Moisture Absorbing Device for Food Packaging

Abstract

A moisture absorbing device, a method of preparing the device, and a method of reducing moisture inside of a food container with the device are disclosed. The device can include a carrier layer and an absorbent layer. The absorbent layer can include a hydrogel composition and, optionally, an adhesive. The device can further include a ventilation layer. The device can further include an attaching layer having an adhesive material on an exposed surface for attaching the device to the food container. The method of preparing the device can include a roll-to-roll assembly process. The method of reducing moisture inside of a food container with the device can include adding food to a first surface of the food container, attaching a moisture absorbing device to a second surface of the food container, and closing the food container.

I/We claim: 
     
         1 . A moisture absorbing device for reducing moisture inside of a food container during use, the device comprising:
 a carrier layer having a first surface and a second surface separated from the first surface by a first spaced distance, wherein the first spaced distance defines a thickness of the carrier layer; and   an absorbent layer having a third surface in continuous contact with the second surface of the carrier layer, and a fourth surface separated from the third surface by a second spaced distance, wherein the second spaced distance defines a thickness of the absorbent layer;   wherein the absorbent layer comprises a hydrogel composition.   
     
     
         2 . The moisture absorbing device of  claim 1 , wherein the absorbent layer further comprises an adhesive. 
     
     
         3 . The moisture absorbing device of  claim 1 , further comprising a ventilation layer having a fifth surface in non-continuous contact with the fourth surface of the absorbent layer and a sixth surface separated by a third spaced distance from the fifth surface. 
     
     
         4 . The moisture absorbing device of  claim 3 , further comprising an attaching layer having a seventh surface in non-continuous contact with the sixth surface of the ventilation layer and an eighth surface separated by a fourth spaced distance from the seventh surface, wherein the fourth spaced distance defines a thickness of the attaching layer;
 wherein the attaching layer comprises an adhesive material on the eighth surface for attaching the device to a surface of the food container.   
     
     
         5 . The moisture absorbing device of  claim 4 , further comprising a removable sheet covering the eighth surface of the attaching layer, wherein the adhesive material on the eight surface is exposed upon removal of the removeable sheet. 
     
     
         6 . The moisture absorbing device of  claim 1 , further comprising a removeable liner covering the first surface of the carrier layer, wherein the first surface of the carrier layer is exposed to the moisture inside of the food container upon removal of the removeable liner. 
     
     
         7 . The moisture absorbing device of  claim 1 , wherein the hydrogel composition comprises a polyacrylic acid, polyacrylamide, polyvinyl alcohol, ethylene, maleic anhydride copolymers, polyvinyl ethers, methyl cellulose, carboxymethyl cellulose, hydroxypropylcellulose, polyvinylmorpholinone, or a salt thereof. 
     
     
         8 . The moisture absorbing device of  claim 7 , wherein the hydrogel composition comprises a polyvinyl alcohol or an alkali metal salt of a polyvinyl alcohol; or
 wherein the hydrogel composition comprises a polyacrylic acid or an alkali metal salt of a polyacrylic acid.   
     
     
         9 . The moisture absorbing device of  claim 8 , wherein the hydrogel composition is present in an amount from about 5 to about 98 weight percent based on total weight of the absorbent layer. 
     
     
         10 . The moisture absorbing device of  claim 1 , wherein the ventilation layer comprises a fluted structure having a first plurality of open channels extending along the second surface of the absorbent layer. 
     
     
         11 . The moisture absorbing device of  claim 3 , wherein the ventilation layer comprises a fluted structure having a first plurality of open channels extending along the second surface of the absorbent layer and a second plurality of open channels extending along the seventh surface of the attaching layer. 
     
     
         12 . The moisture absorbing device of  claim 3 , wherein the ventilation layer is comprised of corrugated paper, paperboard, cardboard, and processed into a fluted, wavy, convoluted, accordion, or honeycomb design. 
     
     
         13 . The moisture absorbing device of  claim 1 , wherein the carrier layer is comprised of a porous material, a fibrous textile, a non-woven fabric, a tight-weaved material, or a combination thereof; and
 wherein the carrier layer is configured to allow moisture-containing air from the food container to reach the absorbent layer.   
     
     
         14 . The moisture absorbing device of  claim 5 , wherein the removable sheet is comprised of an acrylic-based pressure-sensitive adhesive. 
     
     
         15 . A method of reducing the moisture inside of a food container containing cooked food having a temperature above room temperature, comprising:
 adding the cooked food to a first surface of the food container;   attaching a moisture absorbing device to a second surface of the food container, the device comprising:   a carrier layer having a first surface and a second surface separated from the first surface by a first spaced distance, wherein the first spaced distance defines a thickness of the carrier layer; and   an absorbent layer having a third surface in continuous contact with the second surface of the carrier layer, and a fourth surface separated from the third surface by a second spaced distance, wherein the second spaced distance defines a thickness of the absorbent layer;   wherein the absorbent layer comprises a hydrogel composition; and   closing the food container.   
     
     
         16 . The method of  claim 15 , wherein the device further comprises:
 a ventilation layer having a fifth surface in non-continuous contact with the fourth surface of the absorbent layer and a sixth surface separated by a third spaced distance from the fifth surface.   
     
     
         17 . The method of  claim 16 , wherein the device further comprises:
 an attaching layer having a seventh surface in non-continuous contact with the sixth surface of the ventilation layer and an eighth surface separated by a fourth spaced distance from the seventh surface, wherein the fourth spaced distance defines a thickness of the attaching layer;   wherein the attaching layer comprises an adhesive material on the eighth surface for attaching the device to a surface of the food container; and   a removable sheet covering the eighth surface of the attaching layer, wherein the adhesive material on the eight surface is exposed upon removal of the removeable sheet.   
     
     
         18 . The method of  claim 17 , further comprising, prior to attaching the moisture absorbing device to the second surface of the food container,
 removing the removable sheet from the attaching layer.   
     
     
         19 . The method of  claim 16 , wherein the device further comprises a removeable liner covering the first surface of the carrier layer, wherein the first surface of the carrier layer is exposed to the moisture inside of the food container upon removal of the removeable liner; and
 wherein the method further comprising, prior to closing the food container, removing the removeable liner from the carrier layer.   
     
     
         20 . A method of preparing a moisture absorbing device, comprising:
 a carrier layer having a first surface and a second surface separated from the first surface by a first spaced distance, wherein the first spaced distance defines a thickness of the carrier layer;   an absorbent layer having a third surface in continuous contact with the second surface of the carrier layer, and a fourth surface separated from the third surface by a second spaced distance, wherein the second spaced distance defines a thickness of the absorbent layer;   wherein the absorbent layer comprises a hydrogel composition; and   an attaching layer having a seventh surface in non-continuous contact with the sixth surface of the ventilation layer and an eighth surface separated by a fourth spaced distance from the seventh surface, wherein the fourth spaced distance defines a thickness of the attaching layer;   wherein the attaching layer comprises an adhesive material on the eighth surface for attaching the device to a surface of the food container;   the method comprising a roll-to-roll assembly of the device, including:   providing the carrier layer,   depositing the absorbent layer onto the second surface of the carrier layer;   adhering fifth surface of the ventilation layer to the fourth surface of the absorbent layer;   adhering seventh surface of the attaching layer to the sixth surface of the ventilation layer; and   adhering the eight surface of the attaching layer to an interior surface of a food container.