A Tobacco Article Comprising a Coloured Wrapper External Surface and a Related Aerosol Generating Assembly
A tobacco article for a heat-not-burn aerosol generating device. The aerosol generating device may include one or several heating elements. The tobacco article—may include a tobacco substrate portion, and wrapper wrapping the tobacco substrate portion and defining a wrapper external surface intended to be in contact or face at least partially each heating element. The wrapper's external surface is at least partially coloured by a colour such that an emissivity value for an infrared thermometer readings is higher than 0.85.
The present invention concerns a tobacco article for heat-not-burn aerosol generating device.
Particularly, the tobacco article according to the invention is configured to operate with a heat-not-burn aerosol generating device. The tobacco article is for example a flat-shaped tobacco article. The tobacco article comprises for example a solid substrate able to form aerosol when being heated. Thus, the heat-not-burn aerosol generating device is adapted to heat, rather than burn, the substrate by conduction, convection and/or radiation, to generate aerosol for inhalation.
The present invention also concerns an aerosol generating assembly comprising said heat-not-burn aerosol generating device and said tobacco article.
BACKGROUND OF THE INVENTIONThe popularity and use of reduced-risk or modified-risk devices (also known as vaporisers) has grown rapidly in the past few years as an aid to assist habitual smokers wishing to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos, and rolling tobacco. Various devices and systems are available that heat or warm vaporizable substances as opposed to burning tobacco in conventional tobacco products.
A commonly available reduced-risk or modified-risk device is the heated substrate aerosol generation device or heat-not-burn device. Devices of this type generate aerosol or vapour by heating an aerosol substrate that typically comprises moist leaf tobacco or other suitable vaporizable material to a temperature typically in the range 150° C. to 350° C. Heating an aerosol substrate, but not combusting or burning it, releases aerosol that comprises the components sought by the user but not the toxic and carcinogenic by-products of combustion and burning. Furthermore, the aerosol produced by heating the tobacco or other vaporizable material does not typically comprise the burnt or bitter taste resulting from combustion and burning that can be unpleasant for the user and so the substrate does not therefore require the sugars and other additives that are typically added to such materials to make the smoke and/or vapour more palatable for the user.
Tobacco articles, usable with such type of aerosol generating devices can take various forms. Some of them can present an elongated stick or any other suitable shape, like for example a flat shape. However, design of a tobacco article is often a trade-off between its aesthetics and efficiency in heating.
In any of these cases, the tobacco substrate is surrounded by a wrapper preserving the integrity of the tobacco article and improves a clean handling of the substrate. Said wrapper also aims at ensuring that vapour goes through the designed path including a mouthpiece portion of the article. Thus, wrapper makes it possible to avoid vapour leakage, which would reduce the overall vapour efficiency.
However, a wrapper can create a thermal barrier for the heat transfer from heaters of the heat-not-burn aerosol generating device to the tobacco substrate. Due to said thermal barrier, the tobacco substrate may not be sufficiently heated, resulting in reducing the amount of vapour produced by the tobacco substrate.
SUMMARY OF THE INVENTIONOne of the aims of the invention is to provide a tobacco article improving the efficiency of vapour producing.
For this purpose, the invention relates to tobacco article for a heat-not-burn aerosol generating device comprising one or several heating element(s), the tobacco article comprising:
-
- a tobacco substrate portion;
- a wrapper wrapping the tobacco substrate portion and defining a wrapper external surface intended to be in contact or face at least partially the or each heating element;
- wherein the wrapper external surface is at least partially coloured so as its emissivity value for infrared thermometer readings is higher than 0.85, preferably higher than 0.9.
Thanks to these features, the wrapper external surface is coloured so as to enhance heat absorption from the or each heating element. Thus, it is possible to improve the heating of the tobacco substrate by absorbing heat from the device's heater(s), via thermal radiation. In other words, when heating, the device's heater(s) might transfer heat to the tobacco substrate via thermal convection, thermal conduction and/or thermal radiation.
Additionally, colouring may hide any staining or dirty appearance of the wrapper.
A thermal conduction between the device's heater(s) and the tobacco substrate is obtained if the tobacco substrate and/or wrapper is in contact with the device's heater(s).
A thermal convection between the device's heater(s) and the tobacco substrate is obtained when the tobacco substrate is generally distant from the device's heater(s). When being powered, the temperature of the device's heater(s) increases, thus producing an airflow between the device's heater(s) and the tobacco substrate. Such airflow thus transfers energy to the tobacco substrate, inducing a temperature increase of said substrate.
A thermal radiation between the device's heater(s) and the tobacco substrate is obtained in any case. When being powered, the temperature of the device's heater(s) increases. Thus, the device's heater(s) emit(s) radiation comprising different wavelengths. This radiation is an electromagnetic wave. The radiation reaches the external surface of the wrapper. Depending on the material of the wrapper, the colour of the wrapper and the wavelengths of the emitted radiation, at least a part of the radiation's energy is absorbed by the wrapper converting it in heat spreading over the tobacco substrate.
The coloured external wrapper makes it possible to absorb a radiation with a wider range of wavelengths thus leading to a greater amount of energy absorbed and converted into heat for the tobacco substrate.
The absorption is to be understood in this application as a proportion of the radiation energy absorbed by the external wrapper over the radiation energy produced by the device's heater(s). The absorption is characterized by an absorptivity value which is a measure of how much of the radiation is absorbed by the external wrapper.
In a thermal equilibrium with its environment, the absorptivity value of a body is equal to its emissivity value. Particularly, an emissivity value of a body is a measure of how much thermal radiation the body emits to its environment. The emissivity value is a characteristic of each material and for most materials, is function of surface condition, temperature and wavelength of measurement.
In the meaning of the present invention, each emissivity value is measured by infrared thermometer readings. Particularly, these measurements can be carried out using a surface probe meter in combination with an infrared thermometer. For this purpose, a first temperature is read on the surface probe meter. Then, the emissivity of the infrared thermometer is changed until a second temperature given by the infrared temperature reaches the first temperature. This emissivity of the infrared thermometer corresponds thus to the emissivity value of the body.
For some materials, the emissivity value can vary in function of its temperature. In such a case, in the meaning of the present invention, it is understood that that the temperature of the external wrapper for measuring its emissivity value is determined by normal conditions of its storing when the tobacco article is not operated to generate aerosol (20° C. for example). In variant, the temperature of the external wrapper for measuring its emissivity value is determined by operating conditions of the tobacco article. This temperature can be comprised between 200° C. and 350° C.
According to some embodiments, the emissivity value of the wrapper external surface for infrared thermometer readings is comprised between 0.90 and 0.98, preferably between 0.91 and 0.96, and advantageously between 0.92 and 0.95, and even more preferably between 0.93 and 0.94.
With this feature, the heat absorbance of the wrapper external surface is optimized since an emissivity value comprised within said intervals makes it possible to absorb the high majority of energy received.
According to some embodiments, the wrapper external surface's colour is obtained by mixing several dyes, advantageously four dyes.
This feature improves the absorbance of the wrapper since it ensures that the wrapper absorbs the energy of radiation with different wavelengths, corresponding to the colour of each dye. The heating of the tobacco substrate is thus improved.
According to some embodiments, the colour of each dye is chosen in the group comprising: red, green, blue and yellow.
This feature makes it possible to improve heating of the tobacco substrate by optimizing the absorbed wavelengths. Actually, red, blue and yellow are well distributed in the visible spectrum. Blue corresponds to a wavelength comprised between 380 nm and 500 nm. Green corresponds to a wavelength comprised between 500 nm and 580 nm. Yellow corresponds to a wavelength comprised between 580 nm and 590 nm. Red corresponds to a wavelength comprised between 620 nm and 780 nm.
As known per se, each colour reflects wavelengths corresponding to said colour and absorbs other wavelengths. In particular, the wavelengths opposite to the colour's wavelength are the most absorbed.
Thus, the colour of the wrapper external surface may be yellow, red, green, blue or black. Black is defined here as the colour obtained when mixing each dye. The emissivity values of the wrapper external surface having one these colours depends on the nature of the dye. For example, for some dyes, the emissivity values can be comprised between 0.90 and 0.95.
According to some embodiments, said dyes are food dyes.
With this feature, the dye does not present any risk for the user of the heat-not-burn aerosol device.
According to some embodiments, the wrapper comprises vapour impermeable material.
This feature avoids vapour leakage, which would reduce the vapour efficiency.
According to some embodiments, said vapour impermeable material is aluminium.
With this feature, the vapour leakage is further preserved since aluminium is an efficient vapour impermeable material.
According to some embodiments, the area of the coloured part of the wrapper external surface is greater than 50%, preferably greater than 60%, advantageously greater than 70% and more advantageously greater than 80%, of its total area. In some embodiments, the wrapper external surface is entirely coloured.
In some embodiments, the coloured part of the wrapper external surface corresponds to its part which is intended to face or be in contact with one or several heating elements of the aerosol generating device.
Thanks to these features, the coloured part of the wrapper external surface can be optimized for heat absorbing. Additionally, depending on different embodiments of the invention, the coloured part can form a special design effect of the wrapper.
According to some embodiments, the wrapper comprises paper and the wrapper external surface's colour is obtained by colouring the paper.
This feature makes it possible to colour easily at least a part of the wrapper. Actually, it is easy to apply a surface treatment on paper. Due to its high liquid, and powder, absorbance capability, different colouring processes are possible with paper.
For example, paper may be dipped at least partially in a coloured liquid, absorbing said liquid. When drying, water would evaporate from paper and only pigments of the coloured liquid would remain in the paper.
Alternatively, a coloured liquid may be sprayed on parts of the paper intended to form coloured parts. Thanks to its high absorbance capability, the coloured liquid would be absorbed by paper instead of spreading away from the paper. When drying, water would evaporate and only pigments of the coloured liquid would remain in the paper.
According to some embodiments, said dyes are added to pulp forming the paper of the wrapper.
With this feature, while paper manufacturing, the paper is entirely coloured making it possible to ensure a homogeneous distribution of the colouring dye in the paper material.
Then, when using the tobacco article with a heat-not-burn aerosol generating device, thermal radiation would have a homogeneous effect on the external surface of the wrapper leading to a better vapour efficiency.
According to some embodiments, the weight part of each dye in the paper pulp is comprised between 0.1% and 5%.
This feature makes it possible to colour the wrapper while remaining harmless for a user of the tobacco article.
According to some embodiments, the wrapper external surface is mat.
With this feature, a smaller part of the radiation emitted by a device's heater(s) is reflected by the external surface of the wrapper. Actually, when a radiation reaches a surface, a part of it is reflected by the surface, independently of the colour of said surface. This phenomenon is known as reflection. A mat surface has a low reflection factor ensuring a better absorbance of radiation's energy. Thus, this feature improves the heating of the tobacco substrate.
A mat surface may be a surface having a specular reflectance lower than 20 GU at a measurement angle of 60°. The specular reflectance is preferably below 10 GU at a measurement angle of 60°.
According to some embodiments, defining a flat-shape, preferably a flat-shaped cuboid.
According to some embodiments, the colour of the wrapper external surface is chosen to absorb more radiation with wavelengths comprised between 600 nm to 2.5 μm than radiation having other wavelength.
This feature makes it possible to improve the absorbance of the wavelengths which are the most emitted wavelength by the device's heater. Particularly, the wavelengths emitted by the device's heater may comprise at least some wavelengths from the visible spectrum (for example between 600 nm and 700 nm) and at least some wavelengths from the infrared spectrum (from 700 nm to 2.5 μm). Thus, the absorption of the thermal radiation by the wrapper external surface can be optimized.
The invention also relates to a tobacco article as describe here above and a heat-not-burn aerosol generating device adapted to operate with said tobacco article.
The invention and its advantages will be better understood upon reading the following description, which is given solely by way of non-limiting example and which is made with reference to the appended drawings, in which:
Before describing the invention, it is to be understood that it is not limited to the details of construction set forth in the following description. It will be apparent to those skilled in the art having the benefit of the present disclosure that the invention is capable of other embodiments and of being practiced or being carried out in various ways.
As used herein, the term “substantially equal” defines an equality at plus or minus 10%, and preferably an equality at plus or minus 5%.
As used herein, the term “aerosol generating device” or “device” may include a vaping device to deliver an aerosol to a user, including an aerosol for vaping, by means of a heater element explained in further detail below. The device may be portable. “Portable” may refer to the device being for use when held by a user. The device may be adapted to generate a variable amount of aerosol, e.g. by activating the heater element for a variable amount of time (as opposed to a metered dose of aerosol), which can be controlled by a trigger. The trigger may be user activated, such as a vaping button and/or inhalation sensor. The inhalation sensor may be sensitive to the strength of inhalation as well as the duration of inhalation to enable a variable amount of vapour to be provided (so as to mimic the effect of smoking a conventional combustible smoking article such as a cigarette, cigar or pipe, etc.). The device may include a temperature regulation control to drive the temperature of the heater and/or the heated aerosol generating substance (aerosol pre-cursor) to a specified target temperature and thereafter to maintain the temperature at the target temperature that enables efficient generation of aerosol.
As used herein, the term “aerosol” may include a suspension of vaporizable material as one or more of: solid particles; liquid droplets; gas. Said suspension may be in a gas including air. Aerosol herein may generally refer to/include a vapour. Aerosol may include one or more components of the vaporizable material.
As used herein, the term “vaporizable material” or “precursor” may refer to a smokable material which may for example comprise nicotine or tobacco and an aerosol former. Tobacco may take the form of various materials such as shredded tobacco, granulated tobacco, tobacco leaf and/or reconstituted tobacco. Suitable aerosol formers include: a polyol such as sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol; a non-polyol such as monohydric alcohols, acids such as lactic acid, glycerol derivatives, esters such as triacetin, triethylene glycol diacetate, triethyl citrate, glycerin or vegetable glycerin. In some embodiments, the aerosol generating agent may be glycerol, propylene glycol, or a mixture of glycerol and propylene glycol. The substrate may also comprise at least one of a gelling agent, a binding agent, a stabilizing agent, and a humectant.
Referring to
As it is shown in
As it is also shown in
The device body 40 delimits an internal space of the device 11 receiving various elements designed to carry out different functionalities of the device 11. This internal space can for example receive a battery for powering the device 11, a control module for controlling the operation of the device 11, a heating chamber 50 for heating the tobacco article 12, etc. Among these elements, only the heating chamber 50 will be explained in further detail in reference to
Particularly, as it is shown in
The heating chamber 50 further comprises one or several heating elements (not-shown) arranged to heat the substrate portion 15 of the tobacco article 12. According to different embodiments of the invention, the or each heating element can present for example a restive element arranged adjacent to at least one of the wide walls 54A, 54B or narrow walls of the heating chamber 50. The resistive elements may be in ceramic. Advantageously, a resistive heating element, as for example a heating track or a thin film heater, is arranged adjacent to each wide wall 54A, 54B of the heating chamber 50, for example on an external surface of such a wall. In this case, each wide wall 54A, 54B is made of a heat conductive material such as metal or ceramic. In some embodiments, the or each heating element is integrated into the corresponding wide wall 54A, 54B or forms such a wall.
When being powered, the one or several heating elements emit a radiation comprising one or several wavelengths. These wavelength may be mainly comprised between 600 nm and 2.5 μm, corresponding to at least partially infrared wavelengths and at least partially visible wavelengths. When such a heating element is arranged adjacent to the corresponding wide wall 54A, 54B, such a wall is heated and consequently, also emits a radiation comprising one or several wavelengths. The energy of this radiation is then at least partially absorbed by the tobacco article 12 as it is described below.
In order to ensure user's puffs, a not-shown airflow channel is formed inside the aerosol generating device 11. The airflow channel can extend for example between an airflow inlet and a closed end of the heating chamber 50. According to some embodiments, the airflow inlet is arranged in the mouthpiece 42, advantageously in the intermediate portion of the peripheral part 44 of this mouthpiece 42. The airflow inlet can be formed by a through hole.
The airflow channel is formed by an upstream portion extending from the airflow inlet and a downstream portion extending from the upstream portion until the closed end of the heating chamber 50. According to different embodiments of the invention, the downstream portion may extend inside or outside the heating chamber 50. For example, according to one embodiment, the downstream portion extends inside the heating chamber 50 from its opening 60 until the closed end.
In some embodiments, several airflow channels can be formed inside the aerosol generating device 11, each of these channels being similar to the channel described above. For example, these channels can be arranged symmetrically in respect with the through hole 46 of the mouthpiece 42. In the example of the Figures, two airflow channels are arranged symmetrically in respect with the through hole 46.
In the example of this
The tobacco article 12 comprises a tobacco substrate portion 115 and a mouthpiece portion 116 arranged along the article axis X. The substrate portion 115 may for example be slightly longer than the mouthpiece portion 16. For example, the length L2 of the substrate portion 15 according to the article axis X may be substantially equal to 18 mm and the length L1 of the mouthpiece portion 16 according to the article axis X may be substantially equal to 15 mm. The substrate portion 115 defines an abutting end 118 of the article 12 and the mouthpiece portion 116 defines a mouth end 120 of the article 12. The substrate portion 115 and the mouthpiece portion 116 may be fixed one to the other by a wrapper 121 extending around the substrate axis X that will be detailed below.
The mouthpiece portion 116 comprises a core 127 intended to act for example as a cooler to cool slightly the vapour before it is inhaled by the user. The core 127 may comprise for this purpose for example corrugated paper. The core 127 may be formed through an extrusion and/or rolling process into a stable shape. Advantageously, the core 127 is arranged inside the mouthpiece portion 116 to be entirely in contact with an internal surface 128 of the wrapper 121 delimiting this mouthpiece portion 116.
The mouthpiece portion 116 for example intends to be received by the though hole 46 when the tobacco article 12 is received in the device 11.
The substrate portion 115 comprises a vaporizable material, as defined above, and is intended to be heated by the heating chamber 50. The substrate portion 115 for example intends to be received in the heating chamber 50 when the tobacco article 12 is received in the device 11.
In particular, referring again to
If the facing wide walls 114A, 114B, 54A, 54B and the facing narrow walls 113A, 113B, are in contact with each other, heat produced by the heating elements is mainly transferred to the tobacco substrate portion 115 via thermal conduction. If the facing wide walls 114A, 114B, 54A, 54B and the facing narrow walls 113A, 113B are not in contact with each other, heat produced by the heating elements would mainly be transferred to the substrate portion 115 via thermal convection. In both cases, a part of heat is transferred via thermal radiation from heating elements to the substrate portion 115.
Referring to
When using the aerosol assembly, air can enter the heating chamber 50 through the airflow channel and passes first to the substrate portion 115 and then through the mouthpiece portion 116 of the tobacco article 12 before being delivered to the user.
The wrapper 121 forms the narrow and wide walls 113A, 113B, 114A, 114B of the tobacco article 12. Preferably, the wrapper 121 covers neither the abutting end 118 nor the mouth end 120. Alternatively, the abutting end 118 and/or the mouth end 120 is (are) covered by removable portion(s) of the wrapper 121. This or these removal portions should be removed from the article 12 before inserting the article 12 in the device 11.
In some embodiments, the wrapper 121 is formed from a same wrapping sheet. In other embodiments, several wrapping sheets, for example two, can form the wrapper 121.
In the example of
The first layer 131 surrounds the tobacco substrate portion 115 defining an internal surface 135 of the wrapper 121, which is in contact with the tobacco substrate. The first layer 131 may be made of a vapour impermeable material to avoid vapour leakage from it. The first layer 131 may be made of aluminium, preferably aluminium lined paper.
The second layer 132 for example surrounds the first layer 131 defining an external surface 140 of the wrapper 121. The external surface 140 aims at facing the wide walls 54A, 54B, and the narrow walls, of the heating chamber 50 when the tobacco article 12 is inserted in the heat-not-burn aerosol generating device 11. The second layer 132 can comprise paper and is preferably made of paper.
When the wrapper 121 is formed by a single layer, both internal and external surfaces 135, 140 are formed by this single layer. In this case, this single layer can be formed from any appropriate material, such as paper, aluminium, etc. In the following, when it is referred to the second layer 132, this second layer 132 may be considered as the single layer of the wrapper 121 or as a part of the wrapper 121 combined with the first layer 131. It is also considered that the second layer 132 comprises paper or is formed from paper.
The external surface 140 is at least partially coloured to enhance heat absorption from the heating element(s). The coloured part of the wrapper external surface corresponds for example to its part which is intended to face or be in contact with one or several heating elements. The colour of the external surface 140 can be any colour of the visible spectrum enhancing heat absorption. The visible spectrum must be understood here as comprised between 400 nm and 800 nm.
For example, the external surface 140 can be coloured with a dark colour, such as black, violet or indigo. In other words, the external surface does not reflect substantially any light. Preferably, when different wavelengths, for each wavelength, the external surface 140 does not reflect more that 10% of the energy corresponding to said wavelength in the radiation.
The coloured external surface 140 may be obtained by colouring the material forming the wrapper 121, i.e., the second layer 132 material in the example of
As an example, a combination of fours dyes, such as red, green, blue and yellow makes it possible to colour the external surface 140 in a black-like fashion. Actually, red, green, blue and yellow are primary and secondary colours of the subtractive colour synthesis. It is then possible to reach substantially a black colour by mixing them.
The red dye is for example Allura Red AC, also known as E129 dye. Its chemical formulation is C18H14N2Na2O8S2, and its full name is Disodium 6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonate. Its weight part in the second layer 132 may for example be comprised between 0.1% and 5%. The absorbance spectrum of the red dye is maximized at 504 nm.
The green dye is for example Fast Green FCF, also known as E143 dye. Its chemical formulation is C37H34N2Na2O10S3 and its full name is ethyl-[4-[[4-[ethyl-[(3-sulfophenyl)methyl]amino]phenyl]-(4-hydroxy-2-sulfophenyl)methylidene]-1-cyclohexa-2,5-dienylidene]-[(3-sulfophenyl)methyl]azanium. Its weight part in the second layer 132 may for example be comprised between 0.1% and 5%. The absorbance spectrum of the green dye is maximized at 625 nm.
The blue dye is for example Brilliant Blue FCF, also known as E133 dye. Its chemical formulation is C37H34N2Na2O9S3 and its full name is disodium; 2-[[4-[ethyl-[(3-sulfonatophenyl)methyl]amino]phenyl]-[4-[ethyl-[(3-sulfonatophenyl)methyl]azaniumylidene]cyclohexa-2,5-dien-1-ylidene]methyl]benzenesulfonate. Its weight part in the second layer 132 may for example be comprised between 0.1% and 5%. The absorbance spectrum of the blue dye is maximized at 630 nm.
The yellow dye is for example Tartrazine, also known as E102 dye. Its chemical formulation is C16H9N4Na3O9S2 and its full name is Trisodium 5-hydroxy-1-(4-sulfonatophenyl)-4-[(E)-(4-sulfonatophenyl)diazenyl]-1H-pyrazole-3-carboxylate. Its weight part in the second layer 132 may for example be comprised between 0.1% and 5%. The absorbance spectrum of the yellow dye is maximized at 425 nm.
The emissivity value of the wrapper external surface 140 for infrared thermometer readings is comprised between 0.90 and 0.99, preferably between 0.90 and 0.98, more preferably between 0.91 and 0.96, and advantageously between 0.92 and 0.95, and even more preferably between 0.93 and 0.94. These values can be measured when the tobacco article 12 is not operated to generate aerosol and is stored within an ambient temperature, like 20° C.
In addition, the external surface 140 can be mat. Mat's aspect is an optical property that characterizes the light reflexion in a specular direction. The mat's aspect of the external surface 140 makes it possible to limit the amount of radiation's energy reflected from the heating elements.
A mat surface may be a surface having a specular reflectance lower than 20 GU at a measurement angle of 60°. The specular reflectance is preferably below 10 GU at a measurement angle of 60°.
During manufacturing of the second layer 132, the paper may be in a form of pulp forming paper. Each dye is added to the pulp forming paper. Preferably, each dye is diluted in water so that it better spreads in the pulp forming paper. Alternatively, each dye is in the form of a powder. The pulp is thus mixed so that each dye is homogeneously distributed in the pulp. Then, sheets of paper are manufactured according to paper making processes known per se. Finally, coloured sheets of paper are ready to form the second layer 132 of the wrapper 121.
In some non-represented embodiments, the wrapper 121 is formed by separate wrapping sheets wrapping separately the portions 115, 116 and fixed one to the other by any other suitable mean. In this embodiment, the wrapping sheet wrapping the tobacco substrate portion 115 is similar to the wrapper 121 described above. It is thus clear that the external surface of the wrapping sheet wrapping the tobacco substrate portion 115 is coloured.
In these embodiments, the wrapping sheet wrapping the mouthpiece portion 116 can be similar to the wrapping sheet wrapping the tobacco substrate portion 115. In this case, the external surface of the wrapping sheet wrapping the mouthpiece portion 116 is also coloured. Alternatively, the wrapping sheet wrapping the mouthpiece portion 116 is white.
Operation of the Aerosol Generating AssemblyThe operation of the aerosol generating assembly 10 will now be described.
Initially, the tobacco article 12 is inserted in the device 11 such that the tobacco substrate portion 115 faces the heating elements.
The heating elements produces heat. The heat is transferred by conduction to the tobacco substrate portion 116 if the external surface 140 is in contact with said heating elements. If the heating elements are not in contact with the external surface 140, heat is transferred by convection.
In addition, the heat produced by the heating elements make them emit a radiation toward the tobacco article 12. The radiation reaches the external surface 140 wherein the wrapper 121 absorbs a first part of it and reflects a second part of it. Since the external surface is coloured, the wrapper 121 absorbs most of the energy of said radiation, mostly if the external surface 140 has a dark colour such as black. This absorption contributes to the heating of the tobacco substrate portion 116. Actually, the energy absorbed by the wrapper 121 is converted into heat by said wrapper 121.
During a user's puff, air from outside the aerosol generating device 11 flows through the airflow channel and reaches the heating chamber 50. This air then enters the tobacco article 11 through the abutting end 118 and reaches the tobacco substrate portion 115. In the tobacco substrate portion 115, air is mixed with tobacco vapour to become an aerosol. In the mouthpiece portion 116, the aerosol is cooled before reaching the user's mouth.
Claims
1. A tobacco article for a heat-not-burn aerosol generating device comprising one or several heating element(s), the tobacco article comprising:
- a tobacco substrate portion; and
- a wrapper wrapping the tobacco substrate portion and defining a wrapper external surface intended to be in contact or face at least partially each heating element,
- wherein the wrapper external surface is at least partially coloured by a colour such that an emissivity value for an infrared thermometer readings is higher than 0.85.
2. The tobacco article according to claim 1, wherein the emissivity value of the wrapper external surface for the infrared thermometer readings is between 0.90 and 0.98.
3. The tobacco article according to claim 1, wherein the colour is obtained by mixing several dyes.
4. The tobacco article according to claim 3, wherein the colour of each dye of the several dyes is chosen from a group comprising: red, green, blue and/or yellow.
5. The tobacco article according to claim 3, wherein the several dyes are food dyes.
6. The tobacco article according to claim 1, wherein the wrapper comprises vapour impermeable material.
7. The tobacco article according to claim 1, wherein an area of the coloured part of the wrapper external surface is greater than 50% of its total area.
8. The tobacco article according to claim 1, wherein the wrapper comprises paper.
9. The tobacco article according to claim 8, wherein the colour of the wrapper external surface is obtained by colouring the paper.
10. The tobacco article according to claim 8, wherein the colour is obtained by mixing several dyes, and
- wherein said dyes are added to pulp forming the paper of the wrapper.
11. The tobacco article according to claim 10, wherein a weight part of each dye in the pulp is comprised between 0.1% and 5%.
12. The tobacco article according to claim 1, wherein the wrapper external surface is mat.
13. The tobacco article according to claim 1, defining a flat-shape.
14. The tobacco article according to claim 1, wherein the colour is absorbs more radiation with wavelengths comprised between 600 nm to 2.5 μm than radiation having other wavelengths.
15. An aerosol generating assembly, comprising:
- a tobacco article according to claim 1; and
- a heat-not-burn aerosol generating device adapted to operate with said tobacco article.
16. The tobacco article according to claim 9, wherein the colour is obtained by mixing several dyes, and
- wherein said dyes are added to pulp forming the paper of the wrapper.
17. The tobacco article according to claim 1, defining a flat-shaped cuboid.
18. The tobacco article according to claim 1, wherein the wrapper external surface is at least partially coloured by the colour such that the emissivity value for the infrared thermometer reading is higher than 0.9.
19. The tobacco article according to claim 1, wherein an area of the coloured part of the wrapper external surface is greater than 80% of its total area.
Type: Application
Filed: May 16, 2023
Publication Date: Aug 7, 2025
Applicant: JT International SA (Geneva)
Inventor: Alec Wright (Guildford)
Application Number: 18/856,140