CA3167266A1 - Nonwoven fabric comprising cellulose filaments and methods of fabrication thereof - Google Patents

Abstract

There is disclosed a nonwoven fabric. The nonwoven fabric comprises short fibers of plant-based material having a length of about between 2 mm and 5 mm, and cellulose filaments being present at a proportion of up to 10 wt-% of the nonwoven fabric, such that the cellulose filaments bind the short fibers in the nonwoven fabric. Long fibers are optionally added to the nonwoven fabric.

Description

NONWOVEN FABRIC COMPRISING CELLULOSE FILAMENTS AND METHOD OF
FABRICATION THEREOF
FIELD
[0001] The invention relates to nonwoven fabric, and more particularly, although not exclusively, to systems of cellulose-filament-based nonwoven sheet fabrics and methods of fabrication thereof.
BACKGROUND

[0002] The nonwoven fabric material industry continuously creates innovations towards new products, better quality products or lower-cost production methods. Even though nonwoven fabric material production has been known for a long time ago, it continues to be improved.

[0003] Nonwoven fabrics are used in numerous applications, such as in the medical field, household industry, geotextile industry, food industry, personal care field and the like. In most applications, the nonwoven fabrics are designed to meet end-use performance criteria, and so, in dry or wet state. In some instances, the fabrics are designed to be disposable such as being dispersible, recyclable, degradable and/or biodegradable.

[0004] Further, nonwoven fabrics generally benefit from hydrophobicity and low absorbency, which can be obtained, e.g., by adding hydrophobic polymers such as polypropylene. A downside of using polypropylene is that it limits the liquid absorption capacity.

[0005] Hydrophilicity is required for wet wipe applications in order to absorb and retain the wiping solution within the nonwoven fabric. Aside from incorporating naturally hydrophilic materials in the fabric, hydrophilicity is also achieved by surfactant treatment. However, these surfactants are often synthetic chemicals and/or cause a risk of skin irritation.

[0006] It is contemplated to use short cellulose fibers for achieving greater hydrophilicity and/or absorbency, but a chemical binder (typically latex) is generally required to bind these fibers together to prevent linting,dusting and/or sheet degradation during use.

[0007] To meet these above-identified requirements, state-of-the-art nonwoven fabric typically relies on chemical additives, thermoplastics and other non-biodegradable, non-ecofriendly and - 1 ¨
Date Recue/Date Received 2022-07-11 plastic-based materials. Therefore, such fabrics suffer from a drawback and improvements remain important.
Summary

[0008] Features and advantages of the subject matter hereof will become more apparent in light of the following detailed description of selected embodiments, as illustrated in the accompanying figures. As will be realized, the subject matter disclosed and claimed is capable of modifications in various respects, all without departing from the scope of the claims.
Accordingly, the drawings and the description are to be regarded as illustrative in nature and not as restrictive and the full scope of the claimed subject matter.

[0009] This invention relates to a nonwoven fabric made of short cellulose fibers such as wood pulp with a fiber length of approximately 2 mm to 5 mm and cellulose filaments ("CF"), which are a refined fiber with a high aspect ratio. The combination of these two components produces a material having various performant properties, as well as being ecofriendly.

[0010] According to a broad aspect, there is provided a nonwoven fabric comprising short fibers having a length of about between 2 mm and 5 mm, and cellulose filaments (CF) being present at a proportion of up to 10 wt-% of the nonwoven fabric, such that the cellulose filaments help bind the short fibers in the nonwoven fabric giving it advantageous physical properties.

[0011] In accordance with one or more embodiments, the nonwoven fabric further comprises long fibers having a length of more than 5 mm, the long fibers being present at a proportion of up to about 40 wt-% of the nonwoven fabric, such that the cellulose filaments help bind the long fibers in the nonwoven fabric.

[0012] In accordance with one or more embodiments, the proportion of cellulose filaments is between about 2 wt-% and 7 wt-%.

[0013] In accordance with one or more embodiments, the proportion of long fibers is up to about 20 wt-%.

[0014] In accordance with one or more embodiments, the proportion of long fibers is between about 20 wt-% and 40 wt-%.
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Date Recue/Date Received 2022-07-11

[0015] In accordance with one or more embodiments, the long fibers are selected from the group consisting of man-made fibers regenerated cellulose and a mixture thereof.

[0016] In accordance with one or more embodiments, the long fibers are selected from the group consisting of lyocell fibers, viscose fibers, hemp, cotton, hemp, jute, flax and a mixture thereof.

[0017] In accordance with one or more embodiments, the short fibers are derived from a raw material selected from the group consisting of wood pulp, hemp, bamboo, bagasse, flax, natural plant fibers, cotton and a mixture thereof.

[0018] In accordance with one or more embodiments, the nonwoven fabric further comprises an alcohol content of at least about 60% in the liquid phase.

[0019] In accordance with one or more embodiments, the nonwoven fabric has a basis weight of about between about 40 GSM to 85 GSM.

[0020] In accordance with one or more embodiments, the nonwoven fabric has a dry tensile strength of at least about 31.0 N/50mm and a wet tensile strength of at least about 6.4 N/50mm.

[0021] In accordance with one or more embodiments, the nonwoven fabric has a dry maximal elongation of at least about 7% and a wet maximal elongation of at least about 26%.

[0022] In accordance with one or more embodiments, the nonwoven fabric has an alcohol absorptive capacity of at least about 4.2 g/g.

[0023] in accordance with one or more embodiments, the nonwoven fabric has a water absorptive capacity of at least about 6.8 g/g.

[0024] In accordance with one or more embodiments, the nonwoven fabric has a liquid wicking rate of at least about 43.0 mm/305ec.

[0025] In accordance with one or more embodiments, the nonwoven fabric has a slosh box disintegration rate of at least about 60%.

[0026] In accordance with one or more embodiments, the nonwoven fabric has an opacity of at least about 50%.
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Date Recue/Date Received 2022-07-11

[0027] In accordance with one or more embodiments, the nonwoven fabric has a dry linting rate of about 0.01% and a degradation rate of about 2.14%.

[0028] According to another broad aspect, there is provided a method for fabricating a nonwoven fabric, the method comprising:
a) preparing a liquid suspension of i) short fibers having a length of about between 2 mm and 5 mm; and ii) cellulose filaments being present at a proportion of up to 10 wt-% of the dry nonwoven fabric;
b) forming a web from the prepared liquid suspension and dewatering it;
c) hydroentangling the web to obtain a wet fabric; and d) drying the wet fabric.

[0029] In accordance with one or more embodiments, the liquid suspension further comprises long fibers having a length of more than about 5 mm, the long fibers being present at a proportion of up to about 40 wt-% of the nonwoven fabric.

[0030] In accordance with one or more embodiments, said forming the web comprises wet-laying the liquid suspension.

[0031] In accordance with one or more embodiments, the method further comprises patterning the wet fabric.

[0032] In accordance with one or more embodiments, the method further comprises drying the wet fabric.

[0033] In accordance with one or more embodiments, the method further comprises calendaring the dried fabric.

[0034] In accordance with one or more embodiments, the method further comprises embossing the dried fabric.
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Date Recue/Date Received 2022-07-11

[0035] In accordance with one or more embodiments, the method further comprises winding the dried fabric thereby obtaining a roll of fabric.

[0036] According to a broad aspect, there is provided a pulp and paper product comprising short fibers having a length of about between 2 mm and 5 mm and cellulose filaments being present at a proportion of up to 10 wt-% of the nonwoven fabric, such that the cellulose filaments bind the short fibers in the nonwoven fabric.

[0037] Advantages flow from the design and use of the embodiments described herein.

[0038] One advantage is that the present invention provides a product with performant structural properties while being easily disposable.

[0039] Another advantage is that the present invention provides a product that may be essentially conceived using wood pulp and mechanically obtained product thereof.

[0040] Yet another advantage is that the present invention reduces the amount of lint and dust in the manufacturing process, which greatly reduces risk of unwanted fires, air contamination and other accidents.

[0041] In other aspects of this invention, a presence of about 10% of cellulose filaments in the nonwoven fabric allows to reduce the presence of long fibers to less than about 50% while keeping the strength properties of the resulting fabric.
BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration example embodiments thereof and in which:

[0043] FIGURE 1 - represents an electron microscope image of the fiber structure of a nonwoven fabric according to one embodiment of the invention;

[0044] FIGURE 2- represents an electron microscope image of the fiber structure of a nonwoven fabric comprising cellulose filaments according to one embodiment of the invention;

[0045] FIGURE 3 - represents a schematic view of a system for fabricating a nonwoven fabric according to one embodiment of the invention; and - 5 ¨
Date Recue/Date Received 2022-07-11

[0046] FIGURE 4 - represents a flowchart that illustrates a method for fabricating a nonwoven fabric according to one embodiment of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS

[0047] In the following description of the embodiments, references to the accompanying drawings are by way of illustration of an example by which one or more embodiments of the invention may be practiced.

[0048] The term "MD" and "CD" means "machine-direction" and "cross-machine direction", respectively.

[0049] The term "wet-laying" or "wet-laid" refer to a method for depositing a liquid suspension to form a web.

[0050] The term "hydroentangling" or "hydroentanglement" refer to a method for intertwining fiber in a web using water jets.

[0051] The term "hydroembossing" refers a method of patterning a surface by spraying waters jets on sheet in contact with a patterned drum.

[0052] The term "biodegradable" refers to a composition of matter is capable of being decomposed by bacteria or other living organisms within a reasonable period.

[0053] The term "plastic-free" refers to a composition of matter that contains little to no amount of polymer(s), particularly synthetic polymer(s).

[0054] The term "long fiber" and "long cellulose fiber" refers to fiber whose composition, structure and properties were significantly modified in a given process. Generally, "long fiber" and "long cellulose fiber" do not contain synthetic plastic fiber and cellulose filament and have a length of more than 5 mm.

[0055] The expressions "short fiber" and "short cellulose fiber" refer to fibers composed of a polymer matrix, typically glucose, that is derived from a plant-based material through mechanical and/or chemical process. Generally, "short fiber" and "short cellulose fiber"
have a length of between 2 mm and 5 mm.
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Date Recue/Date Received 2022-07-11

[0056] The expression "cellulose filaments" when used herein relates to plant based fibers treated to achieve a high aspect ratio of fibers in comparison to untreated fibers. It will be appreciated that the "cellulose filaments" referred to herein may relate for example, to FilocellTM from Kruger Inc.

[0057] The term "fabric" when used herein relates to any web like material that can be rolled or can be cut to specific sizes.

[0058] The term "about" when used in relation to a numerical amount or ranges of amounts means that deviations of plus or minus 10% of the given value are comprised in the stated amounts or ranges of amounts.

[0059] It will be appreciated that the various properties measured by the creators of the present technology result from various standard test methods.

[0060] The experimental results presented herein with respect to tensile strength and elongation were performed according to ISO standard No. 9073-3:1989 Textiles - Test methods for nonwovens - Part 3: Determination of tensile strength and elongation.

[0061] The experimental results presented herein with respect to disintegration were obtained according to GD4:FG502-Slosh Box Disintegration test.

[0062] The experimental results presented herein with respect to the opacity level were performed according to the standard ISO 2471 Paper and board-determination of the opacity (paper backing).

[0063] The experimental results presented herein with respect to linting were conveniently measured by standardized abrasion test.

[0064] Neither the Title nor the Abstract is to be taken as limiting in any way as the scope of the disclosed invention(s). The title of the present application and headings of sections provided in the present application are for convenience only and are not to be taken as limiting the disclosure in any way.

[0065] Various embodiments are described in the present application and are presented for illustrative purposes only. The described embodiments are not, and are not intended to be, limiting in any sense. The presently disclosed technologies are widely applicable to numerous - 7 ¨
Date Recue/Date Received 2022-07-11 embodiments, as is readily apparent from the disclosure. One of ordinary skill in the art will recognize that the disclosed technologies may be practiced with various modifications and alterations, such as structural and logical modifications. Although particular features of the disclosed technologies may be described with reference to one or more particular embodiments and/or drawings, it should be understood that such features are not limited to usage in the one or more particular embodiments or drawings with reference to which they are described, unless expressly specified otherwise.

[0066] Referring to Figure 1, there is depicted an electron microscope image of the fiber structure of a nonwoven fabric. The image was recorded using backscattered electrons with an initial electrical potential of 10.0 kV, and the image has an enhancement of x500. The nonwoven fabric depicted in Figure 1 is composed of short fibers 10 obtained from Northern Bleached Softwood Kraft (NBSK) pulp and 1.4 dtex 10 mm Lyocell long fibers 20, in an 80%/20%
proportion.

[0067] Short fibers 10 are typically obtained by mechanically or chemically separating cellulose fibers of a plant-based material such as wood. Wood pulp is composed of short fibers 10 that have irregular shapes and that have a length of about 2 mm to 5 mm, and a width and thickness in the 10 microns to 100 microns range. In some embodiments, the short fibers 10 have a rectangular-like cross-section shape. However, the size and shape of the short fibers 10 greatly vary according to the embodiment.

[0068] While most paper is fabricated using mainly wood pulp, nonwoven fabrics often rely on incorporating long fiber having a length greater than or equal to 5 mm fibers 20 to improve the structural aspects of the resulting fabric. Typically, long fibers 20 are obtained by processing cellulose fiber using mechanical and/or chemical processes. For instance, Lyocell, which is a long fiber obtained by dissolving pulp and then reconstituting it by dry jet-wet spinning, is used massively worldwide as long fibers 20 in various products. The person skilled in the art understands that long fibers 20 are commonly referred to as polymers. The long fibers 20 used in the present technology typically have a cylindrical shape having a length between 5 and 14 mm and a radius of tens of microns. As opposed to the short fibers 10 contained in wood pulp, the size and shape of long fibers 20 are generally uniform.

[0069] In the embodiment depicted in Figure 1, short fibers 10 are intertwined with long fibers 20 on a microscopic scale, which suggests a mechanical cohesion between the material composing the nonwoven fabric.
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Date Recue/Date Received 2022-07-11

[0070] Referring to Figure 2, there is depicted an electron microscope image of the fiber structure of a nonwoven fabric comprising cellulose filaments (CF). The image was recorded using backscattered electrons with an initial electrical potential of 10.0 kV, and the image has an enhancement of x500. The nonwoven fabric depicted in Figure 2 is composed of short fiber 10 obtained from NBSK pulp, long fiber 20 and CF 30, in an 80%/15%/5% proportion.

[0071] CF 30 is an engineered groundbreaking material first described in United States Patent Application Publication No. US 2011/0277947 Al (Hua et al.), published on November 17, 2011, entitled "Cellulose Nanofilaments and Method to Produce Same". CF 30 is obtained by mechanically breaking down wood pulp into thin and long polymer chains in a mechanical, chemical free, zero waste process which produces long and thin high aspect ratio filaments in the form of moist or dry fluff ready to be used. As opposed to microfibrillated cellulose (MFC), crystalline nanocellulose (CNC), super microfibrillated cellulose, nanocellulose, cellulose microfibrils, cellulose nanofibrils, nanofibers, nanocellulose, microcrystalline cellulose (MCC), microdenominated cellulose (MDC), and the like, CF 30 provides with unique intrinsic properties and characteristics. More precisely, CF 30 has an average diameter of 30 nm to 500 nm, and an average length of about 200 microns to 2 mm, which results with a much higher aspect ratio than other types of microscopic cellulose-derived products.

[0072] The nonwoven fabric depicted in Figure 2 is composed of 5% CF 30 and has a denser structure than the one depicted in Figure 1. As best seen in the bottom-right corner, CF 30 forms links in the short fibers 10 and Lyocell long fibers 20 matrix. Thus, without being bound by any particular theory, the CF 30 solidifies and strengthens the short fibers 10 and long fibers 20 matrix by acting as a binding agent therein, by providing more entanglement points.
Further below are presented quantitative values of the mechanical properties of CF-based and non-CF-based nonwoven fabrics, in accordance with a given embodiment. It will be appreciated that the bonding induced by CF 30 is related to covalent bonding. In one embodiment, the CF 30 is characterized by a high relative bounding area.

[0073] In one embodiment, the nonwoven fabric has a proportion of CF 30 up to about 10%.

[0074] In one embodiment, the nonwoven fabric has a proportion of long 20 up to 20%, such as in low-strength products. In another embodiment, the embodiment, the nonwoven fabric has a proportion of long 20 of between about 20 wt-% and 40 wt-%, such as in high-strength products.
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Date Recue/Date Received 2022-07-11

[0075] In one embodiment, the long fibers 20 are selected from the group consisting of man-made fibers regenerated cellulose and a mixture thereof.

[0076] In one embodiment, the long fibers 20 are selected from the group consisting of lyocell fibers, viscose fibers, cotton, hemp, jute, flax and a mixture thereof.

[0077] In one embodiment, the short fibers 10 are derived from a raw material selected from the group consisting of wood pulp, hemp, bamboo, bagasse, flax, natural plant fibers, cotton, and a mixture thereof.

[0078] In one embodiment, the nonwoven fabric is contained in a medium having an alcohol content of about 60% in the liquid phase. The person skilled in the art understands that isopropanol (IPA) may be used as an alcohol suited for the present technology.

[0079] It will be appreciated that the basis weight of the fabric may greatly vary according to the product and may vary from about 10 GSM (gram by square meter) to 500 GSM, preferably from 40 GSM to 85 GSM.

[0080] Referring to Figure 3, there is depicted a schematic view of a system 100 for fabricating a nonwoven fabric.

[0081] The system 100 generally comprises a wet-laying unit 110 that forms a web from a liquid suspension, a patterning unit 120 that binds the web into a fabric, a dewatering unit 130 that removes the majority of the water in the fabric, a drying unit 140 that removes any water left in the fabric, a calendering unit 150 that smooths the fabric, a sensing unit 160 that monitors the output or resulting fabric and a winding unit 170 that produces rolls of fabrics. It will be appreciated that the components of the system 100 presented herein may vary between embodiments, and that the present technology is not limited to the presented components.

[0082] In some embodiments, the feedstock entering the system 100 consist of a liquid suspension comprising wood pulp, which is composed of short fibers 10, long fibers 20 and CF
30. The liquid suspension typically has a consistency between 0.01 and 0.05%
The liquid used to form the suspension typically is water.

[0083] In operation, the fibers in suspension are deposited on a porous surface to separate the fibers from the fluid to form a web. The mesh-like porous surface is mounted on a conveyor belt having a defined speed that exits the wet-laying unit 110 with the deposited web. The person - 10 ¨
Date Recue/Date Received 2022-07-11 skilled in the art understands that the speed of the conveyor belt and the flow rate of the liquid suspension affects the thickness and the density of the deposited web. In an embodiment, the output of the wet-laying unit is a web.

[0084] The patterning unit 120 is configured to receive the deposited web and form a fabric therewith. It will be appreciated that the patterning unit 120 may bind the web by various means and processes. For instance, the patterning unit 120 may use a bonding method selected from the group consisting of thermal bonding, hydroentangling, ultrasonic pattern bonding, embossing, needle punching, chemical bonding, melt blowing and the like. While the present technology is not limited to a particular bonding method, a preferred embodiment is presented and detailed below.

[0085] In one embodiment, the patterning unit 120 comprises an hydroentanglement unit. The person skilled in the art is aware that an hydroentanglement unit consists of a series of water jets projecting pressurized water onto the web, thereby causing the fiber content to intertwine and to bind together. An advantage of the hydroentanglement method is that it creates a highly intertwined pattern without using chemical additives or high temperatures.

[0086] In operation, the conveyor belt conveys the fibrous web through the patterning unit 120 in a defined direction, thereby creating a fabric having a first pattern aligned with the defined direction (MD) and a second pattern perpendicular to the defined direction (CD). The person skilled in the art understands that the MD and CD patterns generally have different structures and properties from one another. In one embodiment, the output of the patterning unit 120 is a bound fabric.

[0087] The dewatering unit 130 and/or the drying unit 140 is configured to receive the bound fabric outputted by the patterning unit 120, the bound fabric generally containing water. In the dewatering unit 130, the fabric may be dewatered by stretching the fabric in the MD and/or CD
direction, by blowing heated or non-heated air or other gas onto the fabric and by any other methods promoting the migration of water outside of the fabric. In one embodiment, the dewatering unit 130 comprises a through air drying (TAD) unit, which is a type of unit well known by the person skilled in the art. In one embodiment, the output of the dewatering unit 130 is a dewatered fabric. It will be appreciated that the dewatering unit 130 may be present before and/or after the patterning unit 120, in accordance with the embodiment.
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Date Recue/Date Received 2022-07-11

[0088] The drying unit 140 is configured to receive the dewatered fabric outputted from the dewatering unit 130. During the dewatering step, most of the water used in subsequent steps that is absorbed by the fabric is removed therefrom. However, the fabric typically remains moist when exiting the dewatering unit 130 and generally needs to be further dried before entering the calendering unit 150. The drying unit 140 comprises lamps that project radiation onto the surface of the dewatered fabric thereby heating its content. The heat created by the incoming radiation evaporates the remaining water in the fabric. In one embodiment, the output of the drying unit 140 is an essentially dried fabric.

[0089] In one embodiment, the drying unit 140 comprises infrared (IR) lamps.

[0090] While some patterning and/or web creating methods do not involve water in the process, the person skilled in the art understands that the dewatering unit 130, the drying unit 140 and/or the calendering unit 150 may be optional in some embodiments of the system 100. However, the person skilled in the art also understands that it is preferable that the system 100 includes at least one of the dewatering unit 130 and the drying unit 140 when the patterning unit 120 comprises an hydroentanglement unit and when using a wet-laying unit 110.

[0091] It will be appreciated that the patterning unit 120, the dewatering unit 130 and the drying unit 140 may be combined and/or interchanged with one another, according to the embodiment.

[0092] The calendering unit 150 is configured to receive the essentially dried fabric from the drying unit 140. Generally, the calendering unit 150 comprises a series of rolls that compress the fabric to create a smooth finish and optional patterns and designs on the surface. It will be appreciated that the calendering unit 150 may treat the fabric by various means and processes.
For instance, the calendering unit 150 may use a calendering method selected from the group consisting of beetling, watering, embossing, Schreiner embossing, and the like. In one embodiment, the output of the calendering unit 150 is a calendered fabric.

[0093] In one embodiment, the series of rolls comprised in the calendering unit 150 are heated.

[0094] In some embodiments, the system 100 further comprises an embossing unit. An embossing unit typically consists of using a roll having a patterned surface that apply pressure on a fibrous web, thus reproducing the pattern in the web. In some embodiments, the system 100 comprises an hydroembossing unit, which consist of applying pressure using water jets on the - 12 ¨
Date Recue/Date Received 2022-07-11 fabric that is in contact with a patterned drum. It will be appreciated that hydroembossing is typically done without heating the fabric.

[0095] The sensing unit 160 is configured to receive the calendered and/or embossed fabric. The sensing unit 160 generally comprises humidity sensors, weight scales, spectrometers, opacity sensors and other means of monitoring the fabric. It will be appreciated that the measurement means comprised in the sensing unit 160 vary according to the embodiment.

[0096] The output of the sensing unit 160 is typically the same as its input, i.e., the calendered and/or embossed fabric. Therefore, the person skilled in the art understands that the sensing unit 160 may be optional in some embodiments, as it mainly serves to monitor and control the produced fabric.

[0097] In one or more embodiments, the sensing unit 160 control the process parameters of the subsequent units according to the measurements made on the calendered and/or embossed fabric. For instance, the sensing unit 160 may control the flow rate of the liquid suspension in the wet-laying unit 110, may control the pressure of the water and the number of water jets used in the patterning unit 120, may control the temperature and the flow rate of the air used in the dewatering unit 130, may control the electrical current provided to the lamp in the drying unit 140, may control the pressure or the heat of the rolls in the calendering unit 150 and the like.

[0098] In one embodiment, the sensing unit 160 controls the speed of the conveyor belt used in the system 100.

[0099] The winding unit 170 is configured to receive the resulting fabric and for forming a roll of fabric. In operation, the winding unit 170 is connected to an extremity of the continuous feed of fabric outputted by the calendering unit 150 or the sensing unit 160, and creates a force on the fabric so that the latter remains strait in the various units of the system

100. Once a sufficient amount of fabric is winded by the winding unit, the roll of fabric installed in the system 100 is removed therefrom and a new roll is installed.
[0100] Referring to Figure 4, there is depicted a flowchart that illustrates a method for making a nonwoven fabric.

[0101] According to processing step 200, a suspension is prepared. Generally, the suspension prepared comprises, but is not limited to, CF, long fibers and short fibers.
During the preparation, each component is mixed using a mixer until a sufficiently homogeneous distribution is obtained.
- 13 ¨
Date Recue/Date Received 2022-07-11 Once the mixture is obtained, it is combined with water to obtain the desired consistency to thereby obtain the suspension.

[0102] In one embodiment, the components are directly mixed with water.

[0103] In one embodiment, in the context of air-laying for instance, the mixture is not combined with water.

[0104] According to processing step 210, a web is formed. The formation of the web varies according to the embodiment. In one embodiment, the web is formed by wet-laying, or air-laying carding/crosslapping the suspension. In operation, the suspension or the mixture is deposited on the surface of a conveyor belt thereby forming the web.

[0105] In one embodiment, the fibers contained in the suspension or the mixture are aligned mechanically during processing step 210. The alignment may be MD, CD or any other orientation, in accordance with the embodiment.

[0106] According to processing step 220, a fabric is obtained by binding the web. In operation, the structure of the web formed at processing step 210 is mechanically and/or chemically bound so that it forms a uniform yet nonwoven fabric. It will be appreciated that the web may be bound using a dry process or a wet process, according to the embodiment.

[0107] In one embodiment, the processing step 220 is processed by hydroentangling the web.

[0108] According to processing step 230, the fabric is dried. After being bound, the fabric generally contains a certain amount of water,

[0109] In one embodiment, the processing step 230 comprises a TAD unit.

[0110] In one embodiment, the fabric is dewatered before being dried.

[0111] According to processing step 240, the fabric is calendered. In most cases, the calendering process of processing step 240 is the last step that modify the structure of the fabric. In accordance with the embodiments presented above, the fabric is pressed between rolls so that the surface is smoothed, which provides a proper finish to the fabric. In one or more embodiments, the processing step 240 is performed by beetling, watering or embossing the fabric.

[0112] In one embodiment, the fabric properties are measured after being calendered.
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Date Recue/Date Received 2022-07-11

[0113] In one embodiment, the fabric is winded after being calendered or measured.

[0114] Experimental data

[0115] Hereinunder are presented quantified properties of nonwoven fabrics in accordance with embodiments presented herein.
Table 1 - Sample Compositions Basis Caliper LONG SHORT
CF
weight (mm) FIBERS FIBERS
SAMPLE MATERIALS CONTENT
(GSM) CONTENT CONTENT
(%) (%) (%) Lyocell -Northern PRIOR Bleached 40.9 0.31 0 40 60 ART Softwood Kraft (NBSK) CF - Viscose-2 45.3 0.31 6 30 74 NBSK
CF - Lyocell -3 36.8 0.23 10 20 70 NBSK
Table 2 - Structural Properties Dry MD tensile strength (N/50mm) 10.5 36.0 54 Dry CD tensile strength (N/50mm) 5.8 18.0 31 Wet MD tensile strength (N/50mm) 4.9 5.1 6.5 - 15 ¨
Date Recue/Date Received 2022-07-11 Wet CD tensile strength (N/50mm) 3.1 5.2 6.4 Dry MD elongation (%) 9 7 4 Dry CD elongation (%) 16 27 13 Wet MD elongation (%) 21 32 29 Wet CD elongation (%) 29 33 26 Water absorptive capacity (g/g) 6.68 6.84 8.10 IPA absorptive capacity (g/g) 6.12 5.11 4.24 wicking rate in 10 seconds (mm) 41.5 32.0 27.5 wicking in 30 seconds (mm) 63.5 53.5 43.0 Disintegration rate in 30 minutes (%) 92.4 97.7 100.0 Dry linting (%) 0.63 - 0.01 Dry Degradation (%) 5.96 - 2.14 Opacity ISO (%) 52.06 - 57.01

[0116] It will be appreciated that one or more embodiments of the nonwoven fabric and method disclosed herein are of great advantage.

[0117] More precisely, one advantage of one or more embodiments of the methods and the product disclosed herein is that the present invention provides a product with performant structural properties while being easily disposable.

[0118] Another advantage of the technology disclosed herein is that the present invention provides a product that may be essentially conceived using wood pulp and mechanically obtained product thereof.
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Date Recue/Date Received 2022-07-11

[0119] Another advantage of the technology disclosed herein is that the present invention reduces the amount of lint and dust in the manufacturing process, which greatly reduces risk of unwanted fires and other accidents.

[0120] The embodiments described above are intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the appended claims.
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Date Recue/Date Received 2022-07-11

Claims (26)

1. A nonwoven fabric comprising:
short fibers of plant-based material having a length of about between 2 mm and mm; and cellulose filaments being present at a proportion of up to 10 wt-% of the nonwoven fabric, such that the cellulose filaments bind the short fibers in the nonwoven fabric.

2. The nonwoven fabric of claim 1, further comprising long fibers having a length of more than 5 mm, the long fibers being present at a proportion of up to 40 wt-% of the nonwoven fabric, such that the cellulose filaments bind the long fibers in the nonwoven fabric.

3. The nonwoven fabric of claim 1, wherein the proportion of cellulose filaments is between 2 wt-% and 7 wt-%.

4. The nonwoven fabric of claim 1, wherein the proportion of long fibers is up to 20 wt-%.

5. The nonwoven fabric of claim 1, wherein the proportion of long fibers is between about 20 wt-% and 40 wt-%.

6. The nonwoven fabric of claim 2, wherein the long fibers are selected from the group consisting of man-made fibers regenerated cellulose and a mixture thereof.

7. The nonwoven fabric of claim 2, wherein the long fibers are selected from the group consisting of cotton, hemp, jute, flax and a mixture thereof.

8. The nonwoven fabric of claim 1, wherein the short fibers are derived from a raw material selected from the group consisting of wood pulp, hemp, bamboo, bagasse, flax, natural plant fibers, cotton and a mixture thereof.

9. The nonwoven fabric of claim 1, further comprising an alcohol content of 60% in liquid phase.
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Date Recue/Date Received 2022-07-11

10. The nonwoven fabric of claim 1, characterized in that it has a basis weight of about between 40 GSM to 85 GSM.

11. The nonwoven fabric of claim 1, characterized in that it has a dry tensile strength of at least 31.0 N/50mm and a wet tensile strength of at least 6.4 N/50mm.

12. The nonwoven fabric of claim 1, characterized in that it has a dry maximal elongation of at least 7% and a wet maximal elongation of at least 26%.

13. The nonwoven fabric of claim 1, characterized in that it has a water absorptive capacity of at least 4.2 g/g.

14. The nonwoven fabric of claim 1, characterized in that it has a liquid wicking rate of at least 43.0 mm/305ec.

15. The nonwoven fabric of claim 1, characterized in that it has a disintegration rate of at least 60%.

16. The nonwoven fabric of claim 1, characterized in that it has an opacity of 50%.

17. The nonwoven fabric of claim 1, characterized in that it has a dry linting rate of 0.01%
and a degradation rate of 2.14%.

18. A method for fabricating a nonwoven fabric, the method comprising preparing a liquid suspension of short fibers having a length of about between 2 mm and 5 mm; and cellulose filaments being present at a proportion of up to 10 wt-% of the nonwoven fabric;
forming a web from the prepared liquid suspension and dewatering it;
hydroentangling the web to obtain a wet fabric; and drying the wet fabric. .
- 19 ¨
Date Recue/Date Received 2022-07-11

19. The method as claimed in claim 18, wherein the liquid suspension further comprises long fibers having a length of more than 5 mm, the long fibers being present at a proportion of up to 40 wt-% of the nonwoven fabric.

20. The method as claimed in claim 18, wherein said forming the web comprises wet-laying the liquid suspension.

21. The method as claimed in claim 18, further comprising patterning the wet fabric.

22. The method as claimed in claim 18, further comprising drying the wet fabric.

23. The method as claimed in claim 18, further comprising calendaring the dried fabric.

24. The method as claimed in claim 18, further comprising embossing the dried fabric.

25. The method as claimed in any one of claims 22 to 24, further comprising winding the dried fabric thereby obtaining a roll of fabric.

26. A wetlaid fabric product comprising:
wood pulp short fibers having a length of about between 2 mm and 5 mm; and cellulose filaments being present at a proportion of up to 10 wt-% of the wetlaid fabric, such that the cellulose filaments bind the short fibers in the nonwoven fabric.
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Date Recue/Date Received 2022-07-11