Cigarette heating material and preparation method thereof

Abstract

The invention discloses a heating cigarette heating material and a preparation method thereof. The heating cigarette heating material is composed of a metal-based foil substrate and an infrared coating formed by coating one side of the metal-based foil substrate. The infrared composition for coating comprises carbide, nitride, metal powder and a forming agent; the forming agent is composed of a binder and a solvent. After one side of the metal-based foil substrate is coated with the infrared coating, the metal-based foil substrate is rolled into a concentric circle structure to be placed in tobacco of a heated cigarette, the surface coated with the infrared material faces outwards, the uncoated surface faces inwards, the inner surface and the outer surface both make contact with the tobacco, the concentric circle heating material rapidly generates heat under the electromagnetic induction condition, and the heating effect is good. The radiation effect generated by the infrared material coated on the outer surface can effectively compensate the defect of low heat efficiency caused by continuous reduction of heat flux density during outward heat conduction, and the effect of uniform heat inside and outside is achieved.

Description

Technical Field

[0001] The present invention relates to the field of heating materials for heating cigarettes, and more specifically, to a heating material for heating cigarettes. Background Art

[0002] At present, the development of electromagnetic heating technology low-temperature cigarette products in the market is very rapid. Its principle is mainly that alloy or composite material conductors with good magnetic properties and low resistivity generate eddy current effect in high-frequency induction coils to generate heat. The structure of electromagnetic heating low-temperature cigarette devices and cigarettes mainly includes two forms: central and decentralized. The central type is that the heating metal element is assembled in the device, which is similar to the currently commonly used MCH ceramic resistance heating device; the decentralized type is that the heating metal is built into the cigarette cartridge in the shape of a needle, sheet or rod. This type of structure makes the device design simpler, and there is no need to clean it after smoking, so it is deeply loved by consumers.

[0003] Since the decentralized heating element needs to be built into the cigarette cartridge, it often needs to be continuously formed together during the cigarette cartridge rolling process. Its structure can only be designed to be coaxial. At the same time, in order to ensure the number of tobacco slices and the amount of airflow, the volume of the heating element cannot be too large. Common ones are foil, fine needles, etc. However, this type of structure has the same disadvantages as MCH ceramic resistance heating, such as excessively high local heating temperature and low utilization rate of some tobacco. The use of a heating element with a cylindrical structure can effectively increase the direct heating area of ​​the tobacco slices, making the heating more uniform. However, due to the inconsistent heat flux density in the inner and outer directions of the cylindrical structure, the heating speed of the tobacco inside the cylinder is much higher than that of the tobacco outside the cylinder. Therefore, although the overall heating speed is improved, the uniformity is still poor. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a heating material for heating cigarettes, which is a built-in heating material for heating cigarettes. The heating body has high uniformity in heating inside and outside, which can significantly improve tobacco utilization and enhance user experience.

[0005] Necessarily, the present invention also provides a method for preparing the above-mentioned heating material for heating cigarettes.

[0006] The technical solution provided by the present invention is as follows: A heating material for heating cigarettes, It consists of a metal-based foil substrate and an infrared coating formed by coating the metal-based foil substrate on one side; The infrared composition for coating includes carbides, nitrides, metal powders and forming agents; The molding agent consists of a binder and a solvent.

[0007] The metal-based foil substrate is made of a simple substance or alloy composed of iron, cobalt, nickel and other metal elements, or a conductive material composed of metal and non-metal.

[0008] Wherein, the weight proportion of the metal powder in the infrared composition is 0%-20% of all powders in the infrared composition except the forming agent; The volume fraction of the molding agent in the infrared composition is 40%-60%.

[0009] Wherein, the carbide is selected from one or more of titanium carbide, tungsten carbide and chromium carbide; The nitride is selected from one or more of titanium nitride, aluminum nitride, and chromium nitride; The metal powder is selected from one or more of nickel, cobalt and iron; The binder is selected from phenolic resin; The solvent was ethanol.

[0010] Wherein, the infrared emissivity of the infrared composition is 0.8-0.95.

[0011] Wherein, the thickness of the metal-based foil substrate is 0.01-0.12 mm.

[0012] The thickness ratio between the metal-based foil substrate and the infrared coating coated on one side is 5:1-10:1, and the preferred thickness ratio is 5:1-6:1.

[0013] A method for preparing the above-mentioned heating material for heating cigarettes comprises the following steps: (1) Pickling: Pickling the metal powder and metal foil substrate to remove the surface oxide film and contaminants; (2) Mixing: placing one or more of the mixed powders of carbide, nitride and metal powder into a ball mill according to a certain proportion, and then adding high-purity ethanol to mix the mixed powders by ball milling; (3) Drying: vacuum drying the prepared powder slurry to obtain a mixed powder; (4) Adding glue: Mixing the dried mixed powder with the forming agent and homogenizing them to form an infrared composite, wherein the volume fraction of the forming agent in the mixture of the mixed powder and the forming agent is 40%-60%; the forming agent is composed of a binder and a solvent, and the weight of the binder accounts for 3%-5% of the forming agent; (5) Spray granulation: granulating the slurry mixed with glue in a spray granulator; (6) coating; the granulated powder is evenly coated on a single side surface of the metal foil substrate cleaned in step (1) by thermal spraying or laser cladding to obtain a foil for heating cigarettes; (7) Slitting: The coated heated cigarette foil is cut in width direction by a slitting machine. The cutting width value is determined according to the diameter of the concentric circles. After slitting, the heated cigarette foil is in a continuous strip shape so as to realize continuous feeding in the cigarette rolling process; (8) Annealing: placing the cut heated cigarette foil in an annealing furnace for reduction annealing.

[0014] In step (5), the inlet temperature of the spray granulator is 100-120°C, the outlet temperature is 70-85°C, the pressure is 0.05-0.08MPa, the feed rate is 100-200ml / min, and the average particle size of the particles after granulation is 30-50μm.

[0015] In step (2), the ball-to-material ratio is 6:1-15:1, the rotation speed is 50-350 rpm, and the ball milling time is not less than 1 hour; The drying temperature of step (3) is 70-100°C; The annealing conditions of step (8) are: annealing atmosphere is H2, pressure is 0.8-1.0 bar, annealing temperature is 600-900°C, and holding time is 3-12h.

[0016] Compared with the prior art, the heating material for heating cigarettes of the present invention is composed of a metal-based foil substrate and an infrared coating formed by coating the metal-based foil substrate on one side; the infrared composition used for coating includes carbides, nitrides, metal powders and a forming agent; the forming agent is composed of a binder and a solvent. After the infrared coating is coated on one side of the metal-based foil substrate, the present invention is rolled into a concentric circle structure and placed in the tobacco of the heated cigarette, the surface coated with the infrared material faces outward, the uncoated surface faces inward, and the inner and outer surfaces are in contact with the tobacco. The concentric circle heating material generates heat quickly under electromagnetic induction conditions, and the radiation effect generated by the infrared material coated on the outer surface can effectively compensate for the low thermal efficiency caused by the continuous decrease in heat flux density when conducting heat outward, and achieve the effect of uniform heating inside and outside. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a schematic diagram of the heating material of a heated cigarette. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0021] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" and "several" is two or more, unless otherwise clearly and specifically defined.

[0023] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0024] The sources of materials used in the embodiments of the present invention are as follows: Pure iron foil: Fe≥99.9%; FeNi foil: Ni ≥ 50%; FeCrAl foil; Cr: 10%~25%, Al: 3%~7%; 430 stainless steel foil: commercially available; Tungsten carbide; particle size 6μm, ≥99.9%; Titanium carbide; particle size 6μm, ≥99.9%; Nickel; particle size 20μm≥99.9%; Titanium nitride; particle size 6μm≥99.9%; Phenolic resin;McLean's reagent; FeSi alloy foil; Si: 3%~7%; The remaining substances were from commercial sources.

[0025] Example 1 Prepare the heating material for heating cigarettes by the following method (1) Pickling: Pickle the pure iron foil with a thickness of 0.01 mm to remove the surface oxide film and pollutants; (2) Mixing: The mixed powder of titanium carbide and nickel is placed in a ball mill, and then high-purity ethanol is added for ball milling. The mass fraction of nickel in the mixed powder is 10%, the ball-to-material ratio is 6:1, the rotation speed is 50 rpm, and the ball milling time is 1 h. (3) Drying: The prepared powder slurry is vacuum dried at a temperature of 70°C; (4) Adding glue: The dried mixed powder is mixed with a forming agent and homogenized to form an infrared composite, wherein the forming agent is composed of 97 wt % ethanol as a solvent and 3 wt % phenolic resin as a binder, and the volume fraction of the forming agent in the mixture of the mixed powder and the forming agent is 40.00%, and the infrared emissivity of the obtained infrared composite is 0.93; (5) Spray granulation: the slurry mixed with glue is granulated in a spray granulator with an inlet temperature of 100°C, an outlet temperature of 70°C, a pressure of 0.05 MPa, a feed rate of 100 ml / min, and an average particle size of the particles after granulation of 30 μm; (6) coating; the granulated powder is evenly coated on a single side surface of the pure iron foil described in step (1) by a thermal spraying process, and the coating thickness is 0.002 mm; (7) Slitting: The coated sample is cut in width by a slitting machine. The cutting width is determined according to the diameter of the concentric circles. After slitting, the foil is in a continuous strip shape so as to achieve continuous feeding during the cigarette rolling process.

[0026] (8) Annealing: The slit foil strips are placed in an annealing furnace for reduction annealing. The annealing atmosphere is H2, the pressure is 0.8 bar, the annealing temperature is 600°C, and the holding time is 3 hours.

[0027] Embodiment 2: (1) Pickling: Pickling the FeNi foil with a thickness of 0.12 mm to remove the surface oxide film and contaminants; 2) Mixing: The mixed powder of tungsten carbide and titanium carbide is placed in a ball mill, and then high-purity ethanol is added for ball milling and mixing. The ball-to-material ratio is 15:1, the rotation speed is 350 rpm, and the ball milling time is 10 hours; 3) Drying: The prepared powder slurry is vacuum dried at a temperature of 100°C; 4) Adding glue: Mixing the dried mixed powder with a forming agent and homogenizing to form an infrared composite, wherein the forming agent is composed of 95wt% ethanol as a solvent and 5wt% phenolic resin as a binder, and the volume fraction of the forming agent in the mixture of the mixed powder and the forming agent is 60%, and the infrared emissivity of the obtained infrared composite is 0.95; 5) Spray granulation: the slurry mixed with glue is granulated in a spray granulator, with an inlet temperature of 120°C, an outlet temperature of 85°C, a pressure of 0.08MPa, a feed rate of 200ml / min, and an average particle size of 50μm after granulation; 6) Coating: The granulated powder is evenly coated on the single-side surface of the foil described in step (1) by a thermal spraying process, and the coating thickness is 0.02 mm.

[0028] 7) Slitting: The coated sample is slit in width direction by a slitting machine. The slitting width value is determined according to the diameter of the concentric circles. After slitting, the foil is in a continuous strip shape to achieve continuous feeding during the cigarette rolling process.

[0029] 8) Annealing: Place the cut strip foil in an annealing furnace for reduction annealing. The annealing atmosphere is H2, the pressure is 1.0 bar, the annealing temperature is 900°C, and the holding time is 12 hours.

[0030] Example 3 1) Pickling: Pickle the FeCrAl foil with a thickness of 0.05 mm to remove the surface oxide film and pollutants; 2) Mixing: Put the mixed powder of tungsten carbide and cobalt into a ball mill, then add high-purity ethanol and mix by ball milling. The mass fraction of nickel in the mixed powder is 20%. The ball-to-material ratio is 10:1, the rotation speed is 300 rpm, and the ball milling time is 8 hours. 3) Drying: The prepared powder slurry is vacuum dried at a temperature of 90°C; 4) Adding glue: Mixing the dried mixed powder with a forming agent and homogenizing them to form an infrared composite, wherein the forming agent is composed of 95wt% ethanol as a solvent and 5wt% phenolic resin as a binder, and the volume fraction of the forming agent in the mixture of the mixed powder and the forming agent is 50%; 5) Spray granulation: the slurry mixed with glue is granulated in a spray granulator, with an inlet temperature of 110°C, an outlet temperature of 80°C, a pressure of 0.07MPa, a feed rate of 150ml / min, an average particle size of the particles after granulation of 40μm, and an infrared emissivity of the obtained infrared composition of 0.8; 6) Coating: The granulated powder is evenly coated on the single-side surface of the foil described in step (1) by a thermal spraying process, and the coating thickness is 0.01 mm to 0.05 mm.

[0031] 7) Slitting: The coated sample is slit in width direction by a slitting machine. The slitting width value is determined according to the diameter of the concentric circles. After slitting, the foil is in a continuous strip shape to achieve continuous feeding during the cigarette rolling process.

[0032] 8) Annealing: Place the cut strip foil in an annealing furnace for reduction annealing. The annealing atmosphere is H2, the pressure is 0.9 bar, the annealing temperature is 800°C, and the holding time is 10 hours.

[0033] Embodiment 4: 1) Pickling: Pickle the 430 stainless steel foil with a thickness of 0.10 mm to remove the surface oxide film and pollutants; 2) Mixing: Put the mixed powder of titanium nitride and nickel into a ball mill, then add high-purity ethanol and mix by ball milling. The mass fraction of nickel in the mixed powder is 15%, the ball-to-material ratio is 8:1, the rotation speed is 300rpm, and the ball milling time is 8h; 3) Drying: The prepared powder slurry is vacuum dried at a temperature of 90°C; 4) Adding glue: Mixing the dried mixed powder with a forming agent and homogenizing the mixture, wherein the forming agent is composed of 95wt% ethanol as a solvent and 5wt% phenolic resin as a binder, and the volume fraction of the forming agent in the mixture of the mixed powder and the forming agent is 50%, and the infrared emissivity of the obtained infrared composition is 0.87; 5) Spray granulation: The slurry mixed with glue is granulated in a spray granulator with an inlet temperature of 110°C, an outlet temperature of 80°C, a pressure of 0.07MPa, a feed rate of 130ml / min, and an average particle size of 42μm after granulation; 6) Coating: The granulated powder is evenly coated on the single-side surface of the foil described in step (1) by a thermal spraying process, and the coating thickness is 0.02 mm.

[0034] 7) Slitting: The coated sample is slit in width direction by a slitting machine. The slitting width value is determined according to the diameter of the concentric circles. After slitting, the foil is in a continuous strip shape to achieve continuous feeding during the cigarette rolling process.

[0035] 8) Annealing: Place the cut strip foil in an annealing furnace for reduction annealing. The annealing atmosphere is H2, the pressure is 0.9 bar, the annealing temperature is 700°C, and the holding time is 6 hours.

[0036] Embodiment 5: 1) Pickling: Pickling the FeSi alloy foil with a thickness of 0.10 mm to remove the surface oxide film and pollutants; 2) Mixing: Put tungsten carbide powder into a ball mill, then add high-purity ethanol and mix by ball milling. The ball-to-material ratio is 7:1, the speed is 220rpm, and the ball milling time is 12h; 3) Drying: The prepared powder slurry is vacuum dried at a temperature of 90°C; 4) Adding glue: Mixing the dried mixed powder with a forming agent and homogenizing the mixture, wherein the forming agent is composed of 95wt% ethanol as a solvent and 5wt% phenolic resin as a binder, and the volume fraction of the forming agent in the mixture of the mixed powder and the forming agent is 55%, and the infrared emissivity of the obtained infrared composition is 0.94; 5) Spray granulation: The slurry mixed with glue is granulated in a spray granulator with an inlet temperature of 110°C, an outlet temperature of 80°C, a pressure of 0.08MPa, a feed rate of 120ml / min, and an average particle size of 50μm after granulation; 6) Coating: The granulated powder is evenly coated on the single-side surface of the foil described in step (1) by a thermal spraying process, and the coating thickness is 0.02 mm.

[0037] 7) Slitting: The coated sample is slit in width direction by a slitting machine. The slitting width value is determined according to the diameter of the concentric circles. After slitting, the foil is in a continuous strip shape to achieve continuous feeding during the cigarette rolling process.

[0038] 8) Annealing: Place the cut strip foil in an annealing furnace for reduction annealing. The annealing atmosphere is H2, the pressure is 0.9 bar, the annealing temperature is 700°C, and the holding time is 6 hours.

[0039] Comparative Example 1: 1) Pickling: Pickle the FeCrAl foil with a thickness of 0.05 mm to remove the surface oxide film and pollutants; 2) Slitting: The pickled FeCrAl foil is slit in width direction by a slitting machine. The slitting width value is determined according to the diameter of the concentric circles. After slitting, the foil is in a continuous strip shape so as to realize continuous feeding in the cigarette rolling process.

[0040] 3) Annealing: The slit strip foil is placed in an annealing furnace for reduction annealing. The annealing atmosphere is H2, the pressure is 0.9 bar, the annealing temperature is 800°C, and the holding time is 10 hours.

[0041] Comparative Example 2: 1) Pickling: Pickle the 430 stainless steel foil with a thickness of 0.10 mm to remove the surface oxide film and pollutants; 2) Slitting: The pickled 430 stainless steel foil is slit in width direction through a slitting machine. The slitting width value is determined according to the concentric circle diameter. After slitting, the foil is in a continuous strip shape to achieve continuous feeding during the cigarette rolling process.

[0042] 3) Annealing: The slit strip foil is placed in an annealing furnace for reduction annealing. The annealing atmosphere is H2, the pressure is 0.9 bar, the annealing temperature is 700°C, and the holding time is 6 hours.

[0043] The foils prepared in the examples and comparative examples are rolled into cigarettes, such as Figure 1 As shown, the heating material for heating cigarettes of the present invention is composed of a metal-based foil substrate 1 and an infrared coating 2 formed by coating the metal-based foil substrate on one side. The heating material for heating cigarettes is rolled into a concentric circle structure with the cigarette and placed in the tobacco 4 of the heating cigarette 3. The diameter of the cigarette is 7.6 mm, the diameter of the concentric circle structure is 5 mm, the cigarette model is an HNB original tobacco flavored cigarette cartridge with aluminum foil, the surface of the metal-based foil substrate coated with the infrared coating faces outward, and the uncoated surface faces inward. The inner and outer surfaces of the heating material are in contact with the tobacco, and serve as the heating material for heating cigarettes 3. The foil strips of the comparative example are made into concentric circle structures according to the above method and placed in tobacco 4 of the same heated cigarette 3, and the concentric circle structures have the same diameter.

[0044] After preheating for 15 seconds in the same apparatus, the temperature 1 mm inside and outside the concentric circle structure was measured by a thermocouple. The specific method was to open a channel 1 mm away from the foil structure with a needle tool, and then insert a patch thermocouple to measure the temperature. The results are shown in Table 1:

[0045] It can be seen from the above data that after the infrared coating is added to the metal foil by the method of the present invention, it is rolled into a concentric circle structure and placed in the tobacco of the heated cigarette, with the surface coated with the infrared material facing outward and the uncoated surface facing inward, and the inner and outer surfaces are in contact with the tobacco. The concentric circle heating material quickly generates heat under electromagnetic induction conditions, and the radiation effect generated by the infrared material coated on the outer surface can effectively compensate for the low thermal efficiency caused by the continuous decrease in heat flux density when conducting heat outward, thereby achieving the effect of uniform heating inside and outside.

[0046] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A heating material for heating cigarettes, characterized in that: It consists of a metal-based foil substrate and an infrared coating formed by coating the metal-based foil substrate on one side; The infrared composition for coating includes carbides, nitrides, metal powders and forming agents; The molding agent consists of a binder and a solvent.

2. The heating material for heating cigarettes according to claim 1, characterized in that: The material of the metal-based foil substrate is made of simple substances and alloys composed of iron, cobalt, nickel and other metal elements, or conductive materials composed of metal and non-metal.

3. The heating material for heating cigarettes according to claim 2, characterized in that The weight proportion of the metal powder in the infrared composition is 0%-20% of all powders in the infrared composition except the forming agent; The volume fraction of the molding agent in the infrared composition is 40%-60%.

4. The heating material for heating cigarettes according to claim 3, characterized in that: The carbide is selected from one or more of titanium carbide, tungsten carbide and chromium carbide; The nitride is selected from one or more of titanium nitride, aluminum nitride, and chromium nitride; The metal powder is selected from one or more of nickel, cobalt and iron; The binder is selected from phenolic resin; The solvent was ethanol.

5. The heating material for heating cigarettes according to claim 4, characterized in that: The infrared emissivity of the infrared composition is 0.8-0.

95.

6. The heating material for heating cigarettes according to claim 5, characterized in that: The thickness of the metal-based foil substrate is 0.01-0.12 mm.

7. The heating material for heating cigarettes according to claim 6, characterized in that: The thickness ratio between the metal-based foil substrate and the infrared coating coated on one side is 5:1-10:

1.

8. A method for preparing the heating material for heating cigarettes according to any one of claims 1 to 7, characterized in that The following steps are involved: (1) Pickling: Pickling the metal powder and metal foil substrate to remove the surface oxide film and contaminants; (2) Mixing: placing one or more of the mixed powders of carbide, nitride and metal powder into a ball mill according to a certain proportion, and then adding high-purity ethanol to mix the mixed powders by ball milling; (3) Drying: vacuum drying the prepared powder slurry to obtain a mixed powder; (4) Adding glue: Mixing the dried mixed powder with the forming agent and homogenizing them to form an infrared composite, wherein the volume fraction of the forming agent in the mixture of the mixed powder and the forming agent is 40%-60%; the forming agent is composed of a binder and a solvent, and the weight of the binder accounts for 3%-5% of the forming agent; (5) Spray granulation: granulating the slurry mixed with glue in a spray granulator; (6) coating; the granulated powder is evenly coated on a single side surface of the metal foil substrate cleaned in step (1) by thermal spraying or laser cladding to obtain a foil for heating cigarettes; (7) Slitting: The coated heated cigarette foil is cut in width direction by a slitting machine. The cutting width value is determined according to the diameter of the concentric circles. After slitting, the heated cigarette foil is in a continuous strip shape so as to realize continuous feeding in the cigarette rolling process; (8) Annealing: placing the cut heated cigarette foil in an annealing furnace for reduction annealing.

9. The method for preparing the heating material for heating cigarettes according to claim 8, characterized in that: Step (5), the inlet temperature of the spray granulator is 100-120°C, the outlet temperature is 70-85°C, the pressure is 0.05-0.08MPa, the feed rate is 100-200ml / min, and the average particle size of the particles after granulation is 30-50μm.

10. The method for preparing the heating material for heating cigarettes according to claim 9, characterized in that: In step (2), the ball-to-material ratio is 6:1-15:1, the rotation speed is 50-350 rpm, and the ball milling time is not less than 1 hour; The drying temperature in step (3) is 70-100°C; The annealing conditions of step (8) are: annealing atmosphere is H2, pressure is 0.8-1.0 bar, annealing temperature is 600-900°C, and holding time is 3-12h.

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