An aerosol-forming substrate, a method of making the same and a smoking article

Abstract

The present application provides an aerosol forming substrate, a preparation method thereof and a smoking article, the preparation method comprising the following steps: rolling a tobacco mixture to obtain at least two pieces of aerosol forming sheet; attaching a first flavoring substance to at least one surface of at least one piece of the aerosol forming sheet; and rolling the first flavoring substance between the two pieces of the aerosol forming sheet to obtain the aerosol forming substrate. The preparation method can effectively avoid the loss of the flavoring substance during the preparation of the aerosol forming substrate, and the aerosol forming substrate prepared by the method can also release the flavoring substance slowly when used in a heated cigarette, thereby ensuring the uniformity of the release of the flavoring substance during smoking.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tobacco, in particular to an aerosol forming substrate, a preparation method thereof and a smoking article. BACKGROUND

[0002] In a heated cigarette, the tobacco material is generally in the form of an aerosol forming substrate. Due to the limited volume of the heated cigarette, the filling quality of the tobacco material is small, and flavoring is needed to increase the amount of aroma. When using flavoring to increase the amount of aroma, two methods are generally used to add flavoring to the aerosol forming substrate. One is to mix the flavoring with the raw materials during preparation, and the other is to spray the flavoring on the finished aerosol forming substrate or the aerosol forming substrate filament after the aerosol forming substrate is processed. The first flavoring method has the advantages of uniform flavoring, but the disadvantage is that the aroma is severely lost during the drying of the aerosol forming substrate at the end of the process. When the cigarette is smoked, the aroma is released unevenly to some extent. The second flavoring method has the advantages of simple equipment and easy operation, but the uniformity is difficult to control, and it is easy to cause the aerosol forming substrate to break and crack, which reduces the whole filament rate and is not conducive to rolling. In addition, the flavoring is generally attached to the surface of the aerosol forming substrate after flavoring in this way, and since the heated cigarette is heated simultaneously as a whole, the aroma on the surface is easily released quickly, resulting in uneven distribution of smoke aroma in the pre- and post-suction stages.

[0003] Therefore, how to provide a smoking article suitable for a heated cigarette device becomes a technical problem to be solved in the field. SUMMARY

[0004] The technical problem to be solved by the present application is to provide an aerosol forming substrate suitable for a heated cigarette device, a preparation method thereof and a smoking article. The preparation method can effectively avoid the loss of aroma during the preparation of the aerosol forming substrate, and the prepared aerosol forming substrate can also release the aroma slowly when used in a heated cigarette, ensuring the uniformity of aroma release during smoking.

[0005] To solve the above problems, the present application provides a preparation method of an aerosol forming substrate, comprising the following steps:

[0006] Rolling the tobacco mixture to obtain at least two pieces of aerosol forming substrate;

[0007] Attaching a first aroma to at least one surface of at least one piece of aerosol forming substrate;

[0008] Placing the first aroma between the two pieces of aerosol forming substrate, and rolling the at least two pieces of aerosol forming substrate into one piece of aerosol forming substrate.

[0009] By adopting the technical scheme, the first flavoring substance is located in the internal region of the aerosol-forming substrate, and the aerosol-forming substrate obtained by rolling is subjected to drying in the later stage. At the drying temperature of about 100 DEG C, the moisture is uniformly distributed in each position in the internal region of the aerosol-forming substrate, and can be evaporated to the air quickly and smoothly, so that the aerosol-forming substrate is dried. The first flavoring substance is far away from the surface of the aerosol-forming substrate, and when the moisture in the aerosol-forming substrate is gradually evaporated in the oven, the evaporation speed and degree of the first flavoring substance are greatly reduced due to the blocking of the upper and lower two layers of substances, and the loss amount of the first flavoring substance is greatly reduced, thereby ensuring the effective utilization rate of the essence and flavor in the production process and reducing the production cost.

[0010] Further, the first flavoring substance located in the internal region of the aerosol-forming substrate not only can reduce the use cost of the raw material, but also can slow down the release speed of the first flavoring substance when the aerosol-forming substrate is rolled into a heated cigarette, that is, the slow release of the flavoring substance is realized.

[0011] According to another specific embodiment of the present application, the plurality of aerosol-forming sheets includes a first aerosol-forming sheet and a second aerosol-forming sheet, the first flavoring substance is attached to one face of the first aerosol-forming sheet and / or the second aerosol-forming sheet, the face with the first flavoring substance is taken as the face to be laminated, and the first aerosol-forming sheet and the second aerosol-forming sheet are laminated and rolled into the aerosol-forming substrate by a laminating roller.

[0012] By adopting the technical scheme, the first flavoring substance can be located in the middle region of the aerosol-forming substrate, and the loss of the first flavoring substance in the preparation process and the slow release during smoking can be minimized.

[0013] The first flavoring substance located in the middle region of the aerosol-forming substrate means that the concentration of the first flavoring substance is the largest at about one-half of the thickness direction of the aerosol-forming substrate after rolling, and the concentration of the first flavoring substance decreases from the one-half to the two surfaces perpendicular to the thickness direction.

[0014] It can be understood that, in order to make the first flavoring substance located in the middle region of the aerosol-forming substrate, the aerosol-forming sheets are not limited to two sheets, and can be four sheets, six sheets, etc. as long as the first flavoring substance is located between the two sheets in the middle.

[0015] According to another specific embodiment of the present application, the first flavoring substance is not particularly limited, for example, the first flavoring substance can be a flavoring substance with a boiling point of less than 250 DEG C.

[0016] Alternatively, the first flavoring material can be a flavoring material having a volatility of more than 10% when the flavoring material is uniformly distributed in the aerosol forming substrate and the aerosol forming substrate is baked at 110°C for 5 minutes.

[0017] According to another embodiment of the present application, the method further comprises the steps of:

[0018] pulverizing the tobacco raw material to prepare tobacco particles;

[0019] mixing the tobacco particles, the second flavoring material, the adhesive, the atomizing agent, and water to prepare a dry-wet mixture;

[0020] extruding the dry-wet mixture to prepare a tobacco mixture.

[0021] According to another embodiment of the present application, the at least two aerosol forming sheets are baked after being rolled once to prepare the aerosol forming substrate.

[0022] According to another embodiment of the present application, the second flavoring material has a lower volatility than the first flavoring material in the aerosol forming substrate.

[0023] According to another embodiment of the present application, the present application also provides an aerosol forming substrate prepared by any one of the above-described methods.

[0024] According to another embodiment of the present application, the present application also provides an aerosol forming substrate, wherein the aerosol forming substrate is divided into a surface region and an inner region in a thickness direction, and the concentration of the first flavoring material in the inner region is greater than the concentration of the first flavoring material in the surface region.

[0025] According to another embodiment of the present application, the inner region is a middle region.

[0026] According to another embodiment of the present application, the first flavoring material is a flavoring material having a boiling point of 250°C or less.

[0027] Alternatively, the first flavoring material is a flavoring material having a volatility of more than 10% when the flavoring material is uniformly distributed in the aerosol forming substrate and the aerosol forming substrate is baked at 110°C for 5 minutes.

[0028] According to another embodiment of the present application, the aerosol forming substrate further comprises a second flavoring material, and the second flavoring material is not particularly limited, and preferably, the second flavoring material has a lower volatility than the first flavoring material in the aerosol forming substrate.

[0029] Further, the second flavoring material is a flavoring material having a boiling point of more than 250°C.

[0030] or the second flavoring substance is a flavoring substance whose evaporation rate is not more than 10% if the flavoring substance is uniformly distributed in the aerosol forming substrate and the aerosol forming substrate is then baked at 110°C for 5 minutes.

[0031] According to another specific embodiment of the present application, the present application further discloses a smoking article comprising any of the aforementioned aerosol forming substrates.

[0032] According to another specific embodiment of the present application, the smoking article is a heat-not-burn cigarette. BRIEF DESCRIPTION OF DRAWINGS

[0033] The present application will be further described in details below in conjunction with the accompanying drawings and specific embodiments:

[0034] Figure 1 is a schematic view of the aerosol forming substrate in one embodiment of the present application;

[0035] Figure 2 is a schematic view of the aerosol forming substrate in another embodiment of the present application.

[0036] REFERENCE NUMERALS:

[0037] first aerosol forming sheet 11, 11'

[0038] second aerosol forming sheet 12, 12'

[0039] third aerosol forming sheet 13

[0040] first flavoring substance 21

[0041] second flavoring substance 22

[0042] aerosol forming substrate 30, 30'

[0043] surface region 31

[0044] inner region 32

[0045] intermediate region 33 DETAILED DESCRIPTION

[0046] The following description will be made to the embodiments of the present application by specific examples, and other advantages and effects of the present application can be easily understood by those skilled in the art from the disclosure of the present application. Although the description of the present application will be introduced in combination with the preferred embodiments, it does not mean that the features of the present application are limited to the embodiments. On the contrary, the purpose of introducing the present application in combination with the embodiments is to cover other options or modifications which can be extended based on the claims of the present application. In order to provide a deep understanding of the present application, many specific details will be included in the following description. The present application can also be implemented without using these details. In addition, in order to avoid confusion or ambiguity of the present application, some specific details will be omitted in the description. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0047] It should be noted that in the present specification, similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0048] In the description of the present embodiments, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is usually placed, which is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0049] The terms "first", "second", etc. are only used for differentiation in description, and cannot be understood as indicating or implying relative importance.

[0050] In the description of the present embodiments, it should also be noted that, unless otherwise explicitly specified and limited, the terms "provided", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present embodiments can be understood according to the specific circumstances.

[0051] In order to make the purpose, technical solutions and advantages of the present application more clear, the embodiments of the present application will be further described in detail below in combination with the drawings.

[0052] The present application provides a preparation method of an aerosol forming substrate, comprising the following steps:

[0053] Step one: roll the tobacco mixture to obtain at least two pieces of aerosol forming sheet material;

[0054] Step two: attaching a first flavoring substance on at least one side of at least one of the aerosol forming sheet materials;

[0055] Step three: placing the first flavoring substance between two of the aerosol forming sheet materials, and rolling the at least two aerosol forming sheet materials into one aerosol forming substrate.

[0056] By using the technical solution, the first flavoring substance is located in the inner region of the aerosol forming substrate. When the aerosol forming substrate is rolled into a roll, the first flavoring substance is far away from the surface of the aerosol forming substrate at a drying temperature of about 100°C. When the moisture in the aerosol forming substrate gradually volatilizes in the oven, the first flavoring substance is blocked by the upper and lower substances, the volatilization speed and degree are greatly reduced, the loss of the first flavoring substance is greatly reduced, and the effective utilization rate of the flavoring substance in the production process is ensured, and the production cost is reduced.

[0057] Further, the first flavoring substance located in the inner region of the aerosol forming substrate not only reduces the use cost of such raw materials, but also slows down the release speed of the first flavoring substance when the aerosol forming substrate is rolled into a heated cigarette, that is, the slow release of the flavoring substance is achieved.

[0058] Further, the term "aerosol forming substrate" refers to a solid substrate that, upon heating or combustion of the aerosol forming substrate, releases volatile compounds that form an aerosol. The aerosol forming substrate can conveniently be part of an aerosol-generating article. The aerosol forming substrate can include a tobacco-containing material that contains volatile tobacco flavor compounds released from the substrate upon heating or combustion. Alternatively or additionally, the aerosol forming substrate can include a non-tobacco material. The aerosol forming substrate can further include an aerosol former. Examples of suitable aerosol formers are glycerol and propylene glycol. The aerosol forming substrate can also include other additives and ingredients, such as nicotine or flavorings.

[0059] Further, the term "aerosol forming sheet material" refers to a sheet-like material of volatile compounds that form an aerosol, the width and length of which are greater than the thickness. The aerosol forming sheet material can include a tobacco material, and can further include an aerosol former. Examples of suitable aerosol formers are glycerol and propylene glycol. The aerosol forming sheet material can also include other additives and ingredients, such as nicotine or flavorings.

[0060] According to another specific embodiment of the present application, the number of the at least two pieces of aerosol-forming sheet obtained in step one is not particularly limited, as long as the surface coated with the first flavoring substance is located between the two pieces of aerosol-forming sheet, i.e. at least two pieces of aerosol-forming sheet each has one surface not coated with the first flavoring substance. With the increase of the number of the aerosol-forming sheet, if the thickness of the final aerosol-forming substrate is to be kept unchanged, the thickness of each piece of aerosol-forming sheet is to be reduced. In this way, the first flavoring substance is closer to the surface of the aerosol-forming substrate in the thickness direction, and the first flavoring substance is less hindered from being volatilized by heat.

[0061] Preferably, the at least two pieces of aerosol-forming sheet can be 2-5 pieces of aerosol-forming sheet; more preferably, two pieces of aerosol-forming sheet or three pieces of aerosol-forming sheet; most preferably, two pieces of aerosol-forming sheet, which include a first piece of aerosol-forming sheet and a second piece of aerosol-forming sheet, the first flavoring substance is attached to one surface of the first piece of aerosol-forming sheet or the second piece of aerosol-forming sheet, or the first flavoring substance is attached to one surface of each of the first piece of aerosol-forming sheet and the second piece of aerosol-forming sheet, the surface with the first flavoring substance attached is used as the surface to be laminated, the first flavoring substance is located between the two pieces of aerosol-forming sheet, and the first piece of aerosol-forming sheet and the second piece of aerosol-forming sheet are rolled into an aerosol-forming substrate, and finally the first flavoring substance is located in the middle region of the aerosol-forming substrate.

[0062] Further, there are many kinds of flavoring substances for tobacco, and their volatility is different. The first flavoring substance in the present application is not particularly limited, which can be easily volatile flavoring substance or difficult volatile flavoring substance, or both the easily volatile flavoring substance and the difficult volatile flavoring substance are added as the first flavoring substance to simplify the process, so that both the easily volatile flavoring substance and the difficult volatile flavoring substance are located in the inner region of the aerosol-forming substrate. The designer can also select the first flavoring substance according to the actual needs, for example, the first flavoring substance can be a flavoring substance that the technical personnel think needs to be reduced in production; or a flavoring substance that needs to be further released during smoking; or a flavoring substance that needs to be reduced in loss due to high cost.

[0063] Further, the flavoring substances used in tobacco flavoring are generally a plurality of compounds, mixtures, such as acid, ketone, ester, and other monomer compounds, and mixtures of natural plant extracts, essential oils, and extracts. Generally, boiling is a violent vaporization phenomenon. When a substance is above the boiling point, the substance is converted into a gaseous state more quickly and more completely. For example, the boiling points of small molecule esters such as ethyl acetate and ethyl formate are all below 100°C. Since there is a drying process at about 110°C in the aerosol-forming substrate production process, a large amount of such flavoring substances will be lost in this process. If such flavoring is sprayed on the surface of the aerosol-forming substrate after the aerosol-forming substrate is processed, most of the flavoring will adhere to the surface. When the aerosol-forming substrate is smoked at a smoking temperature of 200-300°C, the flavoring will be released quickly in the early stage of smoking and then sharply decrease in the later stage, resulting in a decrease in the uniformity of sensory quality. In the drying process of the aerosol-forming substrate, if the boiling point of a flavoring substance is higher than the drying temperature, the flavoring substance will not boil, but its volatility will be increased due to the high temperature and air convection in the oven, resulting in a loss of the flavoring substance and a failure to achieve the desired effect. In addition, the loss of the flavoring substance will increase the burden on the deodorization equipment in the production workshop, resulting in an increase in production cost. For example, the boiling point of menthol is above 200°C. When the aerosol-forming substrate is dried at 110°C, a large amount of menthol will volatilize, with a loss rate of more than 30%, and the production site environment will be extremely irritating.

[0064] Therefore, preferably, the first flavoring substance is only an easily volatile flavoring substance. Whether a flavoring substance is easily volatile can be determined according to the needs of the skilled person, or the subsequent production process, or the heating conditions during smoking.

[0065] For example, flavoring substances with a boiling point below 250°C are listed as easily volatile flavoring substances. Alternatively, if a certain flavoring substance is uniformly distributed in the aerosol-forming substrate, and the aerosol-forming substrate is then dried at 110°C for 5 minutes, flavoring substances with a volatilization rate of more than 10% are listed as easily volatile flavoring substances, and other flavoring substances are listed as not easily volatile flavoring substances.

[0066] Since there are hundreds of tobacco flavorings, only some commonly used flavoring substances are listed as examples. Easily volatile flavoring substances include formic acid, acetic acid, ethanol, ethyl acetate, ethyl formate, linalool, carvone, menthol, 2,5-dimethylpyrazine, isovaleric acid isovalerate, and methylcyclopentenolone. Difficult-to-volatilize flavoring substances include vanillin, ethyl maltol, propyl nonalactone, raspberry ketone, propyl dodecalactone, maltol, eugenol, flue-cured tobacco extract, Oriental tobacco extract, and bright flue-cured tobacco extract.

[0067] Further, whether the flavoring substance is added to the inner region of the aerosol-forming substrate by the method disclosed in the present application is not only determined according to its volatility, but also selected according to the production cost control requirement, etc. For example, rose essential oil is expensive and has a certain volatility. In order to avoid loss, it can be directly added to the inner region of the aerosol-forming substrate.

[0068] Further, the second flavoring substance mixed in the tobacco mixture in step one is not easy to volatilize compared with the first flavoring substance.

[0069] Preferably, the second flavoring substance is not easy to volatilize. Whether a certain flavoring substance is easy to volatilize or not can be determined according to the demand of the technician, or the subsequent production process, or the heating condition during smoking.

[0070] For example, the second flavoring substance can be a flavoring substance with a boiling point greater than 250°C; or the second flavoring substance can be a flavoring substance with a volatilization rate of not more than 10% if the flavoring substance is uniformly distributed in the aerosol-forming substrate and then the aerosol-forming substrate is baked at 110°C for 5 min.

[0071] The flavoring substances are classified and added according to their different volatilities, that is, the flavoring substances not easy to volatilize are uniformly added to the aerosol-forming substrate at various positions, so as to avoid insufficient aroma of the flavoring substances not easy to volatilize in the early stage of smoking; and the flavoring substances easy to volatilize are added to the center layer of the aerosol-forming substrate. For example, the flavoring substances easy to volatilize such as menthol are sprayed to the surface of the baked aerosol-forming substrate. After being rolled into a cigarette, the menthol is rapidly volatilized under the condition of heating at 200-300°C, resulting in high content of menthol in the first few puffs of smoke and low content of menthol in the last few puffs of smoke, which causes inconsistent smoke feeling before and after smoking of a cigarette and affects the smoking experience. The flavoring substances easy to volatilize added to the center layer of the aerosol-forming substrate not only can reduce the use cost of the flavoring substances easy to volatilize, but also can slow down the release speed of the flavoring substances easy to volatilize after the aerosol-forming substrate is rolled into a heated cigarette, so as to avoid insufficient aroma of the flavoring substances easy to volatilize in the late stage of smoking.

[0072] Further, the method for preparing the aerosol-forming substrate disclosed in the present application further comprises the following steps:

[0073] The tobacco raw material is crushed to prepare tobacco particles;

[0074] The tobacco particles, the second flavoring substance, the adhesive, the atomizing agent and water are uniformly mixed to prepare a dry-wet mixture;

[0075] The dry-wet mixture is extruded to prepare a tobacco mixture,

[0076] The second flavoring substance is a non-volatile flavoring substance.

[0077] The technology can ensure that the non-volatile flavoring substance and water are uniformly distributed in the aerosol-forming substrate sheet. At a drying temperature of about 100°C, the water can be quickly and smoothly volatilized into the air because the water is uniformly distributed in the aerosol-forming substrate, so that the aerosol-forming substrate can be dried. At the same time, the volatile flavoring substance will not be lost in large quantities at the temperature. In addition, the non-volatile flavoring substance is uniformly distributed in the surface area and the internal area of the aerosol-forming substrate, and the volatile flavoring substance is only distributed in the internal area of the aerosol-forming substrate. Therefore, when heated by smoking, the two substances can be released more uniformly, further ensuring uniform aroma.

[0078] Further, the aerosol-forming substrate can be prepared by the following steps: tobacco particle preparation, first flavoring substance material preparation, wet material preparation, dry-wet material mixing, extrusion, roll forming, and drying. The roll forming includes multiple stages of roll forming, and a first flavoring substance adding process is arranged in one of the multiple stages of roll forming.

[0079] In a specific preferred embodiment, if the entire roll forming process includes five stages of roll forming, the tobacco mixture is subjected to three stages of roll forming to obtain at least two pieces of aerosol-forming sheet, is subjected to one stage of roll forming to obtain one piece of aerosol-forming substrate after the flavoring substance is attached, and is subjected to one stage of roll forming and drying.

[0080] In a specific preferred embodiment, if the entire roll forming process includes five stages of roll forming, the tobacco mixture is subjected to four stages of roll forming to obtain at least two pieces of aerosol-forming sheet, is subjected to one stage of roll forming to obtain one piece of aerosol-forming substrate after the flavoring substance is attached, and is directly dried.

[0081] Further, the present application provides a preparation method of an aerosol-forming substrate, which further includes the following steps.

[0082] S1 tobacco particle preparation: tobacco raw materials are crushed, for example, tobacco leaves, stems, and the like are transported to a crusher after impurities such as non-tobacco substances are removed, and are crushed into tobacco particles A of a certain particle size;

[0083] S2 wet material preparation: a non-volatile flavoring substance material B is uniformly mixed with adhesive, atomizing agent, water, and the like to obtain a wet material D. Generally, the adhesive is first uniformly dispersed in a glycerol atomizing agent, and then mixed with water. The mixed material C is then mixed with the non-volatile flavoring substance material B, and finally a liquid wet material D is obtained;

[0084] S3 dry-wet material mixing: the tobacco particles A are mixed with the liquid wet material D to obtain a dry-wet mixture E;

[0085] S4 extrusion: the dry-wet mixture E is extruded by a screw extruder or other equipment, the purpose is to remove the air in the material E, increase the density of the material, further improve the uniformity of the material, and extrude the granular or irregular material into a relatively regular shape such as a strip or a segment, and obtain the extruded material F (i.e. tobacco mixture material).

[0086] S5 multiple aerosol forming sheet roll forming: the extruded material F is quantitatively distributed into first material F1 and second material F2, and enters two roll forming equipment channels at the same speed, and is respectively roll formed to obtain first sheet G1 and second sheet G2. The first sheet G1 and the second sheet G2 can be obtained by multi-stage roll forming according to the design of the equipment.

[0087] S6 attachment of volatile flavoring substances: the volatile flavoring substance material E is sprayed on one side of the first sheet G1 and the second sheet G2, so that a certain amount of volatile flavoring substances are attached to one side of the G1 and G2 sheets, respectively, to obtain first sheet H1 and second sheet H2.

[0088] S7 laminating and roll forming: the first sheet H1 and the second sheet H2 are laminated and overlapped on the side with the volatile flavoring substances, and further roll formed to obtain an aerosol forming substrate J1. In this way, the volatile flavoring substances are located in the middle layer of the aerosol forming substrate J1 sheet.

[0089] S8 drying: the J1 sheet is a sheet with a relatively high water content, which is then dried in an oven to obtain a finished aerosol forming substrate.

[0090] Further, the composition of the roll-formed finished aerosol forming substrate generally includes: 65-80 parts of tobacco dry matter, 5-15 parts of water, 2-6 parts of adhesive, 10-30 parts of atomizing agent, and 0-5 parts of exogenous plant cellulose.

[0091] Further, in addition to the above-mentioned spraying of volatile flavoring substances onto the two sheets, a coating roller coating method can also be used to add volatile flavoring substances. In addition, volatile flavoring substances can also be added to one of the two sheets, and finally ensure that the added volatile flavoring substances are located in the middle layer after the two sheets are laminated.

[0092] In addition to the quantitative distribution of the extruded material F to the double channel at the beginning, a double channel process can also be set at other upstream process sections, for example, the flow of the material can be set to a double channel from the beginning of the raw material crushing, and finally the double channel processed sheets can be combined. The materials or sheets running in the double channel can also be materials or sheets with different formulations of tobacco materials, adhesives, atomizing agents, etc., to ensure that the double channel material flow is the same, and finally can be overlapped, laminated, and combined into one. In the preparation of wet materials, exogenous fibers and other materials can also be added to improve the tensile strength and other physical properties of the aerosol forming substrate.

[0093] Further, the present application also provides an aerosol forming substrate prepared according to any of the above-mentioned preparation methods.

[0094] Further, the present application also provides an aerosol forming substrate, comprising: being divided into a surface region and an internal region in its thickness direction, the concentration of the first flavoring substance in the internal region is greater than that in the surface region. Specifically, the concentration of the first flavoring substance in a certain region refers to the total content of the first flavoring substance in the region divided by the total volume or total weight of the region.

[0095] In a preferred embodiment, as shown in Figure 1 The aerosol forming substrate is formed by roll pressing the first aerosol forming sheet 11, the second aerosol forming sheet 12 and the third aerosol forming sheet 13, the first flavoring substance 21 is located between two pieces of sheet before the three pieces of aerosol sheet are roll pressed into the aerosol substrate, and is located on the side of the second aerosol forming sheet 12 close to the first aerosol forming sheet 11 and the side of the third aerosol forming sheet 13 close to the second aerosol forming sheet 12; the second flavoring substance 22 is uniformly distributed in the first aerosol forming sheet 11, the second aerosol forming sheet 12 and the third aerosol forming sheet 13, after roll pressing, the three pieces of aerosol forming sheet are roll pressed into one piece of aerosol forming substrate 30, although the first flavoring substance 21 is diffused to some extent due to roll pressing, it is still mainly located at one third and two thirds of the thickness direction of the aerosol forming substrate 30, i.e. in the internal region 32 of the aerosol forming substrate 30, the surface region 31 of the aerosol forming substrate 30 hardly contains the first flavoring substance 21; while the second flavoring substance 22 is still substantially uniformly distributed in the internal region 32 and the surface region 31 of the aerosol forming substrate 30.

[0096] In another preferred embodiment, as shown in Figure 2As shown, the aerosol-forming substrate is formed by laminating two aerosol-forming sheets, i.e. the first aerosol-forming sheet 11' and the second aerosol-forming sheet 12', by rolling. The first flavoring substance 21 is located between the first aerosol-forming sheet 11' and the second aerosol-forming sheet 12' before rolling. Although the first flavoring substance 21 is somewhat diffused due to rolling, it is still mainly located at about one-half of the thickness direction of the aerosol-forming substrate. The concentration of the first flavoring substance at about one-half of the thickness direction of the aerosol-forming substrate is the highest, and the concentration of the first flavoring substance decreases from about one-half of the thickness direction to the two surfaces perpendicular to the thickness direction. That is, the concentration of the first flavoring substance at about one-half of the thickness direction of the aerosol-forming substrate is greater than the concentration of the two surfaces perpendicular to the thickness direction of the aerosol-forming substrate. That is, the first flavoring substance is mainly located in the middle region 33, and the second flavoring substance is uniformly distributed in the middle region 33 and the surface region 31.

[0097] Further, the first flavoring substance can be selected as described in the method for preparing the aerosol-forming substrate, which will not be repeated here. Preferably, the first flavoring substance is a flavoring substance having a boiling point of 250°C or less; or the first flavoring substance is a relative concept, i.e. a flavoring substance having a volatilization rate of more than 10% when uniformly distributed in the aerosol-forming substrate and then baked at 110°C for 5 minutes is defined as the first flavoring substance.

[0098] Further, the aerosol-forming substrate further contains a second flavoring substance. The second flavoring substance has a lower volatility than the first flavoring substance in the aerosol-forming substrate.

[0099] Further, the second flavoring substance is a flavoring substance having a boiling point of more than 250°C; or the second flavoring substance is a flavoring substance having a volatilization rate of not more than 10% when uniformly distributed in the aerosol-forming substrate and then baked at 110°C for 5 minutes.

[0100] Further, the present application further discloses a smoking article comprising any of the aerosol-forming substrates described above.

[0101] Preferably, the smoking article is a heated cigarette.

[0102] The present application will be further described in conjunction with specific examples:

[0103] Test method:

[0104] The prepared sample was randomly divided into 10 parts, and the content of menthol was detected one by one, and the loss rate and the coefficient of variation were calculated, the loss rate = the actual content percentage of menthol in the finished aerosol forming substrate after drying / the added percentage, the coefficient of variation is the standard deviation of the actual content percentage of menthol in the finished aerosol forming substrate after drying / the average of the actual content percentage. In addition, the samples were made into the same specification cigarettes, and the sensory evaluation of the sensory evaluators was carried out, each cigarette was smoked for 10 puffs, and the sensory effect of the aroma amount in the smoke of the finished heat-not-burn cigarette was described.

[0105] Example 1

[0106] According to the process method of the application, two aerosol forming sheet materials are rolled into one aerosol forming substrate. The tobacco extract is used as the main material to prepare the non-volatile flavoring material (second flavoring material), and menthol is used as the main material to prepare the volatile flavoring material (first flavoring material). The non-volatile flavoring material, water, atomizing agent, adhesive and other liquid mixtures are added to the tobacco particles to form a dry-wet mixture, which is extruded and then rolled by a four-stage double-channel continuous roller to obtain two aerosol forming sheet materials. The volatile flavoring material is sprayed onto the bonding surface of the two aerosol forming sheet materials, and then rolled by a final (fifth) channel bonding roller to obtain the aerosol forming substrate.

[0107] Comparative Example 1

[0108] The same raw materials as in Example 1 are used, except that the volatile flavoring material is added to the dry-wet mixture before rolling, and the extruded material is directly rolled into the aerosol forming substrate by a five-stage single-channel continuous roller.

[0109] Table 1

[0110]

[0111] As shown in Table 1, the flavoring material loss of the sample of Example 1 is significantly lower than that of the sample of Comparative Example 1, and the release of aroma amount in the smoke is more uniform and the concentration is higher.

[0112] Example 2

[0113] According to the process method of the present application, two pieces of aerosol forming sheet are rolled into one piece of aerosol forming substrate. The same raw materials as in Example 1 are used, with roasted tobacco extract as the main material for the non-volatile flavoring substance (second flavoring substance) and menthol as the main material for the volatile flavoring substance (first flavoring substance). The non-volatile flavoring substance is added to the tobacco particles together with the liquid mixture of water, atomizing agent, adhesive, etc. to form a dry-wet mixture, which is extruded and then rolled through three stages of double-channel continuous rolling to obtain two pieces of aerosol forming sheet. The volatile flavoring substance is sprayed onto the adhering surface of the two pieces of sheet, and then rolled through four stages of channel adhering and a fifth stage of rolling to obtain the aerosol forming substrate.

[0114] Comparative Example 2

[0115] The same raw materials as in Example 2 are used, except that the volatile flavoring substance is added directly to the surface of the aerosol forming substrate that has been rolled, dried and cut into strips by means of a drum.

[0116] Table 2

[0117]

[0118] As shown in Table 2, in Comparative Example 2, the volatile flavoring substance is added by means of a drum after drying, which avoids loss of the flavoring substance during drying, but a large amount of the flavoring substance adheres to the drum, resulting in a large loss of the flavoring substance. In Example 2, the second rolling assembly is two stages of rolling, and more menthol is dispersed to the surface layer than in Example 1, but the loss rate is still lower than in Comparative Examples 1 and 2. Example 2 has a significantly lower coefficient of variation in the content of the flavoring substance than Comparative Example 2, indicating that it has high uniformity of flavoring, and in addition, the release of aroma in the smoke is more uniform and the concentration is higher.

[0119] Although the present application has been illustrated and described with reference to certain preferred embodiments thereof, it should be understood by those skilled in the art that the foregoing is a description of a preferred embodiment of the application and that various changes can be made in form and details by those skilled in the art without departing from the spirit and scope of the application.

Claims

1. A method for preparing an aerosol-forming substrate, characterized in that, Includes the following steps: Tobacco raw materials are crushed to prepare tobacco granules; The tobacco particles, the second flavoring substance, the adhesive, the atomizing agent and water are mixed to prepare a dry and wet mixture, wherein the second flavoring substance is a non-volatile flavoring substance; The dry-wet mixture is extruded to obtain a tobacco mixture. The tobacco mixture is rolled to obtain at least two aerosol sheets; The first fragrance substance is applied to at least one surface of at least one aerosol-formed sheet by coating or spraying, and the first fragrance substance is only a volatile fragrance substance. The first fragrance substance is placed between two aerosol forming sheets, and the at least two aerosol forming sheets are rolled together to form the aerosol forming substrate.

2. The method for preparing the aerosol forming substrate according to claim 1, characterized in that, The at least two aerosol forming sheets include a first aerosol forming sheet and a second aerosol forming sheet. The first fragrance substance is attached to one side of the first aerosol forming sheet and / or the second aerosol forming sheet, with the side with the first fragrance substance attached serving as the bonding side. The first aerosol forming sheet and the second aerosol forming sheet are rolled together to form the aerosol forming substrate.

3. The method for preparing the aerosol forming substrate according to claim 1 or 2, characterized in that, The first aroma substance is an aroma substance with a boiling point below 250℃; Alternatively, the first fragrance substance may be a fragrance substance with a volatility exceeding 10% if it is uniformly distributed in an aerosol forming substrate and then dried at 110°C for 5 minutes.

4. The method for preparing the aerosol forming substrate according to claim 1 or 2, characterized in that, The at least two aerosol forming sheets are dried after being rolled once to obtain the aerosol forming substrate.

5. An aerosol forming substrate prepared by any one of claims 1-4.

6. The aerosol forming substrate according to claim 5, characterized in that, The aerosol forming substrate is divided into a surface region and an internal region in the thickness direction, and the concentration of the first fragrance substance in the internal region is greater than that in the surface region.

7. The aerosol forming substrate according to claim 6, characterized in that, The internal region is the middle region.

8. The aerosol forming substrate according to claim 6, characterized in that, The first aroma substance is an aroma substance with a boiling point below 250℃; Alternatively, the first fragrance substance may be a fragrance substance with a volatility exceeding 10% if it is uniformly distributed in an aerosol forming substrate and then dried at 110°C for 5 minutes.

9. The aerosol forming substrate according to claim 8, characterized in that, The aerosol forming substrate also contains a second fragrance substance. The second aroma substance is an aroma substance with a boiling point greater than 250℃; Alternatively, the second fragrance substance may be a fragrance substance whose volatile content does not exceed 10% after being uniformly distributed in an aerosol forming substrate and then dried at 110°C for 5 minutes.

10. A smoking product, characterized in that, The aerosol forming substrate includes any one of claims 5-9.

11. The smoking article according to claim 10, characterized in that, The smoking product is heated cigarette.

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