Plastic, resealable elongate valve opening for a vacuum food package

Abstract

A flexible, plastic food package is provided having an elongate opening check valve with an air removal port that allows repeated opening and resealing of the package for removal of air and moisture by vacuuming. The vacuum is established by removing air through the air removal port which encloses a compressible foam material that can be repeatedly penetrated by a blunt-tip aspiration needle associated with a vacuum pump. Following closure of the check valve and inducing a vacuum, the foam material will be compressed to seal the package. The closing force of the valve is sufficient to maintain a vacuum in the package, e.g., −90 kPa at a low temperature of e.g., −60 C for a long period of time. The closing force of the valve can be overcome by hand to enable opening of the food package and access to food therein. Loss of vacuum by migration of air into the package can be reestablished by means of the aspiration needle. The compressed foam in the air removal port will seal along the entry area of the needle when it is withdrawn, and enables repeated use for long periods of time and at extremely low temperatures while still retaining the flavor and edibility of the food due a considerable reduction of ice formation on the frozen food.

1 . A food package providing a plastic film food container defining an open portion; an elongate opening and closure valve means bonded coextensively along the open portion of the food container and interfitting therewith; an air removal port defined by closure of the valve including sponge means, which upon compression by valve closure, forms a vacuum seal along the open portion of the food container, the sponge means defining a structure including a bore for entry of a blunt tip aspirating needle into the food container; whereby, opening of the elongate valve enables entry to the food container, and following closure of the valve, removal of air and moisture by aspiration with the needle enables a high vacuum to be formed within the food container; the sponge structure enabling repeated opening and closure of the valve for access to the food container and the application of a vacuum, thereby enabling long term use of food in the container at low temperatures and vacuum pressures. 
   
   
       2 . The food package of  claim 1 , in which the elongate valve provides a sufficient closing force to maintain a vacuum of about −90 kPa and at a low temperature about −20 C to about −60 C. 
   
   
       3 . The food package of  claim 2 , in which the sponge structure provides about 5-15 repeated insertions of a blunt tip aspiration needle associated with a vacuum pump, thereby inducing a vacuum seal of about −90 kPa. 
   
   
       4 . The food package of  claim 1 , in which the sponge structure is selected from the group consisting of silicone rubbers, thermoplastic rubbers, synthetic rubbers, and polyurethanes. 
   
   
       5 . The food package of  claim 1 , in which the plastic material of the food container is selected from the group consisting of low and high density polyethylenes, nylons, polyesters, polyurethanes, and laminates thereof. 
   
   
       6 . The food package of  claim 1 , in which the aspirating needle is associated with an exhaust pump. 
   
   
       7 . A transparent food package of  claim 1 , providing visual inspection and tactile monitoring of a vacuum in the package, and upon loss of vacuum, insertion of an aspirating needle into the food package enables removal of air and moisture therefrom. 
   
   
       8 . The food package of  claim 1 , in which the closure valve is an elongated trough valve. 
   
   
       9 . A valve for interfitting into an open portion of a food container, the valve comprising engaging closure side elements, the closure side elements defining an air removal port for containment of a sponge element, a bore defined within the sponge element for insertion of an aspirating needle therethrough, whereupon closing of the side elements compresses the sponge element to form a vacuum seal between the sponge element and the food container, thereby enabling repeated aspiration of air and moisture from the container to maintain a vacuum therein. 
   
   
       10 . The food package of  claim 1 , in which the food container includes a paper box and a cylindrical carton. 
   
   
       11 . The food package of  claim 1 , in which the elongate valve provides a sufficient closing force to maintain a vacuum of at least about −90 kPa, at a low temperature about −20 C to about −60 C for about one year.