Cellulosic nonwoven, methods of manufacture thereof and articles comprising the same

Abstract

The present disclosure provides a home-compostable and heat-sealable cellulosic nonwoven, methods for manufacturing the same, and an article including the same. The cellulosic nonwoven includes: a first ply including first fibers and a heat-sealable binder, wherein the heat-sealable binder includes a non-fibrous biodegradable polymer; a second ply including second fibers and a sizing agent, wherein the sizing agent is hydrophobic, wherein the first fibers and the second fibers each independently include cellulosic fibers, and wherein the second ply is disposed on the first ply.

Description

[0001] CELLULOSIC NONWOVEN, METHODS OF MANUFACTURE THEREOF AND ARTICLES COMPRISING THE SAME

[0002] BACKGROUND

[0003] (1) Field

[0004] Disclosed herein is a cellulosic nonwoven, methods of manufacture thereof, and articles comprising the same. In particular, disclosed herein is a home-compostable and heat-sealable cellulosic nonwoven that can be used as filter materials and packaging materials for food items and agricultural products.

[0005] (2) Description of the Related Art

[0006] The use and production of sustainable materials are becoming increasingly desirable due to regulations that pertain to environmental protection standards. In particular, there has been an interest in developing compostable materials for use in, for example, beverage filters, food packaging, packaging, or agricultural or horticultural wrapping papers. Nevertheless, there remains a need for improved materials for use in such applications.

[0007] BRIEF SUMMARY

[0008] The present disclosure provides a home-compostable and heat-sealable cellulosic nonwoven, methods for manufacturing the same, and articles including the same.

[0009] Disclosed herein is a cellulosic nonwoven.

[0010] Disclosed herein too is an article including the cellulosic nonwoven.

[0011] Disclosed herein too is a method of manufacturing the cellulosic nonwoven.

[0012] In an aspect, a cellulosic nonwoven includes a first ply including first fibers and a heat-sealable binder, wherein the heat-sealable binder includes a non-fibrous biodegradable polymer; a second ply including second fibers and a sizing agent, wherein the sizing agent is hydrophobic, wherein the first fibers and the second fibers each independently include cellulosic fibers, and wherein the second ply is disposed on the first ply.

[0013] In an aspect, an article includes the cellulosic nonwoven, wherein the article is a tea bag, a coffee pod, a coffee filter, a food packaging material, a packaging material, or an agricultural or a horticultural wrapping paper.

[0014] In an aspect, a method of manufacturing the cellulosic nonwoven by a wet-laying process includes providing a first ply precursor material including first fibers and a first liquid dispersant; providing a second ply precursor material including second fibers, a second liquid dispersant, and a sizing agent; dispersing the first ply precursor material in a first pulper, and dispersing the second ply precursor material in a second pulper; and the dispersed second ply precursor material through a second headbox; and wet-laying the dispersed first ply precursor material and the second ply precursor material on a forming wire to form a resulting product, wherein the resulting product comprises the second ply disposed on the first ply; disposing a biolatex including the non-fibrous biodegradable polymer to the resulting product, preferably on a side of the first ply, wherein the biolatex is disposed on the first fibers in the form of a liquid or a foam. The biolatex is applied preferably by one side metering size-press or filmpress or spray coating or bar coating; and drying the resulting product to manufacture the cellulosic nonwoven. These application methods are preferred because they apply the biolatex only on one side of the cellulosic nonwoven notably the first ply that does not comprise a sizing agent.

[0015] In an aspect, a cellulosic nonwoven for a heat sealable tea bag filter includes a first ply including first fibers and a heat-sealable binder, wherein the heat-sealable binder includes a non-fibrous biodegradable polymer; a second ply including second fibers and a sizing agent, wherein the sizing agent is hydrophobic; a third ply including third fibers; wherein the first fibers, second fibers, and the third fibers each independently include cellulosic fibers, and wherein the second ply is disposed between the first ply and the third ply.

[0016] In an aspect, a cellulosic nonwoven for a heat sealable coffee pod filter, the cellulosic nonwoven including a first ply including first fibers and a heat-sealable binder, wherein the heat-sealable binder includes a non-fibrous biodegradable polymer; a second ply including second fibers and a sizing agent, wherein the sizing agent is hydrophobic; a third ply including third fibers, wherein the first fibers, second fibers, and the third fibers each independently include cellulosic fibers, and wherein the third ply is disposed between the first ply and the second ply.

[0017] Any combination or permutation of embodiments is envisioned. Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure, particularly when read in conjunction with the appended figures.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 is a schematic illustration of an embodiment of a cellulosic nonwoven comprising a first ply and a second ply;

[0020] FIG. 2 is a schematic illustration of an embodiment of a cellulosic nonwoven comprising a first ply, a second ply, and a third ply;

[0021] FIG. 3 is a schematic illustration of another embodiment of a cellulosic nonwoven comprising a first ply, a second ply, and a third ply;

[0022] FIG. 4A is a scanning electron microscopy image of an embodiment of a cellulosic non wo ven showing the side of a first ply;

[0023] FIG. 4B is a scanning electron microscopy image of the cellulosic nonwoven of FIG. 4 showing the side of a second ply, which is opposite to the first ply; and

[0024] FIG. 4C is a scanning electron microscopy image of the cellulosic nonwoven of FIG. 4 showing a cross-sectional view of the cellulosic nonwoven, wherein the right side is the first ply comprising a heat-sealable binder (HS binder).

[0025] DETAILED DESCRIPTION

[0026] A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

[0027] Disclosed herein is a cellulosic nonwoven that is home-compostable and heat- sealable. Because of increased interest in developing sustainable materials, producing and using compostable cellulosic nonwovens are pivotal in the fields including food and agricultural industries. While industrially-compostable cellulosic nonwovens have been developed, those nonwovens are often not home-compostable. For a material to be home-compostable, stricter temperature and time requirements are often desired, wherein the requirements are further described elsewhere in this disclosure.

[0028] Home-compostable materials may include materials capable of breaking down into natural components when placed in a home composting environment. Home composting typically involves organic waste like food scraps, yard trimmings, and biodegradable materials. Home composting is well-suited for biodegradable kitchen scraps (e.g., fruit and vegetable peels, coffee grounds, eggshells), yard trimmings (e.g., leaves, grass clippings), and some paper products (e.g., shredded paper, cardboard). Outdoor composting (e.g., industrial-composting) may include a broader range of materials, including larger quantities of food waste, yard waste from landscaping operations, compostable packaging and products, and sometimes even animal manure from farms.

[0029] In order for a heat sealable non wo ven to be compostable, the fibers of choice are limited due to the aforementioned stricter requirements. Heat sealable nonwovens comprise thermoplastic polymer fibers such as polyethylene and polypropylene which are typically non-biodegradable. Furthermore, for the nonwoven to be both home- compostable and heat-sealable, commercial manufacturing methods of the nonwovens often limit the choice of heat-sealable binders that can impart heat-sealable properties to the cellulosic nonwoven, yet render the nonwoven home-compostable at the same time. Many biodegradable polymers which can impart home composability to a nonwoven cannot be spun into a fiber, hence can only be applied as a latex solution. Therefore, challenges remain in achieving desired properties, such as runnability of the packaging paper / non-woven on a packaging machine without melting and or sticking to the machine parts, while providing the nonwoven to be home-compostable and heat-sealable.

[0030] To solve the challenges in providing a home-compostable and heat-sealable cellulosic nonwoven that also exhibits desired properties appropriate for use in food and agricultural industries, disclosed herein is a cellulosic non woven comprising at least two plies, wherein a first ply comprises a heat-sealable binder, and a second ply comprises a hydrophobic sizing agent that can prevent the heat-sealable binder from penetrating to the second ply. Thus, one side of the cellulosic nonwoven may be hydrophobic, while the other side of the cellulosic nonwoven may be hydrophilic to allow the heat-sealable binder dispersed in water to be disposed on and to be processed during a wet-laid manufacturing process. It is beneficial to have the heat- sealable binder contained in the first ply for ease of processing on a packaging machine, in particular, to prevent the ply comprising the binder (which serves as an insulating layer) from sticking to the heated clamp during the heat-seal process. Accordingly, the amount of heat-sealable (i.e., heat-seal) fibers present in products from prior art can be reduced or eliminated. The present disclosure thus advantageously provides a cellulosic nonwoven that is both home-compostable and heat-sealable, while providing the desired air permeability, dry peel strength, or the like. In particular, the cellulosic nonwoven provides the desired air permeability in wet applications without collapsing of the structure (e.g., which cellulose fibers tend to do in wet form). Also, the cellulosic nonwoven provides the desired dry peel strength and air permeability in dry applications.

[0031] In an aspect, the cellulosic nonwoven comprises: a first ply comprising first fibers and a heat-sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers and a sizing agent, wherein the sizing agent is hydrophobic, wherein the first fibers and the second fibers each independently comprise cellulosic fibers, and wherein the second ply is disposed on the first ply. FIG. 1 shows an embodiment of the cellulosic non wo ven 100 comprising the first ply 101 and the second ply 102, wherein the second ply is disposed on the first ply along a thickness direction z.

[0032] The first ply 101 comprises the first fibers and the heat-sealable binder.

[0033] The first fibers comprise the cellulosic fibers. The cellulosic fibers may comprise at least one of natural cellulosic fibers (including pulp), synthetic cellulosic fibers, or a mixture of both. While the types and contents of the cellulosic fibers are not particularly limited, the cellulosic fibers may comprise at least one of softwood fibers, hardwood fibers, annual plant fibers, or a combination thereof.

[0034] In an aspect, a content of the cellulosic fibers in the first fibers is at least 70 wt%, at least 75 wt%, at least 80 wt%, and / or less than 100 wt%, less than 95 wt%, less than 90 wt%, relative to a weight of the first fibers. A content of the cellulosic fiber in the first ply may be at least 50 wt%, at least 60, at least 65 wt%, and / or less than 99 wt%, less than 95 wt%, less than 90 wt%, relative to a weight of the first ply.

[0035] In an aspect, the cellulosic fibers in the first fibers comprise the annual plant fibers, wherein a content of the annual plant fibers is 5 wt% or more, 10 wt% or more, 15 wt% or more, and 40 wt% or less, 35 wt% or less, 30 wt% or less, relative to a weight of the cellulosic fibers in the first fibers. Natural cellulose pulp from any annual plant suitable in providing the desired properties of the present invention may be used. An example of an annual plant is abaca. Abaca fibers tend to be relatively long. They can be introduced to provide mechanical strength to the cellulosic nonwoven. This is especially of importance during a paper manufacturing process.

[0036] In an aspect, the cellulosic fibers in the first fibers comprises the softwood fibers, wherein a content of the softwood fibers is 20 wt% or more, 30 wt% or more, 40 wt% or more, 50 wt% or more, and / or 90 wt% or less, 80 wt% or less, 70 wt% or less, relative to the weight of the cellulosic fibers in the first fibers. Softwood fibers are smaller in length relative to abaca fibers but longer than hardwood fibers. In an aspect, the cellulosic fibers in the first fibers comprises the hardwood fibers, wherein a content of the hardwood fibers is 0 wt%, 1 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, and / or 40 wt% or less, 35 wt% or less, 30 wt% or less, 25 wt% or less, relative to a weight of the cellulosic fibers in the first fibers.

[0037] The heat-sealable binder comprises the non-fibrous biodegradable polymer.

[0038] The non-fibrous biodegradable polymer may comprise at least one of polybutylene succinate-co-adipate (PBSA), polyhydroxyalkanoate (PHA), polybutylene adipate terephthalate (PBAT), modified polyurethane (PU), polylactic-gly colic acid (PLGA), poly-caprolactone (PCL), copolymers of polylactic-glycolic acid and polycaprolactone (PCL-PLGA copolymer), polyhydroxy-butyrate-valerate (PHBV), polyorthoester (POE), polyethylene oxide-butylene terephthalate (PEO-PBTP), poly- D,L-lactic acid-p-dioxanone-polyethylene glycol block copolymer (PLA-DX-PEG), or the like, or a combination thereof. For example, the non-fibrous biodegradable polymer comprises at least one of polybutylene succinate-co-adipate, polyhydroxyalkanoate, polybutylene adipate terephthalate, modified polyurethane, or a combination thereof. One preferred non-fibrous biodegradable is modified polyurethane (PU) such as the modified polyurethane emulsion ST6515 commercialized by SciTech.

[0039] The expression “heat-sealable” as used herein refers to a hot-melt property that allows a material to be heat-bonded to itself or to another independent component. In an aspect, a media can be heat-sealed to itself to make a pouch for containing tea, or a media can be attached to a capsule body (e.g., in coffee applications).

[0040] Non-fiber or non-fibrous may be distinguished from fiber or fibrous. “Fiber” as used herein refers to a material form (natural or synthetic) characterized by a high ratio of length to diameter (aspect ratio). The high aspect ratio herein may refer to an aspect ratio that is greater than 5, greater than 100, or greater than 500. In an aspect, the dimensions of heat-sealable fibers are between 1 to 2.5 dtex (grams per 10,000 meters of yarn) and 2 to 13 millimeters (mm), preferably 1 to 2.5 dtex and 2 and 6 mm. The unit "dtex" stands for decitex, which is a measure of linear density used for fibers and refers to the fineness of the fibers. “Non-fiber” as used herein may refer to a material form having the dimensions less than 1 dtex, and less than 2 mm. Non-fibrous materials may coat at least partially some fibers and occupy pores of the nonwoven.

[0041] In an aspect, a content of the heat-sealable binder is 20 wt% or more, 25 wt% or more, 30 wt% or more, and / or 60 wt% or less, 55 wt% or less, 50 wt% or less, relative to the total weight of the first ply.

[0042] The second ply may be substantially free of the heat-sealable binder. Preferably, the second ply comprises 0.01 wt% or more, 0.05 wt% or more, 0.1 wt% or more, and / or 2 wt% or less, 1 wt% or less, 0.5 wt% or less of the heat-sealable binder, relative to a weight of the second ply. When the second ply is substantially free of the heat- sealable binder, it enables easier processing, in particular, it prevents the second ply (which serves as an insulating layer) from sticking to the heated clamp during the heat-seal process.

[0043] The second ply 102 comprises the second fibers and the sizing agent.

[0044] The second fibers comprise the cellulosic fibers. The cellulosic fibers may be the same as those described for the aforementioned first fibers. Contents of the cellulosic fibers in the second ply, and the contents of each of the softwood fibers, hardwood fibers, annual plant fibers, or a combination thereof, may be the same as those described for the first ply.

[0045] The sizing agent may comprise at least one of an alkyl ketene dimer (AKD), a soap rosin, anionic rosin, a cationic rosin, or any combination thereof. In an aspect, the sizing agent herein refers to a substance applied to fibers, yarns, or fabrics to improve their properties such as strength, stiffness, processibility and abrasion resistance to fibers and yarns, and performance during subsequent processing and end-use applications. The sizing agent may be hydrophobic. For example, AKD is composed of saturated hydrocarbon chain containing fatty acids solid dimer and / or liquid emulsion, where the hydrocarbon chain contributes to its hydrophobicity. In an aspect, any suitable material used as a sizing agent and is hydrophobic, for example, a material that is non-polar or has low-polarity, or containing suitably long hydrocarbon chains (e.g., >12 carbons), can be used. In an aspect, a content of the sizing agent may be 0.5 wt% or more, 1 wt% or more, 2 wt% or more, and / or 5 wt% or less, 4 wt% or less, 3 wt% or less, relative to a weight of the second ply. In another aspect, the content of the sizing agent may be 0.05 or more, 0.1 wt% or more, 0.5 wt% or more, and / or 2.65 wt% or less, 2 wt% or less, 1.5 wt% or less, lwt% or less, relative to a weight of the total weight of the cellulosic nonwoven.

[0046] In an aspect, the first ply may or may not comprise the sizing agent. In an embodiment, the first ply is substantially free of the sizing agent, such as, less than 0.5 wt%, preferably less than 0.1 wt%, more preferably less than 0.05 wt%, even more preferably less than 0.001 wt%, for example 0 to 0.5 wt%, or 0 to 0.001 wt%, relative to a weight of the first ply. By maintaining the first ply substantially free of the sizing agent, the first ply is rendered hydrophilic. This permits miscibility between the heat-sealable binder and the first fibers of the first ply. The heat-sealable binder (in the form of a biolatex) contacts the first ply during a wet-laid manufacturing process of the cellulosic nonwoven.

[0047] Manufacturing of the cellulosic nonwoven may be carried out using a paper machine under a wet process (i.e., wet-laid process, or wet-laying process). The wet process may involve the formation of a nonwoven web from a suspension of fibers in water, followed by the consolidation and drying of the web to create a coherent sheet or fabric. It is beneficial to produce a nonwoven having at least two plies joined together without an additional adhesive. Additional adhesive should not be confused with the heat-sealable binder of the present invention, typically an adhesive is applied on a surface to join two separate sheets. Adhesives may clog pores and reduce air permeability, which affects percolation. In the current disclosure, the manufacturing process allows the plies that constitute the cellulosic nonwoven, for example, the first ply and the second ply, to be joined without an additional adhesive. Thus, the cellulosic nonwoven with at least two plies may be obtained without using adhesives or binders between the plies. The fibers of the two plies intermingle together and form a blended area. The intermingling (e.g., interlinking, or entangling) of fibers at the interface area between the first ply and the second ply therefore joins the two plies without the need for an additional adhesive. Furthermore, the current manufacturing process enables the first ply to have the heat-sealable binder disposed thereon, while preventing the heat-sealable binder penetrating to the second ply (attributing to the sizing agent contained in the second ply), when the heat- sealable binder is introduced to the first ply. The resulting cellulosic nonwoven can thus comprise the first ply comprising first fibers and the heat-sealable binder, and the second ply comprising second fibers and the sizing agent, wherein the second ply is substantially free of the heat-sealable binder.

[0048] In an aspect, a method of manufacturing the cellulosic nonwoven by a wet process comprises: providing a first ply precursor material comprising first fibers and a first liquid dispersant; providing a second ply precursor material comprising second fibers, a second liquid dispersant, and a sizing agent; dispersing the first ply precursor material in a first pulper, and dispersing the second ply precursor material in a second pulper; and wet-laying the dispersed first ply precursor material and the dispersed second ply precursor material on a forming wire to form a resulting product, wherein the resulting product comprises the second ply disposed on the first ply; disposing a biolatex comprising the heat-sealable binder comprising the non-fibrous biodegradable polymer to the resulting product, preferably on a side of the first ply, wherein the biolatex is disposed on the first fibers in the form of a liquid or a foam preferably by one side metering size-press or film-press or spray coating or bar coating; and drying the resulting product to manufacture the cellulosic nonwoven.

[0049] In an aspect, the method of manufacturing the cellulosic nonwoven by a wet process comprises: providing a paper machine comprising one headbox with a first compartment and second compartment; providing a first ply precursor material comprising first fibers and a first liquid dispersant; providing a second ply precursor material comprising second fibers, a second liquid dispersant, and a sizing agent; dispersing the first ply precursor material in a first pulper, and dispersing the second ply precursor material in a second pulper; feeding to the paper machine the dispersed first ply precursor material through the first compartment, and the dispersed second ply precursor material through the second compartment; and wet-laying the dispersed first ply precursor material and the dispersed second ply precursor material on a forming wire to form a resulting product, wherein the resulting product comprises the second ply disposed on the first ply; disposing a biolatex comprising a heat-sealable binder comprising a non-fibrous biodegradable polymer to the resulting product, preferably on a side of the first ply, wherein the biolatex is disposed on the first fibers in the form of a liquid or a foam preferably by one side metering size -press or filmpress or spray coating or bar coating; and drying the resulting product to manufacture the cellulosic nonwoven.

[0050] In an aspect, the method of manufacturing the cellulosic nonwoven by a wet process comprises: providing a paper machine comprising at least two headboxes; providing a first ply precursor material comprising first fibers and a first liquid dispersant; providing a second ply precursor material comprising second fibers, a second liquid dispersant, and a sizing agent; dispersing the first ply precursor material in a first pulper, and dispersing the second ply precursor material in a second pulper; feeding to the paper machine the dispersed first ply precursor material through a first headbox, and the dispersed second ply precursor material through a second headbox; and wetlaying the dispersed first ply precursor material and the dispersed second ply precursor material on a forming wire to form a resulting product, wherein the resulting product comprises the second ply disposed on the first ply; disposing a biolatex comprising a heat-sealable binder comprising a non-fibrous biodegradable polymer to the resulting product, preferably on a side of the first ply, wherein the biolatex is disposed on the first fibers in the form of a liquid or a foam preferably by one side metering size-press or film-press or spray coating or bar coating; and drying the resulting product to manufacture the cellulosic nonwoven.

[0051] “Biolatex” herein refers to a water-based (e.g., water-containing) dispersion of biodegradable polymer particles. In other words, the biodegradable polymer particles that form the non-fibrous biodegradable polymer are industrially compostable material according to EN13432 and more preferably home-compostable material. A content (e.g., solid content) of the biodegradable polymer in the biolatex may be 30 wt or more, 35 wt% or more, 40 wt% or more, and / or 60 wt% or less, 55 wt% or less, 50 wt% or less. Using the biolatex comprising the heat-sealable binder is advantageous in the cellulosic nonwoven manufacturing process because it enables broader selection of biodegradable polymers (e.g., non-fibrous) to be used for the binder that imparts heat-sealability that can maximize compostability, without completely blocking the pores of the cellulosic nonwoven. For example, heat-sealable fiber, when used for the binder, is often the limiting factor for home-compostability.

[0052] The first pulper and the second pulper are used to disintegrate and disperse the fibers to be fed to the paper machine.

[0053] The first ply, the second ply, the first fibers, the second fibers, the heat-sealable binder, the non-fibrous biodegradable polymer, and the sizing agent are described elsewhere in this disclosure. The first liquid dispersant and the second liquid dispersant may be water.

[0054] The resulting product comprising the first ply and the second ply is wet-laid on the forming wire. The different plies are formed simultaneously on a continuously moving forming wire of the paper machine. The water may be drained by gravity and / or suction mechanism, and may be further evaporated under room temperature and atmospheric pressure.

[0055] The disposing of the biolatex comprising the heat-sealable binder comprising the non- fibrous biodegradable polymer to the resulting product may be performed when the resulting product is at least partially dried or fully dried. Afterwards, the biolatex- disposed resulting product is fully dried to form the cellulosic nonwoven final product.

[0056] In an aspect, the method further comprises: providing a third ply precursor material comprising a third fiber and a third liquid dispersant; dispersing the third ply precursor material in a third pulper; and wet-laying the dispersed first ply precursor material, the dispersed second ply precursor material, and the dispersed third ply precursor material on the forming wire to form the resulting product further comprising a third ply, wherein the third ply is disposed between the first ply and the second ply, or on a surface of the second ply opposite the first ply.

[0057] In an aspect, the method further comprises: providing a third ply precursor material comprising a third fiber and a third liquid dispersant; dispersing the third ply precursor material in a third pulper; feeding to the paper machine the dispersed third ply precursor material through a separate headbox or a compartment in the same headbox through which first and / or second ply precursor material are channeled; and wet-laying the dispersed first ply precursor material, the second ply precursor material, and the dispersed third ply precursor material on the forming wire to form the resulting product further comprising a third ply, wherein the third ply is disposed between the first ply and the second ply, or on a surface of the second ply opposite the first ply.

[0058] In an aspect, the method of manufacturing the cellulosic nonwoven comprising the third ply may adapt similar methods of manufacturing the cellulosic nonwoven comprising the first and second ply. The method may include using one headbox with three compartments. In preferred aspect, the method of manufacturing the cellulosic non wo ven by a wet process comprises: providing a paper machine comprising one headbox with a first, second and third compartments; providing a first ply precursor material comprising first fibers and a first liquid dispersant; providing a second ply precursor material comprising second fibers, a second liquid dispersant, and a sizing agent; providing a third ply precursor material comprising third fibers and a third liquid dispersant; dispersing the first ply precursor material in a first pulper, dispersing the second ply precursor material in a second pulper, dispersing the third ply precursor material in a third pulper; feeding to the paper machine the dispersed first ply precursor material through the first compartment, the dispersed second ply precursor material through the second compartment and the dispersed third ply precursor material through the third compartment; and wet-laying the dispersed first ply precursor material, the dispersed second ply precursor material and the dispersed third ply precursor material on a forming wire to form a resulting product, wherein the resulting product comprises the third ply disposed between the first ply and the second ply, or on a surface of the second ply opposite the first ply; disposing a biolatex comprising a heat-sealable binder comprising a non-fibrous biodegradable polymer to the resulting product, preferably on a side of the first ply, wherein the biolatex is disposed on the first fibers in the form of a liquid or a foam preferably by one side metering size-press or film-press or spray coating or bar coating; and drying the resulting product to manufacture the cellulosic nonwoven.

[0059] In an aspect, the paper machine may have two headboxes, one of which has two compartments. For example, the first ply precursor material is fed to the paper machine through a first headbox, and a second headbox may have two compartments. The second ply precursor material may be fed to the paper machine through one compartment of the second headbox and the third ply precursor material may be fed through the other compartment of the second headbox. In another example, the third ply precursor material is fed to the paper machine through a dedicated headbox (e.g., the first headbox), and the second headbox may have two compartments. The first ply precursor material may be fed to the paper machine through one compartment of the second headbox and the second ply precursor material may be fed through the other compartment of the second headbox. In yet another example, a first headbox may have two compartments, and the second ply precursor material is fed to the paper machine through a second headbox. The first ply precursor material may be fed to the paper machine through one compartment of the first headbox and the third ply precursor material may be fed through the other compartment of the first headbox.

[0060] In an aspect, the paper machine may have three headboxes to feed to the paper machine individually, the first ply precursor material through the first headbox, the second ply precursor material through the second headbox and the third ply precursor material through the third headbox.

[0061] The third fiber and the third ply are described elsewhere in this disclosure. The third liquid dispersant may be water. The third pulper may have similar features to the first and second pulpers. The third headbox may have similar features to the first and second headboxes.

[0062] FIGS. 4A to 4C shows scanning electron microscopy images of an embodiment of a cellulosic nonwoven. FIG. 4A shows the side of the first ply and the heat-sealable binder is disposed on the first fibers, whereas FIG. 4B shows the side of the second ply with more open spaces between the second fibers. This indicates that the sizing agent disposed in the second ply successfully prevented the heat-sealable binders from penetrating to the second ply. FIG. 4C shows a cross-sectional view of the cellulosic nonwoven, wherein the right side depicts the first ply comprising the heat- sealable binder (HS binder). The second ply, which is disposed on the left side of the first ply, is as also shown in FIG. 4C.

[0063] In an aspect, the first ply and the second ply are interlinked at a first interfacial area between the first ply and the second ply. The first interfacial area between the first ply and the second ply forms a first blended area comprising a first mixture of the first fibers and the second fibers. As used herein, “an interfacial area” refers to an area that separates two plies, where the fibers of the two plies intermingle together and form a blended area. The intermingling of fibers at the interface area therefore joins the two plies without the need for an additional adhesive. It is beneficial to omit additional adhesives or binders, which may cause sustainability problems, and to simplify the manufacturing process.

[0064] As discussed previously, the first fibers and the second fibers (in both the first ply and the second ply respectively) each independently comprise cellulosic fibers. The types and / or contents of the cellulosic fibers in the first ply and the second ply may be different. In an embodiment, types or contents of the cellulosic fibers in the first ply and the second ply may be the same.

[0065] In an aspect, a total content of the cellulosic fibers in the cellulosic nonwoven is 70 wt% or less, at least 75 wt%, at least 80 wt%, and / or less than 100 wt%, less than 95 wt%, less than 90 wt%, relative to a weight of a total fiber in the cellulosic non wo ven. The total content of the cellulosic fiber in the cellulosic nonwoven may be at least 50 wt%, at least 60, at least 65 wt%, and / or less than 99 wt%, less than 95 wt%, less than 90 wt%, relative to a total weight of the cellulosic non wo ven.

[0066] In an aspect, the cellulosic nonwoven may further comprise heat-sealable fibers. The heat-sealable fibers may comprise fibers of at least one of polylactic acid, polybutylene succinate, polybutylene succinate-co-adipate, polyhydroxyalkanoate, polybutylene adipate terephthalate, modified polyurethane, polylactic-glycolic acid, poly-caprolactone, copolymers of polylactic-glycolic acid and poly-caprolactone, polyhydroxy-butyrate-valerate, polyorthoester, polyethylene oxide-butylene terephthalate, poly-D,L-lactic acid-p-dioxanone-polyethylene glycol block copolymer, or a combination thereof. As mentioned above, fibers are distinguished from nonfibers as described elsewhere in this disclosure.

[0067] In an aspect, the cellulosic nonwoven may further comprise heat-sealable fibers, wherein a content of the heat-sealable fibers is 0 wt%, 0.05 wt% or more, 0.1 wt% or more, 1 wt% or more, 3 wt% or more, and / or 15 wt% or less, 10 wt% or less, 7 wt% or less, relative to the total weight of the cellulosic nonwoven. The heat-sealable fibers may be in the first ply, the second ply, or both.

[0068] In an aspect, the cellulosic nonwoven may be substantially free of the heat-sealable fibers, for example, less than 1 wt%, less than 0.5 wt%, or less than 0.1 wt%, between 0 to 0.1 wt%, 0 to 0.05 wt%, or 0 to 0.001 wt%, relative to the total weight of the cellulosic nonwoven. By having the cellulosic nonwoven substantially free of the heat-sealable fibers in such ranges, it may allow the cellulosic nonwoven to be home- compostable. In an aspect, the cellulosic nonwoven is free of the heat-sealable fiber. By having the cellulosic nonwoven comprising the heat-sealable binder comprising the non-fibrous biodegradable polymer, it is advantageous that the heat-sealable fiber, which is often not home-compostable, can be omitted. The heat-sealable fiber can be included in the cellulosic nonwoven depending on the need for a specific cellulosic non wo ven to exhibit desired properties.

[0069] In an aspect, the cellulosic nonwoven comprises the heat-sealable binder, wherein a content of the heat-sealable binder is 5 wt% or more, 10 wt% or more, 15 wt% or more, and / or 40 wt% or less, 35 wt% or less, 30 wt% or less, relative to the total weight of the cellulosic nonwoven.

[0070] In an aspect, the cellulosic nonwoven comprises: the softwood fibers, wherein a content of the softwood fibers is 15 to 80 wt%; and / or the hardwood fibers, wherein a content of the hardwood fibers is 0 to 40 wt%; and / or the annual plant fibers, wherein a content of the annual plant fibers is 10 to 50 wt%; and / or the heat-sealable fibers, wherein a content of the heat-sealable fiber is 0 to 15 wt%; and / or the heat-sealable binder, wherein a content of the heat-sealable binder is 5 to 40 wt%, relative to the total weight of the cellulosic nonwoven. When the composition of the cellulosic nonwoven is provided in the aforementioned range, the cellulosic nonwoven exhibits improved properties.

[0071] In an aspect, a weight ratio of the heat-sealable binder to the sizing agent in the cellulosic nonwoven is 10:1 to 1000:1, 100:1 to 800:1, or 300:1 to 500:1.

[0072] In an aspect, the cellulosic nonwoven may further comprise an additive. The additive may be a wet strength agent such polyamide-epichlorohydrin (PAE). The wet strength agent can be present as in amount of greater than 0 wt%, 0.5 wt% or more, 0.9 wt% or more, and / or 1.5 wt% or less, 1.3 wt% or less, 1.2 wt% or less based on the total weight of the cellulosic nonwoven

[0073] A basis weight of the cellulosic nonwoven (and each ply) may be any suitable value to provide desired properties for use in food and agricultural industries. In an aspect, the basis weight of the cellulosic nonwoven is 12 g / m2or more, 13 g / m2or more, 20 g / m2or more, and / or 250 g / m2or less, 200 g / m2or less, 100 g / m2or less. For example, for a teabag, the basis weight may be about 16 g / m2, and for a coffee filter, the basis weight may be about 25 g / m2. The term “basis weight” as used herein refers to the area density of a paper product. The basis weight of nonwovens may be expressed in weight per unit area, for example in grams per square meter (gsm = g / m2) or ounces per square foot (osf). The terms “basis weight” and “grammage” can be used interchangeably for the purposes of the present invention unless otherwise specifically indicated. The basis weight as used herein was measured following the standard ISO 536. Before disposing the heat-sealable binder, the cellulosic nonwoven may have a basis weight of 12 g / m2or more, 20 g / m2or more, and / or 150 g / m2or less, 130 g / m2or less, 100 g / m2or less.

[0074] A basis weight of the first ply, a second ply, or both, may individually be 3 g / m2or more, 5 g / m2or more, 10 g / m2or more, 20 g / m2or more, and / or 75 g / m2or less, 60 g / m2or less, 50 g / m2or less. A weight ratio of the first ply to the second ply may be 0.5:1 to 1:0.5, for example, 0.75:1 to 1:0.75, or 1:1.

[0075] A total thickness of the cellulosic nonwoven (and each ply) may be any suitable value to provide desired properties for use in food and agricultural industries. In an aspect, the total thickness of the cellulosic nonwoven is 40 pm or more, 80 pm or more, 150 pm or more, and / or 500 pm or less, 400 pm or less, 300 pm or less. A thickness (or a total thickness) may be measured following the standard ISO 534.

[0076] In an aspect, the cellulosic nonwoven may further comprise a third ply 103. The third ply may be between the first ply and the second ply (as shown in an embodiment 100b of the cellulosic nonwoven in FIG. 3), on a surface of the second ply opposite the first ply (as shown in an embodiment 100a of the cellulosic nonwoven in FIG. 2), or both. The third ply may comprise third fibers comprising cellulosic fibers comprising at least one of softwood fibers, hardwood fibers, annual plant fibers, or a combination thereof. Contents of the cellulosic fibers in the third ply, thus contents of each of the softwood fibers, hardwood fibers, annual plant fibers, or a combination thereof, may be the same as those described for the first ply and the second ply. At least a type or a content of the cellulosic fibers in the third ply may be different from a type or a content of the cellulosic fibers in the first ply, the second ply, or both.

[0077] In an aspect, the third ply may be interlinked with the first ply at a second interface area, with the second ply at a third interface area, or both, in a similar manner as the first interface area described above, by forming a blended area between the two plies.

[0078] A basis weight of the third ply may be 3 g / m2or more, 5 g / m2or more, 10 g / m2or more, 20 g / m2or more, and / or 75 g / m2or less, 60 g / m2or less, 50 g / m2or less. A weight ratio of the first ply to the third ply, and / or a weight ratio of the second ply to the third ply may be 0.5:1 to 1:0.5, for example, 0.75:1 to 1:0.75, or 1:1. Optionally, the weight ratio of the first ply to the third ply may be 0.5 to 1, and / or the weight ratio of the second ply to the third ply may be 0.5 to 1.

[0079] The third ply may or may not comprise the heat-sealable binder, preferably, the third ply is substantially free of the heat-sealable binder, for example, the amount of heat- sealable binder is 0.01 wt% or more, 0.05 wt% or more, 0.1 wt% or more, and / or 2 wt% or less, 1 wt% or less, 0.5 wt% or less relative to a weight of the third ply. The third ply may or may not comprise the sizing agent, preferably, the third ply is substantially free of the sizing agent, for example, content of the sizing agent may be 0.5 wt% or more, 1 wt% or more, 2 wt% or more, and / or 5 wt% or less, 4 wt% or less, 3 wt% or less, relative to a weight of the third ply. The third ply may or may not comprise the heat-sealable fibers, wherein a content of the heat-sealable fibers in the third ply is 0 wt%, 0.05 wt% or more, 0.1 wt% or more, 1 wt% or more, 3 wt% or more, and / or 15 wt% or less, 10 wt% or less, 7 wt% or less, relative to the total weight of the cellulosic nonwoven. Preferably the third ply is substantially free of the heat- sealable fibers, for example, between 0 to 0.05 wt%, or 0 to 0.001 wt%, relative to a weight of the third ply. By having the third ply substantially free of the heat-sealable fibers in such ranges, it may allow the cellulosic nonwoven to be home-compostable. Other aspects of the third ply not mentioned otherwise, such as a thickness, may be the same as the first ply or the second ply as mentioned elsewhere in this disclosure.

[0080] In an aspect, the cellulosic nonwoven may further comprise a fourth ply, a fifth ply, or the like, and is not particularly limited with the number of additional plies as long as one outer surface (e.g., that is exposed to air) is the first ply comprising the heat- sealable binder, and the other outer surface (e.g., that is exposed to air) is a ply that does not comprise the heat-sealable binder. Thus, the cellulosic nonwoven has an asymmetric structure (along the thickness direction z). These additional plies may have similar aspects as described for the third ply, such as the contents of the heat- sealable binder, the sizing agent, the heat-sealable fibers, and the thickness.

[0081] In an aspect, the cellulosic nonwoven is a compostable material, preferably an industrially-compostable material, more preferably a home-compostable material. The expression “compostable” may be generally defined in line with EN13432. In an aspect, a “compostable material” may refer to a material comprising a maximum of 10% and preferably of 5% by weight of non-compostable components, thereby meeting EN13432. The expression “compostable” when applied to a material or a product means that the material, or the entire product, will both biodegrade and disintegrate. By “biodegrade” it is meant that the chemical structure or the material breaks down under the action of microorganisms. By the term “disintegrates” it is meant that the material, or the product made from it, will physically fall apart into fine visually indistinguishable fragments, at the end of a typical composting cycle. Herein, an “industrially-compostable material” may refer to a material that disintegrates at a temperature between 55 to 60 °C in less than 3 months and biodegrades at a temperature between 55 to 60 °C in less than 6 months as outlined in EN13432. Herein, a “home-compostable material” may refer to a material that disintegrates at a temperature below 55 °C, preferably between 10 to 45 °C, more preferably between 25 to 30 °C, in less than 6 months and biodegrades at a temperature below 55 °C, preferably between 10 to 45 °C, more preferably between 25 to 30 °C, in less than 12 months. The home compostability test can be carried out following EN13432 except for the disintegration and biodegradation temperatures and durations as indicated above.

[0082] In an aspect, the cellulosic nonwoven is home-compostable and heat-sealable. The non-woven is also food contact safe and complies to any of EU 1935 / 2004, BfR 36, FDA 21 CFA §176-170 & 176-180.

[0083] In an aspect, the cellulosic nonwoven has an air permeability of 500 to 2500 L / m2 / s, for example, 700 to 2200 L / m2 / s, or 1000 to 2000 L / m2 / s, when measured according to ISO 9237. “Air permeability” herein refers to the rate of airflow passing perpendicularly through a known area under a prescribed air pressure differential between the two surfaces of a material. The concept of “air permeability” is widely used in the textile industry to interpret the intrinsic characteristics of fabric. The air permeability is influenced by a fabric’s material and structural properties, including the individual pore structure. By having the air permeability in the aforementioned range, the cellulosic nonwoven may provide desired filtering properties e.g., for usage in coffee pods, tea bags, coffee filters, or desired barrier properties e.g., for usage in food packaging materials, packaging, or agricultural or horticultural wrapping papers.

[0084] In an aspect, the cellulosic nonwoven has a mean flow pore diameter between 20 pm or more, 50 pm or more, 70 pm or more, and / or 200 pm or less, 150 pm or less, 100 pm or less.. The mean flow pore diameter is the diameter at which 50% of the flow passes through the larger pores. In an aspect, the cellulosic nonwoven has a maximum pore diameter of 350 pm or less, 300 pm or less, and / or 30 pm or more, 100 pm or more. The maximum pore diameter provided in the aforementioned ranges would prevent e.g., coffee or tea particles from seeping through. The size (diameter) of the pores in the cellulosic nonwoven may be determined by porometry, using a Porometer (Porolux 1000) and may be reported in micrometers (pm). When the pore diameter features of the cellulosic non wo ven are provided in the aforementioned ranges, the cellulosic nonwoven may exhibit improved air permeability properties.

[0085] In an aspect, the cellulosic non wo ven has a dry peel strength of greater than 0.6 Newton (N), preferably greater than 0.8 N. For example, the dry peel strength may be 0.6 or more, 0.8 N or more, and / or 3 N or less, 2.0 or less. The dry peel strength is measured as follows. Two heat-seal sides of the material are attached using heated clamps at 210°C with a force of 6 bars for 0.5s. The resistance to peel is then measured by applying a peel force at a rate of 200 mm / min on a test piece of 15 mm width. When the dry peel strength of the cellulosic nonwoven is provided in the aforementioned ranges, the packaging does not delaminate easily when used.

[0086] In an aspect, the cellulosic nonwoven has a tear strength (machine direction, MD) of greater than 50 milliNewton (mN), preferably greater than 100 mN. For example, the tear strength may be 100 mN or more, 150 mN or more, and / or 1000 mN or less, 850 mN or less, 800 mN or less. The tear strength is measured according to ISO 1974. This ensures that the cellulosic material can be processed without tear during transformation and also is resistance enough during use.

[0087] Articles comprising the cellulosic nonwoven may be useful in various industries desiring sustainable materials to minimize landfill waste. In an aspect, an article comprises the cellulosic nonwoven, wherein non-limiting examples of the articles are a tea bag, a coffee pod, a coffee filter, a food packaging material, packaging material or an agricultural or a horticultural wrapping paper. The cellulosic nonwoven can be used as a tea bag filter material, self-sealed to provide a pouch that can contain tea while allowing liquid to flow in and out. The cellulosic nonwoven can be used as a coffee filter or can be attached to a coffee pod (capsule). The cellulosic nonwoven can be used as a food packaging material in various food packaging applications, for example, the cellulosic non wo ven can be attached to a container to provide a seal to protect the food inside the container. The cellulosic nonwoven can be used as agricultural or horticultural wrapping paper e.g., to wrap plants for protection while allowing desired air permeability. In an aspect, the article is a tea bag, and comprises the cellulosic nonwoven. The cellulosic non wo ven for a heat sealable tea bag filter, comprises: a first ply comprising first fibers, and a heat-sealable binder comprising a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic; a third ply comprising third fibers; wherein the first fibers, second fibers, and the third fibers each independently comprise cellulosic fibers, and wherein the second ply is disposed between the first ply and the third ply.

[0088] The cellulosic nonwoven for the heat sealable tea bag filter may have an air permeability of 500-2500 L / m2 / s. By having such ranges, improvements in preventing the tea inside of the tea bag from leaking out to the liquid where the tea bag is immersed in, while allowing liquid to flow in and out of the tea bag can be achieved.

[0089] In an aspect, the article is a coffee pod, and comprises the cellulosic nonwoven. The cellulosic non woven for a heat sealable coffee pod filter, comprises: a first ply comprising first fibers, and a heat-sealable binder comprising a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic; a third ply comprising third fibers; wherein the first fibers, second fibers, and the third fibers each independently comprise cellulosic fibers, and wherein the third ply is disposed between the first ply and the second ply.

[0090] The cellulosic nonwoven for the heat sealable coffee pod filter may have a dry peel strength of 0.8 to 2 N, and an air permeability of 500-2500 L / m2 / s. By having such ranges, improvements in the cellulosic nonwoven for use in the heat sealable coffee pod filter can be achieved.

[0091] A cellulosic non woven comprises: a first ply comprising first fibers, and a heat- sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic, wherein the first fibers and the second fibers each independently comprise cellulosic fibers, and wherein the second ply is disposed on the first ply; or cellulosic nonwoven for a heat sealable tea bag filter, the cellulosic nonwoven comprising: a first ply comprising first fibers, and a heat-sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic; a third ply comprising third fibers; wherein the first fibers, second fibers, and the third fibers each independently comprise cellulosic fibers, and wherein the second ply is disposed between the first ply and the third ply, wherein the first ply and the second ply are interlinked at an interface between the first ply and the second ply, and the second ply and the third ply are interlinked at an interface between the second ply and the third ply, wherein each interface is interlinked without an additional adhesive, optionally wherein the cellulosic nonwoven has an air permeability of 500-2500 L / m2 / s; or a cellulosic non wo ven for a heat sealable coffee pod filter, the cellulosic nonwoven comprising: a first ply comprising first fibers, and a heat-sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic; a third ply comprising third fibers; wherein the first fibers, second fibers, and the third fibers each independently comprise cellulosic fibers, and wherein the third ply is disposed between the first ply and the second ply, wherein the first ply and the third ply are interlinked at an interface between the first ply and the third ply, and the second ply and the third ply are interlinked at an interface between the second ply and the third ply, wherein each interface is interlinked without an additional adhesive, optionally wherein the cellulosic non wo ven has a dry peel strength of 0.6 to 3 N, and an air permeability of 500-2500 L / m2 / s; wherein any of the foregoing, the first ply and the second ply are interlinked at an interface between the first ply and the second ply without an additional adhesive, wherein the second ply is substantially free of the heat-sealable binder, preferably the second ply comprises between 0.01 to 2 wt%, more preferably between 0.1 to 1.8 wt% of the heat-sealable binder, relative to a weight of the second ply, wherein the non-fibrous biodegradable polymer comprises at least one of polybutylene succinate-co-adipate, polyhydroxyalkanoate, polybutylene adipate terephthalate, modified polyurethane, polylactic-glycolic acid, poly-caprolactone, copolymers of polylactic-glycolic acid and poly-caprolactone, polyhydroxy-butyrate- valerate, polyorthoester, polyethylene oxide-butylene terephthalate, poly-D,L-lactic acid-p-dioxanone-polyethylene glycol block copolymer, or any combination thereof, wherein the sizing agent comprises at least one of an alkyl ketene dimer, a soap rosin, anionic rosin, a cationic rosin, or any combination thereof, wherein a total content of the cellulosic fiber in the cellulosic non wo ven is at least 70 wt%, preferably at least 80 wt%, relative to a weight of a total fiber in the cellulosic nonwoven, or wherein the total content of the cellulosic fiber in the cellulosic non wo ven is at least 50 wt%, preferably at least 70 wt%, relative to a total weight of the cellulosic nonwoven, wherein the cellulosic fibers comprise at least one of softwood fibers, hardwood fibers, annual plant fibers, or any combination thereof, and optionally wherein at least a type or a content of the cellulosic fibers in the first ply and the second ply are different, wherein the cellulosic nonwoven comprises softwood fibers, wherein a content of the softwood fibers is 15 to 80 wt%, and / or hardwood fibers, wherein a content of the hardwood fibers is 0 to 40 wt%, and / or annual plant fibers, wherein a content of the annual plant fibers is 10 to 50 wt%, and / or heat-sealable fibers, wherein a content of the heat-sealable fibers is 0 to 15 wt%, and / or the heat-sealable binder, wherein a content of the heat-sealable binder is 5 to 40 wt%, relative to a total weight of the cellulosic nonwoven, wherein the heat-sealable fibers comprises fibers of at least one of polylactic acid, polybutylene succinate, polybutylene succinate-co- adipate, polyhydroxy alkanoate, polybutylene adipate terephthalate, modified polyurethane, polylactic-glycolic acid, poly-caprolactone, copolymers of polylactic- glycolic acid and poly-caprolactone, polyhydroxy-butyrate-valerate, polyorthoester, polyethylene oxide-butylene terephthalate, poly-D,L-lactic acid-p-dioxanone- polyethylene glycol block copolymer, or any combination thereof, wherein a basis weight of the cellulosic nonwoven is 12.6 to 250 g / m2, wherein a basis weight of the first ply, second ply, or both, is 3 to 125 g / m2, preferably 3 to 75 g / m2, and wherein a total thickness of the cellulosic nonwoven is 40 to 500 pm, wherein the cellulosic nonwoven further comprises a third ply, wherein the third ply is between the first ply and the second ply, on a surface of the second ply opposite the first ply, or both, wherein the third ply comprises cellulosic fibers comprising at least one of softwood fibers, hardwood fibers, annual plant fibers, or any combination thereof, wherein a basis weight of the third ply is 3 to 50 g / m2, optionally wherein a weight ratio of the first ply to the third ply is 0.5 to 1, and / or a weight ratio of the second ply to the third ply is 0.5 to 1, wherein the cellulosic non wo ven is a compostable material, preferably an industrially-compostable material, more preferably a home-compostable material, wherein the industrially-compostable material disintegrates and biodegrades at a temperature between 55 to 60 °C in less than 6 months, wherein the home- compostable material disintegrates and biodegrades at a temperature below 55 °C, preferably between 10 to 45 °C, more preferably between 25 to 30 °C, in less than 12 months, wherein the cellulosic nonwoven is home-compostable and heat-sealable, wherein the cellulosic non wo ven has at least one of the following properties: an air permeability of 500 to 2500 L / m2 / s, measured according to ISO 9237, a mean flow pore diameter between 20 and 200 pm and a maximum pore diameter of less than 350 pm, a dry peel strength of greater than 0.6 N, or a tear strength in machine direction of greater than 50 mN, wherein an article comprises the cellulosic nonwoven, wherein the article is a tea bag, a coffee pod, a coffee filter, a food packaging material, packaging material, or an agricultural or horticultural wrapping paper, wherein a method of manufacturing a cellulosic non wo ven by a wet-laying process comprises: providing a first ply precursor material comprising first fibers and a first liquid dispersant; providing a second ply precursor material comprising second fibers, a second liquid dispersant, and a sizing agent; dispersing the first ply precursor material in a first pulper, and dispersing the second ply precursor material in a second pulper; and the dispersed second ply precursor material through a second headbox; and wetlaying the dispersed first ply precursor material and the dispersed second ply precursor material on a forming wire to form a resulting product, wherein the resulting product comprises the second ply disposed on the first ply; disposing a biolatex comprising the non-fibrous biodegradable polymer to the resulting product, preferably on a side of the first ply, wherein the biolatex is disposed on the first fibers in the form of a liquid or a foam preferably by one side metering size -press or filmpress or spray coating or bar coating; and drying the resulting product to manufacture the cellulosic nonwoven, wherein the method further comprises: providing a third ply precursor material comprising a third fiber and a third liquid dispersant; dispersing the third ply precursor material in a third pulper; and wet-laying the dispersed first ply precursor material, the dispersed second ply precursor material, and the third ply precursor material on the forming wire to form the resulting product further comprising a third ply on the forming wire, wherein the third ply is disposed between the first ply and the second ply, or on a surface of the second ply opposite the first ply.

[0092] EXAMPLES

[0093] Example 1 : A heat-sealable tea bag a) Preparation method

[0094] Cellulosic non wo vens having the compositions on Table 1 below were made on a paper machine. Where appropriate, the base cellulosic nonwoven is then coated with the biolatex with the provided content. The biolatex comprises about 40% of the biodegradable polymer (with additives) and water. After drying, the properties were measured.

[0095] Table 1: Compositions and compostability of examples

[0096] * relative to a total weight of the cellulosic nonwoven

[0097] Table 1 provides compositions in each ply of the non wo ven examples, and compostability of the nonwoven examples. S citech ST6515 is a modified polyurethane emulsion b) Results

[0098] After drying, different physical properties of the examples were measured and are summarized in Table 2. Evaluation methods of the air permeability, dry peel strength, and tear strength are described elsewhere in this disclosure. It is noted that Example 1 containing the sizing agent (AKD) in the middle ply and the biodegradable polymer (heat-sealable binder comprising the non-fibrous biodegradable polymer) in the base ply was home-compostable, whereas Comparative examples 1 is not home-compostable. The comparative example 1 containing heat- sealable fibers was industrially compostable. The biodegradable polymer is not easily introduced into the nonwoven, whereas in Example 1 , the biodegradable polymer was introduced in the form of the biolatex during manufacturing, where the hydrophobic AKD prevented the hydrophilic biolatex from penetrating to the middle ply and top ply to achieve desired properties.

[0099] Table 2: Physical properties Example 2 and 3: A heat-sealable coffee pod a) Preparation method

[0100] Cellulosic non wo vens having the compositions on Table 3 below were made on a paper machine. Where appropriate, the base cellulosic nonwoven is then coated with the biolatex. After drying, the properties were measured.

[0101] Table 3: Compositions and compostability of examples

[0102] * relative to a total weight of the cellulosic nonwoven

[0103] Table 3 provides compositions in each ply of the non wo ven examples, and compostability of the non wo ven examples. b) Results After drying, different physical properties of the examples were measured and are summarized in Table 4. Evaluation methods of the air permeability, dry peel strength, and tear strength are described elsewhere in this disclosure.

[0104] It is noted that Example 2 containing the sizing agent (AKD) in the middle ply and the biodegradable polymer (heat-sealable binder comprising the non-fibrous biodegradable polymer) in the base ply was home-compostable and Example 3 containing the sizing agent (AKD) in the top ply and the biodegradable polymer (heat-sealable binder comprising the non-fibrous biodegradable polymer) in the base ply and the middle ply were home-compostable, whereas Comparative examples 3 was not home-compostable. The comparative example 3 containing heat-sealable fibers was industrially compostable. The biodegradable polymer is not easily introduced into the non wo ven, whereas in Examples 2 and 3, the biodegradable polymer was introduced in the form of the biolatex during manufacturing. By enabling the introduction of biodegradable polymer into the nonwoven, the heat- sealable and home-compostable cellulosic nonwoven having desired properties was achieved.

[0105] Table 4: Physical properties

[0106] This disclosure further encompasses the following aspects.

[0107] Aspect 1. A cellulosic nonwoven, the cellulosic nonwoven comprising: a first ply comprising first fibers, and a heat-sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic, wherein the first fibers and the second fibers each independently comprise cellulosic fibers, and wherein the second ply is disposed on the first ply.

[0108] Aspect 2. The cellulosic non wo ven of aspect 1, wherein the first ply and the second ply are interlinked at an interface between the first ply and the second ply without an additional adhesive.

[0109] Aspect 3. The cellulosic nonwoven of any of aspects 1 or 2, wherein the second ply is substantially free of the heat-sealable binder, preferably the second ply comprises 0.01 wt% or more, 0.1 wt% or more, and / or 2 wt% or less, 1.8 wt% or less of the heat-sealable binder, relative to a weight of the second ply.

[0110] Aspect 4. The cellulosic non woven of any of aspects 1 or 3, wherein the non- fibrous biodegradable polymer comprises at least one of polybutylene succinate-co- adipate, polyhydroxy alkanoate, polybutylene adipate terephthalate, modified polyurethane, polylactic-glycolic acid, poly-caprolactone, copolymers of polylactic- glycolic acid and poly-caprolactone, polyhydroxy-butyrate-valerate, polyorthoester, polyethylene oxide-butylene terephthalate, poly-D,L-lactic acid-p-dioxanone- polyethylene glycol block copolymer, or any combination thereof.

[0111] Aspect 5. The cellulosic nonwoven of any of aspects 1 to 4, wherein the sizing agent comprises at least one of an alkyl ketene dimer, a soap rosin, anionic rosin, a cationic rosin, or any combination thereof.

[0112] Aspect 6. The cellulosic nonwoven of any of aspects 1 to 5, wherein a total content of the cellulosic fiber in the cellulosic nonwoven is at least 70 wt%, at least 75 wt%, at least 80 wt%, and / or less than 100 wt%, less than 95 wt%, less than 90 wt%, relative to a weight of a total fiber in the cellulosic nonwoven, or wherein the total content of the cellulosic fiber in the cellulosic non wo ven is at least 50 wt%, preferably at least 70 wt%, relative to a total weight of the cellulosic nonwoven.

[0113] Aspect 7. The cellulosic non wo ven of any of aspects 1 to 6, wherein the cellulosic fibers comprise at least one of softwood fibers, hardwood fibers, annual plant fibers, or any combination thereof, and optionally wherein at least a type or a content of the cellulosic fibers in the first ply and the second ply are different.

[0114] Aspect 8. The cellulosic non wo ven of any of aspects 1 to 7, wherein the cellulosic nonwoven comprises softwood fibers, wherein a content of the softwood fibers is 15 to 80 wt%, and / or hardwood fibers, wherein a content of the hardwood fibers is 0 to 40 wt%, and / or annual plant fibers, wherein a content of the annual plant fibers is 10 to 50 wt%, and / or heat-sealable fibers, wherein a content of the heat- sealable fibers is 0 to 15 wt%, and / or the heat-sealable binder, wherein a content of the heat-sealable binder is 5 to 40 wt%, relative to a total weight of the cellulosic nonwoven.

[0115] Aspect 9. The cellulosic nonwoven of aspect 8, wherein the heat-sealable fibers comprises fibers of at least one of polylactic acid, polybutylene succinate, polybutylene succinate-co-adipate, polyhydroxyalkanoate, polybutylene adipate terephthalate, modified polyurethane, polylactic-glycolic acid, poly-caprolactone, copolymers of polylactic-glycolic acid and poly-caprolactone, polyhydroxy-butyrate- valerate, polyorthoester, polyethylene oxide-butylene terephthalate, poly-D,L-lactic acid-p-dioxanone-polyethylene glycol block copolymer, or any combination thereof.

[0116] Aspect 10. The cellulosic non wo ven of any of aspects 1 to 9, wherein a basis weight of the cellulosic non wo ven is 12 g / m2or more, 13 g / m2or more, 20 g / m2or more, and / or 250 g / m2or less, 200 g / m2or less, 100 g / m2or less, wherein a basis weight of the first ply, second ply, or both, is 3 g / m2or more, 5 g / m2or more, 10 g / m2or more, 20 g / m2or more, and / or 75 g / m2or less, 60 g / m2or less, 50 g / m2or less, and wherein a total thickness of the cellulosic nonwoven is 40 pm or more, 80 pm or more, 150 pm or more, and / or 500 pm or less, 400 pm or less, 300 pm or less.

[0117] Aspect 11. The cellulosic nonwoven of any of aspects 1 to 10, wherein the cellulosic nonwoven further comprises a third ply, wherein the third ply is between the first ply and the second ply, on a surface of the second ply opposite the first ply, or both, wherein the third ply comprises cellulosic fibers comprising at least one of softwood fibers, hardwood fibers, annual plant fibers, or any combination thereof. Aspect 12. The cellulosic nonwoven of aspect 11, wherein a basis weight of the third ply is 3 g / m2or more, 5 g / m2or more, 10 g / m2or more, 20 g / m2or more, and / or 75 g / m2or less, 60 g / m2or less, 50 g / m2or less, optionally wherein a weight ratio of the first ply to the third ply is 0.5 to 1 , and / or a weight ratio of the second ply to the third ply is 0.5 to 1.

[0118] Aspect 13. The cellulosic nonwoven of any of aspects 1 to 12, wherein the cellulosic nonwoven is a compostable material, preferably an industrially- compostable material, more preferably a home-compostable material, wherein the industrially-compostable material disintegrates at a temperature between 55 to 60 °C in less than 3 months and biodegrades at a temperature between 55 to 60 °C in less than 6 months as outlined in EN 13432, wherein the home-compostable material disintegrates at a temperature below 55 °C, preferably between 10 to 45 °C, more preferably between 25 to 30 °C, in less than 6 months and biodegrades at a temperature below 55 °C, preferably between 10 to 45 °C, more preferably between 25 to 30 °C, in less than 12 months.

[0119] Aspect 14. The cellulosic nonwoven of aspects 1 to 13, wherein the cellulosic nonwoven is home-compostable and heat-sealable.

[0120] Aspect 15. The cellulosic nonwoven of any of aspects 1 to 14, wherein the cellulosic non wo ven has at least one of the following properties: an air permeability of 500 to 2500 L / m2 / s, measured according to ISO 9237, a mean flow pore diameter of 20 pm or more, 50 pm or more, 70 pm or more and / or 200 pm or less, preferably 150 pm or less, 100 pm or less, and a maximum pore diameter of 350 pm or less, 300 pm or less, and / or 30 pm or more, 100 pm or more, a dry peel strength of 0.6 N or more, 0.8 N or more, and / or 3 N or less, 2.0 or less, or a tear strength in machine direction of 50 mN or more, 100 mN or more, 150 mN or more, and / or 1000 mN or less, 850 mN or less, 800 mN or less.

[0121] Aspect 16. An article comprising the cellulosic non wo ven of any of aspects 1 to 15, wherein the article is a tea bag, a coffee pod, a coffee filter, a food packaging material, packaging material, or an agricultural or horticultural wrapping paper. Aspect 17. A method of manufacturing a cellulosic non wo ven by a wet-laying process, wherein the method comprises: providing a first ply precursor material comprising first fibers and a first liquid dispersant; providing a second ply precursor material comprising second fibers, a second liquid dispersant, and a sizing agent; dispersing the first ply precursor material in a first pulper, and dispersing the second ply precursor material in a second pulper; and wet-laying the dispersed first ply precursor material and the dispersed second ply precursor material on a forming wire to form a resulting product, wherein the resulting product comprises the second ply disposed on the first ply; disposing a biolatex comprising the non-fibrous biodegradable polymer to the resulting product, preferably on a side of the first ply, wherein the biolatex is disposed on the first fibers in the form of a liquid or a foam preferably by one side metering size-press or film-press or spray coating or bar coating; and drying the resulting product to manufacture the cellulosic nonwoven of any of aspects 1 to 16.

[0122] Aspect 18. The method of aspect 17, wherein the method further comprises: providing a third ply precursor material comprising a third fiber and a third liquid dispersant; dispersing the third ply precursor material in a third pulper; and wet-laying the dispersed first ply precursor material, the dispersed second ply precursor material, and the third ply precursor material on the forming wire to form the resulting product further comprising a third ply , wherein the third ply is disposed between the first ply and the second ply, or on a surface of the second ply opposite the first ply.

[0123] Aspect 19. A cellulosic nonwoven for a heat sealable tea bag filter, the cellulosic nonwoven comprising: a first ply comprising first fibers, and a heat-sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic; a third ply comprising third fibers; wherein the first fibers, second fibers, and the third fibers each independently comprise cellulosic fibers, and wherein the second ply is disposed between the first ply and the third ply, wherein the first ply and the second ply are interlinked at an interface between the first ply and the second ply, and the second ply and the third ply are interlinked at an interface between the second ply and the third ply, wherein each interface is interlinked without an additional adhesive, optionally wherein the cellulosic nonwoven has an air permeability of 500-2500 L / m2 / s.

[0124] Aspect 20. A cellulosic nonwoven for a heat sealable coffee pod filter, the cellulosic nonwoven comprising: a first ply comprising first fibers, and a heat-sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic; a third ply comprising third fibers; wherein the first fibers, second fibers, and the third fibers each independently comprise cellulosic fibers, and wherein the third ply is disposed between the first ply and the second ply, wherein the first ply and the third ply are interlinked at an interface between the first ply and the third ply, and the second ply and the third ply are interlinked at an interface between the second ply and the third ply, wherein each interface is interlinked without an additional adhesive, optionally wherein the cellulosic nonwoven has a dry peel strength of 0.6 to 3 N, and an air permeability of 500-2500 L / m2 / s.

[0125] Aspect 21. The cellulosic nonwoven for a heat sealable tea bag filter of aspect 19, or the cellulosic nonwoven for a heat sealable tea bag filter of aspect 20, wherein the first ply and the second ply are interlinked at an interface between the first ply and the second ply without an additional adhesive, wherein the second ply is substantially free of the heat-sealable binder, preferably the second ply comprises 0.01 wt% or more, 0.05 wt% or more, 0.1 wt% or more, and / or 2 wt% or less, 1 wt% or less, even 0.5 wt% or less of the heat-sealable binder, relative to a weight of the second ply, wherein the non-fibrous biodegradable polymer comprises at least one of polybutylene succinate-co-adipate, polyhydroxyalkanoate, polybutylene adipate terephthalate, modified polyurethane, polylactic-glycolic acid, poly-caprolactone, copolymers of polylactic-glycolic acid and poly-caprolactone, polyhydroxy-butyrate- valerate, polyorthoester, polyethylene oxide-butylene terephthalate, poly-D,L-lactic acid-p- dioxanone-polyethylene glycol block copolymer, or any combination thereof, wherein the sizing agent comprises at least one of an alkyl ketene dimer, a soap rosin, anionic rosin, a cationic rosin, or any combination thereof, wherein a total content of the cellulosic fiber in the cellulosic nonwoven is at least 70 wt%, at least 75 wt%, at least 80 wt%, and / or less than 100 wt%, less than 95 wt%, less than 90 wt%, relative to a weight of a total fiber in the cellulosic nonwoven, or wherein the total content of the cellulosic fiber in the cellulosic nonwoven is at least 50 wt%, at least 60, at least 65 wt%, and / or less than 99 wt%, less than 95 wt%, less than 90 wt%, relative to a total weight of the cellulosic nonwoven, wherein the cellulosic fibers comprise at least one of softwood fibers, hardwood fibers, annual plant fibers, or any combination thereof, and optionally wherein at least a type or a content of the cellulosic fibers in the first ply and the second ply are different, wherein the cellulosic nonwoven comprises softwood fibers, wherein a content of the softwood fibers is 15 to 80 wt%, and / or hardwood fibers, wherein a content of the hardwood fibers is 0 to 40 wt%, and / or annual plant fibers, wherein a content of the annual plant fibers is 10 to 50 wt%, and / or heat-sealable fibers, wherein a content of the heat-sealable fibers is 0 to 15 wt%, and / or the heat-sealable binder, wherein a content of the heat-sealable binder is 5 to 40 wt%, relative to a total weight of the cellulosic nonwoven, wherein the heat- sealable fibers comprise fibers of at least one of polylactic acid, polybutylene succinate, polybutylene succinate-co-adipate, polyhydroxyalkanoate, polybutylene adipate terephthalate, modified polyurethane, polylac tic-glycolic acid, polycaprolactone, copolymers of polylactic-glycolic acid and poly-caprolactone, polyhydroxy-butyrate-valerate, polyorthoester, polyethylene oxide-butylene terephthalate, poly-D,L-lactic acid-p-dioxanone-polyethylene glycol block copolymer, or any combination thereof, wherein a basis weight of the cellulosic nonwoven is 12 g / m2or more, 13 g / m2or more, 20 g / m2or more, and / or 250 g / m2or less, 200 g / m2or less, 100 g / m2or less, wherein a basis weight of the first ply, second ply, or both, is 3 g / m2or more, 5 g / m2or more, 10 g / m2or more, 20 g / m2or more, and / or 75 g / m2or less, 60 g / m2or less, 50 g / m2or less, and wherein a total thickness of the cellulosic nonwoven is 40 pm or more, 80 pm or more, 150 pm or more, and / or 500 pm or less, 400 pm or less, 300 pm or less, wherein the cellulosic nonwoven further comprises a third ply, wherein the third ply is between the first ply and the second ply, on a surface of the second ply opposite the first ply, or both, wherein the third ply comprises cellulosic fibers comprising at least one of softwood fibers, hardwood fibers, annual plant fibers, or any combination thereof, wherein a basis weight of the third ply is 3 g / m2or more, 5 g / m2or more, 10 g / m2or more, 20 g / m2or more, and / or 75 g / m2or less, 60 g / m2or less, 50 g / m2or less, optionally wherein a weight ratio of the first ply to the third ply is 0.5 to 1 , and / or a weight ratio of the second ply to the third ply is 0.5 to 1, wherein the cellulosic nonwoven is a compostable material, preferably an industrially-compostable material, more preferably a home-compostable material, wherein the industrially-compostable material disintegrates at a temperature between 55 to 60 °C in less than 3 months and biodegrades at a temperature between 55 to 60 °C in less than 6 months as outlined in EN13432, wherein the home- compostable material disintegrates at a temperature below 55 °C, preferably between 10 to 45 °C, more preferably between 25 to 30 °C, in less than 6 months and biodegrades at a temperature below 55 °C, preferably between 10 to 45 °C, more preferably between 25 to 30 °C, in less than 12 months, wherein the cellulosic nonwoven is home-compostable and heat-sealable, wherein the cellulosic nonwoven has at least one of the following properties: an air permeability of 500 to 2500 L / m2 / s, measured according to ISO 9237, a mean flow pore diameter between 20 pm or more, 50 pm or more, 70 pm or more, and / or 200 pm or less, 150 pm or less, 100 pm or less and a maximum pore diameter of 350 pm or less, 300 pm or less, and / or 30 pm or more, 100 pm, a dry peel strength of 0.6 N or more, 0.8 N or more, and / or 3 N or less, 2.0 or less, or a tear strength in machine direction of greater than 50 mN, greater than 100 mN, 150 mN or more, and / or 1000 mN or less, 850 mN or less, 800 mN or less, wherein a method of manufacturing a cellulosic nonwoven by a wet-laying process comprises: providing a first ply precursor material comprising first fibers and a first liquid dispersant; providing a second ply precursor material comprising second fibers, a second liquid dispersant, and a sizing agent; dispersing the first ply precursor material in a first pulper, and dispersing the second ply precursor material in a second pulper; and wet-laying the dispersed first ply precursor material and the dispersed second ply precursor material on a forming wire to form a resulting product, wherein the resulting product comprises the second ply disposed on the first ply; disposing a biolatex comprising the non-fibrous biodegradable polymer to the resulting product, preferably on a side of the first ply, wherein the biolatex is disposed on the first fibers in the form of a liquid or a foam preferably by one side metering size -press or filmpress or spray coating or bar coating; and drying the resulting product to manufacture the cellulosic nonwoven, wherein the method further comprises: providing a third ply precursor material comprising a third fiber and a third liquid dispersant; dispersing the third ply precursor material in a third pulper; and wet-laying the dispersed first ply precursor material, the dispersed second ply precursor material, and the third ply precursor material on the forming wire to form the resulting product further comprising a third ply , wherein the third ply is disposed between the first ply and the second ply, or on a surface of the second ply opposite the first ply.

[0126] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents. Like reference numerals refer to like elements throughout.

[0127] It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

[0128] It will be understood that, although the terms “first,” “second,” “third” etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, “a first element,” “component,” “region,” “layer” or “section” discussed could be termed a second element, component, region, layer or section without departing from the teachings herein.

[0129] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of “up to 25 wt.%, or, more specifically, 5 wt.% to 25 wt.%”, is inclusive of the endpoints and all intermediate values of the ranges of “5 wt.% to 25 wt.%,” etc.). Also, for example, “heat-sealable binder is 20 wt% or more, 25 wt% or more, 30 wt% or more, and / or 60 wt% or less, 55 wt% or less, 50 wt% or less, relative to the total weight of the first ply” means that the heat-sealable binder may be 20 wt% or more; or 25 wt% or more; or 30 wt% or more; or it may be 60 wt% or less; or 55 wt% or less; or 50 wt% or less, relative to the total weight of the first ply. It also means it may be 20 wt% or more and 60 wt% or less; or 20 wt% or more and 55 wt% or less; or 20 wt% or more and 50 wt% or less; or 25 wt% or more and 60 wt% or less; or 25 wt% or more and 55 wt% or less; or 25 wt% or more and 50 wt% or less; or 30 wt% or more and 60 wt% or less; or 30 wt% or more and 55 wt% or less; or 30 wt% or more and 50 wt% or less, relative to the total weight of the first ply.

[0130] “Combinations” is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms “first,” “second,” and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” and “the” do not denote a limitation of quantity and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Thus, reference to “an” element in a claim followed by reference to “the” element is inclusive of one element and a plurality of the elements. “Or” means “and / or” unless clearly stated otherwise. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and / or groups thereof.

[0131] Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The term “lower,” can therefore, encompasses both an orientation of “lower” and “upper,” depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The terms “below” or “beneath” can, therefore, encompass both an orientation of above and below.

[0132] Reference throughout the specification to “some embodiments”, “an embodiment”, and so forth, means that a particular element described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments. A “combination thereof’ is open and includes any combination comprising at least one of the listed components or properties optionally together with a like or equivalent component or property not listed.

[0133] Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this application belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0134] Unless specified to the contrary herein, all test standards are the most recent standard in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0135] While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims. Additional modifications, changes, and substitutions are intended in the foregoing disclosure. Since many changes could be made in the above construction and many widely different embodiments of this disclosure could be made without departing from the scope thereof, it is intended that all matter contained in the drawings and specification shall be interpreted as illustrative and not in a limiting sense. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure.

Claims

What is claimed is:

1. A cellulosic nonwoven, the cellulosic nonwoven comprising: a first ply comprising first fibers, and a heat-sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic, wherein the first fibers and the second fibers each independently comprise cellulosic fibers, and wherein the second ply is disposed on the first ply.

2. The cellulosic non wo ven of claim 1, wherein the first ply and the second ply are interlinked at an interface between the first ply and the second ply without an additional adhesive.

3. The cellulosic nonwoven of any of claims 1 or 2, wherein the second ply is substantially free of the heat-sealable binder, preferably the second ply comprises 0.01 wt% or more, more preferably 0.1 wt% or more and preferably 2 wt% or less, more preferably 1.8 wt% or less of the heat-sealable binder, relative to a weight of the second ply.

4. The cellulosic non wo ven of any of claims 1 or 3, wherein the non-fibrous biodegradable polymer comprises at least one of polybutylene succinate-co-adipate, polyhydroxyalkanoate, polybutylene adipate terephthalate, modified polyurethane, polylactic-glycolic acid, poly-caprolactone, copolymers of polylactic-glycolic acid and poly-caprolactone, polyhydroxy-butyrate- valerate, polyorthoester, polyethylene oxide-butylene terephthalate, poly-D,L-lactic acid-p-dioxanone-polyethylene glycol block copolymer, or any combination thereof.

5. The cellulosic non wo ven of any of claims 1 to 4, wherein the sizing agent comprises at least one of an alkyl ketene dimer, a soap rosin, anionic rosin, a cationic rosin, or any combination thereof.

6. The cellulosic non wo ven of any of claims 1 to 5, wherein a total content of the cellulosic fiber in the cellulosic non wo ven is at least 70 wt%, preferably at least 75 wt%, more preferably at least 80 wt%, and / or less than 100 wt%, preferably less than 95 wt%, more preferably less than 90 wt%, relative to a weight of a total fiber in the cellulosic nonwoven, or wherein the total content of the cellulosic fiber in the cellulosic nonwoven is at least 50 wt%, preferably at least 70 wt%, relative to a total weight of the cellulosic nonwoven.

7. The cellulosic nonwoven of any of claims 1 to 6, wherein the cellulosic fibers comprise at least one of softwood fibers, hardwood fibers, annual plant fibers, or any combination thereof, and optionally wherein at least a type or a content of the cellulosic fibers in the first ply and the second ply are different.

8. The cellulosic non wo ven of any of claims 1 to 7, wherein the cellulosic non wo ven comprises: softwood fibers, wherein a content of the softwood fibers is 15 to 80 wt%, and / or hardwood fibers, wherein a content of the hardwood fibers is 0 to 40 wt%, and / or annual plant fibers, wherein a content of the annual plant fibers is 10 to 50 wt%, and / or heat-sealable fibers, wherein a content of the heat-sealable fibers is 0 to 15 wt%, and / or the heat-sealable binder, wherein a content of the heat-sealable binder is 5 to 40 wt%, relative to a total weight of the cellulosic non wo ven.

9. The cellulosic nonwoven of claim 8, wherein the heat-sealable fibers comprise fibers of at least one of polylactic acid, polybutylene succinate, polybutylene succinate-co-adipate, polyhydroxyalkanoate, polybutylene adipate terephthalate, modified polyurethane, polylactic-glycolic acid, poly-caprolactone, copolymers of polylactic-glycolic acid and poly-caprolactone, polyhydroxy-butyrate-valerate, polyorthoester, polyethylene oxide-butylene terephthalate, poly-D,L-lactic acid- - dioxanone-polyethylene glycol block copolymer, or any combination thereof.

10. The cellulosic non wo ven of any of claims 1 to 9, wherein a basis weight of the cellulosic nonwoven is 12 g / m2or more, preferably 13 g / m2or more, more preferably 20 g / m2or more, and / or 250 g / m2or less, preferably 200 g / m2or less, more preferably 100 g / m2or less; and / or a total thickness of the cellulosic nonwoven is 40 pm or more, preferably 80 pm or more, more preferably150 pm or more, and / or 500 pm or less, preferably 400 pm or less, more preferably 300 pm or less.

11. The cellulosic nonwoven of any of claims 1 to 10, wherein the cellulosic nonwoven further comprises a third ply, wherein the third ply is between the first ply and the second ply, or on a surface of the second ply opposite the first ply, wherein optionally the third ply comprises cellulosic fibers comprising at least one of softwood fibers, hardwood fibers, annual plant fibers, or any combination thereof.

12. The cellulosic non wo ven of claim 11, wherein a weight ratio of the first ply to the third ply is 0.5 to 1, and / or a weight ratio of the second ply to the third ply is 0.5 to 1.

13. The cellulosic non wo ven of any of claims 1 to 12, wherein the cellulosic nonwoven is a compostable material, preferably an industrially-compostable material according to EN13432, more preferably a home-compostable material, wherein the industrially-compostable material biodegrades at a temperature between 55 to 60 °C in less than 6 months, wherein the home-compostable material biodegrades at a temperature below 55 °C, preferably between 10 to 45 °C, more preferably between 25 to 30 °C, in less than 12 months.

14. The cellulosic non wo ven of claims 1 to 13, wherein the cellulosic non woven is home-compostable and heat-sealable.

15. The cellulosic nonwoven of any of claims 1 to 14, wherein the cellulosic nonwoven has at least one of the following properties:- an air permeability of 500 to 2500 L / m2 / s, measured according to ISO 9237;- a mean flow pore diameter 20 pm or more, preferably 50 pm or more, more preferably 70 pm or more and / or 200 pm or less, preferably 150 pm or less, more preferably 100 pm or less;- a maximum pore diameter of 350 pm or less, preferably 300 pm or less, and / or 30 pm or more, preferably 100 pm or more;- a dry peel strength of 0.6 N or more, preferably 0.8 N or more, and / or 3 N or less, preferably 2.0 or less; or- a tear strength in machine direction of 50 mN or more, 100 mN or more, preferably 150 mN or more, and / or 1000 mN or less, preferably 850 mN or less, more preferably 800 mN or less.

16. An article comprising the cellulosic non wo ven of any of claims 1 to 15,wherein the article is a tea bag, a coffee pod, a coffee filter, a food packaging material, a packaging material, or an agricultural or horticultural wrapping paper.

17. A method of manufacturing a cellulosic nonwoven by a wet-laying process, wherein the method comprises: providing a first ply precursor material comprising first fibers and a first liquid dispersant; providing a second ply precursor material comprising second fibers, a second liquid dispersant, and a sizing agent; dispersing the first ply precursor material in a first pulper, and dispersing the second ply precursor material in a second pulper; and wet-laying the dispersed first ply precursor material and the dispersed second ply precursor material on a forming wire to form a resulting product, wherein the resulting product comprises the second ply disposed on the first ply; disposing a biolatex comprising the non-fibrous biodegradable polymer to the resulting product, preferably on a side of the first ply, wherein the biolatex is disposed on the first fibers in the form of a liquid or a foam; and drying the resulting product to manufacture the cellulosic nonwoven of any of claims 1 to 16.

18. The method of claim 17, wherein the method further comprises: providing a third ply precursor material comprising a third fiber and a third liquid dispersant; dispersing the third ply precursor material in a third pulper; and wet-laying the dispersed first ply precursor material, the dispersed second ply precursor material, and the third ply precursor material on the forming wire to form the resulting product further comprising a third ply, wherein the third ply is disposed between the first ply and the second ply, or on a surface of the second ply opposite the first ply.

19. A cellulosic non wo ven for a heat sealable tea bag filter, the cellulosic non wo ven comprising: a first ply comprising first fibers, and a heat-sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic; a third ply comprising third fibers; wherein the first fibers, second fibers, and the third fibers each independently comprise cellulosic fibers, and wherein the second ply is disposed between the first ply and the third ply, wherein the first ply and the second ply are interlinked at an interface between the first ply and the second ply, and the second ply and the third ply are interlinked at an interface between the second ply and the third ply, wherein each interface is interlinked without an additional adhesive, optionally wherein the cellulosic nonwoven has an air permeability of 500- 2500 L / m2 / s.

20. A cellulosic nonwoven for a heat sealable coffee pod filter, the cellulosic non wo ven comprising: a first ply comprising first fibers, and a heat-sealable binder, wherein the heat-sealable binder comprises a non-fibrous biodegradable polymer; a second ply comprising second fibers, and a sizing agent, wherein the sizing agent is hydrophobic; a third ply comprising third fibers; wherein the first fibers, second fibers, and the third fibers each independently comprise cellulosic fibers, and wherein the third ply is disposed between the first ply and the second ply, wherein the first ply and the third ply are interlinked at an interface between the first ply and the third ply, and the second ply and the third ply are interlinked at an interface between the second ply and the third ply, wherein each interface is interlinked without an additional adhesive, optionally wherein the cellulosic non wo ven has a dry peel strength of 0.6 to 3 N, and an air permeability of 500-2500 L / m2 / s.

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