Alternative Filter Materials and Components for Aerosol Delivery Devices

Abstract

The present disclosure provides a filter material suitable for use as a filter element in an aerosol delivery device, and a method of forming such a filter material suitable for use as a filter element in such a device. The present disclosure, in some embodiments, provides a filter material comprising a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, esparto, kenaf, jute, ramie, wood, reconstituted tobacco, and combinations thereof, the filter material being in the form of a nonwoven sheet or fibrous tow.

Description

Technical Field

[0001] The present disclosure relates to aerosol generating components, aerosol delivery devices, aerosol delivery systems, such as smoking articles, and parts thereof, which utilize an electrically generated heat or a combustible ignition source to heat an aerosol-forming material, preferably without significant combustion, in order to provide an inhalable substance for human consumption in the form of an aerosol. In particular, the present disclosure relates to a filter material for use as a filter element in an aerosol delivery device, such as a cigarette or other smoking article, and related methods for producing such filter materials and related filter elements.

Background Art

[0002] Popular smoking articles, such as cigarettes, can have a substantially cylindrical rod-like structure and can include a filling, roll or cylinder of smokable material, such as shredded tobacco (e.g., in cut filler form), surrounded by a paper wrapper, thereby forming a so-called "smokable rod" or "tobacco rod". Typically, a cigarette has a cylindrical filter element arranged in an end-to-end contact relationship with the tobacco rod. Typically, the filter element includes plasticized cellulose acetate tow circumscribed by a paper material known as "plug wrap", and the filter element is attached to one end of the tobacco rod using a circumscribing wrapping material known as "tipping material". It may also be desirable to perforate the tipping material and the plug wrap to dilute the drawn mainstream smoke with ambient air. Descriptions of cigarettes and various of their parts are set forth in Tobacco Production, Chemistry and Technology, Davis et al. (eds.) (1999). A cigarette is used by a smoker by igniting it at one end and burning the tobacco rod. The smoker then receives the mainstream smoke into their mouth by inhaling at the opposite end of the cigarette (e.g., the filter tip).

Prior Art Documents

Non-Patent Documents

[0003] [Non-Patent Document 1] Tobacco Production, Chemistry and Technology, edited by Davis et al. (1999) [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] The filter technologies currently available for forming filter elements may have several drawbacks. For example, conventional filter elements containing cellulose acetate tow are characterized by biodegradability, but unfortunately, they may require a long time to actually biodegrade. In some cases, the biodegradation period can be about 2 to 10 years. Furthermore, some administrative jurisdictions classify cellulose acetate tow as "single-use plastic," and such classification has led to the regulation of such materials and suppressed their harmful effects on the environment. In response, alternative filter materials such as agglomerated paper, non-woven polypropylene webs, or agglomerated strands of etched webs have been proposed. However, even when filter elements containing such alternative materials exhibit accelerated biodegradability exceeding that of conventional cellulose acetate tow filter elements, their effect on mainstream smoke may not meet smokers' expectations. That is, conventional cellulose acetate tow is generally plasticized with a suitable plasticizer such as triacetin when the tow is bloomed and formed into a filter rod from which a filter element is obtained. In this regard, the triacetin plasticizer provides certain effects (i.e., taste) to the mainstream smoke that are pleasant or as expected by smokers. One problem with alternative filter materials is that such materials may not necessarily be blended with or favorably accept a plasticizer such as triacetin. That is, even when such alternative filter materials accept triacetin, the combined effect on mainstream smoke, such as the taste of the smoke, may not be pleasant for smokers or may not be sufficiently similar to the sensations expected by smokers accustomed to the sensory properties associated with triacetin-treated cellulose acetate tow filter elements.

[0005] Further progress in filter elements and devices, and methods for producing them, may be desirable, such progress maximizing or improving the biodegradability of the filter tow / filter element while being blended with a conventional plasticizer that maintains the perceived effect on mainstream smoke (i.e., the taste of the smoke) expected by smokers.

Means for Solving the Problem

[0006] (Summary of the Invention) The present disclosure relates to an aerosol delivery device that uses an electrically generated heat or a combustible ignition source to heat a substrate carrying one or more aerosol-forming materials so as to provide an inhalable substance for human consumption in the form of an aerosol. More specifically, the present disclosure generally provides filter materials and components suitable for use in an aerosol delivery device, and methods of preparing such filter materials and components. In some aspects, the filter material according to the present disclosure can be formed of a non-woven sheet or fibrous tow including a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, esparto, kenaf, jute, ramie, wood, reconstituted tobacco, and combinations thereof.

[0007] In one aspect, the present disclosure provides a filter material adapted for use as a filter element in an aerosol delivery device. In such embodiments, the filter material can include a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, esparto, kenaf, jute, ramie, wood, and combinations thereof, and the filter material can be in the form of a non-woven sheet or fibrous tow. In some embodiments, the filter material is in the form of a pleated non-woven sheet assembled to form a rod-shaped element. In some embodiments, the non-woven sheet has a basis weight of from about 20 gsm to about 90 gsm, from about 40 gsm to about 80 gsm, or from about 50 gsm to about 70 gsm. In some embodiments, the denier per filament (dpf) of the filter material is from about 1 dpf to about 30 dpf, from about 1 dpf to about 25 dpf, or from about 1 dpf to about 5 dpf.

[0008] In some embodiments, the filter material may optionally be crimped. In some embodiments, for example, the crimped filter material may have a crimp depth of from about 1 micron to about 180 microns, from about 1 micron to about 150 microns, or from about 50 microns to about 100 microns. In some embodiments, the nonwoven sheet has a width of from about 110 mm to about 160 mm or from about 115 mm to about 150 mm. In certain embodiments, the filter material according to the present disclosure may further comprise a plasticizer. In some embodiments, the plasticizer is triacetin. In some embodiments, the filter material according to the present disclosure may further comprise a binder. In such embodiments, the binder may be selected from the group consisting of polyvinyl alcohol (PVOH), pectin, starch, microfibrillated cellulose (MFC), and combinations thereof. As described herein, in some embodiments, the filter material prepared in accordance with the present disclosure may be in the form of a nonwoven sheet. In such embodiments, the nonwoven sheet may be a wet-laid nonwoven sheet, a dry-laid nonwoven sheet, or an air-laid nonwoven sheet.

[0009] Some aspects of the present disclosure provide a filter element adapted for use in an aerosol delivery device, the filter element comprising one or more segments of filter material prepared according to the present disclosure. In some embodiments, one or more segments of the filter material have a hardness of about 75 percent or greater, about 80 percent or greater, or about 85 percent or greater. In some embodiments, the filter element prepared according to the present disclosure may exhibit a pressure drop in the range of from about 40 mmWG to about 400 mmWG or from about 200 mmWG to about 300 mmWG. Another aspect of the present disclosure provides an aerosol delivery device comprising a filter element prepared according to the present disclosure.

[0010] A further aspect of the present disclosure provides a method for forming a filter material suitable for use as a filter element in an aerosol delivery device. In some embodiments, such a method includes receiving a non-woven sheet or fibrous tow, the non-woven sheet or fibrous tow including a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, esparto, kenaf, jute, flax, wood, and combinations thereof, and processing the non-woven sheet or fibrous tow to obtain a filter material suitable for use as a filter element for an aerosol delivery device. In some embodiments, such a method may further include forming the non-woven sheet or fibrous tow, as is known in the art. For example, the non-woven sheet may be formed using a wet-laid, air-laid, or dry-laid forming process. Other forming processes known in the art may also be suitable for forming the filter elements described herein. In some embodiments, for example, the non-woven sheet is formed using a forming process selected from the group consisting of hydroentangling, needle punching, spunbonding, meltblowing, spunlacing, carding, point bonding, spinning, and combinations thereof.

[0011] In some embodiments, the step of forming the fibrous tow may include blending a plurality of fibers to obtain a mixed fiber blend and drawing the mixed fiber blend to produce the fibrous tow. In some embodiments, the step of processing may include gathering the non-woven sheet or fibrous tow to form a rod-shaped element suitable for use as a filter element.

[0012] In still other embodiments, the processing step may include wrapping a rod-shaped element with a wrapping material that circumscribes the rod-shaped element, thereby forming a continuous rod suitable for use as a filter element. In certain embodiments, the processing step may include crimping a nonwoven sheet or fibrous tow. In such embodiments, the crimped nonwoven sheet or crimped fibrous tow may have a crimp depth of from about 1 micron to about 180 microns, from about 1 micron to about 150 microns, or from about 50 microns to about 100 microns.

[0013] In some embodiments, the method of the present disclosure may further include applying a plasticizer to the nonwoven sheet or fibrous tow. In some embodiments, the plasticizer is triacetin. In some embodiments, the method of the present disclosure may further include applying a binder to the nonwoven sheet or fibrous tow. In such embodiments, the binder may be selected from the group consisting of polyvinyl alcohol (PVOH), pectin, starch, microfibrillated cellulose (MFC), and combinations thereof. In some embodiments, the nonwoven sheet may have a basis weight of from about 20 gsm to about 90 gsm, from about 40 gsm to about 80 gsm, or from about 50 gsm to about 70 gsm. In some embodiments, the denier per filament (dpf) of the filter material is from about 1 dpf to about 30 dpf, from about 1 dpf to about 25 dpf, or from about 1 dpf to about 5 dpf. In certain embodiments, the nonwoven sheet may have a width of from about 110 mm to about 160 mm, or from about 115 mm to about 150 mm.

[0014] The present disclosure includes, but is not limited to, the following embodiments. Embodiment 1: A filter material suitable for use as a filter element in an aerosol delivery device, the filter material comprising a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, esparto, kenaf, jute, ramie, wood, and combinations thereof, and being in the form of a nonwoven sheet or fibrous tow.

[0015] Embodiment 2: The filter material according to Embodiment 1, which is in the form of a pleated nonwoven sheet formed by aggregating to form rod-shaped elements.

[0016] Embodiment 3: The filter material according to any one of Embodiments 1 to 2, wherein the nonwoven sheet has a basis weight of about 20 gsm to about 90 gsm.

[0017] Embodiment 4: The filter material according to any one of Embodiments 1 to 3, wherein the nonwoven sheet has a basis weight of about 40 gsm to about 80 gsm.

[0018] Embodiment 5: The filter material according to any one of Embodiments 1 to 4, wherein the nonwoven sheet has a basis weight of about 50 gsm to about 70 gsm.

[0019] Embodiment 6: The filter material according to any one of Embodiments 1 to 5, wherein the denier per filament (dpf) of the filter material is about 1 dpf to about 30 dpf.

[0020] Embodiment 7: The filter material according to any one of Embodiments 1 to 6, wherein the denier per filament (dpf) of the filter material is about 1 dpf to about 25 dpf.

[0021] Embodiment 8: The filter material according to any one of Embodiments 1 to 7, wherein the denier per filament (dpf) of the filter material is about 1 dpf to about 5 dpf.

[0022] Embodiment 9: The filter material according to any one of Embodiments 1 to 8, which is optionally crimped.

[0023] Embodiment 10: The filter material according to any one of Embodiments 1 to 9, wherein the crimped filter material has a crimp depth of about 1 micron to about 180 microns.

[0024] Embodiment 11: The filter material according to any one of Embodiments 1 to 10, wherein the crimped filter material has a crimp depth of about 1 micron to about 150 microns.

[0025] Embodiment 12: A crimped filter material that is any one of the filter materials of Embodiments 1 to 11 and has a crimp depth of about 50 microns to about 100 microns.

[0026] Embodiment 13: A filter material that is any one of the filter materials of Embodiments 1 to 12 and the nonwoven sheet has a width of about 110 mm to about 160 mm.

[0027] Embodiment 14: A filter material that is any one of the filter materials of Embodiments 1 to 13 and the nonwoven sheet has a width of about 115 mm to about 150 mm.

[0028] Embodiment 15: A filter material that is any one of the filter materials of Embodiments 1 to 14 and further contains a plasticizer.

[0029] Embodiment 16: A filter material that is any one of the filter materials of Embodiments 1 to 15 and the plasticizer is triacetin.

[0030] Embodiment 17: A filter material that is any one of the filter materials of Embodiments 1 to 16 and further contains a binder.

[0031] Embodiment 18: A filter material that is any one of the filter materials of Embodiments 1 to 17 and the binder is selected from the group consisting of polyvinyl alcohol (PVOH), pectin, starch, microfibrillated cellulose (MFC), and combinations thereof.

[0032] Embodiment 19: A filter material that is any one of the filter materials of Embodiments 1 to 18 and the nonwoven sheet is a wet-laid nonwoven sheet, a dry-laid nonwoven sheet, or an air-laid nonwoven sheet.

[0033] Embodiment 20: A filter element suitable for use in an aerosol delivery device, the filter element including one or more segments of a filter material according to any one of Embodiments 1 to 19.

[0034] Embodiment 21: The filter element of Embodiment 20, wherein one or more segments of the filter material have a hardness of about 75 percent or more.

[0035] Embodiment 22: The filter element of any one of Embodiments 20 - 21, wherein one or more segments of the filter material have a hardness of about 80 percent or more.

[0036] Embodiment 23: The filter element of any one of Embodiments 20 - 22, wherein one or more segments of the filter material have a hardness of about 85 percent or more.

[0037] Embodiment 24: The filter element of any one of Embodiments 20 - 23, which exhibits a pressure drop in the range of about 40 mmWG to about 400 mmWG.

[0038] Embodiment 25: The filter element of any one of Embodiments 20 - 24, which exhibits a pressure drop in the range of about 200 mmWG to about 300 mmWG.

[0039] Embodiment 26: An aerosol delivery device comprising a filter element according to any one of Embodiments 20 - 25.

[0040] Embodiment 27: A method for forming a filter material suitable for use as a filter element in an aerosol delivery device, the method comprising receiving a non - woven sheet or fibrous tow, wherein the non - woven sheet or fibrous tow comprises a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, esparto, kenaf, jute, ramie, wood, and combinations thereof, the receiving step, and processing the non - woven sheet or fibrous tow to obtain a filter material suitable for use as a filter element in an aerosol delivery device.

[0041] Embodiment 28: The method of Embodiment 27, further comprising forming a non - woven sheet or fibrous tow.

[0042] Embodiment 29: The method according to any one of Embodiments 27 to 28, wherein the nonwoven sheet is formed using a wet laid, air laid or dry laid forming process.

[0043] Embodiment 30: The method according to any one of Embodiments 27 to 29, wherein the nonwoven sheet is formed using a forming process selected from the group consisting of hydroentangling, needle punching, spunbonding, meltblowing, spunlacing, carding, point bonding, spinning and combinations thereof.

[0044] Embodiment 31: The method according to any one of Embodiments 27 to 30, wherein the step of forming the fibrous tow includes blending a plurality of fibers to obtain a mixed fiber blend and drawing the mixed fiber blend to produce the fibrous tow.

[0045] Embodiment 32: The method according to any one of Embodiments 27 to 31, wherein the step of processing includes gathering the nonwoven sheet or the fibrous tow to form a rod-shaped element suitable for use as a filter element.

[0046] Embodiment 33: The method according to any one of Embodiments 27 to 32, wherein the step of processing further includes wrapping the rod-shaped element with a wrapping material that circumscribes the rod-shaped element, thereby forming a continuous rod suitable for use as a filter element.

[0047] Embodiment 34: The method according to any one of Embodiments 27 to 33, wherein the step of processing includes crimping the nonwoven sheet or the fibrous tow.

[0048] Embodiment 35: The method according to any one of Embodiments 27 to 34, wherein the crimped nonwoven sheet or the crimped fibrous tow has a crimp depth of from about 1 micron to about 180 microns.

[0049] Embodiment 36: The method of any one of Embodiments 27 to 35, wherein the crimped nonwoven sheet or the crimped fibrous tow has a crimp depth of about 1 micron to about 150 microns.

[0050] Embodiment 37: The method of any one of Embodiments 27 to 36, wherein the crimped nonwoven sheet or the crimped fibrous tow has a crimp depth of about 50 microns to about 100 microns.

[0051] Embodiment 38: The method of any one of Embodiments 27 to 37, further comprising the step of applying a plasticizer to the nonwoven sheet or the fibrous tow.

[0052] Embodiment 39: The method of any one of Embodiments 27 to 38, wherein the plasticizer is triacetin.

[0053] Embodiment 40: The method of any one of Embodiments 27 to 39, further comprising the step of applying a binder to the nonwoven sheet or the fibrous tow.

[0054] Embodiment 41: The method of any one of Embodiments 27 to 40, wherein the binder is selected from the group consisting of polyvinyl alcohol (PVOH), pectin, starch, microfibrillated cellulose (MFC), and combinations thereof.

[0055] Embodiment 42: The method of any one of Embodiments 27 to 41, wherein the nonwoven sheet has a basis weight of about 20 gsm to about 90 gsm.

[0056] Embodiment 43: The method of any one of Embodiments 27 to 42, wherein the nonwoven sheet has a basis weight of about 40 gsm to about 80 gsm.

[0057] Embodiment 44: The method of any one of Embodiments 27 to 43, wherein the nonwoven sheet has a basis weight of about 50 gsm to about 70 gsm.

[0058] Embodiment 45: The method according to any one of Embodiments 27 to 44, wherein the denier per filament (dpf) of the filter material is from about 1 dpf to about 30 dpf.

[0059] Embodiment 46: The method according to any one of Embodiments 27 to 45, wherein the denier per filament (dpf) of the filter material is from about 1 dpf to about 25 dpf.

[0060] Embodiment 47: The method according to any one of Embodiments 27 to 46, wherein the denier per filament (dpf) of the filter material is from about 1 dpf to about 5 dpf.

[0061] Embodiment 48: The method according to any one of Embodiments 27 to 47, wherein the nonwoven sheet has a width of from about 110 mm to about 160 mm.

[0062] Embodiment 49: The method according to any one of Embodiments 27 to 48, wherein the nonwoven sheet has a width of from about 115 mm to about 150 mm.

[0063] These and other features, aspects, and advantages of the present disclosure will become apparent by reading the following detailed description in conjunction with the accompanying drawings, which are briefly described below. The present invention includes any combination of two, three, four, or more of the embodiments described above, as well as any combination of two, three, four, or more of the features or elements specified in the present disclosure, regardless of whether such features or elements are explicitly combined in the description of the specific embodiments herein. The present disclosure is intended to be read as a whole, and as a result, any separable features or elements of the disclosed invention should be regarded as combinable in any of its various aspects and embodiments, unless it is clearly shown otherwise from the context.

[0064] To assist in understanding the embodiments of the present invention, reference is now made to the accompanying drawings, which are not necessarily drawn to scale. The drawings are exemplary only and should not be construed as limiting the present invention.

Brief Description of the Drawings

[0065]

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DETAILED DESCRIPTION OF THE INVENTION

[0066] The present disclosure is now described more fully hereinafter with reference to its exemplary embodiments. These exemplary embodiments are described so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Indeed, the disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. As used herein, and in the appended claims, the singular forms "a", "an", "the" include plural referents unless the context clearly dictates otherwise.

[0067] As described herein, embodiments of the present disclosure relate to filter materials adapted for use as filter elements in aerosol delivery devices, and methods for producing such filter materials. In this regard, filter materials prepared according to the methods described herein can be used in a variety of aerosol delivery devices including, but not limited to, conventional cigarettes, tobacco heated products, heat-not-burn smoking articles, electronic smoking articles, and the like. References to "filter material" or "filter element" do not imply that the material is used for filtration purposes in all embodiments, but only suggest that the material is capable of filtering gas phase and / or particulate phase components of an aerosol to some level in at least some embodiments. In certain embodiments, the filter material may provide other functions not directly related to filtration, such as mouthfeel or other sensory characteristics, or biodegradability, or draw resistance.

[0068] The filter materials according to the present disclosure are typically in the form of a non-woven sheet-like material or in the form of fibrous tows. In such embodiments, the non-woven sheet or fibrous tow typically contains a plurality of fibers therein. In some embodiments, the filter materials according to the present disclosure can be formed of alternative or recycled fibrous materials (in the form of non-woven sheets or fibrous tows). Such alternative fibrous materials can advantageously result in an increase in biodegradability and / or a decrease in plasticity when compared to the types of fibrous inputs used in conventional cigarette filters, such as cellulose acetate. In some embodiments, the filter materials prepared in accordance with the present disclosure can include a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, kenaf, esparto, jute, ramie, wood, reconstituted tobacco, and combinations thereof. As used herein, the term "fiber" is defined as the basic element of a textile fiber. It should be noted that the filter materials of the present disclosure can contain any of the described fibrous inputs individually or in combination with one or more other fibrous inputs. Fibers are often in the form of rope-like or string-like elements. As used herein, the term "fiber" is intended to include fibers, filaments, continuous filaments, staple fibers, and the like.

[0069] In some embodiments, the filter materials described herein may specifically include regenerated cellulose fibers. It should be noted that the filter material may include only regenerated cellulose fibers, or the regenerated cellulose fibers may be combined with one or more other fiber inputs described herein. Regenerated cellulose fibers are typically prepared by extracting non-cellulosic compounds from wood, contacting the extracted wood with caustic soda, followed by carbon disulfide, and then sodium hydroxide to obtain a viscous solution. Subsequently, the solution is passed through a spinneret head to create a viscous thread of regenerated fiber. Exemplary methods for preparing regenerated cellulose are shown in U.S. Patent No. 4,237,274 to Leoni et al.; U.S. Patent No. 4,268,666 to Baldini et al.; U.S. Patent No. 4,252,766 to Baldini et al.; U.S. Patent No. 4,388,256 to Ishida et al.; U.S. Patent No. 4,535,028 to Yokogi et al.; U.S. Patent No. 5,441,689 to Laity; U.S. Patent No. 5,997,790 to Vos et al.; and U.S. Patent No. 8,177,938 to Sumnicht, which are hereby incorporated by reference. The techniques by which regenerated cellulose is made are not limited and may include, for example, both the rayon process and the TENCEL process. Various suppliers of regenerated cellulose are known and include Lenzing (Austria), Cordenka (Germany), Aditya Birla (India), and Daicel (Japan). Examples of regenerated cellulose fibers include, but are not limited to, rayon, viscose, viscose rayon, lyocell, and the like.

[0070] In other embodiments, the filter material of the present disclosure may include hemp fibers. It should be noted that the filter material may include only hemp fibers, or the hemp fibers may be combined with one or more other fiber inputs described herein. Hemp fibers are widely considered to be one of the strongest members of the natural bast fiber family, which are derived from the plant hemp belonging to the plant species Cannabis. Hemp-based fibers are widely used in composite materials and paper-like materials due to their high biodegradability and low density compared to many artificial fibers. An exemplary method for separating and extracting hemp fibers is shown in U.S. Patent No. 8,591,701 to Sung et al., which is incorporated herein by reference. The technique by which the hemp fibers are prepared is not limited and may include any method commonly known in the art. In some embodiments, reconstituted hemp, specifically sheets of reconstituted hemp, may be incorporated into the filter materials described herein.

[0071] In some embodiments, the filter material of the present disclosure may include reconstituted tobacco material. It should be noted that the filter material may include only reconstituted tobacco material, or the reconstituted tobacco material may be combined with one or more other fiber inputs described herein. The tobacco reconstruction process has long converted parts of tobacco that would otherwise be discarded into a commercially useful form. For example, tobacco stems, fragments of tobacco scraps, and tobacco dust can be used to produce reconstituted tobacco of a somewhat uniform density. The exact amount of each type of tobacco in the tobacco blend used in the manufacture of a particular cigarette brand varies from brand to brand. See, for example, Tobacco Encyclopedia, Voges (ed.) pp. 44-45 (1984), Browne, The Design of Cigarettes, 3rd ed., p. 43 (1990), and Tobacco Production, Chemistry and Technology, Davis et al. (eds.), p. 346 (1999). Reconstituted tobacco materials, and sheets of reconstituted tobacco, are commonly used in the tobacco industry, specifically, to prepare wrapping or tipping materials in conventional cigarette rods. Such reconstituted tobacco sheet materials, and methods of forming such sheet materials, are described in U.S. Patent No. 6,705,325 to Hicks et al.; No. 6,827,087 to Wanna et al.; and U.S. Patent Application Publication Nos. 2004 / 0177856 to Monsalud, Jr. et al. and 2005 / 0056294 to Wanna et al., all of which are incorporated herein by reference.

[0072] In some embodiments, the filter material may include one or more coatings, fillers, binders, additives, and / or other components. In such embodiments, the filter material may include both a plurality of fibers and one or more coatings, fillers, binders, additives, surface treatment agents, or other materials applied to or incorporated into them. One such coating can be, for example, a plasticizer, such as triacetin, which is typically applied to conventional filter materials in conventional amounts using known techniques. In some embodiments, the filter material may include a binder. Exemplary binder materials include, but are not limited to, polyvinyl alcohol (PVOH), pectin, starch, microfibrillated cellulose (MFC), and combinations thereof. In other examples, the materials applied to the filter material may be applied in liquid form and may include, for example, substances such as those mentioned above, triacetin, carbowax, flavoring compounds, propylene glycol, triethyl citrate, or any other suitable substance. Further, in this regard, each coating, filler, or other component applied to the filter material can contribute to some functionality or property of the formed filter rod portion, such as, for example, smoke filtration, smoke taste, water dispersibility, biodegradability, and / or compostability.

[0073] As described herein, the fiber feedstock used to form the filter materials of the present disclosure (e.g., regenerated cellulose, hemp, sisal, kenaf, esparto, flax, jute, wood, reconstituted tobacco, and combinations thereof) is typically in continuous filament form and can have various deniers per filament, i.e., “dpf”. The denier per filament is a measure of the weight per unit length of the individual filaments of the fiber and can be manipulated to achieve a desired pressure drop across the filter material or filter element produced from the fiber. An exemplary dpf range for filaments containing the fiber feedstock can be from about 1 dpf to about 30 dpf (e.g., from about 1 dpf to about 25 dpf, from about 1 to about 15 dpf, from about 1 dpf to about 10 dpf, or from about 1 dpf to about 5 dpf), and the denier is expressed in grams / 9000 meters, although larger and smaller filaments can be used without departing from the present disclosure. In some embodiments, the filter material prepared in accordance with the present disclosure can have a dpf of about 30 dpf or less, about 20 dpf or less, about 10 dpf or less, about 5 dpf or less, about 2.5 dpf or less, or about 1.5 dpf or less.

[0074] Some aspects of the present disclosure provide a method for forming a filter material suitable for use as a filter element in a smoking article. In some embodiments, such a method includes forming a nonwoven web of sheet-like material from a plurality of fibers. In other embodiments, the disclosed method may include receiving a pre-formed nonwoven web of sheet-like material that includes a plurality of fibers. In some embodiments, the plurality of fibers can include regenerated cellulose fibers, hemp fibers, sisal fibers, kenaf fibers, esparto fibers, wood fibers, flax fibers, jute fibers, reconstituted tobacco, and combinations thereof. The term "nonwoven" as used herein relates to fibrous materials, webs, mats, bats, or sheets in which the fibers are arranged in an indeterminate or random orientation. Nonwoven fibers are initially presented as unbonded fibers or filaments. An important step in the manufacture of nonwovens involves bonding various fibers or filaments together. The manner in which the fibers or filaments are bonded can vary and can include thermal, mechanical, and chemical techniques that are selected, at least in part, based on the desired properties of the final filter material.

[0075] The nonwoven sheet-like materials described herein can be produced by conventional forming methods that include drylaid, or airlaid, or wetlaid processes. The terms drylaid, airlaid, or wetlaid may be shown as dry-laid, air-laid, or wet-laid, respectively, are broad in meaning, and are known in the art to incorporate a variety of equipment, processes, and means. The use of drylaid, airlaid, and wetlaid is not limiting and does not define a single process for each manufacturing means.

[0076] As used herein, the term "airlaid" generally refers to a process for producing a fibrous mat or batt using short or long staple fibers, or blends thereof. In this process, air is used to transfer fibers from the fiber opening and arranging section of the process and then to carry those fibers to a forming surface where the fibrous mat or batt is collected and then further bonding or consolidation steps are applied to produce an airlaid nonwoven material.

[0077] As used herein, the term "drylaid" generally refers to a process for producing a fibrous mat or batt by a process that uses mechanical fiber opening and arranging, such as carding, where the fibrous mat or batt is transferred to a conveyor surface by mechanical means rather than by air, and further bonding or consolidation steps are applied to the fibrous mat or batt to produce a drylaid nonwoven material.

[0078] As used herein, the term "wetlaid" generally refers to a process for producing a fibrous sheet by means similar to papermaking where the fibers are suspended in an aqueous medium and a web is formed by filtering the suspension on a conveyor belt or a perforated drum. Depending on the end use application and the fibers used to produce the nonwoven material, some means of bonding or consolidation may be required to obtain the final properties of the wetlaid nonwoven material.

[0079] In other embodiments, the nonwoven sheet-like materials described herein can be produced using alternative methods, such as mechanical, thermal or adhesive bonding or forming techniques. For example, mechanical means rely on creating entanglement between and among fibers to produce desired physical properties, and needle punching and hydroentanglement are non-exclusive examples of such means. Other examples of alternative forming techniques include, but are not limited to, spunbonding, meltblowing, spunlacing, carding, point bonding, spinning, and the like.

[0080] In various embodiments, the formed nonwoven material can be processed to obtain a filter material suitable for use in the filter elements for the smoking articles described herein. For example, in some embodiments, the nonwoven web of sheet-like material can be passed through a web preforming unit and pleated to form a rod-like element comprising a plurality of pleats. Reference is made to the filters, devices and methods discussed in, for example, U.S. Patent No. 4,807,809 to Pryor et al., which is hereby incorporated by reference in its entirety.

[0081] The rod-like element can then be circumscribed with a wrapping material, thereby forming a continuous rod that can be used, for example, as a filter element or a segment of a filter element. The width of the sheet-like material can vary and is typically the width at which pleats are formed to form the rod. The overall width of the strip used to obtain the desired rod can depend on factors such as, for example, the thickness of the sheet-like material, the desired number of pleats, the nature or characteristics of the generated pleats, the surface characteristics of the material (i.e., fibrous surface characteristics vs. smooth surface), the porosity of the material, the moisture content of the material, the lubricity of the material, the frictional characteristics of the web preforming apparatus with respect to the sheet-like material, and other such factors. In some embodiments, for example, the nonwoven sheet-like material can have a width in the range of about 110 mm to about 160 mm, about 115 mm to about 150 mm, or about 120 mm to about 140 mm.

[0082] In some embodiments, the non-woven sheet-like material may optionally be creped. "Crepe" is the texture or undulation of individual fibers or the non-woven sheet-like material as a whole. The crepe amplitude or depth, reported in microns in terms of the amplitude or depth of a single crepe, is an indirect measure of the degree of crepe applied to the non-woven sheet-like material. In some embodiments, creping generally involves passing the non-woven sheet-like material through one or more creping or embossing rollers to cause buckling in the non-woven sheet-like material and obtain a creped non-woven sheet. Typically, the non-woven sheet-like material is passed through a creping or embossing roller of a specific depth in order to achieve a desired crepe amplitude / depth in the creped non-woven sheet. In some embodiments, various crepe levels may be provided, or the non-woven sheet-like material may not be creped. For example, in some embodiments, the crepe amplitude / depth can range from about 1 micron to about 180 microns, from about 1 micron to about 150 microns, from about 75 microns to about 150 microns, or from about 50 microns to about 100 microns.

[0083] Some properties known in the art can be used to characterize the web (i.e., paper) of the sheet-like material. Basis weight and caliper are two parameters used to characterize paper. In some embodiments, the basis weight of the paper containing tobacco pulp described herein can range from about 20 to about 90 g / m 2 , from about 40 to about 80 g / m 2 or from about 50 to about 70 g / m 2 . The caliper of the non-woven sheet-like material described herein can range, for example, from about 0.01 to about 4.0 mils, or from about 0.01 to about 1.0 mils, or from about 0.01 to about 0.5 mils.

[0084] Preferred nonwovens and sheet materials are thin and have a relatively high tensile strength, resilience, and relatively good flexibility. Specifically, the web should have a good "hand" such that it holds folds during the folding or pleating process without tearing, wrinkling, crumbling, or breaking. The modulus of elasticity of the web should be such that pleating is facilitated. Specifically, the web should not be so stiff as to resist pleating, nor should the web be so soft as to result in a rod with poor resilience. Thus, the rod-like elements of the pleated web can be conveyed at high speeds and wrapped within an outer wrapping material.

[0085] In some embodiments, a plasticizer and / or binder can be applied to the nonwoven sheet before, during, or after its formation. In some embodiments, a plasticizer and / or binder is added to the pleated nonwoven sheet during rod formation to obtain desired sensory properties and / or to improve the chemical action of the smoke. In some embodiments, plasticizers that can include triacetin and / or carbowax as described herein can be applied to the nonwoven sheet in conventional amounts using known techniques. In some embodiments, a plasticizer and / or binder can be applied to the nonwoven sheet in an amount of from about 0.1 wt% to about 30 wt% based on the total weight of the nonwoven sheet. In certain embodiments, a plasticizer and / or binder can be applied to the nonwoven sheet in an amount of from about 1 wt% to about 20 wt%, from about 3 wt% to about 15 wt%, or from about 6 wt% to about 12 wt% based on the total weight of the nonwoven sheet. For example, a plasticizer and / or binder can be applied to the nonwoven sheet in an amount of at least about 2 wt%, at least about 4 wt%, at least about 6 wt%, at least about 8 wt%, at least about 10 wt%, at least about 12 wt%, at least about 14 wt%, at least about 16 wt%, or at least about 18 wt% based on the total weight of the nonwoven sheet. Other suitable materials used in connection with the construction of the filter element will be readily apparent to those skilled in the art of cigarette filter design and manufacture. See, for example, U.S. Patent No. 5,387,285 to Rivers, which is incorporated herein by reference.

[0086] In some aspects, the present disclosure provides a method for forming a filter material suitable for use in a filter element for a smoking article. In some embodiments, such a method may include, for example, forming a fibrous tow comprising a plurality of fibers rather than forming a nonwoven sheet-like material previously described herein. In other embodiments, the disclosed method may include receiving a previously formed fibrous tow comprising a plurality of fibers. As used herein, "tow fiber" or "fibrous tow" refers to a substantially untwisted bundle of two or more substantially continuous fibers, such as filaments of a plurality of fibers. The material composition of the plurality of fibers forming the fibrous tow may be varied according to the desired properties of the filter element produced from the fibrous tow. In some embodiments, the plurality of fibers forming the fibrous tow may be selected from the group consisting of regenerated cellulose, hemp, sisal, kenaf, esparto, wood, flax, jute, reconstituted tobacco, and combinations thereof.

[0087] Generally, such a method may optionally include blending a plurality of fibers to form a mixed fiber blend; drawing the mixed fiber blend to reduce the denier per filament of the fibers of the mixed fiber blend and form a drawn fiber blend; and crimping the drawn fiber blend to form a mixed fiber tow. The method may include further steps, for example, incorporating the mixed fiber tow into a filter element suitable for use in a smoking article, which typically involves one or more of the steps of blooming the mixed fiber tow and applying a plasticizer to the mixed fiber tow.

[0088] The plurality of fibers are typically not stretched or are partially stretched prior to the blending step so that the fibers do not tend to break during subsequent stretching steps. The arrangement of the plurality of fibers within the blended fiber blend may vary. In certain embodiments, the longitudinal axes of the plurality of fibers in the blended fiber blend are arranged substantially parallel to each other. In another embodiment, the plurality of fibers of the blended fiber blend are arranged such that the fibers are either arranged alternately across the cross-section of the blended fiber blend and are substantially uniformly dispersed relative to each other.

[0089] As described herein, when a plurality of fibers are combined in a blended fiber blend, the blended fiber blend can then be stretched and crimped to form a blended fiber tow. The drawing or stretching process generally reduces the weight / yard of the fiber bundle and increases its length. In such an example, for instance, depending on the scale of the stretching process for the blended fiber blend, following the stretching process, a component yarn with a slightly higher denier per filament may be provided to facilitate achieving the desired total denier and denier per filament of the blended fiber tow. In the blended fiber blend, it may also be desirable to be heated before and / or during the stretching process to facilitate stretching of the fibers therein.

[0090] A typical stretching process consists of a plurality of stretching stages using equipment known in the art. In one embodiment, the blended fiber blend is removed from the creel and passed through several stretching stands, each of which consists of several rollers that apply tension to the fiber blend. Between the stretching stands, the fiber blend can pass through a heated water bath, a steam chamber, a heated roll, or a combination thereof. The number of stretching stands may vary, but typically 2 to 4 stretching stands are used in a typical stretching process.

[0091] Continuing with the stretching, the blended fiber blend may optionally be subjected to a crimping step. "Crimp" is the texture or undulation of the individual fibers or the blended fiber blend as a whole. The crimp amplitude or depth, reported in microns in terms of the amplitude / depth of a single crimp, is an indirect measure of the degree of crimp applied to the blended fiber blend. In some embodiments, the crimping may generally involve passing the fiber bundle through rollers and also into a "stuffing box" or "stuffer box" where friction generates pressure and causes the fibers to buckle. In some embodiments, various crimp levels may be provided, or the blended fiber blend may not be crimped. For example, in some embodiments, the crimp width may range from about 1 micron to about 180 microns, from about 1 micron to about 150 microns, from about 75 microns to about 150 microns, or from about 50 microns to about 100 microns.

[0092] Once the blended fiber tow has been stretched and optionally crimped, the stretched and optionally crimped blended fiber tow can be processed into a filter element for a smoking article in a manner similar to that of conventional cellulose acetate tow. For example, the blended fiber tow can be bloomed to form a filter element for a smoking article, and the blooming process may also involve or be associated with a plasticizing process, where a suitable plasticizer, such as triacetin, carbowax, and / or triethyl citrate, is applied to the bloomed blended fiber tow. Other suitable materials used in connection with the construction of the filter element will be readily apparent to those skilled in the art of cigarette filter design and manufacture. For example, reference is made to U.S. Patent No. 5,387,285 to Rivers, which is incorporated herein by reference.

[0093] One or more rod-making operations may then be performed on the plasticized fiber product. The rod-making operation may include shaping the plasticized fiber product. For example, the plasticized fiber product may be compressed or shaped to form a continuous cylindrical rod shape. The rod-making operation may optionally include cutting the plasticized fiber product into segments. In this regard, the plasticized fiber product may be longitudinally subdivided into filter segments shaped as cylinders. In some embodiments, the length of the filter segment may be selected based on the desired length of the filter element in a single cigarette. For further illustrative purposes, in another embodiment, the filter segment may be cut to a length equal to twice the length of the filter element in a single cigarette, and the filter segment may later be cut in half. For example, the filter segment may connect two tobacco rods, and the filter segment may be separated to form filters for two cigarettes.

[0094] The filter materials, filter elements, and filter rods for aerosol delivery devices generated in accordance with the present disclosure can be used to obtain multi-segment filter rods. Such multi-segment filter rods can be used to produce filtered cigarettes having multi-segment filter elements. The production of multi-segment filter rods can be carried out using the type of rod-forming unit that is used to obtain multi-segment cigarette filter components. The multi-segment cigarette filter rod can be manufactured using a cigarette filter rod manufacturing device available under the brand name Mulfi from Hauni-Werke Korber & Co. KG, Hamburg, Germany. The filter element components or segments of the filter element in a multi-segment filtered cigarette are typically obtained from filter rods produced using conventional types of rod-forming units, such as those available as KDF-2 and KDF-3E from Hauni-Werke Korber & Co. KG. Typically, filter materials, such as filter tow (i.e., esterified form of pulp), are obtained using a tow processing unit. An exemplary tow processing unit is commercially available as the E-60 supplied by Arjay Equipment Corp., Winston-Salem, NC. Other exemplary tow processing units are commercially available as AF-2, AF-3, and AF-4 from Hauni-Werke Korber & Co. KG. Further, representative techniques and methods for operating the filter material supply unit and the filter manufacturing unit are specified in U.S. Patent No. 4,281,671 to Byrne; U.S. Patent No. 4,862,905 to Green, Jr. et al.; U.S. Patent No. 5,060,664 to Siems et al.; U.S. Patent No. 5,387,285 to Rivers; and U.S. Patent No. 7,074,170 to Lanier, Jr. et al.Other types of technology for supplying filter material to a filter rod forming unit are described in U.S. Patent No. 4,807,809 to Pryor et al. and in Raker's No. 5,025,814, which are incorporated herein by reference.

[0095] Smoking articles incorporating filter elements produced in accordance with the present disclosure can be manufactured using traditional types of cigarette making techniques. For example, so-called "six-up" filter rods, "four-up" filter rods, and "two-up" filter rods, which are of the general formats and configurations conventionally used in the manufacture of filtered cigarettes, can be operated using traditional types or suitably modified cigarette rod handling devices, such as tipping devices available as Lab MAX, MAX, MAX S, or MAX 80 from Hauni-Werke Korber & Co. KG. Reference is made to the types of devices described in, for example, U.S. Patent No. 3,308,600 to Erdmann et al., No. 4,281,670 to Heitmann et al., No. 4,280,187 to Reuland et al., No. 6,229,115 to Vos et al., No. 7,296,578 to Read, Jr., and No. 7,434,585 to Holmes, each of which is incorporated herein by reference. The operation of such types of devices will be readily apparent to those skilled in the art of automated cigarette manufacture.

[0096] The dimensions of a representative smoking article according to the present disclosure may vary. In some embodiments, the smoking article according to the present disclosure is rod-shaped and may have a diameter of about 7.5 mm (e.g., a circumference of about 10 mm to about 35 mm, often about 16 mm to about 24 mm) and a total length of about 60 mm to about 150 mm, often about 80 mm to about 144 mm. However, the length of the smoking article may vary. In some embodiments, for example, the smoking article according to the present disclosure may have a total length of about 140 mm or less, about 100 mm or less, about 80 mm or less, about 60 mm or less, or about 40 mm or less. The length of the filter element may also vary. A typical filter element may have a total length of about 15 mm to about 40 mm, often about 20 mm to about 35 mm.

[0097] A filter element and a smoking article prepared according to the method of the present disclosure may exhibit a desirable resistance to draw. For example, a exemplary smoking article comprising a filter element prepared according to the methods described herein exhibits a pressure drop of about 40 mmWG to about 400 mmWG. In certain embodiments, a smoking article comprising a filter element prepared according to the methods described herein may exhibit a pressure drop value of about 100 mmWG to about 350 mmWG, about 150 mmWG to about 325 mmWG, or about 200 mmWG to about 300 mmWG. Typically, the pressure drop value of a smoking article is measured using Filtrona Quality Test Modules (QTM Series) available from Filtrona Instruments and Automation Ltd.

[0098] Filter elements formed in accordance with the present invention typically exhibit equal or even increased hardness compared to filter elements made from conventional cellulose acetate tow. Filter hardness is a measure of the compressibility of the filter material. Test equipment that can be used for the harness test is the D61 automatic hardness tester available from Sodim SAS. This equipment applies a constant load (e.g., 300 g) to the sample for a certain period of time (e.g., 3 - 5 seconds) and digitally presents the compression value as the percentage difference at the average diameter of the filter element. In certain embodiments, filter elements prepared in accordance with the present disclosure can exhibit a hardness in the range of about 70% to about 99%. In some embodiments, filter elements prepared in accordance with the present disclosure can exhibit a hardness of about 75% or more, about 80% or more, about 85% or more, or about 90% or more. Test procedures for cigarette filter hardness are described, for example, in U.S. Patent No. 3,955,406 to Strydom and U.S. Patent No. 4,232,130 to Baxter et al., both of which are incorporated herein by reference.

[0099] Figure 1 illustrates an exploded view of a smoking article in the form of a cigarette 100 that can be generated by the apparatus, system, and method disclosed herein. The cigarette 100 generally includes a cylindrical rod 102 containing a filling or roll of smokable filler material contained within an outer wrapping material 104. The rod 102 has conventionally been referred to as a "tobacco rod." The ends of the tobacco rod 102 are open to expose the smokable filler material. The cigarette 100 is shown having one optional band 106 (e.g., a printed coating containing a film-forming agent such as starch, ethyl cellulose, or sodium alginate) applied to the wrapping material 104, the band circumscribing the cigarette rod 102 laterally with respect to the longitudinal axis of the cigarette 100. That is, the band 106 provides an intersecting region with respect to the longitudinal axis of the cigarette 100. The band 106 can be printed on the inner surface of the wrapping material 104 (i.e., facing the smokable filler material), or, although less preferred, on the outer surface of the wrapping material. The cigarette can possess a wrapping material having one optional band, but the cigarette can also possess a wrapping material having additional optional bands spaced apart, in two, three, or more numbers.

[0100] One end of the tobacco rod 102 has a lit end 108, and at the mouth end 110, a filter element 112 (e.g., including one or more segments of the filter material disclosed herein) is positioned. The filter element 112 can be generated according to the methods described in this disclosure. The filter element 112 can generally have a cylindrical shape, and its diameter can be essentially equal to the diameter of the tobacco rod 102. The filter element 112 is circumscribed along its outer or longitudinal periphery by a layer of outer plug wrap 114 to form the filter element. The filter element is positioned adjacent to one end of the tobacco rod 102 such that the filter element and the tobacco rod are arranged axially in an end-to-end contacting relationship, preferably abutting each other. The ends of the filter element allow air and smoke to pass therethrough.

[0101] A ventilated or air-diluted smoking article may be provided with optional air dilution means, such as a series of perforations 116, each of which extends through the tipping material 118 and the plug wrap 114. The optional perforations 116 may be made by various techniques known to those skilled in the art, such as laser perforation techniques. Alternatively, so-called offline air dilution techniques may be used (e.g., through the use of a porous paper plug wrap and pre-perforated tipping material). In an air-diluted or ventilated cigarette, the amount or degree of air dilution or ventilation may be varied. Frequently, the amount of air dilution in an air-diluted cigarette exceeds about 10 percent, generally exceeds about 20 percent, often exceeds about 30 percent, and sometimes exceeds about 40 percent. Typically, the upper limit level of air dilution in an air-diluted cigarette is less than about 80 percent, and often less than about 70 percent. As used herein, the term "air dilution" is the ratio (expressed as a percentage) of the volume of air drawn through the air dilution means to the total volume of air and smoke drawn through the cigarette and exiting from the most distal mouth end of the cigarette. The filter element 112 may be attached to the tobacco rod 102 using tipping material 118 (e.g., substantially air-impermeable tipping material) that circumscribes both the entire length of the filter element and the adjacent region of the tobacco rod 102. The inner surface of the tipping material 118 is fixed in place, using a suitable adhesive, to the outer surface of the plug wrap 114 and the outer surface of the wrapping material 104 of the tobacco rod 102 so that the filter element and the tobacco rod are connected to each other to form the cigarette 100.

[0102] It should be noted that the types of smoking articles described herein and depicted in the embodiments referred to above do not mean to limit the present disclosure. Specifically, the filter materials and / or filter elements of the present disclosure can be incorporated into a variety of different smoking articles including, but not limited to, conventional cigarettes, heat-not-burn devices, tobacco heating products, electronic smoking articles, aerosol delivery devices, etc. Some examples of smoking articles that may be suitable for use with the filter materials and filter elements described herein are U.S. Patent No. 4,756,318 to Clearman et al., No. 4,714,082 to Banerjee et al., No. 4,771,795 to White et al., No. 4,793,365 to Sensabaugh et al., No. 4,989,619 to Clearman et al., No. 4,917,128 to Clearman et al., No. 4,961,438 to Korte, No. 4,966,171 to Serrano et al., No. 4,969,476 to Bale et al., No. 4,991,606 to Serrano et al., No. 5,020,548 to Farrier et al., No. 5,027,836 to Shannon et al., No. 5,033,483 to Clearman et al., No. 5,040,551 to Schlatter et al., No. 5,050,621 to Creighton et al., No. 5,052,413 to Baker et al., No. 5,065,776 to Lawson, No. 5,076,296 to Nystrom et al., No. 5,076,297 to Farrier et al., No. 5,099,861 to Clearman et al., No. 5,105,835 to Drewett et al., No. 5,105,837 to Barnes et al., No. 5,115,820 to Hauser et al., No. 5,148,821 to Best et al., No. 5,159,940 to Hayward et al., No. 5,178,167 to Riggs et al., No. 5,183,062 to Clearman et al., No. 5,211,684 to Shannon et al., No. 5,240,014 to Deevi et al., No. 5,240,016 to Nichols et al., No. 5,345,955 to Clearman et al., No. 5,396,Disclosed in U.S. Patent No. 911, U.S. Patent No. 5,551,451 to Riggs, U.S. Patent No. 5,595,577 to Bensalem, U.S. Patent No. 5,727,571 to Meiring, U.S. Patent No. 5,819,751 to Barnes, U.S. Patent No. 6,089,857 to Matsuura, U.S. Patent No. 6,095,152 to Beven, and U.S. Patent No. 6,578,584 to Beven, which are hereby incorporated by reference. Additionally, the filter elements of the present invention can be incorporated within types of smoking articles commercially marketed under the brand names "Premier" and "Eclipse" by the R. J. Reynolds Tobacco Company. For example, reference is made to the types of smoking articles described in Chemical and Biological Studies on New Cigarette Prototypes that Heat Instead of Burn Tobacco, R. J. Reynolds Tobacco Company Monograph (1988) and Inhalation Toxicology, 12:5, pages 1 - 58 (2000), which are hereby incorporated by reference.,

[0103] The disclosed filter materials and filter elements have been generally described above herein in connection with embodiments related to smoking articles. However, it should be understood that the mechanisms, components, and features of such smoking articles can be embodied in many different forms and / or in connection with a variety of smoking articles, as would be understood by those of ordinary skill in the art. For example, the filter materials and filter elements provided herein can be used with embodiments of traditional smoking articles (e.g., cigarettes, cigars, pipes), heat - not - burn cigarettes, electronic smoking articles, aerosol delivery devices, etc. Accordingly, the use of the various filter materials and filter elements with the smoking articles described above herein is discussed only as an example in connection with embodiments related to smoking articles, and it should be understood that such filter materials and filter elements can be embodied and used in a variety of other products and devices.,

[0104] Some embodiments of aerosol delivery devices according to the present disclosure use electrical energy to heat a material to form an inhalable substance (e.g., an electrically heated tobacco product). Other embodiments of aerosol delivery devices according to the present disclosure use an ignitable heat source to heat a material (preferably without burning the material to any significant extent) to form an inhalable substance (e.g., a carbon heated tobacco product). Preferably, the material is heated without burning the material to any significant extent. Components of such devices and systems have a form of an article that is sufficiently compact to be considered a handheld device. That is, the use of components of a preferred aerosol delivery device does not produce a smoke product in the sense that the aerosol is mainly derived from by-products of tobacco combustion or pyrolysis. Rather, the use of such a preferred system produces a vapor product derived from the volatilization or vaporization of certain components incorporated therein. In some exemplary embodiments, components of the aerosol delivery device can be characterized as an electronic cigarette, and such an electronic cigarette can incorporate tobacco and / or components derived from tobacco, and thus deliver tobacco-derived components in aerosol form.

[0105] The aerosol delivery device and / or aerosol providing system according to the present disclosure can provide many of the sensations of smoking a cigarette, cigar or pipe (e.g., the stereotypical actions of inhaling and exhaling, the type of taste or flavor, the sensory stimulating effects, the physical sensations, the stereotypical actions of use, the visual cues, e.g., those obtained by visible aerosol) used by smoking tobacco, without burning any of its components to any significant extent. For example, a user of an aerosol delivery device according to some exemplary embodiments of the present disclosure can hold and use the component in a manner very similar to a smoker using a traditional type of smoking article, suck at one end of the piece to inhale the aerosol generated by the piece, puff or inhale at selected time intervals, etc.

[0106] The aerosol delivery devices and / or aerosol providing systems of the present disclosure may also be characterized as vapor generating articles or pharmaceutical delivery articles. Thus, such articles or devices may be adapted to provide one or more substances (e.g., flavorants and / or pharmaceutically active ingredients) in an inhalable form or state. For example, the inhalable substance may be in the form of substantially vapor (i.e., a substance in the gas phase at a temperature below its critical point). Alternatively, the inhalable substance may be in the form of an aerosol (i.e., a suspension of fine solid particles or droplets in a gas). For the purposes of brevity, the term "aerosol" as used herein means any form or type of vapor, gas, and aerosol suitable for human inhalation, whether visible or invisible, and whether considered to be in a smoky form or not. The physical form of the inhalable substance is not necessarily limited by the nature of the device of the present invention, but rather may be determined by the nature of the medium and the inhalable substance itself with respect to whether it exists in a vaporous state or an aerosol state. In some embodiments, the terms "vapor" and "aerosol" may be interchangeable. Thus, for brevity, the terms "vapor" and "aerosol" used to describe aspects of the present disclosure are understood to be interchangeable unless otherwise specified.

[0107] In some embodiments, the aerosol delivery device and / or aerosol providing system of the present disclosure may include a power source (e.g., a power supply), control components (e.g., means for controlling the flow of current from the power source to other components of the article, e.g., for actuating, controlling, regulating, and stopping the power for heating by, for example, individually or as part of a microcontroller to a microprocessor), a heat source (e.g., an electrical resistance heating element or other component, and / or an induction coil or other related component, and / or one or more radiant heating elements), the filter materials described herein, and some combinations of aerosol generating components including a substrate portion capable of obtaining an aerosol when sufficient heat is applied. It should be noted that it is possible to physically combine one or more of the components described above. For example, in one embodiment, a conductive heater trace may be printed on the surface of a substrate material (e.g., a cellulose-based material film) using conductive ink, such that the heater trace can be powered by a power source and used as a resistance heating element. Exemplary conductive inks include inks containing graphene ink and various metals, such as silver, gold, palladium, platinum, and alloys, or other combinations thereof (e.g., silver-palladium or silver-platinum ink), which can be printed on the surface using processes such as gravure printing, flexographic printing, offset printing, screening printing, inkjet printing, or other suitable printing methods.

[0108] In various embodiments, some of these components may be provided within an outer body or shell, which in some embodiments may be referred to as a housing. The overall design of the outer body or shell may vary, and the format or configuration of the outer body that may define the overall size and shape of the aerosol delivery device may vary. Other configurations are possible, but in some embodiments, an elongated body that resembles the shape of a cigarette or cigar may be formed from a single integral housing, or the elongated housing may be formed from two or more separable bodies. For example, the aerosol delivery device may be substantially tubular in shape and thus may include an elongated shell or body that is similar in shape to a conventional cigarette or cigar. In one example, all of the components of the aerosol delivery device are contained within one housing or body. In other embodiments, the aerosol delivery device may include two or more housings that are joined and separable. For example, the aerosol delivery device may have, at one end, a control body that includes a housing containing one or more reusable components (e.g., an accumulator, by way of example a rechargeable battery and / or a rechargeable supercapacitor, as well as various electronics for controlling the operation of the article), and at the other end, an outer body or shell that removably couples thereto and contains disposable parts (e.g., a disposable flavorant-containing aerosol-generating component).

[0109] In other embodiments, the aerosol delivery device and / or aerosol provision system of the present disclosure may generally include an ignitable heat source configured to heat a base material. At least a portion of the base material and / or heat source may be covered by an outer wrap or wrapping, casing, component, module, member, etc. The overall design of the housing is variable, and the format or configuration of the housing that defines the overall size and shape of the aerosol generating components is also variable. Although other configurations are possible, in some aspects, it may be desirable for the overall design, size, and / or shape of these embodiments to be similar to those of a conventional cigarette or cigar. In various aspects, the heat source may be, for example, a base material related to the aerosol-forming material, an extruded structure and / or substrate, tobacco and / or tobacco-related materials, such as materials naturally found in tobacco in solid or liquid form (e.g., beads, sheets, flakes, wraps), either isolated directly from tobacco or synthetically prepared, to generate heat to aerosolize the base material containing such materials.

[0110] The more specific formats, configurations, and arrangements of the various base materials, aerosol generating components, and components within the aerosol delivery device of the present disclosure will become apparent in light of the further disclosure provided below. Additionally, the selection of the various aerosol delivery device components will be understood in view of commercially available electronic aerosol delivery devices. Further, the arrangement of the components within the aerosol delivery device will also be understood in view of commercially available electronic aerosol delivery devices.

[0111] In this regard, FIG. 2 illustrates an aerosol delivery device 200 according to an exemplary embodiment of the present disclosure. The aerosol delivery device 200 may include a control body 202 and an aerosol generating component 204. In various embodiments, the aerosol generating component 204 and the control body 202 may be arranged permanently or detachably in a functional relationship. In this regard, FIG. 2 illustrates an aerosol delivery device 200 in a connected configuration, while FIG. 3 illustrates an aerosol delivery device 200 in a separated configuration. Various mechanisms can connect the aerosol generating component 204 to the control body 202 to obtain screwing, press-fitting engagement, interference fit, slip fit, magnetic engagement, etc.

[0112] In various embodiments, the aerosol delivery device 200 according to an exemplary embodiment of the present disclosure may have a variety of overall shapes including, but not limited to, an overall shape defined as being substantially rod-shaped, or substantially tubular-shaped, or substantially cylindrical-shaped. In the embodiments of FIGS. 2-3, the device 200 has a substantially circular cross-section, but other cross-sectional shapes (e.g., elliptical, square, triangular) are also encompassed by the present disclosure. For example, in some embodiments, one or both of the control body 202 or the aerosol generating component 204 (and / or any sub-components) may have a substantially rectangular shape, such as a substantially rectangular cuboid shape. In other embodiments, one or both of the control body 202 or the aerosol generating component 204 (and / or any sub-components) may have other handheld shapes. For example, in some embodiments, the control body 202 may have a small box shape, various pod mode shapes, or a fob shape. Thus, such terms, which are descriptions of the physical shape of the article, may also be applied to their individual components including the control body 202 and the aerosol generating component 204.

[0113] The arrangement of components within the aerosol delivery device of the present disclosure may vary across various embodiments. In some embodiments, the substrate portion may be positioned proximate to the heat source so as to maximize aerosol delivery to the user. However, other configurations are not excluded. Generally, the heat source is positioned sufficiently close to the substrate portion such that heat from the heat source volatilizes the substrate portion (as well as, in some embodiments, one or more fragrance substances, active ingredients, etc. that may also be provided for delivery to the user) to form an aerosol that can be delivered to the user. When the heat source heats the substrate portion, an aerosol is formed, released, or generated in a physical form suitable for inhalation by the consumer. It should be noted that the foregoing terms are interchangeable such that references to release, releasing, releases, or released are meant to include form or generate, forming or generating, forms or generates, and formed or generated. Specifically, the inhalable substance is released in the form of vapor or aerosol or a mixture thereof, and such terms are also used interchangeably herein unless specified otherwise.

[0114] As described above, the aerosol delivery devices 200 of various embodiments can incorporate a battery and / or other power source to provide a flow of current sufficient to provide various functionalities to the aerosol delivery device, such as powering a heat source, powering a control system, and powering an indicator. As will be discussed in more detail below, the power source can take various forms. Preferably, the power source can deliver sufficient power to rapidly operate the heat source to form an aerosol and power the aerosol delivery device through a desired duration of use. In some embodiments, the power source is sized to fit conveniently within the aerosol delivery device such that the aerosol delivery device is easily handled. Examples of useful power sources preferably include rechargeable lithium ion batteries (e.g., rechargeable lithium-manganese dioxide batteries). Specifically, lithium polymer batteries can be used such that such batteries can provide enhanced safety. Other types of batteries, such as N50-AAA CADNICA nickel-cadmium batteries, can also be used. Further, the preferred power source is sufficiently lightweight so as not to detract from the desired smoking experience. Some examples of possible power sources are described in U.S. Patent No. 9,484,155 to Peckerar et al. and U.S. Patent Application Publication No. 2017 / 0112191 to Sur et al., the disclosures of which are incorporated herein by reference in their entireties, respectively.

[0115] In a specific embodiment, one or both of the control body 202 and the aerosol generating component 204 may be said to be disposable or reusable. For example, the control body 202 may have a replaceable battery or rechargeable battery, a solid-state battery, a thin-film solid-state battery, a rechargeable supercapacitor, etc., and thus connections to a wall charger, connections to an in-vehicle charger (i.e., a cigarette lighter receptacle), and connections to a computer through, for example, a Universal Serial Bus (USB) cable or connector (e.g., USB 2.0, 3.0, 3.1, USB Type-C), connections to a photovoltaic cell (often referred to as a solar cell) or a solar panel of a solar cell, a wireless charger, for example, a charger using inductive wireless charging (including, for example, wireless charging according to the Qi wireless charging standard from the Wireless Power Consortium (WPC)), or a charger based on wireless radio frequency (RF), and can be combined with any type of recharge technology. An example of an inductive wireless charging system is described in U.S. Patent Application Publication No. 2017 / 0112196 to Sur et al., which is incorporated herein by reference in its entirety. Further, in some embodiments, the aerosol generating component 204 may include a single-use device. A single-use component for use with a control body is disclosed in U.S. Patent No. 8,910,639 to Chang et al., which is incorporated herein by reference in its entirety.

[0116] In a further embodiment, the power source may also include a capacitor. A capacitor can discharge more quickly than a battery, can be charged during puffs, and the battery can discharge into the capacitor at a lower rate than when used to directly power a heat source. For example, a supercapacitor, such as an electric double-layer capacitor (EDLC), can be used separately from or in combination with a battery. When used alone, the supercapacitor can be recharged before each use of the article. Thus, the device may also include a charger component that can be attached to the smoking article during use to recharge the supercapacitor.

[0117] Additional components may be utilized in the aerosol delivery devices of the present disclosure. For example, the aerosol delivery device may include a flow rate sensor (e.g., puff actuation switch) that is sensitive to pressure changes or airflow changes when the consumer inhales on the article. Other conceivable current actuation / deactuation mechanisms may include a temperature-activated on / off switch or a lip pressure-activated switch. Exemplary mechanisms that can provide such puff actuation capabilities include the Model 163PC01D36 silicon sensor manufactured by the MicroSwitch Division of Honeywell, Inc., Freeport, Ill. Representative flow rate sensors, current regulating components, and other current control components including various microcontrollers, sensors, and switches for aerosol delivery devices are described in U.S. Patent No. 4,735,217 to Gerth, all of U.S. Patent Nos. 4,922,901, 4,947,874, and 4,947,875 to Brooks, U.S. Patent No. 5,372,148 to McCafferty, U.S. Patent No. 6,040,560 to Fleischhauer, U.S. Patent No. 7,040,314 to Nguyen, and U.S. Patent No. 8,205,622 to Pan, all of which are hereby incorporated by reference in their entirety. Reference is also made to the control scheme described in U.S. Patent No. 9,423,152 to Ampolini, which is hereby incorporated by reference in its entirety.

[0118] In another example, the aerosol delivery device can include a first conductive surface configured to contact a first body part of a user holding the device and a second conductive surface that is conductively insulated from the first conductive surface and configured to contact a second body part of the user. Thus, if the aerosol delivery device detects a change in conductivity between the first conductive surface and the second conductive surface, the vaporizer can be operated to vaporize the substance, and as a result, the vapor can be inhaled by the user holding the unit. The first body part and the second body part can be part of the lips or the hand(s). The two conductive surfaces can also be used to charge a battery contained in the personal vaporizer unit. The two conductive surfaces can also form or be part of a connector that can be used to output data stored in the memory. Reference is made to U.S. Patent No. 9,861,773 to Terry et al., which is incorporated herein by reference in its entirety.

[0119] Furthermore, U.S. Patent No. 5,154,192 to Sprinkel et al. discloses an indicator for a smoking article, U.S. Patent No. 5,261,424 to Sprinkel Jr. discloses a piezoelectric sensor associated with the mouth end of a device that detects the movement of a user's lips involving suction and then induces heating of a heating device, U.S. Patent No. 5,372,148 to McCafferty et al. discloses a puff sensor for controlling the energy flow into a heating load array in response to a pressure drop through a mouthpiece, U.S. Patent No. 5,967,148 to Harris et al. discloses an identifier that detects non-uniformity in the infrared transmittance of an inserted component and a receptacle within a smoking device that includes a controller that executes a detection routine when the component is inserted into the receptacle, U.S. Patent No. 6,040,560 to Fleischhauer et al. describes a defined executable power cycle having a plurality of differential phases, U.S. Patent No. 5,934,289 to Watkins et al. discloses a photonic optoelectronic component, U.S. Patent No. 5,954,979 to Counts et al. discloses means for varying the draw resistance through a smoking device, U.S. Patent No. 6,803,545 to Blake et al. discloses a particular battery configuration for use in a smoking device, U.S. Patent No. 7,293,565 to Griffen et al. discloses various charging systems for use with a smoking device, U.S. Patent No. 8,402,976 to Fernando et al. discloses computer interfacing means for a smoking device that facilitates charging and enables computer control of the device, U.S. Patent No. 8,689,804 to Fernando et al. discloses an identification system for a smoking device, and International Application No. 2010 / 003480 by Flick discloses a puff display flow sensing system in an aerosol generation system. All of the foregoing disclosures are hereby incorporated by reference in their entirety into this specification.

[0120] Further examples of components related to electronic aerosol delivery articles, and disclosed materials or components that may be used in the present device, include U.S. Patent No. 4,735,217 to Gerth, U.S. Patent No. 5,249,586 to Morgan, U.S. Patent No. 5,666,977 to Higgins, U.S. Patent No. 6,053,176 to Adams, U.S. Patent No. 6,164,287 to White, U.S. Patent No. 6,196,218 to Voges, U.S. Patent No. 6,810,883 to Felter, U.S. Patent No. 6,854,461 to Nichols, U.S. Patent No. 7,832,410 to Hon, U.S. Patent No. 7,513,253 to Kobayashi, U.S. Patent No. 7,896,006 to Hamano, U.S. Patent No. 6,772,756 to Shayan, U.S. Patent Nos. 8,156,944 and 8,375,957 to Hon, U.S. Patent No. 8,794,231 to Thorens, U.S. Patent No. 8,851,083 to Oglesby, U.S. Patent Nos. 8,915,254 and 8,925,555 to Monsees, U.S. Patent No. 9,220,302 to DePiano, U.S. Patent Application Publication Nos. 2006 / 0196518 and 2009 / 0188490 to Hon, U.S. Patent Application Publication No. 2010 / 0024834 to Oglesby, U.S. Patent Application Publication No. 2010 / 0307518 to Wang, International Application No. 2010 / 091593 to Hon, and International Application No. 2013 / 089551 to Foo, each of which is incorporated herein by reference in its entirety. Further, U.S. Patent Application Publication No. 2017 / 0099877 to Worm discloses capsules that may be included in an aerosol delivery device and a fob-shaped configuration for an aerosol delivery device, and is incorporated herein by reference in its entirety. The diverse materials disclosed by the foregoing documents may be incorporated into the present device in various embodiments, and all of the foregoing disclosures are incorporated herein by reference in their entirety.

[0121] Referring to FIG. 3, in the described embodiment, the aerosol generating component 204 includes a heated tip 206 configured to be inserted into the control body 202 and a mouth end 208 through which the user draws to create an aerosol. At least a portion of the heated tip 206 may include a substrate portion 210. In some embodiments, the substrate portion 210 is loaded with an aerosol-forming material. In various embodiments, the substrate portion 210 may include various materials impregnated with an aerosol-forming material. In various embodiments, the aerosol generating component 204, or a portion thereof, may be wrapped with an outer wrap material 212. In various embodiments, the mouth end 208 of the aerosol generating component 204 includes a filter element 214 that may be made of at least one segment of a filter material (i.e., a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, flax, jute, esparto, kenaf, wood fibers, reconstituted tobacco, and combinations thereof) as described hereinabove. In various embodiments, the filter element 214 can improve the structural integrity of the mouth end of the aerosol source member and / or, optionally, produce a filtering performance and / or a draw resistance. In some embodiments, the filter element may include individual segments as described herein. For example, some embodiments may include a segment that produces filtration, a segment that produces draw resistance, a hollow segment that provides a space for the aerosol to cool, a segment that improves structural integrity, other filter segments, and any one or any combination of the above.

[0122] In some embodiments, the material of the wrapper overlap 212 can include a material that resists heat transfer, which can include paper or other fibrous materials, such as cellulose materials. The wrapper overlap material can also include at least one filler material embedded or dispersed within the fibrous material. In various embodiments, the filler material can be in the form of water-insoluble particles. Further, the filler material can incorporate inorganic components. In various embodiments, the wrapper overlap can be formed of multiple layers, such as a base bulk layer and a coating layer, such as a typical wrapping paper in a cigarette. Such materials can include, for example, lightweight “rag fibers” such as flax, hemp, sisal, straw and / or esparto. The wrapper overlap can also include materials typically used in conventional cigarette filter elements, such as cellulose acetate. Further, an excessive length of wrapper overlap at the mouth end 208 of the aerosol-generating component can serve to simply separate the substrate portion 210 from the consumer's oral cavity, or provide a space for positioning the filter material, or affect the draw on the article, or affect the flow characteristics of the vapor or aerosol exiting the device during draw, as described below. Further considerations regarding the composition of wrapper overlap materials that can be used with the present disclosure can be found in U.S. Patent No. 9,078,473 to Worm et al., which is incorporated herein by reference in its entirety.

[0123] FIG. 4 illustrates a perspective schematic view of an aerosol-generating component according to an exemplary embodiment of the present disclosure. Specifically, FIG. 4 illustrates an aerosol-generating component 204 having a substrate portion 210 that includes a series of overlapping layers 230 of a sheet-shaped substrate 220. With respect to the above description, in the depicted embodiment, the substrate sheet 220 includes the films or layers disclosed herein. In various embodiments, the term “overlapping layers” can include bundled, wrinkled, crimped, and / or otherwise assembled layers where the individual layers may not be distinct.

[0124] Figure 5 illustrates a schematic cross - sectional view of a substrate portion of an aerosol - generating component according to an exemplary embodiment of the present disclosure. Specifically, Figure 5 illustrates a substrate portion 210 that includes a series of overlapping layers 230 of a substrate sheet 220. In the depicted embodiment, at least a portion of the overlapping layers 230 is substantially surrounded by a first cover layer 232 around its outer surface. In various embodiments, the composition of the first cover layer 232 may vary, but in the depicted embodiment, the first cover layer 232 includes a combination of a fibrous material, an aerosol - forming material, and a binder material. Reference is made to the discussion herein regarding possible aerosol - forming materials and binder materials. In various embodiments, the first cover layer 232 may be constructed via a casting process, such as that described in U.S. Patent No. 5,697,385 to Seymour et al., the disclosure of which is incorporated herein by reference in its entirety.

[0125] In the depicted embodiment, at least a portion of the overlapping layers 230 and the first cover layer 232 are substantially surrounded by a second cover layer 234 around the outer surface. The composition of the second cover layer 234 may vary, but in the depicted embodiment, the second cover layer 234 includes a metallic foil material, such as an aluminum foil material. In other embodiments, the second cover layer may include a copper material, a tin material, a gold material, an alloy material, a ceramic material, or other thermally conductive amorphous carbon - based materials, and / or other materials including, but not limited to, any combination thereof. The depicted embodiment further includes a third cover layer 236 that substantially surrounds the overlapping layers 230, the first cover layer 232, and the second cover layer 234 around their outer surfaces. In the depicted embodiment, the third cover layer 236 includes a paper material, such as a conventional cigarette wrapping paper. In various embodiments, the paper material may include rag fibers, such as non - wood plant fibers, and may include flax, hemp, sisal, straw, and / or esparto fibers.

[0126] Referring again to FIG. 3, in various embodiments, other components may be present between the base substrate portion 210 and the mouth end 208 of the aerosol-generating component 204. For example, in some embodiments, one or any combination of the following may be positioned between the base substrate portion 210 and the mouth end 208 of the aerosol-generating component 204: a void, a hollow tubular structure, a phase change material for cooling air, a flavorant release medium, an ion exchange fiber capable of selective chemisorption, aerogel particles as a filter medium, and other suitable materials. Some examples of possible phase change materials include salts such as AgNO3, AlCl3, TaCl3, InCl3, SnCl2, AlI3, and TiI4; metals and metal alloys such as selenium, tin, indium, tin-zinc, indium-zinc, or indium-bismuth; and organic compounds such as D-mannitol, succinic acid, p-nitrobenzoic acid, hydroquinone, and adipic acid, but are not limited thereto. Other examples are described in U.S. Patent No. 8,430,106 to Potter et al., which is incorporated herein by reference in its entirety.

[0127] FIG. 6 illustrates a perspective view of an aerosol delivery device according to another exemplary embodiment of the present disclosure, and FIG. 7 illustrates a perspective view of the aerosol-generating component of FIG. 6 with the outer wrap removed. Specifically, FIG. 6 illustrates an aerosol delivery device 300 that includes an outer wrap 302, and FIG. 7 illustrates the aerosol delivery device 300 with the outer wrap 302 removed to reveal the other components of the aerosol delivery device 300. In the illustrated embodiment, the aerosol delivery device 300 of the illustrated embodiment includes a heat source 304, a base substrate portion 310, an intermediate component 308, and a filter element 312. In the illustrated embodiment, the intermediate component 308 and the filter element 312 together include a mouthpiece 314.

[0128] In various embodiments, the heat source 304 can be configured to generate heat upon its ignition. In the depicted embodiment, the heat source 304 generally has a cylindrical shape and includes a combustible fuel element incorporating a combustible carbonaceous material. In other embodiments, the heat source 304 can have a different shape, such as a prism shape having a triangular, cubic, or hexagonal cross-section. The carbonaceous material generally has a high carbon content. Some exemplary carbonaceous materials can consist primarily of carbon and / or typically have a carbon content of more than about 60 percent, generally more than about 70 percent, often more than about 80 percent, and frequently more than about 90 percent on a dry weight basis.

[0129] In some examples, the heat source 304 can incorporate elements other than the combustible carbonaceous material (such as tobacco components, for example powdered tobacco or tobacco extracts; flavorants; salts, such as sodium chloride, potassium chloride, and sodium carbonate; thermally stable graphite fibers; iron oxide powder; glass filaments; powdered calcium carbonate; alumina granules; ammonia sources, such as ammonium salts; binders, such as guar gum, ammonium alginate, and sodium alginate; and / or phase change materials for reducing the temperature of the heat source described hereinabove). The specific dimensions of the applicable heat source can vary, but in some embodiments, the heat source 304 can have an overall length in the inclusive range of approximately 7 mm to approximately 20 mm, and in some embodiments can be approximately 17 mm, and can have an overall diameter in the inclusive range of approximately 3 mm to approximately 8 mm, and in some embodiments can be approximately 4.8 mm (and in some embodiments can be approximately 7 mm). In other embodiments, the heat source can be constructed in various ways, but in the depicted embodiment, the heat source 304 is extruded or compounded using a pulverized or powdered carbonaceous material and has a bulk density of more than about 0.5 g / cm 3 above, often more than about 0.7 g / cm 3 above, frequently more than about 1 g / cm 3It has an ultra-high density. For example, reference is made to the types of components, formulations, and designs of fuel sources as described in U.S. Patent No. 5,551,451 to Riggs et al. and U.S. Patent No. 7,836,897 to Borschke et al., which are hereby incorporated by reference in their entirety. In various embodiments, the heat source can have a variety of forms, including, for example, a substantially solid cylindrical shape or a hollow cylindrical (e.g., tube) shape. However, the heat source 304 of the described embodiment includes an extruded monolithic carbonaceous material, which generally has a cylindrical shape and has a plurality of grooves 316 extending longitudinally from a first end of the extruded monolithic carbonaceous material to an opposing second end of the extruded monolithic carbonaceous material. In some embodiments, the aerosol delivery device, and in particular the heat source, can include heat transfer components. In various embodiments, the heat transfer components may be in proximity to the heat source, and in some embodiments, the heat transfer components may be located within or in the heat source. Some examples of heat transfer components are described in U.S. Patent Application Publication No. 2019 / 0281891 to Hejazi et al., which is hereby incorporated by reference in its entirety.

[0130] In the described embodiments, the grooves 316 of the heat source 304 are substantially equal in width and depth and are substantially equally distributed around the circumference of the heat source 304. However, other embodiments may include only two grooves, and still other embodiments may include only a single groove. Still other embodiments may not include any grooves at all. Additional embodiments may include a plurality of grooves that may have unequal widths and / or depths and may be unevenly spaced around the circumference of the heat source. In still other embodiments, the heat source may include flutes and / or slits that extend longitudinally from a first end of the extruded monolithic carbonaceous material to its opposing second end. In some embodiments, the heat source may include a foamed carbon monolith formed by a foaming process of the type disclosed in Lobovsky U.S. Patent No. 7,615,184, which is hereby incorporated by reference in its entirety. Accordingly, some embodiments may provide advantages with respect to reducing the time required to ignite the heat source. In some other embodiments, the heat source is extruded simultaneously with a layer of insulation (not shown), thereby reducing manufacturing time and cost. Other embodiments of the fuel component include carbon fibers of the type described in Brooks et al. U.S. Patent No. 4,922,901, or other heat source embodiments are disclosed, for example, in Takeuchi et al. U.S. Patent Application Publication No. 2009 / 0044818, each of which is hereby incorporated by reference in its entirety.

[0131] Generally, a heat source is positioned in close proximity to a substrate portion carrying one or more aerosol-forming materials such that an aerosol formed / volatilized by applying heat from the heat source to the aerosol-forming material (as well as any flavorants, pharmaceuticals, etc. also provided for delivery to the user) can be delivered to the user by means of a mouthpiece. That is, when the heat source heats the substrate portion, the aerosol is formed, released or generated in a physical form suitable for inhalation by the consumer. It should be noted that the foregoing terms are interchangeable such that references to emitting, emits, emitting, or emitted are meant to include forming or generating, forms or generates, forms or generates, and formed or generated. Specifically, the inhalable substance is released in the form of a vapor or an aerosol or a mixture thereof.

[0132] Referring again to FIGS. 6 and 7, the outer wrap 302 can be provided to engage or join at least a portion of the heat source 304 with at least a portion of the substrate portion 310 and the mouthpiece 314. In various embodiments, the outer wrap 302 is configured to be retained at the wrapped position by any means of attachment, including by an adhesive or a fastener, etc., to enable the outer wrap 302 to remain at the wrapped position. Otherwise, in some other aspects, the outer wrap 302 can be configured to be removable if desired. For example, when retaining the outer wrap 302 at the wrapped position, the outer wrap 302 can be removable from the heat source 304, the substrate portion 310, and / or the mouthpiece 314.

[0133] In some embodiments, in addition to the outer wrap 302, the aerosol delivery device may also include a liner configured to circumscribe at least a portion of the substrate portion 310 and the heat source 304. In other embodiments, the liner may circumscribe only a portion of the length of the substrate portion 310, but in some embodiments, the liner may circumscribe substantially the entire length of the substrate portion 310. In some embodiments, the outer wrap material 302 may include the liner. Thus, in some embodiments, the outer wrap material 302 and the liner may be another material provided together (e.g., bonded, fused, or joined together as a laminate). In other embodiments, the outer wrap 302 and the liner may be the same material. In any case, the liner may be configured to thermally condition the conduction of heat generated by the ignited heat source 304 radially outside of the liner. Thus, in some embodiments, the liner may be composed of a metallic foil material, an alloy material, a ceramic material, or other thermally conductive amorphous carbon-based material, and / or an aluminum material, and in some embodiments, may include a laminate. In some embodiments, depending on the material of the outer wrap 302 and / or the liner, a thin layer of insulation may be provided radially outside of the liner. Thus, the liner advantageously provides in several ways a means of engaging two or more other components of the aerosol delivery device 300 (e.g., the heat source 304, the substrate portion 310, and / or a portion of the mouthpiece 314), along which it promotes axial heat transfer, but also provides a means of restricting heat conduction radially outward.

[0134] As shown in FIG. 6, the outer wrap 302 (and optionally the liner and substrate portion 310) may also include one or more openings formed therethrough, which allow air to enter when the mouthpiece 314 is suctioned. In various embodiments, the size and number of these openings may vary based on specific design requirements. In the depicted embodiment, a plurality of openings 320 are located proximate the end of the substrate portion 310 closest to the heat source 304, and a plurality of additional cooling openings 321 are formed in the outer wrap 302 (and also the liner in some embodiments) in the region proximate the filter 312 of the mouthpiece 314. While other embodiments may vary, in the depicted embodiment, the openings 320 include a plurality of openings that are substantially evenly spaced around the outer surface of the aerosol delivery device 300, and the openings 321 also include a plurality of openings that are substantially evenly spaced around the outer surface of the aerosol delivery device 300. In various embodiments, the plurality of openings may be formed through the outer wrap 302 (and also the liner in some embodiments) in a variety of ways, but in the depicted embodiment, the plurality of openings 320 and the plurality of additional cooling openings 321 are formed by laser drilling.

[0135] Referring again to FIG. 7, the aerosol delivery device 300 of the depicted embodiment also includes an intermediate component 308 and at least one filter element 312. It should be noted that in various embodiments, the intermediate component 308 or the filter element 312, individually or together, can be considered the mouthpiece 314 of the aerosol delivery device 300. In the depicted embodiment, the intermediate component 308 includes a hollow tubular structure and is included to add structural integrity to the aerosol delivery device 300 and to cool the generated aerosol. In some embodiments, the intermediate component 308 can be used as a container for collecting the aerosol. In various embodiments, such components can be constructed from any of a variety of materials and can include one or more adhesives. Exemplary materials include, but are not limited to, paper, paper layers, cardboard, plastic, cardboard and / or composite materials. In the depicted embodiment, the intermediate component 308 includes a hollow cylindrical element composed of a paper or plastic material (such as ethyl vinyl acetate (EVA) or other polymeric materials, by way of example polyethylene, polyester, silicone, or ceramic (such as silicon carbide, alumina), or other acetate fibers), and the filter element includes at least one segment of a filter material described hereinabove (such as a filter element including a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, flax, sisal, jute, kenaf, wood, reconstituted tobacco and combinations thereof).

[0136] As described, in some embodiments, the mouthpiece 314 may include a filter element 312 configured to receive an aerosol therethrough in response to suction applied to the mouthpiece 314. In various embodiments, the filter element 312 is provided as a disk that is radially and / or longitudinally aligned proximate the second end of the intermediate component 308 in some aspects. In this way, when the mouthpiece 314 is suctioned, the filter element 312 receives the aerosol flowing through the intermediate component 308 of the aerosol delivery device 300. In some embodiments, the filter element 312 may include individual segments. For example, some embodiments may include segments that cause filtration, segments that cause suction resistance, hollow segments that provide a space in which the aerosol is cooled, segments that improve structural integrity, other filter segments, and any one or any combination of the above.

[0137] In various embodiments, the size and shape of the intermediate component 308 and / or the filter element 312 may vary. For example, the length of the intermediate component 308 may be in an inclusive range of approximately 10 mm to approximately 30 mm, the diameter of the intermediate component 308 may be in an inclusive range of approximately 3 mm to approximately 8 mm, the length of the filter element 312 may be in an inclusive range of approximately 10 mm to approximately 20 mm, and the diameter of the filter element 312 may be in an inclusive range of approximately 3 mm to approximately 8 mm. In the described embodiments, the intermediate component 308 has a length of approximately 20 mm and a diameter of approximately 4.8 mm (and in some embodiments, approximately 7 mm), and the filter element 312 has a length of approximately 15 mm and a diameter of approximately 4.8 mm (or in some embodiments, approximately 7 mm).

[0138] In various embodiments, ignition of the heat source 304 causes aerosolization of the aerosol-forming material associated with the substrate portion 310. In certain embodiments, the elements of the substrate portion 310 do not undergo any significant degree of pyrolysis (e.g., charring, burning, or combustion), and the aerosolized components are taken up through the aerosol delivery device 300, which includes the filter element 312, and into the air drawn into the user's oral cavity. In various embodiments, the mouthpiece 314 (e.g., the intermediate component 308 and / or the filter element 312) is configured to receive the generated aerosol in response to suction applied to the mouthpiece 314 by the user. In some embodiments, the mouthpiece 314 can be engaged with the substrate portion 310 so as not to move. For example, adhesives, bonds, welding can be suitable for engaging the mouthpiece 314 to the substrate portion 310 so as not to move. In one example, the mouthpiece 314 is ultrasonically welded and sealed to the end of the substrate portion 310.

[0139] The aerosol delivery device and / or aerosol providing system according to the present disclosure can take a variety of embodiments as discussed in detail above, but the use of the aerosol delivery device and / or aerosol providing system by a consumer is similar with respect to the scope. The foregoing description of the use of the aerosol delivery device and / or aerosol providing system is applicable to the various embodiments described with some modifications, which will become apparent to those skilled in the art in light of the further disclosure provided herein. However, the description of the use is not intended to limit the use of the articles of the present disclosure and is shown to comply with all of the essential requirements of the disclosure herein.

[0140] Many modifications and other embodiments of the present disclosure will come to mind to those of ordinary skill in the art to which this disclosure pertains having the benefit of the teachings presented in the foregoing description and the related drawings. Therefore, it is to be understood that the disclosure is not to be limited to the specific embodiments disclosed herein and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a general and descriptive sense only and not for purposes of limitation.

[0141] Experiment Aspects of the invention are more fully illustrated by the following examples, which are set forth to illustrate certain aspects of the invention and are not to be construed as limiting thereof.

Examples

[0142] Example 1 Tests were conducted to evaluate various properties (e.g., tensile strength, elongation) of filter materials formed from regenerated cellulose or hemp fibers as compared to conventional filter materials formed from cellulose acetate fibers. Additionally, four different binder materials (including, for example, polyvinyl alcohol (PVOH), pectin, starch, and microfibrillated cellulose (MFC)) were evaluated in combination with each of the different fiber materials used.

[0143] The preparation of the filter materials required the formation of wet-laid nonwoven materials by conventional wet-laid papermaking techniques. Twelve different nonwoven materials (labeled samples "A - L" in Table 1 below) were prepared using a combination of one fiber and one binder material. Three replicate samples of each of the twelve nonwoven materials were prepared, and the composition of each sample is discussed in more detail below.

[0144] Samples A1 - A3 represent wet-laid nonwoven materials containing approximately 95% cellulose acetate ("CA") and approximately 4% polyvinyl alcohol (PVOH), each having basis weights of 57.6 gsm, 62.3 gsm, and 62.7 gsm, respectively.

[0145] Samples B1 - B3 represent wet - laid non - woven fabric materials containing approximately 95% regenerated cellulose and approximately 4% polyvinyl alcohol (PVOH), each having basis weights of 59.6 gsm, 64 gsm, and 62.7 gsm respectively.

[0146] Samples C1 - C3 represent wet - laid non - woven fabric materials containing approximately 70% abaca hemp pulp, approximately 26% raw hemp fibers having a length of about 20 mm, and approximately 4% polyvinyl alcohol (PVOH), each having basis weights of 69 gsm, 61.2 gsm, and 63 gsm respectively.

[0147] Samples D1 - D3 represent wet - laid non - woven fabric materials containing approximately 95% cellulose acetate (“CA”) and approximately 4% pectin, each having basis weights of 61.5 gsm, 61.5 gsm, and 61.2 gsm respectively.

[0148] Samples E1 - E3 represent wet - laid non - woven fabric materials containing approximately 95% regenerated cellulose and approximately 4% pectin, each having basis weights of 58.9 gsm, 60.3 gsm, and 60.6 gsm respectively.

[0149] Samples F1 - F3 represent wet - laid non - woven fabric materials containing approximately 70% abaca hemp pulp, approximately 26% raw hemp fibers having a length of about 20 mm, and approximately 4% pectin, each having basis weights of 61.3 gsm, 60.2 gsm, and 64.3 gsm respectively.

[0150] Samples G1 - G3 represent wet - laid non - woven fabric materials containing approximately 95% cellulose acetate (“CA”) and approximately 4% starch, each having basis weights of 61.23 gsm, 61.74 gsm, and 61.23 gsm respectively.

[0151] Samples H1 - H3 represent wet - laid non - woven fabric materials containing approximately 95% regenerated cellulose and approximately 4% starch, each having basis weights of 61.23 gsm, 58.28 gsm, and 58.54 gsm respectively.

[0152] Samples I1 - I3 represent wet - laid non - woven fabric materials containing approximately 70% abaca hemp pulp, approximately 26% raw hemp fibers having a length of about 20 mm, and approximately 4% starch, each having basis weights of 61.2 gsm, 64.2 gsm, and 60.7 gsm respectively.

[0153] Samples J1 - J3 represent wet - laid non - woven fabric materials containing approximately 95% cellulose acetate (「CA」) and approximately 4% microfibrillated cellulose (MFC), each having basis weights of 61.5 gsm, 60.8 gsm, and 61.1 gsm respectively.

[0154] Samples K1 - K3 represent wet - laid non - woven fabric materials containing approximately 95% regenerated cellulose and approximately 4% microfibrillated cellulose (MFC), each having basis weights of 58.6 gsm, 58.9 gsm, and 60.2 gsm respectively.

[0155] Samples L1 - L3 represent wet - laid non - woven fabric materials containing approximately 70% abaca hemp pulp, approximately 26% raw hemp fibers having a length of about 20 mm, and approximately 4% microfibrillated cellulose (MFC), each having basis weights of 58.9 gsm, 60.7 gsm, and 60.2 gsm respectively.

[0156] After preparation of the samples, the samples were evaluated to determine their average tensile strength and average elongation. The average tensile strength was measured using ASTM D - 4595 - 17 (Standard Test Method for Tensile Properties of Geotextiles by the Wide - Width Strip Method). The average elongation was measured using ASTM D - 5034 - 21 (Standard Test Method for Breaking Strength and Elongation of Woven Fabrics (Grab Test)). The results are shown in Table 1 below.

[0157]

Table 1

[0158] As shown in Table 1, the nonwoven materials formed from regenerated cellulose and hemp fibers generally exhibited higher tensile strength and elongation compared to the nonwoven materials formed from cellulose acetate. Furthermore, the nonwoven materials formed from hemp fibers also generally exhibited higher elongation compared to the nonwoven materials formed from cellulose acetate. Regarding the addition of the binder material, it should be noted that the use of PVOH and pectin was found to yield similar results, and the measured tensile strength was significantly higher in the samples containing PVOH or pectin as the binder compared to the samples containing starch or MFC as the binder. Finally, although the difference in effectiveness between PVOH and pectin was observed to be relatively small, it should also be noted that the use of pectin was observed to be more effective in enhancing the tensile strength of the samples containing regenerated cellulose fibers, while the use of PVOH was observed to be more effective in increasing the tensile strength of the samples containing hemp fibers.

[0159] Example 2 Trials were conducted to convert samples of wetlaid nonwoven materials into rod-shaped elements suitable for use as filter elements in smoking articles. First, the wetlaid nonwoven materials of the samples were formed from a variety of different fiber inputs (including, for example, cellulose acetate, hemp, and regenerated cellulose) using conventional wetlaid papermaking techniques. After the formation of the nonwoven samples (10 samples per fiber input), each of the samples was optionally crimped / embossed and then assembled to form a rod-shaped element suitable for use as a filter element. The sample filter elements formed from cellulose acetate were treated as control samples as they represent conventional cellulose acetate-based filters known in the art. Each sample filter element was then measured to determine the weight, circumference, and hardness. The hardness was measured using ASTM D2240 (Standard Test Method for Rubber Properties - Durometer Hardness). Next, the pressure drop across each sample filter element was measured using ASTM D6830 (Standard Test Method for Characterizing the Pressure Drop and Filtration Performance of Cleanable Filter Media). The results are shown in Tables 2 - 7 below.

[0160]

Table 2

[0161] As shown in Table 2, ten control samples prepared from cellulose acetate (「CA」) filter material exhibited an average pressure drop of about 254 mmWG and an average hardness of about 78%.

[0162]

Table 3

[0163] As shown in Table 3, ten sample filter rods were prepared from filter material formed of hemp fibers. The filter material had a width of 130 mm and a crimp width of 121 microns. As shown in Table 3, ten samples prepared from hemp-based filter material exhibited an average pressure drop of about 48 mmWG and an average hardness of about 88%. It should be noted that the pressure drop decreased compared to the CA control filter rod, while the average hardness increased significantly compared to the CA control filter rod. Without intending to be bound by theory, the decreased pressure drop in the hemp filter samples is assumed to be due to the high rigidity of the hemp material, which makes it somewhat difficult to form filter rods sufficiently therefrom, resulting in the differences in the hemp filter samples with decreased pressure drop. It should be noted that such difficulties were not encountered when forming the regenerated cellulose filter samples discussed hereinafter in this specification, particularly the regenerated cellulose filter samples having a lower dpf value.

[0164]

Table 4

[0165] As shown in Table 4, ten sample filter rods were prepared from a filter material formed of regenerated cellulose fibers (e.g., rayon). The filter material had a dpf of about 1.5 and a crimp width of 150 microns. As shown in Table 4, the ten samples prepared from the 1.5 dpf regenerated cellulose filter material exhibited an average pressure drop of about 306 mmWG and an average hardness of about 88%. It should be noted that both the pressure drop and the average hardness were significantly increased compared to the CA control filter rod.

[0166]

Table 5

[0167] As shown in Table 5, ten sample filter rods were prepared from a filter material formed of regenerated cellulose fibers (e.g., viscose rayon). The filter material had a width of 150 mm and a dpf of about 3, and the filter material was prepared without crimping. As shown in Table 5, the ten samples prepared from the 3 dpf regenerated cellulose-based filter material exhibited an average pressure drop of about 196 mmWG and an average hardness of about 80%. It should be noted that the average pressure drop was slightly decreased compared to the CA control filter rod, while the average hardness was slightly increased compared to the CA control filter rod.

[0168]

Table 6

[0169] As shown in Table 6, ten sample filter rods were prepared from a filter material formed of regenerated cellulose fibers (e.g., viscose rayon). The filter material had a width of 115 mm and a dpf of about 4.5, and the filter material was prepared without crimping. As shown in Table 6, the ten samples prepared from the 4.5 dpf regenerated cellulose-based filter material exhibited an average pressure drop of about 237 mmWG and an average hardness of about 87%. It should be noted that the pressure drop was slightly lower compared to the CA control filter rod, while the average hardness was significantly increased compared to the CA control filter rod.

[0170]

Table 7

[0171] As shown in Table 7, ten sample filter rods were prepared from a filter material formed of regenerated cellulose fibers (e.g., viscose rayon). The filter material had a width of 120 mm, a crimp width of 87 microns, and a dpf of about 25. As shown in Table 7, the ten samples prepared from the 25 dpf regenerated cellulose-based filter material exhibited an average pressure drop of about 85 mmWG and an average hardness of about 79%. It should be noted that the pressure drop was significantly lower compared to the CA control filter rod, while the average hardness was slightly increased compared to the CA control filter rod.

[0172] Based on the aforementioned data in Tables 4 to 7, it was determined that the dpf of the regenerated cellulose filter samples can be varied (e.g., blending regenerated cellulose materials with various dpf values) to achieve a desired pressure drop. For example, a higher dpf regenerated cellulose material can be blended with a lower dpf regenerated cellulose material and / or hemp material in various ratios to achieve the desired pressure drop and / or hardness in the final filter material.

[0173] Example 3 Tests were conducted to evaluate the filtration efficiency of filter materials formed from regenerated cellulose compared to filter materials formed from conventional cellulose acetate fibers and traditional paper filters. The preparation of the filter materials required the formation of wet-laid nonwoven materials by conventional wet-laid papermaking techniques. Four different filter samples were prepared using regenerated cellulose with various denier values per filament. The first sample is a regenerated cellulose filter material formed using wet-laid technology and having 1.5 denier per filament (dpf). The second sample is a regenerated cellulose filter material formed using wet-laid technology and having 3 dpf. The third sample is a regenerated cellulose filter material formed using wet-laid technology and having 4.5 dpf. The fourth sample is a regenerated cellulose filter material formed using wet-laid technology and having 25 dpf. Additionally, two control samples were prepared. The first control sample is a conventional cellulose acetate filter material formed using wet-laid technology. The second control sample is a traditional paper filter prepared using wet-laid technology and having a basis weight of 36 grams per square meter (gsm).

[0174] Each of the samples was tested to determine the filtration efficiency measured by the amount of tar delivery in accordance with ISO standards: ISO-8454 (2007), ISO-4387 (2019) and ISO-3308 (2012) (determination of total particulate matter, carbon monoxide and nicotine-free dry particulate matter in the mainstream smoke of cigarettes using a linear smoking machine). The results are shown in Figure 8. It should be noted that the cellulose acetate control sample was ventilated at 49% while the paper filter was ventilated at 28%, while the regenerated cellulose samples (i.e., 1.5 viscose, 3 viscose, 4.5 viscose and 25 viscose) were not ventilated. Therefore, the data obtained in Figure 8 does not necessarily show that the regenerated cellulose samples have lower filtration efficiency / tar delivery compared to the control samples because there was no ventilation in the regenerated cellulose samples. On the contrary, the data shown in Figure 8 surprisingly shows that the filtration efficiency / tar delivery in the regenerated cellulose samples can be changed by varying the dpf of the regenerated cellulose samples. For example, the dpf of the regenerated cellulose filter material may be varied to achieve the desired level of filtration efficiency / tar delivery from the filter material.

[0175] Each of the 6 samples was retested using the same method shown for Figure 8, except that the regenerated cellulose samples were vent-corrected to obtain data equivalent to that of the 2 ventilated control samples. The results are shown in Figure 9. As shown in Figure 9, the 3 dpf regenerated cellulose filter and the 4.5 dpf regenerated cellulose filter exhibited similar filtration efficiency / tar delivery compared to the conventional cellulose acetate control filter. Similarly, the 1.5 dpf regenerated cellulose filter exhibited similar filtration efficiency / tar delivery compared to the conventional paper filter with a basis weight of 36 gsm.

Claims

**Claim 1** A filter material adapted for use as a filter element in an aerosol delivery device, comprising a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, esparto, kenaf, jute, ramie, wood, and combinations thereof, and being in the form of a nonwoven sheet or fibrous tow. **Claim 2** The filter material according to claim 1, which is in the form of a pleated nonwoven sheet assembled to form a rod-shaped element. **Claim 3** The filter material according to claim 1, wherein the nonwoven sheet has a basis weight of from about 20 gsm to about 90 gsm. **Claim 4** The filter material according to claim 1, wherein the nonwoven sheet has a basis weight of from about 40 gsm to about 80 gsm. **Claim 5** The filter material according to claim 1, wherein the nonwoven sheet has a basis weight of from about 50 gsm to about 70 gsm. **Claim 6** The filter material according to claim 1, wherein the denier per filament (dpf) of the filter material is from about 1 dpf to about 30 dpf. **Claim 7** The filter material according to claim 1, wherein the denier per filament (dpf) of the filter material is from about 1 dpf to about 25 dpf. **Claim 8** The filter material according to claim 1, wherein the denier per filament (dpf) of the filter material is from about 1 dpf to about 5 dpf. **Claim 9** The filter material according to any one of claims 1 to 8, optionally being crimped. **Claim 10** The filter material according to claim 9, wherein the crimped filter material has a crimp depth of from about 1 micron to about 180 microns. **Claim 11** The filter material according to claim 9, wherein the crimped filter material has a crimp depth of from about 1 micron to about 150 microns. **Claim 12** The filter material according to claim 9, wherein the crimped filter material has a crimp depth of from about 50 microns to about 100 microns. **Claim 13** The filter material according to any one of claims 1 to 8, wherein the nonwoven sheet has a width of from about 110 mm to about 160 mm. **Claim 14** The filter material according to any one of claims 1 to 8, wherein the nonwoven sheet has a width of from about 115 mm to about 150 mm. **Claim 15** The filter material according to any one of claims 1 to 8, further comprising a plasticizer. **Claim 16** The filter material according to claim 15, wherein the plasticizer is triacetin. **Claim 17** The filter material according to any one of claims 1 to 8, further comprising a binder.

18. The filter material according to claim 17, wherein the binder is selected from the group consisting of polyvinyl alcohol (PVOH), pectin, starch, microfibrillated cellulose (MFC), and combinations thereof.

19. The filter material according to any one of claims 1 to 8, wherein the nonwoven sheet is a wet-laid nonwoven sheet, a dry-laid nonwoven sheet, or an air-laid nonwoven sheet.

20. A filter element suitable for use in an aerosol delivery device, the filter element comprising one or more segments of the filter material according to any one of claims 1 to 8.

21. The filter element according to claim 20, wherein one or more segments of the filter material have a hardness of about 75 percent or more.

22. The filter element according to claim 20, wherein one or more segments of the filter material have a hardness of about 80 percent or more.

23. The filter element according to claim 20, wherein one or more segments of the filter material have a hardness of about 85 percent or more.

24. The filter element according to claim 20, exhibiting a pressure drop in the range of about 40 mmWG to about 400 mmWG.

25. The filter element according to claim 20, exhibiting a pressure drop in the range of about 200 mmWG to about 300 mmWG.

26. An aerosol delivery device comprising the filter element according to claim 20.

27. A method for forming a filter material suitable for use as a filter element in an aerosol delivery device, receiving a nonwoven sheet or fibrous tow, the nonwoven sheet or fibrous tow comprising a plurality of fibers selected from the group consisting of regenerated cellulose, hemp, sisal, esparto, kenaf, jute, ramie, wood, and combinations thereof, processing the nonwoven sheet or fibrous tow to obtain a filter material suitable for use as a filter element for an aerosol delivery device.

28. The method according to claim 27, further comprising forming a nonwoven sheet or fibrous tow.

29. The method according to claim 28, wherein the nonwoven sheet is formed using a wet-laid, air-laid, or dry-laid forming process.

30. The method according to claim 28, wherein the nonwoven sheet is formed using a forming process selected from the group consisting of hydroentangling, needle punching, spunbonding, meltblowing, spunlacing, carding, point bonding, spinning, and combinations thereof.

31. The step of forming the fibrous tow includes the step of blending a plurality of fibers to obtain a mixed fiber blend, and the method according to claim 28, further comprising the step of stretching the mixed fiber blend to produce a fibrous tow.

32. The method according to any one of claims 27 to 31, wherein the step of processing includes the step of aggregating the nonwoven sheet or the fibrous tow to form a rod-shaped element suitable for use as a filter element.

33. The method according to claim 32, wherein the step of processing further includes the step of wrapping the rod-shaped element with a wrapping material that circumscribes the rod-shaped element, thereby forming a continuous rod suitable for use as a filter element.

34. The method according to any one of claims 27 to 31, wherein the step of processing includes the step of crimping the nonwoven sheet or the fibrous tow.

35. The method according to claim 34, wherein the crimped nonwoven sheet or the crimped fibrous tow has a crimp depth of from about 1 micron to about 180 microns.

36. The method according to claim 34, wherein the crimped nonwoven sheet or the crimped fibrous tow has a crimp depth of from about 1 micron to about 150 microns.

37. The method according to claim 34, wherein the crimped nonwoven sheet or the crimped fibrous tow has a crimp depth of from about 50 microns to about 100 microns.

38. The method according to any one of claims 27 to 31, further comprising the step of applying a plasticizer to the nonwoven sheet or the fibrous tow.

39. The method according to claim 38, wherein the plasticizer is triacetin.

40. The method according to any one of claims 27 to 31, further comprising the step of applying a binder to the nonwoven sheet or the fibrous tow.

41. The method according to claim 40, wherein the binder is selected from the group consisting of polyvinyl alcohol (PVOH), pectin, starch, microfibrillated cellulose (MFC), and combinations thereof.

42. The method according to any one of claims 27 to 31, wherein the nonwoven sheet has a basis weight of from about 20 gsm to about 90 gsm.

43. The method according to any one of claims 27 to 31, wherein the nonwoven sheet has a basis weight of from about 40 gsm to about 80 gsm.

44. The method according to any one of claims 27 to 31, wherein the nonwoven sheet has a basis weight of from about 50 gsm to about 70 gsm.

45. The method according to any one of claims 27 to 31, wherein the denier per filament (dpf) of the filter material is from about 1 dpf to about 30 dpf.

46. The method according to any one of claims 27 to 31, wherein the denier per filament (dpf) of the filter material is from about 1 dpf to about 25 dpf.

47. The method according to any one of claims 27 to 31, wherein the denier per filament (dpf) of the filter material is from about 1 dpf to about 5 dpf.

48. The method according to any one of claims 27 to 31, wherein the nonwoven sheet has a width of from about 110 mm to about 160 mm.

49. The method according to any one of claims 27 to 31, wherein the nonwoven sheet has a width of from about 115 mm to about 150 mm.

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