A tobacco article comprising an outer surface of a colored wrapper and an associated aerosol generating assembly

Abstract

The present invention relates to a tobacco article (12) for a heat non-combustion aerosol generating device comprising one or more heating elements, - a tobacco substrate part (115), - a wrapper defining a wrapper outer surface (140) that wraps the tobacco substrate part (115) and is at least partially intended to contact or face the heating element or each heating element, wherein the wrapper outer surface (140) is at least partially colored such that its emissivity value for the reading of an infrared thermometer is greater than 0.85, preferably greater than 0.9.

Description

Technical Field

[0001] The present invention relates to a tobacco article for a heat-not-burn aerosol generating device.

[0002] In particular, the tobacco article according to the present invention is configured to operate in a heat-not-burn aerosol generating device. The tobacco article is, for example, a tobacco article having a flat shape. The tobacco article includes, for example, a solid substrate that can form an aerosol when heated. Thus, the heat-not-burn aerosol generating device is adapted to heat the substrate by conduction, convection, and / or radiation, rather than burning, in order to generate an aerosol for inhalation.

[0003] The present invention also relates to an aerosol generating assembly comprising the above heat-not-burn aerosol generating device and the above tobacco article.

Background Art

[0004] The popularity and use of risk reduction or risk modification devices (also known as vaporizers) has increased rapidly in recent years as an aid to support habitual smokers who wish to quit smoking conventional tobacco products such as cigarettes, cigars, cigarillos, and roll-your-own tobacco. In contrast to burning the tobacco of conventional tobacco products, various devices and systems are available that heat or warm a vaporizable substrate.

[0005] Generally available risk reduction or risk modification devices are aerosol generating devices for heated substrates or heat-not-burn devices. This type of device typically generates an aerosol or vapor by heating an aerosol substrate, typically containing moist leaf tobacco or other suitable vaporizable material, to a temperature in the range of typically 150°C to 350°C. By heating the aerosol substrate without burning or combusting it, an aerosol is released that contains components that are required by the user but are not the toxic and carcinogenic by-products of burning and combustion. Further, the aerosol generated by heating tobacco or other vaporizable material typically does not contain the burnt or bitter tastes resulting from burning and combustion, which can be unpleasant for the user. Thus, the substrate typically does not require sugars and other additives that are typically added to such materials to make the smoke and / or vapor agreeable to the user's mouth.

[0006] Tobacco articles that can be used with such types of aerosol generating devices can take various forms. Some of them can assume an elongated stick or any other suitable shape, such as, for example, a flat shape. However, the design of the tobacco article is often a trade-off between its aesthetics and heating efficiency.

[0007] In any of these cases, the tobacco substrate is surrounded by a package that maintains the integrity of the tobacco article, improving the clean handling of the substrate. The package also aims to ensure that the vapor travels through a designed path that includes the mouthpiece portion of the article. Thus, the package makes it possible to avoid vapor leakage that would reduce the overall vapor efficiency.

[0008] However, the package may create a thermal barrier to the heat transfer from the heater of the heat-not-burn aerosol generating device to the tobacco substrate. Due to the thermal barrier, the tobacco substrate may not be heated sufficiently, which may result in a reduction in the amount of vapor generated by the tobacco substrate. SUMMARY OF THE INVENTION

[0009] One object of the present invention is to provide a tobacco article that improves the steam generation efficiency.

[0010] For this purpose, the present invention relates to a tobacco article for a heat non-combustible aerosol generating device including one or more heating elements, the tobacco article comprising: - a tobacco substrate portion; - a wrapper defining an outer surface of the wrapper that wraps the tobacco substrate portion and is intended to at least partially contact or face the heating element or each heating element; The outer surface of the wrapper is at least partially colored such that its emissivity value for the reading of an infrared thermometer is greater than 0.85, preferably greater than 0.9.

[0011] Due to these features, the outer surface of the wrapper is colored so as to improve the heat absorption from the heating element or each heating element. Therefore, it is possible to improve the heating of the tobacco substrate by absorbing heat from the heater of the device via thermal radiation. In other words, during heating, the heater of the device can transfer heat to the tobacco substrate via heat convection, heat conduction, and / or thermal radiation.

[0012] In addition, coloring can conceal the appearance of stains or dirt on the wrapper.

[0013] When the tobacco substrate and / or the wrapper is in contact with the heater of the device, heat conduction is obtained between the heater of the device and the tobacco substrate.

[0014] When the tobacco substrate is generally separated from the heater of the device, heat convection is obtained between the heater of the device and the tobacco substrate. When power is supplied, the temperature of the heater of the device rises, thus causing an air flow between the heater of the device and the tobacco substrate. Therefore, such an air flow transfers energy to the tobacco substrate, resulting in an increase in the temperature of the substrate.

[0015] Thermal radiation between the heater of the device and the tobacco substrate can be obtained in any case. When power is supplied, the temperature of the heater of the device rises. Therefore, the heater of the device emits radiation including various wavelengths. This radiation is an electromagnetic wave. The radiation reaches the outer surface of the package. Depending on the material of the package, the color of the package, and the wavelength of the emitted radiation, at least part of the energy of the radiation is absorbed by the package, converted into heat, and spreads over the tobacco substrate.

[0016] The colored outer package enables the absorption of radiation having a wider range of wavelengths, whereby a larger amount of energy is absorbed within the tobacco substrate and converted into heat.

[0017] Absorption in this application should be understood as the ratio of the radiation energy absorbed by the outer package to the radiation energy generated by the heater of the device. Absorption is characterized by an absorption rate value, which is an indicator of the amount of radiation energy absorbed by the outer package.

[0018] In thermal equilibrium with its environment, the absorption rate value of the body is equal to its emissivity value. In particular, the emissivity value of the body is an indicator of how much thermal radiation the body emits to its environment. The emissivity value is a characteristic of each material and is a function of the surface state, temperature, and measurement wavelength for most materials.

[0019] In the context of the present invention, each emissivity value is measured by the reading of an infrared thermometer. In particular, these measurements can be carried out using a surface probe meter combined 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 varied until the second temperature given by the infrared thermometer reaches the first temperature. This emissivity of the infrared thermometer thus corresponds to the emissivity value of the body.

[0020] For several materials, the emissivity value can vary as a function of its temperature. In such cases, in the context of the present invention, the temperature of the outer package for measuring the emissivity value is understood to be determined by its normal storage conditions (e.g., 20 °C) when the tobacco article is not being operated to generate aerosol. In a variant, the temperature of the outer package for measuring the emissivity value is determined by the operating conditions of the tobacco article. This temperature can be included in the range of 200 °C to 350 °C.

[0021] In some embodiments, the emissivity value of the outer surface of the package for the reading value of the infrared thermometer is included in the range of 0.90 to 0.98, preferably 0.91 to 0.96, advantageously 0.92 to 0.95, and even more preferably 0.93 to 0.94.

[0022] Due to this feature, with the emissivity value included in the above range, it becomes possible to absorb most of the received energy, so that the heat absorption rate of the outer surface of the package is optimized.

[0023] According to some embodiments, the color of the outer surface of the package is obtained by mixing a plurality of dyes, advantageously four dyes.

[0024] Due to this feature, it is ensured that the package absorbs the energy of radiation having various wavelengths corresponding to the colors of the respective dyes, so that the absorption rate of the package is improved. Therefore, the heating of the tobacco substrate is improved.

[0025] According to some embodiments, the color of each dye is selected from the following group, namely, red, green, blue, and yellow.

[0026] This feature enables the improvement of the heating of the tobacco substrate by optimizing the absorbed wavelength. In fact, red, blue, and yellow are well-distributed in the visible spectrum. Blue corresponds to wavelengths of 380 nm to 500 nm. Green corresponds to wavelengths of 500 nm to 580 nm. Yellow corresponds to wavelengths of 580 nm to 590 nm. Red corresponds to wavelengths of 620 nm to 780 nm.

[0027] As is well known, each color reflects the wavelength corresponding to that color and absorbs other wavelengths. In particular, the wavelength opposite to the wavelength of that color is most absorbed.

[0028] Therefore, the color of the outer surface of the package may be yellow, red, green, blue, or black. Here, black is defined as the color obtained when each pigment is mixed. The emissivity value of the outer surface of the package having one of these colors depends on the nature of the pigment. For example, for some pigments, the emissivity value may be included in the range of 0.90 to 0.95.

[0029] According to some embodiments, the above pigment is an edible pigment.

[0030] This feature ensures that there is no risk to the user of the heat-not-burn aerosol device from the pigment.

[0031] According to some embodiments, the package includes a vapor-impermeable material.

[0032] This feature avoids vapor leakage that reduces vapor efficiency.

[0033] According to some embodiments, the above vapor-impermeable material is aluminum.

[0034] This feature further suppresses vapor leakage because aluminum is an efficient vapor-impermeable material.

[0035] According to some embodiments, the area of the colored portion on the outer surface of the package is more than 50% of its total area, preferably more than 60%, advantageously more than 70%, and more advantageously more than 80%. In some embodiments, the outer surface of the package is entirely colored.

[0036] In some embodiments, the colored portion of the outer surface of the package corresponds to the portion that is intended to face or contact one or more heating elements of the aerosol generating device.

[0037] With these features, the colored portion of the outer surface of the package can be optimized for heat absorption. Additionally, depending on the various embodiments of the present invention, the colored portion can form a special design effect of the package.

[0038] According to some embodiments, the package includes paper, and the color of the outer surface of the package is obtained by coloring the paper.

[0039] This feature enables easy coloring of at least a part of the package. In fact, it is easy to apply a surface treatment on paper. Due to the high liquid and powder absorption capacity of paper, various coloring treatments are possible on paper.

[0040] For example, the paper may be at least partially immersed in a colored liquid and allowed to absorb the liquid. When dried, the water evaporates from the paper, leaving only the pigment of the colored liquid on the paper.

[0041] Alternatively, the colored liquid may be sprayed onto the portion of the paper that is intended to form the colored portion. Due to its high absorption capacity, the colored liquid is absorbed by the paper instead of spreading from the paper. When dried, the water evaporates, leaving only the pigment of the colored liquid inside the paper.

[0042] According to some embodiments, the above pigment is added to the pulp forming the paper of the package.

[0043] Due to this feature, during the manufacture of the paper, the entire paper is colored, ensuring a uniform distribution of the coloring pigment in the paper material.

[0044] Then, when using a tobacco article together with a heat non-combustion aerosol generating device, the heat radiation has a uniform effect on the outer surface of the package, resulting in better vapor efficiency.

[0045] According to some embodiments, the weight portion of each pigment in the paper pulp is included in the range of 0.1% to 5%.

[0046] This feature enables the package to be colored while remaining harmless to the user of the tobacco article.

[0047] According to some embodiments, the outer surface of the package is matte.

[0048] This feature causes less of the radiation emitted from the heater of the device to be reflected by the outer surface of the package. In fact, when the radiation reaches the surface, regardless of the color of the surface, a part of it is reflected by the surface. This phenomenon is known as reflection. A matte surface has a low reflectivity, ensuring better absorption of radiant energy. Therefore, this feature improves the heating of the tobacco substrate.

[0049] The matte surface may be a surface having a specular reflectivity of less than 20 GU at a measurement angle of 60°. The specular reflectivity is preferably less than 10 GU at a measurement angle of 60°.

[0050] According to some embodiments, a flat shape, preferably a rectangular parallelepiped of a flat shape, is defined.

[0051] According to some embodiments, the color of the outer surface of the package is selected to absorb more radiation having wavelengths included in the range of 600 nm to 2.5 μm than radiation having other wavelengths.

[0052] This feature makes it possible to improve the absorbance of the wavelength most emitted by the heater of the device. In particular, the wavelengths emitted by the heater of the device may include at least some wavelengths from the visible spectrum (e.g., 600 nm to 700 nm) and at least some wavelengths from the infrared spectrum (700 nm to 2.5 μm). In this way, the absorbance of the thermal radiation by the outer surface of the package can be optimized.

[0053] The present invention also relates to the tobacco article described above and a heat-not-burn aerosol generating device adapted to operate with the tobacco article.

[0054] The present invention and its advantages will be better understood by reading the following description given as a non-limiting example with reference to the accompanying drawings.

Brief Description of the Drawings

[0055]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0056] Before describing the present invention, it should be understood that the present invention is not limited to the details of the structures described in the following description. It will be apparent to those skilled in the art who enjoy the benefits of this disclosure that the present invention can have other embodiments and can be practiced or carried out in various ways.

[0057] As used herein, the term "substantially equal" defines an equivalence of plus or minus 10%, and preferably plus or minus 5%.

[0058] As used herein, the term "aerosol generating device" or "device" may include an inhalation device for delivering to a user an aerosol containing an aerosol for inhalation, using a heater element described in further detail below. The device may be portable. "Portable" may refer to a device for use when held by a user. The device may be adapted to generate a variable amount of aerosol, for example, by activating the heater element for various amounts of time (as opposed to metering of the aerosol), which can be controlled by a trigger. The trigger may be activated by a user, such as an inhalation button and / or a suction sensor. The suction sensor may be able to sense the suction period, along with the intensity of suction, in order to enable the provision of a variable amount of vapor (so as to mimic the smoking effect of conventional combustible smoking articles such as cigarettes, cigars or pipes, etc.). The device may include a temperature adjustment control device for driving the temperature of the heater and / or the heated aerosol generating substrate (aerosol precursor) to a specific target temperature and then maintaining the temperature at the target temperature at which the aerosol can be efficiently generated.

[0059] As used herein, the term "aerosol" may include a suspension of a vaporizable material as one or more of solid particles, droplets, and gases. The suspension may be in a gaseous state containing air. Herein, the aerosol may generally also refer to / include vapor. The aerosol may include one or more components of the vaporizable material.

[0060] As used herein, the term "vaporizable material" or "precursor" may be a reference to a smokable material that may include, for example, nicotine or tobacco and an aerosol forming agent. Tobacco can take various material forms such as shredded tobacco, granulated tobacco, tobacco leaves and / or reconstituted tobacco. Suitable aerosol forming agents include polyols (such as glycols like sorbitol, glycerol and propylene glycol or triethylene glycol), non-polyols (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 include at least one of a gelling agent, a binder, a stabilizer and a water retention agent.

[0061] Figure 1 shows an aerosol generating assembly 10 comprising a heat-not-burn aerosol generating device 11 and a tobacco article 12. The heat-not-burn aerosol generating device 11 is intended to operate with the tobacco article 12.

[0062] Referring to Figure 1, the heat-not-burn aerosol generating device 11 comprises a device body 40 extending along a device axis Y and a mouthpiece 42. According to the example described below, the mouthpiece 42 and the device body 40 form two different parts. In particular, according to this example, the mouthpiece 42 is designed to be fixed to the fixed end of the device body 40.

[0063] As shown in FIG. 2, the mouthpiece 42 includes a central portion 43 and a peripheral portion 44 extending around the central portion 43. The peripheral portion 44 defines, for example, an annular collar that partially covers the outer surface of the device body 40 when the mouthpiece 42 is fixed to the fixed end of the device body 40. For example, the peripheral portion 44 can be designed to cooperate with a gasket 45 disposed at the fixed end of the device body 40 to seal the space formed between the peripheral portion 44 and the outer surface of the device body 40. The peripheral portion 44 extends, for example, in a transverse direction with respect to the device axis Y and also defines an intermediate portion that forms a transition between the central portion 43 of the mouthpiece 42 and the annular collar defined by the peripheral portion 44. The central portion 43 of the mouthpiece 42 defines a through-hole 46 that is adapted to at least partially receive the tobacco article 12. Advantageously, the through-hole 46 can be adapted to fit securely with the tobacco article 12 so as to avoid or minimize leakage of the flow between the wall partitioning the through-hole 46 and the outer surface of the tobacco article 12. In some embodiments, the tobacco article 12 can be held within the through-hole 46, for example, by friction. In this case, for example, it is possible to first insert the tobacco article 12 inside the through-hole 46 and then fix both elements onto the fixed end of the device body 40.

[0064] As also shown in FIG. 2, an internal volume 47 is formed between the inner surface 48 of the mouthpiece 42 and the fixed end of the device body 40. This internal volume 47 is traversed by the tobacco article 12 when the tobacco article 12 is inserted into the device body 40. For example, the tobacco article 12 can divide the internal volume 47 into two symmetric parts.

[0065] The device body 40 defines an internal space of the device 11 that receives various elements designed to perform various functions of the device 11. This internal space can receive, for example, a battery for supplying power to 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 described in more detail with reference to FIG. 2.

[0066] Specifically, as shown in FIG. 2, the heating chamber 50 can form a cup shape adapted to at least partially receive the tobacco article 12. Further, the heating chamber 50 extends along the device axis Y and includes a pair of parallel wide walls 54A, 54B that also extend along the device axis Y, a pair of parallel narrow walls (not shown) that extend along the device axis Y, and a bottom wall 58 that extends perpendicular to the device axis Y adjacent to each of those walls, and can form a rectangular parallelepiped shape. Thus, the bottom wall 58 forms the closed end of the chamber 50. On the opposite side of the bottom wall 58, the heating chamber 50 defines an opening 60 configured to receive the tobacco article 12.

[0067] The heating chamber 50 further includes one or more heating elements (not shown) arranged to heat the substrate portion 15 of the tobacco article 12. According to various embodiments of the present invention, the heating element or each heating element is arranged adjacent to at least one of the wide walls 54A, 54B or the narrow walls of the heating chamber 50 and can exhibit, for example, a resistive element. The resistive element can be made of ceramic. Advantageously, resistive heating elements such as, for example, heating tracks or thin film heaters are arranged adjacent to each wide wall 54A, 54B of the heating chamber 50, for example, on the outer surface of such walls. In this case, each wide wall 54A, 54B is made of a thermally conductive material such as metal or ceramic. In some embodiments, the heating element or each heating element is incorporated into or forms the corresponding wide wall 54A, 54B.

[0068] When power is supplied, one or more heating elements emit radiation including one or more wavelengths. These wavelengths are mainly included in the range of 600 nm to 2.5 μm and at least partially correspond to infrared wavelengths and at least partially to visible wavelengths. When such heating elements are arranged adjacent to the corresponding wide walls 54A, 54B, such walls are heated and as a result also emit radiation including one or more wavelengths. The energy of this radiation is then at least partially absorbed by the tobacco article 12 as described below.

[0069] To ensure user suction, an air flow path (not shown) is formed inside the aerosol generating device 11. The air flow path can extend, for example, between an air inlet and the closed end of the heating chamber 50. According to some embodiments, the air inlet is arranged in the mouthpiece 42, preferably in the middle part of the peripheral part 44 of this mouthpiece 42. The air inlet can be formed by a through hole.

[0070] The air flow path is formed by an upstream part extending from the air inlet and a downstream part extending from the upstream part to the closed end of the heating chamber 50. According to various embodiments of the present invention, the downstream part can extend inside or outside the heating chamber 50. For example, according to one embodiment, the downstream part extends inside the heating chamber 50 from the opening 60 to the closed end of the heating chamber 50.

[0071] In some embodiments, a plurality of air flow paths can be formed inside the aerosol generating device 11, and each of these flow paths is similar to the flow path described above. For example, these flow paths may be arranged symmetrically with respect to the through hole 46 of the mouthpiece 42. In the illustrated example, two air flow paths are arranged symmetrically with respect to the through hole 46.

[0072] In the example of FIG. 3, the tobacco article 12 is a flat-shaped tobacco article that extends, for example, along the article axis X and presents a rectangular parallelepiped shape with external dimensions L×W×D. In a typical example, the length L of the article 12 along the article axis X is substantially equal to 33 mm, while its width W and depth D are substantially equal to 12 mm and 1.2 mm, respectively. According to different examples, the values L, W, and D can be selected, for example, within the range of ±40%. The depth D of the tobacco article 12 is formed by a pair of parallel walls 113A, 113B, hereinafter referred to as narrow walls 113A, 113B, and the width W of the substrate is formed by a pair of parallel walls 114A, 114B, hereinafter referred to as wide walls 114A, 114B. The tobacco article 121 has a flat shape. In some embodiments, the edges between the wide walls and the narrow walls 113A, 113B, 114A, 114B may be rounded. According to other embodiments of the present invention, the tobacco article 12 may have any other suitable flat shape and / or external dimensions. According to still other embodiments, the tobacco article 12 may present any other suitable shape, such as, for example, a stick shape.

[0073] 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 be, for example, slightly longer than the mouthpiece portion 16. For example, the length L2 of the substrate portion 15 along the article axis X may be substantially equal to 18 mm, and the length L1 of the mouthpiece portion 16 along the article axis X may be substantially equal to 15 mm. The substrate portion 115 defines the abutment end 118 of the article 12, and the mouthpiece portion 116 defines the mouth end 120 of the article 12. The substrate portion 115 and the mouthpiece portion 116 may be fixed to each other by a wrapper 121 extending around the substrate axis X, which will be described in detail below.

[0074] The mouthpiece portion 116 includes, for example, a core 127 intended to function as a cooler for slightly cooling the vapor before the user inhales. The core 127 can be composed of, for example, cardboard for this purpose. The core 127 can be formed into a stable shape through an extrusion and / or rolling process. Advantageously, the core 127 is arranged inside the mouthpiece portion 116 so as to be in complete contact with the inner surface 128 of the wrapper 121 that partitions the mouthpiece portion 116.

[0075] For example, the mouthpiece portion 116 is intended to be received by the through-hole 46 when the tobacco article 12 is received by the device 11.

[0076] The base portion 115 contains a vaporizable material as described above and is intended to be heated by the heating chamber 50. The base portion 115 is intended to be received by the heating chamber 50, for example, when the tobacco article 12 is received by the device 11.

[0077] In particular, referring again to FIG. 2, the tobacco article 12 is intended to be at least partially inserted into the heating chamber 50. The tobacco article 12 is configured to be received in the opening 60 of the heating chamber 50, whereby the corresponding wide walls 114A, 114B of the tobacco article 12 face the corresponding wide walls 54A, 54B of the heating chamber 50, the corresponding narrow walls 113A, 113B of the tobacco article 12 face the corresponding narrow walls of the heating chamber 50, and the abutment end 118 of the tobacco article 12 abuts against the bottom wall 58 or at least a rib extending from the bottom wall 58. Alternatively, the abutment end 118 of the tobacco article 12 faces the bottom wall 58 without contacting the bottom wall 58. Thus, the tobacco article 12 is configured to be received by the heating chamber 50, such that the narrow wall 113A (or 113B) of the tobacco article 12 faces the narrow wall of the heating chamber 50 and the wide wall 114A (or 114B) of the tobacco article 12 faces the wide wall 54B (or 54A) of the heating chamber 50. The facing wide walls 114A, 114B, 54A, 54B and the facing narrow walls 113A, 113B may be in contact with each other or may be spaced apart from each other.

[0078] When the facing wide walls 114A, 114B, 54A, 54B and the facing narrow walls 113A, 113B are in contact with each other, the heat generated by the heating element is mainly transferred to the tobacco substrate portion 115 via heat conduction. When the facing wide walls 114A, 114B, 54A, 54B and the facing narrow walls 113A, 113B are not in contact with each other, the heat generated by the heating element is mainly transferred to the substrate portion 115 via heat convection. In either case, a portion of the heat is transferred via thermal radiation from the heating element to the substrate portion 115.

[0079] Referring to FIG. 2, when the tobacco article 12 is inserted into the heat-not-burn aerosol generating device 11, the downstream portion of the air flow path can be formed between the narrow walls 113A, 113B of the tobacco article 12 and the corresponding narrow walls of the heating chamber 50. According to another embodiment, the downstream portion of the air flow path extends outside the heating chamber 50 through a dedicated flow path extending, for example, along the narrow wall of the heating chamber 50. In this case, the downstream portion opens at the closed end of the heating chamber 50.

[0080] When using the aerosol assembly, air enters the heating chamber 50 through the air flow path, first passes through the substrate portion 115, then through the mouthpiece portion 116 of the tobacco article 12, and can then be delivered to the user.

[0081] The wrapper 121 forms the narrow walls and the wide walls 113A, 113B, 114A, 114B of the tobacco article 12. Preferably, the wrapper 121 does not cover either the abutting end 118 or the mouth end 120. Alternatively, the abutting end 118 and / or the mouth end 120 are covered by a removable portion of the wrapper 121. This removable portion or these removable portions should be removed from the article 12 before inserting the article 12 into the device 11.

[0082] In some embodiments, the wrapper 121 is formed from the same packaging sheet. In other embodiments, for example, two wrapping sheets can form the wrapper 121.

[0083] In the example of FIG. 4, the wrapper 121 includes a first layer 131 and a second layer 132. According to other examples, the wrapper 121 can be formed by a single layer.

[0084] The first layer 131 surrounds the tobacco substrate portion 115 and defines the inner surface 135 of the wrapper 121 that contacts the tobacco substrate. The first layer 131 can be made of a vapor-impermeable material to avoid vapor leakage therefrom. The first layer 131 can be made of aluminum, preferably aluminum-laminated paper.

[0085] The second layer 132 surrounds, for example, the first layer 131 and defines the outer surface 140 of the package 121. The outer surface 140 is intended to face the wide walls 54A, 54B and the narrow wall of the heating chamber 50 when the tobacco article 12 is inserted into the heat-not-burn aerosol generating device 11. The second layer 132 is made of paper and is preferably created from paper.

[0086] When the package 121 is formed by a single layer, both the inner surface 135 and the outer surface 140 are formed by this single layer. In this case, this single layer can be formed from any suitable material such as paper, aluminum, etc. In the following, when referring to the second layer 132, this second layer 132 can be considered as a single layer of the package 121 or as part of the package 121 in combination with the first layer 131. Also, the second layer 132 is considered to contain paper or be formed from paper.

[0087] The outer surface 140 is at least partially colored in order to enhance heat absorption from the heating element. The colored portion of the outer surface of the package corresponds, for example, to the portion intended to face or contact one or more heating elements. The color of the outer surface 140 can be any color in the visible spectrum that enhances heat absorption. It must be understood that the visible spectrum is included in 400 nm to 800 nm.

[0088] For example, the outer surface 140 can be colored with a dark color such as black, purple, blue, etc. In other words, the outer surface reflects substantially no light. Preferably, for a plurality of different wavelengths, for each wavelength, the outer surface 140 does not reflect more than 10% of the energy corresponding to that wavelength in radiation.

[0089] The colored outer surface 140 can be obtained, for example, by coloring the material forming the package 121, i.e., the material of the second layer 132, with a plurality of dyes such as food dyes in the example of FIG. 4.

[0090] As an example, by combining four dyes of red, green, blue, and yellow, it becomes possible to color the outer surface 140 with a color similar to black. In fact, red, green, blue, and yellow are the primary and secondary colors of subtractive color mixing. Then, by mixing them, it is possible to approach substantially black.

[0091] The red dye is, for example, Allura Red AC, also known as E129 dye. Its chemical formula is C 18 H 14 N 2 Na 2 O 8 S 2 and its official name is disodium 6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonate. Its weight fraction in the second layer 132 can be included, for example, in the range of 0.1% to 5%. The absorption spectrum of the red dye is maximized at 504 nm.

[0092] The green dye is, for example, Fast Green FCF, also known as E143 dye. Its chemical formula is C 37 H 34 N 2 Na 2 O 10 S 3 and its official 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 fraction in the second layer 132 can be included, for example, in the range of 0.1% to 5%. The absorption spectrum of the green dye is maximized at 625 nm.

[0093] The blue dye is, for example, Brilliant Blue FCF, also known as E133 dye. Its chemical formula is C 37 H 34 N 2 Na 2 O 9 S 3and its formal 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 portion in the second layer 132 can be included, for example, in the range of 0.1% to 5%. The absorption spectrum of the blue pigment is maximized at 630 nm.

[0094] The yellow pigment is tartrazine, also known as, for example, E102 pigment. Its chemical formula is C 16 H 9 N 4 Na 3 O 9 S 2 and its formal name is trisodium 5-hydroxy-1-(4-sulfonatophenyl)-4-[(E)-(4-sulfonatophenyl)diazenyl]-1H-pyrazole-3-carboxylate. Its weight portion in the second layer 132 can be included, for example, in the range of 0.1% to 5%. The absorption spectrum of the yellow pigment is maximized at 425 nm.

[0095] The emissivity value of the outer surface 140 of the package with respect to the reading value of the infrared thermometer is included in the range of 0.90 to 0.99, preferably 0.90 to 0.98, more preferably 0.91 to 0.96, advantageously 0.92 to 0.95, and even more preferably 0.93 to 0.94. These values can be measured when the tobacco article 12 is not operating to generate an aerosol and is stored within an ambient temperature such as 20 °C.

[0096] In addition, the outer surface 140 can be matte. The matte aspect is an optical property that characterizes the light reflection in the specular reflection direction. The matte property of the outer surface 140 makes it possible to limit the amount of radiant energy reflected from the heating element.

[0097] The matte surface can be a surface having a specular reflectance of less than 20 GU at a measurement angle of 60°. The specular reflectance is preferably less than 10 GU at a measurement angle of 60°.

[0098] During the production of the second layer 132, the paper may be in the form of pulp-forming paper. Each dye is added to the pulp-forming paper. Preferably, each dye is diluted with water, so that it spreads better 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 uniformly distributed within the pulp. Thereafter, a paper sheet is produced according to a well-known papermaking process. Finally, the colored paper sheet is prepared to form the second layer 132 of the package 121.

[0099] In some embodiments not shown, the package 121 is formed by separate packaging sheets that separately package the portions 115, 116 and are fixed to each other by any other suitable means. In this embodiment, the packaging sheet that packages the tobacco substrate portion 115 is the same as the package 121 described above. Thus, it is clear that the outer surface of the packaging sheet that packages the tobacco substrate portion 115 is colored.

[0100] In these embodiments, the packaging sheet that packages the mouthpiece portion 116 can be the same as the packaging sheet that packages the tobacco substrate portion 115. In this case, the outer surface of the packaging sheet that packages the mouthpiece portion 116 is also colored. Alternatively, the packaging sheet that packages the mouthpiece portion 116 is white.

[0101] <Operation of the aerosol generating assembly> The operation of the aerosol generating assembly 10 will be described here.

[0102] First, the tobacco article 12 is inserted into the device 11 such that the tobacco substrate portion 115 faces the heating element.

[0103] The heating element generates heat. When the outer surface 140 is in contact with the heating element, the heat is transferred to the tobacco substrate portion 116 by conduction. When the heating element is not in contact with the outer surface 140, the heat is transferred by convection.

[0104] In addition, heat generated by the heating element causes radiation to be emitted toward the tobacco article 12. The radiation reaches the outer surface 140, where the wrapper 121 absorbs its first portion and reflects its second portion. Since the outer surface is colored, the wrapper 121 absorbs most of the energy of the radiation, mainly when the outer surface 140 is a dark color such as black. This absorption contributes to the heating of the tobacco substrate portion 116. In fact, the energy absorbed by the wrapper 121 is converted into heat by the wrapper 121.

[0105] During the user's inhalation, air from outside the aerosol generating device 11 flows through the air flow path and reaches the heating chamber 50. This air then enters the tobacco article 11 through the abutment end 118 and reaches the tobacco substrate portion 115. In the tobacco substrate portion 115, the air is mixed with tobacco vapor to form an aerosol. In the mouthpiece portion 116, the aerosol is cooled before reaching the user's mouth.

Claims

**Claim 1** A tobacco article (12) for a heat-not-burn aerosol generating device (11) comprising one or more heating elements, a tobacco substrate part (115), a wrapper (121) that wraps the tobacco substrate part (115) and defines an outer wrapper surface (140) that is intended to at least partially contact or face the heating element or each heating element, comprising, the outer wrapper surface (140) is at least partially colored such that its emissivity value for the reading of an infrared thermometer is greater than 0.85, preferably greater than 0.9, tobacco article (12). **Claim 2** The emissivity value of the outer wrapper surface (140) for the reading of the infrared thermometer is included in the range of 0.90 to 0.98, preferably 0.91 to 0.96, advantageously 0.92 to 0.95, and even more preferably 0.93 to 0.94, for the tobacco article (12) according to claim 1. **Claim 3** The color of the outer wrapper surface (140) is obtained by mixing a plurality of dyes, advantageously four dyes, for the tobacco article (12) according to claim 1 or 2. **Claim 4** The color of each dye is selected from the following group: red, green, blue, and yellow, for the tobacco article (12) according to claim 3. **Claim 5** The dyes are food dyes, for the tobacco article (12) according to claim 3 or 4. **Claim 6** The wrapper (121) comprises a vapor-impermeable material (131), for the tobacco article (12) according to any one of claims 1 to 5. **Claim 7** The area of the colored portion of the outer wrapper surface (140) is greater than 50% of its total area, preferably greater than 60%, advantageously greater than 70%, and more advantageously greater than 80%, for the tobacco article (12) according to any one of claims 1 to 6. **Claim 8** The wrapper (121) comprises paper, for the tobacco article (12) according to any one of claims 1 to 7. **Claim 9** The color of the outer wrapper surface is obtained by coloring the paper, for the tobacco article (12) according to claim 8. **Claim 10** The dyes are added to the pulp forming the paper of the wrapper (121), for the tobacco article (12) according to claim 8 or 9 in combination with claim 3. **Claim 11** The weight portion of each dye in the pulp of the paper is included in the range of 0.1% to 5%, for the tobacco article (12) according to claim 10. **Claim 12** The tobacco article (12) according to any one of claims 1 to 11, wherein the outer surface (140) of the package is matte. **Claim 13** The tobacco article (12) according to any one of claims 1 to 12, defining a flat shape, preferably a rectangular parallelepiped of a flat shape. **Claim 14** The tobacco article (12) according to any one of claims 1 to 13, wherein the color of the outer surface (140) of the package is selected to absorb more radiation having a wavelength included in 600 nm to 2.5 μm than radiation having other wavelengths. **Claim 15** An aerosol generating assembly (10), the tobacco article (12) according to any one of claims 1 to 14, a heat-not-burn aerosol generating device (11) adapted to operate with the tobacco article (12), comprising an aerosol generating assembly (10).

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