Heating cigarette with heat-conducting and heat-insulating composite film

Abstract

The invention provides a heating cigarette with a heat-conducting and heat-insulating composite film. The heating cigarette comprises a combustion section, a cigarette core section and a filter tip section which are coaxially connected in sequence; the combustion section, the cigarette core section and the filter tip section are wrapped and formed by cigarette paper; the outer portion of the cigarette core section is further wrapped with a heat conduction and insulation composite film, and the heat conduction and insulation composite film is further wrapped with cigarette paper. According to the heating cigarette, the core contradiction of external heat management is solved, a composite film structure integrating conduction and isolation is creatively provided, directional transportation and directional blocking of heat are achieved in an external wrapping scheme, and the defect that heat is dissipated in a turbulent flow mode due to a pure heat conduction material is overcome.

Description

Technical Field

[0001] This invention belongs to the field of heated cigarette technology, specifically relating to a heated cigarette with a thermally conductive and heat-insulating composite film. Background Technology

[0002] In recent years, heated tobacco products (HNB) have received widespread attention due to their potential to reduce the release of harmful components. Current mainstream products primarily rely on precision electronic devices (such as Ploom and IQOS) as an external heat source to precisely control the temperature of the tobacco. While these products effectively reduce combustion, their user experience is highly dependent on dedicated, rechargeable devices, leading to issues such as inconvenience in portability, battery anxiety, high maintenance costs, and a high barrier to entry for widespread adoption.

[0003] To overcome the reliance on specialized smoking devices, there is an urgent need to develop a self-heating cigarette technology (combustion-type heated cigarette) that provides uniform heating and high thermal efficiency. This is precisely the core technical problem that this patent aims to solve: providing heat through a combustible section (combustion section) of the product itself to directly heat the adjacent core section, which then releases the required active ingredients. Experiments revealed a technical obstacle: without a thermally conductive design, heat is primarily conducted through axial solid materials (core material). These materials are poor conductors of heat, and most of the heat cannot be effectively transferred to the core section, instead dissipating into the environment or remaining inside the combustion section. This directly leads to core defects such as low heat transfer efficiency from the combustion section to the core section, uneven carbonization of the core material, and low utilization rate.

[0004] However, through in-depth research and practice, the inventors have discovered that simply wrapping the combustion section and the core section with a high thermal conductivity material (such as graphene film) can accelerate the axial transfer of heat from the combustion section to the core section, but it also brings a serious problem: the high thermal conductivity material will diffuse heat into the surrounding air of the cigarette with equal efficiency in the radial direction. This accelerates the loss of core heat, resulting in the overall thermal utilization rate not being effectively improved, and may even be reduced. In other words, simple external thermal conductive wrapping is a "double-edged sword," as it enhances axial heat transfer while weakening radial insulation.

[0005] Therefore, there is an urgent need for a new type of external thermal management structure that can efficiently conduct heat in the axial direction and effectively insulate heat in the radial direction, so as to truly achieve directional and efficient heat transfer. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a heated cigarette with a thermally conductive and heat-insulating composite film. The heated cigarette provided by this invention aims to achieve "efficient axial guidance and strong radial heat retention," fundamentally resolving the contradiction between heat loss and heat conduction in external thermal management schemes, and significantly improving the axial transport efficiency and overall utilization rate of combustion heat.

[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a heated cigarette with a thermally conductive and heat-insulating composite film, the heated cigarette comprising a combustion section, a core section and a filter section connected coaxially in sequence; The combustion section, the core section, and the filter section are formed by wrapping cigarette paper. The outer surface of the cigarette core segment is also wrapped with a thermally conductive and heat-insulating composite film, and then wrapped with cigarette paper.

[0008] This invention creatively proposes a composite membrane structure that integrates heat conduction and insulation. Wrapping this composite membrane around the outside of the cigarette core section enables directional heat transport and directional heat containment, overcoming the drawbacks of heat loss due to "turbulent flow" caused by simple thermal conductive materials. This represents a major breakthrough in thermal management concepts.

[0009] Preferably, the conductive-insulating composite film comprises a stacked radial heat insulation layer and an axial heat-conducting layer.

[0010] Preferably, the axial heat-conducting layer is in direct contact with the outer surface of the core section.

[0011] The conductive-insulating composite film of the present invention is tightly bonded to the axial heat-conducting layer and the radial heat-insulating layer, which work together to heat the cigarette. The axial heat-conducting layer quickly guides the high-temperature heat generated in the combustion section to the core section along the axial direction, while the radial heat-insulating layer minimizes the heat loss in the circumferential direction during this process.

[0012] Preferably, the material of the axially oriented thermal layer includes any one or a combination of at least two of the following: axially oriented graphene film, axially arrayed carbon nanotube film, and metallized oriented polymer film.

[0013] Preferably, the thickness of the axial heat-conducting layer is 40-120 μm (e.g., 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, or 120 μm, etc.), and the thermal conductivity is ≥300 W / (m•K), for example, 300 W / (m•K), 400 W / (m•K), 500 W / (m•K), 600 W / (m•K), 700 W / (m•K), 800 W / (m•K), 900 W / (m•K), or 1000 W / (m•K, etc.).

[0014] In this invention, the axial heat-conducting layer is made of a highly thermally conductive material, in which the thermally conductive fibers or grains are preferentially oriented along the cigarette axis, or the heat-conducting layer itself is a thin film with a high in-plane thermal conductivity, and its main function is to efficiently conduct heat along the cigarette axis.

[0015] Preferably, the radial insulation layer is made of any one or a combination of at least two of aerogel felt, ceramic fiber paper, nanoporous insulation film or polymer foam film.

[0016] Preferably, the thickness of the radial insulation layer is 180-450 μm (e.g., it can be 180 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm or 450 μm, etc.), and the thermal conductivity is ≤0.05 W / (m•K), for example, it can be 0.01 W / (m•K), 0.02 W / (m•K), 0.03 W / (m•K) or 0.04 W / (m•K, etc.).

[0017] The radial heat insulation layer of the present invention is composited on the outside of the axial heat-conducting layer and is made of a heat insulation material with low thermal conductivity. Its main function is to block heat from being lost radially into the environment.

[0018] Preferably, the end of the combustion section near the core section is also wrapped with a heat-conducting composite film, and the heat-conducting composite film is then wrapped with cigarette paper.

[0019] Preferably, the length of the heat-conducting and heat-insulating composite membrane wrapped around the combustion section accounts for 30-70% of the total length of the combustion section, for example, it can be 35%, 40%, 45%, 50%, 55%, 60% or 65%, etc.

[0020] Preferably, the combustion section is made of plant fiber and carbon powder.

[0021] Preferably, the mass ratio of plant fiber to carbon powder is (3-5):1, for example, it can be 3:1, 3.2:1, 3.5:1, 3.8:1, 4:1, 4.2:1, 4.5:1 or 4.8:1, etc.

[0022] Preferably, the porosity of the combustion section is ≥50%, for example, it can be 55%, 60%, 65%, 70% or 75%, etc.

[0023] In addition to the hollow channel, the combustion section of the present invention is also provided with a high porosity in its matrix material to ensure that the combustion section can be ignited and maintain stable and complete combustion, while providing a passage for the hot gas flow generated by combustion to the core section.

[0024] Preferably, the components of the core segment include tobacco raw materials, smoking agents, tobacco flavorings, and adhesives.

[0025] Preferably, the components of the tobacco core segment include, by weight, 20-30 parts of tobacco raw material (e.g., 21, 23, 25, 27, or 29 parts), 3-8 parts of smoke-generating agent (e.g., 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8 parts), 0.01-0.3 parts of tobacco flavoring (e.g., 0.01, 0.05, 0.1, 0.15, 0.2, 0.25, or 0.3 parts), and 0.1-0.5 parts of adhesive (e.g., 0.1, 0.2, 0.3, 0.4, or 0.5 parts).

[0026] Preferably, the tobacco raw material includes any one or a combination of at least two of tobacco sheets, tobacco pellets, or shredded tobacco.

[0027] Preferably, the tobacco flavoring includes any one or a combination of at least two of vanillin, succinate, 2-acetylpyrazine, 2,3,5-trimethylpyrazine, isoamyl isovalerate, menthyl acetate, phenethyl alcohol, furanone, or geraniol.

[0028] Preferably, the adhesive comprises any one or a combination of at least two of sodium alginate, sodium carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, chitosan, guar gum, or cellulose acetate.

[0029] Preferably, the smoke-generating agent comprises any one or a combination of at least two of propylene glycol, glycerin, or sorbitol.

[0030] Preferably, the filter tip is made of cellulose acetate or polylactic acid.

[0031] All the specific point values ​​within the above range can be selected, and will not be elaborated on here.

[0032] Compared with the prior art, the present invention has the following beneficial effects: (1) The heated cigarette of the present invention solves the core contradiction of external heat management and creatively proposes a composite membrane structure of "conducting-insulating in one". In the external wrapping scheme, it realizes the directional transport and directional blockage of heat and overcomes the drawback of heat loss due to "turbulent flow" caused by simple heat-conducting materials.

[0033] (2) The thermally conductive and heat-insulating composite membrane of the present invention is composed of an axially conductive heat-conducting layer and a radially insulating layer. The axially conductive heat-conducting layer can quickly conduct heat from the combustion section to the core section; the radially insulating layer prevents heat from "escaping from the road surface". The two work together to maximize the heat flow for effective heating.

[0034] (3) The technical solution of the present invention can be used directly in the existing cigarette forming process, using the pre-made composite functional film as the wrapping layer without complicated internal structure modification. The process integration is high, suitable for large-scale production, and the composite film itself can enhance the physical strength of cigarettes. Detailed Implementation

[0035] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0036] Example 1 This embodiment provides a heated cigarette with a thermally conductive and heat-insulating composite film. The heated cigarette (diameter 8.4 mm) includes a combustion section (length 16 mm), a core section (length 20 mm), and a filter section (length 30 mm) connected coaxially in sequence. The combustion section, the core section, and the filter section are formed by wrapping cigarette paper. The outer surface of the heated cigarette, from the core section to 50% of the length of the combustion section, is also wrapped with a heat-conducting and heat-insulating composite film between itself and the cigarette paper. The thermally conductive composite film consists of a radially insulating layer and an axially conductive layer stacked together. The axial heat-conducting layer is in direct contact with the outer surface of the core section.

[0037] The axially oriented thermal conductive layer is made of an axially oriented graphene film with a thickness of 60 μm and a thermal conductivity of 600 W / (m•K). The radial insulation layer is made of ceramic fiber paper with a thickness of 300 μm and a thermal conductivity of 0.04 W / (m•K).

[0038] The combustion section is made of plant fiber and carbon powder in a mass ratio of 3.5:1; The porosity of the combustion section is 58%; The components of the tobacco core segment, by weight, are 28 parts tobacco raw material, 6 parts smoking agent, 0.2 parts tobacco flavoring and 0.4 parts adhesive; The tobacco raw material is tobacco sheet; The smoke-generating agent is glycerin; The tobacco flavoring is a combination of vanillin and succinate in a mass ratio of 1:1; The adhesive is sodium carboxymethyl cellulose by mass ratio; The filter tip section is made of cellulose acetate.

[0039] Example 2 This embodiment provides a heated cigarette with a thermally conductive and heat-insulating composite film. The heated cigarette (diameter 8.4 mm) includes a combustion section (length 16 mm), a core section (length 20 mm), and a filter section (length 30 mm) connected coaxially in sequence. The combustion section, the core section, and the filter section are formed by wrapping cigarette paper. The outer surface of the heated cigarette, from the core section to 30% of the length of the combustion section, is also wrapped with a heat-conducting and heat-insulating composite film between itself and the cigarette paper. The thermally conductive composite film consists of a radially insulating layer and an axially conductive layer stacked together. The axial heat-conducting layer is in direct contact with the outer surface of the core section.

[0040] The axial thermal conductive layer is made of a carbon nanotube axial array film with a thickness of 80 μm and a thermal conductivity of 500 W / (m•K). The radial heat insulation layer is made of a nanoporous heat insulation film with a thickness of 300 μm and a thermal conductivity of 0.05 W / (m•K).

[0041] The combustion section is made of plant fiber and carbon powder in a mass ratio of 5:1. The porosity of the combustion section is 60%; The components of the tobacco core segment, by weight, are 29 parts tobacco raw material, 8 parts smoking agent, 0.3 parts tobacco flavoring and 0.5 parts adhesive; The tobacco raw material is shredded tobacco; The smoke-generating agent is sorbitol; The tobacco flavoring is composed of 2-acetylpyrazine and furanone in a mass ratio of 1:1; The adhesive is hydroxypropyl methylcellulose; The filter tip section is made of cellulose acetate.

[0042] Example 3 This embodiment provides a heated cigarette with a thermally conductive and heat-insulating composite film. The heated cigarette (diameter 8.4 mm) includes a combustion section (length 16 mm), a core section (length 20 mm), and a filter section (length 30 mm) connected coaxially in sequence. The combustion section, the core section, and the filter section are formed by wrapping cigarette paper. The outer surface of the heated cigarette, from the core section to 70% of the length of the combustion section, is also wrapped with a heat-conducting and heat-insulating composite film between itself and the cigarette paper. The thermally conductive composite film consists of a radially insulating layer and an axially conductive layer stacked together. The axial heat-conducting layer is in direct contact with the outer surface of the core section.

[0043] The axial thermal conductive layer is made of a metallized oriented polymer film with a thickness of 80 μm and a thermal conductivity of 500 W / (m•K). The radial insulation layer is made of aerogel felt with a thickness of 300 μm and a thermal conductivity of 0.03 W / (m•K).

[0044] The combustion section is made of plant fiber and carbon powder in a mass ratio of 3:1. The porosity of the combustion section is 56%; The components of the tobacco core segment, by weight, are 25 parts tobacco raw material, 5 parts smoking agent, 0.2 parts tobacco flavoring and 0.3 parts adhesive; The tobacco raw material is tobacco pellets; The smoke-generating agent is propylene glycol; The tobacco flavoring is 2-acetylpyrazine and 2,3,5-trimethylpyrazine in a mass ratio of 1:2; The adhesive is guar gum; The filter tip section is made of polylactic acid.

[0045] Example 4 This embodiment provides a heated cigarette with a thermally conductive and heat-insulating composite film. The only difference between the heated cigarette and the one in Embodiment 1 is that the entire combustion section is wrapped with a thermally conductive and heat-insulating composite film. The rest of the structure and the components used are the same as those in Embodiment 1.

[0046] Example 5 This embodiment provides a heated cigarette with a thermally conductive and heat-insulating composite film. The only difference between the heated cigarette and the one in Embodiment 1 is that the porosity of the combustion section is 45%, while the rest of the structure and the components used are the same as those in Embodiment 1.

[0047] Comparative Example 1 This comparative example provides a heated cigarette. The only difference between the heated cigarette and Example 1 is that a heat-conducting film (without a heat-insulating film) is wrapped between the outer surface of the cigarette from the core section to 50% of the length of the combustion section and the cigarette paper. The heat-conducting film is an axially oriented graphene film with a thickness of 60 μm and a thermal conductivity of 600 W / (m•K). The rest of the structure and components used are the same as those in Example 1.

[0048] Comparative Example 2 This comparative example provides a heated cigarette. The only difference between the heated cigarette and Example 1 is that the outer surface of the cigarette from the core section to 50% of the length of the combustion section is wrapped with a heat-insulating film (without a heat-conducting film) between it and the cigarette paper. The heat-insulating film is ceramic fiber paper with a thickness of 300 μm and a thermal conductivity of 0.04 W / (m•K). The rest of the structure and components used are the same as those in Example 1.

[0049] Comparative Example 3 This comparative example provides a conventional combustion heated cigarette without a heat-insulating and heat-conducting film. The heated cigarette includes a combustion section, a core section, and a filter section that are coaxially connected in sequence. The combustion section, the core section, and the filter section are formed by wrapping cigarette paper. The composition and materials of the combustion section, core section and filter section of the heated cigarette are the same as in Example 1.

[0050] Test Example 1 Thermocouple temperature sensors were inserted at two different radial positions on the cigarette core segment (point A, 3 mm from the end of the core near the combustion section, and point B, 8 mm from the end of the core near the combustion section). The insertion points were the same for the heated cigarettes in Examples 1-5 and Comparative Examples 1-3, with an insertion depth of 0.5 mm. The cigarettes were then smoked on a smoking machine at a frequency of 30 s / puff and a volume of 55 mL / puff. After 300 s of smoking, the internal temperature of the cigarette core segment at different locations was recorded on the 8th puff, and the average temperature at the two points was calculated. Simultaneously, thermal imaging analysis was used to test the outer surface temperature at the corresponding location on the first position of the cigarette core segment on the 8th puff, and the temperature difference between the inside and outside at that location was calculated. The cigarette core segment was then disassembled, and the carbonization effect of the heated cigarette core segment was compared and analyzed.

[0051] After smoking, the cigarette core section was disassembled, and the carbonization effect of the cigarette core section was compared and analyzed.

[0052] Carbonization effect analysis method: The hot airflow through the tobacco section flows from the end furthest from the filter tip towards the end closest to the filter tip. The carbonization of the core material in the tobacco section begins at the end furthest from the filter tip and gradually progresses longitudinally towards the end closest to the filter tip. Since the carbonization of the core material is affected by the heat conduction and heat transfer of the regulating section, the carbonization of the core material cross-section is relatively uniform. Therefore, the heating effect of the core material can be compared by analyzing the longitudinal carbonization length. In this invention, the total length of the tobacco core section is taken as 100 mm, and the percentage of the carbonized length to the total length represents the carbonization effect of the core material. The results are shown in Table 1.

[0053] Table 1 As shown in Table 1, compared with the ordinary heated cigarettes of Comparative Example 3, the heated cigarettes of Examples 1-3, with the installation of the conductive-insulating composite membrane, exhibited a maximum temperature difference of 129°C between the internal and external temperatures at point A, and a maximum carbonization rate of 95% in the core section. This demonstrates that in this invention, the axial heat-conducting layer rapidly directs heat from the combustion section to the core section; the radial heat-insulating layer prevents heat from escaping, and the two work together to maximize the heat flow for effective heating.

[0054] As can be seen from the comparison between Example 1 and Example 4, the addition of a heat-insulating composite membrane to completely cover the combustion section results in poor air permeability of the combustion section, incomplete combustion, and consequently, difficulty in combustion and testing.

[0055] A comparison between Example 1 and Example 5 shows that, due to the low porosity of the combustion section, the combustion is incomplete, the heat supplied to the core section is reduced, the average internal temperature at points A and B decreases, and the carbonization efficiency of the core material decreases.

[0056] As can be seen from the comparison between Example 1 and Comparative Examples 1-2, when only heat insulation film or heat conduction film is used, the utilization efficiency of heat in the combustion section decreases, resulting in poor carbonization effect of the smoke core.

[0057] The applicant declares that the present invention is illustrated by the above embodiments to provide a heated cigarette with a thermally conductive and heat-insulating composite film, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the 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.

[0058] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0059] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A heated cigarette with a thermally conductive and heat-insulating composite film, characterized in that, The heated cigarette includes a combustion section, a core section, and a filter section that are coaxially connected in sequence. The combustion section, the core section, and the filter section are formed by wrapping cigarette paper. The outer surface of the cigarette core segment is also wrapped with a heat-conducting and heat-insulating composite film, and then wrapped with cigarette paper.

2. The heated cigarette with a thermally conductive and heat-insulating composite film as described in claim 1, characterized in that, The thermally conductive composite membrane comprises a stacked radial thermal insulation layer and an axial thermally conductive layer; Preferably, the axial heat-conducting layer is in direct contact with the outer surface of the core section.

3. The heated cigarette with a thermally conductive and heat-insulating composite film as described in claim 2, characterized in that, The material of the axially oriented thermal layer includes any one or a combination of at least two of the following: axially oriented graphene film, axially arrayed carbon nanotube film, and metallized oriented polymer film.

4. The heated cigarette with a thermally conductive and heat-insulating composite film as described in claim 2 or 3, characterized in that, The thickness of the axial heat-conducting layer is 40-120 μm, and the thermal conductivity is ≥300 W / (m•K).

5. The heated cigarette with a thermally conductive and heat-insulating composite film as described in any one of claims 2-4, characterized in that, The radial insulation layer is made of any one or a combination of at least two of the following: aerogel felt, ceramic fiber paper, nanoporous insulation film, or polymer foam film.

6. The heated cigarette with a thermally conductive and heat-insulating composite film as described in any one of claims 2-5, characterized in that, The thickness of the radial insulation layer is 180-450 μm, and the thermal conductivity is ≤0.05 W / (m•K).

7. The heated cigarette with a thermally conductive and heat-insulating composite film as described in any one of claims 1-6, characterized in that, The end of the combustion section near the core section is also wrapped with a heat-conducting and heat-insulating composite film, and then cigarette paper is wrapped around the heat-conducting and heat-insulating composite film. Preferably, the length of the heat-conducting and heat-insulating composite membrane wrapped around the combustion section accounts for 30-70% of the total length of the combustion section.

8. The heated cigarette with a thermally conductive and heat-insulating composite film as described in any one of claims 1-7, characterized in that, The combustion section is made of plant fiber and carbon powder; Preferably, the porosity of the combustion section is ≥50%.

9. The heated cigarette with a thermally conductive and heat-insulating composite film as described in any one of claims 1-8, characterized in that, The components of the core segment include tobacco raw materials, smoking agents, tobacco flavorings, and adhesives; Preferably, the tobacco raw material includes any one or a combination of at least two of tobacco sheets, tobacco pellets, or shredded tobacco; Preferably, the tobacco flavoring includes any one or a combination of at least two of vanillin, succinate, 2-acetylpyrazine, 2,3,5-trimethylpyrazine, isoamyl isovalerate, menthyl acetate, phenethyl alcohol, furanone, or geraniol. Preferably, the adhesive comprises any one or a combination of at least two of sodium alginate, sodium carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, chitosan, guar gum, or cellulose acetate; Preferably, the smoke-generating agent comprises any one or a combination of at least two of propylene glycol, glycerin, or sorbitol.

10. The heated cigarette with a thermally conductive and heat-insulating composite film as described in any one of claims 1-9, characterized in that, The filter tip is made of cellulose acetate or polylactic acid.

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