Flexible container
A flexible container including two webs sealed with respect to each other to form a void between the webs. A first web forms an opening within a closure area. The opening is positioned along a fold line that passes through the closure area. With the flexible container in an unfolded condition, a layer of adhesive is applied to the first web within said closure area. The webs form two notched areas each at or near one of two opposing outer edges of the flexible container. The fold line intersects with the notched areas. With the flexible container in a folded condition, a portion of each web is folded with respect to the opening and 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.
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 INVENTIONIt 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 DRAWINGSThe drawings show different features of a flexible container, according to preferred embodiments of this invention, wherein:
As shown in
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
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
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
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
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
In one preferred embodiment of this invention, at least one web 20, 40 has at least one structural relief 69. As shown in
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
Further, as shown in
Referring to
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
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
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
As shown in
As shown in
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
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
Referring to
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
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
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
Reinforcement sleeve 105 preferably extends along a length of void 28 of flexible container 10. In certain embodiments of this invention, as shown in
In certain embodiments of this invention, as shown by phantom lines in
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
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.
Claims
1. A flexible container comprising:
- two webs sealed with respect to each other to form a void between said webs, a first web of said webs having a closure area, said first web forming an opening within said closure area, said opening positioned along a fold line passing through said closure area, with the flexible container in an unfolded condition said opening positioned within a layer of adhesive applied to said first web within said closure area, two notched areas formed by each of said first web and said second web, each of said notched areas positioned at one of two opposing outer edges of the flexible container, said fold line intersecting with said notched areas, and said layer of adhesive positioned within at least a portion of each of said notched areas.
2. The flexible container according to claim 1 wherein each said web has at least two layers.
3. The flexible container according to claim 1 wherein at least a portion of said layer of adhesive positioned within at least a portion of each said notched area is removable.
4. The flexible container according to claim 3 wherein a web material covers said portion of said layer of adhesive positioned within at least a portion of each said notched area.
5. The flexible container according to claim 3 wherein a powder material covers said portion of said layer of adhesive positioned within at least a portion of each said notched area.
6. The flexible container according to claim 1 wherein said layer of adhesive extends to each of said opposing outer edges.
7. The flexible container according to claim 1 further comprising:
- a third web sealed with respect to said second web to form a second void between said third web and said second web, said third web forming a second opening, and said second opening positioned between said opposing outer edges.
8. The flexible container according to claim 1 further comprising:
- a cover strip applied to said layer of adhesive, wherein said layer of adhesive is between said closure area of said first web and said cover strip.
9. The flexible container according to claim 1 wherein said webs are sealed about a periphery of the flexible container.
10. The flexible container according to claim 1 further comprising a reinforcement sleeve positioned with respect to said first web and said second web, said reinforcement sleeve extending between said opposing outer edges and extending at least partially along a length of said flexible container.
11. A flexible container comprising:
- two webs sealed with respect to each other to form a void between said webs, each said web having at least two layers, a first web of said webs having a closure area, said first web forming an opening within said closure area, said opening forming at least part of a fold line passing through said closure area, with the flexible container in an unfolded condition a layer of adhesive applied to said first web adjacent two opposing sides of said opening and within said closure area, said first web and said second web forming two notched areas, each of said notched areas positioned near one of two opposing outer edges of the flexible container, said fold line intersecting with said notched areas, and said layer of adhesive covering each of said notched area.
12. The flexible container according to claim 11 wherein said at least two layers comprise a first layer of a polyester or nylon material and a second layer of a polyethylene material.
13. The flexible container of claim 11 wherein a first layer of said at least two layers is coextensive with a second layer of said at least two layers.
14. The flexible container according to claim 11 wherein each of said notched areas extends at least partially between an outer edge of said opposing outer edges and a corresponding end portion of said opening.
15. The flexible container according to claim 11 wherein said webs are sealed with respect to each other with a heat seal, and each of said notched areas extends into said heat seal.
16. The flexible container according to claim 11 wherein a material of said adhesive layer is removable at each of said notched areas.
17. The flexible container according to claim 11 wherein said layer of adhesive comprises a polyester carrier layer positioned between a first layer of adhesive and a second layer of adhesive.
18. A flexible container comprising:
- two webs sealed with respect to each other to form a void between said webs, said first web having an opening within a closure area, said opening positioned along a fold line passing through said closure area, with the flexible container in an unfolded condition a layer of adhesive applied to said first web within said closure area adjacent two opposing sides of said opening, said first web and said second web forming two notched areas each at one of two opposing outer edges of the flexible container, said fold line intersecting with said notched areas, and with the flexible container in a folded condition a first portion of said adhesive layer on a first side of said two opposing sides forming an adhesive-to-adhesive contact with a second portion of said adhesive layer on a second side of said two opposing sides.
19. The flexible container of claim 18 wherein said webs are sealed with respect to each other with a heat seal, and each of said notched areas extends from said one of two opposing outer edges into said heat seal to prevent tearing of the flexible container along the fold line.
20. The flexible container according to claim 18 wherein each of said notched areas extends at least partially between said one of two opposing outer edges and a corresponding end portion of said opening.
21. The flexible container according to claim 18 further comprising:
- a first panel sealed with respect to said first web, said first panel extending between said opposing outer edges and extending between said opening and a bottom seal portion of said flexible container; and
- a second panel sealed with respect to said second web, said second panel extending between said opposing outer edges.
22. The flexible container according to claim 21 wherein the second panel is coterminous with said first panel.
23. A flexible container comprising:
- two webs sealed with respect to each other to form a void between said webs, a first web of said webs having a closure area, said first web forming an opening within said closure area, said opening positioned along a fold line passing through said closure area, with the flexible container in an unfolded condition a layer of adhesive applied to said first web within said closure area and surrounding said opening; and
- a first panel extending between opposing outer edges of said flexible container and extending along a portion of a length of said void when said flexible container is in a folded condition.
24. The flexible container according to claim 23 further comprising a second panel extending between opposing outer edges of said flexible container and extending along a second portion of said length of said void.
25. The flexible container according to claim 23 wherein said first panel extends between said opening and a bottom seal portion of said container.
26. The flexible container according to claim 25 wherein a bottom edge of said first panel terminates short of said bottom seal portion.
27. The flexible container according to claim 25 wherein a top edge of said first panel terminates short of said opening.
28. The flexible container according to claim 23 wherein said first panel is sealed to one of said first web and said second web at each of said opposing outer edges.
29. The flexible container according to claim 23 wherein said first panel is positioned adjacent at least one of an interior surface and an exterior surface of at least one of said first web and said second web.
30. The flexible container according to claim 23 further comprising two notched areas formed by each of said first web and said second web, each of said notched areas positioned at one of said opposing outer edges, said fold line intersecting with said notched areas, and said layer of adhesive positioned within at least a portion of each of said notched areas.
Type: Application
Filed: Jun 14, 2005
Publication Date: Dec 29, 2005
Inventor: Louis Laske (Libertyville, IL)
Application Number: 11/152,668