Abstract:
A can-shaped package is constructed from a single fibrous material, such as cardboard or paper, that is rolled into a cylinder or tube and is sealed at its end by cutting an open end of the tube into flaps and folding the flaps over one another to form an air tight bottom. By utilizing such a configuration, the can-shaped package can be constructed completely from biodegradable materials in a simple and efficient manner.

Description:
[0001]    This application claims the benefit of and priority to U.S. Provisional Application No. 61/446,953 filed Feb. 25, 2011 and PCT International Patent Application No. PCT/US2012/26546 filed Feb. 24, 2012, both of which are incorporated herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The field of the invention is paper containers. 
       BACKGROUND 
       [0003]    The use of can-type packages in the construction of many types of containers is ubiquitous. Often paper cylinders are mated with metal disks that serve as bottoms and tops of the containers, and sometimes metal rims are employed. Other construction methods employ the use of plastic separately or in combination with metal. Environmental concerns about the use of plastic and metal for can types of packaging are encouraging manufacturers to employ paper-only packaging. 
         [0004]    It is known to construct can-type packages without metal or plastic, by employing using a paper bottom, e.g., U.S. Pat. No. 2,074,899 to Gazette and U.S. Pat. Appl. No. 2007/0110928 to Bried (publ. May 2007). Such packages are often used for containing dry goods such as oatmeal or loose teas. A primary goal of this type of packaging is to provide a reasonably air tight vessel for consumer and industrial goods. 
         [0005]    Gazette, Bried, and all other extrinsic materials discussed herein are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply. 
         [0006]    Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints, and open-ended ranges should be interpreted to include commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary. 
         [0007]    It is further known that paper can-type packages can be coated to render them impermeable to moisture, water, air and solvents. See, e.g., U.S. Pat. No. 7,819,251 to West, and U.S. Pat. Appl. No. 2010/0276476 to West (publ. November 2010). However, such containers include multiple pieces that add to the complexity of the containers. U.S. Pat. No. 6,237,845 to Hashimoto also discloses a similar type of container that is created by folding a single sheet of paper. 
         [0008]    Currently there are four primary methods for constructing an end closure member for a tubular can-type package using paper formed into a tube. The first is formed by creating an inward edge curl at one end of the tube, then inserting a disk that is near or the same size of the interior diameter of the cylinder to fit against the edge curl from the inside. The second is formed by using a piece of paper that is drawn/formed into a cap shape; the cap is then attached with adhesive to either the interior or exterior portion of one end of the cylinder. These first two methods are expensive to produce because they require separate pieces to be formed and attached to the cylinder to form a bottom. 
         [0009]    The third method simply crushes or folds opposite sides of one end of a tube to create a closure. This method creates an inexpensive closure, but the bottom is irregular and the container generally will not stand upright on a flat surface. The container is also not substantially airtight, which can allow the container&#39;s contents to suffer moisture damage and oxidation unless a separate piece of material such as tape is applied over the seam. 
         [0010]    The fourth method is a plastic end cap or plug. Conventional plastic plugs include a bottom wall having a substantially circular peripheral edge and a sidewall that extends from the peripheral edge. The outer diameter of the flange is typically larger than the inner diameter of the paper tube and thus the flange acts as a stop or limiting rim that prohibits the plug from being pressed completely into the paper tube. For example, U.S. Publication No. 2005/0173504 to Erdie discloses a modified plug for a paper tube that engages a folded end of the paper tube. 
         [0011]    It is also known to create a paper container from a single sheet of paper having a predetermined pattern embossed with folding lines. For example, U.S. Pat. No. 5,351,879 to Liu discloses such a container created by the specific folding performed such that the side walls are folded up from to bottom and the seams of the walls are heated sealed. However, such methods cannot be used with fibrous materials that cannot be melted to create such a seal. 
         [0012]    Thus, there is still a need for apparatus and methods to create a can-type package with having an inexpensive bottom formed from a single piece, which is substantially airtight and allows the package to remain upright on a flat surface. 
       SUMMARY OF THE INVENTION 
       [0013]    The inventive subject matter provides apparatus, systems and methods in which a fibrous package is formed from a tubular, fibrous material. The fibrous package is preferably formed from a single piece of fibrous material, and is generally formed by rolling a flat fibrous material into a tube to form a tubular body. While the flat fibrous material could be rolled about itself several times in order to form a thick, fibrous wall, the flat fibrous material is preferably only rolled about itself at most twice so that each end of the tubular body is easier to cut. After a tube is formed, an end of the tube comprising the bottom could be cut to form sets of flaps, which could then be folded inwards towards a center axis of the tube, and is then sealed to be substantially air-tight. Preferably, the flaps are pushed inwards slightly towards the middle of the tube to form a depression to ensure that the package stands upright when placed upon a flat surface. 
         [0014]    As used herein, the phrase “can-type package” means a tubular container that has a closed bottom and an open top. As used herein, the term “open top” means that the package defines an opening that is ordinarily open during typical usage. Similarly, as used herein, the term “closed bottom” means that the wall defines a bottom that is ordinarily closed during typical usage. For example, under these definitions, an ordinary shampoo bottle is a vessel having a wall with an open top because the cap is either removed or disposed in an open position during typical usage. Also under these definitions, a Campbell&#39;s soup can with a pull tab top has a wall with an open top because the top is removed during typical. The bottom of such a soup can, however, is closed because the bottom is not removed during typical usage. Preferably, the open top has a pull-tab that opens the top during use. 
         [0015]    As used herein “fibrous material” means materials characterized by a plurality of discrete fibers. The filaments can be plant or animal derived, synthetic, or some combination of these. In “plant-derived fibrous materials” the filaments are at least predominantly of plant origin, examples of which include wood, papyrus, rice, ficus, mulberry, fibers, cotton, yucca, sisal, bowstring hemp and New Zealand flax. Further, as used herein the term “fibrous wall” means a wall comprising a fibrous material as a significant structural constituent. The fibrous walls contemplated herein preferably have at least 2, 5, 10, 20 or even 30 dry weight percent of fibers. Preferably, the fibrous walls have at least 80 or 90 dry weight percent of fibers. Paper is generally a fibrous material that is usually made by pressing and de-watering moist fibers, typically cellulose pulp derived from wood rags, or grasses. Preferably, the fibrous material is rigid and is largely inflexible, as, for example, layered paper or corrugated cardboard. The structure of a fibrous material that is substantially rigid will tend to bend or break if a great deal of pressure is placed upon it, in contrast to a flexible material that will tend to flex and return back to its original shape after the pressure is released. Preferably, each of the portions of the package comprising the fibrous material are all rigid, for example the walls of the tube and the ends of the tube. 
         [0016]    As used herein, an “adhesive” is any compound in a liquid or semi-liquid state used to adhere or bond items together. Before such an adhesive hardens, such adhesives could be pastes (very thick) or glues (relatively fluid). All commercially suitable adhesives are contemplated, including for example library paste or simply glue made from water, milk powder, vinegar, and baking soda (e.g., a biodegradable adhesive). Other suitable permeation barrier materials include those disclosed in U.S. Pat. no. 7,344,784 to Hodson or U.S. Pat. Appl. no. 2005/0130261 to Wils (publ. June 2005). Such adhesives are preferably made from a substance that provides a permeation barrier that is substantially impermeable to air, oil, and water. 
         [0017]    As used herein, a statement that a permeation barrier is “substantially impermeable” to air, oil and/or water means that a wall treated with that additive has a transfer rate of less than or equal to 50 μl of air, water and/or sunflower oil per cm 2  per six-month period of time at room temperature and normal atmospheric pressure (STP). Preferably, the permeation barrier material is substantially impermeable to each of air, water and oil. It is contemplated that the permeation barrier material could be applied to parts of the package prior to assembly, or even after assembly. In preferred embodiments, the outer wall comprises a rolled paper material upon which the permeation barrier material has been coated. It is also contemplated that the permeation barrier material could be: (1) on an exterior surface or interior surface of the outer wall; (2) impregnated within the material forming the outer wall; or (3) disposed between the layers of the outer wall. 
         [0018]    It is contemplated that permeation barriers could be applied to parts of the vessel prior to assembly, or even after assembly. In some contemplated embodiments, the walls comprise a rolled paper upon which an adhesive has been coated and/or impregnated between each layer of the rolled paper. Thus, for example, the walls could include one, two, four, six, eight, or more layers (wraps) of the paper/permeation barrier combination. 
         [0019]    As used herein, a “biodegradable material” means a material that will break down to at least 90% H 2 O, CO 2 , and biomass within a period of six months from the action of naturally occurring micro-organisms such as bacteria, fungi, algae etc. under favorable conditions. For example, milk, baking soda, meat, plants, wood, cotton, polylactic acid polymers, and paper are all deemed herein to be biodegradable. In preferred embodiments, every element of the jar, which could include an inner wall, a cap, a cover, spacers, the bottoms, adhesives, and permeation barrier materials, are biodegradable. 
         [0020]    Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0021]      FIG. 1  is a perspective view of an embodiment of a single-piece can-type package. 
           [0022]      FIG. 2  is a perspective view of the single-piece can-type package of  FIG. 1  having a closed bottom. 
           [0023]      FIG. 3  is a plan view of the single-piece can-type package of  FIG. 1 , showing the dimpled bottom. 
           [0024]      FIG. 4  is a perspective view of an embodiment of a single-piece can-type package having a pull-tab. 
           [0025]      FIG. 5  is a perspective view of an embodiment of a single-piece can-type package having a cap that receives the open top. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    One should appreciate that the disclosed techniques provide many advantageous technical effects including quick and easy formation of a fibrous, biodegradable packaged formed from a single sheet of fibrous material and biodegradable adhesive. 
         [0027]    The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed. 
         [0028]    The can-type package could be formed by cutting an end of a paper container in at least two places, and preferably three or more, and then folding the separate members, or flaps, inward to form a closure. In this manner, it is possible to form a bottom of a paper container such that the separate flaps could interlock together. The formation of a can-type package by using inwardly-folded flaps is preferable in at least one major respect because the package does not require the creation and assembly of separate parts to form a bottom. However, folding flaps together to form a bottom of a cylindrical can-type package could have significant problems. First, the package may be unstable on a flat surface because the flaps could create an irregular bottom surface. Second, the package&#39;s bottom exterior edge may be irregular, which could detract from the package&#39;s esthetics. Finally, this type of closure is not substantially air tight, which could allow the package&#39;s contents to suffer moisture damage, oxidation and/or potentially leakage. 
         [0029]    In  FIG. 1 , a can-type package  100  is shown having a body  101  that is cut in multiple places about the circumference at a bottom end to form a set of flaps  102 . In some contemplated embodiments, the cuts may be parallel to the length of the package  100  and exceed the radius of the opening of the end. Preferably, the cuts have the same length and orientation, although this is not required. The resulting flaps  102  may be cut into any advantageous shape that is desired such that the flaps  102  interlock, overlap or simply meet at least one other flap  102 . While it is possible that the flaps  102  may fail to meet substantially, preferably there is at least 2-5 mm of overlap between the flaps to ensure that when the flaps are folded over one another, the entire bottom of can-type package  100  is covered. 
         [0030]    A second fold could be introduced into each flap  102 , such that when the flaps  102  are folded inwards along crease  103  to form a bottom, the flaps  102  are disposed away from the bottom circumference of the cylindrical body  101 , towards the center axis of the tube. The surface of bottom  105  is preferably flat. In an alternative embodiment, shown in FIG.  3 , the surface of the closed bottom  330  could alternatively be pushed in towards the center of the tube to form dimpled surface  335 . The ensures that the bottom of can-type package  300  does not tilt in any manner one way or another when placed upon a flat surface. In embodiments where the surface of the bottom  105  is dimpled outwards, the dimple preferably does not exceed the bottom edge  106  of the body  101 . It is also possible to simply dimple the folded flaps  102  inwards without a second fold. Folding or dimpling may be advantageously accomplished by forcing/folding/molding the flaps  102  with mechanical pressure over the interior and exterior surfaces of the flaps  102  and base radius. 
         [0031]    It is contemplated that glue or other adhesive could advantageously join at least some of the flaps  102  together substantially between the flap layers, or more advantageously by covering the entire interior flap surface(s) between the cylinder walls with the adhesive. Where adhesive is used to substantially join together the flaps  102 , the flaps  102  should be joined together in a manner such that the resulting bottom creates a reasonable level of air, water, and/or oil tightness by sealing all seams about the flaps  102 . While contemplated adhesives include liquid or hot melt adhesives that could immobilize the flaps  102  and create a substantial air tight barrier, once the flaps  102  and adhesive have set, preferred adhesives are biodegradable, such that the entire body of can-type package biodegrades when placed within a warm, moist environment for an extended period of time. In the embodiments where the flaps  102  do not substantially meet, the adhesive could serve to fill in the gaps between flaps  102  as the bottom of the package  100  for the portions not composed of the flaps  102 . 
         [0032]    Other adhesive systems may be employed that cause one layer of paper filaments to become temporarily disassociated then re-associated with the next layer. This may be accomplished with water or other liquid(s), friction and subsequent removal of the water, or liquid under pressure with one side, preferably the exterior, having a screen mesh surface which allows the water to escape while retaining the fibrous paper within the screen mesh. In this manner, the interior or exterior surfaces, or both, could be coated with a substance that will enhance air and moisture, or even grease and solvent resistance. In addition, the water or liquid may contain a binder or adhesive to facilitate the joining of the flaps. 
         [0033]    While can-type package  100  is shown as a perfect cylinder, can-type package  100  could be sized and dimensioned to have other tubular forms without departing from the scope of the invention, including those that have irregular, oval, triangular, square and polygonal cross sections (not shown). 
         [0034]      FIG. 2  illustrates an embodiment of a can-type package  200  having a closed bottom  204  formed from a set of flaps  202 . Can-type package  200  has a closed bottom  204  and fibrous walls  201  that help keep any contents within the can-type package  200  from spilling out, and has an open top  205  that allows a user to access the contents within the can-type package  200 . Preferably, the fibrous walls  201  and closed bottom  204  are treated with a permeation barrier material to prevent any liquids or semi-solids from leaking out the walls or the closed bottom. As shown in  FIG. 3 , any liquid  320  housed within the lumen of can-type package  300  preferably sits below the top edge of can-type package  300  by at least 5% of the capacity of the container, and more preferably 7% or 10%. 
         [0035]      FIG. 4  illustrate an embodiment of a can-type package having a pull tab  410  incorporated into a closed flap  202 , while  FIG. 5  illustrates an embodiment of a can-type package  500  having a cap  510  that receives a top of the wall  520 . Other known enclosures allowing a user to access the contents of an open top of a can-type package could be utilized without departing from the scope of the invention. 
         [0036]    As used herein, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms “coupled to” and “coupled with” are used synonymously. 
         [0037]    It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the scope of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.