10  by leaving a slight amount of length on the outer layer of exposed wrapping material, thereby completing the wrapping operation. For very poor heat conducting films and laminated wrapping materials, additional heaters may be applied to the crimpers.  
         [0038]    Preferably, a reciprocating nip blade is provided in order to cut a small mark  140  or notch length wise into one end of the wrapped article  10  to permit easy opening by the consumer, such as shown in FIG. 7.  
         [0039]    While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.  
         [0040]    For example, the above equipment could also be utilized to wrap product having cold seal films. For this instance, the above described heater and chiller stations would simply be turned off and a label registration/cut/timing system (not shown) would be added to the cut and wrap station  24 .  
         [0041]    Part List for FIGS.  1 - 7   
                                       10   bulk article       20   feed line       24   cut and wrap station       28   rotatable pocket wheel       32   wrapping material       36   rotary folding box       40   first fold       44   second fold       48   edge       52   edge       56   pressure block       60   heater       64   concave contact surface       68   fin-like section       70   spring loaded mechanism       72   third fold       76   fourth fold       80   cooling station       82   spring loaded mechanism       84   heel       86   contact surface       88   conveyor       90   exit station       94   hold down bar       100   end formers       104   lead-ins       108   slots       112   end heat portion       116   slots       120   block       124   block       130   crimper       140   slot/notch                  
 
         [0042]    It will be readily apparent to one of sufficient skill in the field that certain modifications and variations covering the inventive concepts are possible as recited in the following claims: