Abstract:
The subject matter of the invention is a foil bag for packaging moist tissues, said foil bag, which is formed from a hose-like, flexible foil, comprising on its top side a dispensing opening for one-by-one removal of the moist tissues. To provide a foil bag of the type mentioned herein above that keeps the tissues moist and clean over a long period of time even after the package has been put to use, a mechanically openable and closable closure element ( 16 ) is embedded in an opening provided on the top side ( 12 ) of the foil bag ( 10 ), said closure element forming a substantially airtight engagement with the foil bag ( 10 ) and being reclosable so as to form an airtight engagement after each use.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     DE 20 2004 000 278.7 dated Jan. 10, 2004  
         [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a foil bag for packaging moist tissues, said foil bag, which is formed from a hose-like, flexible foil, comprising on its top side a dispensing opening for one-by-one removal of the moist tissues.  
         [0004]     2. Description of the Prior Art  
         [0005]     Such type moist tissues, which are made from a nonwoven material or from paper, are moistened by adding a moistener and serve for example for body care or for cleaning in household and industry. These moist tissues are packaged either in airtight dispenser boxes or in airtight foil bags, with the dispensing openings being closed by a dispenser device bonded to the foil or by a closure label. In both cases, the difficulty arising is that either the closure label or the dispenser device cannot be fully closed after having been opened for the first time so that the solvent evaporates and the tissues dry out, or there is a risk that the adhesive of the closure label or of the dispenser device bonded thereon will contaminate the moist tissues or induce a chemical reaction, thus negatively affecting the moist tissues.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     In view thereof, it is the object of the present invention to provide a foil bag of the type mentioned herein above that will durably keep the moist tissues moist and clean, even after the package has been put into use.  
         [0007]     As a technical solution to this object, a foil bag in accordance with the features of claim  1  is being proposed. For advantageous developments of this foil bag, the reader is referred to the subordinate claims.  
         [0008]     A foil bag configured in accordance with this technical teaching has the advantage that, since the closure element is opened mechanically, any adhesive may be excluded so that contamination is unlikely to occur. Another advantage is that this mechanically openable and closable closure element is adapted to close so as to maintain an airtight hermetic seal over a long period of time; that is, even after repeated opening and closing, so that the moist tissues are kept in an airtight enclosure even after the package has been put into use, thus eliminating the risk of drying.  
         [0009]     It has thereby been found advantageous to weld the closure element made of a hard plastic material to the foil bag by plastic welding. This dispenses with the need for attaching the closure element by adhesive means so that in this case as well contamination or chemical reaction of the adhesive with the solvent is very unlikely to occur.  
         [0010]     In a preferred embodiment, the closure element is configured to be a frame with a lid attached thereon, said frame circumscribing an accurately defined dispensing opening while the lid is retained on the frame by means of a living hinge. The advantage thereof is that such a closure element is readily manufacturable at a low cost. Another advantage of using a living hinge is that it permits a plurality of opening cycles to be performed without damage to the closure element.  
         [0011]     Manufacturing the closure element using a casting method results in very low manufacturing costs and allows for the use of a hard plastic, which is easy to recycle.  
         [0012]     In a particularly preferred embodiment, a detent means is formed on the closure element. This makes it possible to repeatedly open the lid by allowing it to disengage from the detent, and to close it again by allowing it to engage into the detent, so that a reliable opening and closing mechanism that would be durable in operation is achieved.  
         [0013]     In another preferred embodiment, a perimeter collar, which is oriented so as to conform to the frame and which projects into the dispensing opening when the lid is closed, is formed on the lid. It has thereby been found advantageous to place said collar so as to minimize the spacing between the collar and the opening. The advantage thereof is that, to some extent, the lid is sealed against the frame so that the solvent is prevented from escaping and the moist tissues from drying.  
         [0014]     In a preferred developed implementation, the seal of the closure element is enhanced by having a bearing surface on which the lid is resting in its closed state being formed on the frame.  
         [0015]     In another preferred embodiment, the seal of the closure element is further improved by a perimeter ridge being formed beside the bearing surface on the frame, said ridge being oriented to conform to the lid which it surrounds. It has thereby been found advantageous to minimize the spacing between the ridge and the lid for optimum sealing.  
         [0016]     In still another preferred embodiment, a perimeter welding edge is formed on the frame of the closure element. Said welding edge, which protrudes therefrom in a collar-like fashion, serves to receive a portion of the foil bag so that the foil bag may be welded to the frame of the closure element in the region of its opening using a plastic welding process.  
         [0017]     In a completely different preferred embodiment, the dispensing opening of the closure element is sealed by a sealing plate attached to the frame and providing an airtight hermetic seal. It has thereby been found advantageous to retain the sealing plate on the frame through a perimeter break line so that said sealing plate may be readily removed by a user. If a pivotal ring pull is mounted to the sealing plate, removal of said sealing plate is particularly easy. Such type ring pulls are known from other packages such as from tin cans or canned fish.  
         [0018]     The advantage of such a sealing plate is that the moist tissues are packaged by the manufacturer under the strictest hygienic conditions and that the unbroken seal of the sealing plate indicates to the customer that said package has not yet been opened since the sealing plate can only-be removed by causing damage to the closure element.  
         [0019]     In still another preferred embodiment, an elastomer gasket is provided between the frame and the lid of the closure element, said elastomer gasket being preferably formed from PETP, PP, PE, PTA or PTE. This relatively soft elastomer has the advantage of sealingly fitting corresponding surfaces of the closure element formed from hard plastic, thus further improving the seal of the foil bag. Another advantage is that such an elastomer may be injection molded integral with the closure element formed from hard plastic at a very low cost.  
         [0020]     In a preferred developed implementation, the elastomer gasket is disposed within the closure element so that the closure element provides for a first seal, with the additional elastomer gasket optimizing said seal. The elastomer gasket is disposed within the closure element so as to be already protected from environmental conditions, which results in a very long life of the elastomer gasket.  
         [0021]     In a preferred developed implementation it has been found advantageous to configure the elastomer gasket in such a manner that it is slightly compressed when the lid is closed. The restoring forces inherent in the elastomer are activated as a result thereof, thus reliably pushing the elastomer gasket against the respective confronting wall so that the gap to be sealed is provided with a durable seal, even if irregularities in the material or manufacturing inaccuracies in the sizes of the various component parts result in differently sized gaps.  
         [0022]     In another preferred embodiment, the elastomer gasket is provided on the perimeter. Comprehensive sealing is thus ensured.  
         [0023]     In a particular embodiment, the elastomer gasket is attached to the lid and fits against a shoulder extending along the perimeter of the frame. When the lid is being closed, the elastomer gasket is moved together with the lid toward the opening and is seated onto the corresponding perimeter shoulder. The advantage thereof is that the gasket fits in a defined manner on the perimeter shoulder so that an outstanding seal is achieved. Another advantage is that the gasket can be attached to the lid at low cost.  
         [0024]     In another preferred embodiment, a perimeter collar is formed as an integral part of the lid with the elastomer gasket being embedded in the frame at a shoulder and coming to rest against said collar. The advantage thereof is that the shoulder can be formed to conform to the contour of the elastomer gasket, thus permitting further improved sealing.  
         [0025]     In a preferred developed implementation, the elastomer gasket is configured to have a mushroom-type cross section with the small face of the elastomer gasket being embedded in the shoulder. The advantage thereof is that the relatively wide mushroom head comes to rest against the lid and/or collar so that there is a very large surface available for sealing.  
         [0026]     In another preferred embodiment the elastomer gasket is designed to be of a much larger size than the spacing between the frame and the lid. As a result, the elastomer gasket is partially turned up so that the restoring forces inherent in the elastomer push the elastomer gasket against the lid, thus ensuring a good fit of the elastomer gasket against the lid.  
         [0027]     Further advantages of the foil bag of the invention will become apparent in the appended drawings and in the following description of embodiments thereof. Likewise, the invention lies in each and every novel feature or combination of features mentioned above or described herein after. The embodiments discussed herein are merely exemplary in nature and are not intended to limit the scope of the invention in any manner. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0028]     In the drawing:  
         [0029]      FIG. 1  is a perspective view of a first embodiment of a foil bag of the invention with the sealing plate being shown half open;  
         [0030]      FIG. 2  shows the foil bag of  FIG. 1  in the opened condition;  
         [0031]      FIG. 3  shows the foil bag of  FIG. 1  in the closed condition;  
         [0032]      FIG. 4  is a side view of the foil bag of  FIG. 1 , taken along section line IV-IV of  FIG. 3 ;  
         [0033]      FIG. 5  is a schematic illustration of the device for manufacturing a foil bag of the invention;  
         [0034]      FIG. 6  is a sectional side view of a second embodiment of a foil bag of the invention, taken along section line VI-VI of  FIG. 6   b;    
         [0035]      FIG. 6   a  shows the foil bag of  FIG. 6  with the lid being open;  
         [0036]      FIG. 6   b  is a plan view of the foil bag of  FIG. 6   a;    
         [0037]      FIG. 7  is a sectional side view-of a third embodiment of a foil bag of the invention, taken along section line VII-VII of  FIG. 7   d;    
         [0038]      FIG. 7   a  shows the foil bag of  FIG. 7  with the lid being open;  
         [0039]      FIG. 7   b  is an enlarged detail of the foil bag of  FIG. 7 , taken along line VIIb of  FIG. 7 ;  
         [0040]      FIG. 7   c  is an enlarged detail of the foil bag of  FIG. 7 , taken along line VIIc of  FIG. 7   a;    
         [0041]      FIG. 7   d  is a plan view of the foil bag of  FIG. 7   a;    
         [0042]      FIG. 8  is a sectional side view of a fourth embodiment of a foil bag of the invention, taken along section line VIII-VIII of  FIG. 8   b;    
         [0043]      FIG. 8   a  shows the foil bag of  FIG. 8  with the lid being open;  
         [0044]      FIG. 8   b  is a plan view of the foil bag of  FIG. 8   a.   
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0045]     The  FIGS. 1 through 5  illustrate a first embodiment of a foil package containing moist tissues. Said moist tissues are made from a nonwoven material and are kept moist by means of a solvent. The foil package includes a foil bag  10  at the top side  12  of which, approximately in the center thereof, there is formed a dispensing opening  14  through which the moist tissues can be removed one by one. A closure element  16 , which is made from a hard plastic material by a casting method, is embedded in the top side  12  of the foil bag  10 , said closure element including a substantially square frame  18  and a lid  20  retained on said frame. The lid  20  is pivotally retained on frame  18  by means of a living hinge that has not been illustrated in closer detail herein. To singly remove moist tissues, said lid  20 , which is pivotally retained on frame  18 , can be opened and closed again after removal, with the lid  20  fitting on frame  18  so as to be in airtight engagement therewith.  
         [0046]     At the bottom side of the lid  20 , a perimeter collar  22  that protrudes from the lid  20  is formed. A bearing surface  24 , against which the lid  20  comes to rest in the closed condition, is concurrently provided on the frame  18 . A perimeter ridge  26  is provided on the frame  18  next to the bearing surface  24 , said ridge surrounding the lid  20  in the closed condition. Both the collar  22  and the ridge  26  are thereby placed such that the spacing between the respective ones of the lid  20 , the collar  22  and the frame  18 , and the ridge  26  is minimized so that good airtight closure is achieved.  
         [0047]     To facilitate operation of said closure element  16 , a pull strap  28  is formed on the lid  20 , with the perimeter ridge  26  missing in the region of said pull strap  28 . In this region, a detent means is formed on the closure element  16 , said detent means including a collar protrusion  30  formed on the collar  22  and a frame protrusion  32  formed on the frame  18 , said collar protrusion  30  engaging behind the frame protrusion  32  in the closed condition. A reliable detent means is thus provided which retains the lid  20  in the closed condition while ensuring airtight closure thereof.  
         [0048]     As used herein, airtight means that moisture is kept from escaping from the moist tissues to the greatest possible extent.  
         [0049]     A vertically protruding perimeter-welding edge  34  is formed on the frame  18 , said welding edge engaging inside the foil bag  10 , said foil bag  10  coming to rest against said welding edge  34  and the foil bag  10  being welded to the frame  18  at this welding edge  34 .  
         [0050]     The foil bag  10  is supplied with the dispensing opening  14  defined by the frame  18  being closed by a sealing plate  36 . A pull ring  38  is pivotally attached to the top side  12  of the sealing plate  36 . A break line  40  is provided on the perimeter of the sealing plate  36  so that the sealing plate  36  can be broken out of the closure element  16  along said break line  40 . To this purpose, the user only needs to lift the pull ring  38  on one side so that part of the sealing plate  36  is pushed down by the pull ring  38 , causing a first portion of the break line  40  to break. As the pull ring  38  is pulled further, the break line  40  continues to break until the entire sealing plate  36  is released and can be removed. After that, it is possible to remove the moist tissues one by one.  
         [0051]     The method of manufacturing the foil bag  10  of the invention will be described in detail hereinafter with reference to  FIG. 5 : the foil  44  needed for forming the foil bag  10  is unwound from a foil roll  46  and is guided to a punching station  50  via a deflection pulley  48 . At this punching station  50 , an opening is punched into the foil  44  into which the closure element  16  will be inserted later. Next, the portion of the foil that has been punched out is drawn by vacuum into a suction station  52  and discarded. Next, the prepared closure element  16  is inserted into the opening and the foil  44  thermally welded to the closure element  16  in a welding station  54 . Then, the already prepared stacks of moist tissues  56  are supplied on a conveyor belt  58 -and the foil  44  is wrapped about the moist tissues with the closure element  16  being disposed on the top side  12  of the foil bag  10 . Next, in a welding and separating station  60 , the thus filled and prepared foil bags are welded both on their front side and on their back side and separated from the respective one of the neighboring packages.  
         [0052]     In another embodiment that has not been illustrated herein the welding station is configured to be an ultrasonic welding station so that the foil  44  is connected to the closure element  16  by ultrasonic welding.  
         [0053]     The second embodiment of a foil bag  110  of the invention, which is illustrated in the  FIGS. 6, 6   a  and  6   b,  has a closure element  116  at the lid  120  of which a perimeter elastomer gasket  162  is attached on the inner side thereof. Said elastomer gasket is thereby placed so as to come to rest directly beside the frame  118  when a lid  120  is closed. An inward protruding, perimeter shoulder  164  against which the elastomer gasket  162  comes to rest when the lid  120  is closed is formed as an integral part of the bottom side of the frame  118 . The elastomer gasket  162  is thereby dimensioned so as to extend as far as the shoulder  164 . As for the rest, this second embodiment of a foil bag  110  of the invention is configured analogous to the first embodiment described in the  FIGS. 1 through 5 .  
         [0054]     The  FIGS. 7, 7   a  through  7   d  illustrate a third embodiment of a foil bag  210  of the invention. Like in the first embodiment, a perimeter collar  222  is thereby formed as an integral part of the lid  220  on the inner side thereof. An inward protruding perimeter shoulder  264 , in which an elastomer gasket  262  is also embedded so as to also extend along the perimeter, is integrally formed with the frame  218 . As shown in detail in the  FIGS. 7   b  and  7   c,  this elastomer gasket  262  is configured to have a mushroom-type cross section and has its relatively slim mushroom stem embedded in the shoulder  264 . The wide mushroom head extends beyond the shoulder  264  and is compressed by the perimeter collar  222  when the lid  220  is closed, as shown in  FIG. 7   b.  The restoring forces inherent in the elastomer reliably press the elastomer gasket  262  against the perimeter collar  222 , thus providing good sealing of the inner volume of the foil bag  210 . As for the rest, this third embodiment is configured analogous to the first embodiment shown in the  FIGS. 1 through 5 .  
         [0055]     The  FIGS. 8, 8   a  and  8   b  illustrate a fourth embodiment of a foil bag  310  of the invention the lid  320  of which is not provided with a collar like in the first embodiment. Like in the second and third embodiment illustrated in the  FIGS. 6 and 7 , this fourth embodiment also has an inward protruding perimeter shoulder  364  integrally formed with the frame  318 , said shoulder being retained on a perimeter elastomer gasket  362 . This elastomer gasket  362  is configured to be quite narrow, but very high and extends beyond the frame  318  of the closure element  316 . As a result, the elastomer gasket  362  is partially turned up when the lid  320  is closed, thus reliably and sealingly fitting the lid  320 . As for the rest, this fourth embodiment is configured analogous to the first embodiment of the  FIGS. 1 through 5 .