This invention relates to flexible dispensing containers for limited amounts of liquid which are made from sheets of pliable material sealed around their edges and provided with a narrow outlet channel running through one of the sealed edge sections of the container and terminating near a corner which can be torn off to open the channel and allow the liquid to be dispensed when the container is squeezed.

Background of the Invention

Squeezeable liquid pouch containers with self- sealing outlets have been addressed in the past, their basic embodiment was disclosed in U.S. Patent Number 2,707,581 Kaplan et al which was reissued under Number RE. 24,251. Additional improvements were disclosed in U.S. Patent Number 4,275,840 Staar, Number 4,331,264 Staar and 4,491,245 Jamison. Another U.S. Patent Number 4,592,493 Smith discloses a dispensing container with a self-

sealing passageway with some minimal structural similarities to some aspects of the invention.

The various containers disclosed in this prior art exhibit a variety of defects. In the first place the sealed area, usually located in the upper section of the container, which surround the torturous path of the self-sealing outlet represents a large portion of the overall container, thus limiting the size of the liquid- holding pouch-. The delineation of the tear-off section which usually spans the upper portion of the container does not allow for the placement of multi-functional outlets. More significantly, this prior art did not address the problem of storing soda pop and other carbonated drinks with large variations of positive internal pressure.

Summary of the Invention

The primary object of this invention is to provide a flexible pouch-type liquid container with self-sealing outlet which allows for maximum liquid capacity. Another object of the invention is to provide multiple ways of extracting the contents of

the container through either a self-sealing outlet activated by squeezing the pouch, and by means of a non-sealing spout. A third object of this invention is to provide a means to accommodate large variations in the internal pressure of the liquid holding pouch due to carbonation.

These and other objects are achieved by means of carefully planned configuration of the outlet and spout using tear-off corner sections in the upper part of the container. The inner corner of the liquid-holding ^* pouch proximate to a tear-off corner are carefully rounded to avoid inadvertent puncture of the pouch. An expandable chamber is formed at the conjuncture of the pouch and resealing outlet by means of nesting blisters formed into the walls of the container.

Brief Description of the Drawings

Figure 1 is a perspective view of a flexible liquid container according to the invention;

Figure 2 is a partial frontal view of the working face of a container molding plate;

Figure 3 is a cross-sectional view of a couple

of cooperating molding plates;

Figure 4 is a perspective view of a convex, blister-molding insert;

Figure 5 is a perspective view of a concave, blister-molding insert;

Figure 6 is a frontal view of the upper part of a molding plate showing a first alternate configuration;

Figure 7 is the frontal view of a molding plate showing a second alternate configuration;

Figure 8 -is a diagrammatical and cross- sectional view of an expansion chamber in the deflated condition; and

Figure 9 is the diagrammatical and cross- sectional view of an inflated expansion chamber.

Description of the Preferred Embodiment of the Invention

Referring now to the drawing, there is shown in Figure 1 a flexible liquid container 10 according to the invention. The container is made from two sheets 18 and 19 of pliable synthetic material which has been heat-sealed about their

edge and about a carefully delineated area of the upper portion 20 of the container. The unsealed area between the two sheets 18 and 19 form a pouch 13 for holding a fluid, as well as a self-sealing outlet 11, a pouring spout 12 and a expandable ballast chamber 14.

The construction and operation of those various elements can be best understood by reference to the tool used for fabricating such a container. Figure 2 illustrates the working face of the upper part of a pair of heat-sealing plates 21 and 22. Each plate is preferably made of a highly heat-conductive metal which, as shown in Figure 3 is bonded to a backplate 23. The backplate acts as a heat distributing element. The backplate 23 may be heated by various well-known means such as embedded resistive elements and the like. Area 24 of the working face of each backplate which corresponds to the liquid-holding pouch 13, the outlet 11 and the spout 12 indicated by stippling in Figure 2 has been etched to a depth of a few milimeters. When two overlaid sheets of eight-syllable material are pressed together

between two of such plates where the working - face of each plate is a mirror image of the other, the non-etched areas 25 of the plates by a combination of heat pressure cause a sharply delineated adherence of the two sheets thus forming the edge and upper part of the pouch 13. The etched channel 26 which forms the outlet 11 of the pouch is brought near to one of the upper corners 27- a line of indentation 28 cut across the channel and the corner. Those indentations are designed to create a easily tearable line in the container material. A similar line 29 cutting across a portion 30 of the pouch-corresponding area is provided at the opposite corner 31. The channel 26 is relatively long and narrow so that in the absence of strong internal pressure the walls of the resulting outlet tend to collapse against each other and remain closely stuck under the effect of capillarity even after the outlet has been opened by tearing off the corner part 16. It can now be understood that any fluid stored in the pouch 13 can be extracted by two separate means, either by way of the self- sealing outlet 11 once the corner part 16 has been

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torn away by squeezing the main body of the pouch 13. An alternate way of extracting the contents of the pouch is to tear off the opposite corner section 17 through the non-resealing spout 12. In order to avoid inadvertent puncture of the pouch 13, the corner 32 of the etched area 24 nearest the end of the outlet-shaping channel 26 has been rounded away from the indentation line 28.

The expandable plastic chamber 14 is formed during the manufacturing process of the container 10 by installing a pair of blister-shaping inserts through line-up balls in the plates 21 and 22. One insert 34 offers a concave area on the working face of the plate 22 while the other insert 33 shows a corresponding convex area 36 which is positioned and dimensioned to nest intimately within the concave area 35 of the other insert 34. The inserts are made from a hard material which has a lower heat conductibility than the material from which the plates 21 and 22 are made. The heat transmitted to the insert as well as other relevant parameters are adjusted to cause the forming of nesting blisters in the two layers of the container

material without allowing any material adhesion. Figures 4 and 5 respectively illustrate the shape of the inserts 33 and 34. It should be understood that the threshold between the non-adhesive shaping of the blister and the bonding of the two layers of the synthetic material used in the fabrication of the container depends on the combination of three parameters: heat, pressure and dwell-time. While the dwell-time is common to all areas of the container, the pr-essure applied by the nesting of the two faces 35 and 36 of the inserts may be made different than the pressure applied by the non- etched area 25 of the plates 21 and 22 by carefully contouring and adjusting the faces of the inserts 33 and 34. Similarly the heat transferred to the insert can be adjusted by varying the penetration of the mounting screws 37 and 37A into the body of the inserts 33 and 34 respectively. The choice of insert material between various grades of ceramic and resin will also dictate the amount of heat applied by the insert to form the blister.

Figure 6 illustrates a first alternate treatment of the upper part of the forming plates

21. It should be noted that the ovoid insert 38 extend over the cut-off area 31 of the spout 12; thus providing two inlets 39 and 40 into the blister area. Figure 7 illustrates a second alternate embodiment wherein the blister-forming insert 41 is postitioned under the outlet-forming channel 42.

The operation of the expandable ballast chamber is diagrammatically illustrated in Figures

8 and 9. In the absence of gas pressure the two blister-shaped wall areas 43 and 44 are nested together. Under the action of gases such as when the pouch is holding a carbonated drink, the inner blister area 43 is made to pop out in the opposite direction, thus creating the ballast chamber 45.

One will notice that in the various configurations described above, the expandable ballast chamber has an inlet near the conjuncture of the inner pouch and the beginning of the self-sealing outlet. Accordingly, once the self-sealing outlet 11 has been used and a portion of the liquid has been evacuated from the pouch, any building of gas pressure in this area will tend to expand the

volumetrically variable chamber 44 rather than through the tightly closed outlet 11. The size and shape of the blistered area as well as the gauge and length of outlet can be adjusted to accommodate various types and volumes of carbonated liquid within the pouch 13 and yet allow for an immediate self-sealing of the outlet after first or subsequent drawing of the carbonated drink from the pouch. While the preferred embodiment of the invention has been described and alternate configurations have been suggested, it should be understood that other embodiments may be devised and modifications can be made without departing from the spirit of the invention and the scope of the appended claims.