Liquid-trapping bag for use in vacuum packaging
A bag for use in vacuum packaging comprises a first panel and a second panel overlapping each other. A plurality of channels having a plurality of baffles is formed on one or more of the panels for evacuating air and/or other gases from inside the bag using a suction source, while preventing liquids from being drawn into the suction source. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.
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This application claims priority to the following U.S. Provisional Patent Application:
U.S. Provisional Patent Application No. 60/452,168, entitled “LIQUID-TRAPPING BAG FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01177US0).
CROSS-REFERENCE TO RELATED PATENT APPLICATIONSThis U.S. patent application incorporates by reference all of the following co-pending applications:
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- U.S. Provisional Patent Application No. 60/452,138, entitled “METHOD FOR MANUFACTURING LIQUID-TRAPPING BAG FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01177US1);
- U.S. Provisional Patent Application No. 60/452,172, entitled “SEALABLE BAG HAVING AN INTEGRATED TRAY FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01178US0);
- U.S. Provisional Patent Application No. 60/452,171, entitled “METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED TRAY FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01178US1);
- U.S. Provisional Patent Application No. 60/451,954, entitled “SEALABLE BAG HAVING AN INDICIA FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01179US0);
- U.S. Provisional Patent Application No. 60/451,948, entitled “METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INDICIA FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01179US1);
- U.S. Provisional Patent Application No. 60/452,142, entitled “SEALABLE BAG HAVING AN INTEGRATED ZIPPER FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01180US0);
- U.S. Provisional Patent Application No. 60/452,021, entitled “METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED ZIPPER FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01180US1);
- U.S. Provisional Patent Application No. 60/451,955, entitled “SEALABLE BAG HAVING AN INTEGRATED VALVE STRUCTURE FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01181US0);
- U.S. Provisional Patent Application No. 60/451,956, entitled “METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED VALVE STRUCTURE FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01181US1);
- U.S. Provisional Patent Application No. 60/452,157, entitled “SEALABLE BAG HAVING AN INTEGRATED TIMER/SENSOR FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01182US0);
- U.S. Provisional Patent Application No. 60/452,139, entitled “METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED TIMER/SENSOR FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01182US1);
- U.S. patent application Ser. No. 10/169,485, entitled “METHOD FOR PREPARING AIR CHANNEL EQUIPPED FILM FOR USE IN VACUUM PACKAGE,” filed Jun. 26, 2002;
- U.S. patent application Ser. No. ______, entitled “METHOD FOR MANUFACTURING LIQUID-TRAPPING BAG FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01177US3, filed concurrently;
- U.S. patent application Ser. No. ______, entitled “SEALABLE BAG HAVING AN INTEGRATED TRAY FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01178US2, filed concurrently;
- U.S. patent application Ser. No. ______, entitled “METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED TRAY FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01178US3, filed concurrently;
- U.S. patent application Ser. No. ______, entitled “SEALABLE BAG HAVING AN INDICIA FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01179US2, filed concurrently;
- U.S. patent application Ser. No. ______, entitled “METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INDICIA FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01179US3, filed concurrently;
- U.S. patent application Ser. No. ______, entitled “SEALABLE BAG HAVING AN INTEGRATED ZIPPER FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01180US2, filed concurrently;
- U.S. patent application Ser. No. ______, entitled “METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED ZIPPER FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01180US3, filed concurrently;
- U.S. patent application Ser. No. ______, entitled “SEALABLE BAG HAVING AN INTEGRATED VALVE STRUCTURE FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01181US2, filed concurrently;
- U.S. patent application Ser. No. ______, entitled “METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED VALVE STRUCTURE FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01181US3, filed concurrently;
- U.S. patent application Ser. No. ______, entitled “SEALABLE BAG HAVING AN INTEGRATED TIMER/SENSOR FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01182US2, filed concurrently; and
U.S. patent application Ser. No. ______, entitled“METHOD FOR MANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED TIMER/SENSOR FOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01182US3, filed concurrently.
FIELD OF THE INVENTIONThe present invention relates to bags for use in vacuum packaging and methods and devices for manufacturing bags for use in vacuum packaging.
BACKGROUNDMethods and devices for preserving perishable foods such as fish and meats, processed foods, prepared meals, and left-overs, and non-perishable items are widely known, and widely varied. Foods are perishable because organisms such as bacteria, fungus and mold grow over time after a food container is opened and the food is left exposed to the atmosphere. Most methods and devices preserve food by protecting food from organism-filled air. A common method and device includes placing food into a gas-impermeable plastic bag, evacuating the air from the bag using suction from a vacuum pump or other suction source, and tightly sealing the bag.
A bag for use in vacuum packaging can consist of a first panel and second panel, each panel consisting of a single layer of heat-sealable, plastic-based film (for example, polyethylene). The panels are sealed together along a substantial portion of the periphery of the panels by heat-sealing techniques so as to form an envelope. Perishable products, such as spoilable food, or other products are packed into the envelope via the unsealed portion through which air is subsequently evacuated. After perishable products are packed into the bag and air is evacuated from the inside of the bag, the unsealed portion is heated and pressed such that the panels adhere to each other, sealing the bag.
U.S. Pat. No. 2,778,173, incorporated herein by reference, discloses a method for improving the evacuation of air from the bag by forming channels in at least one of the panels with the aid of embossing techniques. Air escapes from the bag along the channels during evacuation. The embossing forms a pattern of protuberances on at least one of the panels. The protuberances can be discrete pyramids, hemispheres, etc., and are formed by pressing a panel using heated female and male dies. The first panel is overlaid on the second panel such that the protuberances from one panel face the opposite panel. The contacting peripheral edges of the panels are sealed to each other to form an envelope having an inlet at an unsealed portion of the periphery. The perishable or other products are packed into the envelope through the inlet, and the inlet is sealed. Thereafter, an opening is pierced in a part of the panel material that communicates with the charnels, air is removed from the interior of the envelope through the channels and opening, and the opening is sealed. This type of bag requires two additional sealing steps after the perishable or other product is packed into the envelope. One further problem is that embossing creates impressions on the plastic such that indentations are formed on the opposite side of the panel
To avoid additional sealing steps, a vacuum bag is formed having a first panel and a second panel consisting of laminated films. Each panel comprises a heat-sealable inner layer, a gas-impermeable outer layer, and optionally, one or more intermediate layers. Such a bag is described in U.S. Pat. No. Re. 34,929, incorporated herein by reference. At least one film from at least one panel is embossed using an embossing mold to form protuberances and channels defined by the space between protuberances, so that air is readily evacuated from the vacuum bag.
U.S. Pat. No. 5,554,423, incorporated herein by reference, discloses still another bag usable in vacuum packaging. The bag consists of a first and second panel, each panel consisting of a gas-impermeable outer layer and a heat-sealable inner layer. A plurality of heat-sealable strand elements are heat bonded at regular intervals to the inner layer of either the first panel or the second panel. The spaces between strand elements act as channels for the evacuation of air. The strand elements are extruded from an extrusion head and heat bonded to the heat-sealable layer by use of pressure rolls. Separate equipment is required for producing strand elements, and a procedure of heat bonding a plurality of strand elements at regular intervals to the heat-sealable inner layer is complicated. Also, various shapes of pattern are hard to form using this process.
BRIEF DESCRIPTION OF THE FIGURESFurther details of embodiments of the present invention are explained with the help of the attached drawings in which:
The detailed embodiments of the present invention are disclosed herein. It should be understood, however, that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limiting, but merely as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention.
The heat-sealable inner layer 106 typically comprises a thermoplastic resin. For example, the resin can be comprised of polyethylene (PE) suitable for preserving foods and harmless to a human body. A vacuum bag can be manufactured by overlapping two panels such that the heat-sealable inner layers 106 of the two panels are brought into contact and heat is applied to a portion of the periphery of the panels to form an envelope. The thermoplastic resin can be chosen so that the two panels strongly bond to each other when sufficient heat is applied.
The gas-impermeable base layer 108 is fed to the gap between the cooling roll 104 and the laminating roll 102 by a feeding means (not shown). The gas-impermeable base layer can be comprised of polyester, polyamide, ethylene vinyl alcohol (EVOH), nylon, or other material having similar properties, that is capable of being heated and capable of being used in this manufacturing process. The gas-impermeable base layer 108 can consist of one layer, or two or more layers. When employing a multilayer-structured base layer, it should be understood that a total thickness thereof is also adjusted within the allowable range for the total gas-impermeable base layer 108.
An extruder 110 is positioned in such a way that the melt-extruded resin is layered on the gas-impermeable base layer 108 by feeding the melt-extruded resin to a nip between the cooling roll 104 and the gas-impermeable base layer 108. The resin is fed through a nozzle 112 of the extruder 110. The temperature of the melt-extruded resin is dependent on the type of resin used, and can typically range from about 200° C. to about 250° C. The amount of resin extruded into the laminating unit 100 is dependent on the desired thickness of the heat-sealable inner layer 106.
A pattern fabricated on the circumferential surface of the cooling roll 104 in accordance with one embodiment of the present invention can include cavities (and/or protuberances) defining a plurality of discrete channels having a baffled structure. The resin extruded from the nozzle 112 is pressed between the cooling roll 104 and the gas-impermeable base layer 108 and flows into the cavities of the cooling roll 104. The resin quickly cools and solidifies in the desired pattern while adhering to the gas-impermeable base layer 108, thereby forming the heat-sealable inner layer 106 of the panel. The heat-sealable inner layer 106 can be formed while the resin is sufficiently heated to allow the resin to flow, thereby molding the resin, unlike other methods adopting a post-embossing treatment where the heat-sealable inner layer is drawn by a die or embossed between male and female components.
The thickness of each protuberance formed on the heat-sealable inner layer 106 of a panel can be determined by the depth of the cavities of the cooling roll 104, and the width of the channel can be determined by the interval between the cavities. Thus, the shape, width, and thickness of the channels for the evacuation of air and/or other gases can be controlled by changing the specifications for the cavities of the cooling roll 104.
As indicated above, one of ordinary skill in the art can appreciate the multitude of different baffle arrangements for retarding the evacuation of liquid 342 relative to the evacuation of air and/or other gases 340. As shown in
As shown in
It is understood that the trapping of liquid in baffles or vessels formed in the bag is advantageous as this structure retards and prevents liquids from being drawn into the vacuum pump or suction device of a vacuum sealing tool such as disclosed in U.S. Pat. No. 4,941,310, which is incorporated herein by reference.
The foregoing description of preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. It is to be understood that many modifications and variations will be apparent to the practitioner skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalence.
Claims
1. A bag adapted to receive an article, comprising:
- a first panel including a plurality of protuberances;
- a second panel; and
- the first panel and the second panel secured together to form the bag.
2. A bag adapted to receive an article, comprising:
- a first panel having: a first outer layer; and a first inner layer connected with the first outer layer, the first inner layer including a plurality of protuberances; and
- a second panel connected with the first panel such that the first panel and the second panel form an envelope having an inlet, the second panel having: a second outer layer; and a second inner layer connected with the second outer layer;
- wherein when the first inner layer contacts the second inner layer the plurality of protuberances obstruct liquid flow through the inlet.
3. The bag of claim 2, wherein the first outer layer and the second outer layer comprise a gas-impermeable material.
4. The bag of claim 3, wherein the gas-impermeable material is one of polyester, polyamide, ethylene vinyl alcohol, and nylon.
5. The bag of claim 2, wherein the first inner layer and the second inner layer comprise a thermoplastic resin.
6. The bag of claim 5, wherein the thermoplastic resin is polyethylene.
7. The bag of claim 2, wherein the plurality of protuberances define a plurality of channels.
8. The bag of claim 7, wherein the plurality of channels includes a plurality of baffles.
9. The bag of claim 8, wherein the plurality of baffles are arranged in a herringbone pattern.
10. The bag of claim 8, wherein the plurality of baffles form a plurality of pockets for trapping liquid particles.
11. The bag of claim 2, wherein the plurality of protuberances define a plurality of baffles.
12. The bag of claim 11, wherein the plurality of baffles form a plurality of pockets for trapping liquid particles.
13. The bag of claim 8, wherein the plurality of baffles comprise a U-shape.
14. The bag of claim 13, wherein the plurality of baffles include a slit in a trough of the U-shape, the slit being sized such that gas can pass through the slit.
15. A bag adapted to receive an article, comprising:
- a first panel including: a first gas-impermeable layer; and a first inner layer laminated to the first gas-impermeable layer, the first inner layer having a textured exposed surface; wherein the textured exposed surface obstructs liquid flow when gas is evacuated through the heat-sealable opening; and
- a second panel including: a second gas-impermeable layer; and a second inner layer laminated to the second gas-impermeable layer;
- wherein the first panel is connected with the second panel to form an envelope such that the first inner layer opposes the second inner layer, the envelope including a heat-sealable opening for evacuating gas.
16. A heat-sealable bag adapted to receive an article, comprising:
- a first panel including: a first gas-impermeable layer; at least one first intermediate layer connected with the first gas-impermeable layer; and a first inner layer laminated to the at least one first intermediate layer, the first inner layer having a textured exposed surface; wherein the textured exposed surface obstructs liquid flow when gas is evacuated through the heat-sealable opening; and
- a second panel including: a second gas-impermeable layer; at least one second intermediate layer connected with the second gas-impermeable layer; and a second inner layer laminated to the at least one second intermediate layer; wherein the first panel is connected with the second panel to form an envelope such that the first inner layer opposes the second inner layer, the envelope including a heat-sealable opening for evacuating gas.
17. The bag of claim 16, wherein the first gas-impermeable layer and the second gas-impermeable layer comprise one of polyester, polyamide, ethylene vinyl alcohol, and nylon.
18. The bag of claim 16, wherein the first inner layer and the second inner layer comprise a thermoplastic resin.
19. The bag of claim 18, wherein the thermoplastic resin is polyethylene.
20. The bag of claim 16, wherein the textured exposed surface comprises a plurality of channels.
21. The bag of claim 20, wherein the textured exposed surface further comprises a plurality of baffles.
22. The bag of claim 21, wherein the plurality of baffles are arranged in a herringbone pattern.
23. The bag of claim 21, wherein the plurality of baffles form a plurality of pockets for trapping liquid particles.
24. The bag of claim 16, wherein the textured exposed surface comprises a plurality of baffles.
25. The bag of claim 24, wherein the plurality of baffles form a plurality of pockets for trapping liquid particles.
26. The bag of claim 24, wherein the plurality of baffles comprise a U-shape.
27. The bag of claim 26, wherein the plurality of baffles includes a slit in a trough of the U-shape, the slit being sized such that air can pass through the slit.
28. A bag adapted to receive an article, comprising:
- a first panel defining a plurality of receptacles adapted to trap a liquid and a plurality of channels that pass by said receptacles, which channels are adapted to allow the passage of a gas;
- a second panel; and
- the first panel and the second panel secured together to form the bag.
29. A bag adapted to receive an article, comprising:
- a first panel defining a plurality of receptacles adapted to trap a liquid, which receptacles are formed with a first wall that runs about along a length of the bag and a plurality of second walls that run in a direction that is across the length of the bag;
- a second panel; and
- the first panel and the second panel secured together to form the bag.
30. A system for forming a bag including a three-dimensional structure formed on at least one panel, comprising:
- a cooling roll having a plurality of cavities for forming one or more structures;
- wherein the one or more structures include a plurality of receptacles adapted to trap a liquid;
- a laminating roll;
- a backing material; and
- a flowable material that can be flowed into the one or more cavities to form the one or more structures, the flowable material adhering to the backing material.
Type: Application
Filed: Mar 4, 2004
Publication Date: Feb 17, 2005
Applicant: Tilia International, Inc. (San Francisco, CA)
Inventors: Hongyu Wu (San Jose, CA), Charles Albritton (Hercules, CA), David Brakes (Kowloon)
Application Number: 10/795,149