CA3220547A1 - Systems and methods for production of starch-loaded fibrillated fibers - Google Patents

Abstract

A method of making a pulp composition having improved strength characteristics is disclosed. The method includes mixing together a starch and fibrillated fibers to produce a starch/fibrillated fibers mixture, and mixing the starch/fibrillated fibers mixture into wood pulp fibers to produce the pulp composition.

Description

SYSTEMS AND METHODS FOR PRODUCTION OF STARCH-LOADED
FIBRILLATED FIBERS
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims benefit of priority under 35 U.S.C.
119(e) to U.S.
Provisional Patent Application 63/384,465, filed on November 21, 2022, entitled, "Systems and Methods for Production of Starch-Loaded Fibrillated Fibers," the contents of which are incorporated herein by reference in their entirety.
FIELD

[0002] The present invention relates generally to the process of preparing fibrillated fibers loaded with a starch, and more particularly, to using starch-loaded fibrillated fibers for increasing the strength of subsequently manufactured paper or paperboard products.
BACKGROUND

[0003] Pulp fibers, such as wood pulp fibers, are used in a variety of products including, for example, pulp, paper, paperboard, biofiber composites (e.g., fiber cement board, fiber reinforced plastics, etc.), absorbent products (e.g., fluff pulp, hydrogels, etc.), specialty chemicals derived from cellulose (e.g., cellulose acetate, carboxymethyl cellulose (CMC), etc.), and other products.
The pulp fibers can be obtained from a variety of wood types including hardwoods (e.g., oak, gum, maple, poplar, eucalyptus, aspen, birch, etc.), softwoods (e.g., spruce, pine, fir, hemlock, southern pine, redwood, etc.), and non-woods (e.g., kenaf, hemp, straws, bagasse, etc.). The properties of the pulp fibers can impact the properties of the ultimate end paper product.

[0004] The pulp fibers can be processed in a number of ways to achieve different properties, such as strength, of the resulting paper products. Traditional processes for improving the mechanical strength of the resulting paper products typically involve the addition of starch at the wet end, such as at the blend chest or stuff box. These traditional processes can present challenges, such as balancing any starch sourcing limitations with the need for improved strength of resulting paper products.

Date Recue/Date Received 2023-11-20

[0005] Accordingly, there is a need for improved processes of preparing starch-loaded fibrillated fibers for increasing the strength of subsequently manufactured paper or paperboard products.
SUMMARY

[0006] Disclosed embodiments provide systems and methods for production of starch-loaded fibrillated fibers, such as surface enhanced pulp fibers (SEPF), that improve the strength characteristics of resulting paper products.

[0007] Described herein is a method of making a pulp composition for use in the manufacture of paper products having improved strength characteristics. The method includes mixing together a starch and fibrillated fibers to produce a starch/fibrillated fibers mixture. The starch and fibrillated fibers are mixed together, for example, in a storage tank or mixing vessel, downstream of the fibrillated fibers refining process. The method further includes mixing the starch/fibrillated fibers mixture into the wood pulp fibers to produce the pulp composition.

[0008] Described herein is also a method of making a paper product having improved strength characteristics. The method includes mixing together a starch and fibrillated fibers (e.g., SEPF) to produce a starch/fibrillated fibers mixture. The starch/fibrillated fibers mixture is then mixed into wood pulp fibers to produce a pulp composition. The pulp composition is deposited onto a web to form a substrate, which is then at least partially dewatered. The substrate is then dried to form a paper product that has an increased Breaking Length compared to a First Comparative Paper Product, as defined herein.

[0009] Described herein is also a paper product having improved strength characteristics. The paper product includes approximately 0.1 to 2.5 weight percent of a starch, approximately 2 to 20 weight percent fibrillated fibers (e.g., SEPF), and approximately 83 to 97 weight percent wood pulp fibers. The paper product has a lower amount of starch compared to a Second Comparative Paper Product, as defined herein. The paper product is also configured to maintain a Breaking Length within the range of approximately 10 percent compared to the Second Comparative Paper Product.

Date Recue/Date Received 2023-11-20

[0010] Further implementations, features, and aspects of the disclosed technology, and the advantages offered thereby, are described in greater detail hereinafter, and can be understood with reference to the following detailed description, accompanying drawings, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and which illustrate various implementations, aspects, and principles of the disclosed technology. In the drawings:

[0012] FIG. 1 is a block diagram of an example system used for making a pulp composition, in accordance with certain embodiments of the disclosed technology.

[0013] FIG. 2 is a flow diagram illustrating an exemplary method for making a pulp composition, in accordance with certain embodiments of the disclosed technology.
DETAILED DESCRIPTION

[0014] The present invention can be understood more readily by reference to the following detailed description, examples, drawings, and claims, and their previous and following description.
However, before the present devices, systems, and/or methods are disclosed and described, it is to be understood that this invention is not limited to the specific devices, systems, and/or methods disclosed unless otherwise specified, and, as such, can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.

[0015] The following description of the invention is provided as an enabling teaching of the invention in its best, currently known embodiment. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the invention described herein, while still obtaining the beneficial results of the present invention. It will also be apparent that some of the desired benefits of the present invention can be obtained by selecting some of the features of the present invention without utilizing other features.
Accordingly, those who work in the art will recognize that many modifications and adaptations to the present invention are possible and can even be desirable in certain circumstances and are a part of the present invention. It will also be apparent that the various aspects of the invention described Date Recue/Date Received 2023-11-20 herein may be added to other existing devices/systems as an embodiment of the present invention.
Thus, the following description is provided as illustrative of the principles of the present invention and not in limitation thereof.

[0016] As used throughout, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a refiner" can include two or more such refiners unless the context indicates otherwise.

[0017] Ranges can be expressed herein as from "about" or "approximately"
one particular value, and/or to "about" or "approximately" another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about"
or "approximately" it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0018] As used herein, the terms "optional" or "optionally" mean that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0019] The word "or" as used herein means any one member of a particular list and also includes any combination of members of that list. Further, one should note that conditional language, such as, among others, "can," "could," "might," or "can," unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain aspects include, while other aspects do not include, certain features, elements and/or steps.
Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more particular aspects or that one or more particular aspects necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment.

[0020] As used herein, the term "First Comparative Pulp Composition" is a pulp composition including a starch, fibrillated fibers (e.g., SEPF), and wood pulp fibers. A
First Comparative Pulp Composition is made by a process of first mixing together the fibrillated fibers (e.g., SEPF) and Date Recue/Date Received 2023-11-20 the wood pulp fibers to make a fibrillated fibers/wood pulp fibers mixture, and thereafter mixing the starch into the fibrillated fibers/wood pulp fibers mixture to produce the First Comparative Pulp Composition. The process of making a First Comparative Pulp Composition is an alternative process to that of the pulp compositions described herein, which are made by first mixing together fibrillated fibers (e.g., SEPF) and a starch to make a fibrillated fibers/starch mixture, and thereafter mixing the fibrillated fibers/starch mixture into wood pulp fibers to produce a pulp composition.
Other processing conditions, such as mixing speeds, temperatures, and amounts of starch, fibrillated fibers, and wood pulp fibers, remain consistent between processes of making a First Comparative Pulp Composition and the pulp compositions described herein.

[0021] As used herein, the term "First Comparative Paper Product" is a paper product formed from a First Comparative Pulp Composition. The First Comparative Paper Product may be made via a variety of paper-making methods, as described herein.

[0022] As used herein, the term "Second Comparative Pulp Composition" is a pulp composition including a starch, fibrillated fibers (e.g., SEPF), and wood pulp fibers. A Second Comparative Pulp Composition is made by a process of first mixing together fibrillated fibers (e.g., SEPF) and a starch to make a fibrillated fibers/starch mixture, and thereafter mixing the fibrillated fibers/starch mixture into wood pulp fibers to produce the Second Comparative Pulp Composition.
This ordering of processing steps is similar to that used to produce the pulp compositions described herein. A Second Comparative Pulp Composition, however, has a higher amount (e.g., weight percent) of starch than do the pulp compositions described herein. Other processing conditions, such as mixing speeds and temperatures, remain consistent between processes of making a Second Comparative Pulp Composition and the pulp compositions described herein.

[0023] As used herein, the term "Second Comparative Paper Product" is a paper product formed from a Second Comparative Pulp Composition. A Second Comparative Paper Product has a higher amount (e.g., weight percent) of starch than do the paper products described herein. The Second Comparative Paper Product may be made via a variety of paper-making methods, as described herein.

[0024] Disclosed are components that can be used to perform the disclosed methods and systems. These and other components are disclosed herein, and it is understood that when Date Recue/Date Received 2023-11-20 combinations, subsets, interactions, groups, etc. of these components are disclosed that while specific reference of each various individual and collective combinations and permutation of these may not be explicitly disclosed, each is specifically contemplated and described herein, for all methods and systems. This applies to all aspects of this application including, but not limited to, steps in disclosed methods. Thus, if there are a variety of additional steps that can be performed it is understood that each of these additional steps can be performed with any specific embodiment or combination of embodiments of the disclosed methods.

[0025] The present systems and methods may be understood more readily by reference to the following detailed description of preferred embodiments and the Examples included therein, and to the Figures and their previous and following description.

[0026] In general, the invention provides a process for making starch-loaded fibrillated fibers (e.g., starch-loaded SEPF) that improve the strength characteristics of subsequently manufactured paper and paperboard products based on the point of addition of the starch to the fibrillated fibers (e.g., SEPF). For example, rather than mixing the starch with the fibrillated fibers at the fibrillated fibers refining stage, such as in a refiner, the starch is mixed with the fibrillated fibers downstream of the fibrillated fibers refining stage, such as in an external storage vessel or mixing tank. The starch/fibrillated fibers mixture is then mixed with wood pulp fibers to produce a resulting pulp composition that can be later used in the manufacture of paper products, as discussed herein.

[0027] In some embodiments, the resulting pulp composition includes a plurality of highly fibrillated fibers that have at least a type of starch mechanically bonded to the exterior surface of the plurality of fibrillated fibers at a desired weight percentage. In some embodiments, the distribution of starch can be substantially uniform across the plurality of fibrillated fibers in the resulting pulp composition.

[0028] The SEPF used in some embodiments of the present invention can originate from a variety of wood types, including hardwood and softwood. Non-limiting examples of hardwood pulp fibers that can be used in SEPF include, without limitation, oak, gum, maple, poplar, eucalyptus, aspen, birch, and others known to those of skill in the art. Non-limiting examples of softwood pulp fibers that can be used in SEPF include, without limitation, spruce, pine, fir, hemlock, southern pine, redwood, and others known to those of skill in the art. The pulp fibers Date Recue/Date Received 2023-11-20 may be obtained from a chemical source (e.g., a Kraft process, a sulfite process, a soda pulping process, etc.), a mechanical source, (e.g., a thermomechanical process (TMP), a bleached chemi-thermomechanical process (BCTMP), etc.), or combinations thereof. The pulp fibers can also originate from non-wood fibers such as linen, cotton, bagasse, hemp, straw, kenaf, etc. The pulp fibers can be bleached, partially bleached, or unbleached with varying degrees of lignin content and other impurities. In some embodiments, the pulp fibers can be recycled fibers or post-consumer fibers.

[0029] The SEPF used in some embodiments of the present invention can be characterized according to various properties and combinations of properties including, for example, length, specific surface area, change in length, change in specific surface area, surface properties (e.g., surface activity, surface energy, etc.), percentage of fines, drainage properties (e.g., Schopper-Riegler), crill measurement (fibrillation), water absorption properties (e.g., water retention value, wicking rate, etc.), and various combinations thereof. While the following description may not specifically identify each of the various combinations of properties, it should be understood that different embodiments of SEPF may possess one, more than one, or all of the properties described herein.

[0030] The SEPF used in some embodiments of the present invention canhave a length weighted average fiber length of at least about 0.3 millimeters, preferably at least about 0.35 millimeters, with a length of about 0.4 millimeters being most preferred, wherein the number of surface enhanced pulp fibers is at least 12,000/milligram on an oven-dry basis. As used herein, "oven-dry basis" means that the sample is dried in an oven set at 105 C. for 24 hours. In general, the longer the length of the fibers, the greater the strength of the fibers and the resulting product incorporating such fibers. Such SEPF can be useful, for example, in papermaking applications. As used herein, length weighted average length is measured using a LDA02 Fiber Quality Analyzer or a LDA96 Fiber Quality Analyzer, each of which are from OpTest Equipment, Inc. of Hawkesbury, Ontario, Canada, and in accordance with the appropriate procedures specified in the manual accompanying the Fiber Quality Analyzer. As used herein, length weighted average length (LW) is calculated according to the formula:
E ni14:
Lw = _____________________________________ E niLi Date Recue/Date Received 2023-11-20 wherein i refers to the category (or bin) number (e.g., 1, 2,. . . N), n, refers to the fiber count in the category, and L, refers to contour length¨histogram class center length in the 1th category.

[0031] As noted above, one aspect of SEPF used in some embodiments of the present invention is the preservation of the lengths of the fibers following fibrillation. In some embodiments, a plurality of SEPF can have a length weighted average length that is at least 60%
of the length weighted average length of the fibers prior to fibrillation. A
plurality of SEPF, according to some embodiments, can have a length weighted average length that is at least 70% of the length weighted average length of the fibers prior to fibrillation. In determining the percent length preservation, the length weighted average length of a plurality of fibers can be measured (as described above) both before and after fibrillation and the values can be compared using the following formula:
L,õ (before) f ore) ¨ L,õ (after) L,õ (before)

[0032] The SEPF used in some embodiments of the present invention canadvantageously have large hydrodynamic specific surface areas which can be useful in some applications, such as papermaking. In some embodiments of the present invention, SEPF has an average hydrodynamic specific surface area of at least about 10 square meters per gram, and more preferably at least about 12 square meters per gram. For illustrative purposes, a typical unrefined papermaking fiber would have a hydrodynamic specific surface area of 2 m2/g. As used herein, hydrodynamic specific surface area is measured pursuant to the procedure specified in Characterizing the drainage resistance of pulp and microfibrillar suspensions using hydrodynamic flow measurements, N.
Lavrykova-Marrain and B. Ramarao, TAPPI's PaperCon 2012 Conference, available at http://www.tappi .org/Hide/Events/12PaperCon/Papers/12PAP116.aspx, which is hereby incorporated by reference.

[0033] The hydrodynamic specific surface areas of the SEPF are significantly greater than that of the fibers prior to fibrillation. In some embodiments, a plurality of surface enhanced pulp fibers can have an average hydrodynamic specific surface area that is at least 4 times greater than the average specific surface area of the fibers prior to fibrillation, preferably at least 6 times greater than the average specific surface area of the fibers prior to fibrillation, and most preferably at least Date Recue/Date Received 2023-11-20 8 times greater than the average specific surface area of the fibers prior to fibrillation. Such SEPF
can be useful, for example, in papermaking applications.

[0034] As noted above, SEPF advantageously have increased hydrodynamic specific surface areas while preserving fiber lengths. Increasing the hydrodynamic specific surface area can have a number of advantages depending on the use including, without limitation, providing increased fiber bonding, absorbing water or other materials, retention of organics, higher surface energy, and others.

[0035] SEPF can have a length weighted average fiber length of at least about 0.3 millimeters and an average hydrodynamic specific surface area of at least about 10 square meters per gram, wherein the number of surface enhanced pulp fibers is at least 12,000/milligram on an oven-dry basis. A plurality of SEPF can have a length weighted average fiber length of at least about 0.35 millimeters and an average hydrodynamic specific surface area of at least about 12 square meters per gram, wherein the number of surface enhanced pulp fibers is at least 12,000/milligram on an oven-dry basis. A plurality of SEPF can have a length weighted average fiber length of at least about 0.4 millimeters and an average hydrodynamic specific surface area of at least about 12 square meters per gram, wherein the number of surface enhanced pulp fibers is at least 12,000/milligram on an oven-dry basis. Such SEPF can be useful, for example, in papermaking applications.

[0036] SEPF can be refined to minimize the generation of fines. As used herein, the term "fines" is used to refer to pulp fibers having a length of 0.2 millimeters or less. SEPF can have a length weighted fines value of less than 40%, more preferably less than 22%, with less than 20%
being most preferred. SEPF can be useful, for example, in papermaking applications. As used herein, "length weighted fines value" is measured using a LDA02 Fiber Quality Analyzer or a LDA96 Fiber Quality Analyzer, each of which are from OpTest Equipment, Inc. of Hawkesbury, Ontario, Canada, and in accordance with the appropriate procedures specified in the manual accompanying the Fiber Quality Analyzer. As used herein, the percentage of length weighted fines is calculated according to the formula:
E niLi % of length weighted fines = 100 x ____________________ LT

Date Recue/Date Received 2023-11-20 wherein n refers to the number of fibers having a length of less than 0.2 millimeters, L, refers to the fines class midpoint length, and LT refers to total fiber length.

[0037] SEPF can simultaneously offer the advantages of preservation of length and relatively high specific surface area without the detriment of the generation of a large number of fines.
Further, SEPF can simultaneously possess one or more of the other above-referenced properties (e.g., length weighted average fiber length, change in average hydrodynamic specific surface area, and/or surface activity properties) while also having a relatively low percentage of fines. Such fibers can minimize the negative effects on drainage while also retaining or improving the strength of products in which they are incorporated.

[0038] Other advantageous properties of SEPF can be characterized when the fibers are processed into other products and will be described below following a description of methods of making the SEPF.

[0039] The refining techniques used in methods of producing SEPF can advantageously preserve the lengths of the fibers while likewise increasing the amount of surface area. Such methods can also minimize the amount of fines, and/or improve the strength of products (e.g., tensile strength, scott bond strength, wet-web strength of a paper product) incorporating the SEPF.

[0040] One exemplary method for producing SEPF comprises introducing unrefined pulp fibers in a mechanical refiner comprising a pair of refiner plates, wherein the plates have a bar width of 1.3 millimeters or less and a groove width of 2.5 millimeters or less, and refining the fibers until an energy consumption of at least 300 kWh/ton for the refiner is reached to produce SEPF. Persons of ordinary skill in the art are familiar with the dimensions of bar width and groove width in connection with refiner plates. To the extent additional information is sought, reference is made to Christopher J. Biermann, Handbook of Pulping and Papermaking (2d Ed.1996) at p.
145, which is hereby incorporated by reference. The plates can have a bar width of 1.0 millimeters or less and a groove width of 1.6 millimeters or less, and the fibers can be refined until an energy consumption of at least 300 kWh/ton for the refiner is reached to produce SEPF. The plates can have a bar width of 1.0 millimeters or less and a groove width of 1.3 millimeters or less, and the fibers can be refined until an energy consumption of at least 300 kWh/ton for the refiner is reached to produce SEPF. As used herein and as understood by those of ordinary skill in the art, the Date Recue/Date Received 2023-11-20 references to energy consumption or refining energy herein utilize units of kWh/ton with the understanding that "/ton" or "per ton" refers to ton of pulp passing through the refiner on a dry basis. The fibers can be refined until an energy consumption of at least 650 kWh/ton for the refiner is reached. The plurality of fibers can be refined until they possess one or more of the properties described herein related to SEPF. As described in more detail below, persons of skill in the art will recognize that refining energies significantly greater than 300 kWh/ton may be required for certain types of wood fibers and that the amount of refining energy needed to impart the desired properties to the pulp fibers may also vary.

[0041] One exemplary method for producing SEPF comprises introducing unrefined pulp fibers in a mechanical refiner comprising a pair of refiner plates or a series of refiners. The unrefined pulp fibers can include any of the pulp fibers described herein, such as, for example, hardwood pulp fibers or softwood pulp fibers or non-wood pulp fibers, from a variety of processes described herein (e.g., mechanical, chemical, etc.). In addition, the unrefined pulp fibers or pulp fiber source can be provided in a baled or slushed condition. For example, a baled pulp fiber source can comprise between about 7 and about 11% water and between about 89 and about 93%
solids. Likewise, for example, a slush supply of pulp fibers can comprise about 95% water and about 5% solids. The pulp fiber source may not have been dried on a pulp dryer.

[0042] Non-limiting examples of refiners that can be used to produce SEPF
include double disk refiners, conical refiners, single disk refiners, multi-disk refiners or conical and disk(s) refiners in combination. Non-limiting examples of double disk refiners include Beloit DD 3000, Beloit DD 4000 or Andritz DO refiners. Non-limiting example of a conical refiner are Sunds JC01, Sunds JCO2 and Sunds JC03 refiners.

[0043] The design of the refining plates as well as the operating conditions are important in producing SEPF. The bar width, groove width, and groove depth are refiner plate parameters that are used to characterize the refiner plates. In general, refining plates for use in producing SEPF
can be characterized as fine grooved. Such plates can have a bar width of 1.3 millimeters or less and a groove width of 2.5 millimeters or less. Such plates can have a bar width of 1.3 millimeters or less and a groove width of 1.6 millimeters or less. Such plates can have a bar width of 1.0 millimeters or less and a groove width of 1.6 millimeters or less. Such plates can have a bar width Date Recue/Date Received 2023-11-20 of 1.0 millimeters or less and a groove width of 1.3 millimeters or less.
Refining plates having a bar width of 1.0 millimeters or less and a groove width of 1.6 millimeters or less may also be referred to as ultrafine refining plates. Such plates are available under the FINEBARO brand from Aikawa Fiber Technologies (AFT). Under the appropriate operating conditions, such fine grooved plates can increase the number of fibrils on a pulp fiber (i.e., increase the fibrillation) while preserving fiber length and minimizing the production of fines. Conventional plates (e.g., bar widths of greater than 1.3 millimeters and/or groove widths of greater than 2.0 millimeters) and/or improper operating conditions can significantly enhance fiber cutting in the pulp fibers and/or generate an undesirable level of fines.

[0044] The operating conditions of the refiner can also be important in the production of SEPF. The SEPF can be produced by recirculating pulp fibers which were originally unrefined through the refiner(s) until an energy consumption of at least about 300 kWh/ton is reached. The SEPF can be produced by recirculating pulp fibers which were originally unrefined through the refiner(s) until an energy consumption of at least about 450 kWh/ton is reached. The fibers can be recirculated in the refiner until an energy consumption of between about 450 and about 650 kWh/ton is reached. The refiner can operate at a specific edge load between about 0.1 and about 0.3 Ws/m. The refiner can operate at a specific edge load of between about 0.15 and about 0.2 Ws/m. An energy consumption of between about 450 and about 650 kWh/ton can be reached using a specific edge load of between about 0.1 Ws/m and about 0.2 Ws/m to produce the surface enhanced pulp fibers. Specific edge load (or SEL) is a term understood to those of ordinary skill in the art to refer to the quotient of net applied power divided by the product of rotating speed and edge length. SEL is used to characterize the intensity of refining and is expressed as Watt-second/meter (Ws/m).

[0045] Persons of skill in the art will recognize that refining energies significantly greater than 400 kWh/ton may be required for certain types of wood fibers and that the amount of refining energy needed to impart the desired properties to the pulp fibers may also vary. For example, Southern mixed hardwood fibers (e.g., oak, gum, elm, etc.) may require refining energies of between about 450-650 kWh/ton. In contrast, Northern hardwood fibers (e.g., maple, birch, aspen, beech, etc.) may require refining energies of between about 350 and about 500 kWh/ton as Northern hardwood fibers are less coarse than Southern hardwood fibers.
Similarly, Southern Date Recue/Date Received 2023-11-20 softwood fibers (e.g., pine) may require even greater amounts of refining energy. For example, in some embodiments, refining Southern softwood fibers may be significantly higher (e.g., at least 1000 kWh/ton).

[0046] The refining energy can also be provided in a number of ways depending on the amount of refining energy to be provided in a single pass through a refiner and the number of passes desired. The refiners used may operate at lower refining energies per pass (e.g., 100 kWh/ton/pass or less) such that multiple passes or multiple refiners are needed to provide the specified refining energy. For example, a single refiner can operate at 50 kWh/ton/pass, and the pulp fibers can be recirculated through the refiner for a total of 9 passes to provide 450 kWh/ton of refining. Multiple refiners can be provided in series to impart refining energy.

[0047] In situations where pulp fibers reach the desired refining energy by recirculating the fibers through a single refiner, the pulp fibers can be circulated at least two times through the refiner to obtain the desired degree of fibrillation. The pulp fibers can be circulated between about 6 and about 25 times through the refiner to obtain the desired degree of fibrillation. The pulp fibers can be fibrillated in a single refiner by recirculation in a batch process.

[0048] The pulp fibers can be fibrillated in a single refiner using a continuous process. For example, a method can comprise continuously removing a plurality of fibers from the refiner, wherein a portion of the removed fibers are SEPF, and recirculating greater than about 80% of the removed fibers back to the mechanical refiner for further refining. Greater than about 90% of the removed fibers can be recirculated back to the mechanical refiner for further refining. The amount of unrefined fibers introduced to the refiner and the amount of fibers removed from the fiber without recirculation can be controlled such that a predetermined amount of fibers continually pass through the refiner. Put another way, because some amount of fibers are removed from the recirculation loop associated with the refiner, a corresponding amount of unrefined fibers should be added to the refiner in order to maintain a desired level of fibers circulating through the refiner.
To facilitate the production of SEPF having particular properties (e.g., length weighted average fiber length, hydrodynamic specific surface area, etc.), the refining intensity (i.e., specific edge load) per pass will need to be reduced during the process as the number of passes increases.

Date Recue/Date Received 2023-11-20

[0049] Two or more refiners can be arranged in series to circulate the pulp fibers to obtain the desired degree of fibrillation. It should be appreciated that a variety of multi-refiner arrangements can be used to produce SEPF. For example, multiple refiners can be arranged in series that utilize the same refining plates and operate under the same refining parameters (e.g., refining energy per pass, specific edge load, etc.). The fibers may then pass through one of the refiners only once and/or through another of the refiners multiple times.

[0050] A method for producing SEPF comprises introducing unrefined pulp fibers in a first mechanical refiner comprising a pair of refiner plates, wherein the plates have a bar width of 1.3 millimeters or less and a groove width of 2.5 millimeters or less, refining the fibers in the first mechanical refiner, transporting the fibers to at least one additional mechanical refiner comprising a pair of refiner plates, wherein the plates have a bar width of 1.3 millimeters or less and a groove width of 2.5 millimeters or less, and refining the fibers in the at least one additional mechanical refiner until a total energy consumption of at least 300 kWh/ton for the refiners is reached to produce surface enhanced pulp fibers. The fibers can be recirculated through the first mechanical refiner a plurality of times. The fibers can be recirculated through an additional mechanical refiner a plurality of times in some embodiments. The fibers can be recirculated through two or more of the mechanical refiners a plurality of times.

[0051] In a method for producing SEPF utilizing a plurality of refiners, a first mechanical refiner can be used to provide a relatively less fine, initial refining step and one or more subsequent refiners can be used to provide SEPF. For example, the first mechanical refiner can utilize conventional refining plates (e.g., bar width of greater than 1.0 mm and groove width of 1.6 mm or greater) and operate under conventional refining conditions (e.g., specific edge load of 0.25 Ws/m) to provide an initial, relatively less fine fibrillation to the fibers.
The amount of refining energy applied in the first mechanical refiner can be about 100 kWh/ton or less. After the first mechanical refiner, the fibers can then be provided to one or more subsequent refiners that utilizing ultrafine refining plates (e.g., bar width of 1.0 mm or less and groove width of 1.6 mm or less) and operate under conditions (e.g., specific edge load of 0.13 Ws/m) sufficient to produce SEPF. The cutting edge length (CEL) can increase between refinement using conventional refining plates and refinement using ultrafine refining plates depending on the differences between the refining plates.
Cutting Edge Length (or CEL) is the product of bar edge length and the rotational speed. As set Date Recue/Date Received 2023-11-20 forth above, the fibers can pass through or recirculate through the refiners multiple times to achieve the desired refining energy and/or multiple refiners can be used to achieve the desired refining energy.

[0052] A method for producing SEPF comprises introducing unrefined pulp fibers in a first mechanical refiner comprising a pair of refiner plates, wherein the plates have a bar width of greater than 1.0 millimeters and a groove width of 2.0 millimeters or greater.
Refining the fibers in the first mechanical refiner can be used to provide a relatively less fine, initial refining to the fibers in some embodiments. After refining the fibers in the first mechanical refiner, the fibers are transported to at least one additional mechanical refiner comprising a pair of refiner plates, wherein the plates have a bar width of 1.0 millimeters or less and a groove width of 1.6 millimeters or less.
In the one or more additional mechanical refiners, the fibers can be refined until a total energy consumption of at least 300 kWh/ton for the refiners is reached to produce SEPF. The fibers can be recirculated through the first mechanical refiner a plurality of times. The fibers can be recirculated through the one or more additional mechanical refiners a plurality of times.

[0053] With regard to the various methods described herein, the pulp fibers can be refined at low consistency (e.g., between 3 and 5%) in some embodiments. Persons of ordinary skill in the art will understand consistency to reference the ratio of oven dried fibers to the combined amount of oven dried fibers and water. In other words, a consistency of 3% would reflect, for example, the presence of 3 grams of oven dried fibers in 100 milliliters of pulp suspension.

[0054] Other parameters associated with operating refiners to produce SEPF
can readily be determined using techniques known to those of skill in the art. Similarly, persons of ordinary skill in the art can adjust the various parameters (e.g., total refining energy, refining energy per pass, number of passes, number and type of refiners, specific edge load, etc.) to produce SEPF. For example, the refining intensity, or refining energy applied to the fibers per pass utilizing a multi-pass system, should be gradually reduced as the number of passes through a refiner increases in order to get SEPF having desirable properties.

[0055] SEPF can be incorporated into a variety of end products. SEPF can impart favorable properties on the end products in which they are incorporated. Non-limiting examples of such products include pulp, paper, paperboard, biofiber composites (e.g., fiber cement board, fiber Date Recue/Date Received 2023-11-20 reinforced plastics, etc.), absorbent products (e.g., fluff pulp, hydrogels, etc.), specialty chemicals derived from cellulose (e.g., cellulose acetate, carboxymethyl cellulose (CMC), etc.), and other products. Persons of skill in the art can identify other products in which the SEPF might be incorporated based particularly on the properties of the fibers. For example, by increasing the specific surface areas of SEPF (and thereby the surface activity), utilization of SEPF can advantageously increase the strength properties (e.g., dry tensile strength) of some end products while using approximately the same amount of total fibers and/or provide comparable strength properties in an end product while utilizing fewer fibers on a weight basis in the end product.

[0056] With regard to physical properties, SEPF can improve the strength of a paper product.
For example, incorporating a plurality of SEPF into a paper product can improve the strength of the final product. In some embodiments, a paper product incorporating at least 5 weight percent SEPF can result in higher wet-web strength and/or dry strength characteristics, can improve runnability of a paper machine at higher speeds, and/or can improve process performance, while also improving production. Incorporating between about 2 and about 10 weight percent SEPF can help improve the strength and performance of a resulting paper product significantly when compared to a similar product made in the same manner with substantially no SEPF, in some embodiments.

[0057] The SEPF used in the present invention can be mixed with a starch to form a starch/SEPF mixture, which can subsequently be mixed into wood pulp fibers to produce a resulting pulp composition. The pulp composition can then be delivered to the remainder of a papermaking process where paper or paper products can be formed using techniques known to those of skill in the art. For example, the pulp composition can be deposited onto a web to form a substrate, which may then be at least partially dewatered, and dried to form a paper or paperboard product.

[0058] Turning to the Figures, FIG. 1 is a block diagram of an example system 100 used for making a pulp composition, in accordance with certain embodiments of the disclosed technology.

[0059] In some embodiments, the pulp composition 110 is formed by introducing a first process stream, such as starch 102, and a second process stream, such as fibrillated fibers 104 (e.g., Date Recue/Date Received 2023-11-20 SEPF), into a storage tank or other type of mixing vessel. The first and second process streams are mixed together downstream of a refining process, to form a starch/fibrillated fibers mixture 106. After formation of the starch/fibrillated fibers mixture 106, a third process stream includes adding the starch/fibrillated fibers mixture 106 to a plurality of unrefined or refined wood pulp fibers 108 to form the pulp composition 110. As discussed herein, the addition of the starch 102 to the fibrillated fibers 104 after refining of the fibrillated fibers, and before the addition of the wood pulp fibers 108, contributes to improved strength characteristics of the resulting pulp composition 110.

[0060] FIG. 2 is a flow diagram illustrating an exemplary method 200 for making a pulp composition (e.g., pulp composition 110), in accordance with certain embodiments of the disclosed technology.

[0061] In block 202, the method 200 includes mixing a starch (e.g., 102) and fibrillated fibers (e.g., 104) to produce a starch/fibrillated fibers mixture (e.g., 106). In some embodiments, as discussed herein, the starch and fibrillated fibers are mixed together in a mixing vessel or storage tank separate from an upstream refiner.

[0062] In block 204, the method 200 includes mixing the starch/fibrillated fibers mixture (e.g., 106) into the wood pulp fibers (e.g., 108) to produce a pulp composition (e.g., 110). The pulp composition can then be used to make a final paper product, as discussed herein.

[0063] In some embodiments, the paper product may include approximately 0.1 to 2.5 percent starch, such as approximately 0.4 to 2.0 weight percent, approximately 0.2 to 0.4 weight percent, approximately 0.3 to 0.5 weight percent, approximately 0.4 to 0.6 weight percent, approximately 0.7 to 0.9 weight percent, approximately 0.8 to 1.1 weight percent, approximately 1.0 to 1.2 weight percent, approximately 1.1 to 1.3 weight percent, approximately 1.2 to 1.4 weight percent, approximately 1.3 to 1.5 weight percent, approximately 1.4 to 1.6 weight percent, approximately 1.5 to 1.7 weight percent, approximately 1.6 to 1.8 weight percent, approximately 1.7 to 1.9 weight percent, approximately 1.8 to 2.0 weight percent, approximately 1.9 to 2.1 weight percent, approximately 2.0 to 2.2 weight percent, approximately 2.1 to 2.3 weight percent, approximately 2.2 to 2.4 weight percent, and approximately 2.3 to 2.5 weight percent.
"Weight percent" is defined herein as the weight percent of an ingredient on an oven-dry basis.

Date Recue/Date Received 2023-11-20

[0064] In some embodiments the paper product may include approximately 2 to 20 weight percent fibrillated fibers (e.g., SEPF), such as approximately 3 to 17 weight percent fibrillated fibers, approximately 8 to 12 weight percent fibrillated fibers, approximately 2 to 4 weight percent fibrillated fibers, approximately 4 to 6 weight percent fibrillated fibers, approximately 6 to 8 weight percent fibrillated fibers, approximately 8 to 10 weight percent fibrillated fibers, approximately 10 to 12 weight percent fibrillated fibers, approximately 12 to 14 weight percent fibrillated fibers, approximately 14 to 16 weight percent fibrillated fibers, approximately 16 to 18 weight percent fibrillated fibers, and approximately 18 to 20 weight percent fibrillated fibers.

[0065] In some embodiment, the paper product may include approximately 83 to 97 weight percent wood pulp fibers, such as approximately 88 to 92 percent wood pulp fibers, approximately 83 to 85 weight percent wood pulp fibers, 85 to 87 weight percent wood pulp fibers, 87 to 89 weight percent wood pulp fibers, 89 to 91 weight percent wood pulp fibers, 91 to 92 weight percent wood pulp fibers, 92 to 94 weight percent wood pulp fibers, 94 to 96 weight percent wood pulp fibers, 96 to 97 weight percent wood pulp fibers.

[0066] In some embodiments, the paper product may include approximately 0.8 weight percent starch, approximately 10 weight percent fibrillated fibers (e.g., SEPF), and approximately 90 weight percent wood pulp fibers.

[0067] In some embodiments, the starch may include any cationic or amphoteric starch, such as corn starch, potato starch, tapioca starch, waxy maize starch, wheat starch, rice starch, ethylated starch, and/or native or modified versions.
EXAMPLES

[0068] The present invention is also described and demonstrated by way of the following examples. However, the use of these and other examples anywhere in the specification is illustrative only and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to any particular preferred embodiments described here. Indeed, many modifications and variations of the invention may be apparent to those skilled in the art upon reading this specification, and such variations can be made without departing from the invention in spirit or in scope. The invention is therefore to be limited only by the terms of the appended claims along with the full scope of equivalents to which those claims are entitled.

Date Recue/Date Received 2023-11-20 EXAMPLE 1. Effect of Point of Addition of Starch on Paper Product Strength Method

[0069] The purpose of this Example was to evaluate the effect of the point of addition of starch in the production of pulp composition on the strength characteristics of a subsequently produced paper product.

[0070] Samples of SEPF, refined hardwood, and cooked wet end starch were taken from a commercial production site. The SEPF used in this Example was made according to one or more of the SEPF production methods discussed herein.

[0071] A control test was run by mixing together hardwood and SEPF. No starch was added at any point during the control test. The resulting paper product included 90 weight percent hardwood and 10 weight percent SEPF. The control test was run ten separate times, and data was collected on each respective subsequently produced paper product, as provided below in Table 1.

[0072] A first starch test was run by mixing together hardwood and SEPF, followed by the addition of starch. The resulting paper product included 89 weight percent hardwood, 10 weight percent SEPF, and 1 weight percent starch. The first starch test was run ten separate times, and data was collected on each respective subsequently produced paper product, as provided below in Table 1.

[0073] A second test was run by mixing together SEPF and starch, followed by adding the SEPF/starch mixture to the hardwood. The resulting paper product included 10 weight percent SEPF, 1 weight percent starch, and 89 weight percent hardwood. The second test was run ten separate times, and data was collected on each respective subsequently produced paper product, as provided below in Table 1.
Results &Discussion

[0074] Table 1 below provides the data collected on each respective subsequently produced paper product of the control test (Control), first starch test (Ti), and second starch test (T2). The data shown in Table 1 was collected using procedures outlined by the Pulp and Paper Technical Association of Canada (PAPTAC).
Table 1 Date Recue/Date Received 2023-11-20 Control Ti T2 PAPTAC Procedures Unit C . S. Freeness mL 227 424 294 Basis weight, (oven dried) g/m2 61.40 60.56 61.07 Bulk cc/g 1.67 1.63 1.60 Burst index kPa.m2/g 4.74 4.99 5.22 Tear index (4-ply) m1V.m2/g 9.87 9.68 9.48 Breaking length kin 7.02 6.75 7.43 Breaking Length, std. dev. 0.20 0.44 0.14 Stretch % 3.51 3.52 3.72 Stretch, std. dev. 0.34 0.50 0.15 Tensile Energy Absorption J/m2 105 101 117 Tensile Energy Absorption, std. dev. 14 22 7 Porosity, Gurley sec/100mL 79 21 43 Porosity, std. dev. 2.8 1.3 3.0 Optical Properties:
Brightness, ISO, handsheet % 84.4 82.2 83.3 Opacity, ISO % 74.3 74.5 74.5 Basis weight, (oven dried) g/m2 61.40 60.56 61.07 Filter: B
Scattering Coefficient cm2/g 350 338 346 Absorption Coefficient cm2/g 5.02 6.55 5.80 Filter: R (Y) Scattering Coefficient cm2/g 338 327 334 Absorption Coefficient cm2/g 1.87 2.62 2.22

[0075] As shown in Table 1, by adding starch to the SEPF (i.e., downstream of the SEPF
refining process) and before adding to the hardwood (T2), as opposed to adding the starch after mixing the hardwood and SEPF together (Ti), the subsequently produced paper product sees a variety of improved characteristics. For example, the Breaking Length of the paper product increases by about 10%, the Tensile Energy Absorption (TEA) increases by about 16%, the Gurley porosity (air resistance) approximately doubles, the Tear Index decreases by about 2%, the Burst Index increases by about 5%, and stretch increases by about 6%.

[0076] In summary, changing the point of addition of the starch at the SEPF
storage tank, from the traditional point of addition downstream at the blend chest or stuff box aids in increasing the strength, along with improving a variety of other characteristics, of a subsequently produced paper product.
Date Recue/Date Received 2023-11-20 EXAMPLE 2. Effect of Starch Reduction on Paper Product Strength Method

[0077] The purpose of this Example was to evaluate the effect of the amount of starch added to SEPF in the production of pulp composition on the strength characteristics of a subsequently produced paper product.

[0078] Samples of SEPF, refined hardwood, and cooked wet end starch were taken from a commercial production site. The SEPF used in this Example was made according to one or more of the SEPF production methods discussed herein.

[0079] A control test was run by first mixing together hardwood and SEPF, followed by the addition of starch. The resulting paper product included 89.1 weight percent hardwood, 9.9 weight percent SEPF, and 1 weight percent starch. The control test was run ten separate times, and data was collected on each respective subsequently produced paper product, as provided below in Table 2.

[0080] A first starch test was run by mixing together SEPF and starch, followed by adding the SEPF/starch mixture to the hardwood. The resulting paper product included 9.9 weight percent SEPF, 1 weight percent starch, and 89.1 weight percent hardwood. The first starch test was run ten separate times, and data was collected on each respective subsequently produced paper product, as provided below in Table 2.

[0081] A second test was run by mixing together SEPF and starch, followed by adding the SEPF/starch mixture to the hardwood. The resulting paper product included 9.9 weight percent SEPF, 0.8 weight percent starch, and 89.3 weight percent hardwood. The second test was run ten separate times, and data was collected on each respective subsequently produced paper product, as provided below in Table 2. In the first and second starch tests, only the amount of starch added was changed.
Results & Discussion

[0082] Table 2 below provides the data collected on each respective subsequently produced paper product of the control test (Control), first starch test (Ti), and second starch test (T2). The data shown in Table 2 was collected using PAPTAC procedures, as discussed above.

Date Recue/Date Received 2023-11-20 Table 2 Control Ti T2 PAPTAC Procedures Unit C . S. Freeness mL 441 308 306 Basis weight, (oven dried) g/m2 59.00 59.79 60.32 Bulk cc/g 2.05 1.66 1.63 Burst index kPa.m2/g 5.19 5.23 5.04 Tear index (4-ply) m1V.m2/g 9.94 9.44 9.15 Breaking length kin 6.61 7.41 7.33 Breaking Length, std. dev. 0.57 0.12 0.19 Stretch % 3.36 3.67 3.50 Tensile Energy Absorption J/m2 92 111 106 Porosity, Gurley sec/100mL 24 41 52 Internal Bond 0.001 fl-lb/in2 262 252 237 Optical Properties:
Brightness, ISO, handsheet %
Opacity, ISO % 80.7 81.1 81.9 Basis weight, (oven dried) g/m2 75.4 74.4 75.0 Filter: B 59.00 59.79 60.32 Scattering Coefficient cm2/g Absorption Coefficient cm2/g 357 353 356 Filter: R (Y) 8.25 7.76 7.08 Scattering Coefficient cm2/g Absorption Coefficient cm2/g 338 322 333

[0083] As shown in Table 2, decreasing the amount of starch, for example, from approximately 1 weight percent to 0.8 weight percent, while adding the starch to the SEPF prior to mixing into the hardwood pulp fibers, helps to maintain and/or improve the strength characteristics of a subsequently produced paper product.

[0084] For example, adding approximately 1 weight percent of starch to the SEPF prior to mixing with the wood pulp fibers (Ti) results in a Breaking Length of the resulting paper product of 7.41 km. In comparison, a process by which the SEPF and hardwood pulp are mixed before the starch is added (Control), results in a Breaking Length of the resulting paper product of 6.61 km.
Thus, by changing the point of addition of the starch, we can see an approximately 12% increase in Breaking Length.

Date Recue/Date Received 2023-11-20

[0085] Even further, however, decreasing the amount of starch from approximately 1 weight percent to approximately 0.8 weight percent, and adding the starch to the SEPF
prior to mixing with the hardwood pulp (T2), provides a Breaking Length of the resulting paper product of 7.33 km, which is still an approximately 11% increase in Breaking Length compared to the Control.
Thus, the data shows that the Breaking Length of a resulting paper product can be maintained within approximately 10%, or approximately 2%, or approximately 1%, even while decreasing the amount of starch mixed with the SEPF prior to mixing with hardwood pulp fibers to form a pulp composition.

[0086] In summary, changing the point of addition of the starch at the SEPF
storage tank, from the traditional point of addition downstream at the blend chest or stuff box, even while reducing the total amount of starch added, aids in increasing the strength, along with improving a variety of other characteristics, of a subsequently produced paper product.

[0087] In some examples, disclosed methods or products may involve one or more of the following clauses:

[0088] Clause 1: A method of making a pulp composition, the method comprising: mixing together a starch and fibrillated fibers to produce a starch/fibrillated fibers mixture; and mixing the starch/fibrillated fibers mixture into wood pulp fibers to produce the pulp composition.

[0089] Clause 2: The method of clause 1, wherein the wood pulp fibers comprise one or more of hardwood pulp fibers, softwood pulp fibers, non-wood pulp, recycled pulp fibers, or combinations thereof.

[0090] Clause 3: The method of clause 1 or 2, further comprising:
depositing the pulp composition onto a web to form a substrate; at least partially dewatering the substrate; and drying the substrate to form a paper product.

[0091] Clause 4: The method of clause 3, wherein the fibrillated fibers comprise surface enhanced pulp fibers (SEPF).

[0092] Clause 5: The method of clause 4, wherein the paper product comprises approximately 0.1 to 2.5 weight percent starch, approximately 2 to 20 weight percent SEPF, and approximately 83 to 97 weight percent wood pulp fibers.

Date Recue/Date Received 2023-11-20

[0093] Clause 6: The method of clause 4 or 5, wherein the paper produce comprises approximately 0.4 to 2.0 weight percent starch, approximately 3 to 17 weight percent SEPF, and approximately 83 to 97 weight percent wood pulp fibers.

[0094] Clause 7: The method of any of clauses 3-6, wherein the paper product has a Breaking Length of at least approximately 7.0 km.

[0095] Clause 8: The method of any of clauses 3-7, wherein the paper product has a Tensile Energy Absorption (TEA) of at least approximately 110 J/m2.

[0096] Clause 9: The method of any of clauses 3-8, wherein the paper product has a Tear Index of less than at least approximately 9.6 mi\l-m2/g.

[0097] Clause 10: The method of clause 4, wherein the paper product comprises approximately 0.8 percent starch, approximately 10 percent SEPF, and approximately 90 percent wood pulp fibers.

[0098] Clause 11: The method of clause 10, wherein the paper product has a Breaking Length of at least approximately 7.0 km.

[0099] Clause 12: The method of clause 10 or 11, wherein the paper product has a Tensile Energy Absorption (TEA) of at least approximately 106 J/m2.

[00100] Clause 13: A method of making a paper product, the method comprising: mixing together a starch and fibrillated fibers to produce a starch/fibrillated fibers mixture; mixing the starch/fibrillated fibers mixture into wood pulp fibers to produce a pulp composition; depositing the pulp composition onto a web to form a substrate; at least partially dewatering the substrate;
and drying the substrate to form the paper product, wherein the paper product has an increased Breaking Length compared to a First Comparative Paper Product.

[00101] Clause 14: A paper product comprising: a starch in a first amount in the range of approximately 0.1 to 2.5 weight percent; fibrillated fibers in a second amount in the range of approximately 2 to 20 weight percent; and wood pulp fibers in a third amount in the range of approximately 83 to 97 weight percent, wherein the paper product has a lower amount of the starch compared to a Second Comparative Paper Product; and wherein the paper product maintains a Breaking Length within the range of approximately 10 percent compared to a Second Comparative Paper Product.

Date Recue/Date Received 2023-11-20

[00102] Clause 15: The paper product of clause 14, wherein the paper produce maintains a Breaking Length within the range of approximately 2 percent compared to a Second Comparative Paper Product.

[00103] Clause 16: The paper product of clause 14, wherein the paper product comprises approximately 0.1 to 2.5 weight percent starch, approximately 2 to 20 weight percent SEPF, and approximately 83 to 97 weight percent wood pulp fibers.

[00104] Clause 17: The paper product of clause 16, wherein the paper product comprises approximately 0.4 to 2.0 weight percent starch, approximately 3 to 17 weight percent SEPF, and approximately 83 to 97 weight percent wood pulp fibers.

[00105] Clause 18: The paper product of clause 14, wherein the paper product has a Breaking Length of at least approximately 7.0 km.

[00106] Clause 19: The paper product of clause 14, wherein the paper product has a Tensile Energy Absorption (TEA) of at least approximately 110 J/m2.

[00107] Clause 20: The paper product of clause 14, wherein the paper product has a Tear Index of less than at least approximately 9.6 ml\l-m2/g, and wherein the paper product comprises approximately 0.8 percent starch, approximately 10 percent SEPF, and approximately 90 percent wood pulp fibers.

[00108] It should be emphasized that the above-described aspects are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the present disclosure. Many variations and modifications can be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the present disclosure. All such modifications and variations are intended to be included herein within the scope of the present disclosure, and all possible claims to individual aspects or combinations of elements or steps are intended to be supported by the present disclosure.
Moreover, although specific terms are employed herein, as well as in the claims which follow, they are used only in a generic and descriptive sense, and not for the purposes of limiting the described invention, nor the claims which follow.
Date Recue/Date Received 2023-11-20

Claims (20)

What is claimed is:

1. A method of making a pulp composition, the method comprising:
mixing together a starch and fibrillated fibers to produce a starch/fibrillated fibers mixture;
and mixing the starch/fibrillated fibers mixture into wood pulp fibers to produce the pulp compositi on.

2. The method of claim 1, wherein the wood pulp fibers comprise one or more of hardwood pulp fibers, softwood pulp fibers, non-wood pulp, recycled pulp fibers, or combinations thereof.

3. The method of claim 2, further comprising:
depositing the pulp composition onto a web to fomi a substrate;
at least partially dewatering the substrate; and drying the substrate to fomi a paper product.

4. The method of claim 3, wherein the fibrillated fibers comprise surface enhanced pulp fibers (SEPF).

5. The method of claim 4, wherein the paper product comprises approximately 0.1 to 2.5 weight percent starch, approximately 2 to 20 weight percent SEPF, and approximately 83 to 97 weight percent wood pulp fibers.

6. The method of claim 5, wherein the paper product comprises approximately 0.4 to 2.0 weight percent starch, approximately 3 to 17 weight percent SEPF, and approximately 83 to 97 weight percent wood pulp fibers.

7. The method of claim 6, wherein the paper product has a Breaking Length of at least approximately 7.0 km.

Date Recue/Date Received 2023-11-20

8. The method of claim 7, wherein the paper product has a Tensile Energy Absorption (TEA) of at least approximately 110 J/m2.

9. The method of claim 8, wherein the paper product has a Tear Index of less than at least approximately 9.6 mi\l-m2/g.

10. The method of claim 4, wherein the paper product comprises approximately 0.8 percent starch, approximately 10 percent SEPF, and approximately 90 percent wood pulp fibers.

11. The method of claim 10, wherein the paper product has a Breaking Length of at least approximately 7.0 km.

12. The method of claim 11, wherein the paper product has a Tensile Energy Absorption (TEA) of at least approximately 106 J/m2.

13. A method of making a paper product, the method comprising:
mixing together a starch and fibrillated fibers to produce a starch/fibrillated fibers mixture;
mixing the starch/fibrillated fibers mixture into wood pulp fibers to produce a pulp compositi on;
depositing the pulp composition onto a web to fonn a substrate;
at least partially dewatering the substrate; and drying the substrate to fonn the paper product, wherein the paper product has an increased Breaking Length compared to a First Comparative Paper Product.

14. A paper product comprising:
a starch in a first amount in the range of approximately 0.1 to 2.5 weight percent;
fibrillated fibers in a second amount in the range of approximately 2 to 20 weight percent;
and wood pulp fibers in a third amount in the range of approximately 83 to 97 weight percent, Date Recue/Date Received 2023-11-20 wherein the paper product has a lower amount of the starch compared to a Second Comparative Paper Product; and wherein the paper product maintains a Breaking Length within the range of approximately percent compared to a Second Comparative Paper Product.

15. The paper product of claim 14, wherein the paper produce maintains a Breaking Length within the range of approximately 2 percent compared to a Second Comparative Paper Product.

16. The paper product of claim 14, wherein the paper product comprises approximately 0.1 to 2.5 weight percent starch, approximately 2 to 20 weight percent SEPF, and approximately 83 to 97 weight percent wood pulp fibers.

17. The paper product of claim 16, wherein the paper product comprises approximately 0.4 to 2.0 weight percent starch, approximately 3 to 17 weight percent SEPF, and approximately 83 to 97 weight percent wood pulp fibers.

18. The paper product of claim 14, wherein the paper product has a Breaking Length of at least approximately 7.0 km.

19. The paper product of claim 14, wherein the paper product has a Tensile Energy Absorption (TEA) of at least approximately 110 J/m2.

20. The paper product of claim 14, wherein the paper product has a Tear Index of less than at least approximately 9.6 ml\l-m2/g, and wherein the paper product comprises approximately 0.8 percent starch, approximately 10 percent SEPF, and approximately 90 percent wood pulp fibers.

Date Recue/Date Received 2023-11-20