Straightener

Abstract

The present invention discloses a hair straightener, which includes two clamping parts. One end of one of the clamping parts is hinged to one end of the other clamping part, and a circuit board is provided in one of the clamping parts. Each of the clamping parts is provided with the stainless steel substrate, and the stainless steel substrates on the two clamping parts are arranged facing each other. A graphene heating element is provided on one side of any one of the stainless steel substrates facing away from the other stainless steel substrate. The graphene heating element is thermally conductively connected to the stainless steel substrate. The graphene heating element is in the shape of a multi-segment bent strip, and both ends of the graphene heating element are electrically connected to the circuit board. The technical solution of the present invention can improve the heating efficiency of the hair straightener and increase the heating speed of the hair straightener.

Description

Technical Field

[0001] The present invention relates to the field of hair styling tools, and particularly to a hair straightener. Background Art

[0002] A hair straightener, also known as an electric hair straightening iron, is a hair styling tool used for quickly styling straight hair. Traditional hair straighteners generally use methods such as resistance wire heating or PTC heating. However, these heating methods have high heat loss, high energy consumption, and low heating efficiency, making it difficult to achieve a good hair styling effect and resulting in a poor user experience. Summary of the Invention

[0003] The main object of the present invention is to provide a hair straightener, aiming to improve the heating efficiency of the hair straightener.

[0004] To achieve the above object, the hair straightener proposed by the present invention includes:

[0005] Two clamping parts, one end of one of the clamping parts is hinged to one end of the other clamping part, and a circuit board is provided in one of the clamping parts; and

[0006] A stainless steel substrate, each of the clamping parts is provided with the stainless steel substrate, and the stainless steel substrates on the two clamping parts are arranged facing each other;

[0007] On one side of any one of the stainless steel substrates facing away from the other stainless steel substrate, a graphene heating element is provided. The graphene heating element is thermally conductively connected to the stainless steel substrate. The graphene heating element is in the shape of a multi-segment bent strip, and both ends of the graphene heating element are electrically connected to the circuit board.

[0008] Optionally, the graphene heating element includes a connecting section and two extending sections. The two extending sections are arranged in parallel and both extend along the length direction of the stainless steel substrate. The connecting section is connected between the ends of the two extending sections close to the same end of the stainless steel substrate, and one end of each of the two extending sections away from the connecting section is electrically connected to the circuit board.

[0009] Optionally, each of the extending sections is in the shape of a multi-segment bent strip.

[0010] Optionally, the shapes of the two extending sections are axially symmetrically arranged, and the axis of symmetry of the two extending sections extends along the length direction of the stainless steel substrate.

[0011] Optionally, a first connecting layer is sintered and formed on the surface of the stainless steel substrate facing away from the other stainless steel substrate, a second connecting layer is sintered and formed on the surface of the first connecting layer facing away from the stainless steel substrate, and the graphene heating element is sintered and formed on the surface of the second connecting layer.

[0012] Optionally, insulating and heat-conducting layers are provided on the surfaces of the two stainless steel substrates facing each other.

[0013] Optionally, an insulating and heat-insulating layer is provided on one side of any one of the stainless steel substrates facing away from the other stainless steel substrate, and the insulating and heat-insulating layer covers the graphene heating element.

[0014] Optionally, the stainless steel substrate includes a bottom plate and a surrounding plate provided around the periphery of the bottom plate. Installation openings are provided on the surfaces of the two clamping portions facing each other. The bottom plate extends out from the installation openings, the surrounding plate is installed on the clamping portions, and the graphene heating elements are provided on the sides of the bottom plate facing away from the other stainless steel substrate.

[0015] Optionally, a temperature sensor is provided in each clamping portion. The temperature sensor is in thermal conduction connection with the stainless steel substrate, and each temperature sensor is electrically connected to the circuit board.

[0016] Optionally, the hair straightener further includes a rechargeable battery. The rechargeable battery is provided in one of the clamping portions, and the circuit board is provided in the other clamping portion.

[0017] The hair straightener of the technical solution of the present invention uses a graphene heating element as a heating structure. Utilizing the superconducting principle of the graphene material, the electrical conductivity of the graphene heating element is increased, the heating speed is accelerated, the thermal conversion efficiency of the graphene heating element can be relatively high, and rapid electrothermal response can be achieved at low voltage with a fast heating-up speed. Moreover, the graphene heating element doped with the graphene material has a uniform heating temperature, which serves the purpose of protecting and caring for the hair. Compared with the traditional PTC heating method, the heating efficiency of the hair straightener is greatly improved, and the heating-up speed of the stainless steel substrate is increased. Compared with the method of setting the graphene heating element to cover the stainless steel substrate in a whole layer, by setting it in a strip shape with multiple bends, the graphene heating element can be better laid on the stainless steel substrate. While the graphene heating element has a relatively large covering area on the stainless steel substrate, the cross-sectional area of the graphene heating element can be relatively small, which is beneficial to improving the heating speed and can also reduce the material of the graphene heating element and lower the cost. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the hair straightener of the present invention;

[0020] Figure 2 For Figure 1 The exploded view of the straightener in the middle;

[0021] Figure 3 For Figure 1 The schematic structural diagram of the back of the stainless steel substrate in the middle;

[0022] Figure 4 For Figure 3 The cross-sectional view at X-X in the middle

[0023] Figure 5 For Figure 4 The enlarged view at A in the middle.

[0024] Explanation of the reference numerals in the drawings:

[0025] Label Name Label Name 10 Straightener 132 Extension section 11 Clamping part 141 First connection layer 111 Installation opening 142 Second connection layer 112 Body housing 152 Insulating and heat-conducting layer 113 Body cover 153 Insulating and heat-insulating layer 12 Stainless steel substrate 16 Circuit board 121 Bottom plate 171 Charging interface 122 Enclosure 172 Charging battery 13 Graphene heating element 173 Control button 131 Connection section

[0026] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0028] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between the components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0029] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text is that it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or the solution where A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those skilled in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] The present invention provides a hair straightener.

[0031] In an embodiment of the present invention, please refer to Figures 1 to 5 , the hair straightener 10 includes two clamping parts 11. One end of one clamping part 11 is hinged to one end of the other clamping part 11, and a circuit board 16 is provided inside one of the clamping parts 11. Each clamping part 11 is provided with a stainless steel substrate 12, and the stainless steel substrates 12 on the two clamping parts 11 face each other. On one side of any one of the stainless steel substrates 12 facing away from the other stainless steel substrate 12, there is a graphene heating element 13, and the graphene heating element 13 is thermally conductively connected to the stainless steel substrate 12. The graphene heating element 13 is in the shape of a strip bent in multiple segments (at least two segments), and the two ends of the graphene heating element 13 are electrically connected to the circuit board 16.

[0032] In this embodiment, the two clamping parts 11 are used to jointly clamp the hair. When the two clamping parts 11 approach each other, the stainless steel substrates 12 on the two clamping parts 11 approach each other, and the hair can be clamped between the two stainless steel substrates 12. Both ends of each graphene heating element 13 are electrically connected to the circuit board 16 so as to be able to pass an electric current into the graphene heating elements 13 on the two clamping parts 11. When an electric current is passed into the graphene heating element 13, the graphene heating element 13 can generate heat and conduct the heat to the stainless steel substrate 12, causing the stainless steel substrate 12 to heat up, so that the hair between the two stainless steel substrates 12 can be heated to perform a hair straightening action.

[0033] Among them, the bending form of the graphene heating element 13 can be various. For example, the graphene heating element 13 can be arranged in multiple bends in the length direction of the stainless steel substrate 12, that is, the graphene heating element 13 includes a connecting section and multiple extending sections. Any two adjacent extending sections are connected by the connecting section. Each extending section extends along the width direction of the stainless steel substrate 12, and the extending sections are spaced apart in the length direction of the stainless steel substrate 12. Or the graphene heating element 13 can also be arranged in multiple bends in the width direction of the stainless steel substrate 12, that is, the graphene heating element 13 includes a connecting section and multiple extending sections. Any two adjacent extending sections are connected by the connecting section. Each extending section extends along the length direction of the stainless steel substrate 12, and the extending sections are spaced apart in the width direction of the stainless steel substrate 12. Or the graphene heating element 13 is arranged in a spiral shape, etc.

[0034] The graphene heating element 13 contains graphene. Specifically, in one embodiment, the graphene heating element 13 contains NiAlCr alloy powder (where Ni is nickel, Al is aluminum, and Cr is chromium), graphene, glass-ceramic powder, and an organic carrier. During molding, the NiAlCr alloy powder, graphene, glass-ceramic powder, and organic carrier can be mixed, stirred, and ground to obtain a doped graphene alloy resistance paste. The doped graphene alloy resistance paste is printed on the stainless steel substrate 12 in a circuit of a certain shape pattern (a multi-bend strip), and finally the printed sample is placed in an oven for drying. After drying, the sample is taken out and placed in a vacuum furnace for sintering to obtain the graphene heating element 13 formed on the stainless steel substrate 12.

[0035] In another embodiment, the graphene heating element 13 contains NiFe alloy powder (where Ni is nickel and Fe is iron), graphene, glass-ceramic powder, and an organic carrier. The molding method of the graphene heating element 13 can refer to the above embodiment and will not be elaborated here one by one.

[0036] In yet another embodiment, the graphene heating element 13 contains NiCu alloy powder (where Ni is nickel and Cu is copper), graphene, glass-ceramic powder, and an organic carrier. The molding method of the graphene heating element 13 can refer to the above embodiment and will not be elaborated here one by one.

[0037] In still another embodiment, the graphene heating element 13 contains NiB alloy powder (where Ni is nickel and B is boron), graphene, glass-ceramic powder, and an organic carrier. The molding method of the graphene heating element 13 can refer to the above embodiment and will not be elaborated here one by one.

[0038] In an embodiment of the present invention, the organic carrier may include a solvent, a thickening agent, a thixotropic agent, a surfactant, and a binder. Among them, the solvent may be one or more of terpineol, diethylene glycol butyl ether acetate, and dibutyl phthalate. The thickening agent may be a conventional material with a thickening effect in the industry, such as ethyl cellulose. The thixotropic agent may be a conventional material with anti-thixotropy in the industry, such as hydrogenated castor oil. The surfactant may be a conventional material with improved surface activity in the industry, such as oleic acid. The binder may be a conventional material with increased viscosity in the industry, such as polyvinyl butyral.

[0039] In the hair straightener 10 of the technical solution of the present invention, by using the graphene heating element 13 as the heating structure and utilizing the superconducting principle of the graphene material, the electrical conductivity of the graphene heating element 13 is increased, the heating speed is accelerated, the graphene heating element 13 can have a relatively high thermal conversion efficiency, can quickly respond to electrothermal under low voltage, and has a fast heating rate. Moreover, the graphene heating element 13 doped with the graphene material has a uniform heating temperature and serves the purpose of protecting and caring for hair. Compared with the traditional PTC heating method, the heating efficiency of the hair straightener 10 is greatly improved, and the heating rate of the stainless steel substrate 12 is increased. Compared with the method of arranging the graphene heating element 13 in a whole-layer covering manner on the stainless steel substrate 12, by arranging it in a strip shape with multiple bends, the graphene heating element 13 can be better laid on the stainless steel substrate 12. While the graphene heating element 13 has a large covering area on the stainless steel substrate 12, the cross-sectional area of the graphene heating element 13 can be made smaller, which is beneficial to improving the heating speed and can reduce the material of the graphene heating element 13 and lower the cost.

[0040] Please refer to Figure 2 and Figure 3 , in an embodiment, the graphene heating element 13 includes a connecting section 131 and two extending sections 132. The two extending sections 132 are arranged in parallel and both extend along the length direction of the stainless steel substrate 12. The connecting section 131 is connected between the ends of the two extending sections 132 close to the same end of the stainless steel substrate 12. One end of each of the two extending sections 132 away from the connecting section 131 is electrically connected to the circuit board 16. Specifically, the circuit board 16 is provided with connecting wires, and the connecting wires are connected to the ends of the extending sections 132 away from the connecting section 131. In this way, the connection points between both ends of the graphene heating element 13 and the connecting wires are both located at the same end of the stainless steel substrate 12, which is convenient for installation and makes the structure of the hair straightener 10 compact. Of course, in other embodiments, one end of the graphene heating element 13 may be provided at one end of the stainless steel substrate 12, and the other end of the graphene heating element 13 may be provided at the other end of the stainless steel substrate 12.

[0041] In one embodiment, each extension segment 132 is a strip with multiple bends. This can increase the coverage area of the extension segment 132 in the width direction of the stainless steel substrate 12, reduce the distance between the two extension segments 132, improve the coverage uniformity of the graphene heating element 13 on the stainless steel substrate 12, thereby improving the heat conduction uniformity of the stainless steel substrate 12 and ensuring that the hair between the two stainless steel substrates 12 can be heated evenly. Of course, in other embodiments, the extension segment 132 can also be set to be straight, and the connecting segment 131 can be partially set to be a long strip extending along the length direction of the stainless steel substrate 12.

[0042] In one embodiment, the shapes of the two extension segments 132 are axially symmetrically arranged, and the axis of symmetry of the two extension segments 132 extends along the length direction of the stainless steel substrate 12. With this setting, the two extension segments 132 can be evenly distributed on the stainless steel substrate, further improving the coverage uniformity of the graphene heating element 13 on the stainless steel substrate 12 and further improving the heat conduction uniformity of the stainless steel substrate 12. Of course, in other embodiments, the shapes of the two extension segments 132 can also be different.

[0043] Please refer to Figures 3 to 5 , in one embodiment, a first connection layer 141 is sintered and formed on the surface of the stainless steel substrate 12 facing away from the other stainless steel substrate 12, a second connection layer 142 is sintered and formed on the surface of the first connection layer 141 facing away from the stainless steel substrate 12, and the graphene heating element 13 is sintered and formed on the surface of the second connection layer 142. In this embodiment, the first connection layer 141 contains a first glass, the second connection layer 142 contains a second glass, and the melting point of the first glass is higher than that of the second glass.

[0044] During forming, an organic carrier and the first glass-ceramics are mixed, stirred and ground to obtain the first bonding paste. The first bonding medium paste is printed on the surface of the stainless-steel substrate 12 (the surface facing away from the other stainless-steel substrate 12) in a planar pattern by printing, and finally the printed sample is placed in an oven for drying. After drying, the sample is taken out for sintering. An organic carrier and the second glass-ceramics are mixed, stirred and ground to obtain the second bonding paste. The second bonding paste is printed on the surface of the first bonding layer 141 (the surface facing away from the stainless-steel substrate 12) in a planar pattern by printing, and finally the printed sample is placed in an oven for drying. After drying, the sample is taken out for sintering to obtain the second bonding layer 142. Then, the doped graphene alloy resistance paste is printed on the second bonding layer 142 in a circuit of a certain shape pattern (a multi-segment bent strip) by printing (printed on the surface of the second bonding layer 142 facing away from the first bonding layer 141), and finally the printed sample is placed in an oven for drying. After drying, the sample is taken out and placed in a vacuum furnace for sintering to obtain the first bonding layer 141, the second bonding layer 142 and the graphene heating element 13 formed on the stainless-steel substrate 12.

[0045] By using glass-ceramics with different gradient melting points as the composite bonding layers (the first bonding layer 141 and the second bonding layer 142) between the stainless-steel substrate 12 and the graphene heating element 13, the insulation performance between the stainless-steel substrate 12 and the graphene heating element 13 is increased, the problem of poor thermal expansion coefficient matching among the stainless-steel substrate 12, the composite bonding layers (the first bonding layer 141 and the second bonding layer 142), and the graphene heating element 13 is reduced, the bonding force among the three is improved, and at the same time, the heat shock resistance of the graphene heating element 13 and the safety performance of the hair straightener 10 are improved.

[0046] It should be noted that in other embodiments, the first bonding layer 141 can be a composite layer structure. For example, the first bonding layer 141 includes a multi-layer (at least two layers) structure arranged in a stacked manner, and the glass melting points of the respective layer structures of the first bonding layer 141 are gradually decreased in the direction from the stainless-steel substrate 12 to the graphene heating element 13. Similarly, the second bonding layer 142 can be a composite layer structure. For example, the first bonding layer 142 includes a multi-layer (at least two layers) structure arranged in a stacked manner, and the glass melting points of the respective layer structures of the first bonding layer 142 are gradually decreased in the direction from the stainless-steel substrate 12 to the graphene heating element 13.

[0047] In one embodiment, insulating and heat-conducting layers 152 are provided on the mutually facing surfaces of the two stainless-steel substrates 12. That is, when the hair straightener 10 is in use, the insulating and heat-conducting layers 152 are in contact with the hair. By providing the insulating and heat-conducting layers 152, the insulation between the stainless-steel substrate 12 and the user can be improved, the risk of electric leakage of the stainless-steel substrate 12 can be reduced, and the use safety of the hair straightener 10 can be further improved.

[0048] In one embodiment, an insulating and heat-insulating layer 153 is provided on one side of any one of the stainless-steel substrates 12 facing away from the other stainless-steel substrate 12, and the insulating and heat-insulating layer 153 covers the graphene heating element 13. Specifically, the insulating and heat-insulating layer 153 covers the graphene heating element 13 on the back surface of the stainless-steel substrate 12. With such a setting, the insulating and heat-insulating layer 153 can block the heat radiated by the graphene heating element 13 and the stainless-steel substrate 12 into the clamping part 11, so that the heat generated by the graphene heating element 13 can be better radiated towards the outer surface of the stainless-steel substrate 12. Thus, the heat generated by the graphene heating element 13 can be fully utilized to heat the hair, reducing heat loss, improving the heating efficiency of the hair straightener 10, and increasing the heating speed of the stainless-steel substrate 12. Moreover, it can also protect the components inside the hair straightener 10 from being damaged at high temperatures.

[0049] In one embodiment, the stainless-steel substrate 12 includes a bottom plate 121 and a surrounding plate 122 disposed around the periphery of the bottom plate 121. Mounting openings 111 are provided on the surfaces of the two clamping parts 11 facing each other, and the bottom plate 121 extends out from the mounting openings 111. The surrounding plate 122 is mounted on the clamping part 11, and the graphene heating elements 13 are provided on the sides of the bottom plate 121 facing away from the other stainless-steel substrate 12. Specifically, the bottom plate 121 and the surrounding plate 122 are integrally formed, and the stainless-steel substrate 12 is fixed to the clamping part 11 through the surrounding plate 122. With such a setting, while making the bottom plate 121 protrude from the outer surface of the clamping part 11 to ensure sufficient contact between the stainless-steel substrate 12 and the hair, the thickness of the stainless-steel substrate 12 can be made smaller (avoiding the situation of increasing the thickness of the stainless-steel substrate 12 to protrude from the outer surface of the clamping part 11), which is beneficial to improving the heat conduction speed of the stainless-steel substrate 12 and the heat dissipation speed after the power is turned off. Moreover, the graphene heating element 13 is located in the space formed by the surrounding plate 122 and the bottom plate 121, which can effectively protect the graphene heating element 13.

[0050] In one embodiment, a temperature sensor is provided in each clamping part 11. The temperature sensor is thermally connected to the stainless-steel substrate 12, and each temperature sensor is electrically connected to the circuit board 16. Specifically, the temperature sensor is used to detect the temperature of the stainless-steel substrate 12, so that the circuit board 16 can control the heating temperature of the hair straightener 10 to ensure that the stainless-steel substrate 12 is at an appropriate temperature when using the hair straightener 10 and guarantee the hair styling effect.

[0051] Please refer to Figure 2, in one embodiment, the hair straightener 10 further includes a rechargeable battery 172 disposed in one of the clamping portions 11, and the circuit board 16 is disposed in the other clamping portion 11. By arranging the rechargeable battery 172 in the hair straightener 10, the rechargeable battery 172 can be used to provide energy for the graphene heating element 13, so that the hair straightener 10 can be used as a wireless hair straightener 10, reducing the limitations of sockets and power cords, improving the portability of the hair straightener 10, and making it more convenient for users to use. Moreover, when the graphene heating element 13 is adopted, the graphene heating element 13 has a high heating efficiency and consumes less energy, which can improve the battery life of the rechargeable battery 172.

[0052] In one embodiment, the hair straightener 10 further includes a control button 173 disposed on the clamping portion 11. The control button 173 is located on the side of the clamping portion 11 facing away from the other clamping portion 11. The control button 173 and the circuit board 16 are disposed in the same clamping portion 11, and the control button 173 is electrically connected to the circuit board 16. This can make the distance between the circuit board 16 and the control button 173 relatively close, improving the structural compactness.

[0053] In one embodiment, the hair straightener 10 further includes a rechargeable battery 172 and a charging interface 171 electrically connected to the rechargeable battery 172. The rechargeable battery 172 and the charging interface 171 are disposed in the same clamping portion 11. The charging interface 171 is located on the side of the rechargeable battery 172 facing away from the stainless steel substrate 12 and is disposed at the end (rear end) of the clamping portion 11. In another embodiment, the hair straightener 10 includes a rechargeable battery 172 and a charging interface 171 electrically connected to the rechargeable battery 172. The charging interface 171 and the circuit board 16 are disposed in the same clamping portion 11. The charging interface 171 is located on the side of the circuit board 16 facing away from the stainless steel substrate 12 and is disposed at the end (rear end) of the clamping portion 11.

[0054] In one embodiment, the clamping portion 11 includes a body housing 112 and a body cover 113 covering the body housing 112. The body covers 113 of the two clamping portions 11 face each other. The body cover 113 is provided with an installation opening 111 (the clamping portion 11 is provided with an installation opening 111), and the side of the stainless steel substrate 12 facing away from the graphene heating element 13 extends out from the installation opening 111. This facilitates the assembly of the hair straightener 10.

[0055] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A hair straightener, characterized in that, comprising: Two clamping parts, one end of one of the clamping parts is hinged to one end of the other clamping part, and a circuit board is provided in one of the clamping parts; And A stainless steel substrate, each of the clamping parts is provided with the stainless steel substrate, and the stainless steel substrates on the two clamping parts are arranged facing each other; On one side of any one of the stainless steel substrates facing away from the other stainless steel substrate, a graphene heating element is provided, the graphene heating element is thermally conductively connected to the stainless steel substrate, the graphene heating element is in the shape of a multi-segment bent strip, and both ends of the graphene heating element are electrically connected to the circuit board; A first connecting layer is sintered and formed on the surface of the stainless steel substrate facing away from the other stainless steel substrate, a second connecting layer is sintered and formed on the surface of the first connecting layer facing away from the stainless steel substrate, and the graphene heating element is sintered and formed on the surface of the second connecting layer; the first connecting layer contains a first glass, the second connecting layer contains a second glass, and the melting point of the first glass is higher than the melting point of the second glass.

2. The hair straightener according to claim 1, characterized in that, The graphene heating element includes a connecting section and two extending sections, the two extending sections are arranged in parallel and both extend along the length direction of the stainless steel substrate, the connecting section is connected between the ends of the two extending sections close to the same end of the stainless steel substrate, and one end of each of the two extending sections away from the connecting section is electrically connected to the circuit board.

3. The hair straightener according to claim 2, characterized in that, Each of the extending sections is in the shape of a multi-segment bent strip.

4. The hair straightener according to claim 2, characterized in that, The shapes of the two extending sections are axially symmetrically arranged, and the axis of symmetry of the two extending sections extends along the length direction of the stainless steel substrate.

5. The hair straightener according to claim 1, characterized in that, Insulating and heat-conducting layers are covered on the surfaces of the two stainless steel substrates facing each other.

6. The hair straightener according to claim 1, characterized in that, Insulating and heat-insulating layers are covered on one side of any one of the stainless steel substrates facing away from the other stainless steel substrate, and the insulating and heat-insulating layers cover the graphene heating element.

7. The hair straightener according to any one of claims 2 to 6, characterized in that, The stainless steel substrate includes a bottom plate and a surrounding plate disposed around the periphery of the bottom plate. Installation openings are provided on the surfaces of the two clamping parts facing each other. The bottom plate extends out from the installation openings, the surrounding plate is installed on the clamping parts, and the graphene heating element is provided on one side of the bottom plate facing away from the other stainless steel substrate.

8. The hair straightener according to any one of claims 1 to 6, characterized in that, A temperature sensor is provided in each of the clamping parts, the temperature sensor is thermally conductively connected to the stainless steel substrate, and each temperature sensor is electrically connected to the circuit board.

9. The hair straightener according to any one of claims 1 to 6, characterized in that, The hair straightener further includes a rechargeable battery, the rechargeable battery is disposed in one of the clamping parts, and the circuit board is disposed in the other clamping part.

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