Patent Publication Number: US-2004052437-A1

Title: Pouch

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
     [0001] This application claims priority from U.S. provisional application No. 60/406,660, filed Aug. 29, 2002. 
    
    
     
       BACKGROUND OF INVENTION  
       [0002] This invention relates to a flexible plastic pouch containing a flowable product, such as a fluid.  
       [0003] Products may be packaged in flexible pouches as it minimizes the use of packaging material. However, where the product is flowable (such as a granulated product or a liquid), it may be advantageous to design the pouch so that it is self-standing.  
       [0004] It is known to produce a self-standing flexible pouch by utilising additional layers of packaging material, as, for example by gussetting the base of the pouch. This, however, increases the use of packaging material and manufacturing complexity. In another approach, after establishing seals to form the basic pouch, cross-seals are formed in a secondary operation to make the pouch self-standing. For example, in U.S. Pat. No. 6,164,042 to Tobolka, after sealing two sheets of plastic material together to form a liquid filled pouch, the bottom corners of the pouch are pinched flat to form triangular portions. A heat seal is then made along the base of the triangular portions and these triangular portions are then removed. This creates a rectangular base for supporting the pouch in a stand-up position. However, this intrusion into the previously formed pouch in order to form the triangular portions risks interfering with the integrity of the pouch.  
       [0005] A need remains for a robust self-standing pouch which is of simple manufacture.  
       SUMMARY OF INVENTION  
       [0006] In the present invention, the bottom portion of a flexible pouch is configured such that it collapses when on a flat surface to form a stable basal platform for the pouch.  
       [0007] According to the present invention, there is provided a flexible pouch, filled with a flowable product having a front pouch wall joined to a rear pouch wall along opposite side edges and along a bottom edge. The front pouch wall, when flat, has a first width at a first level above the bottom edge and concave or oblique opposite sides between the first level and the bottom edge so that a width of the front pouch wall progressively decreases below the first level, at least down to a second level. In consequence, when the pouch is set down with the bottom edge on a flat surface, the sides between the first level and the bottom edge collapse to provide a stable basal platform for the pouch.  
       [0008] Other features and advantages of the invention will become apparent from a review of the following description in conjunction with the figures. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0009] In the figures which disclose example embodiments of the invention,  
     [0010]FIG. 1 is a perspective view of a pouch filled with a flowable product made in accordance with this invention,  
     [0011]FIG. 2 is a front view of the pouch of FIG. 1,  
     [0012]FIG. 3 is a front view of the pouch of FIG. 1, when empty,  
     [0013]FIG. 4 is a cut-away view showing a portion of the pouch of FIG. 1 during a pouch opening operation,  
     [0014]FIG. 5 is a perspective view of the pouch of FIG. 1 in a second configuration,  
     [0015]FIG. 6 is a schematic view of a folded plastic sheet illustrating the front wall of the pouch of FIG. 1,  
     [0016]FIG. 7 is a schematic view of a folded plastic sheet illustrating formation of a series of pouches of the type illustrated in FIG. 1, and  
     [0017] FIGS.  8  to  15  are front views of empty pouches made in accordance with further embodiments of this invention. 
    
    
     DETAILED DESCRIPTION  
     [0018] Referring to FIGS. 1 and 2, a pouch  20  made in accordance with this invention has a front pouch wall  22  joined to a rear pouch wall  23  (FIG. 5) along opposite side edges  24 ,  26 , along a top edge  30 , and along a bottom edge  32 . The pouch walls are made of a flexible material, such as plastic, and the pouch is filled with a flowable product, such as a fluid (e.g., yoghurt or water.  
     [0019] The front pouch wall may be joined to the rear pouch wall at side edges  24 ,  26  by sealing the walls together at these edges. This forms a sealed band  34  along the side edges. Similarly, the front and rear pouch walls may be joined to each other at one or both of the top and bottom edges by sealing these walls together. As illustrated in FIGS. 1 and 2, the front and rear walls are sealed together at the top edge  30 . On the other hand, the front and rear walls are joined at the bottom edge  32  by virtue of the flexible material from which the pouch is constructed being integral at the bottom edge.  
     [0020] Because the pouch  20  is flexible and filled with a flowable product, the configuration of the pouch differs depending upon which portion of the pouch rests on a supporting surface. As illustrated in FIGS. 1 and 2, the pouch is resting on the pouch rear wall  23  (FIG. 5).  
     [0021] With the flexible pouch resting on its rear pouch wall  23 , the front pouch wall  22  is substantially flat. In this configuration, with specific reference to FIG. 2, the front pouch wall has a maximum width at a first level L 1  above the bottom edge  32  and concave opposite sides  24   b,    26   b  between the first level L 1  and the bottom edge  32 . In consequence, the width of the front pouch wall  22  progressively decreases below the first level L 1  down to a second level, L 2 . In fact, the side edges  24   b,    26   b  form an inwardly directed corner  28  at the second level L 2 . The flowable product in the pouch causes the pouch to bulge, thus, the true shape of the front pouch wall  22  will only be apparent when the pouch is empty.  
     [0022]FIG. 3 illustrates, in front view, an empty pouch  20 ′ such that the front pouch wall  22  is flat. From FIG. 3, it will be apparent that the concave opposite sides  24   b,    26   b  between the first level L 1  and the bottom edge  32  of the pouch trace arcs of a circle. The radius, r, of these arcs may be less than 1.5″ (3.8 cm). The distance, x, between the first level L 1  and the bottom edge  32  of the pouch  20 ′ may be about 27% to 30% of the width, W, of the pouch at the first level, L 1 . Furthermore, a distance, y, measured along said first level, between a corner  38  of the front pouch wall  22  at level L 1  and a corner  40  where the side  24   b  or  26   b  meets the bottom edge  32 , is about, is about 65% to 70% of the distance x. By comparing FIG. 3 with FIG. 2, it will be apparent that with the pouch filled, the radius of the sides  24   b,    26   b  breaks to form the afore-referenced inwardly directed corner  28 . This break point is predictably located. Consequently, with the radius, r, the same for both sides  24   b,    26   b,  this pouch configuration facilitates achieving a vertical orientation for the pouch when stood up.  
     [0023] As is apparent from FIGS.  1  to  3 , the pouch has a narrow neck  44  and an enlarged head  46 . The neck meets the head at a corner  48  so as to provide a tear point which, as illustrated in FIG. 4, facilitates separation of the head from the neck in order to open the pouch. Optionally or additionally, the pouch may be provided with a notch  50  to facilitate tearing the neck of the pouch at this notch. With reference to FIG. 3, for reasons which will become apparent, the sides  24   t,    26   t  at the head  46  are mirror images of the sides  24   b,    26   b  at the base between level L 1  and the bottom edge  32 . Thus, the head  46  has convex opposite sides  24   t,    26   t  such that a width of the front pouch wall progressively increases above the neck  44  and defines the same dimensions, x, y, and r, as are defined at the base of the pouch.  
     [0024] If the filled pouch  20  of FIG. 1 is lifted up and set down on a flat surface bottom edge first, the sides  24   b,    26   b  between the first level L 1  and the bottom edge  32  collapse under the weight of the overlying portions of the pouch to provide a stable basal platform for the pouch. FIG. 5 illustrates the pouch in this configuration. Referring to FIG. 5, it will be apparent that as the pouch is set down, the sides  24   b,    26   b  fold at corners  28 . Further, the bottom edge flattens. The result is a flat basal platform  52  with a hexagonal perimeter and a self-standing pouch.  
     [0025] Because each corner  28  is predictably located, being a function of the radius, r (FIG. 3), with the radius r the same for both sides  24   b,    26   b,  this pouch configuration facilitates achieving a vertical orientation for the pouch when stood up.  
     [0026] Turning to FIG. 6, the pouch may be manufactured from a folded plastic sheet  56  utilising curved heat sealing bars (not shown) which seal the sheet at sides  24 ,  26  and top  30 . The bottom edge  32  naturally results from the fold in the sheet  56 . With reference to FIG. 7, sheet material may be conserved by alternately orienting and nesting adjacent pouches  20  that are formed in the sheet  56 . It is with this approach to forming the pouches  20  that the sides  24   t,    26   t  of the neck are mirror images of the sides  24   b,    26   b  at the bottom of the pouch. Furthermore, with this approach, where one pouch has a top seal  30  and a bottom edge naturally resulting from the fold in the sheet, the adjacent pouch formed from the sheet  56  will have a bottom seal and a top edge naturally resulting from the fold in the sheet.  
     [0027] One convenient manner of forming pouches  20  is to use vertical form, fill, and seal technology. With this approach, a sheet is folded around a product supply pipe and free side edges of the folded sheet are sealed together to form a vertical tube. A bottom seal is then formed in the tube and the tube partially filled with flowable product. Heat sealing bars may then press together to displace the flowable product and form successive pouches which may be cut from the tube. This approach to forming pouches is further described in U.S. Pat. No. 6,164,042 to Tobolka, the contents of which are incorporated herein by reference.  
     [0028]FIGS. 8 through 12 illustrate, in front view, empty pouches  120 ′,  220 ′,  320 ′,  420 ′,  520 ′, respectively, having different pouch configurations. Each of pouches  120 ′,  220 ′,  320 ′,  420 ′,  520 ′ may also suitably be formed from a folded plastic sheet in a nested fashion.  
     [0029] With specific reference to FIG. 10, empty pouch  320 ′ has oblique linear bottom sides  324   b,    326   b  extending between level L 1  and the bottom edge  332  of the pouch. Thus, the width of the front pouch wall  22  progressively decreases below the first level (L 1  down to the bottom edge of the pouch. With this pouch configuration, when the pouch is full, while the bottom sides  324   b,    326   b  will break to form an inwardly directed corner, the location of this corner will not be predictably located (in contrast to the situation where the bottom sides are configured as arcs of a circle). Because of this, the pouch of FIG. 10 might not stand vertically when set down, bottom edge first.  
     [0030] With specific reference to FIG. 11, pouch  420 ′, bottom sides  424   b  and  426   b  have a first linear section  427  between the first level L 1  and a second level L 2   a  and a second linear section  429  between the second level L 2   a  and the bottom edge  432 . In consequence, the front pouch wall  422  is narrower at said second level L 2   a  than at either the first level L 1  or the bottom edge  432 . The pouch of FIG. 11, when filled, will form a predictably positioned inwardly directed corner (between linear sections  427  and  429 ). Consequently, this pouch configuration facilitates achieving a vertical orientation for the pouch when stood up.  
     [0031] The pouch of FIG. 12 differs in that its neck portion  544  is off to one side rather than being centrally located.  
     [0032]FIG. 13 illustrates, in front view, an empty pouch with yet another pouch configuration. With reference to FIG. 13, pouch  620 ′ has linear sides  624 ,  626  above level L 1  and radially concave sides  624   b,    626   b . In consequence, pouch  620 ′ cannot be formed in a nested fashion as can the pouches of the previously described embodiments.  
     [0033]FIG. 14 illustrates, in front view, an empty pouch with a further pouch configuration. With reference to FIG. 14, pouch  720 ′ has concave sides  724   b,    726   b  which flare outwardly proximate the bottom edge  732  of the pouch. In consequence, the width, W, of the front wall  722  of the pouch at level L 1  is actually less than the width, W 2 , of the front wall at the bottom edge  732 . As a result of this configuration, when pouch  720 ′ is full, and set down, bottom edge first, the side walls  724   b,    726   b  collapse leaving projecting tabs at the base of the pouch. If such tabs were considered somewhat unsightly, one of the other pouch configurations could be chosen.  
     [0034]FIG. 15 illustrates, in front view, an empty pouch  820 ′ which has angulated, rather than curved, edges. Thus, pouch  820 ′ has straight edge sections  824 ,  827 ,  829 ,  832 ,  826 ,  830  meeting adjacent edge sections at an angle.  
     [0035] Similar to the designs of a few of the previously referenced pouches, in the pouch  820 ′ of FIG. 15, the medial portion of the side edge sections  824 ,  826  between the concave basal portions  824   b,    826   b  and neck  844  are straight. In consequence, when the pouch contains a flowable product and is set down on its base, these medial side edge portions are vertically oriented. This results in the flowable product being displaced vertically upwardly as the pouch is set down, avoiding distortion of the sides of the pouch, which occur in certain of the other designs, such as pouch  220 ′ of FIG. 9.  
     [0036] If the pouches illustrated in FIGS. 8 through 15 are made by the process described in conjunction with FIGS. 6 and 7, each pouch will have a sealed band along all but either its top edge or its bottom edge, with the front and back walls of the pouch being integral at the edge which is not sealed. By way of example only, the pouches of these figures have been shown in this way, with the pouches of FIGS. 8 through 14 having sealed bands along all but their bottom edges and the pouch of FIG. 15 having a sealed band along all but its top edge.  
     [0037] It will be apparent from the foregoing that it is the geometry of the pouch, interacting with the fluid dynamics in the pouch, that results in the flat base when the pouch is set down. There is no requirement for gussets or secondary cross-seals in order to gain the stand-up feature.  
     [0038] A further advantage of the described pouches is that they may be shipped flat (i.e., resting on their front or back wall as illustrated in FIGS. 1 and 2) to conserve space, without interference from the stand-up feature. Yet further, shipping the pouches flat will not damage the stand up feature, nor stress the .pouch (which could increase the incidence of leaking pouches).  
     [0039] Other advantages and modifications within the scope of the invention will be apparent to those skilled in the art and, therefore, the invention is defined in the claims.