AU2008276353A1

AU2008276353A1 - Storage bag

Info

Publication number: AU2008276353A1
Application number: AU2008276353A
Authority: AU
Inventors: Andrew E. Neltner
Original assignee: Glad Products Co
Current assignee: Glad Products Co
Priority date: 2007-07-17
Filing date: 2008-07-03
Publication date: 2009-01-22
Also published as: WO2009012066A2; WO2009012066A3; US20100177990A1; CA2692274A1

Description

WO 2009/012066 PCT/US2008/069156 STORAGE BAG BACKGROUND OF THE INVENTION [0001] Flexible plastic bags are widely used for a variety of purposes such as storing food items, either temporarily in the case of packaging snacks or long term in the case of freezer storage. Plastic bags of this type typically include one or more pliable sidewalls made of thermoplastic web material such as polyethylene. The sidewalls are arranged to provide an opening and an interior volume accessible through the opening. To close the opening, the bag may include interlocking closure strips attached about the rim of the opening. BRIEF SUMMARY OF THE DISCLOSURE [0002] The invention provides an evacuable storage bag for receiving and storing food items in an evacuated condition. During evacuation, air will be directed through the interior volume to exit the bag. Additionally, as air exits the bag, the sidewalls will collapse against each other and against the stored food items. [0003] To facilitate evacuation and remove liquids and juices from the exiting air flow, the bag is provided with a textured portion on an inner surface of the sidewall. The textured portion can include a plurality of pyramid shaped protrusions or projections arranged in an offset pattern and that project into the interior volume from other regions of the inner surface. The pyramid shaped protrusions can be substantially separated from each other on the inner surface by the other regions of the inner surface. The base of each pyramid shaped protrusion may be outlined or delineated by the planar regions. Because of the offset arrangement, the planar regions are not of uniform shape and size but rather can be categorized into at least first regions that are relatively large and open and second regions that are relatively small and closed. [0004] During evacuation, liquids and juices may pool into and may become trapped in the larger first regions while the air itself can be directed through the smaller and narrower second regions. The liquids and juices, or at least a portion thereof, may be retained within the bag. An advantage of the storage bag is that it may assist in maintaining the hydration of stored food items. Another advantage is that it may 1 WO 2009/012066 PCT/US2008/069156 prevent contamination of valve elements and/or evacuation devices. These and other advantages and features of the invention will become apparent from the following drawings and detailed description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS [0005] FIG. 1 is a perspective view of a flexible plastic bag including a valve element that can operate in conjunction with an evacuation device, the plastic bag having, as shown in cutaway, a textured portion on an inner surface of the sidewall. [0006] FIG. 2 is an elevational view of the area indicated by circle A-A of FIG. 1 illustrating in detail the textured portion including a plurality of pyramid shaped protrusions arranged in an offset pattern. [0007] FIG. 3 is an elevational view similar to that of FIG. 2 illustrating another embodiment of the textured portion including a plurality of pyramid shaped protrusions arranged in a random pattern. [0008] FIG. 4 is a perspective view of another embodiment of a flexible plastic bag having, as shown in cutaway, a textured portion on an inner surface of the sidewall, the plastic bag adapted for use with a counter top style evacuation device. [0009] FIG. 5 is a schematic illustrating various techniques for manufacturing a bag including a textured portion that has a plurality of pyramid shaped protrusions. [0010] FIG. 6 is a front perspective view of a one-way valve element that can be included with a plastic bag such as disclosed in FIG. 1. [0011] FIG. 7 is a rear perspective view of the one-way valve element of FIG. 6. [0012] FIG. 8 is a cross-sectional view through the one-way valve element as taken along line B-B of FIG. 6. [0013] FIG. 9 is an exploded view of another embodiment of a one-way valve element for attachment to a flexible plastic bag. [0014] FIG. 10 is an exploded view of another embodiment of a one-way valve element for attachment to a flexible plastic bag. [0015] FIG. 11 is another embodiment of the textured portion. [0016] FIG. 12 is a cross-sectional view taken along line 12-12 of FIG. 11. [0017] FIG. 13 is another embodiment of the textured portion. [0018] FIG. 14 is a cross-sectional view taken along line 14-14 of FIG. 13. 2 WO 2009/012066 PCT/US2008/069156 [0019] FIG. 15 is another embodiment of the textured portion. [0020] FIG. 16 is another embodiment of the textured portion. DESCRIPTION OF THE EMBODIMENTS [0021] Referring now to the drawings, wherein like reference numbers refer to like elements, there is illustrated in FIG. 1 an evacuable storage bag 100 that can be used for receiving and storing food items. The storage bag 100 includes a first sidewall 102 and an opposing second sidewall 104 overlaying the first sidewall 102 to provide an interior or internal volume 106. Accordingly, the first and second sidewall 102, 104 each includes a respective first inner surface 108 and an opposing second inner surface 109. The first and second sidewalls 102, 104 can be made from flexible and/or pliable webs of thermoplastic material such as, for example, polyethylene. The webs may be monolayer or multilayer films that are typically used for food storage. Multilayer films may be laminations or coextrusions. Resins may include polyethylene including high density polyethylene (HDPE), low density polyethylene (LDPE), and linear low density polyethylene (LLDPE). Other materials suitable for manufacturing sidewalls include nylon, ethylene vinyl alcohol (EVOH), polypropylene (PP), ethylene vinyl acetate (EVA), polyester, ionomers or metallized films. Examples of coextruded multilayer films suitable for the manufacturing of storage bags include layered combinations such as HDPE/tie-layer/EVOH/tie layer/LDPE or nylon/tie-layer/LDPE. [0022] The first and second sidewalls 102, 104 are joined together along a first side edge 110, a parallel second side edge 112, and a closed bottom edge 114 that extends perpendicularly between the first and second side edges. The edges of the first and second sidewalls 102, 104 can be joined together by a heat sealing operation. To access the internal volume 106, the portions of the first and second sidewalls 102, 104 extending along an open top edge 116 remain un-joined. Due to the four orthogonal edges, the flexible bag 100 has a generally rectangular shape. However, it will be appreciated that in other embodiments, the bag can have any suitable shape resulting from any number and orientation of sidewalls and edges. [0023] To close the open top edge 116 after food items have been inserted into the bag 100, the bag can include a closure mechanism such as first and second 3 WO 2009/012066 PCT/US2008/069156 interlocking fastening strips 120, 122. The fastening strips 120, 122 can be made from extruded thermoplastic material and are joined to the bag 100 proximate the open top edge 116. More specifically, the first fastening strip 120 can be joined to the inner surface 108 of the first sidewall 102 and the second fastening strip 122 can be joined to the inner surface 109 of the second sidewall 104. The first and second fastening strips can engage and release with each other to allow for repeated opening and closing of the storage bag. To engage, the fastening strips can be aligned adjacent to each other and pressed together. To release the fastening strips, oppositely directed pulling forces can be applied to the first and second sidewalls proximate the top edge. In other embodiments, it will be appreciated that various other closure mechanisms can be used instead of or in combination with the first and second fastening strips. [0024] To evacuate air trapped in the flexible bag 100 after sealing the open top edge 116, the bag includes a one-way valve element 130, various examples of which will be discussed further below, that is attached to the first sidewall 102 and communicates with the internal volume 106. The one-way valve element 130 is capable of opening to allow entrapped air from the internal volume 106 to escape and closing to prevent the ingress of environmental air into the interior volume. Communication with the internal volume 106 can be accomplished by disposing a hole through the first sidewall 102 and then attaching the valve element 130 over the hole. The valve element 130 can operate in conjunction with a handheld evacuation device 132 that provides a suction force for withdrawing air through the valve element. [0025] To facilitate the evacuation of air from the storage bag, the storage bag 100 can include a textured portion 140 on the inner surface 108, 109 of one or both of the first and second sidewalls 102, 104. The textured portion 140 includes a plurality of raised protrusions 142 or peaks that project into the interior volume 106. [0026] Referring to FIG. 2, each of the protrusions 142 can be generally shaped as a pyramid, and though illustrated as such, the pyramid shaped protrusion is not necessarily a right angle pyramid. Each pyramid shaped protrusion 142 includes a square or rectangular base made of four base edges 144 that are adjacent to otherwise planar regions 160 of the inner surface 109. The pyramid shaped protrusion 142 tapers from the base edges 144 to an apex 146 or peak as the protrusion projects from the planar regions 160. Moreover, the pyramid shaped protrusions 142 can be 4 WO 2009/012066 PCT/US2008/069156 arranged in a pattern in which adjacent protrusions are generally offset from each other. In other embodiments, the pyramid shaped protrusions may be truncated. In one embodiment as shown in FIGS. 13 and 14, the protrusions 842 are truncated. In this embodiment, the protrusion 842 has a flat top portion 843. The truncated feature may be used as appropriate with any of the embodiments herein. [0027] For example, presume the location of the open top and closed bottom edges are indicated by arrows 150 and the location of the first and second side edges is indicated by arrows 152. Given the exemplary rectangular bag configuration, the arrows 150, 152 are orthogonal with each other and, for reference, the direction indicated by arrows 150 can be considered vertical while the direction indicated by arrows 152 can be considered horizontal. Because of the offset pattern, the apexes 146 of adjacent protrusions generally do not align in either the vertical direction or in the horizontal direction. In fact, in the illustrated embodiment, the apexes 146 of adjacent protrusions generally align in the direction indicated by arrow 154 that is oriented at an angle with respect to the vertical and horizontal arrows 150, 152. [0028] Between the pyramid shaped protrusions 142 the inner surface 109 of the sidewall 104 provides the otherwise substantially planar regions 160. The planar regions 160 are generally co-planar or parallel with one another. In the illustrated embodiment, the pyramid shaped protrusions 142 are substantially separated from each other on the inner surface 109 by the planar regions 160 such that the planar regions are generally contiguous with one another. Hence, the base of each pyramid shaped protrusion 142 including base edges 144 is outlined or delineated by the planar regions 160 and the shape of the planar regions is provided by the protrusions and their arrangement. In other embodiments, however, some overlap of the pyramid shaped protrusions may be permitted. [0029] Because of the offset pattern of the pyramid shaped protrusions 142, the planar regions 160 do not have a uniform shape and size. Instead, as illustrated, the planar regions 160 can include a first plurality of relative larger regions or areas 162 and a second plurality of relatively smaller regions or areas 164. The larger areas 162 are relatively open or exposed and are typically located where adjacent pyramids are separated by large gaps or distances. The smaller areas 164 are relatively closed in or congested and may take the form of narrow channels located between closely 5 WO 2009/012066 PCT/US2008/069156 proximate or tightly packed protrusions 142. As an example, the ratio of the surface area of the larger areas 162 to the surface area of the smaller areas 164, as measured in the aggregate, average, or one to one correspondence, can be on the order of about 5:1 to about 10:1. [0030] Referring back to FIG. 1, during evacuation, air will be directed through the interior volume 106 to exit the storage bag 100. As the air is removed, the first and second sidewalls 102, 104 will collapse against and contact each other and against items within the interior volume. This may cause air to become trapped in other parts of the interior volume 106 and unable to exit the bag 100 during evacuation. To prevent or reduce these problems, the textured portion 140 provided by the pyramid shaped protrusions 142 maintains at least a partial clearance between the bag sidewalls 102, 104 and between the sidewalls and any objects located in the bag. More specifically, referring to FIGS. 1 and 2, as the sidewalls 102, 104 collapse together the apexes 146 of the protrusions 142 contact the sidewalls or stored items and thereby provide a standoff or spacer function between the planar regions 160 of the inner surface 109 and the contacted sidewall or item. Thus, the distance between the planar region 160 and the apexes 146 acts as a clearance through which evacuating air can pass. The protrusions can have a height in a first range of 0.003 inches (0.076 mm) to 0.025 inches (0.635 mm), a second range of 0.005 inches (0.127 mm) to 0.015 inches (0.381 mm), and a third range of 0.007 inches (0.178 mm) to 0.012 inches (0.305 mm). In one embodiment, the protrusions can have a height of about 0.010 inches (0.254 mm). [0031] The protrusions 142 and areas 162, 164 may also provide an additional feature. When the user contacts the evacuation device 132 to the bag 100 in order to remove the air from the bag, the downward pressure of the device on the bag sidewalls may cut off the flow of air to the device. The protrusions may provide a standoff for the downward pressure of the device. Thus, the protrusions may require a greater force or downward pressure by the device before the flow of air is cut off. [0032] The offset pattern of the pyramid shaped protrusions 142 provides an additional utility of the texture portion 140. In many instances, food items such meats or fish that are stored in the interior volume contain liquids or juices. To retain those liquids or juices in the bag during evacuation, the first larger areas 162 and second 6 WO 2009/012066 PCT/US2008/069156 smaller areas 164 of the planar region can cooperate to pool and trap the liquids in the interior volume. Specifically, as the air is directed through the clearances provided by the planar regions 160, liquids entrained in the air or otherwise can gather or pool together within the larger areas 162 while the evacuating air can continue through the narrower or smaller areas 164 to exit the bag. The entrances to the smaller areas 164 can also block or impede the continued flow of the liquids gathered in the larger areas 162. Thus, the offset pattern of the pyramid shaped protrusions allows air to be evacuated from the bag while retaining liquids and juices and thus can improve the freshness and hydration of the food items while preventing contamination of an evacuation device. [0033] Another embodiment is shown in FIGS. 11 and 12. This embodiment may be similar to FIG. 2 except that the areas 862, 864 between the protrusions 842 may include a depression 872. In this embodiment, the depression 872 may be a half sphere. In other embodiments, the depression may have other shapes, such as, a rectangle, square, triangle, polygons, parallelogram, trapezoid, or annulus. The depression may allow for retention or pooling of the liquid and the depression may prevent liquid from entering the valve or the evacuation device. The depression may be used as appropriate with any of the embodiments herein. [0034] The pyramid shaped protrusions need not always be rectangular or even of the same size and shape. Moreover, producing the offset arrangement of the protrusions need not be accomplished by patterning the protrusions on an angle with respect to the open top edge and side edges of the storage bag. For example, referring to FIG. 3, there is illustrated another embodiment of a textured portion 240 produced by a plurality of pyramid shaped protrusions 242 projecting from the inner surface 209 of a storage bag sidewall 204. In the illustrated embodiment, the pyramid shaped protrusions 242 are triangular in shape and include a base having three side edges 244 that are adjacent to otherwise smooth and substantially planar regions 260 of the inner surface 209. The pyramid shaped protrusions 242 project from the planar regions 260 and tapers to an apex 246. As in the prior embodiments, the pyramid shaped protrusions need not be geometrically right pyramids. The triangular shaped protrusions may be used as appropriate with any of the embodiments herein. 7 WO 2009/012066 PCT/US2008/069156 [0035] The offset pattern is accomplished by random placement or location of the pyramid shaped protrusions 242 on the inner surface 209. Because of the various sizes and random placement of the protrusions, the planar regions 260 have correspondingly varying shapes and sizes. More particularly, the larger areas 262 and smaller areas 264 have random shapes and surfaces areas, even with respect to each other. However, the textured portion 240 including the larger and smaller areas 262, 264 will generally function to facilitate air direction and retain liquids and juices as described above. In a further variation, the random placement of the pyramid shaped protrusions 242 can be configured so that the smaller areas 264 are concentrated toward the opening of the bag 200 while the larger areas 262 are concentrated toward the bottom. In one embodiment shown in FIG. 15, the random placement of the pyramid shaped protrusions 942 can be configured so that the smaller areas 964 are concentrated toward the opening of the bag while the larger areas 962 are concentrated toward the bottom of the bag. Concentrating the larger and smaller areas in this manner acts to concentrate the retained fluids and juices further away from an evacuation point of the bag. This feature may be used as appropriate with any of the embodiments herein. [0036] In other embodiments, the arrangement of the pyramid shaped protrusions can be random in a localized area but can generally repeat over a broader area. Likewise, the protrusions can be a combination of rectangular pyramids, triangular pyramids, and/or other shapes. In other embodiments, the protrusions can have other shapes, such as, the circular protrusions 1042 shown in FIG. 16. The circular protrusions may be used as appropriate with any of the embodiments herein. Additionally, the textured portion of the protrusion shapes can be combined on different storage bag sidewalls with other textured portions, such as those described in U.S. Patent Application Publication No. 2005/0286808 (U.S. Application No. 10/880,784) herein incorporated by reference in its entirety. [0037] The textured pattern having pyramid shaped protrusions can be incorporated in various different style plastic storage bags. For example, illustrated in FIG. 4 there is illustrated another embodiment of a plastic storage bag 300 having first and second pliable, thermoplastic sidewalls 302, 304 that are overlaid and joined together to provide an interior volume 306 for receiving items such as food stuffs. Formed on the 8 WO 2009/012066 PCT/US2008/069156 inner surface 309 of at least the second sidewall 304 is a textured portion 340 having a plurality of projecting pyramid shaped protrusions 342 projecting into the interior volume 306 and which are substantially separated from each other by substantially planar regions 360 of the inner surface. To seal and evacuate plastic bags 300 of this particular style, a counter top evacuation device 332 of the type illustrated in FIG. 4 can be used. The evacuation device 332 includes a slot 334 into which the open top edge 316 of the plastic bag 300 can be inserted. Air is then drawn from the interior volume 306 through the open top edge 316 after which the device 332 can heat seal the open top edge shut. Hence, storage bags of the present embodiment need not include valve elements or interlocking fastening strips. [0038] Referring to FIG. 5, to manufacture a bag having a textured portion of any of the aforementioned styles, any number of various high speed manufacturing processes can be employed. For example, the finished bag 400 can be produced by initially unwinding in a machine direction indicated by arrow 402 a continuous web or sheet 404 of thermoplastic material from a roll 406 of such material. To form the protrusions, the web 404 can be passed through a pair of opposing rollers 410, 412 one of which has a plurality of knobs that correspond to the pyramid shaped protrusions. As the rollers 410, 412 rotate over the web 404, the protrusions are embossed or coined into the thermoplastic material. [0039] In another method, the protrusions can be placed on the web by depositing moldable material onto the web 404 in a depositing step 420. For example, a depositing machine 422 suspended above the web 404 can deposit by squirting or by direct placement onto the web deposits of liquefied or molten material that correlate to the pyramid shaped protrusions. The material can solidify providing the pyramid shapes. Furthermore, the material can be the same or different than the material comprising the web. In further embodiments, the depositing machine 422 can be moved perpendicularly with respect to the machine direction 402 to provide the offset pattern of the protrusions. In a further embodiment, the textured portion can be initially provided on or formed into a separate film or web 430 of thermoplastic material that is provided on another roll 432. The second web 430 can be unwound from the roll and attached to the first web 404 by an attachment operation 434. 9 WO 2009/012066 PCT/US2008/069156 [0040] To finish the plastic bag, the web 404 can be run through a folding operation 440 that folds the web in half to provide the first and second sidewalls. The side edges of the bag can be produced by an edging machine 442. Specifically, the edging machine 442 forms a seal 446 across the web of folded material to form the side edges of the bag and cuts the web into individual bags. In other operations, a device 451 can attach the interlocking fastening strips 452, 454 and a device 455 can attach the valve elements 456. [0041] In those embodiments of the flexible plastic bag that include a one-way valve element for evacuation, the particular valve element used can be selected from any various types of suitable one-way valve elements. For example, referring to FIGS. 6, 7, and 8, the one-way valve element 500 for use with a storage bag of the foregoing type can include a rigid valve body 510 that cooperates with a movable disk 512 to open and close the valve element. The valve body 510 includes a circular flange portion 514 extending between parallel first and second flange faces 520, 522. Concentric to the flange portion 514 and projecting from the second flange face 522 is a circular boss portion 518 which terminates in a planar boss face 524 that is parallel to the first and second flange faces. The circular boss portion 518 is smaller in diameter than the flange portion 514 so that the outermost annular rim of the second flange face 522 remains exposed. The valve body 510 can be made from any suitable material such as a moldable thermoplastic material like nylon, HDPE, high impact polystyrene (HIPS), polycarbonates (PC), and the like. [0042] Disposed concentrically into the valve body 510 is a counter-bore 528. The counter-bore 528 extends from the first flange face 520 part way towards the boss face 524. The counter-bore 528 defines a cylindrical bore wall 530. Because it extends only part way toward the boss face 524, the counter-bore 528 may form within the valve body 510 a planar valve seat 532. To establish fluid communication across the valve body 510, there is disposed through the valve seat 532 at least one aperture 534. In fact, in the illustrated embodiment, a plurality of apertures 534 are arranged concentrically and spaced inwardly from the cylindrical bore wall 530. [0043] To cooperatively accommodate the movable disk 512, the disk is inserted into the counter-bore 528. Accordingly, the disk 512 is preferably smaller in diameter than the counter-bore 528 and has a thickness as measured between a first disk face 10 WO 2009/012066 PCT/US2008/069156 540 and a second disk face 542 that is substantially less than the length of the counter bore 528 between the first flange face 520 and the valve seat 532. To retain the disk 512 within the counter-bore 528, there is formed proximate to the first flange face 520 a plurality of radially inward extending fingers 544. The disk 512 can be made from any suitable material such as, for example, a resilient elastomer. [0044] Referring to FIG. 8, when the disk 512 within the counter-bore 528 is moved adjacent to the fingers 544, the valve element 500 is in its open configuration allowing air to communicate between the first flange face 520 and the boss face 524. However, when the disk 512 is adjacent the valve seat 532 thereby covering the apertures 534, the valve element 500 is in its closed configuration. To assist in sealing the disk 512 over the apertures 534, a sealing liquid such as oil can be applied to the valve seat 532. Furthermore, a foam or other resilient member may be placed in the counter-bore 528 to provide a tight fit of the disk 512 and the valve seat 532 in the closed position. [0045] To attach the valve element 500 to the first sidewall, referring to FIG. 8, an adhesive can be applied to the exposed annular rim portion of the second flange face 522. The valve element 500 can then be placed adjacent the exterior surface of the first sidewall with the boss portion 518 being received through the hole disposed into the sidewall and thereby pass into the internal volume. Of course, in other embodiments, adhesive can be placed on other portions of the valve element, such as the first flange face, prior to attachment to the sidewall. [0046] In other embodiments, the one-way valve element can have a different construction. For example, as illustrated in FIG. 9, a flexible one-way valve element 610 can include a flexible, circular base layer 612 that cooperates with a correspondingly circular shaped, resilient top layer 614 to open and close the valve element. The top and bottom layers can be made from any suitable material such as, for example, a flexible thermoplastic film. Disposed through the center of the base layer 612 is an aperture 616, thus providing the base layer with an annular shape. The top layer 614 is placed over and adhered to the base layer 612 by two parallel strips of adhesive 618 that extend along either side of the aperture 616, thereby covering the aperture with the top layer and forming a channel. The base layer 612 is then adhered 11 WO 2009/012066 PCT/US2008/069156 by a ring of adhesive 620 to the flexible bag 600 so as to cover the hole 608 disposed through the first sidewall 602. [0047] When a pressure differential is applied across the valve element by, for example, placing the nozzle of an evacuation device adjacent the first sidewall 602 about the valve element, the top layer 614 can be partially displaced from the base layer 612 thereby exposing the aperture 616. Air from the interior volume 606 can pass through the hole 608 and aperture 616 and along the channel formed between the adhesive strips 618 where the removed air enters the evacuation device. When the suction force generated by the evacuation device is removed, the resilient top layer 614 will return to its prior configuration covering and sealing the aperture 616. The valve element 610 may also contain a viscous material such as an oil, grease, or lubricant between the two layers in order to prevent air from reentering the bag. In an embodiment, base layer 612 may also be a rigid sheet material. [0048] Illustrated in FIG. 10 is another embodiment of the valve element 710 that can be attached to the flexible plastic bag 700. The valve element 710 is a rectangular piece of flexible thermoplastic film that includes a first end 712 and a second end 714. The valve element 710 is attached to the first sidewall 702 so as to cover and seal a hole 708 disposed through the first sidewall. The valve element 710 can be attached to the sidewall 702 by patches of adhesive 718 placed on either side of the hole 708 so as to correspond to the first and second ends 712, 714. When the nozzle attached to an evacuation device is placed adjacent the first sidewall 702 about the valve element 710, air from the internal volume 706 displaces the flexible valve element 710 so as to unseal the hole 708. After evacuation of air from the internal volume 706, the valve element 710 will again cover and seal the hole 708. [0049] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. [0050] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," 12 WO 2009/012066 PCT/US2008/069156 "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. [0051] Preferred embodiments of this invention are described herein, including the best mode known to the inventor(s) for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor(s) expect skilled artisans to employ such variations as appropriate, and the inventor(s) intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. 13

Claims

1. A flexible storage bag comprising: a first sidewall of thermoplastic material; a second sidewall of thermoplastic material overlying and joined to the first sidewall to provide an interior volume between opposing first and second inner surfaces of the respective first and second sidewalls; at least one inner surface including a textured portion comprising a plurality of pyramid shaped protrusions projecting into the interior volume, the pyramid shaped protrusions arranged in a substantially offset pattern.

2. The storage bag of claim 1, wherein the inner surface includes substantially planar regions located between the pyramid shaped protrusions.

3. The storage bag of claim 2, wherein the planar regions include first relatively larger areas and second relatively smaller areas.

4. The storage bag of claim 3, wherein the ratio of the surface area of each first larger area to the surface area of each second smaller area is about 5:1 to 10:1.

5. The storage bag of claim 3, wherein the first larger areas are generally square in outline and the second smaller areas are generally rectangular in outline.

6. The storage bag of claim 1, wherein the pyramid shaped protrusions are arranged in a substantially random pattern on the inner surface.

7. The storage bag of claim 2, wherein the planar regions are continuous with one another such that the pyramid shaped protrusions are substantially separated from each other.

8. The storage bag of claims 2, wherein the pyramid shaped protrusions project from the planar regions in a range from 0.076 mm to 0.635 mm.

9. The storage bag of claim 1, further comprising a one-way valve element attached to at least one sidewall and in communication with the interior volume. 14 WO 2009/012066 PCT/US2008/069156

10. The storage bag of claim 1, further comprising first and second interlocking fastening strips attached respectively to the first and second inner surfaces.

11. The storage bag of claim 1, further comprising a depression located between the protrusions.

12. The storage bag of claim 1, wherein the spacing between protrusions near the top of the bag is less than the spacing between protrusions near the bottom of the bag.

13. A method of evacuating a storage bag comprising: (i) providing a bag including a flexible sidewall bounding an interior volume, an opening for accessing the interior volume, and a textured portion included on an inner surface of the sidewall, the textured portion including a plurality of pyramid shaped protrusions projecting into the interior volume and arranged in a substantially offset pattern; (ii) closing the opening; (iii) applying an evacuation device to the storage bag for withdrawing air from the interior volume; (iv) directing air from the interior volume between a first plurality of relatively smaller areas located between the pyramid shaped protrusions; and (v) retaining at least some fluids initially retained in the air within a second plurality of relatively larger areas located between the pyramid shaped openings.

14. The method of claim 13, wherein the step of applying an evacuation device to the storage bag includes the further step of interfacing the evacuation device to a one way valve element attached to the sidewall and communicating with the interior volume.

15. A flexible storage bag comprising: a first sidewall of thermoplastic material; a second sidewall of thermoplastic material overlying and joined to the first sidewall to provide an interior volume between opposing first and second inner surfaces of the respective first and second sidewalls; 15 WO 2009/012066 PCT/US2008/069156 at least one inner surface including a textured portion comprising a plurality of protrusions projecting into the interior volume, the protrusions arranged in a substantially offset pattern.

16. The storage bag of claim 15, wherein the protrusions have a circular base. 16