Insulation packaging process of flexible heating film, insulation electric heating material and application of insulation electric heating material in heater

Abstract

The invention relates to the technical field of electric heating materials and heaters, in particular to an insulation packaging process of a flexible heating film, an insulation electric heating material and application of the insulation electric heating material in the heaters. The electric heating material subjected to insulation packaging has excellent insulation performance under the condition that the thin size is kept, the mineral particles are subjected to hot-pressing curing forming through the adhesive and packaged on the two side faces of the flexible heating film, and therefore the obtained insulation electric heating material has proper strength and stiffness and is convenient to install and construct; the insulation electric heating material has good rigidity so as to meet the requirements of some application fields, and the simple insulation packaging layer area is perforated so as to facilitate installation, so that the insulation electric heating material has good application prospects in heaters. The insulating electric heating material has the advantages of uniform heating, rapid heating, high temperature resistance, high yield and low preparation cost.

Description

Technical Field

[0001] This invention relates to the field of electrothermal materials and heaters, specifically to an insulating encapsulation process for a flexible heating film, an insulating electrothermal material, and its application in a heater. Background Technology

[0002] Traditional electric heating materials are copper coils or copper sheets. These materials consume a lot of electricity, are expensive, have low heating efficiency, and poor heat uniformity. They typically require 220V or higher voltage, and heaters made from them are often damaged due to excessive power. Currently, flexible heating films are increasingly widely used as electric heating materials because of their low power consumption, low material cost, high heating efficiency, good heat uniformity, and the fact that heaters made from them are not easily damaged by excessive power.

[0003] Flexible heating films are typically made by mixing carbon nanotubes, graphene, or conductive carbon black as conductive materials with a resin substrate to form a thin film with a certain conductivity (thickness 0.2-2 mm), and then printing or electroplating electrodes (usually two parallel electrodes, or positive and negative electrodes with a specific wiring layout) to obtain a flexible conductive heating body.

[0004] Flexible heating films possess excellent flexibility, can be rolled up, and are easy to store, making them widely used in the electrothermal field. However, in some applications, their thinness and softness result in a lack of suitable rigidity, making installation and construction difficult. Furthermore, as the heating film itself is a conductor, direct use necessitates consideration of potential electric shock risks and adherence to certain insulation and encapsulation requirements. For example, in the heater industry, including heaters, ovens, industrial heating equipment, and industrial insulation equipment, the poor flexibility, strength, and rigidity of flexible heating films make encapsulation and fixation within equipment challenging. This typically requires the fabrication of fixing brackets or encapsulation frames, leading to complex manufacturing processes, high production difficulty, low efficiency, and high costs.

[0005] In addition, since heaters are typically used for extended periods, heat dissipation needs to be considered. While flexible heating films, using flexible substrates (such as polyimide), meet the requirements for flexibility and bending, their heat dissipation is relatively poor, as they cannot dissipate heat directly through the metal casing. Even with cooling fans to assist heat dissipation, the heat dissipation effect still needs improvement because flexible heating films are usually sheet-like. Furthermore, the risk of electric shock from accidental triggering of the heating film surface during use must be considered, along with its heat resistance and insulation at high temperatures. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the first objective of this invention is to provide an insulating encapsulation process for a flexible heating film. This process enables the encapsulated heating material to have excellent insulation properties, as well as suitable strength and rigidity, and also achieves rigidity, thereby facilitating installation and construction.

[0007] In order to overcome the shortcomings of the prior art, the second objective of the present invention is to provide an insulating electrothermal material that not only has excellent insulation properties, but also has suitable stiffness or rigidity, thereby facilitating installation and construction.

[0008] To overcome the shortcomings of the prior art, a third objective of the present invention is to provide an application of an insulating electrothermal material in a heater.

[0009] To achieve the first objective of the invention, the technical solution adopted by the present invention is as follows:

[0010] This invention provides an insulating encapsulation process for a flexible heating film, comprising the following steps: mixing mineral particles with an adhesive to obtain an encapsulation slurry;

[0011] The encapsulation slurry is coated and dried on a steel strip, then peeled off to form an insulating encapsulation film. At least one sheet of the insulating encapsulation film is then applied to the two surfaces of the flexible heating film using an adhesive and hot-pressed to form an insulating encapsulation layer. Alternatively, the encapsulation slurry is coated onto the two surfaces of the flexible heating film and directly hot-pressed to form an insulating encapsulation layer. Or, the encapsulation slurry is molded and cured on the two surfaces of the flexible heating film to form an insulating encapsulation layer, thus obtaining an insulating electrothermal material, which completes the insulating encapsulation of the flexible heating film.

[0012] In this process, an insulating encapsulation film is first prepared by coating and thermosetting an encapsulation paste. Then, at least one insulating encapsulation film is coated with silicone resin adhesive and hot-pressed or molded onto the surface of a flexible heating film to insulate and encapsulate the flexible heating film. The flexible heating film and the insulating encapsulation film, as well as the insulating encapsulation films themselves, are adhered together by hot-pressing or molding using silicone resin adhesive, thus allowing multiple layers of insulating encapsulation film to be encapsulated on both surfaces of the flexible heating film.

[0013] This invention discloses an insulating encapsulation process for a flexible heating film. By using an encapsulation slurry obtained from a mixture of mineral particles and an adhesive to hot-press or mold the flexible heating film, the encapsulated heating material exhibits excellent insulation performance while maintaining a relatively thin profile. Furthermore, the insulating heating material obtained by hot-pressing and curing the mineral particles with an adhesive onto both sides of the flexible heating film possesses suitable strength and rigidity. By adjusting the amount of encapsulation slurry, the thickness of the insulating encapsulation layer can be adjusted, thereby obtaining insulating heating materials with varying rigidity, facilitating installation and construction. By increasing the thickness of the insulating encapsulation layer or adjusting the formulation of the encapsulation slurry, the insulating heating material can achieve better rigidity to meet the requirements of certain application fields.

[0014] Furthermore, after completing the hot pressing or molding steps, two slots are laser-cut at the two electrodes corresponding to the surface of the flexible heating film to expose the electrodes. Wires are then electrically connected to the electrodes at the slots, and the slots are sealed to obtain the insulating electrothermal material. Since the surface of the flexible heating film typically has two parallel electrodes (positive and negative electrodes) printed or electroplated, or has positive and negative electrodes with a specific wiring layout printed or electroplated, laser-cut slots are used at the corresponding positive and negative electrodes to remove the surface-encapsulated insulating layer, exposing the electrodes at the slot size. Two wires are then welded to the two exposed positive and negative electrodes respectively for electrical connection, and then an insulating sealant (e.g., epoxy resin sealant) is used to insulate and seal the weld joints.

[0015] The present invention uses a flexible heating film with printed or electroplated electrodes (especially two parallel electrodes) as the heating layer of a cylindrical insulating heating material. Compared with the prior art which uses resistance wire or etched circuits as heating methods, it has the advantages of simple preparation process, high yield, uniform heating, rapid heating, high temperature resistance of 260℃~450℃, and low cost.

[0016] Furthermore, glass fiber is added to the encapsulation slurry; that is, the encapsulation slurry is obtained by mixing mineral particles, glass fiber, and adhesive. Adding glass fiber to the encapsulation slurry provides support and a framework, thereby improving the strength and rigidity of the insulating electrothermal material, effectively enhancing its mechanical properties, impact resistance, and heat resistance, while maintaining its lightweight advantage.

[0017] Furthermore, the diameter of the glass fiber is 5 μm to 15 μm; and / or

[0018] The amount of glass fiber used accounts for 8% to 15% of the mass of the mineral particles.

[0019] Furthermore, a dispersant is added to the encapsulating slurry, the amount of which is 3% to 10% of the mass of the mineral particles; wherein, the addition of the dispersant can prevent the agglomeration of mineral particles, making the mineral particles more uniformly dispersed, and can enhance the interfacial bonding between the mineral particles and the adhesive. and / or

[0020] The dispersant is one or a combination of two or more of the following: silane coupling agent, titanate coupling agent, aluminate coupling agent, or stearic acid. Specifically, the silane coupling agent may be KH-550 or KH-570, the titanate coupling agent may be NDZ-201, the aluminate coupling agent may be AS-200, and the stearic acid may be S-18.

[0021] Furthermore, welding holes for electrical connection are pre-drilled using a laser at the two electrodes on the surface of the flexible heating film corresponding to the insulating encapsulation film. After the insulating encapsulation film is thermoformed and encapsulated on the two surfaces of the flexible heating film, the electrodes on the surface of the flexible heating film are exposed at the welding holes.

[0022] Furthermore, the insulating encapsulation process for the flexible heating film further includes perforating the flexible heating film: creating several through holes in the flexible heating film; by creating several through holes in the flexible heating film, on the one hand, when hot-pressing or molding the encapsulation paste on both sides of the flexible heating film, the presence of the through holes allows the encapsulation paste on both sides of the flexible heating film to bond together at the through holes. Based on the surface properties of the same material and intermolecular forces, this greatly enhances the adhesion of the insulating encapsulation layer on the flexible heating film, especially greatly enhancing the adhesion required for rigid encapsulation, giving the resulting insulating electrothermal material excellent structural stability; on the other hand, the presence of several through holes in the flexible heating film gives the insulating electrothermal material good heat dissipation performance. And / or

[0023] The plurality of through holes form a honeycomb-like or arrayed through hole structure; wherein, forming a honeycomb-like through hole structure on the flexible heating film means uniformly opening a plurality of through holes on the flexible heating film, making the flexible heating film resemble a mesh structure, which can better improve the adhesion of the insulating encapsulation layer to the flexible heating film, and better improve the heat dissipation performance of the flexible heating film. and / or

[0024] The diameter of the through-hole is 3mm to 15mm; the flexible heating film with through-holes of this diameter can significantly improve the adhesion of the insulating encapsulation layer to the flexible heating film, and also significantly improve the heat dissipation performance of the flexible heating film. And / or

[0025] The total area of ​​the plurality of through holes accounts for 10% to 60% of the area of ​​the flexible heating film before the holes are opened; wherein, by the ratio of the area of ​​the holes to the total area of ​​the original heating film, the total power and power density of the flexible heating film can be adjusted under the same input voltage and the same flexible heating film material, thereby adjusting the temperature and heat generation of the insulating electric heating material. and / or

[0026] After the flexible heating film is perforated, the encapsulation paste is then formed into an insulating encapsulation layer on both sides of the flexible heating film.

[0027] Furthermore, the mineral particles are one or a combination of two or more of mica powder, calcium carbonate, or gypsum powder; wherein, the mica powder, calcium carbonate, or gypsum powder, as mineral particles, achieve suitable strength and rigidity when formed on the flexible heating film as an insulating encapsulation layer under the action of an adhesive. And / or

[0028] The mineral particles have a particle size of 1 μm to 150 μm; and / or

[0029] The mass ratio of the mineral particles to the adhesive is (90–97):(3–10); and / or

[0030] The adhesive is a silicone resin adhesive; wherein, the silicone resin adhesive has the characteristics of high and low temperature resistance, waterproof and moisture-proof properties, and electrical insulation, and has good adhesion to the insulating encapsulation layer formed with mineral particles. and / or

[0031] The mineral particles and adhesive are first dispersed in a high-speed mixer at a speed of 300 rpm to 500 rpm for 5 min to 15 min, and then mixed at a speed of 1500 rpm to 2000 rpm for 10 min to 20 min. Specifically, the mineral particles and adhesive are first evenly dispersed by low-speed stirring, and then uniformly mixed by high-speed stirring. And / or

[0032] The hot pressing or molding temperature is 100℃~260℃, the hot pressing or molding time is 0.5h~8h, and the hot pressing or molding pressure is 50MPa~100MPa; and / or

[0033] The insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 3mm to 10mm beyond the edge of the flexible heating film. Because the insulating encapsulation layer is larger than the flexible heating film, it provides excellent insulation and encapsulation. Furthermore, the slightly wider size of the insulating encapsulation layer allows for the drilling of mounting holes in the insulating encapsulation layer area to facilitate installation within the heater; and / or

[0034] The thickness of the insulating encapsulation layer is 0.05 mm to 1 mm. When the insulating encapsulation layer is thinner, the resulting insulating electrothermal material can achieve insulation while also possessing a certain degree of hardness and flexibility. When the insulating encapsulation layer is thicker, the resulting insulating electrothermal material can achieve insulation while also possessing good strength, stiffness, and rigidity.

[0035] The thickness of the flexible heating film is generally 0.2mm to 2mm.

[0036] Furthermore, the insulating encapsulation process for the flexible heating film further includes sealing the outer periphery of the insulating heating material with a metal strip; wherein, sealing the outer periphery of the insulating heating material with the metal strip using a pressing machine further enhances the rigidity of the insulating heating material; and / or

[0037] The metal strip is configured as a V-shaped metal strip, and one side of the V-shaped metal strip has several V-shaped notches; wherein, the V-shaped metal strip facilitates the direct covering and pressing of the outer peripheral edge of the insulating heating material using a pressing machine to complete the edge sealing operation; in addition, the V-shaped metal strip includes a first side and a second side, the first side and the second side together forming a V-shaped structure, and several V-shaped notches are opened on the first side or the second side; if the insulating heating material to be sealed is quadrilateral, then three V-shaped notches are opened on the first side or the second side; and / or

[0038] The metal strip is a galvanized iron strip, which has the advantages of corrosion resistance, low cost, and good processing performance. And / or

[0039] A metal strip is used to seal the outer edges of two or more insulating heating materials, encapsulating and connecting them together to form a fixed angle between adjacent materials. The fixed angle between the two materials connected by the metal strip sealing operation can range from 30 degrees to 180 degrees. Furthermore, because the metal strip is relatively thin, the angle between adjacent materials can be adjusted appropriately. After adjusting to the suitable angle according to actual installation needs, the material can be fixed and installed.

[0040] To achieve the second objective of the invention, the technical solution adopted by the present invention is as follows:

[0041] This invention provides an insulating electrothermal material, which is prepared by the insulating encapsulation process of the flexible heating film described above.

[0042] The present invention provides an insulating electric heating material. By hot-pressing or molding a flexible heating film with mineral particles and adhesives to create an insulating encapsulation, the resulting insulating electric heating material not only has excellent insulation properties but also suitable stiffness or rigidity, thus facilitating installation and construction.

[0043] To achieve the third objective of the invention, the technical solution adopted by the present invention is as follows:

[0044] This invention provides an application of an insulating electrothermal material in a heater, wherein the insulating electrothermal material described above or the insulating encapsulation process of the flexible heating film described above is used as the electrothermal material of the heater; and / or

[0045] The heater includes heaters, electric heaters, ovens, baking equipment, incubation equipment, electric water heaters, temperature control equipment, industrial heating equipment, or industrial insulation equipment.

[0046] In the process of manufacturing the heater, it is necessary to install heating materials inside the heater. Existing technologies often use flexible heating films for installation, but due to the flexibility of these films, installation is difficult and they are not well supported, often requiring the fabrication of specific frames and supports. The insulating heating material obtained in this invention possesses suitable strength and rigidity, making it easy to install in heaters and thus showing great promise for applications in heaters.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] (1) The present invention provides an insulating encapsulation process for a flexible heating film. By using an encapsulation slurry obtained from a mixture of mineral particles and an adhesive to hot-press or mold the flexible heating film, the encapsulated heating material can achieve excellent insulation performance while maintaining a relatively thin profile. Furthermore, the insulating heating material obtained by hot-pressing and curing the mineral particles with an adhesive onto both sides of the flexible heating film possesses suitable strength and rigidity. By adjusting the amount of encapsulation slurry, the thickness of the insulating encapsulation layer can be adjusted, thereby obtaining insulating heating materials with different rigidities, facilitating installation and construction. Additionally, by increasing the thickness of the insulating encapsulation layer or adjusting the formulation of the encapsulation slurry, the insulating heating material can achieve better rigidity to meet the requirements of certain application fields.

[0049] (2) The insulating electric heating material of the present invention, by hot-pressing or molding a flexible heating film with mineral particles and adhesives for insulating encapsulation, not only possesses excellent insulation properties but also suitable stiffness or rigidity, thus facilitating installation and construction. Furthermore, this insulating electric heating material also possesses the advantages of uniform heating, rapid heating, high temperature resistance, high yield, and low manufacturing cost. The insulating electric heating material obtained by the present invention can withstand temperatures from 260℃ to 450℃.

[0050] (3) The application of an insulating electric heating material in a heater of the present invention has good application prospects in heaters because the insulating electric heating material has suitable strength and stiffness and can achieve good rigidity. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is a schematic diagram of the structure of an insulating electrothermal material obtained by an insulating encapsulation process of a flexible heating film according to Embodiment 3 of the present invention.

[0053] Figure 2 This is an exploded structural diagram of the insulating electrothermal material obtained by the insulating encapsulation process of a flexible heating film according to Embodiment 10 of the present invention.

[0054] Figure 3 This is a schematic diagram of the structure of the flexible heating film in Embodiments 13 and 14 of the present invention.

[0055] Figure 4 This is an experimental demonstration diagram of the flexible heating film of Embodiment 13 of the present invention during the detection of heating performance.

[0056] Figure 5 This is a schematic diagram of the structure of the flexible heating film in Embodiments 15 and 16 of the present invention.

[0057] Figure 6 This is a product display diagram of the insulating electrothermal material obtained in Embodiment 3 of the present invention.

[0058] Figure 7 This is a schematic diagram of the V-shaped metal strip used for edge sealing in Embodiment 19 of the present invention.

[0059] Figure 8This is a schematic diagram of the structure of the sealed insulating electrothermal material obtained in Embodiment 19 of the present invention.

[0060] Figure 9 This is a schematic diagram of the structure in Embodiment 20 of the present invention, in which two pieces of insulating heating material are encapsulated and connected together to form a fixed angle by sealing with metal strips.

[0061] Figure label:

[0062] 1. Flexible heating film; 2. Electrode; 3. Insulating encapsulation layer; 4. Groove; 5. Wire; 6. Through hole; 7. Welding hole; 8. Metal strip; 81. First side; 82. Second side; 83. V-shaped notch; 9. Silicone rubber cover. Detailed Implementation

[0063] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0064] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. In this invention, the singular forms “a,” “the,” “the,” “first,” and “second” as used in the embodiments and appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0065] The following description is based on specific embodiments.

[0066] Example 1

[0067] This embodiment of an insulating encapsulation process for a flexible heating film includes the following steps: mixing mineral particles with an adhesive to obtain an encapsulation slurry; coating the encapsulation slurry onto both surfaces of the flexible heating film 1 and then hot-pressing it to form an insulating encapsulation layer 3, thus obtaining an insulating electrothermal material, thereby completing the insulating encapsulation of the flexible heating film. Please refer to... Figure 1 and Figure 2 As shown, the surface of the flexible heating film 1 is printed or electroplated with two parallel electrodes 2 (one as a positive electrode and the other as a negative electrode), wherein the electrodes 2 can be copper electrodes, silver electrodes or aluminum electrodes. An insulating encapsulation layer 3 covers and encapsulates the two sides of the flexible heating film 1.

[0068] In this embodiment, the mineral particles are mica powder; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 50 μm; and the mass ratio of mineral particles to adhesive is 95:5.

[0069] In this embodiment, the mineral particles and adhesive are first dispersed at 400 rpm for 10 minutes using a high-speed mixer, and then mixed at 1800 rpm for 15 minutes.

[0070] In this embodiment, the hot pressing temperature is 200°C, the hot pressing time is 0.5 hours, and the hot pressing pressure is 80 MPa.

[0071] In this embodiment, the insulating encapsulation layer 3 is larger than the flexible heating film, and its perimeter extends 5 mm beyond the edge of the flexible heating film 1. The thickness of the insulating encapsulation layer 3 is 0.2 mm. The thickness of the flexible heating film 1 is 1 mm.

[0072] Example 2

[0073] The insulating encapsulation process of a flexible heating film in this embodiment includes the following steps: mixing mineral particles with an adhesive to obtain an encapsulation slurry; molding the encapsulation slurry onto the two surfaces of the flexible heating film 1 and curing it into an insulating encapsulation layer 3 to obtain an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film.

[0074] In this embodiment, the mineral particles are calcium carbonate; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 20 μm; and the mass ratio of the mineral particles to the adhesive is 93:7.

[0075] In this embodiment, the mineral particles and adhesive are first dispersed at 300 rpm for 15 minutes using a high-speed mixer, and then mixed at 1500 rpm for 20 minutes.

[0076] In this embodiment, the molding temperature is 150°C, the molding time is 2 hours, and the molding pressure is 60 MPa.

[0077] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 3mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.25mm. The thickness of the flexible heating film is 0.2mm.

[0078] Example 3

[0079] This embodiment of an insulating encapsulation process for a flexible heating film includes the following steps: mixing mineral particles with an adhesive to obtain an encapsulation slurry; coating the encapsulation slurry onto both surfaces of the flexible heating film 1 and then hot-pressing it into an insulating encapsulation layer 3; laser-cutting two slots 4 on the insulating encapsulation layer 3 corresponding to the two electrodes on the surface of the flexible heating film 1 to expose the electrodes; electrically connecting wires 5 to the electrodes 2 at the slots 4; and sealing the slots 4 to obtain an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film. Figure 1As shown, the surface of the flexible heating film 1 is printed or electroplated with two parallel electrodes 2 (one as the positive electrode and the other as the negative electrode). The electrodes 2 can be copper, silver, or aluminum. An insulating encapsulation layer 3 covers both sides of the flexible heating film 1. A slot 4 is laser-cut on the insulating encapsulation layer 3 at the position corresponding to the electrode 2. The surface-encapsulated insulating encapsulation layer is removed by laser, exposing the electrode 2 at the size of the slot 4. Two wires 5 are then welded to the two exposed positive and negative electrodes respectively for electrical connection. An insulating sealant (e.g., epoxy resin sealant) is then used to seal the weld joint. The wires 5 are copper wires with an insulating layer.

[0080] In this embodiment, the mineral particles are a combination of mica powder and calcium carbonate; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 80 μm; and the mass ratio of mineral particles to adhesive is 92:8.

[0081] In this embodiment, the mineral particles and adhesive are first dispersed at 500 rpm for 5 minutes using a high-speed mixer, and then mixed at 2000 rpm for 10 minutes.

[0082] In this embodiment, the hot pressing temperature is 180°C, the hot pressing time is 1.5 hours, and the hot pressing pressure is 90 MPa.

[0083] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 4mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.2mm. The thickness of the flexible heating film is 0.4mm.

[0084] The product illustration of the insulating electrothermal material prepared in this embodiment is shown below. Figure 6 As shown.

[0085] Example 4

[0086] This embodiment describes an insulating encapsulation process for a flexible heating film. The difference between this embodiment and Embodiment 3 is that in this embodiment, the encapsulation paste is molded onto both surfaces of the flexible heating film 1 and cured to form an insulating encapsulation layer 3. The remaining process steps in this embodiment are the same as in Embodiment 3.

[0087] Example 5

[0088] The insulating encapsulation process of a flexible heating film in this embodiment includes the following steps: mixing mineral particles, glass fiber and adhesive to obtain an encapsulation slurry; coating the encapsulation slurry on both surfaces of the flexible heating film 1 and then hot-pressing it to form an insulating encapsulation layer 3, thereby obtaining an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film.

[0089] In this embodiment, the mineral particles are a combination of mica powder and gypsum powder; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 40 μm; and the mass ratio of mineral particles to adhesive is 94:6.

[0090] In this embodiment, the diameter of the glass fiber is 10 μm; the amount of glass fiber accounts for 10% of the mass of the mineral particles.

[0091] In this embodiment, the mineral particles, glass fibers and adhesive are first dispersed at 350 rpm for 12 minutes using a high-speed mixer, and then mixed at 1600 rpm for 18 minutes.

[0092] In this embodiment, the hot pressing temperature is 210°C, the hot pressing time is 3 hours, and the hot pressing pressure is 90 MPa.

[0093] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 7mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.3mm. The thickness of the flexible heating film is 0.8mm.

[0094] Example 6

[0095] The insulating encapsulation process of a flexible heating film in this embodiment includes the following steps: mixing mineral particles, glass fiber and adhesive to obtain an encapsulation slurry; molding the encapsulation slurry onto the two surfaces of the flexible heating film 1 and curing it into an insulating encapsulation layer 3 to obtain an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film.

[0096] In this embodiment, the mineral particles are mica powder; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 120 μm; and the mass ratio of the mineral particles to the adhesive is 91:9.

[0097] In this embodiment, the diameter of the glass fiber is 12 μm; the amount of glass fiber accounts for 9% of the mass of the mineral particles.

[0098] In this embodiment, the mineral particles, glass fiber and adhesive are first dispersed at 450 rpm for 8 minutes using a high-speed mixer, and then mixed at 1900 rpm for 11 minutes.

[0099] In this embodiment, the molding temperature is 220°C, the molding time is 5.5 hours, and the molding pressure is 70 MPa.

[0100] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 6 mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.4 mm. The thickness of the flexible heating film is 0.7 mm.

[0101] Example 7

[0102] This embodiment presents an insulating encapsulation process for a flexible heating film. The difference between this embodiment and Embodiment 3 is that mineral particles, glass fibers, and adhesives are mixed to obtain the encapsulation slurry. The remaining process steps in this embodiment are the same as in Embodiment 3.

[0103] In this embodiment, the diameter of the glass fiber is 5 μm; the amount of glass fiber accounts for 15% of the mass of the mineral particles.

[0104] Example 8

[0105] The insulating encapsulation process of a flexible heating film in this embodiment includes the following steps: mixing mineral particles, glass fiber, dispersant and adhesive to obtain an encapsulation slurry; coating the encapsulation slurry on both surfaces of the flexible heating film 1 and then hot-pressing it to form an insulating encapsulation layer 3, thereby obtaining an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film.

[0106] In this embodiment, the mineral particles are mica powder; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 130 μm; and the mass ratio of the mineral particles to the adhesive is 93:7.

[0107] In this embodiment, the diameter of the glass fiber is 15 μm; the amount of glass fiber accounts for 8% of the mass of the mineral particles.

[0108] In this embodiment, the amount of dispersant is 5% of the mass of the mineral particles; the dispersant is a silane coupling agent.

[0109] In this embodiment, the mineral particles, glass fiber, dispersant and adhesive are first dispersed at 380 rpm for 13 minutes using a high-speed mixer, and then mixed at 1600 rpm for 17 minutes.

[0110] In this embodiment, the hot pressing temperature is 190°C, the hot pressing time is 6 hours, and the hot pressing pressure is 70 MPa.

[0111] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 9mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.35mm. The thickness of the flexible heating film is 0.6mm.

[0112] Example 9

[0113] The insulating encapsulation process of a flexible heating film in this embodiment includes the following steps: mixing mineral particles, glass fiber, dispersant and adhesive to obtain an encapsulation slurry; molding the encapsulation slurry onto the two surfaces of the flexible heating film 1 and curing it into an insulating encapsulation layer 3 to obtain an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film.

[0114] In this embodiment, the mineral particles are a combination of mica powder and calcium carbonate; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 40 μm; and the mass ratio of mineral particles to adhesive is 90:10.

[0115] In this embodiment, the diameter of the glass fiber is 13 μm; the amount of glass fiber accounts for 13% of the mass of the mineral particles.

[0116] In this embodiment, the amount of dispersant is 7% of the mass of the mineral particles; the dispersant is a combination of silane coupling agent and titanate coupling agent.

[0117] In this embodiment, the mineral particles, glass fiber, dispersant and adhesive are first dispersed at 430 rpm for 6 minutes using a high-speed mixer, and then mixed at 1700 rpm for 14 minutes.

[0118] In this embodiment, the molding temperature is 160°C, the molding time is 7.5 hours, and the molding pressure is 90 MPa.

[0119] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 8mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.5mm. The thickness of the flexible heating film is 0.5mm.

[0120] Example 10

[0121] This embodiment of an insulating encapsulation process for a flexible heating film includes the following steps: mixing mineral particles with an adhesive to obtain an encapsulation slurry; coating and drying the encapsulation slurry on a steel strip and then peeling it off to form an insulating encapsulation film; pre-opening welding holes 7 for electrical connection at the two electrodes corresponding to the surface of the flexible heating film on the insulating encapsulation film. Each insulating encapsulation film has a thickness of 0.05 mm. Two insulating encapsulation films are then simultaneously hot-pressed onto the two surfaces of the flexible heating film using silicone resin adhesive. Each surface of the flexible heating film is hot-pressed with an insulating encapsulation film to form an insulating encapsulation layer. The electrodes 2 on the surface of the flexible heating film 1 are exposed at the welding holes 7, thus obtaining an insulating electrothermal material (such as...). Figure 2 As shown in the figure, this completes the insulating encapsulation of the flexible heating film. The silicone resin adhesive can be coated on the surface of either the insulating encapsulation film or the flexible heating film.

[0122] In this embodiment, the mineral particles are a combination of mica powder and gypsum powder; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 130 μm; and the mass ratio of mineral particles to adhesive is 91:9.

[0123] In this embodiment, the mineral particles and adhesive are first dispersed at 360 rpm for 13 minutes using a high-speed mixer, and then mixed at 1600 rpm for 17 minutes.

[0124] In this embodiment, the temperature for hot pressing or molding is 100°C, the time for hot pressing or molding is 1 hour, and the pressure for hot pressing or molding is 100 MPa.

[0125] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 10 mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.05 mm. The thickness of the flexible heating film is 0.4 mm.

[0126] Example 11

[0127] This embodiment of an insulating encapsulation process for a flexible heating film includes the following steps: mixing mineral particles, a dispersant, and an adhesive to obtain an encapsulation slurry; coating and drying the encapsulation slurry on a steel strip, then peeling it off to form an insulating encapsulation film, wherein each insulating encapsulation film has a thickness of 0.5 mm; then simultaneously encapsulating four insulating encapsulation films onto two surfaces of the flexible heating film using silicone resin adhesive through hot pressing; two insulating encapsulation films are hot-pressed onto each surface of the flexible heating film to form an insulating encapsulation layer, thus obtaining an insulating electrothermal material, thereby completing the insulating encapsulation of the flexible heating film. The flexible heating film and the insulating encapsulation films, as well as the insulating encapsulation films themselves, are bonded together by hot pressing using silicone resin adhesive.

[0128] In this embodiment, the mineral particles are a combination of calcium carbonate and gypsum powder; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 60 μm; and the mass ratio of mineral particles to adhesive is 92:8.

[0129] In this embodiment, the amount of dispersant is 10% of the mass of the mineral particles; the dispersant is a combination of silane coupling agent and aluminate coupling agent.

[0130] In this embodiment, the mineral particles, dispersant and adhesive are first dispersed at 300 rpm for 15 minutes using a high-speed mixer, and then mixed at 1500 rpm for 20 minutes.

[0131] In this embodiment, the temperature for hot pressing or molding is 260°C, the time for hot pressing or molding is 5 hours, and the pressure for hot pressing or molding is 50 MPa.

[0132] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 10mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 1mm. The thickness of the flexible heating film is 2mm.

[0133] Example 12

[0134] The insulating encapsulation process of a flexible heating film according to this embodiment includes the following steps: mixing mineral particles, glass fiber, dispersant and adhesive to obtain an encapsulation slurry; coating the encapsulation slurry on a steel strip, drying it and then peeling it off to form an insulating encapsulation film, wherein the thickness of each insulating encapsulation film is 0.2mm; then hot-pressing eight insulating encapsulation films onto the two surfaces of the flexible heating film, hot-pressing four insulating encapsulation films onto each surface of the flexible heating film to form an insulating encapsulation layer; on the insulating encapsulation film, corresponding to the two electrodes on the surface of the flexible heating film 1, two slots 4 are respectively opened by laser to expose the electrodes; the wire 5 is electrically connected to the electrode 2 at the slot 4, and the slot 4 is sealed to obtain an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film.

[0135] In this embodiment, the mineral particles are mica powder and calcium carbonate; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 140 μm; and the mass ratio of mineral particles to adhesive is 93:7.

[0136] In this embodiment, the diameter of the glass fiber is 7 μm; the amount of glass fiber accounts for 12% of the mass of the mineral particles.

[0137] In this embodiment, the amount of dispersant is 3% of the mass of the mineral particles; the dispersant is a combination of silane coupling agent and stearic acid.

[0138] In this embodiment, the mineral particles, glass fiber, dispersant and adhesive are first dispersed at 500 rpm for 5 minutes using a high-speed mixer, and then mixed at 2000 rpm for 10 minutes.

[0139] In this embodiment, the temperature for hot pressing or molding is 130°C, the time for hot pressing or molding is 8 hours, and the pressure for hot pressing or molding is 60 MPa.

[0140] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 5mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.8mm. The thickness of the flexible heating film is 1.5mm.

[0141] The insulating electrothermal material prepared in this embodiment has good rigidity.

[0142] Example 13

[0143] This embodiment of an insulating encapsulation process for a flexible heating film includes the following steps: Opening a hole in the flexible heating film 1: as shown... Figure 3As shown, a plurality of through holes 6 are formed on the flexible heating film 1. In this embodiment, the diameter of the through holes is 6 mm. In this embodiment, the plurality of through holes 6 form a honeycomb-like structure. In this embodiment, the total area of ​​the plurality of through holes 6 accounts for 50% of the area of ​​the flexible heating film before the holes are formed. Figure 4 As shown, the flexible heating film 1 with honeycomb-shaped through holes has good heating uniformity, and the overall heating temperature of the flexible heating film 1 reaches 211℃. Mineral particles and adhesive are mixed to obtain an encapsulation slurry. The encapsulation slurry is coated on both sides of the flexible heating film 1 and then hot-pressed to form an insulating encapsulation layer 3, thus obtaining an insulating electrothermal material, completing the insulating encapsulation of the flexible heating film. Figure 1 and Figure 2 As shown, the surface of the flexible heating film 1 is printed or electroplated with two parallel electrodes 2 (one as a positive electrode and the other as a negative electrode), wherein the electrodes 2 can be copper electrodes, silver electrodes or aluminum electrodes. An insulating encapsulation layer 3 covers and encapsulates the two sides of the flexible heating film 1.

[0144] In this embodiment, the mineral particles are a combination of mica powder and calcium carbonate; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 150 μm; and the mass ratio of mineral particles to adhesive is 90:10.

[0145] In this embodiment, the mineral particles and adhesive are first dispersed at 370 rpm for 7 minutes using a high-speed mixer, and then mixed at 1400 rpm for 16 minutes.

[0146] In this embodiment, the hot pressing temperature is 230°C, the hot pressing time is 5.5 hours, and the hot pressing pressure is 80 MPa.

[0147] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 5mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.3mm. The thickness of the flexible heating film is 0.7mm.

[0148] Example 14

[0149] This embodiment of an insulating encapsulation process for a flexible heating film includes the following steps: Opening a hole in the flexible heating film 1: as shown... Figure 3 As shown, several through holes 6 are formed on the flexible heating film 1. In this embodiment, the diameter of the through holes is 8 mm. In this embodiment, the several through holes 6 form a honeycomb-like through hole structure. In this embodiment, the total area of ​​the several through holes 6 accounts for 50% of the area of ​​the flexible heating film before the holes are opened. Mineral particles are mixed with adhesive to obtain an encapsulation slurry. The encapsulation slurry is coated on both sides of the flexible heating film 1 and then molded into an insulating encapsulation layer 3 to obtain an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film. Figure 1 and Figure 2As shown, the surface of the flexible heating film 1 is printed or electroplated with two parallel electrodes 2 (one as a positive electrode and the other as a negative electrode), wherein the electrodes 2 can be copper electrodes, silver electrodes or aluminum electrodes. An insulating encapsulation layer 3 covers and encapsulates the two sides of the flexible heating film 1.

[0150] In this embodiment, the mineral particles are gypsum powder; the particle size of the mineral particles is 1 μm; and the mass ratio of the mineral particles to the adhesive is 97:3.

[0151] In this embodiment, the mineral particles and adhesive are first dispersed at 450 rpm for 7 minutes using a high-speed mixer, and then mixed at 1800 rpm for 13 minutes.

[0152] In this embodiment, the molding temperature is 190°C, the molding time is 7 hours, and the molding pressure is 70 MPa.

[0153] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 5mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.25mm. The thickness of the flexible heating film is 0.3mm.

[0154] Example 15

[0155] This embodiment of an insulating encapsulation process for a flexible heating film includes the following steps: Opening a hole in the flexible heating film 1: as shown... Figure 5 As shown, several through holes 6 are formed on the flexible heating film 1. In this embodiment, the diameter of the through holes is 3mm. In this embodiment, the several through holes 6 form an array of through holes. In this embodiment, the total area of ​​the several through holes 6 accounts for 30% of the area of ​​the flexible heating film before the holes are formed. Mineral particles, dispersant and adhesive are mixed to obtain an encapsulation slurry. The encapsulation slurry is coated on both surfaces of the flexible heating film 1 and then hot-pressed to form an insulating encapsulation layer 3. Two slots 4 are formed on the insulating encapsulation layer 3 corresponding to the two electrodes on the surface of the flexible heating film 1 by laser to expose the electrodes. The wire 5 is electrically connected to the electrode 2 at the slot 4 and the slot 4 is sealed to obtain an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film. Figure 1 and Figure 2As shown, the surface of the flexible heating film 1 is printed or electroplated with two parallel electrodes 2 (one as the positive electrode and the other as the negative electrode). The electrodes 2 can be copper, silver, or aluminum. An insulating encapsulation layer 3 covers both sides of the flexible heating film 1. A slot 4 is laser-cut on the insulating encapsulation layer 3 at the position corresponding to the electrode 2. The surface-encapsulated insulating encapsulation layer is removed by laser, exposing the electrode 2 at the size of the slot 4. Two wires 5 are then welded to the two exposed positive and negative electrodes respectively for electrical connection. An insulating sealant (e.g., epoxy resin sealant) is then used to seal the connection. The wires 5 are copper wires with an insulating layer.

[0156] In this embodiment, the mineral particles are mica powder; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 90 μm; and the mass ratio of mineral particles to adhesive is 96:4.

[0157] In this embodiment, the amount of dispersant is 9% of the mass of the mineral particles; the dispersant is a titanate coupling agent.

[0158] In this embodiment, the mineral particles, dispersant and adhesive are first dispersed at 380 rpm for 9 minutes using a high-speed mixer, and then mixed at 1600 rpm for 14 minutes.

[0159] In this embodiment, the hot pressing temperature is 120°C, the hot pressing time is 5h to 8h, and the hot pressing pressure is 90MPa.

[0160] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 6 mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.45 mm. The thickness of the flexible heating film is 0.9 mm.

[0161] Example 16

[0162] This embodiment of an insulating encapsulation process for a flexible heating film includes the following steps: Opening a hole in the flexible heating film 1: as shown... Figure 5 As shown, several through holes 6 are formed on the flexible heating film 1. In this embodiment, the diameter of the through holes is 15 mm. In this embodiment, the several through holes 6 form an array of through holes. In this embodiment, the total area of ​​the several through holes 6 accounts for 30% of the area of ​​the flexible heating film before the holes are formed. Mineral particles, glass fibers, dispersants and adhesives are mixed to obtain an encapsulation slurry. The encapsulation slurry is coated on both surfaces of the flexible heating film 1 and then molded into an insulating encapsulation layer 3. Two slots 4 are formed on the insulating encapsulation layer 3 corresponding to the two electrodes on the surface of the flexible heating film 1 by laser to expose the electrodes. The wires 5 are electrically connected to the electrodes 2 at the slots 4 and the slots 4 are sealed to obtain an insulating electrothermal material, thus completing the insulating encapsulation of the flexible heating film. Figure 1and Figure 2 As shown, the surface of the flexible heating film 1 is printed or electroplated with two parallel electrodes 2 (one as the positive electrode and the other as the negative electrode). The electrodes 2 can be copper, silver, or aluminum. An insulating encapsulation layer 3 covers both sides of the flexible heating film 1. A slot 4 is laser-cut on the insulating encapsulation layer 3 at the position corresponding to the electrode 2. The surface-encapsulated insulating encapsulation layer is removed by laser, exposing the electrode 2 at the size of the slot 4. Two wires 5 are then welded to the two exposed positive and negative electrodes respectively for electrical connection. An insulating sealant (e.g., epoxy resin sealant) is then used to seal the connection. The wires 5 are copper wires with an insulating layer.

[0163] In this embodiment, the mineral particles are a combination of mica powder and calcium carbonate; the adhesive is an organosilicon resin adhesive; the particle size of the mineral particles is 100 μm; and the mass ratio of mineral particles to adhesive is 95:5.

[0164] In this embodiment, the diameter of the glass fiber is 13 μm; the amount of glass fiber accounts for 14% of the mass of the mineral particles.

[0165] In this embodiment, the amount of dispersant is 8% of the mass of the mineral particles; the dispersant is an aluminate coupling agent.

[0166] In this embodiment, the mineral particles, glass fiber, dispersant and adhesive are first dispersed at 360 rpm for 11 minutes using a high-speed mixer, and then mixed at 1700 rpm for 13 minutes.

[0167] In this embodiment, the molding temperature is 240°C, the molding time is 5 hours, and the molding pressure is 80 MPa.

[0168] In this embodiment, the insulating encapsulation layer is larger than the flexible heating film, and its perimeter extends 8mm beyond the edge of the flexible heating film. The thickness of the insulating encapsulation layer is 0.35mm. The thickness of the flexible heating film is 0.5mm.

[0169] Example 17

[0170] This embodiment describes an insulating encapsulation process for a flexible heating film. The difference between this embodiment and Embodiment 13 is that in this embodiment, the total area of ​​the plurality of through holes 6 accounts for 10% of the area of ​​the flexible heating film before the holes are opened. The remaining process methods in this embodiment are the same as those in Embodiment 13.

[0171] Example 18

[0172] This embodiment describes an insulating encapsulation process for a flexible heating film. The difference between this embodiment and Embodiment 13 is that in this embodiment, the total area of ​​the plurality of through holes 6 accounts for 60% of the area of ​​the flexible heating film before the holes are opened. The remaining process methods in this embodiment are the same as those in Embodiment 13.

[0173] Example 19

[0174] This embodiment of the flexible heating film insulation encapsulation process involves sealing the edges of the insulating heating material obtained in Example 3 with metal strips to further improve the rigidity of the insulating heating material. Specifically, the metal strips are sealed at the edges of the insulating heating material using a pressing machine. For example... Figure 7 As shown, the metal strip 8 is configured as a V-shaped metal strip. The V-shaped metal strip 8 includes a first side 81 and a second side 82. The first side 81 and the second side 82 together form a V-shaped structure. Three V-shaped notches 83 are provided on the first side 81. The opening of the V-shaped notches 3 faces outward and extends from one side of the first side 81 to the opposite side of the first side 81.

[0175] Among them, the V-shaped metal strip 8 is convenient to use a pressing machine to directly cover and press the edges of the insulating electric heating material to complete the edge sealing operation; in addition, the metal strip 8 is a galvanized iron strip, which has the advantages of corrosion resistance, low cost and good processing performance.

[0176] In this embodiment, a silicone rubber cover 9 is directly adhered to the welding joint of the wire 5 using high-temperature resistant sealant to cover the welding point and achieve a sealed and aesthetically pleasing effect.

[0177] The structure of the sealed insulating electrothermal material obtained in this embodiment is as follows: Figure 8 As shown.

[0178] Example 20

[0179] This embodiment describes an insulating encapsulation process for a flexible heating film. The insulating heating materials prepared in Examples 1 to 18 are edge-sealed with metal strips around their perimeter, and two pieces of insulating heating material are encapsulated and connected together through this edge-sealing process. Figure 9 As shown, the fixed angle between the two insulating heating materials connected together by sealing with metal strips is 120 degrees.

[0180] Example 21

[0181] An insulating electrothermal material of this embodiment is prepared by an insulating encapsulation process of any one of the flexible heating films in Examples 1 to 20.

[0182] Example 22

[0183] This embodiment describes the application of an insulating electrothermal material in a heater, while Embodiment 21 describes an insulating electrothermal material used as the electrothermal material in a heater. The heater includes a space heater, electric heater, oven, baking equipment, incubator, electric water heater, temperature control equipment, industrial heating equipment, or industrial insulation equipment.

[0184] Experimental Test

[0185] The elastic modulus of the insulating electrothermal materials prepared in Examples 1, 2, 5, 6, 8, 9, and 10-13 was tested to measure their stiffness performance. A higher elastic modulus indicates higher stiffness. The test results of the elastic modulus of the above examples are shown in Table 1 below.

[0186] Table 1. Elastic modulus of the insulating electrothermal materials prepared in Examples 1, 2, 5, 6, 8, 9, 10-13

[0187] Example Example 1 Example 2 Example 5 Example 6 Example 8 Elastic modulus / GPa 5GPa 5.5GPa 7GPa 9GPa 8GPa Example Example 9 Example 10 Example 11 Example 12 Example 13 Elastic modulus / GPa 10GPa 3GPa 20GPa 17GPa 8GPa

[0188] As shown in Table 1, the greater the thickness of the insulating encapsulation layer, the greater the elastic modulus of the insulating heating material, and thus the higher its stiffness. Insulating heating materials with glass fibers added to the encapsulation slurry to form the insulating encapsulation layer have a greater elastic modulus than those without glass fibers. This is because glass fibers have high strength and rigidity, effectively improving the material's bending strength and deformation resistance, thereby increasing its stiffness. Furthermore, insulating heating materials with several through-holes in the flexible heating film have a greater elastic modulus than those without. This is because the insulating encapsulation layers on both sides of the flexible heating film can be bonded together through the through-holes. The adhesion between insulating encapsulation layers is stronger than the adhesion between the insulating encapsulation layer and the flexible heating film, thus increasing the elastic modulus and consequently improving the stiffness of the insulating heating material.

[0189] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An insulating encapsulation process for a flexible heating film, characterized in that, Includes the following steps: Mineral particles are mixed with adhesives to obtain an encapsulation paste; The encapsulation slurry is coated and dried on a steel strip, then peeled off to form an insulating encapsulation film. At least one sheet of the insulating encapsulation film is then applied to the two surfaces of the flexible heating film using an adhesive and hot-pressed to form an insulating encapsulation layer. Alternatively, the encapsulation slurry is coated onto the two surfaces of the flexible heating film and directly hot-pressed to form an insulating encapsulation layer. Or, the encapsulation slurry is molded and cured on the two surfaces of the flexible heating film to form an insulating encapsulation layer, thus obtaining an insulating electrothermal material, which completes the insulating encapsulation of the flexible heating film.

2. The insulating encapsulation process for a flexible heating film as described in claim 1, characterized in that, After completing the hot pressing or molding steps, two slots are opened by laser at the two electrodes corresponding to the surface of the flexible heating film to expose the electrodes. The wires are electrically connected to the electrodes at the slots, and the slots are sealed to obtain the insulating electrothermal material.

3. The insulating encapsulation process for a flexible heating film as described in claim 1, characterized in that, The encapsulation slurry also incorporates glass fibers; that is, the encapsulation slurry is obtained by mixing mineral particles, glass fibers, and adhesives; and / or The glass fibers have a diameter of 5 μm to 15 μm; and / or The amount of glass fiber used accounts for 8% to 15% of the mass of the mineral particles.

4. The insulating encapsulation process for a flexible heating film as described in claim 1 or 3, characterized in that, The encapsulation slurry also contains a dispersant, the amount of which is 3% to 10% of the mass of the mineral particles; and / or The dispersant is one or a combination of two or more of the following: silane coupling agent, titanate coupling agent, aluminate coupling agent, or stearic acid.

5. The insulating encapsulation process for a flexible heating film as described in claim 1, characterized in that, Welding holes for electrical connection are pre-drilled at the two electrodes on the surface of the insulating encapsulation film corresponding to the flexible heating film.

6. The insulating encapsulation process for a flexible heating film as described in claim 1, characterized in that, It also includes perforating the flexible heating film: creating several through holes in the flexible heating film; and / or The plurality of through holes form a honeycomb-shaped through hole or an array of through holes; and / or The diameter of the through hole is 3mm to 15mm; and / or The total area of ​​the plurality of through holes accounts for 10% to 60% of the area of ​​the flexible heating film before the holes are opened; and / or After the flexible heating film is perforated, the encapsulation paste is then formed into an insulating encapsulation layer on both sides of the flexible heating film.

7. The insulating encapsulation process for a flexible heating film as described in claim 1, characterized in that, The mineral particles are one or more of mica powder, calcium carbonate, or gypsum powder; and / or The mineral particles have a particle size of 1 μm to 150 μm; and / or The mass ratio of the mineral particles to the adhesive is (90–97):(3–10); and / or The adhesive is a silicone resin adhesive; and / or The mineral particles and adhesive are first dispersed in a high-speed mixer at a speed of 300 rpm to 500 rpm for 5 min to 15 min, and then mixed at a speed of 1500 rpm to 2000 rpm for 10 min to 20 min; and / or The hot pressing or molding temperature is 100℃~260℃, the hot pressing or molding time is 0.5h~8h, and the hot pressing or molding pressure is 50MPa~100MPa; and / or The insulating encapsulation layer is larger than the flexible heating film, and the perimeter of the insulating encapsulation layer extends 3mm to 10mm beyond the edge of the flexible heating film; and / or The thickness of the insulating encapsulation layer is 0.05mm to 1mm.

8. The insulating encapsulation process for a flexible heating film as described in claim 1, characterized in that, It also includes sealing the outer periphery of the insulating heating material with metal strips; and / or The metal strip is configured as a V-shaped metal strip, and one side of the V-shaped metal strip has a plurality of V-shaped notches; and / or The metal strip is a galvanized iron strip; and / or Metal strips are used to seal the outer edges of two or more insulating heating materials and to encapsulate and connect the two or more insulating heating materials together, so that a fixed angle is formed between adjacent insulating heating materials.

9. An insulating electrothermal material, characterized in that, It is prepared by the insulating encapsulation process of a flexible heating film as described in any one of claims 1 to 8.

10. The application of an insulating electrothermal material in a heater, characterized in that, An insulating electrothermal material as described in claim 9 or an insulating electrothermal material obtained by an insulating encapsulation process of a flexible heating film as described in any one of claims 1 to 8, used as the electrothermal material of a heater; and / or The heater includes heaters, electric heaters, ovens, baking equipment, incubation equipment, electric water heaters, temperature control equipment, industrial heating equipment, or industrial insulation equipment.

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