Abstract:
A disposable container for a pressurized fluid, comprises a fluid resistant bag, and a reinforcing network applied about the bag. A rigid drum structure preferably surrounds the bag. The container is useful for storing fluids to a pressure of around 6 bar and provides a disposable container for transporting beer.

Description:
FIELD AND BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a container for pressurized liquids.  
           [0002]    Draught lager type beer is a pressurized liquid and is generally stored at pressures that typically reach five or six bar. Thus, containers for transporting and storing beer are required to be able to withstand up to six bar of pressure. Six bar requires substantial mechanical containment strength and thus barrels for containing such draught lager type beers are generally made of metal and are of relatively substantial construction. The containers are expensive and thus reused many times, and this requires drinks manufacturers to have to arrange for the containers to be collected after use and washed out for reuse.  
           [0003]    Other requirements generally recognized for beer containers include an ability to withstand a fall of a meter and a half onto a metal surface at an ambient temperature of 4° C., the ability to maintain a pressure seal following a temperature drop from 38° c. to 0° c. over a time period of one hour, maximal leakage of CO 2  of 5% over 180 days of storage at an ambient temperature of 20° c., maximal leakage of N 2  of 5% over 180 days of storage at an ambient temperature of 20° c., a change of 1.5 ppm O 2  over 180 days of storage at an ambient temperature of 20° c., maximal infiltration of 3 ppm of aluminum over 180 days of storage at an ambient temperature of 20° c., ability to withstand up to 200 kg when stacked, ability to withstand up to 1.5 bar of external pressure, and external dimensions of 500 mm height and 180 mm diameter.  
           [0004]    It is not currently possible to make a container that is both able to withstand six bar of pressure and to meet the various other requirements and also to be sufficiently cheap to manufacture as to be disposable. The current reusable containers have to be collected after use at considerable expense and cleaned for reuse, again at considerable expense.  
           [0005]    There is thus a need for, and it would be highly advantageous to have, a container that does not need to be collected and cleaned and is at the same time able to meet the above-mentioned requirements for beer containment.  
         SUMMARY OF THE INVENTION  
         [0006]    According to one aspect of the present invention there is provided a container for a pressurized fluid, comprising a fluid resistant bag, and a reinforcing network applied about said bag.  
           [0007]    Preferably, the bag is a flexible bag.  
           [0008]    The container may further comprise a rigid cylindrical body located externally of said bag and of said reinforcing network.  
           [0009]    The container may further comprise a nozzle for pressure sealing said bag.  
           [0010]    The, said fluid resistant bag, said reinforcing network and said rigid cylindrical body are preferably configured together to withstand up to 6 bar of fluid pressure from within said bag.  
           [0011]    Preferably, there is a gap between said bag and said rigid cylindrical body, and the container comprises a nozzle for pressure sealing said bag and an inserter for inserting fluid into said gap to pump fluid out of said bag.  
           [0012]    Preferably, said pressurized fluid is a carbonated drink.  
           [0013]    The pressurized fluid may be beer.  
           [0014]    The container may use plastics material.  
           [0015]    Preferably, each of said bag, said network body and said rigid body separately comprise a plastics material.  
           [0016]    Preferably, each of said rigid body and said network body comprise plastics material and said bag comprises a metallic foil.  
           [0017]    Preferably, said bag comprises at least two bag layers.  
           [0018]    Preferably, said network body is located between said at least two bag layers.  
           [0019]    Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples provided herein are illustrative only and not intended to be limiting.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.  
         [0021]    In the drawings:  
         [0022]    [0022]FIG. 1 is a simplified schematic illustration showing a perspective view of a flexible fluid-resistant bag, for use in a container for a pressurized fluid according to a preferred embodiment of the present invention;  
         [0023]    [0023]FIG. 2 is a view from above of the bag of FIG. 1;  
         [0024]    [0024]FIG. 3 is a front elevation of the bag of FIG. 1;  
         [0025]    [0025]FIG. 4 is a schematic illustration showing a second embodiment of a bag according to the present invention;  
         [0026]    [0026]FIGS. 5 and 6 are a plan view and a front elevation respectively of the embodiment of FIG. 4;  
         [0027]    [0027]FIG. 7 is a schematic diagram showing a first embodiment of a network reinforcement body for the bag of FIGS.  1 - 6 ;  
         [0028]    [0028]FIG. 8 is a front-elevation of the network body of FIG. 7;  
         [0029]    [0029]FIG. 9 is a side elevation of the network body of FIG. 7;  
         [0030]    [0030]FIG. 10 is a view from above of a network sheet for forming therefrom a network body of the kind shown in FIGS.  7 - 9 ;  
         [0031]    [0031]FIG. 11 is a simplified diagram showing a perspective view of a rigid outer drum for use in the pressurized container of a preferred embodiment of the present invention;  
         [0032]    [0032]FIG. 12 is a plan view of the drum of FIG. 11;  
         [0033]    [0033]FIG. 13 is a side elevation of the drum of FIG. 11;  
         [0034]    [0034]FIG. 14 is a cutaway section of the drum of FIG. 11;  
         [0035]    [0035]FIG. 15 is a simplified diagram showing a perspective view of the network body in situ within the bag of FIG. 1, to form a single reinforced bag body;  
         [0036]    [0036]FIG. 16 is a cutaway view of the body of FIG. 15;  
         [0037]    [0037]FIG. 17 is a front elevation of the body of FIG. 15;  
         [0038]    [0038]FIG. 18 is a side elevation of the body of FIG. 15;  
         [0039]    [0039]FIG. 19 is a simplified diagram showing an upper sheet of the combined bag and network body of FIG. 15;  
         [0040]    [0040]FIG. 20 is a simplified diagram showing a detail of a comer region of the body of FIG. 15;  
         [0041]    [0041]FIG. 21 is a simplified diagram showing a further detail of the body of FIG. 15;  
         [0042]    [0042]FIG. 22 is a detail of the cutaway view of FIG. 16;  
         [0043]    [0043]FIG. 23 is a simplified diagram showing network elements over a single inner layer of the bag of FIG. 1;  
         [0044]    [0044]FIG. 24 is a simplified diagram showing the layers of the combined bag and network body of FIG. 15; and  
         [0045]    [0045]FIG. 25 is a simplified cross-sectional diagram showing a pressurized fluid container according to a preferred embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0046]    The present embodiments disclose a container that is able to withstand the levels of pressure found in carbonated beverages packaged for storage and transport, in particular draught lager type beers and which container is sufficiently cheap to manufacture as to be disposable. The container comprises an inner waterproof bag, which may be flexible and is preferably made of plastic. The inner waterproof bag is reinforced by a latticework or network reinforcement body, which may also be flexible, and both are surrounded by a preferably rigid outer drum or like cylindrical body.  
         [0047]    The principles and operation of a pressurized container according to the present invention may be better understood with reference to the drawings and accompanying descriptions.  
         [0048]    Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.  
         [0049]    Referring now to the drawings, FIG. 1 is a simplified schematic illustration showing a perspective view of a flexible fluid-resistant bag, for use in a container for a pressurized fluid according to a preferred embodiment of the present invention. Bag  10  comprises an outer skin  12  of fluid resistant material, arranged into front  14  and rear  16  panels of flexible material and an upper section  18  which is designed to retain its shape so as to hold the bag open. The outer skin is preferably a multi-layer skin. A pressure resistant nozzle  20  is preferably located in the upper section  18  for insertion and withdrawal of fluid. A seam  22  holds together the panels  22  of the bag.  
         [0050]    Suitable materials for the fluid resistant bag include the following:  
         [0051]    a. LLDPE, metallocene-PE, and various PE copolymers: EVA, EBA, EMA, EAA, etc., provided either in pure form or as blends.  
         [0052]    b. Ionomer (ethylene acid copolymers, in which the acid groups are partially neutralized with either zinc or sodium ions).  
         [0053]    c. Thermoplastic Elastomer (TPE), as minor components in blends, or as a thin layer in the multilayer film.  
         [0054]    d. Polypropylene, homopolymer, block or random copolymers, formed into non-oriented (CPP) or bi-axially oriented films.  
         [0055]    e. Tyvek: very fine high-density polyethylene fibers (film and fabric together to form a single integrated material, the integration giving superior puncture-, tear- and abrasion-resistance).  
         [0056]    f. Polyamide: PA-6, PA-6 blends, in the form of various copolyamides, amorphous polyamide, or aromatic polyamide. These may be manufactured as non-oriented or bi-axially oriented film.  
         [0057]    g. Polyethylene Terephthalate (PET), and biaxially oriented film formed therefrom.  
         [0058]    h. Ethylene-vinyl-alcohol (EVOH) copolymer, with different ethylene content: 29-44 mol %, and non-oriented or bi-axially oriented films formed therefrom.  
         [0059]    i. monoaxially oriented coextruded film, particularly nylon-6/EVOH/nylon-6.  
         [0060]    j. Oxygen scavenging polyamide/nanocomposite, formulated for films where a very high oxygen barrier is required.  
         [0061]    k. Aluminum-foil. The bag of FIG. 1 is fused together on three sides.  
         [0062]    [0062]FIG. 2 is a view from above of the bag of FIG. 1. Parts that are the same as those in previous figures are given the same reference numerals and are not referred to again. FIG. 3 shows a front elevation of the bag of FIG. 1.  
         [0063]    [0063]FIG. 4 is a schematic illustration showing a second embodiment of a bag according to the present invention. The bag of FIG. 4 differs from that of FIG. 1 in that it does not include a semi-rigid top section  18 , and is fused on four sides. FIGS. 5 and 6 are a plan view and a front elevation respectively of the embodiment of FIG. 4.  
         [0064]    Any one of a number of preferred processes may be used for manufacture of the bag. These include a multiplayer cast film process, a double bubble process for forming bi-axially oriented film, a tenter-frame process for bi-axially oriented film, and use of a roll station device for producing mono-axially oriented film. Alternative processing methods may be used such as lamination, and lamination may involve solvents, such as glue, or may be solventless, for example using thermo-lamination and the like.  
         [0065]    Reference is now made to FIG. 7, which is a schematic diagram showing a first embodiment of a network reinforcement body for the bag described above. The body  40  is made of a net of yarns or strings or fibers as preferred. Suitable materials for the production of yarns may include  
         [0066]    High Density PE, LLDPE, metallocene-PE, and various PE copolymers, including EVA, EBA, EMA, EAA, etc., either pure or in blends.  
         [0067]    Thermoplastic Elastomer (TPE), as minor components in blends.  
         [0068]    Polypropylene, homopolymer, block or random copolymers.  
         [0069]    Polyamide: PA-6.6, PA-6, PA blends, various Copolyamides and aromatic Polyamides.  
         [0070]    Aramid resin (Kevlar).  
         [0071]    Polyethylene Terephthalate (PET).  
         [0072]    Poly-vinylidene Fluoride (PVF).  
         [0073]    Poly-vinylidene chloride and copolyamides based on vinylidene chloride units.  
         [0074]    Various types of yarns may be used, such as tapes, monofilaments, multifilament, and combinations thereof.  
         [0075]    The network body  40  may be manufactured by knitting, weaving, directly from a non-woven textile and by any combination thereof.  
         [0076]    Preferably, and depending on the manufacturing method used, two sheets of network are produced and then connected together along a seam region  42 , as will be illustrated in greater detail in FIG. 10. The connection along the seam region  42  may be carried out using any method appropriate to the materials being used in the network body.  
         [0077]    The network body may be reinforced with stronger materials at critical points such as the seam region  42 .  
         [0078]    In a particularly preferred embodiment, the network body is not superimposed upon the bag but rather is embedded within the bag. Embedding may be carried out by inserting the network body during the multi-layer manufacture of the bag.  
         [0079]    [0079]FIG. 8 is a front-elevation of the network body of FIG. 7.  
         [0080]    [0080]FIG. 9 is a side elevation of the network body of FIG. 7.  
         [0081]    [0081]FIG. 10 is a view from above of a network sheet  44  for forming therefrom a network body of the kind shown in FIGS.  7 - 9 . An upper sheet and a lower sheet are joined together around their edges, in particular about seam region  42 .  
         [0082]    Reference is now made to FIG. 11, which is a simplified diagram showing a perspective view of a rigid outer drum  50  for use in the pressurized container of a preferred embodiment of the present invention. The rigid outer drum  50  preferably comprises polypropylene or polypropylene reinforced with fiberglass. It may be manufactured by injection molding or blow molding, and contains a surrounding section  52  and upper or cover and lower or base sections  54  and  56  respectively.  
         [0083]    [0083]FIG. 12 is plan view of the drum of FIG. 11, and FIG. 13 is a side elevation thereof. FIG. 14 is a cutaway section of the drum  50 .  
         [0084]    Reference is now made to FIG. 15, which is a simplified diagram showing a perspective view of the network body in-situ within the bag  10 , therewith to provide a flexible but reinforced body  60  for containing pressurized fluid. FIG. 16 is a cutaway view of the body  60  showing netting elements  62  of the network body  40  embedded within the bag  10 . FIG. 17 is a front elevation of body  60 , and FIG. 18 is a side elevation of body  60 . FIG. 19 shows an upper sheet of the combined bag and network body  60 , two of which may be fused together to form the body  60 . FIG. 20 shows a detail of a corner region of body  60 , and illustrates netting elements  62  emerging from the seam region  42 .  
         [0085]    Reference is now made to FIG. 21, which is a simplified diagram showing a further detail of the body  60 . FIG. 21 illustrates the emergence of nozzle  20  from the combined network body and bag. Nozzle  20  is preferably manufactured as a continuation of seam region  42 , and network elements  62  which would have emerged from the seam region  42  in the region of the nozzle, in fact emerge from the nozzle itself.  
         [0086]    Reference is made to FIG. 22, which is a detail of the cutaway view of FIG. 16. In FIG. 22, network elements  62  are shown embedded between inner layer  70  and outer layer  72  of bag  10 . FIG. 23 is a simplified diagram showing network elements  62  over a single inner layer  70  of the bag  10 .  
         [0087]    Reference is now made to FIG. 24, which is a simplified diagram showing the layers of combined bag and network body  60 . Seam region  42  develops into network layer  80 , which is surrounded by inner bag layer  70  and outer bag layer  72 .  
         [0088]    Reference is now made to FIG. 25, which is a simplified cross-sectional diagram showing a pressurized fluid container  90  according to a preferred embodiment of the present invention. Parts that are the same as those in previous figures are given the same reference numerals and are not referred to again except as necessary for an understanding of the present embodiment. Rigid drum  50  forms an outer layer, within which lies the combined bag and network body  60 . Space  92 , which is included between the outer layer and the body  60 , may be used to inject fluid in order to pressurize body  60  from the outside. Injection of fluid into space  92  thus provides a means of pumping fluid out of the body  60  when required.  
         [0089]    In use, fluid is pumped into body  60  to the required pressured, and nozzle  20  is sealed. The container  90  is transported as required. The rigid drum  50  preferably provides the container with the necessary stacking strength. Subsequently, upon arrival at the destination, the container is unloaded and placed in position, and the container is tapped. The nozzle  20  is released, preferably by insertion of a tube connector  96  having an end  98  appropriately shaped for the nozzle, and the pressurized liquid is pumped out as required. Pumping may be achieved by forcing fluid into space  92  via an auxiliary nozzle. After pumping, the entire container may then be disposed of. Alternatively the body  60  may be disposed of and the rigid cylinder retained for reuse. Because the rigid cylinder never comes into contact with the fluid being stored it need not be washed prior to reuse, thus removing one of the major costs of reuse.  
         [0090]    It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.  
         [0091]    Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.