Moisture Absorbing Device for Food Packaging

This patent application is a continuation-in-part of pending prior U.S. patent application Ser. No. 17/664,623, filed on May 23, 2022 by James Nomoto for MOISTURE ABSORBING DEVICE FOR FOOD PACKAGING, which in turn claims the benefit under 35 U.S.C. 119 (e) of U.S. Provisional Patent Application Ser. No. 63/191,876, filed on May 21, 2021 by James Nomoto for SELECTIVE MOISTURE ABSORBER USEFUL FOR MAINTAINING FOOD QUALITY DURING TRANSPORT THEREOF. The above-identified patent applications are hereby incorporated herein by reference.

When freshly cooked food is packaged for delivery or take-home, its texture and flavor may degrade during a short delivery period because of steam condensing on the package lid. In particular, crispy food like French fries may become soggy. In one solution, a pad of cotton or other absorbent material is adhered to the lid. However, the amount of moisture retainable by the pad may be limited, and excess moisture may drip back onto the food. Other solutions employ a balsa wood platform, spacers, or several absorbent cylindrical rolls. Unfortunately, these solutions may occupy a large volume or be unduly complicated.

Still another approach provides a corrugated cardboard tray surfaced on one side with impermeable lacquer and possibly hydrogel for absorbing meat and other juices. However, toxins in the hydrogel may mix with the food, and there is lacking a closed container solution. Another solution applies superabsorbent materials to thermoplastic fibers (polypropylene and/or polyethylene) for odor absorption in a drawer, but fails to address vapor absorption in a hot food situation, nor to describe a barrier protecting the food.

Containers of fresh cold foods, such as berries or microgreens, may form droplets of condensation on the interior surfaces of the container, which then pool at the bottom of the container tray and hasten disintegration. Existing solutions prescribe absorbent pads which soak up liquids but do little to reduce humidity in the container. Also, there is lacking in the art a prescription for regulating a rate of absorption.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter.

In various embodiments, there is disclosed a vapor absorbing device for capturing moisture released by fresh food stored in an unvented 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 may have a matrix thickness and may layer across the container side of the carrier. The matrix may comprise a fibrous substrate and a food-safe hydrogel infusing the substrate, which 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. The device may also be calibrated to capture the moisture at a predetermined vapor absorption rate.

In another embodiment, there is disclosed a temporary container for keeping fresh food crispy or dry during transportation and storage over a freshness period. The temporary container may comprise a lid closable to a tray for substantially forming a sealed container. The container may include 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 may be disposed on the container side of the carrier sheet. The patch may comprise a non-woven hydrophilic fabric and a hydrogel infusing the non-woven fabric. The hydrogel may include a water soluble polymer. The patch may be configured to mount its container side to an interior surface of the lid or the tray. And, the temporary container may be configured to capture the moisture at a predetermined vapor absorption rate.

In a comparable method, a closable container may be provided comprising a lid and a tray for substantially sealing the container, and may further comprise applying a hydrophilic patch to an interior surface of the lid or the tray. The patch may include a vapor-permeable carrier fabric having a food side for facing the fresh food and a container side facing the lid or the tray. The patch may also include a hydrogel matrix layered across the container side of the carrier and comprising a polyviscose substrate. The method may further include infusing the hydrogel matrix with polyvinyl alcohol (PVOH) and particles of calcium chloride (CaCl)), and selecting the patch having a predetermined vapor absorption rate calibrated to match the freshness period.

Additional objects, advantages and novel features of the technology will be set forth in part in the description which follows, and in part will become more apparent to those skilled in the art upon examination of the following, or may be learned from practice of the technology.

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.

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.

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.

Referring now to, in various embodiments, a moisture absorbing devicefor reducing moisture inside of a food container C during use is provided. The devicecan comprise: a carrier layerhaving a bottom surfaceand a top surfaceseparated from the bottom surfaceby a first spaced distance, wherein the first spaced distance defines a thickness of the carrier layer; and an absorbent layerhaving a bottom surfacein continuous contact with the top surfaceof the carrier layer, and a top surfaceseparated from the bottom surfaceby a second spaced distance, wherein the second spaced distance defines a thickness of the absorbent layer; and wherein the absorbent layercomprises a hydrogel composition.

In some embodiments, the absorbent layerfurther comprises an adhesive.

In some embodiments, the moisture absorbing devicefurther comprises a ventilation layerhaving a bottom surface in non-continuous contact with the top surfaceof the absorbent layerand a top surface separated by a third spaced distance from the bottom surface.

In some embodiments, the moisture absorbing devicecan further comprise an attaching layerhaving a bottom surface in non-continuous contact with the top surface of the ventilation layerand 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 layercomprises an adhesive material on the top surfacefor attaching the device to a surface D of the food container C.

In some embodiments, the moisture absorbing devicecan further comprise a removable sheet covering the top surfaceof the attaching layer, wherein the adhesive material on the top surfaceis exposed upon removal of the removeable sheet.

In some embodiments, the moisture absorbing devicecan further comprise a removeable linercovering the bottom surfaceof the carrier layer, wherein the bottom surfaceof the carrier layeris exposed to the moisture inside of the food container C upon removal of the removeable liner.

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.

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

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

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.

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

In some embodiments, the ventilation layercomprises a fluted structure having a first plurality of open channels(-) extending along the top surfaceof the absorbent layer.

In some embodiments, the ventilation layercomprises a fluted structure having a first plurality of open channels(-) extending along the top surfaceof the absorbent layerand a second plurality of open channels(-) extending along the bottom surfaceof the attaching layer.

In some embodiments, the ventilation layeris comprised of corrugated paper, paperboard, cardboard, and processed into a fluted, wavy, convoluted, accordion, or honeycomb design.

In some embodiments, the carrier layeris comprised of a porous material, a fibrous textile, a non-woven fabric, a tight-weaved material, or a combination thereof; and wherein the carrier layeris configured to allow moisture-containing air from the food container C to reach the absorbent layer.

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

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 deviceto a second surface D of the food container C, the devicecomprising: a carrier layerhaving a bottom surfaceand a top surfaceseparated from the bottom surfaceby a first spaced distance, wherein the first spaced distance defines a thickness of the carrier layer; and an absorbent layerhaving a bottom surfacein continuous contact with the top surfaceof the carrier layer, and a top surfaceseparated from the bottom surfaceby a second spaced distance, wherein the second spaced distance defines a thickness of the absorbent layer; wherein the absorbent layercomprises a hydrogel composition; and closing the food container C.

In some embodiments, the absorbent layerin the deviceof the method further comprises an adhesive; and the method comprises a roll-to-roll assembly of the device, including: providing the carrier layer, depositing the absorbent layeronto the top surfaceof the carrier layer; and adhering the top surfaceof the absorbent layerto an interior surface of a food container.

In some embodiments, the deviceof the method further comprises a ventilation layerhaving a bottom surface in non-continuous contact with the top surfaceof the absorbent layerand a top surface separated by a third spaced distance from the bottom surface.

In some embodiments, the devicein the method further comprises: an attaching layerhaving a bottom surfacein contact with the top surface of the ventilation layerand 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 layercomprises an adhesive material on the top surfacefor attaching the deviceto a surface of the food container C; and a removable sheet covering the top surface of the attaching layer, wherein the adhesive material on the top surface is exposed upon removal of the removeable sheet.

In some embodiments, the method further comprises, prior to attaching the moisture absorbing deviceto the second surface of the food container C, removing the removable sheet from the attaching layer.

In some embodiments, the devicein the method further comprises a removeable linercovering the bottom surfaceof the carrier layer, wherein the bottom surfaceof the carrier layeris exposed to the moisture inside of the food container C upon removal of the removeable liner.

In some embodiments, the method further comprises, prior to closing the food container C, removing the removeable linerfrom the carrier layer.

In various embodiments, a method of preparing a moisture absorbing device, comprising: a carrier layerhaving a bottom surfaceand a top surfaceseparated from the bottom surfaceby a first spaced distance, wherein the first spaced distance defines a thickness of the carrier layer; and an absorbent layerhaving a bottom surfacein continuous contact with the top surfaceof the carrier layer, and a top surfaceseparated from the bottom surfaceby a second spaced distance, wherein the second spaced distance defines a thickness of the absorbent layer; and wherein the absorbent layercomprises a hydrogel composition.

In some embodiments, the absorbent layerin the deviceof the method further comprises an adhesive; and the method comprises: a roll-to-roll assembly of the device, including: providing the carrier layer, depositing the absorbent layeronto the top surfaceof the carrier layer; and joining the top surfaceof the absorbent layerto an interior surface of a food container C.

In some embodiments, the deviceof the method further comprises a ventilation layerhaving a bottom surface in non-continuous contact with the top surfaceof the absorbent layerand a top surface separated by a third spaced distance from the bottom surface; and an attaching layerhaving a bottom surfacein non-continuous contact with the top surface of the ventilation layerand a top surfaceseparated by a fourth spaced distance from the bottom surface, wherein the fourth spaced distance defines a thickness of the attaching layer; wherein the attaching layercomprises an adhesive material on the top surfacefor attaching the deviceto a surface of the food container C; and the method comprising a roll-to-roll assembly of the device, including: providing the carrier layer, depositing the absorbent layeronto the top surfaceof the carrier layer; adhering the bottom surface of the ventilation layerto the top surfaceof the absorbent layer; adhering the bottom surfaceof the attaching layerto the top surface of the ventilation layer; and adhering the top surfaceof the attaching layerto an interior surface of a food container C.

Referring still to, the next 31 or so paragraphs are the Detailed Description from the parent application, without modification.

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.

In various embodiments, as shown in, the moisture absorbing deviceis configured for coupling to the food container C. In some embodiments, consistent with the cross-sectional views in, the moisture absorbing devicecomprises 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 surfaceto the top surfaceof the device. In this context, the term “top surface” refers to the surface of the moisture absorbing devicethat 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 devicethat 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 deviceincludes the carrier layerand the absorbent layer. In some embodiments, the multilayer construction of the moisture absorbing deviceincludes the carrier layer, the absorbent layer, and the ventilation layer. In some embodiments, the moisture absorbing deviceincludes further layers.

The moisture absorbing devicecan 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 devicehas a predetermined height H, as shown in. 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, the moisture absorbing devicecomprises a generally cuboid or rectangular cuboid shape. In such embodiments, the carrier layer, the absorbent layer, and any additional layers have a complementary generally cuboid or rectangular cuboid shape, and the ventilation layerhas a shape configured to fill a generally cuboid or rectangular cuboid void, as shown in.

The moisture absorbing devicecan 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, 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 inshow 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.

In some embodiments, the moisture absorbing devicehas 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 devicecan 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 devicehas a predetermined height H, as shown in, 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, 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. 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.

In some embodiments, during use, the carrier layercomprises a bottom surfacethat faces the food F located on the lower interior surface B of the food container C, and a top surfacethat faces the upper interior surface D of the food container C, as shown in. In some embodiments, the carrier layerprovides a physical barrier between the absorbent layerand the food F. In such embodiments, the carrier layerseparates the food F from the absorbent layer. In some embodiments, the carrier layeris comprised of a material that can absorb one or more components of the absorbent layer, in addition to moisture present in the food container. In such embodiments, if one or more components in the absorbent layerwere to leak, the carrier layerwould absorb those components and prevent the same from contacting the food F.

In some embodiments, the carrier layercomprises a water vapor transmission rate that is efficient enough to permit the steam S emanating from the food F, as shown in, to penetrate through to the absorbent layer. In some embodiments, the carrier layercomprises 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. In some embodiments, the carrier layercomprises 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 layercomprises 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 layercomprises a top surfacethat faces the absorbent layer. In some embodiments, the top surfaceis in contact with a bottom surfaceof the absorbent layer. In some embodiments, the carrier layerserves as a base upon which the absorbent layermay be carried, casted, and/or established on. In such embodiments, the absorbent layercan be deposited on the carrier layer, which will carry the absorbent layerduring the manufacturing process. In such embodiments, the carrier layerand the absorbent layerare 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.

In some embodiments, the absorbent layeris positioned between the carrier layerand the ventilation layer. In some embodiments, the absorbent layercomprises 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 layerinclude 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.

In some embodiments, the absorbent layercomprises 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.

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, including, for example, particles, fibers, flakes, spheres, etc. In some embodiments, the absorbent layercomprises 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.).