A reconstituted tobacco leaf, a preparation method thereof and uses thereof

Abstract

The present invention discloses a magnetic reconstituted tobacco leaf, which comprises a magnetic reconstituted tobacco leaf foil and / or magnetic reconstituted tobacco leaf particles; the thickness of the magnetic reconstituted tobacco leaf foil is 0.10 - 0.30 mm, and the particle size of the magnetic reconstituted tobacco leaf particles is 0.5 - 2 mm; the composition of the magnetic reconstituted tobacco leaf comprises a fiber material, a tobacco material, nanofibers and a magnetic material; the magnetic material is a material that can be converted into heat after absorbing an alternating magnetic field. The present invention also discloses a preparation method and uses of the magnetic reconstituted tobacco leaf.

Description

Technical Field

[0001] The present invention belongs to the field of tobacco, and particularly relates to a reconstituted tobacco leaf, a preparation method thereof, and uses thereof. Background Art

[0002] Existing heat-not-burn aerosol products usually use reconstituted tobacco leaves or tobacco particles as an aerosol-forming matrix. The slurry process and the papermaking process are the main methods for producing the existing reconstituted tobacco leaves used in heat-not-burn aerosol products. The slurry process requires drying to remove a large amount of water, resulting in high process energy consumption; the finished product is brittle, has low strength, and high reconstitution losses are generated during cutting. The papermaking process causes serious loss of flavor substances in the finished product, and also requires a large amount of energy for drying and removing water, and the drying process is complex.

[0003] Existing aerosol products commonly use induction heating to atomize the required components in the aerosol-forming matrix from the product to form an inhalable aerosol. In existing induction heating type aerosol products, the inductor is a separate component and transfers its induced heat to the whole of the aerosol-forming matrix by local contact (central type) or non-contact (circumferential type) with the aerosol-forming matrix. The disadvantage of central heating is that the induced heat of the inductor is transferred from the center of the aerosol-forming matrix in contact with it to its periphery, and the heat significantly attenuates from the inside to the outside; the disadvantage of circumferential heating is that the induced heat of the inductor penetrates through the outer periphery of the wrapping material of the aerosol-forming matrix in contact with it and then transfers to the center of the aerosol-forming matrix, and the heat significantly attenuates from the outside to the inside. Therefore, in order to achieve the desired atomization effect of the aerosol-forming matrix, it is necessary to extend the preheating time of the product and increase the maximum heating temperature, and then increase the output power of the inductor. The adverse effects brought about by this include low thermal utilization efficiency of the aerosol-forming matrix, uneven heat distribution, and increased energy consumption of the heating device for heating the aerosol product.

[0004] Therefore, the present invention is proposed. Summary of the Invention

[0005] To improve the above defects, the present invention proposes a magnetic reconstituted tobacco leaf foil and magnetic reconstituted tobacco leaf particles integrating a magnetic induction material onto an aerosol-forming matrix, and a manufacturing method thereof, aiming to improve the utilization efficiency of induced heat and the heating rate and reduce the energy consumption of the heating device when using an aerosol product made of the magnetic aerosol-forming matrix, and save the manufacturing cost.

[0006] The technical solution of the present invention is as follows:

[0007] The first aspect of the present invention discloses a magnetic reconstituted tobacco, which includes magnetic reconstituted tobacco foil and / or magnetic reconstituted tobacco particles; the thickness of the magnetic reconstituted tobacco foil is 0.10 - 0.30 mm, and the particle size of the magnetic reconstituted tobacco particles is 0.5 - 2 mm; the composition of the magnetic reconstituted tobacco includes fiber materials, tobacco materials, nanofibers, and magnetic materials; the magnetic materials are materials that can be converted into heat after absorbing an alternating magnetic field.

[0008] Preferably, the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is magnetic nanoparticles and / or magnetic nanowires; the length of the magnetic nanowires is 5 - 100 μm, and the diameter is 5 - 500 nm.

[0009] Preferably, the nanofibers are plant nanofibers and / or tobacco nanofibers; the length of the nanofibers is 1 - 10 μm, and the diameter is 5 - 500 nm; the fiber materials are cellulose fibers and / or tobacco fiber materials.

[0010] The second aspect of the present invention discloses a method for preparing the magnetic reconstituted tobacco, which includes the following steps:

[0011] (1) Making the tobacco material and the fiber material into powders with a particle size of 60 - 120 mesh, adding a binder and mixing to obtain a solid mixture; the binder is made of one or several of starch, arabic gum, xanthan gum, guar gum, CMC, and / or nanofiber gel;

[0012] (2) Using the method of vacuum-assisted filtration of nanofiber dispersion liquid and magnetic nanowire suspension liquid to obtain a composite gel of nanofibers and magnetic nanowires; adding glycerol, water, and the surfactant polyvinylpyrrolidone and mixing evenly to obtain a liquid mixture;

[0013] (3) Stirring and mixing the solid mixture in step (1) and the liquid mixture in step (2) to obtain a dough-like substance with a water content of 20 - 40 wt%;

[0014] (4) Compressing and shaping the dough-like substance obtained in step (3) using an extruder into a preform;

[0015] (5) Subjecting the preform obtained in step (4) to multi-stage lamination at a certain temperature to obtain a foil with a thickness of 0.10 - 0.30 mm, and then drying to reduce the water content to 5 - 10 wt%, thus obtaining the reconstituted tobacco foil;

[0016] Or,

[0017] (6) Using a rotary granulator to crush the preform obtained in step (4) into irregular particles, drying to reduce the water content to 1 - 6 wt%; screening to obtain particles with a particle size of 0.5 - 2 mm, thus obtaining the reconstituted tobacco particles.

[0018] Alternatively, the method for preparing the magnetic reconstituted tobacco leaf comprises the following steps:

[0019] (A) Prepare a semi-wet mixture formed by a tobacco material, nanofibers, and magnetic nanomaterials; the method is as follows: Add a surfactant polyvinylpyrrolidone, glycerol, and propylene glycol, and use the method of continuously vacuum-assisted filtering a nanofiber dispersion liquid and a magnetic nanomaterial suspension liquid to prepare a composite gel of nanofibers and magnetic nanomaterials, which is the semi-wet mixture;

[0020] (B) Insert the semi-wet mixture of step (A) into a laminating roller and perform multi-stage lamination at a certain temperature to obtain a thin sheet with a thickness of 0.10 - 0.30 mm; Apply a binder layer to the surface of the laminating roller before inserting the sheet base into the laminating roller; or,

[0021] (C) Prepare a cellulose fiber and / or tobacco fiber sheet base;

[0022] (D) Apply the semi-wet mixture of step (A) to the sheet base of step (C), then insert the obtained sheet base into a laminating roller and perform multi-stage lamination at a certain temperature to obtain a thin sheet with a thickness of 0.10 - 0.30 mm; Apply a binder layer to the surface of the laminating roller before inserting the sheet base into the laminating roller;

[0023] The binder used for the binder layer is made of one or several of starch, gum arabic, xanthan gum, guar gum, CMC, and / or nanofiber gel;

[0024] (E) Dry the thin sheet obtained in step (B) or step (D) to reduce the water content to 5 - 10 wt%, and thus obtain the magnetic laminated reconstituted tobacco leaf foil.

[0025] Alternatively, the method for preparing the magnetic reconstituted tobacco leaf comprises the following steps:

[0026] (a) Pulp the tobacco material and fiber material, and then defibrate to obtain tobacco pulp;

[0027] (b) Mix a nanofiber dispersion liquid and a magnetic nanowire suspension liquid, and then add an adhesive solution and a surfactant polyvinylpyrrolidone and mix to obtain a magnetic nanocomposite fiber pulp;

[0028] (c) Mix the tobacco pulp of step (a) and the magnetic nanocomposite fiber pulp of step (b) to obtain a magnetic pulp, wherein the mass percentage of the magnetic nanocomposite fiber is 1% - 5 wt%; Use a paper making machine to perform oriented alignment papermaking to obtain a magnetic tobacco sheet base;

[0029] Alternatively, use a paper making machine to make a magnetic tobacco sheet base with a core layer of magnetic nanocomposite fibers;

[0030] (d) Preparation of wet-coated tobacco material and semi-wet-coated tobacco material; the steps are as follows: crush the tobacco material and fiber material to obtain a uniform powder with a particle size of 60 - 120 mesh; then add a solid natural binder and mix evenly; add glycerol, propylene glycol and water and mix, maintaining the water content at 50 - 80 wt% to obtain the wet-coated tobacco material; dehydrate to make the water content at 20 - 50 wt% to obtain the semi-wet-coated tobacco material; the binder is made of one or more of starch, gum arabic, xanthan gum, guar gum, CMC and / or nanofiber gel;

[0031] (e1) Multistage laminate the magnetic tobacco sheet base obtained in step (c) at a certain temperature to obtain a magnetic reconstituted tobacco leaf base with a thickness of 0.10 - 0.30 mm;

[0032] (f1) Coat the wet-coated tobacco material in step (4) on the magnetic reconstituted tobacco leaf base obtained in step (e1), and dry to make the water content 5 - 10 wt% to obtain the magnetic reconstituted tobacco leaf foil;

[0033] Or,

[0034] (e2) Coat the semi-wet-coated tobacco material in step (d) on the tobacco sheet base in step (c);

[0035] (f2) Multistage laminate the tobacco sheet base after coating in step (e2), and dry to make the water content 5 - 10 wt% to obtain the magnetic reconstituted tobacco leaf foil.

[0036] Or, the preparation method of the magnetic reconstituted tobacco leaf includes the following steps:

[0037] 1) Pulp the tobacco material and fiber material, and then defibrate to obtain tobacco pulp;

[0038] 2) Add an adhesive solution and the surfactant polyvinylpyrrolidone to the tobacco pulp in step 1) and mix to obtain a composite fiber pulp tobacco pulp; use a sheet former to make a tobacco sheet base;

[0039] 3) Prepare a magnetic coating material, the steps are: vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanowire suspension to obtain a nanofiber and magnetic nanowire composite gel; add the obtained composite gel to a mixed slurry of tobacco mixture powder, tobacco extract, glycerol, propylene glycol and water, and then add an adhesive solution, mix evenly to obtain the magnetic coating material, and maintain the solid content at 50 - 80 wt%;

[0040] 4) Coat the magnetic coating material in step 3) on the tobacco sheet base in step 2), and dry to obtain a magnetic tobacco sheet; ]

[0041] 5) Multistage laminate the magnetic tobacco sheet obtained in step 4) at a certain temperature to obtain a magnetic reconstituted tobacco leaf base with a thickness of 0.10 - 0.30 mm;

[0042] 6) Dry the prepared magnetic reconstituted tobacco leaf base to a water content of 5-10 wt% to obtain a magnetic reconstituted tobacco leaf foil.

[0043] Alternatively, the method for preparing the magnetic reconstituted tobacco leaf includes the following steps:

[0044] (Ⅰ) Crush and defibrate the tobacco material and the fiber material, and form the defibrated fibers into a fiber thin layer by dry air forming.

[0045] (Ⅱ) Mix the nanofiber dispersion and the magnetic nanowire suspension, add the binder solution and the surfactant polyvinylpyrrolidone to obtain a magnetic nanocomposite fiber pulp; then add plant polysaccharide and mix to form a magnetic coating solution.

[0046] (Ⅲ) Spray the magnetic coating solution obtained in step (Ⅱ) onto the fiber thin layer obtained in step (Ⅰ) and then shape it into a magnetic tobacco leaf base.

[0047] (Ⅳ) Prepare a wet coating material and a semi-wet coating material; the steps are as follows: crush the tobacco material and the fiber material to obtain a uniform powder with a particle size of 60-120 mesh; then add a solid natural binder and mix evenly; add glycerol, propylene glycol and water and mix to maintain the water content at 50-80 wt% to obtain a wet coating material; dehydrate to make the water content at 20-50 wt% to obtain a semi-wet coating material; the binder is made of one or more of starch, gum arabic, xanthan gum, guar gum, CMC and / or nanofiber gel.

[0048] (LI) Perform multi-stage lamination on the magnetic tobacco leaf base obtained in step (Ⅱ) at a certain temperature to obtain a magnetic reconstituted tobacco leaf base with a thickness of 0.10-0.30 mm.

[0049] (LXI) Coat the wet coating material obtained in step (Ⅳ) on the magnetic reconstituted tobacco leaf base obtained in step (LI), and dry to make the water content 5-10 wt% to obtain a magnetic reconstituted tobacco leaf foil.

[0050] Alternatively,

[0051] (LⅡ) Coat the semi-wet coating material obtained in step (Ⅳ) on the tobacco leaf base obtained in step (Ⅲ).

[0052] (LXⅡ) Perform multi-stage lamination on the tobacco leaf base coated in step (LⅡ) at a certain temperature, and dry to make the water content 5-10 wt% to obtain a magnetic reconstituted tobacco leaf foil.

[0053] Preferably, the pressure of the multi-stage lamination is 1-5 MPa and the temperature is 70-200 °C.

[0054] The third aspect of the present invention discloses the use of the magnetic reconstituted tobacco leaf as a matrix for forming a magnetic aerosol.

[0055] The magnetic reconstituted tobacco for a magnetic aerosol forming substrate of the present invention comprises a magnetic reconstituted tobacco foil and magnetic reconstituted tobacco particles; the magnetic reconstituted tobacco contains a tobacco mixture, nanofibers and a magnetic material; the nanofibers can be wood nanofibers and / or tobacco nanofibers; the nanofibers can be other plant nanofibers; the diameters and lengths of the nanofibers are 5 - 100 nm and 1 - 10 μm respectively.

[0056] The magnetic material is any material that can be converted into heat after absorbing an alternating magnetic field, such as ferromagnetic materials or ferrimagnetic materials; specifically, such as iron or iron alloys such as stainless steel, nickel, nickel alloys such as the corrosion-resistant Fe-Ni-Cr alloy, etc.; preferably, the magnetic material is a magnetic nanomaterial, such as nanoparticles, nanosheets, nanospheres, nanorods, nanotubes, nanowires, etc., especially nanoparticles and / or nanowires; the nanoparticles and / or nanowires include but are not limited to materials and their alloys such as nickel, cobalt, iron-nickel, cobalt-nickel, cobalt-iron, iron-cobalt-nickel, iron-molybdenum-nickel, etc.; the magnetic material is preferably magnetic nanowires. Its length is 5 - 100 μm and the average diameter is 5 - 500 nm.

[0057] The magnetic reconstituted tobacco foil is obtained by extrusion and rolling of a tobacco mixture, nanofibers and magnetic nanomaterials; the magnetic reconstituted tobacco particles are obtained by extrusion, granulation and screening of a tobacco mixture, nanofibers and magnetic nanomaterials; the preparation method of the magnetic reconstituted tobacco includes: forming a dough-like substance of tobacco, nanofibers and magnetic nanomaterials; adding a surfactant such as polyvinylpyrrolidone (PVP) to the mixture of tobacco, nanofibers and magnetic nanomaterials to facilitate the combination of the magnetic nanomaterials and the nanofibers; adopting a method of continuously vacuum-assisted filtering of the nanofiber dispersion and the magnetic nanomaterial suspension to obtain a composite gel of nanofibers and magnetic nanomaterials; through the extrusion process of the dough-like substance, the magnetic nanomaterials form interconnected magnetic conduction paths through hot extrusion and form a tight combination with the extruded reconstituted tobacco embryo; applying temperature to the rolling rollers, the magnetic nanomaterials form interconnected magnetic conduction paths through hot lamination or further nanowelding and form a closer combination with the whole reconstituted tobacco to obtain a reconstituted tobacco foil; the thickness of the foil can be controlled by adjusting the rolling roller distance; the obtained magnetic reconstituted tobacco foil can be wound into a roll, sliced or shredded, and is used in a magnetic aerosol forming substrate after subsequent processing. The tobacco material can be tobacco powder, debris, tobacco stems, etc.

[0058] The magnetic reconstituted tobacco leaf foil is used for an aerosol-forming substrate, which can be wound into a roll, sliced or shredded, and is formed into an aerosol-forming substrate through subsequent processing; the magnetic aerosol-forming substrate contains materials that can be atomized to form an inhalable aerosol at an appropriate temperature, and the aerosol formed by atomization contains an atomizing agent, a flavor substance and / or nicotine, and may also contain other inhalable components. The magnetic aerosol-forming substrate and the wrapping material are combined into an aerosol generation section, and then combined with other parts including a support section, a cooling section and a filter section to form an aerosol product.

[0059] Advantages of the present invention:

[0060] In the method for preparing the magnetic reconstituted tobacco leaf of the present invention, during the process of the dough-like material being extruded by an extruder, the heater on the extruder can heat the dough-like material through heat conduction. In addition, during the movement process, the dough-like material rubs and shears with the barrel, screw of the extruder and the dough-like material itself, generating a large amount of heat, which causes the magnetic nanomaterials in the preform to undergo hot extrusion. When the extruded preform is hot-pressed into a foil on a rolling mill, the magnetic nanomaterials therein further undergo hot lamination and nano-welding; hot lamination and nano-welding can completely remove the surfactant components (such as PVP) wrapped around the periphery of the magnetic nanowires and sinter the magnetic nanowire joints, significantly reducing the contact resistance, constructing an interconnected, strong and stable magnetic nanowire magnetic conduction path and eddy current network, and at the same time significantly improving the tensile strength of the reconstituted tobacco leaf foil; hot lamination and nano-welding can also significantly increase the heating temperature of the magnetic reconstituted tobacco leaf foil, because the resistance is significantly reduced after welding, resulting in an increase in the induced eddy current and electron transport ability inside the reconstituted tobacco leaf foil; nano-welding can improve the induction heating performance without increasing the content of magnetic nanowires, reducing the use cost of magnetic materials.

[0061] The preparation method of the present invention involves continuous high-pressure homogenization multiple times (generally not less than three times), enabling the uniform and firm dispersion of nanofibers and magnetic nanomaterials into the reconstituted tobacco substrate; vacuum-assisted filtration facilitates the formation of an entangled network of nanofibers through hydrogen bonds, thereby obtaining a super-strong rigid nanostructure with high thermal stability and high transparency, further enhancing the high-temperature resistance and mechanical strength of the magnetic reconstituted tobacco; adding surfactants such as polyvinylpyrrolidone (PVP) during the manufacturing process can coat magnetic nanomaterials such as magnetic nanowires. Through the strong hydrogen bond interaction between the carbonyl group of the additive and the hydroxyl group of the nanofibers, the magnetic nanowires partially wrapped by cellulose play a skeletal role, promoting load transfer and energy dissipation during the stretching process of the magnetic reconstituted tobacco, dispersing stress, and obtaining excellent mechanical properties and structural stability; multi-stage thermal lamination and nano-welding can completely remove the surfactant components (such as PVP) wrapped around the periphery of the magnetic nanowires and sinter the magnetic nanowire joints, significantly reducing the contact resistance, constructing an interconnected, firm, and stable magnetic nanowire magnetic conduction path and eddy current network, and simultaneously greatly increasing the tensile strength of the reconstituted tobacco; multi-stage thermal lamination and nano-welding can also significantly increase the heating temperature of the magnetic reconstituted tobacco because the resistance decreases significantly after welding, resulting in an increase in the induced eddy current and electron transport ability inside the reconstituted tobacco. Nano-welding can improve the induction heating performance without increasing the content of magnetic nanowires, reducing the usage cost of magnetic materials.

[0062] Compared with the traditional papermaking method and the thick slurry method for reconstituted tobacco production processes, the manufacturing processes of the magnetic reconstituted tobacco foil and reconstituted tobacco particles of the present invention require less water, the drying process is significantly reduced, and the production energy consumption is lowered. Since the foil dries faster, the finished reconstituted tobacco has a stronger retention capacity for flavor substances and nicotine, can use less binder, reducing the impact of unpleasant odors generated during the heating process of aerosol products on the smoking flavor. By precisely adjusting the roller gap of the rolling mill, the thickness of the finished reconstituted tobacco can be made uniformly controllable, and the accuracy and stability of its thickness help to ensure the consistency of downstream processes and help to ensure that important product indicators such as nicotine content are within the specified range; due to the increased stability and reliability of the reconstituted tobacco, the working stability of the heating device is also greatly improved. In the preparation method of the present invention, the drying and preheating of tobacco debris and fibers are not necessary; due to the material bonding effect of the extrusion molding process itself, the amount of binder can be significantly reduced. Therefore, the raw material and production costs can be further reduced. The tobacco materials used in the present invention can be tobacco powder, debris, tobacco stems, etc., which can reduce the cost of using pure tobacco leaves as raw materials for traditional particulate aerosol products. The preparation method of the present invention uses the same raw materials and extrusion process to prepare the preforms required for the reconstituted tobacco foil and reconstituted tobacco particles, saving the floor area and capital investment of production equipment, and facilitating the synchronous manufacture of two types of products, namely reconstituted tobacco foil and reconstituted tobacco particles.

[0063] The fiber material of the present invention is cellulose fiber and / or tobacco fiber material, and the flexible nanofibers are entangled with each other so that they can create a nanoscale network; on the one hand, the strength of the fiber network is enhanced by increasing the number of hydrogen bonds between each fiber (fibril) or fibers; on the other hand, the nanofibers with small size, high surface area and flexibility can naturally increase the strength of the network; thus, the nanofibers can successfully improve the tensile strength of reconstituted tobacco leaves; at the same time, the highly active hydroxyl groups in the nanofibers can be modified by chemical and physical treatment to obtain the desired properties, such as increasing their adhesion to magnetic materials.

[0064] The magnetic reconstituted tobacco of the present invention has excellent mechanical properties, thermal stability, flexibility (foil) and porosity; the ferromagnetic nanowires have a high aspect ratio and excellent mechanical properties, which are advantageous for forming flexible magnetic conductive circuits and eddy current networks; the magnetic reconstituted tobacco of the present invention has the characteristics of low driving voltage, rapid heating and high heating temperature, which can meet the requirements of energy saving, rapid heating and instant use when using aerosol products. When the magnetic reconstituted tobacco leaves of the present invention are used in a magnetic aerosol-forming matrix, the magnetic material therein acts as a receptor, uniformly distributed throughout the aerosol-forming matrix and forming a magnetic conductive path. This is different from existing induction heating aerosol products in which the receptor is a separate component and transfers its induced heat to the entire aerosol-forming matrix through local contact (central type) or non-contact (circumferential type) with the aerosol-forming matrix. The disadvantage of central heating is that the induced heat of the receptor is transferred from the center of the aerosol-forming matrix in contact with it to its periphery, and the heat is significantly attenuated from the inside to the outside. The disadvantage of circumferential heating is that the induced heat of the receptor is transferred from the periphery of the aerosol-forming matrix wrapping material in contact with it to the center of the aerosol-forming matrix after penetrating the wrapping material, and the heat is significantly attenuated from the outside to the inside. The integral heating of the magnetic reconstituted tobacco leaves of the present invention is that the magnetic material in the entire aerosol-forming matrix receives the radiated alternating magnetic field, generating induced heat distributed throughout the aerosol-forming matrix. The disadvantages of existing central induction heating also include: the insertion and removal of the sensor on the heating device can easily cause the aerosol-forming matrix to move. Specifically, when inserted, the aerosol-forming matrix is pushed to the mouthpiece end of the aerosol product, which affects heat transfer, aerosol generation, and suction force; when removed, part of the aerosol-forming matrix is carried out into the heating device along with the sensor, and the atomized condensate remains on the surface of the sensor, causing problems with cleaning residues; the above-mentioned built-in sensor in the aerosol product brings difficulties to the processing, placement, and positioning of the sensor in the aerosol-forming matrix during the product manufacturing process. The sensor of the present invention is integrated and homogeneously formed with the magnetic reconstituted tobacco foil and magnetic reconstituted tobacco particles during the manufacturing process, without the need for additional sensor processing, aerosol-forming matrix placement and positioning equipment, and there is no problem of aerosol-forming matrix movement and cleaning residues during the use of the aerosol product.

[0065] The uniform laminated network distribution of the magnetic material in the magnetic reconstituted tobacco leaf of the present invention and the uniform spherical network distribution in the particles significantly shorten the magnetothermal conversion path. The magnetic material in the aerosol formation matrix basically instantaneously transfers its heat to the entire aerosol formation matrix, greatly improving the heat utilization efficiency of the aerosol formation matrix, which in turn will significantly reduce the energy consumption of the heating device. Moreover, since the aerosol formation matrix itself is the induction heating body of the aerosol product containing it, there is no need to set additional sensors inside the aerosol product (such as in the aerosol formation matrix) or on the heating device on the periphery, greatly reducing the volume of the heating device, reducing the manufacturing difficulty of the aerosol product, saving manufacturing costs and facilitating the portability of the heating device.

[0066] Existing induction heating aerosol products belong to the heat transfer method from local to overall. The sensor heat source needs a relatively high temperature to ensure that there is enough heat transferred to the entire aerosol formation matrix. At the same time, to meet the atomization requirements of the aerosol formation matrix and thus the inhalable requirements of the aerosol generated by atomization, the heat in the aerosol formation matrix needs to accumulate to a sufficient amount, which brings two technical bottlenecks: one is that the initial temperature of the sensor needs to be high enough, and the other is that the preheating time of the aerosol product needs to be long enough. This not only increases the energy consumption of the heating device but also makes it impossible for consumers to use the product quickly. The magnetic reconstituted tobacco leaf of the present invention for the magnetic aerosol formation matrix does not apply a whole block magnetic material on the surface or inside of the aerosol formation matrix, but by adjusting the area fraction of a small amount of magnetic nanomaterials in it, and through hot extrusion, hot lamination and nano-welding, spreading the magnetic nanomaterials in the reconstituted tobacco leaf foil, or through hot extrusion and rotational extrusion mixing in the rotational granulation process to mix the magnetic nanomaterials in the reconstituted tobacco particles, which not only greatly increases the magnetic induction surface area but also increases the interconnectivity of the magnetic nanomaterials; due to the relatively thin thickness (0.10 - 0.30 mm) of the magnetic reconstituted tobacco leaf foil and the relatively small particle size (0.5 - 2 mm) of the magnetic reconstituted tobacco leaf particles, the skin depth of the magnetic field inside the magnetic nanomaterials is significantly reduced, not only making the magnetic flux attenuation smaller but also greatly reducing the resistance of the magnetic network; therefore, under the influence of increased electrical conductivity and reduced thermal resistance, the initial temperature set by the heating device can be controllably reduced, and it can be heated to the set working temperature in a very short time, significantly shortening the preheating waiting time of the heating device, and enabling the product to be used immediately; similarly, the aerosol product can be cooled from the working temperature to room temperature in a very short time, greatly reducing the problem of heat accumulation in the aerosol formation matrix and ensuring the consistency of the experience of the aerosol product in each use cycle. Due to the increased electrical conductivity and reduced thermal resistance, the magnetic reconstituted tobacco leaf of the present invention can select magnetic materials with an intrinsic Curie temperature close to the actual working temperature, without the need to select magnetic materials with a high Curie temperature exceeding the actual working temperature, which makes the temperature control of the heating device easier and more accurate.

[0067] The vacuum-assisted filtration method adopted in the present invention is a method of coating magnetic materials on the surface of nanofibers in the form of a suspension by means of vacuum filtration; the vacuum-assisted filtration technology greatly improves the deposition rate of nanomaterials, and the loss of nanomaterials during the preparation process is smaller, which is a very simple method for preparing multifunctional nanocomposites; the vacuum-assisted filtration technology is conducive to the formation of an entangled network of nanofibers through hydrogen bonds, so as to obtain a super-strong rigid nanostructure with high thermal stability and high transparency, further enhancing the high-temperature resistance and mechanical strength of the matrix for forming magnetic aerosol.

[0068] The advantages of using ferromagnetic nanowires in the present invention for the prepared magnetic reconstituted tobacco are further described as follows: 1. By controlling the dosage of magnetic nanowires or the driving voltage, it is easy to adjust the heating performance of the magnetic reconstituted tobacco: for example, when the driving voltage is constant, the magnetic reconstituted tobacco with a high content of ferromagnetic nanowires (such as Fe-Ni NWs) has an increased heating temperature due to the reduced resistance; due to the efficient embedding structure of Fe-Ni NWs and the interconnected electromagnetic Fe-Ni NWs skeleton, by moderately increasing the area fraction of Fe-Ni NWs, a high temperature can be obtained at a lower driving voltage. Typically, when the area fraction of Fe-Ni NWs is 0.5 g / m 2 , at a driving voltage of 3 V, the temperature can rise above 200 °C within 10 s; or when the area fraction of Fe-Ni NWs is 1.0 g / m 2 , at a driving voltage of 2 V, the temperature can rise above 250 °C within 7 s; the beneficial effect of obtaining a high temperature at a low driving voltage is to save electric energy and reduce energy consumption. 2. When an alternating magnetic field is applied to the prepared magnetic reconstituted tobacco, Joule heat is generated due to the inelastic collision between the induced accelerated eddy electrons and phonons in the magnetic nanowires, causing the matrix for forming aerosol to rapidly heat up. When the alternating magnetic field is stopped from being applied to the matrix for forming aerosol, the temperature of the magnetic reconstituted tobacco rapidly drops due to the absence of Joule heat; especially when the area of the magnetic reconstituted tobacco is greatly reduced (such as when the magnetic reconstituted tobacco foil is processed into short filaments, fine filaments or fragments), due to the significant increase in the eddy current density and power density, the heating and cooling rates will increase rapidly, and it is expected to rapidly heat up and cool down within 1 s or even in the millisecond order of magnitude; this is beneficial for the magnetic reconstituted tobacco used in the process of aerosol products, reducing the subsequent sensory changes caused by the accumulation of previous heat in the matrix for forming aerosol; at the same time, the use experience is improved due to the significant shortening of the preheating waiting time; another beneficial effect is that the electric energy consumed for heating the magnetic reconstituted tobacco used in aerosol products to the required temperature is reduced. 3. The composite lamination technology of tobacco materials, nanofibers and magnetic nanomaterials in the preparation method of the present invention has the flexibility of actual production and can precisely control the properties of the final product. 4. The magnetic reconstituted tobacco of the present invention has ideal tensile strength, fragrance retention ability, magnetic controllability and cost-effectiveness.

[0069] The preparation method of the magnetic reconstituted tobacco foil of the present invention can, according to the direction of the inductor-excited magnetic field passing through the aerosol-forming matrix and the distribution of magnetic flux lines, make the magnetic material orientation and distribution in the prepared magnetic tobacco sheet base cooperate with the direction of the inductor-excited magnetic field and the distribution of magnetic flux lines through oriented papermaking, so that the magnetic reconstituted tobacco foil and even the aerosol-forming matrix prepared from the magnetic tobacco sheet base can achieve the maximum magnetic field utilization efficiency and magnetic coupling strength when cooperating with the heating device; the magnetic multi-layer tobacco sheet base can design a tobacco sheet base with different numbers of magnetic material layers according to the subsequent process requirements and characteristics of the actual product, such as a sandwich-type tobacco sheet base, where the inner and outer layers are tobacco fibers and the middle core layer is magnetic nanofiber composite. Using semi-wet coating material, compared with the traditional papermaking method and thick pulp method for reconstituted tobacco manufacturing process, the water consumption is greatly reduced, the drying process is significantly reduced, and the production energy consumption is reduced; since the foil dries faster, the finished reconstituted tobacco foil has a stronger retention capacity for flavor substances and nicotine, can use less binder, and reduces the influence of unpleasant odors generated during the heating process of the aerosol product on the taste.

[0070] The preparation method of the magnetic reconstituted tobacco foil of the present invention includes a step of vacuum-assisted filtration to prepare a composite gel of nanofibers and magnetic nanowires, and the obtained magnetic coating material can be regarded as a magnetic gel. The magnetic gel combines the characteristics of magnetism, high elasticity and flexibility, improves the film-forming property of the coating material, is conducive to the uniform distribution of the magnetic material on the sheet base, and also improves the processing performance of the finished tobacco foil in processes such as winding and gathering.

[0071] Compared with the traditional dry-process reconstituted tobacco, the dry process of the preparation method of the magnetic reconstituted tobacco foil of the present invention obtains a fiber thin layer and then coats and performs multi-stage lamination. It not only retains the looseness of the reconstituted tobacco structure, but also the nanofibers, magnetic nanowires and polysaccharides contained in the magnetic coating solution strengthen the hydrogen bond interaction with the fiber thin layer, enhance the sheet base shaping effect and mechanical properties, and reduce the phenomena of powder dropping, breaking and fracture occurring in the downstream cutting or forming process. Specific embodiments

[0072] In order to make the purpose and technical solution of the present invention clearer, the following embodiments are described in detail. The embodiments are intended to illustrate the content of the present invention, rather than further limiting the protection scope of the present invention. The processes, conditions, reagents, experimental methods, etc., except for the specifically mentioned content below, are all common knowledge and well-known common sense in the art, and the present invention has no special restrictions. The experimental methods without specific conditions indicated in each embodiment usually follow conventional conditions or the conditions recommended by the manufacturer. Unless otherwise stated, the meanings of all professional terms and scientific terms used in this specification are the same as those generally understood by those skilled in the technical field to which the present invention belongs. But in case of conflict, this specification including the definitions shall prevail.

[0073] Example 1: Preparation of magnetic reconstituted tobacco foil, the steps are as follows:

[0074] (1) Screen tobacco debris and fibers, remove large powder lumps by oscillation; remove metal objects with a magnet;

[0075] (2) Dry the tobacco debris and fibers to a water content of 5-10 wt%, grind the solid with an impact mill to obtain a uniform powder with a particle size of 60-120 mesh;

[0076] (3) Mix solid natural binders such as guar gum, xanthan gum or CMC (carboxymethyl cellulose) and others with a belt blender;

[0077] (4) Vacuum-assisted filtration of nanofiber dispersion to obtain a wet viscoelastic nanofiber gel; further vacuum-assisted filtration of magnetic nanowire suspension to obtain a composite gel of nanofibers and magnetic nanowires;

[0078] (5) Use a wet mixer to mix the above composite gel with glycerol and water, and add a surfactant such as polyvinylpyrrolidone (PVP) to ensure the magnetism, humidity and mechanical strength required for reconstituted tobacco;

[0079] (6) Stir and mix the above solid and liquid components with a blender, and maintain the water content at 20-40 wt% to obtain a dough-like substance;

[0080] (7) Feed the above dough-like substance into an extruder, and extrude it into a preform by compression molding;

[0081] (8) Transfer the above preform to a rolling mill, and flatten it into a flat and uniform foil with a thickness of 0.10-0.30 mm under high pressure with a hot roller; the temperature of the hot roller can be set in the range of 70-200 °C; the extrusion pressure is 1-5 MPa;

[0082] (9) Further dry the above-prepared foil through a drying device to reduce the water content to 5-10 wt%.

[0083] (10) According to the final application requirements, wind the foil on a reel or slice or cut it into filaments for use as a matrix for magnetic aerosol formation.

[0084] Example 2: Preparation of magnetic reconstituted tobacco particles, the steps are as follows:

[0085] (1) Prepare a preform using steps 1-7 in Example 1;

[0086] (2) Transfer the above preform to a rotary granulator, and break the preform into irregular particles by rotary granulation;

[0087] (3) Further dry the above-prepared irregular particles through a drying device to reduce the water content to 1-6 wt%;

[0088] (4) Screen the dried irregular particles with a screening machine to obtain particles with a particle size in the range of 0.5 - 2 mm;

[0089] (5) According to the final application requirements, wrap or fill the particles in the components of the aerosol product for forming a magnetic aerosol matrix.

[0090] Example 3: Preparation of magnetic laminated reconstituted tobacco leaves, the steps are as follows:

[0091] (1) Screen the tobacco debris and fibers, remove large powder lumps by oscillation; remove metal objects with a magnet;

[0092] (2) Dry the tobacco debris and fibers to a water content of 5 - 10 wt%, grind the solid with an impact mill to obtain a uniform powder with a particle size of 60 - 120 mesh;

[0093] (3) Mix the solid natural binders guar gum, xanthan gum or CMC (carboxymethyl cellulose) with a belt blender;

[0094] (4) Vacuum-assisted filtration of the nanofiber dispersion to obtain a wet viscoelastic nanofiber gel; further vacuum-assisted filtration of the magnetic nanowire suspension to obtain a composite gel of nanofibers and magnetic nanowires;

[0095] (5) Use a wet mixer to mix the above composite gel with glycerol and propylene glycol, and add a surfactant such as polyvinylpyrrolidone (PVP); to ensure the magnetism, humidity and mechanical strength required for reconstituted tobacco leaves;

[0096] (6) Mix the above solid and liquid components with a high-speed turbine and maintain the water content at 20 - 50 wt% to obtain a semi-wet powder to maintain a low drying cost;

[0097] (7) Through three-stage lamination, pass the above semi-wet powder through several sets of high-pressure rollers with forming functions set at different heating temperatures to form a foil with a thickness of 0.10 - 0.30 mm; the first-stage lamination temperature is 70 - 100 °C, the second-stage lamination temperature is 120 - 150 °C, and the third-stage lamination temperature is 160 - 200 °C; the lamination pressure increases step by step, from 1 MPa in the first stage to 3 MPa in the second stage and then to 5 MPa in the third stage;

[0098] (8) Further dry the obtained foil through a drying device to reduce the water content to 5 - 10 wt%;

[0099] (9) According to the final application requirements, cut the foil into slices or shreds for use in the aerosol formation matrix.

[0100] Example 4: Preparation of magnetic laminated reconstituted tobacco leaf foil, the steps are as follows:

[0101] (1) preparing a roll-shaped sheet base using cellulose fiber and tobacco fiber in advance;

[0102] (2) Prepare a semi-wet powder using steps 1-6 of Example 1;

[0103] (3) laminating the semi-wet powder together with the base sheet through three stages, the specific operation being the same as (7) in Example 1; after lamination, the semi-wet powder is bonded to one side of the base sheet;

[0104] (4) drying the substrate with the semi-wet powder bound to one side, and then bonding the semi-wet powder to the other side of the substrate according to the above step (3);

[0105] (5) The foil with semi-wet powder on both sides is passed through a drying device to reduce the moisture content to 5-10 wt%;

[0106] (6) Depending on the final application requirements, the foil is cut into sheets or shreds for use in an aerosol-forming matrix.

[0107] Example 5: Preparation of magnetic reconstituted tobacco leaf foil, the steps are as follows:

[0108] (1) Screen tobacco debris and fibers, remove large powder blocks by shaking; use a magnet to remove metal objects;

[0109] (2) drying tobacco scraps and fibers to a moisture content of 5-10 wt% and grinding the solids with an impact mill to obtain a uniform powder with a particle size of 60-120 mesh;

[0110] (3) vacuum-assisted filtration of the nanofiber dispersion to obtain a wet viscoelastic nanofiber gel; further vacuum-assisted filtration of the magnetic nanowire suspension to obtain a nanofiber and magnetic nanowire composite gel;

[0111] (4) using a wet mixer to mix the composite gel, glycerol, and propylene glycol, and adding a surfactant, polyvinyl pyrrolidone (PVP), to ensure the required magnetic properties, humidity, and mechanical strength of the reconstituted tobacco leaves;

[0112] (5) mixing the solid and liquid components using a high-speed turbine and maintaining the water content at 20-50 wt % to obtain a semi-wet powder to maintain a low drying cost;

[0113] (6) Immersing the laminating roller in an adhesive mixture bath formed by solid natural adhesives such as guar gum, xanthan gum, and CMC (carboxymethyl cellulose) to adhere an adhesive layer to the roller surface;

[0114] (7) Through three - stage lamination, the above - mentioned semi - wet powder is passed through several sets of high - pressure rollers with a forming function coated with an adhesive layer and set at different heating temperatures to form a foil with a thickness of 0.10 - 0.30 mm; the temperature of the first - stage lamination is 70 - 100 °C, the temperature of the second - stage lamination is 120 - 150 °C, and the temperature of the third - stage lamination is 160 - 200 °C; the lamination pressure can be maintained constant at multiple levels, such as 5 MPa;

[0115] (8) The foil obtained above is further dried by a drying device to reduce the water content to 5 - 10 wt%.

[0116] (9) According to the final application requirements, the foil is cut into slices or shredded for use in the aerosol - forming matrix.

[0117] Example 6: Preparation of magnetic reconstituted tobacco foil, the steps are as follows:

[0118] (1) Mix a certain proportion of tobacco leaves and tobacco stems and beat them into a pulp, remix the mixed pulp with wood pulp, add water to adjust the concentration to 1 - 5 wt%, and further beat to obtain tobacco pulp.

[0119] (2) After defibrating the tobacco pulp with a defibrator, add water to adjust the concentration to 0.2 - 2 wt%, transfer it to a stirring device and stir; mix and stir the nanofiber dispersion and the magnetic nanowire suspension, add an adhesive solution and a surfactant for mixing, and continue stirring to obtain a magnetic nanocomposite fiber pulp; the adhesive solution contains a mixed natural binder such as guar gum, xanthan gum or CMC (carboxymethyl cellulose) and other solutions.

[0120] (3) Mix and stir the above - mentioned tobacco pulp and magnetic nanocomposite fiber pulp to obtain a magnetic pulp, in which the mass percentage of the magnetic nanocomposite fiber is 1 - 5 wt%, and use a sheet - making machine to perform oriented alignment and papermaking to obtain a magnetic tobacco sheet base; or, use a sheet - making machine to make a magnetic multi - layer tobacco sheet base with a magnetic nanocomposite fiber as the core layer.

[0121] (4) Prepare wet coating materials and semi - wet coating materials; the steps are as follows: (a) Crush the tobacco material and fiber material to obtain a uniform powder with a particle size of 60 - 120 mesh; then add a solid natural binder and mix evenly; (b) Add glycerol, propylene glycol and water for mixing, and maintain the water content at 50 - 80 wt% to obtain a wet coating material; or, maintain the water content at 20 - 50 wt% to obtain a semi - wet coating material.

[0122] (51) Perform three - stage lamination on the magnetic tobacco sheet base obtained in step (3) at a certain temperature to obtain a magnetic reconstituted tobacco leaf base with a thickness of 0.10 - 0.30 mm.

[0123] (61) Coating the magnetic reconstituted tobacco leaf base in step (51) with the wet coating material in step (4), and drying to a water content of 5-10 wt% to obtain a magnetic reconstituted tobacco leaf foil;

[0124] Or,

[0125] (52) Coating the semi-wet coating material in step (4) on the tobacco leaf base in step (3);

[0126] (62) Subjecting the tobacco leaf base coated in step (52) to three-stage lamination to obtain a magnetic reconstituted tobacco leaf with a thickness of 0.10-0.30 mm, and drying to a water content of 5-10 wt% to obtain a magnetic reconstituted tobacco leaf foil;

[0127] According to the final application requirements, the obtained magnetic reconstituted tobacco leaf foil is wound into a roll, cut into pieces or shredded for use in an aerosol-forming substrate.

[0128] Among them, the three-stage lamination in steps (51) and (62) uses a high-pressure roll with a forming function set at different heating temperatures, where the temperature of the first-stage lamination is 70-100 °C, the temperature of the second-stage lamination is 120-150 °C, and the temperature of the third-stage lamination is 160-200 °C. The lamination pressure is maintained constant at multiple levels, such as 5 MPa; the pressure can also be increased step by step, such as increasing from 1 MPa in the first stage to 3 MPa in the second stage and then to 5 MPa in the third stage.

[0129] Example 7: Preparation of a magnetic reconstituted tobacco leaf foil, the steps are as follows:

[0130] (1) After adding an adhesive solution to the tobacco slurry prepared according to step (1) in Example 1, a tobacco leaf base is made by using a standard sheet-making machine; wherein the adhesive solution contains a mixed natural binder such as guar gum, xanthan gum or CMC (carboxymethyl cellulose) and other solutions;

[0131] (2) Preparation of a magnetic coating material: Vacuum-assisted filtration of a nanofiber dispersion to obtain a wet viscoelastic nanofiber gel; further vacuum-assisted filtration of a magnetic nanowire suspension to obtain a composite gel of nanofibers and magnetic nanowires;

[0132] Adding the composite gel of the mixed nanofiber dispersion and magnetic nanowire suspension to a mixed slurry containing but not limited to tobacco mixture powder, tobacco extract, glycerol, propylene glycol, water, adding an adhesive solution and a surfactant and mixing evenly to obtain a magnetic coating material, maintaining the solid content at 50-80%; the adhesive solution contains a mixed natural binder such as guar gum, xanthan gum or CMC (carboxymethyl cellulose) and other solutions; the surfactant is polyvinylpyrrolidone (PVP);

[0133] (3) Coating the above magnetic coating material on the tobacco leaf base and drying to obtain a magnetic tobacco leaf;

[0134] (4) Perform three - stage lamination as in Example 1 to obtain a magnetic reconstituted tobacco leaf base with a thickness of 0.10 - 0.30 mm.

[0135] (5) Further dry the foil obtained above through a drying device to reduce the water content to 5 - 10%, obtaining a magnetic reconstituted tobacco leaf foil; according to the final application requirements, roll the foil into a roll, cut it into slices or shred it.

[0136] Example 8: Preparation of magnetic reconstituted tobacco leaf foil, the steps are as follows:

[0137] (1) Screen one or several of wood pulp fibers, hemp pulp fibers, and tobacco fibers, crush and defibrate them to obtain defibrated fibers; form a fiber thin layer by dry - process air forming of the defibrated fibers.

[0138] (3) Add the nanofiber dispersion liquid and the magnetic nanowire suspension liquid into a stirring device, add the binder solution, and stir to obtain a magnetic pulp; the binder solution contains a mixed natural binder such as guar gum, xanthan gum or CMC (carboxymethyl cellulose) and other solutions and a surfactant such as polyvinylpyrrolidone (PVP); then add plant polysaccharides and mix to form a magnetic coating liquid; the plant polysaccharides include but are not limited to starch, cellulose, polysaccharide, pectin, etc.

[0139] (4) Prepare wet coated fabric and semi - wet coated fabric as in Example 1.

[0140] (51) Perform three - stage lamination on the magnetic tobacco leaf base obtained in step (3) at a certain temperature as in Example 1 to obtain a magnetic reconstituted tobacco leaf base with a thickness of 0.10 - 0.30 mm.

[0141] (61) Coat the wet coated fabric in step (4) on the magnetic reconstituted tobacco leaf base in step (51), and dry to make the water content 5 - 10 wt%, obtaining a magnetic reconstituted tobacco leaf foil.

[0142] Or,

[0143] (52) Coat the semi - wet coated fabric in step (4) on the tobacco leaf base in step (3).

[0144] (62) Perform three - stage lamination on the tobacco leaf base coated in step (52), and dry to make the water content 5 - 10 wt%, obtaining a magnetic reconstituted tobacco leaf foil; according to the final application requirements, roll the foil into a roll, cut it into slices or shred it.

[0145] The embodiments are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing magnetic reconstituted tobacco leaves, characterized in that, The magnetic reconstituted tobacco includes magnetic reconstituted tobacco foil and / or magnetic reconstituted tobacco particles; the thickness of the magnetic reconstituted tobacco foil is 0.10 - 0.30 mm, and the particle size of the magnetic reconstituted tobacco particles is 0.5 - 2 mm; the composition of the magnetic reconstituted tobacco includes fiber material, tobacco material, nanofibers and magnetic material; the magnetic material is a material that can be converted into heat after absorbing an alternating magnetic field; the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is a magnetic nanowire; the length of the magnetic nanowire is 5 - 100 μm, and the diameter is 5 - 500 nm; the nanofibers are plant nanofibers and / or tobacco nanofibers; the length of the nanofibers is 1 - 10 μm, and the diameter is 5 - 500 nm; the fiber material is cellulose fiber and / or tobacco fiber material; The preparation method comprises the following steps: (1) Making the tobacco material and the fiber material into powders with a particle size of 60 - 120 mesh, adding a binder and mixing to obtain a solid mixture; the binder is prepared from one or more of starch, gum arabic, xanthan gum, guar gum, CMC and nanofiber gel; (2) Using the method of vacuum-assisted filtration of nanofiber dispersion and magnetic nanowire suspension to obtain a composite gel of nanofibers and magnetic nanowires; adding glycerol, water and the surfactant polyvinylpyrrolidone and mixing evenly to obtain a liquid mixture; (3) Stirring and mixing the solid mixture in step (1) and the liquid mixture in step (2) to obtain a dough-like substance with a water content of 20 - 40 wt%; (4) Compression-molding the dough-like substance obtained in step (3) using an extruder to obtain a preform; (5) Subjecting the preform obtained in step (4) to multi-stage lamination at a certain temperature to obtain a foil with a thickness of 0.10 - 0.30 mm, and then drying to reduce the water content to 5 - 10 wt%, thus obtaining the reconstituted tobacco foil; Or, (6) Crushing the preform obtained in step (4) into irregular particles using a rotary granulator, drying to reduce the water content to 1 - 6 wt%; screening to obtain particles with a particle size of 0.5 - 2 mm, thus obtaining the reconstituted tobacco particles.

2. A preparation method of magnetic reconstituted tobacco leaves, characterized in that, The magnetic reconstituted tobacco includes magnetic reconstituted tobacco foil; the thickness of the magnetic reconstituted tobacco foil is 0.10 - 0.30 mm; the composition of the magnetic reconstituted tobacco includes fiber material, tobacco material, nanofibers and magnetic material; the magnetic material is a material that can be converted into heat after absorbing an alternating magnetic field; the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is a magnetic nanowire; the length of the magnetic nanowire is 5 - 100 μm, and the diameter is 5 - 500 nm; the nanofibers are plant nanofibers and / or tobacco nanofibers; the length of the nanofibers is 1 - 10 μm, and the diameter is 5 - 500 nm; the fiber material is cellulose fiber and / or tobacco fiber material; The preparation method comprises the following steps: (A)Prepare a semi-wet mixture formed by tobacco materials, nanofibers and magnetic nanomaterials; the method is as follows: Add surfactant polyvinylpyrrolidone, glycerol and propylene glycol, and use the method of continuously vacuum-assisted filtering the nanofiber dispersion and the magnetic nanomaterial suspension to prepare a composite gel of nanofibers and magnetic nanomaterials, which is the semi-wet mixture; (B)Insert the semi-wet mixture in step (A) into a laminating roller and perform multi-stage lamination at a certain temperature to obtain a sheet with a thickness of 0.10 - 0.30 mm; Apply a binder layer to the surface of the laminating roller before inserting the sheet base into the laminating roller; Or, (C)Prepare a cellulose fiber and / or tobacco fiber sheet base; (D)Apply the semi-wet mixture in step (A) to the sheet base in step (C), and then insert the obtained sheet base into a laminating roller and perform multi-stage lamination at a certain temperature to obtain a sheet with a thickness of 0.10 - 0.30 mm; Apply a binder layer to the surface of the laminating roller before inserting the sheet base into the laminating roller; The binder used for the binder layer is made of one or several of starch, gum arabic, xanthan gum, guar gum, CMC and nanofiber gel; (E)Dry the sheet obtained in step (B) or step (D) to reduce the water content to 5 - 10 wt%, and thus obtain the magnetic laminated reconstituted tobacco foil.

3. A preparation method of magnetic reconstituted tobacco, characterized in that, The magnetic reconstituted tobacco includes a magnetic reconstituted tobacco foil; the thickness of the magnetic reconstituted tobacco foil is 0.10 - 0.30 mm; the composition of the magnetic reconstituted tobacco includes fiber materials, tobacco materials, nanofibers and magnetic materials; the magnetic material is a material that can be converted into heat after absorbing an alternating magnetic field; the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is a magnetic nanowire; the length of the magnetic nanowire is 5 - 100 μm, and the diameter is 5 - 500 nm; the nanofiber is a plant nanofiber and / or a tobacco nanofiber; the length of the nanofiber is 1 - 10 μm, and the diameter is 5 - 500 nm; the fiber material is a cellulose fiber and / or a tobacco fiber material; The preparation method includes the following steps: (a)Beat the tobacco materials and fiber materials, and then defibrate to obtain tobacco pulp; (b)Mix the nanofiber dispersion and the magnetic nanowire suspension, and then add a binder solution and surfactant polyvinylpyrrolidone and mix to obtain a magnetic nanocomposite fiber pulp; (c)Mix the tobacco pulp in step (a) and the magnetic nanocomposite fiber pulp in step (b) to obtain a magnetic pulp, wherein the mass percentage of the magnetic nanocomposite fiber is 1% - 5 wt%; Use a sheet-making machine to perform oriented alignment and sheet-making to obtain a magnetic tobacco sheet base; Or, use a sheet-making machine to make a magnetic tobacco sheet base with a magnetic nanocomposite fiber as the core layer; (d)Preparing wet coating material and semi-wet coating material; the steps are as follows: crushing tobacco material and fiber material to obtain a uniform powder with a particle size of 60-120 mesh; then adding a solid natural binder and mixing evenly; adding glycerol, propylene glycol and water and mixing to maintain the water content at 50-80 wt% to obtain wet coating material; dehydrating to make the water content at 20-50 wt% to obtain semi-wet coating material; the binder is made of one or several of starch, gum arabic, xanthan gum, guar gum, CMC and nanofiber gel; (e1)Performing multi-stage lamination on the magnetic tobacco sheet base obtained in step (c) at a certain temperature to obtain a magnetic reconstituted tobacco leaf base with a thickness of 0.10-0.30 mm; (f1)Coating the wet coating material in step (4) on the magnetic reconstituted tobacco leaf base obtained in step (e1) and drying to make the water content 5-10 wt%, thus obtaining the magnetic reconstituted tobacco leaf foil; Or, (e2)Coating the semi-wet coating material in step (d) on the tobacco sheet base in step (c); (f2)Performing multi-stage lamination on the tobacco sheet base coated in step (e2) and drying to make the water content 5-10 wt%, thus obtaining the magnetic reconstituted tobacco leaf foil.

4. A preparation method of magnetic reconstituted tobacco leaves, characterized in that, The magnetic reconstituted tobacco leaf includes the magnetic reconstituted tobacco leaf foil; the thickness of the magnetic reconstituted tobacco leaf foil is 0.10-0.30 mm; the composition of the magnetic reconstituted tobacco leaf includes fiber material, tobacco material, nanofiber and magnetic material; the magnetic material is a material that can be converted into heat after absorbing an alternating magnetic field; the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is a magnetic nanowire; the length of the magnetic nanowire is 5-100 μm and the diameter is 5-500 nm; the nanofiber is plant nanofiber and / or tobacco nanofiber; the length of the nanofiber is 1-10 μm and the diameter is 5-500 nm; the fiber material is cellulose fiber and / or tobacco fiber material; The preparation method includes the following steps: 1) Pulping tobacco material and fiber material, and then defibrating to obtain tobacco pulp; 2) Adding a binder solution and a surfactant polyvinylpyrrolidone to the tobacco pulp in step 1) and mixing to obtain a composite fiber pulp tobacco pulp; using a sheet former to make a tobacco sheet base; 3) Preparing magnetic coating material, the steps are: vacuum-assisted filtering of nanofiber dispersion liquid and magnetic nanowire suspension liquid to obtain a nanofiber and magnetic nanowire composite gel; adding the obtained composite gel to a mixed slurry of tobacco mixture powder, tobacco extract, glycerol, propylene glycol and water, and then adding a binder solution, mixing evenly to obtain magnetic coating material, and maintaining the solid content at 50-80 wt%; 4) Coating the magnetic coating material in step 3) on the tobacco sheet base in step 2) and drying to obtain a magnetic tobacco sheet; 5) Performing multi-stage lamination on the magnetic tobacco sheet obtained in step 4) at a certain temperature to obtain a magnetic reconstituted tobacco leaf base with a thickness of 0.10-0.30 mm; 6) Drying the obtained magnetic reconstituted tobacco leaf base to make the water content 5-10 wt% to obtain a magnetic reconstituted tobacco leaf foil.

5. A preparation method of magnetic reconstituted tobacco leaves, characterized in that, The magnetic reconstituted tobacco leaf includes a magnetic reconstituted tobacco leaf foil; the thickness of the magnetic reconstituted tobacco leaf foil is 0.10 - 0.30 mm; the composition of the magnetic reconstituted tobacco leaf includes a fiber material, a tobacco material, nanofibers, and a magnetic material; the magnetic material is a material that can be converted into heat after absorbing an alternating magnetic field; the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is a magnetic nanowire; the length of the magnetic nanowire is 5 - 100 μm, and the diameter is 5 - 500 nm; the nanofibers are plant nanofibers and / or tobacco nanofibers; the length of the nanofibers is 1 - 10 μm, and the diameter is 5 - 500 nm; the fiber material is cellulose fiber and / or tobacco fiber material; The preparation method includes the following steps: (Ⅰ) Crush and defibrate the tobacco material and the fiber material, and dry air form the defibrated fibers to obtain a fiber thin layer; (Ⅱ) Mix the nanofiber dispersion liquid and the magnetic nanowire suspension liquid, add an adhesive solution and the surfactant polyvinylpyrrolidone and mix to obtain a magnetic nanofiber composite pulp; then add plant polysaccharide and mix to form a magnetic coating liquid; (Ⅲ) Spray the magnetic coating liquid in step (Ⅱ) on the fiber thin layer in step (Ⅰ) and then shape it into a magnetic tobacco sheet base; (Ⅳ) Prepare a wet coating material and a semi-wet coating material; the steps are as follows: crush the tobacco material and the fiber material to obtain a uniform powder with a particle size of 60 - 120 mesh; then add a solid natural binder and mix evenly; add glycerol, propylene glycol, and water and mix to maintain the water content at 50 - 80 wt% to obtain a wet coating material; dehydrate to make the water content at 20 - 50 wt% to obtain a semi-wet coating material; the binder is made of one or more of starch, arabic gum, xanthan gum, guar gum, CMC, and nanofiber gel; (LI) Perform multi-stage lamination on the magnetic tobacco sheet base obtained in step (Ⅱ) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness of 0.10 - 0.30 mm; (LXI) Coat the wet coating material in step (Ⅳ) on the magnetic reconstituted tobacco leaf sheet base in step (LI) and dry to make the water content 5 - 10 wt% to obtain a magnetic reconstituted tobacco leaf foil; Or, (LⅡ) Coat the semi-wet coating material in step (Ⅳ) on the tobacco sheet base in step (Ⅲ); (LXⅡ) Perform multi-stage lamination on the tobacco sheet base coated in step (LⅡ) at a certain temperature and dry to make the water content 5 - 10 wt% to obtain a magnetic reconstituted tobacco leaf foil.

6. According to the preparation method described in any one of claims 1-5, it is characterized in that The pressure of the multi-stage lamination is 1 - 5 MPa, and the temperature is 70 - 200 °C.

7. Use of the magnetic reconstituted tobacco leaf prepared by the preparation method according to any one of claims 1 - 5 as a matrix for forming a magnetic aerosol.