Abstract:
Disclosed is a tear-resistant folding carton comprising a paperboard unit, the unit comprising a paperboard layer, an upper film layer laminated to an upper side of the paperboard layer and a lower film layer laminated to a lower side of the paperboard layer, the carton comprising joining areas in which one portion of the unit overlaps and is joined to a second portion of the unit. Also disclosed is a method of making such a carton.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to product packaging and more particularly to tear-resistant or tamper-resistant packaging for consumer products, particularly value-added products that are prone to shop-lifting. 
       BACKGROUND 
       [0002]    U.S. Provisional Patent Application 61/829,080 filed on May 30, 2013 is hereby incorporated by reference in its entirety. 
         [0003]    In order to deter in-store destruction of packaging, a common practice has been to increase the amount and placement of adhesive in order to add increased evidence of fiber tear on the paperboard closing carton flaps, thereby alerting the consumer that the package has been previously opened. U.S. Pat. No. 6,070,790, issued to Colgate-Palmolive, addresses such issues, but does not address methods to prevent items being removed from packaging, and therefore should not be confused with packaging which provides tear resistance. 
         [0004]    Another common practice has been to design packaging with interlocking flaps whereby the carton cannot be opened except by tearing a portion of the carton (U.S. Pat. No. 3,462,066 issued to Reynolds Metals). Although this design is a theft deterrent, it still allows for the paperboard substrate to be torn open. 
         [0005]    Another common practice to prevent in-store theft has been to remove the product from the store shelf and place it behind the counter in a secure area. Lack of shelf presence can adversely affect product sales. 
         [0006]    Another common practice has been to lock the package in a clear plastic container. The consumer needs to take the container to the store clerk, have it unlocked, and then purchase the item. This process is not consumer friendly, is time consuming and adds additional costs associated with each sale. 
         [0007]    Another common practice to prevent theft is attaching a tracking device, such as an RFID chip, to the package. If the thief tries leaving the store an alarm is sounded. This preventative measure does not work if the item is removed from the package, the packaging is left on the shelf and the item is concealed in clothing or a handbag. 
         [0008]    U.S. Pat. No. 7,051,876 issued to Colbert Packaging discloses clamshell packaging for displaying and housing products. The packaging includes a tear-resistant housing that encloses a display chamber. Tear resistance is achieved by adhering an oriented cross grain laminated film or other substrates with cross-grain properties on a single side of a paperboard substrate to provide cut or tear resistance in multiple directions. This patent does not, however, address what is commonly referred to as a folding carton style package. 
         [0009]    There is a need for a folding carton style package which will have tear resistance strong enough to alert store clerks and consumers that a thief is removing an item from the carton in order to conceal it in clothing or a handbag. Chances of in-store theft may be drastically reduced if it becomes apparent that a thief is noticeably struggling to open the package in order to remove the item. 
       SUMMARY 
       [0010]    In one aspect the invention generally features a tamper-resistant folding carton having a cut and scored paperboard blank folded and joined, (e.g., glued at joining areas) in a manner which does not allow for easy access to the package product. In addition the paperboard carton blank has a layer of film (preferably tear resistant polymer film) laminated to the top side of the paperboard surface and a layer of film (also preferably tear resistant polymer film) laminated to the bottom side of the paperboard. These film layers will accept adhesive as a method of sealing portions of the carton to itself. In addition the upper and lower film layers provide the ability to seal portions of the carton to itself using sealing methods such as heat and pressure, infrared, ultrasonic, ultraviolet and radio frequency energy. 
         [0011]    The paperboard layer preferably is a paperboard base stock between 0.006 and 0.040 inches thick and can be identified as Solid Bleached Sulphate (SBS), Solid Unbleached Sulphate (SUS), and Clay Coated News (CCN). 
         [0012]    The laminated film may be linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene and polyethylene terephthalate. The film is either non-oriented or oriented film. If it is oriented, the orientation of the upper film layers is substantially the same as the orientation of the lower film layers. 
         [0013]    Areas of the carton where flaps or panels that are single thickness—i.e., they are not adhered to other flaps or panels—exhibit a machined direction (MD) tear resistance of at least 520, and a cross direction (CD) tear resistance of at least 570, measured by TAPPI Test Method T414, Internal Tearing Resistance of Paper and expressed in units of gram force. Joining areas of the carton where flaps or panels are multilayered—i.e., they are joined or adhered to other flaps or panels—exhibit a MD tear resistance of at least 1600, and a CD tear resistance of at least 1700. In general a preferred method is to seal as many flaps or panels to other portions of the carton to create two plies in which the overall tear resistance as described above (assuming two plies) is at least 1600 in the machine direction and 1700 in the cross direction. More preferably the tear resistance under these conditions is at least 1700 in the machine direction and 1900 in the cross direction. 
         [0014]    The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0015]      FIG. 1  shows a flat blank design for a tear resistant tri-sealed folding carton. 
           [0016]      FIG. 2  shows an enlarged cross-section of the blank design of  FIG. 1 , taken along  1 - 1  of  FIG. 1 . 
           [0017]      FIG. 3  shows a tri-sealed carton showing an application of adhesive to dust flaps. 
           [0018]      FIG. 4  shows forming a tri-seal carton with additional adhesive applied to various locations. 
           [0019]      FIG. 5  shows a completely formed and sealed tri-seal carton. 
           [0020]      FIG. 6  shows a flat blank design for a tear resistant gabled display folding carton. 
           [0021]      FIG. 7  shows a gabled display folding carton with adhesive. 
           [0022]      FIG. 8  shows a completely formed and sealed gabled display folding carton. 
       
    
    
       [0023]    Like reference symbols in the various drawings indicate like elements. 
       DETAILED DESCRIPTION 
       [0024]      FIG. 1  shows a flat blank design for a tear resistant tri-sealed folding carton with score lines  32  and die cut areas identified as bottom closure minor panel  14 , top closure minor panel  16 , bottom closure major panel  18 , top closure major panel  20 , dust flaps  10 , a glue flap  22 , a rear panel  26 , a front panel  28 , a left side panel  30  and a right side panel  24 . 
         [0025]      FIG. 2  identifies composite ply  46  consisting of five layers: paperboard base stock  42  joined to tear resistant film  40  on both sides by adhesive layers  44 . The paperboard base stock  42  can be made from Solid Bleached Sulphate (SBS), Solid 
         [0026]    Unbleached Sulphate (SUS), Clay Coated News (CCN) or other paperboard base stocks commonly used for packaging. Calipers (thickness) can range from 0.006 to 0.040. The laminated paperboard is scored to allow ease in folding. 
         [0027]    Film  40  can be blown or cast film made from Linear Low Density Polyethylene (LLDPE), Low Density Polyethylene (LDPE), Medium Density Polyethylene (MDPE), High Density Polyethylene (HDPE), Polypropylene (PP) Polyester (PET), or other blown or cast films which when laminated to the paperboard provide an MD tear resistance of at least 520 and a CD tear resistance of at least 570. 
         [0028]    Lamination of the film to paperboard can be accomplished using an extrusion process which applies an adhesive molten resin between the paperboard and films thus bonding the three substrates together, or it can be accomplished using an aqueous adhesive between the paperboard and films. 
         [0029]    The above-described configurations provide effective tear resistance by laminating films to both the top side and backside of the paperboard. There is no need to include an additional top coating on the film to achieve appropriate seals. 
         [0030]    To evaluate the tamper resistance, we measure tear resistance using TAPPI Test Method T414, Internal Tearing Resistance of Paper (Elmendorf method). In all cases we report tear resistance in units of gram force. One way to evaluate the product is to measure the tear resistance of a single ply. We measured tear resistance in the machine direction (MD) and in the cross direction (CD) of five different single ply SBS sheets, laminated with LLDPE films. Units are in gram force. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 Single Ply Tear Resistance 
               
               
                 1600 g Pendulum Used 
               
             
          
           
               
                 Sample ID 
                 1 
                 2 
                 3 
                 4 
                 5 
                 Average 
                 Std. Dev. 
               
               
                   
               
             
          
           
               
                 LLDPE Sample #1 
                 MD 
                 744 
                 741 
                 638 
                 666 
                 672 
                 692 
                 48 
               
               
                   
                 CD 
                 648 
                 630 
                 662 
                 666 
                 683 
                 658 
                 20 
               
               
                 LLDPE Sample #2 
                 MD 
                 638 
                 645 
                 618 
                 610 
                 618 
                 626 
                 15 
               
               
                   
                 CD 
                 883 
                 683 
                 686 
                 744 
                 784 
                 756 
                 83 
               
               
                 LLDPE Sample #3 
                 MD 
                 542 
                 522 
                 693 
                 550 
                 659 
                 593 
                 77 
               
               
                   
                 CD 
                 707 
                 579 
                 662 
                 609 
                 571 
                 626 
                 58 
               
               
                   
               
             
          
         
       
     
         [0031]    We prefer to use film and paperboard laminations having a single-ply tear resistance of at least 500 in the machine direction and 600 in the cross direction. More preferably the tear resistance should be at least 600 in the machine direction and 700 in the cross direction. Of course the two-ply configuration we describe below will have greater tear resistance. 
         [0032]    We measured the tear resistance of a two-ply construct when tearing through the sealed peripheral portion. We measured tear resistance in the machine direction (MD) and in the cross direction (CD) of five different two ply SBS sheets, laminated LLDPE film. Units are in gram force. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 Double Ply Tear Resistance 
               
               
                 3200 g Pendulum Used 
               
             
          
           
               
                 Sample ID 
                 1 
                 2 
                 3 
                 4 
                 5 
                 Average 
                 Std. Dev. 
               
               
                   
               
             
          
           
               
                 LLDPE  
                 MD 
                 1891 
                 1878 
                 1830 
                 2029 
                 1824 
                 1891 
                 83 
               
               
                 Sample #1 
                 CD 
                 2099 
                 1878 
                 1884 
                 2029 
                 1779 
                 1934 
                 128 
               
               
                 LLDPE  
                 MD 
                 1619 
                 1594 
                 1798 
                 1632 
                 2070 
                 1743 
                 200 
               
               
                 Sample #2 
                 CD 
                 1872 
                 1910 
                 1885 
                 2230 
                 1824 
                 1944 
                 163 
               
               
                 LLDPE  
                 MD 
                 1754 
                 1817 
                 1645 
                 1709 
                 1891 
                 1763 
                 95 
               
               
                 Sample #3 
                 CD 
                 1933 
                 1837 
                 1798 
                 1760 
                 1856 
                 1837 
                 65 
               
               
                   
               
             
          
         
       
     
         [0033]    Areas of the carton where flaps or panels are adhered to other flaps or panels exhibit a double ply MD tear resistance of at least 1600, and a CD tear resistance of at least 1700. More preferably the tear resistance under these conditions is at least 1700 in the machine direction and 1900 in the cross direction. 
         [0034]      FIG. 3  identifies a tri-sealed carton showing an application of adhesive  12  to four dust flaps  10  after which the bottom closure minor panel  14  and the top closure minor panel  16  are folded upwards to adhere to dust flaps  10 . The carton blank is scored  32  to allow for ease in folding. 
         [0035]      FIG. 4  exhibits a continuation of forming a tri-seal carton whereby additional adhesive  12  is applied to bottom closure minor panel  14 , top closure minor panel  16  and glue flap  22 . The portion of the carton with areas identified by front panel  28 , left side panel  30 , bottom closure major panel  18  and top closure major panel  20  are folded downward, after which the bottom closure major panel  18  is sealed to the bottom closure minor panel  14 , the top closure major panel  20  is sealed to the top closure minor panel  16  and the left side panel  30  is sealed to the glue flap  22 . 
         [0036]      FIG. 5  exhibits a completely formed and sealed tri-seal carton showing the front panel  28 , the left side panel  30 , the bottom closure major panel  18  and a score  32  which allows for ease of folding. 
         [0037]      FIG. 6  shows a flat blank design for a tear resistant gabled display folding carton with score lines  32  and die cut areas identified as bottom closure minor panel  14 , bottom closure major panel  18 , dust flaps  10 , a glue flap  22 , a rear panel  26 , a front panel  28 , a left side panel  30  and a right side panel  24 , a front gable panel  34 , a front hanger tab panel  36 , a rear hanger tab panel  38 . The top dust flaps  10  are scored at a forty-five degree angle to allow appropriate seals to the front gable panel  34 . 
         [0038]      FIG. 7  identifies a gabled display folding carton showing an application of adhesive  12  to upper angled dust flaps  10  and an application of adhesive  12  to the rear hanger tab panel  38 , after which the front gable panel  34  and the front hanger tab panel  36  are folded downward to seal to upper dust flaps  10  and rear hanger tab panel  38 . What is not shown is a similar gluing process as described in  FIGS. 3 and 4 , whereby adhesive  12  is applied to the lower dust flaps  10 . The bottom closure minor panel  14  is then folded upwards to adhere to the lower dust flaps  10 , with a subsequent application of adhesive  12  to the bottom closure minor panel  14 , after which the bottom closure major panel  18  is folded downwards to adhere to the glued bottom closure minor panel  14 . The carton blank is scored  32  to allow for ease in folding. 
         [0039]      FIG. 8  exhibits a completely formed and sealed gabled display folding carton showing the front panel  28 , the right side panel  30 , front gable panel  34 , the front hanger tab panel  36  and a score  32  which allows for ease of folding. 
         [0040]    A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, tear resistant folding cartons commonly referred to as reverse or straight tuck end folding cartons may fall within the scope of the claims. Accordingly, other embodiments are within the scope of the following claims.