Abstract:
The invention relates to a tubular bag packaging ( 10 ) for tabular piece goods ( 14 ) made of a film-like packaging material ( 12 ) having a front packaging side ( 16 ), a rear packaging side ( 18 ) comprising a longitudinal seam ( 20 ), two transverse seams ( 22, 24 ) transverse to the longitudinal seam ( 20 ) disposed at a distance from each other, and at least one linear or lamellar separating area extending on the front packaging side ( 16 ) parallel to the longitudinal seam ( 20 ) as a tear open feature for opening the packaging. The packaging material ( 12 ) is separated in the separating area parallel to the longitudinal seam ( 20 ), disposed overlapping and releasably connected, forming at least one separable longitudinal seam ( 26 ) in the overlapping area.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a tubular-bag pack for articles in bar form, in particular for bars of chocolate, made of a film-like packaging material, having a pack front side, a pack rear side that has a longitudinal sealing seam, two transverse sealing seams that are arranged in a spaced-apart manner transversely with respect to the longitudinal sealing seam, and at least one linear or strip-like separating region that extends parallel to the longitudinal sealing seam on the pack front side as an opening aid for opening the pack. Also in the context of the invention is a method suitable for producing a packaging material for the subsequent production of the tubular-bag pack. 
         [0002]    DE 24 58 462 A1 discloses a tubular-bag pack for bars of chocolate that can be broken into rows. On the pack underside, a longitudinal sealing seam is arranged along a first predetermined breaking point of the bar of chocolate. The longitudinal sealing seam is separated by the bar of chocolate being broken along its predetermined breaking point, with the lever action employed in the breaking of the bar being used for overcoming the adhesive force of the seal, this being necessary for separating the longitudinal sealing seam and thus for opening the pack. 
         [0003]    DE 26 58 631 A1 discloses a wrapper for bars of chocolate that are to be broken in the pack along a predetermined breaking point. A closure seam arranged on the pack underside is, in order to make it easier to separate said seam, provided with a cold adhesive which is applied only partially to that surface of the packaging material that forms the closure seam. 
         [0004]    In the two abovementioned packs, it is disadvantageous that as a rule the unattractive underside of the product is exposed. Pulling apart the longitudinal sealing seam is moreover only possible when the product is used as a lever, this requiring that the product be broken. 
         [0005]    DE 31 15 144 A1 discloses a film pack for bars of chocolate having a laterally arranged longitudinal sealing seam having a longitudinal notch as an opening aid. In order to open the pack, the longitudinal sealing seam, which protrudes from the pack in the form of a visually unattractive, wide tab, is torn away from the rest of the pack along the notch, which forms a predetermined breaking point. 
         [0006]    WO 88/00562 A discloses a tubular-bag pack for bars of chocolate having a longitudinal sealing seam on the pack rear side. Lateral sealing seams are arranged in the packaging material in a manner extending on the pack front side in opposite edge regions parallel to the longitudinal sealing seam. Linear predetermined breaking points delimit a tear-open region. By way of an unsealed edge zone of a transverse sealing seam, the packaging material forming the pack front side can be grasped and, in order to open the pack, be pulled off the rest of the pack as a strip that extends across the width of the bar between the two predetermined breaking points. The opening of the pack front side reveals the attractive top side of the product, and it is easier to open the pack. However, a disadvantage of this pack is the high material consumption, since the two lateral sealing seams have to be folded over three times. 
         [0007]    US-A-2005/276525 discloses a tubular-bag pack having a reclosing system in the form of a label which is incorporated into the packaging film and sealed in an overlapping manner. The attachment of a label with a small overlap results in only slightly increased material consumption. The labels can either already be incorporated in the film or only be attached at the packaging machine. Disadvantages with this pack are that the opening does not extend over the entire surface of the pack and so an article in bar form cannot be removed, and also the high costs of a prefabricated label. 
       SUMMARY OF THE INVENTION 
       [0008]    The object of the invention is to create a pack for articles in bar form which avoids the disadvantages mentioned in the prior art. In particular, it should be possible to produce the pack in a material-saving manner and it should be easy to open the pack over the entire width of the pack front side. 
         [0009]    A further aim of the invention is to provide a method suitable for producing the pack. 
         [0010]    The object is achieved according to the invention in that, in the case of a tubular-bag pack of the type mentioned at the beginning, the packaging material is separated parallel to the longitudinal sealing seam in the separating region, is arranged in an overlapping manner and is connected in a detachable manner in the overlapping region, forming at least one separable longitudinal seam. 
         [0011]    The separable longitudinal seam may extend in an edge region or approximately centrally between the edge regions. It is preferable in this case for the separable longitudinal seam to be arranged in a manner spaced apart from a free longitudinal edge of the packaging material, forming a tear-open tab. The tear-open tab may be configured to form a lug-like grip tab by way of a loop-like cut. 
         [0012]    In a further preferred tubular-bag pack, two separating regions, each having a separable longitudinal seam, are arranged in the two edge regions of the pack front side, forming an opening label that extends substantially over the entire width of the pack front side and can be detached from the pack. Expediently, in this case an unsealed edge zone is arranged in at least one transverse sealing seam, forming a tear-open tab. 
         [0013]    In another preferred tubular-bag pack, two separating regions, each having a separable longitudinal seam, are arranged in the two edge regions of the pack front side, forming an opening label that extends substantially over the entire width of the pack front side and can be partially detached from the pack, wherein, in order to tear off the opening label from the rest of the pack, a weakening line is arranged, parallel to the transverse sealing seam, in the region of one of the transverse sealing seams in the packaging material. 
         [0014]    A first method suitable for producing a tubular-bag pack according to the invention is characterized in that a strip-like packaging material web is deflected continuously about a first angle out of the plane of the packaging material web by lateral pulling-in of packaging material and at a distance is deflected in the opposite direction about a second angle into a plane parallel to the plane of the packaging material web, the packaging material web is severed in the first plane prior to deflection, forming a first packaging material web strip and at least one lateral packaging material web strip located on at least one side of the first packaging material web strip, the deflected parts of the at least one lateral packaging material web strip which are produced by the two deflections of the packaging material are transferred into the second plane, as a result of which the first packaging material web strip narrowly overlaps the at least one lateral packaging material web strip, and the packaging material web strips are connected in a separable manner in the overlapping region by way of an adhesive or a sealing layer, forming the separable longitudinal seams. 
         [0015]    In a preferred embodiment, the packaging material web is severed in the first plane prior to deflection, forming a central packaging material web strip and two lateral packaging material web strips located on either side of the central packaging material web strip, and the deflected parts of the lateral packaging material web strips which are produced by the two deflections of the packaging material are transferred into the second plane, as a result of which the central packaging material web strip narrowly overlaps the lateral packaging material web strips. 
         [0016]    A second method suitable for producing a tubular-bag pack according to the invention is characterized in that a strip-like packaging material web is deflected continuously by lateral pulling-in of packaging material to form at least one fold that projects perpendicularly out of the plane of the packaging material web, the packaging material web is severed in the fold, forming a first packaging material web strip and at least one lateral packaging material web strip located on at least one side of the first packaging material web strip, the parts of the fold which are produced from the packaging material by the severing of the fold and project out of the plane of the packaging material web are guided back into the plane of the packaging material web, as a result of which the first packaging material web strip narrowly overlaps the at least one lateral packaging material web strip, and the packaging material web strips are connected in a separable manner in the overlapping region by way of an adhesive or a sealing seam, forming the separable longitudinal seams. 
         [0017]    Among the advantages achieved by the pack according to the invention are: 
         [0018]    Easy to open pack for articles in bar form; 
         [0019]    When the pack is opened, the attractive top side of the product is exposed; 
         [0020]    The product is not damaged during opening; 
         [0021]    The top side of the pack can be formed over the entire surface area (no disruptive label); 
         [0022]    The material consumption is only slightly greater than in the case of a pack without an opening aid; 
         [0023]    No complex material structures are necessary (the starting material can also be a monofilm); 
         [0024]    Also suitable for “hot seal” materials (e.g. in order to create a “peel seal”); 
         [0025]    The opening aid can be produced continuously in line, without an expensive film provided specially with the opening mechanism having to be used; 
         [0026]    Use can be made of an existing standard tubular-bag machine, to which the module for producing the overlap seal is added; 
         [0027]    Packs can be produced at high speed (cold seal); 
         [0028]    It is not necessary to make any changes to the secondary packaging; 
         [0029]    The opening tab or the opening mechanism does not have to be sought out; 
         [0030]    The pack can be embodied such that it can be reclosed a number of times by way of a suitable sealing layer or an additional closure strip; 
         [0031]    An opening tab can be incorporated; 
         [0032]    The tubular-bag machine can produce packs with or without an opening aid by means of a simple conversion; 
         [0033]    For small production batches, in which it is not worthwhile installing the module for producing the overlap seal on the packaging machine, instead of the method proposed it is possible to produce an identical pack by means of a roll of film having an already incorporated lap seal/opening aid. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]    Further advantages, features and details of the invention are given in the following description of preferred exemplary embodiments and by way of the drawing, which serves merely for illustration and is not to be interpreted in a limiting manner. The drawing schematically shows in: 
           [0035]      FIG. 1  a cross section through a first embodiment of a tubular-bag pack; 
           [0036]      FIG. 2  a cross section through a second embodiment of a tubular-bag pack; 
           [0037]      FIG. 3  the plan view of the embodiment in  FIG. 2  with an additional opening tab; 
           [0038]      FIG. 4  a cross section through a third embodiment of a tubular-bag pack; 
           [0039]      FIG. 5  a cross section through a fourth embodiment of a tubular-bag pack; 
           [0040]      FIG. 6  the plan view of the embodiment in  FIG. 5  with a partial label; 
           [0041]      FIG. 7  a cross section through a fifth embodiment of a tubular-bag pack; 
           [0042]      FIG. 8  a longitudinal section through the embodiment in  FIG. 7 ; 
           [0043]      FIG. 9  a first embodiment of a method for producing a packaging material web for producing tubular-bag packs; 
           [0044]      FIG. 10  a second embodiment of a method for producing a packaging material web for producing tubular-bag packs (heat seal); 
           [0045]      FIG. 11  a third embodiment of a method for producing a packaging material web for producing tubular-bag packs; 
           [0046]      FIG. 12  a fourth embodiment of a method for producing a packaging material web for producing tubular-bag packs; 
           [0047]      FIG. 13  a fifth embodiment of a method for producing a packaging material web for producing tubular-bag packs. 
       
    
    
     DETAILED DESCRIPTION 
       [0048]    A tubular-bag pack  10  illustrated in  FIG. 1  and made of a flexible, film-like packaging material  12  encloses an article in bar form  14 , for example a bar of chocolate, and in this case forms a pack front side  16  and a pack rear side  18 . Located on the pack rear side  18  is a longitudinal sealing seam  20  in the form of a fin, which is known under the technical term “fin seal”. Transversely to the longitudinal sealing seam  20 , the tubular-bag pack, as shown in  FIG. 4   b , is closed at both ends in each case by a transverse sealing seam  22 ,  24 . Arranged on the pack front side  16  and in a lateral edge region parallel to the longitudinal sealing seam  20  is an additional, separable longitudinal seam  26 . The packaging material  12  is severed in this region and sealed in an overlapping manner. This overlapping seal is known under the technical term “lap seal”. The separable longitudinal seam  26  is arranged in a manner spaced apart from a free longitudinal edge  30  of the packaging material  12 , forming a tear-open tab  28 . The tear-open tab  28  extends over the entire length of the pack  10 , so that when the pack  10  is torn open by pulling on the tear-open tab  28  and separating the separable longitudinal seam  26 , the entire pack front side  16  is opened. 
         [0049]    The tubular-bag pack  110  shown in  FIG. 2  differs from the embodiment shown in  FIG. 1  merely in that the separable longitudinal seam  26  with the tear-open tab  28  is arranged approximately in the longitudinal center of the pack front side  16 . In this case, too, when the separable longitudinal seam  26  is separated by pulling on the tear-open tab  28 , the pack is opened over the entire pack front side  16 . 
         [0050]    The tubular-bag pack  110  shown in  FIG. 3  differs from the embodiment shown in  FIG. 2  merely in that the tear-open tab  28  is configured to form a lug-like grip tab  29  by way of a loop-like cut. 
         [0051]    The tubular-bag pack  210  shown in  FIG. 4  differs from the embodiment shown in  FIG. 1  merely in that the separable longitudinal seam  26  with the tear-open tab  28  is in the form of a fin seal. In this case, too, when the separable longitudinal seam  26  is separated by pulling on the tear-open tab  28 , the pack is opened over the entire pack front side  16 . 
         [0052]    The tubular-bag pack  210 ′ shown in  FIG. 5  differs from the embodiment shown in  FIG. 4  in that two separating regions, each having a separable longitudinal seam  26   a ,  26   b , are arranged in the two edge regions of the pack front side  16 , forming an opening label  17 ′ that extends substantially over the entire width of the pack front side  16  and can be partially detached from the pack. As is apparent from  FIG. 6 , in order to tear off the opening label  17 ′ from the rest of the pack, with the two separable longitudinal seams  26   a ,  26   b  being separated, a weakening line  25  is arranged, parallel to the transverse sealing seam  22 , in the region of one of the transverse sealing seams  22 ,  24  in the packaging material. At this weakening line  25 , the pack can be torn and the partial opening label  17 ′ can be pulled off the rest of the pack. 
         [0053]    In the embodiment of a tubular-bag pack  310  shown in  FIG. 7 , two separating regions, each having a separable longitudinal seam  26   a ,  26   b , are arranged in the two edge regions of the pack front side  16 , forming an opening label  17  that extends substantially over the entire width of the pack front side  16  and can be detached from the pack. In order to pull off the opening label  17  from the rest of the pack, with the two separable longitudinal seams  26   a ,  26   b  being separated, an unsealed edge region is arranged at one of the transverse sealing seams  22 ,  24 , forming a tear-open tab  23  ( FIG. 8 ). 
         [0054]    In a method, illustrated in five steps a-e in  FIG. 9 , for the continuous production of a packaging material  12  having two additional separable longitudinal seams  26   a ,  26   b  for producing a tubular-bag pack  310  according to  FIG. 7 , a planar flexible packaging material web  112  is unrolled from a feed roll (not illustrated) (step a) and, in a folding arrangement consisting for example of two pairs of rolls  114   a ,  114   b , is continuously deflected about a first angle out of a first plane by lateral pulling-in of packaging material and at a distance s from the first plane is deflected in the opposite direction about a second angle into a second plane parallel to the first plane (step b). The packaging material web  112  is severed in the first plane upstream of the deflection point, for example by means of cutting wheels  116   a ,  116   b , forming a central packaging material web strip  112   a  and two lateral packaging material web strips  112   b ,  112   c  located on either side of the central packaging material web strip  112   a  (step c). On account of the stiffness of the film-like packaging material, the deflected parts of the lateral packaging material web strips  112   b , which parts correspond substantially to the distance s between the planes that is produced by the two deflections of the packaging material, spring into the second plane, as a result of which the central packaging material web strip  112   a  narrowly overlaps the lateral packaging material web strips  112   b  (step d). By applying pressure to the packaging material web strips  112   a ,  112   b  in the overlap region, said strips are separably sealed by way of strips of cold adhesive  118   a ,  118   b  applied to one side, forming the separable longitudinal seams  26   a ,  26   b . The strips of cold adhesive  118   a ,  118   b  can already be present on the packaging material web  112  that is available as rolled material, or can be applied to the packaging material web  112  before the latter, which may already have been deflected, is severed. 
         [0055]    The method, illustrated in four steps a-d in  FIG. 10 , for the continuous production of a packaging material  12  having two additional separable longitudinal seams  26   a ,  26   b  for producing a tubular-bag pack  310  according to  FIG. 7  differs from the method shown in  FIG. 9  merely by the type of application of the sealing medium. In this case, this is already present as a heat seal layer over the entire surface area on one side of the pack. Sealing takes place by means of heatable sealing tools, e.g. in the form of pairs of sealing rolls  120   a ,  120   b  (step d), with attention being paid to peelable sealing. 
         [0056]    The method, illustrated in five steps a-e in  FIG. 11 , for the continuous production of a packaging material  12  having two additional separable longitudinal seams  26   a ,  26   b  for producing a tubular-bag pack  310  according to  FIG. 7  differs from the method shown in  FIG. 9  likewise merely by the type of application of the sealing medium. In this case, this is sprayed on in the form of hotmelt strips (step d) following the cutting process (step c). By applying pressure to the packaging material web strips  112   a ,  112   b  in the overlap region, said strips are separably sealed by way of the hotmelt strips  118   a ,  118   b  applied to one side, forming the separable longitudinal seams  26   a ,  26   b.    
         [0057]    The method, illustrated in five steps a-e in  FIGS. 12 and 13 , for the continuous production of a packaging material  12  having an additional separable longitudinal seam  26   a  for producing a tubular-bag pack  10  according to  FIG. 1  differs from the method shown in  FIG. 11  in that a strip-like packaging material web  112  is deflected continuously by lateral pulling-in of packaging material to form a fold  122  that projects perpendicularly out of the plane of the packaging material web (step b) and the packaging material web  112  is severed in the fold  122 , forming a first packaging material web strip  112   a  and a lateral packaging material web strip  112   b  located on one side of the first packaging material web strip  112   a  (step c). The parts of the fold  122  which are produced from the packaging material by the severing of the fold  122  and project out of the plane of the packaging material web are guided back into the plane of the packaging material web, as a result of which the first packaging material web strip  112   a  narrowly overlaps the lateral packaging material web strip  112   b . The methods according to  FIGS. 12 and 13  differ merely by the side of the packaging material web on which the fold  122  is formed and severed. 
         [0058]    Advantageously, the seams, in particular also the longitudinal seam (a seal) can be sealed by means of ultrasound. This can firstly reduce the material consumption, in that the longitudinal seam is configured to be narrower. Secondly, the application of heat to the product and also the film is reduced, thereby lowering the risk of the film warping. The design is further improved in that the longitudinal seam not required for opening is less visually apparent. The other seams, too, can be sealed by means of ultrasound.