The present invention generally relates to vacuum packaging. More particularly, the invention is directed to resealable vacuum packaging bags and methods for using and manufacturing resealable vacuum packaging bags.
Vacuum packaging involves removing air or other gases from a storage container and then sealing the container to prevent the contents from being exposed to the air. Vacuum packaging is particularly useful in protecting food and other perishables against oxidation. Oxygen is a main cause of food spoilage and contributes to the growth of bacteria, mold, and yeast. Accordingly, vacuum packaged food often lasts three to five times longer than food stored in ordinary containers. Moreover, vacuum packaging is useful for storing clothes, photographs, silver, and other items to prevent discoloration, corrosion, rust, and tarnishing. Furthermore, vacuum packaging produces tight, strong, and compact packages, reducing the bulk of articles and allowing for more space to store other supplies.
Conventional vacuum packaging bags include two panels attached together with an open end. Typically, the panels each include two or more layers. The inner layer can be a heat sealable material, and the outer layer can be a gas impermeable material to provide a barrier against the influx of air. The plasticity temperature of the inner layer is lower than the outer layer. Accordingly, the bag can be heated to thermally bond the inner layer of each panel together to seal the bag without melting or puncturing the outer layer. A vacuum packaging bag of this type is disclosed in U.S. Pat. No. Re. 34,929, which is hereby incorporated by reference in its entirety.
A conventional vacuum packaging process includes depositing the object 2 in the bag 60 and positioning an open end 62 of the bag 60 in the lower trough 26 of the vacuum packaging appliance 10. Next, the lid 40 pivots downward to form the vacuum chamber with the open end 62 of the bag 60 disposed within the vacuum chamber. The vacuum pump then removes gas from the vacuum chamber and the interior of the bag 60, which is in fluid communication with the vacuum chamber. After the gas has been removed from the interior of the bag 60, the heating element 28 heats a strip of the bag 60 proximate to the open end 62 to melt the inner layer of each panel and thermally seal the bag 60.
One problem with conventional vacuum packaging methods is that thermally sealed bags cannot be resealed and reopened numerous times. More specifically, a thermally sealed bag is opened by cutting the bag below the seal. The bag can be subsequently resealed; however, each time the bag is reopened, another portion of the bag is cut off. Accordingly, there is a need to improve the process of sealing vacuum packaging bags.
A. Overview
The present invention is directed to resealable vacuum packaging bags and methods for using and manufacturing resealable vacuum packaging bags. In the following description, numerous specific details are provided of particular configurations of resealable vacuum packaging bags and vacuum packaging appliances to provide a thorough understanding of and an enabling description for embodiments of the invention. Those of ordinary skill in the art, however, will recognize that the invention can be practiced without one or more of the specific details explained in the following description. In other instances, well-known structures and operations are not shown or described in detail to avoid obscuring aspects of the invention.
Several aspects of the invention are directed to resealable vacuum packaging bags. In one embodiment, a bag includes a first panel and a second panel coupled to the first panel. The first and second panels each have a gas impermeable layer and a heat sealable layer. The bag further includes a first mating member projecting from the first panel and a second mating member projecting from the first or second panel. The second mating member is configured to selectively engage the first mating member to substantially seal the bag. In one aspect of this embodiment, the first mating member includes a rib and the second mating member includes a channel sized to removably receive the rib. The first and second mating members can extend across the entire width of the bag.
In another embodiment, a vacuum packaging bag includes a first panel, a second panel coupled to the first panel, a first complementary member coupled to the first panel, and a second complementary member coupled to the second panel. The first and second panels define an interior region with an open end. The first and second panels each include a gas impermeable layer and a heat sealable layer coupled to the gas impermeable layer. The heat sealable layer of the first panel is configured to be thermally bonded to the heat sealable layer of the second panel across a heat seal zone to substantially hermetically seal the interior region. The heat seal zone is disposed between the open end and the first and second complementary members. The first complementary member is configured to selectively engage the second complementary member to substantially seal the interior region.
Another aspect of the invention is directed to methods of using resealable vacuum packaging bags. In one embodiment, a method includes opening a thermally sealed vacuum packaging bag and engaging a first complementary member on a first panel of the bag with a second complementary member on a second panel of the bag to substantially seal the vacuum packaging bag. In one aspect of this embodiment, the method further includes opening the vacuum packaging bag by disengaging the first and second complementary members after engaging the first and second complementary members.
Another aspect of the invention is directed to methods for manufacturing resealable vacuum packaging bags. In one embodiment, a method includes forming first and second panels, each including a gas impermeable layer and a heat sealable layer coupled to the gas impermeable layer. The method further includes forming a first mating member on the first panel and forming a second mating member on the first or second panel. The second mating member is configured to selectively engage the first mating member to substantially seal the bag.
B. Embodiments of Vacuum Packaging Systems Including Resealable Vacuum Packaging Bags and Vacuum Packaging Appliances
The vacuum packaging appliance 110 further includes a vacuum pump (not shown) operably coupled to the first and/or second chamber portion 126 or 146 to remove gas from the vacuum chamber when the lid 140 is in the closed position. The vacuum pump can also remove gas from the interior of the bag 160 when an open end 162 of the bag 160 is positioned in the vacuum chamber. The bag 160 is configured so that the interior of the bag 160 is in fluid communication with the vacuum chamber when the lid 140 is in the closed position, as described in greater detail below with reference to
In the illustrated embodiment, the vacuum packaging appliance 110 further includes a heating element 128 and a member 150 for pressing the bag 160 against the heating element 128. The heating element 128 can be carried by the base 120, and the member 150 can be carried by and project from the lid 140. The heating element 128 is configured to thermally seal the bag 160 after the gas has been substantially evacuated from the interior of the bag 160. The heating element 128 heats the bag 160 and the member 150 presses the bag 160 against the heating element 128 to ensure a seal is formed across the bag 160, as described in greater detail below with reference to
C. Embodiments of Resealable Vacuum Packaging Bags
The illustrated resealable vacuum packaging bag 160 further includes a first mating member 190 (shown in
In the illustrated embodiment, the second panel 174 includes a plurality of intercommunicating channels 175 configured to exhaust gas from the interior of the bag 160 when the first and second panels 164 and 174 are pressed together as shown in
In the illustrated embodiment, the bag 160 is sealed by exerting a force F against the first panel 164 to cause the first mating member 190 to engage the second mating member 195. More specifically, the rib 192 moves into the channel 197 and thereby prevents ambient gas from entering the interior region 184 of the bag 160. The first and second mating members 190 and 195 can be sized and configured to remain removably engaged until an external force is applied to the bag 160 to disengage the first and second mating members 190 and 195. In other embodiments, the first and second mating members 190 and 195 can have other shapes and/or configurations. For example, the first mating member 190 can include three spaced-apart ribs with two channels sized and configured to receive the ribs 198a-b of the second mating member 195. In additional embodiments, the first and second mating members 190 and 195 can include a configuration similar to the sealing mechanism on zipper bags or ZiplocĀ® bags.
In other embodiments, the bag can have a first open end and a second open end opposite the first open end. The first open end of the bag can be thermally sealed with the vacuum packaging appliance 110. The first and second mating members can be positioned proximate to the second open end to selectively seal the second open end of the bag.
One feature of the resealable vacuum packaging bag 160 of the illustrated embodiment is that the bag 160 can be resealed and reopened repeatedly without consuming and/or damaging the bag 160. An advantage of this feature is that the life of the bag 160 is significantly extended, and accordingly, the cost associated with replacing the bag 160 is reduced. Prior art vacuum packaging bags do not include integral mating members, and accordingly, the bags must be resealed thermally. Each time a prior art bag is thermally sealed, the bag must be cut to be opened. Cutting damages and consumes a portion of the bag, and therefore, thermally sealed prior art bags have a limited life and must be replaced frequently.
D. Other Embodiments of Resealable Vacuum Packaging Bags
In the illustrated embodiment, the first panel 364 further includes an opening 361 through which the interior region 384 of the bag 360 can be accessed. The opening 361 can be selectively closed to at least substantially seal the bag 360, as described in greater detail below with reference to
In one aspect of this embodiment, the rib 392 of the first mating member 390 includes a neck 393 and a head 394 projecting from the neck 393. The neck 393 can have a width W1, and the head 394 can have a width W2 greater than the width W1 of the neck 393. The ribs 398 of the second mating member 395 can also include corresponding heads 399 (identified individually as 399a-b) spaced apart by a distance approximately equal to the width W1 of the neck 393. In this embodiment, the ribs 398a-b of the second mating member 395 can be made of a flexible material to allow the head 394 of the first mating member 390 to move between the heads 399a-b and into or out of the channel 397. Because the width W2 of the head 394 of the first mating member 390 is greater than the distance between the heads 399a-b of the second mating member 395, the first and second mating members 390 and 395 remain engaged until an external force is applied to disengage them. In other embodiments, the first and second mating members 390 and 395 can have other configurations to selectively seal the interior region 384 of the bag 360.
The resealable vacuum packaging bag 360 of the illustrated embodiment can be evacuated, thermally sealed, and subsequently opened and resealed repeatedly by engaging and disengaging the first and second mating members 390 and 395. The bag 360 is opened by exerting a force in a direction S on the first portion 364a to disengage the first and second mating members 390 and 395 and separate the first portion 364a from the second portion 364b. Once the first and second mating members 390 and 395 are disengaged and the first portion 364a is separated from the second portion 364b (as shown in broken lines), the interior region 384 of the bag 360 can be accessed through the opening 361 to place objects into or remove objects from the bag 360. The bag 360 can be subsequently closed and sealed by engaging the first and second mating members 390 and 395.
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
This application claims the benefit of U.S. Provisional Patent Application No. 60/491,722, filed Jul. 31, 2003, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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60491722 | Jul 2003 | US |