Patent Application
20080310773
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1. Field of the Invention
The invention relates generally to an airtight closure mechanism for a reclosable pouch.
2. Description of the Background of the Invention
Thermoplastic pouch openings are frequently sealed using resealable closure assemblies. In addition, resealable closure mechanisms having a single pair of opposing elongate interlocking profiles that are occluded between a user's fingers to create a seal are known. Moreover, it is common to employ closure mechanisms having multiple pairs of elongate interlocking profiles when a stronger and more secure seal is desired.
Recently, efforts have been directed to developing improved closures for resealable packages. For example, one resealable closure mechanism has a first fastener profile that involves a first tape having a protrusion extending along the surface of the tape, and a second fastener profile that involves a second tape having a substantially C-shaped member extending along the surface of the tape. When the pouch is closed, front and back walls of the pouch are captured between the interlocked protrusion and C-shaped member.
Another closure assembly involves a slider-actuated closure mechanism where a thin pliable membrane gets captured between first and second interlockable profiles of the closure mechanism. The membrane may be initially connected to the tops of the profiles across a mouth of the bag such that two layers of membrane material are captured between the closure mechanism profiles. Additionally, the membrane forms a tamper proof hermetic seal in an unopened package that requires the membrane to be sliced open to allow access to the inside of the package.
In another closure assembly, interlocking rib and groove elements act to reclosably seal a pouch opening. A funnel-shaped bag is connected to inner walls of the pouch just below the rib and groove elements and when inverted, the funnel shaped bag may be disposed between the interlocking rib and groove elements.
An additional resealable closure assembly involves interlocking channels disposed along a pouch opening. A flexible strip extends along one side of the pouch up through the pouch and along the interlocking channel disposed on the side of the pouch. When the pouch is closed, the interlocking channels are pressed into each other with the flexible strip disposed between the interlocking channels.
In another closure assembly, a reclosable closure mechanism has a first profile and a second profile where the profiles have complementary bulbous members that interlock in a tight interference fit. The first profile is also provided with an asymmetrical arrow-shaped member that is interlockable with a groove element on the second profile.
In yet another closure assembly, a permanently closing plastic profile fastener has male and female profiles. The male profile is generally arrow-shaped and the female profile has a pair of side jaws which define a groove therebetween. The male profile is restrained from entering the female profile by a frangible diaphragm disposed across ends of the jaws of the female profile. The diaphragm blocks access into the female profile until a predetermined level of force is applied to push the profiles together, thereby fracturing the diaphragm and allowing the male profile to enter.
An additional closure assembly involves first and second mutually interlocking profiles having two sets of interlocking members. In addition, the central portion has at least one profile with a collapsible member. When the first and second mutually interlocking profiles are joined, the collapsible member compresses against the other profile to create a seal.
In one aspect of the present invention, an airtight closure mechanism for a reclosable pouch includes first and second complementary closure elements, the first closure element comprising a first interlocking profile and the second closure element comprising a complementary second interlocking profile. First and second sealing sections are disposed on respective complementary sides of the first and second interlocking profiles. The first sealing section includes a first protuberance having a first distal surface, a second protuberance having a second distal surface, and a sealing flange attached to and extending between the first and second distal surfaces of the first and second protuberances, respectively. The second sealing section includes a sealing member disposed on a base of the second closure element. The sealing member is located a distance from the second interlocking profile that places a distal surface thereof between the first and second protuberances when the first and second interlocking profiles are occluded. Additionally, when the first and second interlocking profiles are occluded, the distal surface urges against the sealing flange to form an airtight seal therebetween.
In another aspect of the present invention, a reclosable pouch includes first and second pouch sidewalls sealed to one another to define an opening. A one-way valve is disposed on or in at least one of the first or second pouch sidewalls. An airtight closure mechanism includes first and second closure elements that include first and second interlocking profiles, and first and second sealing sections, respectively. The first closure element is attached to the first sidewall and the second closure element is attached to the second sidewall proximate the opening to define a pouch interior. The first and second sealing sections are disposed on respective pouch interior sides of the first and second interlocking profiles, and the first sealing section includes a first protuberance having a first distal surface, a second protuberance having a second distal surface, and a sealing flange attached to and extending across the first and second distal surfaces of the first and second protuberances, respectively. The second sealing section includes a sealing member disposed on a base of the second closure element and located a distance from the second interlocking profile that places a distal surface thereof between the first and second protuberances when the first and second interlocking profiles are occluded. When the first and second interlocking profiles are occluded, the sealing member urges against the sealing flange to form an airtight seal therebetween.
In another aspect of the present invention, a sealing section for an airtight closure mechanism includes first and second sealing sections disposed on respective complementary sides of first and second closure elements. The first sealing section includes a first protuberance having a first distal surface, a second protuberance having a second distal surface, and a sealing flange attached to and extending across from the first and second distal surfaces of the first and second protuberances, respectively. The second sealing section includes a sealing member disposed on the second closure element and located on a base of the second closure element so as to urge against the sealing flange attached to and extending across from the first and second protuberances when the first and second closure elements are occluded to form an airtight seal therebetween.
Other aspects and advantages of the present invention will become apparent upon consideration of the following detailed description, wherein similar structures have similar reference numerals.
Referring to
In one embodiment, the pouch 10 may include a second opening 13a through one of the sidewalls 11, 12 covered by a valve 6, such as a check or one-way valve, to allow air to be evacuated from the pouch interior 7 and maintain a vacuum when the closure mechanism 14 has been sealed. As shown in
In one embodiment, the first and second sidewalls 11, 12 and/or the closure mechanism 14 are formed from thermoplastic resins by known extrusion methods. For example, the sidewalls 11, 12 may be independently extruded of thermoplastic material as a single continuous or multi-ply web, and the closure mechanism 14 may be extruded of the same or different thermoplastic material(s) separately as continuous lengths or strands. Illustrative thermoplastic materials include polypropylene (PP), polyethylene (PE), metallocene-polyethylene (mPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ultra low density polyethylene (ULDPE), biaxially-oriented polyethylene terephthalate (BPET), high density polyethylene (HDPE), polyethylene terephthalate (PET), among other polyolefin plastomers and combinations and blends thereof. Further, inner surfaces 15, 17 of the respective sidewalls 11, 12 or a portion or area thereof may, for example, be composed of a polyolefin plastomer such as an AFFINITY™ resin manufactured by Dow Plastics. Such portions or areas include, for example, the area of one or both of the sidewalls 11, 12 proximate and parallel to the closure mechanism 14 to provide an additional cohesive seal between the sidewalls when the pouch 10 is evacuated of fluid. One or more of the sidewalls 11, 12 in other embodiments may also be formed of air-impermeable film. An example of an air-impermeable film includes a film having one or more barrier layers, such as an ethylene-vinyl alcohol copolymer (EVOH) ply or a nylon ply, disposed between or on one or more of the plies of the sidewalls 11, 12. The barrier layer may be, for example, adhesively secured between the PP and/or LDPE plies to provide a multilayer film. Other additives such as colorants, slip agents, and antioxidants, including for example talc, oleamide or hydroxyl hydrocinnamate may also be added as desired. In another embodiment, the closure mechanism 14 may be extruded primarily of molten PE with various amounts of slip component, colorant, and talc additives in a separate process. The fully formed closure mechanism 14 may be attached to the pouch body using a strip of molten thermoplastic weld material, or by an adhesive known by those skilled in the art, for example. Other thermoplastic resins and air-impermeable films useful in the present invention include those disclosed in, for example, Tilman et al. U.S. Patent application publication No 2006/0048483.
Although not shown, one or both sidewalls, such as the second sidewall 12, may also be embossed or otherwise textured with a pattern, such as a diamond pattern, on one or both surfaces spaced between the bottom edge 5b and the closure mechanism 14, or a separate textured or embossed patterned wall may be used to provide flow channels (not shown) within the pouch interior 7. The flow channels may provide fluid communication between the pouch interior 7 and the valve 6 when fluid is being drawn through the valve 6. Illustrative flow channels useful in the present invention include those disclosed in Zimmerman et al. U.S. Patent application publication No. 2005/0286808 and Tilman et al. U.S. Patent application publication No. 2006/0048483. Other flow channels useful in the present invention include those disclosed in, for example, Attorney Docket No. J-4601 (U.S. patent application Ser. No. to be assigned), filed on the same day as the present application.
The resealable bag or pouch described herein can be made by various techniques known to those skilled in the art including those described in, for example, Geiger, et al., U.S. Pat. No. 4,755,248. Other useful techniques to make a resealable pouch include those described in, for example, Zieke et al., U.S. Pat. No. 4,741,789. Additional techniques to make a resealable pouch include those described in, for example, Porchia et al., U.S. Pat. No. 5,012,561. Additional examples of making a resealable pouch as described herein include, for example, a cast post applied process, a cast integral process, and/or a blown process.
Referring to
In a further embodiment, one or both of the first and second closure elements 20, 24 may include one or more textured portions, such as a bump or crosswise groove in one or more of the interlocking profiles 22a, 22b, 26a, 26b in order to provide a tactile sensation, such as a series of clicks, as a user draws the fingers along the closure mechanism 14 to seal the closure elements across the opening. In another embodiment, all of the closure profiles 22a, 22b, 26a, 26b include textured portions along the length of each profile to provide tactile and/or audible sensations when closing the closure mechanism 14. Further, in some embodiments, a sealing material such as a polyolefin material or a caulking composition such as silicone grease may be disposed on or in the interlocking profiles 22a, 22b, 26a, 26b or closure elements 20, 24 to fill in any gaps or spaces therein when occluded. The ends of the interlocking profiles 22a, 22b, 26a, 26b or closure elements 20, 24 may also be welded or sealed by ultrasonic vibrations as is known in the art. Illustrative interlocking profiles, closure elements, sealing materials, tactile or audible closure elements, and/or end seals useful in the present invention include those disclosed in, for example, Pawloski U.S. Pat. No. 4,927,474, Dais et al. U.S. Pat. Nos. 5,070,584, 5,478,228, and 6,021,557, Tomic et al. U.S. Pat. No. 5,655,273, Sprehe U.S. Pat. No. 6,954,969, Kasai et al. U.S. Pat. No. 5,689,866, Ausnit U.S. Pat. No. 6,185,796, Wright et al. U.S. Pat. No. 7,041,249, Pawloski et al. U.S. Pat. No. 7,137,736, Anderson U.S. Patent Application Publication No. 2004/0091179, Pawloski U.S. Patent Application Publication No. 2004/0234172, Tilman et al. U.S. Patent Application Publication No. 2006/0048483, and Anzini et al. U.S. Patent Application Publication Nos. 2006/0093242 and 2006/0111226. Other interlocking profiles and closure elements useful in the present invention include those disclosed in, for example, U.S. patent application Ser. No. 11/725,120, filed Mar. 16, 2007, and Attorney Docket Nos. J-4714B and J-4673 (U.S. patent application Ser. No. to be assigned), each filed on the same day as the present application. It is further appreciated that the interlocking profiles or closure elements disclosed herein may be operated by hand, or a slider (not shown) may be used to assist in occluding and de-occluding the interlocking profiles and closure elements.
As shown in
A second sealing section 27 is disposed on the second closure element 24 between the second and fourth interlocking profiles 26a, 26b, and includes a sealing member 36 having a distal surface 38. In this embodiment, the distal surface 38 is disposed at an apex of a third protuberance 137 that extends from an elongate second base 23 of the second closure element. Although in this embodiment the third protuberance 137 is disposed at an angle of less than 90 degrees relative to the second base 23, it is also contemplated that the third protuberance may be disposed at angles of approximately 90 degrees or greater than 90 degrees. However, by having the third protuberance 137 at a non-90 degree angle, the force necessary to urge the sealing member 36 and the sealing flange 39 together may be less due to the flexibility of the third protuberance as force is applied thereto while the first and second closure elements 20, 24 are being occluded. This flexibility increases as the angle increases past 90 degrees or decreases to less than 90 degrees, and may in some instances assist in maintaining an airtight seal with the sealing flange 39. A central axis 36a of the distal surface 38 of the sealing member 36 is located a distance Z measured along the first base 21 from a line perpendicular to the base and through the distal end 29 of the first interlocking profile 22a when the closure elements 20 and 24 are occluded. In this embodiment, the central axis 36a of the distal surface 38 does not correspond to a central axis (not shown) of the third protuberance 137. The distance Z ranges between the distances X and Y in this embodiment, such that the central axis 36a is disposed between opposing outer edges 35, 37 of the distal surfaces 30, 34, respectively in the occluded state, as shown in
When the closure elements 20, 24 are urged together the first interlocking profile 22a interlocks with the second interlocking profile 26a, and the third interlocking profile 22b interlocks with the fourth interlocking profile 26b. In this embodiment, because the sealing flange 39 is integral with the second pouch sidewall 12, the third and fourth interlocking profiles 22b, 26b interlock with the sealing flange trapped therebetween. In other embodiments, the sealing flange 39 may be made of a thermoplastic film independent of the sidewalls 11, 12 such as, for example, an elastomer or a polyolefin plastomer such as an AFFINITY™ resin manufactured by Dow Plastics, and the third and fourth interlocking profiles 22b, 26b may interlock without the sealing flange trapped therebetween. Additionally, in the occluded state, the first protuberance 28 interlocks with an asymetrically-hooked protuberance 31 that extends from the elongate second base 23 of the second closure element 24. Although the first and second protuberances 28, 32 are illustrated in
In another embodiment illustrated in
Referring to
A first sealing section 87 disposed on the first closure element 80 includes a first protuberance 98 having a distal surface 100 and extending from an elongate first base 83 of the first closure element. A central axis 98a of the first protuberance 98 is located a distance T measured along the first base 83 from a line perpendicular to the base and through a distal end 93 of the first interlocking profile 82. The first sealing section 87 also includes a second and third protuberance, 108, 110 respectively positioned on either side of the first protuberance 98. The second and third protuberances 108, 110 extend from the elongate first base 83 of the first closure element 80 and have respective distal surfaces 109, 114. A second sealing section 89 disposed on the second closure element 84 includes a first sealing member 88 having a distal surface 90 disposed at an apex of a fourth protuberance 188 that extends approximately 90 degrees or perpendicularly from an elongate second base 85 of the second closure element. A central axis 88a of the distal surface 90 generally corresponds in this embodiment to that of the first sealing member 88 and is located a distance R measured along the first base 83 from a line perpendicular to the base and through the distal end 93 of the first interlocking profile 82 when the closure elements 80 and 84 are occluded. The second sealing section 89 further includes a second sealing member 94 having a distal surface 96 that is disposed at an apex of a fifth protuberance 194 and also extends approximately 90 degrees or perpendicularly from the elongate second base 85 of the second closure element 84. A central axis 94a of the distal surface 96 also generally corresponds to that of the second sealing member 94 and is located a distance S measured along the first base 83 from a line perpendicular to the base and through the distal end 93 of the first interlocking profile 82 when the closure elements 80 and 84 are occluded. In this embodiment, the distance S is greater than the distance T, which is greater than the distance R. Although both of the first and second sealing members 88, 94 have generally perpendicularly disposed respective fourth and fifth protuberances 188, 194, it is also contemplated that one or both may be disposed at an angle less than 90 degrees. The first closure element 80 may also include a third interlocking profile (not shown) on a product side of the first sealing section 87, and the second closure element 84 may include a complementary fourth interlocking profile (not shown) on the product side of the second sealing section 89.
A sealing flange 106 is attached respectively to the distal surfaces 100, 109, 114 of the first, second, and third protuberances, 98, 108, 110, respectively. In this embodiment, the sealing flange 106 is a part of the second sidewall 12. However, in other embodiments, the sealing flange 106 may be made of a thermoplastic film independent of the sidewalls 11, 12 such as, for example, an elastomer or a polyolefin plastomer such as an AFFINITY™ resin. The sealing flange 106 also includes a slit along a length thereof to form film flaps 112 to allow penetration of the first and second sealing members 88, 94 into spaces between the first protuberance 98 and the second protuberance 108 and the first protuberance 98 and the third protuberance 110, respectively, when the first closure element 80 and second closure element 84 are occluded. In the occluded state shown in
Referring to
In
Although the present invention has been described relative to specific exemplary embodiments thereof, it will be understood by those skilled in the art that modifications can be made thereto without departing from the scope and spirit of the invention.
An airtight closure mechanism is presented that may be used to pack and store perishable items in an airtight or vacuum environment. The closure mechanism includes first and second closure elements, wherein each of the closure elements has interlocking and sealing sections. A sealing flange is attached across the sealing section of one of the first and second closure elements, and the other of the first and second closure elements includes a sealing member. When the first and second closure elements are occluded, the sealing member is urged against the sealing flange and forms an airtight seal therebetween.
Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved. All patents, patent publications and applications, and other references cited herein are incorporated by reference herein in their entirety.
