RU2671756C2 - Smoking article with single radially separated heat conducting element - Google Patents

Abstract

FIELD: smoking accessories.SUBSTANCE: invention relates to a smoking article. Smoking article comprises a combustible heat source having opposed front and rear faces; aerosol-forming substrate located downstream of the rear surface of the combustible heat source; and a single heat conducting element lying over a rear portion of the combustible heat source and at least a front portion of the aerosol-forming substrate, wherein the single thermal conductive element comprises one or more layers of a heat conductive material, wherein one or more layers of the heat conductive material are radially separated from the combustible heat source and the aerosol-forming substrate, combustible heat source is a blind combustible heat source or a combustible heat source is a non-blind combustible heat source, and the smoking article further comprises a non-combustible, substantially airtight barrier between the non-blind combustible heat source and one or more airflow channels extending from the front surface to the rear surface of the non-blind combustible heat source, and wherein the single heat conducting element comprises an outer layer of the heat conducting material, visible on the outside of the smoking article.EFFECT: improved quality of smoking and improved management 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 smoking.15 cl, 3 dwg

Description

The present invention relates to a smoking article containing a combustible heat source having opposite front and rear surfaces, an aerosol forming substrate located downstream of the rear surface of the combustible heat source, and a single heat-conducting element lying on top of the back of the combustible heat source and at least at least the front of the aerosol forming substrate.

In the technical field to which the invention relates, a number of smoking articles are known in which tobacco is heated rather than burned. Such “heated” smoking articles are intended to reduce the content of known harmful smoke constituents that result from combustion and pyrolytic degradation of tobacco in conventional cigarettes. In a heated smoking article of one known type, aerosol is formed as a result of heat transfer from a combustible heat source to an aerosol forming substrate. The aerosol forming substrate may be located inside, around, or downstream of the combustible heat source. During smoking, volatile compounds are released from the aerosol forming substrate as a result of heat transfer from a combustible heat source and are drawn into the air stream drawn through the smoking article. When the released compounds are cooled, they condense to form an aerosol inhaled by the user. Typically, air is drawn into such known heated smoking articles through one or more channels for air flow provided through a combustible heat source, and heat transfer from the combustible heat source to the aerosol forming substrate occurs by forced convection and heat conduction.

For example, WO-A2-2009 / 022232 discloses a smoking article containing a combustible heat source, an aerosol forming substrate located downstream of the combustible heat source, and a heat conducting element surrounding and in direct contact with the rear portion of the combustible heat source and the adjacent front of the aerosol forming substrate.

A heat-conducting element in a smoking article according to WO-A2-2009 / 022232 conducts heat generated by the combustion of a combustible heat source into an aerosol forming substrate through heat conduction. In smoking articles in which tobacco is heated rather than burned, the temperature obtained in the substrate forming the aerosol significantly affects the ability of aerosol formation perceived by the sensory organs. It is generally desirable to maintain the temperature of the aerosol forming substrate within a certain range in order to optimize the delivery of the aerosol to the user. In some cases, heat loss due to radiation from the outer surface of the heat-conducting element surrounding and in direct contact with the combustible heat source and the aerosol forming substrate can cause the temperature of the combustible heat source and the aerosol forming substrate to fall outside the desired range, most affecting the performance of the smoking article. If the temperature of the substrate forming the aerosol drops too low, for example, this can adversely affect the consistency and amount of aerosol delivered to the user.

EP-A1-2 550 879 discloses a smoking article comprising a multilayer tubular member 9 including at least one metal layer and one paper layer, a carbon heat source 4 located at an end portion of the tubular member 9 so that at least partially in direct close contact with the inner surface of the tubular element 9 and the source 8, releasing a smoking flavor, located in the tubular element 9 so as to abut the carbon source 4 chniku heat, and a holder 14 that holds carbon heat source 4 is in direct contact with said end portion and crimping the carbon heat source 4 to said end portion.

In the embodiment of FIG. 1, the non-combustible wrapper material 9 is formed by attaching a three-layer composite sheet 16 to the outer side of the two-layer composite sheet 15. A portion of the three-layer composite sheet 16 protruding from the two-layer composite sheet 15 forms a holder 14. As shown in FIG. 2, a two-layer composite sheet 15 contains an inner aluminum layer 17 and an outer paper layer 18 and a three-layer composite sheet 16 contains an inner paper layer 18, a central aluminum layer 17 and an outer paper layer 18. The outermost layer of the non-combustible wrapper 9 is an aluminum layer 17 of a two-layer composite sheet 15 and the outermost layer of the non-combustible wrapper 9 is the outer paper layer 18 of the three-layer composite sheet 16.

Some heated smoking articles provide forced convective heat transfer from a combustible heat source to an aerosol forming substrate, in addition to heat transfer by heat conduction via a heat conducting element. For example, in some known heated smoking articles, one or more channels for air flow are provided for passing along a combustible heat source in order to provide for forced convective heating of the aerosol forming substrate. In such smoking articles, the aerosol forming substrate is heated by a combination of heating by heat conduction and forced convective heating.

For example, WO-A2-2009 / 022232 discloses the provision of at least one longitudinal channel for the flow of air passing through a combustible heat source in order to provide for an adjustable amount of forced convective heating of the aerosol forming substrate.

In known heated smoking articles in which heat transfer from a combustible heat source to an aerosol forming substrate occurs mainly by forced convection, forced convective heat transfer and therefore the temperature in the aerosol forming substrate can vary significantly depending on the nature of the implementation puffs by the user. As a result, the composition and, therefore, the organoleptic properties of the main aerosol jet formed by such heated smoking articles, can unfavorably be highly sensitive to the puff mode by the user.

In particular, in known heated smoking articles containing one or more channels for air flow located along a combustible heat source, direct contact between air drawn through one or more channels for air flow and a combustible heat source during a puff performed by a user, leads to increased combustion of a combustible heat source. Therefore, intensive puff modes can lead to a sufficiently high forced convective heat transfer to cause temperature peaks of the substrate forming the aerosol, adversely leading to pyrolysis and potentially even localized burning of the substrate forming the aerosol. As used herein, the term “peak” is used to describe a short-term increase in the temperature of an aerosol forming substrate. As a result, the levels of undesired by-products of pyrolysis and combustion in the main aerosol stream generated by these known heated smoking articles can also unfavorably vary significantly depending on the particular puff mode adopted by the user.

Other heated smoking articles do not provide channels for the flow of air passing through a combustible heat source. In such heated smoking articles, heating of the aerosol forming substrate is achieved primarily due to heat transfer by heat conduction by means of a heat conducting element. In heated smoking articles, where the aerosol forming substrate is heated primarily due to heat transfer by heat conduction, the temperature of the aerosol forming substrate may become more sensitive to changes in temperature of the heat conducting element. This means that any cooling of a heat-conducting element surrounding and in direct contact with a combustible heat source and an aerosol generating substrate caused by the loss of heat due to radiation in such heated smoking articles can have a greater effect on aerosol formation than in heated smoking articles, where The aerosol forming substrate is also heated by forced convective heat transfer.

It would be desirable to provide a heated smoking article containing a combustible heat source having opposite front and rear surfaces and an aerosol forming substrate located downstream of the rear surface of the combustible heat source, which provides improved smoking quality. In particular, it would be desirable to provide a heated smoking article having improved control of the heating of the aerosol forming substrate in order to help maintain the temperature of the aerosol forming substrate within the desired temperature range during smoking.

According to the invention, a smoking article is provided comprising: a combustible heat source having opposite front and rear surfaces, an aerosol forming substrate located downstream of the rear surface of the combustible heat source; and a single heat-conducting element lying on top of the rear of the combustible heat source and at least the front of the aerosol forming substrate. A single heat-conducting element contains one or more layers of heat-conducting material, and one or more layers of heat-conducting material are radially separated from the combustible heat source and the aerosol forming substrate. The combustible heat source is a continuous combustible heat source or the combustible heat source is a discontinuous combustible heat source, and the smoking article further comprises a non-combustible substantially airtight partition between the discontinuous combustible heat source and one or more air flow channels extending from the front surface to the rear surfaces of a non-continuous combustible heat source. A single heat-conducting element contains an outer layer of heat-conducting material visible on the outside of the smoking article.

As used herein, the terms “far”, “upstream” and “front”, and “near”, “downstream”, and “rear” are used to describe the relative positions of the components or parts of the components of the smoking article relative to the direction in which the user is drawn in by the smoking article when using it. The smoking articles of the present invention comprise a proximal end through which, when used, the aerosol exits the smoking article for delivery to the user. The proximal end of the smoking article may also be referred to as the mouth end. In use, the user drags on the proximal end of the smoking article to inhale the aerosol created by the smoking article.

A combustible heat source is located at or near the far end of the smoking article. The end brought to the mouth is downstream than the far end. The proximal end may also be referred to as the downstream end of the smoking article, and the distal end may also be referred to as the upstream end of the smoking article. Components or parts of components of smoking articles according to the present invention can be described as being upstream or downstream relative to each other, based on their relative positions between the proximal end and the distal end of the smoking article.

The front surface of the combustible heat source is located at the upstream end of the combustible heat source. The upstream end of the combustible heat source is the end of the combustible heat source farthest from the proximal end of the smoking article. The rear surface of the combustible heat source is located at the downstream end of the combustible heat source. The downstream end of the combustible heat source is the end of the combustible heat source closest to the proximal end of the smoking article.

As used herein, the term “length” is used to describe the maximum size in the longitudinal direction of a smoking article. In other words, the maximum size 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 having the ability to release volatile compounds upon heating, which can form an aerosol. Aerosols obtained from aerosol forming substrates of smoking articles according to the present invention may be visible or invisible and may contain vapors (for example, fine particles of substances in a gaseous state, which are usually liquid or solid at room temperature), as well as gases and liquid droplets of condensed vapor.

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

As used herein, the term “radial” is used to describe a 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 mean contact between two components without any intermediate material, so that the surfaces of the components are in contact with each other.

The aerosol forming substrate may be in the form of a rod or segment containing material capable of releasing volatile compounds upon heating, which can form an aerosol surrounded by a wrapper. If the substrate forming the aerosol is in the form of such a rod or segment, the entire rod or segment, including the wrapper, is considered the substrate forming the aerosol.

In such embodiments, one or more layers of the heat-conducting material of a single heat-conducting element is radially separated from the wrapper of the aerosol forming substrate.

Smoking articles according to the invention comprise a single heat-conducting element located on top of the rear of the combustible heat source and at least the front of the aerosol forming substrate. A single heat-conducting element contains one or more layers of heat-conducting material, and one or more layers of heat-conducting material are radially separated from the combustible heat source and the aerosol forming substrate.

Smoking articles according to the invention do not contain any additional heat-conducting elements located under a single heat-conducting element or on top of it. In particular, the smoking articles according to the invention do not contain any heat-conducting elements surrounding and in direct contact with one or both of the combustible heat source and the aerosol forming substrate.

Smoking articles according to the invention may comprise a continuous combustible heat source or a non-continuous combustible heat source.

As used herein, the term “solid” is used to describe a combustible heat source, in which there are no air flow channels extending from the front surface to the rear surface of the combustible heat source.

In use, air drawn in through smoking articles according to the present invention containing a continuous combustible heat source for inhalation by a user does not pass through any air flow paths along a continuous combustible heat source. In smoking articles according to the present invention containing a continuous combustible heat source, the heating of the aerosol forming substrate is mainly due to thermal conductivity, and the heating of the aerosol forming substrate due to forced convection is minimized or reduced.

As used herein, the term “air flow passage” is used to describe a channel extending along the length of a combustible heat source through which air can be drawn in downstream for inhalation by a user.

As used herein, the term “non-continuous” is used to describe a combustible heat source, with one or more channels for air flow from the front surface to the rear surface of the combustible heat source.

In use, air drawn in through smoking articles according to the invention, containing a non-continuous combustible heat source, for inhalation by a user, passes through one or more air flow channels along a non-continuous combustible heat source. In smoking articles according to the present invention containing a discontinuous combustible heat source, heating of the aerosol forming substrate occurs due to heat conduction and forced convection.

Smoking articles according to the invention containing a non-continuous combustible heat source further comprise a non-combustible, substantially airtight partition between the non-continuous combustible heat source and one or more air flow passages extending from the front surface to the rear surface of the non-continuous combustible heat source.

As used herein, the term “non-combustible” is used to describe a partition that is substantially non-combustible at temperatures reached by a non-continuous combustible heat source during combustion and ignition.

In the event that the smoking articles according to the invention contain a continuous combustible heat source, the absence of any air flow channels passing through the continuous combustible heat source advantageously substantially prevents or slows down the activation of combustion of the continuous combustible heat source during a puff performed by the user.

Similarly, if the smoking articles according to the invention contain a non-continuous combustible heat source, the inclusion of a non-combustible, substantially airtight partition between the non-continuous combustible heat source and one or more air flow channels extending from the front surface to the rear surface of the non-continuous combustible heat source, advantageously essentially prevents or slows down the activation of combustion of a non-continuous combustible heat source during tightening performed by user.

Preventing or slowing down the activation of combustion of a combustible heat source during a puff performed by a user advantageously substantially prevents or reduces the likelihood of temperature peaks of the aerosol forming substrate of smoking articles according to the invention during a puff performed by a user.

By preventing or slowing down the activation of combustion of a combustible heat source and thus preventing or slowing down an excessive increase in temperature in the aerosol forming substrate, burning or pyrolysis of the aerosol forming substrate of smoking articles according to the invention can be prevented under intensive puff conditions. In addition, the influence of the user puff mode on the composition of the main spray aerosol of smoking articles according to the present invention can be advantageously minimized or reduced.

A single heat-conducting element lies on top of the rear of the combustible heat source and at least the front of the aerosol forming substrate.

One or more layers of the heat-conducting material of a single heat-conducting element is radially separated from a combustible heat source and from an aerosol forming substrate. This limits heat transfer by heat conduction from a combustible heat source to a single heat-conducting element and heat transfer by heat conductivity from a single heat-conducting element to an aerosol forming substrate. When used, this advantageously helps to maintain the temperature obtained in the aerosol forming substrate of the smoking articles of the invention below the temperature at which combustion or pyrolysis of the aerosol forming substrate can occur.

Preferably, heat transfer through heat conduction from a combustible heat source to a single heat-conducting element is substantially reduced. This leads to the fact that the single heat-conducting element of smoking articles according to the invention maintains a lower temperature than the heat-conducting element of known heated smoking articles, in which the heat-conducting element surrounds and is in direct contact with the rear part of the combustible heat source and at least the front part of the substrate, aerosol forming.

In heated smoking articles in which a heat-conducting element surrounds and is in direct contact with the back of the combustible heat source and at least the front of the substrate forming the aerosol, heat leakage caused by heat transfer by heat conduction by the heat-conducting element significantly reduces the temperature of the back of the fuel source heat. This may shorten the burning time of a combustible heat source and may result in unacceptable aerosol delivery.

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

A single heat-conducting element advantageously reduces heat loss from a combustible heat source. The temperature of one or more layers of the heat-conducting material of a single heat-conducting element increases when a smoking article smokes, as heat is generated by a combustible heat source. An increased temperature value of one or more layers of the heat-conducting material of a single heat-conducting element reduces the temperature difference between the combustible heat source and the components of the smoking article lying on top of it so that it is possible to reduce heat loss from the combustible heat source.

By reducing heat loss from a combustible heat source, a single heat-conducting element advantageously contributes to maintaining the temperature of the aerosol forming substrate within the desired temperature range. This improves aerosol formation from the aerosol forming substrate.

One or more layers of heat-conducting material of a single heat-conducting element conduct heat along the smoking article. This improves heat transfer efficiency by conducting heat from a combustible heat source to an aerosol forming substrate, and therefore, heating the aerosol forming substrate. Improving heat transfer through heat conduction achieved by incorporating a single heat-conducting element is particularly useful for smoking articles according to the invention containing a continuous combustible heat source in which there is substantially no forced convective heat transfer.

Radial separation between one or more layers of the heat-conducting material of a single heat-conducting element and a combustible heat source and an aerosol forming substrate is preferably achieved by including one or more intermediate layers of material between one or more layers of a heat-conducting material of a single heat-conducting element and a combustible heat source and a substrate forming spray can. One or more intermediate layers of material can be provided over the entire area on which a single heat-conducting element lies on top of a combustible heat source and an aerosol forming substrate. Alternatively, one or more intermediate layers of material may be provided only on part or parts of this area. In some embodiments, one or more intermediate layers of material may extend beyond one or more layers of heat-conducting material of a single heat-conducting element in an upstream and / or downstream direction.

Preferably, one or more layers of heat-conducting material of a single heat-conducting element is radially separated from a combustible heat source and from an aerosol forming substrate by one or more layers of heat-insulating material. Suitable thermal insulation materials include, but are not limited to, paper, ceramics, and metal oxides.

For example, in certain preferred embodiments of the invention, the back of the combustible heat source and at least the front of the aerosol forming substrate, on top of which lies a single heat-conducting element, are coated with a paper wrapper surrounding the smoking article along at least part of its length. In such embodiments, the paper wrapper separates the single heat-conducting element in a radial direction from the combustible heat source and the aerosol forming substrate, so that there is no direct contact between the single heat-conducting element and the combustible heat source and / or the aerosol forming substrate.

The single heat-conducting element contains an outer layer of heat-conducting material provided on the outside of the smoking article so that the outer layer of the heat-conducting material of the single heat-conducting element is visible from the outside of the smoking article.

In certain embodiments, one or more layers of a heat-conducting material of a single heat-conducting element is radially separated from a combustible heat source and from an aerosol forming substrate by means of a wrapper extending along the entire smoking article or along part thereof. In such embodiments, a wrapper is wrapped around a smoking article over a combustible heat source and an aerosol forming substrate, and a single heat-conducting element is then provided over at least a portion of the wrapper.

The location of a single heat-conducting element on top of the wrapper of the smoking article may provide advantages relative to the appearance of the smoking articles according to the present invention, in particular during and after smoking. In certain cases, it is possible to observe some discoloration of the wrapper in the region of the combustible heat source when the wrapper is exposed to heat from the combustible heat source. The wrapper may further discolor as a result of the migration of volatile compounds from the aerosol forming substrate to a wrapper located around the aerosol forming substrate and downstream of it. In certain embodiments, a single heat-conducting element of smoking articles according to the present invention may be provided over the wrapper around at least the back of the combustible heat source and at least the front of the aerosol forming substrate so that the discoloration of the wrapper is closed and is no longer visible or less visible. In certain embodiments, a single heat-conducting element may extend around the entire length of the aerosol forming substrate. In certain preferred embodiments, a single heat-conducting element may extend downstream of the aerosol forming substrate. Therefore, during smoking, the initial appearance of the smoking article may be maintained.

Alternatively, or in addition to one or more layers of heat-insulating material, located between one or more layers of heat-conducting material of a single heat-conducting element and a combustible heat source and an aerosol forming substrate, at least a portion of the single heat-conducting element can be radially separated from the fuel a heat source and an aerosol forming substrate by an air gap. An air gap may be provided by including one or more separating elements between one or more layers of the heat-conducting material of the single heat-conducting element and the combustible heat source and the aerosol forming substrate to maintain the desired separation between the single heat-conducting element and the combustible heat source and the aerosol forming substrate. One or more separating elements may be, for example, one or more strips of paper wrapped in a radial direction around a combustible heat source and an aerosol forming substrate.

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

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

One or more layers of the heat-conducting material of a single heat-conducting element may comprise any suitable heat-conducting material or a combination of materials with suitable heat-conducting.

Preferably, one or more layers of heat-conducting material of a single heat-conducting element comprise heat-conducting materials having a bulk thermal conductivity of about 10 watts per meter Kelvin (W / (m⋅K)) to about 500 watts per meter Kelvin (W / (m ⋅K)), more preferably from about 15 watts per meter-Kelvin (W / (m⋅K)) to about 400 watts per meter-Kelvin (W / (m⋅K)), at 23 ° C and relative humidity 50% as measured using the modified non-stationary method oskogo source (MTPS). Suitable thermally conductive materials include, but are not limited to, metal foil wrappers, such as, for example, aluminum foil wrappers, steel wrappers, iron foil wrappers, and copper foil wrappers; and metal alloy foil wrappers.

In certain preferred embodiments, a single heat-conducting element comprises one or more layers of aluminum.

Preferably, one or more layers of heat-conducting material of a single heat-conducting element comprise a heat-reflecting material, such as aluminum or steel. In such embodiments, when used, a single heat-conducting element advantageously reflects the heat radiated from the combustible heat source and the aerosol forming substrate back to the combustible heat source and the aerosol forming substrate.

As used herein, the term “heat reflective material” refers to a material having a relatively high heat reflectivity and a relatively low heat emissivity so that the material reflects a larger fraction of the incident radiation from its surface than it 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 a single heat-conducting element reduce heat loss from a combustible heat source and an aerosol forming substrate.

The reflectivity of one or more layers of the heat-conducting material of a single heat-conducting element can be improved by providing one or more layers of heat-conducting material of a single heat-conducting element with a shiny inner surface, the inner surface being a surface facing a combustible heat source and an aerosol forming substrate.

A single heat-conducting element can be made in the form of a single layer of heat-conducting material. Alternatively, the single heat-conducting element may be made of a multilayer or layered material containing at least one layer of heat-conducting material in combination with one or more other heat-conducting layers or non-heat-conducting layers. In such embodiments, the implementation of at least one layer of thermally conductive material may contain any of the thermally conductive materials listed above.

In certain preferred embodiments, the implementation of a single heat-conducting element may be made of a layered material containing 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 single heat-conducting element facing the combustible heat source and the aerosol forming substrate may be a layer of heat-insulating material. Thus, the inner layer of the heat-insulating material provides the necessary radial separation between at least one layer of the heat-conducting material of a single heat-conducting element and a combustible heat source and an aerosol forming substrate.

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

In certain preferred embodiments, the implementation of the single heat-conducting element is a layered material containing a single layer of heat-conducting material and one or more layers of heat-insulating material. In certain particularly preferred embodiments, the single heat-conducting element is a laminate comprising a single layer of heat-conducting material and a single layer of heat-insulating material. Preferably, the single heat-conducting element is a layered material comprising a single outer layer of heat-conducting material and a single inner layer of heat-insulating material.

One example of a particularly suitable laminate for forming a single heat-conducting element is a two-layer laminate comprising an outer layer of aluminum and an inner layer of paper.

The use of a single heat-conducting element containing a layered material can be of additional benefit in the manufacture of smoking articles according to the present invention, since at least one heat-insulating layer may provide additional strength and rigidity. This makes it easier to process the laminate, with less risk of crushing or tearing of at least one heat-conducting layer, which can be relatively thin and brittle.

Preferably, the thickness of a single heat-conducting element is from about 5 microns to about 100 microns, more preferably from about 5 microns to about 80 microns.

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

In certain embodiments, a single heat-conducting element may comprise an aluminum foil having a thickness of about 20 microns.

In certain preferred embodiments, a single heat-conducting element may comprise a laminate comprising an outer layer of aluminum having a thickness of from about 5 microns to about 6 microns, and an inner layer of paper.

As described above, the first heat-conducting element of smoking articles according to the invention lies on top of the back of the combustible heat source and at least the front of the aerosol forming substrate.

The location and extent of the single heat-conducting element relative to the combustible heat source and the aerosol forming substrate can be controlled in order to control the heating of the aerosol forming substrate during smoking. In particular, the extent of a single heat-conducting element relative to a combustible heat source and an aerosol forming substrate in the upstream and downstream directions can be adjusted in order to adjust the aerosol delivery profile of the smoking article.

A single heat-conducting element may extend around the entire circumference of the smoking article or around a part thereof. Preferably, the single heat-conducting element forms a continuous sleeve surrounding the smoking article along part of its length.

Preferably, the back of the combustible heat source, on top of which lies a single heat-conducting element, has a length of from about 2 mm to about 8 mm, more preferably a length of from about 3 mm to about 5 mm.

Preferably, the front of the combustible heat source, over which the first heat-conducting element does not lie, has a length of from about 4 mm to about 15 mm, more preferably a length of from about 5 mm to about 8 mm.

In certain embodiments, a single heat-conducting element lies over the entire length of the aerosol forming substrate. In such embodiments, the downstream end of the single heat-conducting element may be in line with the downstream end of the aerosol forming substrate. Alternatively, a single heat-conducting element may extend outside the aerosol forming substrate in a downstream direction.

In other embodiments, a single heat-conducting element lies on top of only the front of the aerosol forming substrate. In such embodiments, the aerosol forming substrate extends beyond the single heat conducting element in a downstream direction.

In embodiments in which a single heat-conducting element lies on top of only the front of the aerosol forming substrate, the aerosol-forming substrate can extend at least about 3 mm beyond the single heat-conducting element in the downstream direction. For example, an aerosol forming substrate may extend beyond a single heat conducting element to a distance of from about 3 mm to about 10 mm in a downstream direction. Alternatively, the aerosol forming substrate may extend beyond the single heat conducting element to a distance of less than 3 mm in the downstream direction.

In embodiments in which a single heat-conducting element lies on top of only the front of the aerosol forming substrate, the front of the aerosol forming substrate on top of which is the single heat-conducting element may have a length of from about 1 mm to about 10 mm, for example, the front of the substrate forming an aerosol, on top of which lies a single heat-conducting element, may have a length of from about 2 mm to about 8 mm or a length of from about 2 mm to about 6 mm.

Smoking articles according to the invention may contain a continuous combustible source of heat.

It is known to include additives in combustible heat sources of heated smoking articles to improve the ignition and combustion properties of combustible heat sources. However, the inclusion of ignition and combustion additives can lead to the formation of decomposition products and reactions that can adversely enter the air drawn through such known heated smoking articles during use.

The inclusion of a continuous combustible heat source can advantageously substantially prevent or suppress the ingress of combustion products and decomposition products and other materials generated by ignition and combustion of a continuous combustible heat source into the air drawn through the smoking articles of the present invention when used. This is especially advantageous in situations where a continuous combustible heat source contains one or more additives that contribute to the ignition or combustion of a continuous combustible heat source.

In smoking articles according to the present invention containing a continuous combustible heat source, it is especially important to optimize heat transfer by conducting heat between a combustible heat source and an aerosol forming substrate. It was found that the inclusion of a single heat-conducting element radially separated from a combustible heat source and an aerosol forming substrate exerts a particularly advantageous effect on the smoking quality of smoking articles containing continuous heat sources if the aerosol forming substrate is slightly heated or not heated at all forced convection.

It should be understood that smoking articles according to the present invention may contain continuous combustible heat sources containing one or more closed or blocked passage openings through which air cannot be drawn in by the user for inhalation.

For example, smoking articles according to the present invention may contain continuous combustible heat sources containing one or more closed passage openings extending from the front surface at the upstream end of the continuous combustible heat source only along part of the length of the continuous combustible heat source.

The inclusion of one or more closed passage openings for air leads to an increase in the surface area of a continuous combustible heat source, which is affected by oxygen from the air, and can advantageously contribute to ignition and continuous burning of a continuous combustible heat source.

Alternatively, smoking articles according to the invention may comprise a discontinuous combustible heat source, in which there are one or more channels for air flow extending from the front surface to the rear surface of the discontinuous combustible heat source.

One or more channels for air flow may contain one or more closed channels for air flow.

As used herein, the term “enclosed” is used to describe channels for air flow passing through the interior of a non-continuous combustible heat source and surrounded by a non-continuous combustible heat source.

Alternatively or in addition, one or more channels for air flow may contain one or more open channels for air flow. For example, one or more channels for air flow may contain one or more grooves or other open channels for air flow passing along the outer side of a non-continuous combustible heat source.

One or more channels for air flow may contain one or more closed channels for air flow, or one or more open channels for air flow, or a combination thereof.

In certain embodiments, smoking articles of the present invention comprise one, two, or three airflow passages extending from a front surface to a rear surface of a non-continuous combustible heat source.

In certain preferred embodiments, the smoking articles of the present invention comprise a single air flow passage extending from a front surface to a rear surface of a non-continuous combustible heat source.

In certain particularly preferred embodiments, the smoking articles of the present invention comprise one substantially central or axial channel for air flow extending from the front surface to the rear surface of the non-continuous combustible heat source.

In such embodiments, the diameter of one air flow passage is preferably in the range of about 1.5 mm to about 3 mm.

It should be understood that in addition to one or more channels for the flow of air through which air can be drawn in for inhalation by the user, smoking articles according to the present invention can contain non-continuous combustible heat sources containing one or more closed or blocked passage openings through which air cannot be drawn for inhalation by the user.

For example, smoking articles according to the present invention may comprise non-continuous combustible heat sources containing one or more channels for air flow passing from the front surface to the rear surface of the combustible heat source, and one or more closed passage openings passing from the front surface of the non-continuous combustible heat source only along part of the length of the combustible heat source.

The inclusion of one or more closed passage openings for air leads to an increase in the surface area of a non-continuous combustible heat source, which is affected by oxygen from the air, and can advantageously contribute to ignition and continuous burning of a non-continuous combustible heat source.

Smoking articles according to the invention containing a non-continuous combustible heat source further comprise a non-combustible, substantially airtight partition between the non-continuous combustible heat source and one or more air flow passages extending from the front surface to the rear surface of the non-continuous combustible heat source.

The inclusion of a non-combustible, substantially airtight partition between the non-continuous combustible heat source and one or more air flow channels extending from the front surface to the rear surface of the non-continuous combustible heat source can advantageously substantially prevent or suppress the ingress of such combustion and decomposition products resulting from igniting and burning a non-continuous combustible heat source into air drawn into smoking articles through one or more channels in the air stream as it passes the air drawn through one or more channels for air flow. This is especially advantageous in situations where an incomplete combustible heat source contains one or more additives that contribute to ignition or combustion of an incomplete combustible heat source.

The partition between the non-continuous combustible heat source and one or more channels for air flow can be glued or otherwise attached to the non-continuous combustible heat source.

In certain preferred embodiments, the baffle comprises a non-combustible, substantially airtight barrier coating provided on the inner surface of one or more channels for air flow. In such embodiments, the baffle preferably comprises a barrier coating provided at least substantially on the entire inner surface of one or more channels for air flow. More preferably, the partition comprises a barrier coating provided at least substantially on the entire inner surface of one or more channels for air flow.

As used herein, the term “coating” is used to describe a layer of material covering and adhering to a combustible heat source.

In other embodiments, a barrier coating may be provided by introducing an insert into one or more channels for air flow. For example, in cases where one or more channels for air flow contain one or more closed channels for air flow passing through the inner part of a non-continuous combustible heat source, a non-combustible, essentially airtight hollow tube.

Depending on the required characteristics and quality of the smoking article, the partition may have low thermal conductivity or high thermal conductivity. Preferably, the baffle has a low thermal conductivity.

The thickness of the septum can be adjusted accordingly to ensure a satisfactory quality of smoking. In some embodiments, the baffle may have a thickness in the range of from about 30 microns to about 200 microns. In a preferred embodiment, the baffle has a thickness in the range of about 30 microns to about 100 microns.

The partition may be made of one or more suitable materials, which are essentially thermally stable and non-combustible at temperatures reached by a non-continuous combustible heat source during ignition and combustion. Suitable materials are known in the field to which the invention relates, and include, but are not limited to, for example, clays, metal oxides such as iron oxide, alumina, titanium dioxide, silica, silica / alumina, zirconia and cerium oxide, zeolites , zirconium phosphate and other ceramic materials or combinations thereof.

Preferred materials from which the partition can be made include clay, glass, aluminum, iron oxide, and combinations thereof. If necessary, catalytic ingredients, such as those that promote the oxidation of carbon monoxide to carbon dioxide, may be included in the partition. Suitable catalytic ingredients include, but are not limited to, for example, platinum, palladium, transition metals and their oxides.

If the partition contains a barrier coating provided on the inner surface of one or more channels for air flow, the barrier coating may be applied to the inner surface of one or more channels for air flow in any suitable manner, such as the methods described in US-A-5040551. For example, a solution or suspension of a barrier coating can be applied to the inner surface of one or more channels for air flow by spraying, wetting, or staining. In certain preferred embodiments, the implementation of the barrier coating is applied to the inner surface of one or more channels for air flow using the method described in document WO-A2-2009 / 074870, during extrusion of a combustible heat source.

Smoking articles according to the invention may further comprise a non-combustible, substantially airtight partition between the rear surface of the combustible heat source and the aerosol forming substrate.

If the smoking articles of the invention contain a non-continuous combustible heat source and a non-combustible, substantially airtight partition between the rear surface of the combustible heat source and the aerosol forming substrate, the partition must allow air to enter the smoking article through one or more air flow channels extending from the front surface to the back surface of a non-continuous combustible heat source, for drawing it downstream through the smoking article.

The partition may abut against one or both of the rear surface of the combustible heat source and the aerosol forming substrate. Alternatively, the partition may be located at a distance from one or both of the rear surface of the combustible heat source and the aerosol forming substrate.

The partition may be glued or otherwise attached to one or both of the rear surface of the combustible heat source and the aerosol forming substrate.

In certain preferred embodiments, the baffle comprises a non-combustible, substantially airtight barrier coating provided on the rear surface of the combustible heat source. In such embodiments, the partition preferably comprises a barrier coating provided at least substantially on the entire rear surface of the combustible heat source. More preferably, the partition includes a barrier coating provided on the entire rear surface of the combustible heat source.

The partition may advantageously limit the temperature to which the aerosol forming substrate is exposed during ignition and burning of a combustible heat source, and thus helps to prevent or reduce thermal degradation or burning of the aerosol forming substrate during use of the smoking article. This is especially advantageous in situations where a combustible heat source contains one or more additives that contribute to ignition of a combustible heat source.

To facilitate aerosol formation, aerosol forming substrates of heated smoking articles typically contain polyhydric alcohol, such as glycerin, or other known aerosol forming substances. During storage and smoking, such aerosol forming substances can migrate from aerosol forming substrates of known heated smoking articles into their combustible heat sources. Migration of substances for the formation of aerosol into combustible heat sources of known heated smoking articles can adversely lead to decomposition of substances for the formation of aerosol, in particular when smoking heated smoking articles.

The inclusion of a non-combustible, substantially airtight partition between the rear surface of the combustible heat source and the aerosol forming substrate of smoking articles according to the invention can advantageously substantially prevent or slow down the migration of the components of the aerosol forming substrate to the combustible heat source during storage of the smoking article.

Alternatively or in addition, the inclusion of a non-combustible, substantially airtight partition between the rear surface of the combustible heat source and the aerosol forming substrate of smoking articles according to the invention can advantageously substantially prevent or slow down the migration of the components of the aerosol forming substrate to the combustible heat source when used a smoking article.

The inclusion of a non-combustible, substantially airtight partition between the rear surface of the combustible heat source and the aerosol forming substrate is particularly advantageous if the aerosol forming substrate contains at least one aerosol forming substance.

In such embodiments, incorporating a non-combustible, substantially airtight partition between the rear surface of the combustible heat source and the aerosol forming substrate of smoking articles according to the invention can advantageously prevent or slow down the migration of at least one aerosol forming substance from the aerosol forming substrate to the combustible heat source during storage and use of a smoking article. Thus, the decomposition of at least one aerosol forming substance when using a smoking article can advantageously be substantially prevented or reduced.

Depending on the desired characteristics and qualities of the smoking article, a non-combustible, substantially airtight partition between the rear surface of the combustible heat source and the aerosol forming substrate may have low thermal conductivity or high thermal conductivity. In certain embodiments, the baffle may be made of material having a bulk thermal conductivity in the range of about 0.1 watts per meter-Kelvin (W / (m⋅K)) to about 200 watts per meter-Kelvin (W / (m⋅K) )), at a temperature of 23 ° C and a relative humidity of 50%, as measured using the modified unsteady planar source (MTPS) method.

The thickness of the septum can be adjusted accordingly to ensure a satisfactory quality of smoking. In some embodiments, the baffle may have a thickness in the range of from about 10 microns to about 500 microns.

The partition may be made of one or more suitable materials, which are essentially thermally stable and non-combustible at temperatures reached by a combustible heat source during ignition and combustion. Suitable materials are known in the technical field to which the invention relates, 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 a partition can be formed include clay and glass. More preferred materials from which the partition can be formed include copper, aluminum, stainless steel, alloys, alumina (Al ₂ O ₃ ), resins and mineral adhesives.

In certain preferred embodiments, the baffle comprises a clay coating comprising a 50/50 mixture of bentonite and kaolinite provided on the back surface of a combustible heat source. In other preferred embodiments, the baffle comprises a glass coating, more preferably a sintered glass coating provided on the rear surface of the combustible heat source.

In certain particularly preferred embodiments, the partition includes an aluminum coating provided on the back surface of the combustible heat source.

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

Due to the low penetration of air clays in the embodiments where the baffle contains a clay coating provided on the back surface of the combustible heat source, the thickness of the clay coating is more preferably at least about 50 microns and most preferably from about 50 microns to about 350 micron.

In embodiments in which the baffle is formed of one or more materials more impervious to air, such as aluminum, the baffle may be thinner, and will usually preferably have a thickness of less than about 100 microns and more preferably about 20 microns.

In embodiments where the baffle comprises a glass coating provided on the back surface of the combustible heat source, the thickness of the glass coating is preferably less than about 200 microns.

The thickness of the septum can be measured using a microscope, a scanning electron microscope (SEM), or any other suitable measurement methods known in the field to which the invention relates.

If the partition contains a barrier coating provided on the back surface of the combustible heat source, the barrier coating may be applied so as to cover and adhere to the back surface of the combustible heat source by any suitable methods known in the art, including but not limited to sputtering, vapor deposition, immersion, transfer of material (e.g. brushing or gluing), electrostatic precipitation, or any combination thereof.

For example, a barrier coating can be performed by pre-forming a partition with an approximate size and shape of the rear surface of the combustible heat source and applying it to the rear surface of the combustible heat source to cover at least substantially the entire rear surface of the combustible heat source and adhere to it. Alternatively, the barrier coating may be cut off or subjected to other machining after it has been applied to the rear surface of the combustible heat source. In one preferred embodiment, the aluminum foil is deposited on the back surface of the combustible heat source by gluing or pressing to a combustible heat source and cut or subjected to other machining, so that the aluminum foil covers at least substantially the entire rear surface of the combustible heat source, preferably the entire back surface of a combustible heat source, and sticks to it.

In another preferred embodiment, the barrier coating is made by applying a solution or suspension of one or more suitable coating materials to the back surface of a combustible heat source. For example, a barrier coating may be applied to the back surface of a combustible heat source by immersing the back surface of a combustible heat source in a solution or suspension of one or more suitable coating materials, or by brushing or spraying a solution or suspension, or by electrostatic precipitation of a powder or powder mixture of one or several suitable coating materials on the back surface of a combustible heat source. If the barrier coating is applied to the back surface of the combustible heat source by electrostatically depositing a powder or a powder mixture of one or more suitable coating materials on the back surface of the combustible heat source, the back surface of the combustible heat source is preferably pretreated with liquid glass before electrostatic deposition. Preferably, the barrier coating is applied by spraying.

Barrier coating can be accomplished by applying one solution or suspension of one or more suitable coating materials to the back surface of a combustible heat source. Alternatively, the barrier coating may be accomplished by several applying a solution or suspension of one or more suitable coating materials to the back surface of the combustible heat source. For example, a barrier coating may be performed by one, two, three, four, five, six, seven or eight successive applications of a solution or suspension of one or more suitable coating materials on the back surface of a combustible heat source.

Preferably, the barrier coating is made by one to ten applications of a solution or suspension of one or more suitable coating materials on the back surface of the combustible heat source.

After applying a solution or suspension of one or more coating materials to the back surface of a combustible heat source, it can be dried to form a barrier coating.

If the barrier coating is carried out by several applications of a solution or suspension of one or more suitable coating materials on the back surface of a combustible heat source, it may need to be dried between successive applications of the solution or suspension.

Alternatively or in addition to drying, after applying a solution or suspension of one or more coating materials to the rear surface of the combustible heat source, the coating material on the combustible heat source may be sintered to form a barrier coating. Sintering of the barrier coating is particularly preferred if the barrier coating is a glass or ceramic coating. Preferably, the barrier coating is sintered at a temperature of from about 500 ° C to about 900 ° C, and more preferably at about 700 ° C.

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

As used herein, the term “air inlet” is used to describe a recess, slot, slot, or other opening through which air can be drawn into a smoking article.

If the smoking articles of the present invention contain one or more first air inlets around the periphery of the aerosol forming substrate, in use, cold air is drawn into the aerosol forming substrate of the smoking article through the first air inlets. Air drawn into the aerosol forming substrate through the first air inlets passes downstream through the smoking article from the aerosol forming substrate and exits the smoking article through its proximal end.

During a puff performed by a user, cold air drawn in through one or more of the first air inlets around the periphery of the aerosol forming substrate advantageously reduces the temperature of the aerosol forming substrate. This advantageously substantially prevents or reduces the likelihood of temperature peaks in the aerosol forming substrate during puffing by the user.

As used herein, the term “cold air” is used to describe ambient air not substantially heated by a combustible heat source when the user puffs.

By preventing or reducing the likelihood of temperature peaks in the aerosol forming substrate, incorporating one or more of the first first air inlets around the periphery of the aerosol forming substrate advantageously helps to avoid or reduce the burning or pyrolysis of the aerosol forming substrate under intensive puff conditions. In addition, the inclusion of one or more of the first air inlets around the periphery of the aerosol forming substrate advantageously helps to minimize or reduce the influence of the puff mode by the user on the composition of the mainstream aerosol of the smoking article.

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

In certain embodiments, the aerosol forming substrate may abut against the back surface of a combustible heat source.

As used herein, the term “abut” is used to describe an aerosol forming substrate in direct contact with a rear surface of a combustible heat source or a non-combustible, substantially airtight barrier coating provided on a rear surface of a combustible heat source.

In other embodiments, the aerosol forming substrate may be located at a distance from the rear surface of the combustible heat source. In other words, between the substrate forming the aerosol, and the rear surface of the combustible heat source, there may be a space or gap.

As used herein, the term “located at a distance from” is used to describe an aerosol forming substrate that is not in direct contact with the rear surface of the combustible heat source or a non-combustible, substantially airtight barrier coating provided on the rear surface of the combustible heat source.

Alternatively or in addition to one or more of the first air inlets, in such embodiments, smoking articles according to the invention may comprise one or more second air inlets between the rear surface of the combustible heat source and the aerosol forming substrate. In use, cold air is drawn into the space between the combustible heat source and the aerosol forming substrate through the second air inlets. Air drawn into the space between the combustible heat source and the aerosol forming substrate through the second air inlets passes downstream through the smoking article from the space between the combustible heat source and the aerosol forming substrate and exits the smoking article through its proximal end .

During puffs performed by the user, cold air drawn through one or more second inlets between the rear surface of the combustible heat source and the aerosol forming substrate can advantageously reduce the temperature of the aerosol forming substrate. This can advantageously substantially prevent or reduce the likelihood of peaks in temperature of the aerosol forming substrate during puffing by the user.

Alternatively or in addition to one or more first air inlets or one or more second air inlets, smoking articles according to the invention may include one or more third air inlets located downstream of the aerosol forming substrate.

It should be understood 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 back surface of the combustible heat source and the aerosol forming substrate, or one or more third air inlets located downstream of the substrate forming the aerosol, or a combination thereof.

The number, shape, size and location of the air inlets can be adjusted accordingly to achieve satisfactory smoking characteristics.

Preferably, the combustible heat source is a carbon-containing heat source. As used herein, the term “carbonaceous” is used to describe a combustible heat source containing carbon. Preferably, combustible carbonaceous heat sources for use in smoking articles according to the present invention are characterized by a carbon content of at least about 35 percent, more preferably at least about 40 percent, most preferably at least about 45 percent by dry weight of the combustible heat source.

In some embodiments, the combustible heat sources of the present invention are carbon based combustible heat sources. As used herein, the term “carbon-based heat source” is used to describe a heat source containing primarily carbon.

Combustible carbon-based heat sources for use in smoking articles according to the present invention are characterized by a carbon content of at least about 50 percent. For example, combustible carbon-based heat sources for use in smoking articles according to the present invention may have a carbon content of at least about 60 percent, or at least about 70 percent, or at least about 80 percent by dry weight of the combustible heat source based carbon.

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

If necessary, one or more binders can 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 celluloses and cellulose derivatives (e.g. methyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose and hydroxypropyl methyl cellulose), flour, starches, sugars, vegetable oils and combinations thereof.

In one preferred embodiment, the combustible heat source is made from a mixture of coal powder, modified cellulose, flour and sugar.

Instead or in addition to one or more binders, combustible heat sources for use in smoking articles according to the present invention may contain one or more additives to improve the properties of the combustible heat source. Suitable additives include, but are not limited to, additives to improve the solidification of the combustible heat source (e.g., sintering additives), additives to improve the ignition of the combustible heat source (e.g., oxidizing agents such as perchlorates, chlorates, nitrates, peroxides, permanganates, zirconium, and combinations thereof) ), additives to improve the combustion of a combustible heat source (for example, potassium and potassium salts such as potassium citrate) and additives to improve the decomposition of one or more gases resulting from combustion then the heat source (e.g., catalysts, such as CuO, Fe ₂ O ₃ and Al ₂ O _3).

If smoking articles according to the invention contain a barrier coating provided on the rear surface of the combustible heat source, such additives may be included in the combustible heat source before or after applying the barrier coating to the rear surface of the combustible heat source.

In certain preferred embodiments, the combustible heat source is a combustible carbon-containing heat source containing carbon and at least one ignition means. In one preferred embodiment, the combustible heat source is a combustible carbon-containing heat source containing carbon and at least one ignition means, as described in WO-A1-2012 / 164077.

As used herein, the term “ignition aid” is used to describe a material releasing energy and / or oxygen during ignition of a combustible heat source, wherein the rate of release of energy and / or oxygen by the material is not limited by the diffusion of oxygen contained in the ambient air. In other words, the rate of release of one or both of energy and oxygen by a material during ignition of a combustible heat source is largely independent of the rate of oxygen entering the material from the surrounding air. As used herein, the term “ignition aid” is also used to describe an elemental metal releasing energy during ignition of a combustible heat source, wherein the ignition temperature of the elemental metal is below about 500 ° C. and the heat of combustion of the elemental metal is at least about 5 kJ / g

As used herein, the term “igniter” does not apply to alkali metal salts of carboxylic acids (such as citric acid salts of alkali metals, acetic acid salts of alkali metals and succinic acid salts of alkali metals), halide salts of alkali metals (such as chloride salts of alkali metals) , carbonate salts of alkali metals or phosphate salts of alkali metals, which are believed to modify carbon combustion. Even though they are present in large numbers relative to the total mass of the combustible heat source, these burnt alkali metal salts do not release enough energy when igniting the combustible heat source to create an acceptable aerosol for initial 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 iron nitrate; nitrites; other organic and inorganic nitro compounds; chlorates, such as, for example, sodium chlorate and potassium chlorate; perchlorates, such as, for example, sodium perchlorate; chlorites; bromates, such as, for example, sodium bromate and potassium bromate; perbromats; bromites; borates, such as, for example, sodium borate and potassium borate; ferrates, such as, for example, barium ferrate; ferrites; manganates, such as, for example, potassium manganate; permanganates, such as, for example, potassium permanganate; organic peroxides, such as, for example, benzoyl peroxide and acetone peroxide; inorganic peroxides, such as, for example, hydrogen peroxide, strontium peroxide, magnesium peroxide, calcium peroxide, barium peroxide, zinc peroxide and lithium peroxide; superoxides, such as, for example, potassium superoxide and sodium superoxide; iodates; Periods iodites; sulfates; sulfites; other sulfoxides; phosphates; phosphinates; phosphites and phosphanites.

Although they advantageously improve the ignition and combustion properties of a combustible heat source, the inclusion of additives that promote ignition and combustion can lead to an increase in the amount of undesired decomposition and reaction products when using a smoking article. For example, the decomposition of nitrates included in a combustible heat source to facilitate its ignition can lead to the formation of nitrogen oxides.

If the smoking articles according to the invention contain a non-continuous combustible heat source, the inclusion of a non-combustible, substantially airtight partition between one or more air flow channels and a non-continuous combustible heat source can advantageously substantially prevent or suppress such decomposition and reaction products from being drawn into the air drawn into smoking articles according to the invention through one or more channels for air flow, as the drawn air passes through -stand or multiple channels for flow of air.

The inclusion of a non-combustible, substantially airtight partition between the rear surface of the combustible heat source and the aerosol forming substrate can also advantageously substantially prevent or inhibit such decomposition and reaction products from entering the air drawn through the smoking articles of the present invention.

Combustible carbon-containing heat sources for use in smoking articles according to the present invention can be obtained as described in the prior art known to those skilled in the art.

Combustible carbon-containing heat sources for use in smoking articles according to the present invention are preferably formed by mixing one or more carbon-containing materials with one or more binders and other additives, if included, and pre-molding the mixture to give it the desired shape. A mixture of one or more carbon-containing materials, one or more binders and optional other additives can be preformed to give it the desired shape using any suitable known ceramic molding process, such as, for example, slip casting, extrusion, injection molding and stamping or pressing. In some preferred embodiments, the mixture is preformed to give it the desired shape by compression or extrusion, or a combination thereof.

Preferably, a mixture of one or more carbon-containing materials, one or more binders and other additives is preformed into an elongated shaft. However, it is clear that a mixture of one or more carbon-containing materials, one or more binders and other additives can be preformed to give it any desired shape.

After formation, in particular after extrusion, the elongated rod or other desired shape is preferably dried to reduce the moisture content, and then pyrolyzed in a non-oxidizing atmosphere at a temperature sufficient to carburize one or more binders, if any, and essentially remove any volatile substances in elongated shaft or other shape. An elongated rod or other desired shape is pyrolyzed, preferably in a nitrogen atmosphere at a temperature of from about 700 ° C to about 900 ° C.

In certain embodiments, at least one metal nitrate salt is embedded in a combustible heat source by incorporating at least one metal nitrate precursor in a mixture of one or more carbon-containing materials, one or more binders, and other additives. At least one metal nitrate precursor is then subsequently converted in situ to at least one metal nitrate salt by treating the pyrolyzed preformed cylindrical rod or other form with an aqueous nitric acid solution. In one embodiment, the combustible heat source comprises at least one metal nitrate salt with a thermal decomposition temperature of less than about 600 ° C, more preferably less than about 400 ° C. Preferably, the decomposition temperature of the at least one metal nitrate salt is in the range of from about 150 ° C to about 600 ° C, more preferably in the range of from about 200 ° C to about 400 ° C.

In preferred embodiments, the exposure of the combustible heat source to a conventional yellow flame of a lighter or other ignition device should result in decomposition of the at least one nitrate metal salt to release oxygen and energy. This decomposition causes an initial increase in the temperature of the combustible heat source, and also contributes to the ignition of the combustible heat source. After decomposition of at least one nitrate metal salt, the combustible heat source preferably continues to burn at a lower temperature.

The inclusion of at least one nitrate metal salt mainly leads to the initiation of ignition of a combustible heat source, not only in a place located on its surface, but also inside. Preferably, at least one nitrate metal salt is present in the combustible heat source in an amount of from about 20 percent by dry weight to about 50 percent by dry weight of the combustible heat source.

In other embodiments, the combustible heat source comprises at least one peroxide or superoxide actively releasing oxygen at a temperature below about 600 ° C, more preferably at a temperature below about 400 ° C.

Preferably, at least one peroxide or superoxide actively releases oxygen at a temperature in the range of from about 150 ° C to about 600 ° C, more preferably in the range of from about 200 ° C to about 400 ° C, most preferably at a temperature of about 350 ° C .

In use, exposing a combustible heat source to a conventional yellow flame of a lighter or other ignition device should decompose at least one peroxide or superoxide to release oxygen. This causes an initial increase in the temperature of the combustible heat source, and also contributes to the ignition of the combustible heat source. After the decomposition of at least one peroxide or superoxide, the combustible heat source preferably continues to burn at a lower temperature.

The inclusion of at least one peroxide or superoxide mainly leads to ignition of the combustible heat source, not only in the place located on its surface, but also inside.

The combustible heat source preferably has a porosity of from about 20 percent to about 80 percent, more preferably from about 20 percent to 60 percent. If the combustible heat source contains at least one nitrate metal salt, this advantageously allows oxygen to dissipate in the mass of the combustible heat source at a rate sufficient to maintain combustion as the at least one nitrate metal salt decomposes and continues to burn. Even more preferably, the combustible heat source has a porosity of from about 50 percent to about 70 percent, more preferably from about 50 percent to about 60 percent, as measured, for example, by mercury porosimetry or helium pycnometry. The required porosity can be easily achieved during the manufacture of a combustible heat source using traditional methods and technology.

Advantageously, the combustible carbonaceous heat sources for use in smoking articles according to the present invention have an apparent density of about 0.6 g / ^cm3 to about 1 g / cm ^3.

Preferably, the combustible heat source has a mass of from about 300 mg to about 500 mg, more preferably from about 400 mg to about 450 mg.

Preferably, the combustible heat source of the present invention has a length in the range of about 7 mm to about 17 mm, more preferably in the range of about 7 mm to about 15 mm, and most preferably in the range of about 7 mm to about 13 mm.

Preferably, the diameter of the combustible heat source is in the range of from about 5 mm to about 9 mm, more preferably in the range of from about 7 mm to about 8 mm.

Preferably, the combustible heat source has a substantially uniform diameter. However, the combustible heat source may alternatively be conical, so that the diameter of the rear of the continuous combustible heat source exceeds the diameter of its front. Particularly preferred are combustible heat sources that are substantially cylindrical. The combustible heat source may, for example, be a cylinder or conical cylinder with a substantially circular cross-section or a cylinder or conical cylinder with a substantially elliptical cross-section.

Smoking articles according to the present invention preferably comprise an aerosol forming substrate containing at least one aerosol forming material and a material capable of responding to heat by the release of volatile compounds. The aerosol forming substrate may contain other additives and ingredients, including, but not limited to, humectants, flavors, binders, and mixtures thereof.

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

The specified at least one substance for the formation of an aerosol can be any suitable known compounds or mixtures of compounds which, when used, contribute to the formation of a dense and stable aerosol and which, at the operating temperature of the smoking article, are essentially resistant to thermal degradation. Suitable aerosol forming agents are well known in the art to which the invention relates, 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 dimethyldodecandioate and dimethyl tetradecandioate. Preferred aerosol forming agents for use in smoking articles according to the present invention are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1,3-butanediol, and most preferably glycerol.

A material capable of responding to heating by evolution of volatile compounds may be a filling from a material of plant origin. A material capable of responding to heating by evolution of volatile compounds may be a filling from a homogenized material of plant origin. For example, an aerosol forming substrate may contain one or more materials derived from plants, including, but not limited to, tobacco, tea, for example, green tea, peppermint, laurel, eucalyptus, basil, sage, verbena and tarragon.

Preferably, the material capable of releasing volatile compounds upon heating is a tobacco-based material filling, more preferably a tobacco-based homogenized material filling.

The aerosol forming substrate may be in the form of a rod or segment containing material capable of responding to heating by release of volatile compounds, surrounded by a paper or other wrapper. As indicated above, if the substrate forming the aerosol is in the form of such a rod or segment, the entire rod or segment, including any wrapper, is considered the substrate forming the aerosol.

Preferably, the aerosol forming substrate has a length in the range of about 5 mm to about 20 mm, more preferably in the range of about 8 mm to about 12 mm.

In preferred embodiments, the aerosol forming substrate comprises an extruder of tobacco-based material wrapped in fitzella. In particularly preferred embodiments, the aerosol forming substrate comprises an extruder of homogenized tobacco-based material wrapped in fitzella.

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

Preferably, the mouthpiece has a low filtration efficiency, more preferably a very low filtration efficiency. The mouthpiece may be a single-segment or single-component mouthpiece. Alternatively, the mouthpiece may be a multi-segment or multi-component mouthpiece.

The mouthpiece may comprise a filter containing one or more segments containing suitable known filter materials. Suitable filter media are known in the art to which the invention relates, and include, but are not limited to, cellulose acetate and paper. Alternatively or additionally, the mouthpiece may contain one or more segments containing absorbents, adsorbents, flavors and other aerosol modifiers and additives, or combinations thereof.

Preferably, the smoking articles according to the present invention further comprise a transfer element or a separation element between the aerosol forming substrate and the mouthpiece.

The moving element may abut against one or both of the aerosol forming substrate and the mouthpiece. Alternatively, the transfer member may be spaced apart from one or both of the aerosol forming substrate and the mouthpiece.

The inclusion of the moving element mainly allows you to cool the aerosol formed by heat transfer from a combustible heat source to the substrate forming the aerosol. The inclusion of the moving element also advantageously makes it possible to adjust to the desired value the total length of the smoking articles according to the present invention, for example, to a length similar to the length of regular cigarettes by appropriate selection of the length of the moving element.

The moving member may have a length of from about 7 mm to about 50 mm, for example, a length of from about 10 mm to about 45 mm, or from about 15 mm to about 30 mm. The moving element may have other lengths depending on the desired total length of the smoking article and the presence and length of other components in the smoking article.

Preferably, the moving element comprises at least one tubular hollow body with an open end. In such embodiments, when used, air drawn in through the smoking article passes through at least one open end tubular body as it passes downstream of the smoking article from the aerosol forming substrate to its proximal end.

The transfer element may comprise at least one open end tubular body made of one or more suitable materials that are substantially thermally stable at the temperature of the aerosol generated by heat transfer from the combustible heat source to the aerosol forming substrate. Suitable materials are known in the art and include, but are not limited to, paper, cardboard, plastic, such as cellulose acetate, ceramic material, and combinations thereof.

Alternatively or in addition, smoking articles according to the present invention may comprise an aerosol cooling element or a heat exchanger between the aerosol forming substrate and the mouthpiece. The aerosol cooling element may comprise several channels extending in the longitudinal direction.

The aerosol cooling element may comprise an assembled sheet of material selected from the group consisting of metal foil, polymeric material, and substantially non-porous paper or paperboard. In certain embodiments, the aerosol cooling element may comprise an assembled 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 element cooling the aerosol may contain the collected biodegradable polymeric sheet material such as polylactic acid (PLA) or grade Mater-Bi ^® (available on the market series of copolyesters based on starch).

Smoking articles according to the present invention may comprise one or more aerosol modifying agents located downstream of the aerosol forming substrate. For example, one or more of the mouthpiece, the moving element and the aerosol cooling element, of smoking articles according to the present invention may contain one or more aerosol modifying agents.

Suitable aerosol modifying agents include, but are not limited to, flavoring agents and chemically perceptible agents.

As used herein, the term “flavoring” is used to describe any agent that, when used, imparts a taste and / or aroma to an aerosol created by the aerosol forming substrate of a smoking article.

As used herein, the term "chemically perceptible agent" is used to describe any agent that, when used, is perceived in the oral or olfactory cavities of the user by means other than perception through cells of taste buds or olfactory receptors or in addition to them. The perception of chemically perceived agents usually occurs through the “trigeminal reaction” or through the trigeminal nerve, glossopharyngeal nerve, vagus nerve, or some combination thereof. Typically, chemically perceptible agents are perceived as a hot, thrilling sensation, a cooling sensation, or a calming sensation.

Smoking articles according to the present invention may contain one or more aerosol modifying agents, which are both flavoring and chemically perceptible agents located downstream of the aerosol forming substrate. For example, one or more of the mouthpiece, the moving element and the aerosol cooling element, of smoking articles according to the present invention may contain menthol or other flavoring that provides a chemically perceptible cooling effect.

The assembly of smoking articles according to the present invention can be carried out using known methods and equipment.

The present invention will be further described only by way of example with reference to the accompanying graphic materials on which:

FIG. 1 is a schematic longitudinal sectional view of a smoking article in accordance with a first embodiment of the invention;

FIG. 2 is a schematic longitudinal sectional view of a smoking article in accordance with a third embodiment of the invention;

FIG. 3a is a graph of the temperature of the back of a combustible heat source of a smoking article according to the invention during smoking; and

FIG. 3b is a graph of the temperature of the aerosol forming substrate of a smoking article according to the invention during smoking.

The smoking article 2 according to the first embodiment of the invention shown in FIG. 1 contains a continuous combustible heat source 4 having a front surface 6 and an opposite rear surface 8, an aerosol forming substrate 10, a moving element 12, an aerosol cooling element 14, a separation element 16 and a mouthpiece 18 which abut against each other with coaxial alignment .

The continuous combustible heat source 4 is a continuous carbon-containing combustible heat source and is located at the distal end of the smoking article 2. As shown in FIG. 1, a non-combustible, substantially airtight aluminum disk foil baffle 22 is provided between a rear surface 8 of a continuous combustible heat source 4 and an aerosol forming substrate 10. The partition 22 is deposited on the rear surface 8 of a continuous combustible heat source 4 by pressing an aluminum foil disk onto the rear surface 8 of a continuous combustible heat source 4 and abuts against the rear surface 8 of a combustible carbon-containing heat source 4 and an aerosol forming substrate 10.

In other embodiments of the invention (not shown), a non-combustible, substantially airtight partition 22 between the rear surface 8 of the continuous combustible heat source 4 and the aerosol forming substrate 10 may be absent.

The aerosol forming substrate 10 is located directly downstream of the septum 22 deposited on the rear surface 8 of a continuous combustible heat source 4. The aerosol forming substrate 10 comprises a cylindrical extrusion of a homogenized tobacco-based material 24 containing an aerosol forming substance, such as, for example, glycerin wrapped in fitzella 26.

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

The aerosol cooling element 14 is located directly downstream of the moving element 12 and contains an assembled sheet of biodegradable polymeric material, such as, for example, polylactic acid.

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

The mouthpiece 18 is located directly downstream of the separation element 16. As shown in FIG. 1, the mouthpiece 18 is located at the proximal end of the smoking article 2 and contains a cylindrical rod of suitable filter material 32, such as, for example, cellulose acetate fiber with a very low filtration efficiency, wrapped in a filter fitzella 34.

The smoking article may further comprise a strip of rim paper (not shown) surrounding the downstream end portion of the outer wrapper 20.

As shown in FIG. 1, the smoking article 2 further comprises a single heat-conducting element 36 of a suitable material, such as, for example, aluminum foil lying on top of the back of a continuous combustible heat source 4, the entire length of the aerosol forming substrate 10, and the entire length of the transfer member 12.

In other embodiments of the invention (not shown), the transfer member 12 may extend beyond the single heat conducting member 36 in a downstream direction. In other words, a single heat-conducting element 36 may lie on top of only the front of the moving element 12. In other embodiments of the invention (not shown), a single heat-conducting element 36 may not lie on top of any part of the moving element 12.

In further embodiments of the invention (not shown), the aerosol forming substrate 10 may extend outside the single heat conducting element 36 in a downstream direction. In other words, a single heat-conducting element 36 may lie on top of only the front of the aerosol forming substrate 10.

The single heat-conducting element 36 is radially separated from a continuous combustible heat source 4 and an aerosol forming substrate 10 by a wrapper 38 of a heat-insulating sheet material, such as, for example, low breathability cigarette paper, which is wrapped around an aerosol forming substrate 10, a transporting element 12 and the back of a continuous combustible heat source 4.

In the smoking article 2 according to the first embodiment of the invention shown in FIG. 1, a single heat-conducting element 36 and a wrapper 38 separating in a radial direction a single heat-conducting element 36 from a continuous combustible heat source 4 and an aerosol forming substrate 10 extend to approximately the same position on a solid combustible heat source 4 in an upstream direction so that the upstream ends of the single heat conducting element 36 and the wraps 38 are substantially aligned over a continuous combustible heat source 4.

However, it should be understood that in other embodiments of the invention (not shown), a wrapper 38 separating in a radial direction a single heat-conducting element 36 from a continuous combustible heat source 4 and an aerosol forming substrate 10 can extend beyond a single heat-conducting element 36 to upstream.

The smoking article 2 according to 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 FIG. 1, the arrangement of the first air inlets 40 along the circumference is provided in the fitzell 26 of the aerosol forming substrate 10, in a wrapper 38 that radially separates a single heat-conducting element 36 from a continuous combustible heat source 4 and an aerosol forming substrate 10, and in a single heat-conducting element 36 in order to allow cold air (shown by dashed arrows in Fig. 1) to pass into the substrate 10, forming an aerosol.

In use, the user ignites a continuous combustible heat source 4 of the smoke of the smoking article 2 according to the first embodiment of the invention and then pulls through the mouthpiece 18. When the user pulls through the mouthpiece 18, cold air (shown by dashed arrows in Fig. 1) is drawn into the substrate 10, forming aerosol of smoking article 2 through first air inlets 40.

The front part of the aerosol forming substrate 10 is heated by heat conduction through the back surface 8 of a continuous combustible heat source 4 and a partition 22.

The heating of the aerosol forming substrate 10 due to thermal conductivity leads to the release of glycerol and other volatile and semi-volatile compounds from the rod of homogenized tobacco-based material 24. Compounds released from the aerosol forming substrate 10 form an aerosol entrained by the air drawn into the aerosol forming substrate 10 of the smoking article 2 through the first air inlets 40 as it flows through the aerosol forming substrate 10. The drawn-in air and entrained aerosol (shown by dashed-dotted arrows in Fig. 1 and Fig. 2) pass downstream through the moving element 12, the aerosol cooling element 14, and the separation element 16, where they cool and condense. The cooled drawn in air and entrained aerosol pass downstream through the mouthpiece 18 and are delivered to the user through the proximal end of the smoking article 2 according to the first embodiment of the invention. The non-combustible, substantially airtight partition 22 on the rear surface 8 of the continuous combustible heat source 4 isolates the continuous combustible heat source 4 from the air drawn in through the smoking article 2, so that when used, the air drawn in through the smoking article 2 does not directly come into contact with the continuous combustible source of 4 heat.

In use, a single heat-conducting element 36 retains heat inside the smoking article 2, helping to maintain the temperature of the aerosol forming substrate 10, and thus contributes to continuous and improved aerosol delivery. In addition, a single heat-conducting element 36 conducts heat along the aerosol forming substrate 10, so that heat is dissipated through a larger volume of the aerosol forming substrate 10. This helps to provide for more even aerosol delivery by alternating puffs.

The smoking article according to the second embodiment of the invention (not shown) has a structure substantially similar to that of the smoking article according to the first embodiment of the invention shown in FIG. 1. However, in the smoking article according to the second embodiment of the invention, the wrapper 38 separating in the radial direction a single heat-conducting element 36 from a continuous combustible heat source 4 and an aerosol forming substrate 10 is absent and the single heat-conducting element 36 is formed of a laminate containing the outer layer of the heat-conducting material and the inner layer of the insulating material. In a smoking article according to a second embodiment of the invention, the outer layer of the heat-conducting material of the single heat-conducting element 36 is radially separated from the continuous combustible heat source 4 and the aerosol forming substrate 10 by means of the inner layer of the heat-insulating material of the single heat-conducting element 36.

A smoking article 42 according to a third embodiment of the invention shown in FIG. 2 has a structure substantially similar to that of a smoking article according to a first embodiment of the invention shown in FIG. 1. However, in the smoking article 42 according to the second embodiment of the invention, there are no first air inlets 40 around the periphery of the aerosol forming substrate 10, and the combustible heat source 4 is a non-continuous combustible carbon-containing heat source containing a single central flow channel 44 air passing from the front surface 6 to the rear surface 8 of a discontinuous combustible heat source 4.

As shown in FIG. 2, a non-combustible, substantially airtight partition 46 is provided between the combustible heat source 4 and the central air flow passage 44. The baffle 46 comprises a non-combustible, substantially airtight barrier coating provided over the entire inner surface of the single central channel 44 for air flow.

In use, the user ignites a non-continuous combustible heat source 4 of the smoking article 42 according to the third embodiment of the invention and then pulls through the mouthpiece 18. When the user pulls through the mouthpiece 18, cold air (shown by dashed arrows in FIG. 2) is drawn into the substrate 10. forming an aerosol of the smoking article 2 through the Central channel 44 for air flow. A non-combustible, substantially airtight baffle 22 on the rear surface 8 of the non-continuous combustible heat source 4 and a non-combustible, substantially airtight baffle 46 on the inner surface of the single central air flow passage 44 isolate the non-continuous combustible heat source 4 from air drawn through the smoking article 42, such so that in use, the air drawn in through the smoking article 42 does not come into direct contact with the discontinuous combustible heat source 4.

In other embodiments (not shown), a non-combustible, substantially airtight partition 22 between the rear surface 8 of the discontinuous combustible heat source 4 and the aerosol forming substrate 10 may be absent.

The smoking article according to the fourth embodiment of the invention (not shown) has a structure similar to that of the smoking article according to the third embodiment of the invention shown in FIG. 2. However, in the smoking article according to the fourth embodiment of the invention, a wrapper 38 separating in the radial direction a single heat-conducting element 36 from a continuous combustible heat source 4 and an aerosol forming substrate 10 is absent and the single heat-conducting element 36 is formed of a layered material containing the outer layer of the heat-conducting material and the inner layer of the insulating material. In a smoking article according to a fourth embodiment of the invention, the outer layer of the heat-conducting material of the single heat-conducting element 36 is radially separated from the non-continuous combustible heat source 4 and the aerosol forming substrate 10 by the inner layer of the heat-insulating material of the single heat-conducting element 36.

Example A

An assembled smoking article according to the invention having a structure substantially similar to that of a smoking article according to a second embodiment of the invention described above. The smoking article comprises a single heat-conducting element made of a laminate comprising an outer layer of aluminum and an inner layer of paper. The smoking article does not contain an outer wrapper, so that the outer layer of aluminum of the single heat-conducting element is visible on the outside of the smoking article. Instead of arranging the first air inlets along the circumference around the periphery of the aerosol forming substrate, the smoking article comprises arranging the third air inlets along the circumference around the periphery of the transfer member.

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

Comparative Example B

For comparison purposes, a smoking article is made that is not in accordance with the present invention. A smoking article not made in accordance with the present invention comprises a single heat-conducting element made of a laminate comprising an inner layer of aluminum and an outer layer of paper. Otherwise, the smoking article not made in accordance with the present invention has a design identical to that of the smoking article according to the invention from Example A.

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

The temperature values of the rear part of the solid combustible heat sources of the smoking article according to the invention from Example A and the smoking article not made in accordance with the present invention from Comparative Example B are measured in smoking articles during combustion of the combustible heat source using a thermocouple attached to the surface of the smoking articles at a point 1 mm upstream relative to their aerosol forming substrates. The results are shown in FIG. 3a.

The temperature values of the back of the aerosol forming substrates of the smoking article according to the invention from Example A and the smoking article not made in accordance with the present invention from Comparative Example B are measured in smoking articles using a thermocouple attached to the surface of the smoking article during combustion of a combustible heat source products at a point located 6 mm downstream relative to their combustible heat sources. The results are shown in FIG. 3b.

To measure the temperature of the back of solid combustible heat sources and aerosol forming substrates, smoking products are burned using a regular yellow flame of a lighter and smoked in accordance with the Canadian Department of Health reference smoking regimen for 12 puffs with a puff volume of 55 ml, puff duration equal to 2 seconds, and the interval between puffs, equal to 30 seconds, using a smoking machine. Smoking conditions and technical characteristics of a smoking machine are set out in ISO 3308 (ISO 3308: 2000). Atmospheric conditions for preparation and testing are described in ISO 3402.

As shown in FIG. 3a and FIG. 3b, the temperature values of the back of a continuous combustible heat source and the aerosol forming substrate of a smoking article not made in accordance with the invention from comparative example B are reduced compared to the temperature of the smoking article according to the invention, especially during late puffs. This leads to the fact that the supply of total dry particulate matter (DTPM) in a smoking article made not in accordance with the invention from comparative example B (10.3 mg) is lower than the supply of total dry particulate matter (DTPM) in a smoking article according to the invention from example A (17.4 mg).

Certain embodiments described above are intended to illustrate the invention. However, other embodiments may be practiced within the spirit and scope of the invention defined in the claims, and it should be understood that certain embodiments described above are not intended to be limiting.

Claims (20)

1. A smoking article comprising: a combustible heat source having opposite front and rear surfaces; an aerosol forming substrate located downstream of the rear surface of the combustible heat source; and a single heat-conducting element lying on top of the back of the combustible heat source and at least the front of the aerosol forming substrate, wherein the single heat-conducting element contains one or more layers of heat-conducting material, and one or more layers of heat-conducting material are radially separated from the combustible heat source and an aerosol forming substrate, wherein the combustible heat source is a continuous combustible heat source or the combustible heat source is a non-continuous combustible heat source, and the smoking article further comprises a non-combustible, substantially airtight partition between the non-continuous combustible heat source and one or more channels for air flow passing from the front surface to the back surface of a non-continuous combustible heat source, and wherein the single heat-conducting element contains an outer layer of heat-conducting material visible on the outside of the smoking article. 2. A smoking article according to claim 1, characterized in that one or more layers of the heat-conducting material are radially separated from the combustible heat source and the aerosol forming substrate by means of one or more layers of heat-insulating material. 3. A smoking article according to claim 1, characterized in that one or more layers of the heat-conducting material are radially separated from the combustible heat source and the aerosol forming substrate by at least 50 microns. 4. A smoking article according to claim 1, characterized in that the single heat-conducting element is made of a layered material containing one or more layers of heat-conducting material and one or more layers of heat-insulating material. 5. A smoking article according to claim 4, characterized in that one or more layers of the heat-conducting material are radially separated from the combustible heat source and the aerosol forming substrate by at least one of one or more layers of the heat-insulating material. 6. A smoking article according to any one of paragraphs. 1-5, characterized in that one or more layers of heat-conducting material contain heat-reflecting material. 7. A smoking article according to claim 6, characterized in that the heat-reflecting material reflects more than 50% of the incident radiation. 8. A smoking article according to any one of paragraphs. 1-5, characterized in that the single heat-conducting element lies on top of the entire length of the substrate forming the aerosol. 9. A smoking article according to claim 8, characterized in that the single heat-conducting element extends downstream of the substrate forming the aerosol. 10. A smoking article according to any one of paragraphs. 1-5, further comprising a non-combustible, substantially airtight partition between the rear surface of the combustible heat source and the aerosol forming substrate. 11. A smoking article according to any one of paragraphs. 1-5, further comprising one or more first air inlets around the periphery of the aerosol forming substrate. 12. A smoking article according to any one of paragraphs. 1-5, characterized in that the substrate forming the aerosol abuts against the rear surface of the combustible heat source. 13. A smoking article according to any one of paragraphs. 1-5, characterized in that the substrate forming the aerosol is located at a distance from the rear surface of the combustible heat source. 14. A smoking article according to any one of paragraphs. 1-5, further comprising one or more second air inlets between the rear surface of the combustible heat source and the aerosol forming substrate. 15. A smoking article according to any one of paragraphs. 1-5, further comprising one or more aerosol modifying agents located downstream of the aerosol forming substrate.

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