EP0980334B1 - Flexible, collapsible, self-supporting storage bags and containers - Google Patents

Description

FIELD OF THE INVENTION

The present invention relates to flexible storage bags and containers, particularlythose suitable for use in the containment and protection of various items includingperishable materials. The present invention further relates to such flexible storage bagsand containers having improved sealability for containment and protection of itemscontained within under a wide range of in-use conditions.

BACKGROUND OF THE INVENTION

Flexible storage bags for use in the containment and protection of various items,as well as the preservation of perishable materials such as food items, are well known inthe art. Such bags typically comprise a rectangular sheet of polymeric film folded uponitself and sealed along two edges to form a semi-enclosed container having two flexibleopposed sidewalls, three sealed or folded edges, and one open edge. A closure integrallyformed with the bag such as an interlocking rib-type seal or separately provided such as aplastic or paper-clad-wire tie completes the containment assembly.

As utilized herein, the term "flexible" is utilized to refer to materials which arecapable of being flexed or bent, especially repeatedly, such that they are pliant andyieldable in response to externally applied forces. Accordingly, "flexible" issubstantially opposite in meaning to the terms inflexible, rigid, or unyielding. Materialsand structures which are flexible, therefore, may be altered in shape and structure toaccommodate external forces and to conform to the shape of objects brought into contactwith them without losing their integrity. Flexible storage bags of the foregoing varietyare typically formed from polymeric film, such as polyethylene or other members of thepolyolefin family, in thicknesses of between about 0.0002 inches to about 0.002 inches.Such films are frequently transparent but sometimes are opaque and/or colored.

Flexible storage bags of the currently commercially available variety provide ameans of conveniently storing a wide range of objects and materials in a generallydisposable containment device. While flexible storage bags of the foregoing variety haveenjoyed a fair degree of commercial success, their reliance upon mechanical closurestends to cause difficulty in operation for individuals having impaired manual dexteritysuch as children, the elderly, arthritis patients, etc. Moreover, such mechanical closurestypically require alignment of mechanical elements for operation which can prove challenging for those with impaired vision or impaired hand-eye coordination. Manymechanical closure mechanisms also provide leakage sites at such locations as the end ofinterlocking channels where liquid or gases can leak into or out of the bag.

In an attempt to address this issue alternative closure mechanisms have beendeveloped which rely upon strips or regions of adhesive to bond superimposed regions ofthe bag. While these closures address some of the difficulties in utilizing separateclosure elements or interlocking mechanical elements, some adhesive closuremechanisms require removable liners to protect the adhesive from premature activation,thus adding additional elements for assembly and an additional activation step beforeuse. Moreover, some protected adhesive configurations require interlocking grooves,channels, or protrusions which must be properly registered to engage the adhesive, thusagain raising the visual and coordination requirements of conventional mechanicalclosure mechanisms.

While such flexible storage bags are generally highly efficient for storage beforeuse, for many storage situations it is desirable to minimize the amount of air and/or freespace above or around the contents which is trapped within the bag after closure tominimize storage space of filled bags and to aid the effectiveness of the bag inpreservation of perishable items. Notwithstanding the type of closure mechanismemployed, it is often difficult with conventional flexible storage bags to only partiallyclose the bag and expel trapped air before completing the closure as this again requires acertain amount of manual dexterity and visual aptitude.

Conventional flexible storage bags also create an inherent challenge in terms ofbeing able to hold the flexible or flaccid bag in an open condition with at most one handso that the other hand can manipulate another container to pour the contents into the bagor peel, cut, or trim items for insertion into the bag. It is also difficult to maintain theproper (usually upright) orientation of the opening of the bag during such fillingoperations. While rigid containers and flaccid containers with reinforced openingperimeters have been developed for such uses, their comparatively higher cost andlimited economical disposability leave room for improvement. Notwithstanding theissue of maintaining the container or bag opening in an open condition, there alsoremains a need for a flexible yet self-standing container with the foregoing attributes tofacilitate easy hands-free filling. Flexible storage bags on the other hand which areconstructed of more inexpensive materials to promote disposability typically lack thestructure necessary for stable stacking of bags after filling.

With regard to rigid or semi-rigid containers, it is well recognized that suchcontainers have also realized a fair degree of commercial success in providing a means for storing a wide variety of contents. Such containers typically have an opening whichmaintains an open condition for filling and are typically self-supporting with the openingin the proper orientation for filling. Such containers also are frequently provided withflat bottoms and tops to provide stackability. However, such containers are typicallyconstructed of more expensive materials such that disposability is limited. At the sametime, the useful life of such containers is limited by damage, soiling, or other degradationnaturally occurring in use, including degradation of the typical mechanical closuremechanisms. Storage of such three-dimensional, rigid or semi-rigid containers whenempty is also a concern, since they occupy as much volume empty as they do in a filledcondition. Due to their comparatively fixed-volume construction, it is also difficult tominimize the amount of air or free space above or around the contents to minimizestorage space of filled containers and to aid the effectiveness of the container inpreservation of perishable items. Another concern is the task of matching usually-separatelids or closures with their respective containers for use.

Accordingly, it would be desirable to provide a flexible storage bag or containercombining the desirable qualities of both flexible bags and storage containers andminimizing the less desirable qualities of both approaches.

More particularly, it would be desirable to provide a flexible storage bag orcontainer having improved sealability in use.

It would also be desirable to provide a flexible storage bag or container whichfacilitates venting of trapped air before completion of closure.

It would further be desirable to provide such a bag or container which is capableof being self-supporting in an open condition for filling purposes, yet stores easily byfolding into a compact form.

It would still further be desirable to provide a bag or container constructed frominexpensive materials to facilitate disposability which still promotes stable stacking ofbags or containers in a filled condition.

It would be yet further desirable to provide such a bag or container whichprovides the foregoing attributes in a convenient unitary form, obviating the need forseparate closure devices.

SUMMARY OF THE INVENTION

The present invention provides a flexible storage bag comprising at least onesheet of flexible sheet material assembled to form a semi-enclosed container having anopening defined by a hinged peripheral flange. The hinged flange includes a closuremeans for sealing the opening to convert the semi-enclosed container to a closed container. The bag includes at least one pair of opposed gussets formed in the sheetmaterial extending in a direction normal to the opening and a substantially planar bottomextending in a direction substantially parallel to the opening. When the bottom is placedon a horizontal surface the container is self-supporting and maintains the opening in anopen condition.

The present invention also provides a flexible storage bag having an opening anda closure means for sealing the opening to convert the semi-enclosed container to aclosed container. The closure means comprises a strip of material forming at least aportion of the periphery of the opening having a first side facing inwardly toward theopening and a second side facing outwardly of the opening. The first side exhibits anadhesion peel force after activation by a user which is greater than an adhesion peel forceexhibited prior to activation by a user.

The present invention also provides a collapsible, stackable, self-restorablecontainer comprising a unitary continuous tubular sidewall having a first open end and asecond open end defining an axial direction extending through the first and second openends. The first open end has a substantially continuous outwardly-extending flangeforming a periphery. The tubular sidewall is collapsible in response to an externally-appliedforce exerted in its axial direction and is self-restorable when the force isremoved. The container further includes a bottom panel unitarily formed with the secondopen end of the tubular sidewall and enclosing one end of the tubular sidewall to form asemi-enclosed container. A lid attached to the tubular sidewall for selectively convertingthe semi-enclosed container to a closed container completes the storage container, and aclosure means is provided for sealing the lid to the tubular sidewall. The closure meanscomprises a strip of material forming at least a portion of the periphery having a first sidefacing inwardly toward the opening and a second side facing outwardly of the opening,with the first side exhibiting an adhesion peel force after activation by a user which isgreater than an adhesion peel force exhibited prior to activation by a user.

The present invention also provides a collapsible, foldable, stackable, and self-supportingcontainer comprising semi-enclosed container body having two opposed sidewalls, two opposed end walls between the side walls, and a bottom panel enclosing oneend of the container body. Each of the side walls includes a gusset extending in adirection substantially parallel to the bottom panel. The container further includes a lidattached to the container body for selectively converting the semi-enclosed container to aclosed container. Finally, the container includes a closure means for sealing the lid to thecontainer body. In accordance with the present invention the side walls and end walls areinwardly foldable toward one another, such that the container is collapsible in a direction normal to the lid and bottom panel while being substantially self-supporting while theside walls and end walls are in their unfolded orientation.

The present invention also provides a storage container having an opening and aclosure means for sealing the opening to convert the semi-enclosed container to a closedcontainer. The closure means comprises a strip of material forming at least a portion ofthe periphery of the opening having a first side facing inwardly toward the opening and asecond side facing outwardly of the opening. The first side exhibits an adhesion peelforce after activation by a user which is greater than an adhesion peel force exhibitedprior to activation by a user.

Accordingly, the flexible storage bags and containers of the present inventioncombine the desirable qualities of both flexible bags and storage containers and minimizethe less desirable qualities of both approaches by providing improved sealability,facilitating venting of trapped air before closure, being self-supporting in an opencondition for filling, storing easily by folding into a compact form, and being unitarilyconstructed from inexpensive materials to promote disposability and obviate the need forseparate closure devices.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing out anddistinctly claiming the present invention, it is believed that the present invention will bebetter understood from the following description in conjunction with the accompanyingDrawing Figures, in which like reference numerals identify like elements, and wherein:

Figure 1 is a perspective view of a preferred embodiment of a flexible storage bagof the present invention, in an open configuration;

Figure 2 is a perspective view of the flexible storage bag of Figure 1 in a partiallyclosed condition after filling;

Figure 3 is a perspective view of the flexible storage bag of Figure 1 in a closedand sealed condition after filling;

Figure 4 is a perspective view of the flexible storage bag of Figure 1 with thesealed edge of the bag being optionally folded over to provide a flat upper surface forstacking;

Figure 5 is a perspective view of the flexible storage bag of Figure 1 in a partiallyfolded condition;

Figure 6 is a perspective view of the flexible storage bag of Figure 1 in a fully-folded,flattened condition;

Figure 7 is a perspective view similar to Figure 6 of an alternative flexible storagebag having no reinforcing panel;

Figure 8 is a perspective view of a storage container in accordance with thepresent invention in a closed condition;

Figure 9 is a perspective view of the storage container of Figure 8 in an opencondition and partially filled with solid objects;

Figure 10 is a perspective view of the storage container of Figure 8 in a fully-flattenedcondition;

Figure 11 is a partial elevational sectional view of the edge portion of thecontainer of Figure 8 depicting the relationship of the closure means to the rest of thecontainer;

Figure 12 is a partial elevational sectional view similar to that of Figure 11 butdepicting an alternative container construction wherein the peripheral portions of thecontainer body and lid are formed as a composite structure;

Figure 13 is a partial elevational sectional view similar to that of Figure 11 butdepicting the partial collapse of the container in response to an externally applied force;

Figure 14 is a partial elevational sectional view similar to that of Figure 13 butdepicting the container in a fully collapsed condition;

Figure 15 is a perspective view of a storage container in accordance with thepresent invention in a closed condition;

Figure 16 is a perspective view of the storage container of Figure 15 in an opencondition and partially filled with solid objects;

Figure 17 is a perspective view of the storage container of Figure 15 in ahorizontal position in preparation for folding;

Figure 18 is a perspective view of the storage container of Figure 15 in a partiallyfolded and collapsed condition;

Figure 19 is a perspective view of the storage container of Figure 15 in a fullyfolded and collapsed condition;

Figure 20 is a top plan view of a preferred embodiment of a material suitable foruse as a closure means of the present invention, disclosing a piece of material havingtruncated conical protrusions surrounded by an interconnected pattern of substance;

Figure 21 is an enlarged partial top plan view of the material of Figure 20,showing an array of protrusions;

Figure 22 is an elevational sectional view, taken along section line 22-22 ofFigure 21, showing the protrusions acting as standoffs for a substance layer between protrusions, such that a target surface contacting the outermost ends of the protrusionsdoes not contact the substance layer;

Figure 23 is an elevational sectional view similar to Figure 22, showing the effectof pressing the material against the target surface, such that protrusions deform bysubstantially inverting and/or crushing to allow the substance layer between protrusionsto contact the target surface;

Figure 24 is an elevational sectional view of the material of Figures 20-23,showing preferred dimensional relationships of protrusions; and

Figure 25 is a schematic view of a suitable method of making a material suitablefor use as a closure means of the present invention, showing a forming screen as a beltwrapped around a vacuum drum and a drive pulley.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 depicts a presently preferred embodiment of aflexible storage bag 10according to the present invention. In the embodiment depicted in Figure 1, theflexiblestorage bag 10 includes abag body 20 formed from a piece of flexible sheet materialfolded and bonded to itself to form a semi-enclosed container having an opening definedbyflange 31.Flexible storage bag 10 also includes closure means 30 associated withflange 31 for sealing the open end of thecontainer 10 to form a fully-enclosed containeror vessel as shown in Figure 3. Closure means 30 is selectively openable, sealable, andresealable, as will be described hereinafter.

In the preferred configuration depicted in Figure 1, the closure means 30completely encircles the periphery of the opening formed byflange 31. However, undersome circumstances a closure means formed by a lesser degree of encirclement (such as,for example, a closure means disposed along only one side of flange 31) may provideadequate closure integrity. Theflange 31 may be either unitarily formed with thebagbody 20 or provided as a separate material element joined to the bag body. Whenprovided as a separate, preferably more rigid material element, it is presently preferredthat the bag body material be formed into at least a small peripheral flange at its upperedge (defining the opening) with pleated corners so as to form a suitable junction pointfor joining the bag body to the flange.

Flexible storage bag 10 is suitable for containing and protecting a wide variety ofmaterials and/or objects contained within the bag body. Figure 1 depicts thestorage bag10 in an open condition wherein the closure means 30 has been released such thatflange31 may be opened to admit materials and/or objects into the interior of the bag body portion of thestorage bag 10. In Figure 1 a plurality of genericsolid objects 99 areshown within thestorage bag 10.

While the flexible storage bag described above with regard to Figure 1 providesmany advantages compared with flexible storage bags and storage containers commonlyavailable, it also includes additional features to enable the bag to assume a self-supportingconfiguration to facilitate product access and product filling without manualsupport for greater ease of use.

As utilized herein, the term "self-supporting" is utilized to refer to materials,structures, or containers which are capable of maintaining their orientation in a planeparallel to the direction of the force of gravity. For example, a self-supporting material,particularly a sheet material, may be held so that it extends upwardly parallel to thedirection of the force of gravity and maintain its orientation without folding over orcollapsing. Non-self-supporting materials typically will fold over or collapse and not becapable of being held parallel to the force of gravity (i.e., "vertically") unless they areheld so that they extend downwardly from their point of support. Correspondingly, aself-supporting bag or container is capable of maintaining its orientation with surfacesextending upwardly from their base of support in opposition to the force of gravitywithout folding over upon itself or collapsing.

In the preferred embodiment of Figure 1, theflexible storage bag 10 comprisestwo generallyplanar side panels 23, two generally planar,gusseted end panels 21, and agenerally planarbottom panel 50, which panels form a semi-enclosed container havingan opening defined byupper flange 31.Side panels 23 include side edges 22 andbottomedges 26, whileend panels 21 includebottom edges 48 and gussets of generallyconventional design having converging base creases 42 andmedial creases 46. In theconfiguration depicted in Figure 1, the bag is in its self-supporting, open condition.Flange 31 is preferably sufficiently resilient and rigid to aid in holding the open end ofthe bag in an open condition as shown in Figure 1, particularly when the hinges 32 (bestseen in Figure 2) are living hinges which resiliently bias theflange 31 toward the openconfiguration seen in Figure 1. The structure of the flexible storage bag thus enables thebag to assume a self-supporting configuration to facilitate product access and productfilling without manual support.

As is known in the art, gusseted bags typically provide a self-supporting open bagwhich may be readily filled or emptied with a minimum of difficulty. However, unlikemost conventional gusseted bags the flexible storage bags of the present inventioninclude a selectively-activatible closure means 30 as described herein. Accordingly, in addition to being self-supporting the gussetedflexible storage bags 10 also provide thedesirable sealing attributes described herein.

Figure 2 depicts the flexible storage bag of Figure 1 in a partially closedcondition after theobjects 99 have been inserted. As shown in Figure 2, theflange 31preferably includes a pair ofhinges 32 which are preferably unitarily formed in thematerial of theflange 31 as is typical of hinges commonly referred to as "living hinges".Hinges 32 are preferably configured so that they provide at least a slight biasing towardthe open configuration shown in Figure 1 to aid in holding the container in an open, self-supportingcondition.

Figure 3 depicts a flexible storage bag typical of that shown in Figure 1, but in asealed condition such as after insertion of a product into the interior of the bag.Accordingly, themedial creases 46 of the gussets have been pushed inwardly from theconfiguration of Figure 1 in a manner similar to that of Figure 2. However, the closuremeans 30 has been subjected to activation by a user so that overlying superimposedregions of the closure means are adhesively bonded to one another to form a secure,substantially fluid- and vapor-impervious seal for the opening formed by theflange 31 ofthe bag. In the preferred configuration shown in Figure 1, the closure means entirelyencircles the open end of the bag defined by theflange 31 so that complete adhesion ofthe entire periphery is assured upon activation.

As will become apparent by viewing the sequence of steps depicted in Figures 1-3,the flexible sheet material utilized to form the body of the bag is sufficiently flexibleand yieldable to accommodate the motion of the hinged flange as it moves between theopen configuration of Figure 1 and the closed configuration of Figure 3. Moreparticularly, theend panels 21 are sufficiently flexible to fold or pleat upon themselves asthe hinge portion of the flange pivots downwardly toward thebottom panel 50 while theouter portions of the flange (near tabs 35) move upwardly toward one another.

The illustrations of Figures 1-3 also demonstrate another inherent performanceadvantage of the flexible storage bags of the present invention. More particularly, thehinged peripheral flange orients the closure means 30 in a direction perpendicular to theaxis of the opening of the flexible storage bag and perpendicular to the inner wallsurfaces adjacent to the flange. This orientation tends to isolate the closure means fromthe materials being inserted into the bag through the opening and prevent contaminationthereof before use. At the same time, closure of the bag brings the closure meansthrough a 90 degree transition from horizontal to vertical, from perpendicular to the axisof the opening to parallel to the axis of the opening, effectively transitioning closure of the flexible storage bag from that of a container-like device to that of a bag-like device,combining the advantages of both in doing so.

To open the bag of Figure 3, a user may grasp the pair oftabs 35 and pull them inlaterally opposite directions to initiate and propagate separation of the opposed halves offlange 31, and hence closure means 30. Alternatively, marginal edges (which asmentioned above are preferably partially adhesive-free) of the bag above the closuremeans may be grasped and pulled apart.

Figure 4 depicts the closed and sealed bag of Figure 3 with the top portionoptionally folded over substantially parallel to the bottom 50, so that a stable stackableconfiguration is obtained whereupon other containers, articles, or the like may be stablyplaced upon the bag. Again, the flexible nature of the material of the bag body makessuch a folding-over a viable option for efficient storage. The gusseted, pleated sidewallstructure with spaced, defined corners adds additional integrity and stability to the filledbag, improving stackability in use and adding stability as well in terms of overturning orthe like.

In addition to being self-supporting, gussetedflexible storage bags 10 are alsoreadily foldable or collapsible to provide easy storage occupying minimal space. Figure5 depicts a gussetedflexible storage bag 10 as shown in Figure 1 but in a partially foldedor collapsed condition. Accordingly,medial creases 46 have been pushed inwardlytoward one another, bringing side edges 22 toward one another on opposite sides of themedial creases 46 and somewhat parallel to the base creases 42 in their vicinity. Such apredictable folding feature independent of the closure means also permits the volume ofthe container to be diminished after the contents are inserted to minimize the amount ofair and/or free space above or around the contents which is trapped within the bag afterclosure to minimize storage space of filled bags and to aid the effectiveness of the bag inpreservation of perishable items. Figure 6 shows a gussetedflexible storage bag 10 in amore fully folded condition wherein folding continues until the bottom 50 issubstantially parallel with the sides. Also depicted in Figure 6 is the optional reinforcingpanel 55 which adds additional integrity and stability to the generally rectangular, planarbottom panel 50.

The addition of additional reinforcement to the bottom panel lowers the center ofgravity of the empty bag for greater stability prior to and during filling, increases thestiffness of the bottom of the bag for added stability in most circumstances filled orempty, and reduces the likelihood of the bottom of the bag bowing when filled withheavier contents. The inward folding of the flaps forming thebottom panel 50 of the bagbody as shown in Figure 7 also performs a similar role. The reinforcing panel may be of a similar material to the bag material or may be of a different more or less durablematerial, and is secured to the bottom panel by adhesive application or other suitablemeans. It is presently preferred that when a reinforcing panel is employed that it beplaced on the exterior surface of the bottom panel rather than on the interior surface inorder to provide support and reinforcement without adding additional surfaces, joints,and crevices on the interior of the bag where they may provide sites for trapping portionsof the bag contents and creating cleaning difficulties.

Figure 7 depicts a bag similar to that of Figure 6, but without the optionalreinforcing panel on the bottom 50. In Figure 7, therefore, the seam and folding structureof the bottom 50 is clearly visible. Such a folding configuration is typical ofconventional folded, gusseted bags having a square or rectangular bottom and is sealedappropriately by adhesives, heat seals, or the like so as to provide a substantially liquid-tightand gas-tight bottom structure.

Various compositions suitable for constructing the flexible storage bags of thepresent invention include substantially impermeable materials such as polyvinyl chloride(PVC), polyvinylidene chloride (PVDC), polyethylene (PE), polypropylene (PP),aluminum foil, coated (waxed, etc.) and uncoated paper, coated nonwovens etc., andsubstantially permeable materials such as scrims, meshes, wovens, nonwovens, orperforated or porous films, whether predominantly two-dimensional in nature or formedinto three-dimensional structures. Such materials may comprise a single composition orlayer or may be a composite structure of multiple materials, including a substratematerial utilized as a carrier for a substance. Materials found suitable for use inaccordance with the present invention include a low density polyethylene film, 0.004 or0.006 inch thickness, commercially available from Huntsman Film Products Corp. underthe manufacturer's designation X420.

Figure 8 depicts a presently preferred embodiment of a storage container 10Aaccording to the present invention. In the embodiment depicted in Figure 8, the storagecontainer 10A includes acontainer body 20A preferably unitarily formed from a piece ofsheet material and alid 40A preferably unitarily formed with thecontainer body 20A orat least hingedly attached to the container body athinge line 45A. Storage container 10Aalso includes closure means 30A located adjacent to edge 28A for sealing the peripheralportions of thelid 40A andcontainer body 20A to form a fully-enclosed container orvessel as shown in Figure 8. Closure means 30A may comprise the marginal portion ofthelid 40A, themarginal flange portion 25A of thecontainer body 20A, or both.Hingeline 45A preferably comprises a unitary living hinge, and may optionally be provided as a line of weakness by scoring, perforations, or the like which may optionally permit thelid to be separated from the container body.

In the preferred configuration depicted in Figure 8, the closure means 30Acompletely encircles the periphery of the opening formed byedge 28A. However, undersome circumstances a closure means formed by a lesser degree of encirclement (such as,for example, a closure means disposed along all portions ofedge 28A except the hingedportion athinge line 45A) may provide adequate closure integrity.

Storage container 10A is suitable for containing and protecting a wide variety ofmaterials and/or objects contained within the container body. Figure 9 depicts thestorage container 10A in an open condition wherein the closure means 30A has beenreleased such thatedge 28A may be opened to admit materials and/or objects into theinterior of the body portion of the storage container 10A. In Figure 9 a plurality ofgenericsolid objects 99A are shown within the storage container 10A.

Resiliently deformable storage containers of the present invention provide theuser not only with product protection, but with temporary compactability for easy,compact storage wherein the compacted container tends to self-restore to near its originalshape for easy use. In an uncompressed state, the storage container is "self-supporting"in its expanded, restored condition for easy filling and use.

As utilized herein, the term "self-supporting" is utilized to refer to materials,structures, or containers which are capable of maintaining their orientation in a planeparallel to the direction of the force of gravity. For example, a self-supporting material,particularly a sheet material, may be held so that it extends upwardly parallel to thedirection of the force of gravity and maintain its orientation without folding over orcollapsing. Non-self-supporting materials typically will fold over or collapse and not becapable of being held parallel to the force of gravity (i.e., "vertically") unless they areheld so that they extend downwardly from their point of support. Correspondingly, aself-supporting bag or container is capable of maintaining its orientation with surfacesextending upwardly from their base of support in opposition to the force of gravitywithout folding over upon itself or collapsing.

Referring again to Figure 9, thestorage container body 20A comprises adeformable substantially continuous tube or hoop of material. In the illustrativeconfiguration depicted wherein the container has a substantially rectangular shape, thetube or hoop forms a substantially continuous sidewall comprisingsidewall portions21A, 22A, 23A and 24A. The tube or hoop may be of nearly any desired cross-section,but is typically rectangular. Regardless of cross-section, the container body which formsa semi-enclosed container is preferably free of internal corners where walls, bottom panels, etc. join one another to facilitate easy removal of container contents and ease ofcleaning. One end of the tube forming the tubular sidewalls remains open for access tothe interior of the container and is selectively closeable by apivotable lid 40A. The otherend of the tubular sidewall is enclosed by abottom panel 50A, which may be comprisedof the same resilient material as the tubular sidewall. In a particularly preferredembodiment the container comprises a relatively thicker and stiffer lid and bottom wallcomprised of a resiliently deformable material and oriented generally parallel to oneanother.

Resiliently deformable packages of the present invention can be made from lowcost materials, are easy to produce and can undergo numerous deformation cycles whilemaintaining their functionality and aesthetic appearance.

In general, resiliently deformable storage containers of the present invention mayemploy greater side wall thicknesses as the resiliency of the material comprising the sidewalls increases. Conversely, as the resiliency of the materials used to construct the sidewalls decreases, thinner side wall thicknesses are preferably employed to maximize theresiliently deformable characteristic of storage containers of the present invention.

As shown in Figure 10, the circumferential attachment of the intersectingsidewalls 21A, 22A, 23A, and 24A defines a tube or hoop which is easily deformable byan externally applied force "F", as shown by the "pleating" effect depicted along thesidewalls. Depending upon the nature of the materials utilized for the tubular sidewall(s)and the radius of the corners where adjacent sidewalls meet, this pleating effect may bemore or less concentrated at the corners and more generalized bowing or buckling in themedial portions of the sidewalls. This deformation occurs due to the thinness of the sidewalls and the resiliently deformable characteristic of the material comprising the sidewalls. When the deforming force "F" is removed from the top of the resilientlydeformable storage container (lid 40A in Figure 10) the tube or hoop formed by theinterconnected side walls tends to cause thecontainer body 20A to self-restore toward itssubstantially original undeformed shape, as generally shown in Figures 8 and 9,substantially eliminating the folds or pleats depicted in Figure 10. As used herein, theterm "self-restore" refers to the tendency of resiliently deformable storage container 10Ato return toward its original undeformed condition without taking on a permanent set dueto the deformation when the deforming forces are removed. This recovery may not fullyrestore the package to its exact original shape and appearance. However, unlikesubstantially rigid packages of the prior art, resiliently deformable storage container 10Awill self-restore to a degree which is sufficient to at least facilitate continued functionaluse. A more detailed discussion of self-restorable containers is provided in commonly-assigned U.S. Patent No. 5,379,879, issued January 10, 1995 to Muckenfuhs et al., thedisclosure of which is hereby incorporated herein by reference.

If thermoforming is employed to producestorage container body 20A and/orlid40A, it is also feasible to produce highly decorative effects in the resulting storagecontainer at relatively low cost, simply by preparing a suitable mold. For example,textures, logos, instructions, etc., can be molded into thecontainer body 20A and/orlid40A to produce a desirable aesthetic appearance and/or integral brand identificationand/or usage instructions, all without the need for ancillary printing or labelingoperations. Twisting forces which may be applied to the storage container will beresisted not only by the tube or hoop formed by the intersecting side walls 21A-24A, butalso by the torsional resistance of the substantially planar and thicker bottom panel andlid, respectively. Accordingly, both the side walls 21A-24A and the relatively thickerbottom panel and lid help to restore the package toward substantially its originalconfiguration once all of the externally applied forces have been removed from thepackage.

Referring again to Figure 9, while thelid 40A, side walls 21A-24A, and thebottom panel 50A of the resiliently deformable storage container 10A need not beproduced from the same material, there may be certain advantages for doing so. From amanufacturing standpoint, the use of similar materials may make the joining of the lid,the side walls, and the bottom panel to one another easier and less expensive usingknown techniques, e.g., heat sealing, ultrasonics, etc. Furthermore, with regard to therecycling of the storage container at the end of its useful life, it may be easier if all theelements comprising the storage container are comprised of the same material, thuseliminating the need to separate components from one another prior to material recoveryprocessing.

Figure 11 is a partial cross-sectional view of the storage container 10A depictedin Figures 8 and 9 taken through thesidewall 22A, more clearly depicting the structuralrelationship between the various components previously described. Theflange 25A isdepicted as being unitarily formed with thesidewall 22A, which is depicted as beingunitarily formed with thebottom panel 50A.Lid 40A is depicted as being unitary.Figure 12, on the other hand, depicts thelid 40A as comprising acentral lid panel 42Aand alid frame 44A, either of which may also formed of various elements if desired.Theflange 25A is depicted as being smaller, and preferably but optionally still unitarilyformed with thesidewall 22A, which is preferably but optionally still unitarily formedwith thebottom panel 50A. However, the outer portion of the container body nowcomprises outer flange 27A which is affixed to and extends laterally outwardly from theflange 25A. Also shown in Figure 12 is the presence of an optional reinforcingbottompanel 55A provided to enhance the rigidity and resiliency of the bottom of the storagecontainer, and preferably externally provided so as to avoid creating additional surfacesand edges inside the interior of the container body which would create difficulties incleaning and emptying the container.

The addition of additional reinforcement to the bottom panel lowers the center ofgravity of the empty container for greater stability prior to and during filling, increasesthe stiffness of the bottom of the container for added stability in most circumstancesfilled or empty, and reduces the likelihood of the bottom of the container bowing whenfilled with heavier contents. The reinforcing panel may be of a similar material to thecontainer body material or may be of a different more or less durable material, and issecured to the bottom panel by adhesive application or other suitable means. It ispresently preferred that when a reinforcing panel is employed that it be placed on theexterior surface of the bottom panel rather than on the interior surface in order to providesupport and reinforcement without adding additional surfaces, joints, and crevices on theinterior of the container where they may provide sites for trapping portions of thecontents and creating cleaning difficulties.

The ability to construct the container of multiple composite elements permits theuse of diverse materials such as transparent polymeric panels for lid panels or more rigid,resilient materials for flanges and lid frames independently of the tailoring of materialsfor the tubular sidewall.

Figures 13 and 14 are partial cross-sectional views corresponding to Figure 11which depict the storage container in partially and fully-compressed conditions,respectively. As shown in Figure 10, partial collapse or compression of the container inresponse to an externally-applied force F applied in an axial direction with regard to theaxial direction of the tubular sidewall causes a pleating or folding of the tubular sidewall.This collapse continues until a fully-collapsed condition is encountered as depicted inFigure 14 (and Figure 10, in perspective), when overlying pleats or folds meet to form asolid stack of sidewall material and impede further compression of the storage container.Since the sidewall thicknesses are exaggerated beyond those preferred for purposes ofillustrative clarity in Figures 11-14, this condition is preferably only reached when the lidand bottom panel are sufficiently close to one another to provide a truly minimal overallcontainer thickness when fully compressed.

With or without additional venting features, the use of the selectively-activatibleclosure means of the present invention for the primary closure facilitates greater ease ofventing or expelling air and/or free space above or around the contents prior to sealing by providing an easy-to-use sealing mechanism. The body of the storage container may becompressed as described above prior to completing the closure process to reduce theinterior volume of the container and the closure process then completed to seal thecontainer.

Various compositions suitable for constructing the storage containers of thepresent invention include substantially impermeable materials such as polyvinyl chloride(PVC), polyvinylidene chloride (PVDC), polyethylene (PE), polypropylene (PP),aluminum foil, coated (waxed, etc.) and uncoated paper, coated nonwovens etc., andsubstantially permeable materials such as scrims, meshes, wovens, nonwovens, orperforated or porous films, whether predominantly two-dimensional in nature or formedinto three-dimensional structures. Such materials may comprise a single composition orlayer or may be a composite structure of multiple materials, including a substratematerial utilized as a carrier for a substance. Materials found suitable for use inaccordance with the present invention include a polymeric film, 0.012 inch thickness,commercially available from American National Can under the manufacturer'sdesignation DZ-2002-2.

Figure 15 depicts a presently preferred embodiment of a storage container 10Baccording to the present invention. In the embodiment depicted in Figure 15, the storagecontainer 10B includes acontainer body 20B preferably unitarily formed from a piece ofsheet material and alid 40B preferably unitarily formed with thecontainer body 20B orat least hingedly attached to the container body athinge line 45B. Storage container 10Balso includes closure means 30B located adjacent to edge 28B for sealing the peripheralportions of thelid 40B andcontainer body 20B to form a fully-enclosed container orvessel as shown in Figure 15. Closure means 30B may comprise the marginal portion ofthelid 40B, themarginal flange portion 25B of thecontainer body 20B, or both. Closuremeans 30B is selectively openable, sealable, and resealable, as will be describedhereinafter.Hinge line 45B shown in Figure 16 preferably comprises a unitary livinghinge, and may optionally be provided as a line of weakness by scoring, perforations, orthe like which may optionally permit the lid to be separated from the container body.

In the preferred configuration depicted in Figure 15, the closure means 30Bcompletely encircles the periphery of the opening formed byedge 28B. However, undersome circumstances a closure means formed by a lesser degree of encirclement (such as,for example, a closure means disposed along all portions ofedge 28B except the hingedportion athinge line 45B) may provide adequate closure integrity. Theflange 25B maybe either unitarily formed with thecontainer body 20B or provided as a separate materialelement joined to the container body. When provided as a separate, preferably more rigid material element, it is presently preferred that the container body material beformed into at least a small peripheral flange at its upper edge (defining the opening)with pleated corners so as to form a suitable junction point for joining the container bodyto the flange. The closure means may be provided on mating portions of either theflange25B, thelid 40B, or both.

Storage container 10B is suitable for containing and protecting a wide variety ofmaterials and/or objects contained within the container body. Figure 16 depicts thestorage container 10B in an open condition wherein the closure means 30B has beenreleased such thatedge 28B may be opened to admit materials and/or objects into theinterior of the body portion of the storage container 10B. In Figure 16 a plurality ofgenericsolid objects 99B are shown within the storage container 10B.

The ability to construct the container of multiple composite elements permits theuse of diverse materials such as transparent polymeric panels for lid panels or more rigid,resilient materials for flanges and lid frames independently of the tailoring of materialsfor thecontainer body 20B.Lid 40B is depicted as comprising acentral lid panel 42Band alid frame 44B, either of which may also formed of various elements if desired,althoughlid 40B may also be of unitary construction.

In the embodiment of Figure 15, the storage container 10B comprises twogenerallyplanar end panels 50B, two generally planar,gusseted side panels 60B, and agenerally planarbottom panel 70B, which panels form a semi-enclosed container havingan opening defined byupper flange 25B.End panels 50B include side edges 55B andbottom edges 54B, whileside panels 60B includebottom edges 64B and gussets ofgenerally conventional design having converging base creases 62B andmedial creases61B, withlateral creases 63B. In the configuration depicted in Figure 15, the storagecontainer is in its self-supporting, open condition.Flange 25B is preferably sufficientlyresilient and rigid to aid in holding the open end of the container in an open condition asshown in Figure 15.

While the storage container described above with regard to Figure 15 providesmany advantages compared with flexible storage bags and storage containers commonlyavailable, it also includes additional features to enable the container to assume a self-supportingconfiguration to facilitate product access and product filling without manualsupport for greater ease of use.

As utilized herein, the term "self-supporting" is utilized to refer to materials,structures, or containers which are capable of maintaining their orientation in a planeparallel to the direction of the force of gravity. For example, a self-supporting material,particularly a sheet material, may be held so that it extends upwardly parallel to the direction of the force of gravity and maintain its orientation without folding over orcollapsing. Non-self-supporting materials typically will fold over or collapse and not becapable of being held parallel to the force of gravity (i.e., "vertically") unless they areheld so that they extend downwardly from their point of support. Correspondingly, aself-supporting bag or container is capable of maintaining its orientation with surfacesextending upwardly from their base of support in opposition to the force of gravitywithout folding over upon itself or collapsing.

In addition to being self-supporting, gusseted storage container 10B is alsoreadily foldable or collapsible to provide easy storage occupying minimal space. Figure17 depicts a gusseted storage container 10B as shown in Figure 15 positioned laterally onits side in preparation for folding. Figure 18 depicts a gusseted storage container 10B asshown in Figure 15 but in a partially folded or collapses condition. Accordingly,medialcreases 61B have been pushed inwardly toward one another, bringingbottom edges 64Btoward and generally parallel to theflange 25B. Figure 19 shows a gusseted storagecontainer 10B in a more fully folded condition wherein folding continues until thebottom 70B is substantially parallel to and in close proximity to theflange 25B. Alsodepicted in Figure 17 is the optional reinforcingpanel 72B which adds additionalintegrity and stability to the generally rectangular, planarbottom panel 70B. To avoidnegatively impacting upon the foldability of the container body, the reinforcingbottompanel 72B preferably includes creases 71B which substantially align withlateral creases63B for folding as depicted in Figures 17-19. Optional reinforcingpanel 72B may alsoextend upwardly at one or both ends covering or reinforcingend panels 50B.

The addition of additional reinforcement to the bottom panel lowers the center ofgravity of the empty container for greater stability prior to and during filling, increasesthe stiffness of the bottom of the container for added stability in most circumstancesfilled or empty, and reduces the likelihood of the bottom of the container bowing whenfilled with heavier contents. The reinforcing panel may be of a similar material to thecontainer body material or may be of a different more or less durable material, and issecured to the bottom panel by adhesive application or other suitable means. It ispresently preferred that when a reinforcing panel is employed that it be placed on theexterior surface of the bottom panel rather than on the interior surface in order to providesupport and reinforcement without adding additional surfaces, joints, and crevices on theinterior of the container where they may provide sites for trapping portions of thecontents and creating cleaning difficulties.

The flexible sheet material utilized to form the body of the container issufficiently flexible and yieldable to accommodate the folding or collapsing of the container body between the open configuration of Figure 15 and the closed configurationof Figure 19. More particularly, theside panels 60B are sufficiently flexible to fold orpleat upon themselves as theend panels 50B pivot inwardly toward one another as thebottom panel 70B moves toward thelid 40B.

To open the storage container of Figure 15, a user may grasp the pair oftabs 35Band pull them in opposite directions to initiate and propagate separation of the opposedhalves of flange 31B, and hence closure means 30B.

In Figures 15-19, the seam and folding structure of theend panels 50B is clearlyvisible. Such a folding configuration is typical of conventional folded, gusseted bagshaving a square or rectangular bottom and is sealed appropriately by adhesives, heatseals, or the like so as to provide a substantially liquid-tight and gas-tight panel structure.The gusseted, pleated sidewall structure with spaced, defined corners adds additionalintegrity and stability to the filled container, improving stackability in use and addingstability as well in terms of overturning or the like.

More specifically, the manner of folding the container body material to form theend panels 50B, as shown in Figures 15-19, results in multiple layers of material formingoverlappingflaps 51B and 52B, which lends additional stability and rigidity to thecontainer when these panels are in their extended position of Figure 15 since theyfunction as legs or supports for the container. Moreover, the diagonal folded edges of theflaps 51B and 52B, namely edges 53B, is believed to provide diagonal reinforcing foldsor braces which further aid in the construction ofend panels 50B from a flexible materialwhich provide the desired level of integrity, self-supportability, and stackability to thecontainer of the present invention.

Various compositions suitable for constructing the storage containers of thepresent invention include substantially impermeable materials such as polyvinyl chloride(PVC), polyvinylidene chloride (PVDC), polyethylene (PE), polypropylene (PP),aluminum foil, coated (waxed, etc.) and uncoated paper, coated nonwovens etc., andsubstantially permeable materials such as scrims, meshes, wovens, nonwovens, orperforated or porous films, whether predominantly two-dimensional in nature or formedinto three-dimensional structures. Such materials may comprise a single composition orlayer or may be a composite structure of multiple materials, including a substratematerial utilized as a carrier for a substance. Materials found suitable for use inaccordance with the present invention include a low density polyethylene film, 0.006inch thickness, commercially available from Huntsman Film Products Corp. under themanufacturer's designation X420.

Once the desired sheet materials are manufactured in any desirable and suitablemanner, comprising all or part of the materials to be utilized for the bag or containerbody, the bag or container may be constructed in any known and suitable fashion such asthose known in the art for making such bags or containers in commercially availableform. Heat or adhesive sealing technologies may be utilized to join various componentsor elements of the bag to or container themselves or to each other. In addition, the bag orcontainer bodies may be thermoformed, blown, or otherwise molded rather than relianceupon folding and bonding techniques to construct the bag or container bodies from a webor sheet of material.

The closure means depicted in Figures 1-19 may be constructed in any knownfashion utilizing any closure configuration, such as folds, pleats, adhesives, ormechanical interlocking closures such as ribs, beads, and grooves, which are known inthe art. However, it is presently preferred to utilize a selectively activatible adhesive-bearingstructure which provides a secure closure seal upon activation. Accordingly, theclosure means preferably comprises a selectively activatible adhesive-like material whichbonds opposing material surfaces to one another across the opening. The bond betweenthe closure means and a target surface is also sufficient to provide a barrier seal againsttransmission of oxygen, moisture/moisture vapor, odor, etc. such that perishable itemsmay be satisfactorily enclosed and preserved to the extent of the barrier properties of thematerial itself. The target surface may comprise a separate element of the bag or maycomprise another region of the closure means itself.

As utilized herein, the term "selectively activatible" is used to refer to materialswhich exhibit substantially non-adherent properties when brought into contact with targetsurfaces until some action is taken by a user to "activate" the material to reveal adhesiveproperties. Accordingly, selectively-activatible properties differ from permanently-activestrips of adhesive which rely upon removal of liner materials (typically silicone-coatedpaper strips) to expose the adhesive for use.

Selective activation of such materials allows the user to properly positionopposing surfaces before activation and adhesion are accomplished, as well asminimizing the likelihood of contamination of the closure means by bag or containercontents during filling operations. This characteristic permits the flexible storage bag orcontainer to be opened, filled, and/or manipulated in any desired mode withoutencountering the difficulties of premature clinging or adhering of the closure means toitself or to other portions of the opening or bag/container body, and without the need forseparate release sheets, liners, spacers, or the like. Preferably, the selective activationprocess is reversible such that the closure means may be de-activated and the bag or container opened for filling or removal of contents and then re-activated for furtherclosure without significant loss of adhesive capability.

Although material utilized for the closure means may be provided with two activesides or surfaces, if desired for particular applications, in accordance with the presentinvention it is presently preferred to provide such material with only one active side andone inactive or inert side. While under some circumstances it may be acceptable ordesirable to design the closure material so as to form a discontinuous bond pattern withitself or another target surface, such as by having an intermittent or discontinuous layerof adhesive on its active surface, it is presently preferred that the closure material bedesigned so as to exhibit the ability to form a continuous seal or bond with itself and withany sufficiently continuous target surface.

Various means of activation are envisioned as being within the scope of thepresent invention, such as: mechanical activation by compression, mechanical activationby tensile forces, and thermal activation. However, it is envisioned that there may be orbe developed other means of activation which would trigger an adhesive or adhesive-likecharacter which would be capable of functioning as herein described. In a preferredembodiment the active side is activatible by an externally applied force exerted upon thesheet of material. The force may be an externally applied compressive force exerted in adirection substantially normal to the sheet of material, an externally applied tensile forceexerted in a direction substantially parallel to the sheet of material, or a combinationthereof.

Regardless of the manner of activation, materials useful as a closure means inaccordance with the present invention will exhibit an adhesive, adherent, or tackingcharacter as opposed to merely a clinging or affinity character. As utilized herein,therefore, the term "adhesive" is utilized to refer the ability of a material to exhibit anadherent character whether or not it actually includes a composition commonlyunderstood and labelled as an adhesive. Accordingly, such materials will form a bond orseal when in contact with itself or another target surface as opposed to merely beingattracted to such surface. While a number of approaches such as the use of selectivelyadherent materials may be utilized to provide the desired adhesive properties, a presentlypreferred approach is to utilize a pressure-sensitive adhesive.

When designing materials useful as a closure means in accordance with thepresent invention, it may be desirable to tailor the particular choice of adhesive agent soas to provide either a permanent bond or a releasable bond as desired for a particularapplication. Where a permanent bond is desired, opening of the flexible storage bag orcontainer for access to the item(s) therein requires destruction of the bag or container. Releasable bonds, on the other hand, provide access by permitting separation of theclosure means from itself or other portions of the bag or container at the bond sitewithout destruction. Moreover, depending upon the activation mechanism employed inthe design of the material, the releasable bond may additionally be refastenable ifsufficient adhesive character remains after the initial activation/bonding/release cycle.

The closure materials useful in the present invention exhibit an adhesionsufficient to survive the likely degree of handling and external or internal forces theflexible storage bag or container is likely to encounter in use while maintaining thedesired level of sealing engagement with the opposing surface such that preservation ofperishable items is ensured. In general, minimum adhesion which maintains a seal isdesired for a closure means, so that the closure means easily peeled open for access to thestored item(s). At the same time, in a preferred embodiment the closure means is asubstantially clingless material. Suitable methods of measuring and quantifying adhesiveand cling properties are described in greater detail in commonly-assigned, co-pendingU.S. Patent Application Serial No. 08/744,850, filed November 8, 1996 in the names ofHamilton and McGuire, entitled "Material Having A Substance Protected by DeformableStandoffs and Method of Making".

The closure means utilized in accordance with the present invention comprises asheet of material having a first side and a second side. The first side comprises an activeside exhibiting an adhesion peel force after activation by a user which is greater than anadhesion peel force exhibited prior to activation by a user. The active side of the closuremeans preferably exhibits an adhesion peel force of at least about 1 ounce per linear inch,more preferably between about 1 and about 2.5 ounces per linear inch, after activation bya user.

One such material of current interest for use as a closure material in accordancewith the present invention comprises a three-dimensional, conformable web comprisingan active substance such as adhesive on at least one surface protected from externalcontact by the three-dimensional surface topography of the base material. Such materialscomprise a polymeric or other sheet material which is embossed/debossed to form apattern of raised "dimples" on at least one surface which serve as stand-offs to prevent anadhesive therebetween from contacting external surfaces until the stand-offs aredeformed to render the structure more two-dimensional. Representative adhesive carrierstructures include those disclosed in commonly assigned, co-pending U.S. PatentApplication Serial Nos. 08/584,638, filed January 10, 1996 in the names of Hamilton andMcGuire, entitled "Composite Material Releasably Sealable to a Target Surface When Pressed Thereagainst and Method of Making", 08/744,850, filed November 8, 1996 inthe names of Hamilton and McGuire entitled "Material Having A Substance Protected byDeformable Standoffs and Method of Making", 08/745,339, filed November 8, 1996 inthe names of McGuire, Tweddell, and Hamilton, entitled "Three-Dimensional, Nesting-ResistantSheet Materials and Method and Apparatus for Making Same", 08/745,340,filed November 8, 1996 in the names of Hamilton and McGuire, entitled "ImprovedStorage Wrap Materials".

The three-dimensional structure comprises a piece of deformable material whichhas a first side formed to have a plurality of hollow protrusions separated by valleys.The plurality of hollow protrusions have outermost ends. The piece of material has asecond side. The second side has a plurality of depressions therein corresponding to theplurality of hollow protrusions on the first side. The substance adheres to and partiallyfills the valleys between the plurality of hollow protrusions. The substance has a surfacebelow the outermost ends of the plurality of hollow protrusions, so that when a portion ofthe first side of the piece of deformable film is placed against a target surface, theplurality of hollow protrusions prevent contact between the substance and the targetsurface until the portion is deformed at the target surface. Preferably, the plurality ofprotrusions deform by modes which are selected from the group consisting of inverting,crushing, and elongating. Preferably, in the inverting and/or crushing modes, each of theplurality of protrusions will not substantially deform until exposed to a pressure of atleast 0.1 pounds per square inch (0.69 kPa).

Figures 8-12 illustrate a preferred embodiment of a material useful as a closuremeans for flexible storage bags and containers according to the present invention, whichcomprises a three-dimensional sheet-like structure generally indicated as 30 (alsorepresentative for 30A, 30B in Figures 8-19).Material 30 includes adeformed material12 havinghollow protrusions 14 and a layer ofsubstance 16 located betweenprotrusions14.Protrusions 14 are preferably conical in shape with truncated or domed outermostends 18.Protrusions 14 are preferably equally spaced in an equilateral triangular pattern,all extending from the same side of the material.Protrusions 14 are preferably spacedcenter to center a distance of approximately two protrusion base diameters or closer, inorder to minimize the volume of valleys between protrusions and hence the amount ofsubstance located between them. Preferably, theprotrusions 14 have heights which areless than their diameters, so that when they deform, they deform by substantiallyinverting and/or crushing along an axis which is substantially perpendicular to a plane ofthe material. This protrusion shape and mode of deforming discouragesprotrusions 14 from folding over in a direction parallel to a plane of the material so that the protrusionscannot block substance between them from contact with a target surface.

Figure 10 shows atarget surface 90, which is smooth but which may have anysurface topography, being spaced away from layer ofsubstance 16 byoutermost ends 18ofprotrusions 14. Target surfaces in accordance with the present invention will typicallycomprise an opposing portion of the closure periphery which may or may not itselfcomprise a selectively-activatible adhesive-carrying closure means of similar type.Figure 11 showstarget surface 90 contacting layer ofsubstance 16 afterprotrusions 14have been partially deformed under pressure applied to the non-substance side ofmaterial 12, as indicated by force F.

The more protrusions per unit area, the thinner the piece of material andprotrusion walls can be in order to resist a given deformation force. Preferred layer ofsubstance 16 is preferably a latex pressure sensitive adhesive or a hot melt adhesive, suchas that available under specification no. Fuller HL-2115X, made by H. B. Fuller Co. ofVadnais Heights, MN. Any adhesive can be used which suits the needs of the materialapplication. Adhesives may be refastenable, releasable, permanent, or otherwise. Thesize and spacing of protrusions is preferably selected to provide a continuous adhesivepath surrounding protrusions so that air-tight seals may be made with a target surface anda desired level of adhesion with a target surface, while also providing the optimumpattern of standoffs for selective activation.

Film materials may be made from homogeneous resins or blends thereof. Singleor multiple layers within the film structure are contemplated, whether co-extruded,extrusion-coated, laminated or combined by other known means. The key attribute of thefilm material is that it be formable to produce protrusions and valleys. Useful resinsinclude polyethylene, polypropylene, PET, PVC, PVDC, latex structures, nylon, etc.Polyolefins are generally preferred due to their lower cost and ease of forming. Othersuitable materials include aluminum foil, coated (waxed, etc.) and uncoated paper, coatedand uncoated nonwovens, scrims, meshes, wovens, nonwovens, and perforated or porousfilms, and combinations thereof.

Different applications for the formed closure means will dictate ideal size anddensity of protrusions, as well as the selection of the substances used therewith. It isbelieved that the protrusion size, shape and spacing, the web material properties such asflexural modulus, material stiffness, material thickness, hardness, deflection temperatureas well as the forming process determine the strength of the protrusion. A "threshold"protrusion stiffness is required to prevent premature activation of the closure means due to the weight of overlaying layers of sheets or other forces, such as forces induced byshipping vibrations, mishandling, dropping and the like.

Inversion of protrusions minimizes protrusion spring back so that higher adhesionisn't necessary in order to prevent the failure of relatively weak seals. A resilientprotrusion could be used, for example, where it is intended for the bond to be permanent,where aggressive adhesive overcomes spring back. Also, a resilient protrusion may bedesirable where repeat use of the material is intended.

Figure 12 shows a preferred shape of the protrusions and valleys of closure meansof the present invention, which enables protrusions to substantially invert and/or crush asa mode of deforming. The preferred shape minimizes protrusion fold-over andinterference with substance placed in valleys between protrusions, or inside hollowprotrusions, or both. Also, the preferred shape helps to ensure a repeatable, predictable,resistance to protrusion deformation. Figure 12 shows that each protrusion is defined bya height dimension A and a base diameter dimension B. A preferred ratio of basediameter B to height A, which enables protrusions to substantially invert and/or crushwithout fold-over, is at least 2:1.

Figure 13 shows a suitable method for making a material such as thematerial 30useful in accordance with the present invention, which is generally indicated as 180 inFigure 13.

The first step comprises coating a forming screen with a first substance. Theforming screen has a top surface and a plurality of recesses therein. The coating stepapplies the first substance to the top surface without bridging the recesses. A second stepincludes introducing a piece of material, which has a first side and a second side, onto theforming screen such that the first side is in contact with the first substance on the topsurface of the forming screen. The first substance preferentially adheres to the first sideof the piece of material. A third step includes forming the piece of material to create aplurality of hollow protrusions extending from the first side into the recesses of theforming screen. The plurality of hollow protrusions are spaced apart by valleys intowhich the first substance is transferred from the forming screen. The plurality of hollowprotrusions are accurately registered with the first substance by use of a common transferand forming surface. The first substance forms an interconnected layer in the valleysbetween the protrusions.

Formingscreen 181 is threaded overidler pulley 182 and a drivenvacuum roll184. Formingscreen 181 is preferably a stainless steel belt, having the desiredprotrusion pattern etched as recesses in the belt. Covering the outer surface ofvacuum roll 184 is a seamless nickel screen which serves as a porous backing surface for formingscreen 181.

For producing a pressure sensitive adhesive containing material, asubstance 186,preferably hot melt adhesive, is coated onto formingscreen 181 by asubstance applicator188 while formingscreen 181 rotates past the applicator. A web ofmaterial 190 isbrought into contact with the substance coated forming screen at material infeedidler roll192. Hot air is directed radially atmaterial 190 by ahot air source 194 as the materialpasses overvacuum roll 184 and as vacuum is applied to formingscreen 181 throughvacuum roll 184 via fixedvacuum manifold 196 from a vacuum source (not shown). Avacuum is applied as the material is heated byhot air source 194. A formed, substancecoatedmaterial 198 is stripped from formingscreen 181 at strippingroll 200. Becausethe same common forming screen is used to transfer the substance to the material as isused to form the protrusions, the substance pattern is conveniently registered with theprotrusions.

Stainlesssteel forming screen 181 is a fabricated, seamed belt. It is fabricated inseveral steps. The recess pattern is developed by computer program and printed onto atransparency to provide a photomask for photoetching. The photomask is used to createetched and non-etched areas. The etched material is typically stainless steel, but it mayalso be brass, aluminum, copper, magnesium, and other materials including alloys.Additionally, the recess pattern may be etched into photosensitive polymers instead ofmetals. Suitable forming structures are described in greater detail in the above-referencedand above-incorporated Hamilton et al. and McGuire et al. patentapplications.

Materials of the foregoing variety when utilized as a closure means in accordancewith the present invention may be unitarily formed and constructed as part of the body ofthe flexible storage bag or container either before, during, or after assemblage of the bagfrom its material components. Alternatively, such closure means may also be separatelyformed and joined to the body of the flexible storage bag or container either before,during or after assemblage of the bag. Such joining may be edge-wise or may beaccomplished as a lamination or bonding of the material facially onto a superposedportion of the bag or container body, such lamination being particularly advantageouswhen it is desired to add additional thickness, stiffness, and/or resiliency to the region ofthe bag or container comprising the closure means. The material utilized for the closuremeans may be the same as or different from the material utilized to form the bag orcontainer body either in dimensions or in composition.

Particularly useful as a flange material in accordance with the present invention isa self supporting, semi-rigid, resilient polymeric or coated paper sheet material with aclosure means laminated thereto such that the active side of the closure means faces awayfrom the flange material, such that a composite closure means is formed having aplurality of highly-deformable stand-offs with a substantially more resilient, more self-supportingbase material. Materials found suitable for use in accordance with the presentinvention include a low density polyethylene sheet material, 0.020 inch thickness,commercially available from Huntsman Film Products Corp. under the manufacturer'sdesignation X420.

To facilitate separation of adhered or bonded overlying portions of the closuremeans material, various adaptations or modifications may be accomplished in terms ofintegration of the material into the overall structure of the flexible storage bag orcontainer. For example, it may be desirable to provide extension tabs (such astabs 35shown in Figures 1-7) on opposing sides of the opening periphery to facilitate manualinitiation of closure separation. It may also be desirable to leave a small but finiteportion of the bag or container body immediately adjacent to the opening periphery freeof closure material, such that there is a non-adherent rim of material which may beutilized to initiate material separation and hence opening of the flexible storage bag orcontainer.

In accordance with the present invention, the use of selectively-activatibleadhesive materials for the closure means 30 provides the user with an easy-to-operateclosure means for closing and sealing an opening in a flexible storage bag or container.The closure means 30 is easy to manipulate with one or two hands, as the only dexterityrequired is to grasp or pinch the closure means with a pair of opposed digits to activatethe material against an opposing surface of the bag or container body or closure means.Moving the grasping digits across the extent of the opening provides secure adhesion ofthe closure means across the extent of the opening, thereby converting the flexible bag orcontainer from a semi-enclosed container to a fully closed container. Particularly whenthe closure means fully encircles the opening in the bag or container body, the closuremeans 30 is highly tolerant to misalignment as it will adhere to any opposing surfaceunlike mechanical closure mechanisms which typically require precise alignment ofmating elements.

The ability of the closure means to be activated by pinching or graspingsuperimposed portions of the bag or container body is particularly advantageous withflexible, conformable structures such as the flexible storage bags and containers of thepresent invention. More particularly, such structures are yieldable under applied forces and accordingly, it would be difficult to activate a seal by exerting pressure upon the bagor container as a whole against a surface, particularly when filled, as such would tend toexpel bag or container contents as sealing of the closure is attempted. Therefore, the useof a closure means as herein described permits secure, reliable sealing of even highlyflexible storage bags or containers.

Because the closure means in a preferred configuration employs a layer ofadhesive protected by a plurality of three-dimensional protrusions, rather than a three-dimensionalmating pair of interlocking elements, it is possible to employ such a closuremeans successfully in a confined, non-parallel region of the bag or container body suchas the region near thehinges 32 without providing leakage sites such as the ends of themechanical elements. Accordingly, the closure means 30 of the present inventionprovides additional security and confidence in the level of sealing obtained for situationswhere a leakproof seal is important.

Although the self-supporting flexible storage bags illustrated in the foregoingFigures 1-7 and 15-19 have been constructed of flexible sheet material along the lines ofthe approach typically taken for paper grocery-type bags, as illustrated for example inU.S. Patent No. 584,555, issued June 15, 1897 to Lorenz, a wide variety of otherconstructions may be utilized in keeping with the self-supporting approach inconjunction with the use of a closure means in accordance with the present invention.Examples of such other illustrative bag designs include U.S. Patent Nos. 3,970,241,issued July 20, 1976 to Hanson, 5,061,500, issued October 29, 1991 to Mendenhall,5,195,829, issued March 23, 1993 to Watkins et al., and 5,314,252, issued May 24, 1994to Happ. Also illustrative is commonly-assigned U.S. Patent No. 4,898,477, issuedFebruary 6, 1990 to Cox et al.

In addition to such use of sheet material folded and sealed to form the bag orcontainer body, the bags or containers may be constructed in any known and suitablefashion such as those known in the art for making such bags or containers incommercially available form. Heat or adhesive sealing technologies may be utilized tojoin various components or elements of the bag or container to themselves or to eachother. In addition, the bag or container bodies may be thermoformed, blown, orotherwise molded from a starting blank or sheet of material rather than reliance uponfolding and bonding techniques to construct the bag or container bodies from a web orsheet of material.

While particular embodiments of the present invention have been illustrated anddescribed, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention.It is therefore intended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

Claims (9)

1. A flexible storage bag (10) comprising at least one sheet of flexible sheet materialassembled to form a semi-enclosed container having an opening defined by ahinged peripheral flange (31), said hinged flange (31) having aclosure means (32) for sealing said opening to convert said semi-enclosed container toa closed container, wherein said container is self-supporting and maintains saidopening in an upwardly-extending condition,characterized in that saidclosure means comprises a piece of material forming at least a portion of saidhinged flange (31), said piece of material having a first side,said first sideexhibiting an adhesion peel force after activation by a user which is greater thanan adhesion peel force exhibited prior to activation by a user.
2. The flexible storage bag (10) of Claim 1, furthercharacterized in that said bag (10)includes at least one pair of opposed gussets (21) formed in said sheet materialextending in a direction normal to said opening and a substantially planar bottom (50)extending in a direction substantially parallel to said opening, such that when saidbottom (50) is placed on a horizontal surface said container is self-supporting andmaintains said opening in an upwardly-extending condition.
3. A collapsible, stackable, self-restorable container (10A) comprising:

   (a) a unitary continuous tubular sidewall (21A, 22A, 23A, 24A) having a first open end and a secondopen end and defining an axial direction extending through said first andsecond open ends, said first open end having a substantially continuousoutwardly-extending flange (25A) forming a periphery (28A) of said first open end,said tubular sidewall being collapsible in response to an externally-appliedforce exerted in an axial direction and being self-restorable when saidforce is removed;

   (b) a bottom panel (50A) unitarily formed with said second open end of said tubularsidewall and enclosing one end of said tubular sidewall to form a semi-enclosedcontainer;

   (c) a lid (40A) for selectively converting said semi-enclosed container to a closedcontainer; and

   (d) a closure means (30A) for sealing said lid to said flange (25A);

   characterized in that said closure means comprises a piece of material forming atleast a portion of said periphery, said piece of material having a first side,said first side exhibiting an adhesion peel force after activation by a userwhich is greater than an adhesion peel force exhibited prior to activation by auser.
4. The collapsible, stackable, self-restorable container (10A) of Claim 3, furthercharacterized in that said tubular sidewall and said bottom panel arethermoformed from a continuous sheet of material.
5. A collapsible, foldable, stackable, and self-supportable container (10B) comprising:

   (a) a semi-enclosed container body (20B) comprising two opposed side walls (60B), twoopposed end panels (50B) between said side panels, said side panels and said endpanels together forming a tubular structure having two open ends, and abottom panel (70B) enclosing one end of said container body, the other end ofsaid tubular structure opposite from said bottom panel forming aperiphery (28B);

   (b) a lid for (40B) selectively converting said semi-enclosed container to a closedcontainer; and

   (c) a closure means (30B) for sealing said lid to said container body;

   characterized in that said closure means comprises a piece of material forming at least a portion of said closing menus and having a first side exhibiting an adhesion peel force after activation by a user which is greater than an adhesion peel force exhibited prior to activation by a user, and that each of said side panels includes a gusset extending in adirection substantially parallel to said bottom panel said side panels and said endpanels are inwardly foldable toward one another, such that said container iscollapsible in a direction normal to said lid and said bottom panel while beingsubstantially self-supporting while said side panels and said end panels are in theirunfolded orientation.
6. The collapsible, foldable, stackable, and self-supportable container (10B) of Claim 5,furthercharacterized in that said side walls (60B), said end walls (50B), and said bottom panel (70B)are unitarily formed from a continuous sheet of material.
7. The collapsible, stackable, self-supportable container (10B) of Claim 5 or Claim 6,furthercharacterized in that said end panels include diagonal reinforcing folds.
8. The storage bag 10 or container (10A, 10B) of any one of Claims 1 or 3 or 5, furthercharacterized in that said closure means (30, 30A, 30B) is activatible by an externally appliedcompressive force exerted in a direction substantially normal to said flange.
9. The storage bag (10) or container (10A, 10B) of any one of Claims 1 or 3 or 5, furthercharacterized in that said closure means (30, 30A, 30B) comprises a three-dimensional sheetmaterial which is convertible to a substantially two-dimensional sheet materialupon activation by a user to expose an adhesive layer to contact with acomplementary surface of said semi-enclosed container across said opening.

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