BR112016000830B1 - SMOKING ARTICLE COMPRISING A FUEL HEAT SOURCE WITH AT LEAST ONE AIRFLOW CHANNEL - Google Patents

Abstract

SMOKING ITEM COMPRISING A FUEL FUEL HEAT SOURCE WITH AT LEAST ONE AIRFLOW CHANNEL. A smoking article (2, 34, 38, 42, 44, 48) comprises: a combustible heat source (4) having opposing front (6) and rear (8) faces; one or more air flow channels (18) extending from the boundary face (6) to the rear face (8) of the fuel heat source (4); an aerosol forming substrate (10) downstream of the rear face (8) of the fuel heat source (4); a nozzle (14) downstream of the aerosol forming substrate (10); and one or more air inlets (32, 36) located downstream of the rear face (8) of the fuel heat source (4) and upstream of the nozzle (14). One or more air inlets (32, 36) are located between the rear face (8) of the fuel heat source (4) and the downstream end of the aerosol forming substrate (10). In use, air drawn through the aerosol forming substrate (10) enters the smoking article (2, 34, 38, 42, 44, 48) through one or more air flow channels (18) and a or more air inlets (32, 36) and at least some of the air drawn through the aerosol forming substrate (10) comes into direct contact with a combustible portion of the combustible heat source (4).

Description

[001] The present invention relates to a smoking article comprising a combustible heat source with opposite front and rear faces and at least one air flow channel and an aerosol forming substrate downstream of the rear face of the combustible heat source.

[002] Various smoking articles in which the tobacco is heated rather than combusted have already been proposed in the art. One of the goals of such "heated" smoking articles is to reduce the known harmful smoke components of the type produced by the combustion and pyrolytic degradation of tobacco in conventional cigarettes. In a known type of heated smoking article, an aerosol is generated by transferring heat from a combustible heat source to an aerosol forming substrate. The aerosol forming substrate can be located within, around or downstream of the combustible heat source. During the act of smoking, volatile compounds are released from the aerosol-forming substrate via heat transfer from the combustible heat source and puffed along with the air drawn through the smoking article. As released compounds cool, they condense to form an aerosol that is inhaled by the user. Typically, air is drawn into one of these known smoking articles through one or more air flow channels provided along the combustible heat source and by heat transfer from the combustible heat source to the forming substrate. aerosol occurs by forced convection and conduction.

[003] For example, WO-A2-2009/022232 discloses a smoking article comprising a combustible heat source, an aerosol forming substrate downstream of the combustible heat source, and a thermoconductive element around, and in direct contact with a rear portion of the combustible heat source and with an adjacent front portion of the aerosol forming substrate. To provide a controlled amount of forced convective heating of the aerosol forming substrate, at least one longitudinal air flow channel is provided along the combustible heat source.

[004] In known smoking articles in which the heat transfer from the fuel heat source to the aerosol forming substrate occurs primarily by forced convection, the forced convective heat transfer and therefore the temperature of the aerosol forming substrate can vary considerably depending on the user's blowing behavior. As a result, the composition and therefore the main aerosol sensory properties generated by these known heated smoking articles can disadvantageously be highly sensitive to a user's puff regime.

[005] Furthermore, in known heated smoking articles comprising one or more air flow channels along the combustible heat source, direct contact between the drawn air through one or more air flow channels and the source of combustible heat during puffs by a consumer results in activation of combustion of the combustible heat source. Intense blowing regimes can therefore lead to convective heat transfers high enough to cause spikes in the temperature of the aerosol forming substrate, disadvantageously causing pyrolysis and even potentially localized combustion of the aerosol forming substrate. As used herein, the term "peak" is used to describe a brief increase in the temperature of the aerosol forming substrate. As a result, the levels of unwanted pyrolytic by-products or combustion derivatives in the main aerosols generated by these known smoking articles can also vary significantly and disadvantageously, depending on the puff regime adopted by the user.

In US 4,714,082 smoking articles are disclosed which comprise a combustion fuel element, an aerosol generating means and a mouth end filter. In the embodiments shown in Figures 1, 3, 4, 6, 7, 8 and 9, the combustion fuel element 10 comprises one or more longitudinally extending holes 16. In these embodiments, there are no air inlets located between the rear face of the combustion fuel element 10 and the downstream end of the aerosol generating means 12. In the embodiment depicted in Figure 2, the aerosol generating means 12 includes a thermally stable carbonaceous substrate 28 and the combustion fuel element 24 is connected to the aerosol generating means 12 by a heat conducting rod 26 and by a paper tube lined with aluminum foil 14. This embodiment includes a void 30 between the combustion fuel element 10 and the substrate 28 and the portion of the tube lined with aluminum foil 14 around the void 30 includes a plurality of peripheral holes 32 which allow sufficient air to enter the void to provide an appropriate pressure drop. In this embodiment, the combustion fuel element 24 does not include any longitudinally extending orifice 16.

It is known to include additives in the combustible heat sources of heated smoking articles in order to improve the ignition and combustion properties of the combustible heat sources. However, the inclusion of ignition and combustion additives can give rise to reaction or decomposition products which can disadvantageously enter the aspirated air through one or more air flow channels provided along the heat source. fuel of such heated smoking articles during consumption thereof.

[008] In order to facilitate aerosol formation, the aerosol forming substrates of heated smoking articles typically comprise a polyhydric alcohol such as glycerin or other known aerosol formers. During article storage and consumption, such aerosol formers may migrate from the aerosol forming substrates of known smoking articles to the combustible heat sources thereof. Migration of aerosol formers to combustible heat sources from known heated smoking articles can disadvantageously lead to the decomposition of aerosol formers, particularly during consumption of the heated smoking articles.

[009] There is still a need for a heated smoking article comprising a combustible heat source with opposite front and back faces and an aerosol forming substrate downstream of the combustible heat source wherein peaks in the temperature of the aerosol forming substrate aerosols are avoided under intense blowing regimes. There remains, in particular, a need for smoking articles comprising a combustible heat source with opposite front and rear faces and an aerosol forming substrate downstream of the rear face of the combustible heat source in which no combustion or pyrolysis takes place. substantial part of the aerosol formation substrate under intense blowing regimes.

[0010] According to the invention, there is provided a smoking article comprising: a combustible heat source having opposite front and rear faces; one or more air flow channels which extend from the front face to the rear face of the fuel heat source; an aerosol forming substrate downstream of the rear face of the combustible heat source; a nozzle downstream of the aerosol forming substrate; and one or more air inlets located downstream of the rear face of the fuel heat source and upstream of the nozzle. One or more air inlets are located between the rear face of the combustible heat source and a downstream end of the aerosol forming substrate. In use, air drawn through the aerosol forming substrate enters the smoking article through one or more air flow channels and one or more air inlets and at least some of the air drawn through the aerosol forming substrate directly contact a combustible portion of the combustible heat source.

[0011] As used herein, the term "aerosol-forming substrate" is used to describe a substrate capable of releasing, upon heating, volatile compounds that can form an aerosol. Aerosols generated from the aerosol forming substrates of smoking articles according to the invention may be visible or invisible and may include vapors (e.g. fine particles of substances which are in a gaseous state and which are normally liquid or solid in the air. temperature) as well as gases and liquid droplets of condensed vapors.

[0012] The aerosol-forming substrate may be in the form of a plug or segment comprising a material capable of releasing, upon heating, volatile compounds that may form an aerosol, circumscribed by an envelope. Where an aerosol forming substrate is in the form of such a plug or segment, the plug or segment that includes the entire housing is considered to be an aerosol forming substrate.

[0013] As used herein, the terms "upstream", "downstream", "proximal", "distal", "frontier" and "rear", are used to describe the relative positions of components, or portions of components of the smoking article in relation to the direction in which the user draws on the smoking article during consumption thereof. Smoking articles according to the invention comprise a proximal end through which, when in use, an aerosol leaves the smoking article for delivery to a user. The proximal end of the smoking article may also be referred to as the mouth end. In use, a user draws on the proximal end of the smoking article in order to inhale an aerosol generated by a smoking article.

[0014] The heat source is located at or near the distal end. The mouthpiece is located at the proximal end. The mouth end is downstream of the distal end. The proximal end may also be referred to as the downstream end of the smoking article and the distal end may also be referred to as the upstream end of the smoking article. Components, or component parts, of the smoking article according to the invention may be described as being upstream or downstream of each other based on their relative positions between the proximal or downstream mouth ends and the distal or downstream end. amount of the smoking article.

[0015] The front of the combustible heat source is at the upstream end of the combustible heat source. The upstream end of the combustible heat source is the end of the combustible heat source furthest from the proximal end of the smoking article. The rear face of the combustible heat source is at the downstream end of the combustible heat source. The downstream end of the combustible heat source is the end of the combustible heat source closest to the proximal end of the smoking article.

As used herein, the term "extent" is used to describe the maximum longitudinal dimension of the smoking article. That is, the maximum dimension in the direction between the proximal end and the opposite distal end of the smoking article.

[0017] As used in this document, the term "airflow channel" is used to describe a channel that extends along the length of a heat source through which air can be drawn downstream for inhalation by of a user.

[0018] As used herein, the term "direct contact" is used to describe contact between a surface of a combustible portion of the combustible heat source and at least some of the air entering the smoking article through one or more channels of air flow and one or more air inlets and is drawn through the aerosol forming substrate.

Smoking articles according to the invention may comprise an unblinded heat source. As used herein, the term "unblinded" is used to describe a combustible heat source that includes at least one airflow channel.

[0020] The one or more air flow channels may comprise one or more closed air flow channels.

[0021] As used in this document, the term "enclosed" is used to describe air flow channels that extend through the interior of the fuel heat source and are surrounded by the fuel heat source.

[0022] Alternatively or in addition to the one or more airflow channels may comprise one or more unclosed airflow channels. For example, the air flow paths may comprise one or more unclosed air flow grooves or channels that extend along the exterior of the combustible heat source.

[0023] The one or more air flow channels may comprise one or more closed air flow channels or one or more unclosed air flow channels or a combination thereof.

[0024] In some embodiments, smoking articles according to the invention comprise one, two or three air flow channels extending from the front face to the rear face of the combustible heat source.

[0025] In certain preferred embodiments, smoking articles in accordance with the invention comprise a single air flow channel extending from the front face to the rear face of the combustible heat source.

[0026] In certain especially preferred embodiments, smoking articles in accordance with the invention comprise a single substantially axial or central air flow channel extending from the front face to the rear face of the combustible heat source.

[0027] In such embodiments, the diameter of the single airflow channel is preferably between about 1.5 mm and about 3 mm.

[0028] It should be noted that, in addition to one or more air flow channels through which air can be drawn in for inhalation by a user, combustible heat sources of smoking articles according to the invention may also comprise one or more blocked or closed pathways through which air cannot be drawn in for inhalation by a user.

[0029] For example, smoking articles according to the invention may comprise combustible heat sources comprising one or more air flow channels extending from the front face to the rear face of the combustible heat source and one or more pathways that extend from the rear face of the combustible heat source for only half the length of the combustible heat source.

[0030] In such embodiments, the inclusion of one or more closed air passages increases the surface area of the fuel heat source that is exposed to oxygen in the air and can advantageously facilitate ignition and continued combustion of the fuel heat source.

[0031] Smoking articles according to the invention comprise one or more air inlets located downstream of the rear face of the combustible heat source and upstream of the mouthpiece.

As used herein, the term "air inlet" is used to descend a hole, slit, slot or any other opening through which air can be drawn into the smoking article.

[0033] One or more air inlets are located between the rear face of the combustible heat source and a downstream end of the aerosol forming substrate. The one or more air inlets do not include any air inlets located between the downstream end of the aerosol-forming substrate and a final upstream of the nozzle. In other words, smoking articles according to the invention do not comprise any air inlets located downstream of the aerosol forming substrate and upstream of the mouthpiece.

[0034] The quantity, shape, size and location of air intakes can be adjusted accordingly so that a good smoking performance can be achieved.

[0035] In use, air drawn through the aerosol forming substrate of the smoking article enters the smoking article through one or more air flow channels and one or more air inlets. The aspirated air passes downstream through the smoking article to the mouthpiece and leaves the smoking article through the proximal end thereof.

[0036] When in use, at least some of the air drawn through the aerosol-forming substrate comes into direct contact with a combustible portion of the combustible heat source.

[0037] Air drawn through the aerosol forming substrate of the smoking article entering the smoking article through one or more air flow channels may come into direct contact with a combustible portion of the combustible heat source as it passes through one or more airflow channels.

[0038] Alternatively or in addition to this, air drawn through the aerosol forming substrate of the smoking article entering the smoking article through one or more air flow channels may contact the rear face of the source of combustible heat. In such embodiments, air drawn through the smoking article aerosol forming substrate that enters the smoking article through one or more air inlets may also come into direct contact with a rear face of the combustible heat source.

[0039] In the smoking articles according to the invention, heating of the aerosol-forming substrate takes place by conduction and by forced convection.

[0040] During blowing by a user, fresh air drawn through one or more air inlets between the rear face of the combustible heat source and the aerosol forming substrate advantageously reduces the temperature of the substrate from aerosol formation of smoking articles in accordance with the invention. This advantageously prevents or substantially inhibits spikes in the temperature of the aerosol forming substrate of smoking articles according to the invention during puffing by a user.

[0041] As used in this document, the term "fresh air" is used to describe ambient air that is not significantly heated by the combustible heat source during blowing by a user.

[0042] When preventing or inhibiting spikes in the temperature of the aerosol forming substrate, the inclusion of one or more air inlets between the rear face of the combustible heat source and a downstream end of the aerosol forming substrate advantageously aids in reducing combustion or pyrolysis of the aerosol forming substrate of smoking articles according to the invention under intense blowing regimes. In addition, the inclusion of one or more air inlets between the rear end of the fuel heat source and a downstream end of the aerosol forming substrate advantageously aids in minimizing or reducing the impact of a user's blow regime on the composition. of the main aerosol of smoking articles according to the invention.

[0043] One or more air inlets may comprise one or more first air inlets around the periphery of the aerosol forming substrate through which air may be drawn into the aerosol forming substrate. In such embodiments, when in use, fresh air is drawn into the aerosol forming substrate of the smoking article through the first air inlets. Air drawn into the aerosol forming substrate through the first air inlets passes downstream through the smoking article from the aerosol forming substrate to the mouthpiece and leaves the smoking article through the proximal end thereof.

[0044] During puffing by a user, fresh air drawn in through one or more air inlets around the periphery of the aerosol forming substrate advantageously reduces the temperature of the aerosol forming substrate of smoking articles in accordance with the invention. This advantageously prevents or substantially inhibits spikes in the temperature of the aerosol forming substrate of smoking articles according to the invention during puffing by a user.

[0045] In certain preferred embodiments, one or more air inlets are located proximate to the downstream end of the aerosol forming substrate.

[0046] In certain embodiments, the aerosol forming substrate may be adjacent the rear face of the combustible heat source or a first substantially air-impermeable non-combustible barrier coating provided on the rear face of the fuel source. combustible heat.

[0047] As used herein, the term "contiguity" is used to describe the aerosol forming substrate being in direct contact with the rear face of the combustible heat source or with a first substantially impermeable non-combustible barrier coating to the air provided on the rear face of the combustible heat source.

In other embodiments, the aerosol forming substrate may be spaced from the rear face of the combustible heat source. That is, there may be a space or gap between the aerosol forming substrate and the rear face of the combustible heat source.

[0049] In such embodiments, one or more air inlets may comprise one or more second air inlets between the rear face of the combustible heat source and the aerosol forming substrate. When in use, fresh air is drawn into the space between the combustible heat source and the aerosol forming substrate through the second air inlets. Air drawn into the space between the combustible heat source and the aerosol forming substrate through the second air inlets passes downstream through the smoking article from the space between the combustible heat source and the forming substrate of aerosol to the mouthpiece and leaves the smoking article through the proximal end thereof.

[0050] During blowing by a user, fresh air drawn in through one or more second air inlets between the rear face of the combustible heat source and the aerosol forming substrate advantageously reduces the temperature of the substrate of aerosol formation of smoking articles in accordance with the invention. This advantageously prevents or substantially inhibits spikes in the temperature of the aerosol forming substrate of smoking articles according to the invention during puffing by a user.

[0051] It should be understood that smoking articles according to the invention may comprise one or more first air inlets around the periphery of the aerosol forming substrate, or one or more second air inlets between the rear face of the source of combustible heat and the aerosol forming substrate, or a combination of one or more first air inlets and one or more second air inlets between the rear face of the combustible heat source and the aerosol forming substrate.

Smoking articles according to the invention may further comprise either (i) a non-combustible and substantially air-impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate or (ii) a second barrier non-combustible and substantially impermeable to air between the combustible heat source and one or more air flow channels.

[0053] It should be noted that smoking articles according to the invention may not as much comprise (i) a first non-combustible and substantially air-impermeable first barrier between the rear face of the combustible heat source and the aerosol forming substrate, and (ii) a second, non-combustible and substantially air-impermeable barrier between the combustible heat source and one or more air flow channels.

[0054] As used herein, the term "non-combustible" is used to describe a substantially non-combustible barrier at temperatures reached by the combustible heat source during combustion and ignition thereof.

[0055] Where smoking articles according to the invention further comprise (i) a first non-combustible and substantially impermeable to air barrier between the rear face of the combustible heat source and the aerosol forming substrate, the air drawn through the substrate of aerosol which enters the smoking article through one or more air flow channels and one or more air inlets do not come into direct contact with the rear face of the combustible heat source. However, in such embodiments, air drawn through the aerosol forming substrate that enters the smoking article through one or more flow channels actually comes into direct contact with a combustible portion of the combustible heat source as it passes. through one or more airflow channels.

[0056] In such embodiments, the first barrier allows air entering the smoking article through one or more air flow channels to be drawn downstream through the smoking article.

[0057] The first barrier may abut one or both of the rear face of the combustible heat source and the aerosol forming substrate. Alternatively, the first barrier may be spaced from the aerosol-forming substrate and/or the nozzle.

[0058] The first barrier may be adhered or otherwise affixed to one or both rear faces of the fuel heat source and the aerosol forming substrate.

[0059] In certain preferred embodiments, the first barrier comprises a first non-combustible barrier coating substantially impermeable to air supplied over the rear face of the combustible heat source. In such embodiments, preferably the first barrier comprises a first barrier coating over at least substantially the entire rear face of the combustible heat source. More preferably, the first barrier comprises a first barrier coating provided over the entire rear face of the combustible heat source.

[0060] In such embodiments, the first barrier coating allows air to be drawn downstream through one or more air flow channels that extend from the front face to the rear face of the combustible heat source.

[0061] As used herein, the term "coating" is used to describe a layer of material that covers and is adhered to the heat source.

[0062] The first barrier can advantageously limit the temperature to which the aerosol-forming substrate is exposed during ignition and combustion of the combustible heat source, thus helping to prevent or reduce thermal degradation or combustion of the aerosol forming substrate during use of the smoking article. This is particularly advantageous where the combustible heat source comprises one or more additives to assist in igniting the combustible heat source.

[0063] The inclusion of a first substantially air-impermeable non-combustible barrier between the rear face of the combustible heat source and the aerosol forming substrate may also, and advantageously, substantially prevent or inhibit the migration of substrate components from aerosol formation of smoking articles according to the invention to the combustible heat source during storage of the smoking articles.

[0064] Alternatively or in addition to this, the inclusion of a first substantially air-impermeable non-combustible barrier between the rear face of the combustible heat source and the aerosol forming substrate can, and advantageously, substantially prevent or inhibit the migration of aerosol forming substrate components from smoking articles according to the invention to the combustible heat source during consumption of the smoking article.

[0065] The inclusion of a first substantially air-impermeable non-combustible barrier between the rear face of the combustible heat source and the aerosol forming substrate may be particularly advantageous where the aerosol forming substrate comprises at least one aerosol former.

[0066] In such embodiments, the inclusion of a first substantially airtight non-combustible barrier between the rear face of the combustible heat source and the aerosol forming substrate can, and advantageously, substantially prevent or inhibit hair migration minus one aerosol former from the aerosol forming substrate to the combustible heat source during storage and use of the smoking article. Decomposition of the at least one aerosol former during use of the smoking article can, therefore, advantageously be substantially avoided or reduced.

[0067] Depending on the characteristics and performance desired for the smoking article, the first barrier may have a low thermal conductivity or a high thermal conductivity. In certain embodiments, the first barrier can be formed from a material that has a thermal conductivity by mass of between about 0.1 W per meter Kelvin (mWZ(mK)) and about 200 W per meter Kelvin (mWZ(m) ^K)), at 23°C and 50% relative humidity, as measured using the modified transient plane source (MTPS) method.

[0068] The thickness of the first barrier can be adjusted appropriately to achieve good smoking performance. In certain embodiments, the first barrier can be between about 10 microns and about 500 microns thick.

[0069] The first barrier may be formed from one or more suitable materials that are substantially thermally stable and non-combustible at the temperatures reached by the combustible heat source during ignition and combustion. Suitable materials are known in the art and include, but are not limited to, clays (such as, for example, bentonite and kaolinite), glasses, minerals, ceramic materials, metals, resins and combinations thereof.

[0070] Preferred materials from which the first barrier can be formed include clays and glasses. The most preferred materials from which the first barrier can be formed include copper, aluminum, stainless steel, alloys, alumina (Al2O3), resins and mineral glues.

[0071] In certain preferred embodiments, the first barrier comprises a clay coating comprising a 50Z50 mixture of bentonite and kaolinite provided on the rear face of the combustible heat source. In other preferred embodiments, the first barrier comprises a glass coating, more preferably a sintered glass coating, provided on the rear face of the combustible heat source.

[0072] In certain particularly preferred embodiments, the first barrier comprises an aluminum coating provided on the rear face of the combustible heat source.

[0073] Preferably, the first barrier has a thickness of at least about 10 microns.

[0074] Due to the slight permeability of clays to air, in embodiments where the first barrier comprises a clay coating provided on the rear face of the combustible heat source, the clay coating more preferably has a thickness of at least about 50 microns, and more preferably between about 50 microns and about 350 microns.

[0075] In embodiments where the first barrier is formed from one or more air-impermeable materials, such as aluminum, the first barrier may be thinner and will generally preferably have a thickness of less than about 100 microns and more preferably about 20 microns.

[0076] In embodiments where the first barrier comprises a glass coating provided on the rear face of the combustible heat source, the glass coating is preferably less than about 200 microns thick.

[0077] The thickness of the first barrier can be measured using a microscope, a scanning electron microscope (SEM) or any other suitable measurement methods known in the art.

[0078] Where the barrier comprises a first barrier coating provided on a rear face of the combustible heat source, the first barrier coating may be applied so as to mask and adhere to the rear face of the combustible heat source by any known methods within the scope of the art, including, but not limited to, spray coating, vapor deposition, immersion, metal transfer (eg brushing or gluing), electrostatic deposition, or any combination thereof.

[0079] For example, the first barrier coating can be made by preforming a barrier to the approximate size and shape of the rear face of the fuel heat source, and applying it to the rear face of the fuel heat source to mask and adhere to at least substantially the entire rear face of the combustible heat source. Alternatively, the first barrier coating can be cut or otherwise tampered with after its application to the rear face of the combustible heat source. In a preferred embodiment, aluminum foil is applied to the rear face of the fuel heat source by gluing or pressing it to the fuel heat source, and is then cut or otherwise tampered with so that the aluminum foil covers and adheres to the skin. less substantially the entire rear face of the combustible heat source, rather than the rear face of the combustible heat source in its entirety.

[0080] In another preferred embodiment, the first barrier coating is formed by applying a solution or suspension of one or more suitable coating materials to the external face of the combustible heat source. For example, the first barrier coating can be applied to the rear face of the combustible heat source by immersing the rear face of the combustible heat source in a solution or suspension of one or more suitable coating materials or by brushing or spray coating a solution or suspension or electrostatically depositing a powder or powder mixture of one or more suitable coating materials on the external face of the combustible heat source. Where the first barrier coating is applied to the rear face of the fuel heat source by electrostatically depositing a powder or powder mixture of one or more suitable coating materials on the rear face of the fuel heat source, the rear face of the heat source fuel is preferably pretreated with water glass prior to electrostatic deposition. Preferably, the first barrier coating is applied by spray coating.

[0081] The first barrier coating can be formed by a single application of a solution or suspension of one or more suitable coating materials to the rear face of the combustible heat source. Alternatively, the first barrier coating can be formed by multiple applications of a solution or suspension of one or more suitable coating materials to the rear face of the combustible heat source. For example, the barrier coating can be formed by one, two, three, four, five, six, seven or eight successive applications of a solution or suspension of one or more suitable coating materials to the rear face of the combustible heat source.

[0082] Preferably, the first barrier coating is formed by between one and ten applications of a solution or suspension of one or more suitable coating materials to the rear face of the combustible heat source.

[0083] After applying the solution or suspension of one or more coating materials to the rear face thereof, the combustible heat source can be dried to form the barrier coating.

[0084] Where the barrier coating is formed through multiple applications of a solution or suspension of one or more suitable coating materials to the rear face of the same, the combustible heat source may need to be dried between successive applications of the solution or suspension.

[0085] Alternatively to, or in addition to drying, after applying a solution or suspension of one or more coating materials to the rear face of the fuel heat source, the coating material in the fuel heat source may be sintered in a manner to form the barrier coating. Sintering the barrier coating is particularly preferred where the barrier coating is a glass or ceramic coating. Preferably, the first barrier coating is sintered at a temperature between about 500°C and about 900°C, and more preferably at about 700°C.

[0086] Where smoking articles according to the invention further comprise (ii) a second, non-combustible and substantially impermeable to air barrier between the combustible heat source and one or more air flow channels, the air drawn through the substrate. aerosol formation that enters the smoking article through one or more air flow channels does not come into direct contact with a combustible portion of the combustible heat source as it passes through one or more air flow channels. However, in such embodiments, air is drawn through the aerosol-forming substrate into the smoking article through one or more air flow channels actually in direct contact with the rear face of the combustible heat source. In such embodiments, air drawn through the aerosol forming substrate entering the smoking article through one or more air inlets may also come into direct contact with the rear face of the combustible heat source.

[0087] The second barrier can substantially, and advantageously, prevent or inhibit combustion and decomposition by-products formed during ignition and combustion of the combustible heat source of smoking articles according to the invention from entering the air drawn into the interior. of smoking articles in accordance with the invention through one or more air flow channels as aspirated air passes through one or more air flow channels. This is particularly advantageous where the combustible heat source comprises one or more additives to aid in the ignition or combustion of the combustible heat source.

[0088] The inclusion of a second substantially air-impermeable non-combustible barrier between the combustible heat source and one or more air flow channels may also advantageously and substantially prevent or inhibit the activation of combustion of the combustible heat source from smoking articles according to the invention during puffing by a user. This can prevent or inhibit spikes in substrate temperature from aerosol formation during user puffs.

[0089] By preventing or inhibiting the combustion activation of the fuel heat source, and therefore preventing or inhibiting excessive temperature increases in the substrate from aerosol formation, combustion or pyrolysis of the substrate. Aerosol formation of smoking articles according to the invention under intense blowing regimes can advantageously be avoided. Furthermore, the impact of a user's puff regimen on the main aerosol composition of smoking articles according to the invention can advantageously be minimized or reduced.

[0090] The second barrier can be adhered or otherwise affixed to the combustible heat source.

[0091] In given embodiments, the second barrier comprises a second substantially air-impermeable non-combustible barrier coating provided on an inner surface with one or more air flow channels. In such embodiments, the second barrier preferably comprises a second barrier coating provided over at least substantially the entire inner surface of one or more airflow channels. More preferably, the second barrier comprises a second barrier coating provided over at least substantially the entire interior surface of one or more airflow channels.

[0092] In other embodiments, the second barrier coating may be provided by inserting a liner within one or more airflow channels. For example, where one or more air flow channels comprise one or more covert air flow channels extending within the combustible heat source, a hollow non-combustible substantially airtight tube may be inserted into each of the channels. of air flow.

[0093] Depending on the performance and desired characteristics of the smoking article, the second barrier may have low thermal conductivity or high thermal conductivity. Preferably, the second barrier has a low thermal conductivity.

[0094] The thickness of the second barrier can be adjusted appropriately so that it can have a good smoking performance. In certain embodiments, the second barrier can be between about 30 microns and about 200 microns thick. In a preferred embodiment, the second barrier is between about 30 microns and about 100 microns thick.

[0095] The second barrier can be formed from one or more suitable materials that are substantially thermally stable and non-combustible at the temperatures reached by the combustible heat source during ignition and combustion. Suitable materials are known in the art and include, but are not limited to, for example: clays; metal oxides such as iron oxide, alumina, titania, silica, silica-alumina, zirconia and ceria; zeolites; zirconium phosphate; and other ceramic materials or combinations thereof.

[0096] Preferred materials from which the second barrier can be formed include clays, glasses, aluminum, iron oxide and combinations thereof. If desired, catalytic ingredients such as ingredients that promote the oxidation of carbon monoxide to carbon dioxide can be incorporated into the second barrier. Suitable catalytic ingredients include, but are not limited to, for example, platinum, palladium, transition metals and their oxides.

[0097] Where the second barrier comprises a second barrier coating provided on an inner surface of one or more air flow channels, the second barrier coating may be applied to the inner surface of one or more air flow channels of a or more airflow channels by any suitable method, such as the methods described in US-A-5,040,551. For example, the inner surface of one or more airflow channels can be sprayed, moistened or painted with a solution or suspension of the second barrier coating. In certain preferred embodiments, the second barrier coating is applied to the inner surface of one or more airflow channels by the process described in WO-A2-2009/074870 as the combustible heat source is extruded.

[0098] Preferably, smoking articles according to the invention comprise an outer casing circumscribing the aerosol forming substrate and at least a rear portion of the combustible heat source. The outer wrapper should hold the combustible heat source and aerosol forming substrate of the smoking article when the smoking article is assembled.

[0099] More preferably, smoking articles according to the invention comprise an outer shell that circumscribes the mouthpiece, the aerosol forming substrate, any other components of the smoking article downstream of the aerosol forming substrate and upstream of the nozzle and at least a rear portion of the combustible heat source.

[00100] Preferably, the outer casing is substantially impermeable to air.

[00101] Smoking articles according to the invention may comprise outer casings formed from any suitable material or combination of materials. Suitable materials are well known in the art and include, but are not limited to, cigarette paper.

[00102] One or more inlets located between the rear face of the combustible heat source and the downstream end of the aerosol forming substrate are provided in the outer shell and any other materials circumscribing components of smoking articles according to the invention through the which air can be drawn into one or more airflow passageways.

[00103] Where one or more air inlets comprise one or more first air inlets around the periphery of the aerosol forming substrate, one or more first air inlets are provided in the outer shell and any other materials circumscribing the aerosol forming substrate. aerosol formation.

[00104] Where one or more air inlets comprise one or more second air inlets between the rear face of the combustible heat source and the aerosol forming substrate, one or more second air inlets are provided in the outer casing and any materials underlying.

[00105] Preferably, the combustible heat source is a carbonaceous heat source. As used herein, the term "carbonaceous" is used to describe a combustible heat source that comprises carbon. Preferably, carbonaceous combustible heat sources for use in smoking articles according to the invention have a carbon content of at least about 35 percent, more preferably at least about 40 percent, most preferably at least 45 percent per dry weight of the combustible heat source.

[00106] In some embodiments, combustible heat sources according to the invention are carbon-based combustible heat sources. As used herein, the term "carbon-based heat source" is used to describe a heat source composed primarily of carbon.

[00107] Carbon-based combustible heat sources for use in smoking articles according to the invention have a carbon content of at least about 50%. For example, carbon-based combustible heat sources for use in smoking articles according to the invention can have a carbon content of at least about 60 percent, more preferably at least about 70 percent, or at least about 80 percent of the dry weight of the carbon-based fuel heat source.

Smoking articles according to the invention may comprise carbonaceous combustible heat sources formed from one or more suitable carbon-containing materials.

[00109] If desired, one or more binders can be combined with one or more carbon-containing materials. Preferably, one or more binders are organic binders. Known suitable organic binders include, but are not limited to, gums (eg, guar gum), modified celluloses and cellulose derivatives (eg, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose and hydroxypropyl methylcellulose), wheat flour, starches, sugars, oils vegetables and combinations thereof.

[00110] In a preferred embodiment, the fuel heat source is formed from a mixture of carbon powder, modified cellulose, wheat flour and sugar.

[00111] Instead of or in addition to one or more binders, combustible heat sources for use in smoking articles according to the invention may comprise one or more additives in order to improve the properties of the combustible heat source. Suitable additives include, but are not limited to, additives to promote consolidation of the combustible heat source (e.g., sintering aids), additives to promote ignition of the combustible heat source (e.g., oxidizers such as perchlorates, chlorates, nitrates, peroxides, permanganates, zirconium and combinations thereof), additives to promote combustion of the combustible heat source (eg potassium and potassium salts such as potassium citrate) and additives to promote the decomposition of one or more produced gases by combustion of the combustible heat source (eg catalysts such as CuO, Fe2O3 and Al2O3).

[00112] Where smoking articles according to the invention comprise a first barrier coating provided on the rear face of the combustible heat source, such additives may be incorporated into the combustible heat source prior to or after application of the first barrier coating to the rear face of the combustible heat source.

[00113] In certain preferred embodiments, the combustible heat source is a carbonaceous combustible heat source comprising carbon and at least one ignition aid. In a preferred embodiment, the combustible heat source is a carbonaceous combustible heat source comprising carbon and at least one ignition aid as described in WO-A1-2012/164077.

[00114] As used in this document, the term "ignition aid" is used to denote a material that releases energy and/or oxygen during ignition of the combustible heat source where the rate of release of energy and/or oxygen by the material is not limited by the diffusion of ambient oxygen. In other words, the rate of release of oxygen and/or energy by the material during ignition of the combustible heat source is largely independent of the rate at which ambient oxygen can reach the material. As used herein, the term "ignition aid" is also used to denote an elemental metal that releases energy during ignition of the combustible heat source, in which case the ignition temperature of the elemental metal is less than about 500° C, and the elemental metal's heat of combustion is at least about 5 kJ/g.

[00115] As used herein, the term "ignition aid" does not include alkali metal salts of carboxylic acids (such as alkali metal citrate salts, alkali metal acetate salts and alkali metal succinate salts), alkali metal halide (such as alkali metal chloride salts), alkali metal carbonate or alkali metal phosphate salts, which are believed to modify carbon combustion. Even when present in a large amount relative to the total weight of the fuel heat source, such alkali metal burning salts do not release enough energy during ignition of a fuel heat source to produce an acceptable aerosol during the first few puffs.

[00116] Examples of suitable oxidizing agents include, but are not limited to: nitrates such as potassium nitrate, calcium nitrate, strontium nitrate, sodium nitrate, barium nitrate, lithium nitrate, aluminum nitrate and iron nitrate; nitrites; other organic and inorganic nitro compounds; chlorates such as, for example, sodium chlorate and potassium chlorate; perchlorates such as, for example, sodium perchlorate; chlorides; bromates such as, for example, sodium bromate and potassium bromate; perbromates; bromides; borates such as, for example, sodium borate and potassium borate; ferrates, such as, for example, barium ferrate; ferrite; manganates, such as, for example, potassium manganate; permanganates, such as, for example, potassium permanganate; organic peroxides such as, for example, benzoyl peroxide and acetone peroxide; inorganic peroxides, such as, for example, hydrogen peroxide, strontium peroxide, magnesium peroxide, calcium peroxide, barium peroxide, zinc peroxide and lithium peroxide; superoxides, such as, for example, potassium superoxide and sodium superoxide; iodates; periodates; iodides; sulfates; sulfites; other sulfoxides; phosphates; phosphinates; phosphites; and phosphanates.

[00117] While advantageously improving the ignition and combustion properties of the carbonaceous fuel heat source, the inclusion of ignition and combustion additives can give rise to undesirable combustion and decomposition products during consumption of the article to smoke. For example, the decomposition of nitrates included in the carbonaceous combustible heat source to aid in igniting it can result in the formation of nitrogen oxides.

[00118] The inclusion of a second substantially airtight non-combustible barrier between one or more air flow channels and the combustible heat source of smoking articles according to the invention may substantially and advantageously inhibit or prevent such reaction and decomposition products enter the air drawn into the interior of smoking articles according to the invention through one or more air flow channels as the drawn air passes through one or more air flow channels.

[00119] Carbonaceous combustible heat sources for use in smoking articles in accordance with the invention may be prepared as described within the art known to individuals of ordinary skill in the art.

[00120] Carbonaceous combustible heat sources for use in smoking articles according to the invention are preferably formed by mixing one or more carbon-containing materials with one or more binders and other additives, where included, and the Preform the mixture into a desired shape. The mixture of one or more materials containing carbon, one or more binders, and other optional additives can be preformed into a desired shape using any known ceramic forming method, such as slip, extrusion, molding. injection and mold compression or pressing. In certain preferred embodiments, the mixture is preformed into a desired shape by pressing or extrusion or a combination thereof.

[00121] Preferably, the mixture of one or more materials containing carbon, one or more binders and other additives is preformed in an elongated cylinder. However, it should be noted that a mixture of one or more materials containing carbon or more binders and other additives can be preformed into other desired shapes.

[00122] After formation, particularly after extrusion, the elongated cylinder or any other desired shape is preferably dried in order to reduce its moisture content and then pyrolyzed in a non-oxidizing atmosphere at a temperature sufficient to carbonize one or more binders, where present, and substantially eliminate any volatile compounds in the elongated cylinder or other shape. The elongated cylinder, or other desired shape, is preferably pyrolyzed in an atmosphere of nitrogen at a temperature of between about 700°C and about 900°C.

[00123] In certain embodiments, at least one metal nitrate salt is incorporated into the fuel heat source by including at least one metal nitrate precursor in the mixture of one or more materials containing carbons, one or more binders and other additives. The at least one metal nitrate precursor is then converted in-situ to the at least one metal nitrate salt by treating the preformed pyrolyzed barrel (or any other form) with an aqueous solution of nitric acid. In one embodiment, the combustible heat source comprises at least one metal nitrate salt having a thermal decomposition temperature of less than about 600°C, more preferably less than about 400°C. Preferably, at least one metal nitrate salt has a decomposition temperature between about 150°C and about 600°C, more preferably between about 200°C and about 400°C.

[00124] In preferred embodiments, exposure of the combustible heat source to a conventional lighter flame or any other means of ignition should cause at least one metal nitrate salt to decompose and release oxygen and energy. Such decomposition causes an initial rise in the temperature of the combustible heat source and also assists in igniting the combustible heat source. After the decomposition of at least one metal nitrate salt, the combustible heat source preferably continues combustion at a lower temperature.

[00125] The inclusion of at least one metal nitrate salt advantageously results in ignition of the combustible heat source being initiated internally, and not just at a point on the surface thereof. Preferably, the at least one metal nitrate salt is present in the combustible heat source in amounts of from about 20 percent dry weight to about 50 percent dry weight of the combustible heat source.

[00126] In other embodiments, the combustible heat source comprises at least one peroxide or superoxide that actively evolves at a temperature below about 600 °C, more preferably at a temperature below about 400 °C.

[00127] Preferably, the at least one peroxide or superoxide actively evolves oxygen at a temperature between about 150°C and about 600°C, more preferably at a temperature of between about 200°C and about 400°C, more preferably at a temperature of about 350°C.

[00128] In use, exposure of the combustible heat source to a yellow flame of a conventional lighter or any other means of ignition must cause at least one peroxide or superoxide to decompose and release oxygen. This causes an initial rise in the temperature of the combustible heat source and also assists in igniting a combustible heat source. After the decomposition of at least one peroxide or superoxide, the combustible heat source preferably continues its combustion at a lower temperature.

[00129] The inclusion of at least one peroxide or superoxide advantageously results in the ignition of the combustible heat source being initiated internally, and not just at a point on its surface.

The combustible heat source preferably has porosity between about 20 percent and about 80 percent, more preferably between about 20 percent and 60 percent. Where the combustible heat source comprises at least one metal nitrate salt, this advantageously allows oxygen to diffuse into the mass of the combustible heat source at a rate sufficient to maintain combustion while at least one metal nitrate salt decomposes and combustion proceeds. Even more preferably, the combustible heat source has a porosity of between about 50 percent and about 70 percent, more preferably between about 50 percent and about 60 percent as measured by, for example, mercury porosimetry or pycnometry. of helium. The required porosity can be easily achieved during the production of the combustible heat source using conventional technology and methods.

Advantageously, carbonaceous combustible heat sources for use in smoking articles according to the invention have bulk density between about 0.6 g/cm3 and about 1 g/cm3.

[00132] Preferably, the combustible heat source has a mass between about 300mg and about 500mg, more preferably between about 400mg and about 450mg.

[00133] Preferably, the combustible heat source has a length of between about 7 mm and about 17 mm, more preferably between about 7 mm and about 15 mm, more preferably between about 7 mm and about 13 mm .

Preferably, the combustible heat source has a diameter of between about 5 mm and about 9 mm, more preferably between about 7 mm and about 8 mm.

[00135] Preferably, the combustible heat source is of substantially uniform diameter. However, the combustible heat source may alternatively be tapered so that the diameter of a rear portion of the combustible heat source is greater than the diameter of the front portion thereof. Particularly preferred are substantially cylindrical combustible heat sources. The combustible heat source may, for example, be a tapered cylinder or cylinder of substantially circular cross-section or a tapered cylinder or cylinder of substantially elliptical cross-section.

[00136] Preferably, smoking articles according to the invention comprise aerosol forming substrate which comprises at least one aerosol former and a material capable of releasing volatile compounds in reaction to heating. The aerosol forming substrate can comprise other additives and ingredients including, but not limited to, humectants, flavors, binders and mixtures thereof.

[00137] Preferably, the aerosol forming substrate comprises nicotine. More preferably, the aerosol forming substrate comprises tobacco.

[00138] The at least one aerosol former can be any suitable known compound or mixture of compounds which, when in use, facilitate the formation of a dense and stable aerosol and which is substantially resistant to thermal degradation at the operating temperature of the smoking article . Suitable aerosol formers are well known in the art and include, for example, polyhydric alcohols, esters of polyhydric alcohols such as glycerol mono-, dior triacetate and aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers for use in smoking articles in accordance with the invention are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1,3-butanediol and, most preferably, glycerin.

[00139] The material capable of emitting volatile compounds in response to heating can be a load of plant-based material. The material capable of emitting volatile compounds in response to heating may be a homogenized vegetable-based material charge. For example, the aerosol forming substrate can comprise one or more plant-derived materials, including, but not limited to: tobacco; tea, for example green tea; mint; blond; eucalyptus; basil; saves; verbena; and tarragon.

[00140] Preferably, the material capable of emitting volatile compounds in reaction to heating is a load of vegetable-based material, more preferably a load of homogenized tobacco-based material.

[00141] The aerosol forming substrate may take the form of a plug or segment comprising a material capable of emitting volatile compounds in response to heating circumscribed by a paper or other envelope. As stated above, whenever an aerosol forming substrate is in the form of such a plug or segment, the entire plug or segment, including any casing, will be considered to be the aerosol forming substrate.

Preferably, the aerosol forming substrate has a length between about 5 mm and about 20 mm, more preferably between about 8 mm and about 12 mm.

In preferred embodiments, the aerosol forming substrate comprises a plug of tobacco-based material packaged in a paper wrapper. In specifically preferred embodiments, the aerosol forming substrate comprises a plug of homogenized tobacco material packaged in a plug wrap.

[00144] Preferably, smoking articles according to the invention further comprise a heat conduction element around the rear portion of the fuel heat source and at least a front portion of the aerosol forming substrate. The heat conducting element is preferably resistant to combustion. In certain embodiments, the heat-conducting element is oxygen-restricting. In other words, the thermally conductive element inhibits or resists the passage of oxygen through the thermally conductive element to the combustible heat source.

[00145] In certain embodiments, the thermally conductive element may come into direct contact with both the rear portion of the fuel heat source and the aerosol forming substrate. In such embodiments, the thermoconductive element provides a thermal link between the combustible heat source and the aerosol forming substrate of smoking articles in accordance with the invention.

[00146] In other embodiments, the thermally conductive element may be spaced from one or more of the rear portion of the fuel heat source and the aerosol forming substrate, so that there is no direct contact between the thermally conductive element and the rear portion of the combustible heat source and/or the aerosol forming substrate.

[00147] Heat-conducting elements suitable for use in smoking articles in accordance with the invention, include, but are not limited to: foil wrappers such as, for example, aluminum foil wrappers, steel wrappers, aluminum wrappers. iron sheet and copper sheet casings; and metal alloy sheet casings.

[00148] Preferably, the rear portion of the combustible heat source surrounded by the thermoconductive element is between about 2mm and about 8mm in length, more preferably between about 3mm and about 5mm in length.

Preferably, the front portion of the combustible heat source not surrounded by the thermoconductive element is between about 4 mm and about 15 mm in length, more preferably between about 5 mm and about 8 mm in length.

[00150] In certain embodiments, the entire length of the aerosol forming substrate may be surrounded by a thermoconductive element.

[00151] In other embodiments, the thermoconductive element may involve only a front portion of the aerosol forming substrate. In such embodiments, the aerosol forming substrate extends beyond the downstream thermoconductive element.

[00152] In embodiments where the thermally conductive element involves only a front portion of the aerosol forming substrate, the aerosol forming substrate preferably extends at least about 3 mm beyond the first, downstream, thermally conductive element . More preferably, the aerosol forming substrate extends between about 3 mm and about 10 mm beyond the downstream thermoconductive element. However, the forming substrate may extend less than 3 mm beyond the downstream thermoconductive element.

Preferably, the front portion of the aerosol forming substrate surrounded by the thermoconductive element is between about 1 mm and about 10 mm in length, more preferably between about 2 mm and about 8 mm in length, plus preferably still between about 2 mm and about 6 mm in length.

Smoking articles according to the invention comprise a nozzle downstream of the aerosol forming substrate.

[00155] Preferably, the nozzle is of low filtration efficiency, more preferably of very low filtration efficiency. The nozzle can be a single-component or segment nozzle. Alternatively, the nozzle can be a multi-threaded or multi-component nozzle.

[00156] The nozzle may comprise, for example, a filter comprising one or more segments, which comprise known suitable filtration materials. Suitable filtration materials are known in the art and include, but are not limited to, cellulose acetate and paper. Alternatively, or in addition, the mouthpiece may comprise one or more segments comprising absorbents, adsorbents, flavorings and other aerosol modifying additives or combinations thereof.

[00157] Preferably, smoking articles according to the element further comprise a transfer element or spacer element between the aerosol forming substrate and the mouthpiece.

[00158] The transfer element may be adjacent to the aerosol forming substrate and/or the nozzle. Alternatively, the transfer element may be spaced apart from the aerosol-forming substrate and/or the nozzle.

[00159] The inclusion of a transfer element allows, and advantageously, the cooling of the aerosol generated by the transfer of heat from the fuel heat source to the aerosol forming substrate. The inclusion of a transfer element also advantageously allows the overall length of smoking articles according to the invention to be adjusted to a desired value, for example to a length similar to that of conventional cigarettes, by a suitable choice of the length of the transfer element.

[00160] The transfer element may have a length of between about 7mm and about 50mm, for example a length of between about 10mm and about 45mm or between about 15mm and about 30mm . The transfer element may have other lengths, depending on the overall desired length of the smoking article, and the presence and length of other components within the smoking article.

[00161] Preferably, the transfer element is composed of at least one hollow tubular body with an open end. In such embodiments, when in use, air drawn into the smoking article through one or more air inlets passes through the at least one hollow open-end tubular body as it passes downstream through the smoking article of the aerosol forming substrate to the nozzle.

[00162] The transfer element may comprise at least one open-ended hollow tubular body formed from one or more materials substantially thermosetting at the temperature of the aerosol generated by the transfer of heat from the combustible heat source to the aerosol forming substrate . Suitable materials are known in the art and include, but are not limited to, paper, paperboard, plastics such as cellulose acetate, ceramics and combinations thereof.

[00163] Alternatively or additionally, smoking articles according to the invention may comprise an aerosol cooling element or heat exchanger between the aerosol forming substrate and the mouthpiece. The aerosol cooling element may comprise a plurality of longitudinally extending channels.

[00164] The aerosol cooling element may comprise a grouped plate of material selected from a group consisting of metallic foil, polymeric material and substantially non-porous paper or paperboard. In certain embodiments, the aerosol cooling element may comprise a grouped plate of material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil.

In certain preferred embodiments, the aerosol cooling element may comprise a grouped plate of biodegradable polymeric material such as polylactic acid (PLA) or a grade of Mater-Bi® (a family of commercially available starch-based copolyesters ).

Smoking articles according to the invention may comprise one or more aerosol modifying agents downstream of the aerosol forming substrate. For example, one or more of the mouthpiece, transfer element and aerosol refrigeration element of smoking articles according to the invention may comprise one or more aerosol modifying agents.

[00167] Suitable aerosol modifying agents include, but are not limited to: flavorings; and chemoesthetic agents.

As used herein, the term "flavoring" is used to describe any agent which, in use, imparts a taste and/or aroma to an aerosol generated by the aerosol forming substrate of the smoking article.

[00169] As used herein, the term "chemoesthetic agent" is used to describe any agent that, during use, is perceived in the oral or olfactory cavity of a user by means other than, or in addition to, perception through a receptor gustatory or olfactory receptor cells. Perception of chemoesthetic agents is typically through a "trigeminal reaction," or through the trigeminal nerve, the glossopharyngeal nerve, the vagus nerve, or some combination of these. Typically, chemoaesthetic agents are perceived as hot, spicy, refreshing, or soothing sensations.

Smoking articles according to the invention may comprise one or more aerosol modifying agents which are both flavoring and chemoaesthetic downstream of the aerosol forming substrate. For example, one or more of the mouthpiece, transfer element and aerosol refrigeration element of smoking articles according to the invention may comprise menthol or other flavoring which provides a chemoaesthetic cooling effect.

Smoking articles according to the invention can be assembled using known methods and machinery.

[00172] The invention will be described below, by way of example only, with reference to the accompanying drawings, in which: Figure 1a) represents an exploded view of a smoking article according to a first embodiment of the invention; Figure 1b) is an exploded view of a smoking article in accordance with a second embodiment of the invention; Figure 1c) is an exploded view of a smoking article in accordance with a fourth embodiment of the invention; Figure 1d) is an exploded view of a smoking article in accordance with a fifth embodiment of the invention; Figure 1e) is an exploded view of a smoking article in accordance with a seventh embodiment of the invention; Figure 1f) is an exploded view of a smoking article in accordance with an eighth embodiment of the invention; Figure 2 is a schematic longitudinal section of a smoking article in accordance with the first embodiment of the invention shown in Figure 1a); and Figure 3 is a schematic longitudinal section of the smoking article in accordance with the second embodiment of the invention shown in Figure 1b).

[00173] The smoking article 2 according to the first embodiment of the invention shown in Figures 1a) and 2 comprises a combustible heat source 4 with a front face 6 and an opposite rear face 8, an aerosol forming substrate 10, a transfer element 12 and a nozzle 14 in axially contiguous alignment. As shown in Figure 2, the aerosol forming substrate 10, the transfer element 12 and the nozzle 14 and a rear portion of the combustible heat source 4 are encased in an outer shell 16 of plate material, such as, for example. , cigarette paper, low air permeability.

[00174] The combustible heat source 4 comprises a central air flow channel 18 (depicted by dotted lines in Figure 1a) that extends from the front face 6 to the rear face 8 of the combustible heat source 4.

[00175] The aerosol forming substrate 10 is located immediately downstream of the rear face 8 of the fuel heat source 4. The aerosol forming substrate 10 comprises a cylindrical plug of homogenized tobacco-based material 20, which includes a aerosol former such as, for example, glycerin, packaged in a plug wrap 22.

The transfer element 12 is located immediately downstream of the aerosol forming substrate 10 and comprises an open-ended cylindrical hollow tube 24 of suitable material such as, for example, paper, paperboard or cellulose acetate fiber .

The nozzle 14 is located immediately downstream of the transfer element 12 at the proximal end of the smoking article 2. The nozzle 14 comprises a cylindrical plug of suitable filtration material 26 such as, for example, acetate fiber. very low filtration efficiency cellulose, packed in a 28 filter plug wrap.

[00178] The smoking article may further comprise a strip of tip paper (not shown) circumscribing a downstream end portion of the outer shell 16.

[00179] As shown in Figure 2, the smoking article 2 further comprises a thermoconductive element 30 of suitable material such as, for example, aluminum foil around and in direct contact with a rear portion 4b of the carbonaceous heat source 4 and an adjoining front portion 10a of the aerosol forming substrate 10. In the smoking article 2 in accordance with the first embodiment of the invention shown in Figure 2, the aerosol forming substrate extends beyond the thermoconductive element 30, downstream . That is, the thermoconductive element 30 is not around or in direct contact with a rear portion of the aerosol forming substrate 10. However, it should be noted that in other embodiments of the invention (not shown), the element conductive term 30 may be around or in contact with the entire length of the aerosol forming substrate 10.

[00180] The smoking article 2 according to the first embodiment of the invention comprises one or more air inlets located downstream of the rear face 8 of the combustible heat source 4 and upstream of the nozzle 14. One or more air inlets are located between the rear face 8 of the fuel heat source 4 and a downstream end of the aerosol forming substrate 10 and comprise one or more first inlets 32 located around the periphery of the aerosol forming substrate 10.

[00181] As depicted in Figure 2, a circumferential arrangement of first air inlets 32 is provided in the plug housing 22 of the aerosol forming substrate 10 and the overlying outer housing 16 with a view to allowing the entry of fresh air (shown by dotted arrows in Figures 1a) and 2) on the aerosol forming substrate 10. It will be appreciated that in other embodiments of the invention (not shown) in which the thermoconductive element 30 is around and in direct contact with the entire length of the aerosol forming substrate 10, a circumferential array of first air inlets 32 may be provided in the plug housing 22 of the aerosol forming substrate 10, the overlying thermoconductive element 30 and the overlying outer housing 16 with views to admit the entry of fresh air into the aerosol forming substrate 10.

[00182] When in use, a user lights the combustible heat source 4 of the smoking article 2 according to the first embodiment of the invention and then inhales at the nozzle 14. When a user inhales at the nozzle 14, air (shown by the dotted arrows in Figures 1a) and 2) is drawn into the smoking article 2 through the central air flow channel 18 of the fuel heat source 4 and heated as it passes through the central air flow channel 18 of the source of combustible heat 4. When the user draws on the nozzle 14, fresh air (represented by the dotted arrows in Figures 1a) and 2) is also drawn into the aerosol forming substrate 10 of the smoking article 2 through the first inlets of air 32.

The heated air drawn through the central air flow channel 18 of the combustible heat source 4 heats the aerosol forming substrate 10 by forced convection as it passes downstream the aerosol forming substrate 10 towards the nozzle 14 of smoking article 2. Front portion 10a of aerosol forming substrate 10 is also heated by conduction through adjoining rear face 8 of fuel heat source 4 and heat conduction element 28.

[00184] Heating the aerosol forming substrate 10 by conduction and forced convection releases glycerin and other volatile and semi-volatile compounds from the plug of homogenized tobacco-based material 20. The compounds released from the aerosol forming substrate 10 form a aerosol which is entrained in the air drawn in through the central air flow channel 18 of the fuel heat source 4 and the air drawn into the aerosol forming substrate 10 of the smoking article 2 through the first air inlets 32 accordingly. flows through aerosol forming substrate 10. The drawn in air and entrained aerosol (represented by dashed arrows in Figures 1a) and 2) pass downstream through transfer element 12, where they cool and condense. The cooled aspirated air and entrained aerosol pass downstream through the mouthpiece 14 and are delivered to the user through the proximal end of the smoking article 2 in accordance with the first embodiment of the invention.

The smoking article 34 according to the second embodiment of the invention shown in Figures 1b) and 3) is broadly identical in design to the smoking article according to the first embodiment of the invention shown in Figures 1a) and 2. However, in the smoking article 34 in accordance with the second embodiment of the invention, the combustible heat source 4 and the aerosol forming substrate 10 are spaced apart from one another and one or more air inlets located between the rear face 8 of the source. of fuel heat source 4 and the downstream end of the aerosol forming substrate 10 comprise one or more second inlets 36 located between the rear face 8 of the fuel heat source 4 and the aerosol forming substrate 10.

[00186] As shown in Figure 3, a second circumferential arrangement of air inlets 36 is provided in the thermoconductive element 30 and the overlying outer shell 16 between the rear face 8 of the combustible heat source 4 and the final amount of the aerosol forming substrate 10 to admit cold air (indicated by the dotted arrows in figures 1b) and 3) into the space between the combustible heat source 4 and the substrate forming aerosol 10.

[00187] In use, when a user draws into the mouthpiece 14 of the smoking article 34 in accordance with the second embodiment of the invention, air (depicted by dotted arrows in Figures 1b) and 3) is sucked into the smoking article 34 through the air flow channel 18 of the fuel heat source 4 and fresh air is likewise drawn into the space between the fuel heat source 4 and the aerosol forming substrate 10 through the second air inlets 36.

The heated air drawn through the central air flow channel 18 of the combustible heat source 4 heats the aerosol forming substrate 10 by forced convection as it passes downstream the aerosol forming substrate 10 towards the nozzle 14 of smoking article 34. Front portion 10a of aerosol forming substrate 10 is also heated by conduction through thermoconductive element 28.

[00189] Heating the aerosol forming substrate 10 by conduction and convection releases glycerin and other volatile and semi-volatile compounds from the plug of homogenized tobacco-based material 20. The compounds released from the aerosol forming substrate 10 form an aerosol which is drawn in air drawn in through the air flow channel 18 of the fuel heat source 4 and the air drawn into the space between the fuel heat source 4 and the aerosol forming substrate 10 through the second air inlets 36 as it flows through the aerosol-forming substrate 10. The aspirated air and entrained aerosol (represented by dashed arrows in Figures 1b) and 3) pass downstream through transfer element 12, where they cool and condense. The cooled aspirated air and entrained aerosol pass downstream through the mouthpiece 14 and are delivered to the user through the proximal end of the smoking article 34 in accordance with the second embodiment of the invention.

[00190] A smoking article according to the third embodiment of the invention (not shown) is broadly identical in design to the smoking article according to the second embodiment of the invention shown in Figures 1b) and 3. However, in the article for smoking in accordance with the third embodiment of the invention one or more air inlets located between the rear face of the fuel heat source and the downstream end of the aerosol forming substrate comprise one or more second inlets located between the rear face of the fuel source. combustible heat 4 and the aerosol forming substrate 10, as in the smoking article according to the second embodiment of the invention shown in Figures 1b) and 3 and also one or more first inlets located around the periphery of the aerosol forming substrate as in the smoking article according to the first embodiment of the invention shown in Figures 1a) and 2.

[00191] In use, when a user draws into the mouthpiece of the smoking article in accordance with the third embodiment of the invention, air is drawn into the interior of the smoking article through the central air flow channel of the combustible heat source and fresh air is also drawn in between the combustible heat source and the aerosol forming substrate through the second air inlets and into the aerosol forming substrate of the smoking article through the first air inlets.

[00192] Carbonaceous combustible heat sources according to the first, second and third embodiments of the invention can be produced in accordance with Example 1 below, omitting the second clay barrier coating.

[00193] Air drawn through the aerosol forming substrates of smoking articles according to the first, second and third embodiments of the invention, which enters the smoking articles through the central air flow channel of the combustible heat source comes into direct contact with a combustible portion of the combustible heat source as it passes through the airflow channel. Air drawn through the aerosol forming substrates of smoking articles in accordance with the first, second and third embodiments of the invention which enters the smoking articles through the central air flow channel also comes into direct contact with the face rear of the combustible heat source.

The smoking article 38 according to the fourth embodiment of the invention shown in Figures 1c) is broadly identical in design to the smoking article according to the first embodiment of the invention shown in Figures 1a) and 2. However, in the smoking article 38 in accordance with a fourth embodiment of the invention, a first substantially airtight non-combustible barrier 40 is provided between the rear face 8 of the combustible heat source 4 and the aerosol forming substrate 10. As shown in Figure 1c), the first barrier 40 comprises a first substantially air-impermeable non-combustible barrier coating provided over the entire rear face 8 of the combustible heat source 4 and the air flow channel 18 of the combustible heat source 4 extends through the first barrier coating.

[00195] As a result of the inclusion of the first barrier coating, the aerosol forming substrate 10 of the smoking article 38 according to the fourth embodiment of the invention is not in direct contact with the rear face 8 of the carbonaceous fuel heat source 4 .

[00196] As a result of the inclusion of the first barrier coating, when in use, air is drawn through the smoking article 38 according to the fourth embodiment of the invention through the central air flow channel 18 of the combustible heat source 4 either comes into direct contact with the rear face 8 of the carbonaceous combustible heat source 4. Furthermore, as a result of the inclusion of the first barrier coating, when in use, fresh air is drawn into the aerosol forming substrate 10 of the article. for smoking 38 according to the fourth embodiment of the invention through the first air inlets 32 does not directly contact the rear face 8 of the carbonaceous combustible heat source 4.

[00197] However, air is drawn through the aerosol forming substrate 10 of the smoking article 38 according to the fourth embodiment, which enters the smoking article 38 through the central air flow channel 18 of the heat source fuel 4 comes into direct contact with a combustible portion of the fuel heat source as it passes through air flow channel 18.

The smoking article 42 according to the fifth embodiment of the invention shown in Figures 1d) is broadly similar in design to the smoking article according to the second embodiment of the invention shown in Figures 1b) and 3. However, in the smoking article 42 in accordance with a fifth embodiment of the invention, a first substantially airtight non-combustible barrier 40 is provided between the rear face 8 of the combustible heat source 4 and the aerosol forming substrate 10. As shown in the Figure 1d), the first barrier 40 comprises a first substantially air-impermeable non-combustible barrier coating provided over the entire rear face 8 of the combustible heat source 4 and the air flow channel 18 of the combustible heat source 4 extends therethrough. of the first barrier coating.

[00199] As a result of the inclusion of the first barrier coating, when in use, air drawn through the smoking article 42 according to the fifth embodiment of the invention through the central air flow channel 18 of the combustible heat source 4 does not comes into direct contact with the rear face 8 of the carbonaceous combustible heat source 4. Furthermore, as a result of the inclusion of the first barrier coating, when in use, fresh air is drawn into the space between the combustible heat source 4 and the aerosol forming substrate 10 of the smoking article 42 according to the fifth embodiment of the invention through the second air inlets 36 does not directly contact the rear face 8 of the carbonaceous combustible heat source 4.

[00200] However, air is drawn through the aerosol forming substrate 10 of the smoking article 42 according to the fifth embodiment of the invention, which enters the smoking article 42 through the central air flow channel 18 of the source of combustible heat 4 comes into direct contact with a combustible portion of the combustible heat source as it passes through the central air flow channel 18.

A smoking article according to a sixth embodiment of the invention (not shown) is broadly identical in construction to a smoking article according to the third embodiment of the invention (not shown). However, in the smoking article in accordance with the sixth embodiment of the invention, a first non-combustible substantially airtight barrier is provided between the rear face of the combustible heat source and the aerosol forming substrate. The first barrier comprises a first substantially air-impermeable non-combustible barrier coating provided over the entire rear face of the combustible heat source, and the combustible heat source air flow channel extends through the first barrier coating.

[00202] As a result of the inclusion of the first barrier coating, when in use, air drawn through the smoking article according to the sixth embodiment of the invention through the central air flow channel of the combustible heat source does not come into contact direct with the rear face of the carbonaceous combustible heat source. Furthermore, as a result of the inclusion of the first barrier coating, when in use, fresh air is drawn into the space between the combustible heat source and the aerosol forming substrate of the smoking article in accordance with the sixth embodiment of the invention through the second air inlets and into the aerosol forming substrate of the smoking article according to the sixth embodiment of the invention through the first air inlets does not directly contact the rear face of the carbonaceous fuel heat source .

[00203] However, air drawn through the aerosol forming substrate of the smoking article according to the sixth embodiment of the invention, which enters the smoking article through the central air flow channel of the combustible heat source enters in direct contact with a combustible portion of the combustible heat source as it passes through the central airflow channel.

[00204] Carbonaceous combustible heat sources for use in smoking articles according to the fourth, fifth and sixth embodiments of the invention can be produced in accordance with Examples 2, 3 and 4 below.

[00205] The smoking article 44 according to the seventh embodiment of the invention shown in Figures 1e) is broadly similar in design to the smoking article in accordance with the first embodiment of the invention shown in Figures 1a) and 2. smoking article 44 in accordance with the seventh embodiment of the invention a second substantially airtight non-combustible barrier 46 (depicted by broken lines in Figure 1e)) is provided between the combustible heat source 4 and the central air flow channel 18 The second barrier 46 comprises a second substantially air-impermeable non-combustible barrier coating provided over the entire inner surface of the central air flow channel 18.

[00206] As a result of the inclusion of the second barrier coating, when in use, air is drawn into the smoking article 38 according to the seventh embodiment of the invention through the central air flow channel 18 of the combustible heat source 4 does not come into direct contact with a combustible portion of the carbonaceous combustible heat source 4 as it passes through the central air flow channel 18.

[00207] However, air is drawn through the aerosol forming substrate 10 of the smoking article 44 in accordance with the seventh embodiment of the invention, which enters the smoking article 44 through the central air flow channel 18 of the source. combustible heat 4 comes in direct contact with rear face 8 of combustible heat source 4.

The smoking article 48 according to the eighth embodiment of the invention shown in Figures 1f) is broadly identical in design to the smoking article according to the second embodiment of the invention shown in Figures 1b) and 3. However, in the smoking article 48 in accordance with the eighth embodiment of the invention a second substantially airtight non-combustible barrier 46 (depicted by dashed lines in Figure 1f)) is provided between the combustible heat source 4 and the central air flow channel 18. The second barrier 46 comprises a second substantially air-impermeable non-combustible barrier coating provided over the entire inner surface of the central air flow channel 18.

[00209] As a result of the inclusion of the second barrier coating, when in use, air is drawn into the smoking article 48 in accordance with the eighth embodiment of the invention through the central air flow channel 18 of the combustible heat source 4 does not come into direct contact with a combustible portion of the carbonaceous combustible heat source 4 as it passes through the central air flow channel 18.

[00210] However, air is drawn through the aerosol forming substrate 10 of the smoking article 48 in accordance with the eighth embodiment of the invention, which enters the smoking article 48 through the central air flow channel 18 of the source. combustible heat 4 comes into direct contact with the rear face 8 of the combustible heat source 4. Furthermore, fresh air is drawn into the space between the combustible heat source 4 and the aerosol forming substrate 10 of the smoking article 48 according to the eighth modality of the invention through the second air inlets 36 nor does it directly contact the rear face 8 of the fuel heat source 4.

A smoking article according to a ninth embodiment of the invention (not shown) is broadly identical in construction to a smoking article according to the third embodiment of the invention (not shown). However, in the smoking article according to the ninth embodiment of the invention a second substantially airtight non-combustible barrier is provided between the combustible heat source and the central air flow channel. The second barrier comprises a second substantially air-impermeable non-combustible barrier coating provided over the entire inner surface of the central air flow channel.

[00212] As a result of the inclusion of the second barrier coating, when in use, air drawn into the smoking article according to the ninth embodiment of the invention through the central air flow channel of the combustible heat source does not enter in direct contact with the carbonaceous combustible heat source as it passes through the central airflow channel.

[00213] However, air drawn through the aerosol forming substrate of the smoking article according to the ninth embodiment of the invention, which enters the smoking article through the central air flow channel of the fuel heat source, enters in direct contact with the rear face of the combustible heat source. Furthermore, fresh air drawn into the space between the combustible heat source and the aerosol forming substrate of the smoking article according to the ninth embodiment of the invention through the second inlets also contacts the rear face of the combustible heat source.

Carbonaceous combustible heat sources for use in smoking articles according to the seventh, eighth and ninth embodiments of the invention can be produced in accordance with Example 1 below.

EXAMPLE 1 - Preparation of a carbonaceous heat source comprising a second clay barrier coating.

Combustible carbonaceous cylindrical heat sources for use in smoking articles in accordance with the invention may be prepared as described in WO-A2-2009/074870 A2 or any other present technique that is known to one of ordinary skill in the art. A slurry as described in WO-A2-2009/074870 A2 is extruded through a mold with a circular cross-section central mold hole to make the heat source combustible. The mold hole is 8.7 mm in diameter to form cylindrical columns having a length between about 20 cm and about 22 cm and a diameter between about 9.1 cm and about 9.2 mm. A single longitudinal airflow channel is formed in the cylindrical rods by a mandrel mounted centrally in the mold hole. Preferably, the mandrel is circular in cross-section with an outside diameter of approximately 2 mm or approximately 3.5 mm. Alternatively, three airflow channels are formed in the cylindrical columns using three circular cross-section chucks with an outside diameter of approximately 2 mm mounted at regular angles in the mold hole. During the extrusion of the cylindrical columns, a clay-based fluid coating slurry (made from clay, such as natural green clay) is pumped through a feed path that extends through the center of the mandrel or mandrels. to form a thin second barrier coating of about 150 microns to about 300 microns on the inner surface of the airflow channel or channels. Cylindrical columns are dried at a temperature of about 20°C to about 25°C under about 40% to about 50% relative humidity for between approximately 12 hours to approximately 72 hours and are then pyrolyzed in a nitrogen atmosphere at about 750°C for approximately 240 minutes. After pyrolysis, the cylindrical columns are cut and shaped to a defined diameter using a milling machine to form carbonaceous combustible heat sources. The sticks, after cutting and shaping, have a length of about 11 mm, a diameter of about 7.8 mm and a dry mass of about 400 mg. Carbonaceous combustible heat sources are subsequently dried at about 130°C for approximately 1 hour.

[00217] EXAMPLE 2 - Preparation of a carbonaceous combustible heat source comprising a first barrier coating of bentonite/kaolinite.

A first non-combustible and substantially air-impermeable first barrier coating of bentonite/kaolinite is provided on the rear face of a carbonaceous combustible heat source prepared as described in Example 1, but without a second clay barrier coating. The first barrier coating is provided by dipping, brushing or spray coating. Immersion involves inserting the rear face of the carbonaceous combustible heat source into a concentrated bentonite/kaolinite solution. The bentonite/kaolinite immersion solution contains 3.8% bentonite, 12.5% kaolinite and 83.7% H2O [m/m]. The rear face of the carbonaceous combustible heat source is immersed in the bentonite/kaolinite solution for about 1 second, allowing the meniscus to disappear as a result of penetration of the solution into the carbon pores on the back face surface of the carbonaceous combustible heat source. Brushing involves immersing a brush in a concentrated bentonite/kaolinite solution and applying the concentrated bentonite/kaolinite solution to the brush to the surface of the rear face of the carbonaceous combustible heat source until it is covered. The bentonite/kaolinite brushing solution contains 3.8% bentonite, 12.5% kaolinite and 83.7% H2O [m/m].

[00219] After application of the first non-combustible and substantially air-tight coating by dipping or brushing, the carbonaceous combustible heat source is dried in an oven at about 130°C for approximately 30 minutes and placed in a desiccator under about 5% relative humidity over night.

[00220] Spray coating involves a suspension solution, preferably containing 3.6% bentonite, 18.0% kaolinite and 78.4% H2O [m/m] and having a viscosity of about 50 mPas to a shear rate of about 100 s-1 as measured with a rheometer (Physica MCR 300, coaxial arrangement of cylinders). Spray coating is performed with a MiniJet 3000 spray gun using 0.5 mm, 0.8 mm or 1 mm spray nozzles on an SMC E-MY2B linear activator at a speed of about 10 mm/sec. about 100 mm/s. The following spray parameters are used: sample-gun distance, 15 cm; sample speed, 10 mm/s; spray nozzle, 0.5 mm; spray pressure and flat jet spray, 2.5 bar. In a single spray coating event, a coating thickness of about 11 microns is typically achieved. Spray spraying is repeated three times. Between each spray coating, the carbonaceous fuel heat source is dried at room temperature for about 10 minutes. After application of the first substantially airtight, non-combustible barrier coating, the carbonaceous combustible heat source is pyrolyzed at about 700°C for approximately 1 hour.

[00221] EXAMPLE 3 - Preparation of a carbonaceous combustible heat source comprising a first glass barrier coating.

A first substantially airtight, non-combustible barrier coating of glass is provided on the rear face of a carbonaceous combustible heat source prepared as described in Example 1, but without a second clay barrier coating. The first barrier coating is provided by spray coating. Spray coating with glass is performed with a suspension of ground glass using a fine powder. For example, a spray coating suspension containing either 37.5% glass powder (3μm), 2.5% methylcellulose and 60% water with a viscosity of 120 mPa^s, or 37.5% ground glass (3μm), 3.0% bentonite powder and 59.5% water with a viscosity of 60 to 100 mPas, is used. Glasses in powders with the compositions and physical properties corresponding to Glass 1, 2, 3 and 4 in Table 1 can be used.

Tabela 1: Composição de vidros em porcentagem de peso, temperatura de transformação Tg, coeficiente de expansão térmica A20-300 e valor-Ki calculado a partir da composição[00223] Spray coating is performed with a MiniJet 3000 spray gun using 0.5mm, 0.8mm or 1mm spray nozzles on an SMC E-MY2B linear activator at a speed of about 10 mm/s at about 100 mm/s. Spray spraying is preferably repeated several times. Once spraying is complete, the carbonaceous combustible heat source is pyrolyzed at about 700°C for approximately 1 hour.

Table 1: Composition of glasses in weight percentage, transformation temperature Tg, coefficient of thermal expansion A20-300 and Ki-value calculated from the composition

[00224] EXAMPLE 4 - Preparation of a carbonaceous combustible heat source comprising a first aluminum barrier coating.

A first non-combustible and substantially airtight aluminum barrier coating is provided on the rear face of a carbonaceous combustible heat source prepared as described in Example 1, but without a second clay barrier coating. The first barrier coating is provided by laser cutting an aluminum barrier from aluminum coil strips about 20 microns thick. The aluminum barrier has a diameter of about 7.8 mm and a single hole with an outer diameter of about 1.8 mm in the center of it to fit the cross section of the carbonaceous combustible heat source of Example 1. In In an alternative embodiment, the aluminum barrier has three holes which are positioned so as to be aligned with three air flow channels provided in the carbonaceous combustible heat source. The aluminum barrier coating is formed by attaching the aluminum barrier to the rear face of the carbonaceous fuel source and heat using any suitable adhesive.

[00226] When in use, fresh air drawn into one or more air inlets located between the rear face of the fuel heat source and a downstream end of the aerosol forming substrate reduces the temperature of the aerosol forming substrate 10 of smoking articles 2, 34, 38, 42, 44 and 48 in accordance with embodiments of the first to ninth of the invention during puffing by a user.

[00227] This advantageously prevents or inhibits spikes in the temperature of the aerosol forming substrate 10 during puffing by a user and advantageously minimizes or reduces the impact of a user puff regimen on the main aerosol composition of the smoking articles 2, 34, 38, 42, 44, 48 in accordance with the first to ninth embodiments of the invention.

[00228] The specific embodiments described above are intended to illustrate the invention. However, other embodiments can be made without departing from the spirit and scope of the invention as defined in the claims, and it is to be understood that the specific embodiments described above are not intended to be limiting.

Claims (14)

1. A smoking article (2, 34, 38, 42, 44, 48) comprising: a combustible heat source (4) having opposite front and rear faces (6, 8); one or more air flow channels (18) extending from the front face (6) to the rear face (8) of the combustible heat source (4); an aerosol forming substrate (10) downstream of the rear face (8) of the fuel heat source (4); a nozzle (14) downstream of the aerosol forming substrate (10); and a transfer element (12) between the aerosol forming substrate (10) and the nozzle (14), wherein the transfer element (12) comprises an open-ended tubular hollow body; characterized in that the smoking article further comprises one or more air inlets (32, 36) located downstream of the rear face (8) of the fuel heat source (4) and upstream of the mouthpiece (10) in which a or more air inlets (32, 36) are located between the rear face (8) of the combustible heat source (4) and a downstream end of the aerosol forming substrate (10), when in use , air drawn through the aerosol forming substrate (10) enters the smoking article (2, 34, 38, 42, 44, 48) through one or more air flow channels (18) and one or more air inlets (32, 36) and at least part of the air drawn through the aerosol forming substrate (10) enters into direct contract with a combustible portion of the combustible heat source (4) and wherein, during inhalation by a user, cold air drawn in through one or more of the air inlets (32, 36) between the rear face (8) of the fuel heat source (4) and the end downstream of the aerosol forming substrate (10) reduces the temperature of the aerosol forming substrate (10). A smoking article (2, 34) according to claim 1, characterized in that it further comprises an outer casing (16) circumscribing the aerosol forming substrate (10) and at least one rear portion (4b ) of the combustible heat source (4). 3. A smoking article (38, 42, 44, 48) according to claim 1, characterized in that it comprises one of: (i) a first non-combustible and substantially airtight barrier (40) between the face rear (8) of the combustible heat source (4) and the aerosol forming substrate (10); and (ii) a second, non-combustible and substantially air-impermeable barrier (46) between the combustible heat source (4) and one or more air flow channels (18). 4. A smoking article (38, 42) according to claim 1, characterized in that it comprises (i) a first non-combustible and substantially impermeable to air barrier (40) between the rear face (8) of the source of combustible heat (4) and the aerosol forming substrate (10), wherein the first barrier (40) comprises a first barrier coating provided on the rear face (8) of the combustible heat source (4). 5. A smoking article (44, 48) according to claim 1, characterized in that it comprises (ii) a second non-combustible and substantially impermeable to air barrier (46) between the combustible heat source (4) and one or more air flow channels (18) wherein the second barrier (46) comprises a second barrier coating provided on an inner surface of one or more air flow channels (18). 6. A smoking article (2, 38, 44) according to any one of claims 1 to 5, characterized in that one or more air inlets comprises one or more first air inlets (32) around the periphery of the aerosol forming substrate (10). 7. Smoking article (2, 38, 44) according to any one of claims 1 to 6, characterized in that the aerosol forming substrate (10) is adjacent to the rear face. (8) from the combustible heat source (4). 8. A smoking article (34, 42, 48) according to any one of claims 1 to 6, characterized in that the aerosol-forming substrate (10) is spaced from the rear face (8) of the combustible heat source (4). 9. An article for smoking according to claim 8, characterized in that one or more air inlets comprise one or more second air inlets (36) between the rear face (8) of the combustible heat source (4) and the aerosol forming substrate (10). 10. A smoking article (2, 34) according to any one of claims 1 to 9, characterized in that it further comprises: a thermally conductive element (30) around a rear portion (4b) of the source of combustible heat (4) and at least a front portion (10a) of the aerosol forming substrate (10). A smoking article (2, 34) according to any one of claims 1 to 10, characterized in that the aerosol forming substrate comprises tobacco-based material (20) and at least one aerosol former . 12. Smoking article (2, 34, 38, 42, 44, 48) according to any one of claims 1 to 11, characterized in that the combustible heat source (4) is a combustible heat source carbonaceous. 13. Smoking article (2, 34, 38, 42, 44, 48) according to any one of claims 1 to 12, characterized in that the combustible heat source (4) comprises an ignition aid. 14. Smoking article (2, 34, 38, 42, 44, 48) according to any one of claims 1 to 13, characterized in that it comprises one or more aerosol modifying agents downstream of the forming substrate of aerosol (10).

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