Patent Publication Number: US-7717319-B2

Title: Reclosable folding box with tamper-evident closure without adhesive

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims priority based on European patent application EP 07 011 715.5, filed Jun. 14, 2007. 
   FIELD OF THE INVENTION 
   The invention pertains to the field of reclosable folding paperboard boxes. 
   DESCRIPTION OF THE PRIOR ART 
   According to the prior art, folding boxes are known which comprise a tamper-evident closure, wherein the closure must be glued during the final assembly of the folding box. Alternatively, folding boxes are provided with an (adhesive) label or sealed by polyethylene sealant. Because many packaging machines do not have a gluing device, for example, these additional, required steps prolong the final assembly process and make it more expensive. There is therefore a need for a folding box provided with a tamper-evident closure without adhesive. 
   A paperboard pocket with a tamper-evident closure is known from DE 198 09 466 A1. When the paperboard pocket is closed, a flap hinged to a sealing tab engages from the outside in an opening in the side wall of the paperboard pocket in such a way that, when the pocket is opened for the first time, that is, when the sealing tab is pulled out, the flap separates from the sealing tab. In comparison with a folding box, however, a paperboard pocket of this type suffers from the disadvantage that the closure is formed externally on the side wall, and as a result a smooth surface is not present. Smooth surfaces are important for these types of packages for mass-market articles, however, because they have no elevations, slots, etc. which could be gripped by an object. 
   DE 100 46 179 A1 discloses a folding box with tamper-evident closure. The box comprises an additional tab, which, when the box is opened, is completely or at least partially torn off along a perforation line. The disadvantage of this folding box is that, instead of a conventional closing mechanism, a narrow insertion tab is provided, which does not extend over the entire width of the cover flap and therefore interferes with the closing mechanism after the package has been opened for the first time. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is therefore to provide an improved reclosable folding box with a tamper-evident closure, which can be handled as easily and as quickly as a conventional folding box during the final assembly process but which does not require any adhesive bonding or gluing. 
   This object is accomplished by the teaching of claim  1 . Advantageous designs and embodiments are explained in the subclaims. 
   According to the invention, the folding box has retaining means in the interior and a tear-off tab connected to the insertion tab by way of a predetermined break line, and the closure of the folding box is set up in such a way that, the first time the box is opened, the tear-off tab cooperates with the retaining means and is torn off at the predetermined break line when the insertion tab is moved beyond the tearing edge. 
   It is advantageous for the retaining means to be designed as a retaining strip, especially when the paperboard is of such thickness that the end edges which come in contact with each other are able to block each other&#39;s movement. The tear-off tab runs up against this strip when the box is opened for the first time and is then torn off as the user continues to pull the tab in the opening direction. 
   As an alternative to the strip described above, the retaining means are advantageously designed as a retaining tab, which, in the as-delivered state, is folded down along a fold line onto the wide main panel opposite the cover flap, wherein the retaining tab and the wide main panel form a gap, into which the tear-off tab can be introduced in the opening direction of the closure. Because of the intrinsic elasticity of the paperboard material, the gap remains open when the tab is folded down. It is especially advantageous for the retaining tab to be glued to the wide main panel. 
   In a preferred embodiment, the wide main panel or the retaining tab comprises elevations or protections, one in the area to the right of the gap, and one in the area to the left. As a result, it is ensured that the gap remains open in the, as-delivered state. The elevations or projections also guarantee that the gap is effectively formed during the pre-gluing step and remains intact. The adhesive can be applied in the area of the elevations or projections, which results in effective gluing. It is also possible for the adhesive to be applied to other areas of the wide main panel or of the retaining tab outside the gap. 
   If the retaining means are designed as a retaining strip as described above, the elevations can be omitted, because the thickness of the retaining strip ensures that, when the folding box is closed for the first time, the tear-off tab, which, as a result of the intrinsic elasticity of the material, is resting against the wide main panel, will run up against the retaining strip, which offers a resistance which cannot be overcome. 
   In another embodiment, the retaining means are formed as a retaining tab hinged to the wide main panel. This retaining tab has a central opening in the hinge area, through which the tear-off tab can pass during the attempt to open the box and through which it is visible. 
   If the retaining means, the insertion tab, and the tear-off tab are provided with appropriate dimensions, it is also possible for the functionality of the tamper-evident closure to be arranged so that it is invisible from the outside. Thus a user, the first time he opens the box, does not have to use any particular care but rather can simply open the folding box in the conventional way. This prevents the user from being tempted to tamper with the tamper-evident closure in some way. 
   It is advantageous for the inventive folding box to have optical means for recognizing whether the tamper-evident closure has already been opened. Depending on the application, it can be necessary either to conceal completely the presence of a folding box&#39;s tamper-evident closure or to draw particular attention to the presence of the tamper-evident closure. When the latter alternative is realized, for example, the end user or buyer is informed that the purchased product is still in its originally packaged state. 
   In a preferred embodiment, the optical means are formed by a viewing window in the wide main panel, through which the tear-off tab can be seen in its original state. 
   In a preferred embodiment, the insertion tab comprises a central grip opening at the fold line between it and the cover flap. This grip opening makes it easier to open the folding box, because it allows sufficient force to be exerted on the closure during the opening process, as a result of which the tear-off tab can be pulled effectively past the tearing edge and thus effectively torn off. 
   It is especially advantageous for the paperboard blank from which the folding box is made to consist of a single piece of material. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is described in greater detail below with reference to the exemplary embodiment illustrated in the drawings: 
       FIG. 1  shows the flat paperboard blank of a folding box according to a first embodiment of the invention; and 
       FIG. 2  shows the upper part of a flat paperboard blank of a folding box according to a second embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows the flat paperboard blank  100  of an inventive folding box. Blank  100  consists of two wide main panels  101 ,  102  and two narrow main panels  103 ,  104 , wherein a glue tab  105  adjoins one wide main panel  101 . Alternatively, the glue tab  105  could also be located on another main panel. Sealing tabs  106 ,  107  are attached to the ends of each narrow main panel  103 ,  104 . A cover flap  111  is attached to the wide main panel  101 , and opposite it a retaining tab  112  is attached to the main panel  102 . Because  FIG. 1  shows a folding box blank for a folding box with two identical closures, which are arranged with point symmetry, the present invention can be explained on the basis of a description of only one of these closures. The second closure in  FIG. 1  is not described, nor is it provided with any reference numbers. The arrangement of the closures can also be axially symmetric, which would allow both closures to be opened from the same side. 
   An insertion tab  113  is hinged along a fold line  114  to the cover flap  111 . In the embodiment shown here, the insertion tab  113  comprises a grip opening  115  in the middle, along fold line  114 . This opening  115  makes it easier to open the closure, but it can also be omitted. The free corners of insertion tab  113  are rounded to facilitate insertion. On the free, wide side of insertion tab  113 , in the middle, a tear-off tab  116  is located, connected by way of a predetermined break line  117 . The predetermined break line  117  is designed in such a way that it is possible to fold over the tear-off tab by nearly 180° in the direction opposite the folding direction of insertion tab  113 . This is important for the function of the tamper-evident closure, as will be explained in detail in the following. 
   In the embodiment shown in  FIG. 1  retaining tab  112  is hinged to wide main panel  102  by way of a fold line  120 . In the middle of this fold line, an opening  121  is located, which is somewhat wider than tear-off tab  116 . Height of opening  121  is small in comparison to its width. Elevations or protections  122 ,  123 , which can be produced by pleating the other side of the folding box blank appropriately, are provided near fold line  120 , offset laterally from opening  121 . They serve, during the pre-gluing of the folding box, to produce a gap between wide main panel  102  and folded retaining tab  112 , wherein the edge area of retaining tab  112  opposite opening  121  is glued to the area of wide main panel  102  located beyond, or, in this case, below projections  122 ,  123 , In the embodiment shown, retaining tab  112  comprises another opening  124 , the area of which is greater than that of tear-off tab  116 , which allows the tab to fit into the opening. Alternatively, it is possible for the edge area of retaining tab  112  not to be continuous, but rather divided in two (as indicated by the solid line), as a result of which two tabs, pointing away from fold line  120 , would be obtained, which would also be glued to wide main panel  102  on the other side of projections  122 ,  123 . 
     FIG. 2  shows the upper part of a flat paperboard blank of a folding box according to a second embodiment of the invention. The same reference numbers are used for the same elements as those appearing in  FIG. 1 . In this second embodiment, retaining tab  112  is connected at fold line  120  to wide main panel  102  all the way across. As in the first embodiment of  FIG. 1 , retaining tab  112  cooperates with wide main panel  102  to define a gap, into which tear-off tab  116  can fit when the closure is closed. In  FIG. 2 , the position of retaining tab  112  after production of the paperboard blank is shown in solid line, whereas the position of retaining tab  112  after preassembly is shown in broken line. 
   Retaining tab  112  of the second embodiment shown in  FIG. 2  must have certain dimensions in order to fulfill the inventive closure function. The height of retaining tab  112 , that is, the distance between fold line  120  and the free edge of retaining tab  112 , is essentially smaller than the height of insertion tab  113 , which is defined as the distance between fold line  114  and predetermined break line  117  minus the height of tear-off tab  116 . Thus it is guaranteed that, when the closure is closed, the free edge of tear-off tab  116  is located directly in front of opening of the gap formed by gluing retaining tab  112  to wide main panel  102 . 
   In the embodiment according to  FIG. 2 , projections  122 ,  123  are perpendicular to the opening direction. Other arrangements are also possible; however, after retaining tab  112  has been glued to wide main panel  102 , the gap into which tear-off tab  116  will fit during the attempt to open the box should remain preserved. In addition, it is also possible for the gap thus defined to be produced not by projections but rather by intermediate layers of foil or paper, elevations, embossments and the like, for example. 
   An advantage of the embodiment according to  FIG. 2  is that the tamper-evident closure of the closed folding box is not visible. Because fold line  120  extends across the entire width of the connection between retaining tab  112  and main panel  102 , the gap in front of which the tear-off tab is located in the interior is hidden. Since nothing has to be figured out first in order to open the box, the normal user or buyer will therefore proceed in the conventional manner without any particular caution and thus break open the tamper-evident closure more easily than will be the case with the embodiment of  FIG. 1 . 
   The function of the inventive folding box with tamper-evident closure is described in the following in detail on the basis of the embodiment shown in  FIG. 1 . The sequence of steps is not to considered limiting on the invention in any way. 
   The folding box blank shown in  FIG. 1  is produced out of suitable material, including paperboard or the like, and provided in the example with the appropriate pleats, projections, elevations, embossments, fold lines, and predetermined break lines. In the first step, folding tab  112  is folded along fold line  120 . Sufficient adhesive is applied to the gluing area of retaining tab  112  or of wide main panel  102 , and retaining tab  112  is folded down onto wide main panel  102  and glued to it. Sufficient adhesive is then applied to the outside of glue tab  105 , and glue tab  105  is glued to narrow main panel  104 . The result of the pre-gluing process completed so far is a so-called “pre-glued folding box”, which is delivered in the flat-folded state by the package manufacturer (the “as-delivered state”). 
   These types of pre-glued folding boxes are then filled with the products in question by known packaging machines. Before they are filled, the flat, pre-glued folding box is set upright, and side tabs  106 ,  107  at one end of folding box  100  are folded over 90°, and this one end of the folding box is closed. After the inventive folding box with tamper-evident closure has been filled, it is ready to be closed at the other end. For this purpose, first side tabs  106 ,  107  and then cover flap  111  and insertion tab  113  are folded over 90° toward the inside. Tear-off tab  116  is folded almost 180° in the opposite folding direction. Then insertion tab  113 , together with the tear-off tab  116 , is introduced into the opening of the folding box. After cover flap  111  has been closed completely, the pretension of the paperboard material causes tear-off tab  116  to latch itself in the gap formed between retaining tab  112  and wide main panel  102 . If the folding box blank of the embodiment shown in  FIG. 1  is used, the outward-facing surface of tear-off tab  116  is now visible through the viewing window  125 . 
   With the tamper-evident closure now closed, the folding box with its content is now in the “original package” state. In the preferred embodiment, grip opening  115  in insertion tab  113  of the closure is visible. When the user grips this grip opening  115  and pulls cover flap  111  and thus the entire tamper-evident closure outward, that is, in the opening direction, tear-off tab  116  moves through the gap in the opening direction. As a result, tear-off tab  116  becomes visible in opening  121  or even projects out beyond the long edge of the opening. When the cover flap is pulled carefully out even farther in the opening direction, it is possible to feel a latching effect when the predetermined break line  117  of the tear-off tab comes to rest against the break point, i.e., tearing edge, on retaining tab  112 . Movement beyond this tearing edge causes tear-off tab  116  to be torn off along predetermined break line  117 . This tearing-off is clearly visible through viewing window  125 . Viewing window  125  can be formed by a complete cutout, which can have any desired area of sufficient size for viewing, and it can be covered by transparent film, for example, to prevent anyone from tampering with the tamper-evident closure. Torn tear-off tab  116  remains inside the folding box but not in its original position, so that it can be seen at any time that the tamper-evident closure has been broken. 
   With the inventive object, a folding box with tamper-evident closure is provided which can be handled easily and quickly during final assembly and which does not require gluing.