THERMAL ENERGY ABSORBENTS FOR TOBACCO HEATING PRODUCTS.

Abstract

The present invention provides heat absorbers for use in smoking articles. In one embodiment, the smoking article may comprise an outer casing enclosing at least a portion of the smoking article, wherein the smoking article is defined by an illumination end at the upper portion and a mouthpiece end at the lower portion, a carbon heat source positioned close to the illumination end, a tobacco material positioned downstream of the carbon heat source and spatially separated from the mouthpiece end of the smoking article, and a heat absorber at least partially positioned between the tobacco material and the carbon heat source.

Description

THERMAL ENERGY ABSORBENTS FOR TOBACCO HEATING PRODUCTS Field of Invention The present invention relates to smoking articles, sometimes called tobacco heating products, capable of heating tobacco materials without burning the tobacco materials contained in the tobacco heating products. Background of the Invention Many smoking accessories have been proposed over the years as improvements to or alternatives for smoking products based on tobacco combustion. Some examples of these alternatives include devices that burn a solid or liquid fuel to transfer heat to the tobacco. Such devices, commonly known as smoking accessories or tobacco heating products, allow tobacco materials to be heated without significant combustion or burning of the tobacco material itself. The goal of these improvements or alternatives to smoking accessories has generally been to provide the sensations associated with smoking cigarettes, cigars, or pipes without producing substantial amounts of incomplete combustion and pyrolysis products that can be harmful to the user.See, for example, the various alternative smoking articles, aerosol delivery devices, and heat-generating sources set forth in US patent 7,726,320 granted to Robinson et al., as well as US patent applications 2013 / 0255702 by Griffith Jr. et al., 2014 / 0096781 by Sears et al., and 2015 / 0216232 by Bless et al., which are incorporated herein by reference. Furthermore, articles that produce the flavor and sensation of smoking by heating tobacco, tobacco-derived materials, or other plant-derived materials, without a significant degree of burning or combustion, have suffered from inconsistent and detrimental performance characteristics. For example, overheating tobacco heating products can cause unwanted scorching or burning of internal tobacco materials, which can be harmful to a user. Consequently, it may be desirable to provide a smoking article that can provide the sensations of smoking cigarettes, cigars, or pipes without overheating the tobacco material and with advantageous performance characteristics. Summary of the Invention The present invention relates to thermal energy absorbers for smoking articles, such as / sometimes referred to as tobacco heating products. In various embodiments, a smoking article may comprise an outer casing enclosing at least a portion of the smoking article, wherein the smoking article is defined by a cj / nnn / zznz / B / Ywi - A lighting end at the top and a nozzle end at the bottom, a carbon heat source positioned close to the lighting end, a tobacco material positioned downstream of the carbon heat source, and a heat absorber at least partially positioned between the tobacco material and the carbon heat source. In some embodiments, the heat absorber may comprise a metallic or ceramic material. In some embodiments, the heat absorber may be aluminum or an alumina material. In several embodiments, the heat absorber is configured to increase the uniform distribution of heated air through the tobacco material. In certain embodiments, the heat absorber is in the form of one or more circular discs. In some embodiments, one or more circular discs have an individual diameter of approximately 5 mm to approximately 9 mm and a thickness of approximately 0.1 mm to approximately 4 mm. In certain embodiments, one or more circular discs may comprise a plurality of holes. In several other embodiments, the plurality of holes may be irregularly shaped, randomly distributed, or arranged in a pattern. In certain embodiments, the heat absorber may be in the form of a plurality of particles. In some embodiments, the particles are substantially spherical or hollow spheres. In some embodiments, the heat absorber may comprise from approximately 3 to approximately 500 particles. In several embodiments, the particles may have a diameter from approximately 0.1 mm to approximately 5 mm. In some embodiments, the heat absorber comprises a material with a specific heat capacity from approximately 0.1 kJ / kg K to approximately 3 kJ / kg K. In several embodiments, the tobacco material may also include one or more tobacco extracts, an aerosol precursor composition, and a flavoring. 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 through it. In several embodiments, the heat absorber may be configured to lower the peak temperature of the smoking article by between approximately 25°C and approximately 75°C and between approximately 475°C and approximately 525°C. In some of these embodiments, the heat absorber may be configured to lower the temperature by between approximately 50°C and approximately 500°C. In some embodiments, the heat absorber may be configured to lower a total particulate matter (TPM) released during the smoking action of the smoking article.In some other embodiments, the nozzle end in the lower portion may also comprise a filter material. Some modalities provide a method for reducing overheating in a smoking article; the method may comprise: providing a smoking article that cj / nnn / zznz / B / Ywi - 3 comprises a carbon heat source, a tobacco material, a heat absorber, and an outer casing enclosing at least a portion of the smoking article, wherein the smoking article is defined by an illumination end at the upper portion and a mouthpiece end at the lower portion; and placing the heat absorber at least partially between the tobacco material and the carbon heat source such that the peak temperature of the smoking article decreases by approximately 50°C to approximately 500°C when the carbon heat source is ignited. In some embodiments, the heat absorber may be configured to increase the uniform distribution of heated air through the tobacco material. In some embodiments, the heat absorber may be configured to decrease a total particulate matter (TPM) released during the smoking action of the smoking article.In some other embodiments, the nozzle end in the lower portion may also comprise a filter material. The present invention includes, without limitation, the following embodiments: Embodiment 1: A smoking article, comprising an outer casing that circumscribes at least a portion of the smoking article, wherein the smoking article is defined by an illumination end in the upper portion and a mouthpiece end in the lower portion; a carbon heat source positioned close to the illumination end; a tobacco material located downstream of the carbon heat source; and a heat absorber at least partially positioned between the tobacco material and the carbon heat source. Mode 2: The smoking article according to mode 1, wherein the heat energy absorber comprises one or more of a metallic or ceramic material. Mode 3: The smoking article according to any of modes 1-2, wherein the heat energy absorber comprises one or more aluminum or alumina materials. Mode 4: The smoking article according to any of modes 1-3, wherein the thermal energy absorber is configured to increase the uniform distribution of heated air through the tobacco material. Modality 5: The smoking article according to any of modalities 1-4, wherein the thermal energy absorber is in the form of one or more circular discs. Modality 6: The smoking article according to any of modalities 1-5, wherein one or more circular discs have an individual diameter of approximately 5 mm to approximately 9 mm and a thickness of approximately 0.1 mm to approximately 4 mm. Modality 7: The smoking article according to any of modality 1-6, wherein one or more circular discs comprise a plurality of holes. Modality 8: The smoking article according to any of modalities 1-7, wherein the plurality of holes has an irregular shape, is randomly distributed, or is distributed in a pattern. cj / nnn / zznz / B / Ywi - 4Modality 9: The smoking article according to any of modalities 1-4, wherein the thermal energy absorber is in the form of a plurality of particles. Modality 10: The smoking article in accordance with any of modalities 14 and 9, wherein the particles are substantially spherical in shape. Modality 11: The smoking article according to any of modalities 1, 4 and 9-10, wherein the heat energy absorber comprises from approximately 3 to approximately 500 particles. Modality 12: The smoking article in accordance with any of modalities 14 and 9-11, wherein the particles have a diameter of approximately 0.005 mm to approximately 5 mm. Modality 13: The smoking article of any of modality 1-12, wherein the heat energy absorber comprises a material having a specific heat capacity of approximately 0.1 kJ / kg K to approximately 3 kJ / kg K. Modality 14: The smoking article according to any of modalities 113, wherein the tobacco material further includes one or more of a tobacco extract, an aerosol precursor composition, and a flavoring. Modality 15: The smoking article in accordance with any of modalities 114, wherein the tobacco material is in one or more of a crushed or particulate form. Modality 16: The smoking article according to any of modality 115, wherein the carbon heat source has a plurality of air inlet holes extending longitudinally through it. Mode 17: The smoking article according to any of modes 116, wherein the heat energy absorber is configured to decrease the peak temperature of the smoking article by approximately 50°C to approximately 500°C. Modality 18: The smoking article according to any of modalities 117, wherein the mouthpiece end of the lower portion further comprises a filter material. Modality 19: A method for reducing excess heat in a smoking article, the method comprising providing a smoking article comprising a carbon heat source, a tobacco material, a heat energy absorber, and an outer covering circumscribing at least a portion of the smoking article, wherein the smoking article is defined by an illumination end in the upper portion and a mouthpiece end in the lower portion; and placing the heat energy absorber at least partially between the tobacco material and the carbon heat source such that the peak temperature of the smoking article decreases by approximately 50°C to approximately 500°C when the carbon heat source is ignited. Mode 20: The method in accordance with mode 19, wherein the thermal energy absorber is configured to increase the uniform distribution of heated air through the tobacco material. cj / nnn / zznz / B / Ywi Mode 21: The method in accordance with any of modes 19-20, wherein the nozzle end of the lower portion further comprises a filter material. These and other features, aspects, and advantages of the present invention will become apparent from a reading of the following detailed description together with the accompanying drawings, which are briefly described below. The invention includes any combination of two, three, four, or more of the embodiments mentioned above, as well as combinations of two, three, four, or more features or elements set forth in this application, regardless of whether such features or elements are expressly combined in a specific embodiment description herein. This description is intended to be read holistically, such that any separable feature or element of the invention, in any of its various aspects and embodiments, should be considered as being combinable unless the context clearly dictates otherwise. Brief Description of the Figures Having thus described the aspects of the present invention in the above general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and in which: Figure 1 illustrates a partial cross-sectional view of a smoking article according to an exemplary embodiment of the present invention and includes a heat source, a tobacco material, and a thermal energy absorber; Figure 2 illustrates a partial cross-sectional view of a lighting end in the upper portion of a smoking article according to an exemplary embodiment of the present invention, which includes a heat source support; Figure 3 illustrates a partial cross-sectional view of a thermal energy absorber according to an exemplary embodiment of the present invention; Figure 4 illustrates a partial cross-sectional view of a smoking article according to an exemplary embodiment of the present invention, which includes thermal energy absorbers in the form of a plurality of particles; Figure 5 shows a graph illustrating the average peak temperature profiles for smoking articles without thermal energy absorbers and smoking articles including thermal energy absorbers according to the example embodiments of the present invention; Figure 6 shows a graph illustrating the average pressure drop profiles for smoking articles without heat absorbers according to the example embodiments of the present invention; cj / nnn / zznz / B / Ywi Figure 7 is a graph illustrating the total particulate matter (TPM) released during the action of smoking smoking articles with and without thermal energy absorbers according to the embodiment examples of the present invention. Detailed Description of the Invention The present invention will be described in greater detail below with reference to exemplary embodiments thereof. These exemplary embodiments are described to ensure that this disclosure is comprehensive and complete, and fully conveys the scope of the invention to those skilled in the art. Accordingly, the present invention can be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided to enable the present application to satisfy applicable legal requirements. As used in the detailed description and appended claims, the singular forms a, an, the, and the like include plural referents unless the context clearly dictates otherwise.Furthermore, although reference may be made within this document to quantitative measurements, values, geometric relationships or the like, unless otherwise indicated, any or more, if not all, may be absolute or approximate to account for acceptable variations that may occur, such as those due to engineering tolerances or the like. As described below, the examples of embodiments of the present invention relate to heat absorbers for use in smoking articles, such as tobacco heating products. The use of heat absorbers can prevent smoking articles from overheating, which causes unwanted scorching / burning of internal tobacco materials and charring of the cigarette wrapper or mouthpiece. Additionally, overheating of smoking articles can contribute to negative sensory attributes and lead to the release of certain components of the tobacco materials. Many components of tobacco cigarette smoke are products of incomplete combustion (pyrolysis) and thermogenic degradation of tobacco cigarettes through heat (thermogenic degradation).Typical markers of pyrolysis and thermogenic degradation of tobacco cigarettes are acetaldehyde, benzo[a]pyrene, and carbon monoxide. The use of heat absorbers placed downstream of a carbon heat source can decrease the degree of overheating or pyrolysis in smoking articles and thus reduce the negative effects associated with overheating of tobacco materials in smoking articles. Some embodiments of smoking articles according to the present invention use a flammable heat source to heat a material (preferably without burning the material to any significant degree) to form an inhalable substance (e.g., cj / nnn / zznz / B / Ywi - 7. Tobacco products heated with carbon). Preferably, the material is heated without burning it to any significant degree. The components of such systems are in the form of articles that are substantially compact to be considered “portable” devices. That is, the use of components of preferred smoking articles does not result in the production of smoke in the sense that the aerosol results primarily from byproducts of the combustion or pyrolysis of the tobacco, but rather the use of these preferred systems results in the production of vapors from heating, without combustion or burning of the tobacco incorporated therein.In some examples, the components of smoking articles can be characterized as heat-not-burn cigarettes, and those heat-not-burn cigarettes preferably incorporate tobacco and / or tobacco-derived components and thus deliver tobacco-derived components in aerosol form. Smoking articles can provide many of the sensations (e.g., inhalation and exhalation rituals, types of flavors or smells, organoleptic effects, physical sensation, usage rituals, visual cues such as those provided by visible aerosol, and the like) of smoking a cigarette, cigar, or pipe by lighting and burning tobacco (and thus inhaling tobacco smoke), without any substantial degree of combustion of any component thereof. For example, the user of smoking articles according to some embodiments of the present invention can hold and use said component in the same manner as a smoker uses a traditional type of smoking article, position themselves at one end of said article to inhale the aerosol produced by the article, take or draw inhalations at selected time intervals, and so forth. While the systems are generally described herein in terms of modalities associated with smoking articles, it should be understood that the mechanisms, components, features, and methods can be incorporated in many different forms and associated with a variety of articles. For example, the description provided herein may be employed in conjunction with modalities of traditional smoking articles (e.g., cigarettes, cigars, pipes, etc.), heat-not-burn cigarettes, and related packaging for any of the products disclosed herein. Accordingly, it should be understood that the description of the mechanisms, components, features, and methods disclosed is discussed in terms of modalities related to smoking articles only by way of example, and may be incorporated and used in a wide variety of products and methods. The smoking articles of the present invention may also be characterized as vapor-producing articles or drug delivery articles. Therefore, such articles or devices may be adapted to provide one or more substances (e.g., flavors and / or active pharmaceutical ingredients) in an inhalable form or state. For example, the inhalable substances may be substantially in vapor form (i.e., a substance that is in the gaseous phase at a temperature below its critical point). c / / nnn / zznz / B / Ywi 8Alternatively, inhalable substances 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 intended to include vapors, gases, and aerosols of a form or type suitable for human inhalation, whether or not visible, and in a form that may or may not be considered smoke-like. The physical form of the inhalable substance is not necessarily limited by the nature of the innovative devices but may depend on the nature of the medium and the inhalable substance itself insofar as it exists in a vapor or aerosol state. In some embodiments, the terms vapor and aerosol may be interchangeable. Therefore, for simplicity, the terms vapor and aerosol used to describe aspects of the present invention are understood to be interchangeable unless otherwise indicated. In some embodiments, the smoking articles of the present invention may comprise an outer casing enclosing at least a portion of the smoking article, wherein the smoking article is defined by an illumination end at the upper portion and a mouthpiece end at the lower portion, a heat source positioned near the illumination end, a tobacco material positioned downstream of the heat source and spatially separated from the mouthpiece end of the smoking article, and at least one heat absorber positioned at least partially between the tobacco material and the carbon heat source. Alternative formats, configurations, and arrangements of various heat absorbers, smoking articles, and components within the smoking articles of the present invention will become apparent in light of the following further description. Thus, Figure 1 illustrates a smoking article 100 according to an exemplary embodiment of the present invention. The smoking article 100 may include an outer casing 102 enclosing at least a portion of the smoking article 100, wherein the smoking article is defined by an illumination end in the upper portion 104 and a mouthpiece end in the lower portion 106. In some embodiments, the smoking article 100 may further include a heat source 108, a tobacco material 110, and a heat absorber 112. In certain embodiments, the heat source 108 may be positioned close to the illumination end 104. In certain embodiments, the tobacco material 110 may be positioned downstream of the carbon heat source 108 and, optionally, spatially separated from the mouthpiece end 106 of the smoking article 100.In some embodiments, the thermal energy absorber 112 may be at least partially positioned between the tobacco material 110 and the heat source 108. In various embodiments, the smoking articles according to the present invention can have a variety of general shapes, including, but not limited to, a general shape that can be defined as substantially rod-like, substantially tubular, or substantially cylindrical. In the embodiment of Figure 1, article 100 has a cross-section cj / nnn / zznz / B / Ywi - 9 substantially round cross-section; however, other cross-sectional shapes (e.g., oval, square, triangle, etc.) are also encompassed by the present invention. Therefore, such language, which is descriptive of the physical shape of the article, can also be applied to its individual components. On the other hand, the alignment of the components within the smoking article of the present invention may vary between different embodiments. In some embodiments, the heat absorber may be placed entirely between the heat source and the tobacco material. In other embodiments, at least a portion of the heat absorber may be within the tobacco material, such that the heat absorber may be only partially between the heat source and the tobacco material. Other configurations are not necessarily excluded; for example, the heat absorber may be entirely within the tobacco material, such that the heat absorber is not placed between the heat source and the tobacco material.In general, the heat source can be placed close enough to the tobacco material so that the heat from the heat source can heat, without combusting or burning, the tobacco material (as well as, in some modalities, one or more flavorings, medications, or the like that may also be provided for delivery to a user) and form an aerosol for delivery to the user. Other components may be used in the smoking article of the present invention. For example, referring again to Figure 1, the smoking article 100 may include a filter 114 located downstream of the tobacco material 110 and near the mouthpiece end 106 of the lower portion of the smoking article 100. In various embodiments, the filter 114 may be made of cellulose acetate or polypropylene material. The filter 114 may additionally or alternatively contain tobacco strands containing material, as described in US Patent 5,025,814 granted to Raker et al., which is incorporated herein by reference in its entirety. In various embodiments, the filter 114 may increase the structural integrity of the mouthpiece end of the smoking article 100 and / or provide filtering capacity, if desired, and / or provide inhalation resistance. In some embodiments, the filter may comprise discrete segments.For example, some embodiments may include a segment that provides filtration, a segment that provides inhalation resistance, a hollow segment that provides space for the aerosol to cool, a segment that provides greater structural integrity, other filter segments, and any or any combination of the aforementioned. In several additional embodiments, components may exist between the tobacco material 110 and the mouthpiece end 106 of the smoking article 100, in addition to the filter 114.For example, in some embodiments, one or any combination of the following may be placed between the tobacco material 110 and the mouthpiece end 106 of the smoking article 100: an air space; a hollow tube structure; phase-change materials for cooling the air; flavor-releasing media; ion-exchange fibers capable of selective chemical adsorption; aerogel particles as a filter medium; and other suitable materials. Some cj ζηηη / ζζηζ / Β / γίΛΐ. Ten examples of possible phase-change materials include, but are not limited to, salts such as AgNO3, AlCl3, TaCl3, InCl3, SnCl2, AlCl3, and Til4; 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. Further examples are described in US patent 8,430,106 granted to Potter et al., which is incorporated herein by reference in its entirety. As noted previously, in various embodiments, the smoking article 100 may comprise an outer wrapper 102 enclosing at least a portion of the smoking article 100. In some embodiments, the wrapping material of the outer wrapper 102 may comprise a heat-transfer-resistant material, which may include paper or other fibrous material, such as cellulose. The wrapping material used as an outer wrapper to enclose smoking articles may vary. Examples of wrapping material types are known from US patents 4,938,238 and 5,105,837, both granted to Barnes et al. Additionally, some wrapping materials are known from US patent application 2005 / 0005947 to Hampl, Jr. et al. and PCT application publication WO 2005 / 039326 to Rasouli et al., where inner wrapping materials of a configuration called double wrapping may be employed.An exemplary type of heat-conducting wrapper material is set forth in U.S. Patent 5,551,451 granted to Riggs et al.; and other suitable wrapper materials are set forth in U.S. Patent 5,065,776 granted to Lawson et al. and U.S. Patent 6,367,481 granted to Nichols et al.; each of which is incorporated herein by reference. Some examples of wrapper materials, such as paper and metal foil laminates, and papers used as an outer circumscribed wrapping of the heat-generating segment, have been incorporated within the types of cigarettes commercially distributed under the trade names Premier and Eclipse by R.J. Reynolds Tobacco Company. Other representative wrapper materials, and processed wrapper materials, suitable for use in the manufacture of cigarettes are set forth in U.S. Patent 5,220,930 granted to Gentry; 6,976,493 granted to Chapman et al.; and 7,047,982 awarded to Seymour et al.and in US patent application 11 / 377,630 filed March 16, 2006, by Crooks et al., each of which is incorporated herein by reference. The outer wrapper material 102 may also include at least one filler material embedded or dispersed within the fibrous material. In various embodiments, the filler material may be in the form of water-insoluble particles. In addition, the filler material may incorporate inorganic components. In various embodiments, the outer wrapper may consist of multiple layers, such as a bulk underlying layer and an overlay layer, like a typical cigarette wrapper. Such materials may include, for example, lightweight rag fibers such as flax, hemp, sisal, rice straw, and / or esparto grass. The outer wrapper 102 may also include a material typically used in a filter element of a conventional cigarette, such as cellulose acetate. cj / nnn / zznz / B / Ywi-11 In some embodiments, the outer casing 102 may further comprise a heat source support 120 positioned at least near the lighting end 104 of the smoking article 100. In several embodiments, the heat source support 120 may enclose the heat source 108 at a proximal end 120a of the heat source support 120, and the heat energy absorber 112 at a distal end 120b of the heat source support 120, as shown in Figure 2. In several embodiments, the heat source support 120 may possess a certain degree of heat resistance and may have a substantially tubular shape. In some embodiments, the heat source support 120 may contain the heat source 108 such that a predetermined length of the heat source 108 projects from the proximal end of the heat source support 120.In certain embodiments, the heat source support 120 may have a peripheral wall with a laminated, multi-layered structure. For example, the peripheral wall may include one or more laminated layers, metal layers, and paper layers bonded together. In certain embodiments, one or more metallic layers may be included in the heat source support 120 such that when the carbon heat source 108 is burned and the outer envelope 102 is heated by the heat from the carbon heat source 108, one or more metallic layers maintain the heating temperature of the outer envelope 102 below its combustion temperature. Examples of heat source supports for carbon heat sources are described in US patent application 2018 / 0317560 to Shinozaki et al., which is incorporated herein by reference in its entirety. With continued reference to Figure 1, in various embodiments, the smoking article 100 may comprise a heat source 108 located near the lighting end 104. In certain embodiments, the carbon heat source 108 may include combustible carbonaceous materials of various types. In some other embodiments, the carbon heat source 108 may include non-combustible additives in addition to the combustible carbonaceous materials. Examples of carbon heat sources are described in patent application US 2018 / 0317560 to Shinozaki et al., which is incorporated herein by reference in its entirety.In some forms, the carbon 108 heat source may incorporate other elements besides combustible carbonaceous materials (e.g., tobacco components such as tobacco powders or tobacco extracts; flavoring agents; salts such as sodium chloride, potassium chloride and sodium carbonate; alumina granules; ammonia sources such as ammonium salts; and / or binding agents such as guar gum, ammonium alginate and sodium alginate). While the specific dimensions of an applicable carbon 108 heat source may vary, in some modalities, the carbon 108 heat source may have a length ranging inclusively from approximately 5 mm to approximately 20 mm, or approximately 8 mm to approximately 16 mm, or approximately 12 mm, and an overall diameter ranging inclusively from approximately 3 mm to approximately 8 mm. In some cj / nnn / zznz / B / Ywi In 12 embodiments, the carbon heat source 108 can project a predetermined length from the illumination end 104, as shown in Figure 1. With reference again to Figure 2, in some additional embodiments, the carbon heat source 108 can project a predetermined length from the proximal end 120a of the heat source holder 120. The predetermined length can vary; in some embodiments, the predetermined length can be in an inclusive range of approximately 2 mm to approximately 12 mm, or approximately 6 mm to approximately 10 mm, or approximately 8 mm. Although in other embodiments, the carbon heat source 108 can be constructed in various ways; in the embodiment depicted, the carbon heat source 108 is extruded or compounded using a ground or powdered carbon-based material and has a density greater than approximately 0.5 g / cm³, often greater than approximately 0.7 g / cm³, and frequently exceeding approximately 1 g / cm³, on a dry weight basis. See, for example, the component types, formulations, and fuel source designs set forth in US Patent 5,551,451 granted to Riggs et al. and US Patent 7,836,897 granted to Borschke et al., which are incorporated herein by reference in their entirety. Although in various embodiments the carbon 108 heat source may have a variety of shapes, including, for example, a substantially solid cylindrical shape or a hollow cylindrical shape (e.g., tube), the carbon 108 heat source of the embodiment represented comprises an extruded monolithic carbonaceous material that is generally cylindrical but has a plurality of 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 plurality of air inlet holes may be arranged in a pattern or randomly distributed across the face of the carbon heat source and extend longitudinally through it. In some embodiments, the smoking article 100, and in particular the carbon heat source 108, may further include a heat transfer component. In several embodiments, a heat transfer component may be adjacent to the carbon heat source 108, and in some embodiments, a heat transfer component may be located on or within the carbon heat source 108.Some examples of heat transfer components are described in US patent 15 / 923,735, filed on March 16, 2018, and entitled “Smoking Article with Heat Transfer Component,” which is incorporated herein by reference in its entirety. In general, the carbon heat source 108 is placed sufficiently close to a tobacco material 110 such that the aerosol formed by heating the tobacco material 110 is delivered to the user through the mouthpiece 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 intended to be interchangeable such that c / / nnn / zznz / B / YiAi -13Reference to release, release, releasing or releases includes form or generate, formation or generation, forming or generating, and formations or generations. Specifically, an inhalable substance is released in aerosol form. As previously noted, in some embodiments, the smoking article 100 may comprise a tobacco material 110 located downstream of the carbon heat source 108 and optionally spatially separated from the mouthpiece end 106 of the smoking article 100. In some embodiments, the tobacco material 110 may be in particulate, shredded, or leaf form. In some embodiments, the tobacco material may further include one or both of an aerosol precursor composition and a flavoring. The tobacco materials employed may vary. One type of tobacco may be used, or combinations or mixtures of several types of tobacco may be employed. Additionally, different types of tobacco, or different tobacco mixtures, may be used in different locations within the smoking article. For example, in some varieties, the tobacco material employed may include, or may be derived from, tobaccos such as smoke-cured tobacco, Burley tobacco, Oriental tobacco, Maryland tobacco, dark tobacco, dark-cooked tobacco, and Rustica tobacco, as well as other rare or specialty tobaccos, or mixtures thereof. See also, for example, the tobacco types set forth in US patent 6,730,832 granted to Dominguez et al.; and US patent 7,025,066 granted to Lawson et al.; and in US patent application 60 / 818,198, filed June 30, 2006, by Stebbins et al.; which are incorporated herein by reference. Descriptions of various tobacco types, cultivation practices, harvesting practices, and curing practices are set forth in “Tobacco Production: Chemistry and Technology,” Davis et al. (Eds.) (1999). Ideally, the tobacco used should have been properly cured and aged.The techniques and conditions especially preferred for smoke curing tobacco are set forth in Nestor et al., Beitrage Tabakforsch. Int., 20 (2003) 467-475 and in US patent 6,895,974 granted to Peele, which are incorporated herein by reference. Representative techniques and conditions for air curing tobacco are set forth 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. The tobacco material incorporated within the smoking article may be employed in various forms; and combinations of different forms of tobacco may be used, or different forms of tobacco may be employed in different locations within the smoking article. For example, tobacco may be employed in the form of cut or shredded pieces of leaf or stem; in a processed form (e.g., reconstituted tobacco leaf, such as pieces of shredded reconstituted tobacco leaf in a cut-fill form; films incorporating tobacco components; parts or pieces of extruded tobacco; expanded tobacco leaf, such as cut-fill that has been expanded by volume; pieces of processed tobacco stem comparable to cut-fill in size and general appearance; granulated tobacco; cj materials / nnn / zznz / B / Ywi -14foamed tobacco; compressed or pelleted tobacco; or the like); as finely divided pieces of tobacco (e.g., tobacco powder, pulverized tobacco, agglomerated tobacco powder, or the like); or in the form of tobacco extract. See, for example, patent applications US 11 / 194,215 filed August 1, 2005, by Cantrell et al. and US 11 / 377,630 filed March 16, 2006, by Crooks et al.; which are incorporated herein by reference. The smoking article may employ tobacco in the form of leaves and / or stems. As such, tobacco may be used in forms and ways that are virtually identical in many respects to those traditionally used for the manufacture of tobacco products, such as cigarettes. Traditionally, cut or shredded pieces of tobacco leaf and stem have been used as so-called cut filler for cigarette making. Likewise, pieces of stem extracted with water may be used. Tobacco in such a form introduces mass and bulk into the smoking article. The methods and techniques for curing, stripping, aging, moistening, cutting, rearranging, and handling tobacco used as cut filler will be evident to those skilled in the art of tobacco product manufacturing. The processed tobaccos that may be incorporated into the smoking article can vary. Exemplary modes and methods for providing reconstituted tobacco leaves, including casting and papermaking techniques, are disclosed in U.S. patents 4,674,519 granted to Keritsis et al.; 4,941,484 granted to Clapp et al.; 4,987,906 granted to Young et al.; 4,972,854 granted to Kiernan et al.; 5,099,864 granted to Young et al.; 5,143,097 granted to Sohn et al.; 5,159,942 granted to Brinkley et al.; 5,322,076 granted to Brinkley et al.; 5,339,838 granted to Young et al.; and 5,377,698 granted to Litzinger et al. 5,501,237 granted to Young; and 6,216,707 granted to Kumar; each of which is incorporated herein by reference. Exemplary modes and methods for providing extruded forms of processed tobacco are set forth in U.S. patents 4,821,749 granted to Toft et al.; 4,880,018 granted to Graves, Jr. et al.; 5,072.744 granted to Lucas et al.; 4,874,000 granted to Tamol et al.; 5,551,450 granted to Hemsley; 5,649,552 granted to Cho et al.; 5,829,453 granted to White; 6,125,855 granted to Nevett et al.; and 6,182,670 granted to White; all of which are incorporated herein by reference. Extruded tobacco materials may be in the form of cylinders, strands, discs, or the like. Examples of expanded tobaccos (e.g., inflated tobaccos) using the types of techniques set forth in U.S. patents Re 32,013 granted to de la Burde et al.; 3,771,533 granted to Armstrong et al.; and 4,577,646 granted to Ziehn. 4,962,773 granted to White; 5,095,922 granted to Johnson et al.; 5,143,096 granted to Steinberg; 5,172,707 granted to Zambelli; 5,249,588 granted to Brown et al.; 5,687,748 granted to Conrad; and 5,908,032 granted to Poindexter; and in patent application US 2004 / 0182404 of Poindexter et al.; which are incorporated herein by reference.A particularly preferred type of expanded tobacco is dry ice expanded tobacco (DIET). Exemplary forms of tobacco stems cj / nnn / zznz / B / Ywi. Processed tobacco products include cut rolled stalks, expanded cut and rolled stalks, cut puffed stalks, and crushed steam-expanded stalks. Exemplary modes and methods for providing processed tobacco stalks are set forth in US Patent 4,195,646 granted to Kite; and US Patent 5,873,372 granted to Honeycutt et al.; both of which are incorporated herein by reference. Modes and methods for employing tobacco powder are set forth in US Patents 4,341,228 granted to Keritsis et al.; 4,611,608 granted to Vos et al.; 4,706,692 granted to Gellatly; and 5,724,998 granted to Gellatly et al.; both of which are incorporated herein by reference. However, other types of processed tobacco are of the type established in patent application US 2006 / 0162733 by McGrath et al.Tobacco can be used in blended form. Typically, blends of various types and forms of tobacco are provided in a blended cut filler form. For example, certain popular tobacco blends for cigarette making, commonly known as American blends, comprise mixtures of cut or shredded pieces of smoke-cured tobacco, Burley tobacco, and Oriental tobacco; and these blends, in many cases, also contain pieces of processed tobacco, such as processed tobacco stems, volume-expanded tobaccos, and / or reconstituted tobaccos. The precise amount of each type or form of tobacco within a tobacco blend used for the manufacture of a particular smoking article can vary and is a matter of 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.) p.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 mixtures established in U.S. patents 4,836,224 granted to Lawson et al.; 4,924,888 granted to Perfetti et al.; 5,056,537 granted to Brown et al.; and 5,220,930 granted to Gentry; as well as patent application US 2004 / 0255965 by Perfetti et al.; and US 2005 / 0066986 by Nestor et al.; and PCT publication WO 02 / 37990 by Bereman; and Bombicket et al., Fondo. Appl. Toxico / ., 39, p. 11-17 (1997); which are incorporated herein as a reference. Certain processed tobaccos may incorporate ingredients other than tobacco. However, it is preferred that processed tobaccos be composed predominantly of tobacco in some form, based on the dry weights of those processed tobaccos. That is, the majority of the dry weight of those processed tobaccos, and the majority of the weight of a mixture incorporating those processed tobaccos (including a mixture of materials, or materials having additives applied to them or otherwise incorporated into them), is provided by tobacco in some form. For example, those materials may be processed tobaccos incorporating minor amounts of non-tobacco filler materials (e.g., calcium carbonate particles, spongy or absorbent materials, carbonaceous materials including carbon particles and graphite fibers, wood grains or pulp) and / or cj / nnn / zznz / B / Ywi -16 Binding agents (for example, guar gum, sodium alginate, or ammonium alginate); and / or a mixture of such materials may incorporate tobacco substitutes or extenders. Exemplary types of tobacco substitutes or extenders are set forth in US patent application 11 / 489,334, filed July 19, 2006, by Fagg et al., which is incorporated herein by reference. The materials referred to above, and mixtures incorporating such materials, frequently include more than 70 percent tobacco, are often greater than approximately 80 percent tobacco, and generally are greater than approximately 90 percent tobacco, on a dry weight basis, based on the combined weights of the tobacco, the non-tobacco filler material, and the non-tobacco substitute or extender. However, such processed tobaccos may also be made entirely of tobacco and do not incorporate any non-tobacco fillers, substitutes, or extenders. Tobacco may be treated with tobacco additives of the type traditionally used in the manufacture of tobacco products. These additives may include the types of materials used to enhance the flavor and aroma of tobaccos used in the production of cigars, cigarettes, pipes, and the like. For example, these additives may include various cigarette wrapper and / or top-wrap components. See, for instance, U.S. Patents 3,419,015 granted to Wochnowski; 4,054,145 granted to Berndt et al.; 4,887,619 granted to Burcham, Jr. et al.; 5,022,416 granted to Watson; 5,103,842 granted to Strang et al.; and 5,711,320 granted to Martin. Preferred coating materials include water, sugars and syrups (e.g., sucrose, glucose and high fructose corn syrup), humectants (e.g., glycerin or propylene glycol) and flavoring agents (e.g., cocoa and licorice).These added components also include top wrapper materials (e.g., flavoring materials such as menthol). See, for example, US patent 4,449,541 granted to Mays et al. Additives may also be added to tobacco using the types of equipment described in US patent 4,995,405 granted to Lettau, or those available as the MAS Menthol Application System from Kohl Maschinenbau GmbH. The selection of particular wrapper and top wrapper components depends on factors such as the desired sensory characteristics, and the selection and use of such components will be evident to those skilled in the art of cigarette design and manufacture. See Gutcho, Tobacco Flavoring Substances and Methods, Noyes Data Corp. (1972) and Leffingwell et al., Tobacco Flavoring for Smoking Products (1972).Tobacco may also be treated, for example, with ammonia or ammonium hydroxide, or treated in other ways to incorporate ammonia (for example, by adding ammonium salts such as diammonium phosphate). Preferably, the amount of ammonia optionally incorporated into smokable tobacco is less than approximately 5 percent, and generally around 1 to 3 percent, depending on the dry weight of the tobacco. Tobacco may be incorporated with the smoking article in a form other than as cut filler. For example, tobacco leaf and / or reconstituted tobacco leaf may be used. -17 as a wrapper for a tobacco-containing component shaped like a cigar or as an inner wrapper for a double-wrapped cigarette stick. Alternatively, processed tobaccos, such as certain types of reconstituted tobaccos, may be employed as longitudinally extending strands. See, for example, the configuration set forth in U.S. Patent 5,025,814 granted to Raker, which is incorporated herein by reference. In addition, certain types of reconstituted tobacco leaves may be formed, rolled, or assembled into a desired configuration. Likewise, molded, compressed, or extruded segments or pieces of tobacco-containing materials formed into desired shapes (e.g., strands, tubes, cylinders, granules, or the like) may be incorporated within the smoking article. See, for example, U.S. Patents 4,836,225 granted to Sudoh; 4,893,639 granted to White; 4,972,855 awarded to Kuriyama et al.; and 5,293.883 granted to Edwards; which are incorporated herein by reference. If desired, finely ground tobacco or tobacco powder may be incorporated within other types of processed tobacco, such as extruded formulations, reconstituted tobacco leaves, or the like. In addition, finely ground tobacco or tobacco powder may be contained in substrates, such as membranes or screens. If desired, at least a portion of the tobacco may be heat-treated prior to use within the smoking article (for example, by being high-temperature dried, roasted, pre-pyrolyzed, having condensed volatiles collected after heating the tobacco, condensed tobacco smoke components, or the like). Various modes and methods for incorporating tobacco into smoking articles, and in particular smoking articles designed to intentionally not burn virtually all of the tobacco within them, are set forth in US patent 4,947,874 to Brooks et al., US patent application 2005 / 0016549 to Banerjee et al., US patent 11 / 194,215 filed August 1, 2005, by Cantrell et al., and US patent 11 / 377,630 filed March 16, 2006, by Crooks et al. These documents are incorporated herein by reference. Tobacco has also been incorporated into cigarettes that have been commercially distributed under the Premier and Eclipse brands by RJ Reynolds Tobacco Company. See, for example, the 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, p. 1-58 (2000).Tobacco has also been incorporated into a smoking article that has been commercially distributed by Philip Morris Inc. under the Accord brand. As previously noted, 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, as well as any combination thereof. Representative types of materials cj / nnn / zznz / B / Ywi -18 aerosol formers are set forth in US patents 4,793,365 granted to Sensabaugh, Jr. et al.; and US patent 5,101,839 granted to Jakob et al.; as well as in PCT application publication WO 98 / 57556 of Biggs et al.; and in “Chemical and Biological Studies on Novel Heat-Not-Burn Type Cigarette Prototypes,” RJ Reynolds Tobacco Company Monograph (1988); which are incorporated herein by reference in their entirety. Other representative types of aerosol precursor components and formulations are also established and characterized in U.S. Patents 7,726,320 granted to Robinson et al., 8,881,737 granted to Collett et al., and 9,254,002 granted to Chong et al.; and in U.S. Patent Applications 2013 / 0008457 to Zheng et al.; 2015 / 0020823 to Lipowicz et al.; and 2015 / 0020830 to Koller, as well as in PCT Application Publication WO 2014 / 182736 to Bowen et al., which are incorporated herein by reference in their entirety.Other aerosol precursors that may be used include those incorporated into VUSE® products from RJ Reynolds Vapor Company, BLUTM products from Fontem Ventures BV, MISTIC MENTHOL products from Mistic Ecigs, MARK TEN products from Nu Mark LLC, JUUL products from Juul Labs, Inc., and VYPE products from British American Tobacco. Additionally, so-called e-cigarette smoke juices available from Johnson Creek Enterprises LLC are desirable. Further examples of aerosol precursor compositions are sold under the brand 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, and DR. CRIMMYS 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.The various forms of effervescent materials may be used with the aerosol precursor composition and are described, by way of example, in US patent application 2012 / 0055494 to Hunt et al., which is incorporated herein by reference in its entirety. In addition, the use of effervescent materials is described, for example, in US patents 4,639,368 granted to Niazi et al.; 5,178,878 granted to Wehling et al.; 5,223,264 granted to Wehling et al.; 6,974,590 granted to Pather et al.; 7,381,667 granted to Bergquist et al.; 8,424,541 granted to Crawford et al.; 8,627,828 granted to Strickland et al.; and 9,307,787 granted to Sun et al. as well as in patent application US 2010 / 0018539 by Brinkley et al. and in PCT application publication WO 97 / 06786 by Johnson et al., which are incorporated herein by reference in their entirety.Additional description with respect to the modalities of aerosol precursor compositions, including the description of the tobacco or tobacco-derived components included therein, is provided in U.S. patent applications 2018 / 0020722 and 2018 / 0020723, by Davis et al., which are incorporated herein by reference in their entirety. As previously mentioned, Tobacco Material 110 may also include a flavoring. As used herein, the reference to a flavoring is cj / nnn / zznz / B / Ywi -19 refers to compounds or components that can be aerosolized and delivered to a user and that impart 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 (e.g., apple, cherry, strawberry, peach, and citrus flavors, including lime and lemon), maple, menthol, peppermint, spearmint, wintergreen, nutmeg, clove, lavender, cardamom, ginger, honey, anise, sage, rosemary, hibiscus, rosehip, yerba mate, guayusa, honeybush, rooibos, yerba santa, bacopaniera, ginkgo biloba, withania somnifera, cinnamon, sandalwood, jasmine, cascarilla, cocoa, licorice, and flavorings and flavor packs of the type and character traditionally used for the flavoring of cigarettes, cigars, and pipes. Syrups, such as high fructose corn syrup, can also be used.Some examples of plant-derived compositions that may be suitable are disclosed in US Patent 9,107,453 and US Patent Application 2012 / 0152265, both by Dube et al., which are incorporated herein by reference in their entirety. The selection of such additional components is variable depending on factors such as the desired sensory characteristics of the smoking article, its affinity for the tobacco material, its solubilities, and other physicochemical properties. The present invention is intended to encompass any other component that is obvious 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), which are incorporated herein by reference in their entirety.It should be noted that the reference to a flavoring should not be limited to a single flavoring as previously described, and may, in fact, represent a combination of one or more flavorings. Furthermore, as previously noted, in some embodiments, the smoking article 100 may comprise a heat absorber 112, at least partially situated between the tobacco material 110 and the carbon heat source 108. In several embodiments, the heat absorber may be selected from the group consisting of metals and ceramics. In some embodiments, the heat absorber may be an aluminum (Al) or alumina (Al₂O₃) material. In some embodiments, the heat absorbers may comprise any suitable metal, ceramic, or other material with a specific heat capacity of approximately 0.1 kJ / kg K to approximately 3 kJ / kg K, or preferably from approximately 0.5 kJ / kg K to approximately 2 kJ / kg K, or more preferably from approximately 0.75 kJ / kg K to approximately 1 kJ / kg K.The specific properties of materials suitable for use as thermal energy absorbers in the present invention may vary between specific embodiments. Materials suitable for use as thermal energy absorbers in the present invention may include, among others, materials with properties such as high thermal stability, suitable specific heat capacity, or high thermal conductivity. Furthermore, suitable materials cj / nnn / zznz / B / Ywi. -20For use as thermal energy absorbers in the present invention, they may be non-toxic and non-hazardous materials with a minimal negative effect on health. In some embodiments, the heat absorbers according to the present invention can be configured to increase the uniform distribution of heated air through the tobacco material. In some embodiments, the heat absorber can be configured to decrease the peak temperature of the smoking article by approximately 50°C to approximately 500°C. In some embodiments, the heat absorbers can be configured to decrease the peak temperature of the smoking article by at least 50°C, or at least 100°C, or at least 150°C, or at least 200°C, or at least 250°C, or at least 300°C, or at least 350°C, or at least about 400°C, or at least about 450°C, or at least about 500°C.In some configurations, the thermal energy absorber can be set up to deliver average peak temperatures in smoking articles below approximately 500°C, or below approximately 450°C, or below approximately 400°C, or below approximately 350°C, or below approximately 300°C, or below approximately 250°C, or below approximately 200°C, or below approximately 150°C. In various embodiments, the thermal energy absorber can be configured to minimize the reduction of total particulate matter (TPM) released during the smoking action of the smoking article. Advantageously, the thermal energy absorbers according to the present invention can be configured to provide a similar release of TPM during the smoking action of a smoking article with thermal energy absorbers compared to a smoking article without thermal energy absorbers, thereby producing visible aerosols with visual characteristics similar to those of a typical smoking article with the added benefits of the thermal energy absorbers.In some embodiments, the thermal energy absorbers can be configured to maintain a net pressure drop of between approximately -20 mmHg and approximately 20 mmHg, or between approximately -10 mmHg and approximately 10 mmHg, or approximately 0 mmHg in the smoking article during smoking, compared to a control sample of the smoking article without thermal energy absorbers. Advantageously, the thermal energy absorbers according to the present invention can be configured to provide substantially the same pressure drop in a smoking article with thermal energy absorbers compared to a smoking article without thermal energy absorbers, thus maintaining the same inhalation resistance for a user with the added benefits of the thermal energy absorbers. In one or more embodiments, the heat absorber may take the form of one or more circular disks. In some embodiments, one or more circular disks may further comprise a porous or non-porous material. In this regard, Figure 3 illustrates a cj / nnn / zznz / B / Ywi - 21 thermal energy absorber 112 in the form of a circular disc comprising a plurality of holes 130 extending longitudinally therethrough. In some embodiments, the circular discs may have a diameter of approximately 5 mm to approximately 9 mm, or of approximately 6 mm to approximately 8 mm, or approximately 7 mm. In certain embodiments, the circular discs may have a thickness of approximately 0.1 mm to approximately 4 mm, or of approximately 1 mm to approximately 3 mm, or approximately 2 mm.While thermal energy absorbers in various embodiments can have a variety of geometries and design parameters, including, for example, a substantially spherical or triangular shape, the thermal energy absorbers 112 depicted in Figure 3 are generally cylindrical discs with a plurality of holes of substantially similar size and evenly spaced throughout, although variable size and / or spacing are also acceptable. In several other embodiments, the plurality of holes 130 may be irregularly shaped, randomly distributed, patterned, or arranged in any other configuration that allows airflow through the thermal energy absorber. In some embodiments, the individual holes may have a diameter of approximately 0.1 to approximately 1 mm, or approximately 0.2 mm to approximately 0.5 mm.The heat absorber depicted in Figure 3 was manufactured using an additive manufacturing technique for the precise production of alumina discs with a diameter of 6.58 mm and a thickness of 1.5 mm. In the depicted embodiment, the plurality of holes 130 is uniformly distributed across the circular disc to evenly distribute the hot air to the downstream tobacco material. In several other embodiments, one or more circular discs may be sufficiently porous that the plurality of holes is not required. For example, in such embodiments, one or more circular discs may comprise a metallic or ceramic material that is sufficiently porous to provide a pressure drop in the smoking article that is less than the maximum pressure drop limit for such smoking articles.Porosity can range from macroscale to nanoscale. Furthermore, such porous metallic or ceramic materials can have the form of a foam material. In some embodiments, the heat absorber 112 may be in the form of a plurality of particles. In several embodiments, the particles may be substantially spherical or irregularly shaped. In some embodiments, the shape of the particles may vary; for example, the particles may be substantially in the shape of a sphere, a cube, a cylinder, or any other suitable three-dimensional shape. In certain embodiments, the heat absorber may comprise from about 5 to about 500 particles, or from about 7 to about 300 particles, or from about 10 to about 100 particles, or from about 12 to about 30 particles, or preferably from about 15 to about 20 particles. In certain In some embodiments, the particles may have a diameter of between approximately 0.1 mm and approximately 5 mm, or approximately 0.5 mm to approximately 4 mm, or approximately 1 mm to approximately 3 mm, or approximately 2 mm. In some embodiments, particularly those with a higher total number of particles, the particles may have a diameter of less than approximately 0.1 mm, or less than approximately 0.05 mm, or less than approximately 0.01 mm, or less than approximately 0.005 mm. In some embodiments, a 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 heat-absorbing particles may be highest near the heat source and lowest farther from the heat source. Therefore, in some embodiments, the packing density of the heat-absorbing particles may be inversely proportional to their distance from the heat source. In some embodiments, this inverse relationship may provide a uniform heat distribution throughout the tobacco material. In several other embodiments, the heat absorber may be in the form of hollow spheres. In some embodiments, the hollow portion of the spheres may be filled with paraffin, wax, or any other suitable phase-change material.For example, hollow spheres according to such modalities can provide thermal energy absorbers with reduced mass and variable thermal properties. As shown in Figure 4, in one particular embodiment, a smoking article 100 according to the present invention may comprise a plurality of heat absorbers 112 that may have substantially the same shape or be present in substantially different forms. For example, as shown in Figure 4, the heat absorber 112 may include a first heat absorber component 112a that is in the form of one or more circular discs and may include a second heat absorber component 112b that is in the form of one or more particles (e.g., substantially spherical particles). In such embodiments, the first component 112a may be positioned between the tobacco material 110 and the carbon heat source 108, and the second component 112b may be inside the tobacco material 110.In some embodiments, the second component 112b can be configured in such a way that the number of particles, in the plurality of particles, gradually decreases in number the further the particles are from the carbon 108 heat source. In several other embodiments, the present invention provides a method for reducing overheating in a smoking article, the method comprising: providing a smoking article comprising a carbon heat source, a tobacco material, a heat energy absorber, and an outer wrapping material circumscribing at least one cj / nnn / zznz / B / Ywi -23part of the smoking article, wherein the smoking article is defined by an illumination end in the upper portion and a mouthpiece end in the lower portion; and positioning the thermal energy absorber at least partially between the tobacco material and the carbon heat source in such a way that the peak temperature of the smoking article decreases between approximately 25°C to approximately 75°C and approximately 475°C to approximately 525°C when the carbon heat source is ignited. In some embodiments, the thermal energy absorbers prepared according to the current method can be configured to decrease 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 heat absorbers prepared according to the current method can be configured to deliver average peak temperatures in smoking articles below approximately 500°C, or below approximately 450°C, or below approximately 400°C, or below approximately 350°C, or below approximately 300°C, or below approximately 250°C, or below approximately 200°C, or below approximately 150°C. In some embodiments, the method according to the present invention may further include providing a heat absorber configured to increase the uniform distribution of hot air throughout the smoking article. In some embodiments, the method of the present invention may further include providing a filter material positioned near the mouthpiece end of the lower portion of the smoking article. Many modifications and other embodiments of the invention will occur to a person skilled in the art to which the present invention belongs, having benefited from the teachings presented in the previously disclosed description and associated drawings. It is therefore to be understood that the invention is not to be limited to the specific embodiments described herein and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are used herein, they are employed only in a generic and descriptive sense and not for the purpose of limitation. cj / nnn / zznz / B / Ywi Examples To investigate the performance of the thermal energy absorbers described herein, samples of two different types of heat-without-burn cigarettes (hereafter referred to as HNB1 and ΉNB2) were prepared and tested according to the following methods. The HNB1 samples were hand-constructed using 13 mm x 27 mm wrapping patches that combined a section of tobacco beads and a section of tobacco rod. Twenty-four thermal energy absorbers were embedded between the tobacco bead section and the carbon heater. A dual filter system was used in these samples, with a length of 14 mm for the CA filter and a length of 7 mm for the HAT filter. In total, 31 samples were prepared according to this method, and are listed as follows: cj / nnn / zznz / B / Ywi 5 HNB1 control samples 5 HNB1 samples with aluminum discs 3 HNB1 samples with alumina ceramic discs 3 HNB1 samples with 10 aluminum spheres 3 HNB1 samples with 15 aluminum spheres 3 HNB1 samples with 20 aluminum spheres 3 HNB1 samples with 10 ceramic alumina spheres 3 HNB1 samples with 15 ceramic alumina spheres 3 HNB1 samples with 20 ceramic alumina spheres The HNB2 samples were prepared using handmade smoking materials, including a 12 mm carbon tip (8 mm protruding from the paper wrapper), 13 mm of substrate tobacco material (glycerin-loaded caste leaf) behind the carbon tip (covered by aluminum foil), a 37 mm tobacco rod (optionally glycerin-loaded), and a 14 mm cellulose acetate filter followed by a 7 mm hollow acetate tube. The HNB2 samples were modified by making a straight cut in the tobacco rod between the carbon heater and the substrate tobacco section (approximately 4 mm deep) 12 mm (the length of the heat source) from the lit end of the tobacco rod using a utility knife. Heat absorbers were then placed in the cut behind the heat source.Subsequently, the straight cut was wrapped with 13 mm x 27 mm tilting paper, and the paper was glued to the rods to block any air spaces. In total, 76 samples were prepared according to this method, and are listed as follows: HNB2 reference samples 3 HNB2 samples with aluminum discs 3 HNB2 samples with ceramic alumina discs 3 HNB2 samples with 5 aluminum spheres 3 HNB2 samples with 8 aluminum spheres 3 HNB2 samples with 10 aluminum spheres HNB2 samples with 15 aluminum spheres HNB2 samples with 18 aluminum spheres HNB2 samples with 20 aluminum spheres 3 HNB2 samples with 5 ceramic alumina spheres 3 HNB2 samples with 7 ceramic alumina spheres 3 HNB2 samples with 10 ceramic alumina spheres HNB2 reference samples with menthol; HNB2 samples with 15 aluminum spheres with menthol; HNB2 samples with 18 aluminum spheres with menthol; HNB2 samples with 20 aluminum spheres with menthol Example 1 Average peak temperature profiles of the best candidate samples HNB1 and HNB2 with thermal energy absorbers (Figure 5) Thermal analysis experiments were performed on all HNB1 and HNB2 samples to provide temperature profiles along the cigarette rods. A hypodermic needle was used to drill 0.50 mm holes at two locations on the cigarette rods, 15 mm and 24 mm from the illuminated end. Type K thermocouples (manufactured by Omega Engineering, Norwalk, CT) with a 0.26 mm probe diameter were then inserted into the holes and sealed with a small amount of rocker glue (glue 20009766). The thermocouple insertion depth was approximately 3.5 mm, which positioned the thermocouple tip roughly on the centerline of the cigarette rod. Samples HNB1 and HNB2 were held in place by a custom-made labyrinth support of the conventional design.The smoking process was performed using a custom-built smoking machine with an MDrivePlus 17 stepper motor manufactured by Schneider Electric Motion USA. The stepper motor was programmed for the specific inhalation regime described below. The use of a stepper motor allowed for digital control of the piston movements. Finally, data collection was handled using an IntelliLogger (manufactured by Logic Beach, La Mesa, CA), and HyperWare II software (manufactured by Logic Beach, La Mesa, CA) was used to transfer the data to a computer for further analysis. Tests were performed on samples HNB1 and HNB2, which contained circular aluminum discs; circular ceramic alumina discs; 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-made smoking machine, with 19 inhalations using an inhalation volume of 55 ml and a two-second inhalation duration. The first three inhalations were considered illumination inhalations and were essentially performed consecutively. The interval between inhalations between doses 1 and 2, and between doses 2 and 3, was approximately three seconds. The heat source was preheated for approximately one second using an electric lighter (Borgwaldt Electric Lighter R29) prior to dosage 1 and light contact between the lighter head and the heat source was maintained until the end of dosage 2.Dosage 3 was taken with the lighter removed from the heat source. After dosage 3, the intervals between the start of subsequent doses were maintained at 30 seconds. The temperature of the tobacco core (center line cj / nnn / zznz / B / Ywi. -26 rod) at lengths of 15 mm and 24 mm was measured using thermocouples and a temperature profile was generated from this data retrieved by the IntelliLogger. The maximum temperature within each inhalation was identified and termed the peak dosing temperature. Samples exhibiting a peak temperature (collected at 15 mm) lower than that of the HNB2 control samples by 100°C to 300°C were selected as the best high-performance candidates. Based on testing, HNB2 samples with 15, 18, and 20 aluminum spheres were selected as the best candidates. As shown in Figure 5, the average peak temperature profiles (d) were reported based on testing of HNB2 control rods without aluminum spheres and HNB2 rods containing 15, 18, and 20 aluminum spheres.The sample HNB2 rods containing 18 aluminum spheres generated the greatest decrease in peak temperatures (decreasing by more than 300°C) while the smoking action was carried out; however, all three sample rods generated a decrease in peak temperature compared to the control sample. Example 2 Average pressure drop data for the best candidate samples HNB1 and HNB2 with thermal energy absorbers (Figure 6) For an accurate comparison of two cigarette sticks containing different types or components of tobacco, it is essential to evaluate and compare the average pressure drops along the sticks. Air pressure drop is directly proportional to the resistance to the air draw required to draw aerosols through the stick and filter. Pressure drop and inhalation resistance are known to directly influence cigarette performance during smoking. The pressure drop unit incorporated into the Quality Test Module (QTM) was used to measure the air pressure drop of the samples. The QTM provided the percentage of dilution at the filter and the pressure drop, measured and reported separately with the dilution holes open and closed.The dilution holes in the QTM test are prepared using a laser aperture component that cuts a hole in the side of the tobacco rod downstream of the carbon tip. For closed-hole sample testing, the dilution holes are covered while the QTM performs the test, allowing air to enter the samples only from the carbon tip. For open-hole sample testing, the dilution holes are left uncovered while the QTM performs the test, allowing air to enter the sample through both the carbon tip and the dilution holes. The QTM uses an industry-standard protocol of extracting 17.5 cm³ of air per second. The QTM also provided other physical properties of the samples, including rod weight and rod circumference. cj ζηηη / ζζηζ / Β / γίΛΐ - 27Specifically, in Figure 6, a pressure drop analysis was performed on candidate samples that were considered to show the best performance in the temperature analysis described in Example 1. The analyzed samples included HNB2 samples with 15, 18, and 20 aluminum spheres and the HNB2 control sample for the basis of comparison. As seen in Figure 6, pressure drop data were reported for both open and closed hole tests, based on tests of HNB2 control rods and HNB2 rods containing 15 aluminum spheres, HNB2 rods containing 18 aluminum spheres, and HNB2 rods containing 20 aluminum spheres. As noted in Figure 6, the average pressure drop across the HNB2 rods with aluminum spheres was between -5 mmHg and 10 mmHg compared to the control samples of HNB2 rods that did not contain aluminum spheres.It was observed that the pressure drops in the HNB2 control sample were substantially similar to those in the best HNB2 candidate samples. This confirms that the addition of the heat energy absorbers did not significantly affect the pressure drop in the HNB2 samples and led to changes in product performance in terms of the inhalation resistance experienced by the user due to the altered pressure drop. Example 3 Total particulate matter released by the best candidate samples HNB1 and HNB2 with thermal energy absorbers (Figure 7) The total particulate matter (TPM) released during smoking from a smoking device can affect the visibility of the aerosols generated by it. For example, a decrease in the TPM released during smoking from a smoking device can decrease the visibility of the aerosol produced by that device.The TPM analysis experiments were conducted using the custom-made smoking machine described in Example 1. The smoking machine was programmed to deliver a 50 / 30 / 3 inhalation regime (50 ml inhalation volume / 30-second inhalation frequency / 3-second inhalation duration) and was used to quantify the total particulate matter (TPM) during the smoking action of the analyzed samples. A 44 mm diameter Cambridge filter pad was placed in a pad holder and weighed for its initial mass. The holder was then connected to the smoking machine, and a sample was inserted. Twelve inhalations were performed on each sample. Subsequently, the filter pad was removed from the holder, and the final mass was measured using a high-precision scale.The difference between the mass of the filter pads before and after each test yielded an overall TPM value that was averaged over 12 inhalations to calculate the mass on a mg / inhalation basis for each sample tested. As shown in Figure 7, the analyzed samples included HNB2 samples with 15, 18, and 20 aluminum spheres and the HNB2 control sample for comparison. As illustrated in Figure 7, the HNB2 control sample, the HNB2 sample with 15 spheres of cj / nnn / zznz / B / Ywi - 28 aluminum, sample HNB2 with 18 aluminum spheres, and sample HNB2 with 20 aluminum spheres generated TPM values ​​of 1.58, 1.17, 1.00, and 1.00 mg / inhalation, respectively. The results, as illustrated in Figure 7, suggest that the TPM generated in the HNB2 control samples is only slightly higher than the TPM generated from the other samples. HNB2 with thermal energy absorbers. Furthermore, it was observed that the TPM values ​​were inversely proportional to the number of aluminum spheres loaded onto the HNB2 rods. Therefore, the amount of visible aerosols produced in these samples is less affected with a lower number of aluminum spheres, while also providing a reduction in the burning of the tobacco rod components. This test further confirmed that the HNB2 sample with 15 aluminum spheres provided the best combination of minimal reduction in TPM values ​​and maximum reduction in the burning of the tobacco rod components.

Claims

1. A smoking article, comprising: an outer covering enclosing at least a portion of the smoking article, wherein the smoking article is defined by an illumination end in the upper portion and a mouthpiece end in the lower portion; a carbon heat source disposed close to the illumination end; a tobacco material disposed downstream of the carbon heat source; and an energy absorber disposed at least partially between the tobacco material and the carbon heat source.

2. The smoking article according to claim 1, wherein the energy absorber comprises one or more of a metallic or ceramic material.

3. The smoking article according to claim 1, wherein the energy absorber comprises one or more of an aluminum or alumina material.

4. The smoking article according to claim 1, wherein the heat energy absorber is configured to increase the uniform distribution of heated air through the tobacco material.

5. The smoking article according to any of claims 1 to 4, wherein the heat energy absorber is in the form of one or more circular discs.

6. The smoking article according to claim 5, wherein one or more circular discs have an individual diameter of approximately 5 mm to approximately 9 mm and a thickness of approximately 0.1 mm to approximately 4 mm.

7. The smoking article according to claim 5, wherein one or more circular discs comprise a plurality of holes.

8. The smoking article according to claim 7, wherein the plurality of holes has an irregular shape, is randomly distributed, or is distributed in a pattern.

9. The smoking article according to any of claims 1 to 4, wherein the heat energy absorber is in the form of a plurality of particles. cj / nnn / zznz / B / Ywi -SO- IO. The smoking article according to claim 9, wherein the particles are substantially spherical.

11. The smoking article according to claim 9, wherein the heat energy absorber comprises from approximately 3 to approximately 500 particles.

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

13. The smoking article according to any of claims 1 to 4, wherein the heat energy absorber comprises a material having a specific heat capacity of approximately 0.1 kJ / kg K to approximately 3 kJ / kg K.

14. The smoking article according to any of claims 1 to 4, wherein the tobacco material further includes one or more of a tobacco extract, an aerosol precursor composition, and a flavoring.

15. The smoking article according to any of claims 1 to 4, wherein the tobacco material is in one or more of a crushed or particulate form.

16. The smoking article according to any of claims 1 to 4, wherein the carbon heat source has a plurality of air inlet holes extending longitudinally therethrough.

17. The smoking article according to any of claims 1 to 4, wherein the heat energy absorber is configured to decrease the peak temperature of the smoking article by approximately 50°C to approximately 500°C.

18. The smoking article according to any of claims 1 to 4, wherein the mouthpiece end of the lower portion further comprises a filter material.

19. A method for reducing excess heat in a smoking article, the method comprising: providing a smoking article comprising a carbon heat source, a tobacco material, a heat energy absorber, and an outer covering circumscribing at least a portion of the smoking article, wherein the smoking article is defined by an illumination end in the upper portion and a nozzle end in the lower portion; and positioning the heat energy absorber at least partially between the tobacco material and the carbon heat source such that the peak temperature of the smoking article decreases by approximately 50°C to approximately 500°C when the carbon heat source is ignited.

20. The method according to claim 19, wherein the heat absorber is configured to increase the uniform distribution of heated air through the tobacco material.

21. The method according to any of claims 19 to 20, wherein the nozzle end of the lower portion further comprises a filter material.