A planar heating element and its use

Abstract

The present invention belongs to the field of heating elements for non-combustion cigarettes, and specifically relates to a planar heating element and its use. The planar heating element comprises: a base material sheet (1) and an insulating layer (2); the base material sheet (1) comprises a front sheet (1‑1) and a back sheet (1‑2) which are overlapped and conductively connected to each other, and the base material sheet (1) is a heat-generating, heat-conducting, and conductive material; the insulating layer (2) is arranged between the front sheet (1‑1) and the back sheet (1‑2). The present invention designs a planar heating element for the first time, which uses the same material to achieve the functions of heating, heat conduction, and support at the same time, changing the technical bias of separately designing the base support material and the heating circuit in the previous heating elements of smoking articles, effectively simplifying the structure of the heating element and the manufacturing process, and reducing the manufacturing cost.

Description

Technical Field

[0001] The invention belongs to the field of heating elements for non-combustion cigarettes, and in particular relates to a planar heating element and a use thereof. Background Art

[0002] The heating element of a non-burning cigarette device is one of the core components of a non-burning cigarette device. Its most common structural form is a base material plus a heating circuit. In this type of heating element, the heating circuit usually uses a screen printing process to attach the heating slurry to the insulating base material, which is then sintered to make it tightly combined with the base material, and finally the outer surface of the heating element is glazed for protection. When the heating element is working, the Joule heat is transferred to the base material through the heating circuit, and then from the base material to the protective glaze layer, and finally the heating cigarette is heated by the protective glaze layer. In practice, it is found that this type of heating element has the following obvious disadvantages:

[0003] 1) The heating element has a complex structure, a long manufacturing process and high production cost;

[0004] 2) The resistance and temperature coefficient of resistance of the heating element are poorly stable;

[0005] 3) The heat conduction path is long and the heating efficiency is low;

[0006] 4) Insulating base materials are often poor conductors of heat and have low heat transfer efficiency.

[0007] Another common heating element is: the heating circuit is pre-buried in the cavity formed by the base material, and then the heating circuit and the base material are tightly combined by pressing or sintering, and finally the outer surface of the heating element is glazed for protection. When this type of heating element is working, the Joule heat is transferred to the base material through the heating wire, and then from the base material to the protective glaze layer, and finally the heating cigarette is heated by the protective glaze layer. Therefore, the obvious disadvantages of this type of heating element include:

[0008] 1) The heating element has a complex structure, a long manufacturing process and high production cost;

[0009] 2) The heat conduction path is long and the heating efficiency is low;

[0010] 3) Insulating base materials are often poor conductors of heat and have low heat transfer efficiency.

[0011] The present invention is proposed to solve the above-mentioned problems. Summary of the invention

[0012] The present invention provides a planar heating element, which comprises: a rigid electrically conductive and thermally conductive resistance heating material sheet 1 and an insulating layer 2;

[0013] The conductive and thermally conductive resistance heating material sheet 1 comprises a front sheet 1-1 and a back sheet 1-2 which are overlapped and conductively connected to each other, and the insulating layer 2 is arranged between the front sheet 1-1 and the back sheet 1-2.

[0014] The front sheet 1-1 and the back sheet 1-2 are used to connect to the positive and negative electrodes of a power source respectively, and the front sheet 1-1 and the back sheet 1-2 form a conductive loop.

[0015] The insulating layer 2 is in contact with the front sheet 1 - 1 and / or the back sheet 1 - 2; or there is a gap between the insulating layer 2 and the front sheet 1 - 1 and / or the back sheet 1 - 2.

[0016] In some cases, the air layer between the front sheet 1-1 and the back sheet 1-2 can also be used as the insulating layer 2, as long as the front sheet 1-1 and the back sheet 1-2 form a conductor loop.

[0017] Preferably, the insulating layer 2 includes: an insulating layer independent of the electrically conductive and thermally conductive resistance heating material sheet 1, and an insulating coating layer attached to the front sheet 1-1 or the back sheet 1-2.

[0018] Preferably, the electrically conductive and thermally conductive resistance heating material sheet 1 is in the shape of a sheet, a needle, a rod or a sword with ridges.

[0019] Preferably, the surfaces of the front sheet 1-1 and the back sheet 1-2 of the conductive and thermally conductive resistive heating material sheet 1 are independently flat, curved or folded. For example, when both are curved surfaces, the planar heating element can be in the shape of a heating rod, or when both are folded surfaces, it can be in the shape of a sword with a ridge, which can further improve the rigidity and anti-flexing properties of the planar heating element.

[0020] The conductive connection between the front sheet 1-1 and the back sheet 1-2 is preferably located at the top or upper middle part of the two, wherein the upper middle part refers to the distance between the conductive connection and the top being less than 1 / 2 of the total length of the front sheet or the leavening sheet, preferably less than 1 / 3, more preferably less than 1 / 4, still more preferably less than 1 / 5, ... and even more preferably less than 1 / 10.

[0021] Preferably, the front sheet 1 - 1 and the back sheet 1 - 2 of the electrically conductive and thermally conductive resistance heating material sheet 1 are integrally connected.

[0022] Preferably, the material of the electrically conductive and thermally conductive resistance heating material sheet 1 is selected from: metallic conductive material or non-metallic conductive material.

[0023] The conductive thermal conductive resistance heating material sheet 1 of the present invention is firstly a heating material. When electric current passes through the conductive thermal conductive resistance heating material sheet 1, Joule heat will be generated; secondly, the conductive thermal conductive resistance heating material sheet 1 is a thermal conductive material. The Joule heat is directly transmitted to the smoking material in contact with it through the conductive thermal conductive resistance heating material sheet 1; finally, the conductive thermal conductive resistance heating material sheet 1 is a rigid supporting material. The planar heating element relies on the conductive thermal conductive resistance heating material sheet 1 to maintain a certain shape and has a certain strength, so that it will not be deformed or broken during the insertion and removal and heating of the cigarette.

[0024] Preferably, the insulating layer 2 is made of a material selected from glass, ceramic, plastic, or insulating coating.

[0025] Preferably, the material of the electrically conductive and thermally conductive resistive heating material sheet 1 is selected from: aluminum, copper, nickel, tungsten, titanium, silver, gold, platinum, stainless steel, carbon, or silicon.

[0026] The second aspect of the present invention provides a heating device including the planar heating element described in the first aspect, which also includes a power supply, the front sheet 1-1 is connected to the positive pole of the power supply, and the back sheet 1-2 is connected to the negative pole of the power supply; or, the front sheet 1-1 is connected to the negative pole of the power supply, and the back sheet 1-2 is connected to the positive pole of the power supply.

[0027] The third aspect of the present invention provides the planar heating element described in the first aspect as a heating element of a heat-not-burn cigarette smoking article, which simultaneously performs heating, heat conduction and supporting functions in the smoking article.

[0028] The above technical solutions can be freely combined under the premise of no contradiction.

[0029] The present invention has the following beneficial effects:

[0030] 1. The present invention designs a planar heating element for the first time, which uses the same material to achieve the functions of heating, heat conduction and rigid support at the same time, changing the technical bias of separate design of base support materials and heating circuits in previous heating elements of smoking tools, effectively simplifying the heating element structure and manufacturing process, and reducing manufacturing costs.

[0031] 2. The Joule heat conduction path of the traditional heating element is: heating wire-base support material-protective glaze layer-cigarette. The Joule heat conduction path is long and the heat loss during the conduction process is large. Compared with the traditional heating element, the Joule heat conduction path of the invention is: rigid conductive heat conductive resistance heating material sheet-protective glaze layer (can be omitted)-cigarette, which shortens the Joule heat conduction path and improves the heating efficiency of the cigarette. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a front view of a planar heating element in Example 1.

[0033] Figure 2 This is a cross-sectional view of a planar heating element of Example 1 cut along the AA plane.

[0034] Figure 3 This is a schematic diagram of the current flow in the front sheet 1-1 of a planar heating element in Example 1.

[0035] Figure 4 This is a schematic diagram of the current flow in the back sheet 1-2 of a planar heating element in Example 1.

[0036] Figure 5 It is a top view of a planar heating element of Example 2 and a cross-sectional view taken along the BB plane.

[0037] Figure 6 This is a longitudinal cross-sectional view of a planar heating element in Example 3.

[0038] List of reference numerals:

[0039] 1. Electrically conductive and thermally conductive resistive heating material sheet, 1-1. front sheet, 1-2. back sheet, 2. insulating layer. DETAILED DESCRIPTION

[0040] The content of the present invention is further explained below through specific implementation examples.

[0041] Example 1

[0042] like Figure 1-2 As shown, a planar heating element comprises: a conductive and thermally conductive resistive heating material sheet 1 and an insulating layer 2. The planar heating element and the conductive and thermally conductive resistive heating material sheet 1 are in the shape of a sheet, a sword-shaped shape, and a regular plane surface.

[0043] Figure 1 This is a front view of a planar heating element in Example 1. Figure 2 This is a cross-sectional view of a planar heating element of Example 1 cut along the AA plane, and the circle on the right is a partially enlarged view.

[0044] The conductive and thermally conductive resistive heating material sheet 1 comprises a front sheet 1-1 and a back sheet 1-2 which are integrally connected and completely overlapped, and a groove is provided between the front sheet 1-1 and the back sheet 1-2. The cross section of the conductive and thermally conductive resistive heating material sheet 1 is a "concave" structure as a whole; the insulating layer 2 is provided in the groove between the front sheet 1-1 and the back sheet 1-2, and is in contact with the front sheet 1-1 and the back sheet 1-2; the front sheet 1-1 and the back sheet 1-2 are respectively used to connect to the positive and negative electrodes of the power source, and the front sheet 1-1 and the back sheet 1-2 form a conductive loop, and the current direction of the front sheet 1-1 is Figure 3 In the direction indicated by the arrow, the current flow of the reverse sheet 1-2 is as follows Figure 4 Arrow indicates direction.

[0045] The conductive heat-conducting resistance heating material sheet 1 is a stainless steel metal sheet, which is a good heat-conducting material and can make the heating element have a certain strength and rigidity, and will not deform or break during the plugging and heating process of the cigarette. In this embodiment, the outer surface of the stainless steel conductive heat-conducting resistance heating material sheet is not protected by a protective layer.

[0046] The insulating layer 2 is a 92% alumina ceramic layer. In this embodiment, the insulating layer 2 and the electrically conductive and thermally conductive resistive heating material sheet 1 are independent components that are in direct contact.

[0047] Example 2

[0048] A planar heating element, which is different from the embodiment 1 in that the planar heating element and the conductive heat-conducting resistance heating material sheet 1 are in the shape of a rod. The front sheet 1-1 and the back sheet 1-2 of the conductive heat-conducting resistance heating material sheet 1 are both curved surfaces.

[0049] Example 3

[0050] A planar heating element, which is different from the embodiment 1 in that the planar heating element and the conductive heat-conducting resistance heating material sheet 1 are shaped like a sword with a ridge. The front sheet 1-1 and the back sheet 1-2 of the conductive heat-conducting resistance heating material sheet 1 are both folded surfaces.

[0051] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A planar heating element, characterized in that: The planar heating element comprises: a rigid electrically conductive and thermally conductive resistive heating material sheet (1) and an insulating layer (2); The electrically conductive and thermally conductive resistance heating material sheet (1) comprises a front sheet (1-1) and a back sheet (1-2) which are overlapped and electrically connected to each other, and the insulating layer (2) is arranged between the front sheet (1-1) and the back sheet (1-2); The surfaces of the front sheet (1-1) and the back sheet (1-2) of the conductive and thermally conductive resistive heating material sheet (1) are independently flat, curved or folded; the conductive connection between the two is located at the top or upper middle part of the two; The insulating layer (2) comprises: an insulating layer independent of the electrically conductive and thermally conductive resistive heating material sheet (1) or an insulating coating attached to the front sheet (1-1) or the back sheet (1-2); The material of the electrically conductive and thermally conductive resistive heating material sheet (1) is selected from: metallic conductive material or non-metallic conductive material.

2. The planar heating element according to claim 1, characterized in that: The front sheet (1-1) and the back sheet (1-2) of the electrically conductive and thermally conductive resistive heating material sheet (1) are connected in one piece.

3. The planar heating element according to claim 1, characterized in that: The outer surface of the electrically conductive and thermally conductive resistance heating material sheet (1) is provided with a protective layer.

4. The planar heating element according to claim 1, characterized in that: The material of the insulating layer (2) is selected from glass, ceramic, plastic or insulating coating.

5. The planar heating element according to claim 1, characterized in that: The material of the electrically conductive and thermally conductive resistive heating material sheet (1) is selected from the group consisting of: aluminum, copper, nickel, tungsten, titanium, silver, gold, platinum, stainless steel, carbon or silicon.

6. A heating device comprising the planar heating element according to claim 1, characterized in that: It also includes a power supply, the front sheet (1-1) is connected to the positive pole of the power supply, and the back sheet (1-2) is connected to the negative pole of the power supply; or, the front sheet (1-1) is connected to the negative pole of the power supply, and the back sheet (1-2) is connected to the positive pole of the power supply.

7. The planar heating element according to claim 1 is used as a heating element of a heat-not-burn cigarette smoking article and simultaneously performs heating, heat conduction and supporting functions in the smoking article.

Images