Abstract
An aerosol-generating article having upstream and downstream ends is provided, the article defining a longitudinal direction between the upstream and downstream ends, the article including: an aerosol-forming substrate; a tubular element disposed downstream of the substrate and extending along the longitudinal direction, the tubular element including inner and outer tubes, the outer tube being disposed around the inner tube, an outer airflow channel being longitudinally delimited by the inner and outer tubes, an inner airflow channel being longitudinally delimited by the inner tube, and the inner airflow channel is configured for substrate aerosol to flow towards the downstream end; a flavour substrate disposed downstream of the substrate; and a permeability control element including a gel composition, the control element being configured to be fluid permeable when a temperature of the control element is equal to or greater than a permeability transition temperature of the control element.
Claims
1.-15. (canceled)
16. An aerosol-generating article having an upstream end and a downstream end, the aerosol-generating article defining a longitudinal direction between the upstream end and the downstream end, the aerosol-generating article comprising: an aerosol-forming substrate; a tubular element disposed downstream of the aerosol-forming substrate and extending along the longitudinal direction, the tubular element comprising an inner tube and an outer tube, the outer tube being disposed around the inner tube, wherein an outer airflow channel is longitudinally delimited by the inner tube and the outer tube, wherein an inner airflow channel is longitudinally delimited by the inner tube, and wherein at least the inner airflow channel is configured for substrate aerosol to flow towards the downstream end; a flavour substrate disposed downstream of the aerosol-forming substrate; and at least one permeability control element comprising a gel composition, wherein the at least one permeability control element is configured to be fluid permeable when a temperature of the at least one permeability control element is equal to or greater than a permeability transition temperature of the permeability control element, wherein the at least one permeability control element is further configured to be substantially fluid impermeable when the temperature of the at least one permeability control element is lower than the permeability transition temperature of the permeability control element, and wherein the at least one permeability control element is disposed within the outer airflow channel, the at least one permeability control element being further configured to prevent a fluid from flowing along the outer airflow channel downstream of the permeability control element when the temperature of the at least one permeability control element is lower than the permeability transition temperature of the permeability control element, and to allow a fluid to flow along the outer airflow channel downstream of the permeability control element when the temperature of the at least one permeability control element is equal to or greater than the permeability transition temperature of the permeability control element.
17. An aerosol-generating article having an upstream end and a downstream end, the aerosol-generating article defining a longitudinal direction between the upstream end and the downstream end, the aerosol-generating article comprising: an aerosol-forming substrate; a tubular element disposed downstream of the aerosol-forming substrate and extending along the longitudinal direction, the tubular element comprising an inner tube and an outer tube, the outer tube being disposed around the inner tube, wherein an outer airflow channel is longitudinally delimited by the inner tube and the outer tube, wherein an inner airflow channel is longitudinally delimited by the inner tube, and wherein at least the inner airflow channel is configured for substrate aerosol to flow towards the downstream end; a flavour substrate disposed downstream of the aerosol-forming substrate; and at least one permeability control element comprising a gel composition, wherein the at least one permeability control element is disposed within the outer airflow channel, the at least one permeability control element being configured to prevent a fluid from flowing along the outer airflow channel downstream of the permeability control element when a temperature of the at least one permeability control element is 20 degrees Celsius and to allow a fluid to flow along the outer airflow channel downstream of the permeability control element when the temperature of the at least one permeability control element is 85 degrees Celsius.
18. The aerosol-generating article according to claim 16, wherein the flavour substrate is disposed within the outer airflow channel.
19. The aerosol-generating article according to claim 18, wherein the flavour substrate is a permeability control element.
20. The aerosol-generating article according to claim 18, wherein a permeability control element is disposed downstream of the flavour substrate.
21. The aerosol-generating article according to claim 16, wherein a spanning element is disposed within the outer airflow channel upstream of the flavour substrate.
22. The aerosol-generating article according to claim 21, wherein the spanning element is a permeability control element.
23. The aerosol-generating article according to claim 19, wherein the flavour substrate extends longitudinally along the entire outer airflow channel.
24. The aerosol-generating article according to claim 16, further comprising an air inlet configured to allow for intake of outside air into the outer airflow channel.
25. The aerosol-generating article according to claim 24, wherein a spanning element is disposed within the outer airflow channel upstream of the flavour substrate, and wherein the air inlet is disposed downstream of the spanning element.
26. The aerosol-generating article according to claim 24, wherein the flavour substrate is disposed downstream of the air inlet.
27. The aerosol-generating article according to claim 16, further comprising a filter disposed downstream of the tubular element.
28. The aerosol-generating article according to claim 16, wherein the permeability transition temperature of the at least one permeability control element is a phase transition temperature of the at least one permeability control element.
29. The aerosol-generating article according to claim 16, wherein the flavour substrate comprises a flavour material.
30. The aerosol-generating article according to claim 16, wherein the flavour material is a gel composition.
31. An aerosol-generating system comprising: the aerosol-generating article according to claim 16; and an aerosol-generating device comprising a heater, the heater comprising a substrate heating element configured to heat the aerosol-generating article and a downstream heating element disposed downstream of the substrate heating element.
Description
[0432] These and other features and advantages of the invention will become more evident in the light of the following detailed description of preferred embodiments, given only by way of illustrative and non-limiting example, in reference to the attached figures:
[0433] FIG. 1 shows a longitudinal section of an aerosol-generating article in which a tubular element comprises an inner airflow channel and an outer airflow channel.
[0434] FIG. 2 illustrates the aerosol-generating article of FIG. 1 at an instant when an aerosol-forming substrate and a flavour substrate are heated to release aerosol, and a spanning element, the flavour substrate and a permeability control element are fluid permeable.
[0435] FIG. 3 represents a longitudinal section of an aerosol-generating article in which a flavour substrate is disposed in an outer airflow channel of a tubular element.
[0436] FIG. 4 depicts the aerosol-generating article of FIG. 3 at an instant when an aerosol-forming substrate and the flavour substrate are heated to release aerosol, and a spanning element, the flavour substrate and a permeability control element are fluid permeable.
[0437] In FIG. 5, a longitudinal section of an aerosol-generating article is shown, wherein a flavour substrate is the only permeability control element downstream of an air inlet within an outer airflow channel.
[0438] FIG. 6 depicts the aerosol-generating article of FIG. 5 at an instant when an aerosol-forming substrate and the flavour substrate are heated to release aerosol, and a spanning element and the flavour substrate are fluid permeable.
[0439] FIG. 7 represents a longitudinal section of an aerosol-generating article in which an outer airflow channel does not comprise an air inlet.
[0440] FIG. 8 depicts the aerosol-generating article of FIG. 7 at an instant when an aerosol-forming substrate and a flavour substrate are heated to release aerosol, and a spanning element, the flavour substrate and a permeability control element are fluid permeable.
[0441] FIG. 9 shows a longitudinal section of an aerosol-generating article in which a flavour substrate occupies the entire length of an outer airflow channel.
[0442] FIG. 10 depicts the aerosol-generating article of FIG. 9 at an instant when an aerosol-forming substrate and the flavour substrate are heated to release aerosol, and the flavour substrate is fluid permeable.
[0443] FIG. 11 shows a longitudinal section of an aerosol-generating system comprising an aerosol-generating article and an aerosol-generating device.
[0444] FIG. 12 represents a housing of the aerosol-generating device of FIG. 11 receiving an aerosol-generating article.
[0445] FIG. 13 shows a perspective view of the aerosol-generating device of FIGS. 11 and 12.
[0446] FIG. 14 illustrates a perspective view of a downstream inductive heating arrangement.
[0447] FIG. 15 is an exploded view of the downstream inductive heating arrangement of FIG. 1.
[0448] FIG. 1 depicts a longitudinal section of an aerosol-generating article 10 having an upstream end 13 and a downstream end 14, the aerosol-generating article 10 defining a longitudinal direction between the upstream end 13 and the downstream end 14. The article 10 comprises an aerosol-forming substrate 11. In the embodiment of FIG. 1, a tubular element 12 is disposed immediately downstream of the aerosol-forming substrate 11 and extends along the longitudinal direction. The tubular element 12 comprises an outer airflow channel 18 and an inner airflow channel 19. The tubular element 12 comprises an air inlet 15 whereby outside air may be drawn into the outer airflow channel 18. The tubular element 12 defines at least one airflow channel establishing an uninterrupted fluid communication between an upstream end 13 of the tubular element 12 and a downstream end 14 of the tubular element 12.
[0449] In the embodiment of FIG. 1, a flavour substrate 16 is disposed immediately downstream of the tubular element 12 in the longitudinal direction. In this embodiment, the flavour substrate 16 comprises a gel composition. However, other flavour materials different from a gel composition may be used in addition or alternatively to the gel composition.
[0450] The provision of the flavour substrate 16 downstream of the air inlet 15 comprised in the outer airflow channel 18 allows for a regulation in the amount of airflow the flavour substrate 16 is provided with. The gel composition helps generate a uniform substrate upon heating of the flavour substrate 16, which can give rise to a highly consistent aerosol to be entrained with the substrate aerosol generated by the aerosol-forming substrate 11 disposed upstream of the flavour substrate 16.
[0451] In the embodiment of FIG. 1, a permeability control element 20 is disposed within the outer airflow channel 18. The permeability control element 20 is configured to be fluid permeable when the temperature of the permeability control element is equal to or greater than a permeability transition temperature of the permeability control element 20, for instance when the temperature of the permeability control element 20 is 85 degrees Celsius. Likewise, the permeability control element 20 is configured to be substantially fluid impermeable when the temperature of the permeability control element is lower than the permeability transition temperature of the permeability control element, for instance when the temperature of the permeability control element is 20 degrees Celsius. Therefore, the permeability control element 20 may prevent a fluid from flowing along the outer airflow channel 18 downstream of the permeability control element 20 when its temperature is below its permeability transition temperature (as represented in FIG. 1), and to allow a fluid to flow along the outer airflow channel 18 downstream of the permeability control element 20 when its temperature is equal to or greater than its permeability transition temperature (as represented in FIG. 2). This may lead to a change in several properties of the aerosol-generating article 10. Heating the permeability control element 20 to its permeability transition temperature may lead to an increase in the amount of airflow that can flow towards the downstream end 14 of the aerosol-generating article 10 and a reduction in the resistance to draw of the aerosol-generating article 10, since airflow is enabled to flow along the outer airflow channel 18. Likewise, the permeability control element 20 may be advantageously used to regulate the amount of airflow the flavour substrate 16 is provided with.
[0452] It is noted that, in FIGS. 1 to 10, a permeability control element marked with dashed lines denotes that the permeability control element is substantially fluid impermeable, whilst a permeability control element marked with dots denotes that the permeability control element is fluid permeable.
[0453] In the embodiment of FIG. 1, a spanning element 21 is provided in the outer airflow channel 18 to impede or regulate the flow of substrate aerosol into the outer airflow channel 18. The spanning element 21 may be a permeability control element. When the spanning element 21 is a permeability control element, substrate aerosol may flow into the outer airflow channel 18 upon heating of the aerosol-forming substrate 11 if the temperature of spanning element 21 is equal to or greater than the permeability transition temperature of the spanning element 21, for example at 85 degrees Celsius. Likewise, substrate aerosol may be prevented from flowing into the outer airflow channel 18 upon heating of the aerosol-forming substrate 11 if the temperature of spanning element 21 is lower than the permeability transition temperature of the spanning element 21, for example at 20 degrees Celsius.
[0454] In this embodiment, the permeability control element 20 and the spanning element 21 comprise a gel composition. However, in alternative embodiments, the permeability control element 20 and the spanning element 21 comprise other suitable materials to achieve the desired changes of permeability as a function of the temperature of the material.
[0455] The gel composition of a permeability control element 20, a spanning element 21, and/or a flavour material of a flavour substrate 16 may have a composition comprising: glycerin in 50 to 75 percent by weight, preferably in 50 to 65 percent by weight; hydroxic poly methyl cellulose (HPMC) in 15 to 35 percent by weight, preferably 20 to 30 percent by weight; agar in 3 to 10 percent by weight, preferably in 4 to 7 percent by weight; fibers in 0 to 12 percent by weight, preferably in 0 to 7 percent by weight; low methoxyl (LM) (E440i) pectin in 0 to 9 percent by weight, preferably in 0 to 7 percent by weight; lactic acid in 1.7 to 3.1 percent by weight, preferably in 2.1 to 2.9 percent by weight; Ca-lactate in 0 (zero) to 7 percent by weight, preferably in 0 (zero) to 3 percent by weight; and nicotine, nicotine and a flavouring agent, or a flavouring agent, in the amount of 0 to 4 percent by weight, preferably 0 to 2 percent by weight.
[0456] The flavouring agent can be one or more of menthol extract, vanilla extract, and coffee derivate flavourings. Coffee derivative flavourings contain one or more of caffeine; guarana; taurine; and glucuronolactone. When a flavouring agent is present in the gel composition it is preferably present in 0.2 to 4 percent by weight, more preferably 0.4 to 2 percent by weight.
[0457] Examples of the compositions of the gel composition, which may be used in any of the permeability control elements, flavour substrates or spanning elements described herein, are shown in Table 1 below. Table 1 shows the percent by weight of each component of the gel composition:
TABLE-US-00001 Composition A Composition B Non- Non- Flavoured Flavoured Flavoured Flavoured Glycerin 52 53 61 60 Hydroxic poly metyl 21.5 21 21 22 cellulose Nicotine 1.5 1.1 1.8 1.8 Agar 7.6 8 3 2.4 Fibers (cellulose, length 9 6.8 7.2 5.3 8 to 15 ?m) Low methoxyl pectin 4 5 3 4 (E440i) Lactic acid 2.3 2.1 3 2.8 Ca-lactate 2.1 1 0 0 Menthol extract (FDA 0 2 0 0 21CFR182.20), min. 55% Menthol (C.sub.10H.sub.20O) Vanilla extract (FDA 0 0 0 1.7 21CFR169.175), min. 20% Vanillin(C.sub.8H.sub.8O.sub.3)
[0458] The gel compositions as listed above can provide a predictable composition form upon storage or transit from manufacture to the consumer. The gel compositions may substantially maintain their shape. The gel compositions maintain their state at room temperature (about 21 degrees Celsius). The gel compositions are configured to be in solid state within a range of temperatures that covers standard environment temperatures of use of the aerosol-generating article. The suitable range of environment temperatures may be from about minus 20 degrees Celsius to about 70 degrees Celsius. The overall state of the gel compositions may be predominantly solid, or in gel solid state, and fluid impermeable. Above about 70 degrees Celsius the overall state of the composition may be predominantly liquid, and fluid permeable.
[0459] The gel compositions as listed above, when in a solid state, may be configured to have sufficient resistance to deformation in order to provide the flavour substrate with the mechanical stability for its handling during manufacturing, transportation and use of the aerosol-generating article. The gel compositions can have a resistance to deformation strength of 0.5 kgf to 3.0 kgf. The resistance to deformation is preferably between 1.3 kgf to 2.7 kgf, more preferably between 1.9 kgf to 2.5 kgf. The mechanical strength of the gel composition can be tuned to the desired range by adjusting the amount of low methoxyl (LM) pectin in the composition. The use of LM pectin for this purpose will depend on the specific composition formulation, it can be used in proportions between 0.1 to 9 percent by weight, preferably between 0.1 and 7 percent by weight, and most preferably between 1 and 3 percent by weight.
[0460] The composition of the gel composition may be distributed in a variable manner within the flavour substrate. In alternative embodiments, the composition can have a homogeneous distribution. The flavour substrate can include an external layer that is useful to give the flavour substrate the required shape to be disposed within the aerosol-generating article. The external layer may be a shell. The remaining part of the flavour substrate may be a core. The flavour substrate comprising the core and an external layer is manufactured by first depositing a core comprising the remaining part of the flavour substrate and then depositing a layer on the core to form the external layer. There are several types of applicable manufacturing processes. The core and external layer may be manufactured by extrusion. A tubular core may be produced and the next step may be a process of extrusion where the gel composition is uniformly deposited on the external surface of the tubular core. The external layer can be made of the same gel composition as the remaining part of the flavour substrate. The core and external layer may have the same characteristics. The core and the external layer may have different characteristics. In one example, the core is softer, with a lower mechanical strength, than a harder external layer, the shell, by about 5 to about 20 percent, preferably by about 10 to about 15 percent. Alternatively, or in addition, if the gel composition comprises a flavouring agent, the external layer (shell) may not comprise a flavouring agent.
[0461] In the embodiment shown in FIGS. 1 & 2, the permeability control element 20 and the spanning element 21 each comprise non-flavoured composition A or non-flavoured composition B listed above in Table 1.
[0462] In the embodiment shown in FIGS. 1 & 2, the flavour material of the flavour substrate 16 comprises flavoured composition A or flavoured composition B listed above in Table 1.
[0463] In the embodiments of FIGS. 1 to 10, a filter 17 is disposed immediately downstream of the tubular element 12 in the longitudinal direction, and a mouthpiece 22 is disposed immediately downstream of the filter 17.
[0464] The gel composition of the flavour substrate 16 in the embodiment of FIG. 1 may also be configured to become fluid permeable when the temperature of the gel composition is equal to or greater than a permeability transition temperature of the gel composition, as represented with dots in FIG. 1, and to be substantially fluid impermeable when the temperature of the gel composition is lower than the permeability transition temperature of the gel composition, as represented with dashed lines in FIG. 2. Therefore, the flavour substrate 16 may also be a permeability control element. The flavour substrate may therefore have a gel composition as described above for the permeability control element. The gel composition of the embodiment of FIG. 1 may be configured, in other embodiments, to be substantially fluid impermeable at any operating temperature applied to the flavour substrate by an aerosol-generating device. In the latter embodiment, the flavour substrate does not normally extend cross the an entire cross section of the one or more airflow channels, in order to allow for airflow to flow towards the downstream end downstream of the aerosol-generating article. The flavour substrate may be configured to be fluid permeable and to allow a fluid flowing along the airflow channel to flow downstream of the flavour substrate 16 when the temperature of the flavour substrate is equal to or greater than a permeability transition temperature of the flavour substrate, and configured to be substantially fluid impermeable and to prevent a fluid flowing along the airflow channel from flowing downstream of the flavour substrate 16 when the temperature of the flavour substrate is lower than the permeability transition temperature of the flavour substrate, wherein the flavour substrate is a gel composition.
[0465] FIG. 2 is a longitudinal section of the aerosol-generating article of FIG. 1 depicting an instant at which the permeability control element 20, the spanning element 21 and the flavour substrate 16 are each at a temperature at which they are fluid permeable, as represented with dots in the figure. Likewise, the aerosol-forming substrate 11 is heated to generate a substrate aerosol which is entrained with outside air entering the aerosol-generating article 10 on its upstream end 13. A substantial percentage of substrate aerosol flows along the inner airflow channel 19 of the tubular element 12. Since the spanning element 21 is fluid permeable in FIG. 2, a percentage of substrate aerosol flows along the outer airflow channel 18. In examples in which the spanning element is permanently fluid impermeable at any operating temperature of the aerosol-generating article, all the substrate aerosol generated upon heating of the aerosol-forming substrate flows along the inner airflow channel.
[0466] In FIG. 2, outside air is drawn into the outer airflow channel 18 through the air inlet 15. The flow of outside air and substrate aerosol reaches the flavour substrate 16, since the permeability control element 20 is fluid permeable at the instant represented in FIG. 2. The flavour substrate 16 is also fluid permeable and, moreover, is heated to form a flavour aerosol. The flavour aerosol is entrained with the flow of outside air and substrate aerosol to form an aerosol inhalable by a user. The entrained aerosol is filtered by the filter 17 and delivered to a user through the mouthpiece 22.
[0467] FIG. 3 shows a longitudinal section of an aerosol-generating article 10 in which, differently to the aerosol-generating article of FIG. 1, a flavour substrate 16 comprising a gel composition is disposed within an outer airflow channel 18, between an air inlet 15 and a permeability control element 20.
[0468] In this embodiment, the flavour substrate 16 is a permeability control element. Therefore, the flavour substrate 16 prevents airflow from flowing along the outer airflow channel 18 downstream of the flavour substrate 16 when its temperature is below the permeability transition temperature of the gel composition, as represented in FIG. 3. Likewise, the permeability control element 20 prevents airflow from flowing along the outer airflow channel 18 downstream of the permeability control element 20 when its temperatures is below the permeability transition temperature of the permeability control element 20, as is also represented in FIG. 3. The flavour substrate 16 allows airflow to flow along the outer airflow channel 18 downstream of the flavour substrate 16 when its temperature is equal to or greater than the permeability transition temperature of the gel composition, as shown in FIG. 4. The permeability control element 20 allows airflow to flow along the outer airflow channel 18 downstream of the permeability control element 20 when its temperature is equal to or greater than the permeability transition temperature of the permeability control element 20, as is also depicted in FIG. 4.
[0469] A spanning element 21 is disposed within the outer airflow channel 18, upstream of the air inlet 15. The spanning element 21 may be a permeability control element. When the spanning element 21 is a permeability control element, substrate aerosol may flow into the outer airflow channel 18 upon heating of the aerosol-forming substrate 11 when the temperature of the spanning element 21 is equal to or greater than the permeability transition temperature of the spanning element 21.
[0470] FIG. 4 is a longitudinal section of the aerosol-generating article of FIG. 3 depicting an instant at which the permeability control element 20, the spanning element 21 and the flavour substrate 16 are each at a temperature at which they are fluid permeable, as represented with dots in the figure. Likewise, the aerosol-forming substrate 11 is heated to generate a substrate aerosol which is entrained with outside air entering the aerosol-generating article 10 on its upstream end 13. A substantial percentage of substrate aerosol flows along the inner airflow channel 19 of the tubular element 12. Since the spanning element 21 is fluid permeable in FIG. 4, a percentage of substrate aerosol flows along the outer airflow channel 18. In examples in which the spanning element is permanently fluid impermeable, all the substrate aerosol generated upon heating of the aerosol-forming substrate flows along the inner airflow channel.
[0471] In FIG. 4, outside air is drawn into the outer airflow channel 18 through the air inlet 15. The flavour substrate 16 is also fluid permeable and, moreover, is heated to form a flavour aerosol within the outer airflow channel 18. The flavour aerosol is entrained with the flow of outside air and the percentage of substrate aerosol in the outer airflow channel 18. The resulting aerosol reaches the filter 17, since the permeability control element 20 disposed downstream of the flavour substrate 16 is fluid permeable at the instant represented in FIG. 6. The aerosol is then entrained with the percentage of substrate aerosol flowing along the inner airflow channel 19 to form an aerosol inhalable by a user. The aerosol is delivered to a user through the mouthpiece 22.
[0472] In the embodiment shown in FIGS. 3 & 4, the permeability control element 20 and the spanning element 21 each comprise non-flavoured composition A or non-flavoured composition B listed above in Table 1.
[0473] In the embodiment shown in FIGS. 3 & 4, the flavour material of the flavour substrate 16 comprises flavoured composition A or flavoured composition B listed above in Table 1.
[0474] FIG. 5 shows a longitudinal section of an aerosol-generating article 10 in which, differently to the aerosol-generating article of FIG. 3, a flavour substrate 16 comprising a gel composition is the only permeability control element disposed downstream of an air inlet 15 within an outer airflow channel 18. Therefore, the flavour substrate 16 prevents airflow from flowing along the outer airflow channel 18 downstream of the tubular element 12 when its temperature is below the permeability transition temperature of the gel composition, as represented in FIG. 5. Likewise, the flavour substrate 16 allows airflow to flow along the outer airflow channel 18 downstream of the tubular element 12 when its temperature is equal to or greater than the permeability transition temperature of the gel composition, as shown in FIG. 6.
[0475] FIG. 6 is a longitudinal section of the aerosol-generating article of FIG. 5 depicting an instant at which the spanning element 21 and the flavour substrate 16 are each at a temperature at which they are fluid permeable, as represented with dots in the figure. Likewise, the aerosol-forming substrate 11 is heated to generate a substrate aerosol which is entrained with outside air entering the aerosol-generating article 10 on its upstream end 13. A substantial percentage of substrate aerosol flows along the inner airflow channel 19 of the tubular element 12. Since the spanning element 21 is fluid permeable in FIG. 6, a percentage of substrate aerosol also flows along the outer airflow channel 18. In examples in which the spanning element is permanently fluid impermeable, all the substrate aerosol generated upon heating of the aerosol-forming substrate flows along the inner airflow channel.
[0476] In FIG. 6, outside air is drawn into the outer airflow channel 18 through the air inlet 15. The flavour substrate 16 is fluid permeable at the instant of FIG. 6 and, moreover, is heated to form a flavour aerosol within the outer airflow channel 18. Therefore, flavour aerosol is entrained with the flow of outside air and the percentage of substrate aerosol in the outer airflow channel 18. The resulting aerosol is entrained with the percentage of substrate aerosol flowing along the inner airflow channel 19 to form an aerosol inhalable by a user. The aerosol is filtered by the filter 17 and delivered to a user through the mouthpiece 22.
[0477] In the embodiment shown in FIGS. 5 & 6, the spanning element 21 comprises non-flavoured composition A or non-flavoured composition B listed above in Table 1.
[0478] In the embodiment shown in FIGS. 5 & 6, the flavour material of the flavour substrate 16 comprises flavoured composition A or flavoured composition B listed above in Table 1.
[0479] FIG. 7 shows a longitudinal section of an aerosol-generating article 10 in which, differently to the aerosol-generating articles of the three preceding embodiments, the outer airflow channel 18 comprises no air inlet. In the embodiment of FIG. 7, a spanning element 21 is provided within the outer airflow channel 18 upstream of the flavour substrate 16, and a permeability control element 20 is disposed downstream of the flavour substrate 16. The flavour substrate 16 of this embodiment is a permeability control element. Therefore, the airflow along the outer airflow channel 18 downstream of the flavour substrate 16 and the permeability control element 20 may be prevented or allowed as in the embodiment of FIG. 3, by varying the permeability of the flavour substrate 16 and the permeability control element 20, respectively. The spanning element 21 may be a permeability control element. When the spanning element 21 is a permeability control element, it may also prevent or allow airflow from flowing along the outer airflow channel 18. In particular, substrate aerosol may flow into the outer airflow channel 18 upon heating of the aerosol-forming substrate 11 if the temperature of the spanning element 21 is equal to or greater than the permeability transition temperature of the spanning element 21.
[0480] FIG. 8 is a longitudinal section of the aerosol-generating article of FIG. 7 depicting an instant in which the permeability control element 20, the spanning element 21 and the flavour substrate 16 are each at a temperature at which they are fluid permeable, as represented with dots in the figure. Likewise, the aerosol-forming substrate 11 is heated to generate a substrate aerosol which is entrained with outside air entering the aerosol-generating article 10 on its upstream end 13. A substantial percentage of the substrate aerosol flows along the inner airflow channel 19 of the tubular element 12. Since the spanning element 21 is fluid permeable in FIG. 8, a percentage of substrate aerosol also flows along the outer airflow channel 18. In examples in which the spanning element is permanently fluid impermeable, all the substrate aerosol generated upon heating of the aerosol-forming substrate flows along the inner airflow channel.
[0481] At the instant of FIG. 8, the flavour substrate 16 is fluid permeable and, moreover, is heated to form a flavour aerosol within the outer airflow channel 18. Therefore, the flavour aerosol is entrained with the percentage of substrate aerosol in the outer airflow channel 18, without being blended with outside air directly drawn into the airflow channel 18. The resulting aerosol is entrained with the percentage of substrate aerosol flowing along the inner airflow channel 19 to form an aerosol inhalable by a user. The aerosol is filtered by the filter 17 and delivered to a user through the mouthpiece 22.
[0482] In the embodiment shown in FIGS. 7 & 8, the permeability control element 20 and the spanning element 21 each comprise non-flavoured composition A or non-flavoured composition B listed above in Table 1.
[0483] In the embodiment shown in FIGS. 7 & 8, the flavour material of the flavour substrate 16 comprises flavoured composition A or flavoured composition B listed above in Table 1.
[0484] FIG. 9 shows a longitudinal section of an aerosol-generating article 10 in which the flavour substrate 16 occupies the entire length of the outer airflow channel 18. Therefore, in this embodiment, the flavour substrate 16 is the only permeability control element. The flavour substrate 16 also plays the role of the spanning element of the previous embodiments. The flavour substrate 16 prevents airflow from flowing into the outer airflow channel 18 and along the outer airflow channel 18 downstream of tubular element 12 when the temperature of the flavour substrate 16 is lower than the permeability transition temperature of the gel composition, as depicted in FIG. 9 with dashed lines. The flavour substrate 16 allows airflow to flow into the outer airflow channel 18 and along the outer airflow channel 18 downstream of the tubular element 12 when heated at temperatures equal to or greater than the permeability transition temperature of the gel composition, as depicted in FIG. 10.
[0485] FIG. 10 is a longitudinal section of the aerosol-generating article of FIG. 9 depicting an instant in which the flavour substrate 16 is at a temperature at which they the gel composition is fluid permeable, as represented with dots in the figure. Likewise, the aerosol-forming substrate 11 is heated to generate a substrate aerosol which is entrained with outside air entering the aerosol-generating article 10 on its upstream end 13. A substantial percentage of the substrate aerosol flows along the inner airflow channel 19 of the tubular element 12. Since the flavour substrate 16 is fluid permeable in FIG. 10, a percentage of substrate aerosol also flows along the outer airflow channel 18. In examples in which the spanning element is permanently fluid impermeable, all the substrate aerosol generated upon heating of the aerosol-forming substrate flows along the inner airflow channel.
[0486] In FIG. 10, the flavour substrate 16 is heated to form a flavour aerosol within the outer airflow channel 18. Therefore, the flavour aerosol is entrained with the percentage of substrate aerosol in the outer airflow channel 18, without being blended with outside air directly drawn into the airflow channel 18. The resulting aerosol is entrained with the percentage of substrate aerosol flowing along the inner airflow channel 19 to form an aerosol inhalable by a user. The aerosol is filtered by the filter 17 and delivered to a user through the mouthpiece 22.
[0487] In the embodiment shown in FIGS. 9 & 10, the flavour material of the flavour substrate 16 comprises flavoured composition A or flavoured composition B listed above in Table 1.
[0488] FIG. 11 shows a schematic cross-section of an aerosol-generating system comprising an aerosol-generating device 200 and an aerosol-generating article 10. The aerosol-generating article 10 may be any of the articles of FIGS. 1 to 8.
[0489] The aerosol-generating device 200 comprises a substantially cylindrical device housing 207, with a shape and size similar to a conventional cigar.
[0490] The aerosol-generating device 200 further comprises a power supply 201, in the form of a rechargeable nickel-cadmium battery, a controller 202 in the form of a printed circuit board including a microprocessor, an electrical connector 203 and a heater 204. The heater 204 comprises a substrate heating element 205, configured to heat the aerosol-forming substrate 11, and a downstream heating element 206 disposed downstream of the substrate heating element 205. The downstream heating element 206 is configured to heat the flavour substrate 16 and, in the corresponding embodiments, the permeability control element 20 and the spanning element 21.
[0491] In the embodiment of FIG. 11, the substrate heating element 205 and the downstream heating element 206 are respectively a substrate inductive heating arrangement 205 and a downstream inductive heating arrangement 206, each comprising at least one inductor coil and at least one susceptor. However, other forms of heating elements, such as resistive heating elements, may be used.
[0492] The power supply 201, the controller 202 and the inductive heating arrangements 205, 206 are all housed within the device housing 207. The inductive heating arrangements 205, 206 of the aerosol-generating device 200 are arranged at the proximal end of the device 200. The electrical connector 203 is arranged at a distal end of the device housing 207.
[0493] As used herein, the term proximal refers to a user end, or mouth end of the aerosol-generating device or aerosol-generating article. The proximal end of a component of an aerosol-generating device or an aerosol-generating article is the end of the component closest to the user end, or mouth end of the aerosol-generating device or the aerosol-generating article. As used herein, the term distal refers to the end opposite the proximal end.
[0494] The controller 202 is configured to control the supply of power from the power supply 201 to the inductive heating arrangements 205, 206. The controller 202 further comprises a DC/AC inverter, including a Class-D power amplifier. The controller 202 is also configured to control recharging of the power supply 201 from the electrical connector 203. The controller 202 further comprises a puff sensor (not shown) configured to sense when a user is drawing on an aerosol-generating article received in a device cavity 208.
[0495] The substrate inductive heating arrangement 205 comprises a substrate inductor coil 209 and a substrate susceptor 210. The substrate susceptor 210 is a blade susceptor configured to penetrate into the aerosol-forming substrate 11 to provide internal heating to the aerosol-forming substrate 11. The substrate inductor coil 209 is tubular in the embodiment of FIG. 11 and is disposed concentrically around the portion of the cavity 208 configured to receive the aerosol-forming substrate 11.
[0496] The substrate inductor coil 209 is connected to the controller 202 and the power supply 201, and the controller 202 is configured to supply a varying electric current to the substrate inductor coil 209. When the varying electric current is supplied to the substrate inductor coil 209, the substrate inductor coil 209 generates a varying magnetic field, which heats the substrate susceptor 210 by induction.
[0497] The downstream inductive heating arrangement 206 comprises a downstream inductor coil 211 and a downstream susceptor 212. The downstream susceptor 212 is a tubular susceptor configured to be disposed concentrically around the section of the aerosol-generating article 10 comprising the flavour substrate 16, in order to provide external heating to the flavour substrate 16. When the aerosol-generating article 10 comprises a permeability control element 20, a spanning element 21 or both, the downstream susceptor 212 is also configured to be disposed concentrically around the section of the aerosol-generating article 10 comprising the permeability control element 20 and the spanning element 21. The downstream inductor coil 211 is tubular in the embodiment of FIG. 11 and is disposed concentrically the downstream susceptor 212.
[0498] The downstream inductor coil 211 is connected to the controller 202 and the power supply 201, and the controller 202 is configured to supply a varying electric current to the downstream inductor coil 211. When the varying electric current is supplied to the downstream inductor coil 211, the downstream inductor coil 211 generates a varying magnetic field, which heats the downstream susceptor 212 by induction.
[0499] As represented in FIG. 12, the device housing 207 also defines a substrate device air inlet 213 in close proximity to the distal end of the cavity 208 for receiving the aerosol-generating article 10. The substrate device air inlet 213 is configured to enable ambient air to be drawn into the device housing 207 towards the aerosol-forming substrate 11. The device housing 207 also defines a downstream device air inlet 214. The downstream device air inlet 214 is configured to enable ambient air to be drawn into device housing 202 towards the air inlet 15 of the tubular element 12 of the aerosol-generating article 10, in the embodiments in which the tubular element 12 comprises an air inlet 15. For this reason, the downstream device air inlet 214 is configured to substantially match the air inlet 15 of the tubular element 12 when the aerosol-generating article 10 is fully introduced into the device cavity 208.
[0500] FIG. 13 illustrates an outside view of the aerosol-generating device 200 of FIGS. 11 and 12. The external surfaces of the substrate inductive heating arrangement 205 and the downstream inductive heating arrangement 206 are shown in FIG. 13. Downstream of the substrate inductive heating arrangement 205, the aerosol-generating device 200 comprises a button 212 configured to switch on and switch off the components of the heater 204.
[0501] The downstream inductive heating arrangement 206 is also represented in FIG. 14, separated from the rest of the aerosol-generating device 200 to show that, in this embodiment, the downstream inductive heating arrangement 206 can be removably attached to the rest of the aerosol-generating device 200.
[0502] FIG. 15 is an exploded view of the downstream inductive heating arrangement 206 of FIG. 14, depicting the downstream inductor coil 211 and the downstream susceptor 212.
