ES2645727T3 - Smoking article comprising a source of combustible heat with at least one air flow channel - Google Patents

Abstract

An article for smoking (2, 34, 38, 42, 44, 48) comprising: a source of combustible heat (4) having opposite front (6) and rear (8) faces; one or more air flow channels (18) extending from the front 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 combustible 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) where one or more air inlets (32 , 36) are located between the rear face (8) of the combustible heat source (4) and one end downstream of the aerosol forming substrate (10), where, during use, the air sucked through the forming substrate Aerosol (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) comes into direct contact with a combustible portion of the combustible heat source (4).

Description

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DESCRIPTION

 Glass 1 Glass 2 Glass 3 Glass 4

 SiO2

 70 70 65 60

 Na2O

 20 15 20 20

 K2O

          5

 CaO

 10 8 10 10

Smoking article comprising a source of combustible heat with at least one air flow channel

 MgO

    4 5 5

 Al2O3

    3

 Tg (° C)

 517 539 512 465

 Α20-300 (10-6 K-1)

 10.9 9.3 10.2 12.1

 KI-value

 30 21 35 40

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 source of combustible heat

A number of smoking articles have been proposed in the art in which the tobacco is heated rather than burned. An objective of said "heated" smoking articles is to reduce the known harmful constituents of smoke 10 of the type produced by 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 source of combustible heat. During the smoking action, volatile compounds are released from the aerosol-forming substrate by heat transfer from the combustible heat source and are drawn into the air sucked through the smoking article. As the released compounds cool, they condense, to form an aerosol that the user inhales. Typically, air is drawn into such known heated smoking articles, through one or more air flow channels provided, through the source of combustible heat and heat transfer from the source of combustible heat to the Aerosol-forming substrate is produced by conduction and forced convection. twenty

For example, patent document WO-A2-2009 / 022232 describes a smoking article comprising a combustible heat source, an aerosol forming substrate downstream of the combustible heat source, and a heat conducting element around and in direct contact with a rear portion of the combustible heat source and an adjacent front portion of the aerosol forming substrate. To provide a controlled amount of forced convection heating of the aerosol forming substrate, at least one longitudinal air flow channel is provided through the source of combustible heat.

In known heated smoking articles in which heat transfer from the combustible heat source to the aerosol-forming substrate occurs mainly by forced convection, heat transfer by forced convection and therefore the temperature in the substrate Aerosol former can vary considerably depending on the behavior of taking a breath from a user. As a result, the composition and therefore the sensory properties of the main stream aerosol generated by such known heated smoking articles may, disadvantageously, be highly sensitive to a regime of taking a puff from a user. 35

In addition, in known heated smoking articles comprising one or more airflow channels along the combustible heat source, direct contact between the air drawn through one or more airflow channels and the source of combustible heat during the action of taking a breath by a user results in the activation of combustion of the source of combustible heat. The rates of taking an intense breath 40 can therefore lead to a heat transfer by forced convection high enough to cause spikes in the temperature of the aerosol forming substrate, which disadvantageously leads to pyrolysis and potentially even localized combustion of the spray forming substrate. As used herein, the term "peak" is used to describe a short duration increase in the temperature of the aerosol forming substrate. As a result, the levels of pyrolytic and combustion by-products not suitable in the main stream aerosols generated by such known heated smoking articles can also vary significantly disadvantageously depending on the particular regime of taking a puff adopted by a user. .

US Patent 4,714,082 describes smoking articles comprising a fuel element 50, aerosol generating means and a mouth side end filter. In the modalities shown in Figs. 1, 3, 4, 6, 7, 8 and 9 the fuel fuel element 10 comprises one more holes that extend longitudinally 16. In these modalities there are no air inlets located between the rear face of the fuel fuel element 10 and the water end below the aerosol generating means 12. In the mode shown in FIG. 2 the aerosol generating means 12 includes a thermally stable carbonaceous substrate 55 28 and the fuel fuel element 24 is connected to the aerosol generating means 12 by means of a heat conducting rod 26 and by an aligned foil paper tube 14. This embodiment includes an empty space 30 between the fuel fuel element 10 and the substrate 28 and the portion of the aligned sheet tube 14 surrounding the empty space 30 includes a plurality of peripheral holes 32 that allow sufficient air to enter the empty space to provide a drop in appropriate pressure In this embodiment, the fuel element 60 does not include any longitudinally extending hole 16.

It is known to include additives in combustible heat sources of heated smoking articles in order to improve the ignition and combustion properties of combustible heat sources. However, the inclusion of ignition and combustion additives may result in reaction and decomposition products, which may disadvantageously enter sucked air through one or more air flow channels provided along

the source of combustible heat of such heated heated smoking articles known during the use thereof.

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 storage and smoking, such aerosol formers can migrate from the aerosol-forming substrates of known heated smoking articles to the combustible sources of heat thereof. 5 The migration of aerosol formers to combustible heat sources of known heated smoking articles can disadvantageously lead to the decomposition of aerosol formers, particularly during the smoking action of heated smoking articles.

A need remains for heated smoking articles comprising a fuel heat source 10 with opposite front and rear faces and an aerosol forming substrate downstream of the rear face of the fuel heat source in which the peaks in the fuel are avoided. Aerosol-forming substrate temperature under regimes of taking an intense breath. In particular, a need remains for heated 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 essentially 15 is not produced. combustion or pyrolysis of the aerosol forming substrate under regimes of taking a deep breath.

In accordance with the invention, a smoking article is provided comprising: a source of combustible heat having opposite front and rear faces; one or more air flow channels extending from the front face to the rear face of the fuel heat source; an aerosol forming substrate downstream of the rear face of the fuel 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 one end downstream of the aerosol forming substrate. During use, the air sucked through the aerosol forming substrate 25 enters the smoking article through one or more air flow channels and one or more air inlets and at least part of the air sucked through the forming substrate Aerosols come into direct contact with a combustible portion of the combustible heat source.

As used herein, the term "aerosol forming substrate" is used to describe a substrate 30 capable of releasing volatile compounds upon heating, which can form an aerosol. Aerosols generated from aerosol-forming substrates of smoking articles in accordance with the invention may be visible or invisible and may include vapors (for example, fine particles of substances, which are in the gaseous state, which are commonly liquid or solid at room temperature) as well as gases and liquid droplets of condensed vapors. 35

The aerosol-forming substrate may be in the form of a plug or segment comprising a material capable of releasing volatile compounds upon heating, which may form an aerosol, circumscribed by a wrapper. Where an aerosol forming substrate is in the form of such a cap or segment, the entire cap or segment that includes the envelope is considered to be the aerosol forming substrate. 40

As used herein, the terms 'distal', 'upstream' and 'frontal', and 'proximal', 'downstream' and 'rear', are used to describe the relative positions of the components, or portions of the components, of the smoking article in relation to the direction in which a user aspires to the smoking article during its use. The smoking articles according to the invention comprise a proximal end through which, during use, an aerosol leaves the smoking article for delivery to a user. The proximal end of the smoking article can also be referred to as the end of the side of the mouth. During use, a user aspirates from the proximal end of the smoking article in order to inhale an aerosol generated by the smoking article.

The combustible heat source is located at or near the distal end. The nozzle is located at the proximal end 50. The end of the side of the mouth is downstream of the distal end. The proximal end can also be referred to as the downstream end of the smoking article and the distal end can also be referred to as the upstream end of the smoking article. The components, or portions of the components, of the smoking articles according to the invention can be described as upstream or downstream of each other depending on their relative positions between the proximal end and the distal end of the smoking article. 55

The front face of the fuel heat source is at the upstream end of the fuel 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 fuel heat source is at the downstream end of the fuel 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 in the present description, the term "length" is used to describe the maximum dimension in the longitudinal direction 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. 65

As used herein, the term 'air flow channel' is used to describe a channel that extends along the length of a source of combustible heat through which air can be drawn downstream for inhalation. by a user

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

The smoking articles according to the invention comprise a non-blind combustible heat source. 10 As used herein, the term "non-blind" is used to describe a source of combustible heat that includes at least one air flow channel.

One or more airflow channels may comprise one or more enclosed airflow channels.

 fifteen

As used herein, the term "enclosed" is used to describe the airflow channels that extend through the interior of the combustible heat source and that are surrounded by the combustible heat source.

Alternatively or additionally, the one or more airflow channels may comprise one or more unclosed airflow channels. For example, one or more air flow paths may comprise one or more grooves or other unenclosed air flow channels that extend along the outside of the combustible heat source.

The one or more airflow channels may comprise one or more enclosed airflow channels or one or more unclosed airflow channels or one of their combinations. 25

In certain embodiments, smoking articles in accordance with the invention comprise one, two or three air flow channels extending from the front face to the rear face of the combustible heat source.

 30

In preferred embodiments, smoking articles according to the invention comprise a single air flow channel that extends from the front face to the rear face of the combustible heat source.

In particularly preferred embodiments, the smoking articles according to the invention comprise a single essentially central or axial air flow channel extending from the front face to the rear face 35 of the fuel heat source.

In such embodiments, the diameter of the single air flow channel is preferably between about 1.5 mm and about 3 mm.

 40

It will be appreciated that in addition to one or more air flow channels through which the air can be aspirated for inhalation by a user, the sources of combustible heat of the smoking articles according to the invention may also comprise one or more closed or blocked passages through which no air can be aspirated for inhalation by a user.

 Four. Five

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 fuel heat source and one or more passages closed that extend from the front face of the fuel heat source only partly along the length of the fuel heat source.

 fifty

The inclusion of one or more closed air passages increases the surface area of the combustible heat source that is exposed to the oxygen in the air and can advantageously facilitate ignition and sustained combustion of the combustible heat source.

The 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 nozzle.

As used in the present description, the term "air inlet" is used to describe a hole, slit, groove or other opening through which air can be sucked into the smoking article.

 60

One or more air inlets are located between the rear face of the combustible heat source and one end downstream of the aerosol forming substrate. One or more air inlets do not comprise any air inlet located between the downstream end of the aerosol forming substrate and an upstream end of the nozzle. In other words, the smoking articles according to the invention do not comprise any air intake located downstream of the aerosol forming substrate and upstream of the nozzle. 65

The number, shape, size and location of the air inlets can be adjusted appropriately to achieve good smoking performance.

During use, the 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 sucked air passes downstream through the smoking article to the nozzle and leaves the smoking article through the proximal end thereof.

During use at least part of the air drawn through the aerosol forming substrate comes into direct contact with a combustible portion of the combustible heat source. 10

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 air flow channels.

 fifteen

Additionally or alternatively, the 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 the rear face of the combustible heat source . In such embodiments, air drawn through the aerosol forming substrate of the smoking article 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. twenty

In smoking articles in accordance with the invention, heating of the aerosol forming substrate occurs by conduction and forced convection.

During the action of taking a breath by a user, cold 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 aerosol forming substrate of smoking articles in accordance with the invention. This essentially prevents or advantageously inhibits spikes in the temperature of the aerosol forming substrate of the smoking articles according to the invention during the action of taking a puff by a user.

 30

As used herein, the term "cold air" is used to describe ambient air that is not significantly heated by the source of combustible heat after the action of taking a breath by a user.

By 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 helps avoid or reduce combustion or pyrolysis of the aerosol forming substrate of the smoking articles in accordance with the invention under regimens of taking an intense breath. Additionally, the inclusion of one or more air inlets between the rear face and the combustible heat source and a downstream end of the aerosol forming substrate advantageously helps to minimize or reduce the impact of the regime of taking a puff from a user in The main stream aerosol composition of smoking articles in accordance with the invention.

One or more air inlets may comprise one or more first inlets around the periphery of the aerosol forming substrate through which air can be drawn into the aerosol forming substrate. In such embodiments, during use, cold 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 nozzle and exits the smoking article through the proximal end thereof.

 fifty

During the action of taking a breath by a user, cold air sucked through one or more first inlets around the periphery of the aerosol forming substrate advantageously reduces the temperature of the aerosol forming substrate of the smoking articles in accordance with the invention. This essentially prevents or advantageously inhibits spikes in the temperature of the aerosol forming substrate of the smoking articles according to the invention during the action of taking a puff by a user. 55

In certain preferred embodiments, one or more first air inlets are located near the downstream end of the aerosol forming substrate.

In certain embodiments, the aerosol-forming substrate may collide with the rear face of the combustible heat source or a first non-combustible barrier coating essentially impermeable to the air provided on the rear face of the combustible heat source.

As used herein, the term "colindar" is used to describe the aerosol-forming substrate that is in direct contact with the rear face of the combustible heat source or a first non-combustible barrier barrier coating essentially air impermeable provided on the rear face of the heat source

fuel.

In other embodiments, the aerosol forming substrate can be separated from the rear face of the combustible heat source. That is, there may be a gap or opening between the aerosol forming substrate and the rear face of the combustible heat source. 5

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. During use, cold air is drawn into the space between the source of combustible heat 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 10 through the second air inlets passes downstream through the smoking article from the space between the combustible heat source and the substrate forming spray towards the mouthpiece and exit the smoking article through the proximal end thereof.

During the action of taking a breath by a user, cold air drawn through one or more second entries between the rear face of the combustible heat source and the aerosol forming substrate advantageously reduces the temperature of the aerosol forming substrate of smoking articles in accordance with the invention. This essentially prevents or advantageously inhibits spikes in the temperature of the aerosol forming substrate of the smoking articles according to the invention during the action of taking a puff by a user. twenty

It will be appreciated that the 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 combustible heat source and the aerosol forming substrate, or a combination of one or more first air inlets around the periphery of the aerosol forming substrate and one or more second 25 air inlets between the rear face of the combustible heat source and the forming substrate of aerosol.

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

It will be appreciated that the smoking articles according to the invention may not comprise both (i) a first non-combustible barrier, essentially impermeable to air between the rear face of the combustible heat source and the aerosol forming substrate and (ii) a Second non-combustible barrier essentially impermeable to air between the source of combustible heat and one or more air flow channels.

As used herein, the term "non-combustible" is used to describe a barrier that is essentially non-combustible at the temperatures reached by the source of combustible heat during combustion and ignition. 40

Where the smoking articles according to the invention further comprise (i) a first non-combustible barrier essentially impermeable to air between the rear face of the combustible heat source and the aerosol forming substrate, the air sucked through the substrate forming A spray that enters the smoking article through one or more air flow channels and one or more air inlets does not come into direct contact with the rear face of the combustible heat source. However, in such embodiments, the air sucked through the aerosol forming substrate that enters the smoking article through one or more air flow channels comes into direct contact with a combustible portion of the custom fuel source of heat that passes through one or more air flow channels.

 fifty

In such embodiments, the first barrier allows air to enter the smoking article through one or more air flow channels that are sucked downstream through the smoking article.

The first barrier may collide with one or both of the rear face of the fuel heat source and the aerosol forming substrate. Alternatively, the first barrier can be separated from one or both of the aerosol-forming substrate and the nozzle.

The first barrier may adhere or otherwise be fixed to one or both of the rear face of the combustible heat source and the aerosol forming substrate.

 60

In certain preferred embodiments, the first barrier comprises a first non-combustible barrier coating essentially impermeable to the air provided on the rear face of the combustible heat source. In such embodiments, preferably the first barrier comprises a first barrier coating provided at least essentially over the entire rear face of the combustible heat source. More preferably, the first barrier comprises a first barrier coating provided on the entire rear face of the fuel heat source 65.

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.

As used in the present description, the term "coating" is used to describe a layer of material that covers and adheres to the source of combustible heat.

The first barrier can advantageously limit the temperature at which the aerosol forming substrate is exposed during ignition and combustion of the combustible heat source, and thus help prevent or reduce combustion or thermal degradation of the aerosol forming substrate during the Use of the article for smoking. This is particularly advantageous when the fuel heat source comprises one or more additives to aid in ignition of the fuel heat source.

The inclusion of a first essentially non-combustible air-impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate can also essentially prevent or inhibit advantageously the migration of the aerosol forming substrate components of the articles for smoking in accordance with the invention towards the source of combustible heat during storage of the smoking articles.

Alternatively or additionally, the inclusion of a first essentially non-combustible air-impermeable barrier 20 between the rear face of the combustible heat source and the aerosol-forming substrate may essentially prevent or advantageously inhibit the migration of the aerosol-forming substrate components of smoking articles in accordance with the invention towards the source of combustible heat during the use of smoking articles.

 25

The inclusion of a first essentially non-combustible air-impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate can be particularly advantageous when the aerosol forming substrate comprises at least one aerosol former.

In such embodiments, the inclusion of a first essentially non-combustible air impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate can advantageously prevent or inhibit the migration of at least one aerosol former from the substrate. Aerosol former towards the source of combustible heat during storage and use of the smoking article. The decomposition of at least one aerosol former during the use of smoking articles can advantageously thus be avoided or reduced. 35

Depending on the desired characteristics and performance of 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 an apparent thermal conductivity of between approximately 0.1 W per Kelvin meter (W / (m • K)) and approximately 200 W per Kelvin meter (W / ( m • K)), at 23 ° C and a relative humidity of 50% as measured by using the flat modified transient source (MTPS).

The thickness of the first barrier can be adjusted appropriately to achieve a good performance of the smoking action. In certain embodiments, the first barrier may have a thickness of between about 10 microns and about 500 microns. Four. Five

The first barrier can be formed from one or more suitable materials that are essentially thermally stable and non-combustible at the temperatures reached by the source of combustible heat 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, resins, metals and their combinations.

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. 55

In certain preferred embodiments, the first barrier comprises a clay coating comprising a 50/50 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. 60

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

Preferably, the first barrier has a thickness of at least about 10 microns. 65

Due to the slight air permeability of the clays, in the modes 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 most preferably between about 50 microns and about 350 microns.

 5

In embodiments where the first barrier is formed from one or more materials that are more impervious to air, such as aluminum, the first barrier may be thinner, and will generally preferably be less than about 100 microns thick, and more preferably about 20 microns.

In embodiments where the first barrier comprises a glass coating provided on the rear face 10 of the combustible heat source, the glass coating preferably has a thickness of less than about 200 microns.

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

 fifteen

Where the first barrier comprises a first barrier coating provided on the rear face of the combustible heat source, the first barrier coating may be applied to cover and adhere to the rear face of the combustible heat source by any suitable method known in the a technique that includes, but is not limited to, spray coating, vapor deposition, immersion, transfer of materials (for example, by brush or glue), electrostatic deposition or any combination thereof. twenty

For example, the first barrier coating can be made by previously forming a barrier of the approximate size and shape of the rear face of the combustible heat source, and applying it to the rear face of the combustible heat source to cover and adhere at least essentially to the entire rear face of the fuel heat source. Alternatively, the first barrier coating may be cut or otherwise machined after application to the rear face of the combustible heat source. In a preferred embodiment, an aluminum sheet is applied to the rear face of the combustible heat source by gluing or pressing it to the combustible heat source, and is cut or machine such that the aluminum sheet covers and adheres to the less essentially to the entire rear face of the fuel heat source, preferably, to the entire rear face of the fuel heat source. 30

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 rear face of the combustible heat source. For example, the first barrier coating can be applied to the rear face of the fuel heat source by immersion of the rear face of the fuel heat source in a solution or suspension of one or more suitable coating materials or by application with brush or coating by spraying a solution or suspension or by electrostatic deposition of a powder or mixture of powders of one or more suitable coating materials on the rear face of the combustible heat source. Where the first barrier coating is applied to the rear face of the fuel heat source by electrostatic deposition of a powder or mixture of powders of one or more suitable coating materials on the rear face of the fuel heat source 40, the face Rear of the combustible heat source is preferably pretreated with soluble glass before electrostatic deposition. Preferably, the first barrier coating is applied by spray coating.

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 may 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 first barrier coating may 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 50 to the rear face of the source of combustible heat

Preferably, the first barrier coating is formed through 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. 55

After application of the solution or suspension of one or more coating materials to its rear face, the source of combustible heat can be dried to form the first barrier coating.

When the first barrier coating is formed by multiple applications of a solution or suspension 60 of one or more suitable coating materials to its rear face, the source of combustible heat may need to dry between successive applications of the solution or suspension.

Alternatively or additionally to drying, after application of a solution or suspension of one or more coating materials to the rear face of the combustible heat source, the coating material on the combustible heat source can be sintered in order to form the first barrier coating. The

Sintering of the first barrier coating is particularly preferred when the first 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.

 5

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

The second barrier can essentially prevent or inhibit advantageously that the combustion and decomposition products formed during the ignition and combustion of the combustible heat source of the smoking articles according to the invention enter the sucked air into the articles for smoking in accordance with the invention through one or more air flow channels when the aspirated air passes through one or more 20 air flow channels. This is particularly advantageous where the fuel heat source comprises one or more additives to aid in the ignition or combustion of the fuel heat source.

The inclusion of a second essentially non-combustible air-impermeable barrier between the fuel heat source and one or more air flow channels can advantageously also prevent or essentially inhibit the combustion activation of the fuel heat source of the articles for smoking in accordance with the invention during the action of taking a breath by a user. This can essentially prevent or inhibit spikes in the temperature of the aerosol forming substrate during the action of taking a breath by a user.

By preventing or inhibiting the combustion activation of the combustible heat source, and thus preventing or inhibiting the 30 increases in excess of the temperature in the aerosol forming substrate, combustion or pyrolysis of the aerosol forming substrate of the aerosols can be advantageously avoided. smoking articles in accordance with the invention under regimens of intense puffing. Additionally, the impact of a regime of taking a drag of a user on the aerosol composition of the main stream of the smoking articles according to the invention can be minimized or advantageously reduced. 35

The second barrier may adhere or otherwise be attached to the source of combustible heat.

In certain preferred embodiments, the second barrier comprises a second non-combustible barrier coating essentially impermeable to the air provided on an internal surface of one or more air flow channels. In such embodiments, preferably the second barrier comprises a second barrier coating provided on at least essentially the entire internal surface of one or more air flow channels. More preferably, the second barrier comprises a second barrier coating provided over the entire internal surface of one or more air flow channels.

 Four. Five

In other embodiments, the second barrier liner may be provided by inserting a liner into one or more air flow channels. For example, where one or more air flow channels comprise one or more enclosed air flow channels that extend through the interior of the combustible heat source, a non-combustible hollow tube essentially air impermeable can be inserted into each of one or more air flow channels. fifty

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

 55

The thickness of the second barrier can be adjusted appropriately to achieve a good performance of the smoking action. In certain embodiments, the second barrier may have a thickness of between about 30 microns and about 200 microns. In a preferred embodiment, the second barrier has a thickness of between about 30 microns and about 100 microns.

 60

The second barrier may be formed from one or more suitable materials that are essentially thermally stable and non-combustible at the temperatures reached by the source of combustible heat during ignition and combustion. Suitable materials are known in the art and include, but are not limited to those listed, for example: clays; metal oxides, such as iron oxide, alumina, titanium dioxide, silica, silica-alumina, zirconia and cerium dioxide; zeolites; zirconium phosphate; and other ceramic materials or their combinations. 65

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 those listed, for example, platinum, palladium, transition metals and their oxides. 5

Where the second barrier comprises a second barrier coating provided on an internal surface of one or more air flow channels, the second barrier coating may be applied to the internal surface of one or more air flow 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 air flow channels 10 can be sprayed, moistened or painted with a solution or a suspension of the second barrier coating. In certain preferred embodiments, the second barrier coating is applied to the inner surface of one or more air flow channels by the process described in WO-A2-2009 / 074870 when the fuel heat source is extruded.

 fifteen

Preferably, the smoking articles according to the invention comprise an outer envelope circumscribing the aerosol forming substrate and at least a rear portion of the combustible heat source. The outer envelope must hold the fuel heat source and the aerosol forming substrate of the smoking article when the smoking article is assembled.

 twenty

More preferably, the smoking articles according to the invention comprise an outer envelope circumscribing the nozzle, the aerosol forming substrate, any other component of the smoking article downstream of the aerosol forming substrate and upstream of the nozzle, and at least a rear portion of the fuel heat source.

 25

Preferably, the outer shell is essentially air impermeable.

The 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 cigarette paper, but not limited to this. 30

At least one or more air 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 material that circumscribes the components of the conforming smoking articles with the invention through which air can be aspirated into one or more air flow paths. 35

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 material that circumscribes the aerosol forming substrate.

 40

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 shell and any underlying material.

Preferably, the fuel heat source is a carbonaceous heat source. As used herein, the term "carbonaceous" is used to describe a source of combustible heat comprising carbon. Preferably, the 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 , of at least about 45 percent dry weight of the combustible heat source. fifty

In some embodiments, the 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 that primarily comprises carbon.

 55

Carbon-based combustible heat sources for use in smoking articles in accordance with the invention have a carbon content of at least about 50 percent. For example, carbon-based combustible heat sources for use in smoking articles in accordance with the invention may have a carbon content of at least about 60 percent, or at least about 70 percent, or at least approximately 80 percent dry weight of the 60 carbon-based fuel heat source.

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

 65

If desired, one or more binders may be combined with one or more carbon-containing materials.

Preferably, one or more binders are organic binders. Suitable known organic binders include, but are not limited to, gums (e.g. guar gum), modified cellulose and cellulose derivatives (e.g., methylcellulose, carboxymethylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose), wheat flour, starches, sugars, Vegetable oils and their combinations.

 5

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

Instead of, or in addition to one or more binders, combustible heat sources for use in smoking articles in accordance with the invention may comprise one or more additives in order to improve the properties 10 of the combustible heat source. Suitable additives include, but are not limited to, additives to promote the consolidation of the combustible heat source (e.g. sintering auxiliaries), the additives to promote ignition of the combustible heat source (e.g., oxidants such such as perchlorates, chlorates, nitrates, peroxides, permanganates, zirconium and their combinations), additives to promote the combustion of the combustible heat source (for example, potassium and potassium salts, such as potassium citrate) and additives 15 for promote the decomposition of one or more gases produced by combustion of the combustible heat source (for example, catalysts, such as CuO, Fe2O3 and Al2O3).

When the 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 fuel heat source 20 before or after the application of the first barrier coating. to the rear face of the fuel heat source.

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

As used herein, the term 'ignition aid' is used to refer to a material that releases one or both of energy and oxygen during ignition of the combustible heat source, where the rate of release of one or both of energy and oxygen by the material is not limited to the diffusion of ambient oxygen. In other words, the rate of release of one or both of energy and oxygen 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 designate an elemental metal that releases energy during ignition of the combustible heat source, wherein the ignition temperature of the elemental metal is below approximately 500 ° C and the heat of combustion of the elemental metal is at least about 5 kJ / g.

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

Examples of suitable oxidizing agents include, but are not limited to: nitrates such as, for example, potassium nitrate, calcium nitrate, strontium nitrate, sodium nitrate, barium nitrate, lithium nitrate, aluminum nitrate and nitrate. of iron; nitrites; other organic and inorganic nitro compounds; chlorates such as, for example, sodium chlorate and potassium chlorate; perchlorates such as, for example, sodium perchlorate; chlorites; 50 bromates such as, for example, sodium bromate and potassium bromate; perbromatos; jokes; borates such as, for example, sodium borate and potassium borate; ferrates such as, for example, barium ferrate; ferrites; 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; periodata; iodites; sulfates; sulphites; other sulfoxides; phosphates; phosphinates; phosphites; and phosphates.

Although the ignition and combustion properties of the combustible heat source are advantageously improved, the inclusion of the ignition and combustion additives may result in unwanted reaction and decomposition products during the use of the smoking article. For example, the decomposition of nitrates included in the source of combustible heat to aid in their ignition may result in the formation of nitrogen oxides.

 65

The inclusion of a second non-combustible barrier essentially impermeable to air between one or more channels of

air flow and the combustible heat source of the smoking articles in accordance with the invention can essentially prevent or advantageously inhibit such reaction and decomposition products from entering the sucked air into the smoking articles in accordance with the invention through one or more air flow channels when the aspirated air passes through one or more air flow channels.

 5

The carbonaceous combustible heat sources for use in smoking articles in accordance with the invention can be prepared as described in the prior art which is known to those skilled in the art.

The carbonaceous combustible heat sources for use in smoking articles in accordance with the invention are preferably formed by mixing one or more carbon-containing materials with one or more binders and other additives, where included, and pre-form the mixture in a desired way. The mixture of one or more carbon-containing materials, one or more binders and other optional additives can be pre-formed in a desired manner by using any known method of suitable ceramic formation such as, for example, slip, extrusion, injection molding and pressing or die compaction. In certain preferred embodiments, the mixture is previously formed in a form desired by pressing or extrusion or combinations thereof.

Preferably, the mixture of one or more carbon-containing materials, one or more binders and other additives is previously formed on an elongated rod. However, it will be appreciated that the mixture of one or more carbon-containing materials, one or more binders and other additives may be previously formed in other desired forms.

After formation, particularly after extrusion, the elongated rod or other desired shape is preferably dried to reduce its moisture content and then pyrolyzed in a non-oxidizing atmosphere at a temperature sufficient to carbonize one or more binders, where they are present. , and essentially eliminate any volatile substance in the elongated rod or other form. The elongated rod or other desired shape is preferably pyrolyzed in a nitrogen atmosphere at a temperature between about 700 ° C and about 900 ° C.

In certain embodiments, at least one nitrate metal salt is incorporated into the combustible heat source by including at least one metal nitrate precursor in the mixture of one or more carbon-containing materials, one or more binders and other additives At least one metal nitrate precursor is subsequently subsequently converted in place into at least one nitrate metal salt by treating the cylindrical rod or other previously formed form pyrolized with an aqueous solution of nitric acid. In one embodiment, the combustible heat source comprises at least one nitrate metal salt having a thermal decomposition temperature of less than about 600 ° C, more preferably, less than about 35 400 ° C. Preferably, at least one nitrate metal salt has a decomposition temperature of between about 150 ° C and about 600 ° C, more preferably, between about 200 ° C and about 400 ° C.

In preferred embodiments, exposure of the combustible heat source to a conventional yellow flame lighter 40 or other ignition means should cause at least one nitrate metal salt to decompose and release oxygen and energy. This decomposition causes an initial increase in the temperature of the fuel heat source and also helps with ignition of the fuel heat source. After the decomposition of at least one nitrate metal salt, the combustible heat source preferably continues combustion at a lower temperature. Four. Five

The inclusion of at least one nitrate metal salt advantageously results in the ignition of the fuel heat source that is initiated internally, and not only at a point on its surface. Preferably, at least one nitrate metal salt is present in the fuel heat source in an amount of between about 20 percent dry weight and about 50 percent dry weight of the source of combustible heat.

In other embodiments, the combustible heat source comprises at least one peroxide or superoxide that actively generates oxygen at a temperature of less than about 600 ° C, more preferably, at a temperature of less than about 400 ° C. 55

Preferably, at least one peroxide or superoxide actively generates oxygen at a temperature between about 150 ° C and about 600 ° C, more preferably, at a temperature between about 200 ° C and about 400 ° C, most preferably, at a temperature of approximately 350 ° C. 60

During use, exposure of the combustible heat source to a conventional yellow flame lighter or other means of ignition should cause at least one peroxide or superoxide to decompose and release oxygen. This causes an initial increase in the temperature of the fuel heat source and also helps with ignition of the fuel heat source. After the decomposition of at least one peroxide or superoxide, the source of combustible heat 65 preferably continues combustion at a lower temperature.

The inclusion of at least one peroxide or superoxide advantageously results in the ignition of the fuel heat source that is initiated internally, and not only at a point on its surface.

The combustible heat source preferably has a porosity of between about 20 percent and about 80 percent, more preferably between about 20 percent and 60 percent. 5 Where the combustible heat source comprises at least one nitrate metal salt, this advantageously allows oxygen to diffuse in the mass of the combustible heat source at a rate sufficient to maintain combustion when at least one metal salt of Nitrate decomposes and combustion continues. 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 10 60 percent when measured, for example, by porosimetry of mercury or helium pycnometry. The required porosity can be easily achieved during the production of the combustible heat source through the use of conventional methods and technology.

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

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

Preferably, the fuel heat source has a length of between about 7 mm and about 17 mm, more preferably between about 7 mm and about 15 mm, most preferably between about 7 mm and about 13 mm.

 25

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

Preferably, the source of combustible heat is of essentially uniform diameter. However, the fuel heat source may alternatively be tapered so that the diameter of a rear portion of the fuel heat source 30 is larger than the diameter of its front portion. Particularly preferred are combustible heat sources that are essentially cylindrical. The source of combustible heat may be, for example, a tapered cylinder or cylinder of essentially circular cross-section or a tapered cylinder or cylinder of essentially elliptical cross-section.

 35

The smoking articles according to the invention preferably comprise an aerosol forming substrate comprising at least one aerosol former and a material capable of releasing volatile compounds in response to heating. The aerosol forming substrate may comprise other additives and ingredients that include, but are not limited to, humectants, flavorings, binders and mixtures thereof.

 40

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

The at least one aerosol former may be any compound or mixture of suitable known compounds that, during use, facilitate the formation of a dense and stable aerosol and that is essentially resistant to thermal degradation at the operating temperature of the article for smoke. Suitable aerosol formers are well known in the art and include, for example, polyhydric alcohols, esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate, and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. The preferred aerosol formers in smoking articles according to the invention are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1,3-butanediol and, more preferably, glycerin.

The material capable of emitting volatile compounds in response to heating may be a load of material of plant origin. The material capable of emitting volatile compounds in response to heating may be a load of material of homogenized plant origin. For example, the aerosol forming substrate may comprise one or more plant-derived materials that include, but are not limited to: tobacco; tea, for example, green tea; mint; laurel; eucalyptus; basil; sage; verbena; and tarragon.

Preferably, the material capable of emitting volatile compounds in response to heating is a load of tobacco-based material, most preferably, a load of homogenized tobacco-based material. 60

The aerosol-forming substrate may be in 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 indicated above, when an aerosol-forming substrate is in the form of such a cap or segment, the entire cap or segment, which includes any wrapping, is considered to be the aerosol-forming substrate. 65

Preferably, the aerosol forming substrate has a length of 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 wrapped in a plug wrap. In particularly preferred embodiments, the aerosol-forming substrate 5 comprises a plug of homogenized tobacco-based material wrapped in a plug wrap.

Preferably, the smoking articles according to the invention further comprise a heat conducting element around a rear portion of the combustible heat source and at least one front portion of the aerosol forming substrate. The heat conducting element is preferably resistant to combustion. In certain embodiments, the heat conducting element restricts oxygen. In other words, the heat conducting element inhibits or resists the passage of oxygen through the heat conducting element into the source of combustible heat.

In certain embodiments, the heat conducting element may be in direct contact with both the rear portion 15 of the combustible heat source and the aerosol forming substrate. In such embodiments, the heat conducting element provides a thermal bond between the source of combustible heat and the aerosol forming substrate of the smoking articles in accordance with the invention.

In other embodiments, the heat conducting element may be separated from one or both of the rear portions 20 of the combustible heat source and the aerosol forming substrate, so that there is no direct contact between the heat conducting element and one or both of the rear portions of the fuel heat source and the aerosol forming substrate.

Heat conductive elements suitable for use in smoking articles in accordance with the invention include, but are not limited to: metal foil wraps such as, for example, aluminum foil wraps, steel wraps, wraps iron sheets and copper foil wraps; and metal alloy sheet wraps.

Preferably, the rear portion of the fuel heat source surrounded by the heat conducting element is between approximately 2 mm and approximately 8 mm in length, more preferably between approximately 3 mm and approximately 5 mm in length.

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

In certain embodiments, the entire length of the aerosol forming substrate may be surrounded by the heat conducting element.

 40

In other embodiments, the heat conducting element may only surround a front portion of the aerosol forming substrate. In such embodiments, the aerosol forming substrate extends downstream beyond the heat conducting element.

In embodiments in which the heat conducting element surrounds only a front portion of the aerosol forming substrate 45, the aerosol forming substrate preferably extends at least about 3 mm downstream beyond the heat conducting element. More preferably, the aerosol forming substrate extends between about 3 mm and about 10 mm downstream beyond the heat conducting element. However, the aerosol-forming substrate may extend less than 3 mm downstream beyond the heat conducting element. fifty

Preferably, the front portion of the aerosol forming substrate surrounded by the heat conducting element is between about 1 mm and about 10 mm in length, more preferably between about 2 mm and about 8 mm in length, most preferably between about 2 mm and approximately 6 mm in length. 55

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

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

The nozzle may comprise a filter comprising one or more segments comprising suitable known filtration materials. Suitable filtration materials are known in the art and include, but are not limited to, cellulose acetate and paper. Alternatively or additionally, the nozzle may comprise one or more

segments comprising absorbents, adsorbents, flavorings, and other aerosol modifiers and additives or combinations thereof.

The smoking articles according to the element preferably further comprise a transfer element or separating element between the aerosol forming substrate and the nozzle. 5

The transfer element may collide with one or both of the aerosol forming substrate and the nozzle. Alternatively, the transfer element may be separated from one or both of the aerosol forming substrate and the nozzle.

 10

The inclusion of a transfer element advantageously allows the cooling of the aerosol generated by heat transfer from the source of combustible heat to the aerosol forming substrate. The inclusion of a transfer element also advantageously allows the entire length of the 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 transfer element length. fifteen

The transfer element may have a length of between about 7 mm and about 50 mm, for example, a length of between about 10 mm and about 45 mm or between about 15 mm and about 30 mm. The transfer element may have other lengths, depending on the desired total length of the smoking article, and the presence and length of other components 20 within the smoking article.

Preferably, the transfer element comprises at least one hollow open-ended tubular body. In such embodiments, during use, the air sucked into the smoking article through one or more air inlets passes through at least one hollow open-ended tubular body when it passes downstream through the smoking article from the spray forming substrate towards the nozzle.

The transfer element may comprise at least one hollow open-ended tubular body formed from one or more suitable materials that are essentially thermally stable at the temperature of the aerosol generated by transferring heat from the source of combustible heat to the forming substrate. 30 spray Suitable materials are known in the art and include, but are not limited to, paper, cardboard, plastics, such as cellulose acetate, ceramics and combinations thereof.

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

The aerosol cooling element may comprise a gathered sheet of material selected from the group consisting of metal sheet, polymeric material, and essentially non-porous paper or cardboard. In certain embodiments, the aerosol cooling element may comprise a gathered sheet of material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil.

In certain preferred embodiments, the aerosol cooling element may comprise a puckered sheet 45 of biodegradable polymeric material, such as polylactic acid (PLA) or a Mater-Bi® grade (a commercially available family of starch-based copolyesters).

The 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 nozzle, the transfer element and the aerosol cooling element of the smoking articles according to the invention may comprise one or more aerosol modifying agents.

Suitable aerosol modifying agents include, but are not limited to: flavorings; and chemostatic agents. 55

As used herein, the term "flavoring" is used to describe any agent that, during use, imparts one or both of a taste or aroma to an aerosol generated by the aerosol forming substrate of the smoking article.

 60

As used in the present description, the term 'chemo-aesthetic agent' is used to describe any agent that, during use, is perceived in the oral or olfactory cavities of a user by means other than, or in addition to, perception through of taste receptor or olfactory receptor cells. The perception of chemostatic agents is typically performed through a "trigeminal response", whether through the trigeminal nerve, the glossopharyngeal nerve, the vagus nerve, or some combination of these. Typically, chemostatic agents are perceived as sensations of hot, spicy, cooling, or calming.

The smoking articles according to the invention may comprise one or more aerosol modifying agents that are both a flavoring and a chemostatic agent downstream of the aerosol forming substrate. For example, one or more of the nozzle, the transfer element and the aerosol cooling element of the smoking articles according to the invention may comprise menthol or other flavor that provides a chemostatic cooling effect. 5

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

The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

Figure 1a) shows an exploded view of a smoking article in accordance with a first embodiment of the invention;

Figure 1b) shows an exploded view of a smoking article in accordance with a second embodiment of the invention; fifteen

Figure 1c) shows an exploded view of a smoking article in accordance with a fourth embodiment of the invention;

Figure 1d) shows an exploded view of a smoking article in accordance with a fifth embodiment of the invention;

Figure 1e) shows an exploded view of a smoking article in accordance with a seventh embodiment of the invention;

Figure 1f) shows an exploded view of a smoking article in accordance with an eighth embodiment of the invention;

Figure 2 shows a schematic longitudinal cross-section of the smoking article in accordance with the first embodiment of the invention shown in Figure 1a); and 25

Figure 3 shows a schematic longitudinal cross-section of the smoking article in accordance with the second embodiment of the invention shown in Figure 1b).

The smoking article 2 in accordance with the first embodiment of the invention shown in Figures 1a) and 2 comprises a fuel heat source 4 having a front face 6 and an opposite rear face 8, an aerosol-forming substrate 30, a transfer element 12 and a nozzle 14 in adjacent coaxial 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 wrapped in an outer shell 16 of sheet material such as, for example , cigarette paper, low air permeability.

 35

The fuel heat source 4 comprises a central air flow channel 18 (shown by dotted lines in Figure 1a)) which extends from the front face 6 towards the rear face 8 of the fuel heat source 4.

The aerosol-forming substrate 10 is located immediately downstream of the rear face 8 of the combustible heat source 4. The aerosol-forming substrate 10 comprises a cylindrical plug of homogenized tobacco-based material 40 that includes such an aerosol-forming such as glycerin, wrapped in a wrapper of the cap 22.

The transfer element 12 is located immediately downstream of the aerosol-forming substrate 10 and comprises a hollow cylindrical open-ended tube 24 of suitable material such as, for example, paper, cardboard 45 or cellulose acetate tow.

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, very low cellulose acetate tow filtration efficiency, wrapped in a wrapper of filter plug 50 28.

The smoking article may further comprise a nozzle paper strip (not shown) circumscribing an end portion downstream of the outer envelope 16.

 55

As shown in Figure 2, the smoking article 2 further comprises a heat conducting element 30 of a suitable material such as, for example, an aluminum foil, around and in contact with a rear portion 4b of the heat source carbonaceous fuel 4 and an adjacent 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 downstream beyond the element heat conductive 30. That is, the heat conducting element 30 is not around or in contact with a rear portion of the aerosol forming substrate 10. However, it will be appreciated that in other embodiments of the invention (not shown), The heat conducting element 30 may be around and in contact with the entire length of the aerosol forming substrate 10.

 65

The smoking article 2 in accordance with the first embodiment of the invention comprises one or more entries of

air located downstream of the rear face 8 of the fuel 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 one end downstream of the aerosol forming substrate 10 and comprises one or more first entries 32 located around the periphery of the aerosol forming substrate 10.

 5

As shown in Figure 2, a circumferential arrangement of the first air inlets 32 is provided in the envelope of the cap 22 of the aerosol-forming substrate 10 and the superimposed outer envelope 16 to admit cold air (shown by dotted arrows in Figures 1a) and 2) towards the aerosol forming substrate 10. It will be appreciated that in other embodiments of the invention (not shown) in which the heat conducting element 30 is around and in contact with the entire length of the substrate Aerosol former 10, a circumferential arrangement of the first air inlets 32 may be provided in the envelope of the cap 22 of the aerosolizer substrate 10, the superimposed heat conductive element 30 and the superimposed outer envelope 16 to admit the cold air to the spray forming substrate 10.

During use, a user turns on the combustible heat source 4 of the smoking article 2 in accordance with the first embodiment of the invention and then aspirates from the nozzle 14. When a user aspirates from the nozzle 14, the air (shown by dotted arrows in Figures 1a) and 2) are drawn towards the smoking article 2 through the central air flow channel 18 of the combustible heat source 4 and is heated when it passes through the central air flow channel 18 of the combustible heat source 4. When a user aspirates from the nozzle 14, the cold air (shown by dotted arrows in Figure 1a) and 2) is also drawn into the aerosol-forming substrate 10 of the smoking article 20 2 through the first air inlets 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 when it passes downstream through the aerosol forming substrate 10 towards the nozzle 14 of the article for smoking 2. The front portion 10a of the aerosol forming substrate 10 25 is also heated by conduction through the adjacent rear face 8 of the combustible heat source 4 and the heat conducting element 28.

Heating of 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 30 compounds released from the aerosol-forming substrate 10 form an aerosol that it is drawn into the air sucked through the central air flow channel 18 of the combustible heat source 4 and the air sucked into the aerosol-forming substrate 10 of the smoking article 2 through the first air inlets 32 when it flows through the aerosol-forming substrate 10. The aspirated air and the entrained aerosol (shown by dotted arrows in Figures 1a) and 2) pass downstream through the transfer element 12, where they cool and condense. The cold sucked air and entrained spray pass downstream through the nozzle 14 and are supplied 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 in accordance with the second embodiment of the invention shown in Figures 1b) and 3 40 is of a construction largely identical to the smoking article in accordance with the first embodiment of the invention shown in Figures 1a) and 2 However, in the smoking article 34 according to the second embodiment of the invention the fuel heat source 4 and the aerosol forming substrate 10 are separated from each other and one or more air inlets located between the rear face 8 of The combustible 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 combustible heat source 4 and the aerosol forming substrate 10.

As shown in Figure 3, a circumferential arrangement of second air inlets 36 is provided in the heat conducting element 30 and the superimposed outer shell 16 between the rear face 8 of the combustible heat source 4 and the upstream end of the aerosol forming substrate 10 for admitting cold air (shown by 50 dot arrows in Figures 1b) and 3) towards the space between the combustible heat source 4 and the aerosol forming substrate 10.

During use when a user aspirates from the mouthpiece 14 of the smoking article 34 in accordance with the second embodiment of the invention, the air (shown by dotted arrows in Figures 1b) and 3) is drawn into article 55 for smoking 34 through the central air flow channel 18 of the fuel heat source 4 and the cold air is also 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 sucked through the central air flow channel 18 of the combustible heat source 4 heats the aerosol forming substrate 10 by convection when it passes downstream through the aerosol forming substrate 10 towards the nozzle 14 of the article for smoking 34. The front portion 10a of the aerosol forming substrate 10 is also heated by conduction through the heat conducting element 28.

Heating of the aerosol-forming substrate 10 by conduction and convection releases glycerin and 65 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 that is drawn into the air sucked through the central air flow channel 18 of the combustible heat source 4 and the air sucked into the space between the fuel heat source 4 and the aerosol-forming substrate 10 through the second air inlets 36 when it flows through the aerosol-forming substrate 10. The aspirated air and the entrained aerosol (shown by dotted arrows in Figures 1b) and 3) pass downstream through the transfer element 12, where they cool and condense. The cold sucked air and entrained spray pass downstream through the nozzle 14 and are supplied to the user through the proximal end of the smoking article 34 in accordance with the second embodiment of the invention.

A smoking article in accordance with a third embodiment of the invention (not shown) is of a construction that is largely identical to the smoking article in accordance with the second embodiment of the invention shown in Figures 1b) and 3. However, in the smoking article according to the third embodiment of the invention one or more air inlets located between the rear face of the combustible heat source and the downstream end of the aerosol forming substrate comprise one or more second inlets located between the face rear of the combustible heat source 4 and the aerosol-forming substrate 10 as in the smoking article in accordance with the second embodiment of the invention shown in Figures 1b) and 3 and also one or more first entries located around the periphery of the aerosol forming substrate as in the smoking article in accordance with the first embodiment of the invention shown in Fig. uras 1a) and 2.

During use when a user draws from the mouthpiece of the smoking article in accordance with the third embodiment of the invention, air is drawn into the smoking article through the central air flow channel of the combustible heat source and The cold air is also aspirated into the space 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.

 25

The carbonaceous combustible heat sources for use in smoking articles in accordance with the first, second and third embodiments of the invention can be produced in accordance with Example 1 below by omitting the second clay barrier coating.

The air drawn through the aerosol forming substrates of the smoking articles in accordance with the first, second and third embodiments of the invention entering the smoking articles through the central air flow channel of the source of Fuel heat comes into direct contact with a combustible portion of the fuel heat source when it passes through the central air flow channel. The air drawn through the aerosol forming substrates of the smoking articles in accordance with the first, second and third embodiments of the invention entering the smoking articles through the central air flow channel also comes into contact. Direct with the rear face of the fuel heat source.

The smoking article 38 in accordance with the fourth embodiment of the invention shown in Figure 1c) is of construction largely identical to the smoking article in accordance with the first embodiment of the invention shown in Figures 1a) and 2. However, in the smoking article 38 in accordance with the fourth embodiment 40 of the invention a first essentially non-combustible air-impermeable 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 essentially non-combustible air-impermeable barrier coating provided on the entire rear face 8 of the combustible heat source 4 and the central air flow channel 18 of the source of Fuel heat 4 extends through the first barrier coating. Four. Five

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

 fifty

As a result of the inclusion of the first barrier coating, during use, the air sucked through the smoking article 38 in accordance with the fourth embodiment of the invention through the central air flow channel 18 of the combustible heat source 4 also does not directly contact the rear face 8 of the carbonaceous fuel heat source 4. Additionally, as a result of the inclusion of the first barrier coating, during use, cold air drawn into the aerosol-forming substrate 10 of the smoking article 38 In accordance with the fourth embodiment of the invention through the first air inlets 32, it does not directly contact the rear face 8 of the carbonaceous fuel heat source 4.

However, the air drawn through the aerosol-forming substrate 10 of the smoking article 38 in accordance with the fourth embodiment of the invention entering the smoking article 38 through the central air flow channel 60 18 of the source of combustible heat 4 comes into direct contact with a combustible portion of the combustible heat source when it passes through the central air flow channel 18.

The smoking article 42 in accordance with the fifth embodiment of the invention shown in Figure 1d) is of a construction largely identical to the smoking article in accordance with the second embodiment of the invention 65 shown in Figures 1b) and 3. However , in the smoking article 42 in accordance with the fifth modality

of the invention a first essentially non-combustible air-impermeable 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 1d), the first barrier 40 comprises a Essentially air-impermeable non-combustible barrier coating provided on the entire rear face 8 of the combustible heat source 4 and the central air flow channel 18 of the combustible heat source 4 extends through the first barrier coating. 5

As a result of the inclusion of the first barrier coating, during use, the air sucked into the smoking article 42 in accordance with the fifth embodiment of the invention through the central air flow channel 18 of the combustible heat source 4 does not directly contact the rear face 8 of the carbonaceous fuel heat source 4. Additionally, as a result of the inclusion of the first barrier coating, 10 during use, the cold air drawn into the space between the fuel heat source 4 and the aerosol-forming substrate 10 of the smoking article 42 in accordance with 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.

 fifteen

However, the air sucked through the aerosol-forming substrate 10 of the smoking article 42 in accordance with the fifth embodiment of the invention entering the smoking article 42 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 when it passes through the central air flow channel 18.

 twenty

A smoking article in accordance with a sixth embodiment of the invention (not shown) is of a construction largely identical to the smoking article in accordance with the third embodiment of the invention (not shown). However, in the smoking article in accordance with the sixth embodiment of the invention there is provided a first non-combustible barrier essentially impermeable to air between the rear face of the combustible heat source and the aerosol forming substrate. The first barrier comprises an essentially non-combustible barrier coating 25 essentially impermeable to the air provided on every rear face of the combustible heat source and the central air flow channel of the combustible heat source extends through the first barrier coating.

As a result of the inclusion of the first barrier lining, during use, the air sucked into article 30 for smoking in accordance with the sixth embodiment of the invention through the central air flow channel of the non-contactable fuel heat source directly the rear face of the carbonaceous fuel heat source. Additionally, as a result of the inclusion of the first barrier coating, during use, cold air drawn into the space between the source of combustible heat and the aerosol forming substrate of the smoking article in accordance with the sixth embodiment of the invention a through the second air inlets and towards the aerosol forming substrate of the smoking article in accordance with the sixth embodiment of the invention through the first air inlets it does not directly contact the rear face of the carbonaceous combustible heat source.

However, air drawn through the aerosol forming substrate of the smoking article in accordance with the sixth embodiment of the invention entering the smoking article through the central air flow channel of the combustible heat source enters Direct contact with a combustible portion of the combustible heat source when it passes through the central air flow channel.

The carbonaceous combustible heat sources for use in smoking articles in accordance with the fourth, fifth and sixth embodiments of the invention can be produced in accordance with Examples 2, 3 and 4 below.

The smoking article 44 in accordance with the seventh embodiment of the invention shown in Figure 1e) is of a construction largely identical to the smoking article in accordance with the first embodiment of the invention shown in Figures 1a) and 2. However, in the smoking article 44 in accordance with the seventh embodiment 50 of the invention there is provided a second essentially non-combustible air-impermeable barrier 46 (shown by dotted lines in Figure 1e)) between the fuel heat source 4 and the channel of central air flow 18. The second barrier 46 comprises a second non-combustible barrier coating essentially impermeable to the air provided over the entire inner surface of the central air flow channel 18.

 55

As a result of the inclusion of the second barrier coating, during use, the air sucked into the smoking article 38 in accordance with the seventh embodiment of the invention through the central air flow channel 18 of the combustible heat source 4 does not directly contact a combustible portion of the carbonaceous fuel heat source 4 when it passes through the central air flow channel 18.

 60

However, the air drawn through the aerosol forming substrate 10 of the smoking article 44 in accordance with the seventh embodiment of the invention entering the smoking article 44 through the central air flow channel 18 of the heat source Fuel 4 comes into direct contact with the rear face 8 of the fuel heat source 4.

 65

The smoking article 48 in accordance with the eighth embodiment of the invention shown in Figure 1f) is of

construction largely identical to the smoking article in accordance with 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 non-combustible barrier is provided air impermeable 46 (shown by dotted lines in Figure 1f)) between the fuel heat source 4 and the central air flow channel 18. The second barrier 46 comprises a second non-combustible barrier coating essentially air impermeable 5 provided over the entire internal surface of the central air flow channel 18.

As a result of the inclusion of the second barrier coating, during use, the air sucked 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 directly contact the carbonaceous fuel heat source 4 10 when it passes through the central air flow channel 18.

However, the air drawn through the aerosol forming substrate 10 of the smoking article 48 in accordance with the eighth embodiment of the invention entering the smoking article 48 through the central air flow channel 18 of the heat source fuel 4 comes into direct contact with the rear face 8 of the heat source 15 fuel 4. Additionally, the cold air sucked into the space between the fuel heat source 4 and the aerosol forming substrate 10 of the smoking article 48 in accordance with the eighth embodiment of the invention through the second air inlets 36 it also comes into direct contact with the rear face 8 of the fuel heat source 4.

 twenty

A smoking article in accordance with a ninth embodiment of the invention (not shown) is of a construction largely identical to the smoking article in accordance with the third embodiment of the invention (not shown). However, in the smoking article in accordance with the ninth embodiment of the invention there is provided a second air-impermeable non-combustible barrier between the source of combustible heat and the central air flow channel. The second barrier comprises a second non-combustible barrier coating 25 essentially impermeable to the air provided over the entire internal surface of the central air flow channel.

As a result of the inclusion of the second barrier coating, during use, the air sucked into the smoking article in accordance with the ninth embodiment of the invention through the central air flow channel of the fuel heat source does not directly contact The carbonaceous fuel heat source when it passes through the central air flow channel.

However, air drawn through the aerosol forming substrate of the smoking article in accordance with the ninth embodiment of the invention entering the smoking article through the central air flow channel of the combustible heat source comes into contact. Direct with the rear face of the fuel heat source. Additionally, the cold air drawn into the space between the combustible heat source and the aerosol forming substrate of the smoking article in accordance with the ninth embodiment of the invention through the second air inlets also comes into direct contact with the rear face of the fuel heat source.

The carbonaceous combustible heat sources for use in smoking articles in accordance with the seventh, eighth and ninth embodiments of the invention may be produced in accordance with Example 1 below.

Example 1 - Preparation of a carbonaceous fuel heat source comprising a second clay barrier coating

 Four. Five

Cylindrical carbonaceous heat sources for use in smoking articles according to the invention can be prepared as described in WO-A2-2009 / 074870 A2 or any other prior art known to those skilled in the art. The technique. An aqueous suspension, as described in WO-A2-2009 / 074870 A2, is extruded through a die having a central hole of the die of a circular cross-section to manufacture the source of combustible heat. The hole of the die 50 has a diameter of 8.7 mm so that it forms cylindrical rods, which have 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 means of a mandrel centrally mounted in the hole of the die. The mandrel preferably has a circular cross section with an outer diameter of about 2 mm or about 3.5 mm. Alternatively, three air flow channels are formed in the cylindrical rods by using three circular cross-section mandrels with an outer diameter of approximately 2 mm mounted at regular angles in the hole of the die. During extrusion of the cylindrical rods, a clay-based coating suspension (manufactured by using clay, such as natural green clay) is pumped through a feed passage that extends through the center of the mandrel or mandrels to form a second thin barrier coating 60 of about 150 microns to about 300 microns on the inner surface of the channel or air flow channels. The cylindrical rods are dried at a temperature of about 20 ° C to about 25 ° C under about 40% to about 50% relative humidity for between about 12 hours to about 72 hours and then pyrolyzed in a nitrogen atmosphere at about 750 ° C for approximately 240 minutes. After pyrolysis, the cylindrical rods are cut and molded to a defined diameter by using a grinding machine to form individual combustible sources of heat

carbonates The rods after cutting and molding have a length of approximately 11 mm, a diameter of approximately 7.8 mm and a dry mass of approximately 400 mg. Individual carbonaceous combustible heat sources are subsequently dried at approximately 130 ° C for approximately 1 hour.

 5

Example 2 - Preparation of a carbonaceous fuel heat source comprising a first bentonite / kaolinite barrier coating

An essentially non-combustible air-impermeable barrier coating of bentonite / kaolinite is provided on the rear face of a carbonaceous fuel heat source prepared as described in Example 1 10 but without a second clay barrier coating. The first barrier coating is provided by immersion, brush or spray coating. Immersion involves inserting the back face of the carbonaceous fuel heat source into a concentrated solution of bentonite / kaolinite. The bentonite / kaolinite immersion solution contains 3.8% bentonite, 12.5% kaolinite and 83.7% H2O [m / m]. The rear face of the carbonaceous fuel heat source is submerged into the bentonite / kaolinite solution for approximately 1 second and the meniscus allowed to disappear as a result of the penetration of the solution into the carbon pores on the surface of the rear face of the carbonaceous fuel heat source. Brush application involves dipping a brush in a concentrated bentonite / kaolinite solution and applying the concentrated bentonite / kaolinite solution on the brush to the surface of the back face of the carbonaceous combustible heat source until it is covered. The bentonite / kaolinite solution for brush application contains 20 3.8% bentonite, 12.5% kaolinite and 83.7% H2O [m / m].

After applying the essentially non-combustible barrier coating to the air by dipping or brushing, the carbonaceous fuel heat source is dried in an oven at approximately 130 ° C for approximately 30 minutes and placed in a dryer under approximately 5% of relative humidity during the night.

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 mPa ∙ sa a cutting speed of approximately 100 s-1 as measured with a rheometer (Physics MCR 300, coaxial cylinder arrangement 30). Spray coating is done with a Sata MiniJet 3000 spray gun by using spray nozzles of 0.5 mm, 0.8 mm or 1 mm on an SMC E-MY2B linear actuator at a speed of approximately 10 mm / s approximately 100 mm / s. The following spray parameters are used: gun-sample distance 15 cm; sample rate 10 mm / s; spray nozzle 0.5 mm; flat spray jet and spray pressure 2.5 bars. In a single spray coating event, a coating thickness of approximately 11 microns is typically obtained. Spraying is repeated three times. Between each spray coating, the carbonaceous fuel heat source is dried at room temperature for approximately 10 minutes. After applying the essentially non-combustible barrier coating to the air, the carbonaceous fuel heat source is pyrolyzed at about 700 ° C for about 1 hour. 40

Example 3 - Preparation of a carbonaceous fuel heat source comprising a first glass barrier coating

An essentially non-combustible air-impermeable barrier coating is provided on the rear face 45 of a carbonaceous fuel heat source prepared as described in Example 1 but without a second clay barrier coating. The first barrier coating is provided by spray coating. The glass spray coating is done with a chopped glass suspension by using a fine powder. For example, a spray coating suspension is used that contains both 37.5% glass powder (3µm), 2.5% methylcellulose and 60% water with a viscosity of 120 mPa ∙ s, or 37.5 50% glass powder (3µm), 3.0% bentonite powder, and 59.5% water with a viscosity of 60 to 100 mPa ∙ s. Glass powder having the compositions and physical properties corresponding to Glass 1, 2, 3 and 4 can be used in Table 1.

Spray coating is done with a Sata MiniJet 3000 spray gun by using 55 spray nozzles of 0.5 mm, 0.8 mm or 1 mm on an SMC E-MY2B linear actuator at a speed of approximately 10 mm / s approximately 100 mm / s. Spraying is preferably repeated several times. After spraying is complete, the carbonaceous fuel heat source is pyrolyzed at approximately 700 ° C for approximately 1 hour.

 60

 65

 5

Table 1: Glass composition in percent by weight, transformation temperature Tg, thermal expansion coefficient A20-300 and KI value calculated from the composition

Example 4 - Preparation of a carbonaceous fuel heat source comprising a first coating of aluminum barrier

A first non-combustible aluminum barrier coating, essentially air impermeable, 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 bands having a thickness of approximately 20 microns. The aluminum barrier has a diameter of approximately 7.8 mm and a single hole having an external diameter of approximately 1.8 mm at its center to correspond to the cross section of the carbonaceous combustible heat source of Example 1. In a Alternatively, the aluminum barrier has three holes, which are positioned to align with three airflow channels provided in the carbonaceous fuel heat source. The aluminum barrier coating is formed by attaching the aluminum barrier to the rear face of the carbonaceous combustible heat source by using any suitable adhesive.

During use, cold air drawn into one or more air inlets located between the rear face of the combustible heat source and one end downstream of the aerosol forming substrate reduces the temperature of the aerosol forming substrate 10 of the items for smoking 2, 34, 38, 42, 44, 48 in accordance with the first to the ninth modalities of the invention during the action of taking a puff by a user.

This advantageously prevents or inhibits spikes in the temperature of the aerosol forming substrate 10 during the action of taking a breath by a user and minimizes or advantageously minimizes the impact of the regime of taking a breath of a user on the aerosol composition of the mainstream of smoking articles 2, 34, 38, 42, 44, 48 in accordance with the first to the ninth embodiments of the invention.

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

Claims (15)

1. An article for smoking (2, 34, 38, 42, 44, 48) comprising: a combustible heat source (4) having opposite front (6) and rear (8) faces; one or more air flow channels (18) extending from the front face (6) to the rear face 5 (8) of the fuel heat source (4); an aerosol forming substrate (10) downstream of the rear face (8) of the combustible heat source (4); a nozzle (14) downstream of the aerosol forming substrate (10); Y 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) where one or more air inlets (32 , 36) are located between the rear face (8) of the combustible heat source (4) and one end downstream of the aerosol forming substrate (10), wherein, during use, the air sucked 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 15 more air inlets (32, 36) and at least part of the air drawn through the aerosol forming substrate (10) comes into direct contact with a combustible portion of the fuel heat source (4). 2. A smoking article (2, 34) according to claim 1 further comprising an outer shell 20 (16) circumscribing the aerosol forming substrate (10) and at least a rear portion of the combustible heat source ( 4). 3. A smoking article (38, 42, 44, 48) according to claim 1 further comprising one of: (i) a first essentially non-combustible air-impermeable barrier (40) between the rear face (8) of 25 the combustible heat source (4) and the aerosol forming substrate (10); and (ii) a second non-combustible barrier essentially impermeable to air (46) between the source of combustible heat (4) and one or more air flow channels (18). 4. A smoking article (38, 42) according to claim 1 comprising (i) a first non-combustible first barrier 30 essentially impermeable to air (40) between the rear face (8) of the combustible heat source (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 fuel heat source (4). 5. A smoking article (44, 48) according to claim 1 comprising (ii) a second non-combustible barrier essentially impermeable to air (46) between the source of combustible heat (4) and one or more channels of air flow (18), wherein the second barrier (46) comprises a second barrier coating provided on an internal surface of one or more air flow channels (18). 6. A smoking article (2, 38, 44) according to any preceding claim wherein one or more 40 air inlets (32) comprise one or more first air inlets around the periphery of the aerosol forming substrate (10 ). 7. A smoking article (2, 38, 44) according to any preceding claim wherein the aerosol-forming substrate (10) adjoins the rear face (8) of the combustible heat source (4). Four. Five 8. A smoking article (34, 42, 48) according to any claim 1 to 6, wherein the aerosol forming substrate (10) is separated from the rear face (8) of the combustible heat source (4) . 9. A smoking article according to claim 8 wherein one or more air inlets 50 comprise one or more second air inlets (36) between the rear face (8) of the fuel heat source (4) and the aerosol forming substrate (10). 10. An article for smoking (2, 34) in accordance with any preceding claim further comprising: a heat conducting element (30) around a rear portion (4b) of the fuel heat source (4) and at least a front portion (10a) of the aerosol forming substrate (10). 11. A smoking article (2, 34) according to any preceding claim wherein the aerosol forming substrate (10) comprises a tobacco-based material (20) and at least one aerosol former.  60 12. A smoking article (2, 34, 38, 42, 44, 48) according to any preceding claim wherein the source of combustible heat (4) is a source of carbonaceous combustible heat. 13. A smoking article (2, 34, 38, 42, 44, 48) according to any preceding claim, wherein the source of combustible heat (4) comprises an ignition aid. 5 14. An article for smoking (2, 34, 38, 42, 44, 48) in accordance with any preceding claim further comprising: a transfer element (12) between the aerosol forming substrate (10) and the nozzle (14).  10 15. A smoking article (2, 34, 38, 42, 44, 48) according to any preceding claim further comprising one or more aerosol modifying agents downstream of the aerosol forming substrate (10).