Dual state food packaging

• US 5,348,752 A
• Filed: 05/20/1993
• Issued: 09/20/1994
• Est. Priority Date: 05/20/1993
• Status: Expired due to Term

• Current Assignee: Bakery Holdings, LLC
• Original Assignee: World Class Packaging Systems Incorporated
• Inventors: Gorlich, Michael P.
• Primary Examiner(s): WEINSTEIN, STEVEN L
• Application Number:
  US08/064,700
• Time in Patent Office: 488 Days
• Field of Search: 426/124, 426/118, 426/112, 426/129, 426/127, 426/396, 229/125.35, 229/123.1, 220/256, 220/257, 220/258, 53/449, 53/478, 53/329.5, 53/254, 206/484.1, 206/439
• US Class Current: 426/129
• CPC Class Codes: B65B 25/067 combined with its conservation
• CPC Class Codes: B65B 31/028 closed by a lid sealed to the upper rim of the container, e.g. tray-like container
• CPC Class Codes: B65B 7/168 by applying and securing double closures
• CPC Class Codes: B65D 2251/0031 Membrane
• CPC Class Codes: B65D 2251/0093 Membrane
• CPC Class Codes: B65D 2565/388 Materials used for their gas-permeability
• CPC Class Codes: B65D 51/185 the outer closure being a foil membrane
• CPC Class Codes: B65D 77/2024 the cover being welded or adhered to the container
• CPC Class Codes: B65D 77/30 Opening or contents-removing devices added or incorporated during filling or closing of containers B65D77/20 takes precedence
• CPC Class Codes: B65D 81/2076 in an at least partially rigid container
• CPC Class Codes: B65D 81/245 Internal membrane, floating cover or the like isolating the contents from the ambient atmosphere loosely-attached linings B65D25/16; dispensing pistons B65D83/0005; flexible bags for expelling the contents B65D83/0055
• CPC Class Codes: B65D 81/3294 Thermoformed trays or the like with a plurality of recesses for different materials located in different recesses

Abstract

Dual state packaging may be implemented with a tray having a peripheral flange adapted to receive a pair of membranes to enclose the tray. The lower membrane is the more permeable of the two. It may be attached to a first surface of the flange. The second membrane is attached to a second outer surface of the flange without direct connection except through the tray to the more permeable membrane. The two connection surfaces may be separated by a depression to facilitate the cutting away of the material forming the more permeable membrane in a continuous manufacturing process. With the less permeable membrane in place, a desired gaseous environment may be maintained within the package. When it is desired to change the gaseous environment, the upper less permeable membrane may be peeled away allowing gaseous communication through the lower more permeable membrane.

Claims

1. A package for selectively permitting gaseous communication with the atmosphere comprising:

a tray having sidewalls defining a cavity;

a product to be exposed to varying gaseous conditions contained in said cavity of said tray;

said tray comprising an outwardly directed flange extending around the perimeter of said tray;

said flange comprising an inner flange portion adjacent said sidewalls and an outer flange portion that is further away from said sidewalls than said inner flange portion;

said flange further comprising a depressed portion between said inner and outer flange portions, said depressed portion extending downwardly from and connected to both said inner and outer flange portions to form a depression in said flange, said inner and outer flange portions and said depression extending completely around the perimeter of said tray;

said package further comprising an upper membrane and a lower membrane;

said lower membrane being more gas permeable than said upper membrane;

said lower membrane extending entirely across the cavity of said tray and secured to said inner flange portion completely around its perimeter to enclose said product in said tray cavity;

said upper membrane, being less gas permeable than said lower membrane, completely coveting said lower membrane but being unsecured to said lower membrane;

said upper membrane being secured to said outer flange portion to completely seal and enclose the lower membrane and the product in the tray cavity;

said lower membrane not extending outwardly beyond said depression and onto said outer flange portion; and

said lower membrane being obtained from a larger web of material, and said depression is designed to facilitate the cutting of said lower membrane from said web after said web is placed on said tray during manufacture of said package.

2. The package of claim 1 wherein the product is red meat.

3. The package of claim 2 wherein said lower membrane is sufficiently permeable to oxygen to permit blooming of said meat product contained within the package.

4. The package of claim 3 wherein said upper membrane is substantially impermeable to oxygen.

5. The package of claim 1 wherein said upper membrane of said package maintains an atmosphere in said cavity having a substantially lower concentration of oxygen than that found in the ambient atmosphere.

6. The package of claim 1 wherein said depression is integrally formed in said tray.

7. The package of claim 1 wherein said tray is formed of relatively rigid plastic.

8. The package of claim 1 wherein said upper and lower membranes are composed at least in part of plastic.

9. The package of claim 1 wherein said upper membrane is peelable from said tray.