Thermal energy absorber for tobacco heating products

Abstract

The present disclosure provides a thermal energy absorber for use in a smoking article. In an embodiment, the smoking article includes an outer wrap circumscribing at least a portion of the smoking article, wherein the smoking article is defined by an upstream lighting end and a downstream mouth end, the smoking article including a carbon heat source disposed proximate to the lighting end, tobacco material disposed downstream from the carbon heat source and spatially separated from the mouth end of the smoking article, and a thermal energy absorber disposed at least partially between the tobacco material and the carbon heat source.

Description

[Technical Field]

[0001] SUMMARY The present disclosure relates to smoking articles, sometimes referred to as tobacco heating products, that are capable of heating tobacco material contained within the tobacco heating product without burning the tobacco material. [Background technology]

[0002] Many smoking articles have been proposed over the years as improvements or replacements to smoking products that rely on the combustion of tobacco for use. Some alternatives include devices that burn solid or liquid fuels to transfer heat to tobacco. Such devices, commonly referred to as smoking articles or tobacco heating products, allow for the heating of tobacco material without significantly burning or scorching the tobacco material. The focus of improvements or replacements to smoking articles has typically been to provide the sensations associated with cigarette, cigar, or pipe smoking without delivering significant amounts of incomplete combustion and pyrolysis products that can be harmful to the user. See, for example, U.S. Patent No. 7,726,320 to Robinson et al., U.S. Patent Application Publication No. 2013 / 0255702 to Griffith Jr. et al., U.S. Patent Application Publication No. 2014 / 0096781 to Sears et al., and U.S. Patent Application Publication No. 2015 / 0216232 to Bless et al., which are incorporated herein by reference, for various alternative smoking articles, aerosol delivery devices, and heat-generating sources.

[0003] Articles that produce the taste and sensation of smoking by heating tobacco, tobacco-derived materials, or other plant-derived materials without significant toasting or burning suffer from inconsistent and adverse performance characteristics. For example, overheating a tobacco heating product can cause undesirable scorching or burning of the internal tobacco material, which can be harmful to the user. Therefore, it is desirable to provide a smoking article that can provide the sensation of cigarette, cigar, or pipe smoking without overheating the tobacco material, and with advantageous performance characteristics. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 7,726,320 [Patent Document 2] US Patent Application Publication No. 2013 / 0255702 [Patent Document 3] US Patent Application Publication No. 2014 / 0096781 [Patent Document 4] US Patent Application Publication No. 2015 / 0216232 Summary of the Invention

[0005] The present disclosure relates to a thermal energy absorber for a smoking article, such as a tobacco heating product (sometimes referred to as a tobacco heating product). In various embodiments, the smoking article includes an outer wrap circumscribing at least a portion of the smoking article, wherein the smoking article is defined by an upstream lighting end and a downstream mouth end, and the smoking article includes a carbon heat source disposed proximate to the lighting end, a tobacco material disposed downstream from the carbon heat source, and a thermal energy absorber disposed at least partially between the tobacco material and the carbon heat source. In some embodiments, the thermal energy absorber can include a metal material or a ceramic material. In some embodiments, the thermal energy absorber can be an aluminum material or an alumina material. In various embodiments, the thermal energy absorber is configured to improve uniform distribution of heated air across the tobacco material.

[0006] In certain embodiments, the thermal energy absorber is in the form of one or more circular disks. In some embodiments, the one or more circular disks have individual diameters of about 5 mm to about 9 mm and thicknesses of about 0.1 mm to about 4 mm. In certain embodiments, the one or more circular disks can include a plurality of holes. In various other embodiments, the plurality of holes can be irregularly shaped, randomly distributed, or distributed in a pattern.

[0007] In certain embodiments, the thermal energy absorber may be in the form of a plurality of particles. In some embodiments, the particles are substantially spherical or hollow sphere-shaped. In some embodiments, the thermal energy absorber may include between about 3 and about 500 particles. In various embodiments, the particles may have a diameter of about 0.1 mm to about 5 mm. In some embodiments, the thermal energy absorber comprises a material having a specific heat capacity of about 0.1 kJ / kg K to about 3 kJ / kg K.

[0008] In various embodiments, the tobacco material may further comprise one or more of a tobacco extract, an aerosol precursor composition, and a flavoring material. In some embodiments, the tobacco material may be in shredded or particulate form. In some embodiments, the carbon heat source may have a plurality of air inlet holes extending longitudinally therethrough. In various embodiments, the thermal energy absorber may be configured to reduce the peak temperature of the smoking article between about 25°C and about 75°C and between about 475°C and about 525°C. In some such embodiments, the thermal energy absorber may be configured to reduce the peak temperature of the smoking article between about 50°C and about 500°C. In some embodiments, the thermal energy absorber may be configured to reduce total particulate matter (TPM) emitted during smoking of the smoking article. In certain other embodiments, the downstream mouth end may further comprise a filter material.

[0009] Some embodiments provide a method for reducing excessive heating in a smoking article, the method including providing a smoking article including a carbon heat source, tobacco material, a thermal energy absorber, and an outer wrap circumscribing at least a portion of the smoking article, wherein the smoking article is defined by an upstream lighting end and a downstream mouth end, and disposing the thermal energy absorber at least partially between the tobacco material and the carbon heat source such that, when the carbon heat source is lit, the peak temperature of the smoking article is reduced by about 50°C to about 500°C. In some embodiments, the thermal energy absorber can be configured to improve uniform distribution of heated air across the tobacco material. In some embodiments, the thermal energy absorber can be configured to reduce total particulate matter (TPM) emitted during smoking of the smoking article. In certain other embodiments, the downstream mouth end further includes a filter material.

[0010] The disclosure includes, but is not limited to, the following embodiments.

[0011] Embodiment 1: A smoking article comprising an outer wrap circumscribing at least a portion of the smoking article, the smoking article defined by an upstream lighting end and a downstream mouth end, the smoking article comprising a carbon heat source disposed proximate the addition end, tobacco material disposed downstream of the carbon heat source, and a thermal energy absorber disposed at least partially between the tobacco material and the carbon heat source.

[0012] Embodiment 2: The smoking article of embodiment 1, wherein the thermal energy absorber comprises one or more of a metallic material or a ceramic material.

[0013] Embodiment 3: A smoking article according to any one of embodiments 1-2, wherein the thermal energy absorber comprises one or more of an aluminum material or an alumina material.

[0014] Embodiment 4: A smoking article according to any one of embodiments 1 to 3, wherein the thermal energy absorber is configured to improve the even distribution of heated air across the tobacco material.

[0015] Embodiment 5: A smoking article according to any one of embodiments 1 to 4, wherein the thermal energy absorber is in the form of one or more circular discs.

[0016] Embodiment 6: A smoking article according to any one of embodiments 1 to 5, wherein the one or more circular discs have an individual diameter of about 5 mm to about 9 mm and a thickness of about 0.1 mm to about 4 mm.

[0017] Embodiment 7: A smoking article according to any one of embodiments 1 to 6, wherein one or more circular discs comprise a plurality of holes.

[0018] Embodiment 8: A smoking article according to any one of embodiments 1 to 7, wherein the plurality of holes are irregularly shaped, randomly distributed, or distributed in a pattern.

[0019] Embodiment 9: A smoking article according to any one of embodiments 1 to 4, wherein the thermal energy absorber is in the form of a plurality of particles.

[0020] Embodiment 10: A smoking article according to any one of embodiments 1 to 4 and 9, wherein the particles are substantially spherical.

[0021] Embodiment 11: A smoking article according to any one of embodiments 1-4 and 9-10, wherein the thermal energy absorber comprises between about 3 and about 500 particles.

[0022] Embodiment 12: A smoking article according to any one of embodiments 1 to 4 and 9 to 11, wherein the particles have a diameter of from about 0.005 mm to about 5 mm.

[0023] Embodiment 13: A smoking article according to any one of embodiments 1 to 12, wherein the thermal energy absorber comprises a material having a specific heat capacity of about 0.1 kJ / kg K to about 3 kJ / kg K.

[0024] Embodiment 14: A smoking article according to any one of embodiments 1 to 13, wherein the tobacco material further comprises one or more of a tobacco extract, an aerosol precursor composition, and a flavoring material.

[0025] Embodiment 15: A smoking article according to any one of embodiments 1 to 14, wherein the tobacco material is in one or more of shredded or granular form.

[0026] Embodiment 16: A smoking article according to any one of embodiments 1 to 15, wherein the carbon heat source has a plurality of air inlet holes extending longitudinally therethrough.

[0027] Embodiment 17: A smoking article according to any one of embodiments 1 to 16, wherein the thermal energy absorber is configured to reduce the peak temperature of the smoking article by between about 50°C and about 500°C.

[0028] Embodiment 18: A smoking article according to any one of embodiments 1 to 17, wherein the downstream end further comprises a filter material.

[0029] Embodiment 19: A method for reducing excess heating in a smoking article, comprising providing a smoking article comprising a carbon heat source, tobacco material, a thermal energy absorber, and an outer wrap circumscribing at least a portion of the smoking article, wherein the smoking article is defined by an upstream lighting end and a downstream mouth end, and wherein the thermal energy absorber is at least partially disposed between the tobacco material and the carbon heat source such that when the carbon heat source is lit, the peak temperature of the smoking article is reduced by about 50°C to about 500°C.

[0030] Embodiment 20: The method of embodiment 19, wherein the thermal energy absorber is configured to improve uniform distribution of heated air across the tobacco material.

[0031] Embodiment 21: The method of any one of embodiments 19-20, wherein the downstream mouth end further comprises a filter material.

[0032] These and other features, aspects, and advantages of the disclosure will be apparent from a reading of the following detailed description in conjunction with the accompanying figures, which are briefly described below. The present invention includes combinations of two, three, four, or more of the above-described embodiments, and combinations of any two, three, four, or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined in the description of a specific embodiment herein. This disclosure is intended to be read as a whole such that all separable features or elements of the disclosed invention are intended to be combinable in any of its various aspects and embodiments, unless the context clearly dictates otherwise.

[0033] Aspects of the disclosure will now be described in the above general terms and with reference to the accompanying figures, which are not necessarily drawn to scale. [Brief explanation of the drawings]

[0034] [Figure 1] 1 shows a partial cross-sectional view of a smoking article including a heat source, a tobacco material, and a thermal energy absorber according to an exemplary embodiment of the present disclosure. [Figure 2] 1 shows a partial cross-sectional view of an upstream lighting end of a smoking article including a heat source holder according to an exemplary embodiment of the present disclosure. [Figure 3] 1 illustrates a partial cross-sectional view of a thermal energy absorber according to an exemplary embodiment of the present disclosure. [Figure 4] 1 shows a partial cross-sectional view of a smoking article including a thermal energy absorber in the form of a plurality of particles according to an exemplary embodiment of the present disclosure. [Figure 5] 1 is a graph illustrating average apex temperature profiles for a smoking article without a thermal energy absorber and a smoking article with a thermal energy absorber according to an exemplary embodiment of the present disclosure. [Figure 6] 1 is a graph illustrating the average pressure drop profile of a smoking article that does not include a thermal energy absorber according to an exemplary embodiment of the present disclosure. [Figure 7]1 is a graph showing total particulate matter (TPM) emitted during smoking of a smoking article with and without a thermal energy absorber according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0035] The present disclosure will be described more fully below with reference to exemplary embodiments thereof. 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 in the specification and claims, the singular forms "a," "an," "the," and the like include plural referents unless the context clearly dictates otherwise. Also, while quantitative measurements, values, geometric relationships, and the like may be referenced herein, unless otherwise specified, any one or more of these, if not all, may be absolute or approximate to account for possible acceptable variations, such as those due to engineering tolerances, etc.

[0036] As described below, exemplary embodiments of the present disclosure relate to a thermal energy absorber for use in smoking articles, such as tobacco heating products (sometimes referred to as tobacco heating products). The use of a thermal energy absorber can prevent overheating of the smoking article, which can cause undesirable charring / scorching of the internal tobacco material and scorching of the paper at the tip of the cigarette rod. Furthermore, overheating of the smoking article can contribute to negative sensory characteristics and can result in the release of certain components from the tobacco material. Many components of tobacco cigarette smoke are products of incomplete combustion (pyrolysis) and thermal decomposition (pyrolysis) of the tobacco cigarette due to heat. Typical markers of pyrolysis and thermogenic degradation of tobacco cigarettes are acetaldehyde, benzo(a)pyrene, and carbon monoxide. The use of a thermal energy absorber placed downstream of a carbon heat source can help reduce the degree of overheating or pyrolysis in the smoking article, thus reducing the negative effects associated with overheated tobacco material in the smoking article.

[0037] Some embodiments of smoking articles according to the present disclosure use a flammable 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 systems have the form of fairly small articles that are considered handheld devices. That is, use of preferred smoking article components does not result in the production of smoke, in the sense that the aerosol arises primarily from by-products of tobacco combustion or pyrolysis; rather, use of these preferred systems results in the production of vapor due to heating without the burning or combustion of tobacco incorporated therein. In some exemplary embodiments, the smoking article components are characterized as heated cigarettes, which most preferably incorporate tobacco and / or tobacco-derived components and then deliver the tobacco-derived components in the form of an aerosol.

[0038] Smoking articles can provide many of the sensations of smoking a used cigarette, cigar, or pipe (e.g., inhalation and exhalation, taste or flavor profile, organoleptic effects, physical sensations, usage, visual cues such as those provided by visible aerosol, etc.) by lighting and burning tobacco (and then inhaling the tobacco smoke) without any substantial combustion of any of its components. For example, a user of a smoking article according to some exemplary embodiments of the present disclosure can hold and use the component much like a smoker using a traditional type of smoking article, holding one end of the piece in their mouth for inhalation of aerosol generated by the piece, taking puffs on the tobacco at selected intervals, etc.

[0039] Although the system is generally described herein with respect to embodiments related to smoking articles, it should be understood that the features, components, features, and methods may be embodied in many different forms and associated with a variety of articles. For example, the description provided herein may be used in conjunction with traditional smoking articles (e.g., cigarettes, cigars, pipes, etc.), heated tobacco products, and related packaging embodiments for any of the products disclosed herein. Accordingly, it should be understood that the description of the features, components, features, and methods disclosed herein are discussed by way of example only in terms of embodiments related to smoking articles, and may be embodied and used in a variety of other products and methods.

[0040] Smoking articles of the present disclosure may also be characterized as vapor-producing or pharmaceutical delivery articles. Accordingly, such articles or devices may be adapted to provide one or more substances (e.g., flavoring materials and / or pharmaceutical active ingredients) in an inhalable form or state. For example, the inhalable substance may be substantially in vapor form (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 liquid droplets in a gas). For simplicity, the term "aerosol" as used herein is meant to include vapors, gases, and aerosols in any form or type suitable for human inhalation, whether or not visible and whether or not in a form considered to resemble smoke. The physical form of the inhalable substance is not necessarily limited by the nature of the device of the present invention; rather, whether it exists in a vapor or aerosol state may depend on the nature of the medium and the inhalable substance itself. In some embodiments, the terms "vapor" and "aerosol" may be interchangeable. Thus, for simplicity, the terms "vapor" and "aerosol" used to describe aspects of the disclosure will be understood to be interchangeable unless otherwise indicated.

[0041] In some embodiments, a smoking article of the present disclosure includes an outer wrap circumscribing at least a portion of the smoking article, wherein the smoking article is defined by an upstream lighting end and a downstream mouth end, a heat source disposed proximate the lighting end, tobacco material disposed downstream of the heat source and spatially separated from the mouth end of the smoking article, and at least one thermal energy absorber disposed at least partially between the tobacco material and the carbon heat source. Alternative forms, configurations, and arrangements of various thermal energy absorbers, smoking articles, and components within the smoking articles of the present disclosure will be apparent in light of the further disclosure provided below.

[0042] In this regard, FIG. 1 illustrates a smoking article 100 according to an exemplary embodiment of the present disclosure. The smoking article 100 may include an outer wrap 102 circumscribing at least a portion of the smoking article 100, wherein the smoking article is defined by an upstream lighting end 104 and a downstream mouth end 106. In some embodiments, the smoking article 100 may further include a heat source 108, tobacco material 110, and a thermal energy absorber 112. In certain embodiments, the heat source 108 may be disposed proximate to the lighting end 104. In certain embodiments, the tobacco material 110 may be disposed downstream of the carbon heat source 108 and may optionally be spatially separated from the mouth end 106 of the smoking article 100. In some embodiments, the thermal energy absorber 112 may be disposed at least partially between the tobacco material 110 and the heat source 108.

[0043] In various embodiments, smoking articles according to the present disclosure may have a variety of overall shapes, including, but not limited to, those that may be defined as substantially rod-shaped, or substantially tubular, or substantially cylindrical. In the embodiment of Figure 1, smoking article 100 has a substantially round cross-section, although other cross-sectional shapes (e.g., oval, square, triangular, etc.) are also encompassed by the present disclosure. Accordingly, such terms describing the physical shape of the article may also apply to its individual components.

[0044] The arrangement of components within a smoking article of the present disclosure may vary across various embodiments. In some embodiments, the thermal energy absorber may be disposed entirely between the heat source and the tobacco material. In certain other embodiments, at least a portion of the thermal energy absorber may be intermixed with the tobacco material such that the thermal energy absorber is only partially interposed between the heat source and the tobacco material. Other configurations are not necessarily excluded; for example, the thermal energy absorber may be intermixed entirely with the tobacco material such that the thermal energy absorber is not interposed between the heat source and the tobacco material. In general, the heat source may be disposed sufficiently close to the tobacco material so that heat from the heat source can heat the tobacco material (and in some embodiments, one or more flavoring materials, medicinal agents, etc., that may also be provided for delivery to a user) and form an aerosol for delivery to a user without burning or combusting the tobacco material.

[0045] Additional components may be utilized in the smoking articles of the present disclosure. For example, referring again to FIG. 1 , the smoking article 100 may include a filter 114 disposed downstream of the tobacco material 110 and proximate the downstream mouth end 106 of the smoking article 100. In various embodiments, the filter 114 may be made of a cellulose acetate material or a polypropylene material. The filter 114 may additionally or alternatively include strands of tobacco-containing material, as described in U.S. Pat. No. 5,025,814 to Raker et al., incorporated herein by reference in its entirety. In various embodiments, the filter 114 may enhance the structural integrity of the mouth end of the smoking article 100 and / or provide filtration capabilities, if desired, and / or resistance to draw. In some embodiments, the filter may include individual segments. For example, some embodiments may include segments that provide filtration, segments that provide resistance to draw, hollow segments that provide space for aerosol cooling, segments that improve structural integrity, other filter segments, and any one or any combination of the above. In various other embodiments, components in addition to the filter 114 may be present between the tobacco material 110 and the mouth end 106 of the smoking article 100. For example, in some embodiments, one or any combination of an air gap, a hollow tubular structure, a phase change material for cooling the air, a flavor-releasing medium, an ion-exchange fiber capable of selective chemical adsorption, aerogel particles as a filter medium, and other suitable materials may be disposed between the tobacco material 110 and the mouth end 106 of the smoking article 100. Some examples of possible phase change materials include, but are not limited to, 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. Other examples are described in US Pat. No. 8,430,106 to Potter et al., which is incorporated herein by reference in its entirety.

[0046] As described above, in various embodiments, the smoking article 100 can include an outer wrap 102 that circumscribes at least a portion of the smoking article 100. In some embodiments, the wrapping material of the outer wrap 102 can include a material that resists heat transfer, which can include paper or other fibrous materials, such as cellulose materials. A variety of wrapping materials can be used as the outer wrap that circumscribes the smoking article. Exemplary types of wrapping materials are described in U.S. Patent Nos. 4,938,238 to Barnes et al. and 5,105,837 to Barnes et al. Wrapping materials such as those shown in U.S. Patent Application Publication Nos. 2005 / 0005947 to Hampl et al. and 2005 / 039326 to Rasouli et al. can be used as the inner wrapping material in so-called "double wrap" configurations. Exemplary types of thermally conductive wrapping materials are described in U.S. Patent No. 5,551,451 to Riggs et al., and other suitable wrapping materials are described in U.S. Patent No. 5,065,776 to Lawson et al. and U.S. Patent No. 6,367,481 to Nichols et al., each of which is incorporated herein by reference. Cigarette varieties marketed by R.J. Reynolds Tobacco Company under the trade names "Premier" and "Eclipse" incorporate exemplary wrapping materials, such as a laminate of paper and metal foil, and paper used as an outer circumscribing wrapper around the heat-generating segment. Other exemplary wrapping materials and engineered wrapping materials suitable for use in cigarette manufacturing are described in U.S. Patent No. 5,220,930 to Gentry, U.S. Patent No. 6,976,493 to Chapman et al., and U.S. Patent No. 7,047,982 to Seymour et al., and U.S. patent application Ser. No. 11 / 377,630 to Crooks et al., filed March 16, 2006, each of which is incorporated herein by reference. The outer wrap 102 material can also include at least one filler material embedded or dispersed within the fibrous material. In various embodiments, the filler material can have the form of water-insoluble particles. Additionally, the filler material can incorporate inorganic components.In various embodiments, the outer wrap may be formed from multiple layers, such as a bottom layer, a bulk layer, and a top layer, like a typical cigarette wrapper. Such materials may include, for example, lightweight "rag fibers" such as flax, hemp, sisal, rice straw, and / or escutcheon grass. The outer wrap 102 may also include materials typically used in conventional cigarette filter elements, such as cellulose acetate.

[0047] In some embodiments, the outer wrap 102 can further include a heat source holder 120 positioned at least proximate the lighting end 104 of the smoking article 100. In various embodiments, the heat source holder 120 can circumscribe the heat source 108 at a proximal end 120a of the heat source holder 120 and a thermal energy absorber at a distal end 120b of the heat source holder 120, as depicted in FIG. 2 . In various embodiments, the heat source holder 120 can have a degree of heat resistance and can be substantially tubular in shape. In some embodiments, the heat source holder 120 can hold the heat source 108 such that a predetermined length of the heat source 108 protrudes from the proximal end of the heat source holder 120. In certain embodiments, the heat source holder 120 can have a peripheral wall having a laminate structure and multiple layers. For example, the peripheral wall can include one or more laminate layers, metal layers, and paper layers adhered to one another. In certain embodiments, the heat source holder 120 can include one or more metal layers such that when the carbon heat source 108 is fired and the outer wrap 102 is heated by the heat of the carbon heat source 108, the one or more metal layers keep the heating temperature of the outer wrap 102 lower than the firing temperature of the outer wrap 102. An example of a heat source holder for a carbon heat source is described in U.S. Patent Application Publication No. 2018 / 0317560 to Shinozaki et al., the disclosure of which is incorporated herein by reference in its entirety.

[0048] Referring again to FIG. 1 , in various embodiments, the smoking article 100 can include a heat source 108 positioned proximate the lighting end 104. In certain embodiments, the carbon heat source 108 can include various types of combustible carbonaceous materials. In certain other embodiments, the carbon heat source 108 can include a non-burning additive in addition to the combustible carbonaceous material. Examples of carbon heat sources are described in U.S. Patent Application Publication No. 2018 / 0317560 to Shinozaki et al., which is incorporated herein by reference in its entirety. In some embodiments, the carbon heat source 108 can incorporate other elements in addition to the combustible carbonaceous material (e.g., tobacco components such as powdered tobacco or tobacco extract, flavoring agents, salts such as sodium chloride, potassium chloride, and sodium carbonate, alumina granules, ammonia sources such as ammonia salts, and / or binders such as guar gum, ammonium alginate, and sodium alginate).

[0049] While the specific dimensions of applicable carbon heat sources 108 may vary, in some embodiments, the carbon heat source 108 may have a length in the inclusive range of about 5 mm to about 20 mm, or about 8 mm to about 16 mm, or about 12 mm, and an overall diameter in the inclusive range of about 3 mm to about 8 mm. In some embodiments, the carbon heat source 108 may protrude a predetermined length from the lighting end 104, as shown in FIG. 1. Referring again to FIG. 2, in certain other embodiments, the carbon heat source 108 may protrude a predetermined length from the proximal end 120a of the heat source holder 120. The predetermined length may vary, and in some embodiments, the predetermined length may have a length in the inclusive range of about 2 mm to about 12 mm, or about 6 mm to about 10 mm, or about 8 mm. In other embodiments, the carbon heat source 108 may be constructed in various ways, but in the depicted embodiment, the carbon heat source 108 is extruded or compounded with crushed or powdered carbon-based material, having a mass of about 0.5 g / cm on a dry weight basis. 3 often exceeding about 0.7 g / cm 3 and frequently exceeds about 1 g / cm 3, and has a density greater than 100 . See, for example, 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 incorporated herein by reference in their entireties, for the types, formulations, and designs of fuel source components. In various embodiments, the carbon heat source 108 can have a variety of forms, including, for example, a substantially cylindrical or cylindrical (e.g., tubular) shape, although the carbon heat source 108 of the depicted embodiment comprises an extruded monolithic carbonaceous material having a generally cylindrical shape but with multiple air inlet holes extending longitudinally therethrough. The air inlet holes may have a variety of different shapes or substantially the same shape, and in some embodiments, the multiple air inlet holes may be arranged in a pattern or randomly distributed across the face of the carbon heat source and extend longitudinally therethrough. In some embodiments, the smoking article 100, and particularly the carbon heat source 108, can further include a heat transfer component. In various embodiments, the heat transfer component can be proximate to the carbon heat source 108, and in some embodiments, the heat transfer component may be located within or inside the carbon heat source 108. Some examples of heat transfer components are described in U.S. Patent Application No. 15 / 923,735, filed March 16, 2018, and entitled "Smoking Article with Heat Transfer Component," which is incorporated herein by reference in its entirety.

[0050] Generally, the carbon heat source 108 is positioned sufficiently close to the tobacco material 110 so that an aerosol formed by heating the tobacco material 110 is delivered to the user via the mouth end 106. That is, when the carbon heat source 108 heats the tobacco material 110, an aerosol is formed, released, or generated in a physical form suitable for inhalation by a consumer. It should be noted that the above terms are meant to be interchangeable, such that references to release, releasing, releases, or released include form or generate, forming or generating, forms or generates, and formed or generated. Specifically, an inhalable substance is released in the form of an aerosol.

[0051] As mentioned above, in some embodiments, the smoking article 100 can include tobacco material 110 disposed downstream of the carbon heat source 108 and optionally spatially separated from the mouth end 106 of the smoking article 100. In some embodiments, the tobacco material 110 can be in granular, shredded, or sheet form. In some embodiments, the tobacco material can further include one or both of an aerosol precursor composition and a flavoring material. The tobacco material used can vary. A single type of tobacco can be used, or a combination or blend of various types of tobacco can be used. Additionally, different types of tobacco, or different blends of tobacco, can be used in different locations within the smoking article.

[0052] For example, in some embodiments, the tobacco material used may include or be derived from tobaccos such as flue-cured tobacco, burley tobacco, Orient tobacco, Maryland tobacco, dark tobacco, dark fired tobacco, and rustica tobacco, as well as other rare or specialty tobaccos, or blends thereof. See, for example, the tobacco types described in U.S. Patent No. 6,730,832 to Dominguez et al. and U.S. Patent No. 7,025,066 to Lawson et al., and U.S. Patent Application No. 60 / 818,198 to Stebbins et al., filed June 30, 2006, each of which is incorporated herein by reference. Descriptions of various tobacco types, growing practices, harvesting practices, and curing practices are found in Davis et al. (eds.), Tobacco Production, Chemistry and Technology (1999). Most preferably, the tobacco used is properly cured and aged. Particularly preferred techniques and conditions for drying flue-cured tobacco are described in Nestor et al., Beitrage Tabakforsch. Int., 20 (2003) 467-475 and Peele, U.S. Patent No. 6,895,974, which are incorporated herein by reference. Exemplary techniques and conditions for air-curing tobacco are described in Roton et al., Beitrage Tabakforsch. Int., 21 (2005) 305-320 and Staaf et al., Beitrage Tabakforsch. Int., 21 (2005) 321-330, which are incorporated herein by reference.

[0053] The tobacco material incorporated into the smoking article can be used in a variety of forms, a combination of various forms of tobacco can be used, or different forms of tobacco can be used in different locations within the smoking article. For example, tobacco can be used in the form of cut or shredded pieces of lamina or stem, processed forms (e.g., reconstituted tobacco sheet pieces shredded into cut filter form, films incorporating tobacco components, extruded tobacco portions or pieces, expanded tobacco lamina such as volume-expanded cut filters, processed tobacco stem pieces comparable in size and general appearance to cut filters, granulated tobacco, foamed tobacco material, compressed or pelletized tobacco, etc.), finely divided tobacco pieces (e.g., reconstituted tobacco sheet, such as tobacco dust, tobacco powder, agglomerated tobacco powder, etc.), or in the form of tobacco extract. See, for example, U.S. patent application Ser. No. 11 / 194,215 to Cantrell et al., filed Aug. 1, 2005, and U.S. patent application Ser. No. 11 / 377,630 to Crooks et al., filed Mar. 16, 2006, both of which are incorporated herein by reference.

[0054] Smoking articles can use tobacco in the form of lamina and / or stem. Thus, tobacco can be used in many forms and in a manner substantially identical to that traditionally used in the manufacture of tobacco products such as cigarettes. Traditionally, cut or shredded pieces of tobacco lamina and stem have been used as so-called "cut filters" for cigarette manufacturing. Water-extracted stem pieces can also be used. Thus, tobacco in these forms introduces mass and bulk into smoking articles. The manner and methods of heating, stemming, curing, moistening, cutting, reordering, and handling tobacco for use as cut filters will be apparent to those skilled in the art of tobacco product manufacturing.

[0055] There are a variety of processed tobaccos that can be incorporated into smoking articles. Exemplary modes and methods for providing reconstituted tobacco sheets, including casting and papermaking techniques, are described in U.S. Patent No. 4,674,519 to Keritsis et al., U.S. Patent No. 4,941,484 to Clapp et al., U.S. Patent No. 4,987,906 to Young et al., U.S. Patent No. 4,972,854 to Kiernan et al., U.S. Patent No. 5,099,864 to Young et al., U.S. Patent No. 5,143,097 to Sohn et al., U.S. Patent No. 5,159,942 to Brinkley et al., U.S. Patent No. 5,322,076 to Brinkley et al., U.S. Patent No. 5,339,838 to Young et al., U.S. Patent No. 5,377,698 to Litzinger et al., U.S. Patent No. 5,501,237 to Young et al., and U.S. Patent No. 6,216,707 to Kumar (each of which is incorporated herein by reference). Exemplary systems and methods for providing extruded forms of processed tobacco are described in U.S. Patent No. 4,821,749 to Toft et al., U.S. Patent No. 4,880,018 to Graves, Jr. et al., U.S. Patent No. 5,072,744 to Luke et al., U.S. Patent No. 4,874,000 to Tamol et al., U.S. Patent No. 5,551,450 to Hemsley, U.S. Patent No. 5,649,552 to Cho et al., U.S. Patent No. 5,829,453 to White, U.S. Patent No. 6,125,855 to Nevett et al., and U.S. Patent No. 6,182,670 to White, each of which is incorporated herein by reference. The extruded tobacco material may have the form of a cylinder, strand, circular disk, or the like.Exemplary expanded tobaccos (e.g., puffed tobaccos) can be provided using the types of techniques set forth in U.S. Reissue Patent No. 32,013 to de la Brude et al., U.S. Patent No. 3,771,533 to Armstrong et al., U.S. Patent No. 4,577,646 to Ziehn, U.S. Patent No. 4,962,773 to White, U.S. Patent No. 5,095,922 to Johnson et al., U.S. Patent No. 5,143,096 to Steinberg, U.S. Patent No. 5,172,707 to Zambelli, U.S. Patent No. 5,249,588 to Brown et al., U.S. Patent No. 5,687,748 to Conrad, and U.S. Patent No. 5,908,032 to Poindexter, and U.S. Patent Application Publication No. 2004 / 0182404 to Poindexter et al. (each of which is incorporated herein by reference). One particularly preferred type of expanded tobacco is dry ice expanded tobacco (DIET). Exemplary forms of processed tobacco stems include cut and rolled stems, cut, rolled, and puffed stems, cut and puffed (puffed) stems, and shredded puffed stems. Exemplary systems and methods for providing processed tobacco stems are described in U.S. Patent No. 4,195,646 to Kite and U.S. Patent No. 5,873,372 to Honeycutt et al., each of which is incorporated herein by reference. Systems and methods using tobacco dust are described in U.S. Patent No. 4,341,228 to Keritsis et al., U.S. Patent No. 4,611,608 to Vos et al., U.S. Patent No. 4,706,692 to Gellatly, and U.S. Patent No. 5,724,998 to Gellatly et al., each of which is incorporated herein by reference. Still other types of processed tobacco are those of the type set forth in U.S. Patent Application Publication No. 2006 / 0162733 to McGrath et al.

[0056] Tobacco can be used in blended form. Typically, blends of various types and forms of tobacco are provided in the form of blended cut filters. For example, certain popular tobacco blends for cigarette manufacturing, commonly referred to as "American blends," contain a mixture of cut or shredded pieces of flue-cured, burley, and oriental tobacco; such blends often also contain processed tobacco pieces, such as processed tobacco stems, expanded tobacco, and / or reconstituted tobacco. The exact amount of each type or form of tobacco in a tobacco blend used to manufacture a particular smoking article can vary and is a design choice, depending on factors such as the desired sensory characteristics (e.g., flavor and aroma). See, for example, the types of tobacco blends described in 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). See also the representative types of tobacco blends set forth in U.S. Pat. No. 4,836,224 to Lawson et al., U.S. Pat. No. 4,924,888 to Perfetti et al., U.S. Pat. No. 5,056,537 to Brown et al., and U.S. Pat. No. 5,220,930 to Gentry, U.S. Patent Application Publication No. 2004 / 0255965 to Perfetti et al., U.S. Patent Application Publication No. 2005 / 0066986 to Nestor et al., PCT Application Publication No. WO 02 / 37990 to Bereman; and Bombick et al., Fund. Appl. Toxicol., 39, pp. 11-17 (1997), each of which is incorporated herein by reference.

[0057] Certain processed tobaccos can incorporate ingredients other than tobacco. However, processed tobaccos preferably comprise a preponderance of some form of tobacco, based on the dry weight of the processed tobacco. That is, a majority of the dry weight of the processed tobacco and a majority of the weight of any mixture incorporating the processed tobacco (including blends of materials, or materials having additives applied thereto or otherwise incorporated therein) are provided by some form of tobacco. For example, these materials can be processed tobacco incorporating small amounts of non-tobacco filler materials (e.g., calcium carbonate particles, spongy or absorbent materials, carbonaceous materials including carbon particles and graphite fibers, grain or wood pulp) and / or binders (e.g., guar gum, sodium alginate, or ammonium alginate), and / or blends of these materials can incorporate tobacco substitutes or bulking agents. Representative types of tobacco substitutes or bulking agents are set forth in U.S. Patent Application Serial No. 11 / 489,334, filed July 19, 2006, to Fagg et al., which is incorporated herein by reference. The above materials, and blends incorporating these materials, frequently contain greater than about 70 percent tobacco, often greater than about 80 percent tobacco, and typically greater than about 90 percent tobacco, on a dry weight basis, based on the combined weight of tobacco, non-tobacco fillers, and non-tobacco substitutes or extenders. However, these processed tobaccos can also be made substantially entirely from tobacco and do not incorporate any non-tobacco fillers, substitutes, or extenders.

[0058] The tobacco can be treated with tobacco additives of the type traditionally used in the manufacture of tobacco products. These additives can include materials of the type used to enhance the flavor and aroma of tobacco used in the manufacture of cigars, cigarettes, pipes, etc. For example, these additives can include various cigarette casing and / or top layer components. See, e.g., U.S. Pat. No. 3,419,015 to Wochnowski, U.S. Pat. No. 4,054,145 to Berndt et al., U.S. Pat. No. 4,887,619 to Burcham, Jr. et al., U.S. Pat. No. 5,022,416 to Watson, U.S. Pat. No. 5,103,842 to Strang et al., and U.S. Pat. No. 5,711,320 to Martin. Preferred casing materials include water, sugars and syrups (e.g., sucrose, glucose, and high fructose corn syrup), humectants (e.g., glycerin or propylene glycol), and flavorings (e.g., cocoa and licorice). These additional ingredients also include top layer materials (e.g., flavoring materials such as menthol). See, for example, U.S. Patent No. 4,449,541 to Mays et al. Additives can also be added to tobacco using equipment of the type described in U.S. Patent No. 4,995,405 to Lettau or available from Kohl Maschinenbau GmbH as the Menthol Application System MAS. The selection of specific casing and top layer ingredients depends on factors such as the desired sensory characteristics, and the selection and use of these ingredients will be readily apparent to those skilled in the art of cigarette design and manufacture. See, for example, Gutcho, *Tobacco Flavoring Substances and Methods*, Noyes Data Corp. (1972) and Leffingwell et al., *Tobacco Flavoring for Smoking Products* (1972). The tobacco may be treated, for example, with ammonia or ammonium hydroxide, or otherwise treated to incorporate ammonia (e.g., by the addition of an ammonia salt such as diammonium phosphate). Preferably, the amount of ammonia optionally incorporated into the smokable tobacco is less than about 5 percent, and generally from about 1 to about 3 percent, based on the dry weight of the tobacco.

[0059] Tobacco can be incorporated with smoking articles in forms other than cut filter forms. For example, tobacco leaf and / or reconstituted tobacco sheets can be used as the wrapper of a tobacco-containing component having the form of a cigar, or as the inner wrapper of a double-wrapped cigarette rod. Alternatively, processed tobacco, such as certain types of reconstituted tobacco, can be used as longitudinally extending strands. See, for example, the types of configurations shown in U.S. Pat. No. 5,025,814 to Raker, which is incorporated herein by reference. Furthermore, certain reconstituted tobacco sheets can be formed and rolled or gathered into a desired configuration. Furthermore, molded, compressed, or extruded segments or pieces of tobacco-containing material formed into a desired shape (e.g., strand, tube, cylinder, pellet, etc.) can be incorporated into smoking articles. See, for example, U.S. Patent No. 4,836,225 to Sudoh, U.S. Patent No. 4,893,639 to White, U.S. Patent No. 4,972,855 to Kuriyama et al., and U.S. Patent No. 5,293,883 to Edwards (each of which is incorporated herein by reference). If desired, the finely ground tobacco or tobacco dust can be incorporated into other types of processed tobacco, such as extrusion formulations, reconstituted tobacco sheets, etc. Additionally, the finely ground tobacco or tobacco dust can be contained on a substrate, such as a membrane or screen. If desired, at least a portion of the tobacco can be heat-treated (e.g., in the form of high-temperature dried, toasted, pre-pyrolyzed, condensed volatiles, condensed tobacco smoke components, etc., collected after heating the tobacco) prior to use in the smoking article.

[0060] Various modes and methods for incorporating tobacco into smoking articles, particularly those designed to intentionally avoid combustion of substantially all of the tobacco within those smoking articles, are set forth in U.S. Patent No. 4,947,874 to Brooks et al., U.S. Patent Application Publication No. 2005 / 0016549 to Banerjee et al., and U.S. Patent Application No. 11 / 194,215 to Cantrell et al., filed August 1, 2005, and U.S. Patent Application No. 11 / 377,630 to Crooks et al., filed March 16, 2006, which are incorporated herein by reference. Additionally, tobacco has been incorporated into cigarettes marketed by R.J. Reynolds Tobacco Company under the trade names "Premier" and "Eclipse." See, for example, these types of cigarettes described in Chemical and Biological Studies on New Cigarette Prototypes that Heat Instead of Burn Tobacco, RJ Reynolds Tobacco Company Monograph (1988) and Inhalation Toxicology, 12:5, pp. 1-58 (2000). Tobacco has also been incorporated into smoking articles sold by Philip Morris Inc. under the trade name "Accord."

[0061] As noted above, in some embodiments, the tobacco material 110 may further comprise an aerosol precursor composition. In certain embodiments, the aerosol precursor composition may comprise glycerin or propylene glycol. Preferred aerosol-forming materials include polyhydric alcohols (e.g., glycerin, propylene glycol, and triethylene glycol) and / or water, and any other material that produces a visible aerosol, and any combination thereof. Representative types of aerosol-forming materials are described in U.S. Pat. No. 4,793,365 to Sensabaugh, Jr. et al. and U.S. Pat. No. 5,101,839 to Jakob et al., PCT Application Publication No. WO 98 / 57556 to Biggs et al., and Chemical and Biological Studies on New Cigarette Prototypes that Heat Instead of Burn Tobacco, R.J. Reynolds Tobacco Company Monograph (1988), which are incorporated herein by reference in their entireties. Other representative types of aerosol precursor components and formulations are also described and characterized in U.S. Pat. No. 7,726,320 to Robinson et al., U.S. Pat. No. 8,881,737 to Collett et al., U.S. Pat. No. 9,254,002 to Chong et al., and U.S. Patent Application Publication No. 2013 / 0008457 to Zheng et al., U.S. Patent Application Publication No. 2015 / 0020823 to Lipowicz et al., U.S. Patent Application Publication No. 2015 / 0020830 to Koller, and WO 2014 / 182736 to Bowen et al., the disclosures of which are incorporated herein by reference in their entireties. Other aerosol precursors that may be used include the aerosol precursors incorporated into VUSE® products by RJ Reynolds Vapor Company, BLU™ products by Fontem Ventures BV, MISTIC MENTHOL products by Mistic Ecigs, MARK TEN products by Nu Mark LLC, JUUL products by Juul Labs, Inc., and VYPE products by British American Tobacco.Also desirable is so-called "smoke juice" for electronic cigarettes, available from Johnson Creek Enterprises LLC. Further exemplary aerosol precursor compositions are sold under the trade names BLACK NOTE, COSMIC FOG, THE MILKMAN E-LIQUID, FIVE PAWNS, THE VAPOR CHEF, VAPE WILD, BOOSTED, THE STEAM FACTORY, MECH SAUCE, CASEY JONES MAINLINE RESERVE, MITTEN VAPORS, DR. CRIMMY'S V-LIQUID, SMILEY E LIQUID, BEANTOWN VAPOR, CUTTWOOD, CYCLOPS VAPOR, SICBOY, GOOD LIFE VAPOR, TELEOS, PINUP VAPORS, SPACE JAM, MT. BAKER VAPOR, and JIMMY THE JUICE MAN. Embodiments of the foamable material can be used with aerosol precursor compositions, for example, as described in U.S. Patent Application Publication No. 2012 / 0055494 to Hunt et al., which is incorporated herein by reference in its entirety. Further, the use of foamable materials is described in, for example, U.S. Pat. No. 4,639,368 to Niazi et al., U.S. Pat. No. 5,178,878 to Wehling et al., U.S. Pat. No. 5,223,264 to Wehling et al., U.S. Pat. No. 6,974,590 to Pather et al., U.S. Pat. No. 7,381,667 to Bergquist et al., U.S. Pat. No. 8,424,541 to Crawford et al., U.S. Pat. No. 8,627,828 to Strickland et al., and U.S. Pat. No. 9,307,787 to Sun et al., as well as U.S. Patent Application Publication No. 2010 / 0018539 to Brinkley et al. and PCT Publication No. WO 97 / 06786 to Johnson et al., all of which are incorporated herein by reference in their entireties. Additional description of embodiments of aerosol precursor compositions, including descriptions of tobacco or tobacco-derived components contained therein, is provided in U.S. Patent Application Publication Nos. 2018 / 0020722 and 2018 / 0020723, both to Davis et al., which are incorporated by reference in their entireties.

[0062] As mentioned above, the tobacco material 110 may also include flavorings. As used herein, reference to a "flavoring" refers to a compound or ingredient that can be aerosolized, delivered to a user, and provide a sensory experience in terms of taste and / or aroma. Some examples of flavorings include, but are not limited to, vanillin, ethyl vanillin, cream, tea, coffee, fruit (apple, cherry, strawberry, peach, and citrus fruits, including lime and lemon), maple, menthol, mint, parmint, spearmint, wintergreen, nutmeg, clove, lavender, cardamom, ginger, honey, anise, sage, rosemary, hibiscus, rosehip, yerba mate, guayusa, honeybush, rooibos, yerba santac, pa monniera, ginkgo, ashwagandha, cinnamon, sandalwood, jasmine, cascarilla, cocoa, licorice, and flavors and flavor packages of the types and characteristics traditionally used to flavor cigarettes, cigars, and pipe tobacco. Syrups, such as high fructose corn syrup, can also be used. Some examples of potentially suitable plant-derived compositions are disclosed in U.S. Patent No. 9,107,453 to Dube et al. and U.S. Patent Application Publication No. 2012 / 0152265, both of which are incorporated herein by reference in their entireties. The selection of such additional ingredients will vary based on factors such as the sensory characteristics desired in the smoking article, their affinity for the tobacco material, their solubility, and other physiochemical properties. The present disclosure is intended to encompass any such additional ingredients readily apparent to those skilled in the art of tobacco and tobacco-related or tobacco-derived products. See, for example, Gutcho, *Tobacco Flavoring Substances and Methods*, Noyes Data Corp. (1972) and Leffingwell et al., *Tobacco Flavoring for Smoking Products* (1972), the disclosures of which are incorporated herein by reference in their entireties. It should be noted that reference to flavorings should not be limited to any single flavoring mentioned above, and may in fact represent a combination of one or more flavorings.

[0063] As described above, in some embodiments, the smoking article 100 can include a thermal energy absorber 112 disposed at least partially between the tobacco material 110 and the carbon heat source 108. In various embodiments, the thermal energy absorber can be selected from the group consisting of metals and ceramics. In some embodiments, the thermal energy absorber can be an aluminum (Al) material or an alumina (Al2O3) material. In some embodiments, the thermal energy absorber can include any metal, ceramic, or other suitable material having a specific heat capacity of about 0.1 kJ / kg K to about 3 kJ / kg K, preferably about 0.5 kJ / kg K to about 2 kJ / kg K, and more preferably about 0.75 kJ / kg K to about 1 kJ / kg K. The specifics of materials suitable for use as thermal energy absorbers in the present disclosure can vary depending on the particular embodiment. Suitable materials for use as thermal energy absorbers in the present disclosure can include, but are not limited to, materials having properties such as high thermal stability, suitable specific heat capacity, or high thermal conductivity. Additionally, materials suitable for use as thermal energy absorbers in the present disclosure can be non-toxic, non-hazardous materials with minimal negative health effects.

[0064] In some embodiments, thermal energy absorbers according to the present disclosure may be configured to improve the uniform distribution of heated air across the tobacco material. In some embodiments, the thermal energy absorber may be configured to reduce the peak temperature of the smoking article by about 50°C to about 500°C. In some embodiments, the thermal energy absorber may be configured to reduce the peak temperature of the smoking article by at least about 50°C, or at least about 100°C, or at least about 150°C, or at least about 200°C, or at least about 250°C, or at least about 300°C, or at least about 350°C, or at least about 400°C, or at least about 450°C, or at least about 500°C. In some embodiments, the thermal energy absorber may be configured to provide an average peak temperature in the smoking article of less than about 500°C, or less than about 450°C, or less than about 400°C, or less than about 350°C, or less than about 300°C, or less than about 250°C, or less than about 200°C, or less than about 150°C.

[0065] In various embodiments, the thermal energy absorber can be configured to minimize the reduction in total particulate matter (TPM) emitted during smoking of a smoking article. Advantageously, a thermal energy absorber according to the present disclosure can be configured to provide a similar release of TPM during smoking of a smoking article with the thermal energy absorber compared to a smoking article without the thermal energy absorber, thereby producing a visible aerosol with visual characteristics similar to those of a typical smoking article with the added benefit of a thermal energy absorber. In some embodiments, the thermal energy absorber can be configured to maintain a net pressure drop of between about -20 mmHg and about 20 mmHg, between about -10 mmHg and about 10 mmHg, or about 0 mmHg in the smoking article during smoking, compared to a control sample of a smoking article without the thermal energy absorber. Advantageously, a thermal energy absorber according to the present disclosure can be configured to provide substantially the same pressure drop in a smoking article with the thermal energy absorber compared to a smoking article without the thermal energy absorber, thereby maintaining the same resistance to draw for the user with the added benefit of the thermal energy absorber.

[0066] In one or more embodiments, the thermal energy absorber can be in the form of one or more circular disks. In some embodiments, the one or more circular disks can further comprise a porous or non-porous material. In this regard, FIG. 3 illustrates a thermal energy absorber 112 in the form of a circular disk with a plurality of holes 130 extending longitudinally therethrough. In some embodiments, the circular disk can have a diameter of about 5 mm to about 9 mm, or about 6 mm to about 8 mm, or about 7 mm. In particular embodiments, the circular disk can have a thickness of about 0.1 mm to about 4 mm, or about 1 mm to about 3 mm, or about 2 mm. While in various examples the thermal energy absorber can have a variety of geometric shapes and design parameters, including, for example, a substantially spherical or triangular shape, the thermal energy absorber 112 illustrated in FIG. 3 has a generally cylindrical disk shape with a plurality of holes of substantially similar size and evenly spaced therethrough, although different sizes and / or different spacings are also encompassed. In various other embodiments, the plurality of holes 130 can be irregularly shaped, randomly distributed, distributed in a pattern, or distributed in any other configuration that allows airflow through the thermal energy absorber. In some embodiments, the individual holes can have a diameter of about 0.1 to about 1 mm, or about 0.2 to about 0.5 mm. The thermal energy absorber depicted in FIG. 3 was manufactured using additive manufacturing techniques for precision fabrication of an alumina disk 6.58 mm in diameter and 1.5 mm thick. In the depicted embodiment, the plurality of holes 130 are evenly spaced across the circular disk to uniformly distribute heated air to the downstream tobacco material. In various other embodiments, one or more circular disks can be sufficiently porous so that multiple holes 1 are not required in one or more circular disks. For example, in such embodiments, one or more circular disks can comprise a metal or ceramic material that is sufficiently porous to provide a pressure drop across the smoking article that is lower than the maximum pressure drop limit for such a smoking article. The porosity can range from macroscale porosity to nanoscale porosity. Additionally, such porous metallic or ceramic materials may be in the form of foam materials.

[0067] In some embodiments, the thermal energy absorber 112 can be in the form of a plurality of particles. In various embodiments, the particles can be substantially spherical or irregularly shaped. In some embodiments, the shape of the particles can vary, for example, the particles can be substantially spherical, cubic, cylindrical, or any other suitable three-dimensional shape. In certain embodiments, the thermal energy absorber can include about 5 to about 500 particles, or about 7 to about 300 particles, or about 10 to about 100 particles, or about 12 to about 30 particles, or preferably about 15 to about 20 particles. In certain embodiments, the particles can have a diameter of about 0.1 mm to about 5 mm, or about 0.5 mm to about 4 mm, or about 1 mm to about 3 mm, or about 2 mm. In some embodiments, particularly those embodiments having a larger number of total particles, the particles can have a diameter of less than about 0.1 mm, or less than about 0.05 mm, or less than about 0.01 mm, or less than about 0.005 mm. In some embodiments, the thermal energy absorber 112 in the form of a plurality of particles may be configured such that the number of particles in the plurality of particles gradually decreases the further the particles are from the heat source 108. For example, in some embodiments, the packing density of the thermal energy absorber particles is highest closest to the heat source and lowest farthest from the heat source. Thus, in some embodiments, the packing density of the thermal energy absorber particles may be inversely proportional to the distance of the particles from the heat source. In some embodiments, this inverse correlation may further provide a uniform heat distribution across the tobacco material. In various other embodiments, the thermal energy absorber may be in the form of a hollow sphere. In some embodiments, the hollow portion of the hollow sphere may be filled with paraffin, wax, or any other suitable phase change material. For example, hollow spheres according to such embodiments may provide a thermal energy absorber with reduced mass and changing thermal properties.

[0068] As noted in Figure 4, in one particular embodiment, a smoking article 100 according to the present invention may include multiple thermal energy absorbers 112, which may have substantially the same configuration or may exist in substantially different configurations. For example, as shown in Figure 4, the thermal energy absorber 112 may include a first thermal energy absorbing component 112a in the form of one or more circular disks and a second thermal energy absorbing component 112b in the form of one or more particles (e.g., substantially spherical particles). In such an embodiment, the first component 112a is disposed between the tobacco material 110 and the carbon heat source 108, and the second component 112b is mixed with the tobacco material 110. In some embodiments, the second component 112b may be configured such that the number of particles in the multiple particles gradually decreases as the particles move away from the carbon heat source 108.

[0069] In various other embodiments, the present disclosure provides methods for reducing excessive heating in a smoking article, the methods comprising providing a smoking article comprising: a carbon heat source; a tobacco material; a thermal energy absorber; and an outer wrap material circumscribing at least a portion of the smoking article, wherein the smoking article is defined by an upstream lighting end and a downstream mouth end; and disposing the thermal energy absorber at least partially between the tobacco material and the carbon heat source such that, when the carbon heat source is lit, the peak temperature of the smoking article is reduced by between about 25°C and about 75°C, and between about 475°C and about 525°C. In some embodiments, the thermal energy absorber prepared by the present methods may be configured to reduce the peak temperature of the smoking article by at least about 50°C, or at least about 100°C, or at least about 150°C, or at least about 200°C, or at least about 250°C, or at least about 300°C, or at least about 350°C, or at least about 400°C, or at least about 450°C, or at least about 500°C. In some embodiments, the thermal energy absorber prepared by the present methods may be configured to provide an average top temperature in the smoking article of less than about 500°C, or less than about 450°C, or less than about 400°C, or less than about 350°C, or less than about 300°C, or less than about 250°C, or less than about 200°C, or less than about 150°C. In some embodiments, the methods according to the present disclosure may further include providing a thermal energy absorber configured to improve uniform distribution of heated air across the smoking article. In some embodiments, the methods of the present disclosure may further include providing a filter material positioned proximate the downstream mouth end of the smoking article.

[0070] Many modifications and other embodiments of the present disclosure will come to mind to one skilled in the art to which this disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. It is to be understood, therefore, that the present disclosure is not limited to the specific embodiments disclosed herein, but 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 generic and descriptive sense only and not for purposes of limitation. [Example]

[0071] To investigate the performance of the thermal energy absorbers described herein, samples of two different types of heat-not-burn tobacco (hereinafter referred to as "HNB1" and "HNB2") were prepared and tested according to the following method.

[0072] The HNB1 samples were handcrafted with a 13mm x 27mm tip patch made from a combination of tobacco bead and tobacco rod sections. A thermal energy absorber was embedded between the tobacco bead and the carbon heater. These samples used a dual filter system with a 14mm long CA filter and a 7mm long HAT filter. A total of 31 samples were prepared according to this method and are listed below. 5 HNB1 control samples Five HNB1 samples with aluminum discs Three HNB1 specimens with alumina ceramic discs 3 HNB1 samples with 10 aluminum spheres 3 HNB1 samples with 15 aluminum balls 3 HNB1 samples with 20 aluminum spheres Three HNB1 samples with 10 ceramic alumina balls Three HNB1 samples with 15 ceramic alumina balls Three HNB1 samples with 20 ceramic alumina balls

[0073] HNB2 samples were prepared from handmade smoking articles containing a 12 mm carbon tip (8 mm protruding from the paper wrap), 13 mm of base tobacco material (glycerin-loaded cast sheet) behind the carbon tip (covered with aluminum foil), a 37 mm tobacco rod (optionally loaded with glycerin), and a 14 mm cellulose acetate filter, followed by a 7 mm hollow acetate tube. The HNB2 samples were then modified by cutting a straight line into the tobacco rod between the carbon heater and the base tobacco section (approximately 4 mm deep) using a utility knife, 12 mm from the lighting end of the tobacco rod (the length of the heat source). A thermal energy absorber was then inserted into the cut behind the heat source. The straight line cut was then wrapped in 13 mm x 27 mm tipping paper, which was glued to the rod to seal all voids. A total of 76 samples were prepared according to this method and are listed below. 10 HNB2 reference samples Three HNB2 samples with aluminum discs Three HNB2 specimens with ceramic alumina discs Three HNB2 samples with five aluminum spheres Three HNB2 samples with eight aluminum spheres 3 HNB2 samples with 10 aluminum spheres 10 HNB2 samples with 15 aluminum spheres 10 HNB2 samples with 18 aluminum spheres 10 HNB2 samples with 20 aluminum spheres Three HNB2 samples with five ceramic alumina spheres Three HNB2 samples with seven ceramic alumina balls Three HNB2 samples with 10 ceramic alumina spheres 3 HNB2 reference samples with menthol 3 HNB2 samples with 15 aluminum balls with menthol 3 HNB2 samples with 18 aluminum balls with menthol 3 HNB2 samples with 20 aluminum balls with menthol

[0074] [Example 1] Average apex temperature profiles of the best candidate HNB1 and HNB2 samples with thermal energy absorbers (Fig. 5).

[0075] Thermal analysis experiments were performed on all HNB1 and HNB2 samples to provide temperature profiles along the cigarette rod. Using a hypodermic needle, two 0.50 mm holes were drilled into the tobacco rod, 15 mm and 24 mm from the lighting end. A 0.26 mm probe diameter K-type thermocouple (Omega Engineering, Norwalk, CT) was then inserted into the hole and sealed with a small amount of tipping glue (20009766 glue). The thermocouple insertion depth was approximately 3.5 mm, with the thermocouple tip positioned approximately at the centerline of the cigarette rod. HNB1 and HNB2 samples were held in place by a custom-made labyrinth holder of conventional design. The "smoking" process was performed using a custom-built smoking machine equipped with a Schneider Electric Motion USA MDrivePlus 17 stepper motor. The stepper motor was programmed to the specific puff regime described below. The use of the stepper motor allowed for digital control of piston motion. Finally, data collection was performed using an IntelliLogger (Logic Beach, La Mesa, Canada) and data was transferred to a computer for further analysis using HyperWare II software (Logic Beach, La Mesa, Canada).

[0076] Tests were conducted on HNB1 and HNB2 samples containing a circular aluminum disc, a circular ceramic alumina disc, 5, 8, 10, 15, 18, and 20 aluminum spheres, and 5, 7, 10, 15, 18, and 20 ceramic alumina spheres. All products were smoked using the custom-built smoking machine described above, with a 55 mL puff volume and a 2-second puff duration for 19 puffs. The first three puffs were considered ignition puffs and were essentially performed consecutively. The inter-puff intervals between puffs 1 and 2 and between puffs 2 and 3 were approximately 3 seconds. The heat source was preheated for approximately 1 second using an electric lighter (Borgwaldt Electric Lighter R29) before puff 1, and ignition contact was maintained between the ignition tip and the heat source until the end of puff 2. Puff 3 was performed with the lighter removed from the heat source. Following puff 3, the interval between the start of subsequent puffs was maintained at 30 seconds. The temperature of the tobacco core (rod centerline) was measured by a thermocouple at lengths of 15 mm and 24 mm, and a temperature profile was generated from this data read by the IntelliLogger.

[0077] The peak temperature within each puff was identified and designated the "peak temperature" of the puff. Samples whose maximum temperatures (taken at 15 mm) were 100°C to 300°C lower than those of the HNB2 control sample were selected as the "best" candidates for high performance. Based on the testing, HNB2 samples with 15, 18, and 20 aluminum spheres were selected as the best candidates. As seen in Figure 5, average peak temperature profiles were reported based on testing of the control HNB2 rod without aluminum spheres and HNB2 rods containing 15, 18, and 20 aluminum spheres. The sample HNB2 rod containing 18 aluminum spheres experienced the greatest peak temperature decrease during smoking (with a decrease of over 300°C). However, all three sample rods experienced peak temperature decreases when compared to the control sample.

[0078] [Example 2] Average pressure drop data of the best candidate HNB1 and HNB2 samples with thermal energy absorber (Figure 6)

[0079] To accurately compare two cigarette rods with different tobacco types or compositions, it is essential to assess and compare the average pressure drop along the rod. Air pressure drop is directly proportional to the resistance to the air drawing force required to draw the aerosol through the rod and filter. It is known that the pressure drop and resistance to drawing of a cigarette directly affect the cigarette's performance during smoking. A pressure drop unit integrated into the Quality Test Module (QTM) device was used to measure the air pressure drop of the sample. The QTM provided the dilution ratio and pressure drop through the filter, which were measured and reported separately with the dilution hole open and with the dilution hole closed. The dilution hole for the QTM test was prepared using a laser orifice tool that drilled a hole in the tobacco rod downstream of the carbon tip. For the closed sample test, the dilution hole was covered while the QTM was running, allowing air to enter the sample only through the carbon tip. For the open sample test, the dilution hole was left exposed while the QTM was running, allowing air to enter the sample through both the carbon tip and the dilution hole. The QTM was operated at a speed of 17.5 cm per second. 3 The QTM also provided other physical properties of the sample, including the weight of the bar and the circumference of the bar.

[0080] Specifically, in Figure 6, a pressure drop analysis was performed on the candidate samples deemed to exhibit the best performance in the thermal analysis described in Example 1. The samples tested included HNB2 samples with 15, 18, and 20 aluminum spheres, as well as an HNB2 control sample for comparison. As seen in Figure 6, pressure drop data was reported for both open-hole and closed-hole tests based on testing of the control HNB2 rod and HNB2 rods containing 15, 18, and 20 aluminum spheres. As shown in Figure 6, the average pressure drop across the HNB2 rods with aluminum spheres ranged from -5 mmHg to 10 mmHg when compared to the control HNB2 rod without aluminum spheres. It was observed that the pressure drop across the HNB2 control sample was substantially similar compared to the best candidate HNB2 sample. This confirms that the addition of a thermal energy absorber does not significantly affect the pressure drop across the HNB2 sample, resulting in a change in product performance in terms of the resistance to inhalation experienced by the user due to the change in pressure drop.

[0081] [Example 3] Total particulate matter emitted by the best candidate HNB1 and HNB2 samples with thermal energy absorbers (Figure 7).

[0082] The total particulate matter (TPM) emitted during smoking of a smoking article can affect the visibility of the aerosol generated from the smoking article. For example, a reduction in the TPM emitted during smoking of a smoking article can reduce the visibility of the aerosol generated from the smoking article.

[0083] TPM analysis experiments were performed using the custom-built smoking machine described in Example 1. The smoking machine was programmed to perform a 50 / 30 / 3 puff regime (50 ml puff volume / 30-second puff frequency / 3-second puff duration) and was used to quantify total particulate matter (TPM) during smoking of test samples. A 44 mm diameter Cambridge filter pad was placed in the pad holder and weighed for an initial mass. The holder was then connected to the smoking machine and the sample was inserted. Twelve puffs were performed for each sample. The filter pad was then removed from the holder and its final mass was measured using a high-precision scale. The difference in filter pad mass before and after each test gave an overall TPM value, which was averaged over the 12 puffs to calculate the mass on a mg / puff basis for each sample tested.

[0084] As seen in Figure 7, the samples tested included HNB2 samples with 15, 18, and 20 aluminum spheres, as well as an HNB2 control sample for comparison. As seen in Figure 7, the HNB2 control sample, the HNB2 sample containing 15 aluminum spheres, the HNB2 sample containing 18 aluminum spheres, and the HNB2 sample containing 20 aluminum spheres produced TPM values ​​of 1.58, 1.17, 1.00, and 1.00 mg / puff, respectively. As seen in Figure 7, the results suggest that the TPM produced by the HNB2 control sample was only slightly higher than that produced by the HNB2 sample containing the thermal energy absorber. Furthermore, it was noted that the observed TPM values ​​were inversely proportional to the number of aluminum spheres loaded into the HNB2 rod. Thus, the amount of visible aerosol produced by these samples was less affected by the use of fewer aluminum spheres, resulting in reduced charring of the tobacco rod elements. This test also confirmed that the HNB2 sample, having 15 aluminum spheres, provided the best combination of both the least reduction in TPM values ​​and the greatest reduction in scorch on the tobacco rod elements.

Claims

1. A smoking article comprising: Upstream firing end and downstream mouth end; a carbon heat source disposed proximate to said ignition end; an outer wrap circumscribing at least a portion of the smoking article; a tobacco material disposed downstream of the carbon heat source and configured to be heated without combustion; a filter disposed downstream of the tobacco material and adjacent the downstream mouth end of the smoking article; and A thermal energy absorber in the form of a plurality of particles configured to be partially mixed within the tobacco material or completely mixed within the tobacco material. Including, the carbon heat source, the tobacco material, and the thermal energy absorber are arranged such that air heated by the carbon heat source passes through the tobacco material; the thermal energy absorber enhances the even distribution of heat from the air to the tobacco material along the length of the tobacco material; A smoking article, wherein the thermal energy absorber comprises a material having a specific heat capacity of 0.1 kJ / kg K to 3 kJ / kg K.

2. 10. The smoking article of claim 1, wherein the tobacco material further comprises one or more of a tobacco extract, an aerosol precursor composition, and a flavoring material.

3. 10. The smoking article of claim 1, wherein the tobacco material is in one or more of shredded or granular form.

4. The smoking article of claim 1 , wherein the thermal energy absorber comprises a metallic material.

5. The smoking article of claim 1 , wherein the thermal energy absorber comprises a ceramic material.

6. The smoking article of claim 1 , wherein the thermal energy absorber is configured to distribute heat to the tobacco material.

7. The smoking article of claim 1 , wherein the filter comprises a plurality of individual segments.

8. The smoking article of claim 7 , wherein the plurality of individual segments are hollow.

9. 10. The smoking article of claim 1, wherein the carbon heat source has a plurality of air inlet holes extending longitudinally therethrough.

10. The smoking article of claim 1 , wherein the particles are substantially spherical.

11. 10. The smoking article of claim 1, wherein the thermal energy absorber comprises between 3 and 500 particles.

12. 11. The smoking article of claim 10, wherein the particles have a diameter of 0.005 mm to 5 mm.

13. 10. The smoking article of claim 1, wherein the thermal energy absorber is configured to reduce the peak temperature of the smoking article by 50°C to 500°C.

14. 1. A method for reducing excessive heating in a smoking article, comprising: A smoking article is provided, the smoking article comprising: a carbon heat source; a tobacco material disposed downstream of the carbon heat source and configured to heat without combustion; a thermal energy absorber in the form of a plurality of particles; and an outer wrap circumscribing at least a portion of the smoking article, wherein the smoking article is defined by an upstream lighting end and a downstream mouth end; and disposing the thermal energy absorber at least partially between the tobacco material and the carbon heat source such that when the carbon heat source is lit, the peak temperature of the smoking article is reduced by 50°C to 500°C; Including, the carbon heat source, the tobacco material, and the thermal energy absorber are arranged such that air heated by the carbon heat source passes through the tobacco material; the thermal energy absorber enhances the even distribution of heat from the air to the tobacco material along the length of the tobacco material; The method, wherein the thermal energy absorber comprises a material having a specific heat capacity of 0.1 kJ / kg K to 3 kJ / kg K.

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