Abstract:
The present description includes containers having an improved puncture design that can be punctured without substantial deformation of the container. Such containers are particularly suitable for use in preparing beverages using automatic machines, particularly those used for preparation of single serve beverages. Also provided are thermoplastic materials having improved punctureability for use in containers, containers for preparation of a beverage, and methods for preparing a beverage using such containers.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority of U.S. Provisional Application No. 62/010,420, filed on Jun. 10, 2014, the disclosure of which is incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    The present application relates generally to the field of containers for preparation of beverages, especially coffee and tea. These containers commonly are referred to as cartridges, cups, capsules, or pods, and are particularly suitable for use in the preparation of a single-serve beverage. 
         [0003]    In recent years, single-serve beverage machines have become popular in homes and businesses as a quick and convenient manner of brewing beverages. These machines generally brew coffee, tea, or other hot beverages through polymer containers that may have integral filters and are filled with coffee grinds, tea leaves, or other soluble products. Upon brewing of these products, the container may be easily discarded so that the machine is available for preparation of subsequent beverages. These containers thereby enable users to customize their beverages and also enjoy freshly brewed beverages quickly and easily. 
         [0004]    Although convenient, existing containers used for the preparation of beverages have numerous drawbacks. For example, many commercially available containers are prepared using materials that are less easily recycled. This is due at least in part due to the structural characteristics that are required for these containers. For example, the containers must be sufficiently strong to permit puncturing of the base of the container without substantial deformation of the container. 
         [0005]    Containers and materials having improved punctureability recently have been developed and are described in U.S. patent application Ser. Nos. 14/034,307 and 14/034,298, the disclosures of which are incorporated herein by reference. Although these containers have proven to significantly improve punctureability as compared to prior art designs, the modified designs in these applications have experienced some issues during processing using certain types of equipment (e.g., equipment which is designed to pick up and place the container from its base). Thus, there is a need for further design modifications that do not suffer from the difficulties experienced during processing of the containers with existing equipment while also providing the needed improved punctureability. 
       SUMMARY 
       [0006]    Embodiments of the present description address the above-described needs by providing a container including a substantially circular base; a frustoconically shaped wall extending therefrom and defining a cavity therein; and a stacking shoulder which intersects and extends laterally from the wall. The base includes an outer support structure with an inwardly sloping continuous puncture region therein, the continuous puncture region displaying a puncture load of less than 3 kg, measured using a sharp needle, or of less than 5 kg, measured using a dull needle. The outer support structure desirably is positioned an effective distance from the edge of the base to increase the punctureability of the base in the continuous puncture region. 
         [0007]    Also provided in embodiments herein are containers for preparation of a beverage using the above-described container and methods for preparing a beverage using such containers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a forward lower perspective view of a container according to a first embodiment. 
           [0009]      FIG. 2  is a side view of the container illustrated in  FIG. 1 . 
           [0010]      FIG. 3  is a cross-sectional view of the container illustrated in  FIG. 1 . 
           [0011]      FIG. 4  is a top view of the container illustrated in  FIG. 1 . 
           [0012]      FIG. 5  is a schematic of a design that may be applied to the inner surface of a cup base according to an embodiment. 
           [0013]      FIG. 6  is a schematic of a design that may be applied to the inner surface of a cup base according to an embodiment. 
           [0014]      FIG. 7  is a cross-sectional side view of an embodiment of the container illustrated in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Embodiments of the present application address the above-described needs by providing a container for preparation of a beverage. As used herein, the term “container” is synonymous with cartridges, cups, capsules, pods, and the like, that may be used in the preparation of a beverage. 
         [0016]    The container generally comprises a cup-shaped container with a base and a frustoconically shaped sidewall defining an opening. In an embodiment, the base includes an outer support structure. A continuous puncture region disposed within the outer support structure is configured to permit the container base to be punctured in the continuous puncture region during the preparation of the beverage. The outer support structure desirably is positioned an effective distance from the edge of the base to increase the punctureability of the base in the continuous puncture region. 
         [0017]    An exemplary embodiment of a container  10  is further illustrated in  FIGS. 1-4 . The container  10  comprises the base  12  and the frustoconically shaped sidewall  14  defining an opening  16 . The sidewall  14  may include a radially outwardly protruding lip  18  surrounding the opening  16 . In one aspect, the radially outwardly protruding lip  18  further comprises a stacking shoulder  19  that intersects and extends laterally from the sidewall  14 . The base  12  includes an outer support structure  20  surrounding a continuous puncture region  22 , the outer support structure  20  being positioned an effective distance away from the edge  24  of the base  12 . The continuous puncture region disposed inside the outer support structure  20  is configured to permit the puncture of the container base at any position in the continuous puncture region  22  during preparation of the beverage without regard for the position of the puncture region. 
         [0018]    Not wishing to be bound by any theory, the position of the outer support structure an effective distance from the edge of the base changes the mode of failure of the container and increases the rigidity of the base, thereby improving the punctureability of the base in the continuous puncture region. In exemplary embodiments, an effective distance from the edge of the base is from about 1 to about 10 mm, from about 1 to about 5 mm, from about 1.5 to about 2.5 mm, or from about 2.0 to about 2.5 mm. For example, in an embodiment the outer support structure may be positioned about 2.3 mm from the edge of the base. 
         [0019]    The continuous puncture region  22  may be inwardly sloping from horizontal towards the center  26  of the container base  12  (i.e., forming a cone-like shape). In embodiments, the continuous puncture region  22  may extend to the center  26  of the container base  12  (i.e., forming an apex of the cone) or may plateau into a flat region  28  at the center  26  of the container base  12 . As used herein, the term “horizontal” refers to the plane that is perpendicular the longitudinal axis of the container (i.e., the center line extending through the center  26  of the container base to the center of the opening  16  of the container). 
         [0020]    In embodiments, the container further comprises other features to facilitate the punctureability of the base in the continuous puncture region. For example, in an embodiment the container may include a feature in the inner surface of the base of the container. The feature may be effective to weaken the material of the base in the continuous puncture region during its puncture without sacrificing its strength, for example, by providing stress concentrators. Two exemplary embodiments of the feature are illustrated in  FIGS. 5 and 6 , which illustrate the designs that may be imprinted in the inner surface of the base of the container. Other designs also may be used. 
         [0021]    In an embodiment, shown in  FIGS. 4 and 7 , the container may be further characterized by the following mathematical relationship: 
         [0000]        h =( R   l   −R )·tan(90−Φ)
 
         [0000]    wherein h is the height of the container from the base  12  to the stacking shoulder  19 , R l  is the inner radius of the container at the stacking shoulder  19 , R is the radius of the base  12  at the edge  24  of the base, and Φ is the approach angle. 
         [0022]    The container also can further be characterized by the dimensions of the base features ( FIGS. 4 and 7 ): r l  is the radius of the base  12  to the outer support structure  20 , d o  is the effective distance from the edge  24  of the base to the outer support structure  20 , w i  is the width of the flat region  28 , w o  is the width of the continuous puncture region  22  of the base  12 , t l  is the height of the outer support structure  20 , relative the edge  24  of the base, t i  is the height of the center  26  of the base  12 , relative the bottom most portion of the outer support structure  20 , and θ is the taper angle of the base  12 . Accordingly, in certain embodiments the base  12  is further characterized by the following mathematical relationships: 
         [0000]        d   o   =R−r   l &gt;0.01 
         [0000]      R&gt;r l    
         [0000]        w   o   =r   1 −½ w   i  
 
         [0000]    Exemplary ranges of the foregoing variables are summarized in the table below. 
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Dimension 
                 Exemplary Ranges 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 height of the container 
                 H 
                 20.0 mm-100.0 mm 
               
               
                   
                 inner radius of the 
                 R 1   
                 11.0 mm-55.0 mm  
               
               
                   
                 container at the stacking 
               
               
                   
                 shoulder 
               
               
                   
                 radius of the base 
                 R 
                 10.0 mm-50.0 mm  
               
               
                   
                 approach angle of the 
                 Φ 
                 2 degrees-10 degrees 
               
               
                   
                 sidewall 
               
               
                   
                 effective distance from 
                 d o   
                 0.5 mm-10.0 mm 
               
               
                   
                 edge of base to outer 
               
               
                   
                 support structure 
               
               
                   
                 radius of outer support 
                 r 1   
                 4.5 mm-49.5 mm 
               
               
                   
                 structure 
               
               
                   
                 height of outer support 
                 t 1   
                 0.5 mm-5.0 mm  
               
               
                   
                 structure 
               
               
                   
                 width of flat region 
                 w i   
                 0.0 mm-16.0 mm 
               
               
                   
                 height of center of base 
                 t i   
                 0.05 mm-3.0 mm  
               
               
                   
                 taper angle of base 
                 θ 
                 0.5 degrees-10 degrees     
               
               
                   
                   
               
             
          
         
       
     
         [0023]    In an exemplary embodiment, the outer support structure may be disposed about 0.75 to about 1.5 mm from the edge of the base (d o ), the taper angle (θ) may be from about 1 to about 5 degrees relative to horizontal, the flat region may have a width (w i ) from about 5.0 to about 10.0 mm, and the height (t i ) at the center of the base may be from about 0.25 to about 1.0 mm. For example, in an embodiment the outer support structure may be disposed about 1.1 mm from the edge of the base (d o ), the taper angle (θ) may be about 3.2 degrees relative to horizontal, the flat region may have a width (w i ) of about 6.0 mm, and the height (t i ) at the center of the base may be about 0.75 mm. 
         [0024]    In embodiments, a self-supporting filter element (not illustrated) known to those skilled in the art may be disposed in the container and either removably or permanently joined to an interior surface of the container. For example, the filter may be in the shape of an inverted hollow cone having a curved wall tapering evenly from a rim surrounding an opening. The filter element then may be placed in the container so that the apex of the cone is supported on and slightly flattened by the base of the container, thereby enlarging the volume within the cone and providing beneficial support for the filter element. 
         [0025]    In embodiments, the container provided herein further comprises a pierceable cover in a hermetically sealed relationship with the lip of the container, closing the opening to form a cartridge. The cover desirably is formed of an impermeable and imperforate material that may be pierced with an instrument, such as a tubular needle, through which hot water is delivered for preparation of the beverage. For example, in embodiments the cover may comprise a polymer film or a foil heat-sealed to the lip of the container. 
         [0026]    In embodiments, the containers may be prepared by molding and thermoforming the container from a thermoplastic material. Desirably, the thermoplastic material is substantially impermeable and imperforate. Non-limiting examples of suitable thermoplastic materials include polyolefins such as polypropylene and polyethylene, polystyrene, nylon, and other polymers. In particular embodiments, it is particularly desirable that the thermoplastic material be a bio-based resin, readily recyclable, and/or comprise at least a portion of recycled material. For example, in an embodiment the thermoplastic material may comprise a recycled polypropylene base resin. 
         [0027]    In embodiments, the thermoplastic material may be blended with one or more additives to impart the desired mechanical and thermal properties to the container. For example, in embodiments the thermoplastic material may be blended with one or more additives to impart the desired stiffness to the container. In an embodiment, the additive comprises an immiscible polymer that may function as a stress concentrator by hindering the natural ability of the thermoplastic material to deform plastically and promoting controlled crack propagation. Non-limiting examples of immiscible polymers that may be suitable for use with a thermoplastic material comprising polypropylene include acrylics, styrenics, or their blends and copolymers with polyolefins. In an embodiment, the additive comprises a nucleating agent. In an embodiment, a second additive comprises a metallic stearate, non-limiting examples of which include calcium stearate, magnesium stearate, zinc stearate, and combinations thereof. Other non-limiting examples of additives include calcium carbonate, talc, clays, and nano grades of these additives. 
         [0028]    In embodiments, the thermoplastic material comprises a blend of a thermoplastic polymer, a nucleating agent, and a second additive selected from the group consisting of calcium carbonate, talc, clay, and combinations thereof. For example, the nucleating agent may be present in the thermoplastic material in an amount from about 0.5 to about 5% by weight or about 0.5 to about 2.5% by weight, and the second additive may be present in an amount from about 5 to about 25% by weight, about 5 to about 20% by weight, about 7 to about 18% by weight, about 7 to about 12% by weight, or about 9% by weight. For example, in embodiments the thermoplastic material may comprise a polypropylene, a nucleating agent in an amount from about 0.5 to about 2.5% by weight, and a second additive (e.g., talc) in an amount from about 7 to about 12% by weight. Thus, the thermoplastic material may include the thermoplastic polymer in an amount of at least 70% by weight, from about 70 to about 95% by weight, or from about 70 to about 90% by weight. 
         [0029]    In embodiments, the thermoplastic material comprises a monolayer or a multilayer material having at least two layers. Such materials are known to those skilled in the art. For example, the thermoplastic material may include a multilayered film having one or more layers formed of a thermoplastic polymer and a barrier layer configured to improve the barrier properties of the material. The multilayered film also may include one or more tie layers disposed between the barrier layer and adjacent thermoplastic polymer layers and, optionally, one or more layers of regrind. Non-limiting examples of barrier layers commonly used in the art include ethylene vinyl alcohol (EVOH) and nylon, with the amount of the additive in the barrier layer being determined at least in part by the particular application for which the container will be used. 
         [0030]    For example, in an exemplary embodiment the thermoplastic material is a multilayered film having five ( 5 ) layers: thermoplastic polymer/tie layer/barrier layer/tie layer/thermoplastic polymer layer. For example, the thermoplastic polymer may be a polypropylene and the barrier layer may include ethylene vinyl alcohol (EVOH). In another exemplary embodiment, the thermoplastic material is a multilayered film having seven (7) layers: thermoplastic polymer/regrind/tie layer/barrier layer/tie layer/regrind/thermoplastic polymer. Thus, the outermost layer opposite the cavity of the container, the innermost layer adjacent the cavity of the container, or both, may comprise the disclosed thermoplastic polymer layers. In certain embodiments, a multilayer material forming the container includes a barrier layer between the innermost and outermost layers. 
         [0031]    Desirably, the containers provided herein have a puncture load of less than about 6 kg. As used herein, the “puncture load” means the force required to puncture the continuous puncture region in the base of the container using a needle. It should be appreciated that the puncture load depends in part on the type of needle used to measure the puncture load of a container. For example, the puncture load measured using a dull needle generally will be greater than the puncture load measured using a sharp needle. For example, in embodiments the containers may have a puncture load measured using a sharp needle of less than about 3 kg, less than about 2.75 kg, or less than about 2.5 kg. In embodiments, the containers may have a puncture load measured using a sharp needle of about 4.2 to about 3 kg, about 2.99 to about 2.75 kg, or about 2.74 to about 2.5 kg. In embodiments, the containers may have a puncture load measured using a dull needle of less than about 5 kg. For example, the containers may have a puncture load measured using a dull needle of about 4.0 to about 5.0 kg. In one embodiment, the continuous puncture region displays a puncture load of less than 3 kg, measured using a sharp needle, or of less than 5 kg, measured using a dull needle. 
         [0032]    Therefore, the containers described herein advantageously provide improved punctureability due to the base structure, including the outer support structure. The outer support structure may be designed to achieve the desired puncture loads in containers of various materials. In certain embodiments, the container is a polypropylene-based container, meaning the container comprises a monolayer material including polypropylene in an amount of at least 70 percent by weight, or a multilayer material in which at least one layer includes polypropylene in an amount of at least 70 percent by weight. Polypropylene-based containers beneficially may be readily recyclable at commercial recycling facilities. Thus, containers of the present disclosure may be easily recycled and provide the punctureability of similar non-recyclable containers. 
         [0033]    In embodiments, the container may be configured to receive an insert in which the dry beverage ingredients are disposed. For example, the container may be configured to receive an insert comprising a filter cup in which are disposed the ingredients for preparing a beverage. For example, the container may further comprise a filter cup comprising a brew substance, non-limiting examples of which include coffee grinds, ground tea leaves, chocolate, flavored powders, and the like. The brew substance also may include a combination of dry milk, sugar or sugar substitute, or other flavorings to enhance the quality of the resulting beverage. 
         [0034]    The containers embodied herein are particularly suited for use in an automatic machine, such as a coffee brewing machine. Upon placing the container in the machine, a piercing member punctures the cover to introduce pressurized hot water through the hole where it comes into contact with the beverage ingredients disposed in the filter. A second piercing member punctures the base of the container at any position in the continuous puncture region to enable the prepared beverage to flow out of the container and be dispensed into a cup or container for consumption by the consumer. 
         [0035]    The containers provided herein also may be configured for use with other types of food products, non-limiting examples of which include dry ingredients for preparing broths, soups, and sauces that may be eaten be themselves or used to prepare a food dish. 
         [0036]    It should be apparent that the foregoing relates only to certain embodiments of the present application and the resultant patent. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.