FIELD OF THE INVENTION
The invention relates generally to storage containers and more particularly to flexible storage bags configured with closure devices such as interlocking fastening strips. The invention finds particular applicability in the field of food storage.
BACKGROUND OF THE INVENTION
Storage bags are commonly used for a variety of purposes including, for example, storing food items. Such storage bags are typically made from a low cost, pliable thermoplastic material that provides an internal volume into which the food items can be inserted. To access the internal volume, the storage bags are typically formed with an opening. Furthermore, to preserve the food items and to otherwise prevent the contents from spilling out of the bag, the storage bag may also include a closure device that comprises interlocking fastening strips for closing the opening.
As will be apparent to those of skill in the art, interlocking fastening strips are typically formed as elongated strips of flexible, thermoplastic material and are provided as opposing pairs disposed along the opposite edges of the opening. Formed along the length of each strip are engagable closure profiles that are adapted to engage or mate with the corresponding profile formed on the opposing fastening strip. To allow for repeated access to the internal volume, the closure profiles are commonly configured to releasably and repeatedly engage each other.
Because of the flexible characteristic of the fastening strip material and because of variations in alignment between and shape of the closure profiles, engagement between the interlocking fastening strips is often not perfect. Leak paths or crevices may form between the closure profiles that allow for environmental air to pass into the internal volume. Additionally, the leak paths also allow for aromatic gases or liquids stored inside the internal volume to escape. Moreover, in those embodiments which include one-way valve elements or similar devices for evacuation, the leak paths may prevent the storage bag from maintaining the interior volume in an evacuated state.
BRIEF SUMMARY OF THE INVENTION
The invention provides interlocking fastening strips for a storage bag that are adapted to hermetically seal the opening disposed in the bag. To provide the hermetic seal, a sealant is included on or in at least one of the closure profiles formed on the interlocking fastening strips. The sealant can be a viscous liquid, a semi-liquid substance, or semi-rigid substance such as an oil, gel, or wax. When the fastening strips are pressed together to engage the closure profiles, the sealant, if a viscous liquid or semi-liquid substance, displaces or flows to close or fill any voids or leak paths existing between the closure profiles. If the sealant is a semi-rigid substance having resilient characteristics, engagement of the fastening strips can cause the sealant to urge against other components of the fastening strips to provide a positive seal. The sealant thereby provides an adaptable barrier between the engagable closure profiles.
An advantage of the invention is that it provides a low-cost hermetic or airtight seal for use with flexible storage bags. Another advantage is that the displaceable sealant may allow for multiple repeated uses of the storage bag by resiliently reforming so as to recreate the seal during each use. Yet another advantage is that the invention may simplify manufacture by allowing reduced precision and accuracy in forming or shaping the profiles. These and other advantages and features of the invention will be apparent from the detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a storage bag having a closure element in the form of interlocking fastening strips designed in accordance with the teachings of the invention.
FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1 illustrating the interlocking fastening strips including a sealant in an unengaged arrangement.
FIG. 3 is a cross-sectional view taken along line A-A of FIG. 1 illustrating the interlocking fastening strips including a sealant in an engaged arrangement.
FIG. 4 is a cross-sectional view illustrating another embodiment of the interlocking fastening strips including a sealant in an engaged arrangement, the sealant being disposed on only one strip.
FIG. 5 is a cross-sectional view illustrating another embodiment of the interlocking fastening strips including a sealant in an engaged arrangement, the sealant being disposed on only one strip.
FIG. 6 is a cross-sectional view illustrating another embodiment of the interlocking fastening strips including a sealant in an engaged arrangement, the sealant being disposed on only one strip.
FIG. 7 is a cross-sectional view illustrating another embodiment of the interlocking fastening strips including a sealant in an engaged arrangement, the sealant being disposed as a film on the surface of the fastening strips.
FIG. 8 is a detailed view taken of the area indicated in FIG. 7 showing the sealant disposed in capillaries formed in the surface of the interlocking fastening strips.
FIG. 9 is a cross-sectional view illustrating another embodiment of the fastening strips including a sealant in an engaged arrangement.
FIG. 10 is a cross-sectional view illustrating another embodiment of the fastening strips including a sealant in an engaged arrangement.
FIG. 11 is a front perspective view of another embodiment of the storage bag designed in accordance with the teachings of the invention including a slider and a one-way valve element along with an evacuation device.
FIG. 12 is a cross-sectional view taken along line B-B of FIG. 11 illustrating another embodiment of the fastening strip including a sealant in an engaged arrangement.
FIG. 13 is a cross-sectional view illustrating another embodiment of the interlocking fastening strips including a sealant in an unengaged arrangement.
FIG. 14 is a cross-sectional view illustrating the interlocking fastening strips including a sealant in an engaged arrangement.
FIG. 15 is a cross-sectional view illustrating another embodiment of the interlocking fastening strips including a sealant in an engaged arrangement, the sealant being placed on only one strip.
FIG. 16 is a cross-sectional view illustrating another embodiment of the interlocking fastening strips including a sealant in an engaged arrangement, the sealant being placed on only one strip.
FIG. 17 is a cross-sectional view illustrating another embodiment of the interlocking fastening strips including a sealant in an engaged arrangement, the sealant being placed on only one strip.
FIG. 18 is a cross-sectional view illustrating another embodiment of the fastening strips including a sealant in an engaged arrangement.
FIG. 19 is a cross-sectional view taken illustrating another embodiment of the fastening strips including a sealant in an engaged arrangement.
FIG. 20 is a front perspective view of another embodiment of the storage bag designed in accordance with the teachings of the invention including a slider and a one-way valve element along with an evacuation device.
FIG. 21 is a cross-sectional view taken along line B-B of FIG. 20 illustrating a “rolling action” embodiment of the fastening strip including sealant in an engaged arrangement.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Now referring to the drawings, wherein like reference numbers refer to like elements, there is illustrated in FIG. 1 an exemplary flexible storage bag 100 of the type typically used for storing food items. The storage bag includes a first sidewall 102 and an opposing second sidewall 104 overlaying and joined to the first sidewall to provide an internal volume 106. The first and second sidewalls 102, 104 can be made from webs of pliable thermoplastic material. Examples of suitable thermoplastic material include polyethylene (PE), high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polypropylene (PP), ethylene vinyl acetate (EVA), nylon, polyester, polyamide, ethylene vinyl alcohol, and can be formed in single or multiple layers. The thermoplastic material can be transparent, translucent, opaque, or tinted. Furthermore, the material used for the sidewalls can be a gas impermeable material.
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 by, for example, a heat sealing operation. To access the internal volume 106, the top edge 116 of the first side wall 102 and the corresponding top edge 118 of the second sidewall 104 remain unjoined to provide an opening 120. Due to the four orthogonal edges, the illustrated storage bag 100 has a rectangular shape. However, it will be appreciated in other embodiments that the bag can have any suitable shape resulting from any number of sidewalls and edges.
To close the opening 120, a closure device may be provided. The closure device may include a first fastening strip 122 and an interlocking second fastening strip 124. The elongated fastening strips 122, 124 can be formed by extruding a flexible thermoplastic material that demonstrates resilient characteristics. The first and second fastening strips 122, 124 may be attached to an inner surface of the respective first and second sidewalls 102, 104 proximate the respective top edges 116, 118 and extend from the first side edge 110 to the second side edge 112. The fastening strips may also be attached to the outer surface of the sidewalls. To attach the fastening strips, adhesive or a heat sealing operation can be utilized. In addition, the fastening strips may be formed as part of the sidewalls.
To enable the first and second fastening strips 122, 124 to interlock, a respective first and second closure profile may be formed continuously along the length of each strip. The first and second closure profiles may have a complementary shape such that they can engage or mate with each other in an interlocking manner. When so engaged, the complementary closure profiles function to hold the first and second top edges 116, 118 adjacent to each other to close the opening 120. To allow for repeated access to the internal volume 106, the fastening strips 122, 124 are desirably configured to releasably interlock with each other.
In accordance with an aspect of the invention, to improve the seal established by the engaged closure profiles, a sealant is applied to the interlocking fastening strips. In one embodiment, the sealant can be a viscous fluid, a fluid-like substance, a wax-like substance, or other similar material. In one embodiment, a typical characteristic of such materials is that they do not cure or set and therefore remain flowable or displaceable. When the closure profiles engage, the sealant displaces to fill or close crevices or other leak paths that may exist between the flexible closure profiles due to imperfections or misalignment. Thus, the sealant provides an airtight or hermetic seal of the internal volume. The sealant may have a density and viscosity greater than the air or gas that is both contained in the storage bag and in the surrounding environment. Examples of suitable sealant material include silicone oil, mineral oil, monoglycerides, fatty acids, polybutenes, and petroleum jelly. In those embodiments in which the invention is used with bags intended for storing food items, it is desirable that the sealant qualify as a food grade material.
One example of interlocking fastening strips designed in accordance with the invention is illustrated in FIG. 2. The illustrated fastening strips 122, 124 may be referred to as “U-channel” style fastening strips. The first fastening strip 122 is formed with a male closure profile 130 that projects from a flat base member 140 that may be adapted to be attached to an inner surface of the first sidewall. The projecting male closure profile 130 may include first and second projections 142, 144 that are parallel to and spaced-apart from each other a first distance. Formed at the distal tip of each projection 142, 144 are respective first and second hooks or barbs 146, 148 that are generally directed back toward the base member 140. Moreover, the barbs 146, 148 are directed oppositely or away from each other. The distal most surface of the barbs 146, 148 are generally shaped or rounded to provide respective first and second guide surfaces 150, 152. It will be appreciated that the male closure profile 130 including the first and second projections 142, 144 extends substantially over the entire length of the first fastening strip 122.
The second fastening strip 124 of the pair illustrated in FIG. 2 may be formed as a female closure profile 132 that likewise projects from a flat base member 160 that may be adapted to be attached to an inner surface of the second sidewall. The projecting female closure profile 132 may include first and second projections 162, 164 that are parallel to and spaced-apart from each other a second distance. The second distance should be slightly greater than the first distance so that the female closure profile 132 is adapted to receive the projections 142, 144 of the male closure profile 130. Formed at the distal tip of each projection 162, 164 of the female closure profile 132 are respective first and second hooks or barbs 166, 168 that are generally directed back toward the base member 160. Furthermore, the barbs 166, 168 are facing and directed towards each other. The distal most surface of the barbs 166, 168 are generally shaped or rounded to provide respective first and second guide surfaces 170, 172. Additionally, the female closure profile 132 may also include a flange 174 projecting from the base member 160 approximately midway between the first and second projections 162, 166 that extends to approximately the same height as the first and second projections. In other embodiments, the closure profile may not include the flange 174. It will be appreciated that the female closure profile 132 including the first and second projections 162, 164 extends substantially over the entire length of the second fastening strip 124.
On the male closure profile 130, a sealant 136 is deposited into the three-sided gap or channel existing between the first and second projections 142, 144 and the base member 140. Sealant 136 is likewise deposited on the female closure profile 132 into the gap created between the first projection 162 and the flange 174 and between the flange and the second projection 164. In the illustrated embodiment, the sealant should be sufficiently viscous so that it remains in the closure profiles and does not otherwise freely flow out of the gaps.
To engage the male and female closure profiles 130, 132 as illustrated in FIG. 3, the first and second interlocking fastening strips 122, 124 are pressed toward each other until the guide surface 150, 152 on the male projections 142, 144 contact the guide surfaces 170, 172 on the female projections 160, 162. Due to the flexible characteristic of the fastening strip material, contact between the guide surfaces causes the male projections 142, 144 to flex inwardly and the female projections 162, 164 to flex outwardly. The barbs 146, 148 on the male projections 142, 144 and the barbs 166, 168 on the female projections 162, 164 can thereby slide past each other. Once past each other, the flexible characteristic of the fastening strip material cause the male and female projections to flex back moving the barbs into an interlocking engagement with each other. Furthermore, because of the flexible and resilient characteristics of the fastening strip material, a sufficient, oppositely applied pulling force can disengage the male and female closure profiles. The fastening strips may also use a slider to engage and disengage the fastening strips as noted herein.
Referring to FIG. 3, when the male and female closure profiles 130, 132 are thus engaged, the sealant 136 disposed on the male closure profile contacts and interacts with the sealant disposed on the female profile. The sealant thereby provides an airtight barrier or seal across the closure profiles. Moreover, the sealant 136 can displace or wick via capillary action into crevices or leak paths between the engaged barbs.
In other embodiments, the sealant need not be provided on both the first and second fastening strips. For example, referring to FIG. 4, the sealant 236 is only provided on the male closure profile 230 between the first and second projections 242, 244 of the first fastening strip 222. When the first and second fastening strips 222, 224 are pressed together, the flange 274 of the female closure profile 232 is inserted into the sealant 236 to provide the air tight barrier preventing air or other fluids or gases from leaking into or out of the internal volume of the storage bag.
Referring to FIG. 5, the sealant 336 is only provided on the female closure profile 332 in between the gaps provided by the first and second projections 362, 364 and the flange 374. When the first and second fastening strips 322, 324 are pressed together, the guide surfaces 350, 352 of the male projections 342, 344 are pressed into the sealant 336 thereby providing the hermetic barrier preventing air or other fluids or gases from leaking into or out of the internal volume of the storage bag. Moreover, the sealant 336 can displace or wick by capillary action into crevices or leak paths between the engaged barbs.
In other embodiments, the sealant can be located in other areas besides the closure profiles. For example, referring to FIG. 6, in addition to the male closure profile 130, the first fastening strip 422 can include a first flange 476 and a spaced-apart second flange 478 projecting from the flat base member 440. The flanges 476, 478 are located on opposite sides of and spaced-apart from the male profile 430 and extend substantially along the length of the first fastening strip 422. The spacing provides a gap between the first flange 476 and the first male projection 442 and another gap between the second flange 478 and the second male projection 444 into which sealant 436 can be deposited. When the first and second fastening strips 422, 424 are pressed together, the first and second projections 462, 464 of the female closure profile 432 can move around the respective first and second projections 442, 444 of the male closure profile 430 to contact the sealant 436, thereby providing the airtight barrier preventing air from leaking into or out of the internal volume.
Referring to FIG. 7, there is illustrated another embodiment of the “U-channel” style fastening strips where the sealant is disposed on the surfaces of the male and female closure profiles 530, 532. Specifically, sealant 536 is disposed on the surfaces of both the male projections 542, 544 and the female projections 562, 564. The sealant 536 may be a viscous oil such that the sealant remains in place as a film on the surfaces of the closure profiles. When the first and second fastening strips 522, 524 are pressed together, the sealant 536 on the male profile 530 contacts and interacts with the sealant on the female profile 532 thereby providing the hermetic barrier. Moreover, sealant can creep or wick via capillary action into crevices or leak paths that exist between the engaged barbs. In other embodiments, sealant may be disposed only on the surface of the male closure profile or only on the surface of the female closure profile.
In other embodiments, the sealant can be impregnated into the material of the closure profiles. Referring to FIG. 8, in an aspect, to impregnate the closure profiles with sealant 636, a plurality of capillaries 680 can be disposed into unengaged closure profiles. The capillaries 680 can be formed as small grooves or channels disposed along the surface of the closure profiles 630, 632. Sealant 636 is then received into the capillaries 680 by any suitable method. During engagement, when the first and second fastening strips are pressed together, the flexing that the male and female closure profiles undergo to accommodate each other causes sealant 636 to be excreted from the capillaries 680. The sealant can thereafter displace or wick via capillary action to fill or close crevices or leak paths between the engaged closure profiles. In other embodiments, the capillaries can be formed as a plurality of small diameter bores or openings disposed into the material of the closure profiles. For example, the capillaries can be formed by etching. In another example, the closure profiles may include a porous surface and the pores or openings may be the capillaries.
In another aspect, the sealant can be blended into the material of the closure profile itself. The sealant will bloom to the surfaces of the closure profiles where the sealant can displace or wick to fill or close leak paths.
The invention, including those embodiments in which the sealant is provided by depositing into gaps, as a film, in capillaries, or as blended into the closure profile material, can be utilized with a variety of different interlocking fastening strips. For example, illustrated in FIG. 9 is a cross-sectional view of interlocking fastening strips such as those disclosed and described in U.S. Pat. No. 5,664,299, herein incorporated by reference in its entirety. The fastening strips may be referred to as “profile” style fastening strips. The interlocking fastening strips 722, 724 may include a first closure profile 730 projecting from a base member 740 of the first fastening strip 722 adapted to engage a corresponding second closure profile 732 projecting from a base member 760 of the second fastening strip 724.
The first closure profile 730 includes a first pair of projections 742, 744 that are parallel and spaced-apart from each other a first distance. Formed on the distal ends of each of the first projections 742, 744 are respective first hook-like barbs 746, 748 which are pointed generally back toward the base member 740. Moreover, the projections are shaped so that the barbs are arranged in the same direction. The distal most surface of the first projections are generally rounded or shaped to provide first guide surfaces 750, 752.
The second closure profile 732 also includes a pair of second projections 762, 764 that are parallel and spaced-apart from each other a second distance. The second distance between the second projections 762, 764 dimensionally corresponds to the first distance between the first projections 742, 744. Formed on the distal ends of the second projections 762, 764 are respective second hook-like barbs 766, 768 which are generally pointed back toward the base member 740. Moreover, the second projections 762, 764 are shaped so that the second barbs are arranged in the same direction and opposite the direction of the first barbs 746, 748. The distal most surfaces of the second projections are generally rounded or shaped to provide second guide surfaces 770, 772.
In the illustrated embodiment of the fastening strips 722, 724, a sealant 736 can be disposed on the first strip in the gap created between the spaced-apart first projections 742, 744 and the first base member 740. Likewise, a sealant 736 can also be disposed on the second strip in the gap created between the spaced-apart second projections 762, 764 and the second base member 760. The particular sealant 736 may be viscous enough to remain located in the closure profiles 732, 736 and not freely leak from the gaps.
To engage the first and second closure profiles of FIG. 9, the first and second fastening strips 722, 724 are pressed together so that the first projections 742, 744 abut the correspondingly spaced-apart second projections 762, 764. Particularly, the first guide surfaces 750, 752 contact the second guide surfaces 770, 772 causing the first projections 742, 744 and second projections 762, 764 to flex such that the first barbs 746, 748 and oppositely directed second barbs 766, 768 slide about each other and engage. When so engaged, the sealant 736 located between both the first projections 742, 744 and the second projections 762, 764 contacts and interacts to provide the hermetic barrier between the interlocking fastening strips. Moreover, the sealant 736 can displace to fill or close leak paths existing between the engaged barbs.
Referring to FIG. 9, separately or in addition to providing the sealant in the gaps between the projections, the sealant may be provided as noted herein, for example, as a film, in capillaries, or blended into the material of the closure profiles of the interlocking fastening strips. In addition, the sealant can be provided on either or both of the closure profiles. Also, the fastening strips may use a slider as noted herein.
Referring to FIG. 10, there is illustrated in cross-section fastening strips 822, 824 such as those disclosed in U.S. Pat. No. 3,806,998, herein incorporated by reference in its entirety. These fastening strips may be referred to as “arrow-head” or “rib and groove” style fastening strips. The first fastening strip 822 may have a projecting head portion 842 extending from a flat base member 840. The head portion includes a mushroom-shaped head 844 that is located at the end of a reduced neck portion 846 that is connected to the base member 840. The second fastening strip 824 may include a base member 860 and a C-shaped groove portion 862. The projecting head portion 842 of the first fastening strip is receivable in the groove portion 862 of the second fastening strip. Through this arrangement, the fastening strips 822, 824 are adapted to be interlockingly engaged when pressed together and separated by being forcibly pulled apart.
In the illustrated embodiment of the fastening strips, a sealant 836 can be deposited in the groove portion 862. Hence, inserting the projecting head portion 842 into the groove portion 862 simultaneously causes the displaceable sealant 836 to flow around the head portion thereby providing the hermetic barrier between the engaged fastening strips 822, 824.
Referring to FIG. 10, separately or in addition to providing the sealant in the groove portion, the sealant may be provided as noted herein, for example, as a film, in capillaries, or blended into the material of the closure profiles of the interlocking fastening strips.
Referring to FIG. 11, there is illustrated another embodiment of a storage bag. The illustrated storage bag 900 includes a pliable first sidewall 902 overlaid and joined to a second sidewall 904 to provide an internal volume 906. To access the internal volume 906, the respective first and second top edges 916, 918 of the first and second sidewalls 902, 904 remain unjoined to provide an opening 920. To close the opening 920, first and second interlocking fastening strips 922, 924 are attached proximate the respective top edges 916, 918. In the particular storage bag 900 illustrated in FIG. 11, to occlude and de-occlude the fastening strips 916, 918, the storage bag 900 includes a slider 926. The slider 926 is a generally U-shaped structure that straddles the top edges 916, 918 of the sidewalls 902, 904. Moving the slider 926 along the top edges 916, 918 engages or disengages the interlocking fastening strips 922, 924.
In addition to including the slider 926, the storage bag 900 illustrated in FIG. 11 includes a one-valve element 927 for removing latent air from the storage bag. The one-way valve element 927 is attached to the first sidewall 902 and communicates with the internal volume 906. To evacuate the internal volume 906 via the one-way valve element 927, a nozzle 928 connected to a vacuum source 929 can be placed against the valve element or against the first sidewall 902 about the valve element and activated. The vacuum source connected to the nozzle 928 can be any suitable vacuum source including, for example, hand-operated pumps, mechanical pumps, water aspirators, oral suction, and the like. In other embodiments, latent air can be evacuated by pressing the sidewalls 902, 904 together.
The interlocking fastening strips 922, 924 may be as illustrated in FIG. 12 and described in U.S. Pat. No. 5,007,143, herein incorporated by reference in its entirety. The fastening strips may be referred to as the “rolling action” style fastening strips. The strips 922, 924 include profiled tracks 930 and 932 extending along the length thereof parallel to rib and groove elements 936 and 938. The rib and groove elements 936, 938 have complementary cross-sectional shapes such that they are closed by pressing the bottom of the elements together first and then rolling the elements to a closed position toward the top thereof. The rib element 936 is hook shaped and projects from the inner face of strip 922. The complementary groove element 938 includes a lower hook shaped projection 940 and a relatively straight projection 942 which extend from the inner face of the second strip 924. Sealant 934 can be received and held in the groove element 938 as described above. The profiled tracks 930, 932 are inclined inwardly toward each other from their respective strips 922, 924.
The straddling slider 928 comprises an inverted U-shaped plastic member having a back 950 for moving along the top edges of the tracks 930, 932 and with two parallel side walls 952, 954 depending therefrom for cooperating with the tracks and extending from an opening end of the slider to a closing end. A separator finger 956 depends from the back 950 between the side walls 952, 954 and is inserted between the inclined tracks 930, 932. The slider 928 has shoulders 958, 960 projecting inwardly from the depending side walls 952, 954 which are shaped throughout the length thereof for cooperation with the depending separator finger 956 in creating the rolling action in opening and closing the reclosable interlocking rib and groove profile elements 936, 938. Inserting the rib 936 into the groove 938 simultaneously causes the displaceable sealant 934 to flow around the rib thereby providing the hermetic barrier between the engaged fastening strips 922, 924. Furthermore, in those embodiments in which the storage bag 900 includes a valve element 927 for evacuating the internal volume 906, the sealant can help maintain the storage bag in an evacuated state.
Referring to FIG. 12, separately or in addition to providing the sealant in the groove element 936, the sealant may be provided as noted herein, for example, as a film, in capillaries, or blended into the material of the closure profiles of the style interlocking fastening strips.
In accordance with another aspect of the invention, the sealant applied to the interlocking fastening strips can be a semi-rigid substance. Such a material may be freestanding and should not flow like a liquid. However, the semi-rigid material may retain some resilient or compressive properties to facilitate sealing between the engaged closure profiles. By way of example, a gel can be employed as a suitable material for the semi-rigid sealant material. Examples of suitable gels include hydrocarbon gels such as Versagel P100, P200, available from Penreco (a petroleum hydrocarbon), gel adhesive such as the material designated as 555-8808 available from National Starch and Chemical Company (a hot melt adhesive), petrolatums, and jellies. Gels may be any jelly-like material formed from a colloidal solution. Typically, such gels include at least one block copolymer that will bind to a liquid such as a mineral oil thereby enabling the oil to become semi-rigid. Additionally, the semi-rigid sealant material can be a thermoplastic elastomer such as Dynoflex 66703-0001 available from GLS Corporation. Again, in those embodiments in which the invention is to be used with bags intended for storing food items, it is desirable that the sealant qualify as food grade material.
The sealant may be fluorinated oil or a fluorinated grease. The sealant may be a perfluoropolyether (PFPE)—also called perfluoroalkylether (PFAE) or perfluoropolyalkylether (PFPAE)—with the following chemical structure:
F—(CF—CF2—O)n—CF2CF3
- CF3 where n=10-60
In one embodiment, the polymer chain may be completely saturated and contains only carbon, oxygen, and fluorine. In one embodiment, the oil may contain 21.6% carbon, 9.4% oxygen, and 69.0% fluorine on a weight basis. The sealant may have a viscosity for the oil, or the base oil for the grease, in a first range of 1 to 100,000 cSt, a second range of 1 to 10,000 cSt, or a third range of 1 to 1,000 cSt. The sealant may have a density of less than 1.95 g/cc. One example of the sealant is made by Dupont under the name Krytox®. An oil may be Krytox FG40 and a grease may be Krytox FG20.
One example of interlocking fastening strips designed in accordance with the invention is illustrated in FIG. 13. The fastening strips are similar to the fastening strips in FIG. 2 except the sealant is a semi-rigid sealant material. The illustrated fastening strips 1022, 1024 may be referred to as “U-channel” style fastening strips. The first fastening strip 1022 is formed with a male closure profile 1030 that projects from a flat base member 1040 that may be adapted to be attached to an inner surface of the first sidewall. The projecting male closure profile 1030 may include first and second projections 1042, 1044 that are parallel to and spaced-apart from each other a first distance. Formed at the distal tip of each projection 1042, 1044 are respective first and second hooks or barbs 1046, 1048 that are generally directed back toward the base member 1040. Moreover, the barbs 1046, 1048 are directed oppositely or away from each other. The distal most surface of the barbs 1046, 1048 are generally shaped or rounded to provide respective first and second guide surfaces 1050, 1052. It will be appreciated that the male closure profile 1030 including the first and second projections 1042, 1044 extends substantially over the entire length of the first fastening strip 1022.
The second fastening strip 1024 of the pair illustrated in FIG. 13 may be formed as a female closure profile 1032 that likewise projects from a flat base member 1060 that may be adapted to be attached to an inner surface of the second sidewall. The projecting female closure profile 1032 may include first and second projections 1062, 1064 that are parallel to and spaced-apart from each other a second distance. The second distance should be slightly greater than the first distance so that the female closure profile 1032 is adapted to receive the projections 1042, 1044 of the male closure profile 1030. Formed at the distal tip of each projection 1062, 1064 of the female closure profile 1032 are respective first and second hooks or barbs 1066, 1068 that are generally directed back toward the base member 1060. Furthermore, the barbs 1066, 1068 are facing and directed towards each other. The distal most surface of the barbs 1066, 1068 are generally shaped or rounded to provide respective first and second guide surfaces 1070, 1072. Additionally, the female closure profile 1032 may also include a flange 1074 projecting from the base member 1060 approximately midway between the first and second projections 1062, 1066 that extends to approximately the same height as the first and second projections. In other embodiments, the closure profile may not include flange 1074. It will be appreciated that the female closure profile 1032 including the first and second projections 1062, 1064 extends substantially over the entire length of the second fastening strip 1024.
On the male closure profile 1030, a sealant 1036 is placed into the three-sided gap or channel existing between the first and second projections 1042, 1044 and the base member 1040. Sealant 10 is likewise placed on the female closure profile 10 into the gaps created between the first projection 1062 and the flange 1074 and between the flange 1074 and the second projection 1064. In the embodiments in which the sealant is semi-rigid, the sealant can have a sufficient rigidity so that it remains in the closure profiles and does not otherwise freely flow out of the gaps.
To engage the male and female closure profiles 1030, 1032 as illustrated in FIG. 14, the first and second interlocking fastening strips 1022, 1024 are pressed toward each other until the guide surface 1050, 1052 on the male projections 1042, 1044 contact the guide surfaces 1070, 1072 on the female projections 1060, 1062. Due to the flexible characteristic of the fastening strip material, contact between the guide surfaces causes the male projections 1042, 1044 to flex inwardly and the female projections 1062, 1064 to flex outwardly. The barbs 1046, 1048 on the male projections 1042, 1044 and the barbs 1066, 1068 on the female projections 1062, 1064 can thereby slide past each other. Once past each other, the resilient characteristic of the fastening strip material cause the male and female projections to flex back moving the barbs into an interlocking engagement with each other. Because of the flexible and resilient characteristics of the fastening strip material, a sufficient, oppositely applied pulling force can disengage the male and female closure profiles. The fastening strips may also use a slider to engage and disengage the fastening strips as noted herein.
Referring to FIG. 14, when the male and female closure profiles 1032, 1034 are thus engaged, the flange 1074 on the female closure profile 1032 presses into and thereby displaces the sealant 1036 disposed on the male closure profile 1030. In those embodiments in which the sealant 1036 is a semi-rigid substance, the resilient characteristics of the substance cause the sealant to urge back against the flange 1074, thereby providing positive sealing contact. Additionally, the distal most surfaces 1050, 1052 of the barbs 1046, 1048 on the male profile 1030 press into and displace the sealant 1037 of the female closure profile 1032. Again, the resilient characteristic of the semi-rigid material causes the sealant 1037 to urge back against the barbs 1046, 1048 to provide positive sealing contact. Furthermore, the sealant 1036, 1037 on male and female closure profiles 1030, 1032 can contact and urge against each other along contact line 1079 as illustrated in FIG. 14. The sealant thereby provides an airtight barrier or seal across the closure profiles.
In those embodiments in which the sealant is a semi-rigid material, to enable the sealant to displace and urge back against the other components of the closure profiles as described, the sealant material should be softer than the flexible material of the closure profiles. For example, the sealant material can have a hardness value in the range of 0 to 70 points, using the Shore 00 hardness scale. The hardness may be in a second range of 30 to 70 points. In one embodiment, the hardness may be 60 points. The flexible material of the interlocking fastening strips can have a hardness value in the range of 70 to 90 points, using the Shore A hardness scale. Accordingly, the closure profiles can still flex to engage and disengage as described above while still being adapted to press into and displace the sealant.
Furthermore, in those embodiments in which the sealant is a semi-rigid material, the resilient nature can cause the sealant 1036, 1037 to substantially recover to its original form within the male and female closure profiles 1030, 1036 after the closure profiles have been disengaged. Accordingly, the closure profiles can be repeatedly engaged and disengaged while continuing to hermetically seal the interior volume.
In other embodiments, the sealant need not be provided with both the first and second fastening strips. The fastening strips in FIG. 15 are similar to the fastening strips in FIG. 4 except the sealant is a semi-rigid sealant material. Referring to FIG. 15, the sealant 1136 is only provided with the male closure profile 1130 between the first and second projections 1142, 1144 of the first fastening strip 1122. When the first and second fastening strips 1122, 1124 are pressed together, the flange 1174 of the female closure profile 1132 is pressed into and displaces the sealant 536 to provide the air tight barrier preventing air or other fluids or gases from leaking into or out of the internal volume of the storage bag.
The fastening strips in FIG. 16 are similar to the fastening strips in FIG. 5 except the sealant is a semi-rigid sealant material. Referring to FIG. 16, the sealant 1237 is only provided with the female closure profile 1232 in between the gaps provided by the first and second projections 1262, 1264 and the flange 1274. When the first and second fastening strips 1222, 1224 are pressed together, the guide surfaces 1250, 1252 of the male projections 1242, 1244 are pressed into and displace the sealant 1237 thereby providing the hermetic barrier preventing air or other fluids or gases from leaking into or out of the internal volume of the storage bag.
In other embodiments, the sealant can be located in other areas besides the closure profiles. The fastening strips in FIG. 17 are similar to the fastening strips in FIG. 6 except the sealant is a semi-rigid sealant material. Referring to FIG. 17, in addition to the male closure profile 1330, the first fastening strip 1322 can include a first flange 1376 and a spaced-apart second flange 1378 projecting from the flat base member 1340. The flanges 1376, 1378 are located on opposite sides of and spaced-apart from the male profile 1330 and extend substantially along the length of the first fastening strip 1322. The spacing provides a gap between the first flange 1376 and the first male projection 1342 and another gap between the second flange 1378 and the second male projection 1344 into which sealant 1336 can be placed. When the first and second fastening strips 1322, 1324 are engaged together, the first and second projections 1362, 1364 of the female closure profile 1332 can move around the respective first and second projections 1342, 1344 of the male closure profile 1330 to contact and press against the sealant 1336, thereby providing the airtight barrier preventing air from leaking into or out of the internal volume.
The invention, including those embodiments in which the sealant is a semi-rigid material, can be utilized with a variety of different interlocking fastening strips. The fastening strips in FIG. 18 are similar to the fastening strips in FIG. 9 except the sealant is a semi-rigid sealant material. Illustrated in FIG. 18 is a cross-sectional view of interlocking fastening strips such as those disclosed and described in U.S. Pat. No. 5,664,299, herein incorporated by reference in its entirety. The interlocking fastening strips 1422, 1424 include a first closure profile 1430 projecting from a base member 1440 of the first fastening strip 1422 adapted to engage a corresponding second closure profile 1432 projecting from a base member 1460 of the second fastening strip 1424.
The first closure profile 1430 includes a first pair of projections 1442, 1444 that are parallel and spaced-apart from each other a first distance. Formed on the distal ends of each of the first projections 1442, 1444 are respective first hook-like barbs 1446, 1448 which are pointed generally back toward the base member 1440. Moreover, the projections are shaped so that the barbs are arranged in the same direction. The distal most surface of the first projections are generally rounded or shaped to provide first guide surfaces 1450, 1452.
The second closure profile 1432 also includes a pair of second projections 1462, 1464 that are parallel and spaced-apart from each other a second distance. The second distance between the second projections 1462, 1464 dimensionally corresponds to the first distance between the first projections 1442, 1444. Formed on the distal ends of the second projections 1462, 1464 are respective second hook-like barbs 1466, 1468 which are generally pointed back toward the base member 1440. Moreover, the second projections 1462, 1464 are shaped so that the second barbs are arranged in the same direction and opposite the direction of the first barbs 1446, 1448. The distal most surfaces of the second projections are generally rounded or shaped to provide second guide surfaces 1470, 1472.
In the illustrated embodiment of the fastening strips 1422, 1424, a sealant 1436 can be placed on the first strip in the gap created between the spaced-apart first projections 1422, 1444 and the first base member 1440. Likewise, sealant 1437 can also be placed on the second strip in the gap created between the spaced-apart second projections 1462, 1464 and the second base member 1460.
To engage the first and second closure profiles of FIG. 18, the first and second fastening strips 1422, 1424 are pressed together so that the first projections 1442, 1444 abut the correspondingly spaced-apart second projections 1462, 1464. Particularly, the first guide surfaces 1450, 1452 contact the second guide surfaces 1470, 1472 causing the first projections 1442, 1444 and second projections 1462, 1464 to flex such that the first barbs 1446, 1448 and oppositely directed second barbs 1466, 1468 slide about each other and engage. When so engaged, the sealants 1436, 1437 located between both the first projections 1442, 1444 and the second projections 1462, 1464 contacts and urge against each other to provide the hermetic barrier between the interlocking fastening strips. Also, the fastening strips may use a slider as noted herein.
The fastening strips in FIG. 19 are similar to the fastening strips in FIG. 10 except the sealant is a semi-rigid sealant material. Referring to FIG. 19, there is illustrated in cross-section fastening strips 1522, 1524 such as those disclosed in U.S. Pat. No. 3,806,998, herein incorporated by reference in its entirety. The fastening strips may be referred to as an “arrow head” or “rib and groove” style fastening strips. The first fastening strip 1522 may have a projecting head portion 1542 extending from a flat base member 1540. The head portion includes a mushroom-shaped head 1544 that is located at the end of a reduced neck portion 1546 that is connected to the base member 1540. The second fastening strip 1524 may include a base member 1560 and a C-shaped groove portion 1562. The projecting head portion 1542 of the first fastening strip is receivable in the groove portion 1562 of the second fastening strip. Through this arrangement, the fastening strips 1522, 1524 are adapted to be interlockingly engaged when pressed together and separated by being forcibly pulled apart.
In the illustrated embodiment of the fastening strips, a sealant 1536 can be placed and retained in the groove portion 1562. Hence, inserting the projecting head portion 1542 into the C-shaped groove portion 1562 simultaneously causes the semi-rigid sealant 1536 to displace around and urge against the head portion thereby providing the hermetic barrier between the engaged fastening strips 1522, 1524. When the fastening strips are disengaged, the resilient sealant can recover its original position within the groove portion 1562.
The fastening strips in FIG. 20 are similar to the fastening strips in FIG. 11 except the sealant is a semi-rigid sealant material. Referring to FIG. 20, there is illustrated another embodiment of a storage bag. The illustrated storage bag 1600 includes a pliable first sidewall 1602 overlaid and joined to a second sidewall 1604 to provide an internal volume 1606. To access the internal volume 1606, the respective first and second top edges 1616, 1618 of the first and second sidewalls 1602, 1604 remain unjoined to provide an opening 1620. To close the opening 1620, first and second interlocking fastening strips 1622, 1624 are attached proximate the respective top edges 1616, 1618. In the particular storage bag 1600 illustrated in FIG. 20, to occlude and de-occlude the fastening strips 1616, 1618, the storage bag 1600 includes a slider 1626. The slider 1626 is a generally U-shaped structure that straddles the top edges 1616, 1618 of the sidewalls 1602, 1604. Moving the slider 1626 along the top edges 1616, 1618 engages or disengages the interlocking fastening strips 1622, 1624.
In addition to including the slider 1626, the storage bag 1600 illustrated in FIG. 20 includes a one-way valve element 1627 for removing latent air from the storage bag. The one-way valve element 1627 is attached to the first sidewall 1602 and communicates with the internal volume 1606. To evacuate the internal volume 1606 via the one-way valve element 1627, a nozzle 1628 connected to a vacuum source 1629 can be interfaced with the valve element activated. The vacuum source connected to the nozzle 1628 can be any suitable vacuum source including, for example, hand-operated pumps, mechanical pumps, water aspirators, oral suction, and the like. In other embodiments, latent air can be evacuated by pressing the sidewalls 1602, 1604 together.
The fastening strips in FIG. 21 are similar to the fastening strips in FIG. 12 except the sealant is a semi-rigid sealant material. The interlocking fastening strips 1622, 1624 may be as illustrated in FIG. 21 and described in U.S. Pat. No. 5,007,143, herein incorporated by reference in its entirety. The fastening strips may be referred to as “rolling action” style fastening strips. The strips 1622, 1624 include profiled tracks 1630 and 1632 extending along the length thereof parallel to rib and groove elements 1636 and 1638. The rib and groove elements 1636, 1638 have complementary cross-sectional shapes such that they are closed by pressing the bottom of the elements together first and then rolling the elements to a closed position toward the top thereof. The rib element 1636 is hook shaped and projects from the inner face of strip 1622. The complementary groove element 1638 includes a lower hook shaped projection 1640 and a relatively straight projection 1642 which extend from the inner face of the second strip 1624. The semi-rigid sealant 1634 can be placed and retained in the groove element 1638. The profiled tracks 1630, 1632 are inclined inwardly toward each other from their respective strips 1622, 1624.
The straddling slider 1628 comprises an inverted U-shaped plastic member having a back 1650 for moving along the top edges of the tracks 1630, 1632 and with two parallel side walls 1652, 1654 depending therefrom for cooperating with the tracks and extending from an opening end of the slider to a closing end. A separator finger 1656 depends from the back 1650 between the side walls 1652, 1654 and is inserted between the inclined tracks 1630, 1632. The slider 1628 has shoulders 1658, 1660 projecting inwardly from the depending side walls 1652, 1654 which are shaped throughout the length thereof for cooperation with the depending separator finger 1656 in creating the rolling action in opening and closing the reclosable interlocking rib and groove profile elements 1636, 1638. Inserting the rib 1636 into the groove 1638 simultaneously causes the resilient sealant 1634 to displace around and urge against the rib thereby providing the hermetic barrier between the engaged fastening strips 1622, 1624. Furthermore, in those embodiments in which the storage bag 1600 includes a valve element 1627 for evacuating the internal volume 1606, the sealant can help maintain the storage bag in an evacuated state.
The sealant can be included as part of the fastening strips in any suitable way. For example, in the embodiments in which the sealant is a viscous liquid or semi-liquid substance, the sealant can be injected into or otherwise immersed about the closure profiles. In those embodiments in which the sealant is a semi-rigid material and the fastening strips are formed by extrusion, the sealant can be injected into closure profile after extrusion but prior to quenching of the fastening strip in a water bath. Additionally, the fastening strips can be both extruded and quenched into a water bath prior to injection of the sealant material. Furthermore, the fastening strips and sealant can be co-extruded at the same time.
Thus, the invention provides a closure device for a storage bag that includes releasably interlocking fastening strips. To provide an air-tight seal, a sealant is included on at least a portion of the fastening strips. The sealant can be a viscous fluid, a fluid-like substance, a semi-rigid substance, or a wax-like substance. In addition to providing an airtight seal, the sealant can prevent air from entering the internal volume after evacuation, thereby helping to preserve food items contained in the storage bag.
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.
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,” “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.
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.
Patent Application
20100183251
