WO2025056512A1

WO2025056512A1 - Aerosol provision device

Info

Publication number: WO2025056512A1
Application number: PCT/EP2024/075203
Authority: WO
Inventors: Theodora NANNOU; Rita Janoshazi
Original assignee: Nicoventures Trading Limited
Priority date: 2023-09-12
Filing date: 2024-09-10
Publication date: 2025-03-20

Abstract

An aerosol forming article (110) comprises a first surface comprising an aerosol-generating material (306), a second surface opposite the first surface such that an airflow path is defined between the first and second surfaces and an inlet (508) permitting air to flow into the article between the first and second surface, the inlet (508) having an area of at least 0.15 mm².

Description

AEROSOL PROVISION DEVICE

Technical Field

The present invention relates to an article for producing an aerosol.

Background

Smoking articles such as cigarettes, cigars and the like burn tobacco during use to create tobacco smoke. Attempts have been made to provide alternatives to these articles that burn tobacco by creating products that release compounds without burning. Examples of such products are heating devices which release compounds by heating, but not burning, the material. The material may be for example tobacco or other non-tobacco products, which may or may not contain nicotine.

Summary

In an aspect, an aerosol forming article is provided. The aerosol forming article comprises a first surface comprising an aerosol-generating material, a second surface opposite the first surface such that an airflow path is defined between the first and second surfaces, and an inlet permitting air to flow into the article between the first and second surface. The inlet may have an area of at least 0.15 mm².

The inlet may have an area of at least 0.20 mm². The inlet may have an area of at least 0.25 mm². The inlet may have an area of at least 0.30 mm². The inlet may have an area of at least 0.35 mm². The inlet may have an area of at least 0.37 mm². The inlet may have an area of at least 0.40 mm². The inlet may have an area of at least 0.45 mm². The inlet may have an area of at least 0.50 mm². The inlet may have an area of at least 0.51 mm².

The inlet may have an area of less than or equal to 5 mm². The inlet may have an area of less than or equal to 4 mm². The inlet may have an area of less than or equal to 3 mm². The inlet may have an area of less than or equal to 2.61 mm². The inlet may have an area of less than or equal to 1.91 mm². The inlet may have an area of less than or equal to 1.21 mm². The inlet may have an area of less than or equal to 0.86 mm². The inlet may have an area of less than or equal to 0.51 mm². The inlet may have an area that is substantially 0.51 mm². The inlet may have an area that is substantially 0.37 mm².

The aerosol forming article may be formed of a layered structure. The layered structure may comprise a first layer defining the first surface and a second layer defining the second surface. The layered structure may be a folded layered structure. The layered structure may comprise an intermediate layer. The inlet may be formed in the intermediate layer. The aerosol forming article may further comprise a flow control feature positioned such that air from the inlet impinges on the flow control feature, the flow control feature configured to reduce a velocity of the air. The flow control feature may be formed by a cross-member. The flow control feature may be formed in the intermediate layer. The flow control feature may be upstream of the aerosol generating material. The inlet may be formed by removing a portion of the intermediate layer. The layered structure may further comprise a further intermediate layer between the intermediate layer and the first layer. The layered structure further may comprise an additional further intermediate layer between the intermediate layer and the second layer. The airflow path may be free of obstructions between the first and second surfaces at the aerosol-generating material. The second surface may comprise aerosol generating material. The first surface may be substantially planar. The second surface may be substantially planar.

In yet another aspect, an aerosol provision system is provided. The aerosol provision system comprises any of the above-described aerosol forming articles, and an aerosol provision device configured to heat the aerosol generating material to generate aerosol. Brief Description of the Drawings

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

Fig. 1 shows a side view of an aerosol provision system;

Fig. 2 shows a schematic cross-sectional view of an article in a plane parallel to a longitudinal axis of the article;

Fig. 3 shows an exploded view of the substrates and the aerosol generating materials;

Fig. 4A shows an exploded view of intermediate layers of the article;

Fig. 4B shows a cross-sectional view of the third intermediate layer of the article;

Fig. 4C shows a cross-sectional view of the third intermediate layer showing a flow control feature;

Fig. 5 shows a graph of an amount of aerosol carried plotted against a gap size;

Fig. 6A shows a graph of pressure drop against various inlet area;

Fig. 6B shows a graph of the amount of aerosol delivered against various inlet sizes;

Fig. 7A shows a graph of the amount of aerosol delivered for articles with different characteristics including different outlet areas;

Fig. 7B shows a graph of the amount of aerosol delivered against outlet area;

Fig. 8 shows an exploded view of the structure components of various articles tested to produce the data shown in Fig. 7A;

Fig. 9 shows a graph of aerosol delivered for articles with different characteristics;

Fig. 10 shows an exploded view of the structure components of various articles tested to produce the data shown in Fig. 9; and

Fig. 11 shows a schematic cross-sectional view of the article in a plane perpendicular to the longitudinal axis of the article. Detailed Description

As used herein, the term “aerosol-generating material” is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol-generating material may, for example, be in the form of a solid, liquid or gel which may or may not contain an active substance and/or flavourants. Aerosol-generating material may include any plant-based material, such as tobacco-containing material and may, for example, include one or more of tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes. Aerosol-generating material also may include other, non-tobacco, products, which, depending on the product, may or may not contain nicotine. Aerosol-generating material may for example be in the form of a solid, a liquid, a gel, a wax or the like. Aerosol-generating material may for example also be a combination or a blend of materials. Aerosol-generating material may also be known as “smokable material”.

The aerosol-generating material may comprise a binder and an aerosol former. Optionally, an active and/or filler may also be present. Optionally, a solvent, such as water, is also present and one or more other components of the aerosol-generating material may or may not be soluble in the solvent. In some embodiments, the aerosol-generating material is substantially free from botanical material. In some embodiments, the aerosol-generating material is substantially tobacco free.

The aerosol-generating material may comprise or be an “amorphous solid”. The amorphous solid may be a “monolithic solid”. In some embodiments, the amorphous solid may be a dried gel. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. In some embodiments, the aerosolgenerating material may, for example, comprise from about 50wt%, 60wt% or 70wt% of amorphous solid, to about 90wt%, 95wt% or 100wt% of amorphous solid.

The aerosol-generating material may comprise an aerosol-generating film. The aerosol-generating film may comprise or be a sheet, which may optionally be shredded to form a shredded sheet. The aerosol-generating sheet or shredded sheet may be substantially tobacco free. According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user.

In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system.

In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosolgenerating material is not a requirement.

In some embodiments, the non-combustible aerosol provision system is an aerosol-generating material heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating system.

In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosolgenerating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosol-generating material and a solid aerosol-generating material. The solid aerosol-generating material may comprise, for example, tobacco or a non-tobacco product.

Typically, the non-combustible aerosol provision system may comprise a non-combustible aerosol provision device and a consumable for use with the non- combustible aerosol provision device.

In some embodiments, the disclosure relates to consumables comprising aerosol-generating material and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure.

In some embodiments, the non-combustible aerosol provision system, such as a non-combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energised so as to distribute power in the form of heat to an aerosol-generating material or to a heat transfer material in proximity to the exothermic power source.

In some embodiments, the non-combustible aerosol provision system may comprise an area for receiving the consumable, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, a filter and/or an aerosol-modifying agent.

In some embodiments, the consumable for use with the non-combustible aerosol provision device may comprise aerosol-generating material, an aerosolgenerating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and/or an aerosol-modifying agent.

An aerosol generating device can receive an article comprising aerosol generating material for heating. An “article” in this context is a component that includes or contains in use the aerosol generating material, which is heated to volatilise the aerosol generating material, and optionally other components in use. A user may insert the article into the aerosol generating device before it is heated to produce an aerosol, which the user subsequently inhales. The article may be, for example, of a predetermined or specific size that is configured to be placed within a heating chamber of the device which is sized to receive the article.

With reference to Fig. 1 , an aerosol provision system 10 comprises an aerosol provision device 100 for generating aerosol from an aerosol generating material. The aerosol provision system 10 further comprises a replaceable article 110 comprising the aerosol generating material. In broad outline, the aerosol forming device 100 may be used to heat the article 110 to generate an aerosol or other inhalable medium, which is inhaled by a user of the device 100. In the present example the aerosol forming article 110 is for use with the aerosol provision device 100. However, in other examples, the aerosol forming article 110 may be used as the aerosol provision device (e.g. where it is a one piece aerosol provision system which may be single use).

The aerosol forming device 100 comprises a body 102. A housing arrangement surrounds and houses various components of the body 102. An article aperture 104 is formed at one end of the body 102, through which the article 110 may be inserted for heating by an aerosol generator 200. The device 100 may also include a user-operable control element 150, such as a button or switch, which operates the device 100 when pressed. For example, a user may turn on the device 100 by operating the switch 150.

The aerosol generator 200 defines a longitudinal axis, which aligns with an axis of the article 110.

In use, the article 110 may be fully or partially inserted into the aerosol generator 200 where it may be heated by one or more components of the aerosol generator 200.

The device 100 includes an apparatus for heating aerosol-generating material. The apparatus includes an aerosol generating assembly, a controller (control circuit), and a power source. The apparatus forms part of the body 102. The aerosol generating assembly is configured to heat the aerosol-generating material of an article 110 inserted through the article aperture 104, such that an aerosol is generated from the aerosol generating material. The power source supplies electrical power to the aerosol generating assembly, and the aerosol generating assembly converts the supplied electrical energy into heat energy for heating the aerosol-generating material. The power source may be, for example, a battery, such as a rechargeable battery or a non-rechargeable battery. Examples of suitable batteries include, for example, a lithium battery (such as a lithium-ion battery), a nickel battery (such as a nickel-cadmium battery), and an alkaline battery.

The power source may be electrically coupled to the aerosol generating assembly to supply electrical power when required and under control of the controller to heat the aerosol generating material. The control circuit may be configured to activate and deactivate the aerosol generating assembly based on a user input. The user input may be via a button press or opening a door of the device (for example, a door covering a consumable receiving receptacle). The control circuit may be configured to activate and deactivate automatically, for example on insertion of an article.

The aerosol generating assembly may comprise various components to heat the aerosol generating material via an inductive heating process. Induction heating is a process of heating an electrically conducting heating element (such as a susceptor) by electromagnetic induction. An induction heating assembly may comprise an inductive element, for example, one or more inductor coils, and a device for passing a varying electric current, such as an alternating electric current, through the inductive element. The varying electric current in the inductive element produces a varying magnetic field. The varying magnetic field penetrates a susceptor (heating element) suitably positioned with respect to the inductive element, and generates eddy currents inside the susceptor. The susceptor has electrical resistance to the eddy currents, and hence the flow of the eddy currents against this resistance causes the susceptor to be heated by Joule heating. In cases where the susceptor comprises ferromagnetic material such as iron, nickel or cobalt, heat may also be generated by magnetic hysteresis losses in the susceptor, i.e. by the varying orientation of magnetic dipoles in the magnetic material as a result of their alignment with the varying magnetic field. In inductive heating, as compared to heating by conduction for example, heat is generated inside the susceptor, allowing for rapid heating. Further, there need not be any physical contact between the inductive element and the susceptor, allowing for enhanced freedom in construction and application.

With reference to Fig. 2, the article 110 further comprises a first substrate 302 and a second substrate 304. The first and second substrates 302, 304 are each made from an aluminium foil-backed high-grams per square meter (GSM) paper, e.g. 70gsm to 400 gsm or 100gsm to 400gsm paper, such as 240 gsm paper or any paper having a gsm greater than 400 gsm. In some embodiments, the aluminium foil-backed high-GSM paper may be considered to be an aluminium foil- backed higher-GSM paper. In some embodiments, the high GSM paper may have 0.125mm or 0.35mm thickness. In other embodiments, the high GSM paper may have greater or lesser thicknesses. In some embodiments, the first and second substrates 302, 304 may be considered to be bilaminate materials, e.g. card or paper backing with a metallic face. In other words, the first and/or second substrate 302, 304 each comprises a layer of aluminium (i.e. a heating layer) and a layer of paper or board material (i.e. a structural layer). In other examples, a layer of another metal or metal alloy may be used to provide the heating layer of the first and/or second substrates 302, 304 in place of the layer of aluminium.

The article 110 further comprises a first aerosol generating material 306 deposited on the first substrate 302. The article 110 further comprises a second aerosol generating material 308 deposited on the second substrate 304. Each of the first and second aerosol generating materials 306, 308 is an aerosol gel. The aerosol generating materials 306, 308 are deposited directly on the heating layer of the first and second substrates 302, 304. This means that the first and second substrates 302, 304 are arranged so that the heating layer is inside the article 110 and the structural layer is outward of the heating layer, on the outside of the article 110.

The article 110 is arranged so that the first and second aerosol generating materials 306, 308 are positioned to face each other. The article 110 further comprises at least one intermediate layer (not shown in Fig. 2) that separates the first and second aerosol generating materials 306, 308. The at least one intermediate layer is explained in more detail below in relation to Figs. 4A - 4C. In use, the heating layer, more specifically, the aluminium foil can be induced, e.g. via induction, to generate heat thereby heating up the aerosol gel. The heating of the aerosol gel produces an aerosol that can be used by the user, e.g. by inhalation. The first and second aerosol generating materials 306, 308 at least partially define an airflow path therebetween. The aerosol produced by the first and second aerosol generating materials 306, 308 can travel along the airflow path to the user. The article 110 comprises a mouth end and a distal end opposite the mouth end. The mouth end is the end from which the user can use/inhale the aerosol. In some embodiments, the article may have a mouth piece positioned at the mouth end. The mouth piece may be made from a different material from the rest of the article. The mouth piece may have a different construction from the rest of the article.

The article 110 is arranged so that the first aerosol generating material 306 is separated from the second aerosol generating material 308 by a gap d. The size of gap d may affect the flow velocity and/or pressure of the air in the airflow path during use, e.g. when inhaled by the user. The inventors have surprisingly found that particular values of gap d result in more aerosol being produced and/or delivered to the user. This may be due to the flow velocity and/or pressure in the airflow path affecting the degree to which the aerosol generating material is heated (e.g. due to a cooling effect of air) and/or the amount of aerosol that is carried by the airflow to the mouth end and/or user.

As such, if the airflow velocity is not large enough, insufficient aerosol may be carried by the airflow e.g. with aerosol droplets being deposited before the mouth end is reached. If the gap d is too small, the flow velocity may be too high, perhaps resulting in the aerosol generating material being heated to a lower temperature, thereby generating less aerosol.

In this embodiment, the gap d is greater than or equal to 0.9 mm. Advantageously, the inventors have found that d being greater than or equal to 0.9 mm may mean that the mass of aerosol delivered to the user is increased to a surprising degree, e.g. when compared to systems with d being less than 0.9 mm. More surprisingly, it was found that d being greater than or equal to 1.34 mm further improved this effect. More surprisingly, it was found that d being greater than 1.8mm, such as being substantially equal to 1.84 mm, may result in a greater mass of aerosol being generated and/or delivered. The mass of aerosol delivered may plateau or decrease as d increases beyond 1.84 mm. In some embodiments, d may be less than or equal to 4mm, e.g. less than or equal to 2.5 mm, less than or equal to 2.34 mm, less than or equal to 2.2 mm, less than or equal to 2.1 mm, less than or equal to 2.0 mm, less than or equal to 1.9 mm. More aerosol may be delivered to the user as d is reduced from 4mm to 1.84 mm.

In this embodiment, the article is an elongate shape. In other embodiments, the article is not an elongate shape, e.g. the article may have a shape that is a circle or a square. In this embodiment, the article is substantially planar. In other embodiments, the article is not planar. In this embodiment, the first and/or second aerosol generating material is an aerosol gel. In other embodiments, the first and/or second aerosol generating material is not an aerosol gel, e.g. an aerosol solid or an aerosol liquid. In this embodiment, the aerosol is generated via induction heating. In other embodiments, the aerosol is not generated via induction heating with heating taking place by another method e.g. via convection or conduction. In this embodiment, the substrate comprises a component that can be induced via induction to produce heat. In other embodiments, the substrate does not comprise a component that can be induced via induction to produce heat, e.g. the substrate may only comprise wood or paper. In this embodiment, the first substrate is the same as the second substrate. In other embodiments, the first substrate is different from the second substrate. In this embodiment, the aluminium foil is arranged to abut the aerosol generating material. In other embodiments, the aluminium foil is not arranged to abut the aerosol generating material, e.g. the high GSM paper is positioned between the aluminium foil and the aerosol generating material. In this embodiment, the first and/or second substrates are made from aluminium foil- backed high-GSM paper. However, in other embodiments, the first and/or second substrates are not made from aluminium foil-backed high-GSM paper, e.g. first and/or second substrates may be made from copper foil or another material that can produce heat via induction. In this embodiment, the first substrate and the first aerosol generating material are arranged in the same way as the second substrate and the second aerosol generating material. However, in other embodiments, the first substrate and the first aerosol generating material are arranged in a different way to the way the second substrate and the second aerosol generating material are arranged.

With reference to Fig. 3, the first substrate 302 has an elongated shape and extending in a longitudinal direction. The longitudinal direction extends from the mouth end to the distal end. The first aerosol generating material 306 is arranged in a series of discrete first portions 402-410 arranged sequentially along the longitudinal direction. The series of discrete first portion 402-410 are separated and/or spaced apart from each other. Similarly, the second substrate 304 has an elongated shape that is elongated along the longitudinal direction. The second aerosol generating material 308 is arranged in a series of discrete second portions 412-420 arranged sequentially along the longitudinal direction. In use, the discrete portions of the aerosol generating materials are sequentially heated. For example, for each inhalation by the user only one of the discrete portions is heated so as to produce aerosol. However, in other embodiments, for each inhalation by the user a plurality of discrete portions may be heated so as to produce aerosol.

In this embodiment, each of the discrete portions is shaped in a square. In other embodiments, each of the discrete portions is not shaped in a square, e.g. each of the discrete portions is shaped in a circle or diamond. In this embodiment, the discrete portions are the same as each other. In other embodiments, the discrete portions are not the same as each other. In this embodiment, the discrete first portions are the same as the discrete second portions. In other embodiments, the discrete first portions are not the same as the discrete second portions, e.g. the discrete second portions may have different shapes to the shapes of the discrete first portions. In this embodiment, the first and/or second aerosol generating materials are arranged in a series of discrete portions. In other embodiments, the first and/or second aerosol generating materials are not arranged in a series of discrete portions, e.g. the first and/or second continuous aerosol generating materials may be arranged in a strip or a continuous regular shape or a continuous irregular shape.

With reference to Fig. 4A, the article 110 comprises a first intermediate layer 502. The first intermediate layer 502 has a substantially planar shape that is elongate, extending along the longitudinal direction. The first intermediate layer 502 is configured to be coupled to the first aerosol generating material 306. The first intermediate layer 502 comprises a series of first holes. Each of the first holes has a shape that is complementary to a respective discrete first portion 402-410. The first intermediate layer 502 is configured to abut the first aerosol generating material 306 and the first substrate 302 so that each of the discrete first portions 402-410 fits inside its respective hole of the first intermediate layer 502.

In this embodiment, a substantially planar surface can be formed by the first intermediate layer and the first aerosol generating material extending therethrough. In this embodiment, the thickness of the first intermediate layer is substantially the same as the thickness of the first aerosol generating material. In other embodiments, the first intermediate layer and the first aerosol generating material does not form a substantially planar surface, e.g. the first aerosol generating materials extends past the first intermediate layer. In this embodiment, the first intermediate layer comprises a series of first holes. In other embodiments, the first intermediate layer does not comprise a series of first holes, e.g. the first intermediate layer may comprise a single hole that has a complementary shape to the shape of the first aerosol generating material.

With reference to Fig. 4A, article 110 further comprises a second intermediate layer 504. The second intermediate layer 504 has a substantially planar shape that is elongated along the longitudinal direction. The second intermediate layer 504 is configured to be coupled to the second aerosol generating material 308. The second intermediate layer 504 comprises a series of second holes. Each of the series of second holes has a shape that is complementary to a respective discrete second portion 412-420. The second intermediate layer 504 is configured to abut the second aerosol generating material 308 so that each of the discrete second portions 412-420 fits inside its respective second hole. In this way, a substantially planar surface can be formed by the second intermediate layer 504 and the second aerosol generating material 308 extending therethrough. The thickness of the second intermediate layer 504 is substantially the same as the thickness of the second aerosol generating material 308.

In this embodiment, a substantially planar surface can be formed by the second intermediate layer and the second aerosol generating material. In this embodiment, the thickness of the second intermediate layer is substantially the same as the thickness of the second aerosol generating material. In other embodiments, the second intermediate layer and the second aerosol generating material does not form a planar surface, e.g. the second aerosol generating materials extends past the second intermediate layer. In this embodiment, the second intermediate layer comprises a series of second holes. In other embodiments, the second intermediate layer does not comprise the series of second holes, e.g. the second intermediate layer may comprise a single hole that has a complementary shape to the shape of the second aerosol generating material.

With reference to Fig. 4A, the article 110 further comprises a third intermediate layer 506. The third intermediate layer 506 has a substantially planar shape elongated along the longitudinal direction. The third intermediate layer 506 comprises an inlet opening 508 at a first end of the third intermediate layer 506 along the longitudinal direction. A pressure drop across the article 110 may be important for user experience. In order to increase aerosol mass delivered to the user, which may also be important for user experience, it has been found that avoiding obstructions in the air flow path close to the aerosol generating material and increasing the outlet area may be beneficial. However, implementing these features may result in a pressure drop which is too small. It might therefore be beneficial to vary the inlet area to control the pressure drop across the article 110.

The third intermediate layer 506 further comprises an outlet opening 510 at a second end of the third intermediate layer 506 along the longitudinal direction. The first end is opposite to second end along the longitudinal direction. The outlet opening 510 corresponds to the mouth end of the article 110. The user may inhale aerosol from the outlet opening 510. The applicant has also surprisingly found that the area of the outlet opening 510 directly affects the mass of aerosol that may be generated and/or delivered to the user. When the outlet openings are small, the amount of aerosol generated tends to be small. Conversely, when the outlet openings are large, the amount of aerosol generated also tend to be large. Furthermore, increasing the area by increasing the width of the outlet opening instead of the thickness tends to provide a more significant improvement in aerosol generation.

The third intermediate layer 506 further comprises a conduit fluidly coupling the inlet opening 508 to the outlet opening 510. The inlet opening 508 allows air to enter the conduit. The third intermediate layer 506 is configured to provide the separation and/or gap d between the first and second aerosol generating materials 306, 308. As such, the separation caused by the third intermediate layer 506 causes an airflow path to be formed between the first and second aerosol generating materials 306, 308. The conduit is positioned to at least partially overlay the first and second aerosol generating materials 306, 308. The third intermediate layer 506 further comprises a top surface that is configured to be coupled to and/or abut the first intermediate layer 502. The third intermediate layer 506 further comprises a bottom surface opposite to the top surface. The bottom surface is configured to be coupled to and/or abut the second intermediate layer 504. The direction extending from the top surface to the bottom surface is perpendicular to the longitudinal direction. The direction extending from the top surface to the bottom surface is the dimension in which the thicknesses are defined. The thickness of the third intermediate layer 506 defines the size of the gap d. In other words, the thickness of the third intermediate layer 506 is the same as the distance d of the gap. In some embodiments, the size of the gap, d, is defined by the thickness of the third intermediate layer 506 in addition to the thickness of the adhesive layers used to adhere the third intermediate layer 506 to the first and second intermediate layers 502, 504. The third intermediate layer 506 comprises a bridge 512 extending across a width of the third intermediate layer 506. The width is defined in the direction that is perpendicular to both the longitudinal direction and the direction of the thickness. With reference to Fig. 4B, the bridge 512 has a thickness that is less than the thickness of the third intermediate layer 506. Advantageously, this means that the bridge tends to not obstruct the air flow path and/or the conduit. In this embodiment, the bridge is positioned proximate to the bottom surface of the third intermediate layer. In other embodiments, the bridge is not positioned proximate to the bottom surface, e.g. the bridge may be positioned approximate to the top surface of the third intermediate layer. In some embodiments, the bridge may be positioned in the middle between the top and bottom surfaces of the third intermediate layer, i.e. the bridge is position so that the distance between the bridge and the top surface is the same as the distance between the bridge and the bottom surface. In some embodiments, the bridge may be displaced relative to one or more cross members on first and/or second intermediate layers. The one or more cross members may be considered to be the parts of the first and/or second intermediate layers that separate the discrete portions of the aerosol generating materials. In some examples, the bridge may be omitted to provide the airflow path (e.g. with the third intermediate layer in two separate pieces).

With reference to Fig. 4C, the article 110 further comprises a flow control feature 514 that is positioned in the inlet opening 508. In this embodiment, the flow control feature 514 is a rib extending across the width of the inlet opening 508. The rib has a T shape. The bottom of the T shape contacts the second intermediate layer 504. The crossbar portion of the T shape extends the across the entire width of the inlet opening 508. The flow control feature 514 can help to guide air to a preferred region of airflow path thereby increasing the mass of aerosol carried by the airflow. Specifically, the air entering the airflow path may be forced to flow around the flow control feature 514 thereby flowing closer to the first and/or second aerosol generating materials 306, 308. In this embodiment, the T shape of the flow control feature 514 also forces the incoming air to flow into the corner regions of the airflow path, improving mixing.

The flow control feature 514 may also affect the velocity and/or pressure drop of the air in the airflow path during an inhalation by the user. Without such a flow control feature, when the user inhales, the velocity of the air entering the inlet can be much greater than the air at rest within the airflow path. This may also reduce the mixing between the air coming through the inlet and the air that is at rest within the airflow path. This means that a central jet of air tends to be formed by such an article, which is negatively impacts the performance of the article. Advantageously, the flow control features tend to reduce and/or mitigate a central jet of air to form when the user inhales. Furthermore, the flow control feature tends to improve mixing between incoming air through the inlet and the air that is at rest within the airflow path.

Furthermore, the flow control feature may increase the pressure drop in the airflow path. Specifically, the flow control feature tends to reduce the area of the inlet opening when the flow control feature is positioned in the inlet opening. As discussed above, the inlet opening being smaller tends to increase the pressure drop in the airflow path. In other words, the flow control feature may be considered to reduce the area of the inlet opening when positioned in the inlet opening.

In this embodiment, the flow control feature is positioned in the inlet opening. In this embodiment, the flow control feature has a T shape. In other embodiments, the flow control feature does not have a T shape, e.g. the flow control feature has a cross, or rod, or cuboid shape. In this embodiment, the flow control feature extends across the entire width of the inlet opening. In other embodiments, the flow control feature does not extend across the entire width of the inlet opening, e.g. the flow control feature extends across a limited portion of the inlet opening.

In the above embodiments, the thickness of the third intermediate layer defines the size of the gap, d. However, in other embodiments, one or more of the thicknesses of the first, second, and third intermediate layers define the size of the gap, d. In some embodiments, the gap is defined by the space between the first and second aerosol generating materials. In some embodiments, the gap is defined by the space between the first and second substrates. In some embodiments, the gap is defined by one or more of the thickness of the first intermediate layer, the thickness of the second intermediate layer, the thickness of the third intermediate layer, the thickness of the first aerosol generating material, the thickness of second aerosol generating material, the thickness of the first substrate, and the thickness of the second substrate. In the above-embodiments, the article comprises the first, second, and third intermediate layers. However, in other embodiments, the article does not comprise the first, second, and third intermediate layers. In some embodiments, the article comprises one or more of the first, second, and third intermediate layers. In some embodiments, the inlet and/or outlet may be formed by folding or lasering through one or more of the intermediate layers.

Experimentation has been performed on articles of various constructions which support the surprising advantages described in the present description. The results from the experiments on the articles are shown in the graphs in Figs. 5, 6A, 6B, 7A, 7B, and 9. The articles used in the experiments were constructed from individual layers. The individual layers can be cut with Silhouette, CNC, or Laser cutter. The cut profiles can then be positioned and glued together. The assembled articles can be tested in a laboratory with Borgwald equipment, with 5 repeats or more repeats, e.g. 10 repeats. Silhouette cutting tends to be more reliable and have less variability, e.g. compared to than CNC.

Fig. 5 shows a graph of the amount (mass) of aerosol delivered by the airflow to a mouth end where a user can inhale the aerosol, plotted against various experimental articles having varying gap size d (where d is the separation between the first aerosol generating material 306 and the second aerosol generating material 308, as described above with reference to the article 110 that is depicted in Fig. 2). With reference to Fig. 5, it can be seen that it was surprisingly found that when d = 1 .34 mm, the amount of aerosol delivered by the airflow increases. Moreover, it can be seen that further increases in the gap size d result in further increases in mass of aerosol delivered. From Fig. 5, it can be seen that when d = 1.84 mm more aerosol is delivered, with the amount of aerosol produced plateauing as d increases beyond 1.84 mm.

Referring now to Fig. 6A, which shows a graph of pressure drop plotted against various inlet areas. The articles tested to generate the data shown in Fig. 6A and 6B have the same structure as those of A1 in Fig. 8, as described below. From the graph in Fig. 6A it can be seen that the pressure drop increases with decreasing inlet area. In articles with the inlet openings having areas that are less than 0.4 mm² the pressure drop is found to be relatively large, which may detrimentally affect the performance of the system and/or the user’s experience. For example, this may result in the user unable to draw and/or breathe sufficient aerosol from the article. In some embodiments, the inlet opening may have an area that is greater than or equal to 0.15 mm², e.g. greater than or equal to 0.2 mm², greater than or equal to 0.21 mm², greater than or equal to 0.37 mm² greater than or equal to 0.4 mm²’ greater than or equal to 0.4 mm², greater than or equal to 0.5 mm², greater than or equal to 0.6 mm², greater than or equal to 0.7 mm², greater than or equal to 0.8 mm² , or greater than or equal to 0.86 mm². In some embodiments, the inlet opening may comprise two holes.

Referring now to Fig. 6B, which shows a graph of amount (mass) of aerosol delivered plotted against various inlet areas for various articles having inlets with different areas. It is noted that the articles tested for this graph are the same as the articles used for the graph of Fig. 6A. From the graph of Fig. 6B, it can be seen that an inlet area of 0.51 mm² may provide a maximum amount of aerosol delivery. Moreover, as it can be seen from Fig. 6B as inlet areas decreases from 0.51 mm² to 0.37 mm², the amount of aerosol delivered also decreases. The applicant also surprisingly found that below 0.5 mm², the amount of aerosol delivered reduces from the maximum. The applicant has also surprisingly found that for articles with inlet areas greater than 5 mm² the resultant amount of aerosol delivered reduces from the maximum. In some embodiments, the inlet opening may have area that is less than or equal to 5 mm², e.g. less than or equal to 4 mm², less than or equal to 3 mm², e.g. less than or equal to 2.61 mm², less than or equal to 1 .91 mm², less than or equal to 1.21 mm², less than or equal to 0.86 mm².

Fig. 7A shows a graph of the mass of aerosol delivered per puff plotted for various articles with different outlet areas. Table 1 provided below sets out the parameters of the various articles plotted in Fig. 7A.

Table 1

The structures of the various article shown in Fig. 7A are shown in Fig. 8, where:

Sub 1 - 1^st substrate having an aerosol gel deposited thereon;

Sub 2 - 2^nd substrate having an aerosol gel deposited thereon;

1/1a/1b - first intermediate layer;

2/2a/2b - second intermediate layer; and

3/3a/3b/3c - third intermediate layer.

In some of the articles, the first and second intermediate layers are each made from two separate planar components. In some of the articles, the third intermediate layer is made from three separate planar components. In some of the articles, the conduit tapers to the inlet opening. In some articles, the conduits tapers to the outlet opening. In some of the articles the conduits tapers along the longitudinal direction from the outlet opening to the inlet opening. In these the articles, the thicknesses of the layers are substantially constant. In these the articles, the inlet areas are constant.

It can be seen from Fig. 7A that articles with larger outlet openings may deliver larger mass of the aerosol when compared to articles with smaller outlet openings. Specifically, A2, A3, and A5 generate the largest amounts of aerosol compared with the other articles of Fig. 7A. Furthermore, it can be seen from Fig. 7A, that the larger outlet openings may result in increases in the amount of aerosol delivered despite various changes to the structure of the article, e.g. the various degrees of tapering of the conduit. This may be due to the larger outlet openings reducing the turbulence and/or mixing of the airflow exiting the airflow path through the outlet openings. As such, the lager outlet openings may tend to reduce the likelihood that the aerosol separates out from the airflow before delivery to the user. Moreover, the corner portions of the airflow path may trap a certain amount of aerosol. The larger outlet openings may tend to reduce the size of these corner portions thereby reducing the amount of the aerosol that can be trapped in the airflow path.

The outlet opening having an area of at least 2.55 mm² tends to result in larger mass of aerosol to be generated and/or delivered, e.g. when compared to articles with outlet openings having areas of less than 2.55 mm². In particular, outlet openings having areas that is substantially 6.85 mm² may result in particularly greater amounts of aerosol generated and/or amounts of aerosol delivered to the user. The outlet opening may be defined by the thickness of the third intermediate layer and the adhesive used to couple the third intermediate layer to the first and/or second intermediate layer. Additionally or alternatively, the outlet opening may be defined by the thickness of the first and/or second intermediate layer. In some embodiments, the outlet openings may have an area that is greater than or equal to 0.15 mm², e.g. greater than or equal to 0.25 mm², greater than or equal to 0.5 mm², greater than or equal to 0.75 mm², greater than or equal to 1 .0 mm², greater than or equal to 1 .25 mm², greater than or equal to 1 .5 mm², greater than or equal to 1 .75 mm², greater than or equal to 2.0 mm², greater than or equal to 2.25 mm², greater than or equal to 2.55 mm², greater than or equal to 2.8 mm², greater than or equal to 3 mm², greater than or equal to 4 mm², greater than or equal to 5 mm², or greater or equal to 7 mm², or greater or equal to 9 mm², or greater or equal to 10 mm². In some embodiments, the outlet openings may have an area that is less than or equal to 10 mm², e.g. less than or equal to 9 mm², or less than or equal to 8 mm², or less than or equal to 7 mm², or less than or equal to 6 mm² or less than or equal to 5 mm² or less than or equal to 4.11 mm².

Referring to Fig. 7B, which shows a graph of amount of aerosol delivered plotted against various articles having increasing outlet areas. The various articles of Fig. 7B all have the same fixed inlet area. It can be seen from Fig. 7B that the amount of aerosol delivered does not vary greatly when increasing the outlet area to be greater than 4.11 mm².

In this embodiment and in the articles tested in the experimental setups discussed above and shown in Fig. 8, the outlet opening and/or inlet opening is rectangular. As such, the area of the outlet opening and/or inlet may be equal to a width w of the opening multiplied by the thickness of the third intermediate layer. The area of the inlet and/or outlet may be based on the shape of the inlet and/or the outlet. In some embodiments, the inlet and/or outlet opening is not rectangular, e.g. the inlet and/or outlet may be circular. In some embodiments, the area of the outlet and/or inlet opening is defined by the thickness of one or more of the intermediate layers. In some embodiments, the area of the outlet and/or inlet opening is not defined by the thickness of one or more of the intermediate layers, e.g. the inlet and/or outlet openings can be drilled, punctured, or lasered into the intermediate layers. Advantageously, the drilling of the inlet opening may help spread the inlet airflow over the first and/or second aerosol generating materials. In some embodiments, there are a plurality of inlet openings in the distal end. In some embodiments, the inlet opening may have an area of substantially 0.88mm² or 1 .76 mm². In some embodiments, tailoring a pressure drop of 70-90mmWG is particularly beneficial for the user experience. In this embodiment, the inlet and/or outlet is formed in the third intermediate layer. In other embodiments, the inlet and/or outlet is not formed in the third intermediate layer, e.g. the inlet and/or outlet may be formed on any one of the first intermediate layer, second intermediate layer, first substrate, and second substrate. In this embodiment, the intermediate layers are separate from the first and/or second substrates. In other embodiments, the intermediate layers are not separate from the first and/or second substrates, e.g. the intermediate layers may be integrally formed with the first and/or second substrates. In this embodiment, the third intermediate layer is integrally formed. In other embodiments, the third intermediate layer is not integrally formed, e.g. the third intermediate layer may be formed from a plurality of separate components. In this embodiment, the third intermediate layer is planar. In other embodiments, the third intermediate layer is not planar. In this embodiment, the bridge is positioned so as to not overlay the first and second aerosol generating materials. In other embodiments, the bridge is positioned so as to at least partially overlay the first and/or second aerosol generating material.

In some embodiments, the airflow path may be substantially free of obstructions. Ensuring the airflow path is as free from obstructions as possible may be beneficial for the performance of the article, for example, for achieving a particular pressure drop and/or a particular mass of aerosol for delivery. An airflow path that is obstruction free may have no structures positioned within the airflow path adjacent to the aerosol generating material. In other words, there is nothing in the airflow path that can alter the trajectory of the air flowing in the airflow path near to the aerosol generating material. It is noted that the embodiments where the airflow path is obstruction free may coincide with the embodiments where there is a flow control feature positioned in the inlet and/or a bridge comprised in the third intermediate layer. In other words, some embodiments may have both obstruction free airflow paths and flow control features positioned in the inlet opening. The airflow path can be considered to be downstream of the inlet opening. Furthermore, an article comprising the intermediate layers of Fig. 5A may also be considered free of obstructions because there are no obstructions of the aerosol generating material. Specifically, since the bridge and/or the flow control feature are displaced from the aerosol generating material and/or does not overlay the aerosol generating material the flow of the aerosol may not be disturbed or modified by the bridge and/or flow control feature.

Fig. 9 shows a graph of the mass of aerosol delivered plotted against various articles, obtained from experimental testing of engineered articles. The various articles either includes a rib in the airflow path or not. Table 2 provided below sets out the parameters of the various articles plotted in Fig. 9.

Table 2

The structures of the various article shown in Fig. 9 are shown in Fig. 10, where:

Sub 1 - 1^st substrate having an aerosol gel deposited thereon;

Sub 2 - 2^nd substrate having an aerosol gel deposited thereon;

1/1a/1b - first intermediate layer;

2/2a/2b - second intermediate layer; and

3/3a/3b/3c - third intermediate layer.

In some of the articles, the first and second intermediate layers are each made from two separate planar components. In some of the articles the third intermediate layer is made from 3 separate planar components. In some of the article, the conduit tapers to the inlet opening. In some of the article, the conduits tapers to the outlet opening. In some of the articles the conduits tapers along the longitudinal direction from the outlet opening to the inlet opening. The ribs shown in Fig. 10 and table 2 may be considered to be the one or more cross members discussed above that extends across the width of the intermediate layer and/or the conduit.

As can be seen from Fig. 9, the articles that have no obstructions generally result in larger mass of the aerosol delivered when compared to the articles that have obstructions. Specifically, A9, A10, and A13 shows that the airflow path being free of obstructions allows more aerosol to be delivered when compared to articles that have ribs (A8, A11 , and A12). This further suggests that the inlet area is able to provide tailoring of the pressure drop without significantly affecting the other performance factors. In these embodiments, the airflow path is substantially free of obstructions. However, in other embodiments, the airflow path is not free of obstructions.

With reference to Fig. 11, the article 110, when fully assembled, comprises a first substrate 302 on top of the first intermediate layer 502. The first aerosol generating material 306 is shown in phantom extending from a bottom surface of the first substrate 302 into the first intermediate layer 502 through to a bottom surface of the first intermediate layer 502. In some embodiments, the first aerosol generating material 306 may extend past the bottom surface of the first intermediate layer 502. The first intermediate layer 502 is positioned on top of the third intermediate layer 506. The third intermediate layer 506 is positioned on top of the second intermediate layer 504. The second intermediate layer 504 is positioned on top of the second substrate 304. The second aerosol generating material 308 is shown in phantom extending from a top surface of the second substrate 304 into the second intermediate layer 504 through to a top surface of the second intermediate layer 504.

The first intermediate layer 502, the first aerosol generating material 306, the third intermediate layer 506, the second intermediate layer 504, and second aerosol generating material 308 together form a passage that fluidly couples the inlet opening 508 to the outlet opening 510. The first intermediate layer 502, the first aerosol generating material 306, the second intermediate layer 504, and second aerosol generating material 308 can be considered to enclose the conduit of the third intermediate layer 506 thereby forming the passage. The first and/or second aerosol generating materials 306, 308 can be activated to produce aerosol into the passage and/or conduit. The passage and/or conduit may be considered to be the airflow path

In this embodiment, the passage is formed by the first intermediate layer, the first aerosol generating material, the third intermediate layer, the second intermediate layer, and second aerosol generating material. In other embodiments, the cavity is not formed by the first intermediate layer, the first aerosol generating material, the third intermediate layer, the second intermediate layer and second aerosol generating material, e.g. the passage may be formed by one or more of the first intermediate layer, the first aerosol generating material, the third intermediate layer, the second intermediate layer, and second aerosol generating material.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc, other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

1. An aerosol forming article comprising: a first surface comprising an aerosol-generating material; a second surface opposite the first surface such that an airflow path is defined between the first and second surfaces; and an inlet permitting air to flow into the article between the first and second surface, wherein the inlet has an area of at least 0.15 mm².

2. An aerosol forming article according to claim 1 , wherein the inlet has an area of at least 0.25 mm².

3. An aerosol forming article according to claim 2, wherein the inlet has an area of at least 0.37 mm².

4. An aerosol forming article according to claim 3, wherein the inlet has an area of at least 0.45 mm².

5. An aerosol forming article according to claim 4, wherein the inlet has an area of substantially 0.51mm².

6. An aerosol forming article according to any preceding claim, wherein the aerosol forming article is formed of a layered structure, the layered structure comprising a first layer defining the first surface and a second layer defining the second surface.

7. An aerosol forming article according to claim 6, wherein the layered structure is a folded layered structure.

8. An aerosol forming article according to any preceding claim, wherein the layered structure comprises an intermediate layer, wherein the inlet is formed in the intermediate layer.

9. An aerosol forming article according to any preceding claim, further comprising a flow control feature positioned such that air from the inlet impinges on the flow control feature, the flow control feature configured to reduce a velocity of the air.

10. An aerosol forming article according to claim 9, wherein the flow control feature is formed by a cross-member.

11. An aerosol forming article according to claim 9 or claim 10, wherein the flow control feature is formed in the intermediate layer.

12. An aerosol forming article according to any of claims 9 to 11, wherein the flow control feature is upstream of the aerosol generating material.

13. An aerosol forming article according to any preceding claim, wherein the inlet is formed by removing a portion of the intermediate layer.

14. An aerosol forming article according to any preceding claim, wherein the layered structure further comprises a further intermediate layer between the intermediate layer and the first layer.

15. An aerosol forming article according to any preceding claim, wherein the layered structure further comprises an additional further intermediate layer between the intermediate layer and the second layer.

16. An aerosol forming article according to any preceding claim, wherein the airflow path is free of obstructions between the first and second surfaces at the aerosolgenerating material.

17. An aerosol forming article according to any preceding claim, wherein the second surface comprises aerosol generating material.

18. An aerosol forming article according to any preceding claim, wherein the first surface is substantially planar.

19 An aerosol forming article according to any preceding claim, wherein the second surface is substantially planar.

20. An aerosol provision system comprising: an aerosol forming article according to any preceding claim; and an aerosol provision device configured to heat the aerosol generating material to generate aerosol.