WO2025026929A1

WO2025026929A1 - Aerosol generating article

Info

Publication number: WO2025026929A1
Application number: PCT/EP2024/071326
Authority: WO
Inventors: Alec WRIGHT; Laszlo Budai; Johannes Dänner; Thomas JOHAENTGES
Original assignee: JT International SA
Current assignee: JT International SA
Priority date: 2023-07-28
Filing date: 2024-07-26
Publication date: 2025-02-06
Anticipated expiration: 2026-01-28

Abstract

An aerosol generating article for use in an aerosol generating device is disclosed, the aerosol generating article (100) comprising: an aerosol generating substrate (102) comprising a granular based tobacco substrate; a first mouth end segment (106) arranged downstream of the aerosol generating substrate; and a second end segment (104) arranged upstream of the aerosol generating substrate, wherein a ratio of a resistance-to-draw, RTD, of the second end segment to the RTD of the first mouth end segment is less than 1.

Description

AEROSOL GENERATING ARTICLE

FIELD OF INVENTION

The present invention relates to aerosol generating articles for aerosol generation devices, in particular for heat-not-burn and heated tobacco stick devices.

BACKGROUND

Heated tobacco stick (HTS) aerosol generation devices have become increasingly popular over known ready-made-cigarettes and combustible tobacco products. In such devices, a tobacco consumable is inserted into the oven or cavity of an aerosol generation device to be heated so as to generate an inhalable aerosol during a vaping session. After use, known tobacco consumables for heat-not-burn (HNB) devices cause debris remain in the device oven I cavity after the consumable is removed. The residues left in the oven require a cleaning of the oven by the user before the next use of the HNB device. If the user does not clean the oven after removing the HTS, the remaining debris can cause a build-up of dirt or burning and lead to an undesirable generation of vapour when the device is subsequently used.

An object of the present invention to address the problems of known aerosol generating consumables.

SUMMARY OF INVENTION

According to an aspect of the invention there is provided an aerosol generating article for use in an aerosol generating device, the aerosol generating article comprising: an aerosol generating substrate comprising a granular based tobacco substrate; a first mouth end segment arranged downstream of the aerosol generating substrate; and a second end segment arranged upstream of the aerosol generating substrate, wherein a ratio of a resistance-to-draw, RTD, of the second end segment to the RTD of the first mouth end segment is less than 1 . In this way, a granular based tobacco substrate has a higher internal porosity than known tobacco consumables (e.g. shredded tobacco fibres) for heated tobacco stick devices due to its granular structure. The granular based tobacco substrate may be considered as a porous substrate, which includes a plurality of pores, openings or gaps between the tobacco granules to allow air to flow through the substrate. This granular structure has a certain density or porosity that also allows more exchanges between the air flowing through the article and the tobacco material in the substrate. In other words, the granular based tobacco structure provides more aerosol generation per volume of tobacco material over known consumables. This means that for a same weight of tobacco material, a smaller volume is required for the aerosol generating article which allows aerosol generation devices to be constructed more efficiently (e.g. by using a smaller heater) as well as decreasing the costs in manufacturing, including for packaging.

The aerosol generating article of the present invention comprises a first mouth end segment and a second end segment such that the aerosol generating article is used in an aerosol generating device in only one configuration. In other words, the first mouth end segment and the second end segment are not interchangeable about the aerosol generating substrate. The present invention provides a second end segment, i.e. a portion arranged upstream of the aerosol generating substrate, that has a lower draw resistance I RTD than the first mouth end segment, downstream of the aerosol generating substrate. This ensures that the airflow through aerosol generating article is not undesirably limited or interfered by the upstream segment before it reaches the aerosol generating substrate. To put it in another way, the lower RTD, or pressure drop, of the second end segment allows air to more easily enter and flow into the aerosol generating substrate so as to effectively deliver generated aerosol to a user. The first mouth end segment, downstream of the aerosol generating substrate, ensures that the generated aerosol is effectively cooled before it reaches the user’s mouth. The RTD for the first mouth end segment may be no more than (i.e. equal to or less than) 120 mmWG and the RTD for the second upstream segment may be at least (i.e. equal to or greater than) 15 mmWG. In use, a user may place their lips or mouth at the first mouth end segment and draw aerosol generated from the aerosol generating article through the first mouth end segment into their mouth.

By arranging the lower RTD segment (that is the second end segment) upstream of the aerosol generating substrate, the present invention ensures that an optimal amount of air can be effectively provided to the aerosol generating substrate when a user inhales since the airflow from the second end segment into aerosol generating substrate is less impeded. The enhanced airflow into the aerosol generating substrate further ensures that any generated aerosol can be effectively collected and delivered downstream to the first mouth end segment and the user. In known articles, the upstream end segment often has a higher RTD segment than a mouthpiece segment which adversely affects the airflow into the aerosol generating substrate resulting in poorer aerosol delivery.

Preferably, the granular based tobacco substrate is moulded as a singular piece. In this way, the granular based tobacco substrate can be shaped according to design requirements and provide a singular homogeneous porous structure. A granular based tobacco substrate can be formed into different shapes and configurations of the aerosol generating substrate to be effectively formed so as to prevent the aerosol generating substance from breaking apart whilst improving aerosol generation and delivery through the aerosol generating article. For example, the granular based tobacco substrate may be moulded into the shape of a plug. In known products, a tobacco substrate may include a plurality of granules rather than a singular piece of granular based tobacco, as in the present substrate. It has been advantageously found that a granular based tobacco substrate provides a higher internal porosity and improved airflow compared to a substrate comprising shredded tobacco material (or strands or strips of tobacco material). Accordingly, a granular based tobacco substrate allows vapour and aerosol to be more effectively generated as well as allowing generated aerosol to be more readily extracted.

Preferably, the granular based tobacco substrate is moulded in the form of a granular based tobacco sheet and in a rolled configuration. In this way, a granular based tobacco sheet can also be effectively arranged in an aerosol generating article, such as a cylinder, to optimise the transfer of heat from the heater of an aerosol generation device to the aerosol generating substrate. The rolled configuration of the granular based tobacco sheet also effectively enhances airflow and aerosol delivery to a user. In addition, the moulded and rolled configuration of the granular based tobacco substrate provides a cohesive structure that improves the integrity and stability of the substrate, as well as ensuring efficient heat transfer and effective aerosol delivery. In known articles, the aerosol generating substrate is often provided as a plug which adversely restricts airflow since the plug form typically has an undesirably high RTD. As such it is more difficult to extract and deliver vapour or generated aerosol from known tobacco substrates.

Preferably, the aerosol generating substrate is a first aerosol generating substrate, and the aerosol generating article further comprises a second aerosol generating substance arranged with the first aerosol generating substrate. As an example, the second aerosol generating substance may be arranged with a rolled granular based tobacco sheet. In this way, different aerosol generating substance arrangements may be provided in the aerosol generating article, such as tobacco stems rolled in a granular based tobacco sheet, tobacco micro chip arrangements, or e-paper (e.g. paper which contains glycol and gum to make a gel-like substance). Advantageously, different flavours and aerosol generating substances may thus be incorporated into the present aerosol generating article in a way that allows for improved aerosol delivery and experience for the user. It should be understood that the second aerosol generating substance may comprise a non-tobacco substrate. For example, the non-tobacco substrate may include another plant material such as eucalyptus, ginger, mint or different flowers or fruits. The non-tobacco substrate may also be a synthetic flavour material and/or cooling agents such as cyclohexanecarboxamide, N-Ethyl-5-Methyl-2-(1- Methylethyl), N-(Ethoxycarbonylmethyl)-3-p-menthanecarboxamide, (1 R,2S,5R)- N-(4-Methoxyphenyl)-5-methyl-2-(1-methylethyl)cyclohexanecarboxamide, Butanamide, N, 2, 3-trimethyl-2-(1 -methylethyl)-, (N-Ethyl-2,2- diisopropylbutanamide and 1-[(1 R,2R,4R)-2-hydroxy-4- methylcyclohexyl]ethenone, preferably N-(Ethoxycarbonylmethyl)-3-p- menthanecarboxamide.

Preferably, the first aerosol generating substance comprises one or more channels, preferably wherein the one or more channels are formed by pressing the granular based tobacco substrate. In this way, the one or more channels allows aerosol to be generated and collected in the one or more channels for improved delivery of the generated aerosol through article. Preferably, a hole size of the one or more channels, such as the cross-sectional diameter of a channel, may be no more than 2 millimetres. The one or more channels can be strategically placed to ensure efficient heat transfer across the granular based tobacco substrate and allow generated aerosol to be effectively delivered to a user.

The second upstream end segment may comprise a layer arranged across the aerosol generating substrate. Preferably, this layer may comprise one or more holes. For example, the layer may comprise a mesh. Preferably, the second end segment comprises one or more holes arranged to substantially align with one or more channels in the aerosol generating substance. In this way, airflow upstream of the aerosol generating substance can flow more readily into and through aerosol generating substance without interference. One or more holes of the second end segment may also partially align with the one or more channels in the aerosol generating substance.

Each hole in the second end segment may have a size that is smaller than a predetermined minimum tobacco granule size for a tobacco granule in the granular based tobacco substrate. In this way, the second end segment may additionally provide a barrier to prevent loose tobacco, or loose tobacco granules, from falling out of the aerosol generating article (e.g. into an oven or cavity of an aerosol generation device). The second end segment may comprise paper. In this way, the second end segment would be less susceptible to shrinking when heated by a heater of an aerosol generation device. Alternatively, the second end segment may comprise another filtration material, such as cardboard or cellulose acetate, or a combination of materials. Alternatively, the granular based tobacco substrate may be unpressed. The granular based tobacco substrate may include loose tobacco granules that are formed to make the granular based tobacco substrate using other components, such as a binder and gelling agent, without requiring a pressing step in the manufacturing process.

Preferably, tobacco granules in the granular based tobacco substrate comprise a maximum density is 1.2 g/cm³, more preferably wherein the maximum density is 0.8 g/cm³. It has been advantageously found that limiting the maximum density of the tobacco granules in the granular based tobacco substrate allows generated aerosol to be effectively released from the tobacco substrate for delivery to the user.

The granular based tobacco substrate may comprise tobacco granules, a binder, a humectant, and a gelling agent. Preferably, the granular based tobacco substrate comprises a humectant comprising propylene glycol, preferably wherein the granular based tobacco substrate comprises at least 1 % propylene glycol. Preferably, the granular based tobacco substrate comprises no more than 30% propylene glycol. The use of a humectant helps to promote the aerosolization of the tobacco. Propylene glycol has a lower boiling point than glycerol and advantageously allows vapour / aerosol to be generated more readily. In addition, it has been found that the generated aerosol I vapour to have increased sweetness with the use of propylene glycol.

Humectants may require more energy I power to be consumed from the device to deliver aerosol to the user since they capture water and increase the water content in the substrate. Therefore, it is important to control the amount of humectant (e.g. propylene glycol) in the granular based tobacco substrate to optimise the aerosol generation from the substrate for the power consumption of an aerosol generation device. Preferably, an overall resistance to draw, RTD, of the aerosol generating article is at least 50 mmWG. It has been advantageously found that a resistance to draw of at least 50 mm WG for the aerosol generating article provides an effective draw resistance for generated aerosol to be delivered from granular based tobacco substrates through the aerosol generating articles of the present disclosure.

Preferably, a RTD of the one or more aerosol generating substances is at least 30 mmWG. A draw resistance of at least 30 mmWG for the one or more aerosol generating substances ensures that airflow through the aerosol generating substances can deliver a suitable amount of generated aerosol whilst providing a high sensory experience to the user.

Preferably, a RTD of the second end segment is equal to or greater than 15 mmWG and a RTD of the first mouth end segment is equal to or less than 120 mmWG. Importantly, to ensure that the ratio of the RTD of the second end segment to the RTD of the first mouth end segment is less than 1 , the RTD of the second end segment must be less than the RTD of the first mouth end segment. The RTD for the first mouth end segment may be no more than (i.e. equal to or less than) 120 mmWG and the RTD for the second upstream end segment may be at least (i.e. equal to or greater than) 15 mmWG. Accordingly, the granular tobacco substrate preferably has a RTD of at least 30 mmWG where the RTD of the mouth end segment is equal to or less than 120mmWG such that the overall RTD of the aerosol generating article is at least 50 mmWG. Importantly, in the present invention it is necessary that the RTD of the second end segment (e.g. the front plug) is below the RTD of the first mouth end segment to ensure that airflow is effectively provided through the second end segment to the aerosol generating substrate, and for generated aerosol to be optimally delivered to the user.

Preferably, the first mouth end segment comprises one or more of: a paper tube; a hollow filter; a filter plug; and a mouthpiece portion. Each of these components may provide a draw resistance for the first mouth end segment. In addition, these components may allow the generated aerosol to sufficiently cool down before entering a user’s mouth. As will be appreciated, the paper tube may not be necessarily constructed from paper and may be a hollow tube or a centre hole made from another material such as cellulose acetate, a polymer material, or cardboard for example. The filter plug may comprise cellulose acetate or another filtration material known in the art.

Preferably, the aerosol generating article further comprises a wrapper configured to encase the aerosol generating substance, the first mouth end segment and/or the second end segment. Preferably, the wrapper comprises a plurality of perforations, more preferably wherein the wrapper circumscribes the first mouth end segment. In this way, the perforations may allow outside air to enter the first mouth end segment to combine with the generated aerosol before delivery to a user. In another example, the plurality of perforations may circumscribe the second end segment.

According to another aspect of the invention, there is provided an aerosol generation device, comprising: a cavity for receiving an aerosol generating article; the aerosol generating article according to the first aspect; a heater configured to heat the received aerosol generating article; and at least one airflow channel configured to direct air from outside the aerosol generation device to the second end segment of the aerosol generating article.

DESCRIPTION OF DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows a schematic of an aerosol generating article according to the present invention;

Figures 2a and 2b show schematics of different downstream portions for an aerosol generating article according to the present invention; Figure 3 shows a schematic of another downstream portion of an aerosol generating article according to the present invention;

Figures 4a and 4b show schematics of different upstream portions for an aerosol generating article according to the present invention;

Figure 4c shows a schematic of another upstream portion in an aerosol generating article according to the present invention; and

Figure 5 shows a schematic of the aerosol generating article in an aerosol generation device according to the present invention.

DETAILED DESCRIPTION

Figure 1 is a schematic illustration of an aerosol generating article 100 comprising three parts: an aerosol generating substrate 102, an upstream portion 104 and a downstream portion 106.

The aerosol generating substrate 102 comprises a granular based tobacco substrate, which includes: tobacco granules, a binder, a humectant, and a gelling agent. Exemplary components in the aerosol generating substrate 102 may include: tobacco granules, propylene glycol, glycerin, water, gum and a binder, as well as non-reconstituted tobacco such as tobacco leaf. As an example, the aerosol generating substrate 102 may comprise between 30.0 % to 50.0 % tobacco.

The humectant acts to vaporise when the granular composition is heated, to form an aerosol which typically carries flavour components of the tobacco for inhalation. In other words, the humectant acts as an aerosol forming agent. Exemplary humectants include propylene glycol and glycerin. As an example, the aerosol generating substrate 102 may comprise up to 30.0 % propylene glycol and/or up to 30.0 % glycerin. The aerosol generating substrate may comprise propylene glycol up to 30.0 %, preferably at least 1.0 % propylene glycol, more preferably between 1.0 % to 30.0 %, more preferably between 8.0 % to 22.0 %, and even more preferably between 10.0 % to 18.0 %.

In addition, the aerosol generating substrate 102 may comprise up to 5.0 % water. The use of more propylene glycol may require less tobacco to be used in an aerosol generating substrate, since the humectant can increase the flavour or aerosolization of the tobacco in the substrate. For example, an aerosol generating substrate may comprise 16.0 % propylene glycol and 33.0 % tobacco. Alternatively there may be no propylene glycol in the aerosol generating substrate, for example an aerosol generating substrate may comprise 0 % propylene glycol and 50.0 % tobacco, and further comprise a higher amount of glycerin, such as 28.0 % glycerin.

The gelling agent and/or the binder may act to gel or bind the components of the granular composition so as to retain the desired granular composition and to provide a crumbly, soft granular composition. The granular composition may comprise any suitable gelling agent. Examples of suitable gelling agents include, but are not limited to, gellan gum, gum arabic, gelatine, pectin, carrageenan, locust bean gum, alginates, lecithin and agar, as well as combinations thereof. Preferably the gelling agent may comprise gellan gum. As an example, the aerosol generating substrate 102 may comprise between 4.0 % to 7.0 % gum, preferably between 4.5 % to 6.8 % gum.

The granular composition may comprise any suitable binder. Examples of suitable binders include, but are not limited to, cellulose ethers (such as carboxymethylcellulose), modified starch, and hydroxy-alkylated carbohydrates (such as hydroxypropylcellulose), as well as combinations thereof. Preferably the binder may comprise purified carboxymethylcellulose, such as Ceroga 4550 C or CEKOL® 2000 (available from C.E. Roeper GmbH). As an example, the aerosol generating substrate 102 may comprise between 10.0 % to 17.0 % binder, preferably between 11.0 % to 16.4 % binder. As will also be understood by the skilled person, other aerosol-forming ingredients may also be used, such as cannabinoids, herbs and other plant. The granular composition may further comprise one or more additives. Suitable additives would be well known to persons skilled in the art and the additives may be included in the granular compositions in any suitable amounts. Suitably, the granular composition may further comprise one or more additives selected from the group consisting of a flavourant, a stimulant, an active ingredient and a stabiliser.

The upstream portion 104 is a segment of the aerosol generating article 100 that is arranged upstream of the aerosol generating substrate 102 (i.e. where the upstream portion 104 is arranged to receive airflow before the aerosol generating substrate 102). The upstream portion 104 can also be known as a front plug that abuts the upstream end 108 of the aerosol generating substrate 102 to hold the aerosol generating substrate 102 in place in the article 100. The upstream portion 104 may be made of paper and include one or more channels running through the upstream portion 104 from the open end 110 of the aerosol generating article 100 to the upstream end 108 of the aerosol generating substrate 102, as shown in Figure 2. The upstream portion 104 of the present disclosure has a lower resistance-to-draw, RTD, that the RTD of the downstream portion 106 such that the ratio of the RTD of the upstream portion 104 to the RTD of the downstream portion 106 is less than 1.

The downstream portion 106 is another segment of the aerosol generating article 100 that is arranged downstream of the aerosol generating substrate 102 (i.e. where the downstream portion 106 is arranged to receive airflow and generated aerosol from the aerosol generating substrate 102). The downstream portion 106 comprises a number of different components, including: a paper tube 112 and a filter plug 114. The downstream portion 106 may also include a mouthpiece (not shown). Each of these components may provide a draw resistance for the first mouth end segment.

The paper tube 112 is arranged to abut against the downstream end 116 of the aerosol generating substrate 102 and provides a cooling channel for the generated aerosol. The filter plug 114 is arranged further downstream from the paper tube 112 to provide any required filtration and draw resistance to the airflow and generated aerosol before inhalation by a user. The optional mouthpiece may or may not provide a resistance-to-draw to the overall aerosol generating article, as required by design.

The aerosol generating article 100 further includes a wrapping paper or wrapper 118 that encases the aerosol generating substance 102 and the upstream portion 104 and the downstream portion 106. To put it in another way, the wrapper 118 wraps around the aerosol generating substance 102, the upstream portion 104 and the downstream portion 106. In the specific example of Figure 1 , the wrapper 118 is a single component which fully encases (i.e. wraps around or surrounds) the aerosol generating substance 102, the upstream portion 104 and the downstream portion 106. However, as will be understood, the wrapper 118 may comprise multiple wrapping paper portions which respectively hold the upstream portion 104 and downstream portion 106 together with the aerosol generating substrate 102. In addition, the wrapper 118 may not fully encase I wrap around the upstream portion 104 or the downstream portion 106. For example, for the downstream portion 106, the wrapper may extend from the aerosol generating substrate 102 across the paper tube 112 to the filter plug 114 but not fully encase the filter plug 114.

The wrapper 118 may also include a plurality of holes or perforations (not shown) to introduce air inlets into the aerosol generating article 100 at the upstream portion 104 and/or the downstream portion 106.

Exemplary dimensions of the aerosol generating article 100 are as follows:

An upstream portion 104 may typically have a length of 5 mm to 12 mm, preferably 10 mm to 12 mm, in the direction of airflow (i.e. from the open end 110 of the aerosol generating article 100 to upstream end 108 of the aerosol generating substrate 102), - An aerosol generating substrate 102 may, for example, have a length of 8 mm to 10 mm in the direction of airflow (from the upstream end 108 to the downstream end 116 of the aerosol generating substrate 102),

- A downstream portion 106 typically having a length comprised for example between 20 mm and 30 mm, and approximately equal to 40 mm. As an example, the downstream portion may include a paper tube 112 having a length of 20 mm in the direction of airflow (from the downstream end 116 of the aerosol generating substrate 102 to the end of the paper tube abutting the filter plug 114), and a filter plug 114 having a length of 20 mm in the direction of airflow (from the paper tube to the end of the aerosol generating article 100).

Figure 2a shows another schematic of the downstream portion 106 of the aerosol generation article 100. The downstream portion 106 has two parts comprising a paper tube 112 and a filter plug 114.

The paper tube 112 is a hollow tube which is configured to abut against the aerosol generating substrate 102 in an assembled aerosol generation article 100 to keep the substrate 102 in position. The central hollow section in the paper tube 112 allows generated aerosol to cool before entering the filter plug 114. The paper tube 112 may also include one or more holes or perforations (not shown) to allow outside air to enter the hollow section and mix with the generated aerosol.

The filter plug 114 is made of a known filtration material such as cellulose acetate, paper or other material in the art and is arranged at the downstream end of the paper tuber 112.

Figure 2b shows another downstream portion 156 for the aerosol generation article 100. The downstream portion 156 also has two parts comprising an end wall 152 and a filter plug 154.

In some cases, the aerosol generated from the aerosol generating substrate 102 may not require significant cooling and the paper tube 112 of Figure 2a may not be necessary for the aerosol generation article 100. The end wall 152 may be a disc-shaped wall made of paper, cardboard or other suitable material and is configured to abut against the downstream end of the aerosol generating substrate 102 in the aerosol generation article 100. The end wall 152 comprises an opening 153 or central hole to direct generated aerosol into the filter plug 154. The use of an opening or hole 153 in an end wall 152 allows the aerosol delivery and the draw resistance from the aerosol generating substrate to be better controlled.

Figure 3 shows yet another downstream portion 180 for the aerosol generation article 100. The downstream portion 186 has three parts comprising an end wall 182, a paper tube 184 and a filter plug 186. The end wall 182, paper tube 184 and the filter plug 186 are the same as those described in reference to Figures 1 , 2a and 2b, but are assembled in combination to optimise aerosol delivery.

The end wall 182 is arranged at the upstream end of the downstream portion 180 such that it is positioned adjacent to the downstream end of an aerosol generating substrate 102 in an aerosol generation article 100. The central hole 183 in the end wall 182 is configured to direct generated aerosol into the paper tube 184 which is arranged downstream of the end wall 182 to receive the aerosol.

The paper tube 184 cools the received aerosol in the hollow section 185 of the paper tube 184 and directs the aerosol to the filter plug 186, and drawn into a user’s mouth through the filter plug 186.

Figure 4a shows a schematic of an upstream portion 200 for the aerosol generation article 100. The upstream portion 200 two parts comprising a plug 202 and a mesh 204.

The plug 202 is arranged to be positioned at the end of an assembled aerosol generation article 100 and provides a draw resistance when a user inhales through the article 100. The mesh 204 is arranged downstream of the plug 202 and configured to abut I be adjacent to the aerosol generating substrate 102. The mesh 204 may also provide a resistance-to-draw as well as prevent any debris from the aerosol generating substrate 102 from falling into an oven or cavity of an aerosol generation device.

Figure 4b shows yet another upstream portion 250 for the aerosol generation article 100. The upstream portion 250 has three parts comprising a plug 252, a hollow tube 254 and a mesh 256.

As described above, the a ratio of the resistance-to-draw of the upstream portion to the RTD of the downstream portion in the present disclosure is less than 1. Accordingly, the plug 252 in the upstream portion 250 may be a thin plug, like a disc, and the upstream portion 250 includes a hollow tube 254 between the plug 252 and the aerosol generating substrate 102. This may be for design purposes, such as to ensure alignment of a substrate with a heater in an aerosol generation device. A mesh 256 is further provided between the hollow tube 254 and the aerosol generating substrate 102 to prevent debris from falling out of the aerosol generation article 100.

Figure 4c shows a perspective view of the aerosol generation article 100 with another upstream portion 300 and another aerosol generating substrate 350.

The open end 110 of the aerosol generating article 100 I upstream portion 300 includes holes 302 which act as air inlets for the upstream portion 304 I aerosol generating article 100. Airflow entering the holes 302 are directed through channels 304 to deliver air to the aerosol generating substrate 350.

The aerosol generating substrate 350 also includes channels 352. The channels 352 in the aerosol generating substrate 350 are aligned with the channels 304 of the upstream portion 300. In another example, the channels 304 of the upstream portion 300 may be partially aligned, or even not aligned, with the channels of the aerosol generating substrate 350. As will be appreciated the alignment of channels may control the draw resistance of the aerosol generating article, where a greater alignment of respective channels results in a lower draw resistance and a lack of alignment of respective channels causes a higher draw resistance In use, the airflow through the aerosol generating substrate 350 is combined with generated aerosol and is delivered to the downstream portion 106, where it first enters the paper tube 112 and subsequently the filter plug 114. As can be seen in Figure 4c, the filter plug 114 does not include any channels, which provides a significant portion of the draw resistance of the downstream portion 106.

It should be understood that the upstream portion 300 in Figure 4c may be replaced with another upstream portion described herein, such as the upstream portions described in reference to Figures 1 , 4a and 4b. Similarly, the downstream portion 106 in Figure 4c may be replaced with another downstream portion described in the present disclosure, such as the downstream portions in described in reference to Figures 2a, 2b or 3.

Figure 5 is a schematic illustration of the aerosol generating article 100 of the present invention arranged in an aerosol generation device 400. The aerosol generation device 400 has a cavity 402 in which the aerosol generating article 100 is received, and a heater 404 configured to heat the aerosol generating substrate 102 in the received article 100. The heater 404 may be a resistive heater or an inductive heater, as will be understood by a person skilled in the art. As can be seen in Figure 5, a portion of the downstream portion 106 of the aerosol generating article 100 extends beyond the opening 406 of the cavity 402.

The aerosol generation device 400 further includes an air inlet 408 arranged to direct air from outside the aerosol generation device 400 to the closed end 410 of the cavity 402. As will therefore be understood, when a user inhales from a mouthpiece or from the filter plug 114 of the aerosol generating article 100, air from outside the device 400 is drawn into the cavity 402 through the air inlet 408. The outside air is directed to the closed end 410 or the base of the cavity 402, where it is further drawn into the aerosol generating article 100 from the open end 110 of the aerosol generating article 100 into the upstream portion 104.

The air is then drawn through the upstream portion 104 into the aerosol generating substrate 102 which releases generated aerosol when heated by the heater 404 of the device 400. The generated aerosol mixes with the air in the aerosol generating substrate 102 and drawn into the downstream portion 106. In the downstream portion 106, the generated aerosol may be further cooled and combined with additional outside air through one or more ventilation holes in the paper tube 112, just before it enters the filter plug 114. The aerosol is then drawn into the user’s mouth through the filter plug 114.

Claims

1 . An aerosol generating article for use in an aerosol generating device, the aerosol generating article comprising: an aerosol generating substrate comprising a granular based tobacco substrate; a first mouth end segment arranged downstream of the aerosol generating substrate; and a second end segment arranged upstream of the aerosol generating substrate, wherein a ratio of a resistance-to-draw, RTD, of the second end segment to the RTD of the first mouth end segment is less than 1 .

2. The aerosol generating article of claim 1 , wherein the granular based tobacco substrate is moulded as a singular piece.

3. The aerosol generating article of claim 2, wherein the granular based tobacco substrate is moulded in the form of a granular based tobacco sheet and in a rolled configuration.

4. The aerosol generating article of any of claims 1 to 3, wherein the aerosol generating substrate is a first aerosol generating substrate, and wherein the aerosol generating article further comprises a second aerosol generating substance arranged within the first aerosol generating substrate.

5. The aerosol generating article of any of the preceding claims, wherein the first aerosol generating substance comprises one or more channels, preferably wherein the one or more channels are formed by pressing the granular based tobacco substrate.

6. The aerosol generating article of claim 5, wherein the second end segment comprises one or more holes arranged to substantially align with one or more channels in the aerosol generating substance.

7. The aerosol generating article of any of claims 1 to 4, wherein the granular based tobacco substrate is unpressed.

8. The aerosol generating article of any of the preceding claims, wherein tobacco granules in the granular based tobacco substrate comprise a maximum density is 1.2 g/cm³, more preferably wherein the maximum density is 0.8 g/cm³.

9. The aerosol generating article of any of the preceding claims, wherein the humectant comprises propylene glycol, preferably wherein the granular based tobacco substrate comprises at least 1 % propylene glycol.

10. The aerosol generating article of any of the preceding claims, wherein an overall resistance to draw, RTD, of the aerosol generating article is at least 50 mmWG.

11 . The aerosol generating article of any of the preceding claims, wherein a RTD of the one or more aerosol generating substances is at least 30 mmWG.

12. The aerosol generating article of any of the preceding claims, wherein a RTD of the second end segment is equal or greater than 15 mmWG and a RTD of the first mouth end segment is equal or less than 120 mmWG.

13. The aerosol generating article of any of the preceding claims further comprising a wrapper configured to encase the aerosol generating substance, the first mouth end segment and/or the second end segment.

14. The aerosol generating article of claim 14, wherein the wrapper comprises a plurality of perforations, preferably circumscribing the first mouth end segment.

15. An aerosol generating device, comprising: a cavity for receiving an aerosol generating article; the aerosol generating article according to any of the preceding claims; a heater configured to heat the received aerosol generating article; and at least one airflow channel configured to direct air from outside the aerosol generating device to the second end segment of the aerosol generating article.