Container enclosure comprising a heat transfer enclosure

Abstract

The invention refers to a container enclosure comprising a heat transfer enclosure (2), which is arranged along an exterior surface of a container wall (1) and comprises a layer zone impregnated with a hydrogel (3), which includes a cellulose derivative hydrogel, a crosslinking agent, and water. Preferably, said heat transfer enclosure (2) further comprises an outer fibrous substrate layer (4), which is arranged over said layer zone impregnated with a hydrogel (3), and is selected from a group consisting of a paper product comprising a cellulose fiber based porous structure; a woven fabric; an unwoven fabric; a cork substrate, or their composites or derivatives. The heat transfer enclosure (2) contributes to the increasing of the overall heat transfer coefficient, mainly by means of the evaporative cooling principle. Therefore, said container enclosure allows a rapid reduction of temperature of a beverage or food inside a container.

Description

"CONTAINER ENCLOSURE COMPRISING A HEAT TRANSFER ENCLOSURE"

[0001] The present invention refers to containers for beverages or foods comprising at least a layer with enhanced heat transfer properties.

[0002] Temperature control is a fundamental technical characteristic for the packaging industry of different products, such as beverages, food, or pharmaceuticals. Currently, there are several technologies that allow the maintenance of the temperature of products in cold or warm conditions, depending on the storage needs to preserve said products. These technologies are based on thermal insulating materials that allow a reduced heat transfer between the product to the exterior surrounding.Technical Problem

[0003] The patent application No. US2012190259A1 of Frost Douglas R., entitled “Evaporative cooling material” and published on July 26th, 2012, describes a sheet material for absorbing, holding, and releasing water and more specifically to a sheet material optimized for the manufacture of evaporative cooling garments.

[0004] The patent application No. US2005218535A1 of Maisotsenko Valeriyet al,entitled “Indirect evaporative cooling mechanism” and published on Mars 31st, 2005, describes an indirect evaporative cooling assembly that also operates as a heat exchanger comprising: a plurality of parallel, spaced apart, thin, nonstructural plates without the ability to retain their formed shape without support when wet, each plate having two surfaces.

[0005] The patent application No. SG10201407256SA of Chin Jia Minet al,entitled “Method of removing heat energy from an object” and published on June 29th, 2015, describes a method of removing heat energy from an electronic device, a furniture, a vehicle, a structure, a fabric, or a building component, using a hydrated hydrogel in contact with said object.

[0006] Still, there is a need to develop technical solutions that can change the temperature of a product in a short period of time, namely exploiting the principle of the evaporative cooling under negative temperatures.

[0007] In the case of goods that can be safely stored at room temperature conditions, for example above 20 ºC, but they are preferably consumed at below room temperatures conditions, for example from 0 ºC to 10 ºC, there is a consumer need to reduce the temperature of the product in a rapid way. This fact is valid for non-alcoholic beverages such as water, milk, juice, or soda, for alcoholic beverages such as beer, sidra or wine, as well as foods such fruits or late.

[0008] Therefore, there is a lack of solutions that can rapidly change the temperature of a product when placed in a refrigeration machine. Additionally, this solution must be adapted to the shape of traditional materials and / or containers used in these packages and using easily scalable and low-cost production methods, with sustainable materials, in order to guarantee the recyclability of the package.Solution to Problem

[0009] The present invention solves the problems of prior art by using a container enclosure comprising a heat transfer enclosure which includes a layer zone impregnated with a hydrogel, and wherein said layer zone impregnated with a hydrogel includes a cellulose derivative hydrogel, a crosslinking agent, and water, which allows the fast reduction of temperature in beverage or food inside the container. The invention is especially advantageous when the heat transfer enclosure is wetted and placed inside a refrigeration device at below 0 ºC conditions. Preferably, this technology is applied as a cooling enclosure around a container, then it is wetted with water and placed inside a refrigeration device, using the evaporative cooling principle at below 0 ºC conditions.

[0010] The present invention solves the problems of prior art regarding the cool down period, as it enables a faster reduction of temperature, when compared with an uncovered container and a container covered with other fibrous materials.

[0011] Moreover, in the preferred embodiments of the invention, the hydrogel is embedded in a fibrous substrate layer, which is configured to be adapted to the shape of the container, and that can easily adhere to the surface of the container when this is wetted. Moreover, the heat transfer enclosure uses cellulose-based materials, which are traditionally used in the packaging industry. These facts solve several problems of prior art, related to the familiarity of the user and the scalability of the solution. In the most preferred embodiments, the container enclosure further comprises an inner substrate layer arranged under said layer zone impregnated with a hydrogel, wherein said inner substrate layer contributes to improving the overall heat transfer coefficient.Advantageous Effects of Invention

[0012] The heat transfer enclosure (2) contributes to the increasing of the overall heat transfer coefficient, mainly by means of the evaporative cooling principle. Therefore, said container enclosure allows a rapid reduction of temperature of a beverage or food inside a container at different initial temperatures of the beverage or food, for example when the initial temperature of the beverage or food is in the range from about 40ºC to 100ºC, and it is aimed a quick cooling at room temperature. Another example concerns the placement of a container with a beverage or food in a refrigeration device at below 0ºC temperature, being desired a quick cooling as well.

[0013] In the preferred embodiments, the present invention allows a rapid reduction of temperature of the liquid inside a bottle, at least two times faster, due to a more efficient thermal conduction process between the vessel and the freezing dry air inside the refrigeration device. This technology allows the bottle temperature to reach 5 ºC in under 15 minutes, while the control experiments took over 30 minutes and a bottle with wetted paper took around 20 minutes. Also, having a cellulose-based hydrogel layer will give a fresh sensation by using the water feeling on the holder’s fingers. The container enclosure is recyclable and can be reused.

[0014] Also, the hydrogels are essential element of the container enclosure namely when hydrogels are bio-based polymers or from natural-derived materials, which are viable materials to produce a container enclosure given their abundance, low cost, sustainability, recyclability, and flexibility. Moreover, the hydrogels used in the present invention are remarkable materials for the container enclosure as they are flexible and are easily placed around the container.

[0015] With the purpose of promoting an understanding of the principles in accordance with the embodiments of the present invention, reference will be made to the embodiments illustrated in the figures and to the language used to describe the same. Anyway, it must be understood that there is no intention of limiting the scope of the present invention to the contents of the figures. Any alterations or later changes of the inventive features illustrated herein, and any additional application of the principles and embodiments of the invention shown, which would occur normally for one skilled in the art when reading this description, are considered as being within the scope of the claimed invention.Fig.1

[0016] illustrates a side view of a first configuration of a container enclosure comprising a heat transfer enclosure, which is arranged along an exterior surface of a cup wall;

[0017] illustrates a side view of a second configuration of a container enclosure comprising a heat transfer enclosure, which is arranged along an exterior surface of a cup wall;

[0018] illustrates a side view of a first configuration of a container enclosure comprising a heat transfer enclosure, which is arranged along an exterior surface of a bottle wall;

[0019] illustrates a side view of a second configuration of a container enclosure comprising a heat transfer enclosure, which is arranged along an exterior surface of a bottle wall;

[0020] illustrates a side view of a third configuration of a container enclosure comprising a heat transfer enclosure, which is arranged along an exterior surface of a bottle wall;

[0021] illustrates experimental results regarding cooling of a liquid inside a fridge at a temperature below 0 ºC;

[0022] illustrates experimental results regarding cooling of a hot liquid at room temperature;

[0023] illustrates a side view of a preferred configuration of a container enclosure comprising a heat transfer enclosure, which is arranged along an exterior surface of a bottle wall;

[0024] illustrates experimental results regarding cooling of a liquid inside a freezer at a temperature below 0 ºC;

[0025] illustrates experimental results regarding cooling of a liquid at room temperature;

[0026] illustrates experimental results of a container enclosure arranged along the exterior surface of different container materials (aluminum glass and paper).

[0027] The present invention refers to a container enclosure comprising a heat transfer enclosure (2), for being arranged along an exterior surface of a container wall (1) wherein said heat transfer enclosure (2) comprises a layer zone impregnated with a hydrogel (3); and wherein said layer zone impregnated with a hydrogel (3) includes a cellulose derivative hydrogel, a crosslinking agent, and water.

[0028] In the preferred embodiments of the invention, as illustrated in, the heat transfer enclosure (2) further comprises an outer fibrous substrate layer (4), which is arranged over said layer zone impregnated with a hydrogel (3); and wherein said outer fibrous substrate layer (4) is selected from a group consisting of a paper product comprising a cellulose fiber based porous structure; a woven fabric; an unwoven fabric; a cork substrate, or their composites or derivatives.

[0029] In other preferred embodiments of the invention, as illustrated in, the heat transfer enclosure (2) further comprises an outer fibrous substrate layer (4), which is arranged over said layer zone impregnated with a hydrogel (3); and further comprises an inner substrate layer (5) which is arranged under said layer zone impregnated with a hydrogel (3). In these preferred embodiments, the outer fibrous substrate layer (4) is selected from a group consisting of a paper product comprising a cellulose fiber based porous structure; a woven fabric; an unwoven fabric; a cork substrate, or their composites or derivatives. In these preferred embodiments, the inner substrate layer (5) is selected from at least one of the group consisting of a paper product comprising a cellulose fiber based porous structure; a woven fabric; an unwoven fabric; a cork substrate; a plastic film, for example a thin polyethylene film or a thin polypropylene film; an aluminum film; or their composites or their composites or derivatives.

[0030] This preferred embodiment can be produced by arranging said outer fibrous substrate layer (4) over said layer zone impregnated with a hydrogel (3) by means of a hydrophilic adhesive. Alternatively, the mixture of the cellulose derivative hydrogel, the crosslinking agent, and water can be embedded in the outer fibrous substrate layer (4). Furthermore, according to the embedment conditions, it can be carried out in a way that the whole fibrous substrate layer (4) is soaked by the mixture of the cellulose derivative hydrogel, the crosslinking agent, and water. Alternatively, said soaking step may be executed to allow a partial soaking of fibrous substrate layer (4), keeping its outer surface dry. This alternative embodiment has an additional advantage referred to the condition when the outer surface of the fibrous substrate layer (4) is kept dry, providing a comfortable grasp of the enclosure container by the user.

[0031] In the context of the present invention, the container enclosure comprising a heat transfer enclosure (2) for being arranged along an exterior surface of a container wall (1) comprises the heat transfer enclosure (2) for being attached to the exterior surface of a container wall (1).

[0032] As it will be fully understood by a person skilled in the art, the complete or partial soaking of the said outer fibrous substrate layer (4) is function of several variables, for example the soaking time, the drying time, or the amount of water used. Regarding the drying time, an outer fibrous substrate layer (4) soaked with a layer zone impregnated with a hydrogel (3) may be dried at room temperature during approximately two days, wherein this time can be short when carrying out the drying step in an oven, a heated dryer or a vacuum dryer.

[0033] As illustrated in, the container enclosure comprising a heat transfer enclosure (2) is arranged over a side outer surface of a beverage or food container and contributes to increase and / or control the heat transfer rate between the content of said container and the surroundings.

[0034] Without willing to be bonded by any theory whatsoever, the layer zone impregnated with a hydrogel (3) includes a cellulose derivative hydrogel, a crosslinking agent, and water, wherein the crosslinked hydrogel contributes to the increasing of the conductive heat transfer coefficient, and the water contributes to the increasing of the overall heat transfer coefficient by means of the evaporative cooling principle. As it will be further exemplified, when the content of said container is in a temperature higher than the surrounding temperature, a part of the water present in the layer zone impregnated with a hydrogel (3) evaporates and percolates through the crosslinked hydrogel and the outer fibrous substrate layer (4), promoting a cooling effect by evaporative cooling. Moreover, the evaporation of the water in the layer zone impregnated with a hydrogel (3) can also contribute to the increasing of the convective heat transfer coefficient to the environment.

[0035] As illustrated in, the container enclosure comprising a heat transfer enclosure (2) is arranged over a side outer surface of a beverage or food container and comprises a layer zone impregnated with a hydrogel (3), and an outer fibrous substrate layer (4), which is arranged over said layer zone impregnated with a hydrogel (3). The outer fibrous substrate layer (4) is connected and bonded to the layer zone impregnated with a hydrogel (3), wherein said layer zone impregnated with a hydrogel (3) is configured to be an adhesive. Alternatively, a further adhesive layer bonds a first surface of outer fibrous substrate layer (4) and a first surface of said layer zone impregnated with a hydrogel (3).

[0036] The outer fibrous substrate layer (4) contributes to the mechanical stability and integrity of the layer zone impregnated with a hydrogel (3), allowing it to properly enclosure the container according to its exterior shape.

[0037] In the preferred embodiments, the outer fibrous substrate layer (4) is a paper layer having a paper weight in the range of 20 to 140 g m-2,more preferablyin the range of 60 to 90 g m-2. In other embodiments according to the invention, the outer fibrous substrate layer (4) is a microperforated paper layer comprising a plurality of holes arranged transversally said microperforated paper layer. In these embodiments, a hole comprised in said microperforated paper layer has a diameter in the range from 0.05 mm to 3 mm, and the density of said microperforated paper layer is in the range from 0.50 to 300 pin / cm2.

[0038] Alternatively, the outer fibrous substrate layer (4) can be covered by or incorporate a cork, a cloth fabric, a cotton-based cloth, a cardboard, a microperforated paper layer, or mixtures thereof.

[0039] In the context of a container for beverages or foods, a "container" is a receptacle or vessel designed to hold and store these items. It typically comes in various shapes, sizes, and materials, such as bottles, cans, jars, boxes, or bags.

[0040] As illustrated in, the container is a cup, a teacup, a mug, or a glass cup, optionally comprising a lid (10), which is fitted to an opening (9), as it will be fully understood by a person skilled in the art.

[0041] Alternatively, as illustrated in, the container is a bottle, optionally comprising a lid (10), which is fitted to an opening (9), as it will be fully understood by a person skilled in the art.

[0042] The word food in the context of this invention includes that which can be eaten, for the purposes of feeding or hydration, including solid consistency materials, pasty or liquid, including beverages.

[0043] Preferably, the beverage served in the container is selected from the group consisting in coffee, tea, milk, chocolate milk and mixtures thereof. Even more preferably, the referred beverage or food are served hot in the respective container.

[0044] Alternatively, the beverage served in the container is selected from the group consisting in beer, soft drink, soda, water, iced tea, iced coffee, energy drink, isotonic drink, liquors, and mixtures thereof.

[0045] The container wall (1) is preferably made of at least one of the group consisting of a glass, a porcelain, a metal, a paper, a plastic or a foam. As it will be known by a person skilled in the art, any material commonly used for producing containers for foods or beverage may be used to prepare a container wall (1), for example glass, porcelain, aluminum, paper, paper lined or coated with a plastic, paper lined or coated with a wax, expanded polystyrene, polypropylene, polypropylene, or polyethylene.

[0046] In other preferred embodiments of the present invention, the heat transfer enclosure (2) comprises a bottom wall (7), which is arranged over a bottom wall of a container wall, for example a cup, as illustrated in the, or a bottle, as illustrated in the.

[0047] In other preferred embodiments of the present invention, the heat transfer enclosure (2) comprises an upper wall (8), which is arranged over a superior outer portion of a bottle, as illustrated in the. The superior outer portion of a bottle includes at least one of the group consisting of a neck zone, or a dome-shaped zone.

[0048] The heat transfer enclosure (2) is arranged over a side outer surface of a beverage or food container, wherein said arrangement can be removable or static. When the arrangement is removable, the heat transfer enclosure (2) is configured to couple the exterior surface of a container wall (1) as a removable sleeve. When the arrangement is static, the heat transfer enclosure (2) is connected and bonded to the exterior surface of a container wall (1) by means of the inherent surface tension of the water comprised in the layer zone impregnated with a hydrogel (3). Alternatively, to promote a reinforcement of the connection between the heat transfer enclosure (2) and the exterior surface of a container wall (1), a hydrophilic adhesive can be used to connect strongly both surfaces.

[0049] In other embodiments according to the present invention, the cellulose derivative hydrogel is selected from the group consisting of cellulose acetate, cellulose acetate phthalate, cellulose acetate butyrate, cellulose acetate trimellitate, hydroxypropyl methylcellulose phthalate, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethylmethyl cellulose, hydroxyethylpropyl cellulose, hydroxypropyl methylcellulose, bacterial cellulose, cellulose nanofibers, cellulose nanocrystals, microfibrillated cellulose, or their mixtures, copolymers or their composites.

[0050] In the preferred embodiments according to the invention, the layer zone impregnated with a hydrogel (3) comprises the cellulose derivative hydrogel in a mass percentage from about 0.01% to about 50.00% in relation to the overall mass of saidlayer zone impregnated with a hydrogel (3). In the most preferably embodiments, the cellulose derivative hydrogel, for example the sodium carboxymethyl cellulose, carboxymethyl cellulose, or the carboxyethyl cellulose is in a mass percentage from about 0.01% to about 10.00% in relation to the overall mass of saidlayer zone impregnated with a hydrogel (3).

[0051] In other preferred embodiments according to the invention, the layer zone impregnated with a hydrogel (3) comprises the cellulose derivative hydrogel in a concentration from about 5 g / m2to about 500 g / m2in relation to the area of saidlayer zone impregnated with a hydrogel (3). In the most preferred embodiments, when the container enclosure comprising a heat transfer enclosure (2) is used to cool a container comprising a liquid at a low temperature, the layer zone impregnated with a hydrogel (3) comprises the cellulose derivative hydrogel in a concentration from about 5 g / m2to about 50 g / m2in relation to the area of said layer zone impregnated with a hydrogel (3). In the most preferred embodiments, when the container enclosure comprising a heat transfer enclosure (2) is used to cool a container comprising a liquid at a high temperature, the layer zone impregnated with a hydrogel (3) comprises the cellulose derivative hydrogel in a concentration from about 5 g / m2to about 150 g / m2in relation to the area of said layer zone impregnated with a hydrogel (3). A liquid at a low temperature means a liquid at an initial temperature in the range from about 40ºC to about 0ºC. A liquid at a high temperature means a liquid at an initial temperature in the range from about 100ºC to about 40ºC.

[0052] Several hydrogels may be selected according to their sustainable features regarding recycling or compostability, namely hydrogels comprising cellulose-based biopolymers.

[0053] Preferably, the mass ratio between water and the cellulose derivative hydrogel in the layer zone impregnated with a hydrogel (3) is in the range from about 0.01 to about 1000, more preferably said mass ratio is in the range from 1 to 100.

[0054] The hydrogels, as described above, are formed through a chemical or physical cross-linking of individual polymer chains. The chemical crosslinking can be achieved when the polymer is combined through a chemical reaction with ionic salts composed of an anion (mono, di or trivalent) and a cation (mono, di or trivalent). Other forms of chemical cross-linking are also possible, as covalent crosslinking agents, as it will be understood by a person skilled in the art.

[0055] In the preferred embodiments of the present invention, the crosslinking agent includes at least one of the group consisting of an ionic crosslinking agent or a covalent crosslinking agent. The crosslinking agent also contributes to the mechanical stability and integrity of the layer zone impregnated with a hydrogel (3), allowing it to properly enclosure the container according to its exterior shape.

[0056] When the crosslinking agent is an ionic crosslinking agent, it is preferably selected from a group consisting of a divalent cation, or a trivalent cation, wherein said cations are preferably zinc, calcium, magnesium, nickel or copper cations, or their mixtures. In the preferred embodiments according to the present invention, the layer zone impregnated with a hydrogel (3) includes at least a salt in the hydrogel matrix, wherein said salt includes a cation selected from a group consisting of a monovalent cation, a divalent cation, or a trivalent cation, which are used as ionic-crosslinkers, wherein said cations are preferably zinc, calcium, magnesium, nickel, or copper cations. The most preferred salts employed in the present invention are zinc or calcium, which are classified as non-toxic and non-critical materials regarding environmental issues.

[0057] Preferably, the layer zone impregnated with a hydrogel (3) comprises the ionic crosslinking agent in a concentration from about 0.01 M to about 50.00 M in relation to the mass of water in said layer zone impregnated with a hydrogel (3).

[0058] When the crosslinking agent is a covalent crosslinking agent, it is preferably selected from a group consisting of epoxy resins such as epichlorohydrin; dicarboxylic acids such as citric acid, or oxalic acid; dialdehydes such as glutaraldehyde, glyoxal, or polyethylene glycol dialdehyde diethyl acetal; aldehydes such as formaldehyde; hemi acetals such as genipin; acrylamides such as N,N’-methylenebisacrylamide; telechelic poly(vinyl alcohol), boron salts such as borax, N-hydroxysuccinimide esters, divinyl compounds such as divinyl sulfone or their mixtures.

[0059] Preferably, the mass ratio betweenthecovalent crosslinking agent and the cellulose derivative hydrogel in saidlayer zone impregnated with a hydrogel (3) is in the range from about 0.01 to about 100.00.

[0060] It is also possible to add copolymers to the layer zone impregnated with a hydrogel (3), for example a polysaccharide hydrocolloid, preferably selected from a group consisting of an alginate, sodium alginate, gellan gum, carrageenan, guar gum, xanthan gum, locust bean gum, gum arabic, pectin, modified starch, their mixtures or copolymers. These copolymers are additives that can improve some mechanical properties of the layer zone impregnated with a hydrogel (3), for instance to enhance its elasticity or to improve its hygroscopicity.

[0061] Preferably, the mass ratio betweenthepolysaccharide hydrocolloid and the cellulose derivative hydrogel in saidlayer zone impregnated with a hydrogel (3) is in the range from 0.001 to 10 in the layer zone impregnated with a hydrogel (3).

[0062] Preferably, the layer zone impregnated with a hydrogel (3) comprises at least a salt selected from a group consisting of a nitrogen quaternary salt, a urea derivative salt, a salt of general formula MxAyor their mixtures; and wherein M is a cation selected from a group consisting of Na, Li, K, Be, Mg, Ca, Ba, Al, Fe+2, Fe+3; wherein A is an anion selected from a group consisting of F, Cl, Br, I, hydroxide, sulfate, phosphate, carboxylate, carbonate, tosylate, nitrate, acetate, thiocyanate, methanoate, tetrafluoroborate, dicyanamine, tretrafluoroborate, hydrogensulfate, methylsulfonate, tricyanamide, trilfuoromethane-sulfonate, bis(trifluoromethyl)azanide, ethylsulfate, benzoate,tetracyanoborate, salicylate, methoxyethylsulfate, aluminiumtetracholate; wherein x and y are independently integers of value equal or superior to 1 selected to provide the valence of the cation M according to the valence of the combined anion A. The salts abovementioned recited contribute to lowering the melting temperature of the water comprised and the cellulose derivative hydrogel comprised in the layer zone impregnated with a hydrogel (3).

[0063] Preferably, the mass ratio between the cellulose derivative hydrogel and the salt in said layer zone impregnated with a hydrogel (3) is in the range from 0.0001 to 10000.

[0064] Moreover, in the preferred embodiments according to the invention, thelayer zone impregnated with a hydrogel (3) comprises at least one antifreeze additive, preferably selected of the group consisting of the polyvinyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, glycerol, erythritol, sorbitol, mannitol, maltitol, xylitol, polyols, fatty acids, vegetal oils, or mixtures thereof in order to further lower the melting temperature of the water. Preferably, the mass concentration of the antifreeze additive in thelayer zone impregnated with a hydrogel (3) is in the range of 1% to 5%.

[0065] In the preferred embodiments, the layer zone impregnated with a hydrogel (3) has a thickness in the range from about 10 micrometers to about 1 millimeter. Furthermore, the outer fibrous substrate layer (4) has a thickness in the range from about 10 micrometers to about 500 micrometers. More preferably, the ratio between the thickness of the layer zone impregnated with a hydrogel (3) and the outer fibrous substrate layer (4) is in the range from about 0.01 to about 100.

[0066] In other embodiments, the container enclosure further comprises an inner substrate layer (5), which is arranged under said layer zone impregnated with a hydrogel (3), wherein said inner substrate layer (5) is arranged along an exterior surface of a container wall (1). In this embodiment, the layer zone impregnated with a hydrogel (3) is sandwiched between the inner substrate layer (5) and the outer fibrous substrate layer (4).

[0067] In the preferred embodiments according to the invention, said inner substrate layer (5) is selected from at least one of the group consisting of a paper product comprising a cellulose fiber based porous structure; a woven fabric; an unwoven fabric; a cork substrate; a plastic film, for example a thin polyethylene film or a thin polypropylene film; an aluminum film; or their composites or their composites or derivatives.

[0068] Preferably, the inner substrate layer (5) is made of a water permeable material. In other embodiments, the inner substrate layer (5) functions as a hydrophilic adhesive which is simultaneously a label and an adhesive that can be used to be bonded to the layer zone impregnated with a hydrogel (3), wherein this embodiment is properly suitable for bottles or cups.

[0069] More preferably, the outer fibrous substrate layer (4) and the inner substrate layer (5) have hydrophilic features, e.g. when these layers comprise a cellulose fiber based porous structure, said layers function as adhesive layers that can be used to be bonded to the layer zone impregnated with a hydrogel (3), considering Hydrogen bonds and van der Waals forces intermolecular forces.

[0070] In the preferred embodiments, at least one heat transfer enclosure (2) encloses 20% to 90% of the area of a container wall (1). In the most preferred embodiments, at least two heat transfer enclosures (2) enclose 20% to 90% of a container wall (1), wherein each heat transfer enclosure (2) encloses a different portion of the container wall (1).

[0071] In the preferred embodiments, when the container is configured to cool content inside a container at an exterior temperature below 0 ºC, the container enclosure comprises a heat transfer enclosure (2), and wherein said heat transfer enclosure (2) further comprises an outer fibrous substrate layer (4), which is arranged over said layer zone impregnated with a hydrogel (3), and wherein said heat transfer enclosure (2) further comprises an inner substrate layer (5) arranged under said layer zone impregnated with a hydrogel (3). Even more preferably in this embodiment, the inner substrate layer (5) comprises a paper product comprising a cellulose fiber based porous structure, wherein inner substrate layer (5) is configured for water absorption and further configured for hydrating the layer zone impregnated with a hydrogel (3).

[0072] The preferred method of preparation of the heat transfer enclosure (2), according to the present invention, is centered on printing or drop-on-demand methods. This enables a large-scale production of the heat transfer enclosure (2), with the possibility to deposit a layer zone impregnated with a hydrogel (3) on various substrates, such as the inner substrate layer (5) or the outer fibrous substrate layer (4), namely metals, alloys, glass, polymers, composites, paper, and fabrics while maintaining reduced costs of production. The drop-on-demand methods are compatible with large areas.

[0073] In other embodiments of preparation of the flexible pressure or strain mapping device according to the present invention, it is possible to carry out the deposition step by a film application step, for example a Doctor blade; by a screen printing step; by a flexography step; by a spray-coating step; or by an inkjet, a Roll-to-Roll (R2R) compatible, step, as it will be understood by a person skilled in the art.Examples

[0074] An exemplary formulation to be used in the method of preparation of a layer zone impregnated with a hydrogel (3) comprises:

[0075] - Sodium carboxymethyl cellulose - CMC (Sigma Aldrich Mw approximately 250,000): Solution concentration from about 0.1 % to about 10.0 % weight in water;

[0076] - Calcium Chloride (CaCl2) - Concentration from about 0.01 M to about 10.0 M in water;

[0077] - Zinc Chloride (ZnCl2) - Concentration from about 0.01 M to about 10.0 M in water. in water.

[0078] As an example, the salts present in the layer zone impregnated with a hydrogel (3) are:

[0079] 14.2 g NaCl for 60 mL CMC (2.5%);

[0080] CaCl2(12 mL of a solution 1M);

[0081] ZnCl2(12 mL of a solution 1M);

[0082] Therefore, the layer zone impregnated with a hydrogel (3) comprises 1.5 g CMC for 0.012 mol CaCl2(1.33 g), 0.012 mol ZnCl2(1.63 g), 14.2 g NaCl, resulting in 1.5 g CMC for an overall mass of salts of 17.46 g. The mass ratio between CMC and salts is 0.086.

[0083] In this example, besides the ionic crosslinking agents zinc and calcium, epichlorohydrin (ECH) was used as a covalent crosslinking agent, wherein the mass ratio between CMC and ECH is in the range from about 0.02 to about 10, preferably from about 0.7 to about 1.5.

[0084] Glycerol was included in the layer zone impregnated with a hydrogel (3) when preparing container enclosures for carrying out cooling tests under 0ºC, wherein the glycerol was included in a mass concentration of 2.5% in the layer zone impregnated with a hydrogel (3).

[0085] A container enclosure according to the present invention was prepared according to the following specifications:

[0086] Thickness of the layer zone impregnated with a hydrogel: 10 µm to 1 mm;

[0087] Thickness of the 80 g m-2paper layer: 50 µm to 500 µm;

[0088] Dimensions of the paper layer: A5 sheet 14.8 cm x 21 cm having an area of 310.8 cm2.

[0089] Theillustrates a cooling experiment of a bottle of 250 mL containing beer inside a freezer having its internal temperature set up at -18ºC. The graphic label “glass only” means the bottle without any enclosure. The graphic label “tissue paper” means the bottle enclosed solely by a cloth fabric as an outer fibrous substrate layer. The graphic label “Hydrogel” means the bottle enclosed by a heat transfer enclosure according to the example abovementioned recited. The graphic label “office paper” means the bottle enclosed solely by a standard office paper. It is remarkable the increasing of the overall heat transfer coefficient, considering a major contribution on the cooling effect by evaporative cooling of the water comprised in the layer zone impregnated with a hydrogel (3), which percolates the outer fibrous substrate layer (4). Considering the negative surrounding environment and the low humidity inside a freezer, the heat transfer rate is boosted, even with a partial recondensation of water over the outer fibrous substrate layer (4).

[0090] Theillustrates a second cooling experiment of a container of 250 mL containing hot water (> 80 °C) at room temperature. The graphic labels “aluminum can only” and “glass only” means a container without any enclosure. The graphic labels “Hydrogel on aluminum can” and “Hydrogel on glass bottle” means the respective containers enclosed by a heat transfer enclosure according to the example abovementioned recited. It is remarkable the increasing of the overall heat transfer coefficient, considering a major contribution on the cooling effect by evaporative cooling of the water comprised in the layer zone impregnated with a hydrogel (3), which percolates the outer fibrous substrate layer (4) for both cases of containers, namely an aluminum can or a glass bottle.

[0091] These unexpected results for a person skilled in the art provide options to prepare a container enclosure comprising a heat transfer enclosure (2) having controlled heat transfer rates according to the technical features of the layer zone impregnated with a hydrogel (3) and the outer fibrous substrate layer (4), for example exploiting the variables referred to the chemical composition of the hydrogel and the ratio between the thicknesses of said layers. Therefore, as an example, it will be possible to prepare paper cups for hot beverages, for example coffee, wherein the rate transfer is controlled allowing that the beverage can be consumed without accidents and avoiding longer waiting times until the beverage reaches a proper temperature to be consumed.

[0092] Theillustrates a cooling experiment of a bottle of 200 mL containing beer inside a freezer having its internal temperature set up at -2ºC and with air intake ventilation at the top. In this experiment, we have explored the extension of the bottle which was enclosed by the heat transfer enclosure (2) as the main variable. The graphic label “bottle glass only” means the bottle without any enclosure. The graphic label “heat transfer enclosure 100%” means a bottle having its entire side wall enclosed by a heat transfer enclosure (2) comprising a layer zone impregnated with a hydrogel (3) according to the example abovementioned recited further and an inner substrate layer (5) arranged under said layer zone impregnated with a hydrogel (3), wherein said inner substrate layer (5) comprises a paper product comprising a cellulose fiber based porous structure. The graphic label “heat transfer enclosure 83.3%” means a bottle having 83.3% of its side wall enclosed by a single heat transfer enclosure (2) as referred to in this paragraph. The graphic label “heat transfer enclosure 83.3% - 2 Parts” means a bottle having 83.3% of its side wall enclosed by two parts of a heat transfer enclosure (2) as referred to in this paragraph, wherein the first part covers a first portion of the bottle side wall, and the second part covers a second portion of the bottle side wall. The graphic label “heat transfer enclosure 37% - 2 Parts” means a bottle having 37% of its side wall enclosed by two parts of a heat transfer enclosure (2) as referred to in this paragraph, wherein the first part covers a first portion of the bottle side wall, and the second part covers a second portion of the bottle side wall. It is an unexpected result that the experiments carried out with a bottle having 83.3% of its side wall enclosed by two parts of a heat transfer enclosure (2) are better regarding the increase in the overall heat transfer coefficient when compared to results referred to the “heat transfer enclosure 100%”. In this example, in the embodiment wherein two heat transfer enclosures (2) enclose 83.3% or 37% of the container wall, the portions of the container wall uncovered by the heat transfer enclosure (2) promote higher evaporation rates under the principle of the evaporative cooling.

[0093] Theillustrates a cooling experiment of a paper cup of 200 mL containing hot water at room temperature. In this experiment, we have used the embodiment of container enclosure illustrated in. The graphic label “tissue paper” means the inner substrate layer (5) made of a paper product comprising a cellulose fiber based porous structure. The outer fibrous substrate layer (4) is also made of a cellulose fiber based porous structure. The graphic label “Low Hydration” means a layer zone impregnated with a hydrogel (3) according to the example abovementioned recited, wherein the mass of impregnated water is three times the mass of the container enclosure. Alternatively, in the preferred embodiments of a low hydration layer zone impregnated with a hydrogel (3), the mass of impregnated water is in the range of 500 to 700 g / m2in relation to the area of the container enclosure. The graphic label “High Hydration” means a layer zone impregnated with a hydrogel (3) according to the example abovementioned recited, wherein the mass of impregnated water is nine times the mass of the container enclosure. Alternatively, in the preferred embodiments of a high hydration layer zone impregnated with a hydrogel (3), the mass of impregnated water is in the range of 1000 to 1300 g / m2in relation to the area of the container enclosure. Therefore, the duration of the evaporative cooling effect is substantially influenced by the amount of water present in the layer zone impregnated with a hydrogel (3). Other relevant variables for controlling the evaporative cooling time are the thickness of the hydrated layers (layer zone impregnated with a hydrogel (3). and / or highly hydrated inner substrate layer (5) made of a paper product comprising a cellulose fiber based porous structure) as well as the duration for which said layers are being hydrated.

[0094] Theillustrates a cooling experiment of several kinds of containers of 200 mL containing hot water at room temperature. In this experiment, we have used the embodiment of container enclosure illustrated in. The graphic label “tissue paper” means the inner substrate layer (5) made of a paper product comprising a cellulose fiber based porous structure. The graphic label “heat transfer enclosure 100%” means a bottle having its entire side wall enclosed by a heat transfer enclosure (2) comprising a layer zone impregnated with a hydrogel (3) according to the example abovementioned recited further and an inner substrate layer (5) arranged under said layer zone impregnated with a hydrogel (3), wherein said inner substrate layer (5) comprises a paper product comprising a cellulose fiber based porous structure. The container enclosure according to the invention can be arranged along the exterior surface of a container wall, wherein this latter is made of different materials, being observed increased cooling evaporative effects for the illustrated materials. Besides the illustrated container wall materials, the technical effect provided by the container enclosure is also observed for container walls made of polymers, fibrous materials and metals.

[0095] As used in this description, the expressions “about” and “approximately” refer to a range in values of roughly 10% the specified number.

[0096] As used in this description, the expression. “substantially” means that the real value is within an interval of about 10% of the desired value, variable or related limit, particularly within about 5% of the desired value, variable or related limit or particularly within about 1% of the desired value, variable or related limit.

[0097] Moreover, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B.

[0098] In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form.

[0099] Further, as used herein, the term “exemplary” is intended to mean serving as an illustration or example of something and is not intended to indicate a preference.

[0100] The subject matter described above is provided as an illustration of the present invention and must not be interpreted to limit it. The terminology used with the purpose of describing specific embodiments, according to the present invention, must not be interpreted to limit the invention. As used in this description, the definite and indefinite articles, in their singular form, aim to include in the interpretation the plural forms, unless the context of the description explicitly indicates the contrary. It will be understood that the expressions “comprise” and “include”, when used in this description, specify the presence of the characteristics, the elements, the components, the steps and the related operations, but do not exclude the possibility of other characteristics, elements, components, steps and operations from being also contemplated.

[0101] All modifications, providing that they do not modify the essential features of the following claims, must be considered within the scope of protection of the present invention.

[0102] 1. a container wall;

[0103] 2. a heat transfer enclosure;

[0104] 3. a layer zone impregnated with a hydrogel;

[0105] 4. an outer fibrous substrate layer;

[0106] 5. an inner substrate layer;

[0107] 6. a sidewall of a heat transfer enclosure;

[0108] 7. a bottom wall of a heat transfer enclosure;

[0109] 8. an upper wall of a heat transfer enclosure;

[0110] 9. an opening;

[0111] 10. a lid.

[0112] Patent Literature

[0113] patent application No. US2012190259A1 of Frost Douglas R., entitled “Evaporative cooling material” and published on July 26th, 2012;

[0114] patent application No. US2005218535A1 of Maisotsenko Valeriy et al, entitled “Indirect evaporative cooling mechanism” and published on Mars 31st, 2005;

[0115] patent application No. SG10201407256SA of Chin Jia Min et al, entitled “Method of removing heat energy from an object” and published on June 29th, 2015.

Claims

A container enclosure comprising a heat transfer enclosure (2), for being arranged along an exterior surface of a container wall (1)characterized in thatsaid heat transfer enclosure (2) comprises a layer zone impregnated with a hydrogel (3); and wherein said layer zone impregnated with a hydrogel (3) includes a cellulose derivative hydrogel, a crosslinking agent, and water.The container enclosure, according to claim 1,whereinsaid heat transfer enclosure (2) further comprises an outer fibrous substrate layer (4), which is arranged over said layer zone impregnated with a hydrogel (3); and wherein said outer fibrous substrate layer (4) is selected from a group consisting of a paper product comprising a cellulose fiber based porous structure; a woven fabric; an unwoven fabric; a cork substrate, or their composites or derivatives.The container enclosure, according to any of previous claims,whereinthe cellulose derivative hydrogel is selected from the group consisting of cellulose acetate, cellulose acetate phthalate, cellulose acetate butyrate, cellulose acetate trimellitate, hydroxypropyl methylcellulose phthalate, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethylmethyl cellulose, hydroxyethylpropyl cellulose, hydroxypropyl methylcellulose, bacterial cellulose, cellulose nanofibers, cellulose nanocrystals, microfibrillated cellulose, or their mixtures, copolymers or their composites.The container enclosure, according to any of claims 1 to 3,whereinsaidcrosslinking agent includes at least one of the group consisting of an ionic crosslinking agent or a covalent crosslinking agent.The container enclosure, according to claim 4,whereintheionic crosslinking agent is selected from a group consisting of a divalent cation, or a trivalent cation, wherein said cations are preferably zinc, calcium, magnesium, nickel or copper cations, or their mixtures.The container enclosure, according to claim 4,whereinthecovalent crosslinking agent is selected from a group consisting of epoxy resins such as epichlorohydrin; dicarboxylic acids such as citric acid, or oxalic acid; dialdehydes such as glutaraldehyde, glyoxal, or polyethylene glycol dialdehyde diethyl acetal; aldehydes such as formaldehyde; hemi acetals such as genipin; acrylamides such as N,N’-methylenebisacrylamide; telechelic poly(vinyl alcohol), boron salts such as borax, N-hydroxysuccinimide esters, divinyl compounds such as divinyl sulfone or their mixtures.The container enclosure, according to any of the previous claims,whereinsaid layer zone impregnated with a hydrogel (3) comprises at least one polysaccharide hydrocolloid, which is selected from a group consisting of alginate, sodium alginate, gellan gum, carrageenan, guar gum, xanthan gum, locust bean gum, gum arabic, pectin, modified starch, their mixtures or copolymers.The container enclosure, according to any of the previous claims,whereinsaidlayer zone impregnated with a hydrogel (3) comprises at least a salt selected from a group consisting of a nitrogen quaternary salt, a urea derivative salt, a salt of general formula MxAyor their mixtures; andwherein M is a cation selected from a group consisting of Na, Li, K, Be, Mg, Ca, Ba, Al, Fe+2, Fe+3; andwherein A is an anion selected from a group consisting of F, Cl, Br, I, hydroxide, sulfate, phosphate, carboxylate, carbonate, tosylate, nitrate, acetate, thiocyanate, methanoate, tetrafluoroborate, dicyanamine, tretrafluoroborate, hydrogensulfate, methylsulfonate, tricyanamide, trilfuoromethane-sulfonate, bis(trifluoromethyl)azanide, ethylsulfate, benzoate,tetracyanoborate, salicylate, methoxyethylsulfate, aluminiumtetracholate; andwherein x and y are independently integers of value equal or superior to 1 selected to provide the valence of the cation M according to the valence of the combined anion A.The container enclosure, according to any of the previous claims,whereinsaidlayer zone impregnated with a hydrogel (3) comprises at least one antifreeze additive, preferably selected of the group consisting of the polyvinyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, glycerol, erythritol, sorbitol, mannitol, maltitol, xylitol, polyols, fatty acids, vegetal oils, or mixtures thereof.The container enclosure, according to any of the previous claims,whereinsaidlayer zone impregnated with a hydrogel (3) comprises the cellulose derivative hydrogel in a mass percentage from 0.01% to 50.00% in relation to the overall mass of saidlayer zone impregnated with a hydrogel (3).The container enclosure, according to any of the claims 8 to 10,whereinthe mass ratio betweenthe cellulose derivative hydrogel and the salt in saidlayer zone impregnated with a hydrogel (3) is in the range from 0.0001 to 10000.The container enclosure, according to any of the claims 4 to 11,whereinsaidlayer zone impregnated with a hydrogel (3) comprises the ionic crosslinking agent in a concentration from 0.01 M to 50.00 M in relation to the mass of water in saidlayer zone impregnated with a hydrogel (3).The container enclosure, according to any of the previous claims,whereinthe mass ratio between water and the cellulose derivative hydrogel in the layer zone impregnated with a hydrogel (3) is in the range from 0.01 to 1000.The container enclosure, according to any of the claims 7 to 12,whereinthe mass ratio betweenthepolysaccharide hydrocolloid and the cellulose derivative hydrogel in saidlayer zone impregnated with a hydrogel (3) is in the range from 0.001 to 10.The container enclosure, according to any of the claims 4 to 12,whereinthe mass ratio betweenthecovalent crosslinking agent and the cellulose derivative hydrogel in saidlayer zone impregnated with a hydrogel (3) is in the range from 0.01 to 100.00.The container enclosure, according to any of the previous claims,whereinsaidlayer zone impregnated with a hydrogel (3) has a thickness in the range from 10 micrometers to 1 millimeter.The container enclosure, according to any of the previous claims,whereinsaidouter fibrous substrate layer (4) has a thickness in the range from 10 micrometers to 500 micrometers.The container enclosure, according to any of the previous claims, wherein further comprises an inner substrate layer (5) arranged under said layer zone impregnated with a hydrogel (3), wherein said inner substrate layer (5) is selected from at least one of the group consisting of a paper product comprising a cellulose fiber based porous structure; a woven fabric; an unwoven fabric; a cork substrate; a plastic film, for example a thin polyethylene film or a thin polypropylene film; an aluminum film; or their composites or their composites or derivatives.The container enclosure, according to any of the previous claims, wherein at least one heat transfer enclosure (2) encloses 20% to 90% of the area of a container wall (1).

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