ES2671435T3 - Smoking item with a single radially separated heat conducting element - Google Patents

Abstract

An article for smoking (2, 42) comprising: a source of combustible heat (4) having opposite front and rear faces (6, 8); an aerosol-forming substrate (10) downstream 5 of the rear face (8) of the combustible heat source (4); and a single heat conducting element (36) covering a rear portion of the combustible heat source (4) and at least a front portion of the aerosol forming substrate (10), wherein the only heat conducting element (36) It comprises one or more layers of heat conducting material and the one or more layers of heat conducting material are radially separated from the combustible heat source (4) and the aerosol forming substrate (10), where the combustible heat source ( 4) it is either a blind fuel heat source or the fuel heat source is a non-blind fuel heat source and the smoking article (42) further comprises an essentially non-combustible air-impermeable barrier (46) between the source of non-blind combustible heat and one or more air flow channels (44) extending from the front face (6) to the rear face (8) of the non-blind combustible heat source, and wherein the only conductive element of the heat comprises a cap to external heat conductive material that is visible on the outside of the smoking article (2, 42).

Description

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DESCRIPTION

Smoking item with a single radially separated heat conducting element

The present invention relates to a smoking article comprising a fuel heat source having opposite front and rear faces, and an aerosol forming substrate downstream of the rear face of the fuel heat source and a single conductive element of the heat that covers a rear portion of the fuel heat source and at least a front portion of the aerosol forming substrate.

A number of smoking articles have been proposed in the art in which the tobacco is heated rather than burned. An objective of such "heated" smoking articles is to reduce the known harmful constituents of smoke 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.

For example, 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 contact direct with a rear portion of the fuel heat source and an adjacent front portion of the aerosol forming substrate.

The heat conducting element in the smoking article of WO-A2-2009 / 022232 transfers the heat generated during combustion of the combustible heat source to the conductive aerosol forming substrate. In smoking articles in which tobacco is heated rather than burned, the temperature reached in the aerosol forming substrate has a significant impact on the ability to generate a sensorially acceptable aerosol. It is typically convenient to maintain the temperature of the aerosol forming substrate within a certain range in order to optimize the aerosol supply to a user. In some cases, radiation heat losses from the outer surface of a heat conducting element around and in direct contact with the combustible heat source and the aerosol forming substrate may cause the temperature of the combustible heat source and The aerosol forming substrate falls outside a desired range, thus affecting the performance of the smoking article. If the temperature of the aerosol forming substrate falls too low, for example, it can adversely affect the consistency and amount of aerosol supplied to a user.

EP-A1-2 550 879 describes a smoking article comprising a multi-layer tube member 9 that includes at least one metal layer and a paper layer, a carbon heat source 4 disposed at an end portion of the tube member 9 so that it is at least partially in contact by directly directing with an inner surface of the tube member 9 and a flavoring source of smoking release 8 arranged in the tube member 9 to be attached to the carbon heat source 4, and a fastener part 14 that maintains the carbon heat source 4 in direct contact with said end portion and that holds the carbon heat source 4 against said end portion.

In the embodiment shown in Fig. 1 the non-combustible wrapping material 9 is formed by joining a sheet composed of three layers 16 on the outer side of a sheet composed of two layers 15. The part of the sheet composed of three layers 16 protruding from the sheet of two-layer composite material 15 forms the fastener part 14. As shown in Fig. 2, the two-layer composite sheet 15 comprises an inner layer of aluminum 17 and an outer layer of paper 18 The three-layer composite sheet 16 comprises an inner layer of paper 18, a central aluminum layer 17 and an outer layer of paper 18. The innermost layer of the non-combustible envelope 9 is the aluminum layer 17 of the composite sheet of two layers 15 and the outermost layer of the non-combustible envelope 9 is the outer paper layer 18 of the three layer composite sheet 16.

In some heated smoking articles, heat transfer by forced convection from a source of combustible heat and to the aerosol-forming substrate is provided in addition to heat transfer by conduction through a heat conducting element. For example, in some known heated smoking articles one or more air flow channels are provided together with the combustible heat source in order to provide forced convection heating of the aerosol forming substrate. In such smoking articles, the aerosol forming substrate is heated by a combination of conduction heating and forced convection heating.

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For example, WO-A2-2009 / 022232 describes providing at least one longitudinal air flow channel through the fuel heat source to provide a controlled amount of forced convection heating of the aerosol forming substrate.

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 forming substrate Aerosol 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.

In particular, in known heated smoking articles comprising one or more air flow channels along the combustible heat source, the direct contact between the air drawn through one or more air flow channels and the Fuel heat source during the action of taking a breath by a user results in the activation of combustion of the fuel heat source. The rates of taking an intense puff can therefore lead to a heat transfer by forced convection high enough to cause spikes in the temperature of the aerosol forming substrate, which leads disadvantageously to pyrolysis and potentially even to localized combustion of the substrate. spray former 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 mainstream 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.

Other heated smoking articles do not provide air flow channels through the source of combustible heat. In such heated smoking articles the heating of the aerosol forming substrate is mainly achieved by heat transfer by conduction through a heat conducting element. In heated smoking articles in which the aerosol forming substrate is heated primarily by conductive heat transfer, the temperature of the aerosol forming substrate may become more sensitive to changes in the temperature of the heat conducting element. This means that any cooling of the heat conducting element around and in direct contact with the combustible heat source and the aerosol forming substrate due to the loss of heat by radiation in such heated smoking articles can have a greater impact on the generation of aerosol than in heated smoking articles where the aerosol-forming substrate is also heated by heat transfer by forced convection.

It would be convenient to provide a heated smoking article that includes a combustible heat source having opposite front and rear faces and an aerosol forming substrate downstream of the rear face of the combustible heat source which provides improved smoking performance. Particularly, it would be convenient to provide a heated smoking article in which there is an improved control of the heating of the aerosol forming substrate in order to help maintain the temperature of the aerosol forming substrate within a desired temperature range during the smoking action .

In accordance with the invention, a smoking article is provided comprising: a source of combustible heat having opposite front and rear faces; an aerosol forming substrate downstream of the rear face of the fuel heat source; and a single heat conducting element that covers a rear portion of the combustible heat source and at least a front portion of the aerosol forming substrate. The single heat conducting element comprises one or more layers of heat conducting material and the one or more layers of heat conducting material are radially separated from the source of combustible heat and the aerosol forming substrate. The fuel heat source is either a blind fuel heat source or the fuel heat source is a non-blind fuel heat source and the smoking article further comprises an essentially non-combustible air-impermeable barrier between the non-combustible heat source blind and one or more air flow channels extending from the front face to the rear face of the non-blind combustible heat source. The only heat conducting element comprises an outer layer of heat conducting material that is visible on the outside of the smoking article.

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 mouth side end. 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 end of the side of the mouth is downstream of the distal end. The proximal end can also be called the downstream end of the smoking article and the distal end can also be called 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

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upstream or downstream of each other depending on their relative positions between the proximal end and the distal end of the smoking article.

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 closer to the proximal end of the smoking article.

As used herein, 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.

As used herein, the term "aerosol forming substrate" is used to describe a substrate capable of releasing volatile compounds upon heating, which may 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.

As used herein, the term "radially separated" is used to indicate that the one or more layers of heat conducting material of the single heat conducting element are separated from both the combustible heat source and the aerosol forming substrate. in a radial direction, so that there is no direct contact between the one or more layers of heat conducting material of the single heat conducting element and the source of combustible heat or the aerosol forming substrate.

As used herein, the term "radial" is used to describe the direction perpendicular to the direction between the proximal end and the opposite distal end of the smoking article.

As used herein, the term "direct contact" is used to refer to the contact between two components without any intermediate material, so that the surfaces of the components touch each other.

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.

In such embodiments, the one or more layers of heat conducting material of the single heat conducting element are radially separated from the shell of the aerosol forming substrate.

The smoking articles according to the invention comprise a single heat conducting element that covers a rear portion of the combustible heat source and at least one front portion of the aerosol forming substrate. The single heat conducting element comprises one or more layers of heat conducting material and the one or more layers of heat conducting material are radially separated from the source of combustible heat and the aerosol forming substrate.

The smoking articles according to the invention do not comprise any of the additional heat conducting elements that underlie or cover the only heat conducting element. Particularly, the smoking articles according to the invention do not comprise any of the heat conducting elements around and in direct contact with one or both the source of combustible heat and the aerosol forming substrate.

The smoking articles according to the invention may comprise a source of blind combustible heat or a source of non-blind combustible heat.

As used in the present description, the term "blind" is used to describe a source of combustible heat where there are no airflow channels extending from the front face to the rear face of the fuel heat source.

During use, the air drawn through the smoking articles in accordance with the invention comprising a source of blind combustible heat for inhalation by a user does not pass through any air flow channel along the source Heat blind fuel. In smoking articles according to the invention comprising a source of blind combustible heat, the heating of the aerosol forming substrate occurs mainly by conduction and the heating of the aerosol forming substrate by forced convection is minimized or reduced.

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

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As used herein, the term 'non-blind' is used to describe a source of combustible heat where there is one or more airflow channels extending from the front face to the rear face of the heat source. fuel.

During use, the air drawn through the smoking articles in accordance with the invention comprising a source of non-blind combustible heat for inhalation by a user passes through one or more air flow channels along The fuel heat source does not blind. In smoking articles according to the invention comprising a non-blind combustible heat source, heating of the aerosol forming substrate occurs by conduction and forced convection.

The smoking articles according to the invention comprising a non-blind combustible heat source further comprise an essentially non-combustible air impermeable barrier between the non-blind combustible heat source and one or more air flow channels extending from the front face to the rear face of the non-blind fuel heat source.

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

When the smoking articles according to the invention comprise a source of blind combustible heat, the lack of an air flow channel through the source of blind combustible heat advantageously prevents or essentially inhibits the combustion activation of the source of Blind combustible heat during a puff taken by a user.

Similarly, where the smoking articles according to the invention comprise a non-blind combustible heat source inclusion of an essentially non-combustible air-impermeable barrier between the non-blind combustible heat source and the one or more flow channels of air that extends from the front face to the rear face of the non-blind combustible heat source that advantageously prevents or essentially inhibits the combustion activation of the non-blind combustible heat source during the taking of a puff by a user.

Preventing or inhibiting the combustion activation of the combustible heat source during the taking of a puff in an advantageous manner essentially prevents or inhibits spikes in the temperature of the aerosol forming substrate of the smoking articles in accordance with the invention during the taking A puff by a user.

By preventing or inhibiting the activation of combustion of the combustible heat source, and thus preventing or inhibiting increases in excess temperature in the aerosol forming substrate, combustion or pyrolysis of the aerosol forming substrate of the articles can be advantageously avoided for smoking in accordance with the invention under regimes of taking an intense drag. 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.

The only heat conducting element covers a rear portion of the combustible heat source and at least a front portion of the aerosol forming substrate.

The one or more layers of heat conducting material of the single heat conducting element are radially separated from the combustible heat source and the aerosol forming substrate. This limits the transfer of heat by conduction from the source of combustible heat to the sole conductive element of heat and the transfer of heat by conduction from the sole conductive element of heat to the aerosol forming substrate. During use, this advantageously helps to maintain the temperature reached in the aerosol forming substrate of the smoking articles in accordance with the invention below which combustion or pyrolysis of the aerosol forming substrate can occur.

Preferably, the heat transfer by conduction of the combustible heat source to the single heat conducting element is essentially reduced. This results in the only heat conducting element of the smoking articles in accordance with the invention that retains a lower temperature than the heat conducting element of the known heated smoking articles in which the heat conducting element is around and in direct contact with a rear portion of the combustible heat source and at least a front portion of the aerosol forming substrate.

In heated smoking articles in which the heat conducting element is around and in direct contact with a rear portion of the combustible heat source and at least a front portion of the aerosol forming substrate, the heat leakage exerted by the Heat transfer by conduction through the heat conducting element significantly reduces the temperature of the rear portion of the combustible heat source. This may shorten the life of burning of the combustible heat source and may lead to unacceptable aerosol supply.

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The radial separation between the one or more layers of heat conducting material of the single heat conducting element and the combustible heat source and the aerosol forming substrate of the smoking articles according to the invention advantageously reduces the heat leakage exerted by heat transfer by conduction through the only heat conducting element.

The sole heat conducting element advantageously reduces heat losses from the combustible heat source. The one or more layers of heat conducting material of the single heat conducting element increase its temperature during the smoking action of the smoking article, when heat is generated by the source of combustible heat. The increased temperature of the one or more layers of heat conducting material of the single heat conducting element reduces the temperature differential between the source of combustible heat and covering the components of the smoking article, so that heat losses can be reduced from the source of combustible heat.

By reducing the heat losses of the combustible heat source, the sole heat conducting element advantageously helps maintain the temperature of the aerosol forming substrate within a desired temperature range. This improves the aerosol generation of the aerosol forming substrate.

The one or more layers of heat conducting material of the single heat conducting element conducts heat along the smoking article. This improves the efficiency of heat transfer by conduction from the fuel heat source to the aerosol forming substrate and therefore the heating of the aerosol forming substrate. The improvement in heat transfer by conduction achieved through the inclusion of the single heat conducting element is particularly beneficial for smoking articles in accordance with the invention comprising a source of blind combustible heat in which there is essentially no transfer of heat by forced conduction.

The radial separation between the one or more layers of heat conducting material of the single heat conducting element and the combustible heat source and the aerosol forming substrate is preferably achieved through the inclusion of one or more intermediate layers of material between the one or more layers of heat conducting material of the single heat conducting element and the source of combustible heat and the aerosol forming substrate. The one or more intermediate layers of material may be provided over the entire area in which the only heat conducting element covers the combustible heat source and the aerosol forming substrate. Alternatively, one or more intermediate layers of material may be provided only in one part or parts of this area. In some embodiments, the one or more intermediate layers of material may extend beyond the one or more layers of the heat conducting material of the single heat conducting element in one or both of the upstream direction and the downstream direction. Preferably, the one or more layers of heat conducting material of the single heat conducting element are radially separated from the combustible heat source and the aerosol forming substrate by one or more layers of heat insulating material. Suitable heat insulating materials include, but are not limited to, paper, ceramics and metal oxides.

For example, in certain preferred embodiments of the invention, the rear portion of the combustible heat source and the at least one front portion of the aerosol-forming substrate covered by the sole heat conducting element are covered by a paper wrap that circumscribes the smoking article along at least a portion of its length. In such embodiments, the paper wrap radially separates the sole heat conducting element from the combustible heat source and the aerosol forming substrate so that there is no direct contact between the sole heat conducting element and the combustible heat source or the spray forming substrate.

The only heat conducting element comprises an outer layer of heat conducting material provided on the outside of the smoking article, such that the outer layer of heat conducting material of the single heat conducting element is visible on the outside of the article for smoke.

In certain embodiments, the one or more layers of heat conducting material of the single heat conducting element are radially separated from the source of combustible heat and the aerosol forming substrate by a wrap that extends along all or only a portion. of the smoking article. In such embodiments, the wrapper is wrapped around the smoking article on the combustible heat source and the aerosol forming substrate and the only heat conducting element is then provided on at least a portion of the wrapping.

The provision of the single heat conducting element on a wrap of the smoking article may provide benefits in relation to the appearance of the smoking articles in accordance with the invention, particularly during and after smoking. In certain cases, some discoloration of the envelope in the region of the combustible heat source may be observed when the envelope is exposed to the heat of the combustible heat source. The envelope can also be discolored as a result of the migration of volatile compounds from the aerosol forming substrate to the envelope around and downstream of the aerosol forming substrate. In certain embodiments, the only heat conducting element of the smoking articles according to the invention can be provided on the wrap around at least a rear part of the combustible heat source and at least a front part of the aerosol forming substrate of so that the discoloration of the envelope is covered and is no longer visible or less visible. In certain embodiments, the only heat conducting element may extend around the full length of the aerosol forming substrate. In certain preferred embodiments, the only conductive element

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of heat can extend downstream beyond the aerosol forming substrate. The initial appearance of the smoking article can, therefore, be maintained during the smoking action.

Alternatively or additionally to one or more layers of heat insulating material between the one or more layers of heat conducting material of the single heat conducting element and the combustible heat source and the aerosol forming substrate, at least a part of the single conducting element of the Heat can be separated radially from the source of combustible heat and the aerosol-forming substrate by an air gap. An air gap may be provided through the inclusion of one or more separating elements between the one or more layers of heat conducting material of the single heat conducting element and the source of combustible heat and the aerosol forming substrate to maintain a separation defined between the only heat conducting element and the combustible heat source and the aerosol forming substrate. The one or more separator elements may be, for example, one or more strips of paper wrapped radially around the source of combustible heat and the aerosol forming substrate.

Preferably, the one or more layers of heat conducting material of the single heat conducting element are radially separated from the combustible heat source and the aerosol forming substrate by at least 20 microns, more preferably by at least 50 microns. In certain embodiments, the one or more layers of heat conducting material of the single heat conducting element are radially separated from the combustible heat source and the aerosol forming substrate by at least 75 microns or more or by at least 100 microns or more .

Where one or more layers of heat insulating material are provided between the one or more layers of heat conducting material of the single heat conducting element and the source of combustible heat and the aerosol forming substrate, as described above, the radial separation between the one or more layers of heat conducting material of the single heat conducting element and the source of combustible heat and the aerosol forming substrate will be determined by the thickness of the one or more layers of heat insulating material.

The one or more layers of heat conducting material of the single heat conducting element may comprise any suitable heat conducting material or combination of materials with a suitable thermal conductivity.

Preferably, the one or more layers of heat conducting material of the single heat conducting element comprise heat conducting materials having an apparent thermal conductivity of between about 10 W per Kelvin meter (W / (m ^ K)) and about 500 W per Kelvin meter (W / (m ^ K)), more preferably, between approximately 15 W per Kelvin meter (W / (m ^ K)) and approximately 400 W per Kelvin meter (W / (m ^ K)), at 23 ° C and a relative humidity of 50% as measured by the use of the flat modified transient source (MTPS). Suitable heat conducting materials include, but are not limited to: metal foil wraps such as, for example, aluminum foil wraps, steel wraps, iron foil wraps, and copper foil wraps; and metal alloy foil wraps.

In certain preferred embodiments, the only heat conducting element comprises one or more layers of aluminum.

Preferably, the one or more layers of heat conducting material of the single heat conducting element comprise a heat reflective material, such as aluminum or steel. In such embodiments, during use, the single heat conducting element advantageously reflects the heat radiated by the combustible heat source and the aerosol forming substrate returns to the combustible heat source and the aerosol forming substrate.

As used herein, the term "heat reflective material" refers to a material that has a relatively high heat reflectivity and a relatively low heat emissivity so that the material reflects a greater proportion of the radiation incident from its surface that emits. Preferably, the heat reflecting material reflects more than 50% of the incident radiation, more preferably, more than 70% of the incident radiation and most preferably, more than 75% of the incident radiation.

In such embodiments, the relatively high heat reflectivity and relatively low heat emissivity of the single heat conducting element reduces the heat losses of the combustible heat source and the aerosol forming substrate.

The reflectivity of the one or more layers of heat conducting material of the single heat conducting element can be improved by the proportion of the one or more layers of heat conducting material of the single heat conducting element with a bright internal surface, wherein the Internal surface is the surface that is oriented towards the source of combustible heat and the aerosol forming substrate.

The only heat conducting element can be formed by a single layer of heat conducting material. Alternatively, the single heat conducting element may be formed by a multilayer or laminate material comprising at least one layer of heat conducting material in combination with one or more other heat conducting layers or nonconducting layers of heat. In such embodiments, at least one layer of heat conducting material may comprise any of the heat conducting materials mentioned above.

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In certain preferred embodiments, the only heat conducting element may be formed by a laminated material comprising at least one layer of heat conducting material and at least one layer of heat insulating material. In such embodiments, the inner layer of the only heat conducting element that is oriented towards the source of combustible heat and the aerosol forming substrate may be a layer of heat insulating material. In this way, the inner layer of heat insulating material provides the required radial separation between the at least one layer of heat conducting material of the single heat conducting element and the source of combustible heat and the aerosol forming substrate.

In certain preferred embodiments, the only heat conducting element comprises a single layer of heat conducting material.

In certain preferred embodiments, the only heat conducting element is a laminated material comprising a single layer of heat conducting material and one or more layers of heat insulating material. In certain particularly preferred embodiments, the only heat conducting element is a laminated material comprising a single layer of heat conducting material and a single layer of heat insulating material. Preferably, the only heat conducting element is a laminated material comprising a single outer layer of heat conducting material and a single inner layer of heat insulating material.

An example of a particularly suitable laminated material to form the only heat conducting element is a double layer laminated material comprising an outer layer of aluminum and an inner layer of paper.

The use of a single heat conducting element comprising a laminated material may also be beneficial during the production of smoking articles in accordance with the invention, since at least one heat insulating layer can provide greater strength and stiffness. This allows the laminated material to be processed more easily, with a lower risk of collapse or breakage of at least one conductive layer of heat, which can be relatively thin and fragile.

Preferably, the thickness of the single heat conducting element is between about 5 microns and about 100 microns, more preferably, between about 5 microns and about 80 microns.

Preferably, the single heat conducting element comprises one or more layers of heat conducting material having a thickness of between about 2 microns and about 50 microns, more preferably, between about 4 microns and about 30 microns.

In certain embodiments, the only heat conducting element may comprise an aluminum foil that is approximately 20 microns thick.

In certain preferred embodiments, the only heat conducting element may comprise a laminated material comprising an outer layer of aluminum having a thickness of between about 5 microns and about 6 microns and an inner layer of paper.

As described above, the only heat conducting element of the smoking articles according to the invention covers a rear portion of the combustible heat source and at least a front portion of the aerosol forming substrate.

The position and extent of the single heat conducting element relative to the fuel heat source and the aerosol forming substrate can be adjusted in order to control the heating of the aerosol forming substrate during the smoking action. Particularly, the extent of the single heat conducting element in relation to the fuel heat source and the aerosol forming substrate the upstream and downstream direction can be adjusted to adjust the aerosol supply profile of the smoking article.

The only heat conducting element may extend around all or part of the circumference of the smoking article. Preferably, the only heat conducting element forms a continuous sleeve that circumscribes the smoking article along a part of its length.

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

Preferably, the front portion of the combustible heat source not covered by the first 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 only heat conducting element covers the full length of the aerosol forming substrate. In such embodiments, the downstream end of the single heat conducting element can be aligned on the downstream end of the aerosol forming substrate. Alternatively, the only heat conducting element may extend beyond the aerosol forming substrate in the downstream direction.

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

In embodiments in which the only heat conducting element covers only a front portion of the aerosol forming substrate, the aerosol forming substrate may extend at least about 3 mm beyond the only heat conducting element in the downstream direction. For example, the aerosol-forming substrate may extend between about 3 mm and about 10 mm beyond the heat conducting element in the downstream direction. Alternatively, the aerosol-forming substrate may extend less than 3 mm beyond the only heat conducting element in the downstream direction.

In embodiments where the only heat conducting element covers only a front portion of the aerosol forming substrate, the front portion of the aerosol forming substrate covered by the single heat conducting element may be between about 1 mm and about 10 mm of length, for example, the front portion of the aerosol forming substrate covered by the single heat conducting element may be between about 2 mm and about 8 mm in length or between about 2 mm and about 6 mm in length.

The smoking articles according to the invention may comprise a source of blind combustible heat.

It is known to include additives in the sources of combustible heat of the heated smoking articles in order to improve the ignition and combustion properties of the sources of combustible heat. However, the inclusion of ignition and combustion additives may result in reaction and decomposition products, which may disadvantageously enter the aspirated air through such known heated smoking articles during use thereof.

The inclusion of a blind fuel heat source can advantageously prevent or inhibit essentially that the products of combustion and decomposition and other materials formed during ignition and combustion of the blind fuel heat source enter the sucked air through the smoking articles in accordance with the invention during use. This is particularly advantageous when the blind fuel heat source comprises one or more additives to aid in ignition or combustion of the blind fuel heat source.

In smoking articles according to the invention comprising a blind fuel heat source, it is particularly important to optimize the heat transfer by conduction between the fuel heat source and the aerosol forming substrate. It has been found that the inclusion of a single heat conducting element radially separated from the combustible heat source and the aerosol forming substrate has a particularly advantageous effect on the smoking performance of smoking articles that include heat sources blind, where there is little or no heating of the aerosol forming substrate by forced convection.

It will be appreciated that smoking articles in accordance with the invention may comprise blind combustible heat sources comprising one or more closed or blocked passages through which air cannot be drawn for inhalation by a user.

For example, smoking articles in accordance with the invention may comprise blind combustible heat sources comprising one or more closed passages extending from the front face at the upstream end of the blind fuel heat source only one section at a time. Long length of blind fuel heat source.

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

Alternatively, the smoking articles according to the invention may comprise a non-blind combustible heat source where there is one or more air flow channels extending from the front face to the rear face of the non-blind combustible heat source. .

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

As used herein, the term 'closed' is used to describe the air flow channels that extend through the interior of the non-blind combustible heat source and that are surrounded by the non-blind 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 channels may comprise one or more slots or other unclosed air flow channels that extend along the outside of the non-blind combustible heat source.

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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.

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 non-blind combustible heat source.

In certain 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 non-blind combustible heat source.

In certain particularly preferred embodiments, smoking articles in accordance with the invention comprise a single essentially central or axial airflow channel that extends from the front face to the rear face of the non-blind combustible heat source.

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

It will be appreciated that, in addition to one or more air flow channels through which air can be aspirated for inhalation by a user, smoking articles according to the invention may comprise non-blind combustible heat sources comprising one or more more closed or blocked passages through which air cannot be aspirated for inhalation by a user.

For example, smoking articles in accordance with the invention may comprise non-blind combustible heat sources comprising one or more air flow channels extending from the front face to the rear face of the combustible heat source and one or more closed passages that extend from the front face of the fuel heat source do not blind only a section along the length of the fuel heat source.

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

The smoking articles according to the invention comprising a non-blind combustible heat source further comprise an essentially non-combustible air impermeable barrier between the non-blind combustible heat source and one or more air flow channels extending from the front face to the rear face of the non-blind fuel heat source.

The inclusion of an essentially non-combustible air impermeable barrier between the non-blind combustible heat source and one or more air flow channels extending from the front face to the rear face of the non-blind combustible heat source may advantageously, Essentially, preventing or inhibiting the combustion and decomposition of products formed during ignition and combustion of the non-blind combustible heat source from the intake of air sucked into the smoking article through one or more flow channels of air when the aspirated air passes through one or more air flow channels. This is particularly advantageous when the non-blind combustible heat source comprises one or more additives to aid in ignition or combustion of the non-blind combustible heat source.

The barrier between the non-blind combustible heat source and one or more air flow channels may adhere or otherwise be attached to the non-blind combustible heat source.

In certain preferred embodiments, the barrier comprises a 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 barrier comprises a barrier coating provided on at least essentially the entire internal surface of one or more air flow channels. More preferably, the barrier comprises a barrier coating provided over the entire internal surface of one or more air flow channels.

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

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

Depending on the desired characteristics and performance of the smoking article, the barrier may have a

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low thermal conductivity or high thermal conductivity. Preferably, the barrier has a low thermal conductivity.

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

The barrier can be formed from one or more suitable materials that are essentially thermally stable and non-combustible at the temperatures reached by the non-blind combustible heat source 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.

Preferred materials that can be used to form the barrier 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 barrier. Suitable catalytic ingredients include, but are not limited to those listed, for example, platinum, palladium, transition metals and their oxides.

Where the barrier comprises a barrier coating provided on an internal surface of one or more air flow channels, the barrier coating may be applied to the internal surface of one or more air flow channels by any suitable method, such as methods described in patent document uS-A-5,040,551. For example, the inner surface of the one or more air flow channels can be sprayed, moistened or painted with a solution or a suspension of the barrier coating. In certain preferred embodiments, the 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.

The smoking articles according to the invention may further comprise an essentially non-combustible air impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate.

When the smoking articles according to the invention comprise a non-blind combustible heat source and an essentially non-combustible air impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate, the barrier should allow the Air entering the smoking article through one or more air flow channels extending from the front face to the rear face of the non-blind combustible heat source is drawn downstream through the smoking article.

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

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

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

The 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 use. of the smoking article. This is particularly advantageous when the fuel heat source comprises one or more additives to aid in ignition of the fuel heat source.

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 sources of combustible heat thereof. The migration of the aerosol formers to the combustible heat sources of the known heated smoking articles can disadvantageously lead to the decomposition of the aerosol formers, particularly during the smoking action of the heated smoking articles.

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The inclusion of an essentially non-combustible air impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate of the smoking articles according to the invention can advantageously prevent or inhibit, essentially, the migration of the components of the aerosol forming substrate towards the source of combustible heat during storage and use of the smoking article.

Alternatively or additionally, the inclusion of an essentially non-combustible air impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate of the smoking articles according to the invention can advantageously prevent or inhibit, essentially , the migration of the components of the aerosol forming substrate towards the source of combustible heat during the use of the smoking article.

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

In such embodiments, the inclusion of an essentially non-combustible air impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate of the smoking articles according to the invention can advantageously prevent or inhibit the migration of less an aerosol former from the aerosol forming substrate to 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 the smoking article can advantageously thus be avoided or reduced.

Depending on the desired characteristics and performance of the smoking article, the essentially non-combustible air impermeable barrier between the rear face of the combustible heat source and the aerosol forming substrate may have a low thermal conductivity or a high thermal conductivity. In certain embodiments, the 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 / (it ^ K )), at 23 ° C and a relative humidity of 50% as measured by the use of the modified transient flat source (MTPS).

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

The 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, clays (such as, for example, bentonite and kaolinite), glasses, minerals, ceramic materials, resins, metals and combinations thereof.

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

In certain preferred embodiments, the 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 barrier comprises a glass coating, more preferably, a sintered glass coating, provided on the rear face of the combustible heat source.

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

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

Due to the slight permeability of the clays in the air, in the modes where the 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.

In embodiments where the barrier is formed from one or more materials that are more impermeable to air, such as aluminum, the barrier may be thinner, and preferably, will generally have a thickness of less than about 100 microns, and with greater Preference of approximately 20 microns.

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

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

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When the barrier comprises a barrier coating provided on the rear face of the combustible heat source, the 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 art 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.

For example, the 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 entire rear face of the fuel heat source. Alternatively, the barrier coating can 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.

In another preferred embodiment, the 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 barrier coating may 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 brush application or spray coating of a solution or suspension or 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. When the barrier coating is applied to the rear face of the combustible 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 combustible heat source, the rear face of The fuel heat source is preferably pretreated with soluble glass before electrostatic deposition. Preferably, the barrier coating is applied by spray coating.

The 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 barrier coating can be formed by multiple applications of a solution or suspension of one or more suitable coating materials to the rear face of the combustible heat source. For example, the barrier coating 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 to the rear face of the combustible heat source .

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

When the barrier coating is formed by multiple applications of a solution or suspension 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 in addition 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 barrier coating. Sintering of the barrier coating is particularly preferred when the barrier coating is a glass or ceramic coating. Preferably, the barrier coating is sintered at a temperature between about 500 ° C and about 900 ° C, and more preferably, at about 700 ° C.

The smoking articles according to the invention may comprise one or more first air inlets around the periphery of the aerosol forming substrate.

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.

When the smoking articles according to the invention comprise one or more first air inlets around the periphery of the aerosol forming substrate, during use, cold air is sucked 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 and exits the smoking article through the proximal end thereof.

During the taking of a puff by a user, cold air drawn through one or more first air inlets around the periphery of the aerosol forming substrate advantageously reduces the substrate temperature

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spray former This essentially prevents or inhibits, advantageously, the spikes in the temperature of the aerosol forming substrate during the taking of a puff from a user.

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 peaks in the temperature of the aerosol forming substrate, the inclusion of one or more first air inlets around the periphery of the aerosol forming substrate, is advantageously helped to prevent or reduce combustion or pyrolysis of the substrate forming substrate. spray under regimes of intense puffs. In addition, the inclusion of one or more first air inlets around the periphery of the aerosol forming substrate advantageously helps to minimize or reduce the impact of a user's puff regime on the aerosol composition of the mainstream of the smoking article.

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.

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 an essentially non-combustible air impermeable barrier coating provided in the rear face of the fuel heat source.

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.

As used herein, the term "separate" is used to describe the aerosol-forming substrate that is not in direct contact with the rear face of the combustible heat source or an essentially non-combustible air impermeable barrier coating provided. on the rear face of the fuel heat source.

Alternatively or additionally to one or more first air inlets, in such embodiments, smoking articles according to the invention 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 through the second air inlets passes downstream through the smoking article from the space between the combustible heat source and the aerosol forming substrate. and leaves the article for smoking through the proximal end thereof.

During the action of taking a breath by a user, cold air sucked through one or more second entrances between the rear face of the combustible heat source and the aerosol forming substrate can advantageously reduce the temperature of the aerosol forming substrate. This can essentially prevent or inhibit, advantageously, the spikes in the temperature of the aerosol forming substrate during the taking of a puff by a user.

Alternatively or additionally to one or more first air inlets or one or more second air inlets, the smoking articles according to the invention may comprise one or more third air inlets downstream of the aerosol forming substrate.

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 one or more third air inlets downstream of the aerosol forming substrate or any combination thereof.

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

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 fuel 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.

In some embodiments, the sources of combustible heat according to the invention are sources of combustible heat based on carbon. As used herein, the term 'carbon-based heat source' is used to describe a heat source that primarily comprises carbon.

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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 carbon-based fuel heat source.

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

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.

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 additional to one or more binders, sources of combustible heat for use in smoking articles according to the invention may comprise one or more additives in order to improve the properties of the combustible heat source. Suitable additives include, but are not limited to, additives to promote 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 to promote the decomposition of one or more gases produced by combustion of the combustible heat source (for example, catalysts, such as CuO, Fe2O3 and AhO3).

When the smoking articles according to the invention comprise a barrier coating provided on the rear face of the combustible heat source, such additives may be incorporated into the combustible heat source before or after the application of the barrier coating to the face. rear 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 release rate 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 refer to an elemental metal that releases energy during ignition of the combustible heat source, where 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 halide salts (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. .

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; 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, peroxide

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barium, 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 advantageously improve, 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.

When the smoking articles according to the invention comprise a non-blind combustible heat source, the inclusion of an essentially non-combustible air impermeable barrier between one or more air flow channels and the non-blind combustible heat source, advantageously, Essentially, it can prevent or inhibit such reaction and decomposition products from entering the entrained air into the smoking articles according to the invention through one or more air flow channels when the aspirated air passes to through one or more air flow channels.

The inclusion of an essentially non-combustible air impermeable barrier between the rear face of the combustible heat source and the aerosol-forming substrate advantageously, essentially, prevents or inhibits such reaction and decomposition products from entering the aspirated air at through smoking articles in accordance with the invention.

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 fuel heat sources for use in the smoking articles according to the invention are preferably formed by mixing one or more carbon-containing materials with one or more binders and other additives, where it is included, and formed pre-mix 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 desired way 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 others. 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 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 or other ignition medium 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.

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 fuel heat source.

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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.

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.

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 combustible heat source 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. 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 nitrate metal salt. 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 60 percent when measured, for example, by mercury porosimetry 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, carbonaceous fuel 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 approximately 300 mg and

about 500 mg, more preferably, between about 400 mg and about 450 mg. Preferably, the fuel heat source has a length of between about 7 mm and

approximately 17 mm, more preferably between approximately 7 mm and approximately 15 mm, with

the highest preference between about 7 mm and about 13 mm.

Preferably, the combustible heat source has a diameter 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, alternatively, can be tapered so that the diameter of a rear portion of the blind fuel heat source is larger than the diameter of its front portion. Particularly preferred are fuel 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.

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.

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 smoking article . Suitable aerosol formers are well known in the art and include, for example, polyhydric alcohols, esters of polyhydric alcohols, such as glycerol mono-, 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.

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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.

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.

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 comprises a plug of homogenized tobacco-based material wrapped in a plug wrap.

The smoking articles according to the invention preferably comprise a nozzle downstream of the aerosol forming substrate. The mouthpiece is located at the proximal end of the smoking article.

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. Additionally or alternatively, 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.

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.

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.

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 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 through the smoking article passes through at least one hollow open-ended tubular body when it passes downstream through the smoking article from the aerosol forming substrate to its proximal end .

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. 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.

Additionally or alternatively, the smoking articles according to the invention may comprise an aerosol cooling element or heat exchanger between the aerosol forming substrate and the nozzle. He

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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 of biodegradable polymeric material, such as polylactic acid (PLA) or a grade of Mater-Bi® (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.

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.

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 another flavor that provides a chemostatic cooling effect.

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 1 shows a schematic longitudinal cross section of a smoking article in accordance with a first embodiment of the invention;

Figure 2 shows a schematic longitudinal cross section of a smoking article in accordance with a third embodiment of the invention;

Figure 3a shows a graph of the temperature of the rear portion of the combustible heat source of a smoking article in accordance with the invention during the smoking action; Y

Figure 3b shows a graph of the temperature of the aerosol generating substrate of the smoking article in accordance with the invention during the smoking action.

The smoking article 2 in accordance with the first embodiment of the invention shown in Figure 1 comprises a source of blind combustible heat 4 having a front face 6 and an opposite rear face 8, an aerosol forming substrate 10, an element of transfer 12, an aerosol cooling element 14, a separator element 16 and a nozzle 18 in adjacent coaxial alignment.

The blind fuel heat source 4 is a blind carbonaceous fuel heat source and is located at the distal end of the smoking article 2. As shown in Figure 1, an essentially non-combustible air impermeable barrier 22 in the form of a disk Aluminum foil is provided between the rear face 8 of the blind fuel heat source 4 and the aerosol forming substrate 10. The barrier 22 is applied to the rear face 8 of the blind fuel heat source 4 when pressing the disc of Aluminum sheet on the rear face 8 of the blind fuel heat source 4 and adjoins the rear face 8 of the carbonaceous fuel heat source 4 and the aerosol forming substrate 10.

In other embodiments of the invention (not shown), the essentially non-combustible air-impermeable barrier 22 between the rear face 8 of the blind combustible heat source 4 and the aerosol-forming substrate 10 can be omitted.

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The aerosol forming substrate 10 is located immediately downstream of the barrier 22 applied to the rear face 8 of the blind combustible heat source 4. The aerosol forming substrate 10 comprises a cylindrical plug of homogenized tobacco-based material 24 which includes an aerosol former such as, for example, glycerin, wrapped in a wrapper of the cap 26.

The transfer element 12 is located immediately downstream of the aerosol forming substrate 10 and comprises a hollow tube of open end cylindrical cellulose acetate 28.

The aerosol cooling element 14 is located immediately downstream of the transfer element 12 and comprises a gathered sheet of biodegradable polymeric material such as, for example, polylactic acid.

The separator element 16 is located immediately downstream of the aerosol cooling element 14 and comprises a hollow paper tube or open end cylindrical cardboard 30.

The nozzle 18 is located immediately downstream of the separator element 16. As shown in Figure 1, the nozzle 18 is located at the proximal end of the smoking article 2 and comprises a cylindrical plug of a suitable filtration material 32 such as, for example, cellulose acetate tow of very low filtration efficiency, wrapped in a wrapper of the filter plug 34.

The smoking article may further comprise a nozzle paper strip (not shown) which circumscribes an end portion downstream of the outer wrap 20.

As shown in Figure 1, the smoking article 2 further comprises a single heat conducting element 36 of suitable material such as, for example, aluminum foil, which covers a rear portion of the blind fuel heat source 4, all the length of the aerosol forming substrate 10 and the entire length of the transfer element 12.

In other embodiments of the invention (not shown), the transfer element 12 may extend beyond the single heat conducting element 36 in the downstream direction. That is, the only heat conducting element 36 may only cover a front portion of the transfer element 12. In other embodiments of the invention (not shown), the only heat conducting element 36 may not cover any of the transfer elements. 12.

In the additional embodiments of the invention (not shown), the aerosol-forming substrate 10 may extend beyond the single heat conducting element 36 in the downstream direction. That is, the only heat conducting element 36 could only cover a front portion of the aerosol forming substrate 10.

The only heat conducting element 36 is radially separated from the blind combustible heat source 4 and the aerosol forming substrate 10 by a wrapper 38 of thermal insulation sheet material such as, for example, cigarette paper, of low permeability to air, which is wrapped around the aerosol-forming substrate 10, of the transfer element 12 and a rear portion of the blind fuel heat source 4.

In the smoking article 2 in accordance with the first embodiment of the invention shown in Figure 1, the only heat conducting element 36 and the envelope 38 radially separating the only heat conducting element 36 from the blind combustible heat source 4 and the aerosol-forming substrate 10 extends to approximately the same position in the blind combustible heat source 4 in the upstream direction, such that the upstream ends of the single heat conducting element 36 and the envelope 38 essentially align over the blind fuel heat source 4.

However, it will be appreciated that in other embodiments of the invention (not shown), the envelope 38 that radially separates the single heat conducting element 36 from the blind combustible heat source 4 and the aerosol forming substrate 10 may extend beyond of the only heat conducting element 36 in the upstream direction.

The smoking article 2 in accordance with the first embodiment of the invention comprises one or more first air inlets 40 around the periphery of the aerosol forming substrate 10.

As shown in Figure 1, a circumferential arrangement of the first air inlets 40 is provided in the envelope of the cap 26 of the aerosol-forming substrate 10, the envelope 38 radially separating the only heat conducting element 36 from the source of blind combustible heat 4 and the aerosol forming substrate 10 and the only heat conducting element 36 to admit the cold air (shown by the dotted arrows in Figure 1) in the aerosol forming substrate 10.

During use, a user turns on the blind fuel heat source 4 of the smoking article 2 in accordance with the first embodiment of the invention and then sucks in the mouthpiece 18. When a user sucks in the mouthpiece 18, the cold air (shown by the dotted arrows in Figure 1) it is dragged towards the aerosol-forming substrate 10 of the smoking article 2 through the first air inlets 40.

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The front portion of the aerosol forming substrate 10 is heated by conduction through the rear face 8 of the blind combustible heat source 4 and the barrier 22.

Heating of the conductive aerosol-forming substrate 10 releases glycerin and other volatile and semi-volatile compounds from the plug of homogenized tobacco-based material 24. The compounds released from the aerosol-forming substrate 10 form an aerosol that drags into the aspirated air towards the aerosol forming substrate 10 of the smoking article 2 through the first air inlets 40 when it flows through the aerosol forming substrate 10. The aspirated air and the entrained aerosol (shown by dotted arrows in Figures 1 and 2) they pass downstream through the transfer element 12, the aerosol cooling element 14 and the separator element 16, where they are cooled and condensed. The cold sucked air and entrained spray pass downstream through the nozzle 18 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 essentially non-combustible air-impermeable barrier 22 on the rear face 8 of the blind fuel heat source 4 isolates the blind fuel heat source 4 from the air sucked through the smoking article 2 so that, during use, the air sucked through the smoking article 2 does not come into direct contact with the blind fuel heat source 4.

During use, the only heat conducting element 36 retains heat within the smoking article 2 to help maintain the temperature of the aerosol forming substrate 10 and thus facilitate continuous and improved aerosol supply. In addition, the only heat conducting element 36 transfers the heat along the aerosol forming substrate 10, so that heat is dispersed through a larger volume of the aerosol forming substrate 10. This helps provide a more consistent supply Spray puffed by puff.

A smoking article in accordance with a second embodiment of the invention (not shown) is of a construction broadly identical to the smoking article in accordance with the first embodiment of the invention shown in Figure 1. However, in the smoking article in accordance with the second embodiment of the invention, the envelope 38 radially separating the only heat conducting element 36 from the blind combustible heat source 4 and the aerosol forming substrate 10 is omitted and the only heat conducting element 36 is formed of a laminated material comprising an outer layer of heat conducting material and an inner layer of heat insulating material. In the smoking article in accordance with the second embodiment of the invention, the outer layer of heat conducting material of the single heat conducting element 36 is radially separated from the blind combustible heat source 4 and the aerosol forming substrate 10 by the inner layer of heat-insulating material of the only heat conducting element 36.

The smoking article 42 in accordance with the third embodiment of the invention shown in Figure 2 is of construction widely identical to the smoking article in accordance with the first embodiment of the invention shown in Figure 1. However, in the article for smoking 42 in accordance with the second embodiment of the invention, the first air inlets 40 around the periphery of the aerosol forming substrate 10 are omitted and the fuel heat source 4 is a non-blind carbonaceous fuel heat source comprising a single central air flow channel 44 extending from the front face 6 to the rear face 8 of the non-blind combustible heat source 4.

As shown in Figure 2, an essentially non-combustible air-impermeable barrier 46 is provided between the combustible heat source 4 and the central air flow channel 44. The barrier 46 comprises an essentially non-combustible air-impermeable barrier coating. provided over the entire internal surface of the single central air flow channel 44.

During use, a user turns on the non-blind combustible heat source 4 of the smoking article 42 in accordance with the third embodiment of the invention and then sucks in the nozzle 18. When a user sucks in the nozzle 18, cold air ( shown by the dotted arrows in Figures 2) it is dragged towards the aerosol-forming substrate 10 of the smoking article 2 through the central air flow channel 44. The essentially non-combustible air-impermeable barrier 22 on the rear face 8 of the non-blind combustible heat source 4 and the essentially non-combustible air-impermeable barrier 46 on the inner surface of the single central air flow channel 44 isolates the non-blind combustible heat source 4 from the air sucked through the smoking article 42 so that, during use, the air drawn through the smoking article 42 does not come into direct contact with the non-blind combustible heat source 4.

In other embodiments of the invention (not shown), the essentially non-combustible air-impermeable barrier 22 between the rear face 8 of the non-blind combustible heat source 4 and the aerosol-forming substrate 10 can be omitted.

A smoking article in accordance with a fourth embodiment of the invention (not shown) is of a construction broadly identical to the smoking article in accordance with the third embodiment of the invention shown in Figures 2. However, in the smoking article in accordance with the fourth embodiment of the invention, the envelope 38 radially separating the only heat conducting element 36 from the blind combustible heat source 4 and the aerosol forming substrate 10 is omitted and the only heat conducting element 36 is formed of a laminated material comprising an outer layer of heat conducting material and an inner layer of heat insulating material. At

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smoking article in accordance with the fourth embodiment of the invention, the outer layer of heat conducting material of the single heat conducting element 36 is radially separated from the non-blind combustible heat source 4 and the aerosol forming substrate 10 by the layer internal heat-insulating material of the only heat conducting element 36.

Example A

An article for smoking in accordance with the invention is assembled which is of a construction broadly identical to the article for smoking in accordance with the second embodiment of the invention described above. The smoking article comprises a single heat conducting element formed of a laminated material comprising an outer layer of aluminum and an inner layer of paper. The smoking article does not comprise an outer envelope, so that the outer aluminum layer of the single heat conducting element is visible on the outside of the smoking articles. Instead of a circumferential arrangement of the first air inlets around the periphery of the aerosol forming substrate, the smoking article comprises a circumferential arrangement of the third air inlets around the periphery of the transfer element.

In the smoking article according to the invention, the outer aluminum layer of the single heat conducting element is radially separated from the blind combustible heat source and the aerosol forming substrate by the inner paper layer of the single heat conducting element .

Comparative Example B

For comparison purposes, a smoking article is assembled not in accordance with the invention. The smoking article not in accordance with the invention comprises a single heat conducting element formed of a laminated material comprising an inner layer of aluminum and an outer layer of paper. Otherwise, the smoking article not in accordance with the invention is of identical construction to the smoking article in accordance with the invention of Example A.

In the smoking article not in accordance with the invention, the inner aluminum layer of the single heat conducting element is in direct contact with the blind combustible heat source and the aerosol forming substrate.

The temperature of the rear portion of the blind combustible heat sources of the smoking article in accordance with the invention of Example A and the smoking article not in accordance with the invention of Comparative Example B during combustion of the combustible heat source are they measure in the smoking articles by using a thermocouple attached to the surface of the smoking articles in a position 1 mm upstream of the aerosol generating substrates thereof. The results are shown in Figure 3a.

The temperature of the back portion of the aerosol forming substrates of the smoking article in accordance with the invention of Example A and the smoking article not in accordance with the invention of Comparative Example B during combustion of the combustible heat source are measured in smoking articles by using a thermocouple attached to the surface of the smoking articles in a position 6 mm downstream of the combustible heat source thereof. The results are shown in Figure 3b.

To measure the temperatures of the back portion of non-blind combustible heat sources and aerosol-forming substrates, smoking articles are ignited by the use of a conventional yellow flame lighter and are smoked under a Health Canada smoking regime of more than 12 puffs with a puff volume of 55 ml, a puff duration of 2 seconds and a puff interval of 30 seconds through the use of a smoking machine. The smoking conditions and the specifications of the smoking machine are set out in ISO 3308 (ISO 3308: 2000). The atmosphere for conditioning and testing is established in ISO 3402.

As shown in Figures 3a and 3b, the temperature of the rear portion of the blind fuel heat source and the aerosol forming substrate of the smoking article not in accordance with the invention of Comparative Example B is reduced compared to the article for smoking in accordance with the invention, particularly during subsequent puffs. This results in that the total dry particulate matter (DTPM) supply of the smoking article not in accordance with the invention of Comparative Example B (10.3 mg) is less than the total dry particulate matter (DTPM) supply of the smoking article of in accordance with the invention of Example A (17.4 mg).

The specific embodiments described above are intended to illustrate the invention. However, other modalities can be manufactured without departing from the 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)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 1. An article for smoking (2, 42) comprising: a source of combustible heat (4) having opposite front and rear faces (6, 8); an aerosol forming substrate (10) downstream of the rear face (8) of the combustible heat source (4); and a single heat conducting element (36) covering a rear portion of the combustible heat source (4) and at least a front portion of the aerosol forming substrate (10), wherein the only heat conducting element (36) it comprises one or more layers of heat conducting material and the one or more layers of heat conducting material are radially separated from the combustible heat source (4) and the aerosol forming substrate (10), wherein the fuel heat source (4) is either a blind fuel heat source or the fuel heat source is a non-blind fuel heat source and the smoking article (42) further comprises a non-combustible barrier essentially impermeable to air (46) between the non-blind combustible heat source and one or more air flow channels (44) extending from the front face (6) to the rear face (8) of the non-blind combustible heat source, and wherein the only heat conducting element comprises an outer layer of heat conducting material that is visible on the outside of the smoking article (2, 42). 2. A smoking article according to claim 1 wherein the one or more layers of heat conducting material are radially separated from the source of combustible heat and the aerosol forming substrate by one or more layers of heat insulating material (38) . 3. A smoking article according to claim 1 or 2 wherein the one or more layers of heat conducting material are radially separated from the source of combustible heat and the aerosol forming substrate by at least 50 microns. 4. A smoking article according to any preceding claim, wherein the only heat conducting element is formed by a laminated material comprising one or more layers of a heat conducting material and one or more layers of heat insulating material. 5. A smoking article according to claim 4 wherein the one or more layers of heat conducting material are radially separated from the source of combustible heat and the aerosol forming substrate by at least one of the one or more layers of heat insulating material. 6. A smoking article according to any preceding claim, wherein the one or more layers of the heat conducting material comprises a heat reflecting material. 7. A smoking article according to claim 6, wherein the heat reflecting material reflects more than 50% of the incident radiation. 8. A smoking article according to any preceding claim, wherein the only heat conducting element covers the entire length of the aerosol forming substrate. 9. A smoking article according to claim 8, wherein the only heat conducting element extends downstream beyond the aerosol forming substrate. 10. A smoking article according to any preceding claim further comprising a non-combustible barrier essentially impermeable to air (22) between the rear face (8) of the combustible heat source (4) and the aerosol forming substrate (10 ). 11. A smoking article (2) according to any preceding claim further comprising one or more first air inlets (40) around the periphery of the aerosol forming substrate (10). 12. A smoking article according to any preceding claim wherein the aerosol forming substrate adjoins the rear face of the combustible heat source. 13. A smoking article according to any of claims 1 to 12 wherein the aerosol-forming substrate is separated from the rear face of the combustible heat source. 14. A smoking article according to claim 13, further comprising one or more second air inlets between the rear face of the combustible heat source and the aerosol forming substrate. 15. A smoking article according to any preceding claim further comprising one or more aerosol modifying agents downstream of the aerosol forming substrate. 4 6 -26 36 ■ 30 3. 4 image 1 32 Figure 1 4 6 44 10 26 42 28 \ I 38 14 36 36 30 3. 4 image2 32 Figure 2 Temperature / ° C Temperature / ° C image3 Time / seconds Figure 3a image4 Figure 3b