Aerosol-Generating Article Comprising Upstream Element

The present invention relates to an aerosol-generating article comprising an aerosol-generating substrate for generating an inhalable aerosol upon heating. The invention also relates to an aerosol-generating system comprising the aerosol-generating article and an aerosol-generating device configured to heat the aerosol-generating article.

Aerosol-generating articles in which an aerosol-generating substrate comprising aerosol-generating material, such as a tobacco-containing material, is heated rather than combusted are known in the art. An aim of such ‘heated’ aerosol-generating articles is to reduce known harmful smoke constituents of the type produced by the combustion and pyrolytic degradation of tobacco in conventional cigarettes.

Typically, in heated aerosol-generating articles an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate. In use, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source to the aerosol-generating substrate and are entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the user.

One known type of heated aerosol-generating article, commonly referred to as a heat-not-burn tobacco product or heated tobacco product, comprises a solid aerosol-generating substrate comprising tobacco material, which is heated to produce an inhalable aerosol.

A number of handheld aerosol-generating devices configured to heat aerosol-generating substrates of heated aerosol-generating articles are known in the art. These include electrically-operated aerosol-generating devices in which an aerosol is generated by the transfer of heat from one or more electrical heating elements of the aerosol-generating device to the aerosol-generating substrate of the heated aerosol-generating article. Known handheld electrically operated aerosol-generating devices typically comprise a battery, control electronics and one or more electrical heating elements for heating the aerosol-generating substrate of a heated aerosol-generating article designed specifically for use with the aerosol-generating device.

Some known electrically heated aerosol-generating devices comprise an internal heating element that is configured to be inserted into the aerosol-generating substrate of a heated aerosol-generating article. For example, WO 2013/098410 A2 discloses an aerosol-generating system comprising an aerosol-generating article and an electrically-operated aerosol-generating device comprising a heating element in the form of a blade that is inserted into the aerosol-generating substrate of the aerosol-generating article.

Other known electrically-operated aerosol-generating devices comprise one or more external heating elements. For example, WO 2020/115151 A1 discloses an aerosol-generating system comprising an aerosol-generating article and an electrically-operated aerosol-generating device comprising an external heating element that circumscribes the periphery of the aerosol-generating article.

Electrically-operated aerosol-generating devices comprising an inductor configured to inductively heat aerosol-generating substrates of heated aerosol-generating articles are also known. For example, WO 2015/176898 A1 discloses an aerosol-generating system comprising an aerosol-generating article comprising an elongate susceptor in thermal contact with the aerosol-generating substrate and an electrically-operated aerosol-generating device having an inductor for heating the aerosol-generating substrate. In use, the fluctuating or alternating electromagnetic field produced by the inductor induces eddy currents in the susceptor, causing the susceptor to heat up as a result of one or both of resistive losses (Joule heating) and, where the susceptor is magnetic, hysteresis loses. Heat generated in the susceptor is transferred to the aerosol-generating substrate by conduction.

Heated aerosol-generating articles designed for use with an electrically-operated aerosol-generating device are typically inserted into a cavity of the aerosol-generating device in order to be heated. This may cause aerosol-generating material in the aerosol-generating substrate of the aerosol-generating article to be dislodged. Heating of the aerosol-generating substrate during use of the aerosol-generating article may result in drying of aerosol-generating material in the aerosol-generating substrate. This may make the aerosol-generating material more prone to dislodgement. During use of the aerosol-generating article, aerosol-generating material dislodged from the aerosol-generating substrate may fall out of the aerosol-generating article. As a result, the amount and location of aerosol-generating material in the aerosol-generating substrate may vary during use of the aerosol-generating article. This may adversely impact the quality and consistency of aerosol delivered to a user. During use of the aerosol-generating article, aerosol-generating material dislodged from the aerosol-generating substrate may fall into the cavity of the aerosol-generating device. Aerosol-generating material dislodged from the aerosol-generating substrate of the aerosol-generating article that falls into the cavity of the aerosol-generating device may prevent or inhibit optimal functioning of the aerosol-generating device.

It would be desirable to provide an aerosol-generating article for use with an aerosol-generating device in which the quality and consistency of aerosol delivered to a user is improved compared to known heated tobacco products. It would be desirable to provide an aerosol-generating article for use with an aerosol-generating device that allows optimal functioning of the aerosol-generating device.

The present disclosure relates to an aerosol-generating article comprising an aerosol-generating substrate. The aerosol-generating article may comprise an upstream element located upstream of the aerosol-generating substrate. The upstream element may comprise a tubular portion. The tubular portion may define an inner region of the upstream element. The upstream element may comprise a convoluted sheet. The convoluted sheet may define a plurality of longitudinally extending channels in the inner region. The convoluted sheet may have a basis weight of less than or equal to about 100 grams per square metre.

According to a first aspect of the invention, there is provided an aerosol-generating article comprising an aerosol-generating substrate and an upstream element located upstream of the aerosol-generating substrate, wherein the upstream element comprises: a tubular portion defining an inner region of the upstream element, and a convoluted sheet defining a plurality of longitudinally extending channels in the inner region, wherein the convoluted sheet has a basis weight of less than or equal to about 100 grams per square metre.

The present disclosure also relates to an aerosol-generating system. The aerosol-generating system may comprise an aerosol-generating article as described above. The aerosol-generating system may comprise an aerosol-generating device. The aerosol-generating device may be configured to heat the aerosol-generating substrate of the aerosol-generating article. The aerosol-generating device may comprise a housing. The housing may define a cavity. The cavity may be configured to receive the aerosol-generating article.

According to a second aspect of the invention, there is provided an aerosol-generating system comprising: an aerosol-generating article according to the first aspect of the invention; and an aerosol-generating device configured to heat the aerosol-generating substrate of the aerosol-generating article, wherein the aerosol-generating device comprises a housing defining a cavity configured to receive the aerosol-generating article.

As used herein with reference to the invention, the term “aerosol-generating article” is used to describe an article comprising an aerosol-generating substrate that is heated to generate an inhalable aerosol for delivery to a user.

As used herein with reference to the invention, the term “aerosol-generating substrate” is used to describe a substrate comprising aerosol-generating material that is capable of releasing upon heating volatile compounds that can generate an aerosol.

As used herein with reference to the invention, the term “aerosol” is used to describe a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. The aerosol may be visible or invisible. The aerosol may include vapours of substances that are ordinarily liquid or solid at room temperature as well as solid particles, or liquid droplets, or a combination of solid particles and liquid droplets.

As used herein with reference to the invention, the term “aerosol-generating device” is used to describe a device that interacts with the aerosol-generating substrate of the aerosol-generating article to generate an aerosol.

Aerosol-generating articles according to the invention have a proximal end through which, in use, an aerosol exits the aerosol-generating article for delivery to a user. The proximal end of the aerosol-generating article may also be referred to as the downstream end or mouth end of the aerosol-generating article. In use, a user draws directly or indirectly on the proximal end of the aerosol-generating article in order to inhale an aerosol generated by the aerosol-generating article.

Aerosol-generating articles according to the invention have a distal end. The distal end is opposite the proximal end. The distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosol-generating article.

Components of aerosol-generating articles according to the invention may be described as being upstream or downstream of one another based on their relative positions between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article.

As used herein with reference to the invention, the term “longitudinal” is used to describe the direction between the upstream end and the downstream end of the aerosol-generating article. During use, air is drawn through the aerosol-generating article in the longitudinal direction.

As used herein with reference to the invention, the term “length” is used to describe the maximum dimension of the aerosol-generating article or a component of the aerosol-generating article in the longitudinal direction.

As used herein with reference to the invention, the term “transverse” is used to describe the direction perpendicular to the longitudinal direction. Unless otherwise stated, references to the “cross-section” of the aerosol-generating article or a component of the aerosol-generating article refer to the transverse cross-section.

As used herein with reference to the invention, the term “width” denotes the maximum dimension of the aerosol-generating article or a component of the aerosol-generating article in a transverse direction. Where the aerosol-generating article has a substantially circular cross-section, the width of the aerosol-generating article corresponds to the diameter of the aerosol-generating article. Where a component of the aerosol-generating article has a substantially circular cross-section, the width of the component of the aerosol-generating article corresponds to the diameter of the component of the aerosol-generating article.

As used herein with reference to the invention, the term “tubular portion” is used to describe a generally cylindrical portion having a lumen along a longitudinal axis thereof. The tubular portion may have a substantially circular, oval or elliptical cross-section. The inner region of the upstream element corresponds to the lumen of the tubular portion. The lumen may have a substantially circular, oval or elliptical cross-section.

As used herein with reference to the invention, the term “sheet” is used to describe a laminar element having a width and a length substantially greater than a thickness thereof.

As discussed used herein with reference to the invention, the term “convoluted sheet” is used to describe a sheet comprising a plurality of turns.

Unless otherwise stated, references to properties of the convoluted sheet refer to properties of the sheet in its convoluted form in the upstream element of the aerosol-generating article.

Unless otherwise stated, references to properties of the sheet refer to properties of the sheet in its unconvoluted form.

It will be appreciated that some properties of the sheet may be the same in both its convoluted form and unconvoluted form. For example, the basis weight, weight, cross-sectional area, surface area, and length of the convoluted sheet are the same as the basis weight, weight, cross-sectional area, surface area, and length of the sheet in its unconvoluted form.

As used herein with reference to the invention, the basis weight of the convoluted sheet is the total weight of the convoluted sheet divided by the surface area of the convoluted sheet. Where the convoluted sheet is formed from a rectangular sheet, the surface area of the convoluted sheet is the same as the width of the rectangular sheet multiplied by the length of the rectangular sheet. For example, where the convoluted sheet is formed from a rectangular sheet having a width of about 170 millimetres and a length of about 5 millimetres, the surface area of the convoluted sheet is about 850 square millimetres.

Aerosol-generating articles according to the first aspect invention comprise an upstream element comprising a tubular portion defining an inner region of the upstream element, and a convoluted sheet defining a plurality of longitudinally extending channels in the inner region, wherein the convoluted sheet has a basis weight of less than or equal to about 100 grams per square metre. Inclusion of such an upstream element may advantageously reduce or prevent aerosol-generating material being dislodged from the aerosol-generating substrate during storage, transportation and use of the aerosol-generating article while providing an acceptable resistance to draw (RTD). Inclusion of such an upstream element may advantageously reduce or prevent any aerosol-generating material dislodged from the aerosol-generating substrate from falling into a cavity of an aerosol-generating device during use of the aerosol-generating article. Inclusion of such an upstream element may advantageously restrict or prevent longitudinal movement of the aerosol-generating substrate during storage, transportation and use of the aerosol-generating article.

The convoluted sheet partitions the inner region of the upstream element into a plurality of longitudinally extending channels along which air may be drawn through the upstream element. The convoluted sheet may thereby reduce the cross-sectional area of empty space in the upstream element that aerosol-generating material in the aerosol-generating substrate may be dislodged into while providing an acceptable resistance to draw (RTD). This may be particularly advantageous where the aerosol-generating substrate comprises a plurality of shreds, pellets, or granules of aerosol-generating material.

Any aerosol-generating material dislodged from the aerosol-generating substrate must travel upstream through the plurality of longitudinally extending channels defined by the convoluted sheet in order to exit the upstream element and the aerosol-generating article. The convoluted sheet may thereby prevent or restrict aerosol-generating material dislodged from the aerosol-generating substrate from falling into a cavity of an aerosol-generating device during use of the aerosol-generating article.

Inclusion of a convoluted sheet having a basis weight of less than or equal to about 100 grams per square metre may enable the convoluted sheet to have a larger cross-sectional area while retaining an appropriate total weight of the upstream element. The convoluted sheet may thereby partition the inner region of the upstream element into a greater number of longitudinally extending channels, while retaining an appropriate total weight of the upstream element.

The convoluted sheet may advantageously act as a barrier to prevent or restrict longitudinal movement of the aerosol-generating substrate during storage, transportation and use of the aerosol-generating article.

Accordingly, the provision of an aerosol-generating article comprising an upstream element comprising a tubular portion defining an inner region of the upstream element, and a convoluted sheet defining a plurality of longitudinally extending channels in the inner region, wherein the convoluted sheet has a basis weight of less than or equal to about 100 grams per square metre in accordance with the first aspect of the invention may improve the quality and consistency of aerosol delivered to a user compared to known heated tobacco products, and may allow optimal functioning of the aerosol-generating device of an aerosol-generating system in accordance with the second aspect of the invention.

The convoluted sheet comprises a plurality of turns. Preferably, the convoluted sheet comprises a plurality of non-concentric turns.

The convoluted sheet defines a plurality of longitudinally extending channels in the inner region of the upstream element. The convoluted sheet may have been one or more of crimped, folded, gathered, and pleated to define the plurality of longitudinally extending channels.

As used herein with reference to the invention, the term “crimped” denotes a convoluted sheet having a plurality of substantially parallel ridges or corrugations. Preferably, where the convoluted sheet has been crimped, the substantially parallel ridges or corrugations of the convoluted sheet extend in a longitudinal direction of the aerosol-generating article.

As used herein with reference to the invention, the term “gathered” denotes that a sheet is compressed or constricted substantially transversely relative to a longitudinal axis of the aerosol-generating article.

Preferably, the convoluted sheet has been crimped. This may advantageously reduce the variation in the cross-sectional area of the plurality of longitudinally extending channels defined by the convoluted sheet in the inner region of the upstream element.

Inclusion of a convoluted sheet that has been crimped in the upstream element may advantageously avoid or reduce the presence of longitudinally extending channels having a very large cross-sectional area in the inner region of the upstream element. The presence of longitudinally extending channels having a very large cross-sectional area in the inner region of the upstream element may adversely affect the ability of the upstream element to prevent or restrict upstream movement of aerosol-generating material from the aerosol-generating substrate.

Inclusion of a convoluted sheet that has been crimped in the upstream element may advantageously avoid or reduce the presence of longitudinally extending channels having a very small cross-sectional area in the inner region of the upstream element. The presence of longitudinally extending channels having a very small cross-sectional area in the inner region of the upstream element may increase the RTD of the upstream element beyond an acceptable or desired level.

Where the convoluted sheet has been crimped, adjacent ridges or corrugations of the convoluted sheet may be spaced apart from each other by less than or equal to about 1.2 millimetres, less than or equal to about 1 millimetre, or less than or equal to about 0.8 millimetres. For example, adjacent ridges or corrugations may be spaced apart from each other by less than or equal to about 0.5 millimetres. The spacing between adjacent ridges or corrugations may be selected based on a desired size of the plurality of longitudinally extending channels.

The convoluted sheet may have been crimped and then gathered. That is, the convoluted sheet may be a crimped and gathered sheet.

At least some of the plurality of longitudinally extending channels may be defined solely by the convoluted sheet.

At least some of the plurality of longitudinally extending channels may be defined by the convoluted sheet and the tubular portion. For example, one or more longitudinally extending channels adjacent to the tubular portion of the upstream element may be defined by the convoluted sheet and the tubular portion. The convoluted sheet may contact the tubular portion along the longitudinal direction to define a longitudinally extending channel.

The convoluted sheet is located in the inner region of the upstream element. The convoluted sheet may extend part way along the length of the upstream element.