Magnetic reconstituted tobacco leaf foil, preparation method and use thereof

Abstract

The present invention discloses a magnetic reconstituted tobacco foil comprising 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 reconstituted tobacco foil has a thickness of 0.10-0.30 mm. The present invention also discloses a preparation method and use of the magnetic reconstituted tobacco foil.

Description

Technical Field

[0001] The invention belongs to the field of tobacco, and in particular relates to a magnetic reconstituted tobacco leaf foil, a preparation method and application thereof. Background Art

[0002] Existing heat-not-burn aerosol products typically use reconstituted tobacco leaves as the aerosol-forming matrix. The thick slurry method and papermaking method are the primary methods for producing reconstituted tobacco leaves used in heat-not-burn aerosol products. The thick slurry method requires drying to remove a large amount of water, resulting in high energy consumption. The finished product is brittle and weak, and high reconstitution losses occur during cutting. The papermaking method results in significant loss of flavor compounds in the finished product, and drying to remove water also requires significant energy consumption and is complex.

[0003] Existing aerosol products often use induction heating to atomize the desired components in the aerosol-forming matrix from the product to form an inhalable aerosol. In existing induction-heating aerosol products, the susceptor is a separate component and transfers its induction 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 induction heat of the susceptor 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 induction heat of the susceptor 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. Therefore, in order to achieve the desired atomization effect of the aerosol-forming matrix, it is necessary to extend the product preheating time and increase the maximum heating temperature, thereby increasing the output power of the inductor. The adverse effects of this not only cause low heat utilization efficiency and uneven heat distribution of the aerosol-forming matrix, but also increase the energy consumption of the heating device used to heat the aerosol product.

[0004] The present invention is proposed for this purpose. Summary of the Invention

[0005] To improve the above-mentioned defects, the present invention proposes a magnetic reconstituted tobacco leaf foil and a manufacturing method thereof, aiming to improve the utilization efficiency and heating rate of induction heat and reduce the energy consumption of the heating device when using aerosol products made from the magnetic reconstituted tobacco leaf foil.

[0006] The technical solutions of the present invention are as follows:

[0007] A magnetic reconstituted tobacco foil comprises 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 thickness of the magnetic reconstituted tobacco foil is 0.10-0.30 mm.

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

[0009] Preferably, the nanofibers are wood nanofibers and / or tobacco nanofibers; the nanofibers have a length of 1-10 μm and a diameter of 5-500 nm; and the fiber material is wood fiber and / or tobacco fiber.

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

[0011] (1) beating tobacco material and fiber material, and then defibration to obtain tobacco pulp;

[0012] (2) mixing the nanofiber dispersion and the magnetic nanowire suspension, and then adding a binder solution and a surfactant to obtain a magnetic nanocomposite fiber slurry;

[0013] (3) mixing the tobacco pulp of step (1) and the magnetic nanocomposite fiber pulp of step (2) to obtain a magnetic pulp, wherein the mass percentage of the magnetic nanocomposite fibers is 1% to 5wt%; using a sheet machine to carry out oriented arrangement and papermaking to obtain a magnetic tobacco sheet base; or using a sheet machine to papermaking to obtain a magnetic multilayer tobacco sheet base having a core layer of magnetic nanocomposite fibers;

[0014] (4) preparing wet coating materials and semi-wet coating materials;

[0015] (51) performing multi-stage lamination on the magnetic tobacco sheet obtained in step (3) at a certain temperature to obtain a magnetic reconstituted tobacco sheet with a thickness of 0.10-0.30 mm;

[0016] (61) coating the wet coating material of step (4) on the magnetic reconstituted tobacco leaf base of step (51), and drying the coated material to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil;

[0017] or,

[0018] (52) applying the semi-wet coating material of step (4) onto the tobacco sheet base of step (3);

[0019] (62) The tobacco sheet base coated in step (52) is subjected to multi-stage lamination and dried to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil.

[0020] The second aspect of the present invention discloses another method for preparing the magnetic reconstituted tobacco leaf foil, comprising the following steps:

[0021] (1) beating tobacco material and fiber material, and then defibration to obtain tobacco pulp;

[0022] (2) adding a binder solution and a surfactant to the tobacco pulp of step (1) and mixing to obtain a composite fiber pulp tobacco pulp; sheeting the tobacco pulp using a sheeting machine to obtain a tobacco sheet base;

[0023] (3) preparing a magnetic coating material, comprising the following steps: vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanowire suspension to obtain a nanofiber and magnetic nanowire composite gel; adding the obtained composite gel to a mixed slurry of tobacco mixture powder, tobacco extract, glycerin, propylene glycol, and water; and then adding a binder solution, mixing the mixture to obtain a magnetic coating material, maintaining a solid content of 50-80 wt %.

[0024] (4) coating the magnetic coating material from step (3) on the tobacco sheet base from step (2), and drying to obtain a magnetic tobacco sheet;

[0025] (5) performing multi-stage lamination on the magnetic tobacco sheet obtained in step (4) at a certain temperature to obtain a magnetic reconstituted tobacco sheet with a thickness of 0.10-0.30 mm;

[0026] (6) Drying the obtained magnetic reconstituted tobacco leaf base to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil.

[0027] The second aspect of the present invention discloses a third method for preparing the magnetic reconstituted tobacco foil, comprising the following steps:

[0028] (1) crushing the fiber material to defiberize, and dry air forming the defiberized fibers to obtain a fiber thin layer;

[0029] (2) mixing the nanofiber dispersion and the magnetic nanowire suspension, adding a binder solution and a surfactant to obtain a magnetic nanocomposite fiber slurry; and then adding plant polysaccharides to form a magnetic coating liquid;

[0030] (3) spraying the magnetic coating liquid of step (2) onto the fiber thin layer of step (1) and shaping it into a magnetic tobacco sheet;

[0031] (4) preparing wet coating materials and semi-wet coating materials;

[0032] (51) performing multi-stage lamination on the magnetic tobacco sheet obtained in step (3) at a certain temperature to obtain a magnetic reconstituted tobacco sheet with a thickness of 0.10-0.30 mm;

[0033] (61) coating the wet coating material of step (4) on the magnetic reconstituted tobacco leaf base of step (51), and drying the coated material to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil;

[0034] or,

[0035] (52) applying the semi-wet coating material of step (4) onto the tobacco sheet base of step (3);

[0036] (62) The tobacco sheet base coated in step (52) is subjected to multi-stage lamination and dried to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil.

[0037] Preferably, the steps of preparing the wet coating material and the semi-wet coating material are as follows:

[0038] (a) 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 uniformly;

[0039] (b) adding glycerol, propylene glycol and water and mixing them to maintain the water content at 50-80 wt % to obtain a wet coating material; or, maintaining the water content at 20-50 wt % to obtain a semi-wet coating material.

[0040] Preferably, the multi-stage lamination pressure is 1-5 MPa and the temperature is 70-200°C.

[0041] Preferably, the surfactant is polyvinyl pyrrolidone; the binder is one or more of starch, gum arabic, xanthan gum, guar gum, CMC and / or nanofiber gel; the tobacco material includes tobacco powder, debris, tobacco stems; and the plant polysaccharide is one or more of starch, cellulose, polysaccharide or pectin.

[0042] The third aspect of the present invention discloses the use of the magnetic reconstituted tobacco leaf foil as an aerosol-forming matrix.

[0043] The magnetic reconstituted tobacco foil of the present invention is composed of reconstituted tobacco loaded with magnetic material; contains tobacco mixture, nanofiber and magnetic material; the nanofiber can be wood nanofiber and / or tobacco nanofiber; the nanofiber can be other plant nanofiber; preferably, the diameter and length of the nanofiber are 5-100nm and 1-10μm respectively.

[0044] The magnetic material of the present invention is any material that can be converted into heat after absorbing an alternating magnetic field, such as a ferromagnetic material or a ferrimagnetic material. Preferably, the magnetic material is iron or an iron alloy, such as stainless steel, nickel, or a nickel alloy, such as a corrosion-resistant Fe-Ni-Cr alloy. Preferably, the magnetic material is a magnetic nanomaterial, such as nanoparticles, nanosheets, nanospheres, nanorods, nanotubes, and nanowires, particularly nanoparticles and / or nanowires. Such nanoparticles and / or nanowires include, but are not limited to, nickel, cobalt, iron-nickel, cobalt-nickel, cobalt-iron, iron-cobalt-nickel, iron-molybdenum-nickel, and their alloys. The magnetic material is preferably a magnetic nanowire, which has a length of 5-100 μm and an average diameter of 5-500 nm.

[0045] The method for manufacturing magnetic reconstituted tobacco foil includes: adding a surfactant such as polyvinyl pyrrolidone (PVP) to the mixture of tobacco, nanofibers and magnetic nanomaterials to facilitate the combination of magnetic nanomaterials and nanofibers; using continuous vacuum-assisted filtration of nanofiber dispersion and magnetic nanomaterial suspension to obtain a composite gel of nanofibers and magnetic nanomaterials; applying temperature to the roller so that the magnetic nanomaterials form interconnected magnetic conductive paths through thermal lamination or further nano-welding and form a tighter combination with the reconstituted tobacco as a whole; the thickness of the foil can be controlled by adjusting the rolling roller distance; the tobacco mixture includes tobacco powder, debris, tobacco stems, etc.

[0046] Magnetic reconstituted tobacco leaf foil is used as an aerosol-forming matrix. It can be rolled, sliced, or shredded, and subsequently processed into an aerosol-forming matrix. The aerosol-forming matrix contains a material that can be atomized to form an inhalable aerosol at a suitable temperature. The aerosol formed by atomizing the aerosol-forming matrix contains an aerosolizing agent, flavoring substances, and / or nicotine, and may also contain other inhalable ingredients. The aerosol-forming matrix is combined with the wrapping material to form the aerosol-generating section, which is then combined with other components including the support section, cooling section, and filter section to form the aerosol product.

[0047] Beneficial effects of the present invention:

[0048] The magnetic reconstituted tobacco foil of the present invention utilizes nanofibers. The flexible nanofibers are entangled with each other, creating a nanoscale network. This increases the strength of the fiber network by increasing the number of hydrogen bonds between each fiber or between fibers. Furthermore, the small size, high surface area, and flexibility of the nanofibers naturally increase the strength of the network, resulting in the nanofibers successfully improving the tensile strength of reconstituted tobacco. The highly reactive hydroxyl groups in the nanofibers can be modified through chemical and physical treatments to obtain desired properties, such as increasing their adhesion to magnetic materials.

[0049] The magnetic reconstituted tobacco foil produced by the present invention has excellent mechanical properties, thermal stability, flexibility, and porosity. The ferromagnetic nanowires have a high aspect ratio and excellent mechanical properties, making them advantageous for forming flexible magnetic conductive circuits and eddy current networks. The magnetic reconstituted tobacco foil produced by the present invention features low driving voltage, rapid heating, and high heating temperatures, meeting the energy-saving, fast-heating, and ready-to-use requirements of aerosol products. When the magnetic reconstituted tobacco leaf foil is made into an aerosol-forming matrix, the magnetic material therein acts as a receptor, which is evenly distributed throughout the aerosol-forming matrix and forms a magnetic conductive path. This is different from the 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 leaf foil of the present invention is that the magnetic material in the entire magnetic reconstituted tobacco leaf foil receives the radiated alternating magnetic field, forming induced heat distributed throughout the entire magnetic reconstituted tobacco leaf foil. 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, resulting in heat transfer, aerosol generation and suction force being affected; when pulled out, part of the aerosol-forming matrix is brought 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 built-in sensor in the aerosol product brings difficulties to the processing of the sensor, and the process of inserting and positioning the sensor in the aerosol-forming matrix during the product manufacturing process. The magnetic reconstituted tobacco foil sensor of the present invention is integrated and homogeneously formed with the reconstituted tobacco during the manufacturing process, and does not require additional sensor processing, aerosol-forming matrix insertion and positioning equipment. There is no problem of aerosol-forming matrix movement and cleaning residues during the use of the aerosol product. The uniform laminated network distribution of magnetic materials in the reconstituted tobacco leaves greatly shortens the magnetothermal conversion path. The magnetic materials in the magnetic reconstituted tobacco leaf foil basically transfer their heat to the aerosol-forming matrix as a whole instantaneously, and the aerosol-forming matrix greatly improves the efficiency of heat utilization, which in turn greatly reduces the energy consumption of the heating device. At the same time, since the magnetic reconstituted tobacco leaf foil itself is an induction heating body containing an aerosol product, there is no need to set additional sensors inside the magnetic reconstituted tobacco leaf foil (such as inside the aerosol-forming matrix) or on the peripheral heating device, which greatly reduces the volume of the heating device and reduces the difficulty of manufacturing aerosol products, which not only saves manufacturing costs but also facilitates the portability of the heating device.

[0050] Existing induction-heated aerosol products utilize a localized-to-global heat transfer method. This requires a relatively high temperature for the susceptor heat source to ensure sufficient heat transfer to the entire aerosol-forming matrix. Furthermore, sufficient heat accumulation within the aerosol-forming matrix is required to achieve atomization and, therefore, inhalability of the aerosol produced. This creates two technical bottlenecks: a sufficiently high initial susceptor temperature and a sufficiently long preheating time for the aerosol product. This increases the energy consumption of the heating device and hinders consumer use. The magnetic reconstituted tobacco foil of the present invention does not apply a monolithic magnetic material to the surface or interior of the aerosol-forming matrix. Instead, it adjusts the area fraction of a small amount of magnetic nanomaterial in the reconstituted tobacco leaf and spreads the magnetic nanomaterial in the reconstituted tobacco leaf through heat lamination or heat welding, thereby significantly increasing the magnetic induction surface area and increasing the interconnectivity of the magnetic nanomaterial. Due to the thin thickness of the magnetic reconstituted tobacco foil, the skin depth of the magnetic field inside the magnetic nanomaterial is significantly reduced, which not only reduces the magnetic flux attenuation but also greatly reduces the resistance of the magnetic network. Therefore, under the influence of increased conductivity and reduced thermal resistance, the initial temperature set by the heating device can be controllably lowered and heated to the set operating temperature in a very short time, significantly shortening the preheating waiting time of the heating device and enabling the product to be started and used immediately. Similarly, the magnetic reconstituted tobacco foil can be cooled from the operating temperature to room temperature in a very short time, significantly reducing the heat collection problem in the magnetic reconstituted tobacco foil 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 foil of the present invention can select a magnetic material whose intrinsic Curie temperature is close to the actual working temperature, without the need to select a magnetic material with a high Curie temperature exceeding the actual working temperature, which makes the temperature control of the heating device easier and more accurate.

[0051] The preparation method of the present invention can uniformly and firmly disperse nanofibers and magnetic nanomaterials into the tobacco material substrate through continuous high-pressure homogenization for multiple times; the nanofibers form an entangled network through hydrogen bonds, thereby obtaining an ultra-rigid nanostructure with high thermal stability and high transparency, further enhancing the high temperature resistance and mechanical strength of the magnetic reconstituted tobacco foil; the addition of surfactants such as polyvinyl pyrrolidone (PVP) during the manufacturing process can wrap magnetic nanomaterials such as magnetic nanowires, and through the strong hydrogen bond interaction between the carbonyl group of the additive and the hydroxyl group of the nanofiber, or the strong hydrogen bond interaction between the carbonyl group of the additive, the hydroxyl group of the nanofiber, and the hydroxyl group of the plant polysaccharide (Example 3), the magnetic nanowires partially wrapped by the cellulose play a skeleton role, promoting the magnetic reconstituted tobacco foil to The load transfer and energy dissipation during the stretching process disperse the stress and obtain excellent mechanical properties and structural stability; multi-stage 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, greatly reducing the contact resistance, constructing an interconnected, strong and stable magnetic nanowire magnetic conductive path and eddy current network and at the same time greatly improving the tensile strength of the reconstituted tobacco leaves; multi-stage hot lamination and nano-welding can also greatly increase the heating temperature of the magnetic reconstituted tobacco foil, because the resistance is significantly reduced after welding, resulting in an increase in the induced eddy current and electron transmission capacity inside the reconstituted tobacco leaves; nano-welding can improve the induction heating performance without increasing the content of magnetic nanowires, thereby reducing the cost of using magnetic materials.

[0052] The advantages of using ferromagnetic nanowires to prepare magnetic reconstituted tobacco foil are further explained as follows:

[0053] 1. The heating performance of magnetic reconstituted tobacco foil can be easily adjusted by controlling the amount of nanowires or the driving voltage. For example, when the driving voltage is constant, the heating temperature of magnetic reconstituted tobacco foil with a high content of ferromagnetic nanowires (such as Fe-Ni NWs) increases due to the reduced resistance. Due to the efficient Fe-Ni NWs embedded structure and the interconnected electromagnetic Fe-Ni NWs skeleton, high temperature can be obtained at a lower driving voltage by moderately increasing the Fe-Ni NWs area fraction, typically with an Fe-Ni NWs area fraction of 0.5 g / m 2 When the driving voltage is 3V, the temperature can rise to above 200℃ within 10s; or if the area fraction of Fe-Ni NWs is 1.0g / m 22. When an alternating magnetic field is applied to the aerosol-forming matrix made from magnetic reconstituted tobacco leaf foil, the inelastic collisions between the induced accelerated eddy current electrons and phonons in the nanowires generate Joule heating, causing the aerosol-forming matrix to rapidly heat up. When the alternating magnetic field is removed from the aerosol-forming matrix, the temperature of the aerosol-forming matrix rapidly drops due to the lack of Joule heating. In particular, when the area of the aerosol-forming matrix is significantly reduced (e.g., in the form of short filaments, thin wires, or fragments), the eddy current density and power density increase significantly, and the heating and cooling rates increase rapidly, potentially allowing for rapid heating and cooling within 1 second or even milliseconds. This is beneficial during the use of aerosol products, reducing subsequent sensory changes in the aerosol-forming matrix caused by the accumulation of pre-heated heat. At the same time, the user experience is improved by significantly shortening the preheating waiting time. Another beneficial effect is that the electrical energy consumed to heat the aerosol product to the required temperature is reduced.

[0054] One of the preparation methods of the magnetic reconstituted tobacco foil of the present invention (Example 1) can be based on the direction of the inductor excitation magnetic field and the distribution of magnetic flux lines passing through the aerosol-forming matrix, and through directional arrangement and papermaking, so that the magnetic tobacco sheet base obtained has a magnetic material orientation and distribution that is coordinated with the direction of the inductor excitation magnetic field and the distribution of magnetic flux lines, so that the magnetic reconstituted tobacco foil and even the aerosol-forming matrix prepared from the magnetic tobacco sheet base can achieve maximum magnetic field utilization efficiency and magnetic coupling strength when cooperated with a heating device; the magnetic multi-layer tobacco sheet base can be designed with tobacco sheet bases with different numbers of layers of magnetic materials according to the subsequent process requirements and characteristics of the actual product, such as a sandwich-type tobacco sheet base, in which the inner and outer layers are tobacco fibers and the middle core layer is magnetic nano-composite fibers. The use of semi-wet coating materials greatly reduces water consumption, significantly shortens the drying process, and reduces production energy consumption compared to traditional papermaking and thick pulp methods of reconstituted tobacco manufacturing processes. Since the foil dries faster, the finished reconstituted tobacco foil has a stronger ability to retain flavor substances and nicotine, and less adhesive can be used, reducing the impact of unpleasant odors generated during the heating process of aerosol products on the taste of smoking.

[0055] One method for preparing magnetic reconstituted tobacco foil (Example 2) of the present invention includes preparing a composite gel of nanofibers and magnetic nanowires through vacuum-assisted filtration. The resulting magnetic coating material can be considered a magnetic gel. The magnetic gel combines magnetic properties with high elasticity and flexibility, improving the film-forming properties of the coating material and facilitating the uniform distribution of the magnetic material on the sheet substrate. It also improves the processing performance of the finished tobacco foil during rolling and gathering processes.

[0056] Compared with traditional dry-process reconstituted tobacco leaves, one of the preparation methods of the magnetic reconstituted tobacco leaf foil of the present invention (Example 3) obtains a thin fiber layer by dry process and then applies coating for multi-stage lamination, which not only retains the looseness of the reconstituted tobacco leaf structure, but also the nanofibers, magnetic nanowires and polysaccharides contained in the magnetic coating liquid strengthen the hydrogen bond interaction with the thin fiber layer, enhance the sheet base shaping effect and mechanical properties, and reduce the powder loss, breakage and fracture phenomena in the downstream cutting or forming process. DETAILED DESCRIPTION

[0057] In order to make the purpose of the present invention, technical scheme clearer, be described in detail with reference to the following examples, embodiment is intended to illustrate the content of the present invention, rather than further limit the scope of protection of the present invention. The process, conditions, reagents, experimental techniques etc. implemented, except the content specifically mentioned below, are common knowledge and common common sense in this area, and the present invention has no particular restrictions. The experimental techniques for the unremarked specific conditions in each embodiment are usually according to conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise indicated, the implication of all professional terms and scientific terms used in this specification sheets is the same as the implication generally understood by those skilled in the art to which the present invention belongs. However, in case of conflict, the present specification sheets comprising the definitions shall prevail.

[0058] Example 1: Preparation of magnetic reconstituted tobacco leaf foil, the steps are as follows:

[0059] (1) mixing tobacco leaves and tobacco stems in a certain proportion and beating the mixture, mixing the mixture with wood pulp again, adding water to adjust the concentration to 1-5 wt%, and further beating the mixture to obtain tobacco pulp;

[0060] (2) After the tobacco pulp is defibrated using a defiberizer, water is added to the tobacco pulp to a concentration of 0.2-2 wt %, and the mixture is transferred to a stirring device for stirring; the nanofiber dispersion and the magnetic nanowire suspension are mixed and stirred, and a binder solution and a surfactant are added and mixed, and the mixture is stirred continuously to obtain a magnetic nanocomposite fiber pulp; the binder solution comprises a solution of a mixed natural binder such as guar gum, xanthan gum or CMC (carboxymethyl cellulose) and others;

[0061] (3) mixing the tobacco pulp and the magnetic nanocomposite fiber pulp to obtain a magnetic pulp, wherein the mass percentage of the magnetic nanocomposite fibers is, for example, 1-5 wt%, and using a sheet machine to align and arrange the pulp to obtain a magnetic tobacco sheet base; alternatively, using a sheet machine to obtain a magnetic multilayer tobacco sheet base having a core layer of magnetic nanocomposite fibers;

[0062] (4) preparing a wet coating material and a semi-wet coating material; the steps are as follows: (a) 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 uniformly; (b) adding glycerin, propylene glycol and water and mixing to maintain the water content at 50-80 wt% to obtain a wet coating material; alternatively, maintaining the water content at 20-50 wt% to obtain a semi-wet coating material;

[0063] (51) performing three-stage lamination on the magnetic tobacco sheet obtained in step (3) at a certain temperature to obtain a magnetic reconstituted tobacco sheet with a thickness of 0.10-0.30 mm;

[0064] (61) coating the wet coating material of step (4) on the magnetic reconstituted tobacco leaf base of step (51), and drying the coated material to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil;

[0065] or,

[0066] (52) applying the semi-wet coating material of step (4) onto the tobacco sheet base of step (3);

[0067] (62) performing three-stage lamination on the tobacco sheet coated in step (52) to obtain a magnetic reconstituted tobacco leaf having a thickness of 0.10-0.30 mm, and drying the laminate to obtain a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil;

[0068] Depending on the final application requirements, the obtained magnetic reconstituted tobacco foil is rolled or cut into sheets or shredded for use as an aerosol-forming matrix.

[0069] The three-stage lamination in steps (51) and (62) uses high-pressure rollers with forming functions set to different heating temperatures, wherein the lamination temperature of stage 1 is 70-100°C, the lamination temperature of stage 2 is 120-150°C, and the lamination temperature of stage 3 is 160-200°C. The lamination pressure is maintained constant at multiple stages, such as 5 MPa; the pressure can also be increased step by step, such as from 1 MPa at stage 1 to 3 MPa at stage 2 and then to 5 MPa at stage 3.

[0070] Example 2: Preparation of magnetic reconstituted tobacco leaf foil, the steps are as follows:

[0071] (1) Adding a binder solution to the tobacco slurry prepared according to step (1) of Example 1, and then sheeting the tobacco sheet using a standard sheeting machine; wherein the binder solution comprises a solution of a mixed natural binder such as guar gum, xanthan gum or CMC (carboxymethyl cellulose) and other agents;

[0072] (2) Preparation of magnetic coating material: vacuum-assisted filtration of nanofiber dispersion to obtain wet viscoelastic nanofiber gel; further vacuum-assisted filtration of magnetic nanowire suspension to obtain nanofiber and magnetic nanowire composite gel;

[0073] The composite gel of the mixed nanofiber dispersion and magnetic nanowire suspension is added to a mixed slurry comprising, but not limited to, tobacco mixture powder, tobacco extract, glycerin, propylene glycol, and water, and a binder solution and a surfactant are added and mixed uniformly to obtain a magnetic coating material, maintaining a solid content of 50-80%. The binder solution comprises a mixed solution of a natural binder such as guar gum, xanthan gum, or CMC (carboxymethyl cellulose) and others; the surfactant is polyvinyl pyrrolidone (PVP);

[0074] (3) coating the magnetic coating material on a tobacco sheet base and drying the coated material to obtain a magnetic tobacco sheet;

[0075] (4) performing three-stage lamination as in Example 1 to obtain magnetic reconstituted tobacco leaf sheets having a thickness of 0.10-0.30 mm;

[0076] (5) The foil prepared above is further dried by a drying device to reduce the moisture content to 5-10%, thereby obtaining a magnetic reconstituted tobacco leaf foil; and the foil is rolled, cut into sheets, or cut into shreds according to the final application requirements.

[0077] Example 3: Preparation of magnetic reconstituted tobacco leaf foil, the steps are as follows:

[0078] (1) screening one or more of wood pulp fiber, hemp pulp fiber, and tobacco fiber, crushing and defibrating them to obtain defibrated fibers; dry airflow forming the defibrated fibers to form a thin fiber layer.

[0079] (3) adding the nanofiber dispersion and the magnetic nanowire suspension into a stirring device, adding a binder solution, and stirring to obtain a magnetic slurry; the binder solution comprises a mixed natural binder such as guar gum, xanthan gum or CMC (carboxymethyl cellulose) and other solutions and a surfactant such as polyvinyl pyrrolidone (PVP); then adding plant polysaccharides, and mixing to form a magnetic coating liquid; the plant polysaccharides include but are not limited to starch, cellulose, polysaccharides, pectin, etc.;

[0080] (4) preparing wet coating materials and semi-wet coating materials, as in Example 1;

[0081] (51) The magnetic tobacco sheet obtained in step (3) is subjected to three-stage lamination at a certain temperature as in Example 1 to obtain a magnetic reconstituted tobacco sheet with a thickness of 0.10-0.30 mm;

[0082] (61) coating the wet coating material of step (4) on the magnetic reconstituted tobacco leaf base of step (51), and drying the coated material to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil;

[0083] or,

[0084] (52) applying the semi-wet coating material of step (4) onto the tobacco sheet base of step (3);

[0085] (62) The tobacco sheet base coated in step (52) is subjected to three-stage lamination as in Example 1, and dried to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil; the foil is rolled, cut into sheets, or cut into shreds according to the final application requirements.

[0086] The embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a magnetic reconstituted tobacco leaf foil, characterized in that: The magnetic reconstituted tobacco foil 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 thickness of the magnetic reconstituted tobacco foil is 0.10-0.30 mm; the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is a magnetic nanowire; the magnetic nanowire has a length of 5-100 μm and a diameter of 5-500 nm; the nanofiber is a wood nanofiber and / or a tobacco nanofiber; the nanofiber has a length of 1-10 μm and a diameter of 5-500 nm; the fiber material is a wood fiber and / or a tobacco fiber; The preparation method comprises the following steps: (1) beating tobacco material and fiber material, and then defibration to obtain tobacco pulp; the tobacco material includes tobacco powder, debris, and tobacco stems; (2) mixing the nanofiber dispersion and the magnetic nanowire suspension, and then adding a binder solution and a surfactant to mix to obtain a magnetic nanocomposite fiber slurry; the surfactant is polyvinyl pyrrolidone; the binder is one or more of starch, gum arabic, xanthan gum, guar gum, CMC and nanofiber gel; (3) mixing the tobacco pulp of step (1) and the magnetic nanocomposite fiber pulp of step (2) to obtain a magnetic pulp, wherein the mass percentage of the magnetic nanocomposite fibers is 1%-5wt%; and using a sheet machine to carry out directional arrangement and papermaking to obtain a magnetic tobacco sheet base; or using a sheet machine to papermaking to obtain a magnetic multilayer tobacco sheet base having a core layer of magnetic nanocomposite fibers; (4) Preparation of wet coating materials and semi-wet coating materials; (51) performing multi-stage lamination on the magnetic tobacco sheet obtained in step (3) at a certain temperature to obtain a magnetic reconstituted tobacco sheet with a thickness of 0.10-0.30 mm; (61) coating the wet coating material of step (4) on the magnetic reconstituted tobacco leaf base of step (51), and drying the wet coating material to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil; or, (52) applying the semi-wet coating material of step (4) onto the tobacco sheet base of step (3); (62) performing multi-stage lamination on the tobacco sheet coated in step (52), and drying the sheet to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil; The steps for preparing wet coating materials and semi-wet coating materials are as follows: (a) 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 uniformly; the tobacco material includes tobacco powder, scraps, and tobacco stems; (b) adding glycerol, propylene glycol and water and mixing them to maintain the water content at 50-80 wt % to obtain a wet coating material; or maintaining the water content at 20-50 wt % to obtain a semi-wet coating material.

2. A method for preparing a magnetic reconstituted tobacco leaf foil, characterized in that: The magnetic reconstituted tobacco foil 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 thickness of the magnetic reconstituted tobacco foil is 0.10-0.30 mm; the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is a magnetic nanowire; the magnetic nanowire has a length of 5-100 μm and a diameter of 5-500 nm; the nanofiber is a wood nanofiber and / or a tobacco nanofiber; the nanofiber has a length of 1-10 μm and a diameter of 5-500 nm; the fiber material is a wood fiber and / or a tobacco fiber; The preparation method comprises the following steps: (1) beating tobacco material and fiber material, and then defibration to obtain tobacco pulp; the tobacco material includes tobacco powder, debris, and tobacco stems; (2) adding a binder solution and a surfactant to the tobacco pulp of step (1) and mixing to obtain a composite fiber pulp tobacco pulp; sheeting is performed using a sheeting machine to obtain a tobacco sheet base; the surfactant is polyvinyl pyrrolidone; the binder is one or more of starch, gum arabic, xanthan gum, guar gum, CMC and nanofiber gel; (3) preparing a magnetic coating material, comprising the following steps: vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanowire suspension to obtain a nanofiber and magnetic nanowire composite gel; adding the obtained composite gel to a mixed slurry of tobacco mixture powder, tobacco extract, glycerin, propylene glycol, and water, and then adding a binder solution, mixing uniformly to obtain a magnetic coating material, maintaining a solid content of 50-80 wt%; the binder is prepared from one or more of starch, gum arabic, xanthan gum, guar gum, and CMC and the nanofiber gel; (4) coating the magnetic coating material prepared in step (3) on the tobacco sheet base prepared in step (2), and drying the coated material 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 sheet with a thickness of 0.10-0.30 mm; (6) Drying the obtained magnetic reconstituted tobacco leaf base to a moisture content of 5-10 wt% to obtain magnetic reconstituted tobacco leaf foil.

3. A method for preparing magnetic reconstituted tobacco foil, characterized in that: The magnetic reconstituted tobacco foil 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 thickness of the magnetic reconstituted tobacco foil is 0.10-0.30 mm; the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is a magnetic nanowire; the magnetic nanowire has a length of 5-100 μm and a diameter of 5-500 nm; the nanofiber is a wood nanofiber and / or a tobacco nanofiber; the nanofiber has a length of 1-10 μm and a diameter of 5-500 nm; the fiber material is a wood fiber and / or a tobacco fiber; The preparation method comprises the following steps: (1) The fiber material is crushed and defibrated, and the defibrated fibers are formed by dry airflow to obtain a thin fiber layer; (2) mixing the nanofiber dispersion and the magnetic nanowire suspension, adding the binder solution and the surfactant to obtain a magnetic nanocomposite fiber slurry; then adding the plant polysaccharide and mixing to form a magnetic coating liquid; the surfactant is polyvinyl pyrrolidone; the binder is one or more of starch, gum arabic, xanthan gum, guar gum, CMC and nanofiber gel; the plant polysaccharide is one or more of starch, cellulose, polysaccharide or pectin; (3) spraying the magnetic coating liquid of step (2) onto the fiber thin layer of step (1) to form a magnetic tobacco sheet; (4) Preparation of wet coating materials and semi-wet coating materials; (51) performing multi-stage lamination on the magnetic tobacco sheet obtained in step (3) at a certain temperature to obtain a magnetic reconstituted tobacco sheet with a thickness of 0.10-0.30 mm; (61) coating the wet coating material of step (4) on the magnetic reconstituted tobacco leaf base of step (51), and drying the wet coating material to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil; or, (52) applying the semi-wet coating material of step (4) onto the tobacco sheet base of step (3); (62) performing multi-stage lamination on the tobacco sheet coated in step (52), and drying the sheet to a moisture content of 5-10 wt % to obtain a magnetic reconstituted tobacco leaf foil; The steps for preparing wet coating materials and semi-wet coating materials are as follows: (a) 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 uniformly; the tobacco material includes tobacco powder, scraps, and tobacco stems; (b) adding glycerol, propylene glycol and water and mixing them to maintain the water content at 50-80 wt % to obtain a wet coating material; or maintaining the water content at 20-50 wt % to obtain a semi-wet coating material.

4. The preparation method according to any one of claims 1 to 3, characterized in that The multi-stage lamination pressure is 1-5MPa and the temperature is 70-200℃.

5. Use of the magnetic reconstituted tobacco leaf foil prepared by the preparation method according to any one of claims 1 to 3 as an aerosol-forming matrix.