Aerosol-forming substrates and aerosol-forming products

Abstract

The present application provides an aerosol-generating substrate and an aerosol-generating product, the aerosol-generating substrate having passages that penetrate at least one end of the substrate along its length, and pores formed in the aerosol-generating substrate that communicate with the passages. In the aerosol-generating substrate of the present application, the passages can increase the surface area of ​​the aerosol-generating substrate, facilitating heat transfer and improving heating efficiency. When the aerosol-generating substrate receives heat and emits aerosol, the aerosol is collected in the passages by the pores and transported to the suction end by the action of negative suction pressure. The passages reduce the user's inhalation resistance, improving the user's experience.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application is based on a Chinese patent application bearing application number 202310098083.1 filed with the China Patent Office on January 20, 2023, a Chinese patent application bearing application number 202310555607.5 filed with the China Patent Office on May 17, 2023, and a Chinese patent application bearing application number 202320190383.8 filed with the China Patent Office on January 20, 2023, and claims priority to the above three Chinese patent applications, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE INVENTION This application relates to the technical field of smoke-generating products, and in particular to aerosol-generating substrates and aerosol-generating products that generate an aerosol upon heating. [Background technology]

[0003] Smoke-generating products include those that form an aerosol by combustion and those that form an aerosol by a non-combustion method. A typical non-combustion method smoke-generating product contains an aerosol-generating substrate, such as a tobacco material, a flavoring material, and / or an atomizing agent, that can volatilize when heated to generate an aerosol. The aerosol-generating substrate is heated using an external heat source to a temperature that is not high enough to cause combustion but is still capable of releasing an aerosol. The substrate contains a large amount of atomizing agent, and the atomizing agent is released by high-temperature heating during use, forming an aerosol.

[0004] In the prior art, when inhaling smoke-generating products, the resistance to inhalation is high, and the amount of smoke produced varies greatly from inhalation to inhalation. Summary of the Invention

[0005] In light of this, the embodiments of the present application aim to provide an aerosol-generating substrate and an aerosol-generating product that reduce the resistance to inhalation and improve uniformity with each inhalation.

[0006] An embodiment of the present application provides an aerosol-generating substrate having a passageway that penetrates at least one end of the aerosol-generating substrate along its length, and pores formed in the aerosol-generating substrate that communicate with the passageway.

[0007] In some embodiments, the passageway comprises an airway hole that is provided inside the aerosol-generating substrate and passes through opposite ends of the aerosol-generating substrate in the longitudinal direction.

[0008] In some embodiments, the cross-sectional area of ​​the airway opening is 0.0019 mm 2 ~30mm 2 Alternatively, the hydraulic diameter of the airway opening is 0.05 mm to 6 mm.

[0009] In some embodiments, the cross-sectional area of ​​the airway opening is 0.007 mm 2 ~7.1mm 2 Alternatively, the hydraulic diameter of the airway opening is 0.1 mm to 3 mm.

[0010] In some embodiments, the cross-sectional shape of the airway opening in a plane perpendicular to the length of the aerosol-generating substrate is at least one of a circle, an ellipse, a track, a polygon, and a sector.

[0011] In some embodiments, the number of airway holes is multiple, and in a plane perpendicular to the longitudinal direction of the aerosol-generating substrate, the airway holes are distributed point-symmetrically with respect to the center of the aerosol-generating substrate, and / or the airway holes are distributed mirror-symmetrically with respect to the central axial plane of the aerosol-generating substrate.

[0012] In some embodiments, the number of the airway holes is plural, and each of the airway holes has the same cross-sectional shape and size in a plane perpendicular to the length of the aerosol-generating substrate.

[0013] In some embodiments, the passages are not interwoven with airway grooves, the airway grooves being provided on the circumferential surface of the aerosol-generating substrate.

[0014] In some embodiments, the passageway comprises an airway hole, the airway hole being located within the aerosol-generating substrate; In a plane perpendicular to the length of the aerosol-generating substrate, the cross-sectional shape of the airway groove is the same as the local shape of the airway stoma.

[0015] In some embodiments, the pore has a cross-sectional area of ​​0.7 nm 2 or 710 μm 2 Alternatively, the hydraulic diameter of the pores is between 10 nm and 30 μm.

[0016] In some embodiments, the cross-sectional area of ​​the pore is 1963 nm 2 ~20μm 2 Alternatively, the hydraulic diameter of the pores is 50 nm to 5 μm.

[0017] In some embodiments, the maximum size of the contour of the aerosol-generating substrate in a plane perpendicular to the length of the aerosol-generating substrate is between 4 mm and 10 mm.

[0018] In some embodiments, the maximum size of the contour of the aerosol-generating substrate in a plane perpendicular to the length of the aerosol-generating substrate is between 6 mm and 8.6 mm.

[0019] In some embodiments, at least some of the passages extend along straight lines and / or at least some of the passages extend along curved lines.

[0020] In some embodiments, the aerosol-generating substrate is a particle conjugate, and the pores are formed between particles of the particle conjugate.

[0021] In some embodiments, the aerosol-generating substrate is monolithic and / or the cross-sectional area of ​​the passageways is at least 20 times the cross-sectional area of ​​the pores.

[0022] An embodiment of the present application provides an aerosol-generating product, the aerosol-generating product comprising: an aerosol-generating substrate as described in any of the Examples of the present application; a functional segment provided at one end of the aerosol-generating substrate along its length, the functional segment including at least a filter segment for filtering the aerosol; and an outer coating layer that surrounds the functional segment and the circumferential exterior of the aerosol-generating substrate.

[0023] In the aerosol-generating substrate of the present application, the passages can increase the surface area of ​​the aerosol-generating substrate, facilitating heat transfer and improving heating efficiency. When the medium in the aerosol-generating substrate receives heat and releases an aerosol, the aerosol is collected in the passages by the pores and transported to the suction end by the action of negative suction pressure. The passages reduce the user's resistance to inhalation and improve the user experience. Note that the resistance to inhalation is positively correlated with the flow resistance of the aerosol. The smaller the flow resistance the aerosol experiences within the aerosol-generating substrate, the smaller the resistance to inhalation experienced by the user. Conversely, the greater the flow resistance the aerosol experiences within the aerosol-generating substrate, the greater the resistance to inhalation experienced by the user. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram of an aerosol-generating product in one embodiment of the present application. [Figure 2] FIG. 2 is a cross-sectional view of the structure shown in FIG. [Figure 3] FIG. 2 is a schematic diagram of an aerosol-generating product in another embodiment of the present application. [Figure 4] 1 is a schematic diagram of an aerosol-generating substrate in a first embodiment of the present application. [Figure 5] FIG. 5 is a cross-sectional view of the structure shown in FIG. [Figure 6] FIG. 2 is a schematic diagram of an aerosol-generating substrate in a second embodiment of the present application. [Figure 7] FIG. 1 is a schematic diagram of an aerosol-generating substrate in a third embodiment of the present application. [Figure 8] FIG. 1 is a schematic diagram of an aerosol-generating substrate in a fourth embodiment of the present application. [Figure 9] FIG. 1 is a schematic diagram of an aerosol-generating substrate in a fifth embodiment of the present application. [Figure 10] FIG. 10 is a schematic diagram of an aerosol-generating substrate in a sixth embodiment of the present application. [Figure 11] FIG. 10 is a schematic diagram of an aerosol-generating substrate in a seventh embodiment of the present application. [Figure 12] FIG. 10 is a schematic diagram of an aerosol-generating substrate in an eighth embodiment of the present application. [Figure 13] FIG. 10 is a schematic diagram of an aerosol-generating substrate in a ninth embodiment of the present application. [Figure 14] FIG. 13 is a schematic diagram of an aerosol-generating substrate in the tenth embodiment of the present application. [Figure 15] FIG. 14 is a schematic diagram of an aerosol-generating substrate in the eleventh embodiment of the present application. [Figure 16] FIG. 12 is a schematic diagram of an aerosol-generating substrate in a twelfth embodiment of the present application. [Figure 17] FIG. 13 is a schematic diagram of an aerosol-generating substrate in a thirteenth embodiment of the present application. [Figure 18] FIG. 14 is a schematic diagram of an aerosol-generating substrate in a fourteenth embodiment of the present application. [Figure 19] FIG. 15 is a schematic diagram of an aerosol-generating substrate in the fifteenth embodiment of the present application. [Figure 20] FIG. 16 is a schematic diagram of an aerosol-generating substrate in the sixteenth embodiment of the present application. [Figure 21] FIG. 17 is a schematic diagram of an aerosol-generating substrate in the seventeenth embodiment of the present application. [Figure 22] FIG. 18 is a schematic diagram of an aerosol-generating substrate in the eighteenth embodiment of the present application. [Figure 23]1 is a schematic cross-sectional view of the structure of an aerosol-generating substrate in one embodiment of the present application. [Figure 24] FIG. 2 is a schematic diagram of an aerosol-generating product in accordance with another embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0025] The embodiments of the present application will be described in more detail below with reference to the drawings and examples. The following examples are intended to illustrate the present application and are not intended to limit the scope of the present application.

[0026] In describing the examples of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] The embodiment of the present application provides an aerosol-generating substrate 10 that, when heated, generates an aerosol to be inhaled by a user. In the embodiment of the present application, the aerosol-generating substrate 10 is generally cylindrical.

[0028] An embodiment of the present application further provides an aerosol-generating product, which, referring to Figures 1, 2, 3, and 24, comprises a functional segment 30, an outer coating layer 20, and an aerosol-generating substrate 10 in any embodiment of the present application.

[0029] The aerosol-generating product is used in combination with an aerosol-generating device having a heating assembly, specifically, the heating assembly heats and atomizes the aerosol-generating substrate 10 to generate the aerosol.

[0030] It should be noted that the aerosol-generating product generates the aerosol through the aerosol-generating substrate 10, and the functional segment 30 does not generate the aerosol.

[0031] The aerosol-generating product in the embodiments of the present application may be adapted for inhalation by a heating and combustion method or by a heating and non-combustion method. In the embodiments of the present application, the aerosol-generating product 100 will be described as being adapted for inhalation by a heating and non-combustion method.

[0032] The functional segment 30 is provided at one end along the length of the aerosol-generating substrate 10. Here, the functional segment 30 includes at least a filter segment 31 for filtering the aerosol. The filter segment 31 is also called a filter tip. A user inhales the aerosol after it has been filtered by the filter segment 31 of the functional segment 30.

[0033] The outer coating layer 20 surrounds the functional segments 30 and the circumferential exterior of the aerosol-generating substrate 10 .

[0034] The material of the outer coating layer 20 is not limited, and may include, but is not limited to, one or more combinations of materials such as fiber paper, metal foil, metal foil composite fiber paper, polyethylene composite fiber paper, PE, and PBAT.

[0035] In some embodiments, the functional segment 30 includes only the filter segment 31. In other embodiments, in addition to the filter segment 31, the functional segment 30 further includes a support segment and / or a temperature-reducing segment 32 (see FIG. 24 ), which is disposed between the aerosol-generating substrate 10 and the filter segment 31.

[0036] Here, the temperature reduction segment 32 is used to perform a temperature reduction process on the aerosol before the filter segment 31 filters the aerosol, thereby lowering the temperature of the aerosol and thereby improving the phenomenon of the "mouth feeling hot" when the user inhales the aerosol.

[0037] Materials for the temperature reduction segment 32 include, but are not limited to, one or more combinations of polyethylene (PE), polylactic acid (also known as polylactide) (PLA), polybutyleneadipate-co-terephthalate (PBAT), polypropylene (PP), acetate fiber, and propylene fiber materials.

[0038] The material of the filter segment 31 includes, but is not limited to, one or more combinations of polyethylene (PE), polylactic acid (also called polylactide) (PLA), polybutyleneadipate-co-terephthalate (PBAT), polypropylene (PP), acetate fiber, and propylene fiber materials.

[0039] The temperature reduction segment 32 and the filter segment 31 may be made of the same material or different materials.

[0040] The support segments have a certain structural strength and restrict axial movement of the aerosol-generating substrate 10. Specifically, when an aerosol-generating product is inserted into a heating chamber in an aerosol-generating device or when a heating element is inserted into the aerosol-generating substrate 10, the support segments apply a counterforce to the aerosol-generating substrate 10, thereby preventing axial movement of the aerosol-generating substrate 10.

[0041] The heating assembly of the aerosol generating device may have a variety of heating modes, including, for example, central heating and peripheral heating. The central heating mode refers to a mode in which the heating assembly is inserted into the aerosol-generating product and heats the aerosol-generating product from the inside out. The peripheral heating mode refers to a mode in which the heating assembly is disposed around the aerosol-generating product and heats the aerosol-generating product from the outside in. Specific examples of these heating modes include resistance heating, electromagnetic heating, infrared heating, microwave heating, laser heating, and the like, and are not particularly limited herein.

[0042] The specific components of the aerosol-generating substrate 10 are not limited herein, and by way of example, in one embodiment, the aerosol-generating substrate 10 may include a botanical component, an adjuvant component, a smoke-generating agent component, an adhesive component, etc.

[0043] In one embodiment, the plant ingredients are one or more of a combination of powders formed by grinding raw tobacco leaves, tobacco leaf fragments, tobacco stems, tobacco powder, flavor plants, etc. The plant ingredients are the main source of flavor for the product, and endogenous substances in the plant ingredients, such as nicotine, enter the human bloodstream through aerosolization, stimulating the pituitary gland to produce dopamine, thereby providing physiological satisfaction.

[0044] In one embodiment, the auxiliary component may be one or more of an inorganic filler, a lubricant, and an emulsifier. The inorganic filler may include one or more of ground calcium carbonate, light calcium carbonate, zeolite, attapulgite, talc, and diatomaceous earth. The inorganic filler can provide skeletal support for the plant component and, because it also has pores, can increase the porosity of the wall material after the plant component is molded, thereby improving the aerosol release rate.

[0045] The lubricant may be one or more of the following: candelilla wax, carnauba wax, shellac, sunflower wax, rice bran, beeswax, stearic acid, palmitic acid. The lubricant can improve particle flow, reduce friction between particles, make the particle distribution more uniform, reduce the pressure required for molding, and reduce mold wear.

[0046] Emulsifiers include one or more combinations of polyglycerol fatty acid esters, Tween-80, and polyvinyl alcohol. Emulsifiers (also known as surfactants) can reduce the interfacial tension between water-soluble and water-insoluble components in a mixed system, forming a strong thin film on the surface of the microdroplets, or forming an electric double layer on the surface of the microdroplets due to the electric charge imparted by the emulsifier, thereby preventing the microdroplets from coagulating and maintaining a uniform emulsion. The homogeneity of the emulsion of two incompatible components can improve the consistency of product quality.

[0047] The function of the smoke generant component is to generate a large amount of vapor upon heating, thereby improving the aerosol yield of the smoke-generating product. In one embodiment, the smoke generant may include, for example, one or more combinations of monohydric alcohols (e.g., menthol), polyhydric alcohols (e.g., propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin), esters of polyhydric alcohols (e.g., monoacetin, diacetin, triacetin), monocarboxylic acids, polycarboxylic acids (e.g., lauric acid, myristic acid), or aliphatic esters of polycarboxylic acids (e.g., dimethyl dodecanedioate, dimethyl tetradecanedioate, erythritol, 1,3-butanediol, tetraethylene glycol, triethyl citrate, propylene carbonate, ethyl laurate, triactin, mesoerythritol, diacetin mixtures, diethyl suberate, triethyl citrate, benzyl benzoate, benzyl phenylacetate, ethyl vanillate, tributyrin, and lauryl acetate).

[0048] In one embodiment, the adhesive component is a non-ionized modified viscous polysaccharide extracted from a natural plant, and may include one or more combinations of tamarind polysaccharide, pullulan, seaweed polysaccharide, locust bean gum, guar gum, and xyloglucan. The adhesive wets the interfaces of the product's constituent materials, creating intimate contact and intermolecular attraction, thereby adhering the powders, liquids, and other constituent materials. At the same time, the selection of a non-ionized adhesive extracted from a natural plant can avoid the release of harmful substances such as methanol, formaldehyde, and acrolein that are caused by colloidal modification, thereby improving product safety.

[0049] The aerosol-generating substrate 10 has at least one passageway which passes through at least one end of the aerosol-generating substrate 10 along its length, i.e. the passageway extends along the longitudinal direction of the aerosol-generating substrate 10 .

[0050] In some embodiments, and with reference to Figure 21, the passages run through the same end along the length of the aerosol-generating substrate 10, with all other ends being closed.

[0051] In some other embodiments, referring to Figure 22, some of the passages pass through one end of the aerosol-generating substrate 10 along its length, and some of the passages pass through the other end of the aerosol-generating substrate 10 along its length.

[0052] In some other embodiments, referring to Figures 5 to 20, each passage penetrates both ends of the aerosol-generating substrate 10 along the length, and the airflow can flow from one end of the aerosol-generating substrate 10 along the length to the other end of the aerosol-generating substrate 10 along the length through the airway hole 10a, thereby facilitating smooth flow of the airflow in the airway hole 10a and better reducing the inhalation resistance.

[0053] Illustratively, the aerosol-generating substrate 10 is a type of reconstituted tobacco vehicle, such as a reconstituted tobacco vehicle containing components such as a smoke generating agent, tobacco, and the like.

[0054] For example, the aerosol-generating substrate 10 has a monolithic structure, which can be formed by, for example, injection molding, compression molding, or extrusion. Here, extrusion refers to a processing method in which a raw material mixture is fed into an extruder, and the material is heated and shaped by the action between the barrel and screw of the extruder while being extruded forward by the screw, continuously passing through a die to produce products or semi-finished products with various cross sections. The aerosol-generating substrate formed by extrusion is rod-shaped. This allows the aerosol-generating substrate 10 to maintain its monolithic state after being heated and sucked, or after heat exposure is stopped, and is less likely to collapse and fall off. This solves the problems of flake-like, filament-like, or particulate aerosol-generating substrates in the prior art, such as loose flakes, falling off of filament-like or particulate components, difficulty in cleaning, and non-uniform components.

[0055] Referring to FIG. 23 , the aerosol-generating substrate 10 has pores 10d formed therein, which communicate with the passages 10a to form micro-airways. That is, the micro-airways communicate with the passages 10a, and the micro-airways are formed by the communication between the pores 10d, so the pores 10d communicate with the passages 10a. It should be understood that the communication between the pores 10d may mean that some of the pores 10d are connected and the remaining pores 10d are not connected, or that all of the pores 10d are connected to one another. In the aerosol-generating substrate according to the embodiment of the present application, the passages and pores increase the surface area of ​​the aerosol-generating substrate 10, facilitate heat transfer, and improve heating efficiency. When the medium in the aerosol-generating substrate 10 receives heat and releases aerosol, the aerosol is collected in the passages by the pores and transported to the suction end by the negative suction pressure. The passages reduce the user's inhalation resistance and improve the user experience. In addition, the resistance to inhalation is positively correlated with the flow resistance of the aerosol; the smaller the flow resistance the aerosol experiences within the aerosol-generating substrate 10, the smaller the resistance to inhalation experienced by the user; and the greater the flow resistance the aerosol experiences within the aerosol-generating substrate 10, the greater the resistance to inhalation experienced by the user.

[0056] For example, in embodiments in which the aerosol-generating substrate 10 is a particle aggregate, the pores 10d are defined by the gaps between the particles.

[0057] Note that the above passages are macroscopic pores, while the pores are microscopic pores, and the cross-sectional area of ​​the passages is much larger than that of the pores. Here, the size of the pores is determined by the gaps between particles. For example, the cross-sectional area of ​​the passages is at least 20 times that of the pores. If the size of the pores is kept constant, if it is less than 20 times, the size of the passages is too small, making it difficult for the aerosol to be released from the inner wall of the passage into the passage, increasing the user's inhalation resistance and reducing the user's inhalation experience. Therefore, in this embodiment, if the cross-sectional area of ​​the passages is 20 times or more than the cross-sectional area of ​​the pores, the speed at which the aerosol is released from the inner wall of the passage can be ensured, reducing the inhalation resistance and improving the user's inhalation experience.

[0058] In some embodiments, the cross-sectional area of ​​the passages is 20 to 60,000 times that of the pores. If the cross-sectional area of ​​the passages is more than 60,000 times that of the pores, the area of ​​the passages is too large, reducing the overall mass of the smoke generating medium, resulting in low medium utilization and a high heating rate, making it easier for aerosols to be released from the pores into the environment.

[0059] Illustratively, the cross-sectional area of ​​the passage is 100 to 40,000 times the cross-sectional area of ​​the pore.

[0060] The number of passages is not limited, and may be one or more.

[0061] 4 to 20, the passages include airway holes 10a, which are provided inside the aerosol-generating substrate. That is, at least some of the passages function as airway holes 10a. In a cross section perpendicular to the longitudinal direction of the aerosol-generating substrate, the pore walls of the airway holes 10a are closed to form closed pores. The airway holes 10a are advantageous for heat transfer to the internal medium of the aerosol-generating substrate and improve the heat reception uniformity of the internal medium.

[0062] 6, 7, 8, 13, 14, 17, and 20, the passage includes an airway groove 10b, which is provided on the circumferential surface of the aerosol-generating substrate 10. That is, a portion of the outer wall of the aerosol-generating substrate 10 is recessed to form the airway groove 10b, which means that the groove-like airway groove 10b is visible from the outer wall of the aerosol-generating substrate 10.

[0063] 3, the outer coating layer 20 on the periphery of the aerosol-generating substrate 10 can seal the airway grooves 10b on the periphery of the aerosol-generating substrate 10, allowing the airway grooves 10b to function as aerosol airflow passages, thereby improving the air inflow rate and aerosol extraction efficiency. Furthermore, when the heating assembly uses ambient heating, this heating method can also be used to adjust the overall heating rate of the aerosol-generating substrate 10, improving the user's inhalation experience.

[0064] In some embodiments, referring to FIG. 20, all passages are airway grooves 10b, ie, in such embodiments, there are no airway holes.

[0065] In some other embodiments, referring to Figures 4, 5, 9-12, 15, 17-19, all passages are airway holes 10a, that is, in such embodiments there are no airway grooves.

[0066] In still other embodiments, referring to Figures 6 to 8, 13, 14, and 16, some of all passages are airway grooves 10b and some are airway holes 10a, i.e., in these embodiments, there are not only airway holes 10a but also airway grooves 10b.

[0067] The shape of the airway hole 10a is not limited, and for example, the cross-sectional shape of the airway hole in a plane perpendicular to the longitudinal direction of the aerosol-generating substrate 10 includes at least one of a circle, an ellipse, a track, a polygon, and a sector.

[0068] Here, the track shape refers to a shape similar to a running track, and is formed by two semicircles and two parallel straight lines connected alternately.

[0069] When there are multiple airway pores 10a, the cross-sectional shapes of all the airway pores 10a may be completely identical, or some of the airway pores 10a may have different cross-sectional shapes, or some of the airway pores 10a may have different cross-sectional shapes. For example, in some embodiments, the cross-sectional shapes of all the airway pores 10a may be circular, elliptical, triangular, rectangular, etc., and in other embodiments, some of the airway pores 10a may be triangular and some of the airway pores 10a may be circular, etc.

[0070] For example, there are multiple airway holes 10a, and each airway hole 10a has the same shape and size. For example, all of the airway holes 10a are equilateral triangles, and the sides of all of the equilateral triangles have the same length. In another example, all of the airway holes are circles with the same radius. This allows each airway hole 10a of the aerosol-generating substrate 10 to be molded using the same mold, thereby reducing manufacturing costs.

[0071] The number of airway holes 10a is not limited and may be one, two, or more than two.

[0072] Illustratively, the number of airway holes 10a is 730 or less, for example, 1, 5, 20, 50, 100, 200, 300, 500, 600, 700, 730.

[0073] For a given external size of the aerosol-generating substrate 10, there is a negative correlation between the number of airway holes 10a and the wall thickness of the adjacent airway holes 10a. The greater the number of airway holes 10a, the greater the surface area of ​​the airway holes 10a, which reduces the aerosol flow resistance in the aerosol-generating substrate 10 and increases heat transfer efficiency. The thinner the wall thickness of the adjacent airway holes 10a, the more favorable it is for heat penetration or diffusion. The thinner the wall thickness of the adjacent airway holes 10a, the lower the overall mass of the aerosol-generating substrate 10. Due to the reduction in the base material, the aspiration mass and the total amount of aerosol emitted are also relatively reduced. At the same time, the wall thickness of the adjacent airway holes 10a affects the overall structural strength of the aerosol-generating substrate 10; the thinner the wall thickness, the lower the structural strength of the entire structure. Therefore, it is desirable to have no more than 730 airway holes 10a.

[0074] For example, the number of air passage holes 10a is 10 to 500. Note that the fewer the number of air passage holes 10a, the simpler the process and structure and the easier the manufacturing process, the smaller the porosity, the thicker the medium wall, the larger the mass of the aerosol-generating substrate 10, and the more frequent the suctions, but the lower the heat transfer efficiency and the risk of overheating the contact surface with the heat source. On the other hand, the thinner the medium wall thickness of adjacent air passage holes 10a, the smaller the mass of the aerosol-generating substrate 10, the faster the heat transfer rate, and the fewer frequent the suctions.

[0075] The greater the number of airway holes 10a, the more complex the process and structure and the greater the manufacturing difficulty; the thinner the thickness of the medium wall; the shorter the flow path of the aerosol from the fine airways to the airway holes 10a; the greater the porosity; the faster the aerosol release speed after the medium is heated; the faster the heat transfer rate; the fewer the total number of inhalations; but the more uniform the aerosol mouthfeel each time it is inhaled.

[0076] Therefore, when the number of airway holes 10a is 10 to 500, the difficulty of the manufacturing process of the aerosol-generating substrate 10 is moderate, and both an appropriate heat transfer rate and a relatively uniform inhalation sensation can be achieved.

[0077] Illustratively, the cross-sectional area of ​​the airway hole 10a is 0.0019 mm 2 ~30mm 2 (square millimeters). For example, 0.002 mm 2 , 0.1mm 2 , 0.2mm 2 , 0.4mm 2 , 0.5mm 2 , 0.8mm 2 , 1mm 2 , 1.3mm 2 , 1.6mm 2 , 1.8mm 2 , 2mm 2 , 2.1mm 2 , 2.2mm 2 , 2.4mm 2 , 2.6mm 2 , 2.8mm 2 , 3mm 2 , 4mm 2 , 5mm 2 , 6mm 2 And so on.

[0078] In the examples of this application, cross-sectional area refers to the cross-sectional area of ​​the flow path.

[0079] The cross-sectional area of ​​the airway hole 10a is 30 mm 2 If the heating temperature exceeds this value, the number of airway holes 10a will be reduced, the aerosol-generating substrate 10 will be more likely to burn, and the aerosol-generating substrate 10 will be more likely to emit uneven aerosol during the heating process (for example, the amount of aerosol emitted will be large during the first two puffs and small during the subsequent puffs), which will affect the user's smoking experience.

[0080] The cross-sectional area of ​​the airway hole 10a is 0.0019 mm 2If the thickness is less than this, the molding process becomes significantly more difficult, it becomes difficult to control the size of the airway hole 10a, and the reject rate of the aerosol-generating substrate 10 increases.

[0081] The cross-sectional area of ​​the airway hole 10a is 0.0019 mm 2 ~30mm 2 Within this range, the flow resistance of the aerosol-generating substrate 10 is relatively small (i.e., the suction resistance is relatively small), and the aerosol flow rate is appropriate, making it easy to extract the aerosol inside the aerosol-generating substrate 10, resulting in uniform aerosol release and high utilization rate, and the aerosol-generating substrate 10 being less likely to burn, resulting in a better user experience and convenience in processing and manufacturing.

[0082] Preferably, the cross-sectional area of ​​the airway hole 10a is 0.007 mm 2 ~7.1mm 2 (square millimeters). For example, 0.1 mm 2 , 0.2mm 2 , 0.4mm 2 , 0.5mm 2 , 0.8mm 2 , 1mm 2 , 1.3mm 2 , 1.6mm 2 , 1.8mm 2 , 2mm 2 , 2.1mm 2 , 2.2mm 2 , 2.4mm 2 , 2.6mm 2 , 2.8mm 2 , 3mm 2 And so on.

[0083] For example, the hydraulic diameter of the airway hole 10a is 0.05 mm to 6 mm (millimeters), such as 0.05 mm, 0.1 mm, 0.2 mm, 0.4 mm, 0.5 mm, 0.8 mm, 1 mm, 1.3 mm, 1.6 mm, 1.8 mm, 2 mm, 2.1 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, 4 mm, 5 mm, 6 mm, etc.

[0084] In the examples of this application, hydraulic diameter refers to the ratio of four times the cross-sectional area of ​​the flow channel to the perimeter.

[0085] If the hydraulic diameter of the airway holes 10a exceeds 6 mm, the number of airway holes 10a will be reduced, making it easier for the smoke-generating medium segments 10 to burn, and the smoke-generating medium segments 10 are more likely to emit uneven aerosol during the heating process (for example, a large amount of aerosol is emitted during the first two puffs and a small amount during the subsequent puffs), which will affect the user's smoking experience.

[0086] If the hydraulic diameter of the air duct hole 10a is less than 0.05 mm, the molding process becomes significantly more difficult, it becomes difficult to control the size of the air duct hole 10a, and the reject rate of the smoke generating medium segment 10 increases.

[0087] When the hydraulic diameter of the airway hole 10a is within the range of 0.05mm to 6mm, the flow resistance of the aerosol-generating substrate 10 is relatively small (i.e., the suction resistance is relatively small), and the aerosol flow rate is appropriate, making it easy to extract the aerosol inside the smoke-generating medium segment 10, resulting in uniform aerosol release and high utilization rate, and preventing the smoke-generating medium segment 10 from burning, resulting in a relatively high user experience and convenience in processing and manufacturing.

[0088] In some embodiments, the hydraulic diameter of the airway opening 10a is between 0.1 mm and 3 mm (millimeters), such as 0.1 mm, 0.2 mm, 0.4 mm, 0.5 mm, 0.8 mm, 1 mm, 1.3 mm, 1.6 mm, 1.8 mm, 2 mm, 2.1 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, etc.

[0089] In a cross section perpendicular to the longitudinal direction of the aerosol-generating substrate, all of the airway pores may be uniformly or non-uniformly distributed, where uniform distribution refers to a uniform arrangement of the airway pores themselves.

[0090] For example, the airway holes 10 a are distributed point-symmetrically with respect to the center of the aerosol-generating substrate 10 , and / or the airway holes 10 a are distributed mirror-symmetrically with respect to the central axial plane of the aerosol-generating substrate 10 .

[0091] Here, a point-symmetric distribution refers to a state in which the airway holes in a certain region completely overlap with the airway holes in another region after being rotated at a predetermined angle around the center of the aerosol-generating substrate.

[0092] A mirror-symmetric distribution refers to a state in which the plane passing through the central axis of the aerosol-generating substrate 10 is taken as the mirror image plane, and the airway openings 10a on both sides of the mirror image plane are distributed mirror-symmetrically with respect to the mirror image plane.

[0093] In this embodiment, the airway holes 10a are distributed relatively uniformly across the cross section of the aerosol-generating substrate 10, which improves the uniformity of aerosol discharge at the suction end of the aerosol-generating substrate and improves the comfort of inhalation.

[0094] Illustratively, the cross-sectional area of ​​the pore is 0.7 nm 2 (square nanometer) ~ 710μm 2 (square micrometer). For example, 1 nm 2 , 10nm 2 , 25nm 2 , 30nm 2 , 40nm 2 , 50nm 2 , 60nm 2 , 70nm 2 , 80nm 2 , 100 nm 2 , 200 nm 2 , 300 nm 2 , 400nm 2 , 500nm 2 , 600nm 2 , 700nm 2 , 800nm 2 , 900nm 2 , 1 μm 2 , 2 μm 2 , 3 μm 2 And so on.

[0095] Pore ​​cross-sectional area is 0.7 nm 2 If the cross-sectional area range of the pores of the medium body is less than 710 μm, the active ingredient inside the medium will be less likely to volatilize to the airway holes 10a, and the utilization rate of the medium will decrease. 2 If the cross-sectional area of ​​the pores is greater than 0.7 nm, the heat transfer within the pores will be uneven, resulting in a poor inhalation experience. 2 ~710μm 2 By controlling the amount of airflow, not only can the utilization rate of the medium be improved, but also the suction experience can be improved.

[0096] More preferably, the cross-sectional area of ​​the pore is 1963 nm 2 ~20μm 2 is.

[0097] Exemplary pore hydraulic diameters are between 10 nm (nanometers) and 30 μm (micrometers), such as 10 nm, 20 nm, 24 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 2 μm, and 3 μm.

[0098] If the hydraulic diameter of the pores is less than 10 nm, the active ingredient in the medium is less likely to volatilize to the airway pores 10a, resulting in a decrease in the utilization rate of the medium. On the other hand, if the diameter range of the pores in the medium body exceeds 30 μm, the heat transfer within the pores becomes uneven, resulting in a decrease in the inhalation experience. Therefore, in this embodiment, by controlling the hydraulic diameter of the pores to 0.1 nm to 30 μm, not only the utilization rate of the medium but also the inhalation experience can be improved.

[0099] In a plane perpendicular to the longitudinal direction of the aerosol-generating substrate 10, the contour shape of the aerosol-generating substrate 10 is not limited and may be, for example, a circle, an ellipse, a polygon, etc., and is not limited here.

[0100] For illustrative purposes, the aerosol-generating substrate 10 in the examples of the present application is described as having a cylindrical shape, i.e., the cross-sectional profile of the aerosol-generating substrate 10 is approximately circular. The regular shape of the cylindrical aerosol-generating substrate 10 can reduce the difficulty of the manufacturing process.

[0101] For example, the maximum size of the contour of the aerosol-generating substrate 10 in a plane perpendicular to the length of the aerosol-generating substrate is 4 mm to 10 mm, for example, 4 mm, 5 mm, 6 mm, 6.5 mm, 7 mm, 8 mm, 9 mm, or 10 mm. This size range is set so that the aerosol-generating substrate 10 has good structural strength while being convenient for the user to place in the mouth.

[0102] Here, the maximum size of the contour of the aerosol-generating substrate 10 refers to the distance between the two most distant points on the contour of the aerosol-generating substrate 10 in a plane perpendicular to the length direction of the aerosol-generating substrate. For example, if the contour of the aerosol-generating substrate 10 is cylindrical, the maximum size of the contour of the aerosol-generating substrate 10 is the diameter of the circle. If the contour of the aerosol-generating substrate 10 is elliptical, the maximum size of the contour of the aerosol-generating substrate 10 is the major axis of the ellipse.

[0103] For example, the maximum size of the contour of the aerosol-generating substrate 10 in a plane perpendicular to the length direction of the aerosol-generating substrate is 6 mm to 8.6 mm, for example, 6 mm, 6.5 mm, 7 mm, 7.4 mm, 7.7 mm, 8 mm, 8.6 mm, etc.

[0104] The number of airway grooves 10b may be one or more, and is not limited here.

[0105] When multiple airway grooves 10b are provided on the outer wall of the aerosol-generating substrate 10, the cross-sectional shapes of the airway grooves 10b may be identical, or some of the airway grooves 10b may have the same cross-sectional shape and some of the airway grooves 10b may have different cross-sectional shapes. For example, some of the airway grooves 10b may have a semicircular cross-sectional shape and at least one of the airway grooves 10b may have a polygonal cross-sectional shape.

[0106] The shape of the airway groove 10b is not limited herein, and illustratively, in one embodiment, in a plane perpendicular to the longitudinal direction of the aerosol-generating substrate 10, the cross-sectional shape of the airway groove 10b includes, but is not limited to, an arc shape, a V shape, a rectangle or a trapezoid.

[0107] For example, the cross-sectional shape of the airway groove 10b is the same as the local shape of the airway hole 10a in a plane perpendicular to the longitudinal direction of the aerosol-generating substrate 10. In the molding process, the airway groove 10b can be molded based on the same mold as the airway hole 10a, which simplifies the mold design, reduces mold costs, and reduces production costs.

[0108] 4, 6, 7, 8, and 15 to 18, in one embodiment, the center line along the extension direction of one of the multiple airway holes 10a overlaps with the central axis along the length direction of the aerosol-generating substrate 10, i.e., the airway hole 10a is provided at the center of the aerosol-generating substrate 10. Here, the airway hole 10a within the dashed circle overlaps with the central axis of the aerosol-generating substrate 10.

[0109] Here, the central axis along the length of the aerosol-generating substrate 10 is an imaginary reference line.

[0110] Here, overlapping means that the center line along the extension direction of the airway hole 10a and the central axis along the length direction of the aerosol-generating substrate 10 almost overlap; in other words, there may be a certain gap between the center line along the extension direction of the airway hole 10a and the central axis along the length direction of the aerosol-generating substrate 10, and the central axis along the length direction of the aerosol-generating substrate 10 almost penetrates the airway.

[0111] During the heating and inhalation process of the airway hole 10a located on the central axis, the aerosol is collected at the medium outlet (due to the fast flow rate at the medium central hole, a negative pressure area is formed at the outlet of the medium central hole, which collects the aerosol flowing out from the holes), thereby improving the "collapsibility" of the aerosol, which in turn improves the temperature stability of the aerosol at the medium outlet (due to the fast aerosol flow rate at the central hole and the small temperature change of the aerosol, the rate of temperature change after the aerosol is collected can be reduced), further improving the consumer's inhalation experience.

[0112] In some other embodiments, referring to FIGS. 9, 11 to 14 and 19, the airway hole 10a does not have to be provided at the central axis along the length of the aerosol-generating substrate 10.

[0113] It should be noted that the airway hole 10a in the embodiments of the present application may extend along a straight line, or the airway hole 10a may extend along a curved line (for example, extending in a spiral shape).

[0114] In an embodiment in which there are multiple airway holes 10a, the arrangement of the airway holes 10a is not limited.

[0115] For example, all the airway holes are arranged in a matrix, a circular, a "R"-shaped, a "I"-shaped, etc.

[0116] In the examples of the present application, the structures shown in Figures 1 to 18 do not limit the relative size relationship between the airway holes 10a and the aerosol-generating substrate, and the airway holes 10a in the drawings are intended to more clearly show the arrangement relationship of the airway holes 10a, but do not specify a specific size.

[0117] Below, 18 specific embodiments will be briefly described with reference to the drawings.

[0118] In the first embodiment 4 and 5, all passages in the aerosol-generating substrate 10 are airway pores 10a and there are no airway grooves 10b.

[0119] The cross-sectional shape of the airway hole 10a is circular, and each circle has the same diameter.

[0120] The center line of the airway hole 10a in the dashed circle along its extension direction overlaps with the central axis of the aerosol-generating substrate 10 along its length.

[0121] All the airway holes 10a are arranged in a matrix and are uniformly distributed.

[0122] In the second embodiment Referring to Figures 5 and 6, in this embodiment, the aerosol-generating substrate 10 is generally the same as in the first embodiment, but the difference is that an airway groove 10b is provided on the circumferential surface of the aerosol-generating substrate 10 in this embodiment.

[0123] The cross-sectional shape of the airway groove 10b is rectangular.

[0124] In the third embodiment Referring to FIG. 7, in this embodiment, the aerosol-generating substrate 10 is generally the same as that in the second embodiment shown in FIG. 6, except that the cross-sectional shape of the airway groove 10b is semicircular.

[0125] The diameter of the semicircle is the same as the diameter of the circle of the airway stoma 10a.

[0126] In the fourth embodiment Referring to FIG. 8, in this embodiment, the aerosol-generating substrate 10 is generally the same as that in the third embodiment shown in FIG. 7, but differs in the number and arrangement of the airway holes 10a.

[0127] In this embodiment, the number of airway holes 10a is greater than the number of airway holes 10a in the third embodiment.

[0128] All the airways 10a are arranged concentrically.

[0129] In the fifth embodiment Referring to Figure 9, in this embodiment, the aerosol-generating substrate 10 is generally the same as the fourth embodiment shown in Figure 8, but the difference is that in this embodiment, no airway groove is provided and no airway hole is provided on the central axis of the aerosol-generating substrate 10.

[0130] In the sixth embodiment Referring to Figure 10, in this embodiment the aerosol-generating substrate 10 does not have airway grooves.

[0131] One airway hole is provided on the central axis of the aerosol-generating substrate 10, and the airway hole within the dashed circle overlaps with the central axis.

[0132] All the airway holes 10 a are divided into three rows, and these three rows are arranged alternately and point-symmetrically with respect to the center of the aerosol-generating substrate 10 .

[0133] In the seventh embodiment Referring to Figure 11, in this embodiment, the aerosol-generating substrate 10 is generally the same as that of the fifth embodiment shown in Figure 9, but the difference is that in this embodiment, all the airway holes 10a are arranged in a matrix.

[0134] In the eighth embodiment Referring to Figure 12, in this example, the aerosol-generating substrate 10 is generally the same as that of the seventh example shown in Figure 11, but the difference is that in this example, the shape of the airway holes 10a is a regular square.

[0135] In the ninth embodiment Referring to Figure 13, in this embodiment, the aerosol-generating substrate 10 is generally the same as that of the eighth embodiment shown in Figure 12, but the difference is that an airway groove 10b is provided on the circumferential surface of the aerosol-generating substrate 10 in this embodiment.

[0136] Here, the airway groove 10b is semicircular.

[0137] In the tenth embodiment Referring to FIG. 14, in this embodiment, the aerosol-generating substrate 10 is generally the same as that in the ninth embodiment shown in FIG. 13, except that the airway groove 10b in this embodiment is rectangular.

[0138] In the eleventh embodiment Referring to FIG. 15, in this embodiment, the airway holes 10a are diamond-shaped and arranged in a matrix.

[0139] The circumferential surface of the aerosol-generating substrate 10 is free of airway grooves.

[0140] One airway hole is provided on the central axis of the aerosol-generating substrate 10, and the airway hole within the dashed circle overlaps with the central axis.

[0141] In the twelfth embodiment Referring to Figure 16, in this embodiment, the aerosol-generating substrate 10 is generally the same as the 11th embodiment shown in Figure 15, but the difference is that airway grooves are provided on the circumferential surface of the aerosol-generating substrate 10.

[0142] In the thirteenth embodiment Referring to Figure 17, in this embodiment, within the area occupied by all the airway holes 10a, the media walls are arranged in an "I" shape, with some of the airway holes 10a having a rectangular shape and the remaining some of the airways having a fan-shaped shape.

[0143] In the fourteenth embodiment Referring to Figure 18, in this embodiment, within the area occupied by all airway holes 10a, the media walls are distributed radially from the center of the aerosol-generating substrate 10, and all airway holes 10a are fan-shaped and have the same shape and size.

[0144] In the fifteenth embodiment Referring to Figure 19, in this embodiment, the aerosol-generating substrate 10 is generally the same as that of the 14th embodiment shown in Figure 18, but the differences include that the number of media walls in this embodiment is smaller and the number of airway holes 10a is smaller.

[0145] In the 16th embodiment Referring to FIG. 20, in this embodiment, the aerosol-generating substrate 10 is provided with airway grooves 10b but no airway holes 10a.

[0146] In the seventeenth embodiment Referring to Figure 21, in this embodiment, the aerosol-generating substrate 10 is generally the same as the embodiment shown in Figure 5, but the difference is that in this embodiment, all of the airway holes 10a pass through the same end along the length of the aerosol-generating substrate 10, and the other end is closed.

[0147] In the 18th embodiment Referring to Figure 22, in this embodiment, the aerosol-generating substrate 10 is generally the same as the embodiment shown in Figure 21, but the difference is that in this embodiment, some of the airway holes 10a penetrate one end of the aerosol-generating substrate 10 along the length direction, and the remaining some of the airway holes 10a penetrate the other end of the aerosol-generating substrate 10 along the length direction.

[0148] In the embodiments shown in FIGS. 4, 9 to 12, 15, 17 to 19, 21 and 22, airway grooves may also be provided on the circumferential surface of the aerosol-generating substrate 10.

[0149] In the embodiments shown in FIGS. 6 to 8, 13, 14, 16 and 20, the airway grooves do not have to be provided on the circumferential surface of the aerosol-generating substrate 10 either.

[0150] In the description of this application, a statement referring to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples" means that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the embodiments of this application. In this application, general expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art can combine different embodiments or examples described in this application and features of different embodiments or examples, unless they are mutually inconsistent.

[0151] The above is only a preferred embodiment of the present application, and does not limit the present application, and various modifications and variations are possible for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application should all be included in the protection scope of the present application.

Claims

1. An aerosol-generating substrate, the aerosol-generating substrate having a passageway that penetrates at least one end of the aerosol-generating substrate along its length, and pores formed in the aerosol-generating substrate that communicate with the passageway.

2. the passage includes an airway hole, the airway hole being provided inside the aerosol-generating substrate and penetrating both ends opposite to each other in the longitudinal direction of the aerosol-generating substrate; 2. The aerosol-generating substrate of claim 1.

3. The cross-sectional area of ​​the airway hole is 0.0019 mm ２ or 30 mm ２ Or the hydraulic diameter of the airway hole is 0.05 mm to 6 mm.

3. The aerosol-generating substrate of claim 2.

4. The cross-sectional area of ​​the airway hole is 0.007 mm ２ or 7.1 mm ２ Or the hydraulic diameter of the airway opening is 0.1 mm to 3 mm; 3. The aerosol-generating substrate of claim 2.

5. In a plane perpendicular to the length of the aerosol-generating substrate, the cross-sectional shape of the airway hole is at least one of a circle, an ellipse, a track, a polygon, and a sector.

3. The aerosol-generating substrate of claim 2.

6. The number of the airway holes is plural, and in a plane perpendicular to the longitudinal direction of the aerosol-generating substrate, the airway holes are distributed point-symmetrically with respect to the center of the aerosol-generating substrate, and / or the airway holes are distributed mirror-symmetrically with respect to the central axial plane of the aerosol-generating substrate.

6. An aerosol-generating substrate according to any one of claims 2 to 5.

7. the number of the airway holes is plural, and each of the airway holes has the same cross-sectional shape and size in a plane perpendicular to the length direction of the aerosol-generating substrate; 6. An aerosol-generating substrate according to any one of claims 2 to 5.

8. the passage includes an airway groove, the airway groove being provided on a circumferential surface of the aerosol-generating substrate; 2. The aerosol-generating substrate of claim 1.

9. the passageway includes an airway hole, the airway hole being located within the aerosol-generating substrate; the cross-sectional shape of the airway groove in a plane perpendicular to the length of the aerosol-generating substrate is the same as the local shape of the airway stoma; 9. The aerosol-generating substrate of claim 8.

10. The cross-sectional area of ​​the pore is 0.7 nm ２ or 710 μm ２ Or the hydraulic diameter of the pores is 10 nm to 30 μm; 2. The aerosol-generating substrate of claim 1.

11. The cross-sectional area of ​​the pore is 1963 nm ２ to 20 μm ２ Or the hydraulic diameter of the pores is 50 nm to 5 μm; 2. The aerosol-generating substrate of claim 1.

12. the maximum size of the contour of the aerosol-generating substrate in a plane perpendicular to the length of the substrate is between 4 mm and 10 mm; 2. The aerosol-generating substrate of claim 1.

13. the maximum size of the contour of the aerosol-generating substrate in a plane perpendicular to the length of the substrate is between 6 mm and 8.6 mm; 2. The aerosol-generating substrate of claim 1.

14. At least some of the passages extend along straight lines, and / or at least some of the passages extend along curved lines.

2. The aerosol-generating substrate of claim 1.

15. the aerosol-generating substrate is a particle conjugate, and the pores are formed between particles of the particle conjugate; 2. The aerosol-generating substrate of claim 1.

16. the aerosol-generating substrate is of monolithic construction and / or the cross-sectional area of ​​the passages is at least 20 times the cross-sectional area of ​​the pores; 2. The aerosol-generating substrate of claim 1.

17. 1. An aerosol-generating product comprising: An aerosol-forming substrate according to any one of claims 1 to 16; a functional segment provided at one end of the aerosol-generating substrate along its length, the functional segment including at least a filter segment for filtering the aerosol; an outer coating layer that surrounds the functional segment and the circumferential exterior of the aerosol-generating substrate;

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