Vacuum storage bag

Abstract

A vacuum storage bag providing an interior volume for storing food items in an evacuated condition has air flexible sidewalls made of a gas permeable material. The gas permeable sidewalls can be made of multiple layers including a heat sealing innermost layer and a relatively stronger, outwardly disposed gas permeable layer. The heat sealing layer can be low density polyethylene to facilitate forming of the bag with heat seals and the stronger gas permeable layer can be high density polyethylene to provide the bag with sufficient strength and toughness. In various embodiments, the storage bag can include interlocking closure strips for releasably closing an opening, a one-way vacuum valve for evacuating the interior volume, and a textured portion along one sidewall to facilitate evacuation.

Description

BACKGROUND OF THE INVENTION[0001]Flexible plastic bags are used for a variety of purposes including storing food items, either temporarily in the case of packaging snacks or long term as in the case of freezer storage. Plastic bags of this style are typically made from one or more sheets of flexible plastic material arranged to provide an interior volume that is accessible through an opening. To close the opening after insertion of food items, interlocking closure strips may be provided about the rim of the opening. Likewise, the plastic material comprising the rim may be heat sealed together or glued together with a pressure sensitive adhesive to more permanently seal the opening.[0002]One common problem that occurs with such bags is that after the opening has been sealed, latent air may remain trapped in the interior volume. In addition to undesirably increasing the overall size of the bag, the trapped air can cause spoilation or dehydration of the stored food items. Further, in f...

AI Technical Summary

Benefits of technology

[0003]The invention provides a vacuum storage bag made with flexible plastic sidewalls of an air permeable material or materials. To improve manufacturability of the bag and provide adequate toughness for use in vacuum applications, the sidewall materials can include multiple plies or layers of air permeable materials including a heat sealable innermost layer and a tougher and stronger, outwardly situated, gas permeable layer. An example of a material sufficient for the heat sealable inner layer includes low density polyethylene and an example of a material suitable for the stronger gas permeable layer includes high density polyethylene. Though such materials are not truly gas impermeable, they provide sufficient resistance to air penetration to adequately maintain a vacuum state acceptable for food storage.

[0004]When the two sidewalls of the storage bag are overlaid and arranged to provide an interior volume, the heat sealable inner layers of the sidewalls can be joined together by a heat sealing operation to form the closed edges of the bag. The stronger layer, which may not be as susceptible to forming heat seals, provides sufficient toughness to resist destructive deformation or stretching of the bag while under vacuum. For example, in absence of the stronger layer, stretching of the sidewalls about stored food items during evacuation may cause the bag to develop small holes or tears thereby compromising the vacuum.

[0005]An advantage of the inventive vacuum storage bag is that manufacture of the bag is facilitated by having heat sealable inner layers as part of the sidewall. Another advantage is that the stronger, outer layer provides sufficient toughness to preclude destructive deformation of the sidewalls and resist the ingress of air into the interior volume. Another advantage is that the invention provides a vacuum storage bag that can be made from relatively low cost, gas permeable materials. These and other features and advantages of the invention will be apparent from the foregoing drawings and detailed description of the embodiments.

Problems solved by technology

Though such materials are not truly gas impermeable, they provide sufficient resistance to air penetration to adequately maintain a vacuum state acceptable for food storage.

For example, in absence of the stronger layer, stretching of the sidewalls about stored food items during evacuation may cause the bag to develop small holes or tears thereby compromising the vacuum.

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