Multifunctional far infrared composite planar heating material and preparation method thereof

Abstract

The application discloses a multifunctional far-infrared composite planar heating material and a preparation method thereof, which comprises a flexible heating chip and a power supply lead-out wire, wherein the flexible heating chip is formed by two insulating layers and a far-infrared heating layer impregnated with a flexible resin solution through hot pressing and curing; the power supply lead-out wire further comprises a connecting terminal and a power supply line; the connecting terminal is riveted on copper poles at two ends of the flexible heating chip; and the power supply lead-out wire is clamped on a wiring groove of the connecting terminal. The multifunctional far-infrared composite planar heating material is safe to use, and the whole surface is an electronic path under general voltage, the current density is extremely small, and the human body is not harmed.

Description

Technical Field

[0001] This invention relates to an electrothermal material, specifically to a multifunctional far-infrared composite planar heating material and its preparation method. Background Technology

[0002] Far-infrared heating technology emerged in the mid-20th century. It utilizes radiative heat transfer and transmits energy via electromagnetic waves, making it a key energy-saving technology being promoted. When the wavelength of far-infrared rays matches the absorption wavelength of the object being heated, the object absorbs a large amount of far-infrared radiation. At this point, the molecules and atoms inside the object resonate and generate strong vibrations, causing the object's temperature to rise, thus achieving the heating purpose. Early far-infrared heating methods primarily used strip-shaped or wire-shaped heating elements, such as far-infrared electric heating films and far-infrared heating cables.

[0003] With the improvement of people's living standards, the application scenarios of far-infrared radiation have been further expanded, and it is widely used in infrared physiotherapy, building heating, food drying, sterilization, wearable devices, automotive heating, and home appliances. Especially in the fields of infrared physiotherapy, wearable devices, automotive heating, and home appliances, the flexibility of the heating element is highly demanding. Currently, heating wires are generally woven into fabrics, or thermoplastic polymer films are used, which mainly have the following problems: 1) Uneven heating, large temperature differences, and poor user experience; 2) Poor flexibility and impact resistance; 3) Short lifespan, with heating wires and films generally having a lifespan of no more than 30,000 hours.

[0004] Chinese Patent Publication No. CN105208692A discloses a flexible heating film assembly and its preparation method, including a flexible heating layer composed of 5-1000 layers of heating film stacked together, forming a loose and porous structure between the layers. A circuit system is connected to the flexible heating layer, and a protective layer is provided on at least one of its upper and lower sides. The multi-layered heating film of the flexible heating layer, with its loose and porous structure, possesses unique nanopores, a large aspect ratio, and a high specific surface area, giving it excellent elastic modulus and flexural strength, thus ensuring the macroscopic softness and comfortable feel of the flexible heating film assembly. Furthermore, the flexible heating film assembly is ultra-thin, extremely flexible, easy to process and mold, washable, and is a good insulating material. However, its insulation layer is made of thermoplastic plastic films such as polytetrafluoroethylene porous film, polyimide film, polyethylene film, and polyvinyl chloride film. These film materials have a certain degree of flexibility, but poor toughness. During use, the insulation layer is easily damaged due to folding or bending, which in turn damages the heating element.

[0005] In view of the above problems, the present invention discloses a multifunctional far-infrared composite planar heating material and its preparation method, which has the technical features described below to solve the existing problems. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the present invention aims to provide a multifunctional far-infrared composite planar heating material and its preparation method. The entire surface of the material is a heating surface, which heats up evenly, has a small surface temperature difference, good softness and toughness, and can be waterproof to IPX7 level and is washable. When combined with textiles and applied to wearable devices, it has no obvious hard feel and is silent. Its heat is mainly radiated in the form of far-infrared rays, which has a physiotherapy effect.

[0007] A multifunctional far-infrared composite planar heating material comprises: a flexible heating chip and a power lead wire, wherein: the flexible heating chip is formed by hot pressing and curing two insulating layers and a far-infrared heating layer impregnated with a flexible resin solution; the power lead wire further comprises a connecting terminal and a power line, the connecting terminal is riveted to the copper electrodes at both ends of the flexible heating chip, and the power lead wire is snapped into the wiring groove of the connecting terminal.

[0008] The aforementioned multifunctional far-infrared composite planar heating material, wherein: the insulating layer is made of flexible paper material, which is one or more of high-purity wood pulp fiber, polyimide fiber, aramid fiber, polyphenylene sulfide fiber, Tencel fiber, and nanocellulose fiber, and is made by wet papermaking process or dry papermaking process, and the thickness of the flexible paper material is 3-50μm.

[0009] In the aforementioned multifunctional far-infrared composite planar heating material, the long and wide sides of the insulating layer are 5-20 mm larger than the long and wide sides of the far-infrared heating layer.

[0010] The aforementioned multifunctional far-infrared composite planar heating material, wherein: the far-infrared heating layer is made of carbon fiber conductive paper, and two copper foil strips are fixed on both sides of the carbon fiber conductive paper respectively, the two copper foil strips being of the same length as the carbon fiber conductive paper, and the volume resistivity of the conductive paper being 0.1-3Ω·cm.

[0011] The aforementioned multifunctional far-infrared composite planar heating material, wherein the flexible resin solution is a solution formed by mixing resin solvent, resin matrix, flexible body, curing agent and resin activator in a weight ratio of 10:1-2:1.5-2:0.1-0.3:0.2-0.4.

[0012] The aforementioned multifunctional far-infrared composite planar heating material comprises: a resin solvent composed of one or two of ethyl acetate, butyl acetate, or acetone in any ratio; a resin matrix composed of bisphenol A type epoxy resin and high-ortho-phenolic resin in a weight ratio of 3:1-1.5; a flexible body composed of one or two of nitrile rubber and epoxy-based nitrile rubber in any ratio, which enhances the flexibility of the flexible far-infrared composite electrothermal material; a curing agent composed of dicyandiamide curing agent; and a resin activator composed of a flexible crosslinking agent and a silane coupling agent in a weight ratio of 1:1-1.5, wherein the flexible crosslinking agent is dicumyl peroxide, and the silane coupling agent is composed of one or two of vinyltrimethylsilane or methyltri-tert-butylperoxysilane in any ratio.

[0013] In the aforementioned multifunctional far-infrared composite planar heating material, the amount of the far-infrared heating layer impregnated with the flexible resin solution is 30-100 g / m². 2 .

[0014] In the aforementioned multifunctional far-infrared composite planar heating material, the flexible heating chip is hot-pressed at a temperature of 140-195℃ for 90-150 minutes and at a pressure of 50-150 kg / cm². 2

[0015] The aforementioned multifunctional far-infrared composite planar heating material, wherein: the connecting terminal is riveted to the copper electrodes at both ends of the flexible heating chip by a riveting terminal, the connecting terminal is an OT type connecting terminal, the T end wiring groove of the OT type terminal is used to snap and fix the power cord, and the riveting terminal is composed of a hollow copper rivet and a fastening washer.

[0016] In the aforementioned multifunctional far-infrared composite planar heating material, the flexible heating chip has a set of symmetrical circular holes on the copper electrodes at both ends, and the diameter of the circular holes on the flexible heating chip is the same as that of the hollow copper rivets.

[0017] A method for preparing a multifunctional far-infrared composite planar heating material, comprising the following steps:

[0018] Step 1: Prepare a flexible resin solution;

[0019] Step 1.1: Mix and homogenize bisphenol A type epoxy resin and high ortho-phenolic resin according to the weight ratio. The homogenization time is 10-30 min and the homogenization speed is 600-1500 r / min to obtain the resin matrix.

[0020] Step 1.2: Pour the resin bulk and resin solvent obtained in Step 1.1 into a mixing tank according to the weight ratio and mix and homogenize for 10-30 min at a speed of 800-1500 r / min.

[0021] Step 1.3: Pour the flexible material into the homogenized mixing tank from Step 1.2 according to the weight ratio, and homogenize for 15-30 minutes;

[0022] Step 1.4: Pour the curing agent and resin activator into the mixing tank completed in step 1.3 according to the weight ratio and homogenize for 10-30 minutes. After homogenization, a flexible resin solution is obtained.

[0023] Step 2; Cut the insulation layer according to the dimensions;

[0024] Step 3: Prepare the far-infrared heating layer;

[0025] Step 3.1: Cut the conductive paper to the required size;

[0026] Step 3.2: Use a sewing machine to attach copper electrodes to both sides of the cut conductive paper.

[0027] Step 4: Immerse the far-infrared heating layer obtained in Step 3 into the flexible resin solution obtained in Step 1, with an impregnation amount of 30-100 g / m². 2 The impregnation time is 3-10 minutes, which yields a far-infrared heating layer impregnated with a flexible resin solution.

[0028] Step 5: Place the insulating layer, the far-infrared heating layer impregnated with flexible resin solution, and the insulating layer on the centrifuge paper from bottom to top to obtain a flexible heating chip blank, and place a layer of centrifuge paper on the blank.

[0029] Step 6: Place the heating chip blank wrapped in centrifugal paper from Step 5 onto the steel plate;

[0030] Step 7: Repeat steps 5 and 6 2-10 times, and cover the top with a steel plate;

[0031] Step 8: Place the multilayer electrothermal material preform obtained in step 7 into the worktable of the hot press in parallel, start the hot press for hot pressing, and obtain the flexible heating chip after hot pressing.

[0032] Step 9: Cut the flexible heating chip obtained in Step 8 according to the product requirements;

[0033] Step 10: Drill holes along the two copper electrode edges of the flexible heating chip obtained in Step 9, and grind out the copper electrode around the holes using a grinder.

[0034] Step 11: Use crimping pliers to crimp the power lead wire to the OT type terminal;

[0035] Step 12: Rivet the flexible heating chip obtained in step 10 to the wiring terminal obtained in step 11;

[0036] Step 13: Seal the riveted terminals to obtain a multifunctional far-infrared composite planar heating material.

[0037] Because the present invention adopts the above-described solution, it has the following advantages and positive effects compared with the prior art:

[0038] 1) The heat transfer of the multifunctional far-infrared composite planar heating material of the present invention is mainly through far-infrared radiation, with an electrothermal conversion efficiency of up to 99% and an electrothermal radiation conversion efficiency of up to 50%. It has high heat transfer efficiency and is an advanced energy-saving material.

[0039] 2) The multifunctional far-infrared composite planar heating material of the present invention has a heating surface on the entire surface, a Shore hardness of 30-40A, good flexibility, folding resistance, and waterproof performance up to IPX7 level, making it suitable for a wide range of applications.

[0040] 3) The multifunctional far-infrared composite planar heating material of the present invention emits no harmful substances such as formaldehyde, toluene, xylene, or TVOC during use;

[0041] 4) The heating element of the multifunctional far-infrared composite planar heating material of the present invention is a three-dimensional conductive network built with short-cut carbon fibers. Its conductive path is a physical structure built with short-cut carbon fibers, which has the characteristics of structural stability. According to the test of the National Infrared Center, its service life can reach more than 100,000 hours.

[0042] 5) The multifunctional far-infrared composite planar heating material of the present invention can be combined into various heating materials with different powers and temperatures according to power and specification requirements to meet different requirements;

[0043] The multifunctional far-infrared composite planar heating material of the present invention is safe to use. Under normal voltage, the entire surface is an electron pathway with extremely low current density, which is harmless to the human body. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the flexible heating chip in the multifunctional far-infrared composite planar heating material of the present invention;

[0045] Figure 2 This is a schematic diagram of the circular hole structure in the multifunctional far-infrared composite planar heating material of the present invention;

[0046] Figure 3 This is a schematic diagram of the OT-type terminal in the multifunctional far-infrared composite planar heating material of the present invention;

[0047] Figure 4 This is a schematic diagram of the power lead wire in the multifunctional far-infrared composite planar heating material of the present invention;

[0048] Figure 5 This is a schematic diagram of the rivet structure in the multifunctional far-infrared composite planar heating material of the present invention;

[0049] In the diagram: 1. Flexible fabric; 2. Far-infrared heating chip; 3. OT type terminal; 4. Power cord; 5. Rivet; 6. Round hole. Detailed Implementation

[0050] according to Figures 1 to 5 As shown, this invention discloses a multifunctional far-infrared composite planar heating material and its preparation method. The entire surface of the material is a heating surface, which provides uniform heating, has a small surface temperature difference, good softness and toughness, a waterproof rating of up to IPX7, and a service life of up to 100,000 hours.

[0051] The multifunctional far-infrared composite planar heating material of the present invention is achieved through the following technical solution: A multifunctional far-infrared composite planar heating material comprises: a flexible heating chip and a power lead wire. The flexible heating chip is formed by hot-pressing and curing two insulating layers and a far-infrared heating layer impregnated with a flexible resin solution. The power lead wire of the flexible far-infrared composite heating material further includes connecting terminals and a power line. The connecting terminals are riveted to the copper electrodes at both ends of the flexible far-infrared composite heating material, and the power lead wire is snapped into the wiring groove of the connecting terminals.

[0052] The insulating layer is made of flexible paper material, which is one or more of high-purity wood pulp fiber, polyimide fiber, aramid fiber, polyphenylene sulfide fiber, Tencel fiber, and nanocellulose fiber, and is made by wet papermaking or dry papermaking process. The thickness of the flexible paper material is 3-50μm.

[0053] The long and wide sides of the insulating layer are 5-20 mm larger than the long and wide sides of the heating layer.

[0054] The far-infrared heating layer is made of carbon fiber conductive paper. Two copper foil strips are fixed to both sides of the carbon fiber conductive paper, and these strips are of the same length as the paper. The volume resistivity of the conductive paper is 0.1-3 Ω·cm. The carbon fiber conductive paper utilizes a "conductive channel" conductivity mechanism, primarily relying on a three-dimensional conductive filling network constructed from short-cut carbon fibers. Factors affecting its conductivity include the number of contacts, contact resistance, and gap size. Therefore, the conductivity can be determined by adjusting the carbon fiber content and the paper's weight during preparation. For carbon fibers of the same length and diameter: the higher the carbon fiber content, the lower the volume resistivity of the conductive paper, and vice versa. With the same carbon fiber content, the volume resistivity of the conductive paper is constant; the greater the weight of the conductive paper, the lower its resistance and the better its conductivity. The conductivity of the conductive paper depends on its volume resistivity, which is calculated using the following formula:

[0055] Volume resistivity = Cross-sectional area of ​​conductive paper / Distance between copper electrodes * Resistance value.

[0056] The flexible resin solution is a solution formed by mixing resin solvent, resin matrix, flexible body, curing agent and resin activator in a weight ratio of 10:1-2:1.5-2:0.1-0.3:0.2-0.4.

[0057] The resin solvent is composed of one or two of ethyl acetate, butyl acetate, or acetone in any proportion. The resin matrix is ​​composed of bisphenol A type epoxy resin and high-ortho-phenolic resin mixed in a weight ratio of 3:1-1.5. The flexible body is composed of one or two of nitrile rubber and epoxy-based nitrile rubber in any proportion, which can enhance the flexibility of the flexible far-infrared composite electrothermal material. The curing agent is dicyandiamide curing agent. The resin activator is composed of a flexible crosslinking agent and a silane coupling agent mixed in a weight ratio of 1:1-1.5, wherein the flexible crosslinking agent is dicumyl peroxide, and the silane coupling agent is composed of one or two of vinyltrimethylsilane or methyltri-tert-butylperoxysilane in any proportion. Whether it's epoxy resin or phenolic resin, thermosetting resins generally result in composite materials with poor flexibility after thermosetting, typically around 80A Shore hardness. However, by adding a flexible material, which is uniformly dispersed in the solution, the thermosetting process effectively reduces the hardness of the flexible far-infrared composite electrothermal material, lowering its Shore hardness to 30-40A, thus meeting most flexibility requirements.

[0058] The amount of resin impregnated in the far-infrared heating layer with the flexible resin solution is 30-100 g / m². 2 .

[0059] The flexible heating chip is hot-pressed at a temperature of 140-195℃ for 90-150 minutes and at a pressure of 50-150 kg / cm². 2 .

[0060] The connecting terminals are riveted to the copper electrodes at both ends of the flexible heating chip by riveting terminals. The connecting terminals are OT type connecting terminals, and the T-end wiring groove of the OT type terminal is used to snap and fix the power cord. The riveting terminals consist of hollow copper rivets and fastening washers.

[0061] The flexible heating chip has a set of symmetrical circular holes on the copper electrodes at both ends, and the diameter of the circular holes on the flexible heating chip is the same as that of the hollow copper rivet.

[0062] A method for preparing a multifunctional far-infrared composite planar heating material includes at least the following steps:

[0063] Step 1: Prepare a flexible resin solution;

[0064] Step 1.1: Mix and homogenize bisphenol A type epoxy resin and high ortho-phenolic resin according to the weight ratio. The homogenization time is 10-30 min and the homogenization speed is 600-1500 r / min to obtain the resin matrix.

[0065] Step 1.2: Pour the resin bulk and resin solvent obtained in Step 1.1 into a mixing tank according to the weight ratio and mix and homogenize for 10-30 min at a speed of 800-1500 r / min.

[0066] Step 1.3: Pour the flexible material into the homogenized mixing tank from Step 1.2 according to the weight ratio, and homogenize for 15-30 minutes;

[0067] Step 1.4: Pour the curing agent and resin activator into the mixing tank completed in step 1.3 according to the weight ratio and homogenize for 10-30 minutes. After homogenization, a flexible resin solution is obtained.

[0068] Step 2; Cut the insulation layer according to the dimensions;

[0069] Step 3: Prepare the far-infrared heating layer;

[0070] Step 3.1: Cut the conductive paper to the required size;

[0071] Step 3.2: Use a sewing machine to attach copper electrodes to both sides of the cut conductive paper.

[0072] Step 4: Immerse the far-infrared heating layer obtained in Step 3 into the flexible resin solution obtained in Step 1, with an impregnation amount of 30-100 g / m². 2The impregnation time is 3-10 minutes, which yields a far-infrared heating layer impregnated with a flexible resin solution.

[0073] Step 5: Place the insulating layer, the far-infrared heating layer impregnated with flexible resin solution, and the insulating layer on the centrifuge paper from bottom to top to obtain a flexible heating chip blank, and place a layer of centrifuge paper on the blank.

[0074] Step 6: Place the heating chip blank wrapped in centrifugal paper from Step 5 onto the steel plate;

[0075] Step 7: Repeat steps 5 and 6 2-10 times, and cover the top with a steel plate;

[0076] Step 8: Place the multilayer electrothermal material preform obtained in step 7 into the worktable of the hot press in parallel, start the hot press for hot pressing, and obtain the flexible heating chip after hot pressing.

[0077] Step 9: Cut the flexible heating chip obtained in Step 8 according to the product requirements;

[0078] Step 10: Drill holes along the two copper electrode edges of the flexible heating chip obtained in Step 9, and grind out the copper electrode around the holes using a grinder.

[0079] Step 11: Use crimping pliers to crimp the power lead wire to the OT type terminal;

[0080] Step 12: Rivet the flexible heating chip obtained in step 10 to the wiring terminal obtained in step 11;

[0081] Step 13: Seal the riveted terminals to obtain a multifunctional far-infrared composite planar heating material.

[0082] The specific embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific embodiments described above, which are merely examples. For those skilled in the art, any equivalent modifications and substitutions to the system are also within the scope of the present invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims

1. A multifunctional far-infrared composite planar heating material, comprising: The device comprises a flexible heating chip and a power lead wire, characterized in that: the flexible heating chip is formed by hot pressing and curing two insulating layers and a far-infrared heating layer impregnated with a flexible resin solution; the long side and the wide side of the insulating layer are 5-20mm larger than the long side and the wide side of the far-infrared heating layer; the power lead wire further includes a connecting terminal and a power line; the connecting terminal is riveted to the copper poles at both ends of the flexible heating chip; and the power lead wire is snapped into the wiring slot of the connecting terminal. The flexible resin solution is a solution formed by mixing resin solvent, resin matrix, flexible body, curing agent and resin activator in a weight ratio of 10:1-2:1.5-2:0.1-0.3:0.2-0.

4. The resin solvent is composed of one or two of ethyl acetate, butyl acetate, or acetone in any ratio. The resin matrix is ​​composed of bisphenol A type epoxy resin and high ortho-phenolic resin mixed in a weight ratio of 3:1-1.

5. The flexible body is composed of one or two of nitrile rubber and epoxy nitrile rubber in any ratio. The curing agent is dicyandiamide curing agent. The resin activator is composed of a flexible crosslinking agent and a silane coupling agent mixed in a weight ratio of 1:1-1.

5. The flexible crosslinking agent is dicumyl peroxide, and the silane coupling agent is composed of one or two of vinyltrimethylsilane or methyltritert-butylperoxysilane in any ratio. The amount of resin impregnated in the far-infrared heating layer with the flexible resin solution is 30-100 g / m². 2 .

2. The multifunctional far-infrared composite planar heating material according to claim 1, characterized in that: The insulating layer is made of flexible paper material, which is one or more of high-purity wood pulp fiber, polyimide fiber, aramid fiber, polyphenylene sulfide fiber, Tencel fiber, and nanocellulose fiber, and is made by wet papermaking or dry papermaking process. The thickness of the flexible paper material is 3-50μm.

3. The multifunctional far-infrared composite planar heating material according to claim 1, characterized in that: The far-infrared heating layer is made of carbon fiber conductive paper, and two copper foil strips are fixed on both sides of the carbon fiber conductive paper. The two copper foil strips are the same length as the carbon fiber conductive paper, and the volume resistivity of the conductive paper is 0.1-3 Ω·cm.

4. The multifunctional far-infrared composite planar heating material according to claim 1, characterized in that: The flexible heating chip is hot-pressed at a temperature of 140-195℃ for 90-150 minutes and at a pressure of 50-150 kg / cm². 2 .

5. The multifunctional far-infrared composite planar heating material according to claim 1, characterized in that: The connection terminal is riveted to the copper electrodes at both ends of the flexible heating chip by a riveting terminal. The connection terminal is an OT type connection terminal. The T-end wiring groove of the OT type connection terminal is used to snap and fix the power cord. The riveting terminal is composed of a hollow copper rivet and a fastening washer.

6. The multifunctional far-infrared composite planar heating material according to claim 5, characterized in that: The flexible heating chip has a set of symmetrical circular holes on the copper electrodes at both ends, and the diameter of the circular holes on the flexible heating chip is the same as that of the hollow copper rivet.

7. The method for preparing the multifunctional far-infrared composite planar heating material according to any one of claims 1-6, characterized in that: The method includes at least the following steps: Step 1: Prepare a flexible resin solution; Step 1.1: Mix and homogenize bisphenol A type epoxy resin and high ortho-phenolic resin according to the weight ratio. The homogenization time is 10-30 min and the homogenization speed is 600-1500 r / min to obtain the resin matrix. Step 1.2: Pour the resin bulk and resin solvent obtained in Step 1.1 into a mixing tank according to the weight ratio and mix and homogenize for 10-30 min at a speed of 800-1500 r / min. Step 1.3: Pour the flexible material into the homogenized mixing tank from Step 1.2 according to the weight ratio, and homogenize for 15-30 minutes; Step 1.4: Pour the curing agent and resin activator into the mixing tank completed in step 1.3 according to the weight ratio and homogenize for 10-30 minutes. After homogenization, a flexible resin solution is obtained. Step 2: Cut the insulation layer according to the dimensions; Step 3: Prepare the far-infrared heating layer; Step 3.1: Cut the conductive paper to the required size; Step 3.2: Use a sewing machine to attach copper electrodes to both sides of the cut conductive paper; Step 4: Immerse the far-infrared heating layer obtained in Step 3 into the flexible resin solution obtained in Step 1, with an impregnation amount of 30-100 g / m². 2 The impregnation time is 3-10 minutes, which yields a far-infrared heating layer impregnated with a flexible resin solution. Step 5: Place the insulating layer, the far-infrared heating layer impregnated with flexible resin solution, and the insulating layer on the centrifuge paper from bottom to top to obtain a flexible heating chip blank, and place a layer of centrifuge paper on the blank. Step 6: Place the heating chip blank wrapped in centrifugal paper from Step 5 onto the steel plate; Step 7: Repeat steps 5 and 6 2-10 times, and cover the top with a steel plate; Step 8: Place the multilayer electrothermal material preform obtained in step 7 into the worktable of the hot press in parallel, start the hot press for hot pressing, and obtain the flexible heating chip after hot pressing. Step 9: Cut the flexible heating chip obtained in Step 8 according to the product requirements; Step 10: Drill holes along the two copper electrode edges of the flexible heating chip obtained in Step 9, and grind out the copper electrode around the holes using a grinder. Step 11: Use crimping pliers to crimp the power lead wire to the OT type connector terminal; Step 12: Rivet the flexible heating chip obtained in step 10 to the wiring terminal obtained in step 11; Step 13: Seal the riveted terminals to obtain a multifunctional far-infrared composite planar heating material.

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