Process

Abstract

A method includes applying a wetting agent to an airlaid pulp to form an intermediate pulp, and hot pressing the intermediate pulp to form a molded article. The pulp may be formed from a fibrous raw material. The wetting agent may include a functional additive, such as a sol. The sol may include a solvent, an alkoxide, and optionally a catalyst. The airlaid pulp, intermediate pulp, and / or molded article may be free or substantially free of thermoplastic polymers and / or hydrocarbon-based plastics. The molded article may be a fiber-based air bubble film. The fiber-based air bubble film may be formed by a roll-to-roll process.

Description

[0001] SUMMARY

[0002] The present invention relates to the processing of pulp and methods of accomplishing the same. More particularly, the present invention relates to imparting one or more beneficial properties to products formed from air-laid pulp.

[0003] Paper, paperboard, and other materials are commonly used as packaging for commercial products. Material properties of the product, such as the permeability of the packaging material to water, oil, and other fluids, can be controlled through the use of water-impermeable polymeric materials such as plastics or composites. In many industries, such as the food and beverage industry, polymeric materials such as thermoplastics can be applied to other permeable media to facilitate the retention of liquid products within a particular packaging article. In other examples, paper stock based on lignin or cellulose that is treated with polymeric materials can be subjected to high temperatures to treat, solidify, or melt lignin or cellulose present in the paper stock, thereby sealing the pore structure of the material. Similar methods can also be used to prevent the ingress of fluids into articles that can be damaged by exposure to water, air, or other fluids. In cases where polymeric materials such as plastics are used, the plastic materials are typically made from hydrocarbon feedstocks, and their manufacture carries associated environmental costs. The materials or chemicals used to manufacture such plastics, and their associated byproducts, can also be toxic. Some plastics can also degrade over time or with use, producing microplastics or otherwise releasing potentially harmful substances. Similarly, in processes where paper stock is subjected to high temperatures, energy efficiency is often poor, and some processes result in the release of undesirable gaseous or vapor byproducts. Thus, there are ongoing health and environmental concerns associated with the manufacture of many common paper and paperboard packaging materials.

[0004] Paper and paperboard are typically formed from a mixture of plant-based fibers. Raw materials rich in lignin and / or cellulose, such as wood or plant material, are the most common raw material feedstocks, and these materials are processed into pulp from which paper products can be manufactured. Pulp exists in several different forms, such as wet or dry pulp, which can be used to form paper and / or paperboard products having different properties and purposes. For the avoidance of doubt, the term “paper” as used herein is intended to encompass “paperboard,” and thus paperboard products are considered to be paper products for the purposes of the information provided herein. Furthermore, the term “pulp” is intended to refer to materials formed primarily from plant-based fiber materials.

[0005] Wet pulp is a pulp material that uses a liquid-based solvent as a carrier medium for the fibrous raw material medium during processing. Due to the abundance, availability, and relatively low cost of water, the liquid carrier medium used for wet pulp is typically water. However, other solvents that can be used include: alcohols, such as methanol and ethanol; acids, such as acetic acid; organic solvents, such as acetone; combinations of these solvents can also be used depending on the nature and requirements of the pulping process. Wet pulp is typically formed by shredding and / or pulverizing raw material feedstock in a volume of water to disperse the fibrous material and form a pulp. The wet pulp is then transferred through one or more optional further processes to a press, mold, or similar device where the pulp can be shaped or formed into a sheet. Wet pulp products can contain more than 50 wt% of liquid after shaping, and therefore typically must have a large portion of this liquid removed prior to use and / or during the pulp processing. In some examples, wet pulp can contain up to about 90% of liquid. The residual liquid carrier medium is typically removed through one or more drying processes. Therefore, the formation of products from wet pulp requires a large amount of liquid (such as water) and a large amount of energy throughout the manufacturing process. The large amount of liquid (such as water) can also require long periods of circulation, which makes the wet pulp process susceptible to bacterial or fungal growth within the manufacturing equipment. To address this issue, a large amount of disinfectant or antifungal agent is often circulated in the manufacturing system to prevent the adverse buildup of bacteria and / or fungi. The used disinfectant must also be disposed of, which means additional costs and presents further environmental challenges.

[0006] Dry pulp can be formed by drying wet pulp or in other ways utilizing a forming process that does not use a liquid carrying medium, such as water. Typically, dry pulp has a very high water absorbency capacity and is therefore commonly used to form absorbent products, such as diapers, paper towels, feminine hygiene products, and the like. Fluff pulp or air-laid pulp, in particular, eschews the use of a liquid, such as water, as a processing medium, and instead utilizes air or other gas as a means of carrying the fibers. Typically, air-laid pulp is shredded, re-shaped, or re-laid by carrying and / or rotating the fibers in a gaseous medium. Air-laid pulp can be treated with one or more sizing agents prior to or during the carrying and / or rotating process to impart one or more properties to the air-laid pulp. Some air-laid pulp is formed from softwood because this material tends to produce long fibers of low density. Air-laid pulp can form products having different properties than products produced from wet pulp or dry pulp formed by drying wet pulp alone. For example, air-laid pulp can be isotropic. In another example, air-laid pulp can have a greater pore volume than an equivalent wet pulp that is subsequently dried. This property makes fluff pulp or air-laid pulp particularly advantageous for forming products that must carry a very high proportion of liquid volume in use, such as cleaning pads or wet wipes. Forming products from dry pulp typically involves treating the pulp with plastic and / or adhesive, exposing it to high temperatures to melt the plastic and / or adhesive before imparting the desired shape using a mold or press.

[0007] Paper products used for packaging and storing perishable items, such as food and beverages, require properties of stiffness, strength, water and / or gas resistance or impermeability. Paper and paperboard packaging can need to protect the product stored or contained within the package. Paper and paperboard are inherently not fluid resistant or fluid impermeable due to the inherent pore structure of the material, and so paper used for packaging is often treated or processed to provide a fluid barrier, material strength, or other resistance. Wet pulp derived products are often coated with a plastic coating after formation to enable the product to resist the ingress of fluids. Dry pulp derived products can be subjected to a hot press process in which the pulp has optionally been coated with a plastic or polymer precursor. The application of heat during the hot press process is believed to “set” or “cure” the lignocellulosic fibers in the pulp, as well as any plastic or polymer precursor applied to the pulp prior to the hot press step. In practice, the “hot press” process used for pulp processing operates at temperatures of about 100°C to 300°C, as these temperatures are believed to cause changes in the physical and chemical structure of the lignocellulosic fibers, providing a material with mechanical properties similar to plastic.

[0008] The inventors of the present invention have recognized that molded articles formed from air-laid pulp can be formed without the use of large amounts of water, high temperatures, hydrocarbon-based polymers, and / or thermoplastics, and complex manufacturing equipment. In particular, the inventors of the present invention have recognized that molded articles formed from air-laid pulp can have one or more desirable properties, including at least partial elastic deformability and / or smoothness. Further, the inventors of the present invention have recognized that, in the presence of a wetting agent and / or functional additive, such as a sol, fluid-resistant or fluid-impermeable molded paper articles can be formed by applying a hot-pressing process, and optionally a cold-pressing process, to the air-laid pulp. The method can also impart one or more other desirable properties to the molded article depending on the wetting agent or functional additive.

[0009] According to one aspect of the application, a method is provided that includes applying a wetting agent to an air-laid pulp to form an intermediate pulp, and hot pressing the intermediate pulp to form a molded product. The air-laid pulp, the intermediate pulp, and / or the molded product can be free or substantially free of thermoplastic polymers and / or hydrocarbon-based plastics. The method can further include applying a functional coating and / or a barrier to the intermediate pulp or the molded product. The method can further include additional hot pressing and / or cold pressing of the air-laid pulp, the intermediate pulp, or the molded product. The molded product can be a water-resistant or water-impermeable molded product. The wetting agent can be applied to the air-laid pulp by brushing, spraying, spray-drying, rolling, dipping, dropping, injecting, transferring, immersing, impregnating, mixing, spreading, screeding, filling, or any combination thereof. The wetting agent can be applied to the air-laid pulp by spraying. Hot pressing the intermediate pulp can be performed at a temperature greater than 100°C, optionally equal to or greater than 150°C, equal to or greater than 200°C, equal to or greater than 250°C, or equal to or greater than 300°C. In contrast, cold pressing the intermediate pulp can be performed at a temperature less than 100°C, optionally less than 50°C. Hot pressing the intermediate pulp can include pressing the intermediate pulp into at least one mold, pressing the intermediate pulp between at least one plate and at least one other surface, or any combination thereof. Furthermore, hot pressing and / or cold pressing the air-laid pulp, the intermediate pulp, or the molded product can further include pressing the intermediate pulp into at least one mold, pressing the intermediate pulp between at least one plate and at least one other surface, or any combination thereof. The mold, plate, or other surface used to hot press and / or cold press the air-laid pulp, the intermediate pulp, or the molded product can include one or more fluid escape elements configured to allow fluid (optionally the wetting agent in vapor and / or liquid form) to escape, optionally wherein the one or more fluid escape elements include one or more holes, vents, orifices, flow channels, conduits, pipes, passages, or any combination thereof. The method can further include applying heat to dry the air-laid pulp, the intermediate pulp, or the product. The method can further include drying the air-laid pulp, the intermediate pulp, or the product without directly applying energy. The wetting agent can comprise water. The wetting agent can consist essentially of water. The wetting agent can comprise a sol. The sol can comprise a solvent, an alkoxide, and a catalyst. The sol can further comprise a biopolymer. The biopolymer can comprise starch. The starch can comprise cationic starch. The cationic starch can be selected from quaternary ammonium type cationic starch, tertiary ammonium type cationic starch, and any combination thereof. The biopolymer can comprise flour. The flour can comprise 5% to 85% starch, 0% to 30% hemicellulose, 0% to 50% cellulose, 0% to 25% lignin, 0% to 35% protein, and 0% to 25% ash. The flour can be selected from wheat flour, barley flour, lentil flour, bamboo flour, corn flour, oat flour, rye flour, buckwheat flour, rice flour, chickpea flour, green pea flour, or any combination thereof. The catalyst can be at least one of an acid and a base.The catalyst can be selected from the group consisting of hydrochloric acid, citric acid, nitric acid, acetic acid, sodium hydroxide, potassium hydroxide, ammonia, and any combination thereof. The alkoxide can be selected from the group consisting of a silicon alkoxide, a metal alkoxide, a phosphorous alkoxide, and any combination thereof. The alkoxide can be selected from the group consisting of n-propyltriethoxysilane, tetrapropyl orthosilicate, titanium(IV) tert-butoxide, titanium(IV) isopropoxide, triethoxysilane, methyltriethoxysilane, triethoxysilyl(octyl)silane, phenyltriethoxysilane, titanium(IV) ethoxide, triethoxysilylcyclopentane, (3-glycidyloxypropyl)trimethoxysilane, cyclopentyltriethoxysilane, 3-aminopropyltriethoxysilane, triethoxy-3-(2-imidazolin-1-yl)propylsilane, and any combination thereof. The solvent can comprise water, one or more alcohols, and any combination thereof. The solvent can comprise methanol, ethanol, isopropanol, butanol, ethylene glycol, or any combination thereof. The wetting agent can comprise one or more functional additives. The one or more functional additives can comprise a photoinitiator, a resin, an oil, a dye (including a food-grade organic colorant), a salt, an antimicrobial agent, a mineral or other inorganic particle, a surfactant, a biopolymer, a composite particle, and / or a metal particle. The wetting agent can deliver the one or more functional additives into the internal structure of the air-laid pulp. Hot pressing the intermediate pulp can comprise applying a pressure of at least 1000 kg / m 2 to at least a portion of the intermediate pulp. Hot pressing the intermediate pulp can comprise applying a pressure of about 6000 kg / m 2 to a portion of the intermediate pulp. Hot pressing the intermediate pulp can comprise applying a pressure to a portion of the intermediate pulp for a duration of from less than 1 second to up to 10 seconds, optionally wherein the duration of applying the pressure is less than 5 seconds. The molded article can be a fiber-based molded bubble wrap. The molded article can be a food or beverage packaging product. The product can be a non-food or beverage packaging product.

[0010] According to another aspect of the present invention, there is provided a fluid resistant or fluid impermeable fiber-based packaging material comprising an air-laid pulp comprising a molded article formed by the method of the present invention. The fiber-based packaging material can comprise a sol comprising a solvent, an alkoxide, and optionally a biopolymer. The fiber-based packaging material can be a fluid resistant or fluid impermeable fiber-based bubble wrap. The fiber-based bubble wrap can be formed using a roll-to-roll process, a roll-to-sheet process, a sheet-to-roll process, or a sheet-to-sheet process. The fiber-based packaging material can be a fluid resistant or fluid impermeable fiber-based packaging peanut.

[0011] BRIEF DESCRIPTION OF DRAWINGS

[0012] The present invention will now be described with reference to the following drawings, in which:

[0013] Figure 1 A flow chart showing the method according to the present application is shown;

[0014] Figure 2 A flow chart showing a method comprising various optional method steps that can be performed within the scope of the present application is shown;

[0015] Figures 3A to 3E A cross-section of a fibre-based bubble film formed using the method disclosed herein is shown. DETAILED DESCRIPTION

[0017] The method of the present application aims to provide a moulded product based on air-laid pulp with specific properties, without using materials harmful to the environment, such as hydrocarbon-based plastics or applying too much energy. Figure 1 A flow chart showing the method 100 according to the present application is shown. The method 100 comprises applying a wetting agent to an air-laid pulp to form an intermediate product 101, and hot-pressing the intermediate pulp to form a moulded product 102.

[0018] The wetting agent can be any suitable wetting agent that allows the air-laid pulp structure to become at least partially extensible, deformable, moldable, or otherwise shapable. Without being bound by theory, the presence of the wetting agent is believed to act as a lubricant and / or to soften the fibrous material of the air-laid pulp, such that the fibers can move or bend without breaking. Thus, the intermediate pulp formed after applying the wetting agent to the air-laid pulp can be relatively easily shaped into a molded article without the need to heat the pulp significantly above ambient temperature. The inventors of the present invention have also discovered that applying a wetting agent to an air-laid pulp or similar pulp formed without the use of water or other liquids can impart fluid resistance to the molded article formed from the pulp. The use of a wetting agent can also improve the surface smoothness, strength, and / or elasticity of the product formed by molding of the air-laid pulp. Thus, the application of a wetting agent can improve the effectiveness of the hot-pressing process, or reduce cracking or breaking that occurs when the air-laid pulp is pressed to form a molded article. It has been found that when water or other liquids are applied to the final molded article, the product thus formed exhibits greater resistance to further or subsequent deformation. The product can exhibit at least partial elasticity and / or elastically deformable. Without being bound further by theory, it is believed that because the internal structure of the air-laid pulp is water-free or water-free except for inherent water, the properties of the fibers after the air-laid pulp is formed are uniquely suited to form an elastic and elastically deformable product under pressure. It is further believed that the wetting agent applied during product formation, particularly a wetting agent that includes water, hydrates or reacts with the fiber surfaces and initiates physicochemical reactions within the fiber matrix at an early stage that would otherwise be initiated by the later exposure of the molded article to water or other liquids. Thus, the hydration and associated reactions initiated by the application of a wetting agent to the air-laid pulp or similar pulp during the product formation process can prevent or reduce the occurrence or extent of such physicochemical reactions when more water or other liquids are applied to the finished molded article. The reactions initiated in the air-laid pulp by the application of the wetting agent can result in a molded article having a more dense pore structure than would be obtained by pressing the air-laid pulp without the wetting agent. Thus, because of the reduced potential for such water or other liquids to react with, interact with, and / or penetrate the material forming the product, the molded article can better resist deformation, damage, or disintegration upon exposure to water or other fluids after the molded article is formed. Wetting of the air-laid pulp can also improve the efficiency of the process by allowing the pulp to be processed at higher speeds.

[0019] The methods and processes described herein can be advantageous compared to methods and processes known in the art. Some known processes apply a binder, such as a polymeric binder, prior to forming or shaping the fibrous product. Applying the binder in this manner often results in a product that cannot be efficiently recycled, either due to challenges associated with separating the binder and the fibrous product or due to inherent non-recyclable properties of the binder used. Other processes and methods can apply a sealant, functional additive, or other agent after the fibrous product is shaped or formed. Such processes can utilize solvents that react with and / or open the fibrous structure, which can weaken the product formed thereby or reduce the product’s ability to resist moisture ingress over time. Processes and methods of this nature can also have higher environmental costs or energy consumption. The methods and processes described herein that apply a wetting agent during a hot-press process address at least some of the challenges associated with existing methods. More specifically, the methods and processes described herein can use a pulp and / or material that is free, completely free, or substantially free of plastics, binders, sizing agents, additives, fillers, retention aids, wet strength agents, dry strength agents, defoamers, or any combination thereof. Those skilled in the art, with the benefit of this disclosure, will understand the range of additives that can be expressly and intentionally excluded from the pulp and / or material used in the methods and processes described herein. However, such additives can be included where the particular application or end use requires the use of such additives. The methods and processes of the present invention can still be performed in the presence of one or more substances that can be expressly excluded, if inclusion of these substances is desired by those skilled in the art.

[0020] The wetting agent can include one or more functional additives. If present, the one or more functional additives can be selected to impart one or more properties, characteristics, or other performance to the air-laid pulp, the intermediate pulp, and / or the molded article. In some examples, the one or more functional additives can include photoinitiators, resins, oils, dyes (including food-grade organic colorants), salts, antimicrobial agents, minerals or other inorganic particles, surfactants, biopolymers, composite particles, and / or metal particles, or any combination thereof. The one or more functional additives can include one or more adhesives or binders. If present, it can be advantageous for the one or more functional additives to not include materials that can limit the recyclability or reworkability of the molded article. For example, it can be advantageous for the one or more functional additives to not include plastics. The wetting agent can deliver the one or more functional additives onto the surface of and / or into the internal structure of the air-laid pulp. Without being bound by theory, it can be that the functional properties imparted to the air-laid pulp, the intermediate pulp, and / or the molded article using the wetting agent having functional additives can be due to: the formation of a coating on one or more surfaces of the air-laid pulp, the intermediate pulp, and / or the molded article; and / or the filling of pore volumes and / or internal void spaces with the one or more functional additives delivered by the wetting agent into the pore volumes and / or internal void spaces. Further, in some cases, in addition to forming a cross-linked coating, some functional additives can at least partially form a transient nano-, micro-, or suspension dispersion during or after application. The cross-linked coating and / or the transient nano-, micro-, or suspension dispersion can perform a filling function by partially or completely blocking or obstructing additional porous or permeable channels on the surface of the product. Thus, coating the product with functional additives can result in a combination of functional additive coatings that include discrete functional or reactive particles. Further, some functional additives can be present in solution or fine suspension and thus can be carried by the wetting agent into the internal void spaces of the product or intermediate product. When the product or intermediate product is subsequently dried or otherwise processed, then the functional additives can partially or completely fill and / or coat the internal void spaces of the product or intermediate product. One example of a functional additive that can act in this way is a sol. Thus, the wetting agent including one or more functional additives can simultaneously act as a coating, a filler, and a binder for materials having porous and / or permeable properties.

[0021] The wetting agent can be a liquid. The wetting agent can comprise, consist of, or consist essentially of water, one or more alcohols, any other suitable solvent such as an organic solvent, or any combination thereof. Where the solvent includes an organic solvent, the organic solvent can comprise white spirit. If present, the one or more alcohols of the solvent can include methanol, ethanol, butanol, ethylene glycol, isopropyl alcohol, technical denatured alcohol, any isomer of the foregoing alcohols such as t-butyl alcohol, any other suitable alcohol, and any combination thereof. The wetting agent can include, consist of, or consist essentially of water. The wetting agent can include, consist of, or consist essentially of a sol. In the context herein, the term "sol" refers to a dispersion of colloidal particles in a liquid solvent. A sol can also be referred to as a sol mixture. Many sols formed from small colloidal particles are substantially transparent and colorless. For example, sols formed from silicon-based functional materials are often transparent and colorless because the particles forming the sol are small enough that they do not scatter light. Some sols formed from larger particles can be colored and / or at least partially opaque. For example, sols formed from titanium-based functional materials can be visibly white. When applied to a range of materials, sols can form functional coating compositions that are impermeable and / or antimicrobial and / or replaceable. Thus, sols can be used as barrier and / or antimicrobial coating compositions and can provide other functionalities such as hydrophobicity, oleophobicity, stain resistance, anti-biofouling, stain repellency, optical transparency, light opacity, anti-reflectivity, and tackiness. Sols used as barriers can provide a barrier to liquids, vapors, and / or gases such as oxygen. Sols can comprise readily available natural materials to ensure the resulting sols are inexpensive. Furthermore, some sols have been shown to provide durable and heat-resistant coatings, indicating that sols can form functional coatings that are elastic and long-lasting.

[0022] A sol can be formed by dispersing one or more materials having a suitably small particle size in a solution. Some sols can also include other components, such as catalysts or functional components. A sol suitable for use in the methods of the present invention can be any sol that can be applied, coated, or incorporated into an air-laid pulp to impart beneficial properties or characteristics to the resulting product formed from the intermediate pulp formed thereby. A sol suitable for use in the present invention generally includes a functional material and a solvent. The functional material can be present in the sol in any suitable proportion. For example, the functional material can be present in the sol in an amount of about 0.1%, about 0.5%, about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, or any other suitable amount, based on the total weight of the sol. In one example, the methods of the present invention can involve the use of a sol that includes a solvent, a functional metal alkoxide, and optionally a biopolymer and / or optionally a catalyst. The term “metal alkoxide” includes alkoxides that include metals, organically modified alkoxides that include metals, alkoxides that include metalloids, and organically modified alkoxides that include metalloids. The solvent used to form the sol can include water, one or more alcohols, any other suitable solvent, or any combination thereof. If present, the one or more alcohols can include methanol, ethanol, butanol, ethylene glycol, isopropyl alcohol, any other suitable alcohol, and any combination thereof. Bio-solvents, such as bio-ethanol, can also be used. Prior to use as a wetting agent, the sol can be combined with one or more other solvents, where the other solvent is the same as or different from the solvent used in the formation of the sol. The combination of the sol with one or more other solvents can initiate precipitation of the sol, which can be used as a wetting agent for a period of time during which the sol is precipitated. Methods of initiating precipitation of a sol are further described in WO 2021 / 160979. If present, the biopolymer can include a starch-based polymer, a hemicellulose-based polymer, a cellulose-based polymer, a lignin-based polymer, a chitosan-based polymer, any other suitable biopolymer or modified biopolymer, and any combination thereof. The sol can additionally or alternatively include one or more flours derived from natural materials. Suitable flours can include oat flour, barley flour, rye flour, wheat flour, rice flour, bamboo flour, lentil flour, chickpea flour, pea flour, corn flour, or any combination thereof. In cases where the sol includes a functional metal alkoxide, the alkoxide generally conforms to the general formula M(OR) x or R C -M(OR) x where “M” represents any metal that forms a metal alkoxide, which can hydrolyze in the presence of a suitable solvent. “R” and “R CR represents an alkyl group typically having 1 to 30 carbon atoms, which can take any suitable form, such as linear, branched, aromatic, or complex. “x” is typically equal to the valence of the corresponding metal ion “M”. In one example, R can be a methyl, ethyl, propyl, or butyl group. In cases where the metal ion “M” has a valence greater than 1, each R group can be the same. Alternatively, one or more R groups can be different from one or more or all other R groups. R C represents any suitable organic group that will form and maintain a covalent bond with the metal “M” upon hydrolysis of the alkoxide. In some examples, R and R C may be the same. In other examples, R and R C may be different. Any suitable metal alkoxide can be used. Examples of suitable metal alkoxides include Si(OR)4, Ti(OR)4, Al(OR)3, Zr(OR)3, and Sn(OR)4, and R C -Si(OR)3, R C -Ti(OR)3, R C -Al(OR)2, R C -Zr(OR)2, and R C -Sn(OR)3. In specific examples, R can be a methyl, ethyl, propyl, or butyl group. In some specific examples, R Cmay be phenyl, cyclopentyl, or any other suitable organic group capable of maintaining a covalent bond with a metal. The metal of the metal alkoxide can include silicon, titanium, aluminum, zirconium, tin, or any other suitable metal. In particular examples, the metal alkoxide can be selected from Ti(isopropoxy)4, Al(isopropoxy)3, Al(sec-butoxy)3, Zr(n-butoxy)4, Zr(n-propoxy)4, n-propyltriethoxysilane, tetrapropyl orthosilicate, titanium (IV) t-butoxide, titanium (IV) isopropoxide, triethoxysilane, methyltriethoxysilane, triethoxy(octyl)silane, phenyltriethoxysilane, titanium (IV) ethoxide, triethoxysilylcyclopentane, (3-glycidyloxypropyl)trimethoxysilane, cyclopentyltriethoxysilane, 3-aminopropyltriethoxysilane, triethoxy-3-(2-imidazolin-1-yl)propylsilane, and any combination thereof. In selected examples, the metal alkoxide can be selected from tetraethoxysilane, triethoxysilane, phenyltriethoxysilane, methyltriethoxysilane, and any combination thereof. In further selected examples, the metal alkoxide can be selected from tetrapropyl orthosilicate, titanium (IV) t-butoxide, titanium (IV) isopropoxide, triethoxysilane, methyltriethoxysilane, triethoxy(octyl)silane, phenyltriethoxysilane, titanium (IV) ethoxide, triethoxysilylcyclopentane, (3-glycidyloxypropyl)trimethoxysilane, cyclopentyltriethoxysilane, or any combination thereof. In additionally selected examples, the metal alkoxide can be selected from Ti(isopropoxy)4, Al(isopropoxy)3, Al(sec-butoxy)3, Zr(n-butoxy)4, Zr(n-propoxy)4, and n-propyltriethoxysilane-based alkoxide, and any combination thereof. Suitable catalysts for the sol include at least one of an acid or a base. Examples of acid catalysts include hydrochloric acid, citric acid, nitric acid, and acetic acid. Examples of basic catalysts include sodium hydroxide, potassium hydroxide, and ammonia.

[0023] A sol can be prepared by dispersing a functional material having a suitably small particle size in a solvent and optionally adding a catalyst. The functional material can be a particle having at least one dimension in the range of about 1 nm to 1 pm. An alternative method of preparing a sol involves dispersing a functional material in a solution optionally containing a catalyst, followed by the addition of a biopolymer and / or one or more other functional additives. In the presence of a biopolymer and / or one or more other functional additives, a sol containing a functional material can be stored for a period of time prior to the addition of the biopolymer and / or one or more other functional additives. Additional functional additives can be added at any stage during the method of preparing a sol. For example, in a sol containing a biopolymer, additional functional additives can be added before or after dispersing the biopolymer in a solution but before adding an alkoxide, or alternatively after adding the biopolymer and alkoxide to the solution. One or more functional additives can be added at different stages of preparing a sol. Functional additives can be used to adjust the properties of a sol in the same manner that they can be used to adjust the properties of any of the wetting agents described herein, for example, to control the viscosity, density, or rheology of a sol; to make a sol suitable for UV, visible, or IR curing; and / or can be used to add additional functionality to a coating prepared using a sol, for example, color, pH sensitivity, electrical conductivity, fluorescence. The functional additives used will vary depending on the intended use of the sol. Suitable functional additives include photoinitiators, resins, oils, dyes (including pH sensitive dyes, fluorescent dyes, and food-grade organic colorants), salts, surfactants, composite particles, mineral or other inorganic particles (including carbonates, carbides, oxides, hydroxides, nitrates, bromides, etc.), antimicrobial agents, biopolymers, and metal particles (including alloys and particles comprising one or more metals and one or more additional non-metallic components). A sol can also be formed in the absence of any additives, biopolymers, or catalysts. More specifically, a sol can be completely or substantially free of additives and / or biopolymers and / or catalysts during formation and / or use.

[0024] When used in the methods of the present application, the sol can be used without modification prior to use. Thus, the molded articles prepared according to the methods of the present application using sols can be prepared from air-laid pulp and sols without modification of the sol prior to use. For example, water resistant or impervious products can be prepared from air-laid pulp using sols that are substantially free of additives, i.e., water resistant or impervious molded articles are prepared by applying the sol to the air-laid pulp without any functional additives. Alternatively, the sols useful in the methods of the present application can be modified prior to use. For example, when used in the methods of the present application, the sols can be modified by diluting the sol with a solvent, combining the sol with a functional additive, or both diluting the sol with a solvent and combining the sol with a functional additive. Suitable solvents for diluting the sol include the solvent used to disperse the alkoxide in forming the sol (sometimes referred to as the sol solvent), other solvents that are miscible with the sol solvent, or combinations thereof. The functional additives can be used to adjust the properties of the sol, such as the rheology, density, or viscosity of the sol, and / or can be used to add additional functionality to the coating prepared using the sol. The functional additives used will vary depending on the intended use of the sol, and suitable functional additives include photoinitiators, resins, oils, dyes (including pH sensitive dyes, fluorescent dyes, and food grade organic colorants), salts, antimicrobial agents, mineral or other inorganic particles, surfactants, biopolymers, composite particles, and / or metal particles, or any combination thereof.

[0025] By definition, the sol is generally stable. Thus, as part of the methods described herein, the sol can be formed some time prior to use of the sol. For example, the sol can be formed and stored for up to 1 hour, up to 1 day, up to 1 week, up to 1 year, up to 10 years, or more, prior to use of the sol in the methods of the present application. However, the sol can also be formed immediately prior to use of the sol, less than 2 seconds, less than 15 seconds, less than 30 seconds, less than one minute, or less than one hour prior to use of the sol. The sol can be formed in a location geographically proximate to the location of use of the sol. Alternatively, the sol can be formed in a location remote from the location of use of the sol and then transported to that location. In one example, the sol can be formed in an on-line process at a manufacturing site within seconds of application to the air-laid pulp. In another example, the sol can be formed in a separate manufacturing facility and then transported to a geographically distinct location by road, rail, air, sea, pipeline, or equivalent means where the sol is applied to the air-laid pulp. More generally, where appropriate, the sol can be formed in a different location from the pulp to which the sol is ultimately to be applied. In such an example, the sol and the air-laid pulp to which the sol is to be applied will be brought together after formation of the sol. Alternatively, the sol can be formed around the air-laid pulp to which the sol is to be applied such that the formed sol coats and / or penetrates the air-laid pulp immediately, substantially immediately, or shortly after formation.

[0026] The sol or other wetting agent useful in the methods of the present application can optionally include one or more biopolymers. If present, the one or more biopolymers can include one or more polysaccharides. For example, the biopolymers can include starch-based polymers, hemicellulose-based polymers, cellulose-based polymers, lignin-based polymers, chitosan-based polymers, any other suitable biopolymer or modified biopolymer, and any combination thereof. The sol can additionally or alternatively contain one or more flours derived from natural materials. Suitable flours can include oat flour, barley flour, rye flour, wheat flour, rice flour, bamboo flour, lentil flour, chickpea flour, pea flour, corn flour, or any combination thereof. The use of biopolymers in the sol can act as a natural surfactant, forming a network with negatively charged species (such as alkoxides) if present.

[0027] Starches suitable for use in sols that can be used in the methods of the present application include positively charged plant-derived starches or synthetic and derivative equivalents thereof, such as cationic starches. Other starches, such as anionic or neutral starches, can also be used depending on the desired properties of the sol. In some examples, starches and other polysaccharides can be combined in a single sol, which can help to optimise the functionality of the sol. Cationic starches suitable for use in sols that can be used in the methods of the present application include primary, secondary, tertiary and quaternary cationic starches. Quaternary ammonium-type starches are cationic in both high and low pH solutions, whereas primary, secondary and tertiary ammonium-type starches are cationic only in low pH solutions. Thus, different types of cationic starches can be suitable for different applications. Sol comprising one or more starches or cationic starches can be water- and / or oil- and / or vapor- and / or gas- and / or antimicrobial- and / or hydrophobic- and / or oleophobic- and / or antifouling- and / or antibiofouling- and / or stain- and / or anti-reflection resistant. In particular, quaternary ammonium-type starches have been found to be particularly effective at imparting antimicrobial properties to the sol. Generally speaking, the antimicrobial sol can be antibacterial and / or antifungal and / or antiviral and / or antialgal and / or antiparasitic. Sol including starch has also been shown to be effective at preventing the growth of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus hirae.

[0028] Flours suitable for use in the sols useful in the methods of the present application include plant-derived flours that are positively or negatively charged or synthetic and derivative equivalents thereof. Other flours, such as neutral flours, can also be used depending on the desired properties of the sol. Different flours can be combined in a single sol, which can help to optimize the functionality of the sol. Additionally or alternatively, the flours can be combined with one or more additional polysaccharides depending on the desired properties and functionality of the sol. Typically, plant-derived flours are in the form of a powder of plant material such as wheat. Flours include a range of constituent components including proteins, fats, sugars, starches, amino acids, vitamins, and trace elements. The composition of the flour depends on the composition of the material from which it is derived. For example, oat flour can contain a greater proportion of cellulose than wheat flour. Exemplary compositions of various plant flours that can be used in the sols useful in the methods of the present application are provided in Table 1. The flours used in the sols useful in the methods of the present application can be selected from oat flour, barley flour, rye flour, wheat flour, buckwheat flour, rice flour, bamboo flour, lentil flour, chickpea flour, green pea flour, corn flour, and combinations thereof. Other plant-derived flours including starches, hemicelluloses, celluloses, lignins, or other polysaccharides can also be used.

[0029] Table 1 Exemplary compositions of flours derived from various plant materials

[0030]

[0031]

[0032] Generally, plant-derived flours that can be used in the sols useful in the methods of the present application can comprise 5 wt% to 85 wt% starch, optionally in combination with 0 wt% to 30 wt% hemicellulose, 0 wt% to 50 wt% cellulose, 0 wt% to 25 wt% lignin, 0 wt% to 35 wt% protein, and 0 wt% to 25 wt% ash. Other suitable flours can comprise 20 wt% to 80 wt% starch, optionally in combination with 5 wt% to 30 wt% hemicellulose, 0 wt% to 50 wt% cellulose, 0 wt% to 25 wt% lignin, 0 wt% to 35 wt% protein, and 0 wt% to 25 wt% ash. Still other suitable flours can comprise 45 wt% to 80 wt% starch, optionally in combination with 5 wt% to 30 wt% hemicellulose, 0 wt% to 50 wt% cellulose, 0 wt% to 25 wt% lignin, 0 wt% to 35 wt% protein, and 0 wt% to 25 wt% ash. Other flours suitable for use in the sols of the present application can comprise 45 wt% to 70 wt% starch, optionally in combination with 5 wt% to 15 wt% hemicellulose, 0 wt% to 10 wt% cellulose, 0 wt% to 7 wt% lignin, 10 wt% to 15 wt% protein, and 0 wt% to 5 wt% ash. In other examples, suitable flours can comprise 20 wt% to 70 wt% starch, optionally in combination with 0 wt% to 15 wt% hemicellulose, 0 wt% to 10 wt% cellulose, 0 wt% to 10 wt% lignin, 5 wt% to 35 wt% protein, and 0 wt% to 25 wt% ash. Additionally or alternatively, suitable flours can comprise 45 wt% to 70 wt% starch, optionally in combination with 5 wt% to 15 wt% hemicellulose, 0 wt% to 10 wt% cellulose, 0 wt% to 10 wt% lignin, 5 wt% to 15 wt% protein, and 0 wt% to 10 wt% ash. Still further, flours suitable for use in the sols of the present application can comprise 45 wt% to 85 wt% starch, optionally in combination with 0 wt% to 15 wt% hemicellulose, 0 wt% to 10 wt% cellulose, 0 wt% to 10 wt% lignin, 0 wt% to 15 wt% protein, and 0 wt% to 10 wt% ash.

[0033] The wetting agent described herein can be applied to any suitable air-laid pulp material prior to hot pressing the intermediate pulp formed thereby to form a molded product. For the avoidance of doubt, the term "air-laid pulp" in the context of the method content of the present invention refers to a pulp formed after carrying, laying, forming and / or spinning a fibrous material in a gaseous medium. As described herein before, the fibres can be treated with one or more sizing agents, binders or other additives prior to or during the laying process. However, as also described herein, such sizing agents, binders and / or other additives can also be absent. In one example, the air-laid pulp can be formed at least partially from wood fibres. In another example, the air-laid pulp can be formed from non-wood plant fibres. In yet another example, the air-laid pulp can be formed at least partially from synthetic fibres. Thus, the air-laid pulp can comprise plant fibres, wood fibres, natural fibres, any other suitable fibres or any combination thereof. The air-laid pulp can be an air-laid pulp, fluff pulp, recycled pulp, any other suitable category and / or classification of pulp considered to constitute an air-laid pulp or any combination thereof. The air-laid pulp can comprise, consist of, or consist essentially of wood-based fibres. The air-laid pulp can comprise, consist of, or consist essentially of plant-based fibrous material and / or naturally derived fibrous material. The air-laid pulp can be free or substantially free of synthetic fibres. The air-laid pulp can be free or substantially free of textile fibres. The use of air-laid pulp is considered advantageous as air-laid pulp does not require large amounts of water, sterilising agents and other chemicals typically associated with the production and / or processing of wet pulp. Thus, the preferential use of air-laid pulp over wet pulp is environmentally advantageous. In the case of the use of a wetting agent having a particular functionality, the method can provide further advantages depending on the wetting agent used. In one example, the sols disclosed herein are typically antimicrobial / antibacterial, and thus can allow for a further reduction or elimination of sterilising agents or similar agents in product production. Antimicrobial and antibacterial products that do not require the use of additional or specific antimicrobial or antibacterial agents can be advantageous in applications where the product is to be used in the food or beverage industry, where microbial growth is undesirable, but some alternative sterilising agents can themselves pose a health risk to humans. Air-laid pulp also typically has a more open pore structure than equivalent wet pulp or wet-laid pulp. The more open pore structure can allow the wetting agent to penetrate the structure of the air-laid pulp better, such that the wetting agent can better treat a greater proportion of the air-laid pulp structure, and any functional additives and / or sols forming part of the wetting agent can be more thoroughly dispersed throughout the material. In the case where the air-laid pulp is recycled pulp, the recycled air-laid pulp can be formed from or include material from one or more products previously manufactured using the methods described herein.When the recycled air-laid pulp includes material from a product formed using the method of the present application, the recycled air-laid pulp can retain at least a portion of the functional properties and / or components applied to the air-laid pulp during the manufacture of the now recycled product. Where applicable, the recycled air-laid pulp can retain at least some of the functionality imparted by the functional additives and / or sols forming part of the wetting agent during its original manufacturing process. Accordingly, by reducing the amount of functional additives or sols applied to the air-laid pulp in proportion to the amount of functional additives and / or sols remaining in the recycled material, the desired properties of the product formed from the recycled air-laid pulp can be imparted.

[0034] The method includes applying a wetting agent to the air-laid pulp. The amount of wetting agent applied to the pulp depends on the wetting agent used, the material forming the air-laid pulp to which the wetting agent is to be applied, and the desired properties of the intermediate pulp and / or product formed after the wetting agent is applied to the air-laid pulp. In one example, 5 ml of wetting agent can be applied to 10 cm 2 5 ml of wetting agent can be applied to the surface. In another example, 100 ml of wetting agent can be applied to 10 cm 2 5 ml of wetting agent can be applied to the surface. In another example, 100 ml of wetting agent can be applied to 10 cm 22 liters of wetting agent is applied to the surface area of ​​the air-laid pulp. The amount of wetting agent applied to the air-laid pulp can be determined based on the dry weight of the air-laid pulp. (For the avoidance of doubt, the term "dry weight" as used herein refers to the weight of the air-laid pulp as supplied, not the weight of the air-laid pulp after drying at a sufficient temperature to remove any moisture (e.g., water) inherent in the air-laid pulp structure.) For example, a wetting agent equal to or greater than about 10%, about 12%, about 14%, about 16%, about 18%, about 20%, about 22%, about 24%, about 26%, about 28%, about 30%, about 35%, about 40%, about 45%, about 50%, about 60%, about 70%, about 80%, about 90%, about 100%, about 125%, about 150%, about 175%, or about 200% by weight of the dry weight of the air-laid pulp can be added. Thus, in these examples, the wetting agent may be added in an amount of about 10% to about 200% of the dry weight of the airlaid pulp. In other examples, about 10% to about 190%, about 10% to about 180%, about 10% to about 170%, about 10% to about 160%, about 10% to about 150%, about 10% to about 140%, about 10% to about 130%, about 10% to about 120%, about 10% to about 110%, about 10% to about 100%, about 10% to about 90%, about 10% to about 80%, about 10% to about 70%, about 10% to about 60%, about 10% to about 80%, about 10% to about 90%, about 10% to about 100%, about 10% to about 110%, about 10% to about 10 ... %, about 10% to about 50%, about 10% to about 40%, about 10% to about 30%, about 10% to about 20%, about 20% to about 200%, about 20% to about 190%, about 20% to about 180%, about 20% to about 170%, about 20% to about 160%, about 20% to about 150%, about 20% to about 140%, about 20% to about 130%, about 20% to about 120%, about 20% to about 110%, about 20% to about 100%, about 20% to about 90%, about 20% to about 80%, about 20% to about 70%, about 20% to about 60%, about 20% to about 50%, about 20% to about 40%, about 20% to about 30%, about 30% to about 200%, about 30% to about 200%, about 30% to about 190%, about 30% to about 180%, about 30% to about 170%, about 30% to about 160%, about 30% to about 150%, about 30% to about 140%, about 30% to about 130%, about 3 0% to about 120%, about 30% to about 110%, about 30% to about 100%, about 30% to about 90%, about 30% to about 80%, about 30% to about 70%, about 30% to about 60%, about 30% to about 50%, about 30% to about 40%, about 40% to about 200%, about 40% to about 190%, about 40% to about 180%, about 40% to about 170%, about 40% to about 160%, about 40% to about 150%, about 40% to about 140%,about 60% to about 70%. However, the methods and processes described herein can also use amounts of wetting agent of about 10% or less. For example, an amount of wetting agent of up to about 8% of the dry weight of the air-laid pulp can be added. The amount of wetting agent applied to the air-laid pulp will depend on: the properties of the air-laid pulp, such as thickness, structure, pore volume, surface area, etc.; the mold or equipment used to hot press the intermediate pulp to form the molded article; the nature and / or chemistry of the fibers forming the air-laid pulp; and / or the presence and type of any sizing agents, binders, or other additives used in the manufacture of the air-laid pulp. For example, hot pressing an intermediate pulp formed from an air-laid pulp that includes a binder can cause at least some of the binder to melt and act similarly to a wetting agent, or can cause the binder to dissolve in the wetting agent. In such examples, the methods of the present invention can require less wetting agent to achieve the same technical effect as a method for forming a molded article from an air-laid pulp that does not contain a binder. Those skilled in the art, with the benefit of this disclosure, will be able to determine the appropriate proportion of wetting agent to be applied in a particular process or method. In the methods described herein, the term “intermediate pulp” is used to describe the pulp material that has been applied with wetting agent. The pulp can be applied with wetting agent by any suitable means, including but not limited to brushing, spraying, spray drying, rolling, dropping, injecting, transferring, immersing, impregnating, mixing, spreading, troweling,filling or any combination thereof. In one example, it can be advantageous to apply the wetting agent to the air-laid pulp by a spray application technique. In another example, it can be advantageous to apply the wetting agent to the air-laid pulp by one or more roll-based techniques. In examples where the air-laid pulp is free of water or substantially free of water, applying 100% of the wetting agent by dry weight will result in an intermediate pulp of about 50% wetting agent and 50% pulp. Similarly, in an example where 200% of the wetting agent is applied by weight of the dry air-laid pulp, the intermediate pulp includes about 33% by weight of pulp and about 66% of wetting agent. Even though the mass of wetting agent applied exceeds the mass of the dry material, the total wetting agent content of the intermediate pulp will remain below the 90% or more water present in a wet pulp application.

[0035] Applying a wetting agent or a wetting agent including a functional additive to a pulp can cause different volumes or masses of air-laid pulp to adhere together. Applying a wetting agent or a wetting agent including one or more functional additives to a surface of an air-laid pulp and then contacting the wetting agent-applied surface with another surface of a different volume or mass of air-laid pulp can cause the volumes or masses of air-laid pulp to adhere together. In one example, applying a wetting agent or a wetting agent including a functional additive (such as a sol) to a sheet of air-laid pulp before contacting the sheet of air-laid pulp with a second sheet of air-laid pulp can cause the two sheets of air-laid pulp to adhere together before further processing and / or forming a molded article.

[0036] The methods of the present invention include hot pressing the intermediate pulp to which the wetting agent has been applied to form a molded article. In this context, a hot pressing process involves applying pressure to a material in the presence of heat, thereby providing heat and / or thermal energy to the material being pressed, rather than just heat and / or thermal energy that results from the mechanical forces involved in the compression. In some examples, the hot pressing process can involve actively heating the material being pressed. For the avoidance of doubt, “actively heating” a material involves intentionally applying heat and / or thermal energy to increase the temperature of the material. This can be achieved by flowing a heated fluid through one or more conduits present in the hot pressing apparatus, hot pressing in a heated room or atmosphere, or any other suitable manner of heating. In other examples, the hot pressing method can be performed by heating the pressing apparatus, mold, or the like using an oven or similar device prior to using the pressing apparatus or mold in the methods described herein. Thus, the hot pressing process, the hot pressing apparatus, or the material subjected to the hot pressing process can be at a temperature greater than 100°C or greater than 150°C, optionally about 105°C, about 110°C, about 115°C, about 120°C, about 125°C, about 130°C, about 135°C, about 140°C, about 145°C, about 150°C, about 155°C, about 160°C, about 165°C, about 170°C, about 175°C, about 180°C, about 185°C, about 190°C, about 195°C, about 200°C, about 205°C, about 210°C, about 215°C, about 220°C, about 225°C, about 230°C, about 235°C, about 240°C, about 245°C, about 250°C, about 255°C, about 260°C, about 265°C, about 270°C, about 275°C, about 280°C, about 285°C, about 290°C, about 295°C, and / or about 300°C. The hot pressing process, the hot pressing apparatus, or the material subjected to the hot pressing process can be at a temperature range having a lower range and an upper range of any of the temperatures described herein in relation to the hot pressing process. For example, one of skill in the art, with the benefit of this disclosure, will appreciate that a temperature range of about 100°C to about 300°C, about 135°C to about 225°C, or any other temperature range defined by the hot pressing temperatures described herein can be used. It can be advantageous to perform the hot pressing method at a temperature below the boiling point of the wetting agent and / or one or more components of the pulp. As will be described in greater detail below, it can be particularly advantageous to perform the hot pressing method at a temperature below the boiling point of the wetting agent and / or each component of the pulp.

[0037] In contrast, in this context, cold pressing processes involve applying pressure to a material without heating the material or applying additional energy to the material beyond the mechanical forces generated in compression. In examples that include additional cold pressing of air-laid pulp, intermediate pulp, or a molded article, the additional cold pressing method step can involve actively cooling the material being pressed. For the avoidance of doubt, "actively cooling" a material involves intentionally removing heat and / or thermal energy to lower or reduce the temperature of the material. This can be accomplished by flowing a coolant through one or more conduits present in the cold pressing apparatus, performing additional cold pressing in a cold room or atmosphere, or any other suitable manner of cooling. In other examples that include additional cold pressing of air-laid pulp, intermediate pulp, or a molded article, the additional cold pressing method step can be performed at room or ambient temperature, so long as steps are not taken to raise the temperature of the material being pressed above that which such material would normally experience when pressed in an ambient temperature and pressure environment. Thus, the additional cold pressing method step, cold pressing apparatus, or material subjected to the additional cold pressing method step can be at a temperature of less than about -10°C, less than about -5°C, less than about -5°C, less than about 0°C, less than about 5°C, less than about 10°C, less than about 15°C, less than about 20°C, less than about 25°C, less than about 30°C, less than about 35°C, less than about 40°C, less than about 45°C, less than about 50°C, less than about 60°C, less than about 70°C, less than about 80°C, less than about 90°C, and / or less than about 100°C. Generally, any example of the inventive method that includes an additional cold pressing method step can be performed such that the air-laid pulp, intermediate pulp, and / or wetting agent is not heated to a temperature above 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 70°C, 80°C, 90°C, and / or 100°C or used at such temperatures during the cold pressing method step. Notably, it can be advantageous to perform any additional cold pressing method step at a temperature that exceeds the freezing point of one or more components of the wetting agent. In examples where the wetting agent includes water, the additional cold pressing method step can be performed at a temperature that exceeds 0°C but is less than 25°C. In one example, the additional cold pressing of the intermediate pulp is performed at a temperature less than 100°C. In another example, the additional cold pressing of the intermediate pulp is performed at a temperature less than 50°C. Likewise, it can be advantageous to perform any additional cold pressing method at a temperature below the boiling point of one or more components of the wetting agent and / or pulp. As will be described in greater detail below, it can be particularly advantageous to perform any additional cold pressing method step at a temperature below the boiling point of each component of the wetting agent and / or pulp.

[0038] The hot and cold pressing processes described herein both involve the application of force and pressure to the intermediate pulp formed after the application of the wetting agent. Thus, as the intermediate pulp mass is compressed, the pressing process will cause any wetting agent and / or other fluids present in the intermediate pulp to be forced out of the intermediate pulp. For example, any residual wetting agent can be forced out of the intermediate pulp after the application of pressure. During the hot pressing process, particularly where the hot pressing process is performed at a temperature above the boiling point of the wetting agent and / or one or more components of the intermediate pulp, gases can form that are also forced out of the intermediate pulp as pressure and heat are applied to the pulp. For the avoidance of doubt, the formation of the intermediate pulp from the air-laid pulp will typically result in the intermediate pulp containing air or other gases from the atmosphere in which the air-laid pulp and / or the intermediate pulp reside. These gases can also be expelled from the pulp as the hot or cold pressing process is performed. The removal or expulsion of fluids from the intermediate pulp during the pressing process can compromise the quality of the molded article. For example, the concentration of expelled fluids at the surface of the molded article can result in localized pressure build-up that causes damage or tearing at the surface of the molded article. Additionally or alternatively, the concentration of expelled fluids in one or more portions of the internal structure of the intermediate pulp can cause the concentrated fluids to escape from the internal structure of the intermediate pulp through the path of least resistance, causing the structure of the molded article to break as the fluids are expelled during the pressing of the intermediate pulp. To mitigate and / or alleviate these issues, it can be beneficial to include one or more fluid escape elements, such as holes, vents, orifices, flow channels, conduits, pipes, passages, etc., in the mold, plate, associated equipment, or other surface used to hot and / or cold press the air-laid pulp, intermediate pulp, or molded article so that fluids (optionally wetting agent in vapor and / or liquid form) can escape. For example, where the hot pressing method is performed at a temperature above the boiling point of the wetting agent and / or one or more components of the pulp, the mold, press, or other equipment used to form the molded shape of the intermediate pulp can include one or more fluid escape elements configured to allow fluids (e.g., wetting agent in vapor and / or liquid form) to escape so that the fluids exit the mold, press, or other equipment without damaging the molded article formed from the intermediate pulp. In one example, the mold can include multiple components, some of which are used for the shaping of the molded article and others of which provide additional or alternative functionality. The holes, channels, flow channels, orifices, or fluid escape elements intended to allow fluids to escape from the pressing process can be included in any suitable component. For example, one or more fluid escape elements can be included in the cavity portion of the main plate used to shape the molded article. Additionally or alternatively, one or more fluid escape elements or other fluid directing components can be present in auxiliary components of the equipment or in portions of the equipment that do not directly participate in the formation of the molded shape.In these examples, one or more components of the mold that do not participate in forming the molded shape can be used to vent, transport, direct, release, and / or otherwise remove moisture and / or vapor from the mold during or after the formation of the molded shape. In one example, a mold comprising two major plates can include a third component positioned between the major plates, the third component having a structure that provides an exit path for liquid and / or vapor. The application of pressure and / or temperature can cause the material to expand and / or phase change of one or more components present in the mold. To prevent mold failure and / or damage to the product, intermediate product, and / or molded shape, or other undesirable consequences, it can be advantageous to provide a means to allow any excess material, fluid, etc. to exit the mold in a controlled manner. Such a device can include one or more fluid escape elements, optionally in the form of a hole, vent, orifice, flow channel, conduit, duct, passage, etc. In another example, where the hot pressing does not raise the temperature of the intermediate product above the boiling point of one or more components of the wetting agent, the mold or pressing apparatus can include one or more fluid escape elements to allow liquid (e.g., liquid form of the wetting agent) released from the air-laid pulp during pressing to escape so that the fluid exits the mold, press, or other apparatus without damaging the molded product formed from the intermediate pulp. In one particular example, the liquid can escape at the interface between two portions of the mold or pressing apparatus during the pressing and / or molding process. The inclusion of one or more fluid escape elements can improve the quality and / or consistency of the molded product. Thus, the one or more fluid escape elements are intended to allow fluid to exit the mold or pressing apparatus during the hot pressing method steps, they are not intended to allow the removal of the molded product from the mold or pressing apparatus after the completion of the hot pressing method steps. In some known processes, holes, vents, conduits, etc. in the mold are used to direct air or gas into the mold to aid in the removal of the product from the mold. In the methods and apparatus of the present disclosure, the one or more fluid escape elements can not be used to deliver air or gas into the mold when the molded product is left in the mold, as any fluid that exits the molding process through the one or more fluid escape elements would be forced back into the molded product, which can cause damage to the material surface. Thus, at least when the molded product is left in the mold, the one or more fluid escape elements, such as holes, channels, passages, conduits, orifices, or other structures, used to transport, direct, and / or otherwise remove fluid from the mold can not be connected to an air or gas delivery system that delivers gas into the mold. When the molded product is no longer in the mold, fluid, liquid, or gas (such as air) can be used to clean, unblock, or clear the fluid escape elements, as material, fibers, particles, etc. can clog the fluid escape elements during use.

[0039] The number of fluid escape elements provided within the mold or pressing apparatus, as well as the size, diameter, or ratio of these fluid escape elements, can be adjusted to reduce the risk of damage to the intermediate pulp during pressing. If the mold or apparatus includes too few fluid escape elements, or the size of the fluid escape elements is too small, the intermediate pulp may tear during the formation of the molded article due to increased pressure and / or increased forces involved in the dynamics of the fluid moving in, around, and through the intermediate pulp, apparatus, and / or fluid escape elements. However, if the mold or apparatus includes too many fluid escape elements, or the size of the fluid escape elements is too large, the surface properties of the molded article may be adversely affected. Furthermore, the number and size of the fluid escape elements can be varied depending on their location within the mold or apparatus, as well as the size and shape of the mold or apparatus. Fluid escape elements are typically located in areas of the mold or apparatus where large amounts of wetting agent are expected to accumulate, as this will reduce local increases in pressure. For example, in a dome-shaped mold, there might be a hole at the top and center of the mold (with the dome being considered to be pointing upwards), as it is expected that local pressure and wetting agent content are likely to be highest during or immediately after pressing. Alternatively, in a flat mold, the holes can be more evenly distributed, optionally with a higher concentration of holes towards the center of the plate if the plate is large. A flat shape can be expected to result in less local increase in pressure, but it may be necessary to allow liquid located toward the middle of the plate to exit the mold faster and / or in a larger volume than would be required for liquid located toward the periphery of the plate. The shape of the mold will also affect the number and size of fluid escape elements, as shapes that include pathways or other features that allow wetting agent to be directed can inherently reduce the risk of damaging the center pulp. Furthermore, it may be advantageous for the mold or apparatus to include fluid escape elements of different sizes, shapes, types, cross-sections, morphologies, and / or designs.

[0040] The hot pressing process step and any additional hot pressing or cold pressing process steps included in the present invention can be performed at any suitable pressure. Typically, the hot pressing process step and any additional hot pressing or cold pressing process steps included in the present invention can be performed at a pressure that is reduced or lower than the pressure required to process wet pulp material or pulp material including thermoplastics or hydrocarbon-based polymers. The hot pressing process step can apply at least or about 1000 kg / m 2 , at least or about 1500kg / m 2 , at least or about 2000kg / m 2 , at least or about 2500kg / m 2 , at least or about 3000kg / m 2 , at least or about 4000kg / m 2 , at least or about 5000kg / m 2 or at least or about 6000kg / m2 The hot pressing method step can be performed over a range of pressures. For example, the method can be performed over a range of pressures from about 1000 kg / m 2 to about 5000 kg / m 2 . The range of pressures from any suitable pressure disclosed herein and extending to any suitable pressure disclosed herein can be used as the range of pressures for the hot pressing process. Any additional cold pressing method steps can apply a pressure to the intermediate pulp of less than 25000 kg / m 2 , less than 5000 kg / m 2 , less than 4000 kg / m 2 , less than 3000 kg / m 2 , less than 2000 kg / m 2 , less than 1000 kg / m 2 , less than 500 kg / m 2 , less than 300 kg / m 2 , less than 250 kg / m 2 , less than 200 kg / m 2 , less than 150 kg / m 2 , less than 100 kg / m 2 , less than 50 kg / m 2 , less than 40 kg / m 2 , less than 30 kg / m 2 , less than 20 kg / m 2 , less than 10 kg / m 2 , or any other suitable pressure to form the molded article. For example, the hot pressing method step and any additional cold pressing method steps can apply a pressure of about 1000 kg / m 2 , about 2000 kg / m 2 , about 3000 kg / m 2 , about 4000 kg / m 2 , about 5000 kg / m 2 , about 6000 kg / m 2 , about 7000 kg / m 2 , about 8000 kg / m 2 , about 9000 kg / m 2 , about 10000 kg / m 2 , or more. In one particular example, a pressure of 6000 kg / m 2 can be used. In another particular example, a pressure of 3000 kg / m 2pressure. Hot pressing and any additional cold pressing of the intermediate pulp can include pressing the intermediate pulp into at least one mold, pressing the intermediate pulp between at least one plate and at least one other surface, or any combination thereof. Thus, the product can be formed using one or more molding shapes, templates, or casts or otherwise shaped. The term "mold" is used herein to generally define a component of an apparatus that includes a shaped recess into which the intermediate pulp can be directed to shape the intermediate pulp. The mold generally provides one or more entry orifices for the intermediate pulp to enter the shaped recess on a single side of the recess to complete the three-dimensional shape of the recess during the pressing process when the mold is brought together with another mold or surface. However, some molds can allow the intermediate pulp to enter the shaped recess from multiple sides or portions of the recess. The exact configuration of the mold will depend on the properties and requirements of the molded product being produced. Those skilled in the art, with the benefit of this disclosure, will be able to identify a suitable mold for a particular product. Thus, hot pressing and any additional cold pressing of the intermediate pulp can include passing the material through an orifice, where the orifice is formed by at least one roller that includes one or more shaped mold recesses and at least one other surface. For example, hot pressing and any additional cold pressing of the intermediate pulp can involve passing the intermediate pulp between two rollers, where at least one of the rollers includes one or more shaped mold recesses, thereby exerting pressure on the intermediate pulp and forming the molded product. In another example, hot pressing and any additional cold pressing of the intermediate pulp can involve placing the intermediate pulp in a mold and then pressing the intermediate pulp with a plate or counter-shape such that it occupies the shape of the mold. In one example, the intermediate pulp can be placed in a first male or female mold and then a second corresponding male or female mold shape can be applied to shape the intermediate pulp. In such an example, the first and second molds can include male and female molds. Pressure can be applied using another mold portion, pressure plate, or other suitable pressure application device. Returning to the example of male and female molds, either the male or female mold can exert pressure by pressing against the intermediate pulp that resides in or is pressed against the other male or female mold. Generally, the mold or mold apparatus can include one or more fluid escape elements, such as drainage channels, conduits, pathways, etc., to allow any excess fluid to be drained from the intermediate pulp as pressure is applied during the cold pressing process. The hot pressing method steps and any additional cold pressing method steps can include applying pressure to the intermediate pulp and for any suitable period of time. Advantageously, the methods of the present invention allow the molded product to be formed using pressure applied to the intermediate pulp for only a short period of time.The pressure can be applied to the intermediate pulp for a duration of less than or equal to about 20 seconds, less than or equal to about 15 seconds, less than or equal to about 10 seconds, less than or equal to about 8 seconds, less than or equal to about 6 seconds, less than or equal to about 5 seconds, less than or equal to about 4 seconds, less than or equal to about 3 seconds, less than or equal to about 2 seconds, less than or equal to about 1 second, less than or equal to about half a second, or less than or equal to about a quarter of a second, optionally for a duration of about 20 seconds, about 15 seconds, about 10 seconds, about 9 seconds, about 8 seconds, about 7 seconds, about 6 seconds, about 5 seconds, about 4 seconds, about 3 seconds, about 2 seconds, about 1 second, about half a second, or about a quarter of a second. For the avoidance of doubt, applying pressure in this context can refer to applying pressure to all or a portion of a given volume or mass of intermediate pulp. In one example, pressure can be applied to the intermediate pulp for less than about 1 second. In another example, pressure can be applied to the intermediate pulp for less than about 0.5 seconds. In one particular example of a hot-pressing method step, the intermediate pulp can be processed into a molded article using a roll-to-roll process, a roll-to-sheet process, a sheet-to-roll process, or a sheet-to-sheet process. In a sheet-to-roll or sheet-to-sheet process, a sheet of raw pulp material is fed into the apparatus and processed, then fed into a spool system or removed from the apparatus in the form of a sheet of molded article. In the formation of a spool, a batch and / or non-continuous process can form a roll of molded articles, which can then be used in one or more continuous or intermittently continuous processes. In a roll-to-roll or roll-to-sheet process, the intermediate pulp can form a continuous mass that is fed at high speed through rollers that include one or more shaped die recesses. The pressure used in such an arrangement need only be sufficient to form the molded shape. The application of a wetting agent prior to pressing the intermediate pulp ensures that the intermediate pulp has the proper ductility for high speed processing, while the resulting minimal contact time with the pressing apparatus and relatively low pressure prevents the intermediate pulp fibers from being damaged. Furthermore, a relatively small amount of wetting agent can be applied to air-laid pulp that is intended to be processed into a molded article using a roll-to-roll process, a roll-to-sheet process, a sheet-to-roll process, or a sheet-to-sheet process. Utilizing a roll-to-roll process can be particularly advantageous because such a process allows for rapid processing of air-laid pulp material in a continuous or semi-continuous manner to form further continuous or semi-continuous molded article material. Such a process allows for processing of large amounts of material at higher speeds and throughputs than can be achieved with a “sheet” process in which sheets must be loaded or removed from the beginning or end of the process, respectively. Furthermore, use of a roll die with a roll-to-roll process can allow for the application of pressure to any given portion of the intermediate pulp material for a relatively short duration, such as less than or equal to about 1 second, less than or equal to about 0.5 seconds, or less than or equal to about 0.25 seconds, which can reduce the risk of damaging the intermediate pulp material and / or the molded article from excessive or prolonged application of pressure. The application of pressure to the intermediate pulp using two rollers or the like also provides a relatively small area of application of pressure to the intermediate pulp when compared to an intermittent process using sheets and a press.Applying pressure to the intermediate pulp in only a small surface area portion of the intermediate pulp fed into the roll can allow fluid, gas, and / or liquid in the intermediate pulp to escape from the roll press along the sides of one or both rolls without risking damage to the intermediate pulp and / or the molded article using such rolls, reels, and the like. For example, a roll contact area width of less than 1 cm, about 1 cm, about 1.5 cm, or up to about 2 cm can allow fluid to escape along the sides of one or both rolls. In these examples, the roll and mold can not need one or more fluid escape elements to prevent fluid escaping from the pulp from damaging the molded article. In cases where a larger contact area width is applied, the roll and mold can still include the fluid escape elements described herein to allow fluid to escape the intermediate pulp and / or the molded article through the fluid escape elements in the mold, roll, and the like. In addition to the small contact area provided by using a roll mold in a roll-to-roll process, the combination of short contact pressure times can also allow fluid escaping from the intermediate pulp and / or the molded article to be carried away from where pressure is applied to the intermediate pulp.

[0041] Hot pressing of the intermediate pulp forms a molded product. As used herein, the term "product" is intended to include intermediate products, semi-finished products, and unfinished products, as well as finished products and articles, and assemblies thereof. For example, the molded product formed from hot pressing or cold pressing of the intermediate pulp can be a finished product, such as a paper shape, a ready-to-use paperboard can, and the like. In other examples, the product can be an intermediate assembly for forming or assembling a larger product. The product can be a water resistant or water impermeable product. In the case where the product is a water resistant or water impermeable product, the water resistance or water impermeability of the product can be imparted by hot pressing or cold pressing the intermediate pulp to which the anti-bleed-promoting functional additive is applied. The sol used as at least a portion of the wetting agent can facilitate the formation of the water resistant or gas resistant or water impermeable or gas impermeable product. Thus, the methods of the present invention can be used to form products, such as packaging materials. In one example, the mold, press, or template can be shaped such that the intermediate pulp is formed into a fiber-based bubble film that includes raised and lowered portions, the raised portions enclosing a hollow interior to replicate a functional standard bubble film. In another example, the mold, press, or template can be shaped such that the intermediate pulp is formed into a sphere, a hemisphere, a substantially sphere, and / or a substantially hemisphere. Thus, the product formed by the methods described herein can include a water resistant or water impermeable fiber-based packaging material. The water resistant or water impermeable fiber-based packaging material can be a water resistant or water impermeable fiber-based bubble film. Alternatively, the water resistant or water impermeable fiber-based packaging material can be a water resistant or water impermeable fiber-based sphere or hemisphere. In the case where the product is a water resistant or water impermeable fiber-based sphere or hemisphere, the product can be used in place of a packaging pellet, such as a packaging "filler." Other uses include forming a 3D shaped product, a cup such as a coffee cup, a container lid, a cup lid such as a coffee lid, a bottle assembly, a tray, any other suitable 3D shape, and the like. In one particular example, the product can be formed into a shaped packaging insert to protect a boxed electronic product, a white good, or similar article that can benefit from a packaging material shaped to conform to the particular product. Indeed, the shape and size of the product formed by the methods of the present invention can be limited only by the shape and configuration imparted by the available pressing equipment, molds, and the like. Thus, the product can include a three-dimensional shape that includes an air-laid pulp and one or more wetting agents. In another example, the product can include a three-dimensional shape that includes an air-laid pulp and one or more sols.

[0042] The air-laid pulp, the intermediate pulp, and / or the molded article can be free or substantially free of hydrocarbon-based polymers and plastics. Thus, the air-laid pulp used in the methods of the present invention or the intermediate pulp and / or the products formed using the methods of the present invention can be free or substantially free of components derived from oil and gas feedstocks. In many traditional products formed from pulp, a thermal process using temperatures as high as 300 °C or higher is used to form an impermeable barrier from a plastic or hydrocarbon-based polymer applied to the intermediate pulp, which melts to form the impermeable barrier. The inventors of the present invention have appreciated that, without the plastic or hydrocarbon-based polymer, the application of a fluid resistance or fluid impermeability-promoting functional additive as a wetting agent, such as a sol, to the pulp can form a water-resistant or water-impermeable product. Without being bound by theory, it is believed that the fluid resistance or fluid impermeability-promoting wetting agent (such as a sol) described herein forms a network structure that plugs the pore structure of the fibrous material and prevents the passage of fluids. In cases where the components of the fluid resistance or fluid impermeability-promoting functional additive are selected to impart one or more additional or alternative functionalities, the network formed can reside on or near the surface of the fibrous product, such that the network is able to provide functionality at the interface points of the fibrous product. In one example, the sol applied to the air-laid pulp can penetrate the pore volume and internal void volume of the air-laid pulp. When the resulting intermediate pulp is hot-pressed according to the methods described herein, the pore structure will collapse at least partially around the sol contained therein, promoting contact between the interior pore and / or void walls and the sol. When the sol dries naturally or by other means, the sol can plug the pore volume of the fibrous material and form a coating on the surface of the hot-pressed molded product, thereby forming a fluid-resistant or fluid-impermeable barrier. Some wetting agents (such as water) can increase the water resistance or fluid resistance of the molded article without imparting long-term impermeability thereto. The use of such wetting agents prior to hot-pressing the intermediate pulp is believed to initiate hydration and other reactions within the structure of the air-laid pulp, which can result in the closure and / or narrowing of the pore structure in the resulting molded article. Thus, the closed pore structure is more effective at resisting the permeation of fluids than a molded article having a more open pore structure.

[0043] The method can include any number of additional method steps as desired. The method can include one or more additional wetting steps in which a liquid is applied to the air-laid pulp, the intermediate pulp, and / or the product. Wetting the air-laid pulp, the intermediate pulp, and / or the product can further facilitate processing the air-laid pulp, the intermediate pulp, and / or the product through one or more additional processes that form part of the method. Where one or more further wetting steps are present, the wetting agent used in each step can be the same or different depending on the end user’s purpose. In one example, a first wetting agent can be applied during a first wetting step to impart water resistance or water impermeability to the molded article. A second wetting step can then be performed to impart the desired optical properties to the molded article. The method can include applying a functional coating and / or barrier to the intermediate pulp or the molded article. The functional coating can be formed from any material selected to impart one or more desired properties to the intermediate pulp and / or the product. The functional coating and / or barrier can be a water-based coating and / or barrier or can be formed from a water-based functional material. For example, the functional coating can be formed from one or more sols described herein. The functional coating can be formed from a material selected to promote hydrophobicity, oleophobicity, anti-fouling, anti-biofouling, stain resistance, antimicrobial properties, optical transparency, optical opacity, anti-reflectivity, tackiness, any other suitable property, or any combination thereof. The method can include one or more additional hot- or cold-pressing method steps. Additional hot- or cold-pressing steps can be performed on the air-laid pulp, the intermediate pulp, and / or the molded article as desired. The method can include one or more additional hot- or cold-pressing steps in which the pulp, the intermediate pulp, or the product is subjected to pressure. The method can include drying the pulp, the intermediate pulp, and / or the product. Drying the pulp, the intermediate pulp, and / or the product can involve heating and / or applying energy to the pulp, the intermediate pulp, and / or the molded article using a heater, an oven, a heat exchanger, a heat gun, an infrared source, any other suitable drying device, or any combination thereof. The method can include cutting, slicing, or otherwise releasing discrete shapes from the air-laid pulp, the intermediate pulp, and / or the molded article during one or more pressing steps. For example, where the intermediate pulp is present in a mold, applying pressure through one or more other molds, plates, or equivalent components can also cut, slice, or separate portions of the intermediate pulp from other portions of the intermediate pulp present in the mold. In this way, smaller products, smaller portions of products, or shapes that cannot be achieved without cutting or slicing the intermediate pulp can be obtained using the methods described herein. For the avoidance of doubt, the product, intermediate product, or raw air-laid pulp material can be cut, sliced, and / or separated at any suitable point in the method. In one example, the product can be cut, sliced, and / or separated after the pulp is pressed and dried.In another example, when the product is an intermediate product between any two other method steps, the product can be cut, sliced and / or separated.

[0044] Figure 2 Flow diagrams showing various permutations of the method 200 within the scope of the invention. Figure 2 The method 200 of the first aspect includes the following method steps: applying a wetting agent to an air-laid pulp to form an intermediate pulp 201, and hot-pressing the intermediate pulp to form a molded article 202. Figure 2 The method of the first aspect includes various optional additional method steps, which can be performed prior to applying a wetting agent to the air-laid pulp. These steps include applying a functional coating and / or barrier to the air-laid pulp 203A, drying the air-laid pulp 203B, hot-pressing the air-laid pulp 203C or cold-pressing the air-laid pulp 203D. Various other optional additional method steps are shown, which can be performed prior to cold-pressing the intermediate pulp to form a molded article. These steps include applying a wetting agent to the intermediate pulp, applying a functional coating and / or barrier to the intermediate pulp 204A, drying the intermediate pulp 204B, hot-pressing the intermediate pulp 204C or cold-pressing the intermediate pulp 204D. Further optional additional method steps are shown, which can be applied to the product after it has been formed by cold-pressing. These steps include applying a wetting agent to the molded article 205A, applying a functional coating and / or barrier to the molded article 205B, drying the molded article 205C, hot-pressing the molded article 205D or cold-pressing the molded article 205E. Although Figure 2 Flow diagrams showing only one of steps 203A to 203D, 204A to 204D and 205A to 205E being performed at a time as the method is performed are shown, but the skilled person, having the benefit of the present disclosure, will understand that any number of these steps can be performed at any point in the method in any combination depending on the purpose of the method.

[0045] Figures 3A to 3E Examples of fiber-based bubble films that can be formed using the methods described herein are shown. Figure 3A A cross-section of a sheet of fiber-based bubble film 310 is shown, showing bridging portions 311 and hemispherical protrusions 312. The protrusions 312 each protrude in the same direction relative to the bridging portions 311, such that when the bridging portions 311 are positioned such that they are aligned substantially linearly and / or substantially planar, the protrusions 312 are all on the same side of the fiber-based bubble film 310. The hemispherical protrusions each define a cavity 313 within the sheet of fiber-based bubble film 310. The fiber-based bubble film 310 can be stacked with sheets of other fiber-based bubble films 310 by placing the protrusions 312 of one sheet in the cavities 313 of another sheet to be stacked with the fiber-based bubble film. Figure 3BA cross-section of a sheet of fibre-based bubble film 320 is shown, showing bridge portions 321 and hemispherical protrusions 322 and 323. Protrusion 322 protrudes upwards relative to bridge portions 321, while protrusion 323 protrudes downwards relative to bridge portions 321, such that when the bridge portions 321 are positioned such that they are aligned substantially linearly and / or substantially planarly, the upwards protrusion 322 and the downwards protrusion 323 each lie on a different side of the fibre-based bubble film 320. Hemispherical protrusions 322 and 323 each define a cavity 324 within the sheet of fibre-based bubble film 320. By placing the protrusions 322 and 323 of one sheet into the cavities 3324 of another sheet to be stacked with the fibre-based bubble film, the fibre-based bubble film 320 can be stacked with sheets of other fibre-based bubble films 320.

[0046] Figure 3C A cross-section of a sheet of fibre-based bubble film 330 is shown, showing bridge portions 331 and hemispherical protrusions 332. In a similar manner to the bubble film shown in Figure 3A Figure 3C The fibre-based bubble film 330 has protrusions 332 protruding upwards on the same side of the bridge portions 331. The cavities 333 of the bubble film 330 are closed, such that the cavities 333 contain a closed pocket of gas, which can be air. While the fibre-based bubble film 330 is described with reference to closed cavities 333, the cavities can instead be at least partially filled with paper pulp, and thus can be formed from and / or at least partially filled by the same paper pulp material used to form the sheet of fibre-based bubble film 330. In this way, the hemispherical protrusions 332 can be filled, such that they are partially or substantially solid. Figure 3D A cross-section of a sheet of fibre-based bubble film 340 is shown, showing bridge portions 341 and hemispherical protrusions 342 and 343. In a similar manner to the bubble film shown in Figure 3B Figure 3D The fibre-based bubble film 340 has upwards protrusions 343 and downwards protrusions 344, which protrude from different sides of the bridge portions 341 when the bridge portions 341 are arranged such that they are arranged in a substantially linear and / or substantially planar manner. The cavities 344 of the bubble film 340 are closed, such that the cavities 344 contain a closed pocket of gas, which can be air. While the fibre-based bubble film 340 is described with reference to closed cavities 344, the cavities can instead be at least partially filled with paper pulp, and thus can be formed from and / or at least partially filled by the same paper pulp material used to form the sheet of fibre-based bubble film 340. In this way, the hemispherical protrusions 342 and / or 343 can be filled, such that they are partially or substantially solid.

[0047] ​​Figure 3E Another example of a fiber-based bubble film 350 that can be formed using the methods disclosed herein is shown. The fiber-based bubble film 350 includes a bridge portion 351 and a generally spherical portion formed by an upward protrusion 352 and a downward protrusion 353. Each generally spherical portion includes an interior volume 354 that can be a hollow cavity or can be at least partially filled with a solid. The solid, if any, in the interior volume 354 can be a pulp material that is a remainder of a sheet used to form the fiber-based bubble film 350. The sheet of the fiber-based bubble film 350 can be formed in one piece. For example, a male mold and a female mold can be used to form the upward and downward protrusions 352 and 353 from a single pulp block used to manufacture the fiber-based bubble film 350. Alternatively, the generally spherical portions formed by the upward and downward protrusions 352 and 353 can be formed by cutting the sheet of the fiber-based bubble film 350 into a plurality of pieces, each of which includes a bridge portion and a generally spherical portion. The pieces can then be placed together and adhered and / or sealed to form the fiber-based bubble film 350. Figure 3A The two sheets of the fiber-based bubble film 310 shown are placed together and adhered and / or sealed to form the fiber-based bubble film 350. Figure 3E The fiber-based bubble films 310, 320, 330, 340, and 350, once formed, can undergo one or more further processes. In one example, a cutting process can be used to release the generally spherical portions formed by the upward protrusions 352 and the downward protrusions 353 from the bridge portions 351. The spherical portions so released from the sheet can then be used as a packaging filler.

[0048] The fiber-based bubble films 310, 320, 330, 340, and 350 are merely examples, and other configurations of fiber-based bubble films can be contemplated. A fiber-based bubble film can lack one or more or any bridge portions. For example, the protruding portions can be adjacent, substantially adjacent, tessellated, etc. The fiber-based bubble film can be flexible or elastically deformable, the properties of which depend on the density of the air-laid pulp, the properties of the wetting agent, and / or any functional additives used in its formation. For example, using an air-laid pulp with a greater grams per square meter (gsm) can increase the strength of the molded article. When the fiber-based bubble film has a plurality of protrusions, each protrusion can be located on the same side of the fiber-based bubble film when the fiber-based bubble film is arranged to be substantially planar. Alternatively, one or more of the plurality of protrusions can be located on a different side of the fiber-based bubble film than another one or more of the plurality of protrusions when the fiber-based bubble film is arranged to be substantially planar. Although the fiber-based bubble films are shown to have a generally spherical shape, the fiber-based bubble film can have any suitable three-dimensional shape. For example, the fiber-based bubble film can have a generally cubic shape, a generally pyramidal shape, a generally irregular shape, or any other suitable shape. Figures 3A to 3E The fiber-based bubble films are shown to have protrusions that are substantially hemispherical in shape, but the protrusions can be any suitable three-dimensional shape, such as a cubic shape, a pyramidal shape, an irregular shape, or any other suitable shape. Each protrusion of the fiber-based bubble film can be substantially identical. Alternatively, one or more or each protrusion of the fiber-based bubble film can be different from another protrusion of the fiber-based bubble film. Figures 3A to 3EThe cross-section in FIG. 1 1 shows a sheet of bubble film with a pattern of protrusions that can be repeated on both the x and y axes of the sheet of bubble film oriented substantially in the x-y plane. In cases where the protrusions are arranged to protrude upward and / or downward from the x-y plane, the protrusions can be arranged in linear rows, alternating offset rows, or any other suitable pattern. Alternatively, one or more protrusions can be arranged such that they are not arranged in a regular pattern. For example, the distribution of protrusions can be irregular or substantially random. In cases where the fiber-based bubble film has a plurality of protrusions, the dimensions of each protrusion can be the same. For example, one or more dimensions of each of the plurality of protrusions can be substantially the same. Alternatively, one or more of the protrusions or one or more dimensions or each dimension of each of the protrusions can be different. The fiber-based bubble film can be formed using a roll-to-roll process that can use one or more roll dies. In this way, the fiber-based bubble film can be formed using a continuous or intermittent continuous process. Alternatively, the fiber-based bubble film can be formed in an intermittent process using a press apparatus or the like. Other processes can be used, including a roll-to-sheet process, a sheet-to-roll process, or a sheet-to-sheet process. The process used to form the fiber-based bubble film can be used to form a packaging filler by including one or more blade portions in the die such that a protruding portion of the fiber-based bubble film is separated from the sheet of fiber-based bubble film. As Figures 3A to 3DIn the case where the fiber-based bubble film includes only hemispherical protrusions, as shown, the hemispherical portions can bond together to form a substantially spherical packing filler. Those skilled in the art, with the benefit of this disclosure, will understand that protrusions of other shapes can be adhered in a similar manner to form non-spherical shapes in substantially the same manner. In the case where two or more fiber-based moldings are adhered, they can be adhered using a wetting agent. If the adhesion is formed prior to the moldings drying, any wetting agent residue in the moldings can be used, which can be sufficient to form the adhesion. In another example, a functional cellulose additive, such as nanocellulose, can be used to adhere two or more fiber-based moldings. The fiber-based bubble film can be used in applications such as packaging, cushioning, and the like. The fiber-based bubble film can also be used as at least a portion of another product, composite material, and the like. For example, the fiber-based bubble film can be used as a portion of an insulating air gap. Examples of applications in which the fiber-based bubble film can be used as a portion of an insulating air gap include building materials, furniture, and the like. The fiber-based bubble film can impart strength or elasticity to an insulating layer that would otherwise involve an air gap or a gas gap. The fiber-based bubble film can be placed in and / or throughout an air or gas insulating cavity to strengthen a material or product that includes such an air or gas insulating cavity. The fiber-based bubble film can be used as a portion of a composite material. In the case where the composite material includes an insulating layer, the fiber-based bubble film can be used as a portion of such an insulating layer to impart strength and / or fluid resistance or impermeability to the composite material. In the case where the fiber-based bubble film is used in a composite material, the fiber-based bubble film can impart one or more properties of the fiber-based bubble film to the composite material. Properties that the fiber-based bubble film can impart to the composite material include strength, fluid resistance or impermeability, thermal insulation, or any other property of the fiber-based bubble film.

[0049] Accordingly, the methods of the present invention are suitable for the purpose of forming fluid resistant or fluid impermeable fiber-based molded articles without the use of hydrocarbon-based plastic polymers, reducing the amount of water used in forming fluid resistant or fluid impermeable fiber-based products, and in some cases, increasing the speed of manufacture of fiber-based products. In particular, the methods disclosed herein allow for the formation of fiber-based products without the use of large amounts of water, sanitizers, and / or antimicrobials associated with traditional wet pulp processes. The molded articles formed using the methods of the present invention can be used in a range of industries, such as automotive, engineering, construction, aerospace, marine, defense, electronics (including optoelectronic devices and sensors), energy (including batteries, energy storage, and renewable energy), photonics, food, medical, household products, paper, adhesives, indoor or outdoor decoration, home improvement, additive manufacturing, oil and gas, separation and purification, fashion, general packaging, and cosmetics industries. In one example, the methods of the present invention can be used to form primary, secondary, or tertiary packaging materials for any suitable industry or purpose. EMBODIMENTS

[0050] The present invention can be further understood in view of the following examples. All chemicals were used as received without further purification.

[0051] Example 1

[0052] Water was run onto the surface of the air-laid pulp, which was subsequently cold-press molded using a roll-to-roll cold press molding to form a fibrous bubble film.

[0053] Examples 2-20 provide various methods by which a wetting agent sol can be formed that can be applied to the pulp itself.

[0054] Formation of Example 2 Sol:

[0055] Tetraethoxysilane (100%, 5.5 ml) was added dropwise to a mixture of ethanol (7 ml) and aqueous HC1 (0.1 M, 1.7 ml). The solution was stirred for about 40 hours until a sol was formed.

[0056] Formation of Example 3 Sol:

[0057] Titanium (IV) ethoxide (100%, 5.5 ml) was added dropwise to a mixture of ethanol (7 ml) and aqueous HC1 (0.1 M, 1.7 ml). The solution was stirred for about 2 hours until a sol was formed.

[0058] Formation of Example 4 Sol:

[0059] Methyltriethoxysilane (100%, 7.5 ml) was added dropwise to a mixture of ethanol (15 ml) and aqueous HC1 (0.1 M, 2 ml). The solution was stirred for about 1 hour until a sol was formed.

[0060] Example 5 Formation of a sol:

[0061] Titanium isopropoxide (9 g) was added to a mixture of ethanol (6.5 ml) and aqueous HCI (0.1 M, 1.8 ml). The mixture was stirred for about 30 minutes until a sol was formed.

[0062] Example 6 Formation of a sol:

[0063] Zirconium isopropoxide (8.5 g) was added to a mixture of ethanol (6.3 ml) and aqueous HCI (0.1 M, 1.6 ml). The mixture was stirred for about 1 hour until a sol was formed.

[0064] Example 7 Formation of a sol:

[0065] Methyltriethoxysilane (100%, 5.8 ml) was added dropwise to a mixture of ethanol (6.2 ml) and aqueous NaOH (0.1 M, 1.5 ml). The solution was stirred for about 30 minutes until a sol was formed.

[0066] Example 8 Formation of a sol:

[0067] Aluminium isopropoxide (9.2 g) was added to a mixture of ethanol (6.5 ml) and aqueous HCI (0.1 M, 1.6 ml). The mixture was stirred for about 1 hour until a sol was formed.

[0068] Example 9 Formation of a sol:

[0069] A silicon alkoxide precursor mixture consisting of 50% tetraethoxysilane and 50% methyltriethoxysilane (5 ml) was added dropwise to a mixture of ethanol (10 ml) and aqueous NaOH (0.1 M, 2 ml). The solution was stirred for about 30 minutes until a sol was formed.

[0070] Example 10 Formation of a sol:

[0071] Solution A - Titanium (IV) ethoxide (5 ml) was added dropwise to ethanol (10 ml). Solution B - 5 ml of solution A was added to a silicon alkoxide precursor mixture consisting of 50% tetraethoxysilane and 50% phenyltriethoxysilane (5.2 ml). The mixture was added dropwise to a mixture of ethanol (8.2 ml) and aqueous HCI (0.1 M, 1.8 ml). The solution was stirred at room temperature for about 1 hour until a sol was formed.

[0072] Example 11 Formation of a sol:

[0073] A mixture of silanol precursor consisting of 50% tetraethoxysilane and 50% phenyltriethoxysilane (5.2 ml) was added dropwise to a mixture of ethanol (10 ml) and aqueous HCI (0.1 M, 2 ml). The solution was stirred at room temperature for about 6 hours until a sol was formed.

[0074] Example 12 Formation of a sol:

[0075] Cationic starch (CS; 7 mg) was dispersed in a mixture of ethanol (10 ml) and aqueous HCI (0.1 M, 1.6 ml) to give a solution of pH 2. To this stirred solution was added dropwise a silanol precursor consisting of 100% tetraethoxysilane (5.2 ml) and stirring was continued for a further 8 hours.

[0076] Example 13 Formation of a sol:

[0077] Cationic starch (CS; 7 mg) was dispersed in a mixture of ethanol (10 ml) and aqueous HCI (0.1 M, 1.6 ml) to give a solution of pH 2. To this stirred solution was added dropwise a silanol precursor consisting of 100% tetraethoxysilane (5.2 ml) and stirring was continued for a further 8 hours.

[0078] Example 14 Formation of a sol:

[0079] Chitosan (6 mg) was dispersed in a mixture of ethanol (12 ml) and aqueous HCI (0.1 M, 2 ml) to give a solution of pH 2. To this stirred solution was added dropwise a mixture of silanol precursors consisting of 50% tetraethoxysilane and 50% phenyltriethoxysilane (6 ml) and stirring was continued for a further 1.5 hours.

[0080] Example 15 Formation of a sol:

[0081] Wheat flour (7 mg) was dispersed in a mixture of ethanol (8 ml) and aqueous NaOH (0.1 M, 2 ml) to give a solution of pH 13. To this stirred solution was added dropwise a mixture of silanol precursors consisting of 50% tetraethoxysilane and 50% methyltriethoxysilane (5.2 ml) and stirring was continued for a further 30 minutes.

[0082] Example 16 Formation of a sol:

[0083] Cationic starch (CS; 5 mg) was dispersed in a mixture of ethanol (10 ml) and aqueous NaOH (0.1 M, 1.5 ml) to give a solution of pH 13. To this stirred solution was added dropwise methyltriethoxysilane (5.2 ml) and stirring was continued for a further 20 minutes.

[0084] Example 17 Formation of a sol:

[0085] Wheat flour (5 mg) was dispersed in a mixture of ethanol (6 ml), aqueous NaOH (0.1 M, 1 ml) and methyltriethoxysilane (1 ml) to produce a solution of pH 13. To this stirred solution was added dropwise a mixture of silanolate precursors consisting of 50% tetraethoxysilane and 50% phenyltriethoxysilane (1 ml) and stirring was continued for a further 30 minutes.

[0086] Example 18 Formation of a sol:

[0087] Cationic starch (CS; 5 mg) was dispersed in a mixture of ethanol (7.6 ml) and aqueous HC1 (0.1 M, 1.6 ml) to produce a solution of pH 2. To this stirred solution was added dropwise a mixture of silanolate precursors consisting of 50% tetraethoxysilane and 50% phenyltriethoxysilane (5.2 ml) and stirring was continued for a further 1 hour.

[0088] Example 19 Formation of a sol:

[0089] Wheat flour (5 mg) was dispersed in a mixture of ethanol (6 ml), aqueous NaOH (0.1 M, 1 ml) and methyltriethoxysilane (1 ml) to produce a solution of pH 13. To this stirred solution was added dropwise triethoxysilane (1 ml) and stirring was continued for a further 1 hour.

[0090] Example 20 Formation of a sol:

[0091] Wheat flour (5 mg) was dispersed in a mixture of ethanol (6 ml), aqueous NaOH (0.1 M, 1 ml) and methyltriethoxysilane (1 ml) to produce a solution of pH 13. To this stirred solution was added dropwise a mixture of silanolate precursors consisting of 50% tetraethoxysilane and 50% phenyltriethoxysilane (1 ml) and stirring was continued for a further 1 hour.

[0092] Examples 21 to 28 given in Table 2 demonstrate various wetting agents comprising sols containing various solvents, biopolymers and alkoxides.

[0093] Table 2 Other sol examples matrix

[0094]

[0095] Examples 29 to 35 provide examples of various methods of forming products within the scope of the present application.

[0096] Example 29

[0097] The sol formed in Example 2, 3, 10, 13, 15, 16, 17, 18, 19, and 20 were each diluted with water, a mixture of water and ethanol, or a mixture of water and any other solvent disclosed herein to provide a 5% solution of each sol, which was then applied to an air-laid pulp using a spray application technique. The pulp was formed using a press at a pressure of about 1000 kg / m 2 and 6000 kg / m 2 The pulp was formed using a press at a pressure of about 1000 kg / m

[0098] Example 30

[0099] The sol formed in Example 24 was sprayed onto an air-laid pulp and the intermediate pulp formed thereby was molded according to Example 29 using a hot press process. The hot pressed product was then subjected to a gas barrier coating before being treated with an additional hot press step. The resulting twice hot pressed product was tested for water impermeability. A water droplet was placed on the molded product and allowed to sit for 2 hours. No water penetration into the surface of the product was observed.

[0100] Example 31

[0101] The sol formed in Example 26 was sprayed onto an air-laid pulp and the intermediate pulp formed thereby was molded according to Example 29 using a hot press process. The hot pressed product was then subjected to a further hot press molding. The twice hot pressed product was then tested for water impermeability. A water droplet was placed on the molded product and allowed to sit for 2 hours. No water penetration into the surface of the product was observed.

[0102] Example 32

[0103] A wetting agent including water, a sol, and a sol including a biopolymer was applied to an air-laid pulp at different weight percentages of wetting agent to dry air-laid pulp mass and each intermediate pulp formed thereby was molded according to Example 29. A control sample was also formed that did not use any form of wetting agent (i.e., 0 wt%) and dry pulp. All products formed using a wetting agent exhibited water resistance and impermeability to water when tested. The surface finish of all products was visually evaluated and summarized in Table 3 below.

[0104] Table 3 Surface Properties of Sol Wetting Agent at Different Weight Percentages

[0105] 1000 kg / m 2 ]]> 6000 kg / m 2 ]]> 0 wt% Rough surface Surface tear 25 wt% - Moderate surface smoothness 40 wt% - Moderate surface smoothness 50 wt% Moderate surface smoothness Good surface smoothness 75 wt% - Good surface smoothness 100 wt% Moderate surface smoothness Good surface smoothness 150 wt% Moderate surface smoothness Good surface smoothness

Claims

1. A method comprising: applying a wetting agent to the airlaid pulp to form an intermediate pulp; and hot-pressing the intermediate pulp to form a molded product.

2. The method according to claim 1, wherein the airlaid pulp, intermediate pulp and / or molded article is free or essentially free of thermoplastic polymers and / or hydrocarbon-based plastics.

3. The method according to claim 1 or claim 2, further comprising applying a functional coating and / or barrier to the intermediate pulp or molded article.

4. The method according to any one of the preceding claims, further comprising subjecting the airlaid pulp, intermediate pulp or molded article to additional hot pressing and / or cold pressing.

5. The method according to any one of the preceding claims, wherein the molding is a water-resistant or water-impermeable molding.

6. The method according to any one of the preceding claims, wherein the wetting agent is applied to the airlaid pulp by brushing, spraying, spray drying, rolling, dipping, dripping, injecting, transferring, immersing, soaking, mixing, spreading, doctoring, filling or any combination thereof.

7. The method of claim 6, wherein the wetting agent is applied to the airlaid pulp by spraying.

8. The method according to any one of the preceding claims, wherein the intermediate pulp is hot pressed at a temperature above 100°C.

9. The method according to claim 8, wherein the intermediate pulp is hot pressed at a temperature above 150°C.

10. The method according to any one of the preceding claims, wherein hot pressing the intermediate pulp comprises: The intermediate pulp is pressed into at least one mold, pressed between at least one plate and at least one other surface, or any combination thereof.

11. The method according to any one of claims 4 to 10, wherein the method further comprises subjecting the airlaid pulp, intermediate pulp or molded article to additional hot pressing and / or cold pressing, further wherein subjecting the intermediate pulp to additional hot pressing and / or cold pressing comprises: The intermediate pulp is pressed into at least one mold, pressed between at least one plate and at least one other surface, or any combination thereof.

12. The method of claim 10 or 11, wherein the mold comprises one or more fluid escape elements configured to allow a fluid, optionally a wetting agent in vapor and / or liquid form, to exit the mold, optionally wherein the one or more fluid escape elements comprise one or more holes, vents, orifices, flow channels, conduits, ducts, passages, or any combination thereof.

13. The method according to any one of the preceding claims, further comprising applying heat to dry the airlaid pulp, intermediate pulp or product.

14. The method according to any one of the preceding claims, further comprising drying the airlaid pulp, intermediate pulp or product without directly applying energy.

15. The method of any preceding claim, wherein the wetting agent comprises water.

16. The method of any preceding claim, wherein the wetting agent comprises a sol.

17. The method according to any one of claims 16, wherein the sol comprises a solvent, an alkoxide and a catalyst.

18. The method of claim 17, wherein the sol further comprises a biopolymer.

19. The method of claim 18, wherein the biopolymer comprises starch.

20. The method of claim 19, wherein the starch comprises cationic starch.

21. The method according to claim 20, wherein the cationic starch is selected from quaternary ammonium cationic starch, tertiary ammonium cationic starch, and any combination thereof.

22. The method of claim 21, wherein the biopolymer comprises flour.

23. The method of claim 22, wherein the flour comprises 5% to 85% starch, 0% to 30% hemicellulose, 0% to 50% cellulose, 0% to 25% lignin, 0% to 35% protein, and 0% to 25% ash.

24. The method according to claim 22 or 23, wherein the flour is selected from wheat flour, barley flour, lentil flour, bamboo flour, corn flour, oat flour, rye flour, buckwheat flour, rice flour, chickpea flour, green pea flour, or any combination thereof.

25. The method of any one of claims 17 to 24, wherein the catalyst is at least one of an acid and a base.

26. The method of claim 25, wherein the catalyst is selected from the group consisting of hydrochloric acid, citric acid, nitric acid, acetic acid, sodium hydroxide, potassium hydroxide, ammonia, and any combination thereof.

27. The method of any one of claims 17 to 26, wherein the alkoxide is selected from the group consisting of silicon alkoxides, metal alkoxides, phosphorus alkoxides, and any combination thereof.

28. The method of any one of claims 17 to 26, wherein the alkoxide is selected from the group consisting of n-propyltriethoxysilane, tetrapropyl orthosilicate, titanium (IV) tert-butoxide, titanium (IV) isopropoxide, triethoxysilane, methyltriethoxysilane, triethoxy(octyl)silane, phenyltriethoxysilane, titanium (IV) ethoxide, triethoxysilylcyclopentane, (3-glycidyloxypropyl)trimethoxysilane, cyclopentyltriethoxysilane, 3-aminopropyltriethoxysilane, triethoxy-3-(2-imidazolin-1-yl)propylsilane, and any combination thereof.

29. The method of any one of claims 17 to 28, wherein the solvent comprises water, one or more alcohols, and any combination thereof.

30. The method of claim 29, wherein the solvent comprises methanol, ethanol, isopropanol, butanol, ethylene glycol, or any combination thereof.

31. The method of any preceding claim, wherein the wetting agent comprises one or more functional additives.

32. The method of claim 31 , wherein the one or more functional additives comprise photoinitiators, resins, oils, dyes, salts, biocides, mineral or other inorganic particles, surfactants, biopolymers, composite particles, and / or metallic particles.

33. The method of claim 31 or 32, wherein the wetting agent delivers the one or more functional additives into the internal structure of the airlaid pulp.

34. The method according to any one of the preceding claims, wherein hot pressing the intermediate pulp comprises applying a pressure of at least 1000 kg / m 2 pressure.

35. The method according to any one of claims 1 to 33, wherein hot pressing the intermediate pulp comprises applying a pressure of about 6000 kg / m 2 pressure.

36. The method according to any of the preceding claims, wherein hot pressing the intermediate pulp comprises applying pressure to a portion of the intermediate pulp for a duration of from less than or equal to 1 second to at most 10 seconds, optionally wherein the duration of applying pressure is less than or equal to 5 seconds.

37. The method of any one of the preceding claims, wherein the molded article is a fiber-based molded bubble film.

38. The method according to any one of the preceding claims, wherein the molded article is a food or beverage packaging product.

39. A fluid resistant or fluid impermeable fiber-based packaging material comprising an airlaid pulp comprising a molded article formed by the method of any one of the preceding claims.

40. The fiber-based packaging material of claim 39, comprising a sol comprising a solvent, an alkoxide, and optionally a biopolymer.

41. The fiber-based packaging material according to claim 39 or 40, wherein the fiber-based packaging material is a fiber-based bubble film.

42. The fiber-based packaging material of claim 41, wherein the fiber-based bubble film is formed using a roll-to-roll process, a roll-to-sheet process, a sheet-to-roll process, or a sheet-to-sheet process.

43. The fiber based packaging material according to claim 39 or 40, wherein the fiber based packaging material is a fiber based packaging filler.

Images