Heating tube, aerosol-generating product and preparation method for heating tube

Abstract

This application relates to a heating tube, an aerosol-generating article, and a preparation method for a heating tube. A tube body of the heating tube includes an anti-leakage layer, an induction heating element of a strip-shaped structure, and a heat insulation layer. The anti-leakage layer has at least an inner anti-leakage portion that encloses to form an accommodating space, the induction heating element is located on an outer side of the inner anti-leakage portion, and is spirally arranged in a circumferential direction of the tube body, and the induction heating element heats an aerosol-generating substrate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese Patent Application No. 202311630289.0, filed on November 30, 2023, and entitled "HEATING TUBE, AEROSOL-GENERATING ARTICLE, AND PREPARATION METHOD FOR HEATING TUBE", which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present invention relates to the field of heat-not-burn technology, and in particular, to an induction heating tube, an aerosol-generating article, and a preparation method for an induction heating tube.BACKGROUND

[0003] A heat-not-burn apparatus based on a magnetic induction heating principle is becoming well known to the public due to characteristics such as relatively high heat efficiency and fast heating speed. Currently, in most heat-not-burn apparatuses based on the magnetic induction heating principle, an induction coil is disposed in a smoking set and around an aerosol-generating substrate accommodating cavity, a heating element made of magnetically permeable material is disposed at a center position of the aerosol-generating substrate accommodating cavity, and the heating element is embedded into a center position of an aerosol-generating substrate, so as to heat the aerosol-generating substrate.

[0004] Because the heating element is disposed at the center position of the aerosol-generating substrate, heat is transferred outward from the center of the aerosol-generating substrate in a radial direction of the aerosol-generating substrate. This may lead to excessive heating of the center position of the aerosol-generating substrate and insufficient heating of a radial periphery of the aerosol-generating substrate, that is, lead to non-uniform heating of the aerosol-generating substrate.SUMMARY

[0005] A technical problem to be mainly resolved in this application is to provide a heating tube, an aerosol-generating article, and a preparation method for a heating tube, so as to resolve a technical problem of non-uniform heating of an aerosol-generating substrate.

[0006] According to a first aspect, an embodiment provides a heating tube. The heating tube has a tube body and an accommodating space located in the tube body, where the accommodating space is configured to accommodate an aerosol-generating substrate, and the tube body includes: an anti-leakage layer, where the anti-leakage layer is arranged around an axis of the tube body, and the anti-leakage layer has at least an inner anti-leakage portion that encloses to form the accommodating space; an induction heating layer, including an induction heating element of a strip-shaped structure, where the induction heating element extends in an axial direction of the tube body, and is spirally arranged in a circumferential direction of the tube body, and the induction heating element is located on an outer side of the inner anti-leakage portion in a radial direction of the tube body; and a heat insulation layer, where the heat insulation layer is arranged around the accommodating space in the circumferential direction of the tube body, and the heat insulation layer covers at least an outer side of the induction heating element in the radial direction of the tube body.

[0007] In an optional embodiment, the induction heating element has a plurality of heating portions arranged in the axial direction of the tube body, and each heating portion is spirally disposed around a periphery of the inner anti-leakage portion.

[0008] In an optional embodiment, the plurality of the heating portions are arranged at intervals in the axial direction of the tube body, and two adjacent heating portions are staggered in the axial direction of the tube body.

[0009] In an optional embodiment, the plurality of heating portions are disposed side by side at intervals in the axial direction of the tube body, and two adjacent heating portions at least partially overlap in the axial direction of the tube body.

[0010] In an optional embodiment, a number of turns of the spirally arranged induction heating element on a radial outer side of the inner anti-leakage portion is an odd number.

[0011] In an optional embodiment, the anti-leakage layer further has an outer anti-leakage portion located on an outer side of the inner anti-leakage portion in the radial direction of the tube body, the outer anti-leakage portion is connected to the inner anti-leakage portion, the outer anti-leakage portion is wound around an axis of the inner anti-leakage portion, and at least a part of the induction heating element is wound between the outer anti-leakage portion and the inner anti-leakage layer in the radial direction of the tube body.

[0012] In an optional embodiment, the outer anti-leakage portion is wound around the axis of the tube body to form a multi-layer structure arranged in the radial direction of the tube body, and at least a part of the induction heating element is wound between two adjacent layers of the outer anti-leakage portion.

[0013] In an optional embodiment, the heat insulation layer includes a heat insulation body of a strip-shaped structure, and the heat insulation body is spirally arranged in the axial direction of the tube body.

[0014] In an optional embodiment, the heat insulation body has a plurality of heat insulation portions arranged in the axial direction of the tube body, each heat insulation portion is of a spiral structure, the heat insulation portion corresponds to the heating portion, and the heat insulation portion covers an outer side of the corresponding heating portion in the radial direction of the tube body.

[0015] In an optional embodiment, the anti-leakage layer is fixedly connected to the induction heating layer, and the induction heating layer is fixedly connected to the heat insulation layer.

[0016] According to a second aspect, an embodiment provides an aerosol-generating article. The aerosol-generating article includes an aerosol-generating substrate and the heating tube according to any one of the foregoing implementations, where the aerosol-generating substrate is located in the accommodating space.

[0017] According to a third aspect, an embodiment provides a preparation method for a heating tube. The heating tube includes an anti-leakage layer, an induction heating element, and a heat insulation layer, where the induction heating element is of a strip-shaped structure. The preparation method for a heating tube includes: stacking the anti-leakage layer, the induction heating element, and the heat insulation layer in sequence to form a multi-layer structure; winding the multi-layer structure around a winding rod to form a tube body, including: winding the multi-layer structure by attaching at least a part of the anti-leakage layer to an outer peripheral surface of the winding rod, spirally disposing the induction heating element around the anti-leakage layer at an inclined angle, and covering at least an outer side of the induction heating element with the heat insulation layer; and removing the tube body from the winding rod in an axial direction of the winding rod.

[0018] In an optional embodiment, the covering at least an outer side of the induction heating element with the heat insulation layer includes: winding and wrapping the heat insulation layer around the anti-leakage layer around which the induction heating element is wound after spirally disposing the induction heating element around the anti-leakage layer at an inclined angle.

[0019] In an optional embodiment, the heat insulation layer includes a heat insulation body of a strip-shaped structure; and the winding the multi-layer structure around a winding rod to form a tube body further includes: covering an outer side of the corresponding induction heating element with the heat insulation body, and winding the induction heating element and the heat insulation body together.

[0020] In an optional embodiment, the anti-leakage layer extends in a first direction, and the stacking the anti-leakage layer, the induction heating element, and the heat insulation layer in sequence to form a multi-layer structure includes: staggering a winding start end of the anti-leakage layer and a winding start end of the induction heating element in the first direction.

[0021] In an optional embodiment, the anti-leakage layer extends in a first direction; and the stacking the anti-leakage layer, the induction heating element, and the heat insulation layer in sequence to form a multi-layer structure includes: arranging an extension direction of the induction heating element and the first direction to be at an included angle of 35°-65°.

[0022] In an optional embodiment, the winding the multi-layer structure by attaching at least a part of the anti-leakage layer to an outer peripheral surface of the winding rod includes: tightly attaching the winding start end of the anti-leakage layer to the outer peripheral surface of the winding rod, and arranging an axis direction of the winding rod to be perpendicular to the first direction.

[0023] According to the heating tube, the aerosol-generating article, and the preparation method for a heating tube in the foregoing embodiments, a tube body of the heating tube includes an anti-leakage layer, an induction heating element, and a heat insulation layer. The anti-leakage layer has at least an inner anti-leakage portion that encloses to form an accommodating space, and an aerosol-generating substrate in the accommodating space may be prevented from leaking out by using the inner anti-leakage portion. The induction heating element is located on an outer side of the inner anti-leakage portion in a radial direction of the tube body, extends in an axial direction of the tube body, and is spirally arranged in a circumferential direction of the tube body. The induction heating element can generate heat in an alternating magnetic field, so as to heat the aerosol-generating substrate in the accommodating space. In addition, because the entire heating tube is located on a radial outer side of the aerosol-generating substrate, a heated surface of the aerosol-generating substrate is an outer peripheral surface used to be in contact with the inner anti-leakage portion. In this way, an area of the heated surface of the aerosol-generating substrate can be increased. In addition, heat is transferred inward from the radial outer side, thereby improving heating efficiency of the aerosol-generating substrate, reducing a temperature difference between a periphery of the aerosol-generating substrate and a center position, and helping improve heating uniformity of the entire aerosol-generating substrate. The heat insulation layer covers the outer side of the induction heating element in the radial direction of the tube body, so that outward heat loss can be avoided through a heat insulation action of the heat insulation layer, thereby further reducing a temperature difference between inside and outside the aerosol-generating substrate, further improving heating uniformity of the entire aerosol-generating substrate, and preventing normal operation of a smoking set from being affected by a generated high temperature.BRIEF DESCRIPTION OF DRAWINGS

[0024] FIG. 1 is a schematic structural diagram of a side surface of a heating tube according to an embodiment; FIG. 2 is a schematic structural diagram of a side surface of a heating tube according to another embodiment; FIG. 3 is a schematic structural diagram of a side surface of a heating tube according to still another embodiment; FIG. 4 is a schematic diagram of an expanded structure of a tube wall of a tube body in a heating tube according to an embodiment; FIG. 5 is a schematic structural diagram of a position relationship between an anti-leakage layer, an induction heating element, and a heat insulation layer of a heating tube in a radial direction of a tube body according to an embodiment; FIG. 6 is a schematic structural diagram of a position relationship between an anti-leakage layer, an induction heating element, and a heat insulation layer of a heating tube in a radial direction of a tube body according to another embodiment; FIG. 7 is a schematic structural diagram of a position relationship between an anti-leakage layer, an induction heating element, and a heat insulation layer in a vertical stacking direction in a heating tube preparation process according to an embodiment; FIG. 8 is a schematic structural diagram of a position relationship between an anti-leakage layer, an induction heating element, and a heat insulation layer in a vertical stacking direction in a heating tube preparation process according to another embodiment; FIG. 9 is a flowchart of a preparation method for a heating tube according to an embodiment; and FIG. 10 is a schematic structural diagram of an aerosol-generating article according to an embodiment.

[0025] In the figures: 1: outer tube body; 2: filter member; 3: limiting member; 4: heating tube; 41: anti-leakage layer; 411: inner anti-leakage portion; 412: outer anti-leakage portion; 42: induction heating element; 421: heating portion; 43: heat insulation layer; 430: heat insulation body; 431: heat insulation portion; 44: accommodating space; 45: base.DESCRIPTION OF EMBODIMENTS

[0026] The following further describes this application in detail through specific implementations with reference to the accompanying drawings. Associated and similar reference numerals are used for similar elements in different implementations. In the following implementations, many details are described so that this application can be better understood. However, a person skilled in the art may readily recognize that some of the features may be omitted in different cases, or may be replaced by another element, material, or method. In some cases, some operations related to this application are not shown or described in this specification to avoid obscuring a core part of this application with excessive description. For a person skilled in the art, a detailed description of the related operations is not necessary. A person skilled in the art can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0027] In addition, the characteristics, operations, or features described in the specification may be combined in any appropriate manner to form various implementations. In addition, the steps or actions in the method descriptions may also be sequentially switched or adjusted in a manner obvious to a person skilled in the art. Therefore, the sequence in the specification and the accompanying drawings is merely intended to clearly describe an embodiment, and does not imply a necessary sequence unless otherwise stated that a sequence must be followed.

[0028] Sequence numbers in this specification, such as "first" and "second", are only used for distinguishing described objects, and do not have any sequence or technical meaning. The terms "connected" and "coupled" used in this application, unless otherwise specified, include both direct and indirect connections (or couplings).

[0029] Referring to FIG. 1 to FIG. 8, this application provides a heating tube 4. The heating tube 4 includes a tube body and an accommodating space 44 located in the tube body. The accommodating space 44 is configured to accommodate an aerosol-generating substrate. The tube body includes an anti-leakage layer 41, an induction heating layer, and a heat insulation layer 43. The anti-leakage layer 41 is arranged around an axis of the tube body, and the anti-leakage layer 41 has at least an inner anti-leakage portion 411 that encloses to form the accommodating space 44. The inner anti-leakage portion 411 can effectively prevent the aerosol-generating substrate in the accommodating space 44 from leaking out.

[0030] The induction heating layer includes an induction heating element 42 of a strip-shaped structure. The induction heating element 42 extends in an axial direction of the tube body, and is spirally arranged in a circumferential direction of the tube body. The induction heating element 42 is located on an outer side of the inner anti-leakage portion 411 in a radial direction of the tube body. The induction heating element 42 can generate heat in an alternating magnetic field, and heat passes through the inner anti-leakage portion 411 to heat the aerosol-generating substrate, so that an outer peripheral surface of the aerosol-generating substrate is a heated surface. Compared with a structure of inserting a heating element into a center position of an aerosol-generating substrate in a conventional technology, a heating area of the entire aerosol-generating substrate can be effectively increased, thereby improving inward heat transfer efficiency of the aerosol-generating substrate, reducing a temperature difference between the center position of the aerosol-generating substrate and a periphery of the aerosol-generating substrate, and helping improve overall heating uniformity.

[0031] The heat insulation layer 43 is arranged around the accommodating space 44 in the circumferential direction of the tube body. The heat insulation layer 43 covers at least an outer side of the induction heating element 42 in the radial direction of the tube body to prevent heat of the induction heating element 42 from dissipating outward. This enables the heat to be encapsulated on a radial inner side of the heat insulation layer 43, which helps reduce heat loss. In this way, heating uniformity of the entire aerosol-generating substrate can be further improved, and normal operation of a smoking set can be prevented from being affected by a high temperature generated by the heating tube 4.

[0032] It should be noted that in each of the heating tubes 4 in FIG. 1 to FIG. 8, a solid line is an outer contour line of the anti-leakage layer 41, a dashed line is an outer contour line of the induction heating element 42, a dot dash line is an outer contour line of the heat insulation layer 43, and a structure denoted by hatched section lines is the heat insulation layer 43. In FIG. 1 to FIG. 4 and FIG. 10, the outer contour line of the induction heating element 42 coincides with the outer contour line of the heat insulation layer 43, and the heat insulation layer 43 covers the induction heating element 42. In FIG. 7, a double dot dash line is a base 45.

[0033] As shown in FIG. 1 to FIG. 8, the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 may each be of a sheet-shaped structure, and the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 may be stacked and then wound to form the tube body. For example, in some embodiments, the anti-leakage layer 41 is set to have a rectangular sheet-shaped structure, the anti-leakage layer 41 may be made of cellulose paper, carbon nanotube paper, aramid paper or the like, and material of the anti-leakage layer 41 can prevent the aerosol-generating substrate from penetrating through the anti-leakage layer 41 to leak out. A thickness of the anti-leakage layer 41 is relatively small, and the thickness and tensile strength of the anti-leakage layer 41 need to meet a requirement of preventing the anti-leakage layer 41 from being punctured by the induction heating element 42 in a winding process. For example, in an embodiment, the thickness of the anti-leakage layer 41 is 50-100 µm, to facilitate heat conduction, and the tensile strength is 1.1-2.0 KN / m.

[0034] The induction heating element 42 includes magnetically permeable material and can generate heat in the alternating magnetic field. The magnetically permeable material may be a monomer or compound that includes iron, copper, chromium, nickel, or the like. The induction heating element 42 specifically has a strip-shaped and magnetic sheet layer structure. As shown in FIG. 8, the induction heating element 42 may be separately stacked with the anti-leakage layer 41, or as shown in FIG. 7, the induction heating element 42 may alternatively be integrated on the base 45. The induction heating element 42 and the base 45 are combined to form the induction heating layer. For example, the induction heating element 42 is integrated on relatively thin cellulose paper, and is then stacked with the anti-leakage layer 41.

[0035] The heat insulation layer 43 may be formed from at least one of aerogel, polysaccharide gel, diatomaceous earth, and molecular sieve. The heat insulation layer 43 has a porous sheet-shaped structure, and a thickness and tensile strength of the heat insulation layer 43 also need to meet a requirement of preventing the heat insulation layer 43 from being punctured by the induction heating element 42 in a winding process. For example, in an embodiment, the thickness of the heat insulation layer 43 is greater than 100 µm, a porosity is greater than 65%, and the tensile strength may be the same as that of the anti-leakage layer 41, to facilitate winding.

[0036] In some embodiments, for the anti-leakage layer 41, the anti-leakage layer 41 is of a rectangular sheet-shaped structure before winding, and before winding, a length direction of the anti-leakage layer 41 is perpendicular to an axis direction of a winding rod (not shown in the figure). The anti-leakage layer 41 has an inner anti-leakage portion 411 located on a radial inner side in the radial direction of the tube body, the inner anti-leakage portion 411 is disposed around an axis of the tube body by 360°, the inner anti-leakage portion 411 is of a tubular structure with openings at two ends after winding, and an inner space of the tubular structure is the accommodating space 44. In this way, the aerosol-generating substrate can be fully encapsulated inside the tube body, thereby implementing encapsulation and anti-leakage effects.

[0037] In some embodiments, the anti-leakage layer 41 further has an outer anti-leakage portion 412. In a process of winding the anti-leakage layer 41, the anti-leakage layer 41 may be wound around the winding rod in two or more turns. In this way, an innermost anti-leakage layer 41 in the radial direction of the tube body forms the inner anti-leakage portion 411, and a portion located on a radial outer side of the inner anti-leakage portion 411 is the outer anti-leakage portion 412. The outer anti-leakage portion 412 is connected to the inner anti-leakage portion 411 in a circumferential direction of the tube body, and the outer anti-leakage portion 412 is wound around an axis of the inner anti-leakage portion 411. Because the entire anti-leakage layer 41 and the induction heating element 42 are stacked and then wound together, at least a part of the induction heating element 42 is disposed between the inner anti-leakage portion 411 and the outer anti-leakage portion 412. In addition, in a structure in which the outer anti-leakage portion 412 is wound around the axis of the tube body in a plurality of turns, the outer anti-leakage portion 412 forms a multi-layer structure arranged in the radial direction of the tube body. In this way, at least a part of the induction heating element 42 is also disposed between two adjacent layers of the outer anti-leakage portion 412, as shown in FIG. 5 and FIG. 6.

[0038] Certainly, in some other embodiments, if a size of the anti-leakage layer 41 in the circumferential direction of the tube body is relatively small, the anti-leakage layer 41 may have only the inner anti-leakage portion 411. Alternatively, if the size of the anti-leakage layer 41 in the circumferential direction of the tube body is limited, the anti-leakage layer 41 may have an inner anti-leakage portion 411 and one turn of outer anti-leakage portion 412, at least a part of the induction heating element 42 is disposed between the inner anti-leakage portion 411 and the outer anti-leakage portion 412, and the remaining part of the induction heating element 42 may be spirally wound around an outer peripheral surface of the outer anti-leakage portion 412.

[0039] It should be noted that in this application, "the outer anti-leakage portion 412 is wound around the axis of the tube body in a plurality of turns" may be understood as that a number of turns of the outer anti-leakage portion 412 around the inner anti-leakage portion 411 is greater than one, may be an integer, or may be a non-integer.

[0040] For the induction heating element 42, in some embodiments, the induction heating element 42 has a plurality of heating portions 421 sequentially and continuously disposed in an extension direction of a spiral structure of the induction heating element 42, and each heating portion 421 is spirally disposed around a periphery of the inner anti-leakage portion 411, that is, the induction heating element 42 has a plurality of heating portions 421 of a strip-shaped structure.

[0041] For example, in an embodiment, referring to FIG. 2, an outer contour of the induction heating element 42 coincides with an outer contour of the heat insulation layer 43 in FIG. 2. Two heating portions 421 are disposed, and the two heating portions 421 are arranged at intervals in the axial direction of the tube body. The two adjacent heating portions 421 are staggered in the axial direction of the tube body, and the two heating portions 421 can separately heat different positions of the aerosol-generating substrate in the axial direction of the tube body. For example, the heating tube 4 may be divided into a first portion and a second portion in an axial direction of the heating tube 4. One of the two heating portions 421 is located in the first portion and the other is located in the second portion, so that the two heating portions 421 are staggered in the axial direction of the tube body. The heating portion 421 located in the first portion is configured to heat the aerosol-generating substrate corresponding to the first portion, and the heating portion 421 located in the second portion is configured to heat the aerosol-generating substrate corresponding to the second portion.

[0042] In this way, independent coils may be disposed on the smoking set corresponding to the first portion and the second portion, so that the two coils respectively perform independent heating in an initial stage of inhalation and a later stage of inhalation, that is, in an entire inhalation process, the two heating portions 421 respectively heat the aerosol-generating substrate in the initial stage of inhalation and the later stage of inhalation, thereby reducing waste caused by excessive heating of the aerosol-generating substrate in the initial stage of inhalation, increasing a vapor amount of the later stage of inhalation, and improving heating efficiency of the aerosol-generating substrate.

[0043] In another embodiment, referring to FIG. 3, an outer contour of the induction heating element 42 coincides with an outer contour of the heat insulation layer 43 in FIG. 3. Two heating portions 421 are disposed, and the two heating portions 421 are arranged side by side at intervals in the axial direction of the tube body. The two heating portions 421 are disposed side by side at intervals in a direction perpendicular to a spiral line. The two heating portions 421 may be disposed side by side at intervals before winding, and a side-by-side direction of the two heating portions 421 is perpendicular to an extension direction of each heating portion 421. In this way, after winding, two spiral heating portions 421 arranged side by side are formed.

[0044] Certainly, in some other embodiments, a quantity of heating portions 421 may alternatively be three, four, or the like. Alternatively, in some other embodiments, the induction heating element 42 may alternatively have only one heating portion 421, that is, the induction heating element 42 with one strip-shaped structure is wound into a spiral shape in the circumferential direction of the tube body. When the induction heating element 42 has a plurality of separately disposed heating portions 421, the heating portions 421 of the induction heating element 42 may be integrated on a same base 45, and are combined with the base 45 to form the induction heating layer. In this way, winding processing and positioning can be facilitated.

[0045] In some embodiments, because the induction heating element 42 and the anti-leakage layer 41 are stacked and then wound together, referring to FIG. 5 and FIG. 6, at least a part of the induction heating element 42 is disposed between the inner anti-leakage portion 411 and the outer anti-leakage portion 412. Alternatively, in some other embodiments, at least a part of the induction heating element 42 is disposed between two adjacent layers of the outer anti-leakage portion 412.

[0046] Referring to FIG. 1, in an embodiment in which the outer anti-leakage portion 412 is not disposed in the anti-leakage layer 41, that is, the anti-leakage layer 41 is wound in only one turn, the anti-leakage layer 41 has only the inner anti-leakage portion 411, and the induction heating element 42 is spirally wound, in a cylindrical shape, around an outer peripheral surface of the inner anti-leakage portion 411.

[0047] In an embodiment in which the outer anti-leakage portion 412 in the anti-leakage layer 41 is wound in only one turn, the induction heating element 42 is wound in one or more turns, and the induction heating element 42 is spirally wound between the inner anti-leakage portion 411 and the outer anti-leakage portion 412 and around an exterior of the outer anti-leakage portion 412, a first turn of the induction heating element 42 is located between the inner anti-leakage portion 411 and the outer anti-leakage portion 412, and a second turn of the induction heating element 42 or a plurality of turns on a radial outer side are located on a radial outer side of the outer anti-leakage portion 412.

[0048] In an embodiment in which the outer anti-leakage portion 412 in the anti-leakage layer 41 is wound in a plurality of turns, the anti-leakage layer 41 and the induction heating element 42 have a relatively large overlapping area when stacked. In this way, after the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 are wound, referring to FIG. 5 and FIG. 6, two adjacent turns of the induction heating element 42 are separated by one turn or one layer of the outer anti-leakage portion 412. In addition, in a winding process, two adjacent layers of the outer anti-leakage portion 412 may have a relatively good clamping action on an end portion of the induction heating element 42, so that the induction heating element 42 can be prevented from moving relative to the anti-leakage layer 41 in the circumferential direction of the tube body in the winding process.

[0049] In an embodiment in which the induction heating element 42 is wound in a plurality of turns, referring to FIG. 1, two adjacent turns of the induction heating element 42 are arranged at intervals in the axial direction of the tube body at a same position in the circumferential direction of the tube body. For example, the turns in the induction heating element 42 may be divided into a winding front section, a winding middle section, and a winding rear section that are sequentially and continuously arranged in the circumferential direction of the tube body, and an angle corresponding to each section in the circumferential direction of the tube body is 120°. Two adjacent turns of the winding front section are arranged at intervals in the axial direction of the tube body, two adjacent turns of the winding middle section are arranged at intervals in the axial direction of the tube body, and two adjacent turns of the winding rear section are also arranged at intervals in the axial direction of the tube body. In this way, the induction heating element 42 can be prevented from forming a shielding structure on the radial outer side of the inner anti-leakage portion 411, and local overheating of the aerosol-generating substrate can also be avoided, thereby contributing to heating uniformity of the aerosol-generating substrate.

[0050] Referring to FIG. 1, a number of winding turns of the induction heating element 42 is set to an odd number, which may be 3 in FIG. 1. Alternatively, in another embodiment, the number of winding turns of the induction heating element 42 may be 5, 7, or 9 or a higher odd number. In this way, the induction heating element 42 with an odd number of turns may form a triangular mesh-based electromagnetic field, so that thermal field distribution of the induction heating element 42 is more uniform, thereby contributing to heating uniformity of the aerosol-generating substrate.

[0051] For the heat insulation layer 43, in some embodiments, the heat insulation layer 43 may be of a tubular structure, and the heat insulation layer 43 is of a rectangular or square sheet-shaped structure before winding. When the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 are stacked, the heat insulation layer 43 is located at a position of a winding tail end. Referring to FIG. 7, in a winding process, the heat insulation layer 43 is wound in only one turn to form the tubular structure that covers the radial outer sides of the induction heating element 42 and the anti-leakage layer 41, as shown in FIG. 6.

[0052] Certainly, in the embodiment shown in FIG. 5, the heat insulation layer 43 may further include a heat insulation body 430 of a strip-shaped sheet layer structure. The heat insulation body 430 extends in the axial direction of the tube body, and is spirally arranged in the circumferential direction of the tube body. In an embodiment, the heat insulation body 430 has a plurality of heat insulation portions 431 arranged in the axial direction of the tube body, and each heat insulation portion 431 is of a strip-shaped sheet layer structure. Each heat insulation portion 431 is spirally disposed in the circumferential direction of the tube body, the heat insulation portion 431 corresponds to the heating portion 421, and the heat insulation portion 431 covers an outer side of the corresponding heating portion 421 in the radial direction of the tube body. This may be understood as that, when the heat insulation layer 43 is stacked with the anti-leakage layer 41 and the induction heating element 42 before winding, the heat insulation body 430 fully covers a side surface of the induction heating element 42 facing away from the anti-leakage layer 41. Referring to FIG. 4, a width size of the strip-shaped structure of the heat insulation body 430 may be equal to a width size of the strip-shaped structure of the induction heating element 42. Alternatively, referring to FIG. 8, in some other embodiments, a width size of the strip-shaped structure of the heat insulation body 430 may be greater than a width size of the strip-shaped structure of the induction heating element 42. Both the two structures can meet that an orthographic projection of the induction heating element 42 on the heat insulation body 430 in a stacking direction is entirely located on the heat insulation body 430, so that after winding, the heat insulation body 430 fully covers an outer side of the induction heating element 42 in the radial direction of the tube body.

[0053] In some embodiments, the width size of the strip-shaped structure of the heat insulation body 430 is set to be greater than the width size of the strip-shaped structure of the induction heating element 42. In addition, after the induction heating element 42 and the heat insulation body 430 are wound, two adjacent turns of the induction heating element 42 are arranged at intervals in the axial direction of the tube body at a same position in the circumferential direction of the tube body, and two adjacent turns of the heat insulation body 430 are staggered and continuously disposed or partially overlap in the axial direction of the tube body at a same position in the circumferential direction of the tube body (in the embodiment in which two adjacent turns of the heat insulation body 430 partially overlap in the axial direction of the tube body at a same position in the circumferential direction of the tube body, it is necessary to meet that the heat insulation body 430 located on the radial inner side and the induction heating element 42 located on the radial outer side do not overlap in the axial direction of the tube body). In this way, heat generated by the induction heating element 42 is fully encapsulated on the radial inner side of the heat insulation layer 43 by a plurality of turns of the heat insulation body 430 continuously arranged in the axial direction, thereby preventing the heat from escaping through a gap between two adjacent turns of the heat insulation body 430.

[0054] In some embodiments, to avoid relative movement of the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 in a winding direction in a winding process, after the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 are stacked in sequence, the anti-leakage layer 41 is fixedly connected to the induction heating element 42 by using an adhesive, and the induction heating element 42 is fixedly connected to the heat insulation layer 43 by using an adhesive. In a process of implementing a fixed connection between the anti-leakage layer 41 and the induction heating element 42, the adhesive may be applied only to a side surface of the induction heating element 42 facing the anti-leakage layer 41 at a winding start end. In a process of implementing a fixed connection between the induction heating element 42 and the heat insulation layer 43, the adhesive may be applied only to a side surface of the induction heating element 42 facing the heat insulation layer 43 at a winding tail end. Certainly, the adhesive may alternatively be applied to both sides of the induction heating element 42 to increase structural stability of the fixed connection between the induction heating element 42 and the anti-leakage layer 41 and the fixed connection between the induction heating element 42 and the heat insulation layer 43.

[0055] Alternatively, in some other embodiments, there is no fixed connection relationship between the induction heating element 42 and the anti-leakage layer 41 and between the induction heating element 42 and the heat insulation layer 43. In the winding process, a clamping action between the inner anti-leakage portion 411 and the outer anti-leakage portion 412 or a clamping action between the anti-leakage layer 41 and the heat insulation layer 43 may be used to ensure that a position of the induction heating element 42 in the winding direction does not change.

[0056] In the radial direction of the tube body, the anti-leakage layer 41 has a winding start end located on an inner side and a winding tail end located on an outer side, and similarly, the induction heating element 42 also has a winding start end and a winding tail end. In an embodiment in which there is no fixed connection relationship between the induction heating element 42 and the anti-leakage layer 41 and between the induction heating element 42 and the heat insulation layer 43, to facilitate winding of the induction heating element 42, the anti-leakage layer 41 is set to extend in a first direction in a process of stacking the anti-leakage layer 41 and the induction heating element 42, and the first direction is a length direction of the anti-leakage layer 41. The winding start end of the anti-leakage layer 41 and the winding start end of the induction heating element 42 are staggered in the first direction, as shown in FIG. 6 to FIG. 8. In this way, when winding is performed by using a winding rod, the anti-leakage layer 41 is first wound around the winding rod, so that when the induction heating element 42 starts to be wound, a pressing action between the anti-leakage layer 41 and the winding rod can prevent the induction heating element 42 from moving relative to the anti-leakage layer 41.

[0057] This application further provides a preparation method for a heating tube 4. The heating tube 4 may be the heating tube 4 described in any one of the foregoing embodiments. Referring to FIG. 9, the preparation method for the heating tube 4 includes step 100 to step 300.

[0058] Step 100: Stack the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 in sequence to form a multi-layer structure, where the induction heating element 42 is disposed between the anti-leakage layer 41 and the heat insulation layer 43 in a stacking direction. It may be understood that the heating tube 4 may have more than three layers. For example, a specific layer may be a multi-layer composite structure. For example, the induction heating element 42 and the base 45 may be combined to form the induction heating layer. Alternatively, another layer, such as an adhesive layer, is further disposed between two adjacent layers. For ease of understanding, the following embodiments are described by using a three-layer structure as an example.

[0059] In some embodiments, referring to FIG. 4, the anti-leakage layer 41 is of a rectangular sheet-shaped structure, the induction heating element 42 is of a strip-shaped sheet layer structure, the heat insulation layer 43 includes the heat insulation body 430 of a strip-shaped sheet layer structure shown in FIG. 4, and a size and a shape of the heat insulation body 430 are the same as a size and a shape of the induction heating element 42.

[0060] After the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 are stacked in sequence, sizes of the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 may be equal in a length direction of the anti-leakage layer 41.

[0061] To ensure that a relative position between the induction heating element 42 and the anti-leakage layer 41 does not change in a process of winding the induction heating element 42 around the winding rod, in some preferred embodiments, the length direction of the anti-leakage layer 41 is defined as a first direction, and the anti-leakage layer 41 extends in the first direction. Step 100 further includes: staggering a winding start end of the anti-leakage layer 41 and a winding start end of the induction heating element 42 in the first direction.

[0062] In an embodiment, referring to FIG. 6 to FIG. 8, the winding start end of the anti-leakage layer 41 is exposed on an outer side of the induction heating element 42. When the three-layer structure is wound by using the winding rod, the winding start end of the anti-leakage layer 41 is first wound around the winding rod, so that when the winding start end of the induction heating element 42 starts to be wound, a pressing action between the anti-leakage layer 41 and the winding rod can prevent the induction heating element 42 from moving relative to the anti-leakage layer 41.

[0063] In addition, to improve heating efficiency of the heating tube 4, and reduce a size of a gap between two adjacent turns of the induction heating element 42 in the axial direction of the tube body, in some embodiments, step 100 is set to further include: arranging a length direction of the induction heating element 42 and the first direction to be at an included angle of 35°-65°.

[0064] If the included angle is excessively small, two adjacent turns of the induction heating element 42 on the formed heating tube 4 may overlap in the axial direction, which, although also possible, is not conducive to improving heating efficiency of the heating tube 4. If the included angle is excessively large, a gap between two adjacent turns of the induction heating element 42 on the formed heating tube 4 may be too large, which reduces heating efficiency of the heating tube 4. Therefore, setting the included angle between the induction heating element 42 and the first direction during stacking to 35°-65° not only can meet that there is a specific gap between two adjacent turns of the induction heating element 42 on the formed heating tube 4 in the axial direction, but also can prevent the gap from being excessively large to affect heating efficiency of the aerosol-generating substrate.

[0065] Step 200: Wind the multi-layer structure around the winding rod to form a tube body, including: winding the multi-layer structure by attaching at least a part of the anti-leakage layer 41 to an outer peripheral surface of the winding rod to enclose to form a tubular structure, spirally disposing the induction heating element 42 around the anti-leakage layer 41 at an inclined angle, and covering at least an outer side of the induction heating element 42 with the heat insulation layer 43.

[0066] In some embodiments, to ensure that at least a part of the anti-leakage layer 41 is attached to the outer peripheral surface of the winding rod and encloses to form the tubular structure, a length size of the anti-leakage layer 41 is set to be at least greater than a circumferential size of the winding rod, and the tubular structure enclosed by the at least a part of the anti-leakage layer 41 is the inner anti-leakage portion 411 in the foregoing embodiments of the heating tube 4.

[0067] The winding rod may be a rod-shaped structure with a circular cross-section shape, a diameter of the winding rod may be 6 mm-7.2 mm, and the multi-layer structure is wound around the winding rod in a clockwise direction to form the tube body. Alternatively, in some other embodiments, the cross-section shape of the winding rod may be an elliptical shape.

[0068] To enable the induction heating element 42 to be spirally disposed around the tubular structure at an inclined angle after winding, a length direction of the strip-shaped structure of the induction heating element 42 and the length direction of the anti-leakage layer 41 are set to be at an acute angle when the anti-leakage layer 41, the induction heating element 42, and the heat insulation layer 43 are stacked in step 100.

[0069] The heat insulation layer 43 may cover at least the outer side of the induction heating element 42 by using the following two embodiments. In some embodiments, referring to FIG. 1, FIG. 4, FIG. 5, and FIG. 8, the heat insulation layer 43 is set to include a heat insulation body 430 of a strip-shaped sheet layer structure. A width size of the strip-shaped structure of the heat insulation body 430 is greater than or equal to a width size of the strip-shaped structure of the induction heating element 42. In step 100, a length direction of the heat insulation body 430 is the same as the length direction of the induction heating element 42, and the heat insulation body 430 covers a side surface of the induction heating element 42 facing away from the anti-leakage layer 41, so that an orthographic projection of the induction heating element 42 on the heat insulation body 430 in a vertical stacking direction is entirely located on the heat insulation body 430 to be fully blocked by the heat insulation body 430. In this way, in a process of winding the multi-layer structure in step 200, the heat insulation body 430 covers the outer side of the corresponding induction heating element 42, and the induction heating element 42 and the heat insulation body 430 are wound together, so that the heat insulation body 430 fully covers the outer side of the induction heating element 42 in a radial direction of the tube body. Alternatively, the width size of the strip-shaped structure of the heat insulation body 430 may be increased, so that after winding, the heat insulation body 430 forms a tubular structure that is continuous in an axial direction of the tube body, so as to cover the heat insulation layer 43 and a part of the anti-leakage layer 41, thereby improving a heat insulation effect of the heat insulation layer 43.

[0070] In some other embodiments, referring to FIG. 6 and FIG. 7, the heat insulation layer 43 is set to have a rectangular sheet-shaped structure. In step 100, the heat insulation layer 43 is stacked on the winding tail end of the induction heating element 42 in the length direction of the anti-leakage layer 41, that is, in the first direction, and overlaps the winding tail end of the induction heating element 42. In this way, in step 200, the heat insulation layer 43 is wound around the winding rod at a winding rear section, and a width size of the heat insulation layer 43 is set to be equal to a width size of the anti-leakage layer 41 and a size of the induction heating element 42 in a direction perpendicular to the first direction. In this way, after winding is completed, the heat insulation layer 43 fully covers the outer side of the anti-leakage layer 41 around which the induction heating element 42 is wound, so as to provide a relatively good heat insulation effect.

[0071] In some embodiments, to avoid subsequent trimming of the formed heating tube 4 or to reduce a trimming amount of the formed heating tube 4, the winding the three-layer structure around the winding rod to form a tube body in step 200 is set to further include: tightly attaching the winding start end of the anti-leakage layer 41 to the outer peripheral surface of the winding rod, and arranging a length direction of the winding rod to be perpendicular to the first direction.

[0072] In this way, the three-layer structure is wound around the winding rod with the first direction being perpendicular to the length direction of the winding rod, which helps align axial end surfaces of the wound heating tube 4. In addition, the formed heating tube 4 can be directly used without trimming when a width size of the anti-leakage layer 41 meets a requirement. Alternatively, in a process in which the formed heating tube 4 needs to be trimmed, a trimming amount of the heating tube 4 can be reduced, thereby saving a material usage amount and costs.

[0073] Step 300: Remove the tube body from the winding rod in an axial direction of the winding rod.

[0074] In some embodiments, after the three-layer structure is wound around the winding rod to form the tube body, friction between two adjacent layers in the three-layer structure formed through winding maintains the tube body to be of a tubular structure, and a heating tube can be formed by removing the tube body from the winding rod. Certainly, in some other embodiments, if a size of a tube body formed by winding the three-layer structure does not meet a requirement, the tube body may be trimmed into a desired size after the tube body is removed from the winding rod.

[0075] This application further provides an aerosol-generating article, including an aerosol-generating substrate and the heating tube 4 described in any one of the foregoing embodiments. The aerosol-generating substrate is located in an accommodating space 44 of the heating tube 4, and the aerosol-generating substrate includes at least one of a granular structure, a disordered filamentous structure, a sheet-shaped structure, a paste-like structure or a columnar porous structure made of tobacco material.

[0076] For example, in some embodiments, referring to FIG. 10, the aerosol-generating substrate includes granular vapor generating material. To prevent the granular vapor generating material from leaking out of an end portion of the heating tube 4, the aerosol-generating article is set to further include a sealing member, and the sealing member is fastened to at least one end of the heating tube 4 in an axial direction. For example, the heating tube 4 may be fixedly connected to the sealing member only at one end of the heating tube 4 by using an adhesive.

[0077] In some embodiments, the aerosol-generating article further includes an outer tube body 1, a filter member 2, and a limiting member 3. The limiting member 3 and the heating tube 4 filled with the vapor generating material may be sequentially loaded into one end of the outer tube body 1 in a length direction, and the filter member 2 is disposed on the other end of the outer tube body 1 in the length direction. For example, after the heating tube 4 is manufactured, the heating tube 4 is formed as a hard tube body.

[0078] In an embodiment, the limiting member 3 is spaced apart from the filter member 2 to form a hollow cooling channel between the limiting member 3 and the filter member 2. It may be understood that a cooling channel may not be reserved between the limiting member 3 and the filter member 2, but the limiting member 3 and the filter member 2 are in direct contact. In this case, the limiting member 3 is a cooling component, and an aerosol channel of the limiting member 3 serves as the cooling channel.

[0079] The heating tube 4 that is filled with the granular, filamentous, or sheet-shaped loose vapor generating material and that is sealed at one end by the sealing member is loaded into the outer tube body from one end of the outer tube body, and an open end of the heating tube 4 is arranged to face the limiting member 3, so that the other end of the heating tube 4 is sealed by using the limiting member 3, to prevent the vapor generating material from leaking out of the heating tube 4. The aerosol channel through which aerosol can pass is formed on a center or an outer wall of the limiting member 3.

[0080] In some other embodiments, the vapor generating material in the aerosol-generating substrate may be set to be sheet-shaped vapor generating material, a paste-like structure or a columnar porous structure. In this way, the sealing member and the limiting member 3 may not be disposed in the aerosol-generating article. Alternatively, the outer tube body 1 and the filter member 2 may not be disposed, and the heating tube 4 filled with the vapor generating material may form the entire aerosol-generating article, provided that a heating cavity that accommodates the aerosol-generating substrate and a separate mouthpiece in communication with the heating cavity are disposed on a smoking set to serve as the filter member 2.

[0081] In some embodiments, after the heating tube 4 is manufactured, the heating tube 4 is formed as a hard tube body, and may be used as the outer tube body of the aerosol-generating article. The limiting member 3 and the vapor generating material may be sequentially loaded into one end of the heating tube 4 in the length direction, and the filter member 2 is disposed on the other end of the heating tube 4 in the length direction, and the induction heating element 42 is formed only on an outer peripheral surface corresponding to the vapor generating material.

Claims

1. A heating tube, having a tube body and an accommodating space located in the tube body, wherein the accommodating space is configured to accommodate an aerosol-generating substrate, and the tube body comprises: an anti-leakage layer, wherein the anti-leakage layer is arranged around an axis of the tube body, and the anti-leakage layer has at least an inner anti-leakage portion that encloses to form the accommodating space; an induction heating layer, comprising an induction heating element of a strip-shaped structure, wherein the induction heating element extends in an axial direction of the tube body, and is spirally arranged in a circumferential direction of the tube body, and the induction heating element is located on an outer side of the inner anti-leakage portion in a radial direction of the tube body; and a heat insulation layer, wherein the heat insulation layer is arranged around the accommodating space in the circumferential direction of the tube body, and the heat insulation layer covers at least an outer side of the induction heating element in the radial direction of the tube body.

2. The heating tube according to claim 1, wherein the induction heating element has a plurality of heating portions arranged in the axial direction of the tube body, and each heating portion is spirally disposed around a periphery of the inner anti-leakage portion.

3. The heating tube according to claim 2, wherein the plurality of the heating portions are arranged at intervals in the axial direction of the tube body, and two adjacent heating portions are staggered in the axial direction of the tube body.

4. The heating tube according to claim 2, wherein the plurality of heating portions are disposed side by side at intervals in the axial direction of the tube body, and two adjacent heating portions at least partially overlap in the axial direction of the tube body.

5. The heating tube according to claim 1, wherein a number of turns of the spirally arranged induction heating element on a radial outer side of the inner anti-leakage portion is an odd number.

6. The heating tube according to claim 1, wherein the anti-leakage layer further has an outer anti-leakage portion located on an outer side of the inner anti-leakage portion in the radial direction of the tube body, the outer anti-leakage portion is connected to the inner anti-leakage portion, the outer anti-leakage portion is wound around an axis of the inner anti-leakage portion, and at least a part of the induction heating element is wound between the outer anti-leakage portion and the inner anti-leakage layer in the radial direction of the tube body.

7. The heating tube according to claim 6, wherein the outer anti-leakage portion is wound around the axis of the tube body to form a multi-layer structure arranged in the radial direction of the tube body, and at least a part of the induction heating element is wound between two adjacent layers of the outer anti-leakage portion.

8. The heating tube according to any one of claims 1 to 7, wherein the heat insulation layer comprises a heat insulation body of a strip-shaped structure, and the heat insulation body is spirally arranged in the axial direction of the tube body.

9. An aerosol-generating article, comprising an aerosol-generating substrate and the heating tube according to any one of claims 1 to 8, wherein the aerosol-generating substrate is located in the accommodating space.

10. A preparation method for a heating tube, wherein the heating tube comprises an anti-leakage layer, an induction heating element, and a heat insulation layer, wherein the induction heating element is of a strip-shaped structure, and the preparation method for a heating tube comprises: stacking the anti-leakage layer, the induction heating element, and the heat insulation layer in sequence to form a multi-layer structure; winding the multi-layer structure around a winding rod to form a tube body, comprising: winding the multi-layer structure by attaching at least a part of the anti-leakage layer to an outer peripheral surface of the winding rod, spirally disposing the induction heating element around the anti-leakage layer at an inclined angle, and covering at least an outer side of the induction heating element with the heat insulation layer; and removing the tube body from the winding rod in an axial direction of the winding rod.

11. The preparation method for a heating tube according to claim 10, wherein the anti-leakage layer extends in a first direction, and the stacking the anti-leakage layer, the induction heating element, and the heat insulation layer in sequence to form a multi-layer structure comprises: staggering a winding start end of the anti-leakage layer and a winding start end of the induction heating element in the first direction.

12. The preparation method for a heating tube according to claim 10, wherein the anti-leakage layer extends in a first direction; and the stacking the anti-leakage layer, the induction heating element, and the heat insulation layer in sequence to form a multi-layer structure comprises: arranging an extension direction of the induction heating element and the first direction to be at an included angle of 35°-65°.

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