WO2015130713A1

WO2015130713A1 - Films with stress relief intra-chamber seals

Info

Publication number: WO2015130713A1
Application number: PCT/US2015/017393
Authority: WO
Inventors: Thomas D. Wetsch
Original assignee: Pregis Innovative Packaging Llc
Priority date: 2014-02-25
Filing date: 2015-02-24
Publication date: 2015-09-03
Also published as: US20150239633A1; US20180037389A1

Abstract

The present disclosure relates to an inflatable cushion including a first film ply and a second film ply that is sealed to the first ply. The first and second plies can define an inflation chamber therebetween that can be inflatable with a fluid and operable to contain the fluid. An interior seal can be disposed within the inflation chamber attaching the first and second plies together. The interior seal can include a perimeter seal that encloses an inner portion in which the first and second plies are unattached from one another.

Description

FILMS WITH STRESS RELIEF INTRA-CHAMBER SEALS Related Applications

[0001] The present application claims priority from U.S. Patent Application Nos.

61/944,515, filed Feb. 25, 2014; 62/077,815, filed Nov. 10, 2014; and 62/103,504, filed Jan. 14, 2015, the disclosures of which are incorporated herein by reference in their entireties.

Technical Field

[0002] The present disclosure is directed to flexible structures that may be inflated and used as cushioning or protection for packaging and shipping. Background

[0003] A variety of inflated cushions are well-known and used for sundry packaging applications. For example, inflated cushions are often used as void- fill packaging in a manner similar to or in place of foam peanuts, crumpled paper, and similar products. Also for example, inflated cushions are often used as protective packaging in place of molded or extruded packaging components.

[0004] Generally, inflated cushions are formed from films having two plies that are joined together by seals. The seals can be formed simultaneously with inflation, so as to capture air therein, or prior to inflation to define a film configuration having inflatable chambers. The inflatable chambers can be inflated with air or another gas or thereafter sealed to inhibit or prevent release of the air or gas.

[0005] Such film configurations can be stored in rolls or fan-folded boxes in which adjacent inflatable cushions are separated from each other by perforations. During use, a film configuration is inflated to form cushions and adjacent cushions or adjacent stands of cushions are separated from each other along the perforations. [0006] A variety of film configurations are currently available. Many of these film configurations include seal configurations that tend to waste material, inhibit separation of adjacent inflated cushions, and/or form inflated cushions that are susceptible to under- inflation or leakage, thereby inhibiting utility.

[0007] The films are typically inflated by being pulled from a bulk quantity of the film and passed over or proximal to a nozzle. The nozzle blows air in between the films forming cushions. Heat is then used to bind two plies of the film together forming a seal which limits air from escaping. Frequently the films are poorly aligned or have too much freedom (e.g. slack) to be efficiently delivered to the nozzle for inflation. Additionally, due to the heat and pressures used in the process, the films may stick to machine surfaces or the plies may be pulled apart while still hot and exiting the mechanism.

Summary

[0008] In one embodiment, the present disclosure relates generally to an inflatable flexible structure. The inflatable flexible structure may comprise a first film ply. The inflatable flexible structure may comprise a second film ply that is sealed to the first ply to define an inflation chamber therebetween that is inflatable with a fluid and operable to contain the fluid. The inflatable flexible structure may comprise an interior seal disposed within the inflation chamber attaching the first and second plies together, the interior seal including a perimeter seal that encloses an inner portion in which the first and second plies are unattached from one another.

[0009] In various embodiments, the perimeter seal may entirely enclose the inner portion, separating the inner portion from the inflation chamber. The interior seal may be disposed within the inflation chamber. The interior seal may be disposed entirely within the inflation chamber. The interior seal may include a first elongated portion extending from the perimeter seal. The interior seal may include another perimeter seal. The first elongated portion may extend from the perimeter seal to the other perimeter seal. The interior seal may include an intersection between the perimeter seal and the elongated portion, such that the intersection has three leg portions which are part of the perimeter seal and the elongated portion, the interior seal having an increased width at the intersection compared to the perimeter seal and elongated portion, thereby forming a gusset that resists localized stresses in the sealed film plies. The interior seal may include a second intersection between the perimeter seal and a second elongated portion, such that the second intersection has three second leg portions which are part of the perimeter seal and the second elongated portion, the interior seal having an increased width at the second intersection compared to the perimeter seal and second elongated portion, thereby forming a second gusset that resists localized stresses in the sealed film plies. [0010] In various embodiments, the first elongated portion may extend from the perimeter seal to a second perimeter seal, and wherein the second elongated portion extends from the perimeter seal to a third perimeter seal. The inner portion may be at least 10 times wider than the elongated portion. The inflatable flexible structure may include a plurality of said interior seals. The first and second plies may be sealed to one another to define a plurality of inflation chambers therebetween, the plurality of inflation chambers including the inflation chamber and a second inflation chamber. The second inflation chamber may include a second interior seal attaching the first and second plies together. The second interior seal may include a second perimeter seal that encloses a second inner portion in which the first and second plies are unattached from one another. The inner portion may be configured to remain uninflated when the inflation chamber is inflated with the fluid. The first and second plies may be heat sealed together to form the interior seal. The first and second plies may be sealed together with an adhesive to form the interior seal.

Brief Description of the Drawings [0011] Figs. 1A-D are schematics of various embodiments of flexible structures as used in conjunction with an inflation and sealing device;

[0012] Fig. IE is a partial view showing an interior seal of Fig. 1C shown along view II- II;

[0013] Fig. IF is a partial view showing an interior seal of Fig. 1C shown along view III- III;

[0014] Fig. 2 is perspective view of an inflation and sealing device in accordance with various embodiments;

[0015] Fig. 3 is a perspective, exploded view thereof;

[0016] Fig. 4 is a top, right-side view as seen along axis Y of a material support thereof;

[0017] Fig. 5 is a right-side view of a partially assembled system thereof;

[0018] Fig. 6 is a front view of the partially assembled device of Fig. 5;

[0019] Fig. 7 is a perspective, exploded view of a material support and brake of the device of Fig. 2;

[0020] Fig. 8 is a right-side view of the material support and brake of the device of Fig. 2;

[0021] Fig. 9 is a right-side view of a sealing mechanism of the device of Fig. 2;

[0022] Fig. 10 is a front, right perspective view thereof;

[0023] Fig. 11 is a front, cross-sectional view of post-sealing control elements taken along line XI-XI of Fig. 9; and

[0024] Figs. 12A-B are a perspective view of a film structure that forms a container. Detailed Description

[0025] The present disclosure is directed to flexible structures that may be inflated and used as cushioning or protection for packaging and shipping. Specifically, mechanisms prior to sealing and inflation and mechanisms post-sealing and inflation may improve the overall efficiency and speed of the process of forming the cushions. Prior to sealing and inflation, the system may include a material support element which better stores, controls, and delivers the material to the sealing and inflation mechanisms. After the sealing and inflation of the material, material control elements may better direct the material out of the system without damaging the seal or failing to release the heater material from the contact surfaces. [0026] Illustrative embodiments will now be described to provide an overall understanding of the disclosed apparatus. Those of ordinary skill in the art will understand that the disclosed apparatus can be adapted and modified to provide alternative embodiments of the apparatus for other applications, and that other additions and modifications can be made to the disclosed apparatus without departing from the scope of the present disclosure. For example, features of the illustrative embodiments can be combined, separated, interchanged, and/or rearranged to generate other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure.

[0027] Figs. 1A-1D illustrate schematics of various embodiments of flexible structures. The flexible structures may be formed in a variety of manners such as flexible structure 1040 shown in Fig. 1A, flexible structure 1042 shown in Fig. IB, flexible structure 1044 shown in Fig. 1C, or flexible structure 1046 shown in Fig. ID. The flexible structure, such as a multi-ply web 100 of film, for inflatable cushions is provided. The web includes a first web film layer, or ply, 105 having a first longitudinal edge 102 and a second longitudinal edge 104, and a second web film layer, or ply, 107 having a first longitudinal edge 106 and a second longitudinal edge 108. The second ply 107 is aligned to be overlapping and can be generally coextensive with the first ply 105 (as shown in Figs. 1A-1D), i.e., at least respective first longitudinal edges 102,106 are aligned with each other and/or second longitudinal edges 104,108 are aligned with each other. In some embodiments, the layers, or plies 105, 107, can be partially overlapping with inflatable areas in the region of overlap. The plies 105, 107 may be joined to define a first longitudinal edge 110 and a second longitudinal edge 112 of the film 100. The first and second plies 105,107 can be formed from a single sheet of web material, a flattened tube of web material with one edge slit, or two sheets of web material. For example, the first and second plies 105,107 can include a single sheet of web material that is folded to define the joined second edges 104,108 (e.g., "c-fold film"). Alternatively, for example, the first and second plies 105,107 can include a tube of web material (e.g., a flatten tube) that is slit along the aligned first longitudinal edges 102,106. Also, for example, the first and second plies 105,107 can include two independent sheets of web material joined, sealed, or otherwise attached together along the aligned second edges 104, 108.

[0028] The web 100 can be formed from any of a variety of web materials known to those of ordinary skill in the art. Such web materials may include ethylene vinyl acetates (EVAs), metallocenes, polyethylene resins such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE), and blends thereof. Other materials and constructions can be used. The disclosed web 100 can be rolled on a hollow tube, a solid core, or folded in a fan folded box, or in another desired form for storage and shipment. [0029] As shown in Figs. 1A-D, the web 100 can include a series of transverse seals 118 disposed along the longitudinal extent of the web 100. Each transverse seal 118 extends from the longitudinal edge 112 towards the inflation channel 1 14, and in the embodiment shown, toward the first longitudinal edge 110. Each transverse seal 1 18 has a first end 122 proximate the second longitudinal edge 112 and a second end 124 spaced a transverse dimension d from the first longitudinal edge 110 of the film 110. A chamber 120 is defined within a boundary formed by the longitudinal seal 112 and pair of adjacent transverse seals 118.

[0030] Each transverse seal 118 embodied in Figs. 1A-D is substantially straight and extends substantially perpendicular to the second longitudinal edge 112. It is appreciated, however, that other arrangements of the transverse seals 118 are also possible. For example, in some embodiments, the transverse seals 118 have undulating or zigzag patterns.

[0031] The transverse seals 118 as well as the sealed longitudinal edges 110,112 can be formed from any of a variety of techniques known to those of ordinary skill in the art. Such techniques include, but are not limited to, adhesion, friction, welding, fusion, heat sealing, laser sealing, and ultrasonic welding. An inflation region, such as a closed passageway, which can be a longitudinal inflation channel 114, can be provided. The longitudinal inflation channel 114, as shown in Figs. 1A-D, is disposed between the second end 124 of the transverse seals 118 and the first longitudinal edge 110 of the film. The longitudinal inflation channel 114 may extends longitudinally along the longitudinal side 110 and an inflation opening 116 is disposed on at least one end of the longitudinal inflation channel 114. The longitudinal inflation channel 114 has a transverse width D. In the preferred embodiment, the transverse width D is substantially the same distance as the transverse dimension d between the longitudinal edge 110 and second ends 124. It is appreciated, however, that in other configurations other suitable transverse width D sizes can be used. In some embodiments, the inflation opening 1 16 includes a one-way valve such as those disclosed in U.S. Pat. No. US7926507, herein incorporated by reference in its entirety.

[0032] The longitudinal seal 112 and transverse seals 118 cooperatively define boundaries of inflatable chambers 120. In one preferred embodiment, the inflatable chambers 120 may further include one or more interior seals 128. The interior seals 128 may seal the plies 105, 107 to one another at intermediate areas within the chamber 120. As shown in Figs. 1A-D, opposing interior seals 128 may be transversely aligned across the chamber 120. The interior seals 128 may create bendable lines that allow for a more flexible web 100 that can be easily bent or folded. Such flexibility allows for the film 100 to wrap around regular and irregular shaped objects.

[0033] As shown in Figs. 1A-1F, interior seal 128 may include a perimeter seal 132, which may enclose an inner portion or seal section in which the first and second plies 105, 107 are unattached from one another. The perimeter seal 132 may entirely enclose the inner portion, separating the inner portion from the inflation chamber 120. For example, the inner portion may be configured to remain uninflated when the inflation chamber 120 is inflated with the fluid.

[0034] The interior seal 128 may be disposed within the inflation chamber 120. For example, the interior seal 128 may be disposed entirely within the inflation chamber 120, and is spaced and unconnected from the boundaries (e.g., 112, 118) of the inflation chamber 120 in which the interior seal 128 is disposed. In alternative embodiments, the interior seal 128 may be connected to a portion of the chamber boundary (e.g., a transverse seal 118 or a longitudinal seal 112). In cases where the interior seal 128 is a connected directly by a seal to a transverse seal 118, the interior seal 128 may be configured so that the inner portion/seal section 129 is transversely wider than the connection to the transverse seal 118, so that there is a pinched region between the wider area of the inner portion 129 and the transverse seal 118. In cases where the interior seal 128 forms a part of a longitudinal seal 112, the interior seal 128 may have one or more portions that are substantially wider than the connection to the transverse seal 118, so that there is a pinched region between the wider area of the inner portion 129 and the transverse seal 118.

[0035] Figs. IE and IF are partial views of Fig. 1C shown along view II- II and view III- III, respectively. In accordance with various embodiments, such as those illustrated in Figs. IE and IF, interior seal 128 may include an elongated portion 131. The elongated portion 131 may extend transversely across chamber 120. Additionally or alternatively, the elongated portion 131 may extend longitudinally or in another desired direction within the chamber 120. In some embodiments, an interior seal 128 may include other features, such as two or more perimeter seals 132 that enclose inner portions 129, and an elongated portion 131 may extend from one of these features to another, such as between perimeter seals 132, thus connecting the perimeter seals 132. For example, the two perimeter seals 132 and the elongated portion 131 may together form a "barbell" shape. As shown in Figs. 1C and ID, in some embodiments, an interior seal 128 may include three perimeter seals 132 that enclose inner portions 129, with the perimeter seals 132 connected to one another by two elongated portions 131. Those in the art will appreciate that an interior seal 128 of other embodiments may include additional perimeter seals 132 and elongated portions 131 while remaining within the scope of this disclosure. Figs. 1A-1D show chambers 120 having similar interior seal 128 configurations as illustrative examples of the various structures discussed herein. For example, a web 100 may have a first chamber 120 that has a first interior seal 128 having a first configuration (e.g., having a first number of perimeter seals 132 and a first number of elongated portions 131), and a second chamber 120 that has a second interior seal 128 having a second configuration (e.g., having a second number of perimeter seals 132 and a second number of elongated portions 131). Also, while Fig. 1C shows a chamber 120 having two interior seals 128 having similar configurations, those in the art will appreciate that a chamber 120 may have a plurality of interior seals 128 having various configurations (e.g., having varying numbers of perimeter seals 132 or varying numbers of elongated portions 131) while remaining within the scope of this disclosure. The web 100 may include any number of interior seals 128, having any suitable number of perimeter seals 132 and any suitable number of elongated portions 131 disposed within an inflation chamber 120. [0036] The perimeter seal 132 may enclose an inner portion 129 of the plies 105, 107. Inner portion 129, defined by the perimeter seal 132, may have a larger width compared to the width of the elongated portion 131. For example, the inner portion 129 may be at least 5 times wider than the elongated portion 131. For example, the inner portion 129 may be at least 10 times wider than the elongated portion 131. For example, the inner portion 129 may be at least 15 times wider than the elongated portion 131. A solid seal across inner portion 129 (i.e. where the plies 105, 107 are attached) may form a stiffer section of the web 100. A non-solid seal across inner portion 129 (i.e. where the plies 105, 107 are unattached) may be a more flexible web 100. [0037] In order to enclose inner portion 129, the interior seal 128 may have a transition. The transition can form an intersection between the perimeter seal 132 and the elongated portion 131, such that the intersection has three leg portions 134a-c, which are part of the perimeter seal 132 and elongated portion 131. The interior seal 128 may have an increased width at the intersection compared to the perimeter seal 132 and the elongated portion 131, to form a gusset 127. The gusset 127 may resist localized stresses in the sealed film plies 105, 107. The gusset 127 may have a width that is wider than the elongated portion 131. For example the elongated portion 131 may have a width of J. The gusset 127 may widen from width J to 1½ times wider to 10 times wider. For example the gusset 127 may be 5 times wider. The gusset may then narrow again to width K above and below the transition area. The gusset 127 may widen to the entire width of the transition area and then narrow back to width J as the interior seal 128 continues. The gusset 127 may be concave as viewed from the chamber 120. This may allow the transition to be gradual or not sharp. The gradual transition may reduce stresses at the inner portion 129. A sharp transition may be a stress riser such as if the inner portion 129 and the elongated portion formed a 90 degree angle. [0038] Fig. IE shows a perimeter seal 132 that has two elongated portions 131 extending therefrom. For example, as shown in Figs. 1C and ID, an interior seal 128 can include three perimeter seals 132 extending transversely, and the middle perimeter seal 132 can include first and second elongated portions 131 extending therefrom. The first and second elongated portions 131 may extend substantially collinear to each other, and/or the elongated portions 131 may extend substantially parallel to the transverse seals 118. As shown in Fig. IE, the interior seal 128 may include a second intersection between the perimeter seal 132 and the second elongated portion 131, such that the second intersection has three second leg portions 134d-f, which are part of the perimeter seal 132 and the second elongated portion 131. The interior seal 128 may have an increased width at the second intersection compared to the perimeter seal 132 and the elongated portion 131, to form a second gusset 127, which may resist localized stressed in the sealed film plies 105, 107.

[0039] In accordance with various embodiments, the perimeter seal 128 and/or the inner portion 129 may be circular, oval, triangular, or any other shape. As shown in Figs. IE and IF, the perimeter seal 128 may be circular and may define an inner portion 129 that is a circle.

[0040] In accordance with various embodiments, the plies, walls, structures, etc., discussed herein may be sealed together (e.g., to form interior seals 128, longitudinal seals 110, 112, and/or transverse seals 118) to form the described structures with any process such as adhesively bonding, friction, welding, fusion, heat sealing, laser sealing, and ultrasonic welding. In various embodiments, an adhesive suitable to connect separate portions of the materials discussed herein may be utilized. The adhesive may be a pressure sensitive, time dependent, evaluative, radiation sensitive, or other forms of adhesives. For example, the adhesive may be cured by exposing the adhesive to an electromagnetic radiation. The adhesive may be sensitive to electromagnetic radiations in specific areas of the

electromagnetic radiation spectrum. For example, the adhesive may be a ultraviolet light (UV) curable adhesive. The adhesives may be applied to the plies, walls, or other structures discussed herein by painting, printing, rolling, etc. An adhesive that is operable to seal the inflation chambers sufficiently to contain gas under shipping pressures may be suitable. These pressures may be those formed by stacking the flexible structure under multiple layers of the shipped product or other environmental pressures on the flexible structure internal or external that would occur during shipping, storage, or use. As discussed herein any of the seals may be made by just heat sealing, just adhesive sealing, both types of sealing, or any other type of sealing.

[0041] In accordance with various examples, the plies 105, 107 may be sealed together forming an interior inflation chamber according to any suitable method. Furthermore, the flexible structure 100 already formed of plies 105, 107 may be sealed to itself or another portion of flexible structure 100 in order to form specific structures such as for example container 50 (see Figs. 12A-B).

[0042] As shown in Figs. 12A-B, each separate flexible structure (e.g. 100) may be utilized to form a container 50. Figs. 12A-B show a c-fold structure as one example of forming container 50. For example, the container 50 may be formed by sealing two separate flexible structures 100. The container 50 may be structured from any number of sheets of flexible structure 100 forming more than two walls as the various application dictates. Fig. 12A illustrates a schematic of the flexible structure being folded in accordance with various embodiments. As discussed above, the flexible structure 100 may be folded along intermittent seal 153. This intermittent seal may be anywhere and in any number, such that flexible structure 100 may be folded with any number of folds. In various embodiments, the flexible structure 100 may be folded along the centerline as illustrated in the example of Fig. 12A. Folding the flexible structure 100 in this way may allow the edges 102,106 and 104,108 to align. With the flexible structure 100 folded, the first wall and the second wall may be sealed along a plurality of seals. For example, as illustrated in Fig. 12B, these seals may include one or more of top seal 145, external longitudinal seal 142, internal longitudinal seal 141, and bottom seal 159. A second transvers seal similar to the seal 145 may additionally be formed along the transverse edge 149. The second transfer seal may be an alternative seal to seal 145. In some embodiments, the container may include handles 50, which may also be sealed together at 150. These seals may be made after produce, or other content, has been placed in the container 50. The seals may be made with mechanical attachment (e.g. zip style), with heat, with an adhesive, or any other way known in the art. The first wall and the second wall of the container 50 may be sealed along adhesive seals shown in Fig. 12A. For example, seals on the first wall 50a may include one or more of

141a, 142a, 159a, 150a and 145a. Seals on the second wall 50b may include one or more of 141b, 142b, 159b, 150b and 145b. The seals may form the boundary around an unattached portion defining the interior 147 of the container 50. The interior 147 may receive the produce or other content. Seals 141a, 142a, 159a, 150a 145a, 141b, 142b, 159b, 150b and 145b are operable to connect walls which are made up of multiple plies of film. Thus these seals do not necessarily extend between plies 105, 107 but may do so. This seals may extend merely from plie 105 to ply 105 or ply 107 to ply 107, thus forming walls of the containers. It should be noted that in situation in which an adhesive is used, it may be placed on each of the "a" and "b" locations, such as 141a and 141b for example. However it may be placed on only one of these locations such as 141a and when the structure 100 is folded 141a may align with 141b such that he seal is formed in both locations. This may apply to 142a,b 159a,b and 145a,b as well.

[0043] The plies 105, 107 or similar structures may be heat-sealed together. Alternatively the plies 105, 107 may be adhesively sealed together with a UV curable adhesive. The UV curable adhesive may be applied to one or both plies 105, 107, the plies may then be laid over top of one another and then sealed together by applying an ultraviolet light. In various embodiments, the adhesive may be printed onto one or both plies 105, 107 to form the various designs, patterns, or like that make up the internal structures such as the air chambers. The UV curable adhesively sealed plies 105, 107 may be folded over to form separate walls of container 50. The separate walls may also have a UV curable adhesive printed thereon and then be sealed together with the UV light to form the container 50. After forming the container 50, the inflation chambers formed between plies 105, 107 may be inflated and sealed off via heat sealing to keep the chambers inflated.

[0044] A series of lines of weaknesses 126 is disposed along the longitudinal extent of the film and extends transversely across the first and second plies of the film 100. Each transverse line of weakness 126 extends from the second longitudinal edge 112 and towards the first longitudinal edge 110. Each transverse lines of weakness 126 in the web 100 is disposed between a pair of adjacent chambers 120. Preferably, each line of weakness 126 is disposed between two adjacent transverse seals 118 and between two adjacent chambers 120, as depicted in Figs. 1A-D. The transverse lines of weakness 126 facilitate separation of adjacent inflatable cushions 120.

[0045] The transverse lines of weakness 126 can include a variety of lines of weakness known by those of ordinary skill in the art. For example, in some embodiments, the transverse lines of weakness 126 include rows of perforations, in which a row of perforations includes alternating lands and slits spaced along the transverse extent of the row. The lands and slits can occur at regular or irregular intervals along the transverse extent of the row. Alternatively, for example, in some embodiments, the transverse lines of weakness 126 include score lines or the like formed in the web material.

[0046] The transverse lines of weakness 126 can be formed from a variety of techniques known to those of ordinary skill in the art. Such techniques include, but are not limited to, cutting (e.g., techniques that use a cutting or toothed element, such as a bar, blade, block, roller, wheel, or the like) and/or scoring (e.g., techniques that reduce the strength or thickness of material in the first and second plies, such as electromagnetic (e.g., laser) scoring and mechanical scoring). [0047] In accordance with various embodiments, the inflatable flexible structure may be usable with variety of inflation and sealing devices. As an example, turning now to Fig. 2, an inflation and sealing device 101 for converting a flexible structure such as web 100 of uninflated material into a series of inflated pillows or cushions 120 is provided. As shown in Fig. 2, the uninflated web 100 can be a bulk quantity of supply, uninflated material. For example, the bulk quantity of uninflated material may be a roll of the material 134 as illustrated in Figs 2 and 3. The web 100 may be rolled around an inner support tube 133.

[0048] The inflation and sealing device lOlmay include a bulk material support 136. The bulk quantity of uninflated material may be supported by the bulk material support 136. For example, the bulk material support may be a tray operable to hold the uninflated material, which tray can be provided by a fixed surface or a plurality of rollers for example. To hold a roll of material the tray may be concave around the roll or the tray may convex with the roll suspended over the tray. The bulk material support may include multiple rollers which suspend the web. The bulk material support may include a single roller that accommodates the center of the roll of web material 134. As illustrated in Figs. 2-4, the roll of the material 134 may be suspended over the bulk material support 136, such as a spindle passing through the core 133 of the roll of the material 134. Typically, the roll core is made of cardboard or other suitable materials. The material support 136 may rotate about an axis Y.

[0049] The web 100 may be suspended over a guide 138 after being pulled off of the supply of uninflated material (e.g., roll 134). The guide may provide support to the web 100 upon a transition from the bulk quantity of uninflated material to the sealing and inflation

mechanism 103. The guide may be a stationary rod extending from a support member 141. The guide 138 directs the web 100 away from the bulk quantity of uninflated material (e.g. roll 134) and steadily along a material path "B" along which the material is processed in a longitudinal direction "A". As the bulk quantity of uninflated material may change position or dimension as the web 100 is continuously pulled from it (e.g. the roll 134 may decrease in diameter as material is pulled off), the guide may maintain alignment with the sealing and inflation mechanism despite these changes, and preferably with the upstream end of inflation tip 142. The guide 138 can be configured to limit the material 134 from sagging between the inflation nozzle 140 and roll 134, and can help maintain any desired tension in the web 100 of the material. [0050] Fig. 4 illustrates a view of the inflation and sealing device 101 along axis Y. The material support 136 is shown on its end, and the length of the guide 138 is shown in an isometric view illustrating an angular difference between the two. Fig. 5 illustrates a front view showing the end of guide 138 but a bottom isometric view of material support 136. In accordance with embodiments discussed herein, the material support 136 and the guide 138 may rotate around axes Y and X respectively. The axis X may be perpendicular to the support member 141 with Y being non-perpendicular to the support member 141.

[0051] In accordance with various embodiments, the web 100 may travel through the inflation and sealing device 101 along path E. As illustrated in Figs. 3 and 4, the film path E extends along the nozzle 140. An axis Z is located where the film path E follows the nozzle 140. In accordance with various embodiments, the direction that nozzle 140 points is the same direction axis Y points. For example if nozzle 140 points up (e.g. away from base 183) then axis Y points up. If nozzle 140 points down (e.g. toward base 183) then axis Y points down.

[0052] In various embodiments, the web 100 may pass above the guide 138. In such embodiments, the material support 136 and axis Y may be angled with respect to guide 138 such that the material support 136 and axis Y point in the same direction as the web 100 passes over guide 138. If web 100 passes over guide 138 then the material support 136 may point up relative to the guide 138. If web 100 passes under then guide 138, then the material support 136 may point down relative to guide 138.

[0053] In accordance with various embodiments, the web 100 passes through the inflation and sealing assembly 103 and extends away from the inflation and sealing device 101 in a transverse direction which is perpendicular to longitudinal direction A in which the web 100 exits the inflation and sealing device 101.

[0054] When the web 100 is removed from the material support 136 and is positioned at an angle different from the guide 138, the web 100 includes a slight twist as it is removed from the bulk quantity of uninflated material (e.g. roll 134) and re-aligned over and in contact with guide 138. The web 100 may roll off of material support 136 tangentially and thereby forming a plane (or a surface that approximates a plane tangential with the surface of the roll 134) that is parallel with the axis of material support 136. The web 100 may also engage guide 138 tangentially forming a different plane (or approximating a different plane tangent with the guide 138). The web may merely reflect tangential planes as if it maintained tangential contact with the material support 136 or guide 138 even if in practice there is tension on one transverse end of the web 100 and slack on the other transvers end of the web 100. In order to accommodate both tangential contacts the web 100 may realign or twist slightly between the material support 136 and guide 138. [0055] In accordance with various embodiments, the nozzle 140 may inflate web 100 not only at a transverse edge but may engage an inflation channel located at any transverse distance between the longitudinal edges; i.e., the inflation and sealing device 101 fills a central channel with chambers on both transverse sides of the inflation channel. The web 100 may roll off of material support 136 and over guide 138 in a manner that aligns such a central inflation channel with the nozzle 140.

[0056] In various embodiments the material support 136 may include a spindle 200. The spindle 200 may be axially aligned along axis Y with a motor 220. The motor 220 and the spindle 200 may be attached via a bulkhead connector 222. The bulk head connector 222 may have a mounting surface 223. The mounting surface may attach to the backside of the support member 141 such that the motor 220 may be positioned on one side and the spindle 200 may be positioned on the other side as illustrated in Fig. 6. The mounting surface 223 may form an angle with axis Y such that axis Y is not perpendicular thereto. For example, Fig. 6 shows mounting surface 223 as parallel with vertical plate 184. As such, λ represents the angle between mounting surface 223 and Y. Instead, the mounting surface 223 may be angled such that as it attaches to the back side of the support member 141, it tilts the spindle 200 and motor 220 relative to the support member 141. An example of this structure is shown in Fig. 6 with the angle λ which may also represent the angle between mounting surface 223 and the axis Y. Spindle 200 may be supported within the bulk head connector 222 by bearings 214 and 224. The bearings 214,224 may allow the spindle 200 to be rotatable independent of the bulkhead connector 222 and ultimately the support member 141, to which the bulkhead connector 222 attaches. In various embodiments, the spindle may be supported on a shaft, surface bearings, or by the motor directly. The spindle 200 may be locked into place on the bulk head 222 with clip 226. Cover 228 and bulk head connector 222 may form an enclosure around motor 220. [0057] The spindle 200 may include two sections, a body portion 202 and a tip portion 204. The body portion 202 and the tip portion 204 may be formed of different materials. 6. The spindle 200 preferably has core support portions 206, which are outwardly facing surfaces spaced circumferentially about axis Y from each other to provide radially recessed areas 208 therebetween. The core support portions 206 protrude radially from the axis Y higher than the surfaces of the spindle 200 in the radially recessed areas 208. The core support portions can collectively define and be positioned along a phantom cylindrical surface that will correspond closely to the interior, hollow, surface within a supply roll 134. If other shaped cores are to be used, the core support portions can be arranged in other shapes. The core support portions 206 can be curved circumferentially along this phantom cylindrical surface or can be flat or have other shapes. The recessed areas 208 are positioned radially inward of the phantom cylinder, so that they entirely or in large part do not contact the interior of a supply roll mounted on the spindle 200. The recessed areas 208 have substantially flat surfaces in the embodiment shown, but other configurations can be used.

[0058] In the embodiment of Fig. 7, the recessed areas 208 lie below the phantom cylinder 207, and the core support portions 206 generally follow the phantom cylinder 207, although other shapes can be used. In this manner, the spindle 200 may be generally triangular in shape having three core support portions 206, but can alternatively have four, five, or more core support surfaces, and the core support portions can be evenly or unevenly distributed circumferentially about the spindle. In one example, as shown in Fig. 8 viewed down the Y axis, the spindle 200 may have an axial cross section that forms a triangle. The core support surfaces 206 preferably extend substantially axially with respect to the spindle (transversely with respect to the material path or machine direction in the embodiment of Fig. 2) to help in sliding a web roll core 133 on and off the spindle.

[0059] By providing the recessed areas between the core support portions 206 provides the spindle with a discontinuous support surface in which the contact area it has with a core 133 of a supply web roll 134 can be reduced compared to traditional, continuous- surface cylindrical spindles. This reduces the friction between the spindle 200 and core 133, allowing the core 133 to be more easily inserted and slid off from the spindle 200. Additionally, as is common and can be seen in Fig. 4, the core 133 can be deformed, such as by damage during shipping of the supply material roll 134. Damaged, out-of-round cores can be very difficult or impossible to insert onto a fully cylindrical spindle. The recessed areas 208 on the discontinuous spindle surface can accommodate deformations of the core 133 that extend inwardly between the core support portions 206, allowing dented or flattened cores to remain useable. In this way, the core support surfaces 206 a,b,c or a plurality of grip elements 210 which extend from the core support surfaces 206 a,b,c, may contacts or occupy only a fraction of the outer core surface circumference. The plurality of contacts may contact a finite number of points within an internal surface of a hollow tube onto which the web of material is rolled. In various examples, the plurality of grip elements 210 may extend beyond the generally cylindrical shape shown by line 207. The plurality of contacts may form a larger diameter around the spindle than the size of the inner diameter of inner support tube 133. This structure would allow the plurality of contacts to engage in an interference fit with the core 133 while the minimized outer cylindrical surface segments 206 a,b,c minimize other contact within the core 133. Preferably, the grip elements 210 are biased outwardly and are resiliently movable inwardly into the spindle 200. Such bias can be provided by springs within the spindle. The outer surface of the grip elements 210 can be spherical, conical, or have another shape that preferably facilitates sliding of the core 133 during loading and unloading on or from the spindle, and that grips the inner surface of the core 133 during use, to help transfer torque from the spindle to the roll, and preferably from the brake 137, described below. A chamfer 204 at the end of tip portion 204 may additionally reduce the effort of inserting spindle 200 into the inner support tube 133.

[0060] Referring back to Figs. 2-6, the support element 136 may be connected with a brake 137. The brake 137 may prevent or inhibit bunching up of the web material 100 and maintain a desired tension in the web material 100 as it is unwound from the roll 134 and as it is fed onto and/or into the inflation and sealing mechanism. The brake 137 may prevent or inhibit release of the bulk uninflated material from the support 136. For example, the brake 137 may inhibit the free unwinding of the roll 134. The brake may also assure that the roll 134 is unwound at a steady and controlled rate. The brake 137 may be provided by any mechanism that provides control. For example, according to one embodiment, a spring-loaded leather strap or other friction mechanism can be used as a drag brake on the bulk material support 136. In another embodiment, the brake 134 may be an electric motor or other actuator used to provide resistance to the rotation of the bulk material support 136 as the roll 134 is unwound. As shown in Figs. 7-8, the support element 136 is spindle 200 which is axially connected to a brake which may operate as a resistance mechanism. The resistance mechanism resists rotation of the support element 136 (e.g. spindle 200). The resistance mechanism may be motor 220 which controls rotation of the spindle 200, thereby controlling advancement of the web 100 by either positively driving rotation of spindle 200 or retarding the rotation of spindle 200. By retarding the rotation of spindle 200, the brake can also increase tension on the twisted web proximal to the support member 141, maintaining proper alignment with the inflating/sealing mechanism. [0061] Preferably, the inflation and sealing device 101 is configured for continuous inflation of the web 100 as it is unraveled from the roll 134. The roll 134, preferably, comprises a plurality of chain of chambers 120 that are arranged in series. To begin manufacturing the inflated pillows from the web material 100, the inflation opening 116 of the web 100 is inserted around an inflation assembly, such as an inflation nozzle 140. In the embodiment shown in Fig. 2, preferably, the web 100 is advanced over the inflation nozzle 140 with the chambers 120 extending transversely with respect to the inflation nozzle 140 and outlet 146. The outlet 146, which can be disposed on a radial side and/or the upstream tip of the nozzle 140, for example, directs fluid from nozzle body 144 into the chambers 120 to inflate the chambers 120 as the web 100 advances along the material path "E" in a longitudinal direction "A". The inflated web 100 is then sealed by a sealing drum 166 in the sealing area 174 to form a chain of inflated pillows or cushions.

[0062] The side inflation area 168 in the embodiment of Fig. 3 is shown as the portion of the inflation and sealing device 101 along the path "E" adjacent the side outlets 146 in which air from the side outlets 146 can inflate the chambers 120. In some embodiments, the inflation area 168 is the area disposed between the inflation tip 142 and entry pinch area 176, described below. The web 100 is inserted around the inflation nozzle 140 at the inflation tip 142, which may be disposed at the forward-most end of the inflation nozzle 140. The inflation nozzle 140 inserts fluid, such as pressured air, along fluid path B into the uninflated web material through nozzle outlets, inflating the material into inflated pillows or cushions 120. The inflation nozzle 140 can include a nozzle inflation channel that fluidly connects a fluid source with the nozzle outlets. It is appreciated that in other configurations, the fluid can be other suitable pressured gas, foam, or liquid. Figs. 3, 9, 10, and 11 illustrates a various view of the inflation and sealing device 101. As discussed in various embodiments, the fluid source can be disposed behind the support member 141 having a horizontal plate 183 and vertical plate 184 or other structural support for the nozzle and sealing assemblies, and preferably behind the inflation nozzle 140. The fluid source is connected to and feeds the fluid inflation nozzle conduit 143. The web 100 is fed over the inflation nozzle 140, which directs the web to the inflation and sealing assembly 103. The web 100 is advanced or driven through the inflation and sealing device 101 by a drive mechanism, such as by a driver or sealing drum 166 or the drive roller 160, in a downstream direction along a material path "E".

[0063] In accordance with various embodiments, the nozzle, blower sealing assembly, and drive mechanisms, and their various components or related systems may be structured, positioned, and operated as disclosed in any of the various embodiments described in the incorporated references such as for example U.S. Patent Application No. 13/844,741. Each of these embodiments may be incorporated to the inflation and sealing device 10 las discussed herein. [0064] After being fed through the web feed area 164, the first and second plies 105,107 are sealed together by the sealing assembly and exit the sealing drum 166. The sealing drum 166 includes heating elements, such as thermocouples, which melt, fuse, join, bind, or unite together the two plies 105,107, or other types of welding or sealing elements. The web 100 is continuously advanced through the sealing assembly along the material path "E" and past the sealing drum 166 at a sealing area 174 to form a continuous longitudinal seal 170 along the web by sealing the first and second web plies 105,107 together, and exits the sealing area at an exit pinch area 178. The exit pinch area 178 is the area disposed downstream the entry pinch area 164 between the belt 162 and the sealing drum 166, as shown in Fig. 4. The sealing area 174 is the area between the entry pinch area 164 and exit pinch area 178 in which the web 100 is being sealed by the sealing drum 166. The longitudinal seal 170 is shown as the phantom line in Figs. 1A-D. Preferably, the longitudinal seal 170 is disposed a transverse distance from the first longitudinal edge 102,106, and, most preferably, the longitudinal seal 170 is disposed along the mouths 125 of each of the chambers 120.

[0065] As shown in Fig. 4, the sealing drum 166 may be arranged above the belt 162. The drive roller 160 may be positioned downstream the feed roller 158 and tension roller 156 with the sealing drum 166 there between. The sealing drum 166 may be disposed such that a portion of the sealing drum 166 vertically overlaps the feed roller 158, tension roller 156, and drive roller 160 so that the belt 162 is deformed at the sealing area 174 to have a generally U- configuration. Such configuration increases the tension of the belt 162 at the sealing area 174, and facilitates the pinching of the web 100 between the sealing drum 166 and the belt 162 at the sealing area 174. The inflation and sealing assembly 103 configuration described also reduces the amount of contact of the web 100 during sealing, which reduces bending of the inflated web. As shown in Fig. 7, the contact area is the sealing area 174 between the entering pinch area 164 and exiting pinch area 174. [0066] In the embodiment shown, the web 100 enters the sealing assembly at the entry pinch area 176 at an angle sloping downward with respect to the horizontal. Additionally, the web 100 exits the sealing area 174 at an angle sloping upward with the respect to the horizontal so that the web 100 is exiting facing upwards toward the user. By having the intake and outtake sloped as described herein, the inflation and sealing device 101 allows for easy loading and extracting of the web as well as easy access to the web. Thus, the inflation and sealing device 101 can be positioned below eye level, such as on a table top, without the need of a high stand. The sloping downward intake and sloping upward outtake of the web 100 from the sealing assembly provides for the material path "E" to be bent at an angle a between the entry pinch area 176 and the exit pinch area 174 (the entry pinch area 176 and exit pinch area 174 are further described below). The angle a between the entry pinch area 176 and exit pinch area 174 is, for example, at least about 40 degrees up to at most about 180 degrees. The angle a may be about 90 degrees. Other entry and exit angles can be employed as known in the art in alternative embodiments.

[0067] In accordance with various embodiments, the sealing assembly may be protected by a removable cover. Likewise, the belt mechanism, e.g. belt 162, tension roller 156, and feed roller 158 may also include a removable cover 173. This allows for a user to easily remove the web or clear up or fix jams within the machine.

[0068] In accordance with various embodiments, one or more of the elements of inflation and sealing device lOlmay drive web 100 through the system. For example, the sealing drum 166 may be connected to a motor which rotates it in a direction "F". As described in various embodiments (see e.g. Application No. 13/844,741), other elements may also drive the system, such as roller 160. In other embodiments discussed in the incorporated references, roller 160 is indicated as a drive roller; however, it may be noted that roller 160 may be either an idler roller or an active drive roller. For example, roller 160 may be connected to the same motor or the same drive mechanism associated with the sealer drum 166 that causes the drum to rotate. In other configurations, the sealing drum 166 may be passive (e.g. an idler) or actively driven by a motor. In one example, the sealing drum 166 may be passive and merely be rotated in response to the advancing web 100 or belt 162.

[0069] In accordance with various embodiments, the inflation and sealing device can have more than one belt. For example one belt may drive the various rollers and a second belt may pinch the web against the sealing drum. In various embodiments, the inflation and sealing device may have no belts. For example the sealing drum may pinch the web against a stationary platform and drive the web thorough the inflation and sealing device at the same time. Additional description and embodiments of such structures may be disclosed in U.S. Patent Nos. 8,061,110 and 8,128,770 and Publication No. 2011/0172072 each of which is herein incorporated by reference.

[0070] Although some embodiments do not have a post-seal control element, the inflation and sealing assembly 103 shown in Fig. 2 includes a plurality of post-seal control elements. In various embodiments, the post-seal control element may be a movable or stationary surface, a roller, or any device that can contact the belt 162 or the web 100. For example, a post-seal control element can include roller 160 as discussed above. The roller 160 supports the web 100 exiting from the inflation and sealing assembly 103 and may be operable to guide the belt. As illustrated in Figs. 9-11, the roller 172 may also be a post-seal control element. In various embodiments, there may be a single post-seal control element such as roller 160 as depicted in embodiments disclosed in the incorporated references (see e.g. 13/844,741). In other embodiments, there may be multiple post-seal control elements as illustrated in Figs 9-11. For example, a first post-seal control element (e.g. roller 172) can be disposed directly above a second post-seal control element (e.g. roller 160).

[0071] The two post-seal control elements (e.g. two rollers 160,172) pinch or press the web 100 so that the belt 162 abuts one or both of the surfaces of the elements. As the rollers 160,173 are disposed immediately downstream of the heating drum (or other heating mechanism in other embodiments), they provide a cooling region 179 disposed between two rollers 160,172. Roller 160 in this embodiment acts as a principle cooling roller, since the sealed and cooling film is drawn around this roller 160. Pinch roller 172 maintains the web in contact with the principle cooling roller 160 to help maintain the pressure between the two film plies as the seal cools to support the seal and surrounding area mechanically. In embodiments, such as the one shown, in which the belt 162 extends around roller 160, the outer surface of this roller remain substantially stationary with respect to the web 100, further helping support the seal in it's delicate state before it has cooled sufficiently. Roller 160 is typically made of a hard and tough material, such as steel or aluminum, to withstand the pressures and heat from the belt 162, although a plastic or other material could be used in some embodiments.

[0072] In various embodiments, the post-seal control element such as roller 172 may have a larger-diameter area 171 opposing the belt than in adjacent parts of pinch roller 172. This annular ridge 171 allows contact against the web 100, while an adjacent smaller-diameter portion of roller 172 can remain out of contact therewith to help prevent sticking to the hot web. The roller 172 may be biased against the belt 162, web 100, and roller 160 by a spring- loaded tensioner 169. The tension provided by the tensioner 169 may further hold the seal closed by the post-seal control element, and can allow the pinch roller 172 to be lifted off the web when needed.

[0073] To prevent or reduce sticking of the hot web 100 to the pinch roller 172, the pinch roller is preferably made of, or has a surface of, a non-stick or low adhesion material such as polytetrafluoroethylene (PTFE) or other suitable material as discussed below. In accordance with various embodiments, the post-seal control element such as roller 160 may include a recessed annular surface 163. The recessed annular surface 163 may receive the belt 162.

[0074] When the web exits pinch area 178 between rollers 160 and 172 (these two rollers 160, 172 are at the exit of the sealing mechanism, such as the downstream exit from the device) there is a possibility that the hot film will stick to one of these rollers instead of cleanly exiting the device. In various embodiments, an element can be provided to help separate the film from the post-seal control elements. For example, roller 172 can have an annular ridge 161 extending proud the belt 162 or outer surface 167 of the roller 160 that supports the belt 162 against the web 100, or that contacts the web 100. This ridge 161 can be annular or have another suitable shape and can run around the roller to contact the web 100, preferably transversely adjacent the longitudinal seal on the inflated web 100, such as against the transverse end of the inflated chambers 120 adjacent the longitudinal seal 112. At the pinch area 178, the annular ridge 161 contacts the web 100, typically against a transverse side of the inflated chambers 120 where due to the inflated shape, the chambers 120 have a degree of rigidity compared to the uninflated film. The elevated ridge provides a bump-off element that forcing the web 100 to deflect off the roller 160. The annular ridge 161 is a second surface that causes the web to bend. The bend may cause a portion of the web 100, located in the lateral direction relative to a first portion of the web 100 that is pressed between the first post-seal control element (e.g. roller 172) and the second post-seal control element (e.g. roller 160), to not stay in the same plane as the first portion of the web. Forcing different portions of web 100 into different planes may cause the web 100 to unseat, and often unstick, from the belt and/or the roller 160. As such, the annular ridge 161 aids in automatically peeling the web 100 off the post-seal control elements. While described with respect to a roller, alternative embodiments can have a stationary ridge provided adjacent the roller 160 to guide the web off the cylinder. [0075] As the heated web 100 may have a tendency to stick to the post-seal control elements, non-stick materials may mitigate this issue. For example, one or both post-seal control elements may be made from of coated with polytetrafluoroethylene (PTFE), anodized aluminum, ceramic, silicone, or like non-stick/low-adhesion materials. [0076] In the embodiments shown, the inflation and sealing device 101 further includes a cutting assembly 186 to cut the web off the inflation nozzle when an inflation channel that receives and is closed around a longitudinal inflation nozzle 140 is used. As with other system components discussed herein, the cutting assembly may also be structured, provided, or included in accordance with the various embodiments described by the incorporated references discussed above.

[0077] While the inflatable packaging product 100 may be formed using the disclosed inflation and sealing device 101, the inflation and sealing device is exemplary, and it should be well understood that other devices can be used to form the inflatable packaging product 100, instead of or in addition to the sealing device 101. [0078] Any and all references specifically identified in the specification of the present application are expressly incorporated herein in their entirety by reference thereto. The term "about," as used herein, should generally be understood to refer to both the corresponding number and a range of numbers. Moreover, all numerical ranges herein should be understood to include each whole integer within the range. The content of U.S. Patent Application No. 13/844,741 is hereby incorporated by reference in its entirety. While useful features of the disclosure are discussed above, it will be appreciated that such features can be provided in ornamental arrangements on a web material.

[0079] While illustrative embodiments of the invention are disclosed herein, it will be appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. For example, the features for the various embodiments can be used in other embodiments. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments that come within the spirit and scope of the present invention.

Claims

CLAIMS What is claimed is:

1. An inflatable flexible structure, comprising:

a first film ply;

a second film ply that is sealed to the first ply to define an inflation chamber therebetween that is inflatable with a fluid and operable to contain the fluid; and

an interior seal disposed within the inflation chamber attaching the first and second plies together, the interior seal including a perimeter seal that encloses an inner portion in which the first and second plies are unattached from one another.

2. The inflatable flexible structure of claim 1, wherein the perimeter seal entirely encloses the inner portion, separating the inner portion from the inflation chamber.

3. The inflatable flexible structure of claim 1, wherein the interior seal is disposed within the inflation chamber.

4. The inflatable flexible structure of claim 3, wherein the interior seal is disposed entirely within the inflation chamber.

5. The inflatable flexible structure of claim 1, wherein the interior seal includes a first elongated portion extending from the perimeter seal.

6. The inflatable flexible structure of claim 5, wherein the interior seal includes another perimeter seal, and wherein the first elongated portion extends from the perimeter seal to the other perimeter seal.

7. The inflatable flexible structure of claim 5, wherein the interior seal includes an intersection between the perimeter seal and the elongated portion, such that the intersection has three leg portions which are part of the perimeter seal and the elongated portion, the interior seal having an increased width at the intersection compared to the perimeter seal and elongated portion, thereby forming a gusset that resists localized stresses in the sealed film plies.

8. The inflatable flexible structure of claim 7, wherein the interior seal includes a second intersection between the perimeter seal and a second elongated portion, such that the second intersection has three second leg portions which are part of the perimeter seal and the second elongated portion, the interior seal having an increased width at the second intersection compared to the perimeter seal and second elongated portion, thereby forming a second gusset that resists localized stresses in the sealed film plies.

9. The inflatable flexible structure of claim 8, wherein the first elongated portion extends from the perimeter seal to a second perimeter seal, and wherein the second elongated portion extends from the perimeter seal to a third perimeter seal.

10. The inflatable flexible structure of claim 5, wherein the inner portion is at least 10 times wider than the elongated portion.

11. The inflatable flexible structure of claim 1, comprising a plurality of said interior seals.

12. The inflatable flexible structure of claim 1, wherein the first and second plies are sealed to one another to define a plurality of inflation chambers therebetween, the plurality of inflation chambers including the inflation chamber and a second inflation chamber.

13. The inflatable flexible structure of claim 12, wherein the second inflation chamber includes a second interior seal attaching the first and second plies together, the second interior seal including a second perimeter seal that encloses a second inner portion in which the first and second plies are unattached from one another.

14. The inflatable flexible structure of claim 1, wherein the inner portion is configured to remain uninflated when the inflation chamber is inflated with the fluid.

15. The inflatable flexible structure of claim 1, wherein the first and second plies are heat sealed together to form the interior seal.

16. The inflatable flexible structure of claim 1, wherein the first and second plies are sealed together with an adhesive to form the interior seal.