Heat-not-burn composite cigarette and preparation method thereof

Abstract

The invention provides a heat-not-burn composite cigarette and a preparation method thereof, and the preparation method comprises the following steps: (1) mixing tobacco powder, an atomizing agent, a binder and water for granulation, and then freeze-drying to obtain porous particles; and (2) attaching the porous particles obtained in the step (1) to the surface of a tobacco sheet through silk-screen printing, rolling to obtain a cigarette inner core, and processing to obtain the heat-not-burn composite cigarette. The heat-not-burn composite cigarette is low in suction resistance, large in smoke release amount, high in puff-by-puff smoke release amount consistency and high in atomization efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of heated tobacco products, and particularly relates to a heat-not-burn composite cigarette and a preparation method thereof. Background Art

[0002] The heat-not-burn cigarette generates smoke by heating the reconstituted tobacco, and the generated smoke mainly comes from the atomized smoke of glycerol / propylene glycol and flavorings. Since the heating temperature is lower than 500 °C, far lower than that of traditional cigarettes, the harmful chemical components and biological toxicity in the generated smoke are significantly reduced compared with traditional tobacco.

[0003] However, there are many problems with existing heat-not-burn cigarettes. On the one hand, the heat conduction coefficient of the smoking matrix is low and the contact area with the heat source is insufficient, resulting in difficult heat transfer and uneven heating of the tobacco core section. Specifically, conventional cigarettes are prepared into atomized cartridges in the form of regular or irregular cut tobacco or tobacco flakes wrapped into cigarettes. Whether it is central heating or peripheral heating, the temperature of the part in contact with the heat source is too high, causing the atomizing agent to be completely released prematurely. As the heating continues, the smoking matrix at this part is easily scorched, producing an unpleasant smell; while the temperature of the part far from the heat source is relatively low, and the atomizing agent is difficult to release, resulting in insufficient overall smoke volume during suction, uneven release per puff, and a burnt smell in the later stage, seriously affecting the suction experience.

[0004] On the other hand, at present, there are heat-not-burn cigarettes using particulate smoking matrices. Although smaller particle sizes theoretically bring a larger specific surface area, which can increase the contact area with heat and improve the atomization efficiency to a certain extent. However, in practice, smaller particulate smoking particles are prone to dense packing, resulting in an increase in draw resistance and difficulty in smoke penetration. At the same time, the specific surface area of the densely packed particles is lost, and the contact area with heat will decrease, thus still greatly limiting the release of the smoke volume.

[0005] At present, there is also a method of loading particles on a porous substrate, but the poor thermal conductivity of the used porous substrate affects the atomization efficiency. At the same time, the direct coating method will cause uneven dispersion of the particles, which will also lead to local dense packing and loss of specific surface area, being unfavorable for the release of smoke.

[0006] Therefore, how to provide a heat-not-burn cigarette with a large smoke release volume and uniform release has become an urgent problem to be solved. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a heat-not-burn composite cigarette and a preparation method thereof. The heat-not-burn composite cigarette provided by the present invention has a low draw resistance, a large smoke release volume, a high consistency of smoke release volume per puff, and a high atomization efficiency.

[0008] To achieve the object of the present invention, the present invention adopts the following technical solutions:

[0009] On the one hand, the present invention provides a method for preparing a heat-not-burn composite cigarette, and the preparation method includes the following steps:

[0010] (1) Mix tobacco powder, atomizing agent, binder and water to granulate, and then freeze-dry to obtain porous particles;

[0011] (2) Attach the porous particles obtained in step (1) to the surface of the tobacco sheet by screen printing, roll to obtain the inner core of the cigarette, and process to obtain the heat-not-burn composite cigarette.

[0012] The above method treats the smoke particles by freeze-drying to obtain porous smoke particles, which can increase the specific surface area of the particles, thereby increasing the contact area with the heat source, increasing the penetrability of the hot air flow, improving the atomization efficiency, and increasing the smoke release amount; the particles are attached to the surface of the tobacco sheet by screen, compared with the method of directly coating on the surface of the sheet, the particle distribution is more uniform, further avoiding the dense accumulation of smoke particles, and effectively improving the draw resistance and smoke release amount.

[0013] Preferably, the mixing in step (1) further includes mixing with essence.

[0014] Preferably, the diameter of the porous particles in step (1) is 0.1-2 mm, such as 0.1 mm, 0.5 mm, 1 mm, 1.5 mm or 2 mm, etc., but not limited to the above-listed values, and other unlisted values within the above value range are equally applicable.

[0015] Preferably, before the screen printing in step (2), a mixture of heat-conducting powder (any one or at least two combinations of aluminum powder, copper powder, silver powder, nickel powder, silver-coated copper powder, aluminum nitride powder, boron nitride powder, graphite powder or graphene powder, and the addition amount is 0.1-20% of the mass of the edible glue) and edible glue (any one or at least two combinations of sodium carboxymethylcellulose, sodium alginate) is screen-printed on the surface of the tobacco sheet.

[0016] The above process uses an edible glue doped with heat-conducting powder to coat the substrate, which can increase the heat-conducting performance of the substrate and solve the problem of poor heat conductivity of the porous substrate.

[0017] Preferably, the tobacco sheet in step (2) includes a porous fiber substrate or a tobacco sheet prepared by including the following steps:

[0018] Mix tobacco powder, binder, atomizing agent and water, and then press on the surface of the porous fiber substrate to obtain the tobacco sheet.

[0019] The above method uses a porous fiber substrate as a carrier to carry a smoke powder mixture to make a tobacco sheet, providing an attachment basis for the smoke particles, avoiding the dense accumulation of the smoke particles, and reducing the draw resistance.

[0020] Preferably, the mixing of the smoke powder, the binder, the atomizing agent and water further includes mixing with essence.

[0021] Preferably, the porous fiber substrate includes any one or a combination of at least two of porous cotton fiber, porous hemp fiber, porous corn fiber, porous soybean fiber, porous wheat fiber, porous rice fiber, porous tobacco fiber, porous PA (nylon) fiber or porous PET (polyethylene terephthalate) fiber.

[0022] Preferably, the screen printing in step (2) is carried out in a gradient manner, and the gradient is at least 2.

[0023] Preferably, the gradient is 2, and the specific manner of the screen printing includes:

[0024] The tobacco sheet is divided into two sections according to the distance from the heat source. The screen aperture of the section close to the heat source is not less than 1.1 times the diameter of the porous particles and less than 2 times the diameter of the porous particles. The screen aperture of the section far from the heat source is not less than the diameter of the porous particles and not higher than 1.1 times the diameter of the porous particles. The difference between the screen aperture of the section close to the heat source and the screen aperture of the section far from the heat source is not less than 0.05 mm.

[0025] Preferably, the gradient is 3, and the specific manner of the screen printing includes:

[0026] The tobacco sheet is divided into three sections according to the distance from the heat source. The screen aperture of the section close to the heat source is not less than 1.1 times the diameter of the porous particles and less than 2 times the diameter of the porous particles. The screen aperture of the section far from the heat source is not less than the diameter of the porous particles and not higher than 1.1 times the diameter of the porous particles. The screen aperture of the middle section is higher than the screen aperture of the section close to the heat source and less than 2 times the diameter of the porous particles. The difference between any two of the screen aperture of the section close to the heat source, the screen aperture of the section far from the heat source and the screen aperture of the middle section is not less than 0.05 mm.

[0027] The above method sets the layout of the smoke particles according to the heat transfer effect, effectively improving the consistency of the puff-by-puff smoke release amount.

[0028] On the other hand, the present invention also provides a heat-not-burn composite cigarette prepared by the preparation method as described above.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides a method for preparing a heat-not-burn composite cigarette. By treating the smoke particles through freeze-drying, porous smoke particles are obtained, which can increase the specific surface area of the particles, thereby increasing the contact area with the heat source, enhancing the penetrability of the hot air flow, improving the atomization efficiency, and increasing the smoke release amount. The particles are attached to the surface of the tobacco sheet through a wire mesh. Compared with the method of directly coating on the surface of the sheet, the particle distribution is more uniform, further avoiding the dense accumulation of the smoke particles, and effectively improving the draw resistance and the smoke release amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the per-puff atomization release diagram of Example 2, Example 5, and Example 6.

[0032] Figure 2 is the per-puff atomization release diagram of Example 2, Example 7, and Example 8. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be construed as specific limitations on the present invention.

[0034] In the following examples, the porous cotton fiber is purchased from Guangzhou Yixian Non-woven Fabric Co., Ltd.

[0035] Example 1

[0036] This example provides a heat-not-burn composite cigarette, and the preparation method is as follows:

[0037] Step 1. Prepare the sheet:

[0038] By mass, 40 parts of tobacco powder, 40 parts of atomizing agent (30 parts of propylene glycol and 10 parts of glycerol), 1 part of binder (sodium carboxymethyl cellulose), 1 part of mint essence, and 18 parts of water are weighed. The average mesh number of the tobacco powder is 200 meshes. These substances are fully mixed and kneaded into a dough-like tobacco powder mixture. The porous cotton fiber is selected as the porous fiber substrate, and its thickness is 0.1 mm. The tobacco powder mixture is pressed onto the surface of the cotton fiber substrate using a roll press, and the rolling rate is 2 r / min. After rolling 3 times, a sheet with a thickness of 0.2 mm is made.

[0039] Step 2. Prepare the smoke particles:

[0040] By mass fraction, take 48 parts of tobacco powder, 35 parts of atomizing agent (25 parts of propylene glycol and 10 parts of glycerol), 1 part of binder (sodium carboxymethyl cellulose), 1 part of mint essence, and 15 parts of water. The average mesh number of the tobacco powder is 200 mesh. Granulate through a granulator, and then the temperature for processing the made granules in vacuum freeze-drying is -18°C, the vacuum degree is -0.08 Mpa, and the vacuum pumping time is 8 h. Obtain smoke-emitting granules with porous surfaces, and then obtain porous granules with a diameter of 0.27 mm through vibrating screening.

[0041] Step 3. Prepare a particle composite sheet:

[0042] By mass fraction, take 2 parts of sodium carboxymethyl cellulose, 18 parts of copper powder, and 80 parts of water, mix them into a colloid, and brush-coat it on the sheet prepared in Step 1 through a wire mesh with a mesh size of 200 mesh. Then, evenly scrape-coat the smoke-emitting granules prepared in Step 2 through a 48-mesh wire mesh (select a wire mesh slightly larger than the particle diameter to make the particles easily pass through) on the sheet after coating with glue, and put it into an oven and bake at 45°C for 5 h to obtain a particle composite sheet.

[0043] Step 4. Roll a cigarette:

[0044] Cut the particle composite sheet into an appropriate width so that its weight is about 0.3 g, roll it into a cigarette inner core, use ordinary fiber paper as cigarette paper, and make a heat-not-burn cigarette with a diameter of 7.3 mm through a cigarette-making machine.

[0045] Example 2

[0046] This example provides a heat-not-burn composite cigarette, and the preparation method is as follows:

[0047] Step 1. Prepare a sheet:

[0048] By mass fraction, weigh 42 parts of tobacco powder, 35 parts of atomizing agent (25 parts of propylene glycol and 10 parts of glycerol), 2 parts of sodium carboxymethyl cellulose, 1 part of mint essence, and 20 parts of water, mix them evenly to obtain a tobacco powder mixture. The average mesh number of the tobacco powder is 100 mesh. Select porous cotton fiber as the porous fiber substrate with a thickness of 0.2 mm. Use a roller press to press the tobacco powder mixture on the surface of the cotton fiber substrate at a rolling rate of 4 r / min, and roll it twice to make a sheet with a thickness of 0.4 mm.

[0049] Step 2. Prepare smoke-emitting granules:

[0050] By mass fraction, take 45 parts of tobacco powder, 35 parts of atomizing agent (25 parts of propylene glycol and 10 parts of glycerol), 2 parts of sodium methylcellulose, 1 part of mint essence, and 17 parts of water. The average mesh number of the tobacco powder is 100 mesh. Granulate through a granulator, and then the temperature for processing the prepared granules in vacuum freeze-drying is -18 °C, the vacuum degree is -0.08 Mpa, and the vacuum pumping time is 8 h to obtain smoke-emitting granules with porous surfaces. Then, obtain porous granules with a diameter of 0.5 mm through vibrating screening.

[0051] Step 3. Prepare the particle composite sheet:

[0052] By mass fraction, take 5 parts of starch, 15 parts of aluminum powder, and 80 parts of water, mix them to form a colloid, brush-coat it on the sheet through a wire mesh with a mesh size of 200 mesh, and then evenly scrape-coat the smoke-emitting granules prepared in Step 2 through a 30-mesh wire mesh on the glued sheet, and bake at 50 °C for 4 h.

[0053] Step 4. Roll the cigarette rod:

[0054] Similar to Example 1, make a heat-not-burn cigarette with a diameter of 7.3 mm.

[0055] Example 3

[0056] This example provides a heat-not-burn composite cigarette, and the preparation method is as follows:

[0057] Step 1. Prepare the sheet:

[0058] By mass fraction, weigh 87 parts of atomizing agent (60 parts of propylene glycol and 27 parts of glycerol), 3 parts of mint essence, and 10 parts of water, mix them evenly to obtain an atomizing liquid. Select a porous cotton fiber substrate as the porous fiber substrate with a thickness of 0.8 mm. Immerse the substrate in the above atomizing liquid. After it is fully infiltrated, use a roll press to press the surface of the cotton fiber substrate at a rolling rate of 3 r / min and roll 2 times to squeeze out the excess atomizing liquid to make a sheet containing the atomizing liquid but not leaking.

[0059] Step 2. Prepare the smoke-emitting granules:

[0060] By mass fraction, take 50 parts of tobacco powder, 30 parts of atomizing agent (20 parts of propylene glycol and 10 parts of glycerol), 2 parts of sodium methylcellulose, 3 parts of mint essence, and 15 parts of water. The average mesh number of the tobacco powder is 100 mesh. Granulate through a granulator, and then the temperature for processing the prepared granules in vacuum freeze-drying is -18 °C, the vacuum degree is -0.08 Mpa, and the vacuum pumping time is 8 h to obtain smoke-emitting granules with porous surfaces. Then, obtain porous granules with a diameter of 1 mm through vibrating screening.

[0061] Step 3. Prepare the particle composite sheet:

[0062] By mass fraction, take 2 parts of sodium alginate, 10 parts of graphite powder, and 88 parts of water, mix them to form a colloid, brush it on the thin sheet through a wire mesh with a mesh size of 200 meshes, and evenly scrape the fuming particles through a wire mesh with a mesh size of 14 meshes on the thin sheet coated with glue, and bake it at 50 °C for 4 h.

[0063] Step 4. Rolling the cigarette stick:

[0064] Similar to Example 1, make a heat-not-burn cigarette with a diameter of 7.3 mm.

[0065] Example 4

[0066] This example provides a heat-not-burn composite cigarette, and the preparation method is as follows:

[0067] Similar to Example 3, the difference is only that the cotton fiber substrate (with a thickness of 0.8 mm) in Step 1 does not contain the atomizing liquid and is directly used as the carrier thin sheet for particle attachment. The subsequent preparation processes of 1 mm porous fuming particles and the particle composite thin sheet are the same as those in Example 3, and finally a heat-not-burn cigarette with a diameter of 7.3 mm is obtained.

[0068] Example 5

[0069] This example provides a heat-not-burn composite cigarette, and the preparation method is as follows:

[0070] Step 1. The same as the preparation of the thin sheet in Example 2 to obtain a thin sheet with a thickness of 0.4 mm.

[0071] Step 2. The same as the preparation of the fuming particles in Example 2 to obtain porous particles with a diameter of 0.5 mm.

[0072] Step 3. Gluing the thin sheet: The same as Example 2, by mass fraction, take 5 parts of starch, 15 parts of aluminum powder, and 80 parts of water, mix them to form a colloid, and brush it on the thin sheet through a wire mesh with a mesh size of 200 meshes to obtain the thin sheet coated with glue.

[0073] Step 4. Particle arrangement: Control the distribution density of the particles through wire meshes with different mesh numbers. Divide the cigarette stick axially into a gradient 2-section for particle layout.

[0074] Basis for selecting the wire mesh number of the upper half section (near the heat source end):

[0075] Given that the particle size is 0.5 mm, the wire mesh aperture can be selected in the range of 0.55 mm < wire mesh aperture < 1.0 mm to ensure that each mesh can only accommodate 1 0.5 mm particle passing through. The larger the wire mesh aperture within the range, the larger the particle spacing and the lower the distribution density. In this example, a 24-mesh (0.7 mm) wire mesh is selected.

[0076] Basis for selecting the wire mesh number of the lower half section (far from the heat source end, near the filter tip):

[0077] Given that the particle size is 0.5 mm, to ensure that the particles can easily pass through the wire mesh and achieve a relatively high density, the aperture of the wire mesh can be selected to be slightly larger than 0.5 mm. In this embodiment, a 30-mesh (0.55 mm) wire mesh is selected.

[0078] Drying: Dry at 50 °C for 4 hours to form a gradient particle composite thin sheet.

[0079] Step 5. Rolling the cigarette stick: Similar to Example 1, a heat-not-burn cigarette with a diameter of 7.3 mm is made.

[0080] Example 6

[0081] Similar to Example 5, the difference lies in that in Step 4. Particle arrangement, the aperture of the upper half and the lower half of the wire mesh are swapped.

[0082] Example 7

[0083] Similar to Example 5, the difference lies in that the cigarette stick is axially divided into three gradient sections for arranging the smoke-generating particles.

[0084] Specific steps

[0085] Step 1. Similar to the thin sheet preparation in Example 5, a thin sheet with a thickness of 0.4 mm is obtained.

[0086] Step 2. Similar to the smoke-generating particle preparation in Example 5, porous particles with a diameter of 0.5 mm are obtained.

[0087] Step 3. Similar to the thin sheet gluing in Example 5, take 5 parts of starch, 15 parts of aluminum powder, and 80 parts of water by mass to make a colloid, and brush it on the thin sheet through a wire mesh with a mesh size of 200 meshes to obtain a glued thin sheet.

[0088] Step 4. Particle arrangement: Similar to Example 5, the distribution density of the particles is controlled by wire meshes of different mesh numbers. The difference is that in this embodiment, the thin sheet is divided into three equal-length upper, middle, and lower sections:

[0089] Upper section (closest to the heat source end): The smoke-generating particles are evenly spread on the glued thin sheet through a 24-mesh wire mesh.

[0090] Middle section: The smoke-generating particles are evenly spread on the glued thin sheet through an 18-mesh (0.88 mm) wire mesh.

[0091] Lower section (farthest from the heat source end): The smoke-generating particles are evenly spread on the glued thin sheet through a 30-mesh wire mesh. (The aperture of the wire mesh is smaller, the particle spacing is smaller, and the distribution density is higher, corresponding to the late stage of high temperature to compensate for the smoke volume).

[0092] Drying: Dry at 50 °C for 4 hours.

[0093] Step 5: The rolling process is the same as that in Example 5.

[0094] Example 8

[0095] Similar to Example 7, the difference lies in that in step 4. Particle arrangement, a 18-mesh wire mesh is used in the upper section, 30-mesh in the middle section, and 24-mesh in the lower section.

[0096] Comparative Example 1

[0097] This comparative example provides a heat-not-burn cigarette, and the preparation method is as follows:

[0098] The preparation of the thin sheet is the same as step 1 in Example 2 to obtain a thin sheet with a thickness of 0.4 mm. It is cut into cut tobacco strips about 1 mm wide and rolled into a cigarette with a cigarette core weight of about 0.3 g and a diameter of 7.3 mm.

[0099] The difference from Example 2 is that the filling form in the cigarette core is cut tobacco.

[0100] Comparative Example 2

[0101] This comparative example provides a heat-not-burn cigarette, and the preparation method is as follows:

[0102] The preparation of the smoke-generating particles is the same as step 2 in Example 2, except that only extrusion granulation and screening are carried out by a granulator without freeze-drying treatment, and finally non-porous ordinary smoke-generating particles with a diameter of 0.5 mm are obtained. The smoke-generating particles are filled in the cigarette core part and rolled into a cigarette with a cigarette core weight of about 0.3 g and a diameter of 7.3 mm.

[0103] The differences from Example 2 are: 1) The filling form in the cigarette core is only smoke-generating particles; 2) The smoke-generating particles are non-porous ordinary smoke-generating particles.

[0104] Comparative Example 3

[0105] This comparative example provides a heat-not-burn cigarette, and the preparation method is as follows:

[0106] Step 1. Preparation of the thin sheet: The same as in Example 2, to obtain a thin sheet with a thickness of 0.4 mm.

[0107] Step 2. Preparation of the smoke-generating particles: The same as in Example 2, except that only granulation and screening are carried out by a granulator without freeze-drying treatment, and finally non-porous ordinary smoke-generating particles with a diameter of 0.5 mm are obtained.

[0108] Step 3. Preparation of the particle composite thin sheet: By mass, take 13 parts of starch and 87 parts of water and mix them into a colloid.

[0109] The difference from Example 2 is that no thermal conductive powder is added to the colloid. Then the colloid is directly coated on the surface of the sheet obtained in step 1, and then the smoke particles obtained in step 2 are directly attached to the surface of the sheet after the colloid is coated, and baked at 50° C. for 4 hours.

[0110] Step 4. Rolling cigarettes: Same as in Example 2, making heat-not-burn cigarettes with a diameter of 7.3 mm.

[0111] The difference from Example 2 is that: 1) the smoke particles are ordinary non-porous smoke particles; 2) the colloid coated on the surface of the sheet does not contain thermal conductive powder; 3) the colloid and particles are not attached to the surface of the sheet through screen coating, but are directly coated and attached to the surface of the sheet.

[0112] Effect test:

[0113] The cigarettes provided in the above example were tested as follows:

[0114] 1. Draw resistance test: Take the cigarette samples of Examples 1-8 and Comparative Examples 1-3, and use the cigarette physical index comprehensive test bench to test the draw resistance. The results are shown in Table 1. It can be seen from the draw resistance data that the draw resistance of the cigarettes in each embodiment is lower than that in Comparative Examples 2-3, indicating that the technical solution of the present invention can make the particles evenly dispersed and avoid dense accumulation, thus solving the problem of large draw resistance caused by dense accumulation or uneven distribution of smoke particles.

[0115] 2. Atomization test: Take the cigarette samples of Examples 1-8 and Comparative Examples 1-3, connect the matching smoking utensils, and conduct a smoking experiment on a linear smoking machine according to the standard GB / T16450-2004. The puffing parameters are: 15 puffs, 35 mL puffing volume, 2 seconds duration, 30 seconds puffing interval, and use a 44 mm Cambridge filter to capture the aerosol released during the puffing process. Each puffing channel only captures the aerosol released from a certain puff, and the weight gain of the channel collector is measured to reflect the aerosol release amount of the puff. The greater the weight gain, the more aerosol is released from the puff, that is, the greater the smoke volume.

[0116] Table 1 Absorption resistance test results

[0117]

[0118]

[0119] Table 2 Puff by Puff atomization test results

[0120]

[0121] As can be seen from the results in Table 2, for Examples 2, 5 - 8, and Comparative Examples 1 - 3, the initial content of the aerosol former is the same. The overall aerosolization amount of the cigarette samples in the examples for 15 puffs is higher than that of Comparative Examples 1 - 3, which is more likely to bring smoking satisfaction. This indicates that the orderly arrangement of the smoke particles avoids excessive draw resistance caused by dense packing. At the same time, the porous and uniformly dispersed particles increase the contact area between the particles and the heat source, thereby increasing the effective aerosolization area and improving the aerosolization efficiency.

[0122] Further analysis was made by comparing Example 2 with Comparative Example 3. The difference between them is that the smoke particles in Example 2 are porous particles, the colloid between the particles and the thin sheet is doped with heat - conducting powder, and the particles are attached to the surface of the thin sheet by means of screen coating. The total aerosolization amount of the first 15 puffs in Example 2 is higher than that in Comparative Example 3, which further shows that porous and uniformly dispersed smoke particles can increase the penetrability of the hot air flow and the effective aerosolization area, improve the aerosolization efficiency, and are more conducive to the release of aerosol. At the same time, the colloid coated on the surface of the thin sheet contains heat - conducting powder, which further improves the heat - conducting efficiency and increases the aerosolization release amount.

[0123] Further analysis was made by comparing Example 2 with Comparative Example 3. The difference between them is that the smoke particles in Example 2 are porous particles, the colloid between the particles and the thin sheet is doped with heat - conducting powder, and the particles are attached to the surface of the thin sheet by means of screen coating. The total aerosolization amount of the first 15 puffs in Example 2 is higher than that in Comparative Example 3, which further shows that porous and uniformly dispersed smoke particles can increase the penetrability of the hot air flow and the effective aerosolization area, improve the aerosolization efficiency, and are more conducive to the release of aerosol. At the same time, the colloid coated on the surface of the thin sheet contains heat - conducting powder, which further improves the heat - conducting efficiency and increases the aerosolization release amount.

[0124] Table 3 Particle distribution layout in the cigarette core

[0125]

[0126] Furthermore, the per - puff aerosolization release diagrams of Example 2, Examples 5 - 8 were taken for further comparative analysis. Different from Example 2, the internal particle layouts of Examples 5 - 8 are all segmented (Table 3). Examples 5 and 6 have a two - segment layout. For Example 5, the particle distribution density is less at the top and more at the bottom, that is, the particle distribution is less near the heat - source end and more away from the heat - source end. For Example 6, the particle distribution is opposite to that of Example 5, more at the top and less at the bottom. Figure 1It can be seen that the puff-by-puff smoke release curve of Example 5 is overall smoother, with a smaller attenuation amplitude before and after, while the performance of Example 6 is the opposite, with the puff-by-puff smoke release curve having the largest attenuation amplitude before and after, and rapidly attenuating in the later stage. For Example 5, the low-density particles at the heat source end can suppress the excessive release in the early stage, and the high-density particles at the filter end can compensate for the later release, achieving a "stable at the front and sufficient at the back" smoke volume distribution. On the contrary, the high-density particles at the heat source end of Example 6 lead to larger smoke in the early stage, and the low-density particles at the filter end show a state of lack of follow-up, unable to compensate for the lack of smoke in the later stage, resulting in a "saturated at the front and weak at the back" smoke volume distribution.

[0127] Embodiment 7 and Embodiment 8 are three-stage layouts. The particle distribution density of Embodiment 7 is medium, less, and more from top to bottom. The difference between Embodiment 8 and Embodiment 8 is that the particle distribution density is less, more, and medium from top to bottom. Figure 2 It can be seen that the puff-by-puff smoke release curve of Example 7 is overall more gentle, with a smaller attenuation amplitude before and after, while the puff-by-puff smoke release curve of Example 8 has a larger overall fluctuation. For Example 7, the medium number of particles in the upper section corresponds to the initial temperature rise stage at the early stage of puffing, releasing a medium amount of smoke, the smaller number of particles in the middle section corresponds to the high temperature stage, avoiding excessive smoke release, and the larger number of particles in the lower section corresponds to the high temperature late stage, compensating for the smoke release amount, and achieving a more balanced atomization amount distribution in all stages. On the contrary, the performance of Example 8 is an unbalanced state of insufficient in the early stage, oversaturation in the middle stage, and attenuation in the late stage.

[0128] The above results show that: (1) Low-density particles at the heat source end can inhibit excessive release in the early stage, and high-density particles at the filter end can compensate for the later release, achieving a "stable front and sufficient back" smoke volume distribution. (2) The particle layout of the screen-coated glue can regulate the release state of the aerosol. When the particle distribution layout matches the heat transfer law, it is conducive to the smooth release of the aerosol, solving the problem of "oversaturation in the early stage and insufficient volume in the later stage" in traditional technology, and optimizing the consistency of the smoking experience. The above advantages verify the practicality and innovation of the present invention.

[0129] The applicant declares that the present invention illustrates the heat-not-burn composite cigarette and its preparation method through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0130] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0131] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not separately describe various possible combination manners.

Claims

1. A preparation method of a heat-not-burn composite cigarette, characterized in that, The preparation method comprises the following steps: (1) Mix tobacco powder, atomizing agent, binder and water to granulate, and then freeze-dry to obtain porous particles; (2) Attach the porous particles obtained in step (1) to the surface of the tobacco sheet by screen printing, roll to obtain the inner core of the cigarette, and process to obtain the heat-not-burn composite cigarette.

2. The preparation method of the non-combustible heated composite cigarette according to claim 1, characterized in that, The mixing in step (1) further includes mixing with essence.

3. The preparation method of the heat-not-burn composite cigarette according to claim 1 or 2, characterized in that, The diameter of the porous particles in step (1) is 0.1-2 mm.

4. The preparation method of the heat-not-burn composite cigarette according to any one of claims 1-3, characterized in that Before the screen printing in step (2), it further includes screen-printing a mixture of heat-conducting powder and edible glue on the surface of the tobacco sheet.

5. The preparation method of the non-combustible heated composite cigarette according to any one of claims 1-4, characterized in that, The tobacco sheet in step (2) includes a porous fiber substrate or a tobacco sheet prepared by the following steps: Mix tobacco powder, binder, atomizing agent and water, and then press on the surface of the porous fiber substrate to obtain the tobacco sheet; Preferably, the mixing of tobacco powder, binder, atomizing agent and water further includes mixing with essence.

6. The preparation method of the non-combustible heated composite cigarette according to claim 5, wherein, The porous fiber substrate includes any one or a combination of at least two of porous cotton fiber, porous hemp fiber, porous corn fiber, porous soybean fiber, porous wheat fiber, porous rice fiber, porous tobacco fiber, porous nylon fiber or porous polyethylene terephthalate fiber.

7. The preparation method of the heat-not-burn composite cigarette according to any one of claims 1-6, characterized in that, The screen printing in step (2) is carried out in a gradient manner, and the gradient is at least 2.

8. The preparation method of the heat-not-burn composite cigarette according to claim 7, characterized in that, When the gradient is 2, the specific method of screen printing includes: Divide the tobacco sheet into two sections according to the distance from the heat source. The screen aperture of the section close to the heat source is not less than 1.1 times the diameter of the porous particles and less than 2 times the diameter of the porous particles. The screen aperture of the section far from the heat source is not less than the diameter of the porous particles and not more than 1.1 times the diameter of the porous particles. The difference between the screen aperture of the section close to the heat source and the screen aperture of the section far from the heat source is not less than 0.05 mm.

9. The preparation method of the heat-not-burn composite cigarette according to claim 7, characterized in that, When the gradient is 3, the specific method of screen printing includes: Divide the tobacco sheet into three sections according to the distance from the heat source. The screen aperture of the section close to the heat source is not less than 1.1 times the diameter of the porous particles and less than 2 times the diameter of the porous particles. The screen aperture of the section far from the heat source is not less than the diameter of the porous particles and not more than 1.1 times the diameter of the porous particles. The screen aperture of the middle section is higher than the screen aperture of the section close to the heat source and less than 2 times the diameter of the porous particles. The difference between any two of the screen aperture of the section close to the heat source, the screen aperture of the section far from the heat source and the screen aperture of the middle section is not less than 0.05 mm.

10. A heat-not-burn composite cigarette prepared by the preparation method according to any one of claims 1-9.

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