Reconstituted tobacco, preparation method therefor, and use thereof

Abstract

The present invention discloses a magnetic reconstituted tobacco leaf, including a magnetic reconstituted tobacco leaf foil and / or magnetic reconstituted tobacco leaf particles. A thickness of the magnetic reconstituted tobacco leaf foil is in a range from 0.10 mm to 0.30 mm, and a particle size of the magnetic reconstituted tobacco leaf particles is in a range from 0.5 mm to 2 mm. A composition of the magnetic reconstituted tobacco leaf includes a fiber material, a tobacco material, nanofibers, and a magnetic material; and the magnetic material is a material that can be converted into heat after absorbing an alternating magnetic field. The present invention further discloses a preparation method and use of the magnetic reconstituted tobacco leaf.

Description

TECHNICAL FIELD

[0001] The present invention belongs to the technical field of tobaccos, and particularly relates to a reconstituted tobacco leaf, a preparation method therefor, and use thereof.BACKGROUND

[0002] Existing heat-not-burning aerosol products typically use reconstituted tobacco leaves or tobacco particles as an aerosol-forming matrix. A thick pulp method and a papermaking method are main methods for producing existing reconstituted tobacco leaves for heat-not-burning aerosol products. The thick pulp method requires drying to remove a large amount of water, and the process has high energy consumption; and a finished product is brittle, has low strength, and may cause high reconstitution losses during cutting. The papermaking method causes significant loss of aromatic substances in a finished product, and drying for water removal also requires a large amount of energy consumption and a complex drying process.

[0003] The existing aerosol products commonly use an induction heating method to atomize the required components in the aerosol-forming matrix from the products, so as to form inhalable aerosol. In existing induction heating aerosol products, a receptor is a separate element 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 type heating is that the induction heat of the receptor is transferred from a center of the aerosol-forming matrix in contact with it to its periphery, and the heat is significantly attenuated from the inside out. The disadvantage of circumferential type heating is that the induction heat of the receptor penetrates through a wrapping material from an outer periphery of the aerosol-forming matrix wrapping material in contact with it and then is transferred to the center of the aerosol-forming matrix, and the heat is significantly attenuated from the outside in. Therefore, in order to achieve an expected atomization effect of the aerosol-forming matrix, it is necessary to extend a preheating time of the products and increase a maximum heating temperature, thereby improving output power of an inductor. This not only causes low thermal utilization efficiency and uneven heat distribution of the aerosol-forming matrix, but also increases energy consumption of a heating device for heating the aerosol products.

[0004] Therefore, the present invention is proposed.SUMMARY

[0005] To alleviate the above defects, the present invention proposes a magnetic reconstituted tobacco leaf foil and magnetic reconstituted tobacco leaf particles which integrate a magnetic induction material into an aerosol-forming matrix, and a manufacturing method therefor, aiming to increase utilization efficiency of induction heat and a heating rate and reduce energy consumption of a heating device when using aerosol products made of a magnetic aerosol-forming matrix, and save manufacturing costs.

[0006] The technical solutions of the present invention are as follows: A first aspect of the present invention discloses a magnetic reconstituted tobacco leaf, including a magnetic reconstituted tobacco leaf foil and / or magnetic reconstituted tobacco leaf particles. A thickness of the magnetic reconstituted tobacco leaf foil is in a range from 0.10 mm to 0.30 mm, and a particle size of the magnetic reconstituted tobacco leaf particles is in a range from 0.5 mm to 2 mm. A composition of the magnetic reconstituted tobacco leaf includes a fiber material, a tobacco material, nanofibers, and a magnetic material; and the magnetic material is a material that can be converted into heat after absorbing an alternating magnetic field.

[0007] Preferably, the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is magnetic nanoparticles and / or magnetic nanowires; and the magnetic nanowires have a length ranging from 5 µm to 100 µm and a diameter ranging from 5 nm to 500 nm.

[0008] Preferably, the nanofibers are plant nanofibers and / or tobacco nanofibers; the nanofibers have a length ranging from 1 µm to 10 µm and a diameter ranging from 5 nm to 500 nm; and the fiber material is a cellulose fiber and / or tobacco fiber material.

[0009] A second aspect of the present invention discloses a preparation method of a magnetic reconstituted tobacco leaf, including the following steps: (1) making a tobacco material and a fiber material into powder with a particle size ranging from 60 meshes to 120 meshes, adding a binder and mixing to obtain a solid mixture, wherein the binder is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; (2) obtaining nanofiber and magnetic nanowire composite gel by using a method of vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanowire suspension; and adding glycerol, water, and a surfactant polyvinylpyrrolidone and mixing evenly to obtain a liquid mixture; (3) stirring and mixing the solid mixture from step (1) and the liquid mixture from step (2) to obtain a dough-like substance with a moisture content of 20-40wt%; (4) compressing and shaping the dough-like substance obtained from step (3) into a parison by using an extruder; (5) obtaining a foil with a thickness ranging from 0.10 mm to 0.30 mm by performing multi-stage lamination on the parison obtained from step (4) at a certain temperature, and then drying the foil to reduce a moisture content to 5-10wt%, so as to obtain a reconstituted tobacco leaf foil; or, (6) breaking the parison obtained from step (4) into irregular particles by using a rotary granulator, and drying the irregular particles to reduce a moisture content to 1-6wt%; and sieving to obtain particles with a particle size ranging from 0.5 mm to 2 mm, so as to obtain reconstituted tobacco leaf particles.

[0010] Alternatively, the preparation method of the magnetic reconstituted tobacco leaf includes the following steps: (A) preparing a semi-wet mixture formed by a tobacco material, nanofibers, and a magnetic nanomaterial, wherein the method is as follows: adding a surfactant polyvinylpyrrolidone, glycerol and propylene glycol, and preparing nanofiber and magnetic nanomaterial composite gel, namely the semi-wet mixture, by using a method of consecutive vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanomaterial suspension; (B) inserting the semi-wet mixture from step (A) into a laminating roller and performing multi-stage lamination at a certain temperature to obtain a sheet with a thickness ranging from 0.10 mm to 0.30 mm; and applying a binder layer onto a surface of the laminating roller before inserting a sheet base into the laminating roller; or (C) preparing a cellulose fiber and / or tobacco fiber sheet base; (D) applying the semi-wet mixture from step (A) onto the sheet base from step (C), then inserting the obtained sheet base into a laminating roller and performing multi-stage lamination at a certain temperature to obtain a sheet with a thickness ranging from 0.10 mm to 0.30 mm; and applying a binder layer onto a surface of the laminating roller before inserting the sheet base into the laminating roller; a binder used in the binder layer is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; and (E) drying the sheet obtained from step (B) or step (D) to reduce a moisture content to 5-10wt%, so as to obtain a magnetic laminated reconstituted tobacco leaf foil.

[0011] Alternatively, the preparation method of the magnetic reconstituted tobacco leaf includes the following steps: (a) pulping a tobacco material and a fiber material, and then performing defibrination to obtain a tobacco pulp; (b) mixing a nanofiber dispersion and a magnetic nanowire suspension, then adding an adhesive solution and a surfactant polyvinylpyrrolidone and mixing to obtain a magnetic nanocomposite fiber pulp; (c) obtaining a magnetic pulp by mixing the tobacco pulp from step (a) and the magnetic nanocomposite fiber pulp from step (b), wherein a mass percentage of magnetic nanocomposite fibers is in a range from 1wt% to 5wt%; and obtaining a magnetic tobacco sheet base by performing directional arrangement and papermaking using a sheet former; or, obtaining a magnetic tobacco sheet base with a core layer of magnetic nanocomposite fibers by performing papermaking using a sheet former; (d) preparing a wet coating material and a semi-wet coating material, wherein the steps are as follows: breaking a tobacco material and a fiber material to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; then adding a solid natural binder and mixing evenly; adding and mixing glycerol, propylene glycol, and water, and maintaining a moisture content of 50-80wt% to obtain the wet coating material; and performing dehydration to make a moisture content to be 20-50wt% to obtain the semi-wet coating material; wherein the binder is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; (e1) performing multi-stage lamination on the magnetic tobacco sheet base obtained from step (c) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (f1) coating the magnetic reconstituted tobacco leaf sheet base obtained from step (e1) with the wet coating material from step (4), and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (e2) coating the tobacco sheet base from step (c) with the semi-wet coating material from step (d); and (f2) performing multi-stage lamination on the coated tobacco sheet base from step (e2), and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil.

[0012] Alternatively, the preparation method of the magnetic reconstituted tobacco leaf includes the following steps: 1) pulping a tobacco material and a fiber material, and then performing defibrination to obtain a tobacco pulp; 2) adding an adhesive solution and a surfactant polyvinylpyrrolidone to the tobacco pulp from step 1) and mixing to obtain a composite fiber tobacco pulp; and obtaining a tobacco sheet base by performing papermaking using a sheet former; 3) preparing a magnetic coating material, wherein the steps are as follows: obtaining nanofiber and magnetic nanowire composite gel by vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanowire suspension; adding the obtained composite gel to a mixed pulp of tobacco mixture powder, a tobacco extract, glycerol, propylene glycol and water, then adding an adhesive solution, and mixing evenly to obtain the magnetic coating material, wherein a solid content is kept at 50-80wt%; 4) coating the tobacco sheet base from step 2) with the magnetic coating material from step 3), and drying to obtain a magnetic tobacco sheet; 5) performing multi-stage lamination on the magnetic tobacco sheet obtained from step 4) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; and 6) drying the prepared magnetic reconstituted tobacco leaf sheet base to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil.

[0013] Alternatively, the preparation method of the magnetic reconstituted tobacco leaf includes the following steps: (I) crushing and defibrinating a tobacco material and a fiber material, and obtaining a thin fiber layer by performing dry airflow forming on defibrinated fibers; (II) mixing a nanofiber dispersion and a magnetic nanowire suspension, adding an adhesive solution and a surfactant polyvinylpyrrolidone and mixing to obtain a magnetic nanocomposite fiber pulp; and then adding a plant polysaccharide and mixing to form a magnetic coating solution; (III) spraying the magnetic coating solution from step (II) onto the thin fiber layer from step (I) and then shaping the thin fiber layer into a magnetic tobacco sheet base; (IV) preparing a wet coating material and a semi-wet coating material, wherein the steps are as follows: breaking a tobacco material and a fiber material to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; then adding a solid natural binder and mixing evenly; adding and mixing glycerol, propylene glycol, and water, and maintaining a moisture content of 50-80wt% to obtain the wet coating material; and performing dehydration to make a moisture content to be 20-50wt% to obtain the semi-wet coating material; wherein the binder is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; (LI) performing multi-stage lamination on the magnetic tobacco sheet base obtained from step (III) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (LXI) coating the magnetic reconstituted tobacco leaf sheet base from step (LI) with the wet coating material from step (IV), and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (LII) coating the tobacco sheet base from step (III) with the semi-wet coating material from step (IV); and (LXII) performing multi-stage lamination on the coated tobacco sheet base from step (LII) at a certain temperature, and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil.

[0014] Preferably, a pressure for multi-stage lamination is in a range from 1 MPa to 5 MPa and a temperature is in a range from 70°C to 200°C.

[0015] A third aspect of the present invention discloses use of the magnetic reconstituted tobacco leaf as a magnetic aerosol-forming matrix.

[0016] The magnetic reconstituted tobacco leaf for the magnetic aerosol-forming matrix in the present invention includes a magnetic reconstituted tobacco leaf foil and magnetic reconstituted tobacco leaf particles. The magnetic reconstituted tobacco leaf contains a tobacco mixture, nanofibers, and a magnetic material. The nanofibers may be wood nanofibers and / or tobacco nanofibers. The nanofibers may be other plant nanofibers. The nanofibers have a diameter ranging from 5 nm to 100 nm and a length ranging from 1 µm to 10 µm, respectively.

[0017] The magnetic material is any material that can be converted into heat after absorbing an alternating magnetic field, such as a ferromagnetic material or a ferrimagnetic material. Specifically, the magnetic material is, for example, iron or an iron alloy such as stainless steel, nickel, and a nickel alloy such as a corrosion-resistant Fe-Ni-Cr alloy, etc. Preferably, the magnetic material is a magnetic nanomaterial, such as nanoparticles, nanosheets, nanospheres, nanorods, nanotubes, and nanowires, especially nanoparticles and / or nanowires. The nanoparticles and / or the nanowires include but are not limited to nickel, cobalt, iron nickel, cobalt nickel, cobalt iron, iron cobalt nickel, iron molybdenum nickel, and other materials and alloys thereof. The magnetic material is preferably magnetic nanowires. The magnetic material has a length ranging from 5 µm to 100 µm, and an average diameter ranging from 5 nm to 500 nm.

[0018] The magnetic reconstituted tobacco leaf foil is obtained by extruding and rolling a tobacco mixture, nanofibers, and a magnetic nanomaterial. The magnetic reconstituted tobacco leaf particles are obtained by extruding, granulating, and sieving a tobacco mixture, nanofibers, and a magnetic nanomaterial. A preparation method for the magnetic reconstituted tobacco leaf includes: forming a dough-like substance of tobacco, nanofibers, and a magnetic nanomaterial; adding a surfactant such as polyvinylpyrrolidone (PVP) to a mixture of the tobacco, the nanofibers, and the magnetic nanomaterial to facilitate combination of the magnetic nanomaterial and the nanofibers; obtaining nanofiber and magnetic nanomaterial composite gel by using a method of consecutive vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanomaterial suspension; extruding the dough-like substance, so that the magnetic nanomaterial is thermally extruded to form an interconnected magnetic conducting pathway and is tightly combined with an extruded reconstituted tobacco leaf parison; and applying a temperature to a rolling roller, so that the magnetic nanomaterial is thermally laminated or further nanowelded to form an interconnected magnetic conducting pathway and more tightly combined with the reconstituted tobacco leaf as a whole to obtain a reconstituted tobacco leaf foil. A thickness of the foil may be controlled by adjusting a rolling roller spacing; and the obtained magnetic reconstituted tobacco leaf foil may be rolled, sliced or shredded, and then subjected to subsequent processing for use in the magnetic aerosol-forming matrix. The tobacco material may be tobacco powder, debris, tobacco stems, etc.

[0019] The magnetic reconstituted tobacco leaf foil is used for the aerosol-forming matrix, and may be rolled, sliced or shredded, and then subsequently processed to form the aerosol-forming matrix. The magnetic aerosol-forming matrix contains materials that can be atomized into inhalable aerosols at an appropriate temperature. The atomized aerosols contain an atomizing agent, an aromatic substance, and / or nicotine, and may further contain other inhalable components. The magnetic aerosol-forming matrix and a wrapping material are combined to form an aerosol generation section, which is then combined with other parts including a support section, a cooling section, and a filter section to form an aerosol product.

[0020] The present invention has the following beneficial effects: According to the preparation method for the magnetic reconstituted tobacco leaf in the present invention, a heater on an extruder may heat the dough-like substance through heat conduction in a process of extruding the dough-like substance by the extruder. In addition, the dough-like substance rubs and shears against a cylinder and a screw of the extruder, and a material of the dough-like substance during its movement, and a large amount of heat may be generated, so that the magnetic nanomaterial in the parison is thermally extruded. When the extruded parison is high-pressure hot pressed into the foil on a rolling mill, the magnetic nanomaterial therein further undergoes thermal lamination and nanowelding. Thermal lamination and nanowelding can completely remove the surfactant components (such as PVP) wrapped around the magnetic nanowires and sinter magnetic nanowire joints, thereby significantly reducing contact resistance, constructing the interconnected, robust, and stable magnetic nanowire magnetic conduction pathway and eddy current network, and significantly improving a tensile strength of the reconstituted tobacco leaf foil. Thermal lamination and nanowelding can further significantly increase a heating temperature of the magnetic reconstituted tobacco leaf foil, as the resistance significantly decreases after welding, leading to an increase in induced eddy current and electron transfer capacity inside the reconstituted tobacco leaf foil. Nanowelding can improve induction heating performance and reduce the use cost of the magnetic material without increasing the content of the magnetic nanowires.

[0021] According to the preparation method in the present invention, through consecutive multiple high-pressure homogenization (generally not less than three times), the nanofibers and the magnetic nanomaterial can be uniformly and firmly dispersed into a reconstituted tobacco substrate. Vacuum-assisted filtration is beneficial for the nanofibers to form an entangled network through a hydrogen bond, thereby obtaining a super rigid nanostructure with high thermal stability and high transparency, and further enhancing high temperature resistance and a mechanical strength of the magnetic reconstituted tobacco leaf. Adding the surfactant such as the polyvinylpyrrolidone (PVP) during a manufacturing process can wrap the magnetic nanomaterial such as the magnetic nanowires. Through a strong hydrogen bond interaction between a carbonyl of an additive and a hydroxyl of the nanofibers, the magnetic nanowires partially wrapped by cellulose act as a skeleton, promoting load transfer and energy dissipation during a stretching process of the magnetic reconstituted tobacco leaf, dispersing stress, and achieving excellent mechanical properties and structural stability. Multi-stage thermal lamination and nanowelding can completely remove the surfactant components (such as PVP) wrapped around the magnetic nanowires and sinter magnetic nanowire joints, thereby significantly reducing the contact resistance, constructing the interconnected, robust, and stable magnetic nanowire magnetic conduction pathway and eddy current network, and significantly improving the tensile strength of the reconstituted tobacco leaf foil. Multi-stage thermal lamination and nanowelding can further significantly increase the heating temperature of the magnetic reconstituted tobacco leaf, as the resistance significantly decreases after welding, leading to an increase in induced eddy current and electron transfer capacity inside the reconstituted tobacco leaf. Nanowelding can improve the induction heating performance and reduce the use cost of the magnetic material without increasing the content of the magnetic nanowires.

[0022] Compared to a traditional process for reconstituting tobacco leaves through a papermaking method and a thick pulp method, the manufacturing process for the magnetic reconstituted tobacco leaf foil and the reconstituted tobacco particles of the present invention requires less water, significantly reduces drying procedures, and lowers production energy consumption. Due to the faster drying of the foil, the finished reconstituted tobacco leaf has a stronger ability to retain aroma substances and nicotine, allowing for the use of fewer binders, which reduces the impact of unpleasant odors generated during the heating process of aerosol products on smoking taste. By precisely adjusting the roller spacing of the rolling mill, the thickness of the finished reconstituted tobacco leaf is uniformly controlled, and the precision and stability of its thickness help ensure the consistency of downstream processes and ensure that important product indicators such as a nicotine content are within the specified range. Due to the increased stability and reliability of the reconstituted tobacco leaf, the working stability of the heating device is also greatly improved. According to the preparation method of the present invention, drying preheating of tobacco debris and fibers is not necessary. Due to the material bonding effect inherent in an extrusion molding process, the use amount of the binder may be significantly decreased. Therefore, the raw material and production costs may be further reduced. The tobacco material used in the present invention may be tobacco powder, debris, tobacco stems, etc., which can reduce the cost of using pure tobacco leaves as raw materials for traditional granular aerosol products. According to the preparation method of the present invention, the same raw material and extrusion process are used to prepare the parison required for the reconstituted tobacco leaf foil and the reconstituted tobacco particles, thereby saving the floor space and capital investment of production equipment, and facilitating the simultaneous manufacturing of two types of products such as the reconstituted tobacco leaf foil and the reconstituted tobacco particles.

[0023] The fiber material of the present invention is a cellulose fiber and / or tobacco fiber material, with flexible nanofibers intertwined with each other to create a nanoscale network. On the one hand, the strength of the fiber network is enhanced by increasing the number of hydrogen bonds in each fibril or the number of hydrogen bonds between the fibers. On the other hand, 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 the reconstituted tobacco leaf. Meanwhile, the highly-active hydroxyl in the nanofibers can be modified through chemical and physical treatments to achieve desired properties, such as increasing its adhesion to the magnetic material.

[0024] The magnetic reconstituted tobacco leaf 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 a flexible magnetic conduction circuit and an eddy current network. The magnetic reconstituted tobacco leaf of the present invention has the characteristics of low driving voltage, fast heating, and high heating temperature, which can meet the requirements of energy saving, fast heating, and instant use when using the aerosol products. When the magnetic reconstituted tobacco leaf of the present invention is used for the magnetic aerosol-forming matrix, the magnetic material therein serves as a receptor, is uniformly distributed throughout the aerosol-forming matrix and forms a magnetic conduction pathway. It is different from existing induction heating type aerosol products, where the receptor is a separate element 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 type heating is that the induction heat of the receptor is transferred from a center of the aerosol-forming matrix in contact with it to its periphery, and the heat is significantly attenuated from the inside out. The disadvantage of circumferential type heating is that the induction heat of the receptor penetrates through a wrapping material from an outer periphery of the aerosol-forming matrix wrapping material in contact with it and then is transferred to the center of the aerosol-forming matrix, and the heat is significantly attenuated from the outside in. The integrated heating of the magnetic reconstituted tobacco leaf in the present invention is the induction heat distributed throughout the aerosol-forming matrix after the magnetic material in the entire aerosol-forming matrix receives an alternating magnetic field of radiation. The disadvantage of existing central type induction heating further includes that the insertion and pull-out of the receptor on the heating device is prone to causing the aerosol-forming matrix to move. Specifically, when inserted, it causes the aerosol-forming matrix to be pushed towards a suction nozzle end of the aerosol product, which affects heat transfer, aerosol generation, and suction force. When pulled out, it causes some aerosol-forming matrixes to be brought out into the heating device along with the receptor, as well as a problem of cleaning residues caused by atomized condensate remaining on the surface of the receptor. The above-mentioned method of embedding the receptor in the aerosol product poses difficulties for the processing, placement, and positioning of the receptor in the aerosol-forming matrix during the manufacturing process of the product. The receptor of the present invention is homogeneously formed in an integrated manner with the magnetic reconstituted tobacco leaf foil and the magnetic reconstituted tobacco leaf particles during the manufacturing process, without the need for additional receptor processing, aerosol-forming matrix placement and positioning equipment. There is also no problem of movement of the aerosol-forming matrix and residue cleaning during the use of the aerosol product.

[0025] The magnetic material in the magnetic reconstituted tobacco leaf of the present invention has a uniform layered network-type distribution in the reconstituted tobacco leaf foil and a uniform spherical network-type distribution in the particles, which greatly shortens a magnet-heat conversion path. The magnetic material in the aerosol-forming matrix basically instantaneously transfers its heat to the entire aerosol-forming matrix. The heat utilization efficiency of the aerosol-forming matrix is greatly improved, which in turn greatly reduces the energy consumption of the heating device. Moreover, since the aerosol-forming matrix itself is an induction heating element of the aerosol product containing it, there is no need to arrange an additional receptor inside the aerosol product (such as inside the aerosol-forming matrix) or on the heating device on the periphery, which greatly reduces the volume of the heating device and lowers the manufacturing difficulty of the aerosol product, thereby not only saving the manufacturing costs but also facilitating the portability of the heating device.

[0026] The existing induction heating type aerosol product belongs to a heat transfer manner from local to overall. The receptor heat source requires a high temperature to ensure sufficient heat transfer to the entire aerosol-forming matrix. At the same time, in order to meet the atomization requirements of the aerosol-forming matrix and then achieve the inhalability requirements of the aerosol generated by atomization, the heat accumulation in the aerosol-forming matrix needs to be sufficient, which brings two technical bottlenecks: first, the initial temperature of the receptor needs to be high enough, and second, 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 prevents a consumer from using the product quickly. The way of using the magnetic reconstituted tobacco leaf of the present invention for the magnetic aerosol-forming matrix is not to apply an entire bulky magnetic material on the surface or interior of the aerosol-forming matrix. Instead, by adjusting an area fraction of a small amount of magnetic nanomaterial in it, the magnetic nanomaterial is spread in the reconstituted tobacco leaf foil through hot extrusion, thermal lamination, and nanowelding, or the magnetic nanomaterial is mixed evenly in the reconstituted tobacco particles through rotational extrusion during hot extrusion and rotary granulation processes, thus the magnetic induction surface area is greatly increased, and the interconnectivity of the magnetic nanomaterial is improved. Due to the thin thickness (0.10-0.30 mm) of the magnetic reconstituted tobacco leaf foil and the small particle size (0.5-2 mm) of the magnetic reconstituted tobacco leaf particles, a skin depth of the magnetic field inside the magnetic nanomaterial is significantly reduced. This not only reduces the attenuation of magnetic flux, but also greatly lowers the resistance of the magnetic network. Therefore, under the influence of increased electrical conductivity and decreased thermal resistance, the initial temperature set by the heating device may be controllably reduced, and the temperature may be raised to the set operating temperature in a very short time, thereby greatly shortening the preheating waiting time of the heating device and achieving immediate use of the product. Similarly, the aerosol product may be cooled from the operating temperature to a room temperature in a very short period of time, thereby significantly reducing the heat accumulation problem in the aerosol-forming matrix and ensuring consistent experience of the aerosol product throughout each usage cycle. Due to the increased electrical conductivity and reduced thermal resistance, the magnetic reconstituted tobacco leaf of the present invention may choose a magnetic material with intrinsic Curie temperature close to the actual operating temperature, without the need to choose a magnetic material with high Curie temperature beyond the actual operating temperature. This makes the temperature control of the heating device easier and more accurate.

[0027] The vacuum-assisted filtration method used in the present invention is a method of coating the magnetic material in a suspension form on the surfaces of nanofibers using vacuum filtration. A vacuum-assisted filtration technology greatly increases a deposition rate of the nanomaterial, has fewer losses of the nanomaterial during the preparation process, and thus is a very simple and convenient method for preparing multifunctional nanocomposites. The vacuum-assisted filtration technology facilitates the formation of the entangled network of the nanofibers through a hydrogen bond, thereby obtaining the super rigid nanostructure with high thermal stability and high transparency, and further enhancing the high temperature resistance and mechanical strength of the magnetic aerosol-forming matrix.

[0028] The present invention uses the ferromagnetic nanowires to further illustrate the advantages of the prepared magnetic reconstituted tobacco leaf as follows. 1. By controlling the use amount of the magnetic nanowires or driving voltage, it is easy to adjust the heating performance of the magnetic reconstituted tobacco leaf. For example, when the driving voltage is constant, the magnetic reconstituted tobacco leaf with the high content of ferromagnetic nanowires (such as Fe-Ni NWs) have reduced resistance and thus increased heating temperature. Due to an efficient Fe-Ni NWs embedding structure and an interconnected electromagnetic Fe-Ni NWs skeleton, the high temperature can be achieved under the lower driving voltage by moderately increasing the area fraction of the Fe-Ni NWs. Typically, when the area fraction of the Fe-Ni NWs is 0.5 g / m 2< , the temperature may rise to 200°C or above within 10 seconds under a 3V driving voltage. Alternatively, when the area fraction of the Fe-Ni NWs is 1.0 g / m 2< , the temperature may rise to 250°C or above within 7 seconds under a 2V driving voltage. The beneficial effect of obtaining the high temperature with the low driving voltage is to save electric energy and reduce energy consumption. 2. When the alternating magnetic field is applied to the prepared magnetic reconstituted tobacco leaf, Joule heat is generated by the inelastic collision between eddy current electrons accelerated by induction in the magnetic nanowires and phonons, causing the aerosol-forming matrix to rapidly heat up. However, when applying of the alternating magnetic field to the aerosol-forming matrix is stopped, the temperature of the magnetic reconstituted tobacco leaf rapidly decreases due to the absence of Joule heat. Especially when the area of the magnetic reconstituted tobacco leaf is significantly reduced (such as processing the magnetic reconstituted tobacco leaf foil into short filaments, fine filaments, or fragmented shapes), due to the significant increase in eddy current density and power density, the heating and cooling rates rapidly increase, with the potential for rapid heating and cooling in the order of 1 second or even milliseconds. This is beneficial for reducing the subsequent sensory changes caused by the accumulation of previous heat in the aerosol-forming matrix during the use of the magnetic reconstituted tobacco leaf for the aerosol product. At the same time, the use experience is improved by significantly reducing the preheating waiting time. Another beneficial effect is that electric energy consumed to heat the magnetic reconstituted tobacco leaf to the desired temperature for use in the aerosol product is reduced. 3. According to the preparation method of the present invention, the composite lamination technology for the tobacco material, the nanofibers and the magnetic nanomaterial has practical production flexibility and can accurately manipulate the properties of the final product. 4. The magnetic reconstituted tobacco leaf of the present invention has ideal tensile strength, aroma retention, magnetic controllability, and cost-effectiveness.

[0029] According to the preparation method for the magnetic reconstituted tobacco leaf foil of the present invention, based on a direction of the inductor-excited magnetic field passing through the aerosol-forming matrix and the distribution of magnetic flux lines, by directional arrangement and papermaking, the prepared magnetic tobacco sheet base has the magnetic material orientation and distribution that synergistically align with the direction of the inductor-excited magnetic field and the distribution of the magnetic flux lines, so that the magnetic reconstituted tobacco leaf foil prepared from the magnetic tobacco sheet base and even the aerosol-forming matrix can achieve the maximum magnetic field utilization efficiency and magnetic coupling strength when matching with the heating device. A magnetic multi-layer tobacco sheet base may be designed with magnetic materials having different numbers of layers according to the subsequent process requirements and characteristics of actual products, such as a sandwich-type tobacco sheet base, where the inner and outer layers are tobacco fibers and the middle core layer is magnetic nanocomposite fibers. By using the semi-wet coating material, compared with the traditional process for reconstituting tobacco leaves through the papermaking method and the thick pulp method, water consumption is significantly reduced, drying procedures are significantly reduced, and the production energy consumption is reduced. Due to the faster drying of the foil, the finished reconstituted tobacco leaf foil has a stronger ability to retain aroma substances and nicotine, allowing for the use of fewer binders, which reduces the impact of unpleasant odors generated during the heating process of the aerosol product on smoking taste.

[0030] The preparation method for the magnetic reconstituted tobacco leaf foil of the present invention includes the step of vacuum-assisted filtration to prepare the composite gel of the nanofibers and the magnetic nanowires, and the magnetic coating material obtained may be regarded as magnetic gel. The magnetic gel combines the characteristics of magnetism, high elasticity and flexibility, improves the film-forming property of the coating material, facilitates the uniform distribution of the magnetic material on the sheet base, and also improves the processing performance of a finished tobacco foil in processes such as coiling and gathering.

[0031] Compared to a traditional dry-process reconstituted tobacco leaf, the preparation method for the magnetic reconstituted tobacco leaf foil of the present invention obtains the thin fiber layer through the dry process and then applies the thin fiber layer for multi-stage lamination, which not only retains the looseness of the reconstituted tobacco leaf structure, but also enhances the hydrogen bond interaction with the thin fiber layer by the nanofibers, the magnetic nanowires, and polysaccharides contained in the magnetic coating solution, strengthens the sheet base setting effect and mechanical properties, and reduces the phenomena of powder falling, crushing, and fracture occurred in downstream shredding or forming processes.DETAILED DESCRIPTION

[0032] In order to clarify the objectives and technical solutions of the present invention, detailed illustration is made in conjunction with the following embodiments. The embodiments are intended to illustrate the content of the present invention, rather than further limiting the scope of protection of the present invention. The implementation process, conditions, reagents, experimental methods, etc., except for those specifically mentioned below, are all common knowledge and common sense in this field, and the content is not particularly limited in the present invention. The experimental methods without specific conditions specified in each embodiment are usually carried out under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, meanings of all professional terms and scientific expressions used in this specification have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. But in case of conflict, this specification containing definitions shall prevail.

[0033] Embodiment 1: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) solid natural binders such as guar gum, xanthan gum, carboxymethyl cellulose (CMC), and others are mixed using a ribbon blender; (4) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (5) a wet mixer is used to mix the above composite gel, glycerol and water, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humidity and mechanical strength of a reconstituted tobacco leaf; (6) the above solid and liquid components are stirred and mixed with a mixer, and a moisture content is maintained at 20-40wt% to obtain a dough-like substance; (7) the above dough-like substance is fed into an extruder, compressed and shaped into a parison, and then extruded; (8) the above parison is transferred onto a rolling mill and flattened into a flat and uniform foil with a thickness ranging from 0.10 mm to 0.30 mm using a hot roller under a high pressure; a temperature of the hot roller may be set within a range of 70°C to 200°C; and an extrusion pressure is in a range from 1 MPa to 5 MPa; (9) the foil prepared above is further dried using a drying device to reduce the moisture content to 5-10wt%; and (10) according to the final application requirements, the foil is wound on a roll or sliced or shredded to be used in a magnetic aerosol-forming matrix.

[0034] Embodiment 2: Preparation of magnetic reconstituted tobacco leaf particles, with steps as follows: (1) steps 1-7 in Embodiment 1 are used to prepare the parison; (2) the above parison is transferred to a rotary granulator, and broken into irregular particles by rotary granulation; (3) the irregular particles prepared above are further dried using a drying device to reduce a moisture content to 1-6wt%; (4) the dried irregular particles are sieved with a sieving machine to obtain particles with a particle size ranging from 0.5 mm to 2 mm; and (5) according to the final application requirements, the particles are wrapped or filled into an assembly of an aerosol product to be used in a magnetic aerosol-forming matrix.

[0035] Embodiment 3: Preparation of a magnetic laminated reconstituted tobacco leaf, with steps as follows: (1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) solid natural binders such as guar gum, xanthan gum, or carboxymethyl cellulose (CMC) are mixed using a ribbon blender; (4) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (5) a wet mixer is used to mix the above composite gel, glycerol and propylene glycol, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humidity and mechanical strength of a reconstituted tobacco leaf; (6) the above solid and liquid components are mixed with a high-speed turbine, and a moisture content is maintained at 20-50wt% to obtain semi-wet powder to maintain a lower drying cost; (7) by three-stage lamination, the above semi-wet powder is formed into a foil with a thickness ranging from 0.10 mm to 0.30 mm through several sets of high-pressure rollers having a molding function and set at different heating temperatures; a first-stage laminating temperature is in a range from 70°C to 100°C, a second-stage laminating temperature is in a range from 120°C to 150°C, and a third-stage laminating temperature is in a range from 160°C to 200°C; and a laminating pressure gradually increases from 1 MPa in the first stage to 3 MPa in the second stage, and then to 5 MPa in the third stage; (8) the foil prepared above is further dried using a drying device to reduce the moisture content to 5-10wt%; and (9) according to the final application requirements, the foil is sliced or shredded to be used in an aerosol-forming matrix.

[0036] Embodiment 4: Preparation of a magnetic laminated reconstituted tobacco leaf foil, with steps as follows: (1) a roll-form sheet base is prepared in advance using cellulose fibers and tobacco fibers; (2) steps 1-6 in Embodiment 1 are used to prepare semi-wet powder; (3) the above semi-wet powder together with the above sheet base are subjected to three-stage lamination, wherein the specific operation is the same as that in (7) in Embodiment 1; and after lamination, the semi-wet powder is combined onto one side of the sheet base; (4) the sheet base with the semi-wet powder combined onto one side is dried, and then the semi-wet powder is combined onto the other side of the sheet base according to step (3) above; (5) the foil with the semi-wet powder combined onto two sides is dried to reduce the moisture content to 5-10wt% using a drying device; and (6) according to the final application requirements, the foil is sliced or shredded to be used in an aerosol-forming matrix.

[0037] Embodiment 5: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (4) a wet mixer is used to mix the above composite gel, glycerol and propylene glycol, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humidity and mechanical strength of a reconstituted tobacco leaf; (5) the above solid and liquid components are mixed with a high-speed turbine, and a moisture content is maintained at 20-50wt% to obtain semi-wet powder to maintain a lower drying cost; (6) a laminating roller is immersed in a mixed binder bath of solid natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and a binder layer is attached to a surface of the roller; (7) by three-stage lamination, the above semi-wet powder is formed into a foil with a thickness ranging from 0.10 mm to 0.30 mm through several sets of high-pressure rollers coated with the binder layer, set at different heating temperatures and having a molding function; a first-stage laminating temperature is in a range from 70°C to 100°C, a second-stage laminating temperature is in a range from 120°C to 150°C, and a third-stage laminating temperature is in a range from 160°C to 200°C; and a laminating pressure may be maintained constant in multiple stages, such as 5 MPa; (8) the foil prepared above is further dried using a drying device to reduce the moisture content to 5-10wt%; and (9) according to the final application requirements, the foil is sliced or shredded to be used in an aerosol-forming matrix.

[0038] Embodiment 6: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) a certain proportion of tobacco leaves and tobacco stems are mixed and pulped, a mixed pulp and a wood pulp are mixed again, water is added to adjust the concentration to 1-5wt%, and further pulping is performed to obtain a tobacco pulp; (2) after the tobacco pulp is subjected to defibrination using a fluffer, water is added to adjust the concentration to 0.2-2wt%, and the tobacco pulp is transferred into a stirring device to be stirred; and a nanofiber dispersion and a magnetic nanowire suspension are mixed and stirred, an adhesive solution and a surfactant are added for mixing, and stirring is continued to obtain a magnetic nanocomposite fiber pulp; wherein the adhesive solution includes a mixture of natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and other solutions; (3) a magnetic pulp is obtained by mixing and stirring the above tobacco pulp and magnetic nanocomposite fiber pulp, wherein a mass percentage of magnetic nanocomposite fibers is, for example, in a range from 1wt% to 5wt%; a magnetic tobacco sheet base is obtained by performing directional arrangement and papermaking using a sheet former; or, a magnetic multi-layer tobacco sheet base with a core layer of magnetic nanocomposite fibers is obtained by performing papermaking using a sheet former; (4) a wet coating material and a semi-wet coating material are prepared, wherein the steps are as follows: (a) a tobacco material and a fiber material are broken to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; and then a solid natural binder is added and mixed evenly; (b) glycerol, propylene glycol, and water are added and mixed, and a moisture content is maintained at 50-80wt% to obtain the wet coating material; or a moisture content is maintained at 20-50wt% to obtain the semi-wet coating material; (51) three-stage lamination is performed on the magnetic tobacco sheet base obtained from step (3) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (61) the magnetic reconstituted tobacco leaf sheet base obtained from step (51) is coated with the wet coating material from step (4), and drying is performed to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (52) the tobacco sheet base from step (3) is coated with the semi-wet coating material from step (4); and (62) three-stage lamination is performed on the coated tobacco sheet base from step (52) to obtain a magnetic reconstituted tobacco leaf with a thickness ranging from 0.10 mm to 0.30 mm, and drying is performed to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; according to the final application requirements, the obtained magnetic reconstituted tobacco leaf foil is wound, or sliced or shredded to be used in an aerosol-forming matrix.

[0039] Three-stage lamination in steps (51) and (62) uses high-pressure rollers having a molding function and set at different heating temperatures; wherein a first-stage laminating temperature is in a range from 70°C to 100°C, a second-stage laminating temperature is in a range from 120°C to 150°C, and a third-stage laminating temperature is in a range from 160°C to 200°C. A laminating pressure is maintained constant in multiple stages, such as 5 MPa; or the laminating pressure may gradually increase, for example, from 1 MPa in the first stage to 3 MPa in the second stage, and then to 5 MPa in the third stage.

[0040] Embodiment 7: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) after an adhesive solution is added to the tobacco pulp prepared according to step (1) in Embodiment 1, a tobacco sheet base is obtained by papermaking using a standard sheet former; wherein the adhesive solution includes a mixture of natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and other solutions; (2) preparation of a magnetic coating material: vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; the composite gel of the mixed nanofiber dispersion and the magnetic nanowire suspension is added into a mixed pulp including but not limited to tobacco mixture powder, a tobacco extract, glycerol, propylene glycol and water, the adhesive solution and a surfactant are added and mixed evenly to obtain the magnetic coating material, and a solid content is maintained at 50-80%; wherein the adhesive solution includes a mixture of natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and other solutions; and the surfactant is polyvinylpyrrolidone (PVP); (3) the tobacco sheet base is coated with the above magnetic coating material, and drying is performed to obtain a magnetic tobacco sheet; (4) three-stage lamination as that in Embodiment 1 is performed to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; and (5) the foil prepared above is further dried using a drying device to reduce the moisture content to 5-10wt%, so that the magnetic reconstituted tobacco leaf foil is obtained; and according to the final application requirements, the foil is wound, or sliced or shredded.

[0041] Embodiment 8: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) one or more of wood pulp fibers, hemp pulp fibers, and tobacco fibers are screened and then crushed and defibrinated to obtain defibrinated fibers; and dry airflow forming is performed on the defibrinated fibers to form a thin fiber layer; (3) a nanofiber dispersion and a magnetic nanowire suspension are added into a stirring device, an adhesive solution is added, and stirring is performed to obtain a magnetic pulp; the adhesive solution includes a mixture of natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and other solutions, and a surfactant is, for example, polyvinylpyrrolidone (PVP); and then plant polysaccharides are added and mixed to form a magnetic coating solution, wherein the plant polysaccharides include but are not limited to starch, cellulose, polysaccharides, pectin, etc.; (4) a wet coating material and a semi-wet coating material are prepared as that in

[0042] Embodiment 1; (51) three-stage lamination as that in Embodiment 1 is performed on the magnetic tobacco sheet base obtained from step (3) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (61) the magnetic reconstituted tobacco leaf sheet base obtained from step (51) is coated with the wet coating material from step (4), and drying is performed to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (52) the tobacco sheet base from step (3) is coated with the semi-wet coating material from step (4); and (62) three-stage lamination as that in Embodiment 1 is performed on the coated tobacco sheet base from step (52), and drying is performed to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; and according to the final application requirements, the foil is wound, or sliced or shredded.

[0043] 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, the present invention can have various changes and variations. Any modification, equivalent replacement, improvement and the like made in the spirit and principle of the present invention shall all be contained in the scope of protection of the present invention.

Examples

embodiment 1

[0033] Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows:

(1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) solid natural binders such as guar gum, xanthan gum, carboxymethyl cellulose (CMC), and others are mixed using a ribbon blender; (4) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (5) a wet mixer is used to mix the above composite gel, glycerol and water, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humidity and...

embodiment 2

[0034] Preparation of magnetic reconstituted tobacco leaf particles, with steps as follows:

(1) steps 1-7 in Embodiment 1 are used to prepare the parison; (2) the above parison is transferred to a rotary granulator, and broken into irregular particles by rotary granulation; (3) the irregular particles prepared above are further dried using a drying device to reduce a moisture content to 1-6wt%; (4) the dried irregular particles are sieved with a sieving machine to obtain particles with a particle size ranging from 0.5 mm to 2 mm; and (5) according to the final application requirements, the particles are wrapped or filled into an assembly of an aerosol product to be used in a magnetic aerosol-forming matrix.

embodiment 3

[0035] Preparation of a magnetic laminated reconstituted tobacco leaf, with steps as follows:

(1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) solid natural binders such as guar gum, xanthan gum, or carboxymethyl cellulose (CMC) are mixed using a ribbon blender; (4) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (5) a wet mixer is used to mix the above composite gel, glycerol and propylene glycol, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humid...

TECHNICAL FIELD

[0001] The present invention belongs to the technical field of tobaccos, and particularly relates to a reconstituted tobacco leaf, a preparation method therefor, and use thereof.BACKGROUND

[0002] Existing heat-not-burning aerosol products typically use reconstituted tobacco leaves or tobacco particles as an aerosol-forming matrix. A thick pulp method and a papermaking method are main methods for producing existing reconstituted tobacco leaves for heat-not-burning aerosol products. The thick pulp method requires drying to remove a large amount of water, and the process has high energy consumption; and a finished product is brittle, has low strength, and may cause high reconstitution losses during cutting. The papermaking method causes significant loss of aromatic substances in a finished product, and drying for water removal also requires a large amount of energy consumption and a complex drying process.

[0003] The existing aerosol products commonly use an induction heating method to atomize the required components in the aerosol-forming matrix from the products, so as to form inhalable aerosol. In existing induction heating aerosol products, a receptor is a separate element 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 type heating is that the induction heat of the receptor is transferred from a center of the aerosol-forming matrix in contact with it to its periphery, and the heat is significantly attenuated from the inside out. The disadvantage of circumferential type heating is that the induction heat of the receptor penetrates through a wrapping material from an outer periphery of the aerosol-forming matrix wrapping material in contact with it and then is transferred to the center of the aerosol-forming matrix, and the heat is significantly attenuated from the outside in. Therefore, in order to achieve an expected atomization effect of the aerosol-forming matrix, it is necessary to extend a preheating time of the products and increase a maximum heating temperature, thereby improving output power of an inductor. This not only causes low thermal utilization efficiency and uneven heat distribution of the aerosol-forming matrix, but also increases energy consumption of a heating device for heating the aerosol products.

[0004] Therefore, the present invention is proposed.SUMMARY

[0005] To alleviate the above defects, the present invention proposes a magnetic reconstituted tobacco leaf foil and magnetic reconstituted tobacco leaf particles which integrate a magnetic induction material into an aerosol-forming matrix, and a manufacturing method therefor, aiming to increase utilization efficiency of induction heat and a heating rate and reduce energy consumption of a heating device when using aerosol products made of a magnetic aerosol-forming matrix, and save manufacturing costs.

[0006] The technical solutions of the present invention are as follows: A first aspect of the present invention discloses a magnetic reconstituted tobacco leaf, including a magnetic reconstituted tobacco leaf foil and / or magnetic reconstituted tobacco leaf particles. A thickness of the magnetic reconstituted tobacco leaf foil is in a range from 0.10 mm to 0.30 mm, and a particle size of the magnetic reconstituted tobacco leaf particles is in a range from 0.5 mm to 2 mm. A composition of the magnetic reconstituted tobacco leaf includes a fiber material, a tobacco material, nanofibers, and a magnetic material; and the magnetic material is a material that can be converted into heat after absorbing an alternating magnetic field.

[0007] Preferably, the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is magnetic nanoparticles and / or magnetic nanowires; and the magnetic nanowires have a length ranging from 5 µm to 100 µm and a diameter ranging from 5 nm to 500 nm.

[0008] Preferably, the nanofibers are plant nanofibers and / or tobacco nanofibers; the nanofibers have a length ranging from 1 µm to 10 µm and a diameter ranging from 5 nm to 500 nm; and the fiber material is a cellulose fiber and / or tobacco fiber material.

[0009] A second aspect of the present invention discloses a preparation method of a magnetic reconstituted tobacco leaf, including the following steps: (1) making a tobacco material and a fiber material into powder with a particle size ranging from 60 meshes to 120 meshes, adding a binder and mixing to obtain a solid mixture, wherein the binder is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; (2) obtaining nanofiber and magnetic nanowire composite gel by using a method of vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanowire suspension; and adding glycerol, water, and a surfactant polyvinylpyrrolidone and mixing evenly to obtain a liquid mixture; (3) stirring and mixing the solid mixture from step (1) and the liquid mixture from step (2) to obtain a dough-like substance with a moisture content of 20-40wt%; (4) compressing and shaping the dough-like substance obtained from step (3) into a parison by using an extruder; (5) obtaining a foil with a thickness ranging from 0.10 mm to 0.30 mm by performing multi-stage lamination on the parison obtained from step (4) at a certain temperature, and then drying the foil to reduce a moisture content to 5-10wt%, so as to obtain a reconstituted tobacco leaf foil; or, (6) breaking the parison obtained from step (4) into irregular particles by using a rotary granulator, and drying the irregular particles to reduce a moisture content to 1-6wt%; and sieving to obtain particles with a particle size ranging from 0.5 mm to 2 mm, so as to obtain reconstituted tobacco leaf particles.

[0010] Alternatively, the preparation method of the magnetic reconstituted tobacco leaf includes the following steps: (A) preparing a semi-wet mixture formed by a tobacco material, nanofibers, and a magnetic nanomaterial, wherein the method is as follows: adding a surfactant polyvinylpyrrolidone, glycerol and propylene glycol, and preparing nanofiber and magnetic nanomaterial composite gel, namely the semi-wet mixture, by using a method of consecutive vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanomaterial suspension; (B) inserting the semi-wet mixture from step (A) into a laminating roller and performing multi-stage lamination at a certain temperature to obtain a sheet with a thickness ranging from 0.10 mm to 0.30 mm; and applying a binder layer onto a surface of the laminating roller before inserting a sheet base into the laminating roller; or (C) preparing a cellulose fiber and / or tobacco fiber sheet base; (D) applying the semi-wet mixture from step (A) onto the sheet base from step (C), then inserting the obtained sheet base into a laminating roller and performing multi-stage lamination at a certain temperature to obtain a sheet with a thickness ranging from 0.10 mm to 0.30 mm; and applying a binder layer onto a surface of the laminating roller before inserting the sheet base into the laminating roller; a binder used in the binder layer is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; and (E) drying the sheet obtained from step (B) or step (D) to reduce a moisture content to 5-10wt%, so as to obtain a magnetic laminated reconstituted tobacco leaf foil.

[0011] Alternatively, the preparation method of the magnetic reconstituted tobacco leaf includes the following steps: (a) pulping a tobacco material and a fiber material, and then performing defibrination to obtain a tobacco pulp; (b) mixing a nanofiber dispersion and a magnetic nanowire suspension, then adding an adhesive solution and a surfactant polyvinylpyrrolidone and mixing to obtain a magnetic nanocomposite fiber pulp; (c) obtaining a magnetic pulp by mixing the tobacco pulp from step (a) and the magnetic nanocomposite fiber pulp from step (b), wherein a mass percentage of magnetic nanocomposite fibers is in a range from 1wt% to 5wt%; and obtaining a magnetic tobacco sheet base by performing directional arrangement and papermaking using a sheet former; or, obtaining a magnetic tobacco sheet base with a core layer of magnetic nanocomposite fibers by performing papermaking using a sheet former; (d) preparing a wet coating material and a semi-wet coating material, wherein the steps are as follows: breaking a tobacco material and a fiber material to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; then adding a solid natural binder and mixing evenly; adding and mixing glycerol, propylene glycol, and water, and maintaining a moisture content of 50-80wt% to obtain the wet coating material; and performing dehydration to make a moisture content to be 20-50wt% to obtain the semi-wet coating material; wherein the binder is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; (e1) performing multi-stage lamination on the magnetic tobacco sheet base obtained from step (c) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (f1) coating the magnetic reconstituted tobacco leaf sheet base obtained from step (e1) with the wet coating material from step (4), and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (e2) coating the tobacco sheet base from step (c) with the semi-wet coating material from step (d); and (f2) performing multi-stage lamination on the coated tobacco sheet base from step (e2), and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil.

[0012] Alternatively, the preparation method of the magnetic reconstituted tobacco leaf includes the following steps: 1) pulping a tobacco material and a fiber material, and then performing defibrination to obtain a tobacco pulp; 2) adding an adhesive solution and a surfactant polyvinylpyrrolidone to the tobacco pulp from step 1) and mixing to obtain a composite fiber tobacco pulp; and obtaining a tobacco sheet base by performing papermaking using a sheet former; 3) preparing a magnetic coating material, wherein the steps are as follows: obtaining nanofiber and magnetic nanowire composite gel by vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanowire suspension; adding the obtained composite gel to a mixed pulp of tobacco mixture powder, a tobacco extract, glycerol, propylene glycol and water, then adding an adhesive solution, and mixing evenly to obtain the magnetic coating material, wherein a solid content is kept at 50-80wt%; 4) coating the tobacco sheet base from step 2) with the magnetic coating material from step 3), and drying to obtain a magnetic tobacco sheet; 5) performing multi-stage lamination on the magnetic tobacco sheet obtained from step 4) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; and 6) drying the prepared magnetic reconstituted tobacco leaf sheet base to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil.

[0013] Alternatively, the preparation method of the magnetic reconstituted tobacco leaf includes the following steps: (I) crushing and defibrinating a tobacco material and a fiber material, and obtaining a thin fiber layer by performing dry airflow forming on defibrinated fibers; (II) mixing a nanofiber dispersion and a magnetic nanowire suspension, adding an adhesive solution and a surfactant polyvinylpyrrolidone and mixing to obtain a magnetic nanocomposite fiber pulp; and then adding a plant polysaccharide and mixing to form a magnetic coating solution; (III) spraying the magnetic coating solution from step (II) onto the thin fiber layer from step (I) and then shaping the thin fiber layer into a magnetic tobacco sheet base; (IV) preparing a wet coating material and a semi-wet coating material, wherein the steps are as follows: breaking a tobacco material and a fiber material to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; then adding a solid natural binder and mixing evenly; adding and mixing glycerol, propylene glycol, and water, and maintaining a moisture content of 50-80wt% to obtain the wet coating material; and performing dehydration to make a moisture content to be 20-50wt% to obtain the semi-wet coating material; wherein the binder is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; (LI) performing multi-stage lamination on the magnetic tobacco sheet base obtained from step (III) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (LXI) coating the magnetic reconstituted tobacco leaf sheet base from step (LI) with the wet coating material from step (IV), and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (LII) coating the tobacco sheet base from step (III) with the semi-wet coating material from step (IV); and (LXII) performing multi-stage lamination on the coated tobacco sheet base from step (LII) at a certain temperature, and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil.

[0014] Preferably, a pressure for multi-stage lamination is in a range from 1 MPa to 5 MPa and a temperature is in a range from 70°C to 200°C.

[0015] A third aspect of the present invention discloses use of the magnetic reconstituted tobacco leaf as a magnetic aerosol-forming matrix.

[0016] The magnetic reconstituted tobacco leaf for the magnetic aerosol-forming matrix in the present invention includes a magnetic reconstituted tobacco leaf foil and magnetic reconstituted tobacco leaf particles. The magnetic reconstituted tobacco leaf contains a tobacco mixture, nanofibers, and a magnetic material. The nanofibers may be wood nanofibers and / or tobacco nanofibers. The nanofibers may be other plant nanofibers. The nanofibers have a diameter ranging from 5 nm to 100 nm and a length ranging from 1 µm to 10 µm, respectively.

[0017] The magnetic material is any material that can be converted into heat after absorbing an alternating magnetic field, such as a ferromagnetic material or a ferrimagnetic material. Specifically, the magnetic material is, for example, iron or an iron alloy such as stainless steel, nickel, and a nickel alloy such as a corrosion-resistant Fe-Ni-Cr alloy, etc. Preferably, the magnetic material is a magnetic nanomaterial, such as nanoparticles, nanosheets, nanospheres, nanorods, nanotubes, and nanowires, especially nanoparticles and / or nanowires. The nanoparticles and / or the nanowires include but are not limited to nickel, cobalt, iron nickel, cobalt nickel, cobalt iron, iron cobalt nickel, iron molybdenum nickel, and other materials and alloys thereof. The magnetic material is preferably magnetic nanowires. The magnetic material has a length ranging from 5 µm to 100 µm, and an average diameter ranging from 5 nm to 500 nm.

[0018] The magnetic reconstituted tobacco leaf foil is obtained by extruding and rolling a tobacco mixture, nanofibers, and a magnetic nanomaterial. The magnetic reconstituted tobacco leaf particles are obtained by extruding, granulating, and sieving a tobacco mixture, nanofibers, and a magnetic nanomaterial. A preparation method for the magnetic reconstituted tobacco leaf includes: forming a dough-like substance of tobacco, nanofibers, and a magnetic nanomaterial; adding a surfactant such as polyvinylpyrrolidone (PVP) to a mixture of the tobacco, the nanofibers, and the magnetic nanomaterial to facilitate combination of the magnetic nanomaterial and the nanofibers; obtaining nanofiber and magnetic nanomaterial composite gel by using a method of consecutive vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanomaterial suspension; extruding the dough-like substance, so that the magnetic nanomaterial is thermally extruded to form an interconnected magnetic conducting pathway and is tightly combined with an extruded reconstituted tobacco leaf parison; and applying a temperature to a rolling roller, so that the magnetic nanomaterial is thermally laminated or further nanowelded to form an interconnected magnetic conducting pathway and more tightly combined with the reconstituted tobacco leaf as a whole to obtain a reconstituted tobacco leaf foil. A thickness of the foil may be controlled by adjusting a rolling roller spacing; and the obtained magnetic reconstituted tobacco leaf foil may be rolled, sliced or shredded, and then subjected to subsequent processing for use in the magnetic aerosol-forming matrix. The tobacco material may be tobacco powder, debris, tobacco stems, etc.

[0019] The magnetic reconstituted tobacco leaf foil is used for the aerosol-forming matrix, and may be rolled, sliced or shredded, and then subsequently processed to form the aerosol-forming matrix. The magnetic aerosol-forming matrix contains materials that can be atomized into inhalable aerosols at an appropriate temperature. The atomized aerosols contain an atomizing agent, an aromatic substance, and / or nicotine, and may further contain other inhalable components. The magnetic aerosol-forming matrix and a wrapping material are combined to form an aerosol generation section, which is then combined with other parts including a support section, a cooling section, and a filter section to form an aerosol product.

[0020] The present invention has the following beneficial effects: According to the preparation method for the magnetic reconstituted tobacco leaf in the present invention, a heater on an extruder may heat the dough-like substance through heat conduction in a process of extruding the dough-like substance by the extruder. In addition, the dough-like substance rubs and shears against a cylinder and a screw of the extruder, and a material of the dough-like substance during its movement, and a large amount of heat may be generated, so that the magnetic nanomaterial in the parison is thermally extruded. When the extruded parison is high-pressure hot pressed into the foil on a rolling mill, the magnetic nanomaterial therein further undergoes thermal lamination and nanowelding. Thermal lamination and nanowelding can completely remove the surfactant components (such as PVP) wrapped around the magnetic nanowires and sinter magnetic nanowire joints, thereby significantly reducing contact resistance, constructing the interconnected, robust, and stable magnetic nanowire magnetic conduction pathway and eddy current network, and significantly improving a tensile strength of the reconstituted tobacco leaf foil. Thermal lamination and nanowelding can further significantly increase a heating temperature of the magnetic reconstituted tobacco leaf foil, as the resistance significantly decreases after welding, leading to an increase in induced eddy current and electron transfer capacity inside the reconstituted tobacco leaf foil. Nanowelding can improve induction heating performance and reduce the use cost of the magnetic material without increasing the content of the magnetic nanowires.

[0021] According to the preparation method in the present invention, through consecutive multiple high-pressure homogenization (generally not less than three times), the nanofibers and the magnetic nanomaterial can be uniformly and firmly dispersed into a reconstituted tobacco substrate. Vacuum-assisted filtration is beneficial for the nanofibers to form an entangled network through a hydrogen bond, thereby obtaining a super rigid nanostructure with high thermal stability and high transparency, and further enhancing high temperature resistance and a mechanical strength of the magnetic reconstituted tobacco leaf. Adding the surfactant such as the polyvinylpyrrolidone (PVP) during a manufacturing process can wrap the magnetic nanomaterial such as the magnetic nanowires. Through a strong hydrogen bond interaction between a carbonyl of an additive and a hydroxyl of the nanofibers, the magnetic nanowires partially wrapped by cellulose act as a skeleton, promoting load transfer and energy dissipation during a stretching process of the magnetic reconstituted tobacco leaf, dispersing stress, and achieving excellent mechanical properties and structural stability. Multi-stage thermal lamination and nanowelding can completely remove the surfactant components (such as PVP) wrapped around the magnetic nanowires and sinter magnetic nanowire joints, thereby significantly reducing the contact resistance, constructing the interconnected, robust, and stable magnetic nanowire magnetic conduction pathway and eddy current network, and significantly improving the tensile strength of the reconstituted tobacco leaf foil. Multi-stage thermal lamination and nanowelding can further significantly increase the heating temperature of the magnetic reconstituted tobacco leaf, as the resistance significantly decreases after welding, leading to an increase in induced eddy current and electron transfer capacity inside the reconstituted tobacco leaf. Nanowelding can improve the induction heating performance and reduce the use cost of the magnetic material without increasing the content of the magnetic nanowires.

[0022] Compared to a traditional process for reconstituting tobacco leaves through a papermaking method and a thick pulp method, the manufacturing process for the magnetic reconstituted tobacco leaf foil and the reconstituted tobacco particles of the present invention requires less water, significantly reduces drying procedures, and lowers production energy consumption. Due to the faster drying of the foil, the finished reconstituted tobacco leaf has a stronger ability to retain aroma substances and nicotine, allowing for the use of fewer binders, which reduces the impact of unpleasant odors generated during the heating process of aerosol products on smoking taste. By precisely adjusting the roller spacing of the rolling mill, the thickness of the finished reconstituted tobacco leaf is uniformly controlled, and the precision and stability of its thickness help ensure the consistency of downstream processes and ensure that important product indicators such as a nicotine content are within the specified range. Due to the increased stability and reliability of the reconstituted tobacco leaf, the working stability of the heating device is also greatly improved. According to the preparation method of the present invention, drying preheating of tobacco debris and fibers is not necessary. Due to the material bonding effect inherent in an extrusion molding process, the use amount of the binder may be significantly decreased. Therefore, the raw material and production costs may be further reduced. The tobacco material used in the present invention may be tobacco powder, debris, tobacco stems, etc., which can reduce the cost of using pure tobacco leaves as raw materials for traditional granular aerosol products. According to the preparation method of the present invention, the same raw material and extrusion process are used to prepare the parison required for the reconstituted tobacco leaf foil and the reconstituted tobacco particles, thereby saving the floor space and capital investment of production equipment, and facilitating the simultaneous manufacturing of two types of products such as the reconstituted tobacco leaf foil and the reconstituted tobacco particles.

[0023] The fiber material of the present invention is a cellulose fiber and / or tobacco fiber material, with flexible nanofibers intertwined with each other to create a nanoscale network. On the one hand, the strength of the fiber network is enhanced by increasing the number of hydrogen bonds in each fibril or the number of hydrogen bonds between the fibers. On the other hand, 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 the reconstituted tobacco leaf. Meanwhile, the highly-active hydroxyl in the nanofibers can be modified through chemical and physical treatments to achieve desired properties, such as increasing its adhesion to the magnetic material.

[0024] The magnetic reconstituted tobacco leaf 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 a flexible magnetic conduction circuit and an eddy current network. The magnetic reconstituted tobacco leaf of the present invention has the characteristics of low driving voltage, fast heating, and high heating temperature, which can meet the requirements of energy saving, fast heating, and instant use when using the aerosol products. When the magnetic reconstituted tobacco leaf of the present invention is used for the magnetic aerosol-forming matrix, the magnetic material therein serves as a receptor, is uniformly distributed throughout the aerosol-forming matrix and forms a magnetic conduction pathway. It is different from existing induction heating type aerosol products, where the receptor is a separate element 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 type heating is that the induction heat of the receptor is transferred from a center of the aerosol-forming matrix in contact with it to its periphery, and the heat is significantly attenuated from the inside out. The disadvantage of circumferential type heating is that the induction heat of the receptor penetrates through a wrapping material from an outer periphery of the aerosol-forming matrix wrapping material in contact with it and then is transferred to the center of the aerosol-forming matrix, and the heat is significantly attenuated from the outside in. The integrated heating of the magnetic reconstituted tobacco leaf in the present invention is the induction heat distributed throughout the aerosol-forming matrix after the magnetic material in the entire aerosol-forming matrix receives an alternating magnetic field of radiation. The disadvantage of existing central type induction heating further includes that the insertion and pull-out of the receptor on the heating device is prone to causing the aerosol-forming matrix to move. Specifically, when inserted, it causes the aerosol-forming matrix to be pushed towards a suction nozzle end of the aerosol product, which affects heat transfer, aerosol generation, and suction force. When pulled out, it causes some aerosol-forming matrixes to be brought out into the heating device along with the receptor, as well as a problem of cleaning residues caused by atomized condensate remaining on the surface of the receptor. The above-mentioned method of embedding the receptor in the aerosol product poses difficulties for the processing, placement, and positioning of the receptor in the aerosol-forming matrix during the manufacturing process of the product. The receptor of the present invention is homogeneously formed in an integrated manner with the magnetic reconstituted tobacco leaf foil and the magnetic reconstituted tobacco leaf particles during the manufacturing process, without the need for additional receptor processing, aerosol-forming matrix placement and positioning equipment. There is also no problem of movement of the aerosol-forming matrix and residue cleaning during the use of the aerosol product.

[0025] The magnetic material in the magnetic reconstituted tobacco leaf of the present invention has a uniform layered network-type distribution in the reconstituted tobacco leaf foil and a uniform spherical network-type distribution in the particles, which greatly shortens a magnet-heat conversion path. The magnetic material in the aerosol-forming matrix basically instantaneously transfers its heat to the entire aerosol-forming matrix. The heat utilization efficiency of the aerosol-forming matrix is greatly improved, which in turn greatly reduces the energy consumption of the heating device. Moreover, since the aerosol-forming matrix itself is an induction heating element of the aerosol product containing it, there is no need to arrange an additional receptor inside the aerosol product (such as inside the aerosol-forming matrix) or on the heating device on the periphery, which greatly reduces the volume of the heating device and lowers the manufacturing difficulty of the aerosol product, thereby not only saving the manufacturing costs but also facilitating the portability of the heating device.

[0026] The existing induction heating type aerosol product belongs to a heat transfer manner from local to overall. The receptor heat source requires a high temperature to ensure sufficient heat transfer to the entire aerosol-forming matrix. At the same time, in order to meet the atomization requirements of the aerosol-forming matrix and then achieve the inhalability requirements of the aerosol generated by atomization, the heat accumulation in the aerosol-forming matrix needs to be sufficient, which brings two technical bottlenecks: first, the initial temperature of the receptor needs to be high enough, and second, 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 prevents a consumer from using the product quickly. The way of using the magnetic reconstituted tobacco leaf of the present invention for the magnetic aerosol-forming matrix is not to apply an entire bulky magnetic material on the surface or interior of the aerosol-forming matrix. Instead, by adjusting an area fraction of a small amount of magnetic nanomaterial in it, the magnetic nanomaterial is spread in the reconstituted tobacco leaf foil through hot extrusion, thermal lamination, and nanowelding, or the magnetic nanomaterial is mixed evenly in the reconstituted tobacco particles through rotational extrusion during hot extrusion and rotary granulation processes, thus the magnetic induction surface area is greatly increased, and the interconnectivity of the magnetic nanomaterial is improved. Due to the thin thickness (0.10-0.30 mm) of the magnetic reconstituted tobacco leaf foil and the small particle size (0.5-2 mm) of the magnetic reconstituted tobacco leaf particles, a skin depth of the magnetic field inside the magnetic nanomaterial is significantly reduced. This not only reduces the attenuation of magnetic flux, but also greatly lowers the resistance of the magnetic network. Therefore, under the influence of increased electrical conductivity and decreased thermal resistance, the initial temperature set by the heating device may be controllably reduced, and the temperature may be raised to the set operating temperature in a very short time, thereby greatly shortening the preheating waiting time of the heating device and achieving immediate use of the product. Similarly, the aerosol product may be cooled from the operating temperature to a room temperature in a very short period of time, thereby significantly reducing the heat accumulation problem in the aerosol-forming matrix and ensuring consistent experience of the aerosol product throughout each usage cycle. Due to the increased electrical conductivity and reduced thermal resistance, the magnetic reconstituted tobacco leaf of the present invention may choose a magnetic material with intrinsic Curie temperature close to the actual operating temperature, without the need to choose a magnetic material with high Curie temperature beyond the actual operating temperature. This makes the temperature control of the heating device easier and more accurate.

[0027] The vacuum-assisted filtration method used in the present invention is a method of coating the magnetic material in a suspension form on the surfaces of nanofibers using vacuum filtration. A vacuum-assisted filtration technology greatly increases a deposition rate of the nanomaterial, has fewer losses of the nanomaterial during the preparation process, and thus is a very simple and convenient method for preparing multifunctional nanocomposites. The vacuum-assisted filtration technology facilitates the formation of the entangled network of the nanofibers through a hydrogen bond, thereby obtaining the super rigid nanostructure with high thermal stability and high transparency, and further enhancing the high temperature resistance and mechanical strength of the magnetic aerosol-forming matrix.

[0028] The present invention uses the ferromagnetic nanowires to further illustrate the advantages of the prepared magnetic reconstituted tobacco leaf as follows. 1. By controlling the use amount of the magnetic nanowires or driving voltage, it is easy to adjust the heating performance of the magnetic reconstituted tobacco leaf. For example, when the driving voltage is constant, the magnetic reconstituted tobacco leaf with the high content of ferromagnetic nanowires (such as Fe-Ni NWs) have reduced resistance and thus increased heating temperature. Due to an efficient Fe-Ni NWs embedding structure and an interconnected electromagnetic Fe-Ni NWs skeleton, the high temperature can be achieved under the lower driving voltage by moderately increasing the area fraction of the Fe-Ni NWs. Typically, when the area fraction of the Fe-Ni NWs is 0.5 g / m 2< , the temperature may rise to 200°C or above within 10 seconds under a 3V driving voltage. Alternatively, when the area fraction of the Fe-Ni NWs is 1.0 g / m 2< , the temperature may rise to 250°C or above within 7 seconds under a 2V driving voltage. The beneficial effect of obtaining the high temperature with the low driving voltage is to save electric energy and reduce energy consumption. 2. When the alternating magnetic field is applied to the prepared magnetic reconstituted tobacco leaf, Joule heat is generated by the inelastic collision between eddy current electrons accelerated by induction in the magnetic nanowires and phonons, causing the aerosol-forming matrix to rapidly heat up. However, when applying of the alternating magnetic field to the aerosol-forming matrix is stopped, the temperature of the magnetic reconstituted tobacco leaf rapidly decreases due to the absence of Joule heat. Especially when the area of the magnetic reconstituted tobacco leaf is significantly reduced (such as processing the magnetic reconstituted tobacco leaf foil into short filaments, fine filaments, or fragmented shapes), due to the significant increase in eddy current density and power density, the heating and cooling rates rapidly increase, with the potential for rapid heating and cooling in the order of 1 second or even milliseconds. This is beneficial for reducing the subsequent sensory changes caused by the accumulation of previous heat in the aerosol-forming matrix during the use of the magnetic reconstituted tobacco leaf for the aerosol product. At the same time, the use experience is improved by significantly reducing the preheating waiting time. Another beneficial effect is that electric energy consumed to heat the magnetic reconstituted tobacco leaf to the desired temperature for use in the aerosol product is reduced. 3. According to the preparation method of the present invention, the composite lamination technology for the tobacco material, the nanofibers and the magnetic nanomaterial has practical production flexibility and can accurately manipulate the properties of the final product. 4. The magnetic reconstituted tobacco leaf of the present invention has ideal tensile strength, aroma retention, magnetic controllability, and cost-effectiveness.

[0029] According to the preparation method for the magnetic reconstituted tobacco leaf foil of the present invention, based on a direction of the inductor-excited magnetic field passing through the aerosol-forming matrix and the distribution of magnetic flux lines, by directional arrangement and papermaking, the prepared magnetic tobacco sheet base has the magnetic material orientation and distribution that synergistically align with the direction of the inductor-excited magnetic field and the distribution of the magnetic flux lines, so that the magnetic reconstituted tobacco leaf foil prepared from the magnetic tobacco sheet base and even the aerosol-forming matrix can achieve the maximum magnetic field utilization efficiency and magnetic coupling strength when matching with the heating device. A magnetic multi-layer tobacco sheet base may be designed with magnetic materials having different numbers of layers according to the subsequent process requirements and characteristics of actual products, such as a sandwich-type tobacco sheet base, where the inner and outer layers are tobacco fibers and the middle core layer is magnetic nanocomposite fibers. By using the semi-wet coating material, compared with the traditional process for reconstituting tobacco leaves through the papermaking method and the thick pulp method, water consumption is significantly reduced, drying procedures are significantly reduced, and the production energy consumption is reduced. Due to the faster drying of the foil, the finished reconstituted tobacco leaf foil has a stronger ability to retain aroma substances and nicotine, allowing for the use of fewer binders, which reduces the impact of unpleasant odors generated during the heating process of the aerosol product on smoking taste.

[0030] The preparation method for the magnetic reconstituted tobacco leaf foil of the present invention includes the step of vacuum-assisted filtration to prepare the composite gel of the nanofibers and the magnetic nanowires, and the magnetic coating material obtained may be regarded as magnetic gel. The magnetic gel combines the characteristics of magnetism, high elasticity and flexibility, improves the film-forming property of the coating material, facilitates the uniform distribution of the magnetic material on the sheet base, and also improves the processing performance of a finished tobacco foil in processes such as coiling and gathering.

[0031] Compared to a traditional dry-process reconstituted tobacco leaf, the preparation method for the magnetic reconstituted tobacco leaf foil of the present invention obtains the thin fiber layer through the dry process and then applies the thin fiber layer for multi-stage lamination, which not only retains the looseness of the reconstituted tobacco leaf structure, but also enhances the hydrogen bond interaction with the thin fiber layer by the nanofibers, the magnetic nanowires, and polysaccharides contained in the magnetic coating solution, strengthens the sheet base setting effect and mechanical properties, and reduces the phenomena of powder falling, crushing, and fracture occurred in downstream shredding or forming processes.DETAILED DESCRIPTION

[0032] In order to clarify the objectives and technical solutions of the present invention, detailed illustration is made in conjunction with the following embodiments. The embodiments are intended to illustrate the content of the present invention, rather than further limiting the scope of protection of the present invention. The implementation process, conditions, reagents, experimental methods, etc., except for those specifically mentioned below, are all common knowledge and common sense in this field, and the content is not particularly limited in the present invention. The experimental methods without specific conditions specified in each embodiment are usually carried out under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, meanings of all professional terms and scientific expressions used in this specification have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. But in case of conflict, this specification containing definitions shall prevail.

[0033] Embodiment 1: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) solid natural binders such as guar gum, xanthan gum, carboxymethyl cellulose (CMC), and others are mixed using a ribbon blender; (4) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (5) a wet mixer is used to mix the above composite gel, glycerol and water, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humidity and mechanical strength of a reconstituted tobacco leaf; (6) the above solid and liquid components are stirred and mixed with a mixer, and a moisture content is maintained at 20-40wt% to obtain a dough-like substance; (7) the above dough-like substance is fed into an extruder, compressed and shaped into a parison, and then extruded; (8) the above parison is transferred onto a rolling mill and flattened into a flat and uniform foil with a thickness ranging from 0.10 mm to 0.30 mm using a hot roller under a high pressure; a temperature of the hot roller may be set within a range of 70°C to 200°C; and an extrusion pressure is in a range from 1 MPa to 5 MPa; (9) the foil prepared above is further dried using a drying device to reduce the moisture content to 5-10wt%; and (10) according to the final application requirements, the foil is wound on a roll or sliced or shredded to be used in a magnetic aerosol-forming matrix.

[0034] Embodiment 2: Preparation of magnetic reconstituted tobacco leaf particles, with steps as follows: (1) steps 1-7 in Embodiment 1 are used to prepare the parison; (2) the above parison is transferred to a rotary granulator, and broken into irregular particles by rotary granulation; (3) the irregular particles prepared above are further dried using a drying device to reduce a moisture content to 1-6wt%; (4) the dried irregular particles are sieved with a sieving machine to obtain particles with a particle size ranging from 0.5 mm to 2 mm; and (5) according to the final application requirements, the particles are wrapped or filled into an assembly of an aerosol product to be used in a magnetic aerosol-forming matrix.

[0035] Embodiment 3: Preparation of a magnetic laminated reconstituted tobacco leaf, with steps as follows: (1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) solid natural binders such as guar gum, xanthan gum, or carboxymethyl cellulose (CMC) are mixed using a ribbon blender; (4) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (5) a wet mixer is used to mix the above composite gel, glycerol and propylene glycol, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humidity and mechanical strength of a reconstituted tobacco leaf; (6) the above solid and liquid components are mixed with a high-speed turbine, and a moisture content is maintained at 20-50wt% to obtain semi-wet powder to maintain a lower drying cost; (7) by three-stage lamination, the above semi-wet powder is formed into a foil with a thickness ranging from 0.10 mm to 0.30 mm through several sets of high-pressure rollers having a molding function and set at different heating temperatures; a first-stage laminating temperature is in a range from 70°C to 100°C, a second-stage laminating temperature is in a range from 120°C to 150°C, and a third-stage laminating temperature is in a range from 160°C to 200°C; and a laminating pressure gradually increases from 1 MPa in the first stage to 3 MPa in the second stage, and then to 5 MPa in the third stage; (8) the foil prepared above is further dried using a drying device to reduce the moisture content to 5-10wt%; and (9) according to the final application requirements, the foil is sliced or shredded to be used in an aerosol-forming matrix.

[0036] Embodiment 4: Preparation of a magnetic laminated reconstituted tobacco leaf foil, with steps as follows: (1) a roll-form sheet base is prepared in advance using cellulose fibers and tobacco fibers; (2) steps 1-6 in Embodiment 1 are used to prepare semi-wet powder; (3) the above semi-wet powder together with the above sheet base are subjected to three-stage lamination, wherein the specific operation is the same as that in (7) in Embodiment 1; and after lamination, the semi-wet powder is combined onto one side of the sheet base; (4) the sheet base with the semi-wet powder combined onto one side is dried, and then the semi-wet powder is combined onto the other side of the sheet base according to step (3) above; (5) the foil with the semi-wet powder combined onto two sides is dried to reduce the moisture content to 5-10wt% using a drying device; and (6) according to the final application requirements, the foil is sliced or shredded to be used in an aerosol-forming matrix.

[0037] Embodiment 5: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (4) a wet mixer is used to mix the above composite gel, glycerol and propylene glycol, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humidity and mechanical strength of a reconstituted tobacco leaf; (5) the above solid and liquid components are mixed with a high-speed turbine, and a moisture content is maintained at 20-50wt% to obtain semi-wet powder to maintain a lower drying cost; (6) a laminating roller is immersed in a mixed binder bath of solid natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and a binder layer is attached to a surface of the roller; (7) by three-stage lamination, the above semi-wet powder is formed into a foil with a thickness ranging from 0.10 mm to 0.30 mm through several sets of high-pressure rollers coated with the binder layer, set at different heating temperatures and having a molding function; a first-stage laminating temperature is in a range from 70°C to 100°C, a second-stage laminating temperature is in a range from 120°C to 150°C, and a third-stage laminating temperature is in a range from 160°C to 200°C; and a laminating pressure may be maintained constant in multiple stages, such as 5 MPa; (8) the foil prepared above is further dried using a drying device to reduce the moisture content to 5-10wt%; and (9) according to the final application requirements, the foil is sliced or shredded to be used in an aerosol-forming matrix.

[0038] Embodiment 6: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) a certain proportion of tobacco leaves and tobacco stems are mixed and pulped, a mixed pulp and a wood pulp are mixed again, water is added to adjust the concentration to 1-5wt%, and further pulping is performed to obtain a tobacco pulp; (2) after the tobacco pulp is subjected to defibrination using a fluffer, water is added to adjust the concentration to 0.2-2wt%, and the tobacco pulp is transferred into a stirring device to be stirred; and a nanofiber dispersion and a magnetic nanowire suspension are mixed and stirred, an adhesive solution and a surfactant are added for mixing, and stirring is continued to obtain a magnetic nanocomposite fiber pulp; wherein the adhesive solution includes a mixture of natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and other solutions; (3) a magnetic pulp is obtained by mixing and stirring the above tobacco pulp and magnetic nanocomposite fiber pulp, wherein a mass percentage of magnetic nanocomposite fibers is, for example, in a range from 1wt% to 5wt%; a magnetic tobacco sheet base is obtained by performing directional arrangement and papermaking using a sheet former; or, a magnetic multi-layer tobacco sheet base with a core layer of magnetic nanocomposite fibers is obtained by performing papermaking using a sheet former; (4) a wet coating material and a semi-wet coating material are prepared, wherein the steps are as follows: (a) a tobacco material and a fiber material are broken to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; and then a solid natural binder is added and mixed evenly; (b) glycerol, propylene glycol, and water are added and mixed, and a moisture content is maintained at 50-80wt% to obtain the wet coating material; or a moisture content is maintained at 20-50wt% to obtain the semi-wet coating material; (51) three-stage lamination is performed on the magnetic tobacco sheet base obtained from step (3) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (61) the magnetic reconstituted tobacco leaf sheet base obtained from step (51) is coated with the wet coating material from step (4), and drying is performed to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (52) the tobacco sheet base from step (3) is coated with the semi-wet coating material from step (4); and (62) three-stage lamination is performed on the coated tobacco sheet base from step (52) to obtain a magnetic reconstituted tobacco leaf with a thickness ranging from 0.10 mm to 0.30 mm, and drying is performed to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; according to the final application requirements, the obtained magnetic reconstituted tobacco leaf foil is wound, or sliced or shredded to be used in an aerosol-forming matrix.

[0039] Three-stage lamination in steps (51) and (62) uses high-pressure rollers having a molding function and set at different heating temperatures; wherein a first-stage laminating temperature is in a range from 70°C to 100°C, a second-stage laminating temperature is in a range from 120°C to 150°C, and a third-stage laminating temperature is in a range from 160°C to 200°C. A laminating pressure is maintained constant in multiple stages, such as 5 MPa; or the laminating pressure may gradually increase, for example, from 1 MPa in the first stage to 3 MPa in the second stage, and then to 5 MPa in the third stage.

[0040] Embodiment 7: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) after an adhesive solution is added to the tobacco pulp prepared according to step (1) in Embodiment 1, a tobacco sheet base is obtained by papermaking using a standard sheet former; wherein the adhesive solution includes a mixture of natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and other solutions; (2) preparation of a magnetic coating material: vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; the composite gel of the mixed nanofiber dispersion and the magnetic nanowire suspension is added into a mixed pulp including but not limited to tobacco mixture powder, a tobacco extract, glycerol, propylene glycol and water, the adhesive solution and a surfactant are added and mixed evenly to obtain the magnetic coating material, and a solid content is maintained at 50-80%; wherein the adhesive solution includes a mixture of natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and other solutions; and the surfactant is polyvinylpyrrolidone (PVP); (3) the tobacco sheet base is coated with the above magnetic coating material, and drying is performed to obtain a magnetic tobacco sheet; (4) three-stage lamination as that in Embodiment 1 is performed to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; and (5) the foil prepared above is further dried using a drying device to reduce the moisture content to 5-10wt%, so that the magnetic reconstituted tobacco leaf foil is obtained; and according to the final application requirements, the foil is wound, or sliced or shredded.

[0041] Embodiment 8: Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows: (1) one or more of wood pulp fibers, hemp pulp fibers, and tobacco fibers are screened and then crushed and defibrinated to obtain defibrinated fibers; and dry airflow forming is performed on the defibrinated fibers to form a thin fiber layer; (3) a nanofiber dispersion and a magnetic nanowire suspension are added into a stirring device, an adhesive solution is added, and stirring is performed to obtain a magnetic pulp; the adhesive solution includes a mixture of natural binders such as guar gum, xanthan gum, and carboxymethyl cellulose (CMC), and other solutions, and a surfactant is, for example, polyvinylpyrrolidone (PVP); and then plant polysaccharides are added and mixed to form a magnetic coating solution, wherein the plant polysaccharides include but are not limited to starch, cellulose, polysaccharides, pectin, etc.; (4) a wet coating material and a semi-wet coating material are prepared as that in

[0042] Embodiment 1; (51) three-stage lamination as that in Embodiment 1 is performed on the magnetic tobacco sheet base obtained from step (3) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (61) the magnetic reconstituted tobacco leaf sheet base obtained from step (51) is coated with the wet coating material from step (4), and drying is performed to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (52) the tobacco sheet base from step (3) is coated with the semi-wet coating material from step (4); and (62) three-stage lamination as that in Embodiment 1 is performed on the coated tobacco sheet base from step (52), and drying is performed to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; and according to the final application requirements, the foil is wound, or sliced or shredded.

[0043] 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, the present invention can have various changes and variations. Any modification, equivalent replacement, improvement and the like made in the spirit and principle of the present invention shall all be contained in the scope of protection of the present invention.

Examples

embodiment 1

[0033] Preparation of a magnetic reconstituted tobacco leaf foil, with steps as follows:

(1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) solid natural binders such as guar gum, xanthan gum, carboxymethyl cellulose (CMC), and others are mixed using a ribbon blender; (4) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (5) a wet mixer is used to mix the above composite gel, glycerol and water, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humidity and...

embodiment 2

[0034] Preparation of magnetic reconstituted tobacco leaf particles, with steps as follows:

(1) steps 1-7 in Embodiment 1 are used to prepare the parison; (2) the above parison is transferred to a rotary granulator, and broken into irregular particles by rotary granulation; (3) the irregular particles prepared above are further dried using a drying device to reduce a moisture content to 1-6wt%; (4) the dried irregular particles are sieved with a sieving machine to obtain particles with a particle size ranging from 0.5 mm to 2 mm; and (5) according to the final application requirements, the particles are wrapped or filled into an assembly of an aerosol product to be used in a magnetic aerosol-forming matrix.

embodiment 3

[0035] Preparation of a magnetic laminated reconstituted tobacco leaf, with steps as follows:

(1) tobacco debris and fibers are sieved, large powder blocks are removed by shaking, and metals are removed by using magnets; (2) the tobacco debris and the fibers are dried to a moisture content of 5-10wt%, and a solid is ground using an impact mill to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; (3) solid natural binders such as guar gum, xanthan gum, or carboxymethyl cellulose (CMC) are mixed using a ribbon blender; (4) vacuum-assisted filtration of a nanofiber dispersion is performed to obtain wet viscoelastic nanofiber gel; and further vacuum-assisted filtration of a magnetic nanowire suspension is performed to obtain nanofiber and magnetic nanowire composite gel; (5) a wet mixer is used to mix the above composite gel, glycerol and propylene glycol, and a surfactant such as polyvinylpyrrolidone (PVP) is added to ensure the required magnetism, humid...

Claims

1. A magnetic reconstituted tobacco leaf, characterized by comprising a magnetic reconstituted tobacco leaf foil and / or magnetic reconstituted tobacco leaf particles, wherein a thickness of the magnetic reconstituted tobacco leaf foil is in a range from 0.10 mm to 0.30 mm, and a particle size of the magnetic reconstituted tobacco leaf particles is in a range from 0.5 mm to 2 mm; a composition of the magnetic reconstituted tobacco leaf comprises a fiber material, a tobacco material, nanofibers, and a magnetic material; and the magnetic material is a material that is able to be converted into heat after absorbing an alternating magnetic field.

2. The magnetic reconstituted tobacco leaf according to claim 1, characterized in that the magnetic material is a magnetic nanomaterial, and the magnetic nanomaterial is magnetic nanoparticles and / or magnetic nanowires; and the magnetic nanowires have a length ranging from 5 µm to 100 µm and a diameter ranging from 5 nm to 500 nm.

3. The magnetic reconstituted tobacco leaf according to claim 1, characterized in that the nanofibers are plant nanofibers and / or tobacco nanofibers; the nanofibers have a length ranging from 1 µm to 10 µm and a diameter ranging from 5 nm to 500 nm; and the fiber material is a cellulose fiber and / or tobacco fiber material.

4. A preparation method for the magnetic reconstituted tobacco leaf according to claim 1, characterized by comprising the following steps: (1) making a tobacco material and a fiber material into powder with a particle size ranging from 60 meshes to 120 meshes, adding a binder and mixing to obtain a solid mixture, wherein the binder is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; (2) obtaining nanofiber and magnetic nanowire composite gel by using a method of vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanowire suspension; and adding glycerol, water, and a surfactant polyvinylpyrrolidone and mixing evenly to obtain a liquid mixture; (3) stirring and mixing the solid mixture from step (1) and the liquid mixture from step (2) to obtain a dough-like substance with a moisture content of 20-40wt%; (4) compressing and shaping the dough-like substance obtained from step (3) into a parison by using an extruder; (5) obtaining a foil with a thickness ranging from 0.10 mm to 0.30 mm by performing multi-stage lamination on the parison obtained from step (4) at a certain temperature, and then drying the foil to reduce a moisture content to 5-10wt%, so as to obtain a reconstituted tobacco leaf foil; or, (6) breaking the parison obtained from step (4) into irregular particles by using a rotary granulator, and drying the irregular particles to reduce a moisture content to 1-6wt%; and sieving to obtain particles with a particle size ranging from 0.5 mm to 2 mm, so as to obtain reconstituted tobacco leaf particles.

5. A preparation method for the magnetic reconstituted tobacco leaf according to claim 1, characterized by comprising the following steps: (A) preparing a semi-wet mixture formed by a tobacco material, nanofibers, and a magnetic nanomaterial, wherein the method is as follows: adding a surfactant polyvinylpyrrolidone, glycerol and propylene glycol, and preparing nanofiber and magnetic nanomaterial composite gel, namely the semi-wet mixture, by using a method of consecutive vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanomaterial suspension; (B) inserting the semi-wet mixture from step (A) into a laminating roller and performing multi-stage lamination at a certain temperature to obtain a sheet with a thickness ranging from 0.10 mm to 0.30 mm; and applying a binder layer onto a surface of the laminating roller before inserting a sheet base into the laminating roller; or (C) preparing a cellulose fiber and / or tobacco fiber sheet base; (D) applying the semi-wet mixture from step (A) onto the sheet base from step (C), then inserting the obtained sheet base into a laminating roller and performing multi-stage lamination at a certain temperature to obtain a sheet with a thickness ranging from 0.10 mm to 0.30 mm; and applying a binder layer onto a surface of the laminating roller before inserting the sheet base into the laminating roller; a binder used in the binder layer is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; and (E) drying the sheet obtained from step (B) or step (D) to reduce a moisture content to 5-10wt%, so as to obtain a magnetic laminated reconstituted tobacco leaf foil.

6. A preparation method for the magnetic reconstituted tobacco leaf according to claim 1, characterized by comprising the following steps: (a) pulping a tobacco material and a fiber material, and then performing defibrination to obtain a tobacco pulp; (b) mixing a nanofiber dispersion and a magnetic nanowire suspension, then adding an adhesive solution and a surfactant polyvinylpyrrolidone and mixing to obtain a magnetic nanocomposite fiber pulp; (c) obtaining a magnetic pulp by mixing the tobacco pulp from step (a) and the magnetic nanocomposite fiber pulp from step (b), wherein a mass percentage of magnetic nanocomposite fibers is in a range from 1wt% to 5wt%; and obtaining a magnetic tobacco sheet base by performing directional arrangement and papermaking using a sheet former; or, obtaining a magnetic tobacco sheet base with a core layer of magnetic nanocomposite fibers by performing papermaking using a sheet former; (d) preparing a wet coating material and a semi-wet coating material, wherein the steps are as follows: breaking a tobacco material and a fiber material to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; then adding a solid natural binder and mixing evenly; adding and mixing glycerol, propylene glycol, and water, and maintaining a moisture content of 50-80wt% to obtain the wet coating material; and performing dehydration to make a moisture content to be 20-50wt% to obtain the semi-wet coating material; wherein the binder is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; (e1) performing multi-stage lamination on the magnetic tobacco sheet base obtained from step (c) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (f1) coating the magnetic reconstituted tobacco leaf sheet base obtained from step (e1) with the wet coating material from step (4), and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (e2) coating the tobacco sheet base from step (c) with the semi-wet coating material from step (d); and (f2) performing multi-stage lamination on the coated tobacco sheet base from step (e2), and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil.

7. A preparation method for the magnetic reconstituted tobacco leaf according to claim 1, characterized by comprising the following steps: 1) pulping a tobacco material and a fiber material, and then performing defibrination to obtain a tobacco pulp; 2) adding an adhesive solution and a surfactant polyvinylpyrrolidone to the tobacco pulp from step 1) and mixing to obtain a composite fiber tobacco pulp; and obtaining a tobacco sheet base by performing papermaking using a sheet former; 3) preparing a magnetic coating material, wherein the steps are as follows: obtaining nanofiber and magnetic nanowire composite gel by vacuum-assisted filtration of a nanofiber dispersion and a magnetic nanowire suspension; adding the obtained composite gel to a mixed pulp of tobacco mixture powder, a tobacco extract, glycerol, propylene glycol and water, then adding an adhesive solution, and mixing evenly to obtain the magnetic coating material, wherein a solid content is kept at 50-80wt%; 4) coating the tobacco sheet base from step 2) with the magnetic coating material from step 3), and drying to obtain a magnetic tobacco sheet; 5) performing multi-stage lamination on the magnetic tobacco sheet obtained from step 4) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; and 6) drying the prepared magnetic reconstituted tobacco leaf sheet base to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil.

8. A preparation method for the magnetic reconstituted tobacco leaf according to claim 1, characterized by comprising the following steps: (I) crushing and defibrinating a tobacco material and a fiber material, and obtaining a thin fiber layer by performing dry airflow forming on defibrinated fibers; (II) mixing a nanofiber dispersion and a magnetic nanowire suspension, adding an adhesive solution and a surfactant polyvinylpyrrolidone and mixing to obtain a magnetic nanocomposite fiber pulp; and then adding a plant polysaccharide and mixing to form a magnetic coating solution; (III) spraying the magnetic coating solution from step (II) onto the thin fiber layer from step (I) and then shaping the thin fiber layer into a magnetic tobacco sheet base; (IV) preparing a wet coating material and a semi-wet coating material, wherein the steps are as follows: breaking a tobacco material and a fiber material to obtain uniform powder with a particle size ranging from 60 meshes to 120 meshes; then adding a solid natural binder and mixing evenly; adding and mixing glycerol, propylene glycol, and water, and maintaining a moisture content of 50-80wt% to obtain the wet coating material; and performing dehydration to make a moisture content to be 20-50wt% to obtain the semi-wet coating material; wherein the binder is made of one or more of starch, Arabic gum, xanthan gum, guar gum, and CMC and / or nanofiber gel; (LI) performing multi-stage lamination on the magnetic tobacco sheet base obtained from step (III) at a certain temperature to obtain a magnetic reconstituted tobacco leaf sheet base with a thickness ranging from 0.10 mm to 0.30 mm; (LXI) coating the magnetic reconstituted tobacco leaf sheet base from step (LI) with the wet coating material from step (IV), and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil; or, (LII) coating the tobacco sheet base from step (III) with the semi-wet coating material from step (IV); and (LXII) performing multi-stage lamination on the coated tobacco sheet base from step (LII) at a certain temperature, and drying to make a moisture content to be 5-10wt%, so as to obtain a magnetic reconstituted tobacco leaf foil.

9. The preparation method according to any one of claims 4 to 8, characterized in that a pressure for multi-stage lamination is in a range from 1 MPa to 5 MPa and a temperature is in a range from 70°C to 200°C.

10. Use of the magnetic reconstituted tobacco leaf according to any one of claims 1 to 3 as a magnetic aerosol-forming matrix.

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