A manufacturing method for a special-shaped surface heating element

Abstract

The present invention discloses a manufacturing method for a special-shaped surface heating element, which relates to the technical field of electric heating. It includes an upper insulating base layer, a lower insulating base layer and a core. The core is fixed in the middle sandwich layer of the upper insulating base layer and the lower insulating base layer; the core includes a heating circuit; the upper insulating base layer and the lower insulating base layer are made of high-temperature resistant rubber, high-temperature resistant resin materials, and high-temperature resistant thermoplastic engineering plastics. The beneficial effect of the present invention is that: for the manufacturing method of this special-shaped surface heating element, the special-shaped curved surface heating element that cannot be flattened is divided into multiple small heating blocks similar to a plane, and then these blocks are spliced into a curved surface shape on a mold. Through pressurizing and heating the mold, and utilizing the calendering and welding properties of high-temperature resistant resin and high-temperature thermoplastic polymer materials, a complete special-shaped curved surface heating element is finally manufactured, so as to better conduct close heating on the surface of the special-shaped curved surface by using this heating element.

Description

Technical Field

[0001] The present invention relates to the technical field of electric heating, and particularly to a manufacturing method for a heating element with a special-shaped surface. Background Art

[0002] In surface heating applications, heating of some special-shaped and complex surfaces is often encountered. How to make the heating element closely adhere to the surface to be heated is often a difficult point. For example, when repairing some special-shaped composite material surfaces (such as the surfaces of some aircraft with composite skins), it is often necessary to perform surface heating on the resin at the repair site to achieve rapid curing of the resin. For some curved surfaces, such as pipelines, their surface can be flattened, and the heating element can be made into the shape of its flattened surface to achieve heating while closely adhering to its surface. However, for some curved surfaces that cannot be flattened, such as the heating of spherical surfaces, new process means must be found to achieve this. For this reason, we have proposed a manufacturing method for a heating element with a special-shaped surface. In addition, for heating elements of rubber-like curved surfaces, due to their good ductility, the method of vacuum adsorption can be used to adapt to the surface heating of more special-shaped curved surfaces. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a manufacturing method for a heating element with a special-shaped surface, which solves the problems raised in the above background art.

[0004] To achieve the above objectives, the present invention is realized through the following technical solutions: A heating element with a special-shaped surface includes an upper insulating base layer, a lower insulating base layer, and a core. The core is fixed in the middle sandwich layer between the upper insulating base layer and the lower insulating base layer;

[0005] The core includes a heating circuit;

[0006] The upper insulating base layer and the lower insulating base layer are made of high-temperature resistant rubber, high-temperature resistant resin materials, and high-temperature resistant thermoplastic engineering plastics.

[0007] Further in the present invention, the heating circuit is an electric wire heating circuit.

[0008] Further in the present invention, the heating circuit is an etched heating circuit.

[0009] Further in the present invention, the heating circuit is a laser engraving heating circuit.

[0010] Further in the present invention, the upper insulating base layer and the lower insulating base layer can be made of high-temperature resistant rubber, and the above high-temperature resistant rubber is silicone rubber and fluororubber.

[0011] Further in the present invention, the upper insulating base layer and the lower insulating base layer can also adopt high-temperature resistant resin materials and high-temperature resistant thermoplastic engineering plastics. The high-temperature resistant resin materials are epoxy resins and acrylic resins, and the high-temperature resistant thermoplastic engineering plastics are FEP perfluoroethylenepropylene, thermoplastic polyimide, and thermoplastic polyester (PET).

[0012] A manufacturing method of a special-shaped surface heating element includes the following steps:

[0013] S1. Divide the insulating base material of the heated curved surface so that each piece can be approximately unfolded into a plane;

[0014] S2. Adopt the template cold pressing method to fix the heating wire on the cut sheet-shaped high-temperature resistant rubber insulating base material, and temporarily fix the heating circuit on one side of the bottom high-temperature resistant rubber insulating base material; or adopt the template hot pressing method to fix the etched heating circuit or the laser engraved heating circuit on the sheet-shaped high-temperature resistant insulating base material, and fix the heating circuit on one side of the bottom high-temperature resistant rubber insulating base material;

[0015] S3. Cast a pair of male and female molds with the same curved surface shape as above using metal aluminum or cast iron according to the shape of the heated curved surface;

[0016] S4. Electric heating tubes and temperature sensors can be arranged inside the female mold or the male mold;

[0017] S5. Arrange the sheet-shaped insulating base material with the heating circuit arranged on the surface of the male mold in an approximate curved surface shape in sequence, cover the surface layer insulating base material, then press the upper female mold and fix it;

[0018] S6. Pressurize and heat the whole mold;

[0019] S7. Cool the heated mold.

[0020] Further in the present invention, in S2, one of the three heating circuits can be hot-pressed between the upper and lower sheet-shaped insulating base materials to complete the installation of the heating circuit; the above three heating circuits are respectively: the heating wire heating circuit, the etched heating circuit, and the laser engraved heating circuit.

[0021] Further in the present invention, in S6, the heating degree is to heat to the softening starting temperature, curing temperature or vulcanization temperature of the sheet-shaped insulating base material and keep it for 5 - 20 minutes.

[0022] Further in the present invention, in S5, the female mold and the male mold can be pressurized and fixed by using clamps and screws. The whole mold can also be directly pressurized by a press.

[0023] The present invention provides a manufacturing method of a special-shaped surface heating element, which has the following beneficial effects:

[0024] The manufacturing method of the special-shaped surface heating element divides the special-shaped curved surface heating element that cannot be flattened into multiple small heating blocks similar to a plane, and then splices these blocks into a curved surface shape on a mold. Through mold pressing and heating, using the calendering and welding properties of high-temperature resistant resin and high-temperature thermoplastic polymer materials, a complete special-shaped curved surface heating element is finally manufactured, thus making it more convenient to manufacture the heating element for the special-shaped surface. Brief Description of the Drawings

[0025] Figure 1 It is a schematic flow chart of the manufacturing method in the present invention;

[0026] Figure 2 It is the arrangement mode of the heating wire heating circuit in the present invention;

[0027] Figure 3 It is the arrangement mode of the etched heating circuit in the present invention. Detailed Embodiments

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0029] Refer to Figures 1-3 , the present invention provides a technical solution:

[0030] Embodiment 1: Hemispherical silicone rubber flexible heating element

[0031] Raw materials: semi-vulcanized silicone rubber sheet with a thickness of about 1 mm (this sheet can be reinforced by glass fiber); heating wire with a diameter of about 1 mm, which is composed of 2080 heating wires spirally wound on a glass fiber core bundle.

[0032] Manufacturing process: 1. According to the shape and size of the 3D three-dimensional curved surface silicone rubber heating element, cast the required male and female molds with aluminum. And pre-bury heating pipes in the molds for heating the molds.

[0033] 2. According to the shape and size of the 3D three-dimensional curved surface, use the sheet metal unfolding method to approximately divide the 3D three-dimensional curved surface into several pieces. In this example, the hemispherical silicone rubber heating element is divided into 8 pieces, and each piece has the same "blade" shape.

[0034] 3. Then, according to the applied voltage and required power, design the heating circuit and determine the series and parallel relationships between the 8 silicone rubber heating divided elements.

[0035] 4. Use a template or a manipulator to press and attach the heating wire onto the semi-vulcanized silicone rubber flexible sheet. Then cover it with another semi-vulcanized silicone rubber flexible sheet of the same shape.

[0036] 5. Apply a release agent on the male and female cast aluminum molds. In this example, silicone oil is used as the release agent.

[0037] 6. Arrange 8 silicone rubber heating dividing elements in sequence on the male cast aluminum mold. If the gap between the elements is too large, it can be appropriately filled with uncured silicone rubber clay.

[0038] 7. Close the female mold, add a fixture, and heat it to the vulcanization temperature of silicone rubber, which is 150 - 200 degrees, and maintain it at this temperature for 10 - 20 minutes. Then disconnect the heating power supply, and after cooling, take out the silicone rubber heating element.

[0039] 8. Connect the 8 pairs of leads corresponding to the 8 silicone rubber flexible sheets in series and parallel according to the design, and seal the lead connection points with silicone rubber to obtain the finished hemispherical silicone rubber flexible heating element.

[0040] Example 2: Hemispherical epoxy resin heating element

[0041] Raw materials: 1. Uncured epoxy resin sheet (this sheet can also be reinforced with glass fiber); 2. 304 stainless steel foil.

[0042] Manufacturing process: 1. According to the shape and size of the 3D curved surface epoxy resin heating element, cast the required male and female molds with aluminum, and etch the heating circuit in the mold for heating the mold.

[0043] 2. According to the shape and size of the 3D curved surface, approximately divide the 3D curved surface into several pieces by means of sheet metal unfolding. In this example, the hemispherical epoxy resin heating element is divided into 8 pieces, and each piece has the same "blade" shape.

[0044] 3. Then, design the heating circuit according to the applied voltage and required power, and determine the series and parallel relationship between the 8 epoxy resin heating dividing elements.

[0045] 4. According to the heating circuit designed on the computer, cut the 304 stainless steel foil by laser or etch it into a heating circuit. Then cover it with another uncured epoxy resin sheet of the same shape.

[0046] 5. Apply a release agent on the male and female cast aluminum molds. In this example, silicone oil is used as the release agent.

[0047] 6. Arrange 8 uncured epoxy resin flexible sheets with electric heating wires attached thereto in sequence on the male cast aluminum mold. If the gap between sheets is too large, it can be appropriately filled with uncured epoxy resin.

[0048] 7. Close the female mold, add the fixture, and heat it to the curing temperature of the epoxy resin, which is 180 - 200 degrees, and maintain it at this temperature for about 60 minutes. Then disconnect the heating power supply, and after cooling, take out the epoxy resin heating element.

[0049] 8. Connect the 8 pairs of leads corresponding to the 8 epoxy resin sheets in series and parallel according to the design, and seal the lead connection points with epoxy resin to obtain the finished hemispherical epoxy resin heating element.

[0050] In summary, for the manufacturing method of the special-shaped surface heating element, during use, according to the shape of the surface to be heated, a pair of female and male molds with the same surface shape as described above are cast using metal aluminum or cast iron. An electric heating tube and a temperature sensor can be arranged inside the female mold or the male mold.

[0051] Arrange the sheet-shaped insulating substrate with the heating circuit arranged thereon in sequence on the surface of the male mold to form an approximate surface shape, then press the female mold on it, and fix it with a fixture or bolt pressure, or place it on a hot press for pressure, or put it in an oven after adding a fixture. Next, heat the whole mold to the softening starting temperature, curing temperature or vulcanization temperature of the sheet-shaped insulating substrate, and maintain it for 5 - 20 minutes. Then, cut off the power and cool it. Finally, open the mold to obtain the finished special-shaped surface heating element.

[0052] The special-shaped curved surface heating element is manufactured in blocks mainly to prevent the heating circuit from shifting significantly during the hot pressing process, which seriously affects the heating uniformity of the special-shaped surface heating element. The block-manufactured planar heating elements are rolled and welded, or vulcanized, or cured with each other in the mold under the conditions of heating and pressure, and finally form an integrated 3D three-dimensional shaped special-shaped curved surface heating element.

[0053] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A manufacturing method of a special-shaped surface heating element, including a heating element, Characterized in that: The heating element includes an upper insulating base layer, a lower insulating base layer and a core, and the core is fixed in the middle sandwich layer between the upper insulating base layer and the lower insulating base layer; The core includes a heating circuit; The upper insulating base layer and the lower insulating base layer are made of high-temperature resistant rubber, high-temperature resistant resin material, and high-temperature resistant thermoplastic engineering plastic; The manufacturing method of the special-shaped surface heating element includes the following steps: S1. Divide the insulating base material of the heated curved surface so that each piece can be flattened; S2. Adopt the template cold pressing method to temporarily fix the heating circuit on one side of the bottom high-temperature resistant rubber insulating base material; or adopt the template hot pressing method to fix the etched heating circuit or the laser engraved heating circuit on one side of the bottom high-temperature resistant rubber insulating base material; S3. According to the shape of the heated curved surface, cast a pair of male and female molds with the same curved surface shape as above with aluminum or cast iron; S4. An electric heating tube and a temperature sensor are arranged inside one of the female mold or the male mold; S5. Arrange the sheet-shaped insulating base material with the heating circuit arranged on the surface of the male mold in an approximate curved surface shape in sequence, cover the top insulating base material, then press the upper female mold and fix it; S6. Pressurize and heat the whole mold, and the heating degree in S6 is to heat to the softening starting temperature, curing temperature or vulcanization temperature of the sheet-shaped insulating base material and keep it for 5-20 minutes; S7. Cool the heated mold.

2. The manufacturing method of a special-shaped surface heating element according to claim 1, Characterized in that: The heating circuit is an electric heating wire heating circuit.

3. The manufacturing method of a special-shaped surface heating element according to claim 1, Characterized in that: The heating circuit is an etched heating circuit.

4. The manufacturing method of a special-shaped surface heating element according to claim 1, Characterized in that: The heating circuit is a laser engraved heating circuit.

5. The manufacturing method of a special-shaped surface heating element according to claim 1, Characterized in that: The upper insulating base layer and the lower insulating base layer are made of high-temperature resistant rubber, and the high-temperature resistant rubber is silicone rubber and fluororubber.

6. The manufacturing method of a special-shaped surface heating element according to claim 1, Characterized in that: The upper insulating base layer and the lower insulating base layer adopt high-temperature resistant resin materials and high-temperature resistant thermoplastic engineering plastics. The high-temperature resistant resin materials are epoxy resin and acrylic resin, and the high-temperature resistant thermoplastic engineering plastics are FEP perfluoroethylene-propylene, thermoplastic polyimide, and thermoplastic polyester (PET).

7. The manufacturing method of a special-shaped surface heating element according to claim 1, Characterized in that: In S2, one of the three heating circuits is hot-pressed between the upper and lower sheet-shaped insulating base materials to complete the installation of the heating circuit; the above three heating circuits are: an electric heating wire heating circuit, an etched heating circuit, and a laser engraved heating circuit.

8. The manufacturing method of a special-shaped surface heating element according to claim 1, Characterized in that: In S5, the female mold and the male mold are fixed under pressure by using jigs and screws, or the whole mold is directly pressed by a press.

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