Patent Publication Number: US-8540116-B2

Title: Non-round moisture-tight re-sealable containers with round sealing surfaces

Description:
This patent application is a divisional application of U.S. Ser. No. 12/398,475 filed Mar. 5, 2009, now U.S. Pat. No. 8,100,288, which application is a continuation of International Application Serial No. PCT/US2007/077702 (International Publication No. WO 2008/030920), having an International filing date of Sep. 6, 2007 and makes reference to, claims priority to and claims benefit from U.S. provisional patent application Ser. No. 60/824,720 filed on Sep. 6, 2006. Each of these applications is incorporated by reference in its entirety. 
    
    
     CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is related to U.S. application Ser. Nos. 11/171,171, filed Jun. 30, 2005; 10/683,311, filed Oct. 10, 2003; and 60/417,533, filed Oct. 10, 2002. Each of these applications is incorporated by reference in its entirety. 
     BACKGROUND 
     Background may be found in U.S. Published Application Nos. US2005/0258174 A1 and 2004/0173612. Each of these applications is incorporated herein by reference. 
     The subject of the invention is a container useful, for example, for the primary bulk packaging of pharmaceutical and medical device products. These pharmaceutical and medical device products degrade in the presence of moisture. Therefore, these products must be packaged in a substantially moisture-free environment throughout the product shelf life. 
     Consumers prefer bulk package designs that are flat and incorporate innovative, user-friendly shapes (i.e., non-round). These package designs can be conveniently placed in a pocket or purse. When a package shape is non-round, the primary sealing surfaces in the package have also been non-round. 
     Packages that have non-round sealing surfaces typically incorporate a gasket in the sealing area. The gasket is a compliant material that when compressed, creates a moisture-tight seal in a package sealing region. The gasket, however, is a second material that increases the cost of the overall package. Incorporating a gasket requires two-shot injection molding or a secondary assembly operation. 
     SUMMARY 
     The inventor has found that if the sealing surface is substantially or exactly round in shape, a gasket material is not required to create a moisture-tight seal. In some embodiments, this simplifies the mold, the assembly process and the overall cost of the bulk package. In some embodiments, the container and seal elements are made of the same material. 
     An aspect of the invention is a hinged container including a base, a lid, and a hinge joining the base and lid. The base has an outer perimeter, and so does the lid. The hinge allows the lid to pivot open or closed relative to the base. 
     The container has an at least substantially circular, outwardly tapered outer seal member that defines a center axis and an at least generally frustoconical surface. The outer seal member is mounted in fixed relation to one of the base and the lid and is exposed at least partially within the corresponding outer perimeter of the base or lid to which it is mounted. 
     The container has an at least substantially circular, inwardly tapered inner seal member that defines a center axis and an at least generally frustoconical surface. The inner seal member is mounted in fixed relation to the other of the base and the lid, relative to the outer seal member, and is disposed at least partially within the corresponding outer perimeter of the part to which it is mounted. 
     The inner and outer seal members are positioned to engage concentrically to wedge the inwardly and outwardly tapered surfaces together and form a seal when the base and the lid are closed. The inner and outer seal members are positioned to disengage concentrically to part the inwardly and outwardly tapered surfaces when the base and the lid are opened. 
     Optionally, the inner and outer seal members are configured to provide a moisture-tight seal. 
     Optionally, the inner and outer seal members are configured to be resealable. 
     Optionally, the base and lid perimeters are substantially congruent. 
     Optionally, the base and lid perimeters are substantially registered when the base and lid are closed. 
     Optionally, the hinged container is generally clam shell shaped. 
     Optionally, the hinge is integral with the base and lid. 
     Optionally, the base has a non-round outer perimeter. 
     Optionally, the lid has a non-round outer perimeter. 
     Optionally, the perimeters are registered when the container is closed. 
     Optionally, any one or more of the lid, the seal member mounted in the lid, the base, the seal member mounted in the base, and the hinge are made of the same material. 
     Optionally, any one or more of, or all of, the lid, the seal member mounted in the lid, the base, the seal member mounted in the base, and the hinge are made of polypropylene. 
     Optionally, the hinged container incorporates a child safety feature that makes the container more difficult to open by a young child. In one embodiment the child safety feature includes at least one push tab that protrudes from a notch in the base when in its closed or home position. When the push tab is depressed, it causes a latch mechanism on the child safety feature to clear a catch feature on the lid, thereby allowing the lid to be opened. A spring element associated with the push tab forces the push tab back to its home position. 
     The present invention enables non-round package shapes by maintaining a round, re-sealable surface between the base and top package components. In some embodiments, a separate gasket material is not required to obtain a moisture-tight seal. In some embodiments, the advantages of a round sealing surface can be provided in a non-round package shape. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING FIGURES 
         FIG. 1  is a side elevation of a container according to the present invention, with the container base and lid shown in section to illustrate the elements of the seal within the container. 
         FIG. 2  is a plan view of the base of the container of  FIG. 1 , with the lid removed. 
         FIG. 3  is a detail view of the seal elements of the container of  FIGS. 1 and 2 . 
         FIG. 4  is an exploded sectional view of the components of the container of  FIGS. 1-3 . 
         FIG. 5  is an exploded view of the components of an alternative embodiment of the container. 
         FIG. 6  is a top plan view of the child safety component of the alternative embodiment of  FIG. 5 . 
         FIG. 7  is a front view of the alternative embodiment of the container as assembled, and cut away to show the latching mechanism of the child safety component. 
         FIG. 8  is a top plan view of the assembled container of  FIG. 5  shown with the side tabs of the child safety feature in their depressed position. 
         FIG. 9  is a cross sectional view taken along line  9 - 9  in  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     A typical bulk package of the present invention includes at least two components: (1) a base or first component and a (2) lid or second component. In an embodiment, the base can function as a lid or vice versa. A flip-top hinge may join the two components, forming what is sometimes referred to as a clamshell package or a hinged container assembly. The bulk package is manufactured using an injection molding process. In one embodiment, the lid and base components are composed of polypropylene (PP) or polyethylene (PE). PP and PE are commodity plastic resins that have good moisture barrier properties. Other suitable materials may include, but are not limited to: polyethylene (PE—high density, low density, LLD, VLLD), polypropylene (PP), polyvinyl chloride (PVC), high impact polystyrene (HIPS), cyclic olefin co-polymer (CoC) polyethylene vinyl acetate (EVA), polystyrene (PS), polycarbonate (PC), polyester terephthalate (PET), polyamide (nylon), acetal copolymer or homopolymer resin, and liquid crystal polymer. In another embodiment, the base component may incorporate a desiccant plastic material and be composed of a PP or PE exterior surface and a desiccant plastic interior surface. 
     The product is typically bulk filled into the base component. In one embodiment, a product guide component is assembled on to the filled base component. After product filling, the lid component is closed onto the base component. In one embodiment, the lid component is closed onto the product guide component that is assembled into the base component. During the closing process (i.e., snapping the components together), a moisture-tight seal is created between the lid and base components. In one embodiment, during the closing process, a moisture-tight seal is created between the lid and the product guide component that is assembled into the base component. 
     The present invention relates to a resealable container, more particularly, an edible film package assembly having an internal sealing mechanism for storing and packaging moisture-sensitive items. 
     The assembly comprises an upper and lower component that may be attached by a hinge. The upper component has a circular inner skirt or seal partially or completely spaced inward from the outer perimeter. The lower component has a skirt or seal surface partially or completely spaced inward from the outer perimeter. In various embodiments the outer perimeters can be round or non-round, and can optionally be substantially congruent and registered. 
     In an embodiment, within the lower component is a rectangular feature, referred to as the product tray. The product tray is formed on three sides by vertical walls or stops and on the fourth side by a sloped wall, referred to as the ramp. The compartment created by these walls may be used to hold a stack of edible films. 
     The circular sealing surface of the lower component includes a wall that engages with the upper lid, providing a tight interference fit between the upper and lower components. In an embodiment, when the package is in the closed position, a moisture-tight seal is created. 
     In one embodiment, the container may be molded in accordance with the mold(s) similar to that disclosed in U.S. Pat. Nos. 4,783,056 and 4,812,116 respectively. In a further embodiment, with such a process and mold, the assembly, including the cap, container, spring, and hinge may be produced in accordance with the operation disclosed in U.S. Pat. Nos. 4,783,056 and 4,812,116 or, in another embodiment, may be produced in accordance with U.S. Pat. No. 5,723,085 or 6,303,064. The disclosure of these patents are incorporated by reference herein. In these references, the container is closed immediately after molding to create a moisture-tight seal. 
     In yet another embodiment, a moisture-tight seal may be achieved in the container using a flexible lip feature. The flexible lip seal is disclosed in publication W/O 2005/074571 A3. 
     In an embodiment a film guide is assembled onto the lower component. The film guide is assembled after product filling. The film guide snaps onto the lower component forming a permanent sealed or unsealed connection with the lower component. The film guide has a circular feature along the top surface which forms a resealable moisture-tight seal with the sealing surface of the upper component. 
     The overall shape of the bulk package of the present invention is very flexible. The shape may be symmetrical or asymmetrical in nature. Suitable shapes include a square, optionally with rounded corners, a triangle, optionally with rounded corners, an ellipse, a rectangle, optionally with rounded corners, a trapezoid, optionally with rounded corners, and numerous others. 
     In another embodiment, the present invention relates to a moisture-tight and resealable container and lid assembly. The term “resealable” means that the lid of the container can be opened or reopened and closed or reclosed many times (e.g. more than 10 times) and still retain its moisture-tight properties. As used herein, the terms “moisture-tight” and “moisture-sensitive” mean the moisture ingress of the container (after 1 day) is less than about 1500 micrograms of water, in another embodiment, about 500 micrograms of water, in a further embodiment, about 300 micrograms of water, determined by the following test method: (a) place one gram plus or minus 0.25 grams of molecular sieve in the container and record the weight; (b) assemble the container; (c) place the closed container in an environmental chamber at conditions of 80% relative humidity and 22.2° C.; (d) after one day, weigh the container containing the molecular sieve; (e) after 14 days, weigh the container containing the molecular sieve; and (f) subtract the 14-day sample weight from the initial weight and divide by the number of days (14) to calculate the moisture ingress of the container in units of micrograms of water per day. 
     In a further embodiment, the container is resealable after repeated lid openings and closings. For example, the seal maintains a low ingression rate after repeated lid openings/closings. In one specific example, the seal maintains its low moisture ingress performance after 50 cycles of lid openings and closings. U.S. Pat. Nos. 4,812,116, 4,807,425, 5,723,085, and 6,769,558 describe examples of embodiments of the sealing arrangement. These references are incorporated herein by reference. In another specific example, a resealable container can be achieved by incorporating a flexible lip seal geometry. The flexible lip seal is disclosed in publication W/O 2005/074571 A3. 
     In another embodiment a desiccant may be incorporated into the package by making one or more of the package components using a desiccant plastic. In one embodiment the base component of the hinged container has a desiccant plastic interior surface and a PP or PE exterior surface. The base component may be made using a 2-shot injection molding process. In yet another embodiment, the film guide may be made of desiccant plastic. 
     When the container is repeatedly opened and closed, the desiccant-entrained plastic re-establishes the low relative humidity environment inside the container assembly in a short period of time (e.g. in as low as less than about 10-minutes). 
     The desiccant-entrained plastic may contain a desiccant such as silica gel or molecular sieve as the desiccant. Depending on the application, such as the application intended by the end user, molecular sieve or silica gel desiccant can be provided in the sleeve. For example, molecular sieve can be used for applications that require a low relative humidity (RH) (e.g. less than &lt;10% RH) maintained over the shelf life. In another example, silica gel can maintain a RH of 10-30% over the product shelf life. 
     Suitable desiccant entrained plastics include, but are not limited to, the desiccant plastics disclosed in U.S. Pat. Nos. 5,911,937, 6,214,255, 6,130,263, 6,080,350, 6,174,952, 6,124,006, and 6,221,446. These references are incorporated herein by reference. By varying the desiccant loading and polymer types in the formulation, the overall moisture capacity and uptake rate of the desiccant entrained plastic can be controlled. 
     In a further embodiment the container is provided with a child safety feature that allows the container to be opened relatively easily by an adult, but makes opening the container more difficult for a child. In a preferred aspect of this embodiment, the child safety feature can meet the standards for a Child Resistant Closure (CRC). The U.S. government has established a CR protocol to evaluate the effectiveness of closures. Child Resistant Protocol testing is defined under CFR Title 16, Part 1700 by the Food and Drug Administration. In general, a child resistant closure must be effective with children under 5 years old and be generally user friendly for users over 50 years old, particularly with users over 60 years old. 
     Referring to  FIGS. 1-4 , an embodiment of a hinged container  10  is shown including a base  12 , a lid  14 , and a hinge  16  joining the base and lid. In the illustrated embodiment, the hinged container  10  is generally clam shell shaped, although this is not essential. For example, the hinge  16  could be omitted, or the base  12  and lid  14  could be differently configured. Optionally, the base  12 , the lid  14 , or both can have a non-round outer perimeter, as shown in the Figures, although the perimeter could instead be round. 
     The base  12  has an outer perimeter  18 , and the lid  14  has an outer perimeter  20 . Optionally, the base and lid perimeters  18  and  20  are substantially congruent (have substantially the same shape), and are substantially registered (i.e. the perimeters are substantially aligned with each other all the way around) when the base and lid are closed. Congruence and registration are not, however, required because it is not essential that the base and lid perimeters  18  and  20  meet to form a seal, in the illustrated embodiment. Further, the perimeters  18  and  20  could be congruent but not registered. For example, they could be offset. 
     The hinge  16  allows the lid  14  to pivot open or closed relative to the base  12 . Optionally, the hinge is integral with the base  12  and the lid  14 , although it does not need to be integral with the base  12 , the lid  14 , or either of them. Optionally, a pin hinge or other type of hinge can be used. 
     A film guide  22  is provided as well to dispense a stack of product sheets  24 . The construction, features, and attachment of the film guide are described in more detail later. 
     The container  10 , and in this embodiment the lid  14 , has a circular, outwardly tapered outer seal member  26  that defines a center axis  28 . The taper is outward, proceeding vertically down (as shown in  FIGS. 3 and 4 ) to the distal end of the flange forming the outer seal member  26 . In other words, the distal end has a larger diameter than a point spaced above the distal end of the flange forming the outer seal member  26 . 
     The outer seal member  26  is mounted in fixed relation to one of the base and the lid (as illustrated, the lid), and is disposed at least partially within the corresponding outer perimeter of the base or lid to which it is mounted. In this embodiment, the outer seal member  26  and the lid  14  are integral, and as illustrated are parts of a single piece of material. Alternatively, they could be separate parts, or could instead be made in a single injection mold with one shot of material. 
     The container  10 , and in this embodiment the base  12 , has a circular, inwardly tapered inner seal member  30  that defines a center axis (also  28 , as the two axes are collinear in this embodiment when the container is closed). The taper is inward, proceeding vertically up the side wall  32  of the film guide  22  as shown in  FIGS. 3 and 4 ). In other words, the side wall  32  has a smaller diameter at the top corner as shown in  FIGS. 1 ,  3 , and  4  than in the seal area beneath the top corner. 
     The degrees of taper illustrated in the Figures are just examples, and may vary if the materials used are harder, softer, or more or less resilient than polypropylene, or if the dimensions of the seal members are set to make them more or less flexible, or depending on the coefficient of friction between the seal members  26  and  30 , among other factors. 
     The side wall  32  does not need to be tapered from bottom to top, nor does the flange defining the outer seal member  26  need to be tapered from bottom to top. It will suffice if the portions of the inner seal member  30  and the outer seal member  26  that engage each other are tapered, which facilitates wedging them together to form a seal. 
     The inner seal member  30  is mounted in fixed relation to the other of the base and the lid (here, the base), relative to the outer seal member  26 , and is disposed at least partially within the corresponding outer perimeter  18  of the part to which it is mounted. In the illustrated embodiment, the inner seal member  30  is an upper and outer part of the film guide  22 , which is a separate part from the base  12 . In alternative embodiments, the inner seal member  30  and the base  12  can be integral or made in a single injection mold with one shot of material. Optionally, any one or more of the lid, the seal member mounted in the lid, the base, the seal member mounted in the base, and the hinge are made of the same material. Optionally, they can all be made of the same material, which does not need to be soft enough to form a conventional gasket. Thus, the material can be substantially rigid, not noticeably flexing while the container  10  is normally used. Optionally, any one or more of, or all of, the lid, the seal member mounted in the lid, the base, the seal member mounted in the base, and the hinge can be made of polypropylene. 
     The inner and outer seal members are positioned to engage concentrically to wedge the inwardly and outwardly tapered surfaces together and form a seal when the base and the lid are closed. The inner and outer seal members  30  and  26  are positioned to disengage concentrically (i.e. with both axes substantially coinciding, as shown in the Figures) to part the inwardly and outwardly tapered surfaces when the base and the lid are opened. The seal or contact length of the inner and outer seal members  30  and  26  from top to bottom is relatively short, so the deviation from concentricity as the lid  14  is pivoted relative to the base  12  is slight. Another expedient is to allow some lateral “play” in the hinge  16  in a direction perpendicular to the axis  28  as the lid  14  is pivoted open, so the lid  14  and base  12  can be kept more nearly concentric while the seal members  26  and  30  are parting. This can be provided in an integral hinge by elongating the narrow cross-section at the fold of the hinge, making the fold of the hinge thinner or weaker, providing a longer, more strap-like integral hinge, or in other ways known in the art. 
     Optionally, the inner and outer seal members  30  and  26  are configured to provide a moisture-tight seal, as defined in this specification. Optionally, the inner and outer seal members  30  and  26  are configured to be resealable, as defined in this specification. 
     Return now to the film guide  22 . The film guide  22  has a side wall or outer flange  32  and an inner flange  34  (shown in  FIG. 4 ), which in this embodiment is concentric with the outer flange  32 , although it does not need to be concentric. The flanges are joined by a circular web  36 . The web  36  has a dispensing opening  38  and a depending lip  40 . 
     The base  12  has certain features that cooperate with the film guide  22  to define a dispenser for the stack of sheets  24  within the container  10 . The base  12  has a circular flange  42 , a re-entrant portion  44  defining a ramp that rises from left to right as shown in  FIG. 4 , and a stop  46  to confine the product stack  24  to a well-defined location on the ramp. Additional stops (not shown) can be placed on the sides of the stack to further define its location. 
       FIG. 4  is an exploded view of the container  10 , and in particular the film guide  22  is a separate piece, shown raised above its assembled position. When the film guide  22  is lowered into assembled position, its inner and outer flanges  32  and  34  receive the flange  42  of the base  12 , and either or both of the flanges  32  and  34  engage the flange  42  to fasten the film guide  22  in position relative to the base  12 . It is useful to precisely locate the film guide  22  in a fixed position relative to the base  12 , so the inner and outer seal members  30  and  26  will mate properly. The flanges  32 ,  34 , and  42  need to be complementary, but do not need to be round, although they can be round and, if desired, they can define inner and outer sealing members analogous to the inner and outer seal members  30  and  26 . This might be useful if an inner sealed container within the outer sealed container is desired, or if the film guide  22  functions as the lid of the container. 
     Additionally, when the film guide  22  is lowered into assembled position, the angled lip  40  can abut the ramp defined by the re-entrant portion  44 , and the stops such as  46  can abut the web  36 . This may be useful to prevent sheets from the stack  24  from sliding laterally out of position. In the assembled container, with the lid  14  open, a user can insert a finger through the dispensing opening  38 , adhere the top sheet of the stack  24  to the finger, and slide the top sheet up the inclined top surface of the depending lip  40  to dispense the top sheet of the stack. This motion can be repeated to dispense additional sheets. The sheets can be edible, for example, dissolving sheets of a breath freshening compound. 
     Other dispensing expedients can also be provided. For example, the film guide  22  can be omitted, the flange  42  can extend further to abut the lid  14  when the container  10  is closed, and the flanges  26  and  42  can interact as the inner and outer sealing members, or vice versa. Then a supply of tablets, capsules, a cake of cosmetic powder, cream, or gel, or other items or materials to be dispensed can be contained within the flange  42  and bounded by the webs of the base  12  and lid  14 . 
     Referring to  FIGS. 5-9 , an alternative embodiment of the container employing a child safety feature is illustrated. In this embodiment, the inner seal member  130  and the outer seal member (not shown) are similar in shape, and function in a similar manner as the inner seal member  30  and the outer seal member  26  illustrated in  FIGS. 1-4 , to form a seal when the base  112  and the lid  114  are closed. The base  112 , however, has alternative features that cooperate with the film guide  122  to fasten the film guide  122  in its fixed position relative to the base  112 . These alternative features include a plurality of locating pins  150 , for example, four locating pins  150 , mounted on the base  112 , which fit within corresponding recesses on the lower surface of the film guide when the film guide  122  is lowered into its assembled position on the base  112 . The locating pins keep the film guide  122  in a fixed position relative to the base  112 . 
     The child safety feature  152  employed in this embodiment is formed from a flexible plastic material and includes a latch mechanism, shown generally at  154 , and at least one push tab, here shown as two push tabs  156 , one on each side of the child safety feature. The latch mechanism engages a catch feature  170  on the lid  114  to lock the lid to the base  112  when the lid is closed. When the push tabs are depressed, as shown in  FIGS. 8 and 9 , the latch mechanism is released from the catch to thereby allow the lid to be opened, as will be explained in detail below. Associated with each push tab  156  is a spring  158  which is deflected by the push tab  156  when the push tab is depressed. This action creates a bias in the spring which causes the push tab  156  to return back to its home position when pressure on the push tab is released. 
     As illustrated in  FIG. 6 , the child safety feature  152  can be mounted on a bottom plate  160 , which can then be joined to the base  112 . Alternatively, the child safety feature could be incorporated into the base  112 . The base  112  is provided with a notch  162  on each side of the base to receive each push tab  156  when the child safety feature  152  and bottom plate  160  are assembled to the base  112 . When assembled, the push tabs  156  project outwardly from the sidewalls of the base  112  through the notches  162 . 
     The latch mechanism  154  projects through an opening  155  in the base  112  and includes at least one latch portion  164  (here shown as two latch portions  164 ) having a downward facing abutment  166 . In this instance, “downward” means facing away from the direction in which the lid  114  opens, and not necessarily referring to the orientation of the container relative to its surroundings. Each latch portion  164  engages a catch  170  (here shown as two catches  170 ) that extends downwardly from the lid  114 . Each catch has an upward facing abutment  172  that receives the downward facing abutment  166  of the latch portion  164  when the lid  114  is in its closed position on the base  112  to lock the lid  114  onto the base  112 . In this instance “upward” means facing in the direction in which the lid  114  opens, and not necessarily referring to the orientation of the container relative to its surroundings. 
     To unlock the lid  114  and open the container, a user depresses the push tabs  156  inward toward the container. This action causes each downward facing abutment  166  on each latch portion  164  to move away from the upward facing abutment  172  on each catch  170  so that the latch portion  164  clears the catch  170 . Once the latch portion clears the catch, the lid  114  can be opened. Releasing pressure on the push tabs  156  enables each spring  158  to force each push tab back to its outwardly projecting home position. 
     Although the child safety feature is illustrated as being joined to the base, it is contemplated that the child safety feature could be incorporated into the lid. In such an embodiment, the latch mechanism could be located on the lid while the catch feature could be located on the base. Further, although the child safety feature is shown incorporated into a container that is relatively flat, it is contemplated that the child safety feature could be incorporated into a container of virtually any shape, as long as the container employed a base, a lid, and a hinge joining the lid to the base. 
     The foregoing description is illustrative of many contemplated embodiments of the invention, and does not limit the scope of the invention as defined by the claims.