Patent Publication Number: US-2022212835-A1

Title: Container having a leak resistant seal

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Utility patent application Ser. No. 17/685,989, filed on 3 Mar. 2022, which is a continuation of U.S. Utility patent application Ser. No. 16/816,281, filed 12 Mar. 2020, which is a continuation of U.S. Utility patent application Ser. No. 16/566,779, filed 10 Sep. 2019, issued as U.S. Pat. No. 10,625,906, which is a continuation-in-part of U.S. Utility patent application Ser. No. 16/193,978, filed 16 Nov. 2018, issued as U.S. Pat. No. 10,407,217, the specifications of which are hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     Embodiments of the invention generally relate to the field of manufacturing of storage and transport bags and containers and seals for these bags and containers. More particularly, but not by way of limitation, one or more embodiments relate to an inside out method of manufacturing a container with a leak resistant seal that includes forming an elastomer or a plastic or any combination thereof into a container inside out to facilitate manufacturing, for example using less steps and to provide a seal with enhanced leak resistance, for example that can maintain a seal that resists leakage of liquids and solids from the container during storage and transport without the aid of an external structure to maintain the seal. 
     Description of the Related Art 
     Sealable bags and containers have been made for many years but are difficult to manufacture when using seals that must engage to remain closed. For example, manufacturing sealable plastic bags generally requires extruded parts, including seals that may be part of the container or later bonded to the container wherein the containers are cut with hot knives to create sealed edges. Plastic bags are generally created for single use and have chemicals that are undesirable for food storage for example. The resulting number of plastic bags thrown away on an annual basis is very high. Elastomeric bags, which have been made for reuse have generally been molded, for example with compression molding or liquid injection molding. The resulting elastomeric bags are highly elastic compared to plastic bags and their seals are generally bonded or molded into the inner portion of the bag. Elastomeric sealable bags are more durable than their plastic throwaway counterparts and a single reusable bag can save hundreds if not thousands of plastic bags. For example, both Munguia in US Patent Publication 2013/0105352 and LeBoeuf in US Patent Publication 2009/0110335 teach silicone food storage bags with seals. The problems with both of these devices is that they require external clamps or other external structures to seal the bags because their seals are not strong enough to be leak resistant. Svec, U.S. Pat. No. 2,780,261 shows one embodiment that can hold liquid inside of it, namely as shown and described with respect to  FIG. 7 . This is another example of a device that requires a structure external to the seal, namely sidewalls that allow liquid in the container to extend up and around the seal, i.e., which requires more material in the manufacturing process and provides hard to clean areas that are not easy to clean or even remove liquids and solids from when the container is inverted for example. Other attempts to make a silicone container with a leak resistant seal have failed including U.S. Patent Application Publication No. 2014/0270579, also published as WO 2014/163712, which includes a seal that readily leaks on both ends when configured without a “tightening mechanism” attached at both ends of the seal. 
     A limitation of the existing sealable bags is that the integrated seal designs provide relatively weak sealing force based on the elastic nature of elastomers. Plastic bags provide a weak sealing force, but for a different reason, mainly because the seals are extremely small, with ridges that are approximately 10 times thinner than a human fingernail, 0.1 mm. For example, Ziploc® bags are closeable, but they are not leak proof. This lack of leak resistance is a consequence of the relatively small sealing area and the simple track and groove shapes of the Ziploc® seal. To make the ridges leak resistant for storage and not for undergoing internal forces, the rigidity of the seal, when made this small has to be outside of the Shore A scale and well into the Shore D scale, i.e., 45-85 Shore D, typically in the 45-60 Shore D range and usually above 50 Shore D. In addition, extrusion imperfections when making the seals with this rigidity yield slight variations in the thickness of the seal and this provides a lower yield of containers that have acceptable leak resistance. Attempts to make the seals strong require use of sliders to open and close the bags, i.e., to allow children or elderly or weak individuals to open and close the bags. Sliders generally provide an opening on the end of the slider that leaks. In these devices, extra structure must be utilized to form a seal around the portion of the slider that maintains a separation in the seal, i.e., to seal the slider portion itself from leaking. Sliders also provide a choking hazard for children when they are dislodged. 
     This difficulty in providing an integrated leak resistant seal was taught in 1946 by Koeppel in U.S. Pat. No. 2,500,363. As Koeppel states: “Closures for containers of this nature have been formed in various ways, but when the opening in the bag or container is made sufficiently large to receive ice cubes or relatively large lumps of ice it is difficult to seal the opening effectively. Efforts have been made to overcome this difficulty by providing the container with a thickened portion about the mouth of the opening with complementary zig-zag or tongue and groove surfaces to form a seal. However, even such constructions are ineffective to prevent leakage unless they are pressed together with considerable force.” Koeppel then teaches a design using an external mechanical clip attached to a bag to provide the necessary sealing force. In this sense Koeppel arrives at a similar solution to LeBoeuf using an external clasp. 
     Silverman, U.S. Pat. No. 2,674,289 teaches a rubber container, namely a tobacco pouch that is molded inside out. This eliminates the step of bonding a seal to the container and simplifies the mold since the container can be inverted after molding. However, Silverman&#39;s seal tapers at the ends and when inverted for use, results in a complete lack of sealing force at the ends since the seal tapering produces no contact for ridges and indentations at the ends of the seal i.e., no seal at the ends. Silverman&#39;s design thus requires rivets, leather jacketing and a separate zipper e.g., external structures, to hold the seal together. Silverman also requires extra manufacturing steps of riveting the ends of the seal, etc., and is not leak resistant unless the external structure, e.g., rivets, are utilized. 
     While use of external clips or mechanical clasps can provide seals, they are less convenient for the user and they require additional manufacturing cost and complexity. Molding elastic containers inside out to simplify mold design to date has not provided any advantage for manufacture, again, since additional structure and steps to add that structure are required. Therefore, there is a need for an inside out method of manufacturing a container with a leak resistant seal, which forms the container and seal for example in as little as one step and which results in a seal that does not require such additional elements to enhance sealing force to remain leak resistant for example when external forces are applied to the container or when the container is inverted. 
     BRIEF SUMMARY OF THE INVENTION 
     Embodiments of the invention generally relate to an inside out method of manufacturing a container with a leak resistant seal that includes forming an elastomer or a plastic or any combination thereof into a container inside out. In at least one embodiment, the method includes forming an outside portion of the container on an internal surface of the container before inverting the container and forming an inside portion of the container on an external surface of the container before inverting the container. By way of at least one embodiment, the method includes forming or coupling a leak resistant seal on the external surface of the container before inverting the container. In at least one embodiment, the leak resistant seal provides access to the inside portion of the container when the leak resistant seal is open after inverting the container and holds at least liquid internal to the container when applying an external force to the container without use of an external structure to keep the leak resistant seal closed after inverting the container. 
     One or more embodiments includes inverting the external surface of the container and the leak resistant seal with the internal surface of the container such that the inside portion of the container and the leak resistant seal are located within the container and the outside portion of the container is located outside of the container. 
     In at least one embodiment of the invention, forming the inside portion of the container on the external surface of the container includes forming a gap on the external surface between a first side of the leak resistant seal and a second side of the leak resistant seal that engage each other after inverting the container. In one or more embodiments, the gap provides an abutment that each end of the first side and second side of the leak resistant seal contact to keep the leak resistant seal from leaking when the applying the external force to the container occurs. In one or more embodiments, the gap is less than or equal to a thickness of the leak resistant seal. 
     By way of at least one embodiment of the invention, the gap or each end of the first side and second side of the leak resistant seal include at least one gap seal, wherein the at least one gap seal is a protrusion that protrudes from the gap or from at least one of or from each end of the first side and second side of the leak resistant seal. In one or more embodiments, the protrusion provides a wandering path along the gap that provides a longer distance for water to travel, and thus increases leak resistance. In one or more embodiments, the material that forms the gap is thick enough, so that when inverted compresses the seal ends together and compresses the protrusions against the gap or male or female portions of the seal or any combination thereof to increase the leak resistance. The method of forming a gap between the seal ends and gap seals on the ends with forming a thickness of the material at the gap thick enough to compress the seal and gap seal is unknown in the art. 
     In one or more embodiments of the invention, forming or coupling the leak resistant seal includes utilizing a leak resistant seal with a first seal portion and a second seal portion that couple with each other along a boundary to seal the container and decouple from each other along the boundary to open the container. 
     In at least one embodiment of the invention, the first seal portion and the second seal portion are at least 1 mm thick, or at least 2 mm thick, or at least 3 mm thick, or greater than 3 mm thick. 
     According to one or more embodiments of the invention, the boundary defines a path of contact between the first seal portion and the second seal portion that is at least 2 times a horizontal distance between a start of the path and an end of the path. In one or more embodiments, the path is at least 2.5 times the horizontal distance between the start of the path and the end of the path, or at least 3 times, or at least 4 times or at least 5 times the horizontal distance between the start of the path and the end of the path. Other metrics for measuring the seal may include measuring the path of the boundary for the seal starting at a point where the seal diverges from the base of the seal, or a flat portion of the seal, along the path of contact between each side of the seal and to a point next to the original starting point back on the flat portion of the seal. This metric for the winding path may yield ratios of at least 4, 5, 6, 7, 8, 9, or greater than 10. In addition, the seal may have gaps within it to enable the seal to open more easily. The gaps may be symmetrical on each side of any protrusion or cavity for example or may be asymmetrical. By including a gap on one side of the protrusion, the seal may be opened more easily from the side having the gap for example. 
     In at least one embodiment of the invention, the first seal portion and the second seal portion include at least one corresponding protrusion or indentation that includes a geometric shape that is wider than another portion of the at least one corresponding protrusion or indentation. The seal may also include gaps meaning that the shapes of ridges and recesses that correspond to one another, i.e., that fit into one another, whether in full contact across the entire boundary or not, may be of different shapes. 
     In one or more embodiments of the invention, utilizing the leak resistant seal includes utilizing the protrusion or the indentation having a height of at least 2 mm and utilizing the geometric shape having a width of at least 1 mm thicker than the protrusion or the indentation. 
     By way of at least one embodiment, utilizing the leak resistant seal includes utilizing the protrusion or the indentation having a height of at least 2 mm and utilizing the geometric shape having a width of at least 2 mm thicker than the protrusion or the indentation. 
     According to one or more embodiments, utilizing the leak resistant seal includes utilizing two or more of the at least one corresponding protrusion and the at least one corresponding indentation in the leak resistant seal. 
     At least one embodiment of the invention includes forming the container with a width near the leak resistant seal that is larger than an opposing width of the container away from the leak resistant seal. In one or more embodiments, the leak resistant seal includes a first side and a second side that engage each other. In at least one embodiment, the first side includes a different average thickness than the second side. In one or more embodiments, the first side is made from a different material than the second side. In at least one embodiment, the first side includes a different hardness value than the second side. 
     By way of one or more embodiments, the leak resistant seal is made from a different material than a remaining portion of the container that does not include the leak resistant seal. In at least one embodiment of the invention, the leak resistant seal includes a different hardness value than the remaining portion of the container that does not include the leak resistant seal. 
     One or more embodiments of the invention include forming the elastomer into the container with a hardness of between 70 and 80 on a Shore A durometer scale. At least one embodiment of the invention includes forming the elastomer into the container with a hardness of between 40 and 90, or at least less than or equal to 100 on a Shore A durometer scale. 
     In one or more embodiments of the invention, forming the container includes forming the leak resistant seal at opposing edges of the container that are at least as thick as the leak resistant seal between the opposing edges. By way of at least one embodiment, forming the elastomer into the container includes transfer molding, plastic injection molding, liquid injection molding or compression molding. 
     One or more embodiments include utilizing an uncured, heat curable elastomer, wherein forming the elastomer into the container includes heat curing the container. 
     At least one embodiment of the invention includes forming the container in one molding step without attaching any material to the container after the molding. In other embodiments, multiple parts may be formed before bonding them together and before inverting the container. One example would be to separately mold a top enclosure and bottom enclosure, each of which define a portion of the volume that results in the inner portion of the container, then bond them together and then invert the container inside out. This requires an extra step of coupling the parts together, e.g., via bonding, wherein when the top enclosure and bottom enclosure are formed in a mold at the same time, they are coupled together with the same material in one step. A container still has two parts designated as the top enclosure and bottom enclosure that are merely designations of sides of the container in this example. Thus, “coupled to” covers a container made from two separate parts or two parts formed at the same time and coupled within the mold, i.e., during the molding process. 
     In one or more embodiments, coupling the leak resistant seal includes gluing, bonding or attaching the leak resistant seal to the container to couple the leak resistant seal by co-molding the container and the leak resistant seal together or by over-molding the container to the leak resistant seal or by over-molding the leak resistant seal to the container. 
     At least one embodiment of the invention includes forming the leak resistant seal without bonding or gluing opposing sides of the leak resistant seal at opposing ends of the leak resistant seal, i.e., so that there is a gap between one side of the seal and the other at the ends, wherein when inverted inside out, the two seal portions eliminate the gap to provide a leak resistant seal. One or more embodiments of the invention include forming a bottom on the container such that the container may stand upright. 
     At least one embodiment of the invention includes forming the container with a thickness of 0.6 mm that increases to 1.8 mm at opposing sides of the leak resistant seal at opposing ends of the container. 
     One or more embodiments of the invention include forming the container with a thickness of between 0.3 and 0.9 mm that increases to 1.2 to 2.4 mm at opposing sides of the leak resistant seal at opposing ends of the container. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of at least one embodiment of the invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings, wherein: 
         FIG. 1  illustrates an exemplary flowchart of the method of manufacturing a container with a leak resistant seal. 
         FIG. 2  shows a perspective view of the container formed inside out with the leak resistant seal on the outside. 
         FIG. 3  shows a cross-section view of a left side of the container formed inside out. 
         FIG. 4  shows a front view of the container formed inside out. 
         FIG. 5  shows a back view of the container formed inside out. 
         FIG. 6  shows a side view of the container formed inside out. 
         FIG. 7  shows a top view of the container formed inside out. 
         FIG. 8  shows a bottom view of the container formed inside out. 
         FIG. 9  shows a perspective view of ends of the leak resistant seal. 
         FIG. 10  shows a side view of a first side of the leak resistant seal. 
         FIG. 11  shows a side view of a second side of the leak resistant seal. 
         FIG. 12  shows the gap between the first and second side of the leak resistant seal and gap seals on the first side and the second side of the leak resistant seal. 
         FIG. 13  shows a cross-section view of the container, namely an internal surface of the container before being inverted showing the flutes that reside on the outside of the container after the container is inverted. Flutes increase the stiffness of the container and allow the container to stand upright. 
         FIG. 14  shows a front view of the container after being inverted. 
         FIG. 15  shows an exemplary winding or wandering path calculation for an embodiment of the seal. 
         FIG. 16A  shows an alternate embodiment of a seal profile having a gap on the external portion of the container to make the container easier to open from the outside than from the inside.  FIG. 16B  shows a second alternate embodiment of a seal profile having gaps. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description is of the best mode presently contemplated for carrying out at least one embodiment of the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims. 
       FIG. 1  illustrates an exemplary flowchart of the inside out method of manufacturing a container with a leak resistant seal, and  FIG. 2  shows a perspective view of the container after manufacture and before the container is inverted, i.e., before being configured for use as a container with a leak resistant seal, according to one or more embodiments of the invention. Embodiments of the invention generally relate to a method of manufacturing a container  200  with a leak resistant seal  203  that includes  101  forming an elastomer or a plastic, or thermoplastic elastomers, which are plastics that can behave in some ways like elastomers depending on their specific characteristics, or any combination thereof into a container  200 , for example inside out. In at least one embodiment, the method includes  102  forming an outside portion  201  of the container  200  on an internal surface  211  of the container  200  before inverting the container  200 , and  103  forming an inside portion  202  of the container on an external surface  212  of the container before inverting the container  200 . By way of at least one embodiment, the method includes  104  forming or coupling a leak resistant seal  203  on the external surface  212  of the container before inverting the container. In at least one embodiment, the leak resistant seal  203  providing access to the inside portion  202  of the container  200  when the leak resistant seal  203  is open after inverting the container  200 , and when the container is sealed holding at least liquid, and/or another substance, internal to the container  200  when applying an external force to the container  200  without use of an external structure to keep the leak resistant seal  203  closed after inverting the container  200 . Part of the manufacturing process may optionally include inverting the external surface of the container and the leak resistant seal with the internal surface of the container at  105 . In other embodiments, the container may be delivered inside out where the end user or customer inverts the container. In one or more embodiments, part of the manufacturing process may optionally include forming a gap on an external surface between a first side of the leak resistant seal and a second side of the leak resistant seal that engage each other after inverting the container, and wherein the gap provides an abutment that each end of the first side and second side of the leak resistant seal contact at  106 . By way of at least one embodiment, the leak resistant seal  206  provides access to the inner portion of the container  200  and allows the container  200  to hold the at least liquid internally with a liquid tight seal for storage and during transport for example. 
       FIG. 13  shows a cross-section view, specifically an upper perspective cross-section view, of the internal surface of the container before being inverted and  FIG. 14  shows a front view of the container after being inverted, according to one or more embodiments of the invention. As shown in  FIG. 13 , the container  200  may include a tab  440  and flutes  350  on the internal surface  211 , i.e., that becomes the outside portion  201  of the container after the container is inverted. 
     As shown in  FIG. 14 , one or more embodiments of the invention includes inverting the external surface  212  of the container  200  and the leak resistant seal  203  (not shown in  FIG. 14 ) with the internal surface  211  of the container  200  such that the inside portion  202  of the container and the leak resistant seal  203  are located within the container  200  and the outside portion  201  of the container is located outside of the container  200 , to form a container  1400  ready for use. In one or more embodiments, as shown in  FIG. 14 , when the container  200  is inverted, the tabs  440  and the flutes  350  are shown on the outside portion  201 . In one or more embodiments, the enclosures shown in  FIGS. 13 and 14  may be formed separately and coupled to one another via bonding or coupled to one another at the same time as forming the enclosures, i.e., in a mold. In any case, the container as a whole has two enclosure parts that define an inner volume, whether merely a designation of a single container when formed simultaneously, i.e., coupled to one another during molding, or whether formed separately and then coupled to one another, i.e., via bonding. The parts may be formed as shown in  FIGS. 13 and 14  or in any other manner, e.g., could be made in at least two parts across the cross-section plan shown in  FIG. 3 , with a mirror image part on the other side of the plane that are then bonded for example. 
       FIG. 3  shows a cross-section view of a left side of the container before the container is inverted, according to one or more embodiments of the invention. As shown in  FIG. 3 , in at least one embodiment, the container  200  includes the leak resistant seal  203  with a first side  204  and a second side  205 . One or more embodiments of the invention include forming a bottom  330 , such as a rim or feet, on the container  200  such that the container  200  may stand upright. As such, in at least one embodiment, when the container  200  is inverted, the bottom  330  protrudes or faces outward away from the container  200 , and after being inverted the bottom  330  protrudes or faces inward towards and into the container  200 . According to one or more embodiments, before the container  200  is inverted, the edges of the leak resistant seal  203  on both edges of the container  200  protrude or face outward away from the container  200 , and after being inverted, the edges of the leak resistant seal  203  protrude or face inward towards each other in an inner portion of the container  200 . 
     By way of one or more embodiments, the flutes  350  of the container  200  may end at a predetermined distance from a top edge of the container  200 , wherein the top edge is opposite that of the bottom  330 . For example, in at least one embodiment, the predetermined distance may be 15 mm, less than 15 mm or more than 15 mm. According to one or more embodiments of the invention, the flutes  350  end at the predetermined distance from the top edge of the container  200  in order to avoid interference when inverting the container  200  along the edge to make the seal with the leak resistant seal  203 . 
     In one or more embodiments, the leak resistant seal  203  includes a first side  204  and a second side  205  that engage each other. In at least one embodiment, the first side  204  may include a different average thickness than the second side  205 . In one or more embodiments, the first side  204  may be made from a different material than the second side  205 . In at least one embodiment, the first side  204  may include a different hardness value than the second side  205 . 
     By way of one or more embodiments, the leak resistant seal  203  may be made from a different material than a remaining portion of the container  200  that does not include the leak resistant seal  203 . In at least one embodiment of the invention, the leak resistant seal  203  may include a different hardness value than the remaining portion of the container  200  that does not include the leak resistant seal  203 . 
     One or more embodiments of the invention include forming the elastomer into the container  200  with a hardness of between 70 and 80 on a Shore A durometer scale. At least one embodiment of the invention includes forming the elastomer into the container  200  with a hardness of between 40 and 90 on a Shore A durometer scale, or in any case less than 100 Shore A. 
       FIG. 4  shows a front view of the container before being inverted, according to one or more embodiments of the invention and  FIG. 5  shows a back view of the container before being inverted, according to one or more embodiments of the invention. 
     At least one embodiment of the invention includes forming the container  200  with a width near the leak resistant seal  203  that is larger than an opposing width of the container  200  away from the leak resistant seal  203 . In at least one embodiment of the invention, the container  200  may include a tab  440 , wherein the tab  440  may include a tab side on each side of the container  200  and each side of the leak resistant seal  203 . 
     In one or more embodiments of the invention, forming the container  200  includes forming the leak resistant seal  203  at opposing edges  550 ,  560  of the container  200  that are at least as thick as the leak resistant seal  203  between the opposing edges  550   560 . By way of at least one embodiment, forming the elastomer into the container  200  includes liquid injection molding, plastic injection molding or compression molding. One or more embodiments may include forming the container by utilizing thermoplastic elastomers wherein forming the container includes melting the elastomer and injection molding the material. 
     One or more embodiments include utilizing an uncured, heat curable elastomer, wherein forming the elastomer into the container  200  includes heat curing the container  200 . 
     At least one embodiment of the invention includes forming the container  200  in one molding step without attaching any material to the container  200  after the molding. This provides an extremely rapid method of manufacturing a leak resistant seal for storage and transport that does not require external structures or clips to hold the seal together. 
     In one or more embodiments, coupling the leak resistant seal  203  includes one or more of gluing, bonding and attaching the leak resistant seal  203  to the container  200  to couple the leak resistant seal  203  by co-molding the container  200  and the leak resistant seal  203  together or by over-molding the container  200  to the leak resistant seal  203  or by over-molding the leak resistant seal  203  to the container  200 . This enables different types of materials to be utilized in the manufacturing of the container but requires more steps than the one step method described herein. 
     At least one embodiment of the invention includes forming the leak resistant seal  203  without bonding or gluing opposing sides  204 ,  205  of the leak resistant seal  203  at opposing ends of the leak resistant seal  203 , for example at ends  620  and  621 . 
       FIG. 6  shows a side view of the container before being inverted, according to one or more embodiments of the invention. In at least one embodiment of the invention, forming the inside portion  202  of the container  200  on the external surface  212  of the container  200  includes forming a gap  206  on the external surface  212  between the first side  204  of the leak resistant seal  203  and the second side  205  of the leak resistant seal  203  that engage each other after inverting the container  200 . In at least one embodiment, the gap  206  may be a flat area between the first side  204  and the second side  205 . In one or more embodiments, the gap  206  provides an abutment that each end of the first side  204  and second side  205  of the leak resistant seal  203  contact to keep the leak resistant seal  203  from leaking when applying an external force to the container  200 . In one or more embodiments, the gap  206  is less than or equal to a thickness of the leak resistant seal  203 . In this embodiment the seal portions on the ends compress and the relatively smaller gap elastically stretches and provides force to hold the seal together at the ends. 
     By way of at least one embodiment of the invention, the gap  206  or each end of the first side  204  and second side  205  of the leak resistant seal  203  include at least one gap seal  610 , wherein the at least one gap seal  610  is a protrusion, such as a raised rib, that protrudes out. For example, in at least one embodiment of the invention, the gap seal  610  protrudes from the gap  206  as shown in  FIG. 6 , or from each end of the first side  204  and second side  205  of the leak resistant seal  203  as shown in  FIG. 12 . According to at least one embodiment, the gap seal  610  is a protruding surface that creates a tight seal after the container  200  is inverted, through contact with the inner surface of the flat edge of the gap  206 . This embodiment provides additional strength for the seal at the ends, increases the length of the path that any liquid must travel to escape from the container to provide a more leak resistant for example. 
     By way of at least one embodiment, each end of the first side  204  and second side  205  may include a gap seal, or one end of one of the first side  204  and the second side  205  may include a gap seal, or the gap  206  may include a gap seal, or any combination thereof. 
     In one or more embodiments of the invention, forming or coupling the leak resistant seal  203  includes utilizing a leak resistant seal  203  with a first seal portion  620  and a second seal portion  621  that couple with each other along a boundary to seal the container  200  and decouple from each other along the boundary to open the container  200 . In at least one embodiment, the boundary is a line that defines an area between the first seal portion  620  and the second seal portion  621  that allows the first seal portion  620  to contact or to mate or couple or engage with the second seal portion  621 . 
     According to one or more embodiments of the invention, the boundary defines a path of contact or coupling or mating or engagement between the first seal portion  620  and the second seal portion  621  that is at least 2 times a horizontal distance between a start of the path and an end of the path. In one or more embodiments, the path is at least 2.5 times the horizontal distance between the start of the path and the end of the path, or at least 3 times the horizontal distance between the start of the path and the end of the path, or at least 5 times the horizontal distance between the start of the path and the end of the path as described below. 
       FIG. 15  shows an exemplary embodiment of the winding path of the seal with a leftmost horizontal length of the portion of the seal that is in contact with the corresponding portion on the other half of the seal. In this case, the length is 1.0. (The lengths shown are only relative to one another; they are not expressed in any specific units.) In the embodiment shown, the total length  1503  of the winding boundary path is 17.5. The horizontal distance  1501  between the start and end of the path is 7.0. Thus, the path length is approximately 2.5 times the horizontal distance. This ratio of path length to horizontal distance is a quantification of the extent to which the boundary path winds and changes directions, which contributes to the sealing force and the leak resistance. Some embodiments of the invention, have a boundary path length of at least twice the horizontal distance between the start and end of the path, for example if the horizontal portion of the contact area is larger or if the ridges on the seal are shorter, etc. For example, other embodiments may have a path length that is at least 3 times, or at least 4 times or at least 5 times the horizontal distance between the start of the path and the end of the path. Other metrics for measuring the seal may include measuring the path of the boundary for the seal starting at a point where the seal diverges from the base of the seal, or a flat portion of the seal, along the path of contact between each side of the seal and to a point next to the original starting point back on the flat portion of the seal. This metric for the winding path may yield ratios of at least 4, 5, 6, 7, 8, 9, or greater than 10. As shown if using only one protrusion as a male portion of the leak resistant seal, e.g., if the seal only is implemented with the upper portion of the Christmas tree as the male component, then the ratio is calculated as A=(0.3+0.5+0.3+1.4)*2 (for both sides since symmetrical)=5.0, divided by the width of the base=1.1 yields a ratio of 4.5. If calculating this metric using both levels of ridges, i.e., with the seal as shown, but with any type of side portion of the seal, or no side portion at all, then the ratio is calculated as above but with the lower portion to add, namely B=(0.5+0.7+0.2+1.0)*2 (since approximately symmetrical)=4.8. Hence, A+B, i.e., the total length of the full “Christmas tree” embodiment of the seal equals 9.8. The width of the lower portion of the seal that acts as the base portion for purposes of the calculation is 1.2 as shown, which results in a ratio of approximately 8. The longer the path, for a given base, the higher the ratio and generally the more leak resistant the seal is. 
     In at least one embodiment of the invention, the first seal portion  620  and the second seal portion  621  are at least 1 mm thick, or at least 2 mm thick, or at least 3 mm thick. The average thickness of the first and second seal portions are in general less than the maximum thickness. Maximum thickness is easier to measure, e.g., with a ruler, versus average thickness that is calculated by determining the volume and dividing by the width. 
       FIG. 7  shows a top view of the container before being inverted and  FIG. 8  shows a bottom view of the container before being inverted, according to one or more embodiments of the invention. 
     At least one embodiment of the invention includes forming the container  200  with a thickness of 0.6 mm that increases to 1.8 mm at opposing sides  204 ,  205  of the leak resistant seal  203  at opposing ends of the container  203 , for example at ends  550  and  560 . 
     One or more embodiments of the invention include forming the container  200  with a thickness of between 0.3 and 0.9 mm that increases to 1.2 to 2.4 mm at opposing sides  204 ,  205  of the leak resistant seal  203  at opposing ends of the container  200 , for example at ends  550  and  560 . 
       FIG. 9  shows a perspective view of ends of the leak resistant seal before being inverted to engage one another, according to one or more embodiments of the invention.  FIG. 10  shows a side view of a first side of the leak resistant seal before being inverted and  FIG. 11  shows a side view of a second side of the leak resistant seal before being inverted, according to one or more embodiments of the invention. 
     As shown in  FIG. 9 ,  FIG. 10  and  FIG. 11 , according to one or more embodiments of the invention, the leak resistant seal  203  may include a gap seal  610  on the gap  206 , and two gap seals  610  on the second seal portion  621 , thus creating a three-level seal. In one or more embodiments, the three-level seal is created from each of the three gap seals  610 , wherein each gap seal  610  contact and engage with the flat surface of the gap  206  such that the three-way seal is created via each gap seal  610  layered above another gap seal  610  vertically along the gap  206 . In at least one embodiment of the invention, the first seal portion  620  and the second seal portion  621  include at least one corresponding protrusion or indentation  940 ,  950 . Each protrusion or indentation shown may be a simple bump and groove or may include a geometric shape that is wider than another portion of the at least one corresponding protrusion or indentation  940 ,  950 . This may include ridges or any other shape where the outer portion of the protrusion away from the surface on which the protrusion is located is larger than the corresponding entry to the indentation. Thus, the large male and female seal portions  620  and  621  may be produced on a smaller scale as gap seal components if desired. 
     In one or more embodiments of the invention, the gap  206  includes a gap seal  610  on a flat portion of the gap  206 , and the first seal portion  620  includes a corresponding indentation that folds over and fits into the gap seal  610  of the gap  206 , when inverting the container  200 . 
     In at least one embodiment of the invention, the geometric shape of the at least one protrusion and/or indentation may be shaped as a “Christmas tree” and/or a double-headed arrow with varying widths at each head and/or a protrusion or indentation with multiple ridges that protrude out. 
     In one or more embodiments of the invention, utilizing the leak resistant seal  203  includes utilizing the protrusion or the indentation  940 ,  950  having a height of at least 2 mm and utilizing the geometric shape having a width of at least 1 mm thicker than the protrusion or the indentation  940 ,  950 . 
     By way of at least one embodiment, utilizing the leak resistant seal  203  includes utilizing the protrusion or the indentation  940 ,  950  having a height of at least 2 mm and utilizing the geometric shape having a width of at least 2 mm thicker than the protrusion or the indentation  940 ,  950 . 
     According to one or more embodiments, utilizing the leak resistant seal  203  includes utilizing two or more of the at least one corresponding protrusion  940  and the at least one corresponding indentation  950  in the leak resistant seal  203 . 
       FIG. 12  shows gap seals on the first side and the second side of the leak resistant seal before being inverted, according to one or more embodiments of the invention. As shown in  FIG. 12 , by way of at least one embodiment, the gap  206  may not include a gap seal. In one or more embodiments, the side  204  and the second side  205  of the leak resistant seal  203 , such as at the first seal portion  620  and at the second seal portion  621 , may each include at least one gap seal  610 , and the second seal portion  620  includes one gap seal  610 , and the first seal portion  610  includes two gap seals  610 . As such, in one or more embodiments, when inverting the container  200 , the gap seals  610  shown in  FIG. 12  fold over to contact the gap  206  in the center of the first seal portion  620  and the second seal portion  621 , and thus create a three level seal where the gap  206  is thicker than the remaining portions of the outside of the container  200 . By way of at least one embodiment, when the first seal portion  620  and the second seal portion  621  are folded over to invert the container  200 , the thicker portion of the gap  206  with the gap seals  610  in contact therewith provide more force and are stronger than the remaining portion of the gap  206  and provide force to engage the first side  204  and the second side  205 . 
     According to one or more embodiments of the invention, the container  200  includes wall edges on either side wall of the container  200  that includes the wall of the gap  206 , wherein the wall of the gap  206  is thicker than the edges on either side of the container  200 . In at least one embodiment of the invention, the wall thickness of the wall of the gap  206  is thickened and tapers smoothly on both sides of the container  200  away from the wall of the gap  206  to create the container side walls, such that the side walls of the container  200  are thinner than the walls of the gaps  206  on both opposing edges  550 ,  560  of the container  200 . In one or more embodiments of the invention, the thicker portion of the container walls that includes the wall of the gap  206  includes additional material thickness on the internal surface  211  of the container  200 , wherein such additional material thickness creates a clamping force when the container  200  is inverted, thus promoting and engaging a tight seal in the leak resistant seal  200 . 
     By way of at least one embodiment of the invention, the gap  206  or each end of the first side  204  and second side  205  of the leak resistant seal  203  include at least one gap seal  610 , wherein the at least one gap seal  610  is a protrusion that protrudes from the gap  206  as shown in  FIG. 6 , or from each end of the first side  204  and second side  205  of the leak resistant seal  203  as shown in  FIG. 12 . By way of at least one embodiment, each end of the first side  204  and second side  205  may include a gap seal, or one end of one of the first side  204  and the second side  205  may include a gap seal, or the gap  206  may include a gap seal, or any combination thereof. 
     According to one or more embodiments of the invention, the gap  206  may be thicker than a portion of the container  200 , such that when the container  200  is inverted, a compressive force is developed from stretching of the material at the ends. This is the material thickness as looking into the figure, i.e., the thickness of the material in the gap region. This force, as applied, pulls the first seal portion  610  and the second seal portion  620  together at each and both ends of the seal portions, to provide a liquid tight barrier that is leak resistant for storage and transport, i.e., resists the leakage of liquids when external forces are applied to the container without requiring any external structure to hold the seal together. In addition, the width of the gap may be less than the height of element  621  for example to compress elements  620  and  621  together when inverted. Either the thickness of the material at the gap and/or the width of the gap may be made thicker and narrower alone or in combination to increase the sealing force at the ends of the leak resistant seal. 
     In at least one embodiment of the invention, end portions of the leak resistant seal may be thicker than a middle portion of the leak resistant seal, such that the edges of the leak resistant seal  206  are thicker than the remaining portions of the leak resistant seal  206 . 
       FIG. 16A  shows an alternate embodiment of a seal profile having a gap on the external portion of the container to make the container easier to open from the outside than from the inside, wherein the outside of the container is on the right side of the figure.  FIG. 16B  shows a second alternate embodiment of a seal profile having gaps, for example under one or more of the ridges when the seal is closed. As shown in both figures the initial point of contact  1620  is where the first seal portion  1601 , as shown primarily a female component, contacts second seal portion  1602 , primarily a male component. As the path of contact continues inward toward the center of the seal, a gap  1610  occurs where there is no contact between the first seal portion  1601  and second seal portion  1602 . The path ends where the contact ends, i.e., when continuing to traverse the seal surfaces in one direction, specifically at  1630 . In  FIG. 16A , gap  1610  enables that right portion of the seal as shown to more easily open than the left portion. In  FIG. 16B , the seal includes four gaps, which make the seal easier to open in general. One or more of the gaps shown in  FIG. 16B  are optional, such that the design may have gaps there or even above the uppermost point of the element  1602 , i.e., a gap in element  1601 , not shown for brevity. 
     In one or more embodiments, the leak resistant seal includes a path comprising a length along a surface of the first seal portion or the second seal portion that is at least 2 times a horizontal distance between a start of said path and an end of said path where an initial contact and final contact between said first seal portion or said second seal portion occurs respectively, e.g., between points  1620  and  1630  wherein the path includes the length of the surface of either first seal portion  1601  or second seal portion  1602 . Thus, gaps still count in the calculation since liquid must traverse the gap and the path therefore in continuous in that some of the liquid will traverse the longest boundary face and some of the liquid will traverse the shortest boundary face generally on female and male seal components respectively. In one or more embodiments, the path, i.e., along the surface of either, (or even both) the first seal portion or second seal portion, is at least 2.5 times the horizontal distance between the start of the path  1620  and the end of said path  1630 . In one or more embodiments, the path begins at a base portion of the leak resistant seal, i.e., where the contact point moves vertical at  1640 , and wherein the path is at least 4.5 times the horizontal distance between the start of the path and the end of the path, i.e., where the path moves down vertically at  1650  with respect to a base width of the leak resistant seal, specifically where the leak resistant seal diverges from a flat portion of the leak resistant seal. 
     Definitions 
     Elastomer—A material which at room temperature can be stretched repeatedly to at least twice its original length and, upon immediate release of the stress, will return with force to its approximate original length. 
     Boundary—a length of a surface of either the first seal portion or second seal portion between an initial point of contact and final point of contact between the first seal portion and second seal portion when the leak resistant seal is closed. In a seal profile with no gaps, the boundary is the same length whether measured along the surface of element  1601  or  1602 . In a seal profile with gaps, the boundary used for calculations of the path is either that length of the surface of either the first seal portion or second seal portion, wherein the female portion in general will have a larger boundary in a seal having gaps where no contact exists between some portions of the seal. Either the larger number or smaller number in this case can be utilized to show the length of the path. See also  FIGS. 16A-B . 
     Leak resistant seal—A seal that resists leakage of liquids and solids from the container during storage and transport without the aid of an external structure to maintain the seal. 
     Coupled to—In terms of a single container, the container may be made in an integrated mold wherein all parts of the container are formed and therefore coupled to one another during the molding process, wherein the coupling material is the container material itself, i.e., an elastomer or plastic or thermoplastic elastomer. The single container may also be made from parts formed before coupling the parts together to form a single container. In either case a single container has multiple parts that are all coupled together, or they would fall apart. 
     Corresponding indentations—The shapes of the protrusions and recesses may be of the same shape where there are no gaps in the seal or may be of different shapes if the seal has gaps, e.g., when closed. In addition, the protrusions and recesses may be of different shapes so that when closed, there is at least one contact boundary along the length of the seal. In either case, the corresponding indentations for ridges may be of the same shape or different shape. 
     It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teaching. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention.