Flexible container with arcuate self-sealable spout
United States Patent [1 1 Carlisle Apr. 22, 1975 FLEXIBLE CONTAINER WITH ARCUATE SELF-SEALABLE SPOUT Richard S. Carlisle, Rye. NY.  
 American Can Company, Greenwich. Conn.  
 Filed: June 10, 1974 Appl. No.: 477,755 I Related U.S. Application Data Inventor:  
 Assignee:  
 Continuation-impart of Ser. No. 231,288, March 2,  
 1972, Pat. No. 3.815.794.  
 References Cited UNITED STATES PATENTS 6/l974 Carlislc 222/49] Primary E.\&#39;antinerStanley H. Tollberg Attorney, Agent, or Firm-Robert P. Auber; lra S. Dorman; George P. Ziehmer ABSTRACT A fluid-dispensing container is provided which consists of a pair of relatively supple films joined in a face-to-face relationship by a peripheral seam. The seam defines a body and a generally arcuatelyextending spout, the latter at least in part being delineated by correspondingly-curved seam elements which define substantially eccentric and divergent arcs. Distension of inner wall portions of the spout by contained fluid effects a seal across an intermediate portion of the spout. The seal is overcome at increased levels of internal pressure, to permit the fluid contents to, discharge through the spout; upon reduction of the level of internal pressure. the sealing relationship may be reestablished.  
 27 Claims, 8 Drawing Figures PLTENTEBAPRZZHYS 3.878.977  
 sum 1 f 2 FLEXIBLE CONTAINER WITH ARCUATE SELF-SEALABLE SPOUT CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of copending application Ser. No. 231,288, filed 03/02/72, now issued as U.S. Pat. No. 3,815,794.  
  BACKGROUND OF THE INVENTION The above-identified copcnding application discloses containers which are highly beneficially employed for the containment and dispensing of a wide variety of fluid products, and which have seals that are pressurereleasable and automatically self-restoring upon diminution of the internal pressure below a certain level. While the articles specifically described in the aforesaid application are highly useful and entirely satisfactory for numerous applications, improvements in the manner of operation, the convenience and advantage of use, and in the appearance thereof are, of course, desirable.  
  Accordingly, it is an object of the present invention to provide a novel container for fluids having means for forming a seal, which seal may be releasable by internal pressure of relatively low magnitude, and functions smoothly and in a well-controlled manner.  
  A related object of the invention is to provide such a container which may be fabricated from films exhibiting a significant degree of rigidity.  
  Another object of the invention is to provide such a container having a spout which is relatively short, but  
 in which the seal forms at a location spaced a considerable distance inwardly from its discharge end, thus affording enhanced protection against contamination and evaporation of the contents.  
  Still another object of the invention is to provide such a container having a spout which is disposed for optimum convenience of use and sanitation.  
  A further object of the invention is to provide such a container which is comfortable to use, pleasing in appearance, and stably supportable with its discharge opening maintained away from contaminating surfaces.  
 SUMMARY OF THE DISCLOSURE It has now been found that the foregoing and related objects of the present invention are readily attained in a container for fluids having a body and a spout extending generally arcuately therefrom. The spout of the container has congruent opposed walls of supple, imperforate material, and it is defined by laterally-spaced seams which unite the walls and dispose them in substantially face-to-face contact when the spout is empty. The seams, in turn, include first, correspondinglycurvcd seam elements defining substantially eccentric arcs which extend divergently, at least from about an intermediate portion of the spout, generally toward the body. The container is dimensioned and configured to provide means for forming a releasable seal across the intermediate portion of its spout, and first sections of the opposed walls lying between the correspondinglycurved seam elements are free of interconnection and are adapted to readily become distended by contained fluid. Such distension causes the first wall sections to converge into sealing abutment with one another with the center lines thereof forming, at points adjacent the abutment therebetween, an angle of less than about 60. With the first sections so disposed, second sections of the opposed walls coextend from the abutment with their center lines in general alignment with the center line of one of the first wall sections and at an angle to the center line of the other of the first wall sections, thus enabling sealing of the spout without need of auxiliary sealing means.  
  In preferred embodiments ofthe container, the spout is configured with a continuous taper in the discharge direction, the seams defining the spout are of smoothly curvilinear configuration, and they are relatively narrow (generally from about 0.02 to 0.1 inch wide) and are located substantially at the lateral edges of the spout. The are radii of the first seam elements should be from about A to 12 inches in length, and preferably their length is in the range of about 1 to 6 inches. Most desirably, the first elements of the seams defining the spout extend from the intermediate portion thereof and, in sealing abutment, center lines of the first wall sections preferably form an angle of about 15 to 45, at points adjacent the abutment.  
  Generally, the container will be dimensioned and configured so as to render the seal across the spout releasable in response to internal pressure of a higher magnitude than that at which contained fluid will cause distension of the first wall sections, and consequent sealing of the spout. Preferably, the dimensions and configurations of the container will be such as to cause the location of the abutment to proceed outwardly along the spout in response to progressively increased levels of internal pressure above the distension pressure, so as to ultimately overcome the seal and thereby permit the fluid contents to discharge from the container. The distance over which the abutment location moves may desirably be at least half the total length of the spout, and most desirably the container will be dimensioned and configured to render the seal selfrestoring upon diminution of the pressure below the aforesaid higher magnitude thereof. The container will normally include fluid contents and will be completely closed to provide an integral package, and the spout may advantageously have a fused closure portion adjacent its outer end, which portion is adapted for removal to provide a discharge opening or orifice.  
  In especially preferred embodiments of the invention, a container is provided in which congruent opposed walls of supple, imperforate material are united, and disposed in face-to-face contact when the container is empty, by at least one bond. The opposed congruent walls provide integral walls of a fluid-containing body, and of a spout which extends generally arcuately therefrom, with the spout being defined by laterallyspaced seams provided by the bond. The seams include first, correspondingly-curved seam elements defining substantially eccentric arcs which extend divergently, at least from about an intermediate portion of the spout, generally toward the body. The container is dimensioned and configured to provide means for forming a releasable seal across the spout at the intermediate portion thereof, and the seal, wall abutment and center line relationships are substantially as described hereinabove.  
  The walls of the container will generally be comprised of a synthetic resinous thermoplastic material, with the bond being provided. as a relatively narrow heat seal located substantially at the edge of the container. The walls may desirably comprise a laminate containing at least two distinct materials, and in some instances one of the materials may desirably be selected from the group consisting of metal foils, paper and molecularly oriented plastics.  
  In certain embodiments of the invention, the body of the container may have, in a flat disposition. a generally rectilinear edge which extends thereacross at a location remote from the spout, and which is of a length that is less than the width of the walls of the body at a location spaced a short distance therefrom. By making intermediate portions of the body walls which lie between the rectilinear edge and the spaced location narrower than the body walls at such location, the stability of support may be maximized. Thus, placing a container so constructed in an upright position, with the rectilinear edge disposed thereunder on a support surface, causes the outer margins of the intermediate wall portions to tend to fold inwardly of the body; this, in turn, permits distension of the wall portions therebetween under the weight of the fluid contents, and thereby provides an extended base area for stably supporting the container. Preferably, the intermediate wall portions of such a container are defined by generally slanting seam portions which extend outwardly from the ends of the rectilinear edge. Most desirably, the upper sections of the seam portions are convexly curved to avoid relatively sharp corners thereat, which serves to enhance the level of stability of support for the container; preferably, the radius of curvature of such sections will be at least about one-half inch in length.  
  In a specific embodiment of the invention, the body of the container has an elongate configuration and provides means for supporting the container on an underlying surface with its longitudinal axis extending generally horizontally. The spout thereof is located adjacent one end of the body, and it is configured to extend in a generally upward direction from the body with the container so supported. Such a container is ideally suited for the containment and dispensing of a pluralphase liquid mixture.  
  In another specific embodiment of the invention, a container for fluids is provided, having a body and a spout extending outwardly therefrom. The spout has congruent opposed walls of supple, imperforate materials and is defined by laterally-spaced seams uniting the walls and disposing them in substantially face-to-face contact when the spout is empty. In addition, the spout has a tapered channel leading to the outlet end thereof, which is defined by a generally rectilinear seam element slanting from adjacent one edge of the spout toward the other edge thereof. The seams include first seam elements extending divergently, at least from an intermediate portion of the spout, generally toward the body, and the container is dimensioned and configured to provide means for forming a releasable seal across the spout at the intermediate portion thereof. First sections of the opposed walls between the first scam elements are fre of interconnection, and are adapted to readily become distended by contained fluid. Such distension causes the first wall sections to converge into sealing abutment with one another, with the centerlines of the first wall sections adjacent the abutment forming an angle of less than about 90, and with opposing second sections of said opposed walls coextending from the abutment with the center lines thereof in general alignment with the center line of one of the first wall sections and at an angle to the center line of the other of the said first wall sections. As a result, the spout can be sealed without auxiliary sealing means.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view ofa filled and sealed container embodying the present invention;  
  FIG. 2 is a left end elevational view of the container of FIG. 1 with a small portion of the tip removed to permit dispensing of the contents, and showing, in phatom line, a discharge position of the spout thereof;  
  FIG. 3 is a fragmentary, cross-sectional view of another end portion of the spout of the container of FIG. 1, taken along line 3-3 thereof and drawn to an enlarged scale;  
  FIG. 4 is a cross-sectional view of the spout of the container of FIG. 1, taken along line 44 thereof and drawn to the scale of FIG. 3;  
  FIG. 5 is a side elevational view ofa second configuration of containers embodying the invention, in an unfilled condition;  
  FIG. 6 is a side elevational view of the container of FIG. 5 in a filled condition and seated in a stably supported disposition;  
  FIG. 7 is a side elevational view of another configuration of containers embodying the invention, with a portion broken away to expose the two-phase liquid mixture contained therewithin, and shown in a stably supported disposition; and  
  FIG. 8 is a side elevational view of the container of FIG. 7, in an inverted position for dispensing of one of the components of the mixture contained therewithin, and showing, in phantom line, an alternate inverted position in which the other of the components of the twophase mixture may be dispensed therefrom, spout portions being broken away to expose the contents of the container.  
 DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Turning now in detail to FIGS. 1-4 of the appended drawings, therein illustrated is a container embodying the present invention, which is especially suited for the containment and dispensing of wine or the other beverages, typically for direct consumption by the consumer. The container consists of a pair of face-to-face, relatively supple films 10, which are joined together by a relatively narrow marginal seam, generally designated by the numeral 12, extending about the periphery thereof. The container is comprised of a substantially oval body portion, generally designated by the numeral 14, from which extends arcuately a spout, generally designated by the numeral 16; the juncture of the body 14 and spout 16 may be regarded to reside approximately at the phantom line XX. As will be noted, the inner portion of the spout 16 is defined by arcuate seam sections 13 and 13&#34;, which sections have radii R and R on eccentric centers C and C&#34;, respectively. As a result, and because the centers C, C are disposed on the same side of the spout 16, it extends arcuately; it also has a continuous taper in the discharge direction.  
  As will also be noted, the tip of the spout 16 is provided with a V-shaped seal 18, which defines a more sharply tapered channel portion thereat. Although nicks, such as 20, may be provided on either side of the seal 18 to locate and facilitate severance, so as to produce an optimum discharge opening, the V-shaped seal 18 permits the dimensions of the opening to be varied throughout a fairly widerange, by appropriate selection of the point at which the sealed tip is severed from the spout 16. This, in turn, enables a degree of control of the flow characteristics of the fluid issuing from the container.  
  As is best seen in FIGS. 2 and 3, the opposed portions of the walls 10 between the seam elements 13, 13 are distended by the hydraulic head of the container contents, with no external force being applied thereto. Due essentially to the configurations of the seam elements 13, 13&#34;, the distended wall portions 10&#39; converge at an angle a to form a sealing abutment at an intermediate location 22 of the spout 16. The end portion 24 of the spout 16 is deflected or canted to one side of the medial plane between the walls 10, with the center line of one of the wall portions 10&#39; being substantially linear (albeit with a slight convex curvature), and with the center line of the other of the wall portions 10 changing direction abruptly at the location 22 and projecting at an angle thereto. In addition to the canted attitude, the end portion 24 also developes a slight transverse curvature or warp at and below the location 22, as illustrated by FIG. 4.  
  After removal of the tip portion of the spout 16, all or a portion of the contents of the container may be discharged by manually squeezing the container at a location remote from the spout 16 to increase the level of internal pressure therewithin. The pressure increase is, of course, transmitted to the intermediate location 22 of the spout 16, tending to straighten the end portion 24 and to distcnd the wall portions 10 thereat, thereby causing the abutment to proceed outwardly along the end portion 24. Ultimately,&#39;the seal is overcome to effect a discharge of the contents 26 from the container; this is the condition depicted in phantom line in FIG. 2 of the drawings. As can be seen, the body 14 has a number of puckers 28 thereabout, which form as a consequence of filling the container. These puckers 28 are advantageous in that they promote inward folding of the seam portions thereat. and outward movement of the adjacent wall portions, thus enabling stable seating ofthe container on its edge, at virtually any point about the body 14.  
  Although the theory underlying the desirable manner of operation of the containers of the invention is not fully understood, it is believed that the configurations and relationships between the seams defining the spout portion and to a lesser extent, the characteristics of the wall portions thereat, enable distension to occur, generally in the absence of applied external pressure, throughout only a limited, inner portion of the spout. Outwardly of the intermediate location described, distension does not initially occur, and the differences in the wall portion shapes which result produce both the canted attitude and also the transverse curvature of the spout end portion. In addition, the arcuate, eccentric, divergent relationships that exist between the seam elements inwardly of the intermediate location provides a gradual transition zone, while also tending to limit the wall-to-wall angle a, previously referred to. These factors. in turn, permit the seal to release at relatively low levels of internal pressure (generally created by applied external force), and in a very smooth and wellcontrolled manner. The spout taper is important in that it affords a secure seal which is readily established and released, and in generally requiring a constant (albeit gentle) buildup of pressure to effect release, as is desirable to avoid abrupt or gushing operation. Upon release of the pressure exerted on the container, the clastic memory of the wall material (as affected by the film gage, the dimensions involved, etc.) will normally be capable of effecting an automatic reestablishment of the abutted relationship, and thereby a reclosure of the container. Because of the operational facility and control which the spout configuration of these containers affords, will be appreciated that films having a degree of rigidity, such as would be imparted by the presence of paper, or oriented polymer, or a metal foil in a laminated construction, may be employed in the fabrication thereof; these factors also permit the use of wider (and hence more rigid) seams, as may be necessary or desirable to prevent leakage or rupture of the container.  
  Turning now in detail to FIGS. 5 and 6 of the drawings, a second form of container embodying the present invention is illustrated in empty and filled conditions, respectively. As in the case of the container of FIGS. 1-4, this container is fabricated from a pair of face-toface films 30 (only one of which is visible), which are joined together by a continuous, narrow, peripheral seam, generally designated 32. The container has a substantially symmetrical body, generally designated by the numeral 34, and a spout generally designated by the numeral 36, which extends generally arcuately to one side of the longitudinal axis of the body 34. As can be seen in FIG. 6, the walls 30 merge into sealing abutment at an intermediate location 38, spaced inwardly from the discharge end of the spout 36. It will be noted that the eccentric, arcuate seam elements 33, 33 of this container do not extend directly from the intermediate location 38, but rather commence at points spaced slightly inwardly therefrom. If the advantages of the instant invention are to be realized, such arcuate elements should commence at points which are spaced no more than about two inches inwardly from the location at which the abutment seal initially forms (i.e., the intermediate location 38).  
  The seam 32 of the container of FIGS. 5 and 6 includes a rectilinear element 40 which defines, relative to the spout 36, a remote edge of the container. Elements 42 of the seam 32 extend upwardly and outwardly from the opposite ends of the element 40, and curve convexly to blend into the other seam elements. This configuration of the seam 32 enhances the level of stability of the filled container seated in an upright position, as shown in FIG. 6, by promoting the inward folding of the seam elements 42 and the consequential outward movement of the portions of the walls 30 lying therebetween, The curvature of the elements 42 is beneficial in avoiding sharp corners which, upon deformation of the container in its supported position, would tend to create pivot points on which the container might rock. It will be appreciated that, in operation, the container of FIGS. 5 and 6 functions essentially in the same manner and with the same advantages as that which is described in the preceding figures.  
  Turning finally to FIGS. 7 and 8 in detail, the container illustrated therein is dimensioned and configured, as arethe containers of the foregoing figures, to provide an abutment seal, and it is especially well suited for the containment and dispensing of a pluralphase liquid mixture; for example, oil and vinegar. As in the previous embodiments, the container of FIGS. 7 and 8 is fabricated by joining in face-to-face relationship a pair of relatively supple films (only one of which is visible) by sealing them together about their common peripheral edge, to provide thereat a narrow seam, generally designated by the numeral 52. The instant container has a elongate body, generally designated by the numeral 54, and a spout, generally designated by the numeral 56, extending arcuately at one end thereof. The spout 56 is defined by arcuate seam elements 58, 58&#34; which have relatively long radii and thereby provide a rather uniform and gently-tapered configuration. It also has a generally rectilinear slant seam element 59, which extends thereacross and defines an outwardly tapered channel 61. A small notch 63 is formed in the wall 50 to facilitate severance across the spout 56 at an optinum point; however, severance may desirably be effected at any point along the length of the seam element 59, and the ability to so control the nature of the resulting orifice is a principal benefit of the provision of such an element. In addition, the angular attitude of the element 59 may be relied upon to control the flow direction of the fluid issuing from the spout 56, and it can be produced easily and with relatively little concern about critical registration with other portions of the seam 52.  
  In addition, the seam 52 further includes a rectilinear element 60 extending generally parallel to the longitudinal axis of the body 54 and affording, as in the container of FIGS. and 6, enhanced stability of seating upon a support surface. As can be seen in FIG. 7, when the container is situated in its normally supported position, the spout 56 extends in a generally upward direction, and is thereby maintained in an attitude of minimized potential contact upon unsanitary surfaces. As can also be seen in FIG. 7, an abutment seal is formed across the spout 56 at an intermediate location 62 thereof, and the container is filled with a two-phase mixture ofa relatively dense liquid 64 (such as vinegar) and a relatively light liquid 66 (such oil).  
  In FIG. 8, the container is disposed in a first inverted dispensing position (shown in full line) permitting the lighter phase liquid 66 to be discharged through the spout 56 under the influence of applied pressure. Tilting the spout 56 to a more downwardly directed attitude (as shown in phantom line) causes the denser liquid 64 to be presented to the orifice of the spout 56, and thereby to be discharged when force is applied to the container. As will be appreciated, the configuration of the container illustrated is well suited for hand-held operation, and is very comfortable in such use; a selfclosing container is especially desirable in this application.  
  It will be evident from the foregoing that a common feature of the containers of the present invention is the spout which curves outwardly and non-symmetrically from the body; it is that feature which is defined by reference herein to a spout which extends generally arcuately from the body, and to scam elements which are correspondingly curved&#34;. As employed herein,  
 the term eccentric is intended to have a broad connotation. Thus, truely arcuate curved elements of the spout seam must not be concentric, since undesirable parallelism will thereby exist in the significant portion of the spout. On the other hand, curved seam elements of changing radius may have a common point of reference, and nevertheless be regarded to eccentric hereunder. In all instances, the centers of both arcs will be disposed on one side of the spout and, while the are of greater radius will normally be the more external of the two, that is not necessarily the case.  
  The relationships of the seam elements described affords, as a primary advantage, lower release pressures and smoother operation, as compared to containers in which the spout is defined by seams which are otherwise related. For example, a spout defined by arcuate seam elements having the same length radii but being oppositely, rather than correspondingly, curved (i.e., in which the arc centers are disposed to opposite sides of the spout), may well function to provide a pressure releasable container; however, the level of pressure necessary to effect such release, and the measure of control thereover, will tend to be appreciably greater and lesser, respectively. While it is possible to achieve comparably gradual release at low pressures in a container having a spout with oppositely-directed curved seam elements, the radius lengths, and consequently the length of the spout, may be unduly extended in achieving such a result.  
  As pointed out, the containers of the invention function to produce a seal at an intermediate location of the spout, in response to the internal force of the contained fluid. Thus, the fluid bears upon the wall sections of the inner end of the spout, distending them and causing their convergence into sealing abutment with one another. Normally, the seal will form in the absence of applied external pressure; in any event, it should form when the container, filled to at least percent of its capacity, is inverted to bring the maximum hydraulic head to bear upon the spout. Because the location at which the abutment of the wall sections occurs will vary among different containers (and even among those having the same nominal construction), well as within a single container, depending upon the level of effective pressure brought to bear, it is not possible to accurately define the point at which the seal should be considered to exist; accordingly it is characterized herein as being at an intermediate portion of the spout. While, as noted above, the correspondingly-curved, divergently-extending seam elements need not commence at the intermediate spout location, optimal operation will generally be achieved if those elements do extend at least to the point of abutment; indeed, in preferred embodiments they extend beyond the abutment and, most desirably, they go all the way to the discharge opening of the spout.  
  Due to the curvature of the wall sections at the point of abutment, measurement of the wall-to-wall angle therebetween is, of necessity, rather imprecise. Thus, although the angle of convergence is typically quite uniform in the area approaching the abutment, the angle between the walls directly adjacent thereto tends to be appreciably greater. However, in terms of desirable operation of the seal, such directly-adjacent portions of the walls may be ignored as a practical matter, and the angular relationships referred to herein are those which exist at locations slightly inwardly of any such areas of relatively abrupt convergence. Thus, the angles determined at a location approximately one fourth to one-half inch inwardly of the abutment will have the values set forth herein. The angles involved are those which exist between the center lines&#34; of the wall sections, which phrase refers to the locus of midpoints between the seams defining the corresponding passageway. In addition to the advantages previously mentioned, maintaining the wall-to-wall angle below an upper limit 60, and preferably in the range of about to 45, has the added advantage of avoiding permanent distortion in the films, which would tend to permit leakage from the container. Thus, by restricting the wall-to-wall angle the risk of exceeding the elastic limits of the wall materials is minimized, with the result that no substantial amount of permanent deformation occurs.  
  A primary benefit that results from the novel container construction herein described is the ability to utilize, for the walls, films which are supple and yet exhibit a degree of rigidity. One measure of this characteristic is the extent to which the film will yield under the influence of applied force, and it has been found that films which are sufficiently rigid to experience as little as one percent elongation under the force of a 6 pound weight may satisfactorily be used in the fabrication containers which typify this invention. More particularly, the following structures were found to produce wellfunctioning containers embodying the invention: (1) polypropylene (3 mils)/aluminum foil one-third mil)- Jpolyethylene terephthalate resin (one-half mil); (2)  
 uniaxiallyoriented nylon (three-fourths mil)/low density polyethylene (2 mils); (3) medium density polyethylene (2 mils)/polyethylene terephthalate resin (onehalf mil); and (4) SURLYN (ethylenc/carboxylic acid ionomer) (2 mils)/aluminum foil (one-third mil)/SUR- LYN (2 mils). Strips of the foregoing films (12 inches X 1 inch) subjected to the force of a 6 pound weight, applied longitudinally and during a brief time period, showed the following percentages of elongation, respectively: (l) 0.98%; (2) 7.8%; (3) 5.5% and (4) 5.9%. Exemplary other films which are suitable for use herein include the following laminates: (5) polyethylene terephthalate resin (one-half mil )/medium density polyethylene (2 mils); (6) polyethylene terephthalate resin (one-half mil)/adhesive (one-tenth mil)/polyethy- [ene-ethylene vinyl acetate copolymer blend (2 mils); (7) polyethylene terephthalate resin (one-half mil)/low density polyethylene (one-half mil)/aluminum foil (one-third mil)/ethylene acrylic acid copolymer (twothirds mil)lpolycthylene-ethylene vinyl acetate copolymer blend 1 /2 mils); (8) polypropylene (three-fourths mil)/low density polyethylene (one-half mil)/aluminum foil (one-three mil)/polyvinyl chloride (onetenth mil)- /medium density polyethylene (2 mils); and (9) paper (one-fourth mil)/low density polyethylene (one-half mil)/aluminum foil (one-third mil)/low density polyethylene (2 mils). it should be appreciated that, as evidenced by the foregoing, the term films&#34;, as used herein, is given a rather broad definition, both in terms of the materials used and also the gauges thereof. Generally, the film thickness will be in the range of about /2 to mils, and preferably it will be about 2 to 7 mils.  
  The containers of the present invention may be fabricated in any suitable manner, and appropriate techniques for doing so are disclosed in the identified copending application. In any event, it is important that the films be so disposed that, in the unfilled condition, they lie in face-to-face contact with one another. Notwithstanding this, a slight amount of separation, such as may result ajacent the seams due to the effects of heat sealing, may be tolerated, but such separation should be minimized to prevent channels through which leakage might occur. As employed herein, the term liquid is used in a broad sense to include not only true liquids, but also other fluid materials, such as mixtures 10 containing solid particles and/or gases. The intended contents of the container will, to some extent, dictate the composition of the film used in the fabrication, as will be apparent to those skilled in the art.  
 Thus, it can be seen that the present invention provides a novel container for fluids having means for forming a seal, which seal may be releasable by internal pressure of relatively low magnitude. and which functions smoothly and in a well-controlled manner. The container may be fabricated from films exhibiting a degree of rigidity, and it may have a relatively short spout in which the seal forms at a location spaced .1 considerable distance inwardly from its discharge end, thereby affording enhanced protection. against contamination and evaporation of the contents. The spout may be disposed for optimum convenience of use and sanitation. and the container may be constructed to afford comfortable use, a pleasing appearance, and stability of support in an upright disposition.  
 Having thus described the invention, I claim:  
  1. A container for fluids having a body and a spout extending generally arcuately from said body, said spout having congruent opposed walls of supple, imperforatc material and being defined by laterally-spaced seams uniting said walls and disposing them in substantially face-to-face contact when said spout is empty, said seams including first, correspondingly-curved seam elements defining substantially eccentric arcs which extend divergently, at least from about an intermediate portion of the spout, generally toward said body, said container being dimensioned and configured to provide means for forming a releasable seal across said spout at said intermediate portion thereof, first sections of said opposed walls between said first seam elements being free of interconnection and being adapted to readily become distended by contained fluid, such distension causing said first wall sections to converge into scaling abutment with one another, with the center lines of said first wall sections adjacent said abutment forming an angle of less than about 60, and with second sections of said opposed walls coextending from said abutment with the center lines thereof in general alignment with the center line of one of said first wall sections and at an angle to the center line of the other of said first wall sections, whereby said spout can be sealed without auxiliary means.  
  2. The container of claim 1 wlherein said spout is configured with a continuous taper in the direction of discharge of contained fluid therefrom.  
  3. The container of claim 2 wherein said seams defining said spout are of smoothly curvilinear configuratron.  
  4. The container of claim 3 wherein said curvilinear seams are about 0.02 to 0.1 inch in width and are located substantially at the lateral edges of said spout.  
  5. The container of claim 1 wherein the are radii of said first seam elements are from about /1. to 12 inches in length.  
  6. The container of claim 5 wherein said are radii are from about 1 to 6 inches in length.  
  7. The container of claim 5 wherein said first seam elements extend from said intermediate portion of said spout.  
  8. The container of claim 1 wherein said first wall sections adjacent said abutment form an angle of from about 15 to 45.  
  9. The container of claim 1 wherein said dimensions and configurations thereof render said seal releasable in response to internal pressure of a higher magnitude than the seal-forming distension pressure of such contained fluid.  
  10. The container of claim 9 wherein said dimensions and configuration thereof cause the location of said abutment to proceed outwardly along said spout in response to progressively increased levels of internal pressure above said distension pressure, to ultimately overcome the seal and to thereby permit fluid contents to discharge from said container.  
 11. The container of claim 10 wherein said abutment location moves over a distance which is at least about half of the total length of said spout.  
  12. The container of claim 9 wherein said dimensions and configuration thereof render said seal self-restoring upon diminution of the internal pressure below said higher magnitude thereof.  
  13. The container of claim 1 wherein said container additionally includes fluid contents therewithin and is completely closed, to thereby provide an integral package.  
  l4. The container of claim 13 wherein said spout has a fused closure portion adjacent its outer end, said closure portion being removable to provide a discharge opening for said spout.  
  15. A container having congruant opposed walls of supple. imperforate material having at least one bond uniting said walls and disposing them in face-to-face contact when said container is empty, said opposed congruant walls providing integral walls of a body for containing fluids and of a spout extending generaliy arcuately from said body, said spout being defined by laterally-spaced seams provided by said bond and including first, correspondingly curved seam elements defining substantially eccentric arcs which extend divergently. at least from about an intermediate portion of said spout, generally towards said body, said container being dimensioned and configured to provide means for forming a releasable seal across said spout at said intermediate portion thereof, first sections of said opposed walls between said first seam elements being free of interconnection and being adapted to readily become distended by contained fluid, such distension causing said first wall sections to converge into sealing abutment with one another, with the center lines of said first wall sections adjacent said abutment forming an angle of less than about 60, and with second sections of said opposed walls coextending from said abutment, with the center lines thereof in general alignment with the center line with one of said first wall sections and at an angle to the center line of the other of said first wall sections, whereby said spout can be sealed without auxiliary sealing means.  
  16. The container of claim 15 wherein said walls are comprised of synthetic resinous thermoplastic material.  
  17. The container of claim 16 wherein said bond is a relatively narrow heat seal located substantially at the edge of said container.  
  18. The container of claim 16 wherein each of said walls comprises a laminate containing at least two distinct materials.  
  19. The container of claim 18 wherein at least one of said materials is selected from the group consisting of metal foils, paper and molecularly oriented plastics.  
  20. The container of claim 15 wherein said body has, in a flat disposition, a generally rectilinear edge extending thereacross at a location remote from said spout, said edge being of a length that is less than the width of said walls of said body at a location spaced a short distance therefrom, intermediate portions of said body walls lying between said edge and said location being narrower than said body walls at said location so that, when said container is placed in an upright position with said edge disposed thereunder on a support surface, the outer margins of said intermediate wall portions tend to fold inwardly of said body, in turn permiting distension of said wall portions therebetween under the weight of fluid contents, thereby providing an extended base area for supporting said container in a relatively stable, upright position.  
  21. The container of claim 20 wherein said intermediate wall portions are defined by generally slanting seam portions extending outwardly from the ends of said rectilinear edge.  
  22. The container of claim 21 wherein the upper sections of said seam portions are convexly curved to avoid relatively sharp corners thereat, thereby enhancing the level of stability of support for said container.  
  23. The container of claim 15 wherein said body is of elongate configuration, and wherein said spout is located adjacent one end thereof.  
  24. The container of claim 23 wherein said body is configured to provide means for supporting said container on an underlying surface with the longitudinal axis of said body extending generally horizontally, said spout being configured to extend in a generally upward direction from said body with said container so supported.  
  25. The container of claim 24 additionally including a plural-phase liquid mixture contained therewithin.  
  26. The container of claim 15 wherein said spout has a tapered channel leading to the outlet orifice thereof, said channel being defined by a generally rectilinear seam element slanting from adjacent one edge of said spout toward the other edge thereof.  
  27. A container for fluids having a body and a spout extending outwardly from said body, said spout having congruent opposed walls of supple, imperforate material and being defined by laterally-spaced seams uniting said walls and disposing them in substantially face-toface contact when said spout is empty, said seams including first seam elements extending divergently, at least from an intermediate portion of the spout, generally toward said body, said container being dimensioned and configured to provide means for forming a releasable seal across said spout at said intermediate portion thereof, first sections of said opposed walls between said first seam elements being free of intercon nection and being adapted to readily become distended by contained fluid, such distension causing said first wall sections to converge into sealing abutment with one another, with the centerlines of said first wall sections adjacent said abutment forming an angle of less than about and with opposing second sections of said opposed walls coextending from said abutment with the center lines thereof in general alignment with the center line of one of said first wall sections and at an angle to the center line of the other of said first wall sections, whereby said spout can be sealed without auxiliary sealing means, said spout having a tapered channel leading to the outlet end thereof, said channel be ng defined by a generally rectilinear seam element slanting from adjacent one edge of said spout toward the other edge thereof.