BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a flexible container, particularly a flexible container that can withstand high sustained internal pressures and extreme temperature conditions, making it suitable for containing and transporting toxic and other hazardous materials both by ground and by high-altitude aircraft.
2. Description of Related Art
Under new Federal Aviation Administration (FAA) testing criteria, in the United States, a container must be able to withstand a sustained internal pressure of about 14 psi for at least about 30 minutes in order to be suitable for transporting toxic and other hazardous materials, using air transportation. For example, if an airplane traveling at an elevation of about 42,000 feet is depressurized, the container must withstand a net effect of an internal pressure of about 14 psi in order to remain sealed. Many conventional containers, particularly flexible containers, cannot withstand such high internal pressure. As a result, a conventional flexible container leaks through a closure which sealably closes a container opening, breaks at a weak peripheral seal or deforms or expands at a region and develops an opening, whereby the materials contained within the container leak from the container.
For example, it is very difficult to provide a flexible container that can withstand high internal pressures and maintain a leak-proof closure. To withstand high internal pressures, conventional flexible containers are constructed of relatively thick materials that require a longer sealing dwell time to effect a peripheral seal that allows the internal pressure to approach a limit or maximum strength of the container material. With heavier materials it becomes increasingly difficult to provide a leak-proof container closure.
Thus, leaks develop at a weak portion of the closure or seal joining the materials, particularly when the flexible container is subjected to a high internal pressure. Further, when the thick materials are folded to form a seal about an opening in the container, the walls of the container near the opening do not sufficiently contact each other to form a leak-proof seal. The materials forming the walls of the container have a shape memory or bias force which urges the materials from a sealed position to an initial flat position.
Conventional flexible containers may not be able to withstand extreme temperatures, particularly as they occur at or near endpoints of a range from about −40° F. to about 130° F., and particularly over a prolonged time period, for example at least about 2 hours.
There is an apparent need for a flexible container which is suitable for shipping or transporting hazardous materials by air.
There is also an apparent need for a flexible container which can withstand a high sustained internal pressure, for example when subjected to decompression pressure effects at high altitudes, and/or where the materials and closure structure can withstand a temperature operating range of about −40° F. to about 130° F., particularly over a prolonged time period.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a flexible container that can withstand a high sustained internal pressure and that provides a leak-proof closure during extreme temperatures, particularly over a prolonged time period.
It is another object of this invention to provide a flexible container that can withstand a sustained internal pressure of about 14 psi for at least about 30 minutes in order to be suitable for transporting toxic or other hazardous materials using air transportation, such as an airplane.
It is yet another object of this invention to provide a flexible container able to withstand extreme temperatures ranging from about −40° F. to about 130° F., over a prolonged period of time.
The new FAA testing criteria require that a container for transporting hazardous materials must be able to withstand a sustained internal pressure of about 14 psi and a temperature operating range of −40° F. to 130° F. for a prolonged period of time.
The above and other objects of this invention are accomplished with a flexible container having at least two webs sealed with respect to each other about a periphery of the flexible container, to form a void between the webs. Preferably, each web has at least two layers, wherein a first layer is coextensive with a second layer. The first layer and the second layer of each web may comprise any suitable material. For example, at least one web may include a first layer of a polyester or nylon material and a second layer of a polyethylene material or other suitable polymer material. Suitable materials for forming the web layers are known to those skilled in the art of flexible bag construction and manufacturing.
The first web has a closure area and forms an opening within the closure area. The opening can be positioned along and/or form at least part of a fold line passing through the closure area. An adhesive layer can be applied to or positioned on the first web before or after the opening is formed in the first web, in order to maximize efficiency and/or minimize time and expense associated with the manufacturing process used to make the flexible container. For example, the adhesive layer may be applied to the first web within the closure area, and then the opening can be formed through the adhesive layer and the first web, resulting in adhesive applied to the first web at, adjacent, near, next to and/or in the proximity of two opposing sides of the opening. Preferably, the opening is completely surrounded by the adhesive layer, such that adhesive is applied to the first web at, adjacent, near, next to and/or in the proximity of the opposing sides of the opening and at, adjacent, near, next to and/or in the proximity of the opposing end portions of the opening.
Alternatively, the opening may be formed before the adhesive layer is applied to the first web. Such a manufacturing process similarly results in adhesive applied at, adjacent, near, next to and/or in the proximity of the opposing sides of the opening and/or the opening end portions.
With the flexible container in an unfolded condition, the adhesive layer is applied to the first web and is positioned at, adjacent, near, next to and/or in the proximity of the opposing sides of the opening and within the closure area. With the flexible container in a folded condition, a first portion of the adhesive layer on a first side of the opening forms an adhesive-to-adhesive contact with a second portion of the adhesive layer on an opposing second side of the opening.
In one preferred embodiment of this invention, two opposing notched areas are formed by, in and/or through the first web and the second web. Each notched area is positioned at or near one of two opposing outer edges of the flexible container, and the fold line intersects with each notched area. Each notched area can extend at least partially between a respective outer edge of the flexible container and a corresponding end portion of the opening. The webs are sealed with respect to each other, such as with a heat seal, and each notched area extends from a respective outer edge of the flexible container into the heat seal.
In one preferred embodiment of this invention, the adhesive layer is positioned within at least a portion of at least one of the notched areas, and preferably extends to a corresponding or respective outer edge of the flexible container. An exposed portion of the adhesive layer that is positioned within the notched area is removable from the adhesive layer. Preferably, but not necessarily, a material, such as a web material preferably the same or similar to the first web and/or the second web, a paper material and/or a powder material, covers at least a portion or side of the exposed portion of the adhesive layer that is positioned within the notched area.
In one preferred embodiment of this invention, the flexible container includes a third web sealed with respect to the second web to form a second void between the third web and the second web. The third web may form an opening extending or positioned between opposing outer edges of the flexible container and may provide access to the second void. Materials including information regarding the material contained within the flexible container, such as documents or papers including a description of the contained material, an instruction sheet, a label and/or any other suitable document or paper, can be positioned within the second void and preferably visible or viewable through the third web material.
The third web can extend across the first web and/or the second web, to add structural strength to the flexible container formed by the first and second webs. For example, the third web can act as a girdle or a structural restraint to restrict or restrain expansion of the flexible container, particularly in a middle portion, when the flexible container has a positive pressure within the first void or the holding compartment formed by the first void.
Other objects and advantages of this invention will be apparent to those skilled in the art from the following detailed description taken in conjunction with the appended claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings show different features of a flexible container, according to preferred embodiments of this invention, wherein:
FIG. 1 is a plan front view of a flexible container in a flat or unfolded condition, according to one preferred embodiment of this invention;
FIG. 2 is a cross-sectional side view of a flexible container along sectional line A-A as shown in FIG. 1, according to one preferred embodiment of this invention;
FIG. 3 is a partial cross-sectional side view of a flexible container, according to one preferred embodiment of this invention;
FIG. 4 is a partial cross-sectional side view of a flexible container, according to one preferred embodiment of this invention;
FIG. 5 is a partial cross-sectional side view of a flexible container, according to one preferred embodiment of this invention;
FIG. 6 is a partial cross-sectional side view of a flexible container, according to one preferred embodiment of this invention;
FIG. 7 is a partial cross-sectional side view of a flexible container, wherein each side of the flexible container has two webs, according to another preferred embodiment of this invention;
FIG. 8 is a partial cross-sectional side view of a flexible container, wherein each side of the flexible container has two webs, according to another preferred embodiment of this invention;
FIG. 9 is a partial cross-sectional side view of a flexible container, wherein each side of the flexible container has one web, showing a portion of the flexible container in a folded position;
FIG. 10 is a plan front view of a flexible container in a flat or unfolded condition, according to one preferred embodiment of this invention;
FIG. 11 is a partial cross-sectional side view of a flexible container, showing a portion of the flexible container in a folded position;
FIG. 12 is a plan front view of a flexible container in a flat or unfolded condition, according to one preferred embodiment of this invention; and
FIG. 13 is a cross-sectional side view of a flexible container along sectional line B-B as shown in FIG. 12, according to one preferred embodiment of this invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIGS. 1-6, in one preferred embodiment of this invention, a flexible container 10 comprises a first web of material 20 and a second web of material 40, one on each side of flexible container 10, sealed with respect to each other to form a void 28 between webs 20, 40. FIGS. 7 and 8 show other embodiments of flexible container 10 having four total webs: a primary first web 20 and a secondary first web 20 on one side of flexible container 10; and a primary second web 40 and a secondary second web 40 on the other side of flexible container 10. Also, any side of flexible container 10 can have more than two webs 20, 40.
The term “flexible” refers to the ability of flexible container 10 to bend, stretch, expand or contract, for example, without permanent deformation or failure, to adapt to changing environments, for example a change in pressure or change in temperature. It is apparent that flexible container 10 and/or void 28 formed between webs 20, 40 can have any suitable shape and/or dimensions which allows flexible container 10 to function properly for a particular purpose. Flexible container 10 may comprise at least one component or element similar to a corresponding component or element as taught in U.S. Pat. No. 5,336,123 issued to Laske et al. on Aug. 9, 1994, the disclosure of which is incorporated by reference into this specification.
Throughout this specification, as discussed above, one side of flexible container 10 may include one or more first webs 20 and the opposing side of flexible container 10 may comprise one or more second webs 40. As different elements and features are discussed throughout this specification, when referring to one first web 20 and/or one second web 40, such discussion can be interchanged with discussion related to either side of flexible 10 having two or more first webs 20 and/or two or more second webs 40.
Preferably, first web 20 and second web 40 are heat sealed to form a continuous seal 30 about a periphery of flexible container 10, as shown in FIG. 1. Any other suitable process for sealing, as known to those skilled in the art, can be used to form one or more continuous seals between webs 20, 40. In one embodiment, seal 30 preferably has a width of at least about 0.125 inch, and more preferably at least about 0.375 inch, or larger or smaller depending upon the overall size of flexible container 10 and the material which flexible container 10 may contain. In another embodiment, seal 30 can have a variable width and/or any other shape at any point or in any direction about the periphery of seal 30. It is apparent that other suitable bonding means, for example adhesives and the like, may be used to form seal 30 and attach or bond webs 20, 40. Flexible container 10 may comprise additional seals, as required. For example, if the side of flexible container 10 that has opening 60 has two or more first webs 20, then a seal 31 such as shown in FIG. 1 can be used to heat seal the two or more first webs 20 together, wherein seal 31 surrounds or is below opening 60, as shown in FIG. 1. In another embodiment, a seal 32 extends along at least a portion at or near a top edge and/or a bottom edge of flexible container 10 to seal first web 20 to second web 40.
Preferably, each web 20, 40 has a total thickness of about 0.003 inch to about 0.010 inch and comprises at least two layers of material that are coextensive. The term “coextensive” as used throughout this specification and in the claims refers to the positioning of web 20 with respect to web 40, wherein web 20 is aligned with web 40 such that web 20 and web 40 generally have the same or similar outer boundaries, for example boundaries forming the edges of flexible container 10. In one preferred embodiment of this invention, first web 20 includes a first or outer layer 22 made of a polymer material, such as a polyester or nylon or other similar material, having a thickness of about 0.00025 inch to about 0.0015 inch and a second or inner sealant layer 24 made of a polymer material having a thickness of about 0.0005 inch to about 0.006 inch. First layer 22 may comprise a 0.00060 inch, for example, biaxial oriented nylon material, such as available from Clear-Lam, located in Illinois, United States. The biaxial oriented nylon material provides a strong structure due to equal or similar tensile strengths in the longitudinal-direction and the lateral direction of the material. Preferably, second layer 24 comprises a 0.0015 inch polyethylene material available from Southern Films located in Florida, U.S.A., a material which is known as a linear low density polyethylene. Other suitable materials known to those skilled in the art may be used to make the first layer and/or the second layer of first web 20 and/or second web 40.
Similarly, second web 40 includes a first layer 42 and a second layer 44. Preferably, but not necessarily, first layer 42 comprises a material the same or similar to first layer 22 of first web 20 and second layer 44 comprises a material the same or similar to second layer 24 of first web 20. Alternatively, first layer 42 and second layer 44 may comprise a different material than first layer 22 and second layer 24, respectively. In one preferred embodiment of this invention as shown in FIG. 7, second first web 20 and first and second webs 40 each comprises a third layer sealed with respect to layers 22, 24 and/or 42, 44, respectively. For example, a third layer 26 (not shown) made of 0.0015 inch polyethylene, for example, may be sealed with respect to first layer 22 to sandwich or position first layer 22 between second layer 24 and third layer 26.
First layers 22, 42 and second layers 24, 44, and any additional layers, may be made of any suitable compatible materials, for example polymer materials, which when combined to form one or more of each of webs 20, 40 exhibit a combined strength capable of withstanding a wide pressure and/or temperature range. The multiple layer, multiple web construction of flexible container 10 provides a strong structure because one layer supports the other layer. Preferably, flexible container 10 is capable of withstanding a constant or sustained internal pressure of at least about 14 psi. The closure at closure area 62 and the corresponding material of the closure can withstand temperatures of about 40° F. to about 130° F., without deformation of and/or leakage through the closure.
Referring to FIGS. 1-3, first web 20 forms an opening 60 at or within a closure area 62 defined by first web 20 to provide access to void 28. Preferably, but not necessarily, opening 60 comprises a slit which is positioned along, at or near a fold line 100, which passes through closure area 62, as shown in FIG. 1. Opening 60 may extend outward in a direction toward seal 30 any suitable distance. Opening 60 may stop short of seal 30, may extend up to an inner edge of seal 30, may extend into seal 30, may extend up to an outer edge of seal 30, and/or may extend beyond seal 30 into a skirt 75. To whatever point opening 60 extends, there should be a sufficient area of adhesive contact, either adhesive-to-adhesive or adhesive to web 20, to ensure a fight seal at or near end portions 71, 73 of opening 60 to provide a leak-tight seal about opening 60 when flexible container 10 is folded about fold line 100. Further, as a distance between end portion 71 and/or 73 and seal 30 decrease, a width of seal 30 and/or a width of skirt 75 defined by a portion of flexible container 10 between edges 15, 13 of flexible container 10, respectively, and an outer edge of seal 30 preferably, but not necessarily, increases.
In one preferred embodiment of this invention, first web 20 has a second thickness in closure area 62 which is less than the first thickness of first web 20. For example, preferably only one of first layer 22 and second layer 24 extends to form a portion of opening 60. As shown in FIG. 3, first layer 22 may extend along only a portion of second layer 24 and terminate at an edge 61. Second layer 24 forms at least a portion of opening 60 defined by an edge 63. Preferably, edge 61 terminates at a distance 65 from edge 63, to form a cutout area 64. Distance 65 is about 0.125 inch to about 1.0 inch, preferably about 0.75 inch, or any other suitable length. Additionally, on an opposite side of opening 60, second layer 24 can extend to form a portion of opening 60 along a second edge of second layer 24 opposing edge 63 and first layer 22 can terminate a distance from the second edge of second layer 24, equal to or different than distance 65. In one embodiment of this invention, cutout area 64 is formed about opening 60 in one or more layers of one or more first webs 20. In such embodiment cutout area 64 has a length in a longitudinal direction of flexible container 10 of about 0.25 inch to about 2.0 inch, or any other suitable length, and a width which extends at least partially over an entire width of flexible container 10. If opening 60 and notched areas 70 are in the same layer of any first web 20, then opening 60 extends less than a distance between inner edges of two corresponding notched areas 70. If opening 60 and notched area 70 is each within a different layer of 22 or 24 of any first web 20, then at least a portion of opening 60 can overlap with notched area 70.
An adhesive layer 68 is applied to at least a portion of first web 20 at closure area 62 and/or cutout area 64. Any suitable adhesive known to those skilled in the art can be used to form adhesive layer 68. Any adhesive can be used, which provides a sufficiently strong adhesive seal to close opening 60. A cover strip 50 can be applied to or positioned on adhesive layer 68, such that adhesive layer 68 is sandwiched or positioned between first web 20 at closure area 62 and cover strip 50. Preferably, cover strip 50 and adhesive layer 68 form a pressure sensitive tape material, as is well known in the art. The pressure sensitive material can be applied as a preformed material or can be applied in manufacturing steps as the adhesive layer 68 and the cover strip 50.
Referring to FIG. 4, in one embodiment of this invention, first web 20 forms cutout area 64 at closure area 62. In one preferred embodiment of this invention, a fold layer 66 overlaps onto a portion of first web 20 and is sealed to any first web 20 on one side of flexible container 10, about cutout area 64. Preferably, but not necessarily, fold layer 66 is heat sealed to first web 20 to form a continuous seal 33. Seal 33 can extend about cutout area 64 and/or can extend into seal 30. As shown in FIG. 4, fold layer 66 is sealed to an inner surface of second layer 24. Alternatively, as shown in FIG. 5, fold layer 66 may be sealed to an outer surface of first layer 22. Preferably, fold layer 66 has a thickness less than a thickness of first web 20, and thus a lesser magnitude of shape memory, to allow a continuous adhesive seal to form about opening 60 when flexible container 10 is folded along fold line 100. As shown in FIG. 1, fold line 100 is collinear with opening 60, but in other embodiments, fold line 100 can be above and/or below opening 60. It is apparent to those skilled in the art that fold layer 66 can be bonded, adhered or otherwise attached to first web 20 using any suitable means which provides a leak-proof seal. Alternatively, fold layer 66 can be integrated with first layer 22 and/or second layer 24 of first web 20. Adhesive layer 68 is applied to at least a portion of an outer surface of fold layer 66 and cover strip 50 is applied to or positioned on adhesive layer 68, such that adhesive layer 68 is sandwiched or positioned between closure area 62 of first web 20 and cover strip 50, as is shown in FIG. 4, or adhesive layer 68 is positioned between fold layer 66 and cover strip 50, as is shown in FIG. 5.
In one preferred embodiment of this invention, at least one web 20, 40 has at least one structural relief 69. As shown in FIG. 1, structural relief 69 is formed by notched areas 70 positioned at or near end portion 71 and/or 73 of opening 60. The term “structural relief” as used throughout this specification and in the claims refers to any structural feature or material property of any one or more layers of web 20, 40 that decreases a magnitude of the shape memory or bias force of web 20, 40. As discussed above, shape memory relates to a folded web 20, 40 that urges itself back to an unfolded position or state, and is one problem associated with conventional flexible containers, and is directly related to container leakage.
In one preferred embodiment of this invention, structural relief 69 comprises a notched area 70 formed in one or more layers of web 20 and/or one or more layers of web 40 and extending a distance on each side of fold line 100, as shown in FIG. 1. Notched area 70 may be formed by removing or otherwise eliminating at least one layer of first web 20 and/or second web 40 at notched area 70. Preferably, first web 20 and/or second web 40 comprises notched area 70 at or near one or both side edges 13, 15 of flexible container 10. As shown on the right side of FIG. 1, notched area 70 need not extend to or have a common boundary with an outer edge 13, 15. Notched area 70 extends at least partially between outer edge 13, 15 of flexible container 10 and respective end portion 73, 71 of opening 60. Depending on the number of layers in each web 20, 40, notched area 70 can extend inward further than end portion 71 and/or 73. Further, notched area 70 may extend through only one layer or more than one layer of first web 20 and/or second web 40, and may extend laterally into a corresponding portion of seal 30.
Further, as shown in FIG. 6, structural relief 69 may also comprise at least one of the layers of web 20 and/or at least one of the layers of web 40 having a reduced thickness at fold line 100. In other preferred embodiments of this invention, structural relief 69 may comprise a second slit formed within at least one other web 20, 40 and/or may comprise a score line within at least one web 20, 40. Structural relief 69 may be continuous or intermittent, as required or desired.
Referring to FIGS. 1-6, when adhesively sealing opening 60 of flexible container 10 at closure area 62, cover strip 50 is removed, for example by peeling cover strip 50 from adhesive layer 68. As shown in FIG. 9, a top portion 12 of flexible container 10, above fold line 100, is folded to contact a bottom portion 14 of flexible container 10, below fold line 100. Preferably, to provide a tight leak-proof seal, flexible container 10 is folded along fold line 100. Adhesive layer 68 provides a leak-proof seal about opening 60 in closure area 62. In one preferred embodiment of this invention as shown in FIG. 1, at least one structural relief 69, for example notched area 70 is formed in first web 20 and/or second web 40 by preferably, but not necessarily, removing or otherwise eliminating, such as through a manufacturing process, a portion of at least one layer 22, 24 of first web 20 and/or at least one layer 42, 44 of web 40. Preferably, fold line 100 passes through notched area 70. Fold line 100 defines the longitudinal position of opening 60 with respect to flexible container 10.
In one embodiment of this invention, when flexible container 10 is folded about fold line 100, adhesive layer 68 folds over onto itself to form an adhesive-to-adhesive bond and/or folds over onto an outer surface of at least one layer 22, 24 of at least one first web 20 to form an adhesive-to-layer bond. In either case, because of the shape memory or bias force within the at least one layer 22, 24, at fold line 100 the at least one layer 22, 24 has a tenancy to unfold or open flat. By applying more pressure to the at least one layer 22, 24 at fold line 100, the adhesive-to-adhesive and/or the adhesive-to-layer bond strength is increased. Providing one or more notched areas 70 at fold line 100 allows more direct pressure applied at fold line 100 which enhances the bond strength provided by adhesive layer 68.
Further, top portion 12 may include a reference mark 83 and bottom portion 14 may include a reference mark 85 to assist in properly sealing flexible container 10. For example, reference mark 85 may comprise a star which is positionable within reference mark 83, comprising a box, when flexible container 10 is folded to properly register top portion 12 and bottom portion 14 to seal flexible container 10. It is apparent that reference marks 83, 85 can be any desirable mark which allows registration of top portion 12 with bottom portion 14 when flexible container 10 is folded to seal opening 60.
Referring to FIGS. 10 and 11, in certain embodiments of this invention, flexible container 10 includes first web of material 20 and second web of material 40 sealed with respect to each other to form void 28 between webs 20, 40. First web 20 and second web 40 are sealed about a periphery of flexible container 10 using any suitable sealing process, such as a heat sealing process. Preferably, but not necessarily, each web 20, 40 includes at least two layers of material. For example, in one embodiment of this invention, a first layer may include a polyester or nylon material and a second layer may include a polyethylene material. The first layer can be coextensive with the second layer, particularly about or along the heat seals.
First web 20 forms or includes opening 60 at or within closure area 62 which can be defined by first web 20, for example to provide access to void 28. Opening 60 is positioned along and/or forms at least part of fold line 100, which passes through closure area 62. Adhesive layer 68 is applied to at least a portion of first web 20 adjacent two opposing sides 76, 78 of opening 60 at closure area 62. Any suitable adhesive known to those skilled in the art can be used to form adhesive layer 68, which provides a sufficiently strong adhesive seal to close opening 60.
Adhesive layer 68 can be applied to first web 20 before or after opening 60 is formed in first web 20, in order to increase efficiency and/or reduce time and expense associated with the manufacturing process used to make flexible container 10. For example, adhesive layer 68 may be applied to first web 20 within closure area 62, and then opening 60 can be formed through adhesive layer 68 and first web 20 within closure area 62. Such manufacturing process may be time and/or cost efficient and result in adhesive applied to first web 20 at, adjacent, near, next to and/or in the proximity of opposing sides 76, 78 of opening 60, as shown in FIG. 10. When it is desired to hermetically seal void 28, opening 60 can be completely surrounded by adhesive layer 68. For example, adhesive can be applied to first web 20 at, adjacent, near, next to and/or in the proximity of opposing sides 76, 78, and at, adjacent, near, next to and/or in the proximity of end portions 71, 73 of opening 60. Alternatively, opening 60 may be formed before adhesive layer 68 is applied to first web 20 and within closure area 62. During such a manufacturing process, adhesive layer 68 can be applied at, adjacent, near, next to and/or in the proximity of opposing sides 76, 78 and/or end portions 71, 73 of opening 60.
Cover strip 50 can be applied to or positioned on adhesive layer 68, such that adhesive layer 68 is positioned between first web 20 and cover strip 50. Cover strip 50 and adhesive layer 68 can form a pressure sensitive tape material, as is well known to those skilled in the art. The pressure sensitive material can be applied as a preformed material or can be applied in one or more manufacturing steps as adhesive layer 68 and cover strip 50.
With flexible container 10 in an unfolded condition, as shown in FIG. 10, opening 60 is positioned within adhesive layer 68 which is applied to first web 20 within closure area 62. Referring to FIG. 11, with flexible container 10 in a folded condition, a portion of each web 20, 40 is folded with respect to opening 60 along fold line 100. In certain embodiments of this invention, a first portion 93 of adhesive layer 68 on side 76 of opening 60 contacts a second portion 94 of adhesive layer 68 on opposing side 78 of opening 60, as shown in FIG. 11. Thus, side 76 forms an adhesive-to-adhesive contact with opposing side 78 to seal or close opening 60. Preferably, the adhesive-to-adhesive contact extends around opening end portions 71, 73 to completely surround and seal opening 60 and thus hermetically seal void 28.
As shown in FIG. 10, flexible container 10 can include at least one notched area 70 formed by, in or through at least one layer of first web 20 and/or at least one layer of second web 40. In one preferred embodiment of this invention, two notched areas 70 are formed by, in or through each web 20, 40. As shown in FIG. 10, each notched area 70 can be formed through each web 20, 40 such that a boundary of first web 20 forming notched areas 70 is coextensive with a boundary of second web 40 forming notched areas 70. A first notched area 70 is positioned or formed at and/or exposed to outer edge 13 of flexible container 10, and a second notched area 70 is positioned or formed at and/or exposed to outer edge 15 of flexible container 10.
As shown in FIG. 10, fold line 100 intersects with each notched area 70. In certain embodiments of this invention, webs 20, 40 are sealed with respect to each other along seal 30 and notched areas 70 extend into seal 30. For example, webs 20, 40 are preferably sealed with respect to each other with a heat seal, and notched area 70 extends from outer edge 13 or outer edge 15, respectively, into the heat seal. As shown in FIG. 10, a first notched area 70 preferably extends at least partially between outer edge 13 and a corresponding end portion 73 of opening 60. Similarly, a second notched area 70 can extend at least partially between opposing outer edge 15 and corresponding end portion 71 of opening 60.
In certain embodiments of this invention, adhesive layer 68 is positioned within at least a portion of at least one notched area 70. Adhesive layer 68 can be positioned within one or both notched areas 70 and may or may not extend to, and be coextensive with, respective outer edge 13 and/or outer edge 15 of flexible container 10, as shown in FIG. 10. Adhesive layer 68 may be partially positioned within one notched area 70 or both notched areas 70 and may extend partially between a boundary of flexible container 10 forming notched area 70 and respective outer edge 13 and/or outer edge 15. Thus, an exposed portion 95 of adhesive layer 68 may be positioned completely within one notched area 70 or both notched areas 70 and/or may be partially positioned within one notched area 70 or both notched areas 70, as desired. As shown in FIG. 10, adhesive layer 68 is positioned completely within each notched area 70 and extends to respective outer edge 13 or outer edge 15.
A material of adhesive layer 68, such as exposed portion 95 at least partially positioned within at least one notched area 70, can be removable from adhesive layer 68, if desired. For example, exposed portion 95 covering notched areas 70, as shown in FIG. 10, can be removed by using a suitable force to tear or separate exposed portion 95 from adhesive layer 68, for example at or near a boundary of flexible container 10 forming or defining notched area 70. Exposed portion 95 may or may not be covered with a material, such as a web material preferably the same or similar to first web 20 and/or second web 40, a paper material, a powder material, and/or any other suitable material that prevents undesirable contact with exposed portion 95.
Referring to FIG. 13, in certain embodiments of this invention, adhesive layer 68 includes a polyester carrier layer or liner 140 and/or any suitable carrier structure. Liner 140 may be applied to, positioned on or positioned within adhesive layer 68 to provide sufficient or desirable support or structure to adhesive layer 68 and maintain adhesive layer 68 properly positioned with respect to first web 20. Liner 140 may be positioned within adhesive layer 68. Liner 140 may be positioned between a first layer of adhesive 68 and a second layer of adhesive 68, such as shown in FIG. 13. In one preferred embodiment of this invention, liner 140 has a thickness of about 0.5 mils. Liner 140 may have any suitable thickness, greater than or less than 0.5 mils. In addition or alternatively, adhesive layer 68 may have a thickness of about 3-4 mils. With adhesive layer 68 having a thickness of about 3-4 mils, depending upon the type of adhesive, it may not be necessary to include a carrier layer, such as liner 140, in adhesive layer 68. Adhesive layer 68 may have any suitable thickness, greater than or less than 3-4 mils.
In addition to the exposed adhesive portion positioned within notched areas 70, or alternatively, cover strip 50 may cover at least a portion of each notched area 70. Cover strip 50 may completely cover one notched area 70 or both notched areas 70 and/or may partially cover one notched area 70 or both notched areas 70, as desired. In certain embodiments, cover strip 50 covers each notched area 70, which may or may not include exposed portion 95 of adhesive layer 68, and extends to outer edges 13, 15 of flexible container 10, as shown in FIG. 10. In other embodiments of this invention, cover strip 50 may extend towards outer edge 13 and/or outer edge 15 to cover only a portion of each respective notched area 70.
In certain embodiments of this invention, adhesive layer 68 and/or cover strip 50 overlaps at least a portion of each notched area 70. The term “overlap” refers to a layered structure wherein notched areas 70 are formed in each web 20, 40 and thus can be considered coplanar with each web 20, 40, and adhesive layer 68 completely extends or partially extends across or overlaps each notched area 70 in a plane generally parallel and adjacent to the plane of first web 20. An exposed portion 95 of adhesive layer 68 and/or cover strip 50 may completely overlap one notched area 70 or both notched areas 70 and/or may partially overlap one notched area 70 or both notched areas 70, as desired. Preferably, adhesive layer 68 and/or cover strip 50 overlaps each notched area 70 and extends to outer edges 13, 15 of flexible container 10. In other preferred embodiments of this invention, adhesive layer 68 and/or cover strip 50 may extend from first web 20 and overlap only a portion of each notched area 70.
As shown in FIG. 11, flexible container 10 preferably includes a third web 80 sealed with respect to second web 40 to form a second void 96 between third web 80 and second web 40. Third web 80 can be but need not be coextensive with first web 20 and/or second web 40. Third web 80 may include any suitable web material, including without limitation the materials described above in reference to first web 20 and/or second web 40. Third web 80 can form a second opening 98 that extends between or is positioned between opposing outer edges 13, 15 of flexible container 10. Second opening 98 may or may not provide access to second void 96. Informative materials or documents including information regarding the material contained within void 28 of flexible container 10, such as documents or papers including a description of the contained material, an instruction sheet, a label and/or any other suitable object, document or paper, may be positioned within second void 96 and preferably but not necessarily viewable through the third web material.
In some embodiments of this invention, third web 80 can be used to form a reinforcement girdle or sleeve 105 positioned and/or sized to reinforce or provide support to flexible container 10. Reinforcement sleeve 105 can be positioned within at least a central area 106 of flexible container 10, as shown in FIG. 12. With flexible container 10 at least partially filled with a pressurized fluid, material or substance, the internal pressure applies a force against webs 20, 40. Depending on the shape of void 28, the heat seals and/or the web materials along central area 106 maybe subjected to an increased and/or a maximum force or pressure. Reinforcement sleeve 105 may include a continuous sheet of material that is positioned about flexible container 10 and heat sealed with respect to each of first web 20 and second web 40, for example along heat seal 30. Alternatively, reinforcement sleeve 105 may include one or more reinforcement panels or sheets 115, 120 that are on or positioned and/or sealed with respect to first web 20 and/or second web 40. Further, reinforcement sleeve 105 may be made of any suitable material having sufficient or desirable structural strength including, without limitation, the materials described above in reference to first web 20 and/or second web 40.
Reinforcement sleeve 105 preferably extends along a length of void 28 of flexible container 10. In certain embodiments of this invention, as shown in FIG. 12, with respect to first web 20 which has opening 60, reinforcement sleeve 105 extends between opening 60 and bottom edge 109 of flexible container 10. With respect to second web 40 which has no opening 60, reinforcement sleeve 105 extends between top edge 107 and bottom edge 109 of flexible container 10. Reinforcement sleeve 105 can extend along only a portion of the length, along a vertical direction as shown in FIG. 12, of void 28 of flexible container 10, in order to reduce the amount of material required to make reinforcement sleeve 105 and, therefore, to reduce the cost associated with producing or manufacturing flexible container 10. Because relatively large pressure forces result along central area 106 that occupies about 60-70% of the length of void 28 when flexible container 10 is in a closed or folded condition, reinforcement sleeve 105 can extend along 60-70% of the length of void 28, when flexible container 10 is in a closed condition, such as shown in FIG. 11. Manufacturing and material costs can be reduced by extending reinforcement sleeve 105 along only a portion of the length of void 28, when flexible container 10 is in a closed condition. Further, the thickness of first web 20 and/or the thickness of second web 40 may be reduced, if desired, when flexible container 10 includes reinforcement sleeve 105, thereby reducing the cost associated with producing or manufacturing flexible container 10.
In certain embodiments of this invention, as shown by phantom lines in FIG. 12, reinforcement sleeve 105 comprises a first panel 115 positioned and/or sealed with respect to first web 20 and a second panel 120, on the reverse side as shown in FIG. 12, positioned and/or sealed with respect to second web 40. First panel 115 and/or second panel 120 can be sealed with respect to respective web 20, 40 using any suitable seal, such as heat seal 30 and/or secondary heat seal 130. Heat seal 30 and/or 130 each preferably extends along opposing edges 116 and 117 of first panel 115. Additionally, heat seal 130 may extend along top edge 118 and/or bottom edge 119 of first panel 115. Similarly, heat seal 30 and/or 130 may extend along opposing edges 121 and 122 of second panel 120. Additionally, heat seal 30 and/or 130 may extend along a top edge and/or a bottom edge, with respect to the direction shown in FIG. 12, of second panel 120.
First panel 115 and second panel 120 may be made of one continuous sheet of material or may be made of two separate or independent panels of material. First panel 115 can extend with respect to first web 20 between opposing outer edges 13, 15 and at least partially along the length of flexible container 10. As shown in FIG. 12, first panel 115 extends along only a portion of the length of void 28, between bottom portion 110 of heat seal 30 and opening 60. Preferably, the bottom edge of first panel 115 stops or terminates short of bottom portion 110 of heat seal 30 and/or the top edge of first panel 115 stops or terminates short of opening 60. First panel 115 may extend to the bottom edge of cover strip 50. Second panel 120 extends with respect to second web 40 between opposing outer edges 13, 15 and at least partially along the length of void 28 of flexible container 10.
FIG. 13 shows second panel 120 extending along about 60-70%, but could be more or less, of the length of void 28. In the view shown in FIG. 13, when flexible container 10 is pressurized or filled, void 28 can assume a shape having an overall elliptical or football-shaped cross section.
First panel 115 may be positioned and/or sealed with respect to an exterior surface of first web 20 or an interior surface of first web 20. Similarly, second panel 120 may be positioned with respect to an exterior surface of second web 40 or an interior surface of second web 40.
While in the foregoing specification the invention has been described in relation to certain preferred embodiments, and many details are set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described in the specification and in the claims can be varied considerably without departing from the basic principles of the invention.
Patent Application
20050286816
