Nanocrystalline magnetic isolation sheet for electromagnetic induction heating electronic cigarette and its preparation and application

Abstract

The present invention belongs to the technical fields of electromagnetic shielding materials and electronic cigarettes, and discloses a nanocrystalline magnetic isolation sheet for an electromagnetic induction heating electronic cigarette, as well as its preparation method and application. The preparation method is as follows: heat-treat an Fe-based nanocrystalline ribbon, laminate 2 to 3 layers of the heat-treated nanocrystalline ribbons to form a composite laminate, and bond adjacent nanocrystalline ribbons and the surfaces of the nanocrystalline ribbons through an adhesive layer to obtain a magnetic laminate structure; subject the obtained magnetic laminate structure to fragmentation treatment so that its initial magnetic permeability at a frequency of 100 kHz is 200 to 2000; then laminate the fragmented magnetic laminate structure in multiple layers to obtain a nanocrystalline magnetic isolation sheet for an electromagnetic induction heating electronic cigarette with a multi-layer magnetic laminate structure. The present invention adopts a multi-layer magnetic laminate structure and combines fragmentation treatment with a flexible adhesive layer, enabling the nanocrystalline magnetic isolation sheet to achieve good coating on the electromagnetic induction heating coil, and achieving very good magnetic isolation and heating effects.

Description

Technical Field

[0001] The present invention belongs to the technical fields of electromagnetic shielding materials and electronic cigarettes, and particularly relates to a nanocrystalline magnetic isolation sheet for an electromagnetic induction heating electronic cigarette, and its preparation and application. Background Art

[0002] Since the heating temperature of electronic cigarettes generally does not exceed 400 °C, which is much lower than 800 °C when traditional cigarettes burn, they not only retain a smoking sensation similar to that of traditional cigarettes but also have advantages in many aspects such as controlling harmful components in the smoke, measuring and releasing mainstream smoke, and reducing soot pollution. Related products have shown explosive growth in recent years and have a broad market in the future. Early, more mature electronic cigarette products on the market generally used a resistive heating method, but it had technical defects such as long heating and preheating times, low efficiency, poor thermal uniformity, easy breakage and damage of the heating element, and inconvenient cleaning. The application of electromagnetic induction heating technology to electronic cigarettes can greatly avoid the above-mentioned resistive heating problems. Electromagnetic induction heating is to generate an alternating magnetic field by passing an alternating current through a coil. Eddy currents are generated on the surface of the metal workpiece in the alternating magnetic field and are quickly heated. It has significant advantages over resistive heating in terms of energy conversion efficiency, heating and temperature rise time, heating element layout method, and uniformity and accuracy of the material heating position, and will become a major trend in the development of electronic cigarettes. Improving the heating performance of electronic cigarettes has always been the main direction of research and development of various electronic cigarette manufacturers.

[0003] To improve the heating performance of induction heating electronic cigarettes, in addition to optimizing the circuit design, structural design and material selection optimization are essential. The principle of induction heating is to generate an alternating magnetic field by passing an alternating current through a coil. In a limited space, this alternating magnetic field mainly acts on the metal inside the coil to achieve the heating effect, and at the same time, it inevitably causes certain interference to electronic devices or metal casings outside the coil, resulting in energy dissipation. Therefore, to improve the heating performance of induction heating electronic cigarettes, magnetic field shielding outside the coil should be considered.

[0004] Patent CN105595437A discloses an electronic cigarette atomizing device and an electronic cigarette, including: an outer tube, a heating tube disposed in the outer tube for placing tobacco or cigarette sticks, a battery, and a circuit control board. A magnetic induction coil is coated outside the heating tube. The circuit control board is electrically connected to the magnetic induction coil. The circuit control board generates an alternating electromagnetic field through the magnetic induction coil to heat the tobacco or cigarette stick by the heating tube to generate smoke. An electromagnetic shielding cover is further provided outside the heating tube, and the electromagnetic shielding cover is made of conductive rubber. Patent CN208192145U discloses an atomizing component and its electronic cigarette. An electromagnetic shielding layer is provided outside the atomizing sleeve. The electromagnetic shielding cover can isolate the electromagnetic waves generated when the heating element works and reduce the harm caused by electromagnetic wave radiation to the surroundings. The electromagnetic shielding cover is made of conductive rubber. Patent CN110946334A discloses an electronic cigarette, including an electronic cigarette main body and an electromagnetic transmitting device. The electromagnetic transmitting device further includes an electromagnetic shielding layer disposed on the housing, and the electromagnetic shielding layer surrounds the outside of the inductor. Through the arrangement of the electromagnetic shielding layer, the eddy current phenomenon generated by other metals close to the outer sleeve can be shielded. The electromagnetic shielding layer can be in the form of a sheet, a strip, a cylinder, etc. Patent CN213719923U discloses an electronic cigarette. In order to prevent the alternating magnetic field generated by the excitation coil from interfering with electronic components or consuming energy, an insulating magnetic shielding layer is provided outside or inside the second heat insulation layer. The insulating magnetic shielding layer is used to guide and shield the alternating magnetic field generated by the excitation coil to prevent the magnetic force lines from leaking outside the insulating magnetic shielding layer. The material of the insulating magnetic shielding layer can be, for example, ferrite material. On the one hand, since it is an insulating material, an alternating magnetic field will not form eddy currents in it, so the insulating magnetic shielding layer will not heat up under the action of the alternating magnetic field. In addition, because it has ferromagnetic material, it can conduct magnetic flux well, achieving the purpose of guiding and shielding the magnetic force lines.

[0005] In the above prior art, the electromagnetic shielding layer mainly uses conductive rubber or ferrite material. The main reason is that the shielding layer for electronic cigarettes generally needs to be processed into a cylindrical shape to achieve good electromagnetic shielding effect. Using conductive rubber or ferrite material has good processing performance. However, the inductance, saturation current, and magnetic permeability performance of conductive rubber or ferrite material are relatively low. When used for magnetic shielding in electronic cigarettes, the current in the energized magnetic induction coil is limited, the heating rate is not high, and the number of winding turns needs to be increased.

[0006] Compared with conductive rubber or ferrite materials, nanocrystalline electromagnetic shielding materials have higher inductance and saturation current, and better magnetic permeability performance regulation. However, they are currently mainly used in the field of electromagnetic shielding for wireless charging and are rarely used in the field of e-cigarettes. Generally speaking, in the field of wireless charging, in order to obtain the required magnetic permeability, heat treatment is required for nanocrystalline ribbons. At the same time, heat treatment will enhance the brittleness of the nanocrystalline ribbons, so as to form fragmented pieces during subsequent fragmentation treatment to reduce eddy current loss and heat generation. There is little public disclosure about the structure and performance design of nanocrystalline magnetic isolation sheets for electromagnetic induction heating e-cigarettes. Summary of the Invention

[0007] Aiming at the shortcomings and deficiencies of the above existing technologies, the primary object of the present invention is to provide a preparation method for a nanocrystalline magnetic isolation sheet of an electromagnetic induction heating e-cigarette.

[0008] Another object of the present invention is to provide a nanocrystalline magnetic isolation sheet prepared by the above method.

[0009] Another object of the present invention is to provide the application of the above nanocrystalline magnetic isolation sheet in an electromagnetic induction heating e-cigarette atomization component.

[0010] The nanocrystalline magnetic isolation sheet applicable to an electromagnetic induction heating e-cigarette of the present invention adopts a multi-layer magnetic laminated structure. Through the combination of fragmentation treatment and a flexible adhesive layer, the nanocrystalline magnetic isolation sheet can achieve good coating on the electromagnetic induction heating coil, and can achieve very good magnetic isolation and heating effects.

[0011] The object of the present invention is achieved through the following technical solutions:

[0012] A preparation method for a nanocrystalline magnetic isolation sheet of an electromagnetic induction heating e-cigarette, comprising the following preparation steps:

[0013] (1) Perform heat treatment on the Fe-based nanocrystalline ribbon, laminate 2 to 3 layers of the heat-treated nanocrystalline ribbons, and bond them through an adhesive layer between adjacent nanocrystalline ribbons and on the surface of the nanocrystalline ribbons to obtain a magnetic laminated structure;

[0014] (2) Perform fragmentation treatment on the magnetic laminated structure obtained in step (1). After fragmentation treatment, the initial magnetic permeability of the magnetic laminated structure at a frequency of 100 kHz is 200 to 2000;

[0015] (3) Then perform multi-layer lamination on the magnetic laminated structure after fragmentation treatment in step (2) to obtain a multi-layer magnetic laminated structure;

[0016] (4) Cut the magnetic laminated structure obtained in step (2) or (3) into a specific pattern through die cutting or laser cutting to obtain a nanocrystalline magnetic isolation sheet of an electromagnetic induction heating e-cigarette.

[0017] Further, the Fe-based nanocrystalline ribbon in step (1) is preferably an Fe-Cu-Nb-Si-B nanocrystalline ribbon. The thickness of the preferred Fe-based nanocrystalline ribbon is 18-20 μm.

[0018] Further, the heat treatment temperature in step (1) is 500-650 °C; the heat treatment atmosphere is an inert atmosphere or vacuum.

[0019] Further, the adhesive layer in step (1) is a double-sided adhesive with a thickness of 2-10 μm.

[0020] Further, the fragmentation treatment in step (2) uses transverse or longitudinal roller shearing, rolling with a round roller or flat plate with bumps, or other methods that can cause uniform fracture cracks in the nanocrystalline ribbon; the size of the fragmented fine pieces after the fragmentation treatment is 0.1-3 mm; the width of the fracture cracks is 0.02-10 μm. In the present invention, in addition to adjusting the magnetic permeability performance, the role of the fragmentation treatment is also to enable the brittle nanocrystalline ribbon to be well coated around the coil sleeve under the bonding of the adhesive layer, achieving a better magnetic isolation effect.

[0021] Further, the total thickness of the nanocrystalline magnetic isolation sheet of the electromagnetic induction heating electronic cigarette in step (4) is 45 μm-500 μm.

[0022] A nanocrystalline magnetic isolation sheet of an electromagnetic induction heating electronic cigarette is prepared by the above method.

[0023] The application of the above nanocrystalline magnetic isolation sheet in the atomization component of an electromagnetic induction heating electronic cigarette, the atomization component includes a heating cavity and an electromagnetic induction heating coil wound outside the heating cavity, and the nanocrystalline magnetic isolation sheet is wound and coated on the surface of the electromagnetic induction heating coil.

[0024] Further, the outside of the nanocrystalline magnetic isolation sheet is also wrapped with a copper foil or aluminum foil with a thickness of 5-100 μm.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] (1) The present invention creatively applies the fragmented nanocrystalline magnetic isolation sheet to the field of electronic cigarettes. Compared with conventional conductive rubber or ferrite materials, it has the effects of a smaller shielding sheet thickness, a higher inductance value (fewer winding turns can be used), a wider adjustable range of inductance values (stronger coil adaptability), a higher heating rate (a higher current can be passed), a stable heating rate (good temperature stability), and lower energy consumption (high Q value, small magnetic loss).

[0027] (2) By designing the structure of the nanocrystalline magnetic isolation sheet, a multi-layer magnetic laminated structure is adopted, and through the combination of fragmentation treatment and flexible adhesive layer, it can be well applied to the electromagnetic induction heating electronic cigarette atomization component and achieve a better magnetic isolation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of the magnetic composite laminated structure obtained in Example 2.

[0029] Figure 2 It is a schematic structural diagram of the magnetic composite laminated structure obtained in Example 3. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention will be further described in detail below in conjunction with the embodiments and the drawings, but the embodiments of the present invention are not limited thereto.

[0031] COMPARATIVE EXAMPLE

[0032] In this comparative example, a ferrite magnetic isolation sheet sample with better performance on the market was selected, its thickness was measured to be 0.27 mm, and the initial magnetic permeability at a test frequency of 100 kHz was about 100 according to this thickness, which was marked as the comparative sample.

[0033] EXAMPLE 1

[0034] A preparation method of a nanocrystalline magnetic isolation sheet for an electromagnetic induction heating electronic cigarette in this example includes the following preparation steps:

[0035] (1) Select Fe-Cu-Nb-Si-B nanocrystalline ribbon with a single-layer thickness of 18 - 20 μm (commercially available) and perform heat treatment in a nitrogen atmosphere. The heat treatment temperature is 550 °C. Stack two layers of heat-treated nanocrystalline ribbons for compound lamination, and bond them with a double-sided adhesive with a thickness of about 3 μm between adjacent nanocrystalline ribbons and on the surface of the nanocrystalline ribbons to obtain a magnetic laminated structure.

[0036] (2) Perform fragmentation treatment on the magnetic laminated structure obtained in step (1). The fragmentation treatment adopts the method of die pressing and crushing to obtain uniformly fragmented magnetic fine sheets. By adjusting the die and pressure of die pressing and crushing, control the size of the fragmented fine sheets to be about 0.6 mm and the width of the fragmentation gap to be about 0.1 μm. Make the initial magnetic permeability of the magnetic single laminated structure after fragmentation treatment be 1400 at a test frequency of 100 kHz.

[0037] (3) Stack the magnetic single laminated structure after fragmentation treatment in step (2) in four layers to obtain a magnetic composite laminated structure containing 8 layers of nanocrystals. Marked as sample 1#.

[0038] EXAMPLE 2

[0039] A preparation method of a nanocrystalline magnetic isolation sheet for an electromagnetic induction heating electronic cigarette according to this embodiment includes the following preparation steps:

[0040] (1) Select Fe-Cu-Nb-Si-B nanocrystalline ribbon with a single-layer thickness of 18 - 20 μm (purchased commercially) and perform heat treatment in a nitrogen atmosphere at a heat treatment temperature of 580 °C. Stack three layers of the heat-treated nanocrystalline ribbons in a composite manner, and bond adjacent nanocrystalline ribbons and the surfaces of the nanocrystalline ribbons with double-sided tape with a thickness of about 3 μm to obtain a magnetic laminated structure.

[0041] (2) Perform fragmentation treatment on the magnetic laminated structure obtained in step (1). The fragmentation treatment adopts a method of die pressing and crushing to obtain uniformly fragmented magnetic fine sheets. By adjusting the die and pressure of die pressing and crushing, control the size of the fragmented fine sheets to be about 0.5 mm and the width of the fragmentation gap to be about 0.2 μm. Make the initial magnetic permeability of the magnetic single laminated structure after fragmentation treatment be 700 at a test frequency of 100 kHz.

[0042] (3) Stack the magnetic single laminated structure after fragmentation treatment in step (2) in four layers to obtain a magnetic composite laminated structure containing 12 layers of nanocrystals. Mark it as sample 2#.

[0043] The structural schematic diagram of the magnetic composite laminated structure obtained in this embodiment is as Figure 1 shown.

[0044] Example 3

[0045] A preparation method of a nanocrystalline magnetic isolation sheet for an electromagnetic induction heating electronic cigarette according to this embodiment includes the following preparation steps:

[0046] (1) Select Fe-Cu-Nb-Si-B nanocrystalline ribbon with a single-layer thickness of 18 - 20 μm (purchased commercially) and perform heat treatment in a nitrogen atmosphere at a heat treatment temperature of 600 °C. Stack two layers of the heat-treated nanocrystalline ribbons in a composite manner, and bond adjacent nanocrystalline ribbons and the surfaces of the nanocrystalline ribbons with double-sided tape with a thickness of about 3 μm to obtain a magnetic laminated structure.

[0047] (2) Perform fragmentation treatment on the magnetic laminated structure obtained in step (1). The fragmentation treatment adopts a method of die pressing and crushing to obtain uniformly fragmented magnetic fine sheets. By adjusting the die and pressure of die pressing and crushing, control the size of the fragmented fine sheets to be about 0.5 mm and the width of the fragmentation gap to be about 0.25 μm. Make the initial magnetic permeability of the magnetic single laminated structure after fragmentation treatment be 400 at a test frequency of 100 kHz.

[0048] (3) Stack the magnetic single laminated structure after fragmentation treatment in step (2) in four layers to obtain a magnetic composite laminated structure containing 8 layers of nanocrystals. Mark it as sample 3#.

[0049] The structural schematic diagram of the magnetic composite laminated structure obtained in this embodiment is as Figure 2 shown.

[0050] Example 4

[0051] A preparation method of a nanocrystalline magnetic isolation sheet for an electromagnetic induction heating electronic cigarette in this embodiment includes the following preparation steps:

[0052] (1) Select Fe-Cu-Nb-Si-B nanocrystalline ribbon with a single-layer thickness of 18 - 20 μm (purchased commercially) and perform heat treatment in a nitrogen atmosphere at a heat treatment temperature of 600 °C. Stack two layers of the heat-treated nanocrystalline ribbons in a composite manner, and bond adjacent nanocrystalline ribbons and the surfaces of the nanocrystalline ribbons with double-sided adhesive tape with a thickness of about 3 μm to obtain a magnetic laminated structure.

[0053] (2) Perform fragmentation treatment on the magnetic laminated structure obtained in step (1). The fragmentation treatment is carried out by die pressing and crushing to obtain uniformly fragmented magnetic fine sheets. By adjusting the die and pressure of die pressing and crushing, control the size of the fragmented fine sheets to be about 0.5 mm and the width of the fragmentation gaps to be about 0.25 μm. Make the initial magnetic permeability of the magnetic single-laminated structure 400 at a test frequency of 100 kHz after fragmentation treatment.

[0054] (3) Stack two layers of the fragmented magnetic single-laminated structure obtained in step (2) to obtain a magnetic composite laminated structure containing 4 layers of nanocrystals. Label it as sample 4#.

[0055] Example 5

[0056] A preparation method of a nanocrystalline magnetic isolation sheet for an electromagnetic induction heating electronic cigarette in this embodiment includes the following preparation steps:

[0057] (1) Select Fe-Cu-Nb-Si-B nanocrystalline ribbon with a single-layer thickness of 18 - 20 μm (purchased commercially) and perform heat treatment in a nitrogen atmosphere at a heat treatment temperature of 620 °C. Stack two layers of the heat-treated nanocrystalline ribbons in a composite manner, and bond adjacent nanocrystalline ribbons and the surfaces of the nanocrystalline ribbons with double-sided adhesive tape with a thickness of about 3 μm to obtain a magnetic laminated structure.

[0058] (2) Perform fragmentation treatment on the magnetic laminated structure obtained in step (1). The fragmentation treatment is carried out by die pressing and crushing to obtain uniformly fragmented magnetic fine sheets. By adjusting the die and pressure of die pressing and crushing, control the size of the fragmented fine sheets to be about 0.4 mm and the width of the fragmentation gaps to be about 0.25 μm. Make the initial magnetic permeability of the magnetic single-laminated structure 300 at a test frequency of 100 kHz after fragmentation treatment.

[0059] (3) Stack the magnetically fragmented single-layer structures obtained in step (2) in two layers to obtain a magnetic composite laminated structure containing 4 layers of nanocrystals. Labeled as Sample 5#.

[0060] Cut the comparative sample and Samples 1# - 5# into a unified specification of 51 mm in length × 43 mm in width, measure the thickness, and then match the same coil to test the saturation current Is, inductance Ls, and resistance Rs. Calculate the quality factor Q value through Ls, Rs, and the test parameters. The test data is shown in Table 1 below.

[0061] Table 1. Comparison of Test Data

[0062]

[0063] As can be seen from the results in Table 1, compared with the comparative sample, when using a nanocrystal magnetic shielding film for inductive heating e-cigarettes, the following effects can be achieved: a smaller thickness of the shielding sheet, a higher inductance value (fewer turns of the winding can be used), a wider adjustable range of the inductance value (stronger coil adaptability), a higher heating rate (a higher current can be passed), a stable heating rate (good temperature stability), and lower energy consumption (high Q value, low magnetic loss).

[0064] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. Application of a nanocrystalline magnetic isolation sheet in an electromagnetic induction heating electronic cigarette atomization component, characterized in that, The atomization component includes a heating cavity and an electromagnetic induction heating coil wound around the outside of the heating cavity, and the nanocrystalline magnetic isolation sheet is wound and coated on the surface of the electromagnetic induction heating coil; The nanocrystalline magnetic isolation sheet is prepared by the following method: (1) Heat-treat the Fe-based nanocrystalline ribbon, laminate 2 to 3 layers of heat-treated nanocrystalline ribbons, and bond adjacent nanocrystalline ribbons and the surfaces of the nanocrystalline ribbons through an adhesive layer to obtain a magnetic laminated structure; (2) Fragmentize the magnetic laminated structure obtained in step (1), and the initial permeability of the magnetic laminated structure at a frequency of 100 kHz after fragmentation is 200 to 2000; (3) Then laminate the magnetic laminated structure after fragmentation treatment in step (2) in multiple layers to obtain a magnetic laminated structure with multiple layers; (4) Cut the magnetic laminated structure obtained in step (2) or (3) into a specific pattern by die-cutting or laser cutting to obtain the nanocrystalline magnetic isolation sheet of the electromagnetic induction heating electronic cigarette; In step (1), the Fe-based nanocrystalline ribbon is an Fe-Cu-Nb-Si-B nanocrystalline ribbon; the thickness of the Fe-based nanocrystalline ribbon is 18 to 20 μm; In step (2), the size of the fragmented fine pieces after fragmentation treatment is 0.1 to 3 mm; the width of the fragmentation gap is 0.02 to 10 μm.

2. The application of a nanocrystalline magnetic isolation sheet in an electromagnetic induction heating electronic cigarette atomization component according to claim 1, wherein In step (1), the heat treatment temperature is 500 to 650 °C; the heat treatment atmosphere is an inert atmosphere or vacuum.

3. The application of a nanocrystalline magnetic isolation sheet in an electromagnetic induction heating electronic cigarette atomization component according to claim 1, wherein In step (1), the adhesive layer is a double-sided adhesive with a thickness of 2 to 10 μm.

4. The application of a nanocrystalline magnetic isolation sheet in an electromagnetic induction heating electronic cigarette atomization component according to claim 1, characterized in that, In step (3), the total thickness of the nanocrystalline magnetic isolation sheet of the electromagnetic induction heating electronic cigarette is 45 μm to 500 μm.

5. Use of a nanocrystalline magnetic isolation sheet as described in claim 1 in an electromagnetic induction heating electronic cigarette atomization component, characterized in that, The outside of the nanocrystalline magnetic isolation sheet is also wrapped with a copper foil or an aluminum foil with a thickness of 5 to 100 μm.

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