Patent Publication Number: US-2011058755-A1

Title: Packaging pouch

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage Entry of International Application No. PCT/FR2008/000661, filed on May 13, 2008, which claims priority to French Application 0754972, filed on May 10, 2007, both of which are incorporated by reference herein. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to a packing bag intended to contain and dispense products, for example moist towelettes, substantially in the shape of folded sheets stacked inside the packing bag, and also products in the shape of granules or powder. The invention relates to the field of the packing of products in general and more particularly to the packing of impregnated supports. 
     STATE OF THE PRIOR ART 
     In the state of the art, the European patent No 1 244 589 is known which discloses a bag for packing towelettes having the general shape of an envelope with a dispensing opening covered by an adhesive flap or liable to be stuck back, wherein the dispensing opening is covered by a transversal sealing strip which makes it possible to make a part of the internal layer of the flap integral with the external surface of the envelope, so as to provide a correct positioning of the flap on the opening. In this solution, making the flap integral with the front face of the packing bag when the latter is full remains a problem. As a matter of fact, the packing bag is swollen when it is full. It is then delicate to seal the flap on the external surface of the envelope or to keep it sealed during the opening and closing cycles. 
     It is also known from the state of the art the document WO 07/002,430 which discloses a packing bag provided with a flap covering a dispensing opening having an upper gusset. However, the means for fixing the flap of the envelope on the packing bag is not described in details and does not seem to make it possible to improve the strength of the product. More particularly, such a flap may be torn. On the other hand, using multilayer complex films having a heat-sealable internal layer (polyethylene) and a printable external layer (PVC, polypropylene, PET) also makes the operation of sealing the internal layer of the flap on the external surface of the envelope complicated, and gives bad results which can sometimes lead to the tearing of the flap on the constraints applied to this flap are too important. 
     SUMMARY 
     The aim of the present invention is to provide an improvement of such packing bag, so as to facilitate and improve the sealing of the flap with respect to the envelope. For this purpose, the invention provides to add an upper gusset linking the front and back faces of the packing bag and to make the flap integral with the upper gusset through a cut provided on the front face of the packing bag. For this purpose, the invention, in its broadest sense, aims at a packing bag having the general shape of an envelope more particularly including a back face and a front face, the front face being provided with a dispensing opening which can be closed by a flap, the upper edges of the back and front faces being sealed on the internal layer of the gusset, said upper gusset, the flap and the front face being integral. On the other hand, the upper edge of the front face has at least one cut through which at least a part of the internal layer of the upper edge of the flap is sealed on a part of the internal layer of the upper gusset. 
     The presence of an upper gusset thus facilitates the operation of sealing the flap on the external surface of the envelope even though the packing bag is full. In addition, this configuration makes it possible to seal the internal layer of the flap with the internal layer of the upper gusset which makes it possible to improve the strength of the assembly thanks to the composition of the complex films. It should be noted that the external layers of the various elements (the upper gusset, the front face, the back face or the flap) forming the packing bag correspond to the faces which form the external envelope of the packing bag. On the contrary, the internal layers of such elements correspond to the face inside the packing bag when the latter is assembled or in the case of flap  8 , to the face oriented inwards the bag. 
     In particular embodiments: 
     the part of the internal layer of the upper edge of the flap intended to be sealed is coated with a sealing varnish; 
     the part of the internal layer of the upper edge of the flap intended to be sealed is free of any adhesive means; 
     In these alternative solutions, the part of the flap which must be sealed is free of adhesive or the adhesive has been neutralised. By thus welding the internal layers of the multilayer films, the quality of the welding of the flap with the envelope is substantially improved. The flap of the packing bag thus obtained has less risk to be torn. 
     Preferably, the cut on the front face is continuous. Advantageously, the cut of the front face substantially represents three fourths of the width of the packing bag. According to an advantageous embodiment, the flap has two pre-cuts originating from the upper edge of the flap which define together a central area of the flap and the spacing between the pre-cuts substantially represents half the length of the sealing area on the flap, preferably between two thirds and three fifths of the length of this sealing area. 
     Pre-cuts can be used as a pilfer proof system. As a matter of fact, when the packing bags are opened, the pre-cuts are torn and become easily detectable. Preferably, the pre-cuts are positioned on either side of the dispensing opening, when the flap is stuck on the front face. Advantageously, the flap has at least one adhesive rim provided with an adhesive coating which makes it possible to be peeled off and stuck back several times. Preferably, the upper gusset and the upper edges of the flap and the front and back faces are gone through by a European hole. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Other characteristics and advantages of the invention will appear upon reading the following description of detailed exemplary embodiments, and referring to the Figures which respectively show: 
         FIG. 1 , a perspective view of a packing bag according to the invention, ready for use; 
         FIG. 2 , an exploded view of the exemplary embodiment of the packing bag of  FIG. 1 ; 
         FIGS. 3   a  and  3   b , front and back views of an exemplary embodiment of the packing bag according to  FIG. 3  and showing a European hole; and 
         FIG. 4 , an exemplary embodiment of a packing bag according to a second aspect of the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  show a first exemplary embodiment of a packing bag  2  according to the invention, formed from films composing the back face  4 , the front face  6 , the flap  8 , the lower gusset  10  and the upper gusset  12  of the packing bag  2 . These films are multilayer films and include a heat-sealable internal layer made for example of polyethylene, an intermediate barrier layer such as aluminium, and an external layer made of a plastic material such as PVC, polypropylene or PET which can be printed (by screen printing, photogravure, flexographic printing etc.). According to this provision, only the internal layers can be heat-sealable together. 
     The back  4  and front  6  faces have a substantially rectangular shape. They each have two upper  4   a ,  6   a  and lower  4   b ,  6   b  rectilinear edges, as well as two slightly curved side edges  4   c ,  6   c , in the utilisation position. The internal layers of the side edges  4   c ,  6   c  of the back  4  and front  6  faces are welded together. The internal layers of the upper edges  4   a ,  6   a  of the back  4  and front  6  faces are welded on the internal layer of the upper gusset  12  and the internal layers of the lower edges  4   b ,  6   b  of the back  4  and front  6  faces are welded on the internal layer of the lower gusset  10 . 
     The front face  6  includes the dispensing opening  14  making it possible to successively take a plurality of products stacked inside the packing bag  2 . The dispensing opening  14  has side edges  14   c  diverging towards the upper edge  6   a  of the front face  6  and connecting with the upper edges  14   a  by rounded ends. The geometry of this dispensing opening  14  advantageously makes it possible to peel off the flap  8  without damaging the appearance and the shape of the front face  6  of the packing bag  2 . 
     The side edges  6   c  of the front face  6  are welded to the side edges  4   c  of the back face  4 . The upper  6   a ,  4   a  and lower  6   b ,  4   b  edges of the front  6  and back  4  faces are welded respectively on the internal layer of the upper  12  and lower  10  gussets. 
     The function of the flap  8  consists in covering the dispensing opening  14  on the front face  6  of the packing bag  2 . For this purpose, and in order to provide a sealed packing, the flap  8  is coated with glue or a repositionable adhesive which can also be coloured on the greatest part thereof. Such glue or such adhesive makes it possible to perform a succession of opening and closing cycles, while preserving a correct tightness around the dispensing opening  14 . 
     According to another embodiment, the glue covers only a peripheral rim on the dispensing opening  14  so as to reduce more particularly the manufacturing costs. Preferably, the flap  8  also has an opening tab  16  which makes it possible to be easily peeled off from the front face  6 . In this first exemplary embodiment, the flap  8  also includes two pre-cuts  18  positioned perpendicularly to the upper edge  8   a  of the flap  8 . These pre-cuts  18  extend from the lower edge to the welding limit of the flap  8 . 
     Advantageously, the spacing between the pre-cuts  18  is determined so that, when the flap  8  is stuck on the front face  6  of the packing bag  2 , the pre-cuts  18  are on either side of the dispensing opening  14 . Then, the part of the flap  8  contained between the two pre-cuts only gets peeled off from the front face  6 . The spacing between the pre-cuts  18  is thus defined so that the central part of the flap  8  rests on a plane area of the packing bag  2  even when the latter is much swollen. 
     Also preferably, these pre-cuts are symmetrical with respect to the median axis of the flap and the spacing between the pre-cuts  18  at the welding of the flap  8  with the front face  6  or the upper gusset  12 , corresponds to two thirds of the length of the welding. Thus, the ends of the welding are not submitted to the mechanical stresses relating to the opening and closing cycles of the flap  8 . The risk that the welding might be peeled off is thus significantly reduced. According to a particular embodiment, the pre-cuts  18  are not rectilinear and have some oblique or curved parts. Then, it is possible to vary the dimensions of the surface which can be peeled off from the flap  8 . 
       FIG. 2  more particularly illustrates an exploded view of the packing bag  2  of  FIG. 1 , wherein the front face  6  has a continuous cut  22  positioned on the upper edge of the front face  6 . In an alternative solution, the cut  22  could also be discontinuous. Ideally, this cut  22  represents three quarters of the width of the packing bag  2 . The thickness of this cut  22  is slightly lower than the thickness of the welding seam between the front face and the gusset, so that, in spite of the cut  22 , the front face is always sealed on the upper gusset  12 . 
     The height of the upper edge  8   a  of the flap  8  corresponds to the height of the cut  22  of the front face  6 . In this alternative solution, the part of the flap which will be welded is free of adhesive or the adhesive has been neutralised or the adhesive does not prevent it to be sealed. Then the internal layer of the upper edge  8   a  of the flap  8  is welded to the internal layer of the upper gusset  12  through the cut  22  of the front face  6 . 
     The quality of the heat-sealing of the flap  8  with the upper gusset  12  is improved because the internal layers of the upper gusset  12  and the flap  8  are made of polyethylene or compatible heat-sealing materials. In this exemplary embodiment, the thickness of the welding seam is 7 millimetres, the thickness of the cut  22  is 4 millimetres and consequently at the cut  22 , the upper edge  6   a  of the front face  6  is welded to the upper gusset on the thickness of 3 millimetres. Besides, according to this exemplary embodiment, the lower  10  and upper  12  gussets have two shutters. Such lower  10  and upper  12  gussets may, however, have an accordion-like structure and thus have more than two shutters. According to a particular embodiment, the cut  22  could be discontinuous (for example notched, teethed, etc.) so as to distribute the tearing stresses imparted to the flap  8  on the welding string. 
       FIGS. 3   a  and  3   b  respectively show the front and back views of a second exemplary embodiment close to the first exemplary embodiment of  FIGS. 1 and 2 . However, in this second exemplary embodiment the upper edge  6   a  of the front face  6  has a thickness of 15 mm and the cut  22  a thickness of 8.5 mm, so as to enable the cutting of a European hole  24  on the packing bag without deteriorating the sealing of the internal layer of the upper edge  8   a  of the flap  8 . Preferably, this European hole  24  is positioned at the cutting line  22  of the upper edge  6   a  of the front face  6  so that said European hole  24  goes through the upper gusset  12  as well as the upper edges  8   a ,  6   a ,  4   a  of the flap  8  and the front  6  and back  4  faces. 
     The assembling of the front  6  and back  4  faces with the upper gusset  12  is preferably performed prior to the cutting of the European hole  24 . Besides, it should be noted that in this exemplary embodiment, the internal layer of the upper edge  8   a  of the flap  8  is also partially welded on the front face  6 . Then the upper edge  8   a  of the flap  8  which represents the sealing part of this flap  8  on the surface of the envelope of the packing bag can also be: 
     free of a repositionable adhesive; 
     provided with a repositionable adhesive the properties of which are not affected by the quality of the sealing; 
     provided with a repositionable adhesive itself coated with a sealing varnish which makes it possible to neutralise the glue of the repositionable adhesive placed on the internal layer of the flap  8 . This sealing varnish can be a heat-sealable material-based varnish making it possible to efficiently seal the polyethylene layer of the multilayer complex film on the front face  6 . Then, the risks of tearing the flap are much reduced. 
     Thus, similarly as above, the upper edge  8   a  of the internal layer of the flap  8  which represents the sealable portion of said flap  8  is free of adhesive which could affect the quality of the sealing on the portion of the welding  6   a  of the front face  6  of the bag it covers. 
     The invention is not limited to the described and shown exemplary embodiments. The invention may, for example, be embodied in a packing bag  2  having no lower gusset  10 . Another possible although less advantageous exemplary embodiment would consist in placing the cut  22  no longer on the perimeter but on the internal part of the front face  6 . This embodiment could make it possible to save on adhesives. In addition, according to another aspect of the invention shown in  FIG. 4 , the external layer of the upper edge  6   a  of the front face  6  could have a sealing area  20  on which the part of the internal layer of the upper edge  8   a  of the flap  8  would be sealed.