WO2022214463A1

WO2022214463A1 - Storage compartment for an aerosol generation device

Info

Publication number: WO2022214463A1
Application number: PCT/EP2022/058951
Authority: WO
Inventors: Jaakko MCEVOY; Christoph LUNGENSCHMID
Original assignee: Jt International Sa
Priority date: 2021-04-06
Filing date: 2022-04-05
Publication date: 2022-10-13

Abstract

The invention provides a storage compartment (10) for an aerosol generation device storing a vaporizable material (12) and extending according to a longitudinal direction from an inlet end (38) defining an air inlet (20) to an outlet end (40) defining an air outlet (24); the storage compartment (10) comprising a plurality of heating and flow guiding elements (26) configured to heat the vaporizable material (12) by cooperating with at least a part of a heating system of the aerosol generation device and/or to guide an airflow; wherein: - the heating and flow guiding elements (26) are arranged inside the storage compartment (10) to contribute to formation of one or several airflow paths configured to guide airflow between the air inlet (20) and the air outlet (24), the length of the or each airflow path being greater than the distance between the inlet end (38) and the outlet end (40) according to the longitudinal direction; - the air inlet (20) opens directly to the vaporizable material (12) stored in the storage compartment.

Description

STORAGE COMPARTMENT FOR AN AEROSOL GENERATION DEVICE

TECHNICAL FIELD

The invention relates to a storage compartment for an aerosol generation device. TECHNICAL BACKGROUND

Aerosol generation devices have become popular as a replacement for conventional smoking articles, such as cigarettes. In such devices, an aerosol is generated from an aerosol forming article, such as a tobacco substrate stick. Such a stick is typically inserted into a tubular heater and heated. In such a case, the storage compartment described herein is integrated in the tobacco substrate stick. Alternatively, the storage compartment can be integrated in the aerosol generation device and can then be appropriately filled with tobacco or any other suitable substance to be heated. In this context, a uniform temperature distribution across the aerosol forming material is of particular concern.

In this context, EP 3610736 A1 is related to a heating element extending into the aerosol forming material and comprising plural air outlets from which the air directly flows into the aerosol forming material. Further, WO 2020/174028 A1 is related to an aerosol generating system comprising a susceptor having holes, which cooperates with a surrounding induction coil for generating heat. According to WO 2019/238704 A1 a cartridge comprises two compartments, each containing a single heating element, so that there is only one heating element per compartment. Each heating element heats a different vaporizing material. Thus, the flow of air is heated only when contacting the first and second heating element in a single direction, and the airflow path is a defined gap between the heating element and the vaporisable material (nicotine or acid). Finally, US 2017/156403A1, US 2020/054068A1 and US 2021/046262A1 are related to flow guiding elements arranged in a direction transverse to the airflow direction. SUMMARY OF THE INVENTION

Against this background, it is an object underlying the invention to provide a storage compartment for an aerosol generation device, in which heat can be distributed particularly well.

This object is solved by the subject-matter of claim 1, according to which the storage compartment stores a vaporizable material and extends according to a longitudinal direction from an air inlet end to an air outlet end. The storage compartment has a plurality of heating and flow guiding elements configured to heat the vaporizable material by cooperating with at least a part of a heating system and to guide an airflow.

The heating and flow guiding elements are arranged inside the storage compartment to contribute to the formation of one or several airflow paths configured to guide airflow between the air inlet and the air outlet, the length of the or each airflow path being greater than the distance between the inlet end and the outlet end along the longitudinal direction. Finally, the air inlet opens directly to the vaporizable material stored in the storage compartment. Thus, the vaporizable material is arranged in the airflow path to be traversed by the air flow, so that air passes through the material and not along it. Since the vaporizable material is arranged in the airflow path of the storage compartment, and the storage compartment comprises heating and flow guiding elements configured to heat the vaporizable material and to guide the airflow, the heating elements can be considered to be embedded in the vaporizable material.

According to the above-mentioned feature, the air inlet is, in other words, not located inside any heating element embedded in the vaporizable material but is formed in the storage compartment surrounding the vaporizable material. It should be mentioned that the storage compartment is generally cylindrical and its cross- section can be circular, square, rectangular, or any other suitable shape.

In accordance with the invention, air flowing through the vaporizable material in order to heat same is essentially rerouted from the direct connection between inlet and outlet. In other words, the flow of air is continuously heated as it changes direction. This solves the problem encountered in the prior art, in which vaporizable material located near the inlet remains at a lower temperature than material closer to the outlet. This commonly results in vaporizable material close to the inlet being left unheated and unutilized. Consequently, less puffs than the amount of vaporizable material would allow, are available to the user. This kind of airflow, which is improved according to the invention, is particularly supported by the fact that tobacco is oftentimes in the form of elongated strips or strands, which allows for little or no mixing of the airflow under an angle relative to the longitudinal direction. Thus, in particular peripheral regions experience low airflow rates. This is achieved by heating and flow guiding elements which are arranged in the longitudinal direction or at an angle thereto, with the angle being less than 90°, so that transverse elements are avoided, which could stop the airflow.

According to the invention, by forcing the air to take an “elongated” path through the vaporizable material a more even temperature distribution can be achieved, and a greater amount of vaporizable material can be utilized. This is particularly supported by the presence of a plurality of heating and flow guiding elements and the fact that each airflow path is greater than the distance between inlet and outlet. In other words, a direct, straight flow between inlet and outlet is blocked by the measures described in detail herein. On this occasion, it should be mentioned, that the above described heating and flow guiding elements will be called heating elements hereinafter, but it should be emphasized that also pure flow guiding elements would provide the advantages associated with the teaching described herein. In particular, due to the heating and flow guiding elements having a significantly higher thermal conductivity than tobacco, heat can be rapidly and evenly distributed throughout the vaporizable material.

As mentioned above, the storage compartment can be integrated into an aerosol generation device, so that such a device having at least one storage compartment described herein is considered to be a subject-matter of the present disclosure. This also applies to a stick or any other shape of vaporizable material, in particular tobacco, which comprises the storage department described herein and is insertable to an aerosol generation device as a consumable component.

Preferably, the storage compartment forms a section of an aerosol generation article such as a tobacco stick which is to be heated. The storage compartment is preferably wrapped by a wrapper. The wrapper may form a cylindrical wall of the storage compartment. Preferably, the wrapper is made of paper material. The vaporizable material according to the invention is porous to air. It is preferably a tobacco-based material. It is preferably stored in the storage compartment in the form of: sheet, web, shreds, strips, granules, powder, foam, fragments and any possible combinations thereof. As the vaporizable material is porous, air can easily pass through the material as it is stored in the air flow path of the storage compartment. The degree of compaction of the material and the resulting pressure drop of the compartment in the storage compartment are adapted to maintain an acceptable resistance to puff.

The tobacco substrate is preferably homogenized tobacco substrate and/or leaf tobacco. Homogenized tobacco substrate refers to any reconstituted tobacco material formed by agglomeration of tobacco particles obtained by grinding or other particles size reduction process from tobacco lamina and/or stems. The amount of tobacco in the homogenized tobacco substrate is for example, comprised between 30 wt. % to 90 wt. %, preferably 50 wt. % to 85 wt. % in dry basis of the substrate. The homogenized tobacco substrate further generally contains aerosol forming agents, such as glycerine, glycerol, propylene glycol (PG), 1 ,3-butanediol, triethyl citrate (TEC) or triacetin. The amount of aerosol forming agent in the homogenized tobacco substrate may be comprised between 5 wt. % to 25 wt. %, preferably 8 to 18 wt. % in dry basis of the substrate. The substrate may further comprise additives such as binder, thickener, foam stabilizer, plasticizer, solvents, cellulose of non-tobacco origin, solvents and combinations thereof. For example, the substrate may contain binder such gum, starch, carboxymethylcellulose (CMC). For example, the content of additives may vary from 1.0 wt. % to 15 wt. % in dry basis of the homogenized tobacco substrate. The homogenized tobacco substrate may be formed as sheet by casting, paper making processes, extrusion, extrusion and lamination, foaming and any other suitable processes. The homogenized tobacco substrate may be mixed with other materials, preferably in minor amount, such as cellulose fibre, tobacco lamina, inert filler and combinations.

Preferred embodiments are described in the further claims.

In order to further promote the described elongation of the flow path, it will provide advantages, if the air inlet is formed at the periphery of the inlet end of the storage compartment, and the air outlet is formed at the center of the outlet end thereof. In particular, such a structure can be realized by simple means, if a non-(air-) permeable cap is arranged in the center of the inlet end and substantially perpendicular to the longitudinal direction. Thus, the air is forced to enter the periphery around the cap.

Such a cap can be adjacent at least to one heating element or can be formed integral so as to form a single piece with this heating element. In either case, the structure is simple.

In view of simple structures, it is currently preferred to form at least one heating element as a plate.

It is expected that the advantages described above can be particularly efficiently achieved by arranging at least one heating element transversely to a direction connecting the air inlet and outlet, and the heating element having at least one hole. Thus, at least one airflow path will pass through the hole and, as a consequence, is rerouted to contribute to uniform heating.

This is further enhanced by at least one heating element having a plurality of holes, each hole being crossed by at least one airflow path.

In this context, the density and/or dimensions of the holes can advantageously increase in the longitudinal direction from inlet to outlet. In this manner, draw resistance and convective heat transfer can be influenced in order to achieve advantageous values. Particularly if the heating elements thus formed are provided with an angle relative to the longitudinal direction, in particular located at or close to a center portion at the inlet end, and at or close to a peripheral portion at the outlet end, enhanced heating of peripheral portions of the vaporizable material at the inlet end will be promoted, which contributes to uniform heating.

Nevertheless, the effects described herein can also be achieved by one or more heating element extending parallel to the longitudinal direction. In any case, the holes can have any suitable shape, and the above-described increase of density and/or dimensions of the holes increases the mean flow path and ensures an even airflow also through peripheral regions.

Rerouting of the airflow, as previously mentioned herein can also be achieved by arranging at least one heating element such that a portion of at least one airflow path guides the airflow in a direction opposite the longitudinal direction as seen from inlet to outlet. In other words, the airflow is at least in some portion forced to flow “backwards”, in order to evenly distribute the heat. Such an airflow can also be called meandering.

In such a situation while at the same time keeping a comparably a simple structure, at least two heating elements can be arranged so as to form at least three parallel portions of at least one airflow path. In other words, there can be a minimum of two 180° turns as compared to the direct distance between inlet and outlet.

In this context, at least two portions of at least one airflow path can have cross- sections of different dimensions. This will influence airflow velocity and can for example be used to accelerate the airflow in peripheral portions by reducing the cross-sectional dimension, in order to prevent condensation and humectant deposition or formation in these areas.

Particularly good results are expected for cooperation with an inductive heating system comprising a coil, so that at least one heating element is a susceptor capable of generating heat when being placed in the magnetic field created by the coil.

Alternatively, at least one heating element can form at least a part of at least one blade heater or being in contact with such a blade heater which is arranged inside the storage compartment. Such an arrangement can be called passive heating of the heating element, whereas inductive heating could be considered active heating. In either case, heat is conducted and distributed.

Finally, the storage compartment described herein can also be used with a heater cup arranged outside and around the storage compartment, at least one heating element being in contact with the heater cup. Thus, the “heating and flow guiding elements”, since they are in contact with the heating cup, and support heat transfer, can be considered “heating elements” and contribute to uniform temperature distribution as described herein. The invention also relates to an aerosol generating article comprising a storage compartment, wherein the storage compartment forms a first section, wherein the article comprises a second section adjacent the storage compartment providing support to the compartment and defining an air path, and a third section comprising a filter downstream the second section.

The first, second and third sections are assembled by a common wrapper, preferably a paper wrapper. The second section and third section may be wrapped with another wrapper such that the common wrapper overlaps the other wrapper.

The aerosol generating article preferably forms a cylindrical stick.

The second section may comprise at least one hollow tubular member. The hollow tubular member may be a paper tube, a filter tube or a combination thereof.

The filter may comprise at least one segment made of cellulose acetate or paper filtering material. Preferably, the filter comprises several segments such as a charcoal segment, a cellulose acetate filter segment or a capsule segment. The filter may further comprise a cavity between two filter segments or a cavity at one end of the filter.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, the invention will be further described with reference to exemplary embodiments thereof and with reference to the drawings, in which:

Fig. 1 is a schematic cross-sectional view of the storage compartment described herein;

Fig. 2 is a plan view of a first embodiment of a heating element formed as a plate;

Fig. 3 is a plan view of a second embodiment of a heating element formed as a plate;

Figs. 4a to c are cross-sectional views of various embodiments of a heating element combined with a cap;

Figs. 5 to 8 are cross-sectional views of alternative embodiments of the storage compartment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

As can be taken from figure 1, the storage compartment 10 described herein is in this case integrated in a stick, which essentially comprises three sections, a first section storing vaporizable material 12, such as tobacco, a second section 14 providing support and defining an air path 16, and a third section 18 comprising a filter. Thus, in this example, the storage compartment 10 corresponds to the first section of the stick. In a general case, the storage compartment 10 extends along a longitudinal direction between an inlet end 38 and an outlet end 40. In the example of figure 1 , the inlet end 38 delimits transversally the stick at the left side and the outlet end 40 is adjacent to the second portion 14. As indicated by the arrows, the air essentially flows from left to right according to figure 1 , in other words, it enters the storage compartment at an inlet 20 arranged at the inlet end end 40 of the compartment 10. This also applies to an embodiment, in which the storage compartment, in particular the section storing the vaporizable material 12, is integrated in an aerosol generation device

In the embodiment shown, two heating elements 26 are provided in this case parallel to the longitudinal direction extending from the inlet end 38 to the outlet end 40. Moreover, in this embodiment, a non-permeable plug or cap 30 is provided at approximately the center of the inlet end 38. Further, as can be taken from approximately the center part of figure 1, air path 16, through which the aerosol or vapor can leave the storage compartment 10 is provided at approximately the center of the outlet end 40 as seen in a cross-section or side view. Consequently, air entering at the inlet 20 around the cap 30 has to flow through one of the heating elements 26, so that a particularly good utilization of the vaporizable material 12 and/or uniform temperature distribution can be achieved. The heating elements in this case as well as in the embodiments in figures 5 and 6 described below act as susceptors cooperating with a surrounding coil (not shown in figures 1 , 5 and 6), which typically has a length matching that of the storage compartment 10.

As can be taken from the plan view of figure 2, the heating elements 26 can be informed as plates and can have plural openings 32, which are, in the case shown, rectangular and slit-like, parallel to each other. Further, in the case shown, their density increases towards the outlet end 40, i.e. towards the right in figure 2. In other words, the distance between the holes 32 decreases in this direction so as to decrease the flow resistance. As can be taken from additionally considering figure 1 , this particularly ensures sufficient airflow in peripheral regions of the vaporizable material 12 near the inlet 20.

The same effect is achieved by the embodiment of figure 3, in which the holes 32 are generally shaped in a similar manner, but their size increases towards the outlet. In the embodiment shown, also the distance between the holes 32 decreases in this direction in order to achieve the described effect. Either embodiment shown can be considered with a perforated heating element 26 or a heating element 26 having porosity. It should already be mentioned in this context, that the structure shown in figures 2 and 3 is particularly suitable for the embodiment of figure 5. Returning to figure 4, at least one heating element 26 can be formed integral with the cap 30 perpendicular thereto, in particular bent at a right angle, as shown in figure 4a, or they can be separate components as shown in figure 4b. In this case, the cap 30 can be formed of a particularly high temperature resistant material, whereas the material of the heating elements 26 can be optimized for heat transfer. Finally, as indicated in figure 4c, two heating elements 26 can be formed integrally with the cap 30 so as to provide the internal components of the first section according to figure 1 in a single piece.

This can generally also be realized in the embodiment of figure 5, in which two heating elements 26 are provided each at an angle relative to the longitudinal direction. In particular, they extend from a center part at the inlet end 38 to the peripheral part at the outlet end 40 so as to form a V-shape. In this manner, a cap 30 as shown in figure 1 is not necessary, and the air is nevertheless forced to flow through all regions of the vaporizable material 12. Particularly, using such an arrangement of the heating elements 26, air can still enter at the peripheral region of the inlet end 38.

According to figure 6 the heating elements 26 will typically not have holes, and will not extend all the way between inlet end 38 and outlet end 40. Rather, as indicated for the two bottom and the two top heating elements 26, they will alternately leave a flow path at the inlet end 38 and outlet end 40, so that a meandering flow path is provided. In other words, air enters at the peripheral region of the inlet 20, and will flow through the peripheral region of the vaporizable material 12. At the outlet end 40, which is blocked in this area, it will be forced to flow back towards the inlet end 38, where it will again be rerouted, in this case by the cap 30 so as to flow towards the center part of the outlet end 40 (i.e. towards the outlet 24) where it can enter the air path 16, as shown in figure 1. In this context, it goes without saying that sections 14 and 18 shown in figure 1 are also present in the embodiments of figures 5 to 8, in which only the first section is shown.

In the embodiment of figure 6, the flow path dimensions can be varied by varying distances hi, h2 and h3 independent from each other so as to control the draw resistance and/or appropriately adjust the airflow, for example accelerate it by reducing the cross-sectional area. In this embodiment, the outer heating elements 26 can be hotter than heating elements closer to the center, as they are close to a coil surrounding the storage compartment 10 and as a consequence at a position, where the magnetic flux is highest.

Figure 7 shows the embodiment of figure 6 combined with a heater cup 34, with which at least one heating element, in the case shown the top and bottom one, is in contact so as to transfer heat to the vaporizable material 12. Further, these heating elements as well as the two center ones act as flow guides and, due to their higher thermal conductivity, evenly distribute the heat, which is, in the embodiment of figure 7, applied mainly peripherally.

The same effect is achieved by the embodiment of figure 8, in which two heater blades 36 are provided, of which the right half according to figure 8 is not actively heated, but advantageously conducts and evenly distributes the heat, and moreover, act as flow guides like the two center heating and flow guiding elements corresponding to those of figures 6 and 7. Thus, unlike in the embodiment of figures 1 , 5 and 6, the heating elements are in this case not acting as susceptors cooperating with a surrounding coil (not shown in figures 1 , 5 and 6).

Claims

1. A storage compartment (10) for an aerosol generation device storing a vaporizable material (12) and extending according to a longitudinal direction from an inlet end (38) defining an air inlet (20) to an outlet end (40) defining an air outlet (24); the storage compartment (10) comprising a plurality of heating and flow guiding elements (26) configured to heat the vaporizable material (12) by cooperating with at least a part of a heating system of the aerosol generation device and to guide an airflow; wherein:

- the heating and flow guiding elements (26) are arranged inside the storage compartment (10) in the longitudinal direction or at an angle to the longitudinal direction, to contribute to formation of one or several airflow paths configured to guide airflow in the longitudinal direction between the air inlet (20) and the air outlet (24), the length of the or each airflow path being greater than the distance between the inlet end (38) and the outlet end (40) according to the longitudinal direction;

- the air inlet (20) opens directly to the vaporizable material (12) stored in the storage compartment.

2. The storage compartment (10) according to claim 1, wherein the air inlet (20) is formed at the periphery of the inlet end (38) and the air outlet (24) is formed at the center of the outlet end (40).

3. The storage compartment (10) according to claim 1 or 2, wherein the inlet end (38) comprises a non-permeable cap (30) arranged in the center of the inlet end (38) substantially perpendicularly to the longitudinal direction.

4. The storage compartment (10) according to claim 3, wherein the non- permeable cap (30) is adjacent to at least one heating and flow guiding element (26) or forms a single piece with at least one heating and flow guiding element (26).

5. The storage compartment (10) according to any one of the preceding claims, wherein at least one heating and flow guiding element (26) forms a plate.

6. The storage compartment (10) according to any one of the preceding claims, wherein at least one heating and flow guiding element (26) defines at least one hole (32) and is arranged transversally to a direction connecting the air inlet (20) and the air outlet (24); at least one airflow path passing through said hole (32).

7. The storage compartment (10) according to claim 6, wherein at least one heating and flow guiding element (26) defines a plurality of holes (32), each hole (32) being crossed by at least one airflow path.

8. The storage compartment (10) according to claim 7, wherein the density and/or the dimensions of the holes (32) increase(s) according to the longitudinal direction.

9. The storage compartment (10) according to any one of claims 6 to 8, wherein at least one heating and flow guiding element (26) extends between the inlet end (38) and the outlet end (40) parallel to the longitudinal direction or with an angle with this direction.

10. The storage compartment (10) according to any one of the preceding claims, wherein at least one heating and flow guiding element (26) is arranged so that a portion of at least one airflow path guides the airflow in a direction opposite to the longitudinal direction.

11. The storage compartment (10) according to claim 10, wherein at least two heating and flow guiding elements (26) are arranged so as to form at least three parallel portions of at least one airflow path.

12. The storage compartment (10) according to claim 11, wherein at least two portions among said three parallel portions form cross-sections of different dimensions.

13. The storage compartment (10) according to any one of the preceding claims, wherein the heating system of the aerosol generation device is an inductive heating system comprising a coil, at least one heating and flow guiding element (26) being a susceptor able to generate heat when it is placed in a magnetic field created by the coil.

14. The storage compartment (10) according to any one of claim 1 to 12, wherein the heating system of the aerosol generation device comprises at least one blade heater (36) arranged inside the storage compartment, each heating and flow guiding element (26) forming at least a part of at least one blade heater (36) or being in contact with this blade heater (36).

15. The storage compartment (10) according to any one of claims 1 to 12, wherein the heating system of the aerosol generation device comprises a heater cup (34) arranged outside the storage compartment, at least one heating and flow guiding element (26) being in contact with the heater cup (34).

16. An aerosol generating article comprising a storage compartment according to any one of claims 1 to 15, wherein the storage compartment (10) forms a first section, wherein the article comprises a second section (14) adjacent the storage compartment (10) providing support to the compartment and defining an air path (16), and a third section (18) comprising a filter downstream the second section (14).

17. An aerosol generating article according to claim 16, wherein it forms a cylindrical stick.

18. An aerosol generating article according to claim 16 or 17, wherein the second section comprises at least one hollow tubular member.

19. An aerosol generating article according to claim 18, wherein the hollow tubular member is a paper tube and/or a filter tube.

20. An aerosol generating article according to any one of claims 16 to 19, wherein the filter comprises at least one segment made of cellulose acetate or paper filtering material.