Aerosol-generating article and system

Abstract

An aerosol-generating article (10) has: a magnetizable material (24) placed in an end segment (18) of the article (10), and a thermal bridge (26) in an aerosol generating substrate (16) of the article (10). An aerosol-generating system (30) has the described article (10) and an aerosol-generating device (32) having a sensor (36), such as a Hall effect sensor, adapted to sense the magnetic field of the magnetizable material (24) placed inside the aerosol- generating article (10), which is insertable into the device (32).

Description

[0001] Aerosol-generating article and system

[0002] Technical Field

[0003] The present invention relates to an aerosol-generating article and an aerosol-generating system .

[0004] Background

[0005] Heat-not-burn (HNB ) devices that use heated tobacco sticks (HTS ) have become increasingly popular over known ready-made- cigarettes and combustible tobacco products . In such devices , the tobacco consumable / article is inserted into a heating chamber to be heated so as to generate an inhalable aerosol during a vaping session .

[0006] To enhance user experience , it is necessary to keep the temperature of an aerosol generating substrate within a defined range . In order to achieve this , the temperature of the aerosol generating substrate needs to be measured .

[0007] This can be done accurately, when an internal heater is provided in the aerosol generating substrate . The internal heater can for example be constituted by a plate or rod placed inside the substrate , when this is to be heated, and can be heated using resistance heating . In this case , the temperature can then be sensed using the heater resistance , which changes with temperature .

[0008] Further, internal heating can be provided by one or more susceptors located in the substrate and cooperating with an external coil . Also in this case , the susceptor material ' s properties change with temperature , so that the temperature can be sensed . However, there are also devices which use external heating, for example by having a heater cup, in which the stick to be heated is placed . Such heater cups can have one or more temperature sensors , which can contact the stick, but they can, in any case , only measure the surface temperature , which is generally signi ficantly di f ferent from a core temperature . This di f ference in temperature is particularly high at the beginning of the session, so that there remains a need for accurate temperature measurement when external heating is provided for an aerosol generating article .

[0009] In this context , EP 4 106 564 Al is related to an aerosol generating device having a magnetic force detector configured to detect a change in magnetic force of a rod constituting a susceptor in an induction heating system used in the device .

[0010] Summary of the Invention

[0011] In view of the above , it is an obj ect of the present invention to provide an aerosol generating article , in which the temperature of an aerosol generating substrate can be measured ef ficiently and accurately . Further, an aerosol generating system having such an article is to be provided .

[0012] This is achieved by means of the article described in claim 1 and the system as described in claim 10 .

[0013] Accordingly, the article or stick described herein has an end segment , which can for example be a filter segment , such as a filter plug which lacks any aerosol generating substrate , such as tobacco . Such an end segment provides the advantages of keeping material of the aerosol generating substrate , such as tobacco safely and cleanly within the stick .

[0014] Nevertheless , temperature of the aerosol generating substrate can accurately be measured by providing a magneti zable material in the end segment and a thermal bridge in the aerosol generating substrate , despite the aerosol generating substrate being, due to the end segment , signi ficantly distant from a sensor provided in the device . This is , because the thermal bridge is adapted to conduct heat from the aerosol generating substrate to the end segment and / or the magneti zable material , and an aerosol generating device , in which the article can be inserted, typically has a sensor, such as a Hall ef fect sensor, which is adapted to sense the magnetic field of the magneti zable material in order to derive a temperature therefrom . In this manner, when the article is externally heated and no temperature sensor is provided on a heater cup, temperature of the aerosol generating substrate can be accurately measured by conducting heat to the magneti zable material by means of the thermal bridge and sensing the magnetic properties of the magneti zable material .

[0015] Since the article including the magneti zable material does usually not move , a magnetic field sensor, such as a Hall ef fect sensor, can easily detect the magnetic field during a session, in particular a heating phase thereof . Generally, the teaching of the invention will help to better understand thermal dynamics of aerosol generating articles . Further, it is noted that certain decisions , such as whether to continue or stop heating in view of a desired temperature profile , the time until the first puf f is enabled, whether the device may be extracted from a holder and / or charger for use , etc . are made by a controller of an aerosol generating device based on a temperature of the aerosol generating substrate . Such decisions have a better basis in the article and system according to the present invention, since accuracy of the temperature measurements can be improved . This is particularly relevant at the beginning of the session, when the temperature gradient is at a maximum .

[0016] Preferred embodiments are described in the further claims . The magneti zable material can be one or more of a sheet , a bar and a powder, which can all be placed ef ficiently in an end segment having filter material . In order to provide the desired ef fect of being able to calculate the temperature by sensing the magnetic properties , the magneti zable material merely needs to have magnetic remanence such that magneti zation remains to some extent , even after an external magnetic field is removed .

[0017] In order to further improve accuracy of the measurements and resulting temperature calculation, it is beneficial to provide the magneti zable material and / or the thermal bridge centrally inside the article with regard to a cross-section transverse to the longitudinal direction of the article . As regards the thermal bridge , such a placement will most accurately allow detection of the core temperature of the aerosol generating substrate . A corresponding placement of magneti zable material will lead to a temperature thereof , which corresponds well to the core temperature of the substrate . Finally, central placement of the magneti zable material will allow accurate detection by a sensor in the device , which is preferably also arranged centrally with regard to the transverse cross-section of the article .

[0018] As already indicated before , it provides advantages with regard to a clean appearance , when the end segment has a filter and / or correspondingly lacks any aerosol generating substrate or substance , such as tobacco material .

[0019] As regards the filter in the end segment , one or more of cellulose acetate , polylactic acid, natural pulp and natural fiber are preferred as materials and advantageously provide the above indicated ef fect .

[0020] In order to provide good thermal conductivity from the thermal bridge to the magneti zable material , it will be preferred for the thermal bridge to contact the magneti zable material and / or the end segment .

[0021] Concerning the shape of the thermal bridge , good results are expected for a metallic sheet or a bar constituting the thermal bridge .

[0022] This also applies to aluminum and / or copper which are currently preferred to be contained in the thermal bridge .

[0023] In order to provide a particularly accurate temperature measurement along the longitudinal direction of the aerosol generating substrate , it provides advantages to extend the thermal bridge to at least the center of the aerosol generating substrate in a longitudinal direction . However, the thermal bridge could also be slightly longer than the aerosol generating substrate so to conduct heat from the entire aerosol generating substrate to the magneti zable material and / or the end segment .

[0024] As already indicated above , an aerosol generating system has the article as described above and an aerosol generating device which has a sensor, such as a Hall ef fect sensor, in the device , which is adapted to sense the magnetic field of the magneti zable material . This sensing is based on a state , in which the article is inserted into the device .

[0025] The described sensor is preferably out of contact with the article , when inserted, so that the positional relationship between the sensor and the article is less critical , and the temperature can nevertheless be sensed accurately .

[0026] This is further enhanced by a positioning of the sensor which overlaps with the cross-section perpendicular to the insertion direction, i . e . the longitudinal direction of the article , when inserted . This ef fect is particularly pronounced, when the sensor is placed centrally with regard to a cross-section perpendicular to the insertion direction of the article .

[0027] It is noted that the novel measures for temperature measurement as described herein can be supplemented by additionally sensing the outer stick temperature . This is based on a preferred embodiment of the device described herein further comprising a heater, surrounding or constituting a chamber for receiving the article .

[0028] In this case , the device preferably further comprises a temperature sensor located on the heater and / or adapted to contact the article , so that the outer temperature of the article can be measured, and further information regarding temperature and / or temperature gradients within the article can advantageously be obtained . When such an additional temperature sensor is provided, a comparison can be made by the control of the device between the temperature at the surface of the article on the one hand, and the inner or core temperature of the article on the other hand . An algorithm can then take a decision to only allow use of the device , when the two mentioned temperatures are suf ficiently similar . This will avoid operation of the device in temperature areas , where for example the inner temperature may still have a high gradient , i . e . may still be rising to a necessary level , whereas the outer temperature may already have reached a certain level .

[0029] Brief Description of the Drawings

[0030] Hereinafter, the invention will be further described with reference to a preferred embodiment thereof , in which

[0031] Fig . 1 shows a schematic cut view of the system according to the invention, Fig . 2 shows a schematic cut exploded view of the article ,

[0032] Fig . 3 shows a transverse cut view of a tobacco rod of Fig . 2 in a first embodiment , and

[0033] Fig . 4 shows a transverse cut view of a tobacco rod of Fig . 2 in a second embodiment .

[0034] Detailed Description of Preferred Embodiments

[0035] Fig . 1 shows the aerosol generating system 30 of the invention comprising an aerosol generating article 10 and an aerosol generating device 32 . As can be taken from Fig . 1 , the device 32 comprises a heating chamber 34 configured to receive the article 10 . In the embodiment shown, a heating element 20 is provided near the bottom of the chamber 34 . The heating element 20 can for example be a resistance heating element or a coil cooperating with a susceptor within the article 10 . Although not detailed in the drawing, the device 32 further comprises a power supply configured to supply power to the heating element 20 , such as a battery, as well as any suitable control , display and / or operating means such as knobs for actuating the device 32 .

[0036] Moreover, as shown by the arrows A, the device is adapted to allow air to flow to the bottom or device end of the article 10 . The air then flows through the article and starting in an aerosol generating substrate ( see Fig . 2 ) , aerosol 22 flows out of the end of the article 10 opposite the device 32 so as to be inhalable by a user .

[0037] As can be seen in Fig . 1 , the bottom of the heating chamber 34 is , in the embodiment shown, open, and a Hall ef fect sensor 36 is provided on a printed circuit board 38 of the device . As will be described in additional detail with reference to Fig . 2 , the sensor 36 interacts with magneti zable material in the article 10 so as to derive a temperature of an aerosol generating substrate thereof .

[0038] The sensor 36 and PCB 38 are again indicated in Fig . 2 , and the article 10 is shown to have a structure with a filter 12 at a mouth end, two hollow sections 14 upstream thereof , an aerosol generating substrate 16 , such as a tobacco rod again upstream and a filter plug 18 at the very upstream end . As indicated by 24 , magneti zable material is provided in the filter plug 18 , and a thermal bridge 26 is provided in the tobacco rod 16 . In the embodiment shown, the magneti zable material 24 and the thermal bridge 26 are provided approximately at a radial center of the filter plug 18 and the tobacco rod 16 , respectively . This also applies to the sensor 36 , so that accurate detection of magnetic properties of the magneti zable material 24 can be obtained . Since these magnetic properties depend on temperature , and since the thermal bridge 26 conducts heat from approximately the center of the tobacco rod 16 to the magneti zable material 24 , temperature in the center of the tobacco rod 16 can be determined without the need of contacting the article 10 .

[0039] As can further be taken from Fig . 2 , the thermal bridge 26 extends along the longitudinal direction of the article 10 , i . e . in the vertical direction of Fig . 2 somewhat beyond the center of the tobacco rod 16 , so that temperature in the very center of the tobacco rod, in the embodiment shown both radially and axially, can be detected .

[0040] As can schematically be derived from Fig . 2 , the filter 12 , the downstream hollow section 14 and the filter plug 18 can be the shortest segments and can have a length of 5 to 10 mm, preferably 7 to 8 mm . The upstream hollow section 14 and the tobacco rod 16 can have a length of 15 to 25 mm, preferably about 20 mm .

[0041] Fig . 3 additionally shows a bar, in the case shown with a circular cross-section having a diameter of 10 to 20% of the tobacco rod' s diameter, constituting the thermal bridge 26 .

[0042] Finally, in the embodiment of Fig . 4 the thermal bridge 6 is constituted by a sheet extending approximately 60 to 80% across the diameter of the tobacco rod 16 .

Claims

Claims1. An aerosol-generating article (10) having: a magnetizable material (24) placed in an end segment (18) of the article (10) , and a thermal bridge (26) in an aerosol generating substrate (16) of the article (10) .

2. The aerosol-generating article (10) of claim 1, characterized in that the magnetizable material (24) is one or more of a sheet, a bar and a powder.

3. The aerosol-generating system of claim 1 or 2, characterized in that the magnetizable material (24) and / or the thermal bridge (26) is placed centrally inside the article (10) with regard to a cross-section transverse to the longitudinal direction of the article (10) .

4. The aerosol-generating article (10) of one of claims 1 to 3, characterized in that the end segment (18) has a filter and / or lacks any aerosol generating substrate (16) such as tobacco material.

5. The aerosol-generating article (10) of claim 4, characterized in that the filter contains one or more of cellulose acetate, polylactic acid, natural pulp and natural fiber .

6. The aerosol-generating article (10) of one of claims 1 to5, characterized in that the thermal bridge (26) contacts the magnetizable material (24) and / or the end segment (18) .

7. The aerosol-generating article (10) of one of claims 1 to6, characterized in that the thermal bridge (26) is a metallic sheet or bar.

8. The aerosol-generating article (10) of one of claims 1 to7, characterized in that the thermal bridge (26) contains aluminum and / or copper.

9. The aerosol-generating article (10) of one of claims 1 to8, characterized in that the thermal bridge (26) extends at least to the center of the aerosol generating substrate (16) in a longitudinal direction.

10. An aerosol-generating system (30) having the article (10) of one of claims 1 to 9 and an aerosol-generating device (32) having a sensor (36) , such as a Hall effect sensor, adapted to sense the magnetic field of the magnetizable material (24) placed inside the aerosol-generating article (10) , which is insertable into the device (32) .

11. The aerosol-generating system (30) of claim (10) , characterized in that the sensor (36) is out of contact with the aerosol-generating article (10) , when inserted.

12. The aerosol-generating system (30) of one of claims (10) to 11, characterized in that the sensor (36) overlaps with a cross section perpendicular to the insertion direction of the aerosol-generating article (10) , when inserted.

13. The aerosol-generating system (30) of claim 12, characterized in that the sensor (36) is placed centrally with regard to a cross-section perpendicular to the insertion direction of the aerosol-generating article (10) , when inserted .

14. The aerosol-generating system (30) of one of claims (10) to 13, characterized in that the device (32) further comprises a heater (20) surrounding or constituting a chamber (34) for receiving the aerosol-generating article (10) .

15. The aerosol-generating system (30) of claim 14, characterized in that the device (32) further comprises a temperature sensor located on the heater (20) and / or adapted to contact the aerosol-generating article (10) .

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