A method for manufacturing a patterned groove on the surface of a ceramic insulator and a ceramic insulator

Abstract

The present application relates to a kind of methods for manufacturing patterned groove on the surface of ceramic insulator and ceramic insulator, wherein the method of the present application is by using prefabricated flexible mold to emboss in the wet body forming stage of ceramic insulator, and the patterned groove is integrally formed on the surface of green body, so as to avoid mechanical processing on the brittle porcelain body and glaze layer after sintering, the method realizes the stable manufacturing of patterned groove under the premise of not damaging the continuity of glaze layer and the integrity of matrix, and can be highly compatible with subsequent glazing, sintering process, ensure the overall performance and service life of insulator. At the same time, the method has good replicability and large-scale application potential, can provide solid process support for the popularization of embedded RTV coating structure in actual power grid. The present application provides a new way for the engineering application of embedded coating structure on ceramic insulator.

Description

Technical Field

[0001] This invention relates to the field of ceramic insulator manufacturing, and in particular to a method for manufacturing patterned grooves on the surface of a ceramic insulator and a ceramic insulator thereof. Background Technology

[0002] Room temperature vulcanized silicone rubber (RTV) anti-flashover coatings are widely used in power systems, but they commonly detach during operation. Once the RTV coating detaches, the hydrophilic substrate is directly exposed, leading to loss of hydrophobicity, a significant drop in flashover voltage, and a high risk of flashover accidents. To ensure safe line operation, power grid companies typically have to reapply the RTV coating every 3-5 years, affecting the reliability and widespread application of anti-flashover technology. To delay coating detachment, existing technologies have proposed embedded RTV coating structures from the perspective of "increasing the bonding area and improving adhesion." The basic idea of ​​this structure is to process grooves with specific patterns on the surface of the insulator substrate and fill them with the RTV coating to form an integrated embedded RTV coating structure. Compared with traditional planar coating, the embedded structure effectively increases the bonding area between the coating and the substrate, thereby improving the coating's peel resistance and durability. Current research mainly focuses on experimental verification of flat glass or epoxy resin samples, initially demonstrating the feasibility and advantages of the embedded structure in external insulation applications.

[0003] However, when the aforementioned embedded RTV coating structure is applied to ceramic insulators, the following problems arise. Specifically, existing methods typically involve etching grooves onto the surface of the ceramic insulator using mechanical processing. However, ceramics are typically brittle materials, significantly different from flat glass or epoxy materials. Therefore, this mechanical processing method can cause cracks or micro-defects in the ceramic insulator during the fabrication of patterned grooves, leading to a sharp decrease in strength. Furthermore, the surface of ceramic insulators is usually covered with a glaze. This glaze layer introduces pre-stress into the ceramic surface, thereby improving the overall mechanical strength of the insulator. It also covers micro-cracks in the ceramic insulator, preventing moisture from seeping into the substrate along crack channels. If grooves are etched onto the surface of the ceramic insulator using mechanical processing, the continuity of the glaze layer will inevitably be disrupted, causing "fatal damage." This weakens the mechanical strength of the ceramic insulator and destroys its waterproof barrier, significantly reducing the insulator's service life and mechanical stability.

[0004] Therefore, when preparing patterned grooves on the surface of ceramic insulators, how to avoid cracks or micro-defects while maintaining the continuity of the glaze layer structure has become a technical problem that needs to be solved in the existing technology.

[0005] It should be noted that the information disclosed in the background section above is only for understanding the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] This application provides a method for manufacturing patterned grooves on the surface of a ceramic insulator and a ceramic insulator in general, in order to solve the technical problem of "how to maintain the structural integrity and long service life of a ceramic insulator while preparing patterned grooves on its surface".

[0007] The technical solution adopted in this application to solve the above-mentioned technical problems is as follows.

[0008] The first aspect of this application provides a method for manufacturing patterned grooves on the surface of a ceramic insulator, comprising the following steps: An embossing mold is provided, wherein a raised structure is provided on the embossing surface; Provide a wet ceramic insulator blank, and cover the target surface of the wet blank with the imprinting surface of the imprinting die; Pressure is applied to the embossing die to press the raised structure into the target surface of the wet blank to form a patterned groove; Remove the stamping mold, and then dry, glaze, and sinter the wet blank to form a ceramic insulator with patterned grooves on the surface.

[0009] In some embodiments, the embossing die is made of a flexible material.

[0010] In some embodiments, the hardness of the flexible material is between 30 Shore A and 60 Shore A.

[0011] In some embodiments, the following steps are also included: During the manufacturing process of the embossing mold, the radius of curvature of the embossing surface of the embossing mold is made smaller than the radius of curvature of the corresponding surface of the ceramic insulator.

[0012] In some embodiments, the following steps are also included: When designing the raised structure of the embossing mold, the size of the raised structure is set based on the volume shrinkage rate of the wet blank during the sintering process, the glaze thickness, and the target size of the patterned groove.

[0013] In some embodiments, the corners of the protruding structure are rounded.

[0014] In some embodiments, the embossing mold is manufactured using a vacuum casting process, and the manufacturing of the embossing mold includes the following steps: A master template is provided, which has a graphic structure corresponding to the imprinting surface of the embossing die; In a vacuum environment, liquid flexible material is poured onto the master plate; After the flexible material has cured, it is demolded from the master mold to obtain the embossing mold.

[0015] A second aspect of this application provides a ceramic insulator whose surface includes patterned grooves manufactured by the method described in the first aspect.

[0016] A third aspect of this application provides an embedded coated insulator system, including the ceramic insulator described in the second aspect, and an anti-flashover coating coated in a patterned groove.

[0017] The fourth aspect of this application provides an embossing apparatus for performing the method described in the first aspect for creating patterned grooves on the surface of a ceramic insulator.

[0018] The present invention has the following beneficial effects: The first aspect of this invention provides a method for manufacturing patterned grooves on the surface of a ceramic insulator, which involves pressing the ceramic blank using an impression die during the wet blank stage. Due to the plasticity of the wet blank, applying pressure to the impression die allows the raised structure to be pressed into the target surface of the wet blank, forming a patterned groove. This avoids the "hard damage" problems such as stress concentration and crack initiation caused by traditional machining on brittle ceramic materials, thereby fundamentally ensuring the structural integrity and mechanical properties of the insulator matrix, effectively preventing cracks and micro-defects in the ceramic matrix, and guaranteeing the mechanical strength and long-term reliability of the insulator.

[0019] Furthermore, this application involves glazing and sintering after the patterned grooves are formed. The subsequent glazing and sintering processes ensure that the glaze evenly covers the entire insulator surface, including the patterned grooves, ultimately forming a continuous, complete, and mechanically undamaged glaze layer. This glaze layer effectively introduces pre-stress, covers microscopic defects, and blocks moisture penetration channels, fully preserving the continuity of the glaze structure. It fully leverages the reinforcing and protective functions of the glaze layer, solving the problems of strength reduction and waterproofing failure caused by direct damage to the continuity of the finished glaze layer during machining.

[0020] Furthermore, because the imprinting mold of this application is made of a flexible material, it can uniformly transmit pressure and adapt to curved shapes, improving the fit between the mold and the ceramic insulator. In addition, this application has precisely compensated and optimized the curvature, size, and structural details of the imprinting mold, ensuring that the final sintered groove size and shape meet the design requirements, with clear groove shape, smooth edges, and no stress concentration points. This provides a large bonding area and mechanical interlocking structure for subsequent filling of anti-flashover coatings such as RTV, significantly enhancing the adhesion and peel resistance of the coating. Through the above design, this application achieves high-precision, high-fidelity patterned groove preparation while also providing an excellent adhesion foundation for embedded coatings.

[0021] In summary, this application provides a highly reliable and long-life method for manufacturing patterned groove ceramic insulators. By using a pre-fabricated flexible mold to imprint patterned grooves onto the surface of the ceramic insulator during the wet blank forming stage, patterned grooves are integrally formed, thus avoiding mechanical processing of the brittle ceramic body and glaze layer after sintering. This method achieves stable manufacturing of patterned grooves without compromising the continuity of the glaze layer and the integrity of the substrate, and is highly compatible with subsequent glazing and sintering processes, ensuring the overall performance and service life of the insulator. Furthermore, this method possesses good reproducibility and scalable application potential, providing solid technological support for the promotion of embedded RTV coating structures in actual power grids. It offers a novel approach for the engineering application of embedded coating structures in ceramic insulators.

[0022] Other beneficial effects of the present invention will be further described below. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart of the method steps of the present invention; Figure 2 Engineering drawings for embossing molds; Figure 3 Rendering of the embossing mold; Figure 4 This is a cross-sectional view of the vacuum-coated film. Figure 5 for Figure 4 A magnified view of the area corresponding to the marked box. Detailed Implementation

[0024] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0027] This application provides a method for manufacturing patterned grooves on the surface of ceramic insulators. This method uses a silicone rubber film for imprinting during the wet blank forming stage of the ceramic insulator to prepare the target patterned groove structure, thereby effectively avoiding the problems of reduced mechanical strength and glaze damage that exist in traditional machining.

[0028] like Figure 1 Specifically, it includes the following steps: S1. An impression mold is provided, wherein the impression mold has a raised structure on the impression surface; S2. Provide a wet ceramic insulator blank and cover the target surface of the wet blank with the imprinting surface of the imprinting mold; S3. Apply pressure to the embossing die to press the raised structure into the target surface of the wet blank to form a patterned groove. S4. Remove the stamping mold, and perform drying, glazing and sintering operations on the wet blank to form a ceramic insulator with patterned grooves on the surface.

[0029] In some embodiments, the embossing mold is made of a flexible material, such as silicone. Optionally, the hardness of the flexible material is between 30 Shore A and 60 Shore A.

[0030] like Figures 2 to 5 As shown, in some embodiments, the preparation of the embossing mold in step S1 includes the following steps: Step 1: Parametric modeling of the embossing mold (silicone film) Using a ceramic insulator with a rated mechanical load of 550 kN as the fabrication carrier, the goal is to form patterned grooves suitable for embedded RTV coating structures in the shed area. Based on the insulator's geometry, the radius of curvature of the green shed is 500 mm. Considering that the silicone film may undergo slight plastic deformation during long-term flat storage or folding, leading to poor adhesion with the shed bonding surface, the radius of curvature of the inner curved surface of the silicone film is set to 497 mm in the design to compensate for deformation errors and ensure adhesion during the imprinting process.

[0031] A patterned raised structure is designed on the inner curved surface of the silicone film. Taking a grid-like interconnected structure as an example, the geometric unit is a 15 mm × 15 mm square with a geometric center spacing of 18 mm, meaning the width of the raised strip is 3 mm. Considering the volume shrinkage rate of the ceramic body during sintering (approximately 4%–5%) and the glaze thickness (approximately 0.2–0.3 mm), the estimated width of the groove formed after sintering is approximately 2.82–2.86 mm. Therefore, in the design of the silicone film, the raised width needs to be calculated backward from the target size.

[0032] Given that ceramics are typically brittle materials, sharp angles can easily cause stress concentration and lead to microcracks. Therefore, all corners must be rounded during soft mold modeling. The chamfer curvature is selected based on the protrusion width. In this embodiment, the chamfer radius is set to 1.3 mm to ensure uniform stress distribution during subsequent imprinting.

[0033] Step 2: Manufacturing of silicone soft molds based on vacuum molding process After modeling, a silicone soft film is prepared using a vacuum molding process. First, a photopolymer 3D printing technique (0.05 mm resolution) is used to print a photosensitive epoxy resin master. The master surface is then treated with slagging and precision polishing, with the surface roughness controlled to (arithmetic mean deviation Ra) ≤ 0.5 μm to ensure replication accuracy.

[0034] Subsequently, the master mold is fixed in a vacuum chamber measuring 600 mm × 600 mm × 160 mm, and a vacuum is drawn to -0.095 MPa at 60±2 ℃. A transparent silicone rubber mixture with a ratio of A component to B component = 1:1 is injected into the chamber for vacuum lamination. The mold is parted along the central axis of the soft film, and a complete silicone soft film mold is obtained after demolding. In some embodiments, the main components of component A (base adhesive) are methylsiloxane, methyl silicone oil, and silica. The main components of component B (curing agent) are organotin compounds such as tetraethyl orthosilicate and dibutyltin dilaurate.

[0035] During the film-forming stage, transparent silicone rubber is injected through the injection port, with the hardness controlled at 40 Shore A. After the soft film cures, it is cured in a constant temperature oven for 4 hours (60 ℃) and then naturally cooled to room temperature. The surface is then treated with a release agent before use.

[0036] Understandably, a Shore A hardness of 40 ensures that the soft film can fully conform to the curved surface of the umbrella skirt, while its sufficient elasticity helps to demold after imprinting without damaging the surface of the wet blank, ensuring flexibility while improving the molding quality of the imprinted structure. In addition, the silicone soft film with a Shore A hardness of 40 is easy for users to fold and carry.

[0037] In some embodiments, applying pressure to the embossing die to press the raised structure into the target surface of the wet blank to form a patterned groove further includes the following steps: After the ceramic insulator is pressed into a rough wet blank and manually trimmed, it enters the patterned groove imprinting process. The prepared silicone film is positioned along the insulator's central axis and covered on the surface of the upper shed, ensuring alignment and eliminating air bubbles. A lightweight wooden or rubber mallet is used to evenly tap the surface of the film, fully pressing the raised structure into the wet blank surface. The tapping torque is controlled within the range of 1.0–1.5 N·m to prevent localized collapse or indentation of the shed. After imprinting, the edges of the shed and the area sealed with the steel cap are inspected to ensure there are no cracks, defects, or structural deformation.

[0038] In some embodiments, removing the impression mold and performing drying, glazing, and sintering operations on the wet blank to form a ceramic insulator with patterned grooves on the surface further includes the following steps: The green blanks, after being dried and pressed in the factory environment, are naturally dried at room temperature (25 ℃) for 48 hours, ensuring a moisture content below 1% to obtain the dried blank. Next comes the glazing process: the dried blank is mounted on a rotary glazing machine and immersed evenly in the glaze slurry at a speed of 5–8 rpm for 8–10 seconds. After removal, it is allowed to drip dry naturally, and the fidelity of the patterned grooves and the amount of glaze residue are checked.

[0039] After drying, the glazed blanks were placed in a kiln for sintering. After sintering, the surface smoothness and groove size of the sample were checked. The actual measured groove width was about 2.845±0.12 mm, which was consistent with the design value. The surface glaze layer was continuous and intact, without cracks, glaze peeling or collapse.

[0040] Another embodiment of this application also provides a ceramic insulator, the surface of which includes patterned grooves manufactured by the method of the present invention.

[0041] Another embodiment of this application also provides an embedded coated insulator system, including the ceramic insulator of the present invention and an anti-flashover coating coated in a patterned groove.

[0042] Another embodiment of this application also provides an embossing apparatus for performing the method of the present invention for creating patterned grooves on the surface of a ceramic insulator.

[0043] In summary, the innovation of this invention lies in: (1) This invention is the first to propose a complete manufacturing method for silicone soft film from parametric modeling to vacuum molding, which realizes high-precision replication of the skirt area of ​​complex curved ceramic insulators. By systematically modeling and correcting key parameters such as curvature, shrinkage rate, and chamfer radius, the soft film can be accurately attached to the surface of the insulator in the subsequent wet blank imprinting stage, which significantly improves the structural forming accuracy and repeatability, and provides a new path for the manufacturing of microstructures on complex ceramic surfaces.

[0044] (2) This invention introduces silicone soft film imprinting technology into the ceramic wet blank stage for the first time, directly forming patterned groove structures while the blank still has plasticity, avoiding stress concentration and glaze damage caused by machining. This process can be carried out at room temperature, and the imprinting process is simple and controllable. It can obtain groove structures with clear morphology and smooth boundaries while ensuring the integrity of the blank, providing a low-loss and high-efficiency new process idea for the manufacturing of microstructures of ceramic insulators.

[0045] (3) The process route of this invention is fully compatible with the traditional ceramic insulator production process chain (press molding—drying—glazing—sintering), without the need for new expensive equipment or changes to the production process, and has excellent scalability and industrial application prospects. This method realizes the leap from laboratory sample preparation to mass production process, and provides a key manufacturing foundation for the engineering implementation of embedded RTV coating structure in actual power equipment.

[0046] The background section of this invention may include background information about the problems or environment in which the invention is being developed, and is not necessarily a description of prior art. Therefore, the content included in the background section does not constitute an admission of prior art by the applicant.

[0047] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A method for manufacturing patterned grooves on the surface of a ceramic insulator, characterized in that, Includes the following steps: An embossing mold is provided, wherein a raised structure is provided on the embossing surface; A wet ceramic insulator blank is provided, and the imprinting surface of the imprinting mold is covered on the corresponding surface of the wet blank; Pressure is applied to the embossing mold to press the raised structure into the corresponding surface of the wet blank to form a patterned groove; the pressure is applied by evenly tapping the surface of the embossing mold with a light wooden mallet or rubber mallet, and controlling the tapping torque within the range of 1.0–1.5 N·m to prevent the umbrella skirt of the wet blank from collapsing locally or forming indentations; Remove the embossing mold, and perform drying, glazing and sintering operations on the wet blank to form a ceramic insulator with patterned grooves on the surface; The embossing mold is made of a flexible material with a hardness of 30 Shore A to 60 Shore A, to ensure that the embossing mold can fully conform to the curved surface of the umbrella skirt of the ceramic insulator, so that the embossing mold can be demolded after embossing without damaging the surface of the wet blank, ensuring flexibility while improving the forming quality of the embossed structure, and also making it easy for users to fold the embossing mold for easy carrying. During manufacturing, the radius of curvature of the embossing surface of the embossing mold is made smaller than the radius of curvature of the corresponding surface of the ceramic insulator to compensate for deformation errors and ensure the fit during the embossing process. When designing the protruding structure of the embossing mold, the size of the protruding structure is determined by reverse calculation based on the volume shrinkage rate of the wet blank during sintering, the glaze thickness, and the target size of the patterned groove. The corners of the protruding structure are rounded, and the radius of the rounded corners is selected according to the width of the protruding structure to ensure that the final sintered patterned groove has a clear shape, smooth edges, and no stress concentration points, thus providing bonding area and mechanical interlocking structure for subsequent filling of embedded coating structure.

2. The method for manufacturing patterned grooves on the surface of a ceramic insulator according to claim 1, characterized in that, The embossing mold is manufactured using a vacuum casting process, and the manufacturing of the embossing mold includes the following steps: A master template is provided, the master template having a graphic structure corresponding to the imprinting surface of the imprinting mold; In a vacuum environment, the liquid flexible material is poured onto the master plate; After the flexible material has cured, it is demolded from the master mold to obtain the embossing mold.

3. A ceramic insulator, characterized in that, The surface of the ceramic insulator includes patterned grooves manufactured according to any one of claims 1-2.

4. An embedded coated insulator system, characterized in that, It includes the ceramic insulator as described in claim 3, and an anti-flashover coating applied to the patterned groove.

5. An embossing device, characterized in that, The embossing equipment is used to perform the method of creating patterned grooves on the surface of a ceramic insulator according to any one of claims 1-2.

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