WO1986000868A1

WO1986000868A1 - Flexible container with improved fluid flow guide

Info

Publication number: WO1986000868A1
Application number: PCT/US1985/000660
Authority: WO
Inventors: William R. Scholle; William T. Lloyd-Davies; William J. Scholle
Original assignee: Scholle Corporation
Priority date: 1984-07-30
Filing date: 1985-04-11
Publication date: 1986-02-13
Also published as: AU4218085A; EP0191770A4; EP0191770A1

Abstract

Collapsible bag container for use in fluid dispensing systems. One of the major problems associated with collapsible bag dispensers is the tendency of the walls of the collapsing bag to block access of the fluid to the bag outlet. The present invention obviates this problem by providing an elongated flexible strip of plastic in a flexible bag (12) which guides liquid in the bag to the bag outlet (14, 236) when a vacuum is applied to the outlet. The flow guide has structure which forms a plurality of interconnected spaces that in turn form flow paths to the outlet. The guide can take many forms including a net-like configuration (18), a pattern of alternate recesses and projections on each face of a strip (50), woven material (104), open cell sponge-like material (84), bunched randomly oriented fibers (106), material having spaced air bubbles between strips of plastic (86), or other such structures that can form flow paths. Also disclosed is a stretched flexible tube having a spiral slot formed therein to serve as a flow guide (60). Methods of making the bags and guides are further disclosed, including heat sealing a flange on the guides to an outlet spout.

Description

FLEXIBLE CONTAINER WITH IMPROVED FLUID FLOW GUIDE

Background of the Invention

This invention relates to flexible-film bags used as containers for liquid, and more particularly to improved flow guides that permit suction extraction of the bag contents, and to methods of making the containers.

Flexible bags confined within a paperboard box are coming into increasing and widespread use for containing a large variety of liquids, particularly liquid food products. Such constructions offer a number of advantages and conveniences. As liquid is withdrawn from the bag, the bag collapses around the remaining contents, and air does not displace the liquid. This is desirable in that the absence of air helps maintain freshness and delays spoilage of the bag contents.

Typically the container includes a relatively rigid ^'• spout which is secured to an opening in one of the flexible film walls. In dispensing the contents, the container may be oriented with its spout in different positions. With the box and container supported with, the spout at a lower-most point, the emptying action is gravity controlled such that the contents may usually be readily dispensed since liquid in the bag flows to the dispensing outlet. However, in some operations, it is desirable to orient the container with its outlet at^' or near its upper end or in some other orientation where the majority of the product will not flow out by gravity. With such an orientation, dispensing of the contents is provided by attachment of a suction tube to the spout. In such a situation, the collapsing upper portions of the flexible bag are adjacent the outlet with the-result that, as the contents are withdrawn, the side walls of the bag can collapse against each other and block the lower portion of the bag from the outlet, so that the bag cannot be emptied. A suction or dip tube can be attached to the dispenser pump and extend downwardly into the bag in an attempt to overcome this problem; however, the lower end of this suction tube can also be blocked by a lower wall of the bag being sucked into it. Further, pockets of liquid in the upper portion of the bag can be sealed from the lower end. As another attempt at resolving the problem, a tube has been developed that has a plurality of slits extending axially in the side walls of the tube, with a rigid support structure within the tube to prevent the tube from collapsing. This construction, which is shown in U.S. Patent No. 4,286,636, prevents the walls of the bag from sealing off all inlets to the tube in that there is some portion of the tube open at all times to the liquid in the bag. A tube formed by a coil spring having spaced coils,.- is shown in U.S. Patent No. 4,138,036. U.S. Patent No. ^•■ 3,420,43 discloses a slotted tube; and U.S. Patent No. 2,859,899 shows a perforated tube. However, the relatively rigid or thick tube approaches have some manufacturing and use disadvantages. _

One of the features contributing to the low cost of flexible bags, as opposed to rigid containers, is that the bags can be made in a continuous interconnected strip of bags and then separated from the strip when the bag is to be placed into a box. Typically, the strip of bags^'' is folded into a carton for shipment to a customer, and the bags are then withdrawn from the carton, and separated from the strip when they are to be used. Thus, when a relatively rigid suction tube is to be added, it is necessary that this operation be a separate manual step, which adds to the complexity and expense of- use by the customer. Various types of mechanical arrangements have been developed for connecting suction tubes to the bag spout. In prior containers, a flow tube has included a hook or snap, or similar mechanical fastening device, formed at one end. The flow guide is inserted into the container and mechanically connected by means of its hook or other fastening device to a part of the bag adjacent the spout. This procedure unduly complicates the container manufacturing process. Because of the high volume usage of flexible bag containers, any cost saving in the manufacture or use of the containers can be quite significant.

^" Also, U.S. Patent No. 4,381 ,846-Heck discloses a flexible wall container oriented with its outlet at its lower-most position and provided with a flexible mesh screen which is freely movable in liquid filled container. As the liquid is dispensed from the lower end of the container, the screen moves to a position overlying the container outlet so as to produce flow channels between a collapsing container wall and the container" outlet to enable the liquid to continuously empty from the container. Such an arrangement does not function effectively with the container oriented with its outlet in - an position other than the low position in that the screen moves to the bottom as the liquid level drops, thereby allowing the collapsing bag walls above the liquid to block passage to the outlet.

Thus , a need still exists for improved systems for ensuring that the contents of a flexible bag container are properly emptied, regardless of its orientation.

Summary of the Invention

In accordance with the invention, there is provided a * thin, flexible wall liquid container for positioning in a surrounding support box. A fluid flow guide is positioned within the container, with one end being heat sealed to an outlet spout or close to the spout in a flexible wall of the container, and the other end extending remotely from the outlet. The guide is an elongated, preferably strip¬ like element having structures which, when engaged by walls of the flexible container defines a plurality of paths which lead to the outlet. That is, as the contents of the container are withdrawn, the flexible walls.- collapse against the flow guide, but the guide structure prevents the container walls from blocking the paths created by the guide and the collapsed container walls. _ Thus, so long as fluid is open to any of the guide spaces forming a flow path, fluid can continue- to flow to. the outlet. The size of the spaces is such that even thin inner layers of multi-layered walls will not block the spaces.

In accordance with a preferred embodiment of the invention, a flow guide, which includes means for spacing portions of the walls from each other to provide liquid flow passages between the container spout and a remote part of the container, is formed with a flat attachment flange that is fixedly connected to the spout.

A preferred method of manufacturing a container embodying principles of the present invention includes securing the spout to a first wall of thin flexible ^"material, positioning a flow guide adjacent the first wall with one end at the spout, heat-sealing the one flow guide end to the spout, and then securing a second wall of thin flexible material to the first wall with the flow guide interposed between the wall.

According to specific features of the invention, the flow guide is formed with thin, flat attachment means, which may take several forms, such as a pair of thin flat, continuous side flanges, extending along the side edges of the flow guide. The attachment means may also comprise a portion adjacent one end of the flow guide that is compressed to form a thin, flat attachment flange which can be readily heat-sealed to the spout during manuf cturin .

Detailed Description of the Invention

FIGURE 1 is a cross-sectional view of the container of the invention with the flexible bag filled with liquid.

FIGURE 2 is a view similar to that of FIGURE 1 , with a., large portion of the liquid removed such that the bag • walls have collapsed against the flow guide in the bag.

FIGURE 3 is an enlarged perspective view of the flow guide of FIGURE 1 and a portion of the bag.

FIGURE 4 is an enlarged perspective of a section of the flow guide.

FIGURE 5 is a cross-sectional view on line 5-5 of FIGURE 4.

FIGURE 6 is a cross-sectional view on line 6-6 of FIGURE 4. -^''

FIGURE 7 is a perspective view of an interconnected series of flow guide strips.

FIGURE 8 is a perspective view of a series of flattened containers of the invention illustrating the manner in which the flow guides may be secured tb the bags-.

FIGURE 9 is an enlarged cross-sectional view on line 9-9 of Figure 8.

FIGURE 10 is a plan view of a portion of another flow guide useful in a flexible bag container. FIGURE 11 is a cross-sectional view on line 11-11 of Figure 1 .

FIGURE 12 is a perspective view of a woven flow guide construction.

FIGURE 13 is a perspective view of yet another flow guide useful in a flexible bag.

FIGURE 14 is a schematic, fragmentary, perspective view of a flexible, multi-layered bag construction.

FIGURE 15 is an end view of a flow guide made of two layers of the flow guide material illustrated in Figures 3 and 4 with the layers joined so that a gap exists between their central portions.

FIGURE 16 is a schematic, fragmentary, perspective view of a strip of open-celled foam used as a flow guide.

FIGURE 17 is a schematic, fragmentary, perspective., view of flow guide material having air filled plastic "• bubbles between flexible plastic sheets.

FIGURE 18 illustrates a schematic, fragmentary, perspective view of strips of a fastener material that may be utilized as flow guides. .

FIGURE 19 shows a schematic, fragmentary, perspective view of woven material that may be used as a flow guide.

FIGURE 20 illustrates a schematic, fragmentary, perspective view of a bunched fiber material to be used as a flow guide.

FIGURE 21 illustrates a cross section of a corrugated flow guide.

FIGURE 22 is a schematic illustration of a method of making a strip of interconnected flexible bags each having a flow guide positioned therein during the manufacturing process.

FIGURE 23 is a perspective view of a portion of a continuous strip of a plurality of thin-walled, flexible plastic containers;

FIGURES 24 and 25 illustrate individual ones of the containers after they have been inserted in supporting boxes , showing nearly full and partly full containers , respectively;

FIGURE 26 is an exploded perspective view of a single container embodying principles of the present invention;

FIGURE 27 is a pictorial view of a part of a flow guide embodying principles of the present invention;

FIGURE 28 illustrates^' the attachment of the flow guide of Figure 27 to a bag spout;

FIGURE 28a illustrates an alternative attachment of the flow guide to a bag spout;

FIGURES 29 and 30 are cross sections of the spout and flow guide of Figure 28 taken on lines 29-29 and 30-30, respectively;

FIGURE 31 shows a modification of the flow guide of Figure 27;

FIGURE 32 shows the flow guide of Figure 31 with its '■ side flanges bent toward and sealed to the spout;

FIGURE 33 illustrates another exemplary configuration of a flow guide;

FIGURE 34 shows a modification of the flow guide • of Figure 27;

FIGURES 35 and 36 illustrate the flow guide of Figure 34 connected to a spout;

FIGURE 35a illustrates a flow guide attached to a spout in an alternative form; and

FIGURES 37 and 38 show still another modified form of flow guide.

Detailed Description of the Invention Embodiment of Figures 1-6

Referring to Figure 1, there is illustrated a box 10 and a bag or container 12 confined therein, with the container having thin, flexible, liquid impervious walls and being almost completely filled with liquid 1.3, such that the bag basically conforms to the shape of the box. The container includes an outlet 14 in the form of a tubular nozzle or spout and an elongated flow guide 18 having one end connected to the outlet in some suitable manner and having its other end extending downwardly into the bag to a point remote from the outlet, near the bottom of the bag. The flow guide 18 has a strip-like, generally flat configuration and is rather flexible. It normally extends in roughly a single plane, but it may undulate or twist somewhat if unsupported. at its lower end. It is illustrated in Figure 1 in a twisted configuration merely to illustrate that it has a relatively wide front and back face, but is quite thin.

When the contents of the bag are to be withdrawn, a vacuum pump or other means for applying suction to the bag is applied through the outlet. If the box is oriented so that the outlet 14 is at the lower end of the bag, the liquid will flow out by gravity. As the liquid is.- withdrawn, the flexible walls of the bag are drawn inwardly in that air does not displace the liquid, and the bag might take the shape illustrated in Figure 2 when there is not much liqxtid 13 left in the bag. As can be visualized from Figure 2, the bag walls would actually be drawn against each other if the flow guide 18 were not provided and such action would seal the outlet from the liquid in the lower end of the bag. The presence of the flow guide enables liquid to be withdrawn out of the outlet even though the bag walls are pressed against^''the sides of the flow guide. In accordance with the invention, the flow guide is constructed such that it forms a plurality of interconnected spaces which define flow paths leading to the outlet so long as any significant portion of the flow guide strip is in contact with the liquid.

Referring to Figure 3, it may be seen that the flow guide 18 has a net-like configuration formed by a large number of individual strands or elements creating a repeating, diamond-shaped pattern. More specifically, there are a plurality of spaced^' parallel strands 20 that extend at an angle with respect to the direction to the outlet 14, or at an angle with respect to vertical, as viewed in Figures 1-3, and a plurality of spaced parallel strands 22 that are positioned behind the strands 20, as viewed in Figure 3, or beneath the strands 20, as viewed in Figures 4-6. The strands 22 extend at an angle with respect to vertical approximately the same as that of the strands 20, but intersecting the strands 20. In the fabrication of the net material, the groups of strands engage each other in a heated, softened state such that when cooled the strands are joined at the intersections 24.

Although the strands are joined at the intersections 24, they are not pressed together so as to be all in a single plane. The strands are somewhat merged at the.- intersections, but the center lines of the upper strands '• form an approximate plane which is spaced from and parallel to a lower approximate plane formed by the centerlines of the lower strands 22. Stated differently, the upper strands 20 form an upper face of the guide strip and the lower strands form a lower face, recognizing that the guide can be in any orientation such that the terms upper and lower are merely used for reference purposes.

Thus, the upper strands 20, as viewed in Figure 6, define a plurality of spaces 26, open to one face of-^''the strip while the lower strands 22, as viewed in Figure 5, define a plurality of spaces 28 open to the -other face. The spaces 26 and 28 are all open to the side edges of the strip. Also, the spaces are offset with respect to each other but are open to each other at each diamond-shaped space 27 defined by two segments of the upper strands 20 and two segments of the lower strands 22. That is, each space 27 is formed by portions of the spaces 26 and 28. Consequently, even when the bag walls 12 are compressed against the strip as illustrated in Figures 5 and 6, fluid may flow through the netting spaces. That is, it can be seen from Figure 5, that the spaces 28 are not closed off by the bag wall 12. Similarly, as seen in Figure 6, the spaces 26 are not closed by the bag wall 12. Consequently, even with the bag walls pressed against the flow guide, the flow guide structure defines a plurality of tortuous paths as indicated by the arrows 30 in Figure 4. That is, liquid flowing in the spaces 28 defined by the strands 22 flows under the strands 20, but such liquid can flow into the spaces 26 over the strands 22 at any of the diamond-shaped spaces 27. Such tortuous flow paths can lead to the bag outlet.

The actual dimensions and spacing of the flow guides strands is selected or coordinated with the flexibility of the material forming the bag walls. That is, if the strands are too widely spaced, the bag material can be.- drawn into the space between the strands such that seals - could be formed by the opposite bag walls engaging across the spaces 26 and 28, that is, through the spaces 27. 0f_ course, the bag walls will extend inwardly to some extent into the spaces between strands , and thus the strand diameters cannot be made too small or else the bag walls could seal or the flow passages would be too small. In the arrangement illustrated, the spaces between the strands are about twice as large as the strand diameters. In a successful prototype product, a -^'net having strands of about .045 inch were used making a net strip thickness of about .085 inch.

The width of the guide itself should also be coordinated with the size of the strands and the spaces to provide the desired combined flow path. In a workable embodiment of the invention, the flow guide strip was about two inches in width. Wider or narrower strips may be employed, or a plurality of strips may. be utilized. Also, multiple layers of strands can be used. Preferably, the length of the strip should be about equal to the height of the box 10 which surrounds the bag 12. This will ensure that the flow guide is always exposed to liquid, even when the liquid level is quite low.

The flow guide strip must be selected from material which is compatible with the liquid to be contained in the bag. Further, the material is preferably heat sealable and is relatively inexpensive inasmuch as the containers are disposable. It is also desirable that the material be relatively flexible and that it not be so rigid as to present a puncturing problem to the bag. On the other hand, it should be sufficiently stiff that it will tend to remain in its position extending from the outlet to the other end of the bag, unless intentionally folded. A less stiff material can be used if the end of the guide remote from the outlet is attached to the bag. Embodiment of Figures 7-9

Referring to Figures 7, one of the advantages of using ^'• heat sealable, flexible material, is that the flow guide may be made as a continuous strip 32 of flow guides 18 with sections 36 between flow guides 18 being compressed so that they are not much thicker than the bag , wall material. With this arrangement, the flow guide strips may be heat sealed to the flexible bag, with one end of the flow guide being heat sealed to one end seam of the bag and the other end of the flow guide being heat sealed to the seam formed at the opposite end of the bag. This can be done in a variety of ways. In a preferred arrangement, the bags are formed in a continuous strip as shown in Figure 8 and a continuous strip of flow guides is inserted in the bags properly located so that the flattened sections are aligned with the locations at which the bag insea s are to be formed. Thus, the bag end- seams 38 and 40 may be heat sealed at the same time that the ends of the flow guides are heat sealed into the seam, as illustrated in Figures 8 and 9.

Alternatively, the flow guide strip 32 of Figure 7 can be severed at sections 36, and each guide individually heat sealed to a single bag 12 as the end seams 38 and 40 in the bag are formed.

In yet another approach, a flattened section of an individual flow guide 18 may be heat sealed to the bag walls at some location near to, but spaced from the end seams of the bag, or one flattened end preferably heat sealed to the outlet spout 14.

It should be noted that for any of the foregoing methods, one end of the strip should be attached to or positioned in close proximity to the bag outlet so as to make sure that the flow guide strip is in communication with the outlet. ^' That is, the bag walls should not be able to seal between the flow guide and the bag outlet. Flow Guide of Figure 12

It should be recognized from the the foregoing that-- elongated strip-like, generally flat, flow guides can be ^' formed with a variety of structures and patterns. A common requirement is that the flow guide must have structure which forms a plurality of interconnected spaces that form in combination with the bag walls one or_, more paths leading to the bag outlet. Thus, netting having any number of different patterns may be employed with the structure having a plurality of spaced strands somewhat like that described above. Further, the strands can actually be in a woven configuration, so long as they continue to define spaces that are interconnected and not blockable by the bag walls .

One example of this is shown in Figure 12, wherein a plurality of strands 58 extending at one angle are woven with a plurality of strands 59 into a configuration forming spaces 57 between the strands. The- strands are interconnected at their intersections so that the spaces are permanent. Since the strands extend alternately over and under each other, the spaces 57 are interconnected to form flow paths. It should be recognized from Figure 12 that merely two strands could be woven into a repeating, figure eight configuration with the strands alternating under and over each other. Further, interconnecting a group of such figure eight lengths in side by side relation would increase flow capacity. Of course, weaves or braids of three or more strands could also be used. Flow Guide of Figures 10 and 11

Figures 10 and 11 illustrate another suitable arrangement wherein a flat strip 50 made of suitable plastic is formed with a plurality of rows of raised portions or projections 52 alternately arranged with a plurality of recesses 54. This positions each projection 52 surrounded by a portion of the planar strip 50 and further surrounded by four of the recesses 54 as well two of the other projections 52. Thus, there is space 56 around each of the projections into which liquid may flow.- even when the bag wall 12 engages the projections as ^' illustrated in Figure 11. Further, the recesses 54, open to the space 56, provide additional flow path area through which liquid may flow.

One of the other major advantages of his construction, as observed from Figure 11, is that the strip surface forming a pro ection 52 on one face of the strip forms a recess 54 on the other face of the strip-. Similarly, each recess 52 on one face of the strip forms a projection 52 on the other face of the strip. This construction minimizes the material required while maximizing the flow space. Reduced material not only reduces cost but also minimizes the amount of plastic that may absorb some of the liquid. A pattern of this nature can of course be made very inexpensively through a stamping or rolling operation. Further, if desired, holes may be formed through the strip to provide intercommunication between both faces of the strip. A variety of different patterns and shapes for the projections and recesses may be employed. Further, a construction with only projections extending from a flat sheet may be employed.

Flow Guide of Figure 13

In the arrangement of Figure 13, a flow guide is formed by utilizing a plastic tube 60 which is formed with one or more curved slits in its wall, and the tube is then stretched beyond its memory to form one or more slots or gaps 62. Preferably the slot is in the range of .015 to

.030 inches in width. In the form illustrated, the slot

62 has a continuous spiral configuration.

Flexible Container Wall of Figure 14

As indicated above, the size of the spaces and the flow paths within the various flow guide constructions must be coordinated with the flexibility and thickness of the bag walls. Such bags are made of a variety of.- materials of different thicknesses and often the wall has - more than one layer. A better understanding of this relationship may be realized by considering one type of currently used bag wall construction, illustrated in

Figure 14 as having four layers of material. This includes an upper layer 66 which represents the inner wall of a bag, a middle layer 68 having an aluminized surface coating 70, and a bottom or outer layer 72. The layers

66, 68 and 72 are thin flexible sheets of plastic such as polyethylene or polyester. In one example, the inner layer 66 is made of polyethylene and is one mil thick, i.e. .001 inch, the middle layer 68 is made of polyester

.0015 inch in thickness, with the aluminum coating being very, very thin, and the outer layer 72 being a polyester film .001 inch thick. Thus, the total bag wall thickness is only slightly more than .0035 inch. In other examples, the total wall thickness may be .004 or .0045 inches. The layers are not usually bonded together throughout their entire surface but instead only on the edges or spaced intervals. Thus it is really the inner layer 66 which must receive the primary consideration with regard to cooperating with the flow guide. A film of polyethylene one mil thick is very flexible and is also quite stretchy or extendable such that it can be drawn into small spaces by fluid pressure. Accordingly, in selecting the proper flow guide structure it is critical that the construction be such that the thin inner layer- of the bag wall cannot be drawn so far into the flow guide structure by the pressure differential applied to the bag during emptying that the wall on one side of the flow guide can seal against the wall on the other side of the flow guide so as to block the flow.

Flow Guide of Figure 15

Another flow guide structure that has been found to be particularly useful with very thin inner bag walls is that illustrated in Figure 15. Shown is a two layer flow guide.- 74 having a lower layer 76 and an upper layer 78. Each ^• layer is made of material like that shown in Figures 3 and 4, but of course, the layered approach can also be employed with the other flow guide structures described herein. The upper and lower layers are.joined at their longitudinal edges 79 and 80 in a manner such^' that a slight gap 82 is formed between the layers. The gap is exaggerated in Figure 15 for purposes of illustration. The advantage of the gap is that the pressure applied to the bag walls, in relation to the stiffness of the -flow guide is such that the layers 76 and 78 cannot be completely pressed together. This coupled with the double thickness and with proper spacing between the strands of the flow guide prevents even the most flexible inner bag walls from being drawn inwardly so far that they seal the flow paths.

In another aspect of the invention, the flow guide 74 of Figure 15 may be conveniently formed by first joining one longitudinal edge 79 of the upper and lower layers 76 and 78. The edges are preferably joined by heat sealing. The two layers, while stacked, are then bent or rolled into an arc of about 90° and held in that position while the other edges 80 of the upper and lower strips are joined. When the structure is then released, it will return to a generally flat configuration as illustrated in

Figure 15, but with the gap 82 being established.

Flow Guide of Figure 16

Another suitable flow guide material that has been found to be successful is open-celled foam, which is schematically illustrated at 84 in Figure 16. The material is formed from a thermo-plastic and comes in a variety of densities and porosities. Typically, an open cell foam is made of thermo-plastic bubbles filled with gas which is allowed to expand and break during the manufacturing process. When the bubbles break, the bubble walls at the inter-engaging surfaces of the bubbles remain- to form an open, net-like structure that has sufficient strength or stiffness, but the material remains flexible and resilient. The open nature of the cells forms a large_, number of flow paths through which liquid can flow even when resilient flexible bag walls are pressing against- the surfaces of a flow guide made of such open cell material.

As indicated, the open-celled foam comes in many varieties, typically being made of polyester or other suitable thermo-plastic. In one satisfactory arrangement, the material has a porosity of approximately twenty holes per inch and a density of only three percent of solid. That is, the flow guide only displaced three percent of the liquid that would be displaced by a completely solid element. An example of such material is sold by Scott Paper Company of Chester, Pennsylvania, .for -"a variety of uses, one being to be positioned beneath vegetables on display tables in supermarkets. Flow Guide of Figure 17

Figure 17 illustrates another structure 86 that has been found to be practical as a flow guide. That structure includes a plurality of spaced vertically extending, cylindrically shaped hollow elements 88 made of plastic and positioned between a lower film layer 90 and an upper layer 92. Spaces 94 are created between each of the hollow elements 88. A material of this nature is commonly utilized as cushioning material for packing breakable items. One example of such material is sold by Sealed Air Corporation under the trademark Bubble Pak. The "bubbles" or hollow elements 88, can be made in a variety of configurations, such as completely spherical or flattened spheres, as well as the cylinders illustrated. Also, the hollow elements may be made of different sizes and have differing spacing between them. One type of packaging material has about three bubbles per inch. However, for use as a flow guide it is preferred that.- there be about fifteen bubbles per inch. This provides a - plurality of small passages such that thin bag walls cannot be drawn very far into them. The liquid flow is , _ of course, through the spaces 94 formed between the hollow elements 88 and the upper and lower films 90 and 92. - Flow Guide of Figure 18

Another readily available material, useful as a flow guide, is the well known fastener material sold under the trademark Velcro. Such material is illustrated in Figure 18 comprising a lower layer 96 of thermo-plastic ma e- ial having a plurality of upwardly extending finger-like elements 98, and an upper layer of material 1-00 having a plurality of flexible loops 1 2 extending therefrom. Either material by itself is useful as a flow guide and the two layers may be used when fastened together in face to face relation. The fingers 98 actually have hooks on the end but fingers without hooks are also satisfactory. Flow Guide of Figure 19

Figure 19 illustrates a flow guide 104 having a knitted construction formed of continuous inter-engaging loops. Such structure is preferably made in a manner that the loops are permanently interconnected at their points of intersection, but the structure also functions as a flow guide if the loops are loosely connected, so long as the loops are sufficiently stiff to continue to create a plurality of interconnected spaces that can define fluid flow paths when the flexible walls of a bag engage the guide. Flow Guide of Figure 20

Figure 20 illustrates yet another suitable flow guide structure 106 which is formed of a plurality of randomly oriented fibers that define a plurality of interconnected spaces to form flow paths even when under some compressive force from the collapsing walls of a flexible bag. Again, the randomly oriented fibers are preferably permanently interconnected at their intersection points , and many - materials are commercially available now that have such ^• structure. They are typically made of thermo-plastic material, wherein the fibers are connected at their_, intersecting points during the manufacturing process. One example of such material is that used for air filters- for furnaces. However, if the fibers have sufficient stiffness and friction they will not totally compress even if they are not actually interconnected at their intersection points. The material will compress to some extent but will still maintain spacing between the fibers. Flow Guide of Figure 21

Figure 21 illustrates the cross section of -yet another elongated strip 107 forming a flow guide. As can be seen, the strip has a generally corrugated configuration wherein the strip forms with the bag walls a plurality of flow paths 109. . ^■-

Method of Figure 22

Figure 22 schematically illustrates another manner in which flow guides may be inserted into flexible bags formed in continuous strip form. . An upper layer of film 110 is shown extending between a pair of rollers 112 together with a lower layer of material 111. These two layers form one wall 113 of a flexible bag. Spaced holes

114 are formed by a suitable punch 116 in wall 113, and a suitable spout or nozzle 118 is positioned in each hole and preferably heat sealed to the wall. The bottom bag wall 119 is also shown being formed of multi-layers 120 and 122, which are fed from supply rolls between suitable forming rollers 124. Before the bottom wall is mated with the upper wall 113, a length of flow guide strip 126, cut from a roll 128 of flow guide material, is secured by heat sealing or other suitable means to the flange of nozzle

118 which is in the interior of the bag. The flow guide lies flat and extends away from the nozzle, but its length is less than the distance between adjacent nozzles. The end remote from the nozzle, can be attached to the bag if.- desired. The upper and lower bag walls are then joined ■ along their side edges by heat sealing or other suitable means, with the flow guide being thereby confined between the bag walls.

The flat tubular strip of bag material is then_, heat sealed transversely across the strip at spaced intervals to form end seams of a series of interconnected bags. The bag end seams are formed between the nozzle of one bag and the adjacent end of the flow guide which is attached to the nozzle of the adjacent bag. That is, the flow guide does not extend into the bag seams. As explained above, in one method of manufacture, the flow guide can intersect the seam. However, the thickness of the material of some flow guides make it desirable that the flow guide strip not intersect the end seam, to not disrupt the sealing of the end seam. The strip of bags can be -conveniently folded and shipped and stored in a box until use. The user thus does not need to take any assembly steps for inserting a flow guide into each bag.

Some strips of bags are formed without having nozzles or holes for nozzles formed in the bags. Instead, all edges of the bags are sealed and a liquid inlet or outlet port is formed by a probe or other such element inserted into the bag when the bag is to be filled. In that situation, the flow guide should be attached to the bag at or near the location that the outlet is to be formed. Embodiment of Figures 23-26

As shown in Figure 23, a plurality of containers 220, 221 , 222, and 223 are formed of continuous upper and lower sheets of a thin, flexible plastic material bonded together around peripheral boundaries that interconnect the two sheets along their side edges 224, 225 and along spaced transverse paths, such as paths 226, 227 of bag 221 , that completely separate one bag from the next. The continuous length of bags may be cut along the transverse paths to separate the individual bags. Each bag includes., a spout, such as spout 230 of bag 220, and an internal ^•. flow guide, such flow guide 231 of this bag.

The construction of an individual bag is more specifically illustrated in Figure 26, which shows the portions of a single bag formed of an upper sheet .232 having a hole 234 into which is inserted a spout 236 having a neck 238 and a continuous annular base or flange 240, the upper side of which is heat-sealed to the downwardly facing side of upper sheet 232 during the manufacturing process. Neck 238 of the spout stands upwardly and projects outwardly of the outer surface of upper sheet 232. The spout is relatively rigid, being made of material considerably thicker than the sheet material of the bag walls . The spout base is thinner than the spout neck, but still thicker than the bag wall^'s. A flow guide in the form of a thin, flexible elongated strip of extruded material 242 has one end 244 secured to the spout and extends along the inner surface of supper sheet 232, without conn'ection thereto, to a second end 246 at a point which is positioned at an area of the bag remote from the spout, a point which may be at the bottom of t he bag when the bag is in use as illustrated in Figure 25. A second or bottom sheet 248 is then secured to the upper sheet 232, as by heat-sealing around the entire peripheral mating boundaries of the two sheets to define a chamber, with the flow guide 242 interposed therebetween. This completes the manufacture of a single bag, which, of course, must still be cut from the continuous strip of bags that are made in this fashion.

As illustrated in Figure 24, a single bag is placed in a suitably sized inexpensive container, such as a cardboard or paperboard container 250, having a top 252 through which protrudes spout 236. With the container filled with liquid, guide strip 242, which may have a density somewhat greater than the density of the contained liquid, will hang in a generally downwardly extending.- direction and may be spaced from one or all of the ^'• container walls. For dispensing liquid from the boxed container (Figure 25) , a suction line (not shown) is attached to the spout 236 and liquid is drawn from the container. Because air cannot enter the container - as liquid is extracted by the suction line, the container walls tend to collapse, and, without the guide strip, would be tightly pressed against one another by external atmospheric pressure, thereby blocking flow of liquid to the spout. However, the flow guide prevents contact between collapsing walls of the container, at least in the area along the length of the flow guide, and, in addition, provides a continuous flow passage for flowing liquid to the spout from a remote portion of the liquid chamber defined within the container. Embodiment of Figures 27-30

Shown in Figures 27-30 is a flow guide constructed according to one embodiment of the principles of the present invention. It includes a long, flexible integral strip, preferably of a suitable plastic material extruded in a continuous length, that is cut into sections. The extrusion has a flow guide bottom 250 and a plurality of closely-spaced, continuous upstanding ribs including those indicated at 253, 254, 255, 256, and 257 extending for the full length of the flow guide. Figure 27 shows only one end portion of this elongated extrusion, which is made with a width greater than its thickness so as to make the flow guide as thin as possible while maintaining an adequate total area of flow passages. The guide is formed with upstanding side panels 261 , 262 extending along the full length of the bottom 250 and attached to the edges of the bottom. The side panels terminate in outwardly- directed thin, flat attachment flanges 264, 266 that lie substantially in the plane of the outer or free ends of the ribs 254-257, extending parallel to the flow guide bottom 250. Side panels 261 and 262, and in particular.- flow guide attachment flanges 264, 266, are made '- considerably thinner than the flow guide bottom 250 and spout base 240. In an exemplary embodiment, the flanges may be fifteen to twenty thousandths of an inch thick, whereas the bottom may be in the order of s.ixty thousandths of an inch thick. The ribs need not be as thick as the flow guide bottom, but are preferably thicker and thus more rigid than the attachment flanges 264, 266. The flow guide has an end 265 positioned at the periphery of spout base 240 (Figure 28) and extends entirely across the spout base to the remote part of the bag. The attachment flanges 264, 2-66 overlap diametrically opposite sides of the spout base and are heat-sealed thereto, as indicated at the cross hatched segments in Figure 28. Alternatively, the flow guide end may be positioned at or near the center of -the spout, a position in which there is less overlapping areas for heat-sealing to the spout base. Similarly, instead of having the entire overlapping flange area heat-sealed, a substantial spot 268 of overlapping area may be heat- sealed on each side, as shown in Figure 28a. As shown in Figure 30, when the flow guide is secured to the spout base, a plurality of continuous linear flow passages, such as passage 267, is formed between each pair of adjacent ribs and between each outer rib and the flow guide side panels 261, 262. It may be noted that, even though the flow guides described herein are relatively thin and flexible, they must have at least enough thickness to form the necessary flow passages. Therefore, the required configuration of any flow guide involves a flow guide thickness and construction that prevent a direct heat-sealing attachment of the flow guide strip to the spout.

The attachment flanges are needed solely at that end portion of the flow guide which is attached to the spout. These flanges are made flat and thin and.- positioned in the plane defined generally by the free ends ^'• of the ribs so as to facilitate heat-sealing of the flow guide to the spout base during the course of ordinary manufacture of the bags. It will be readily appreciated that the attachment flanges 264, 266 need not extend, for the entire length of the flow guide, but need extend only for a distance comparable to the length by which these flanges will overlap the spout flange 240 (as seen in Figure 28) when the flow guide is attached to the spout. However, because in a presently preferred embodiment-^" the flow guide is made as an integral extrusion, it is found most convenient to form the flow guide with flanges 264, 266 extending continuously for the full length of the guide.

In the manufacture of a bag containing such a flow guide, the sequence of steps is generally as- follows. A continuous length of upper sheet material, including an upper sheet 232, is apertured at successive spaced points at a first station through which the continuous upper sheet passes. The spouts are inserted into each aperture and heat-sealed to the upper sheet at the next station. At a third station the flow guides are positioned, each with its side flanges in contact with the inner side of the spout base, and the side attachment flanges of the flow guides are heat-sealed to the spout. (As an alternative approach the spout flange could be positioned on the top side of the upper sheet and the sheet heat- sealed to the flange) . The flow guide would thus engage and be heat-sealed to the lower side of the top sheet backed by the spout flange. At the next station, the bottom sheet is heat-sealed to the peripheral boundary of the upper sheet, and thus .the manufacture of the bag is complete, except for the severing of the individual containers from the single continuous strip of nearly completed except for the severing containers. Of course, the continuous length of multiple bags may be handled and., shipped without detaching individual bags, which may be ^•. severed from the remainder only at the point and time of use. The described steps provide a novel manufacturing procedure, eliminating difficulties - of the prior art involved with forming special loops or connecting devices on the spout or container sheet, and making the necessary mechanical connection. The mechanical connection required in the prior art for securing the flow guide in position is considerably more complex and costly, may required added manual steps, and may very well result in decreased production rate. Flow Guide of Figures 31 and 32

Modification of the flow guide of Figures 27-30 is illustrated in Figures 31 and 32 wherein attachment flanges 264a and 266a are formed as direct lateral extensions of the bottom 250a, without the need for intermediate upstanding side panels, such as panels 261 , 262 of the embodiment of Figures 27-30. In the embodiment of Figures 31 and 32, the thin, flexible attachment flanges 264a and 26fia are bent upwardly toward the spout base 240 by the heat-sealing pressure heads to provide a configuration of attached flow guide and spout illustrated in the cross section of Figure 32. Flow Guide of Figure 33

Figure 33 illustrates still another modified configuration of the flow guide in which the construction is substantially identical to that illustrated in Figures 27-30 except that each of the ribs is made in a T-shape with a continuous longitudinally extending cross flange 271 , 272 and the like formed integrally with the free end of each rib. In this arrangement, the flow guide includes a bottom 273 to the side edges of which are secured thin, flat attachment flanges 274, 275 which function in the same manner and are attached to the spout base in the same manner as are the corresponding flanges of the embodiment of Figures 27-30. With the use of T-shaped ribs, the.- spacing between adjacent ribs may be increased slightly '• because the space between adjacent edges of rib cross arms, such as arms 271, 272 is still sufficiently small to prevent suction induced entry of the very thin flexible container walls into the flow passages defined between, the ribs. Flow Guide of Figures 34-36

The flow guide of Figures 27-30 may be modified as illustrated in Figures 34-36, so as to be formed without the side flanges. In such an arrangement, one end portion 294 of the flow guide is compressed and flattened by a suitable pressure head, so that this flattened- portion 284 forms a relatively thin, flat attachment flange which then may be heat-sealed to the spout base 240 as illustrated by the cross-hatched segment in Figures 35 and 36. ^' The entire cross-hatched area need not be heat-sealed, and instead a smaller spot of heat-sealing may be used, similar to that explained above in connection with Figure 28a. Further, with thin flow guides, it is not mandatory that a flange be formed on the strip. Instead, a pressure heat-seal spot may be directly formed between an end portion of any of the flat, strip flow guides and a spout flange, as shown in Fig. 35a.

Flow Guide of Figures 37 and 38

Still another form of flow guide is illustrated in

Figures 37 and 38 wherein the guide is extruded, or otherwise formed, from a thin, wide length of open weave mesh 276 which provides a number of tortuous passages that are continuous from end to end of the flow guide strip , passing through the holes in the mesh from one side of the mesh to the other and along the mesh, between the mesh of the two container sides. Similar to Figure 4, the mesh includes mutually angulated sets of parallel upper strands or elements 280, 281 intersecting lower elements 284, 285 to form apertures 287 which interconnect the channels between the upper elements with those between the lower " elements. The strands are integral at their ^' intersections. An end portion 288 of mesh 276 is crushed and flattened to provide a thin, flat attachment flange. that may be heat-sealed to the spout flange in the same manner that the crushed end attachment^' flange of ^• the embodiment of Figures 25-26 is heat-sealed to the spout.

Thus, it will be seen that simply by crushing an end portion of the ribbed flow guide an adequately thin and flat attachment flange is provided for heat sealing to the spout. Instead of crushing merely one end portion to provide a thin, flat attachment flange on the end of the flow guide, narrow areas along each side portion of the flow guide where it overlaps the spout base may be crushed to provide a pair of thin, flat attachment flanges that may be readily heat-sealed to diametrically opposed portions of the spout flange.

It will be readily understood that the several types of flow guides described herein are merely exemplary of the many different configurations of flow guides that may be modified by application of principles of the present invention. Thus, the thin, flat flanges or crushed side or end portions described herein may be formed on flow guides of the several different configurations disclosed in Figures 4, 10, 15-21, and such flanges heat-sealed to the spout flange.

Claims

IN THE CLAIMS:

1. A liquid container comprising: first and second thin flexible walls formed of one or more layers with the walls joined to one another around a container boundary to define a closed chamber, one of said walls having an opening therein, a spout positioned in said opening and secured to said one wall, and a flow guide comprising an elongated strip of material within said chamber and extending from said spout to a part of said chamber remote from said spout, said flow guide including means for spacing portions of said first wall from portions of said second wall adjacent said guide to provide liquid flow passage means between said spout and said part of the-- chamber remote from the spout, said strip of material ^'• being heat-sealed to said spout or said one wall at said spout.

2. The liquid container of Claim 1, wherein said flow guide includes first and second flanges extending along opposite edges of said elongated strip of material, said strip of material being heat-sealed to said spout at said flanges .

3. The liquid container of Claim 2, wherein said spout includes an annular base, and wherein said fla'nges are heat-sealed to said annular base.

4. The container of Claim 3, wherein - said first flange is heat sealed to one side of said base and said second flange is heat sealed to a diametrically opposite side of the base.

5. The container of Claim 3, wherein said flow guide spacing means extends laterally about equal to the diameter of an opening in said spout and said flanges extend laterally from said spout opening.

6. The liquid container of Claim 1 wherein said flow guide includes a strip bottom, a plurality of ribs upstanding from said bottom and extending along said flow guide, and first and second flat attachment flanges extending laterally outwardly away from said ribs , said strip of material being heat-sealed to said spout at said flanges.

7. The liquid container of Claim 2 wherein said elongated strip of material comprises an integral strip of extruded material having a guide bottom, a plurality of parallel, longitudinally-extending ribs upstanding from said guide bottom and mutually spaced to form a plurality of flow passages along said flow guide, and at least one thin, flat attachment flange extending laterally outwardly from a side edge of said elongated strip of material, said attachment flange running substantially the full length of said elongated strip of material, said strip of material., being heat-sealed to said spout at a part of said ^•- attachment flange.

8. The liquid container of Claim 1 wherein said strip of material comprises a bottom member and a plurality of closely spaced ribs upstanding from .said bottom member and running the full length of said flow guide, said ribs being crushed against said bottom member at one end of said flow guide to provide a flat attachment flange at which the strip of material is heat-sealed to said spout.

9. The liquid container of Claim 1 wherein said flow guide comprises an integral extrusion having means defining longitudinally extending flow passages extending along the length of the extrusion, a portion of said extrusion being compressed and flattened to define a flat attachment flange at which the strip of material is heat- sealed to said spout.

10. The container of claim 1 wherein said flow passages means includes structures which forms a plurality of interconnecter spares throughout the guide forming interconnecter paths leading to the bag outlet.

11. the container of claim 1 wherein said structures have a .net-like configuration.

12. The liquid container of any one of Claims 6, 7, 8, and 9 wherein said spout includes a flat annular flange that is heat-sealed to an attachment flange of said flow guide.

13. The method of manufacturing a liquid container comprising the steps of: forming a spout opening in a first sheet of thin flexible material for ec ico one or more layers; heat-sealing a spou^'; cσ said first sheet at said spout opening; forming an elongated flow guide having a plurality of liquid flow passage extending along the flow guide; positioning said flow guide adjacent said first^" sheet with one end thereof at said spout; heat-sealing said one end of said flow guide to. said spout; and securing a second sheet of thin flexible material to said first sheet around a container boundary with said flow guide interposed between the sheets.

14. The method of Claim 13 including the step of forming an attachment flange on at least said one end of said flow guide, and wherein said step of heat-sealing'^' one end of said flow guide comprises heat-sealing said attachment flange to said spout.

.

15. The method of Claim 14 wherein said spout includes a base that is considerably thicker than said first sheet, wherein said step of forming an attachment flange comprises forming first and second attachment flanges integral with and extending substantially the full length of said flow guide, and wherein said step of heat- sealing one end of said flow guide comprises heat-sealing both said attachment flanges to the base of said spout.

16. The method of Claim 14 including the step of crushing a portion of said flow guide to form an attachment flange, and wherein said step of heat-sealing comprises heat-sealing said attachment flange to said spout base.

17. A liquid container comprising: first and second thin flexible walls sealed to one another around a container boundary to define a closed chamber, one of said walls having an opening therein; a spout positioned in said opening and secured to said one wall; and a flow guide comprising an elongated strip of material extending within said chamber from said spout to a part of said chamber remote from said spout, said., flow guide including means for spacing portions of ' said first wall from portions of said second wall adjacent said guide to provide liquid flow passage means between said spout and said part of the chamber remote from the spout, said flow guide including .flat attachment flange means fixedly connected to said elongated strip of material and to said spout.

18. The liquid container of Claim 17 wherein said attachment flange means comprises first and second attachment flanges extending along opposite edges of -^'said elongated strip of material and formed integrally therewith.

19. The liquid container of Claim 18. wherein said spout includes an annular base, and wherein said attachment flanges are heat-sealed to said annular base.

20. The liquid container of Claim 17, -wherein said flow guide comprises an extruded strip having a strip bottom, a plurality of ribs upstanding from said bottom and extending along said flow guide, said attachment flange means including first and second flat attachment flanges extending laterally outward away from said ribs.

21. The liquid container of Claim 17 wherein said flow guide comprises an integral strip of extruded material having a guide bottom, a plurality of parallel, longitudinally-extending ribs upstanding from said guide bottom and mutually spaced to form a plurality of flow passages along said flow guide, said attachment flange means comprising a pair of thin, flat attachment flanges extending laterally outwardly from opposite side edges of said integral strip and running substantially the full length of said integral strip.

22. The liquid container of Claim 17 wherein said flow guide comprises a bottom member and a plurality of closely spaced ribs upstanding from said bottom member and running the full length of said flow guide, said ribs being crushed against said bottom portion at one end of said flow guide to provide at least part of said flat attachment flange means.

23. The liquid container of Claim 17 wherein said- flow guide comprises an integral extrusion having means defining longitudinally extending flow passages extending along the length of the extrusion, said flat attachment flange means comprising a portion of said extrusion that is compressed and flattened to eliminate said flow passages at said portion.

24. The liquid container of any one of Claims 17, 18, 20, 21, 22, and 23 wherein said spout includes a flat annular base that is heat-sealed to said flat attachment flange means of said flow guide.

25. A flow guide for a liquid container having a spout communicating with a chamber defined by thin flexible walls sealed to each other, said flow guide preventing mutual contact of said walls and providing flow passage to said spout, said flow guide comprising: an elongated integral strip of material which is relatively flat, but has structure which is sufficiently thick to provide said flow passage; and first and second flat attachment flanges extending along said ribs at opposite side edges of said structure, said flanges being thinner than said structure.