Additive for use with cellulose fiber products and methods of making the same

Abstract

Disclosed herein is a method of making a cellulose fiber product. The method comprises preparing an additive, associating the additive with cellulose fibers to form a cellulose fiber mixture, and forming the cellulose fiber mixture into the cellulose fiber product. The additive comprises any one or more of a chitosan polymer, an organic acid, a polyvinyl alcohol, a cationic acid, a microfibrillated cellulose, montmorillonite clay, a cationic wax, a cationic retention aid, and an anionic retention aid.

Description

Attorney Docket No. 2967050.3. WO1Customer No. 190456ADDITIVE FOR USE WITH CELLULOSE FIBER PRODUCTS AND METHODS OF MAKING THE SAME

[0001] All patents, patent applications, and publications cited herein are hereby incorporated by reference in their entirety. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein.

[0002] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.Government Interests

[0003] Not applicable.Cross-Reference to Related Applications

[0004] This application claims priority to U.S. Provisional Application No. 63 / 713,453, entitled “METHODS OF ASSOCIATING AN ADDITIVE WITH CELLULOSE FIBERS,” filed October 29, 2024, the contents of which is incorporated herein by reference in its entirety.Field of the Disclosure

[0005] This application relates in general to an additive for use with cellulose fibers and cellulose fiber products, and methods of making the same. More specifically, this application relates to an additive for use with cellulose fibers and cellulose fiber products wherein the additive is configured to increase strength, stiffness, and / or water resistance of the cellulose fibers and / or cellulose fiber products.Attorney Docket No. 2967050.3. WO1Customer No. 190456Background

[0006] This section is intended to introduce various aspects of the art, which may be associated with exemplary embodiments of the present disclosure. This discussion is believed to assist in providing a framework to facilitate a better understanding of particular aspects of the present disclosure. Accordingly, it should be understood that this section should be read in this light, and not necessarily as admissions of prior art.

[0007] Sustainable packaging has grown in popularity over recent years due to its reduced environmental impact as compared to plastics and other materials harmful to the environment. Traditional plastic packaging does not biodegrade and thus significantly contributes to pollution. These plastics often end up in landfills or littered in the ocean, wherein they may leach harmful chemicals into the environment. Moreover, producing plastics generally requires the use of non-renewable fossil fuels, the extraction of which contributes to carbon emissions.

[0008] Sustainable packaging is typically biodegradable, meaning that it may naturally decompose or break down into non-toxic components when disposed of properly, and renewable, meaning the materials / resources used can be regrown and harvested sustainably. Recycling processes are often employed such that the sustainable packaging may be reused, for example in a new sustainable packaging after being broken down and repurposed.

[0009] Sustainable packaging may be made from a variety of materials, including cellulose fibers. Cellulose fibers are long, chain-like molecules that are the main component of plant cell walls. They are made up of repeating units of glucose molecules linked together to form a tough, rigid structure. Using cellulose fibers in sustainable packaging has many advantages, including that the fibers are derived from a renewable resource, biodegradable, compostable, and generally versatile. These fibers are often used to make paper products dueAttorney Docket No. 2967050.3. WO1Customer No. 190456 in part to the cellulose fibers’ ability to provide strength and stiffness to the products. These paper products include, but are not limited to, copy paper, packaging board, cardboard, and molded fiber.

[0010] While sustainable packing made with cellulose fibers has many advantages, there are certain properties of the fibers that render them undesirable in certain applications. One major issue with cellulose fibers is that they naturally absorb water. Thus, when cellulose fibers that have been made into paper products are exposed to moisture, the fiber absorbs the moisture and causes the paper product to lose its strength. Paper that is used for packaging is often exposed to water and other liquids wherein it quickly loses strength, stiffness, and the ability to protect is contents.

[0011] Cellulose fiber’s tendency to absorb water has limited the applications in which paper products made from these fibers is reasonable. Existing additive treatments allow for short term exposure of paper products to moisture but fail after a brief period of time. Moreover, many existing additive treatments cause the paper products to which they are applied to no longer be biodegradable or compostable. Therefore, a need exists for an additive that prevents, for an extended period of time, cellulose fibers from absorbing liquid, thus allowing paper products made from the fibers to maintain strength and stiffness. Moreover, a need exists for the additive to allow the paper product to which it is applied to remain biodegradable and compostable. The present disclosure attempts to address the limitations and deficiencies in prior solutions according to the principles and embodiments disclosed herein.Summary

[0012] Disclosed herein is an additive for use with cellulose fibers and cellulose fiber products, and methods of making the same, wherein the additive is configured to increase theAttorney Docket No. 2967050.3. WO1Customer No. 190456 strength, stiffness, and / or water resistance of the cellulose fibers and / or the cellulose fiber product.

[0013] One aspect of the present disclosure may be a method of making a cellulose fiber product. The method may include preparing an additive, associating the additive with cellulose fibers to form a cellulose fiber mixture, and forming the cellulose fiber mixture into the cellulose fiber product. The additive may comprise any one or more of a chitosan polymer, an organic acid, a polyvinyl alcohol, a cationic rosin, a microfibrillated cellulose (MFC), a montmorillonite clay, a cationic wax, a cationic retention aid, and an anionic retention aid.

[0014] In certain embodiments, preparing the additive may include mixing the chitosan polymer and the organic acid.

[0015] In certain embodiments, preparing the additive may include stirring the chitosan polymer and the organic acid for about 5 minutes to about 20 minutes.

[0016] In certain embodiments, preparing the additive may include mixing the polyvinyl alcohol with water.

[0017] In certain embodiments, preparing the additive may include heating the polyvinyl alcohol and water to a temperature of about 60 degrees Celsius to about 100 degrees Celsius.

[0018] In certain embodiments, preparing the additive may include mixing a first mixture including the chitosan polymer and the organic acid with a second mixture including the polyvinyl alcohol.Attorney Docket No. 2967050.3. WO1Customer No. 190456

[0019] In certain embodiments, preparing the additive may include mixing a first mixture including the chitosan polymer, the organic acid, and the polyvinyl alcohol with any one or more of the MFC, montmorillonite clay, and cationic wax.

[0020] In certain embodiments, preparing the additive may include mixing a first mixture including the chitosan polymer, the organic acid, and the polyvinyl alcohol with any one or more of the MFC, montmorillonite clay, and cationic wax, for about 1 minute to about 20 minutes.

[0021] In certain embodiments, preparing the additive may include mixing a first mixture including the chitosan polymer, the organic acid, the polyvinyl alcohol, the MFC, the montmorillonite clay, and the cationic wax, or any combination thereof, with the cationic rosin.

[0022] In certain embodiments, preparing the additive may include mixing a first mixture including the chitosan polymer, the organic acid, the polyvinyl alcohol, the MFC, the montmorillonite clay, and the cationic wax, or any combination thereof, with cationic rosin, fo about 1 minute to about 20 minutes.

[0023] In certain embodiments, associating the additive with the cellulose fibers to form a cellulose fiber mixture may include treating the cellulose fibers with the cationic retention aid.

[0024] In certain embodiments, treating the cellulose fibers with the cationic retention aid may include mixing the cationic retention aid with a pulp mixture or slurry comprising the cellulose fibers.

[0025] In certain embodiments, associating the additive with the cellulose fibers to form a cellulose fiber mixture may include mixing a first mixture including one or more of the chitosan polymer, the organic acid, the polyvinyl alcohol, the microfibrillated cellulose, theAttorney Docket No. 2967050.3. WO1Customer No. 190456 montmorillonite clay, the cationic wax, and the cationic rosin with the pulp mixture or slurry comprising the treated cellulose fibers.

[0026] In certain embodiments, associating the additive with the cellulose fibers to form a cellulose fiber mixture may include stirring the first mixture and the pulp mixture or slurry comprising the treated cellulose fibers for about 1 minute to about 20 minutes.

[0027] In certain embodiments, associating the additive with the cellulose fibers to form a cellulose fiber mixture may include mixing a first mixture including the chitosan polymer, the organic acid, the polyvinyl alcohol, the microfibrillated cellulose, the montmorillonite clay, the cationic wax, the cationic rosin, the cationic retention aid, and the cellulose fiber, or any combination thereof, with the anionic retention aid.

[0028] In certain embodiments, forming the cellulose fiber mixture into the cellulose fiber product may include removing at least a portion of a liquid of the cellulose fiber mixture.

[0029] In certain embodiments, forming the cellulose fiber mixture into the cellulose fiber product may include drying the cellulose fiber mixture.

[0030] In certain embodiments, forming the cellulose fiber mixture into the cellulose fiber product may include cutting, shaping, molding, or forming, or a combination thereof, the cellulose fiber mixture.

[0031] Another aspect of the present disclosure is an additive associable with cellulose fiber. The additive may comprise a chitosan polymer, an organic acid, a polyvinyl alcohol, a cationic rosin, a cationic retention aid, and an anionic retention aid and any one or more of a microfibrillated cellulose, a montmorillonite clay, and a cationic wax.Attorney Docket No. 2967050.3. WO1Customer No. 190456

[0032] Another aspect of the present disclosure is a slurry for use in the formation of a cellulose fiber product. The slurry may comprise a chitosan polymer, an organic acid, a polyvinyl alcohol, a cationic rosin, a cationic retention aid, an anionic retention aid, and cellulose fibers and any one or more of a microfibrillated cellulose, a montmorillonite clay, a cationic wax.

[0033] The foregoing has outlined rather broadly the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter that form the subject of the claims of the disclosure.

[0034] It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It also should be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features that are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.Brief Description of the Drawings

[0010] Certain illustrations, charts, or flow charts are provided to allow for a better understanding for the present invention. It is to be noted, however, that the drawings illustrate only selected embodiments of the inventions and are therefore not to be considered limiting ofAttorney Docket No. 2967050.3. WO1Customer No. 190456 scope. Additional and equally effective embodiments and applications of the present invention exist.

[0011] Fig. 1 is a block diagram depicting a method of associating an additive with cellulose fibers.Detailed Description

[0012] This application relates in general to an additive for use with cellulose fibers and / or a cellulose fiber product, and methods of making the same, wherein the additive is configured to increase the strength, stiffness, and / or water resistance of the cellulose fibers and / or the cellulose fiber product, according to the present disclosure.

[0013] So that the manner in which the present application can be better understood, certain illustrations and figures are appended hereto. It is to be noted, however, that the drawings illustrate only selected embodiments and elements of the systems and methods described herein and are therefore not to be considered limiting in scope for the systems and methods as described herein may admit to other equally effective embodiments and applications. Various embodiments of the present disclosure will be described in detail with reference to the drawings having like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the disclosure, which is limited only by the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the claimed disclosure.

[0014] The singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. The use of the word “a” or “an” when used in conjunctionAttorney Docket No. 2967050.3. WO1Customer No. 190456 with the term “comprising” in the claims and / or the specification can mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”

[0015] Wherever any of the phrases “for example,” “such as,” “including” and the like are used herein, the phrase “and without limitation” is understood to follow unless explicitly stated otherwise. Similarly, “an example,” “exemplary” and the like are understood to be nonlimiting.

[0016] The term “substantially” allows for deviations from the descriptor that do not negatively impact the intended purpose. Descriptive terms are understood to be modified by the term “substantially” even if the word “substantially” is not explicitly recited. Therefore, for example, the phrase “wherein the lever extends vertically” means “wherein the lever extends substantially vertically” so long as a precise vertical arrangement is not necessary for the lever to perform its function.

[0017] The terms “comprising” and “including” and “having” and “involving” (and similarly “comprises,” “includes,” “has,” and “involves”) and the like are used interchangeably and have the same meaning. Specifically, each of the terms is defined consistent with the common United States patent law definition of “comprising” and is therefore interpreted to be an open term meaning “at least the following,” and is also interpreted not to exclude additional features, limitations, aspects, etc. Thus, for example, “a process involving steps a, b, and c” means that the process includes at least steps a, b, and c. Wherever the terms “a” or “an” are used, “one or more” is understood, unless such interpretation is nonsensical in context.

[0018] As used herein the term “about” is used herein to mean approximately, roughly, around, or in the region of. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical valuesAttorney Docket No. 2967050.3. WO1Customer No. 190456 set forth. In general, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 20 percent up or down (higher or lower).

[0019] Disclosed herein is an additive 100 configured to increase strength, stiffness, and / or water resistance of cellulose fibers and / or cellulose fiber products. Moreover, in certain optional embodiments, the additive 100 may be configured to generally mitigate the absorption of liquid in cellulose fibers and / or cellulose fiber products. The additive 100 may also be referred to herein as an additive array 100. In certain optional embodiments, the additive array 100 may be configured to be added to a finished product having cellulose fibers, such as a cellulose fiber product, or to the materials / ingredients of a cellulose fiber product during production. For example, the additive array 100 may be mixed into a material mixture during production, such as a pulp mixture or slurry for paper products. In another example, the additive array 100 may take the form of a homogenous mixture having flowable or viscous layers which may be deposited on the surface of a finished cellulose fiber product. In certain optional embodiments, one or more rollers, flow coaters, and / or sprayers may be used as vehicles to deposit a layer of the additive array 100 on the finished cellulose fiber product.

[0020] In accordance with certain optional embodiments, the additive array 100 may comprise one or more of a chitosan polymer, an organic acid, a polyvinyl alcohol, a cationic rosin, a microfibrillated cellulose (MFC), a montmorillonite clay, a cationic wax, a cationic retention aid, and an anionic retention aid. The chitosan polymer, organic acid, polyvinyl alcohol, cationic rosin, MFC, montmorillonite clay, cationic wax, cationic retention aid, anionic retention aid, or combinations thereof may be referred to collectively herein as the additive ingredients, or each individually as an additive ingredient. While each of the additive ingredients may form a portion of the additive array 100, the additive ingredients may be mixed together to form the additive array 100 prior to associating the additive array 100 with celluloseAttorney Docket No. 2967050.3. WO1Customer No. 190456 fibers, or certain additive ingredients may be associated with the cellulose fibers separate from the remaining additive ingredients.

[0021] In certain optional embodiments, the additive array 100 may be mixed into, added to, or otherwise associated with cellulose fibers to form a cellulose fiber mixture. In certain optional embodiments, the additive array 100 may be mixed into, added to, or otherwise associated a paper pulp mixture containing the cellulose fibers to form the cellulose fiber mixture. Thus, the paper pulp mixture as referred to herein includes cellulose fibers. The paper pulp mixture may include dry fibers of varying lengths and qualities depending on the desired characteristics of an intended use. In certain optional embodiments, the paper pulp mixture may be mixed with a liquid, such as water to name one example, to form a slurry. In certain optional embodiments, the additive array 100 may be mixed into, added to, or otherwise associated with slurry to form the cellulose fiber mixture. In other optional embodiments, the additive array 100 may be mixed into, added to, or otherwise associated with the paper pulp mixture to form the cellulose fiber mixture.

[0022] The cellulose fiber mixture may be formed into a cellulose fiber product. The cellulose fiber product may be a paper product to name example. The cellulose fiber mixture may be formed into a cellulose fiber product by manufacturing processes. For example, the cellulose fiber product may be formed by pouring the cellulose fiber mixture through a screen or like device to drain at least a portion of the liquid from the cellulose fiber mixture. In certain optional embodiments, the cellulose fiber mixture may be pressed between rollers, or shaped dies, made of metal or plastic to name a few examples, or like devices to further remove liquid from the cellulose fiber mixture and compact or press the cellulose fibers contained therein. In certain optional embodiments, the cellulose fiber mixture may be dried via heated rollers, heated dies, drying racks, or the like. In certain optional embodiments, the cellulose fiberAttorney Docket No. 2967050.3. WO1Customer No. 190456 mixture may be finished, wherein the cellulose fiber mixture is cut, shaped, molded, and / or formed into a desired product.

[0023] The cellulose fiber product to which the additive array 100 has been added or otherwise applied to may be referred to herein as a “treated product.” The cellulose fiber product may be a paper product as discussed herein, such as plates, bowls, trays, and / or other storage containers used to store food and / or other consumer goods, to name a few examples. However, the present disclosure should not be limited to paper products as the additive array 100 may be added or otherwise applied to a variety of other products having fibers therein. Materials to which the additive array 100 may be added to may include, for example, wood, plywood, OSB, plastic, metals, wallboard, cardboard, medium density fiberboard (MDF), particle board, and / or any material or composite material suitable.

[0024] The chitosan polymer may enhance the strength and / or stiffness of a treated product and / or the cellulose fibers associated with the treated product. The chitosan polymer may bind, or otherwise aid in binding, the cellulose fibers associated with a treated product together. The chitosan polymer may be a blend of chitosan, having a molecular formula of C56H103N9O39, and other natural and synthetic polymers such as zein, curdlan, sodium alginate, konjac, polylactic acid, glucomannan, poly caprolactone, polyethylene oxide), graphene oxide, and poly(vinyl pyrollidine) to name a few examples. The additive array 100 may comprise an amount of chitosan polymer equal to about 0.5% to about 20% relative to the dry fiber content of the paper pulp mixture. In certain embodiments, the additive array 100 may comprise an amount of chitosan polymer equal to about 1% to about 4% relative to the dry fiber content of the paper pulp mixture. The chitosan polymer may have a degree of deacetylation from about 30% to about 99%.Attorney Docket No. 2967050.3. WO1Customer No. 190456

[0025] The organic acid may be oxalic acid, citric acid, malic acid, formic acid, or the like. The organic acid may be cross-linked or otherwise associated with the chitosan polymer. The organic acid may enhance the chitosan polymer’s ability to attach to the cellulose fibers associated with a treated product. The additive array 100 may comprise an amount of organic acid equal to about 0.5% to about 20% relative to the dry fiber content of the paper pulp mixture. In certain embodiments, the additive array 100 may comprise an amount of organic acid equal to about 2% to about 5% relative to the dry fiber content of the paper pulp mixture.

[0026] The polyvinyl alcohol may provide liquid-resistant qualities to the additive array 100. The polyvinyl alcohol may be retained in the cellulose fibers such that it prevents, or otherwise mitigates, the cellulose fibers from absorbing liquid. The additive array 100 may comprise an amount of polyvinyl alcohol equal to about 0.5% to about 20% relative to the dry fiber content of the paper pulp mixture. In certain embodiments, the additive array 100 may comprise an amount of polyvinyl alcohol equal to about 0.5% to about 2.5% relative to the dry fiber content of the paper pulp mixture. The polyvinyl alcohol may have a degree of hydrolysis from about 80% to about 99%. The polyvinyl alcohol may be highly insoluble in water. The solubility of the polyvinyl alcohol may depend on its degree of hydrolysis and molecular weight, wherein the degree of hydrolysis may be inversely proportional to its solubility.

[0027] The cationic rosin may provide liquid-resistant qualities to the additive array 100. The cationic rosin may be retained in the cellulose fibers such that it prevents, or otherwise mitigates, the cellulose fibers from absorbing liquid. The cationic rosin may prevent, or otherwise mitigate, discoloration and / or yellowing of the cellulose fibers when the cellulose fibers are exposed to liquid. The additive array 100 may comprise an amount of cationic rosin equal to about 0.5% to about 20% relative to the dry fiber content of the paper pulp mixture. InAttorney Docket No. 2967050.3. WO1Customer No. 190456 certain embodiments, the additive array 100 may comprise an amount of cationic rosin equal to about 2% to about 5% relative to the dry fiber content of the paper pulp mixture.

[0028] The MFC may enhance the strength and / or stiffness of a treated product and / or the cellulose fibers associated with the treated product. The additive array 100 may comprise an amount of MFC equal to about 0.5% to about 20% relative to the dry fiber content of the paper pulp mixture. In certain embodiments, the additive array 100 may comprise an amount of MFC equal to about 1% to about 4% relative to the dry fiber content of the paper pulp mixture.

[0029] The cationic wax may provide liquid-resistant qualities to the additive array 100. The cationic wax may be retained in the cellulose fibers such that it prevents, or otherwise mitigates, the cellulose fibers from absorbing liquid. The additive array 100 may comprise an amount of cationic wax equal to about 2% to about 10% relative to the dry fiber content of the paper pulp mixture. In certain embodiments, the additive array 100 may comprise an amount of cationic wax equal to about 0.5% to about 2.5% relative to the dry fiber content of the paper pulp mixture. The cationic wax may be highly insoluble in water.

[0030] The montmorillonite clay may have a synergistic impact on the chitosan polymer; and the synergistic impact may only occur when the montmorillonite clay is added in low doses. The montmorillonite clay may, in combination with the chitosan polymer or independent thereof, may enhance the strength and / or stiffness of a treated product and / or the cellulose fibers associated with a treated product. The additive array 100 may comprise an amount of montmorillonite clay equal to about 0.5% to about 10% relative to the dry fiber content of the paper pulp mixture. In certain embodiments, the additive array 100 may comprise an amount of montmorillonite clay equal to about 1% to about 4% relative to the dry fiber content of the paper pulp mixture.Attorney Docket No. 2967050.3. WO1Customer No. 190456

[0031] The cationic retention aid may aid in binding or otherwise retaining the additive array 100 to the cellulose fibers associated with a treated product. The additive array 100 may comprise an amount of cationic retention aid equal to about 0.5% to about 20% relative to the dry fiber content of the paper pulp mixture. In certain embodiments, the additive array 100 may comprise an amount of cationic retention aid equal to about 0.5% to about 2.5% relative to the dry fiber content of the paper pulp mixture.

[0032] The anionic retention aid may aid in binding or otherwise retaining the additive array 100 to the cellulose fibers associated with a treated product. The additive array 100 may comprise an amount of anionic retention aid equal to about 0.5% to about 20% relative to the dry fiber content of the paper pulp mixture. In certain embodiments, the additive array 100 may comprise an amount of anionic retention aid equal to about 0.5% to about 2.5% relative to the dry fiber content of the paper pulp mixture.

[0033] In certain embodiments, the amount of chitosan polymer and the amount of cationic rosin may be balanced. In other words, the amount of chitosan polymer in the additive array 100 may depend at least in part on the amount of cationic rosin, and vice versa. Without being bound by theory, the chitosan polymer and the cationic rosin may compete for common attachment sites on the cellulose fibers.

[0034] The additive array 100 may be configured to mitigate the absorption of liquid in one or more cellulose fibers and / or the treated product. When the additive array 100 is applied to or otherwise associated with a treated product, such as a paper product, the treated product may retain strength and / or stiffness when exposed to a liquid.

[0035] One exemplary advantage of the present disclosure may be that a food storage container associated with the additive array 100 may maintain improved strength and stiffnessAttorney Docket No. 2967050.3. WO1Customer No. 190456 when exposed to liquid, either from condensation or otherwise, as compared to a prior art food storage container.

[0036] In certain embodiments, the additive array 100 may be associated with a paper pulp mixture and / or slurry. The additive array 100 may be associated with a paper pulp mixture, and the paper pulp mixture may then be made into a treated slurry. Alternatively, the additive array 100 may be associated with a slurry, and the slurry may then be considered a treated slurry. The treated slurry may then be used in the formation of a cellulose fiber-based product, such as a food storage container, or other fiber-based product.Methods of Making a Cellulose Fiber Product Including by Associating an Additive with Cellulose Fibers

[0037] Another aspect of the present disclosure relates to methods of making a cellulose fiber product. In certain optional embodiments, a method 200 of making a cellulose fiber product comprises preparing the additive 100. The additive 100 may comprise any one or more of the chitosan polymer, the organic acid, the polyvinyl alcohol, the cationic rosin, the MFC, the montmorillonite clay, the cationic wax, the cationic retention aid, and the anionic retention aid.

[0038] In certain optional embodiments, preparing the additive 100 includes mixing the chitosan polymer and organic acid. The mixture of the chitosan polymer and organic acid may be referred to herein as the chitosan polymer and organic acid mixture. The chitosan polymer and organic acid may be mixed such that a stable pH of about 4.0 is achieved. The chitosan polymer and organic acid may be stirred or otherwise agitated for about 5 minutes to about 20Attorney Docket No. 2967050.3. WO1Customer No. 190456 minutes. In certain optional embodiments, the chitosan polymer and organic acid may be stirred or otherwise agitated for about 10 minutes.

[0039] In certain optional embodiments, the method 200 may further comprise mixing the polyvinyl alcohol with water. The mixture of the polyvinyl alcohol and water may be referred to herein as the polyvinyl alcohol and water mixture. Prior to mixing, the polyvinyl alcohol may exist in a solid state. The polyvinyl alcohol and water may be mixed via a homogenizer or the like. The polyvinyl alcohol and water may be heated until a temperature of about 60 degrees Celsius to about 100 degrees Celsius is reached. In certain optional embodiments, the polyvinyl alcohol and water may be heated until a temperature of about 80 degrees Celsius is reached. The polyvinyl alcohol and water may be heated such that the temperature of the polyvinyl alcohol and water mixture increases at a rate of about 1 degree Celsius to about 10 degrees Celsius per minute. In certain optional embodiments, the polyvinyl alcohol and water may be heated such that the temperature of the polyvinyl alcohol and water mixture increases at a rate of about 2 degrees Celsius per minute. After mixing the polyvinyl alcohol with water, the polyvinyl alcohol may be substantially dissolved in the water.

[0040] In certain optional embodiments, the method 200 may further comprise adding the chitosan polymer and organic acid mixture to the polyvinyl alcohol and water mixture. The mixture of the chitosan polymer and organic acid mixture and the polyvinyl alcohol and water mixture may be referred to herein as the chitosan polymer, organic acid, polyvinyl alcohol, and water mixture.

[0041] In certain optional embodiments, the montmorillonite clay may have a synergistic impact on the chitosan polymer, and the synergistic impact may only occur when the montmorillonite clay is added in low doses. The montmorillonite clay may, in combination with the chitosan polymer or independent thereof, enhance the strength and / or stiffness of aAttorney Docket No. 2967050.3. WO1Customer No. 190456 treated product and / or the cellulose fibers associated with a treated product. The additive array 100 may comprise an amount of montmorillonite clay equal to about 0.5% to about 20% relative to the dry fiber content of the cellulose fiber mixture. In certain embodiments, the additive array 100 may comprise an amount of montmorillonite clay equal to about 1% to about 4% relative to the dry fiber content of the cellulose fiber mixture.

[0042] In certain optional embodiments, the method 200 may further comprise stirring or otherwise agitating the chitosan polymer, organic acid, polyvinyl alcohol, and water mixture. In various embodiments, the MFC, montmorillonite clay, cationic wax, or any combination thereof may be added to the chitosan polymer, organic acid, polyvinyl alcohol, and water mixture after a period of time. In certain optional embodiments, any one or more of the MFC, montmorillonite clay, and cationic wax may be added to the chitosan polymer, organic acid, polyvinyl alcohol, and water mixture after stirring or otherwise agitating for a period of about 1 minute to about 10 minutes. In certain optional embodiments, any one or more of the MFC, montmorillonite clay, and cationic wax may be added to the chitosan polymer, organic acid, polyvinyl alcohol, and water mixture after stirring or otherwise agitating for a period of about 5 minutes. The mixture of the chitosan polymer, organic acid, polyvinyl alcohol, and water mixture and the MFC, montmorillonite clay, and cationic wax may be referred to herein as the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, and cationic wax mixture, as applicable. In certain optional embodiments, any one or more of the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, and cationic wax mixture may continue to be stirred or otherwise agitated, but in other optional embodiments any one or more of the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, and cationic wax mixture may not be stirred or otherwise agitated.Attorney Docket No. 2967050.3. WO1Customer No. 190456

[0043] In certain optional embodiments, the method 200 may further comprise adding the cationic rosin to the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, and cationic wax mixture a period of time after adding the MFC, montmorillonite clay, and cationic wax to the chitosan polymer, organic acid, polyvinyl alcohol, and water mixture. The mixture of the cationic rosin and the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, and cationic wax mixture may be referred to herein as the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, and cationic rosin mixture. The cationic rosin may be added after about 1 minute to about 10 minutes. In certain optional embodiments, the cationic rosin may be added after about 5 minutes.

[0044] In certain optional embodiments, the method 200 may further comprise stirring or otherwise agitating the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, and cationic rosin mixture for a period of time. The chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, and cationic rosin mixture may be stirred or otherwise agitated for about 1 to about 20 minutes. In certain optional embodiments, the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, and cationic rosin mixture may be stirred or otherwise agitated for about 10 minutes.

[0045] In certain optional embodiments, the method 200 may further comprise treating the cellulose fibers with the cationic retention aid. Treating the cellulose fibers with the cationic retention aid may include mixing or otherwise adding the cationic retention aid to the paper pulp mixture and / or the slurry. In certain optional embodiments, the method disclosed herein may further comprise stirring or otherwise agitating the cationic retention aid and the paper pulp mixture or slurry for a period of time. The cationic retention aid and the paper pulp mixtureAttorney Docket No. 2967050.3. WO1Customer No. 190456 or slurry may be stirred or otherwise agitated for about 1 minute to about 10 minutes. In certain optional embodiments, the cationic retention aid and the paper pulp mixture or slurry may be stirred or otherwise agitated for about 5 minutes.

[0046] In certain optional embodiments, the method disclosed herein may further comprise adding the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, and cationic rosin mixture to the treated cellulose fiber. Any one or more of the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, and the cationic rosin mixture may be stirred or otherwise agitated with the treated cellulose fiber for about 1 minute to about 10 minutes. In certain optional embodiments, the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, and cationic rosin mixture and the treated cellulose fiber may be stirred or otherwise agitated for about 5 minutes. The mixture of the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax and cationic rosin mixture and the treated cellulose fiber may be referred to herein as the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, cationic rosin, and treated cellulose fiber mixture, as applicable.

[0047] In certain optional embodiments, the method disclosed herein may further comprise adding the anionic retention aid to the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, cationic rosin, and treated cellulose fiber mixture. The anionic retention aid and the chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax, cationic rosin, and treated cellulose fiber mixture may be stirred or otherwise agitated. The anionic retention aid and chitosan polymer, organic acid, polyvinyl alcohol, water, MFC, montmorillonite clay, cationic wax,Attorney Docket No. 2967050.3. WO1Customer No. 190456 cationic rosin, and treated cellulose fiber mixture may be referred to herein as the cellulose fiber mixture.

[0048] In certain optional embodiments, the cellulose fiber mixture may be formed into the cellulose fiber product. The cellulose fiber product may be formed via conventional manufacturing processes. For example, the cellulose fiber mixture may be formed wherein the cellulose fiber mixture is poured through a screen or like device to drain at least a portion of the liquid from the cellulose fiber mixture. In certain optional embodiments, the cellulose fiber mixture may be pressed between rollers, or shaped dies made of metal or plastic to name a few examples, or like devices to further remove liquid from the cellulose fiber mixture and compact or press the cellulose fibers contained therein. In certain optional embodiments, the cellulose fiber mixture may be dried via heated rollers, heated dies, drying racks, or the like. In certain optional embodiments, the cellulose fiber mixture may be finished, wherein the cellulose fiber mixture is cut, shaped, molded, and / or formed into a desired product.

[0049] The steps of the method 200 may be performed in any order and should not be limited to a sequence as disclosed herein. However, certain advantages may exist to performing certain steps of the method 200 in the order as disclosed herein.

[0050] The method 200 may result in a treated product having increased strength, stiffness, and / or liquid resistance. Without being bound by theory, the method 200 may result in a treated product having at least three times the strength and / or stiffness of an untreated product. Again, without being bound by theory, the method 200 may result in a treated product having at least three times the strength and / or stiffness of an untreated product when each product is exposed to a liquid such as water.

[0051] Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is notAttorney Docket No. 2967050.3. WO1Customer No. 190456 considered limited to the example chosen for purposes of disclosure and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. This written description provides an illustrative explanation and / or account of the present invention. It may be possible to deliver equivalent benefits using variations of the specific embodiments, without departing from the inventive concept. This description and these drawings, therefore, are to be regarded as illustrative and not restrictive.

[0052] Even though particular combinations of features are recited in the present application, these combinations are not intended to limit the disclosure of the invention. In fact, many of these features may be combined in ways not specifically recited in this application. In other words, any of the features mentioned in this application may be included in this new invention in any combination or combinations to allow the functionality required for the desired operations.

[0053] No element, act, or instruction used in the present application should be construed as critical or essential to the invention unless explicitly described as such. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.

Claims

Attorney Docket No. 2967050.

3. WO1Customer No. 190456ClaimsWhat is claimed is:

1. A method of making a cellulose fiber product, the method comprising: preparing an additive, the additive comprising any one or more of a chitosan polymer, an organic acid, a polyvinyl alcohol, a cationic rosin, a microfibrillated cellulose, montmorillonite clay, a cationic wax, a cationic retention aid, and an anionic retention aid; associating the additive with cellulose fibers to form a cellulose fiber mixture; and forming the cellulose fiber mixture into the cellulose fiber product.

2. The method of claim 1, wherein: preparing the additive includes mixing the chitosan polymer and the organic acid.

3. The method of claim 2, wherein: preparing the additive includes stirring the chitosan polymer and the organic acid for about 5 minutes to about 20 minutes.

4. The method of claim 1, wherein: preparing the additive includes mixing the polyvinyl alcohol with water.

5. The method of claim 4, wherein: preparing the additive includes heating the polyvinyl alcohol and water to a temperature of about 60 degrees Celsius to about 100 degrees Celsius.Attorney Docket No. 2967050.

3. WO1Customer No. 1904566. The method of claim 1, wherein: preparing the additive incudes mixing a first mixture including the chitosan polymer and the organic acid with a second mixture including the polyvinyl alcohol.

7. The method of claim 1, wherein: preparing the additive incudes mixing a first mixture including the chitosan polymer, the organic acid, and the polyvinyl alcohol with any one or more of the microfibrillated cellulose, montmorillonite clay, and cationic wax.

8. The method of claim 7, wherein: preparing the additive incudes mixing the first mixture including the chitosan polymer, the organic acid, and the polyvinyl alcohol with any one or more of the microfibrillated cellulose, montmorillonite clay, and cationic wax, for about 1 minute to about 20 minutes.

9. The method of claim 1, wherein: preparing the additive incudes mixing a first mixture including the chitosan polymer, the organic acid, the polyvinyl alcohol, the microfibrillated cellulose, the montmorillonite clay, and the cationic wax, or any combination thereof, with cationic rosin.

10. The method of claim 9, wherein: preparing the additive incudes mixing a first mixture including the chitosan polymer, the organic acid, the polyvinyl alcohol, the microfibrillated cellulose, the montmorillonite clay, and the cationic wax, or any combination thereof, and cationic rosin, for about 1 minute to about 20 minutes.Attorney Docket No. 2967050.

3. WO1Customer No. 19045611. The method of claim 1, wherein: associating the additive with the cellulose fibers to form a cellulose fiber mixture includes treating the cellulose fibers with the cationic retention aid.

12. The method of claim 11, wherein: treating the cellulose fibers with the cationic retention aid includes mixing the cationic retention aid with a pulp mixture or slurry comprising the cellulose fibers.

13. The method of claim 11, wherein: associating the additive with the cellulose fibers to form a cellulose fiber mixture includes mixing a first mixture including one or more of the chitosan polymer, the organic acid, the polyvinyl alcohol, the microfibrillated cellulose, the montmorillonite clay, the cationic wax, and the cationic rosin with the pulp mixture or slurry comprising the treated cellulose fibers.

14. The method of claim 13, wherein: associating the additive with the cellulose fibers to form a cellulose fiber mixture includes stirring the first mixture and the pulp mixture or slurry comprising the treated cellulose fibers for about 1 minute to about 20 minutes.

15. The method of claim 1, wherein: associating the additive with the cellulose fibers to form a cellulose fiber mixture includes mixing a first mixture including the chitosan polymer, the organic acid, the polyvinyl alcohol, the microfibrillated cellulose, the montmorillonite clay, the cationic wax, the cationic rosin, theAttorney Docket No. 2967050.

3. WO1Customer No. 190456 cationic retention aid, and the cellulose fiber, or any combination thereof, with the anionic retention aid.

16. The method of claim 1, wherein: forming the cellulose fiber mixture into the cellulose fiber product includes removing at least a portion of a liquid of the cellulose fiber mixture.

17. The method of claim 1, wherein: forming the cellulose fiber mixture into the cellulose fiber product includes drying the cellulose fiber mixture.

18. The method of claim 1, wherein: forming the cellulose fiber mixture into the cellulose fiber product includes cutting, shaping, molding, or forming, or a combination thereof, the cellulose fiber mixture.

19. An additive associable with cellulose fibers, the additive comprising: a chitosan polymer, an organic acid, a polyvinyl alcohol, a cationic rosin, a cationic retention aid, and an anionic retention aid and any one or more of a microfibrillated cellulose, a montmorillonite clay, and a cationic wax.

20. A slurry for use in the formation of a cellulose fiber product, the slurry comprising: a chitosan polymer, an organic acid, a polyvinyl alcohol, a cationic rosin, a cationic retention aid, an anionic retention aid, and cellulose fibers and any one or more of a microfibrillated cellulose, a montmorillonite clay, a cationic wax.

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