WO2017114760A1

WO2017114760A1 - Breakable aerosol generating article

Info

Publication number: WO2017114760A1
Application number: PCT/EP2016/082469
Authority: WO
Inventors: Alexandre Malgat
Original assignee: Philip Morris Products S.A.
Priority date: 2015-12-31
Filing date: 2016-12-22
Publication date: 2017-07-06
Also published as: CA3006238A1; CN108366618A; MX2018007730A; RU2018127755A3; US20190014820A1; KR20180093004A; EP3397084B1; RU2018127755A; JP6918800B2; RU2719273C2; EP3397084A1; CN108366618B; JP2019505184A; IL259521A

Abstract

The present invention relates to an aerosol generating article (100) having a first section (114) including a combustible heat source (102) and an aerosol-forming substrate(104) and a second section (118) including a tubular element (150) defining a recess (152) at one end of the second section(118). The first and second sections (114, 118) are integrally connected at a region of weakness(122) and are separable at the region of weakness. This enables the tubular element (150) to be placed over the combustible heat source(102), after use of the aerosol generating article, such that the combustible heat source is at least partially received in the recess (152) to reduce the ignition propensity of the smoking article. The first section is upstream of the second section when the first and second sections are integrally connected and the tubular element is at least partically open at both of its ends such that air may be drawn through the tubular element. The tubular element is either at the downstream end of the second section such that the recess forms a mouth end cavity,or is at the upstream end such that the recess forms a transfer element.

Description

BREAKABLE AEROSOL GENERATING ARTICLE

The present invention relates to an aerosol generating article, such as a smoking article, having a combustible heat source for heating an aerosol-forming substrate downstream of the combustible heat source.

A number of smoking articles in which tobacco is heated rather than combusted have been proposed in the art. An aim of such 'heated' smoking articles is to reduce known harmful smoke constituents of the type produced by the combustion and pyrolytic degradation of tobacco in conventional cigarettes. In one known type of heated smoking article, an aerosol is generated by the transfer of heat from a combustible heat source to a physically separate aerosol-forming substrate, such as tobacco. The aerosol-forming substrate may be located within, around or downstream of the combustible heat source. For example, WO-A2- 2009/022232 discloses a smoking article comprising a combustible heat source, an aerosol- forming substrate downstream of the combustible heat source, and a heat-conducting element around and in contact with a rear portion of the combustible heat source and an adjacent front portion of the aerosol-forming substrate. During smoking, volatile compounds are released from the aerosol-forming substrate by heat transfer from the combustible heat source and entrained in air drawn through the smoking article. As the released compounds cool, they condense to form an aerosol that is inhaled by the user.

Smoking articles which include a combustible fuel element or heat source may have a combustion zone or zone of heating that is larger, more dense, and not as readily extinguished by crushing or "stubbing out" the heat source compared to a conventional cigarette, in which tobacco is burnt or combusted to heat and release volatile compounds from the tobacco. Such smoking articles may have a heat source that contains significantly more energy in the form of heat than found in the combustion zone of a conventional cigarette. Consequently, such smoking articles may require more effort to extinguish or to remove sufficient heat to facilitate disposal.

It would be desirable to provide an improved aerosol generating article, particularly one that includes a combustible fuel element or heat source. In particular, it would be desirable to provide an aerosol generating article having an element for facilitating disposal of the aerosol generating article after use and which is both simple to manufacture and use.

According to the present invention, there is provided an aerosol generating article comprising: a first section having a combustible heat source and an aerosol-forming substrate; and a second section having a tubular element defining a recess at one end of the second section, wherein the first and second sections are integrally connected at a region of weakness, the first section and second section being separable at the region of weakness to enable the tubular element to be placed over the combustible heat source, after use of the aerosol generating article, such that the combustible heat source is at least partially received in the recess wherein the first section is upstream of the second section when the first and second sections are integrally connected at the region of weakness, wherein the tubular element is at least partially open at both of its ends such that, during use of the aerosol generating article, air may be drawn along the aerosol generating article through the tubular element, and wherein the tubular element is either at the downstream end of the second section, such that the recess forms a mouth end cavity of the aerosol generating article when the first and section sections are integrally connected, or the tubular element is at the upstream end of the second section and forms a transfer element of the aerosol generating article when the first and section sections are integrally connected.

Advantageously, the present invention provides a simple to manufacture and simple to use aerosol generating article having an integral means of facilitating disposal. By placing the tubular element over the combustible heat source while the heat source is combusting or hot, a barrier is formed between the combustible heat source and an outer surface of the aerosol generating article. Thus, the heat source may be shielded by the tubular element until it has cooled to a sufficiently low temperature to be disposed of easily. In some preferred embodiments, when the heat source is received in the recess, the tubular element hinders a supply of air to the combustible heat source, facilitating the extinguishing of the combustible heat source. This may be particularly advantageous, since the combustion zone or zone of heating of aerosol generating articles having a combustible heat source is larger, more dense, and not as readily extinguished by crushing or "stubbing out" compared to a conventional cigarette.

Further, by integrally connecting the first and second sections and providing such a tubular element as part of the second section, the tubular element is formed as an integral part of the aerosol generating article. This results in a reduced chance of accidental separation of the tubular element from the rest of the aerosol generating article, for example during transport or storage, in comparison to aerosol generating articles having a separately formed extinguisher cap. It may also prevent the tubular element from being mislayed, or misplaced prior to use, as may be the case with aerosol generating articles having a separately formed extinguisher cap.

Connecting the first and second sections at a region of weakness advantageously allows the aerosol generating article to be split in two by a user without undue burden by separating the first and second sections. The tubular element can then be placed over the heat source after use of the aerosol generating article. In addition, providing the tubular element as an integral part of the aerosol generating article mitigates difficulties arising from size variations due to manufacturing tolerances that may occur when assembling aerosol generating articles having a separately formed extinguisher cap or heat shielding element.

The region of weakness may be present as a result of the first and second sections having an interface at the region. In some examples, preferably the tensile strength of any wrapping for example paper layer at the interface at the region of weekness is less than the tensile strength of inner elements of the first section and the second section such that separation occurs in the region of the interface. Preferably the tensile strength of the wrapping is less than 50%, or less than 20% or less than 10% of the inner elements. In some examples, the region of weakness, for example one or more perforations or other formation is provided at the region of weakness, for example to reduce the tensile strength of the wrapping or other connection at the region of weakness. For example, where a metallised wrapping is present at the interface of the first and second sections, preferably the metallised wrapping includes one or more perforations.

As used herein, the terms "integral" and "integrally" are used to mean that the first and second sections share at least one component by which they are joined. That is, the first and second sections are joined by a component forming part of both the first section and the second section. For example, the first section and second section may be integrally connected by a wrapper forming part of both the first and second sections. The term "integrally connected" excludes discrete first and second sections which are held together by friction or by fastening means, such as glue or a threaded connection.

The first section, which includes the heat source and the aerosol forming substrate, is upstream of the second section when the first and second sections are integrally connected at the region of weakness. The tubular element is at least partially open at both of its ends such that during use of the aerosol generating article air may be drawn along the aerosol generating article through the tubular element. In other words, the tubular element defines part of the airflow pathway through the assembled aerosol-generating article. With this arrangement, the first and second sections do not require separation prior to use and may remain integrally connected during use. Thus, the user is not required to hold the two separate sections during use of the aerosol generating article but can separate the sections and immediately place the tubular element over the heat source in one action. By having a tubular element which defines part of the airflow pathway through the assembled aerosol-generating article, the overall length of the aerosol generating article may be easily adjusted to a desired value, for example to a length similar to that of a conventional cigarette, through an appropriate choice of the length of the tubular element. Where the first and second sections are circumscribed by a wrapper, for example an outer wrapper of the aerosol-generating article, the arrangement of the present invention allows the tubular element to be provided entirely within the outer diameter of the wrapper. This means that the outer diameter of the assembled aerosol-generating article may be substantially unaffected by the presence of the tubular element. This may be beneficial for ease of use and for overall appearance of the assembled aerosol-generating article.

In certain preferred embodiments, the tubular element is a hollow tube that is open at both ends. In such embodiments, air may be drawn along the aerosol generating article through the tubular element without the tubular element having any significant effect on the resistance to draw of the aerosol generating article.

The resistance-to-draw (RTD) of an aerosol generating article refers to the static pressure difference between the two ends of the specimen when it is traversed by an air flow under steady conditions in which the volumetric flow is 17.5 millilitres per second at the output end. The RTD of a specimen can be measured using the method set out in ISO Standard 6565:2002.

Where the first section is upstream of the second section, the second section may form a downstream end, or mouth end, of the aerosol generating article. In such embodiments, the tubular element may be at any suitable position along the second section, provided that the combustible heat source can be received in the recess defined by the tubular element when the first and second sections have been separated at the region of weakness.

In certain embodiuments, the tubular element is at the downstream end of the second section and forms a mouth end cavity of the aerosol generating article when the first and second sections are integrally connected.

The tubular element may be at the upstream end of the second section and form a transfer element of the aerosol generating article. The tubular element may be at the upstream end of the second section and form a transfer element of the aerosol generating article between the aerosol-forming substrate and a mouthpiece of the aerosol generating article. The tubular element may be at the upstream end of the second section and form a transfer element of the aerosol generating article between the aerosol-forming substrate and a mouthpiece of the second section.

The aerosol generating article may further comprise a removable cap at the distal end of the first section for protecting the heat source prior to use of the aerosol generating article.

As used herein, the term 'cap' refers to a protective cover that substantially surrounds the distal end of the aerosol generating article, including the end face . By providing a removable cap, either as a separate component or with the tubular element, the user is inhibited from readily igniting the heat source until the cap is removed, unlike paper wrappers, which do not prevent or obstruct the user from igniting the heat source while the paper wrapper remains intact and covering the heat source. Similarly, providing a removable cap that is removed prior to ignition of the heat source may lead to a reduction in ash generation and flaming compared to aerosol generating articles with a paper wrapper that covers the heat source during ignition. If present, a paper wrapper can burn rapidly leading to flaming and generation of ash when the aerosol generating article is ignited. The removable cap may enable a more hygienic aerosol generating article to be provided. In addition, the cap reduces the risk of the user coming into direct contact with the heat source, and so reduces the risk that the heat source will soil the user's clothes or hands.

Similarly, during manufacture, the provision of the removable cap advantageously reduces the risk of the heat source dirtying the manufacturing equipment, and staining adjacent aerosol generating articles. In effect, the removable cap acts to isolate the heat source from the surrounding equipment and aerosol generating articles. In addition, it provides physical protection during manufacture to help prevent the heat source from breaking or chipping off.

For example, aerosol generating articles according to the invention may comprise a removable cap attached at a line of weakness to the distal end of the aerosol generating article, wherein the cap comprises a cylindrical plug of material circumscribed by a wrapper as described in WO-A1 -2014/086998.

The aerosol-forming substrate may be downstream of the heat source. The aerosol- forming substrate may be positioned concentrically within or around the heat source.

As used herein, the terms 'upstream' and 'front', and 'downstream' and 'rear', are used to describe the relative positions of segments or components of the aerosol generating article in relation to the direction in which a user draws on the aerosol generating article during use thereof. Aerosol generating articles according to the invention comprise a mouth end and an opposed distal end. In use, a user draws on the mouth end of the aerosol generating article. The mouth end is downstream of the distal end. The heat source is located at or proximate to the distal end.

In any of the above embodiments the tubular element may be substantially rigid. With such an arrangement, the shape of the recess may be substantially maintained during placement of the tubular element over the combustible heat source. This facilitates receipt of the combustible heat source in the recess after use of the aerosol generating article.

Preferably, the tubular element has a wall thickness between about 100 micrometer and 300 micrometer, for example 200 micrometer. The above mentioned wall thicknesses can provide suitable stability in some examples, for example where the tubular element comprises paper or cardboard for when the heat source is inserted into the tubular element. The tubular element may include a reinforcing formation, for example a tubular insert.

When the tubular element is placed over the combustible heat source after use of the aerosol generating article, the combustible heat source is at least partially received in the recess to facilitate disposal of the aerosol generating article. For example, the tubular element may be arranged such that when the combustible heat source is received in the recess, the tubular element extends along at least 90 percent of the length of the combustible heat source, for example leaving about 1 mm of the length of the combustible heat source uncovered. Preferably, the tubular element is arranged such that, when the combustible heat source is received in the recess, the tubular element extends along substantially the entire length of the combustible heat source.

Preferably, the tubular element is arranged such that, when the combustible heat source is ignited and received within the recess, the tubular element sufficiently restricts the supply of air to the combustible heat source that the combustible heat source is extinguished by the tubular element. Preferably, the tubular element is substantially impermeable to air. In this configuration, the gap between the external surface of the heat source and the internal surface of the tubular element is preferably less than about 2 mm, more preferably less than about 1 mm. With this small gap, there is restricted access of oxygen to the heat source as compared to when the heat source is free to burn without the tubular element. In addition, the emission of combustion gases from the heat source further restricts the flow of oxygen to the heat source because the small gap between the tubular element and the heat source reduces the mixing rate of the combustion gases with the surrounding air.

Preferably, the tubular element is configured such that, when the combustible heat source is received within the recess, there is a frictional fit between the inner surface of the tubular element and the outer surface of the combustible heat source. Providing such a frictional fit allows the tubular element to be held over the combusibtle heat source without any additional connecting means to be provided.

An inner surface of the tubular element may comprise a non-combustible material. The tubular element may be formed from a non-combustible material. An inner surface of the tubular element may be lined with a non-combustible material. Where an inner surface of the tubular element is lined with a non-combustible material, the non-combustible material may be applied as a coating formed by applying one or more intumescent varnishes, paints, lacquers, or any combination thereof on the inner surface of the tubular element. For example, by brushing, rolling, dipping or spraying or by using a non-combustible sheet that is formed into the final shape of the tubular element by any known manufacturing processes, such as cutting, rolling and gluing systems. The non-combustible material may be at least one of: a metal; a metal oxide; a ceramic; and a stone. Further, the non-combustible material may be graphite.

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

The tubular element may comprise a thermochromatic material or pigment.

Thermochromatic pigments or materials change colour with respect to temperature. This has the advantage of providing a user with a visual cue of the temperature near the heat source on the aerosol generating article. Furthermore, the use of a thermochromatic pigment or material may provide a simple visual indication of when the aerosol generating article has reached a temperature that is low enough to be disposed of without additional precautionary measures.

The tubular element may comprise a heat reactive material that is arranged to deform in response to heat from the combustible heat source when the combustible heat source is received in the recess such that the tubular element fits tightly against the combustible heat source to reduce the air supply to the combustible heat source.

Such an arrangement may enable the tubular element to form a seal, or partial seal, around the combustible heat source. This may reduce, even further, the time taken for the heat source to become extinguished. In addition, the heat reactive material may act as an improved thermal barrier between the heat source and an external surface of the aerosol generating article to reduce the temperature of the external surface relative to embodiments in which no heat reactive material is present.

The heat reactive material may comprise an intumescent material.

As used herein, the term 'intumescent material' is used to describe a material that expands upon exposure to elevated temperatures, other than only as a result of its coefficient of thermal expansion.

The intumescent material may comprise any suitable material or materials. In certain embodiments, the intumescent material forms an insulating foam when exposed to heat from the combustible heat source of the aerosol generating article. In one embodiment, the intumescent material comprises a carbon source, such as starch or one or more pentaerythritols (or other types of polyalcohol), an acid source, such as ammonium polyphosphate, a blowing agent such as melamine, and a binder, such as soy lecithin. In an alternative embodiment, the intumescent material comprises a mixture of sodium silicate and graphite such that a hard char foam may be produced when the intumescent material is exposed to heat from the combustible heat source of the aerosol generating article.

The intumescent material may be applied as a heat reactive coating formed by applying one or more intumescent varnishes, paints, lacquers, or any combination thereof on an interior surface of the tubular element. For example, by brushing, rolling, dipping or spraying or by using intumescent paper or plastic-based sheet that is formed into the final shape of the tubular element by any known manufacturing processes, such as cutting, rolling and gluing systems. In one embodiment, the intumescent material is a latex solution applied by spraying.

The intumescent material may expand by any suitable amount when exposed to heat from the combustible heat source of the aerosol generating article. Preferably, the intumescent material expands by a factor of between about 10 and about 100 times its original dimensions when exposed to heat. Where the intumescent material is applied as a heat reactive coating on an interior surface of the tubular element, preferably the thickness of the coating is from about 10 microns to about 100 microns and increases to from about 1 mm to about 2 mm when exposed to heat from the combustible heat source of the aerosol generating article.

The heat reactive material may comprise a heat-shrink material.

As used herein, the term 'heat shrink material' is used to describe a material that shrinks as a result of heat exposure.

Where the heat reactive material comprises a heat-shrink material, the heat-shrink material may be configured to deform the tubular element to hinder air flow to the combustible heat source.

In certain embodiments, the heat shrink material may be a mechanically expanded polymer layer which returns to its unexpanded dimensions as a result of heat exposure. For example, the heat shrink material may be manufactured from a thermoplastic material such as nylon, polyolefin, fluroropolymer (such as FEP, PTFE or Kynar), PVC, neoprene, silicone elastomer, Viton, or any combination thereof. In certain embodiments, the heat shrink material is a fluoroplastic Kynar with a shrink temperature of about 135°C and a shrink ratio of about 2:1. In such embodiments, the fluoroplastic Kynar may be provided as a layer of the material used to form the tubular element.

In certain embodiments, the heat shrink material is applied as a heat reactive coating on an inner surface of the tubular element. In such embodiments, the coating may be applied by any suitable method. For example, the coating may be applied as a sheet or film which is adhered to the tubular element, for example by gluing or welding.

The heat reactive material may be provided along the entire length of the tubular element. The heat reactive material may be provided along only part of the length of the tubular element. The heat reactive material may be provided at the downstream end of the tubular element. With this arrangement, the downstream end of the tubular element may form a seal or partial seal around the combustible heat source. This may result in a layer of air being present between the tubular element and the combustible heat source, upstream of the heat reactive material to form a thermally insulating barrier.

During use of the aerosol generating article, the combustible heat source may reach high temperatures. For example, a heat source of an aerosol generating article may reach an average temperature of around 500 degrees Celsius and in certain cases the temperature of the heat source may reach up to about 800 degrees Celsius. Thus, the tubular element may comprise thermally insulating material arranged to reduce the temperature of an external surface of the aerosol generating article when the combustible heat source is received in the recess while combusting or while hot. The tubular element may comprise a barrier material to thermally isolate the combustible heat source when the combustible heat source is received in the recess while combusting or while hot. Suitable thermally insulating materials have a low thermal conductivity or substantially no thermal conductivity. Suitable thermally insulating materials may include, for example, cardboards, foams, polymers or ceramic materials, or other materials that have a low thermal conductivity.

As used herein, the term "thermally insulating material" is used to describe material having a bulk thermal conductivity of less than about 50 milliwatts per metre Kelvin (mW/(m K)) at 23°C and a relative humidity of 50% as measured using the modified transient plane source (MTPS) method.

The tubular element may be formed from a suitable barrier material such as a substantially non-combustible material or a substantially flame retardant material. Preferably, the barrier material is thermally stable in air at the highest temperature achieved by the heat source of the aerosol generating article. Suitable barrier materials may, for example, include metallic materials, or ceramic materials.

The tubular element may comprise one or more materials that undergo a phase change when heated. The tubular element may comprise one or more materials that melt and extinguish the heat source by flowing over the heat source and eliminating or restricting oxygen supply to the heat source. The tubular element may comprise one or more materials that undergo an endothermic reaction or phase change and consume heat energy produced by the heat source, thereby cooling the heat source. The tubular element may comprise one or more materials that decompose when brought in contact with the heat source and produce a decomposition product that extinguishes the heat source. Examples of materials that may undergo a phase change when in proximity to the heat source include, for example, certain polymers and waxes.

The tubular element may comprise one or more materials selected from the group consisting of barrier materials, non-combustible materials, flame retardant materials, thermally conductive materials, thermally insulating materials, foam materials, phase-changing materials, metallic materials, and ceramic materials. For example, the tubular element may comprise one or more materials selected from the group consisting of non-combustible materials, flame- retardant materials, thermally conductive materials and thermally insulating materials.

In some embodiments, the tubular element may comprise a heat-reflective material which advantageously may modulate the heat radiating from the combustible heat source.

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

The tubular element may be formed from a composite material, such as a material comprising a plurality of layers. The layers of the composite material for the tubular element may be formed from two or more of the materials described herein. For example, the tubular element may be formed from material comprising an external insulating layer, a second layer of intumescent or heat reactive material, and an internal layer of non-combustible material.

The tubular element may reduce the emission of undesirable odours when the combustible heat source is received in the recess. The tubular element may reduce the emission of odours by comprising a material which absorbs or adsorbs the odours.

Alternatively, or in addition, the tubular element may comprise a heat-released flavour compound. The flavour compound may be a nanoparticle formed from a low melting point wax encapsulating the flavour compound. The flavour compound is preferably volatile such that it is released into the atmosphere on activation of the nanoparticle.

The tubular element may be tapered. The tubular element may be substantially cylindrical in shape. The tubular element may have any suitable cross-sectional shape, for example, circular, oval, or polygonal.

The region of weakness is a region at which the aerosol generating article is easily broken in order to separate the first and second sections. The region of weakness may be formed by a region of weakness in one or more internal components of the aerosol generating article. For example, the region of weakness may be formed by a local reduction in thickness of one or more internal components of the aerosol generating article. The region of weakness may be formed by a join between two or more internal components of the aerosol generating article.

The region of weakness may be an area of weakness. In preferred embodiments, the region of weakness is a line of weakness along which the first and second sections are separable.

The aerosol generating article preferably comprises a wrapper that circumscribes at least a portion of the first section and at least a portion of the second section. The wrapper enables the first and second sections to be integrally connected during manufacture. The region of weakness may comprise a weakness formation provided in the wrapper.

The weakness formation may comprise a local reduction in thickness of the wrapper. For example, the weakness formation may comprise one or more ablated regions or lines, one or more scored lines, or a combination thereof. The weakness formation may comprise a section of different, weaker, wrapper material. The weakness formation may comprise a plurality of perforations in the wrapper. The plurality of perforations may extend around at least a portion of the aerosol generating article. The plurality of perforations may circumscribe the aerosol generating article.

The wrapper may be affixed to the first section and to the second section, remote from the region of weakness. By affixing the wrapper remote from the region of weakness, the wrapper may be more easily broken at the region of weakness when the user wants to separate the first and second sections. The wrapper is preferably affixed to the first and second sections using glue. The glue may be provided in a line extending from, or adjacent to, the distal end of the aerosol generating article towards the mouth end of the aerosol generating article. The line of glue may be interrupted adjacent to, or at, the line of weakness.

The wrapper may be a cigarette paper. A cigarette paper may be any suitable material for wrapping components of an aerosol generating article in the form of a rod. The cigarette paper may circumscribe the component elements of the aerosol generating article such that the paper grips the component elements of the aerosol generating article when the article is assembled and hold them in position within the rod. Suitable materials are well known in the art.

The region of weakness, and thus the location at which the aerosol generating article is separable into discrete first and second sections, may be provided at any suitable distance along the aerosol generating article. Preferably, the region of weakness is located at least 10 mm from either end of the aerosol generating article. More preferably, the region of weakness is located at least 20 mm from either end of the aerosol generating article. This arrangement allows the user to separate the first and second sections and place the tubular element over the heat source without having to hold either the first or second sections at a position particularly close to the combustible heat source, reducing the risk of the user being exposed to high surface temperatures near the heat source, or to soiling from the combustible heat source.

In certain particular embodiments, the region of weakness is located from about 10% to about 90% along the length of the aerosol generating article, where 0% refers to the upstream end and 100% refers to the upstream end, or mouth end, of the aerosol generating article. The region of weakness may be located from about 20% to about 80% along the length of the aerosol generating article, from about about 30% to about 70% along the length of the aerosol generating article, or from about 40% to about 60% along the length of the aerosol generating article. In one particular embodiment, the the region of weakness is located at about 50% along the length of the aerosol generating article.

Aerosol-generating articles according to the present invention comprise a first section having a combustible heat source and an aerosol forming substrate. The aerosol-generating articles may comprise a plurality of elements assembled in the form of a rod.

As used herein, the term 'aerosol-generating article' is used to denote an article comprising an aerosol-forming substrate that is capable of releasing volatile compounds that can form an aerosol. An aerosol-generating article may be a non-combustible aerosol- generating article, which is an article that releases volatile compounds without the combustion of the aerosol-forming substrate. An aerosol-generating article may be a heated aerosol- generating article, which is an aerosol-generating article comprising an aerosol-forming substrate that is intended to be heated rather than combusted in order to release volatile compounds that can form an aerosol. A heated aerosol-generating article may comprise an onboard heating means forming part of the aerosol-generating article, or may be configured to interact with an external heater forming part of a separate aerosol-generating device

An aerosol-generating article may be a smoking article that generates an aerosol that is directly inhalable into a user's lungs through the user's mouth. An aerosol-generating article may resemble a conventional smoking article, such as a cigarette. An aerosol-generating article may comprise tobacco. An aerosol-generating article may be disposable. An aerosol- generating article may be partially-reusable and comprise a replenishable or replaceable aerosol-forming substrate.

The combustible heat source is preferably a solid heat source, and may comprise any suitable combustible fuel including, but not limited to, carbon and carbon-based materials containing aluminium, magnesium, one or more carbides, one or more nitrides and combinations thereof. Solid combustible heat sources for heated smoking articles and methods for producing such heat sources are known in the art and described in, for example, US-A-5,040,552 and US-A-5,595,577. Typically, known solid combustible heat sources for heated smoking articles are carbon-based, that is they comprise carbon as a primary combustible material.

The combustible heat source may be a combustible carbonaceous heat source.

The combustible heat source is preferably a blind combustible heat source.

As used herein, the term 'blind' describes a heat source that does not comprise any air flow channels extending from the front end face to the rear end face of the combustible heat source. As used herein, the term 'blind' is also used to describe a combustible heat source including one or more airflow channels extending from the front end face of the combustible heat source to the rear end face of the combustible heat source, wherein a combustible substantially air impermeable barrier between the rear end face of the combustible heat source and the aerosol-forming substrate barrier prevents air from being drawn along the length of the combustible heat source through the one or more airflow channels.

The inclusion of one or more closed air passageways increases the surface area of the blind combustible heat source that is exposed to oxygen from the air and may advantageously facilitate ignition and sustained combustion of the blind combustible heat source. Aerosol generating articles according to the invention comprising blind combustible heat sources comprise one or more air inlets downstream of the rear end face of the combustible heat source for drawing air into one or more airflow pathways through the aerosol generating article. Aerosol generating articles according to the invention comprising non-blind combustible heat sources may also comprise one or more air inlets downstream of the rear end face of the combustible heat source for drawing air into one or more airflow pathways through the aerosol generating article.

In some embodiments, aerosol generating articles according to the invention comprising blind combustible heat sources comprise one or more air inlets located proximate to the downstream end of the aerosol-forming substrate.

In use, air drawn along the one or more airflow pathways of aerosol generating articles according to the invention comprising a blind combustible heat source does not pass through any airflow channels along the blind combustible heat source. The lack of any airflow channels through the blind combustible heat source advantageously substantially prevents or inhibits activation of combustion of the blind combustible heat source during puffing by a user. This substantially prevents or inhibits spikes in the temperature of the aerosol-forming substrate during puffing by a user. By preventing or inhibiting activation of combustion of the blind combustible heat source, and so preventing or inhibiting excess temperature increases in the aerosol-forming substrate, combustion or pyrolysis of the aerosol-forming substrate under intense puffing regimes may be advantageously avoided. In addition, the impact of a user's puffing regime on the composition of the mainstream aerosol may be advantageously minimised or reduced.

The inclusion of a blind combustible heat source may also advantageously substantially prevent or inhibit combustion and decomposition products and other materials formed during ignition and combustion of the blind combustible heat source from entering air drawn through aerosol generating articles according to the invention during use thereof. This is particularly advantageous where the blind combustible heat source comprises one or more additives to aid ignition or combustion of the blind combustible heat source.

In aerosol generating articles according to the invention comprising a blind combustible heat source, heat transfer from the blind combustible heat source to the aerosol-forming substrate occurs primarily by conduction. Heating of the aerosol-forming substrate by forced convection is minimised or reduced. This may advantageously help to minimise or reduce the impact of a user's puffing regime on the composition of the mainstream aerosol of articles according to the invention.

In aerosol generating articles according to the invention comprising a blind combustible heat source, it is particularly important to optimise the conductive heat transfer between the combustible heat source and the aerosol-forming substrate. As described further below, the inclusion of one or more heat-conducting elements around at least a rear portion of the combustible carbonaceous heat source and at least a front portion of the aerosol-forming substrate is particularly preferred in aerosol generating articles according to the invention including blind heat sources, where there is little if any heating of the aerosol-forming substrate by forced convection.

In certain embodiments of the invention, the combustible heat source comprises at least one longitudinal airflow channel, which provides one or more airflow pathways through the heat source. The term "airflow channel" is used herein to describe a channel extending along the length of the heat source through which air may be drawn through the aerosol generating article. Such heat sources including one or more longitudinal airflow channels are referred to herein as "non-blind" heat sources.

The diameter of the at least one longitudinal airflow channel may be between about 1 .5 mm and about 3 mm, more preferably between about 2 mm and about 2.5 mm. The inner surface of the at least one longitudinal airflow channel may be partially or entirely coated, as described in more detail in WO-A-2009/022232.

In embodiments of aerosol generating articles that are conventional lit-end cigarettes, the heat source will be a volume of tobacco.

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

The aerosol-forming substrate may be a solid aerosol-forming substrate. Alternatively, the aerosol-forming substrate may comprise both solid and liquid components. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds, which are released from the substrate upon heating. Alternatively, the aerosol- forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may further comprise one or more aerosol formers. Examples of suitable aerosol formers include, but are not limited to, glycerine and propylene glycol.

The aerosol-forming substrate may be a rod comprising a tobacco-containing material. If the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol- forming substrate may comprise, for example, one or more of: powder, granules, pellets, shreds, spaghetti strands, strips or sheets containing one or more of: herb leaf, tobacco leaf, fragments of tobacco ribs, reconstituted tobacco, homogenised tobacco, extruded tobacco and expanded tobacco. The solid aerosol-forming substrate may be in loose form, or may be provided in a suitable container or cartridge. For example, the aerosol-forming material of the solid aerosol-forming substrate may be contained within a paper or other wrapper and have the form of a plug. Where an aerosol-forming substrate is in the form of a plug, the entire plug including any wrapper is considered to be the aerosol-forming substrate.

Optionally, the solid aerosol-forming substrate may contain additional tobacco or non- tobacco volatile flavour compounds, to be released upon heating of the solid aerosol-forming substrate. The solid aerosol-forming substrate may also contain capsules that, for example, include the additional tobacco or non-tobacco volatile flavour compounds and such capsules may melt during heating of the solid aerosol-forming substrate.

Optionally, the solid aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The carrier may take the form of powder, granules, pellets, shreds, spaghetti strands, strips or sheets. The solid aerosol-forming substrate may be deposited on the surface of the carrier in the form of, for example, a sheet, foam, gel or slurry. The solid aerosol-forming substrate may be deposited on the entire surface of the carrier, or alternatively, may be deposited in a pattern in order to provide a non-uniform flavour delivery during use.

The aerosol-forming substrate may be in the form of a plug or segment comprising a material capable of emitting volatile compounds in response to heating circumscribed by a paper or other wrapper. Where an aerosol-forming substrate is in the form of such a plug or segment, the entire plug or segment including any wrapper is considered to be the aerosol- forming substrate.

The aerosol-forming substrate preferably has a length of between about 5 mm and about 20 mm. In certain embodiments, the aerosol-forming substrate may have a length of between about 6 mm and about 15 mm or a length of between about 7 mm and about 12 mm.

The aerosol-forming substrate may comprise a plug of tobacco-based material wrapped in a plug wrap. In preferred embodiments, the aerosol-forming substrate comprises a plug of homogenised tobacco-based material wrapped in a plug wrap.

In any of the above embodiments, the combustible heat source and the aerosol-forming substrate may be in abutting coaxial alignment. As used herein, the terms "abutting" and "abut" are used to describe a component, or a portion of a component, being in direct contact with another component, or portion of a component.

Aerosol generating articles according to the invention may comprise a heat-conducting element around and in direct contact with both at least a rear portion of the combustible heat source and at least a front portion of the aerosol-forming substrate. In such embodiments, the heat-conducting element provides a thermal link between the combustible heat source and the aerosol-forming substrate of aerosol generating articles according to the invention and advantageously helps to facilitate adequate heat transfer from the combustible heat source to the aerosol-forming substrate to provide an acceptable aerosol.

Alternatively or in addition, aerosol generating articles according to the invention may comprise a heat-conducting element spaced apart from one or both of the combustible heat source and the aerosol-forming substrate, such that there is no direct contact between the heat- conducting element and one or both of the combustible heat source and the aerosol-forming substrate.

Where the aerosol generating article comprises a heat-conducting element around at least a rear portion of the combustible heat source and at least a front portion of the aerosol-forming substrate, the heat-conducting element may be formed by the wrapper. For example, the wrapper may comprise one or more layers of heat conductive material which form the one or more heat-conducting elements.

The one or more heat-conducting elements are preferably non-combustible. In certain embodiments, the one or more heat-conducting elements may be oxygen restricting. In other words, the one or more heat-conducting elements may inhibit or resist the passage of oxygen through the heat-conducting element.

Suitable heat-conducting elements include, but are not limited to: metal foil wrappers such as, for example, aluminium foil wrappers, steel wrappers, iron foil wrappers and copper foil wrappers; and metal alloy foil wrappers.

Aerosol generating articles according to the invention may comprise a transfer element, or spacer element, downstream of the aerosol-forming substrate. Such an element may take the form of a hollow tube that is located downstream of an aerosol-forming substrate.

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

The inclusion of a transfer element advantageously allows cooling of the aerosol generated by heat transfer from the combustible heat source to the aerosol forming substrate. The inclusion of a transfer element also advantageously allows the overall length of the aerosol generating article to be adjusted to a desired value, for example to a length similar to that of a conventional cigarette, through an appropriate choice of the length of the transfer element.

The transfer element may have a length of between about 7 mm and about 50 mm, for example a length of between about 10 mm and about 45 mm or of between about 15 mm and about 30 mm. The transfer element may have other lengths depending upon the desired overall length of the aerosol generating article, and the presence and length of other components within the aerosol generating article. The term "transfer element" refers to an element which comprises at least one open- ended tubular hollow body. When the aerosol-generating article is in its assembled state, that is, when first and second sections are integrally connected at the region of weakness, the transfer element provides a hollow body defining part of the airflow pathway through the article. Where the aerosol-generating article comprises a transfer element, in use, air drawn into the aerosol generating article passes through the at least one open-ended tubular hollow body of the transfer element as it passes downstream through the aerosol generating article from the aerosol-forming substrate to the distal end of the aerosol generating article.

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

In embodiments of aerosol generating article in which the first section, which includes the heat source and the aerosol forming substrate, is upstream of the second section when the first and second sections are integrally connected at the region of weakness and the tubular element is a hollow tube that is open at both ends, the transfer element may comprise the tubular element. The transfer element may be formed by the tubular element.

Aerosol generating articles according to the invention may comprise an aerosol-cooling element or heat exchanger downstream of the aerosol-forming substrate. The aerosol-cooling element may comprise a plurality of longitudinally extending channels.

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

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

Preferably, the aerosol generating article comprises a mouthpiece downstream of the aerosol-forming substrate and positioned at the downstream end of the aerosol generating article. The mouthpiece may form part of the first section or the second section. The mouthpiece may be provided as a separate component, or as part of a third section that is integrally connected to the first or second sections, either directly or via one or more intermediate components.

The mouthpiece may comprise a filter. For example, the mouthpiece may comprise a filter plug having one or more segments. Where the mouthpiece comprises a filter plug, preferably the filter plug is a single segment filter plug. The filter plug may comprise one or more segments comprising cellulose acetate, paper or other suitable known filtration materials, or combinations thereof. Preferably, the filter plug comprises filtration material of low filtration efficiency.

The aerosol generating article may be substantially cylindrical in shape. The aerosol generating article may be substantially elongate. The aerosol generating article has a length and a circumference substantially perpendicular to the length.

The aerosol-forming substrate may be substantially cylindrical in shape. The aerosol- forming substrate may be substantially elongate. The aerosol-forming substrate also has a length and a circumference substantially perpendicular to the length. The aerosol-forming substrate may be located in the aerosol generating article such that the length of the aerosol- forming substrate is substantially parallel to the airflow direction in the aerosol generating article.

The transfer section or element may be substantially elongate.

The aerosol generating article may have any desired length. For example, the aerosol generating article may have a total length of between approximately 65 mm and approximately 100 mm.

The aerosol generating article may have any desired external diameter. For example, the aerosol generating article may have an external diameter of between approximately 5 mm and approximately 12 mm.

The aerosol generating article may be circumscribed by an outer wrapper of, for example, cigarette paper, which has low air permeability. Alternatively or in addition, the mouthpiece may be circumscribed by tipping paper.

It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.

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

Figure 1 shows a schematic longitudinal cross-sectional view of a first embodiment of a smoking article according to the present invention;

Figure 2 shows a schematic longitudinal cross-sectional view of the smoking article of

Figure 1 , in which the smoking article is in an extinguishing configuration; Figure 3 shows a schematic longitudinal cross-sectional view of a second embodiment of a smoking article according to the present invention;

Figure 4 shows a schematic longitudinal cross-sectional view of the smoking article of Figure 3, in which the smoking article is in an extinguishing configuration;

Figure 5 shows a schematic longitudinal cross-sectional view of a third embodiment of a smoking article, which is included for background interest only; and

Figure 6 shows a schematic longitudinal cross-sectional view of the smoking article of Figure 5, in which the removable cap is removed.

The smoking article 100 according to the first embodiment of the invention shown in Figure 1 comprises a blind combustible carbonaceous heat source 102, an aerosol-forming substrate 104, an airflow directing element 106, an aerosol-cooling element 108, and a mouthpiece 1 10 in abutting coaxial alignment. The combustible carbonaceous heat source 102, aerosol-forming substrate 104 and airflow directing element 106 are overwrapped in a first outer wrapper 1 12 of cigarette paper of low air permeability, forming a first section 1 14 of the smoking article 100. The aerosol-cooling element 108 and mouthpiece 1 10 are overwrapped in a second outer wrapper 1 16 of cigarette paper of low air permeability, forming a second section 1 18 of the smoking article 100. The first section 1 14 is thus upstream of the second section 1 18. The smoking article 100 further includes a band of tipping paper 120 circumscribing at least a downstream portion of the first section 1 14 and at least an upstream portion of the second section 1 18. The first section 1 14 and the second section 1 18 are integrally connected by the tipping paper 120 along a first line of weakness 122 which comprises a plurality of perforations that circumscribe the smoking article 100. The first line of weakness 122 defines a weakness formation in the tipping paper 120.

A removable cap 124 is provided at the distal end of the smoking article 100, and is directly adjacent to the heat source 102. The removable cap 124 comprises a central portion 126, and is wrapped in a portion 128 of the first outer wrapper 1 12. In the embodiment shown, the central portion 126 comprises a desiccant, such as glycerine, provided to preferentially absorb moisture as compared to the heat source. The portion 128 of the first outer wrapper is connected to the rest of the first outer wrapper 1 12 along a second line of weakness 130. The line of weakness 130 comprises a plurality of perforations in the first outer wrapper 1 12 that circumscribe the smoking article 100.

The aerosol-forming substrate 104 is located immediately downstream of the combustible carbonaceous heat source 102 and comprises a cylindrical plug 132 of tobacco material, comprising glycerine as an aerosol former, that is circumscribed by plug wrap 134.

A non-combustible, substantially air impermeable barrier 136 is provided between the downstream end of the combustible heat source 102 and the upstream end of the aerosol- forming substrate 104. As shown in Figure 1 , the non-combustible, substantially air impermeable barrier consists of a non-combustible, substantially air impermeable, barrier coating 136, which is provided on the entire rear face of the combustible carbonaceous heat source 102.

A heat conducting element (not shown) consisting of a tubular layer of aluminium foil surrounds and is in direct contact with a rear portion of the combustible carbonaceous heat source 102 and an abutting front portion of the aerosol-forming substrate 104.

The airflow directing element 106 is located downstream of the aerosol-forming substrate 104 and comprises an open-ended, substantially air impermeable hollow tube 138 made of, for example, cardboard, which is of reduced diameter compared to the aerosol-forming substrate 104. The upstream end of the open-ended hollow tube 138 abuts the aerosol-forming substrate 104. The open-ended hollow tube 138 is circumscribed by an annular air permeable diffuser 140 made of, for example, cellulose acetate tow, which is of substantially the same diameter as the aerosol-forming substrate 104.

The open-ended hollow tube 138, and annular air permeable diffuser 140 may be separate components that are adhered or otherwise connected together to form the airflow directing element 106 prior to assembly of the smoking article 100. In yet further embodiments, the open-ended hollow tube 138 and annular air permeable diffuser 140 may be parts of a single component. For example, the open-ended hollow tube and annular air permeable diffuser may be parts of a single hollow tube of air permeable material having a substantially air impermeable coating applied to its inner surface.

In a particularly preferred embodiment the central portion 1 16 of the removable cap 1 14 is manufactured from the same material as the airflow directing element, and so comprises an open-ended substantially air impermeable hollow tube circumscribed by an annular air permeable diffuser.

As shown in Figure 1 , a circumferential arrangement of air inlets 142 is provided in the first outer wrapper 1 12 circumscribing the first section 1 14 in the region of the airflow directing element 106.

The aerosol-cooling element 108 is located immediately downstream of the airflow directing element 106 and comprises a gathered sheet of biodegradable polymeric material, such as, for example, polylactic acid.

The mouthpiece 1 10 of the smoking article 100 is located immediately downstream of the aerosol-cooling element 108 and comprises a filter segment 144, having a cylindrical plug 146 of suitable filtration material such as, for example, cellulose acetate tow of very low filtration efficiency circumscribed by filter plug wrap 148, and a tubular element 150 immediately downstream of the filter segment 144. The tubular element 150 comprises a cylindrical tube of suitable, substantially rigid material such as, for example cardboard, stiff paper or heat resistant rigid plastic. The tubular element 150 defines a recess 152 at the mouth end of the smoking article 100. The mouthpiece 1 10 thus has a mouth end cavity formed by the recess 152.

To use the smoking article 100, the user removes the removable cap 124 by transversely compressing the cap by pinching it between thumb and finger. By compressing the cap 124, sufficient force is provided to the second line of weakness 130 to locally break the first outer wrapper 1 12. The user then removes the cap 124 by twisting the cap to break the remaining portion of the second line of weakness 130. When the cap 124 is removed the heat source 102 is partially exposed which enables the user to light the smoking article 100.

In use, the user ignites the combustible heat source 102 which heats the aerosol-forming substrate 104 to produce an aerosol. When the user inhales on the mouthpiece 1 10 air is drawn through the air inlets 142, through the aerosol-forming substrate 104, airflow directing element 106, aerosol-cooling element 108, and mouthpiece 1 10, as indicated by the arrows in Figure 1 , and into the user's mouth.

After use of the smoking article 100, the user breaks the smoking article in two by breaking the tipping paper 120 along the first line of weakness 122 to separate the first section 1 14 and the second section 1 18 across separation plane 1000. The user then places the downstream end of the second section 1 18 over the upstream end of the first section 1 14 so that the combustible heat source 102 is received in the recess 152 of the tubular element 150, as shown in Figure 2.

In the extinguishing configuration shown in Figure 2, the tubular element 150 is a frictional fit over the combustible heat source 102, such that it is retained over the combustible heat source 102 and the first and second sections 1 14, 188 are held together. The tubular element 150, which may be made from any suitable material, such as flame-retardant material, sufficiently restricts the supply of oxygen to the combustible heat source so that the heat source extinguishes, and thus cools down. In this way, the user is provided with a simple and self- contained means of extinguishing the combustible heat source after use of the smoking article.

Further, the tubular element may be provided with a fragrance that may be evolved when the tubular element is heated by the combustible heat source. The fragrance may be released into the atmosphere and may act to mask any unpleasant odours released by the heat source as it is being extinguished. The fragrance may provide an air freshening effect by emitting pleasant odours and fragrances. Preferably the fragrance is sufficiently volatile that it swiftly evaporates after the tubular element is placed over the combustible heat source.

In preferred embodiments the fragrance may include one or more fragrance ingredient selected from the list consisting of Amyl Cinnamal, Amylcinnamyl Alcohol, Benzyl Alcohol, Benzyl Salicylate, Cinnamyl Alcohol, Cinnamal, Citral, Coumarin, Eugenol, Geraniol, Hydroxycitronellal, Hyroxymethylpentylcyclohexenecarboxaldehyde, Isoeugenol, Anisyl Alcohol, Benzyl Benzoate, Benyl Cinnamate, Citronellol, Farnesol, Hexyl Cinnamaldehyde 2-methyl-3- (4-tert-butylbenzyl)propionaldehyde, d-Limonene, Linalool, Methyl heptine carbonate, and 3- Methyl-4-(2,6,6-trimethyl-2-cyclohexen-1 -yl)-buten-2-one.

Figures 3 and 4 show a second embodiment of a smoking article 300. The smoking article 300 is of similar construction to the first embodiment of smoking article 100 shown in Figures 1 and 2, and where the same features are present, like reference numerals have been used. However, as shown in Figure 3, the tubular element 350 of smoking article 300 of the second embodiment is located immediately upstream of the aerosol-cooling element 308 and is at the upstream end of the second section 318, rather than at the downstream end of the second section. The recess 352 defined by the tubular element 350 forms a transfer element, or spacer element, between the airflow directing element 306 and the aerosol-cooling element 308. Instead of having a mouth end cavity formed by the tubular element, as in the first embodiment of smoking article shown in Figure 1 , the mouthpiece 310 and mouth end of the smoking article 300 are formed by the filter segment 344.

To use the smoking article 300, the user removes the removable cap 324, in the same way as described with reference to Figures 1 and 2, to partially expose the combustible heat source 302 which enables the user to light the smoking article 300.

In use, the user ignites the combustible heat source 302 which heats the aerosol-forming substrate 304 to produce an aerosol. When the user inhales on the mouthpiece 310 air is drawn through the air inlets 342, through the aerosol-forming substrate 304, airflow directing element 306, tubular element 346, aerosol-cooling element 308, and mouthpiece 310, as indicated by the arrows in Figure 3, and into the user's mouth.

After use of the smoking article 300, the user breaks the smoking article in two by breaking the tipping paper 320 along the first line of weakness 322 to separate the first section 314 and the second section 318 across separation plane 3000. The user then places the upstream end of the second section 318 over the upstream end of the first section 314 so that the combustible heat source 302 is received in the recess 352 of the tubular element 350, as shown in Figure 4.

In the extinguishing configuration shown in Figure 4, as with the smoking article 100 of the first embodiment, the tubular element 350 is a frictional fit over the combustible heat source 302, such that it is retained over the combustible heat source 302 to sufficiently restrict the supply of oxygen to the combustible heat source so that the heat source extinguishes, and thus cools down. In this embodment, the recess 352 defined by the tubular element 350 preferably has a length greater than that of the exposed portion of the heat source 302 received in the recess 352. This avoids direct contact between the combustible heat source 302 and the aerosol-cooling element 308, reducing the risk of exposing the aerosol-cooling element 308 to excessive heat from the heat source during extinguishing which may otherwise result in the emission of unpleasant odours from melting of the aerosol-cooling element 308.

Alternatively, or in addition, the tubular element 350 may comprise a thermally insulating material to reduce the heat transfer from the heat source 302 to the aerosol-cooling element 308 during extinguishing.

Figures 5 and 6 show a third embodiment of smoking article 500 which is included for background interest only. The smoking article 500 is similar to the first and second embodiments of smoking article 100, 300 shown in Figures 1 to 4, and where the same features are present, like reference numerals have been used. However, with the smoking article 500 of the third embodiment, the first section 514 is downstream of the second section 518 and comprises comprises a blind combustible carbonaceous heat source 502, an aerosol-forming substrate 504, an airflow directing element 506, an aerosol-cooling element 508, a transfer element 509 and a mouthpiece 510 in abutting coaxial alignment. As with the smoking article 300 of the second embodiment, the mouthpiece 510 and mouth end of the smoking article 500 are formed by filter segment 544.

The combustible carbonaceous heat source 502, aerosol-forming substrate 504 and airflow directing element 506 are overwrapped in a first outer wrapper 512 of cigarette paper of low air permeability, forming a first part of the first section 514. The aerosol-cooling element 508, transfer element 509 and mouthpiece 510 are overwrapped in a second outer wrapper 516 of cigarette paper of low air permeability, forming a second part of the first section 514. The first section 514 further includes a band of tipping paper 520 circumscribing at least a downstream portion of the first outer wrapper 512 and at least an upstream portion of the second outer wrapper 516 to hold the two parts of the first section 514 together.

As with the smoking articles 100, 300 of the first and second embodiments, smoking article 500 also includes a removable cap 524 at the distal end of the smoking article 500 and directly adjacent to the heat source 502. The removable cap 124 comprises a central portion 526, and is wrapped in a portion 528 of the first outer wrapper 512. The portion 528 of the first outer wrapper which circumscribes the cap 524 is connected to the rest of the first outer wrapper 512 along a line of weakness 522. The line of weakness 522 comprises a plurality of perforations in the first outer wrapper 512 that circumscribe the smoking article 500. The line of weakness 522 defines a weakness formation in the first outer wrapper 512.

Unlike the smoking articles 100, 300 of the first and second embodiments, in this embodiment, the tubular element 550 is provided as part of the cap 524, forming the second section 514 of the smoking article 500. The tubular element 550 circumscribes the central portion 526 of the cap 524 and at least part of the length of the heat source 502. In this manner, the heat source 502 is received in the recess 552 defined by the tubular element 550 prior to use of the smoking article. The portion 528 of the first outer wrapper 512 which circumscribes the cap also circumscribes the tubular element 550 and integrally connects the first section 514 and the second section 518.

To use the smoking article 500, the user separates the first and second sections 514, 518 across separation plane 5000 by twisting the cap 524 and the tubular element 550 to break the first outer wrapper 512 along the line of weakness 522 and separate the first portion 528 of wrapper from the rest of the first outer wrapper 512. When the first and second sections 514 518 are separated, as shown in Figure 6, the heat source 502 is partially exposed enabling the user to light the smoking article 500.

In use, the user ignites the combustible heat source 502 which heats the aerosol-forming substrate 504 to produce an aerosol. When the user inhales on the mouthpiece 510 air is drawn through the air inlets 542, through the aerosol-forming substrate 504, airflow directing element 506, aerosol-cooling element 508, transfer element 509 and mouthpiece 510, as indicated by the arrows in Figure 6, and into the user's mouth.

After use of the smoking article 500, the user returns the second section 518 to its initial position at the upstream end of the first section 514 so that the combustible heat source 502 is received in the recess 552 of the tubular element 550. In this position, the tubular element 550 is a frictional fit over the combustible heat source 502 and sufficiently restricts the supply of oxygen to the combustible heat source so that the heat source extinguishes, and thus cools down.

In all of the above described embodiments, the tubular element may comprise an intumescent material, or heat-shrink material which reacts to the heat of the combustible heat source to further restrict the supply of oxygen to the heat source when the smoking article is in the extinguishing configuration. The intumescent or heat-shrink material may also at least partially close the open end of the tubular element to further restrict the supply of oxygen to the heat source. In addition to yet further restricting the supply of oxygen, the at least partially closed end of the tubular element may provide a physical barrier between the heat source and any external materials.

The specific embodiments and examples described above illustrate but do not limit the invention. It is to be understood that other embodiments of the invention may be made and the specific embodiments and examples described herein are not exhaustive.

Claims

CLAIMS:

1 . An aerosol generating article comprising:

a first section having a combustible heat source and an aerosol-forming substrate; and a second section having a tubular element defining a recess at one end of the second section,

wherein the first and second sections are integrally connected at a region of weakness, the first section and second section being separable at the region of weakness to enable the tubular element to be placed over the combustible heat source, such that the combustible heat source is at least partially received in the recess,

wherein the first section is upstream of the second section when the first and second sections are integrally connected at the region of weakness,

wherein the tubular element is at least partially open at both of its ends such that, during use of the aerosol generating article, air may be drawn along the aerosol generating article through the tubular element, and

wherein the tubular element is either at the downstream end of the second section, such that the recess forms a mouth end cavity of the aerosol generating article when the first and section sections are integrally connected, or the tubular element is at the upstream end of the second section and forms a transfer element of the aerosol generating article when the first and section sections are integrally connected.

2. An aerosol generating article according to claim 1 , wherein the tubular element is arranged such that, when the combustible heat source is received in the recess, the tubular element extends along substantially the entire length of the combustible heat source.

3. An aerosol generating article according to any preceding claim, wherein the tubular element is arranged such that, when the combustible heat source is ignited and received within the recess, the tubular element sufficiently restricts the supply of air to the combustible heat source that the combustible heat source is extinguished by the tubular element.

4. An aerosol generating article according to claim 3, wherein the tubular element is dimensioned such that, when the combustible heat source is received within the recess, there is a frictional fit between the inner surface of the tubular element and the outer surface of the combustible heat source.

5. An aerosol generating article according to any preceding claim, wherein an inner surface of the tubular element comprises non-combustible material and wherein, preferably, the non- combustible material is at least one of: a metal; a metal oxide; a ceramic; and a stone.

6. An aerosol generating article according to any preceding claim, wherein the tubular element comprises a heat reactive material that is arranged to deform in response to heat from the combustible heat source when the combustible heat source is received in the recess such that the tubular element fits tightly against the combustible heat source to restrict the air supply to the combustible heat source.

7. An aerosol generating article according to claim 6, wherein the heat reactive material comprises an intumescent material.

8. An aerosol generating article according to claim 6, wherein the heat reactive material comprises a heat-shrink material.

9. An aerosol generating article according to any preceding claim, wherein the region of weakness is a line of weakness.

10. An aerosol generating article according to any preceding claim, wherein the first and second sections are circumscribed by a wrapper and wherein the region of weakness comprises a weakness formation provided in the wrapper.

1 1 . An aerosol generating article according to claim 10, wherein the weakness formation comprises a plurality of perforations in the wrapper, the plurality of perforations circumscribing the aerosol generating article.

12. An aerosol generating article according to any preceding claim, wherein the region of weakness is located at least about 10 mm, preferably at least about 20 mm, from either end of the aerosol generating article.