MOISTURE ABSORBING DEVICE FOR FOOD PACKAGING

Abstract

There is disclosed a vapor absorbing device for capturing moisture released by fresh food stored in an unvented and closed container. The device may comprise a vapor-permeable carrier fabric having a food side for facing the fresh food and a container side opposite the food side. An absorbent matrix having a matrix thickness may layer across the container side of the carrier. The matrix may comprise a fibrous substrate and a food-safe hydrogel infusing the substrate. The hydrogel may include a water soluble polymer. The device may be configured to dispose a container side of the matrix against an interior surface of the food container. And, the matrix may be configured to capture the moisture at a predetermined vapor absorption rate.

Claims

1. A vapor absorbing device for capturing moisture released by fresh food stored in an unvented container, the device comprising: a vapor-permeable carrier fabric having a food side for facing the fresh food and a container side opposite the food side; an absorbent matrix having a matrix thickness and layering across the container side of the carrier, the matrix comprising: 1) a fibrous substrate; and 2) a food-safe hydrogel infusing the substrate and including a water soluble polymer; and where the device is configured to dispose a container side of the matrix against an interior surface of the food container, and where the device is calibrated to capture the moisture at a predetermined vapor absorption rate.

2. The device of claim 1, wherein: the fibrous substrate is formed of a non-woven fabric.

3. The device of claim 1, wherein: the fibrous substrate is formed of viscose polyester (polyviscose).

4. The device of claim 1, wherein: the water soluble polymer is polyvinyl alcohol (PVOH) or a salt thereof.

5. The device of claim 4, wherein: an upper limit on the PVOH concentration is around 2% by weight.

6. The device of claim 1, further comprising: a deliquescent embedded in the hydrogel for enhancing the predetermined vapor absorption rate of the device.

7. The device of claim 6, wherein: the matrix thickness and a concentration of the deliquescent are adjusted together in approximate direct proportion for optimizing the predetermined absorption rate operative during a freshness period over which the moisture capturing is intended to occur.

8. The device of claim 6, wherein: the deliquescent is calcium chloride (CaCl.sub.2)).

9. The device of claim 7, wherein: the concentration of the CaCl.sub.2) is less than around 20% by weight.

10. The device of claim 1, further comprising: a matrix mass of the absorbent matrix for establishing the predetermined vapor absorption rate is between approximately 30 and approximately 150 grams per quart of a container volume, depending on a food exudation.

11. The device of claim 1, further comprising: an activation liner disposed on the carrier food-facing side for sealing the absorbent matrix from moisture prior to use.

12. The device of claim 1, further comprising: an attaching layer disposable on the matrix container side for attaching the device to the interior surface of the food container.

13. The device of claim 12, wherein: the attaching layer is a pressure sensitive adhesive.

14. The device of claim 1, further comprising: a barrier cloth layering across an opposite side of the hydrogel matrix and edge-sealed to the carrier fabric along their respective perimeters to form a sachet isolating the absorbent matrix from the fresh food.

15. The device of claim 1, further comprising: a fluted, corrugated, or porous ventilation layer mountable between the absorbent matrix and the container interior, the ventilation for increasing a surface area of the matrix.

16. A temporary container for keeping fresh food crispy or dry during transportation and storage over a freshness period, the temporary container comprising: a lid closable to a tray for substantially forming a sealed container; a vapor-permeable carrier sheet having a food side for facing the fresh food and a container side opposite the food side; an absorbent patch having a patch thickness and disposed on the container side of the carrier sheet, the patch comprising: 1) a non-woven hydrophilic fabric; and 2) a hydrogel infusing the non-woven fabric and including a water soluble polymer; and where the patch is configured to mount its container side to an interior surface of the lid or the tray, and where the temporary container is configured to capture the moisture at a predetermined vapor absorption rate.

17. The container of claim 16, further comprising: a deliquescent embedded in the hydrogel for enhancing the predetermined vapor absorption rate of the container.

18. The container of claim 17, wherein: the soluble polymer is a polyvinyl alcohol having a matrix concentration of between about 0.2% and about 2%, and wherein the deliquescent is CaCl.sub.2) having a matrix concentration of between about 1% and about 10%.

19. A method for packaging fresh food to stay crispy or dry during transportation and storage over a freshness period, the method comprising: providing a closable container comprising a lid and a tray for substantially sealing the container; applying a hydrophilic patch to an interior surface of the lid or the tray, the patch comprising: 1) a vapor-permeable carrier fabric having a food side for facing the fresh food and a container side facing the lid or the tray; 2) a hydrogel matrix layered across the container side of the carrier and comprising a polyviscose substrate infused with polyvinyl alcohol (PVOH) and particles of calcium chloride (CaCl.sub.2)); and selecting the patch having a predetermined vapor absorption rate calibrated to match the freshness period.

20. The device of claim 19, wherein: the patch, when selected for the lid of a hot food-to-go container, is calibrated to a hot freshness period of between about 15 minutes and an hour, and where the patch, when selected for the tray of a refrigeration container, is calibrated to a cold freshness period of between about two days and about two weeks.

21. The device of claim 19, wherein: the selected patch was calibrated by adjusting one or more of the following parameters: a size of the patch, a concentration of the PVOH, a concentration of the CaCl.sub.2), and a permeability of the carrier fabric.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Non-limiting and non-exhaustive embodiments of the present invention, including the preferred embodiment, are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. Illustrative embodiments of the invention are illustrated in the drawings, in which:

[0011] FIG. 1 illustrates a cross-sectional view of a moisture absorbing device with a ventilation layer, in accordance with an embodiment of the present disclosure.

[0012] FIG. 2 illustrates a cross-sectional view of the moisture absorbing device without the carrier liner, in accordance with an embodiment of the present disclosure.

[0013] FIG. 3 illustrates a perspective view of peeling off the carrier liner for the moisture absorbing device, in accordance with an embodiment of the present disclosure.

[0014] FIG. 4 illustrates a perspective view of the moisture absorbing device of FIG. 3 after attachment to an open food container, in accordance with an embodiment of the present disclosure.

[0015] FIG. 5 illustrates a cross-sectional view of the moisture absorbing device attached to the closed food container, in accordance with an embodiment of the present disclosure.

[0016] FIG. 6 illustrates a cross-sectional view of a moisture absorbing device having deliquescent particles in an absorbent matrix, in accordance with an embodiment of the present disclosure.

[0017] FIG. 7 illustrates a cross-sectional view of the moisture absorbing device of FIG. 6 mounted in a container for hot food, in accordance with an embodiment of the present disclosure.

[0018] FIG. 8 illustrates a cross-sectional view of the moisture absorbing device of FIG. 6 mounted in a container for cold food, in accordance with an embodiment of the present disclosure.

[0019] FIG. 9 illustrates a cross-sectional view of the moisture absorbing device of FIG. 8 with a ventilation layer, in accordance with an embodiment of the present disclosure.

[0020] FIG. 10 illustrates a perspective view of peeling off the activating carrier liner for the moisture absorbing device in FIG. 6, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0021] Embodiments are described more fully below in sufficient detail to enable those skilled in the art to practice the system and method. However, embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense.

[0022] When elements are referred to as being connected or coupled, the elements can be directly connected or coupled together or one or more intervening elements may also be present. In contrast, when elements are referred to as being directly connected or directly coupled, there are no intervening elements present.

[0023] The following 26 or so paragraphs are a copy of the parent Summary which assert the original claims; reference numbers have been added for clarity with no change in verbiage. Following this parent Summary is the Detailed Description from the parent application providing an expansion of the Summary. Following that original Description is new material describing FIGS. 6-10.

[0024] Referring now to FIGS. 1-5, in various embodiments, a moisture absorbing device 100 for reducing moisture inside of a food container C during use is provided. The device 100 can comprise: a carrier layer 110 having a bottom surface 109 and a top surface 111 separated from the bottom surface 109 by a first spaced distance, wherein the first spaced distance defines a thickness of the carrier layer 110; and an absorbent layer 115 having a bottom surface 114 in continuous contact with the top surface 111 of the carrier layer 110, and a top surface 111 separated from the bottom surface 109 by a second spaced distance, wherein the second spaced distance defines a thickness of the absorbent layer 115; and wherein the absorbent layer 115 comprises a hydrogel composition.

[0025] In some embodiments, the absorbent layer 115 further comprises an adhesive 125.

[0026] In some embodiments, the moisture absorbing device 100 further comprises a ventilation layer 120 having a bottom surface in non-continuous contact with the top surface 116 of the absorbent layer 115 and a top surface separated by a third spaced distance from the bottom surface.

[0027] In some embodiments, the moisture absorbing device 100 can further comprise an attaching layer 125 having a bottom surface in non-continuous contact with the top surface of the ventilation layer 120 and a top surface separated by a fourth spaced distance from the bottom surface, wherein the fourth spaced distance defines a thickness of the attaching layer; wherein the attaching layer 125 comprises an adhesive material on the top surface 126 for attaching the device to a surface D of the food container C.

[0028] In some embodiments, the moisture absorbing device 100 can further comprise a removable sheet covering the top surface 126 of the attaching layer 125, wherein the adhesive material on the top surface 126 is exposed upon removal of the removeable sheet.

[0029] In some embodiments, the moisture absorbing device 100 can further comprise a removeable liner 105 covering the bottom surface 109 of the carrier layer 110, wherein the bottom surface 109 of the carrier layer 110 is exposed to the moisture inside of the food container C upon removal of the removeable liner 105.

[0030] In some embodiments, the hydrogel composition can comprise a polyacrylic acid, polyacrylamide, polyvinyl alcohol, ethylene, maleic anhydride copolymers, polyvinyl ethers, methyl cellulose, carboxymethyl cellulose, hydroxypropylcellulose, polyvinylmorpholinone, or a salt thereof.

[0031] In some embodiments, the hydrogel composition can comprise a polyacrylic acid or an alkali metal salt of a polyacrylic acid.

[0032] In some embodiments, the hydrogel composition can comprise a polyvinyl alcohol or an alkali metal salt of a polyvinyl alcohol.

[0033] In some embodiments, the hydrogel composition is present in an amount from about 5 to about 98 weight percent based on total weight of the absorbent layer.

[0034] In some embodiments, the hydrogel composition can absorb at least 10 times its weight in moisture.

[0035] In some embodiments, the ventilation layer 120 comprises a fluted structure having a first plurality of open channels 119 (a-c) extending along the top surface 116 of the absorbent layer 115.

[0036] In some embodiments, the ventilation layer 120 comprises a fluted structure having a first plurality of open channels 119 (a-c) extending along the top surface 116 of the absorbent layer 115 and a second plurality of open channels 121 (a-c) extending along the bottom surface 124 of the attaching layer 125.

[0037] In some embodiments, the ventilation layer 120 is comprised of corrugated paper, paperboard, cardboard, and processed into a fluted, wavy, convoluted, accordion, or honeycomb design.

[0038] In some embodiments, the carrier layer 110 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 110 is configured to allow moisture-containing air from the food container C to reach the absorbent layer 115.

[0039] In some embodiments, the removable sheet is comprised of an acrylic-based pressure-sensitive adhesive.

[0040] In various embodiments, a method of reducing the moisture inside of a food container C containing food F is provided. In some embodiments, the food F is cooked food having a temperature above room temperature. In some embodiments, the method comprises: adding the food F to a first surface B of the food container C; attaching a moisture absorbing device 100 to a second surface D of the food container C, the device 100 comprising: a carrier layer 110 having a bottom surface 109 and a top surface 111 separated from the bottom surface 109 by a first spaced distance, wherein the first spaced distance defines a thickness of the carrier layer; and an absorbent layer 115 having a bottom surface 114 in continuous contact with the top surface 111 of the carrier layer 110, and a top surface 116 separated from the bottom surface 114 by a second spaced distance, wherein the second spaced distance defines a thickness of the absorbent layer 115; wherein the absorbent layer 115 comprises a hydrogel composition; and closing the food container C.

[0041] In some embodiments, the absorbent layer 115 in the device 100 of the method further comprises an adhesive; and the method comprises a roll-to-roll assembly of the device 100, including: providing the carrier layer 110, depositing the absorbent layer 115 onto the top surface 111 of the carrier layer; and adhering the top surface 116 of the absorbent layer 115 to an interior surface of a food container.

[0042] In some embodiments, the device 100 of the method further comprises a ventilation layer 120 having a bottom surface in non-continuous contact with the top surface 116 of the absorbent layer 115 and a top surface separated by a third spaced distance from the bottom surface.

[0043] In some embodiments, the device 100 in the method further comprises: an attaching layer 125 having a bottom surface 124 in contact with the top surface of the ventilation layer 120 and a top surface separated by a fourth spaced distance from the bottom surface, wherein the fourth spaced distance defines a thickness of the attaching layer 125; wherein the attaching layer 125 comprises an adhesive material on the top surface 126 for attaching the device 100 to a surface of the food container C; and a removable sheet covering the top surface of the attaching layer 125, wherein the adhesive material on the top surface is exposed upon removal of the removeable sheet.

[0044] In some embodiments, the method further comprises, prior to attaching the moisture absorbing device 100 to the second surface of the food container C, removing the removable sheet from the attaching layer 125.

[0045] In some embodiments, the device 100 in the method further comprises a removeable liner 105 covering the bottom surface 109 of the carrier layer 110, wherein the bottom surface 109 of the carrier layer 110 is exposed to the moisture inside of the food container C upon removal of the removeable liner 105.

[0046] In some embodiments, the method further comprises, prior to closing the food container C, removing the removeable liner 105 from the carrier layer 110.

[0047] In various embodiments, a method of preparing a moisture absorbing device 100, comprising: a carrier layer 110 having a bottom surface 109 and a top surface 111 separated from the bottom surface 109 by a first spaced distance, wherein the first spaced distance defines a thickness of the carrier layer 110; and an absorbent layer 115 having a bottom surface 114 in continuous contact with the top surface 111 of the carrier layer 110, and a top surface 116 separated from the bottom surface 114 by a second spaced distance, wherein the second spaced distance defines a thickness of the absorbent layer 115; and wherein the absorbent layer 115 comprises a hydrogel composition.

[0048] In some embodiments, the absorbent layer 115 in the device 100 of the method further comprises an adhesive; and the method comprises: a roll-to-roll assembly of the device 100, including: providing the carrier layer 110, depositing the absorbent layer 115 onto the top surface 111 of the carrier layer 110; and joining the top surface 116 of the absorbent layer 115 to an interior surface of a food container C.

[0049] In some embodiments, the device 100 of the method further comprises a ventilation layer 120 having a bottom surface in non-continuous contact with the top surface 116 of the absorbent layer 115 and a top surface separated by a third spaced distance from the bottom surface; and an attaching layer 125 having a bottom surface 124 in non-continuous contact with the top surface of the ventilation layer 120 and a top surface 126 separated by a fourth spaced distance from the bottom surface, wherein the fourth spaced distance defines a thickness of the attaching layer 125; wherein the attaching layer 125 comprises an adhesive material on the top surface 126 for attaching the device 100 to a surface of the food container C; and the method comprising a roll-to-roll assembly of the device 100, including: providing the carrier layer 110, depositing the absorbent layer 115 onto the top surface 111 of the carrier layer 110; adhering the bottom surface of the ventilation layer 120 to the top surface 116 of the absorbent layer 115; adhering the bottom surface 124 of the attaching layer 125 to the top surface of the ventilation layer 120; and adhering the top surface 126 of the attaching layer 125 to an interior surface of a food container C.

[0050] Referring still to FIGS. 1-5, the next 31 or so paragraphs are the Detailed Description from the parent application, without modification.

[0051] In various embodiments, a moisture absorbing device and method of using the device to reduce the moisture present inside of a food container are provided. The device is configured to be attached to various food containers, including disposable food containers. The disposable food containers can be paper, paperboard, corrugated fiberboard, plastic- or wax-coated paper, wood, thermoforming (plastics), molded pulp, chip board, or other materials. Examples of disposable food containers include corrugated cardboard pizza boxes, foam (e.g., Styrofoam) clamshells, paperboard clamshells, insulated paper containers, or other existing food containers currently available for packaging food for delivery. In some embodiments, the disposable food container is produced using in-line machinery.

[0052] In various embodiments, as shown in FIGS. 1-5, the moisture absorbing device 100 is configured for coupling to the food container C. In some embodiments, consistent with the cross-sectional views in FIGS. 1 and 2, the moisture absorbing device 100 comprises a multilayer internal construction, in which adjacent layers of a plurality of layers are sequentially positioned, one on top of the next, such that the device extends from the bottom surface 104 to the top surface 126 of the device. In this context, the term top surface refers to the surface of the moisture absorbing device 100 that is configured to contact and attach to the upper interior surface D of the food container C, and the term bottom surface refers to the surface of the moisture absorbing device 100 that faces the lower interior surface B of the food container C and the food F. In various embodiments, the multilayer construction of the moisture absorbing device 100 includes the carrier layer 110 and the absorbent layer 115. In some embodiments, the multilayer construction of the moisture absorbing device 100 includes the carrier layer 110, the absorbent layer 115, and the ventilation layer 120. In some embodiments, the moisture absorbing device 100 includes further layers.

[0053] The moisture absorbing device 100 can have any suitable three-dimensional shape, including, for example, shapes that are generally cuboid, rectangular cuboid, cylinder, hemisphere, prism, etc. In such embodiments, the moisture absorbing device 100 has a predetermined height H, as shown in FIG. 2. In this context, the term generally is used as a qualifier because certain portions of the device may not fit within the specific shape. For example, if the device is packaged as a pouch, then it could have a crimped boundary portion; and, therefore, the majority (e.g., 75%, 80%, 85%, 90%, 95%, 98%, etc.) of the device would have the stated shape, but the edges in the boundary portion could be tapered and crimped to seal the pouch. In some embodiments, consistent with the perspective views in FIGS. 3 and 4, the moisture absorbing device 100 comprises a generally cuboid or rectangular cuboid shape. In such embodiments, the carrier layer 110, the absorbent layer 115, and any additional layers have a complementary generally cuboid or rectangular cuboid shape, and the ventilation layer 120 has a shape configured to fill a generally cuboid or rectangular cuboid void, as shown in FIGS. 1 and 2.

[0054] The moisture absorbing device 100 can have any suitable length L and width W. In some embodiments, the length and width are identical (e.g., square); in other embodiments, the length and width are different (e.g., rectangle). When the length and width are different, as shown in FIG. 3, the width extends laterally about the x-axis and the length extends longitudinally about the y-axis. The height extends along the z-axis. The cross-sectional views in FIGS. 1 and 2 show the width W. In some embodiments, the length L and width W can span from about 1 cm to about 50 cm, or from about 2 cm to about 40 cm, or from about 3 cm to about 30 cm, or from about 4 cm to about 20 cm, or from about 5 cm to about 10 cm, etc.

[0055] In some embodiments, the moisture absorbing device 100 has a substantially flat and planar shape so that it can be applied in a manner similar to how a label would be attached to a food container. For example, in some embodiments, the moisture absorbing device 100 can be rolled onto the food container C during a manufacturing step in, for example, a roll-to-roll fabrication process. In such embodiments, the moisture absorbing device 100 has a predetermined height H, as shown in FIG. 2, but the height can span a short distance (e.g., 1-10 mm, including 2 mm, 3 mm, 4 mm, etc.) and therefore appear to be a flat or coplanar device from certain perspectives. In various embodiments, the height H of the moisture absorbing device 100, along with the internal space of the food container, will determine the distance between food contained inside the food container and the moisture absorbing device 100. During use, the distance between the device and the food is preferably at least 1 cm, or in a range of between about 1 cm and about 10 cm, including any subranges, such as between about 2 cm and about 5 cm, etc. A predetermined distance between the device and the food allows the moisture released from the food (e.g., steam) to be efficiently captured by the device.

[0056] In some embodiments, during use, the carrier layer 110 comprises a bottom surface 109 that faces the food F located on the lower interior surface B of the food container C, and a top surface 111 that faces the upper interior surface D of the food container C, as shown in FIGS. 1-5. In some embodiments, the carrier layer 110 provides a physical barrier between the absorbent layer 115 and the food F. In such embodiments, the carrier layer 110 separates the food F from the absorbent layer 115. In some embodiments, the carrier layer 110 is comprised of a material that can absorb one or more components of the absorbent layer 115, in addition to moisture present in the food container. In such embodiments, if one or more components in the absorbent layer 115 were to leak, the carrier layer 110 would absorb those components and prevent the same from contacting the food F.

[0057] In some embodiments, the carrier layer 110 comprises a water vapor transmission rate that is efficient enough to permit the steam S emanating from the food F, as shown in FIG. 5, to penetrate through to the absorbent layer 115. In some embodiments, the carrier layer 110 comprises a porous material, a fibrous textile, a non-woven fabric, a tight-weaved material, or a combination thereof, which permits the steam S emanating from the food F to penetrate from the atmosphere inside the food container C to the absorbent layer 115. In some embodiments, the carrier layer 110 comprises a fibrous textile, non-woven fabric, tight weaved material, porous material, or a combination thereof. In some embodiments, the fibrous textile, non-woven fabric, and/or porous material comprises one or more vents, slots, and/or channels to assist in the flow of air from the container to the absorbent layer. In some embodiments, the carrier layer 110 comprises one or more vents, slots, and/or channels to assist in the flow of air from the container to the absorbent layer 115.

[0058] In some embodiments, the carrier layer 110 comprises a top surface 111 that faces the absorbent layer 115. In some embodiments, the top surface 111 is in contact with a bottom surface 114 of the absorbent layer 115. In some embodiments, the carrier layer 110 serves as a base upon which the absorbent layer 115 may be carried, casted, and/or established on. In such embodiments, the absorbent layer 115 can be deposited on the carrier layer 110, which will carry the absorbent layer 115 during the manufacturing process. In such embodiments, the carrier layer 110 and the absorbent layer 115 are fused together through physical and/or chemical bonding. In some embodiments, the physical and/or chemical bonding is optionally facilitated, catalyzed, or created by an adhesive material.

[0059] In some embodiments, the absorbent layer 115 is positioned between the carrier layer 110 and the ventilation layer 120. In some embodiments, the absorbent layer 115 comprises one or more materials or components that are capable of absorbing moisture, whether in a liquid or gas state, or in the form of a droplet, vapor, steam, etc. The one or more absorbing materials can absorb the moisture by physical means, chemical means, or a combination thereof. Suitable absorbent materials for the absorbent layer 115 include organic materials, such as fibrous materials and polymeric materials, and inorganic materials. Organic fibrous materials include woody or non-woody pulp such as cotton, combined cotton, rayon, recycled paper, and pulp fluff. Organic polymeric materials include superabsorbent materials. In this context, a superabsorbent material refers to a water-swellable, water soluble organic or inorganic material capable, under favorable conditions, of absorbing at least about 10 times its weight, or at least about 20 times its weight, in an aqueous solution containing 0.9 weight percent sodium chloride. Suitable organic superabsorbent materials include natural materials such as guar gum, agar, gelatin, collagen, pectin and the like, and synthetic materials, such as hydrogel polymers.

[0060] In some embodiments, the absorbent layer 115 comprises a hydrogel composition that is capable of absorbing moisture, whether in a liquid or gas state, or in the form of a droplet, vapor, steam, etc. In such embodiments, the hydrogel composition can include, for example, one or more of the following: alkali metal salts of polyacrylic acids, polyacrylamides, polyvinyl alcohol, ethylene, maleic anhydride copolymers, polyvinyl ethers, cellulose, okara cellulose, methyl cellulose, carboxymethyl cellulose, hydroxypropylcellulose, polyvinylmorpholinone, and polymers and copolymers of vinyl sulfonic acid, polyacrylates, polyacrylamides, polyvinylpyrridine, and the like. Other suitable superabsorbent materials include hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, hyaluronic acid, chitosan, alginate, and isobutylene maleic anhydride polymers and mixtures thereof.

[0061] In some embodiments, the hydrogel composition comprises polymers that are crosslinked to render the materials substantially water insoluble. In such embodiments, the crosslinking may be accomplished, for example, by irradiation or by covalent, ionic, van der Waals, or hydrogen bonding. The superabsorbent materials may be in any form suitable for use in the absorbent layer 115, including, for example, particles, fibers, flakes, spheres, etc. In some embodiments, the absorbent layer 115 comprises the superabsorbent material in an amount from about 5 to about 98 weight percent based on total weight of the absorbent layer, whereby the stated range includes any intermediate endpoints and subranges (e.g., from about 10 to about 95 weight percent, about 15 to about 90 weight percent, about 20 to about 85 weight percent, etc.).

[0062] In some embodiments, the absorbent layer 115 comprises a hydrogel composition that is stable enough to be dried during the manufacturing and/or assembly process for the moisture absorbing device 100. In such embodiments, for example, the absorbent layer 115 or the moisture absorbing device 100 may be inserted into an oven to fully remove any moisture residing in the hydrogel, the absorbent layer 115, the carrier layer 110, and/or the ventilation layer 120.

[0063] In some embodiments, the absorbent layer 115 further comprises one or more absorption enhancers that increase the rate of condensation (droplet formation) and/or moisture absorption in the absorbent layer 115 or in the superabsorbent hydrogel contained therein. In some embodiments, the absorption enhancer is a salt or salt mixture. In some embodiments, the salt is calcium chloride (CaCl2)) or the like. In various embodiments, the combination of the one or more absorbing materials and the absorption enhancer allows the device to absorb and hold substantially more moisture (e.g., water) than if the absorbent layer 115 were comprised only of a fabric or a similar textile-based absorbent material.

[0064] In some embodiments, the absorbent layer 115 further comprises one or more adhesives configured to attach the moisture absorbing device 100 to an inside surface of a food container. In such embodiments, the adhesive can be a synthetic rubber-based or water-borne acrylic-based pressure-sensitive adhesive (PSA) material. In some embodiments, the adhesive is a hot-melt adhesive configured for application via a hot glue gun or the like. Existing hot-melt adhesives that can be utilized include, for example, tackifying resins, waxes, plasticizers, fugitive glues, etc.

[0065] In some embodiments, absorbent layer 115 comprises a sheet that is removably attached to and configured to cover the top surface 116. The removable sheet be any suitable material, whereby the suitability is based on its ability to be readily released from the absorbent layer 115 while allowing the absorbent layer 115 to maintain its ability to be attached to a food container. For example, in some embodiments, the absorbent layer 115 comprises an adhesive or other fastening material that can facilitate the coupling of the moisture absorbing device 100 to a food container, but the removable sheet must be non-reactive and allow the absorbent layer 115 to maintain its adhesive and fastening properties. In some embodiments, the absorbent layer 115 includes a synthetic rubber-based or water-borne acrylic-based pressure-sensitive adhesive (PSA) material.

[0066] In some embodiments, the moisture absorbing device 100 further comprises the ventilation layer 120. In such embodiments, the ventilation layer 120 is secured to the top surface 116 of the absorbent layer 115. In some embodiments, the ventilation layer 120 is in continuous contact with the top surface 116 of the absorbent layer 115. In other embodiments, the ventilation layer 120 is in non-continuous contact with the top surface 116 of the absorbent layer 115. In some embodiments, ventilation layer 120 comprises a fluted, wavy, convoluted, accordion, or honeycomb design that is designed to increase the exposed surface area of the top surface 116 of the absorbent layer 115. In some embodiments, as shown in FIGS. 1 and 2, for example, the ventilation layer 120 comprises a fluted structure. In such embodiments, the fluted structure comprises a plurality of lower channels, including channels 119 a, 119 b, 119 c, along the surface of top surface 116 of the absorbent layer 115. The plurality of lower channels provides access to the absorbent layer 115, and therefore increases the surface area of the absorbent layer 115 that is exposed to water vapors during use of the moisture absorbing device 100.

[0067] The ventilation layer 120 can be comprised of any suitable material. For example, in some embodiments, the ventilation layer 120 is corrugated paper, paperboard, cardboard, or a similar material that can be processed into a fluted, wavy, convoluted, accordion, or honeycomb design. In some embodiments, the ventilation layer 120 comprises a single layer of material, and in other embodiments, the ventilation layer 120 comprises a plurality of material layers. Single face corrugated paper, for example, generally comprises a medium layer that includes the three-dimensional design (fluted, wavy, etc.), and a liner material having flat surfaces attached to the same. In embodiments comprising a single layer of material, the medium layer of the corrugated paper can be utilized as the ventilation layer 120; i.e., without the liner layer.

[0068] In some embodiments, the moisture absorbing device 100 further comprises an attaching layer 125, as shown in FIGS. 1 and 2. In such embodiments, the attaching layer 125 comprises a top surface 126 and a bottom surface 124. In such embodiments, the attaching layer 125 is configured to attach the moisture absorbing device 100 to an inside surface of a food container. The illustrations in FIGS. 4 and 5, for example, show the moisture absorbing device 100 attached to the upper surface D of the food container C. The moisture absorbing device 100 can be attached to the food container C using any suitable means, including physical attachment and/or chemical attachment. In this context, physical attachment includes coupling the device to the container without an adhesive. For example, if the device has a rectangular shape, two or more corners thereof can be slid into slots present in a surface of the food container C.

[0069] As shown in FIG. 1, the attaching layer 125 can be coupled to the ventilation layer 120. In such embodiments, the ventilation layer 120 is positioned between the absorbent layer 115 and the attaching layer 125. In such embodiments, the fluted structure of the ventilation layer 120 comprises a plurality of upper channels, including channels 121 a, 121 b, 121 c, along the bottom surface 124 of the attaching layer 125.

[0070] In some embodiments, the attaching layer 125 comprises a sheet that is removably attached to and configured to cover the top surface 126. The removable sheet be any suitable material, whereby the suitability is based on its ability to be readily released from the attaching layer 125 while allowing the attaching layer 125 to maintain its ability to be attached to a food container. For example, in some embodiments, the attaching layer 125 comprises an adhesive or other fastening material that can facilitate the coupling of the moisture absorbing device 100 to a food container, but the removable sheet must be non-reactive and allow the attaching layer 125 to maintain its adhesive and fastening properties. In some embodiments, the attaching layer 125 includes a synthetic rubber-based or water-borne acrylic-based pressure-sensitive adhesive (PSA) material. In some embodiments, the adhesive is a hot-melt adhesive configured for application via a hot glue gun or the like. Existing hot-melt adhesives that can be utilized include, for example, tackifying resins, waxes, plasticizers, fugitive glues, etc.

[0071] In some embodiments, the moisture absorbing device 100 further comprises a removable liner 105, as shown in FIG. 1, which is adhered to and covers the bottom surface 109 of the carrier layer 110. FIG. 2 shows the moisture absorbing device 100 with the liner 105 removed and top surface 111 of the carrier layer 110 exposed. During use, as shown in the difference between FIGS. 4 and 5, the liner 105 is removed and the bottom surface 109 of the carrier layer 110 is exposed and accessible to any moisture (e.g., steam S) in the food container C, thus activating the moisture absorbing device 100. The liner 105 can be any suitable material, whereby the suitability is based on its ability to be readily released from the carrier layer 110.

[0072] During use, the moisture absorbing device described herein is configured to remove moisture from the inside space of a food container. The function of absorbing moisture in this context must be initiated quickly and last for the amount of time that is typical for food delivery or take out, which ranges about from 5 to 60 minutes, or from about 10 to 45 minutes, or from about 15 to 30 minutes. During such a time period, the moisture absorbing device functions by absorbing the moisture present in the atmosphere, which in turn results in more appetizing food (e.g., dried or fried hot foods).

[0073] The adjacent layers of the multilayer construction of the moisture absorbing device 100 can be assembled using any suitable method, including, for example, double-sided tape, glue or another liquid adhesive, or an aerosol adhesive. The moisture absorbing device 100 can be manufactured manually or mechanically. In some embodiments, for example, the moisture absorbing device 100 can be assembled in a roll-to-roll process. In some embodiments, the assembly of the moisture absorbing device 100 can be coupled to the manufacturing process of a food container. In such embodiments, the food container can be manufactured using mechanical systems and then sent to a machine that uses a roll-to-roll process to adhere the device to the food container. In the roll-to-roll process, the moisture absorbing device 100 may be applied to a food container with or without adhesive. In some embodiments, the moisture absorbing device 100 comprises an adhesive material to join the device to a food container. In other embodiments, the adhesive material is absent from the moisture absorbing device 100 and the process utilizes roll-to-roll machines that are configured to apply an adhesive layer to the device before joining it to a food container. And in further embodiments, the moisture absorbing device 100 is joined to a food container without adhesive. In such embodiments, the device is joined to the food container mechanically. For example, the lid of the food container can include slits or tabs that are configured to receive the moisture absorbing device 100.

[0074] The following examples are provided to aid in the understanding of the present disclosure, the true scope of which is set forth in the appended claims. One of skill in the art would appreciate that modifications can be made in the procedures set forth without departing from the spirit of the disclosure.

[0075] Example 1. A moisture absorbing device comprising an absorbent layer, a carrier layer, a ventilation layer, and an attaching layer, configured in a manner consistent with the device shown in FIG. 2. The absorbent layer comprises a hydrogel composition and a calcium chloride absorption enhancer. The hydrogel composition comprises an alkali metal salt of polyvinyl alcohol. The carrier layer comprises a porous fabric upon which the absorbent layer is deposited on. The device spans about 10 cm in length, about 5 cm in width, and about 3 mm in height. The device was coupled to a first food container using adhesive contained on the top surface of the attaching layer. The first food container included hot food, including French fries, that was purchased from a restaurant and then taken away. A second food container containing the same food was also purchased from the restaurant for use as a control. The second food container did not include the moisture absorbing device. The food inside of the first and second food containers was stored for approximately 30 minutes and then tested. The food contained in the first food container was deemed fresher and crispier than the food contained in the second food container. The food in the second food container was somewhat soggy. The food in the first food container was not soggy. The food in the first food container was more appetizing due to the fresh and crispy nature of the food after the approximately 30 minutes of travel time.

[0076] Example 2. A moisture absorbing device comprising a carrier layer and an absorbent layer which is a modified version of the device shown in FIG. 2, whereby the modification includes the absence of the ventilation layer and the absence of the attaching layer. In this example, the absorbent layer comprises a hydrogel composition and an adhesive material. The combination of the hydrogel and the adhesive provides a dual functionality for the absorbent layer. More specifically, the hydrogel composition is capable of absorbing moisture from the atmosphere inside of a food container having food contained therein, and the adhesive is capable of attaching the device to the food container. In this example, the top surface 116 of the adhesive layer 115 is joined directly to the inside surface D of the food container C.

[0077] A recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. As will be understood by one skilled in the art, ranges disclosed herein encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art, language such as up to, at least, greater than, less than, and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a component provided in 1-3 grams refers to the component being provided in 1, 2, or 3 grams.

[0078] As used herein, the use of examples, or exemplary language (e.g., such as), is intended to illuminate the embodiments and does not pose a limitation on the scope of the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential.

[0079] As used herein, the terms about and substantially will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, about and substantially will mean up to plus or minus 10% of the particular term.

[0080] Exemplary embodiments of the methods are described above in detail. The methods are not limited to the specific embodiments described herein, but rather, steps of the method may be utilized independently and separately from other steps described herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.

[0081] Referring now to new FIGS. 6-10, in various embodiments, new material is now disclosed. Some element names have been modified to more clearly distinguish the elements from each other while keeping the categories and reference numbers consistent with the parent application. Notations are given in the following description cross-referencing the new nomenclature with parent nomenclature.

[0082] As may be appreciated, based on the disclosure, there exists a need in the art for an inexpensive device to remove excess vapor and liquid moisture for both cold and hot temporary containers over differing periods of time. Additionally, there exists a need in the art for a means of calibrating a rate of vapor absorption over a freshness period of transporting or storing the food. Also, there exists a need in the art for a low toxicity, and preferably recyclable, method of storing large amounts of moisture in a small volume of the device.

[0083] In various embodiments, a vapor absorbing device 200 is disclosed for capturing moisture released by fresh food F stored in an unvented container C. The device 200 may comprise a vapor-permeable carrier fabric 210 having a food-facing side 209 for facing the fresh food and a container-facing side 211 opposite the food side 209. The moisture generated by the food F may include vapor, steam S, and/or water droplets 201 (condensation, FIG. 9). The food F may be freshly cooked and/or hot food (such as a pizza or deli take-out) exuding steam S at a high rate and placeable in the unvented container C for short term storage and transportation to a customer. Preferably, the device 200 may be optimized to capture excess moisture so as to maintain any crispiness, texture, and flavor of the food F over a freshness period of between about 15 minutes and an hour.

[0084] In the case of hot food F, the device 200 may be configured to attach to an upper interior surface D (or lid) of the container C, in which case the food-facing side 209 of the carrier 210 is a bottom side and the container-facing side 211 is a top side of carrier 210. The fresh food F may also be cold food or food designated for refrigeration (such as a berries or meat) and placeable in the unvented container C for longer term transportation to and storage by a customer. Preferably, the device 200 may be optimized to capture excess vapor and condensation 201 so as to moderate a humidity of an interior of the container C and keep the cold food F from sitting in moisture over a freshness period of between about two days and about 2 weeks.

[0085] In the case of cold food F, the device 200 may be configured to attach to a lower interior surface B (or tray) of the container C, in which case the food-facing side 209 of the carrier 210 is a top side and the container-facing side 211 is a bottom side of carrier 210. Vapor-permeable carrier fabric 210 may be preferably chosen for a high rate of liquid wicking, a high water vapor transmission rate (WVTR), low cost, food safety, biodegradability or recyclability, and availability as a roll good. In one embodiment, the carrier fabric 210 may be a polyester fabric. In a preferred embodiment, the carrier 210 may be a co-polyester weighted at about 3-4 ounces per square yard, and may comprise a 40/24 dull polyester plus a hydrophilic co-polyester. Sintered PTFE (Teflon) films may also be used as the carrier 210, and which may have a lower rate of liquid reversion back to the airspace in the container interior, but may cost more than polyester.

[0086] Continuing with FIGS. 6-10, in various embodiments, vapor-absorbing device 200 may further comprise an absorbent matrix 215 layering across the container side 211 of the carrier 210. The matrix layer 215 may have a thickness 217 and may generally be a planar absorbent layer capable of absorbing vapor and liquid through the permeable carrier fabric 210. The carrier fabric 210 may be a flexible, porous, and structural barrier configured to suspend or cover the absorbent matrix 215 while conveying a moderated flow of moisture from the container interior. In an alternative embodiment, the carrier fabric 210 may include perforations 212 sized and spaced to optimize a vapor absorption rate of the device 200. Another function of the carrier fabric 210 may be to promoting the wicking of vapor and liquid into the matrix 215 while protecting the food from stored moisture dripping out of a saturated absorbent matrix 215.

[0087] The absorbent matrix 215 may comprise a fibrous substrate 230 and a food-safe hydrogel 231 infusing or coating the substrate 230, the matrix 215 for capturing the moisture and keeping the fresh food F crispy or dry during transportation and storage over the freshness period. The hydrogel 231 may include a water soluble polymer for attracting moisture into the fibrous substrate 230 much faster than a mere patch of cotton or other substrate material. Beneficially, the hydrogel matrix 231, when it has absorbed water fully, may be solid like Jell-O, but not wet. The fibrous substrate 230 may be a natural or synthetic fibrous layer comprising hydrophilic fibers bonded together for rapidly absorbing and tightly holding many times it's weight in water. In a preferred embodiment, the fibrous substrate 230 may be formed of a non-woven fabric, which may be a spun-laced or hydroentangled fabric, or any fabric produced by mechanical, thermal, or chemical means.

[0088] Referring still to FIGS. 6-10, in a preferred embodiment, the fibrous substrate 230 may be formed of viscose polyester (polyviscose), viscose being a lightweight and breathable form of rayon made from cellulose. A typical thickness of the polyviscose substrate may be around (3 mm), while the overall matrix thickness 217 of the absorbent hydrogel matrix 231 containing the substrate 230 may be approximately (about 6-7 mm). Matrix thickness 217 may be increased to about 15 mm () for maximizing an absorbent capacity of the device 200. However, above 15 mm, the vapor absorption rate may decrease to an impractically slow rate.

[0089] In alternative embodiments, cotton, hemp, bamboo, or a woven fabric may be used for the fibrous substrate 230, but may have less wicking action than polyviscose. Additionally, wool may perform well as the substrate 230 but may be significantly more expensive than polyviscose.

[0090] Continuing with FIGS. 6-10, in preferred embodiments, the water soluble polymer in the hydrogel 231 may optimally be polyvinyl alcohol (PVOH) or a PVOH blend. In one embodiment, a concentration of the PVOH may be optimal at less than around 2% by weight. In a preferred embodiment, an upper limit on the PVOH concentration may be less than around 1% by weight. At concentrations above 1-2%, the vapor absorption rate may decrease to unacceptably lower matrix performance. Concentrations higher than 2%, however, may be useful to more slowly absorb moisture over an extended cold freshness period. Beneficially, at room temperature, PVOH may provide a partial barrier to moisture absorption, allowing the device to be handled prior to food storage without absorbing much humidity. And because of this barrier feature, PVOH may substantially self-calibrate across cold and hot applications by speeding up the vapor absorption rate at hot food temperatures and slowing it down by several times at cold food temperatures.

[0091] In other embodiments, derivatives and co-polymers of PVOH, such as PVOH plus polyethylene glycol (PVOH-PEG), may be useful for some applications as these derivatives and co-polymers may enable adjustments to the mechanical properties, absorption capacity, and/or the absorption rate. For example, a PVOH-PEG hydrogel may double the absorption capacity at hot food temperatures. A salt of the PVOH may also perform well, but may be less food safe and thus require sealing the device from the contained food F. Alternatively, carboxymethyl cellulose (CMC), agar, methyl cellulose, colloids, and gelatin may also formulate the hydrogel, but may not provide the needed rate control, absorption capacity, food safety, recyclability, and/or manufacturing feasibility.

[0092] Referring still to FIGS. 6-10, in various embodiments, the vapor-absorbing device 200 may be configured to dispose a container side 216 of the absorbent matrix 215 against an interior surface 202 of the food container. For hot food applications, the device 200 may be configured to mount to the upper interior surface D of the food container C. For cold food applications, the device 200 may be configured to mount to the lower interior surface B of the food container C. Given a wide range of possible container shapes and other device form factors, including non-planar form factors, the interior surface 202 of the food container C may be mountable to interior side surfaces or other non-planar surfaces of the container C.

[0093] Continuing, the device 200 may also include an attaching layer 225 disposable on the matrix container side 216 for attaching the device 200 to the interior surface 202 of the food container C. The layer 225 may have a bottom surface 224 for facing the absorbent matrix 115 and a top surface 226 for attaching to an interior surface 202 of the container C. The attaching layer 225 may be an adhesive layer, and in a preferred embodiment may be a pressure sensitive adhesive for adhering the device 200 to the container interior surface 202. The attaching layer 225 may also be a barrier cloth made of polyester cloth or another fabric for enclosing the container-side surface 216 of the matrix 215, and may further include the adhesive layer between the barrier cloth and the container interior surface 202 for adhering the barrier cloth to the container interior surface 202. The barrier cloth may be impermeable to limit moisture transit on the container-facing side of the device 200. As an alternative, the attaching layer 225 may include a mechanical means for affixing the device 200 to the container C.

[0094] Referring to FIGS. 7-8, in another embodiment, the barrier cloth 225 may be permeable and layered across the container side 216 of the hydrogel matrix 215. Further, the barrier cloth 225 may be edge-sealed 227 to the carrier fabric 210 along their respective perimeters 228 to form an absorbent sachet (not shown) isolating the absorbent matrix from the fresh food. Said sachet device 200 may be then dropped into a flexible produce bag instead of being affixed to a rigid container, for keeping food such as lettuce fresh.

[0095] The attaching layer 225 may also include a removable sheet (not shown) on a container side of the absorption device 200 and sticking to the adhesive, the sheet being removable prior to adhering the device 200 to the container C. On the other side of the vapor absorbing device 200, an activation liner 205 may be disposed on the food-facing side 209 of the carrier 210, the liner 205 for sealing the absorbent matrix 215 from moisture prior to use and presenting a liner bottom surface 204 (FIG. 10).

[0096] Returning to FIGS. 6-10, in various embodiments, the vapor absorbing device 200 may be configured to capture the moisture at a predetermined vapor absorption rate in order to support the freshness period over which the moisture capturing is intended to occur. Significant differences in the absorption rate may be necessary in order to accommodate one or more of the following: 1) the differences in a rate of moisture production between foods that are cold versus foods that are hot, 2) differences in the length of the freshness period over which the moisture capturing is intended to occur, and 3) the exudation rate of different types of foods (e.g. meat vs. fruit vs. bread).

[0097] One parameter with which to calibrate the vapor absorption rate may be the choice of water soluble polymer (e.g. PVOH vs. PVOH-PEG). And, as mentioned above, PVOH may substantially self-calibrate across cold and hot applications by speeding up the vapor absorption rate at hot food temperatures. Also, varying the concentration of the PVOH soluble polymer from say 0.2% and 2% may effect a several fold shift in the absorption rate. Additionally, varying a permeability of the carrier fabric 210, including the disposition of carrier perforations 212, may modulate the vapor absorption rate of the device 200. Additional parameters for predetermining the absorption rate of the device 200 will be disclosed below.

[0098] Continuing, in various embodiments, a deliquescent 232 may be embedded in, or mixed with, the hydrogel 231 for enhancing the predetermined vapor absorption rate of the device 200. The deliquescent 232 may exist as solid particles which absorb water and eventually dissolve; they may direct airborne vapor to condense on and be absorbed by the hydrogel 231. The deliquescent 232 included in the hydrogel 231 might be potassium chloride, magnesium chloride, zinc chloride, or lithium chloride. However, based on food safety, cost, and availability, calcium chloride (CaCl2) may be a preferred embodiment for the deliquescent 232, and a matrix concentration of around 5% to around 20% may be used, and, in at least some embodiments, a matrix concentration of around 7% by weight may be optimal. Additionally, varying the matrix concentration of CaCl.sub.2) between about 1% and about 10% may provide a useful operating range for the predetermined rate of vapor absorption. Beneficially, the rate of moisture absorption of CaCl2 may increase above 25 C.

[0099] Prototype testing may suggest that a common matrix 215 construction and PVOH and CaCl.sub.2) concentrations, with minor modifications, perform well for both the hot food applications (and correspondingly short freshness period) and the cold food applications (and correspondingly long freshness period). The matrix thickness 217 and a concentration of the deliquescent 232 may be adjusted together in direct approximate proportion to optimize the predetermined rate of vapor absorption. A capacity of moisture absorption may also be optimized and scaled to accommodate large food containers (packages) and small food containers C. There may be a roughly linear relationship between an area of the planar device 200 and the amount (capacity) of total moisture that can be removed from the enclosed container C.

[0100] Large food containers C with larger amounts of food may generally require a larger surface area in the absorbent matrix 215. For example, a small device 200 absorbent patch may be approximately 55 in size. A medium sized patch may be approximately 88 in size. And a large patch may measure approximately 1111. Prototype testing may suggest that a thick device pad 200 having a matrix mass of between approximately 30 grams and approximately 150 grams per quart of a container volume may establish an effective vapor absorption rate, depending on a rate of food exudation. More particularly, the matrix mass may be between about 60 and 100 grams for a one quart refrigeration container C, and may be between about 50 and 120 grams for a one quart hot food-to-go container C.

[0101] Referring especially to FIG. 9, in an embodiment, the vapor absorption device 200 may include a fluted, corrugated, or porous ventilation layer 220 mountable between the container side 216 of the absorbent matrix 215 and the container interior 202 or lower interior surface (tray bottom) B. The ventilation 220 may increase a surface area of the absorbent matrix 215, and may also increase a volume of moisture storable should the matrix 215 reach capacity due to excessive air flow into the refrigeration container C (for cold food F). The attaching layer 225 (not shown) may be included between the ventilation layer 220 and the interior surface 202 of the container C for facilitating attachment.

[0102] In another embodiment, referring to FIGS. 7-9, a temporary vapor-absorbing container C may be provided for keeping fresh food crispy or dry during transportation and storage over a freshness period. The container C may include a lid closable to a tray for substantially forming a sealed container. The vapor-absorbing container may further comprise a permeable carrier sheet 210 and an absorbent patch 215 having a patch thickness 217 and disposed on the container-facing side 211 of the carrier sheet 210. The patch 215 may comprise a non-woven hydrophilic fabric 230 and a hydrogel 231 infusing the fabric 230. The patch 215 may be configured to mount its container side 216 to an interior surface 202 of the lid or the tray. The patch 215 may be selected from two or more calibrated patches to match the required freshness period to a predetermined vapor absorption rate.

[0103] Although the above embodiments have been described in language that is specific to certain structures, elements, compositions, and methodological steps, it is to be understood that the technology defined in the appended claims is not necessarily limited to the specific structures, elements, compositions and/or steps described. Rather, the specific aspects and steps are described as forms of implementing the claimed technology. Since many embodiments of the technology can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.