A round head sand blasting compression enamel suspension type insulator and a preparation method thereof

Abstract

The application discloses a kind of round head sand blasting compression glaze suspension insulator and its preparation method in the technical field of insulator manufacturing, and the round head sand blasting compression glaze suspension insulator takes round head hollow umbrella skirt integrated blank as porcelain blank, first by round head compression glaze glazing, round head compression glaze surface sand blasting, umbrella skirt compression glaze glazing is obtained after sectional sintering porcelain piece, then cement reinforced adhesive is used to glue and dress iron cap, steel foot and porcelain round head, and then sealed treatment is carried out, and obtained after maintenance.The application optimizes the low-expansion formula of compression glaze, significantly improves the anti-cracking strength of the prepared insulator head, and has high interface bonding reliability.The cement reinforced adhesive formula is optimized to improve the sealing performance of the insulator, which is suitable for ultra-high voltage, high altitude and large temperature difference scenes, significantly reduces the risk of operation fracture, and has high practical value and popularization prospect.

Description

Technical Field

[0001] This invention relates to the field of insulator manufacturing technology, specifically to a round-headed sandblasted compressed glaze suspension insulator and its preparation method. Background Technology

[0002] Suspension insulators are core insulating components in power transmission lines, primarily used for electrical insulation and mechanical fixation between conductors and towers. Their performance directly affects the safe and stable operation of transmission lines. With the rapid development of the power industry, transmission lines are increasingly moving towards ultra-high voltage and long-distance transmission, leading to increasingly harsh operating environments for insulators. Environmental factors such as high altitude, large temperature differences, and strong ultraviolet radiation place higher demands on the electromechanical performance, crack resistance, and interface reliability of insulators.

[0003] Suspension porcelain insulators mainly consist of four parts: cement-reinforced adhesive, porcelain body and iron cap, and steel feet (metal accessories), with the porcelain body being the primary insulating component. Most existing suspension insulators use a common glaze structure, with the porcelain head and metal accessories bonded together using cement-reinforced adhesive. In practical applications, the following technical defects are prone to occur: the thermal expansion coefficients of the common glaze and the porcelain body are poorly matched, making the glaze prone to cracking under conditions of large temperature variations, leading to decreased insulation performance and even fracture failure; the interfacial bonding strength between the insulator head and the cement-reinforced adhesive is insufficient, especially under long-term vibration and temperature cycling conditions, easily resulting in interfacial peeling and sand particle shedding, severely affecting the insulator's mechanical load-bearing capacity; existing sintering processes mostly use a single heating mode, easily leading to insufficient or excessive sintering of the glaze, further reducing the bonding strength between the glaze and the porcelain body, while also resulting in poor sealing performance, allowing moisture to easily penetrate and corrode the metal accessories, shortening the insulator's service life.

[0004] To address the aforementioned technical deficiencies, existing technologies often improve insulator performance by adjusting glaze formulations, optimizing adhesive bonding processes, or sintering processes, but the effects are limited and cannot meet current application requirements. Therefore, developing a suspension insulator manufacturing method that can improve head crack resistance, interfacial bonding strength, and sealing reliability, and is suitable for harsh environments, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a round-headed sandblasted compressed glaze suspension insulator and its preparation method, so as to solve the technical problems mentioned in the background art.

[0006] The present invention achieves the above objectives through the following technical solutions: In a first aspect, the present invention provides a round-head sandblasted compression glaze suspension insulator, wherein the round-head sandblasted compression glaze suspension insulator uses a round-head hollow umbrella skirt integral blank as the ceramic blank, and first undergoes round-head compression glaze application, round-head compression glaze surface sandblasting, umbrella skirt compression glaze application, and then sintering in sections to obtain the ceramic blank, and then uses cement-reinforced adhesive to glue the iron cap and steel foot to the round head of the ceramic blank, and then undergoes sealing treatment and curing to obtain the final product; The compressed glaze, by weight percentage, includes 15-20% potassium feldspar, 8-10% quartz, 10-15% kaolin, 10-15% magnesium feldspar powder, 24-40% cordierite powder, 8-14% talc powder, 3-5% zinc oxide, and 1-5% barium carbonate.

[0007] As a further optimization of the present invention, the raw materials for preparing the round-headed hollow umbrella skirt integral blank include, by mass percentage, 25-30% kaolin, 35-42% low titanium bauxite, 15-20% feldspar, 10-15% clay and 4-8% magnesium carbonate.

[0008] As a further optimization of the present invention, the glaze-coated sand used for the round-head compressed glaze sandblasting is obtained by uniformly mixing porcelain sand, room temperature vulcanized silicone rubber, and glaze powder in a mass ratio of 200:13:60, aging for 24 hours, and then screening through a 15-mesh sieve.

[0009] As a further optimization of the present invention, the cement-reinforcing adhesive is prepared by using 42.5 grade ordinary Portland cement, quartz sand and water in a mass ratio of 1:2:0.4, and adding 0.4-0.6% aramid pulp composite reinforcing material to the adhesive and stirring evenly.

[0010] As a further optimization of the present invention, the aramid pulp composite reinforcing material is obtained by mixing 30% polypropylene, 54% 400-mesh wollastonite, 10% aramid pulp, 5% maleic anhydride-grafted PP, and 1% antioxidant in a mixer for 5 minutes by mass percentage, and then granulating by single-screw extrusion at a heating temperature of 220°C.

[0011] As a further optimization of the present invention, the aramid pulp composite reinforcing material is obtained by mixing 30% polypropylene, 54% 400-mesh wollastonite, 10% aramid pulp, 5% maleic anhydride-grafted PP, and 1% antioxidant in a mixer for 5 minutes by mass percentage, and then granulating by single-screw extrusion at a heating temperature of 220°C.

[0012] A second aspect of the present invention also provides a method for preparing a round-head sandblasted compression glaze suspension insulator as described in any one of the above claims, comprising the following steps: (1) After adding deionized water to the raw material for preparing the round-headed hollow umbrella skirt integrated blank, the raw material is ball-milled, iron removed, and filtered into mud cake. The mud cake is then vacuum-kneaded, and after kneading, it is extruded, molded, and dried to obtain the round-headed hollow umbrella skirt integrated blank. (2) Prepare compressed glaze. Apply compressed glaze to the inner and outer walls of the head of the round-headed hollow umbrella skirt integral blank using an automatic spraying equipment. Prepare glaze-coated sand. Suspend the round-headed hollow umbrella skirt integral blank after applying compressed glaze in a sandblasting equipment with the head facing down. Sandblast the compressed glaze surface of the inner and outer walls of the head of the round-headed hollow umbrella skirt integral blank. Apply compressed glaze to the umbrella skirt surface of the round-headed hollow umbrella skirt integral blank by immersion glaze method. (3) The glazed round-headed hollow umbrella skirt integral body is subjected to programmed heating and sintering to obtain porcelain pieces; (4) Using cement-reinforced adhesive, the iron cap, steel foot and porcelain head are glued together. After pressure curing, the gap between the iron cap and porcelain is sealed with vulcanized silicone rubber sealant. After room temperature curing, the round-head sandblasted compression glaze suspension insulator is obtained.

[0013] As a further optimization of the present invention, in step (1), the raw material for preparing the round-headed hollow umbrella skirt integrated blank is ball-milled with water until the particle size of ≤10μm is ≥76%, and after sieving to remove iron, it is pressed and filtered into mud cake. The mud cake is then vacuum-kneaded and extruded into a round-headed hollow umbrella skirt integrated blank, and dried until the moisture content is ≤2% and the roundness tolerance of the head is ≤0.1mm.

[0014] As a further optimization of the present invention, in step (2), the thickness of the compressed glaze layer on the inner wall of the head of the round-headed hollow umbrella skirt integral blank is controlled to be 0.2-0.25mm, the thickness of the compressed glaze layer on the outer wall of the head is controlled to be 0.3-0.4mm, and the top of the head is treated to avoid glaze.

[0015] As a further optimization of the present invention, in step (2), the compression glaze of the umbrella skirt of the round-headed hollow umbrella skirt integral blank is controlled to be 0.15-0.25mm.

[0016] As a further optimization of the present invention, the heating and sintering process in step (5) is as follows: heat preservation at 250-350℃ for 0.5h to remove moisture, heat preservation at 850-1000℃ for 3h to oxidize, heat preservation at 1255-1260℃ for 2-3h to sinter, and after sintering, cooling down to room temperature at a rate of 4-7℃ / h.

[0017] The beneficial effects of this invention are as follows: First, this invention optimizes the compressed glaze formula, selecting potassium feldspar, quartz, and kaolin as basic structural components to ensure glaze layer formation. By adding cordierite powder and talc powder, the core control of low thermal expansion performance is achieved, matching the thermal expansion coefficient of the ceramic body and ensuring the thermal stability of the glaze layer. By adding magnesium feldspar, the bending strength of the glaze layer is improved, forming a dense crystalline phase network, filling internal defects in the glaze layer, and enhancing the glaze layer's fracture resistance. The synergistic effect between the components makes the compressed glaze material and the body more compatible, forming a stable pre-compression stress after sintering, which improves the crack resistance of the insulator head, enabling it to adapt to temperature cycling shocks in high-altitude environments with large temperature differences, and effectively inhibiting crack generation and propagation.

[0018] Secondly, this invention employs a glazed sandblasting process to enhance the interfacial bonding strength between the head and the cement adhesive. Furthermore, by designing the components of the cement-reinforced adhesive, it improves the reliability of the interfacial bonding, avoiding interfacial peeling problems during long-term operation. In addition, it uses vulcanized silicone rubber to seal the gaps, strengthening the adhesive and sealing, thereby improving the sealing performance of the insulator. This effectively prevents moisture intrusion, avoids corrosion of metal accessories, and extends the service life of the insulator. Detailed Implementation

[0019] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0020] Unless otherwise specified, all methods used below are conventional methods known to those skilled in the art, and all reagents and materials used are commercially available products. Example 1

[0021] This embodiment provides a compressed glaze, the raw material composition of which, by mass percentage, includes potassium feldspar, quartz powder, kaolin, cordierite powder, magnesium feldspar powder, talc powder, zinc oxide, and barium carbonate; To optimize the performance of the compressed glaze, the formulation ratio of the compressed glaze in this embodiment is adjusted according to Table 1.

[0022] Table 1. Formulation and proportioning of compressed glaze (by weight percentage) According to the formulation ratios of each group of compressed glazes given in Table 1, accurately weigh each raw material, add it to the deionized ball mill for 6 hours, and control the specific gravity after ball milling to 1.45-1.50 g / cm³. 3 The preferred value is 1.50 g / cm³. 3 Each group of compressed glaze slurry was obtained, and the flexural strength and average linear thermal expansion coefficient of each group of compressed glaze slurry were tested. The specific testing process is as follows: First, each group of compressed glaze slurry was applied to the ceramic blanks using an automatic spraying device at a pressure of 0.25 MPa. The glaze thickness was monitored in real time using a laser thickness gauge, and the spraying rate was adjusted accordingly to achieve a final glaze thickness of 0.35 mm. The glazed ceramic blanks were then placed in a roller kiln for programmed temperature sintering. The specific sintering process was as follows: the temperature was increased from room temperature to 300°C at a rate of 5°C / min, and held at 300°C for 0.5 hours to remove moisture; the temperature was then increased to 900°C at a rate of 3°C / min, and held at 900°C for 3 hours for oxidation; the temperature was then increased to 1258°C at a rate of 2°C / min, and held at 1258°C for 2.5 hours for sintering; after sintering, the temperature was reduced to room temperature at a rate of 5°C / hour, and the glazed ceramic samples were taken out and labeled Y-1 to Y-8. For each group of compressed glaze slurry, five ceramic samples were used for glazing testing.

[0023] The porcelain blanks, by weight percentage, consist of 25% kaolin, 42% low-titanium bauxite, 15% feldspar, 10% clay, and 8% magnesium carbonate. Following the above formula, each raw material is accurately weighed, mixed, and ball-milled with water until the particle size ≤10μm accounts for ≥76%. After sieving to remove iron, the mixture is pressed into a clay cake. The clay cake is then vacuum-kneaded, extruded, and shaped into porcelain blanks, which are then dried to a moisture content ≤2%. The dimensions of the porcelain blanks are determined based on the dimensions required for testing bending strength and the average linear thermal expansion coefficient.

[0024] Then, referring to QB / T 1321-2012 "Method for Determination of Average Linear Thermal Expansion Coefficient of Ceramic Materials", the linear thermal expansion coefficient was determined. The cross-sectional dimensions of the glazed ceramic sample were set to 5mm × 5mm. The sample was placed in a dilatometer, allowed to stand for 5 minutes, and then heated to 800℃ at a heating rate of 4℃ / min. The average linear thermal expansion coefficient was calculated according to the following formula: α = ΔL / (ΔT×L1) + A; Where α is the average linear thermal expansion coefficient, ΔL is the elongation of the sample from room temperature to 800℃, ΔT is the temperature difference from room temperature to 800℃, L1 is the length of the sample at room temperature, and A is the instrument calibration value.

[0025] Bending strength was tested according to GB / T 8411.2-2008 "Ceramic and Glass Insulating Materials - Part 2: Test Methods". A glazed ceramic sample was taken, with a length of 120 mm and a rectangular cross-section of 10 mm in length and 10 mm in thickness. The clamping rod had a diameter of 10 mm and a span of 100 mm. The three-point bending method was used, with a bending force of 30 N·s. 1 The loading rate is gradually increased on a single indenter until the specimen fractures, and the peak load is recorded. The bending strength σ is calculated using the following formula. f The unit is MPa: σf =3×F×l / (2×L×H) 2 ); Where F is the peak load, l is the span, L is the length of the rectangular section, and H is the thickness of the rectangular section.

[0026] The average values ​​of the test results for bending strength and linear thermal expansion coefficient are shown in Table 2.

[0027] Table 2. Test results of bending strength and average linear thermal expansion coefficient As shown in Table 2, in the formulation ratios of the compressed glazes specified for groups Y-1 to Y-3, potassium feldspar, quartz, and kaolin form the basic glaze structure. Zinc oxide and barium carbonate act as fluxes to regulate the melting state of the glaze. Cordierite powder has an extremely low coefficient of thermal expansion, which regulates the overall coefficient of thermal expansion of the glaze. Magnesia feldspar possesses excellent high-temperature stability and mechanical strength. During the sintering process of the compressed glaze, it acts as a reinforcing nucleus, promoting the crystallization reaction of the glassy phase of the glaze and forming a continuous crystal network structure. This effectively fills the defects such as pores and microcracks inside the glaze layer, significantly improving the density and resistance to bending fracture of the glaze layer. At the same time, magnesium feldspar powder optimizes the high-temperature melting characteristics of the glaze, reduces the performance impact caused by fluctuations in the sintering temperature of the glaze layer, and ensures uniform sintering of the glaze layer. The synergistic effect between the components results in good bending strength of the compressed glazes in groups Y-1 to Y-3, with a value range of 225.1 to 237.6 MPa and a low average coefficient of linear thermal expansion, with a value of (0.59 to 0.65) × 10⁻⁶. -6 ℃ -1 It has excellent performance. Example 2

[0028] This embodiment provides a method for preparing a round-headed sandblasted compression glaze suspension insulator, including the following steps: (1) Preparation of round-headed hollow umbrella skirt integrated blank: According to the mass percentage, weigh 28% kaolin, 38% low titanium bauxite, 18% feldspar, 12% clay, and 4% magnesium carbonate, add an appropriate amount of deionized water, place in a ball mill and ball mill for 8 hours. After ball milling, the fineness of the slurry ≤10μm particles accounts for 78%. After sieving through a 200-mesh sieve to remove iron, use a plate and frame filter press to filter into mud cake. Put the mud cake into a vacuum mud refining machine for refining. The vacuum degree is controlled at -0.09MPa. After refining, it is extruded into a round-headed hollow umbrella skirt integrated blank by an extrusion molding machine. Place the blank in a drying oven and dry at 80℃ for 12 hours. After drying, the moisture content of the blank is 1.8%. The roundness tolerance of the head is 0.08mm. (2) Preparation of glaze-coated sand: Select round and blunt granular porcelain sand, screen it through an 18-mesh sieve and remove iron. Mix it evenly according to the mass ratio of porcelain sand: room temperature vulcanized silicone rubber (107 rubber): glaze powder = 200: 13: 60, place it in a sealed container to age for 24 hours, and after aging, screen it through a 15-mesh sieve for later use. (3) Preparation of compressed glaze: Weigh out 20% potassium feldspar, 8% quartz powder, 10% kaolin, 40% cordierite powder, 10% magnesium feldspar powder, 8% talc powder, 3% zinc oxide, and 1% barium carbonate by mass percentage. Add deionized water and ball mill for 6 hours. After ball milling, control the specific gravity of the glaze to be 1.50 g / cm³. 3 ; (4) Applying compressed glaze to the head of the blank: Apply compressed glaze to the inner and outer walls of the head of the blank using an automatic spraying equipment. The spraying pressure is 0.25MPa. The thickness of the glaze layer is fed back in real time by a laser thickness gauge, and the spraying rate is adjusted. Finally, the thickness of the glaze layer on the inner wall is controlled to be 0.22mm and the thickness of the glaze layer on the outer wall is 0.35mm. The top of the head of the blank is protected by a shielding part to avoid glaze. (5) Sandblasting treatment of the round head of the blank: The blank after applying the compressed glaze is suspended in the sandblasting equipment with the head facing down. The inner wall is coated with glue evenly using a sponge roller with glue-adhesive sand, and the outer wall is sprayed with glaze-coated sand using a spray gun. The spraying pressure is 0.25MPa. During the spraying process, the blank is rotated at a constant speed to ensure that the sand layer coverage rate is 100%, with no accumulation and no exposed glaze. (6) Applying compressed glaze to the umbrella skirt surface of the body: Apply compressed glaze to the umbrella skirt surface of the body by immersion glaze method, with an immersion time of 3s and a compressed glaze thickness of 0.20mm after glazing. (7) Segmented sintering: The glazed body is placed in a roller kiln for programmed temperature rise sintering. The specific process is as follows: the temperature is raised from room temperature to 300℃ at a rate of 5℃ / min, and held at 300℃ for 0.5h to remove moisture; the temperature is further raised to 900℃ at a rate of 3℃ / min, and held at 900℃ for 3h to oxidize; the temperature is then raised to 1258℃ at a rate of 2℃ / min, and held at 1258℃ for 2.5h to sinter; after sintering, the temperature is lowered to room temperature at a rate of 5℃ / h, and the porcelain pieces are removed. (8) The sintered porcelain parts were inspected. There were no bubbles or sand particles falling off. The diameter tolerance of the head was ±0.15mm. The crack resistance of the porcelain part head was tested with reference to GB / T 1001.1-2021 "Insulators for overhead lines with nominal voltage higher than 1000V - Part 1: Definition, test methods and judgment criteria for porcelain or glass insulators for AC systems". The test value was 13.2kN. The breakdown voltage was tested and the test value was 125kV / cm. Both met the design requirements. (9) Preparation of metal accessories: Select Q235 material iron cap and steel foot, and perform hot-dip galvanizing treatment. The zinc coating thickness is 85μm. The inner wall of the cap opening is processed into a single arc shape with an arc radius of 15mm to match the upper arc of the steel foot. (10) Cement bonding: First, use 42.5 grade ordinary Portland cement, quartz sand and water in a mass ratio of 1:2:0.4 to prepare an adhesive, and add 0.4% aramid pulp composite reinforcing material to the adhesive. After stirring evenly, the cement-reinforced adhesive is obtained. The cement-reinforced adhesive is injected into the gap between the iron cap and the head of the ceramic part, and steel feet are installed at the same time. It is placed in a pressure-holding device for pressure-holding and curing for 24 hours. The pressure-holding pressure is 0.3MPa. Among them, the aramid pulp composite reinforcing material is obtained by mixing 30% polypropylene, 54% 400-mesh wollastonite, 10% aramid pulp, 5% maleic anhydride-grafted PP and 1% antioxidant in a mixer for 5 minutes by mass percentage, and then granulating by single screw extrusion at a heating temperature of 220℃. (11) Sealing treatment: Apply vulcanized silicone rubber sealant evenly to the gap between the iron cap and the ceramic part, with a coating thickness of 2mm, and cure at room temperature for 4 hours; (12) Overall curing: Place the sealed insulator in a normal temperature curing room for 72 hours to obtain a round-head sandblasted compression glaze suspension insulator.

[0029] The prepared round-head sandblasted compressed glaze suspension insulators were subjected to pre-shipment testing: Referring to GB / T 1001.1-2021 "Insulators for Overhead Lines with Nominal Voltage Higher Than 1000V - Part 1: Definitions, Test Methods and Judgment Criteria for Porcelain or Glass Insulators for AC Systems", the tensile strength was tested at 186kN. The insulation resistance was tested using a 5000V megohmmeter and was ≥1000MΩ. The head interface was inspected using an ultrasonic flaw detector and no peeling defects were found. Referring to GB / T 4208-2017 "Degrees of Protection Provided by Enclosures (IP Code)", the sealing rating of the insulator was measured to be IP66. In addition, after the insulator was subjected to a temperature difference cycle of -40℃ to 80℃ for 50 cycles, the glaze showed no cracks and no sand particles fell off, indicating stable insulation performance. Example 3

[0030] The method for preparing a round-head sandblasted compressed glaze suspension insulator provided in this embodiment differs from that in Embodiment 2 in that steps (1), (7), and (10) are as follows: (1) Preparation of round-headed hollow umbrella skirt integrated blank: Weigh 30% kaolin, 35% low titanium bauxite, 20% feldspar, 10% clay and 5% magnesium carbonate by mass percentage, add appropriate amount of deionized water, place in ball mill for 8h, after ball milling the slurry fineness ≤10μm particles account for 78%, pass through 200 mesh screen to remove iron, use plate and frame filter press to filter into mud cake, put the mud cake into vacuum mud kneading machine to knead mud, the vacuum degree is controlled at -0.09MPa, after kneading mud, extrude into round-headed hollow umbrella skirt integrated blank by extrusion molding machine, put the blank into drying oven, dry at 80℃ for 12h, after drying the blank moisture content is 1.8%, the head roundness tolerance is 0.08mm. (7) Segmented sintering: The glazed body is placed in a roller kiln for programmed temperature rise sintering. The specific process is as follows: the temperature is raised from room temperature to 300℃ at a rate of 5℃ / min, and held at 300℃ for 0.5h to remove moisture; the temperature is raised to 900℃ at a rate of 3℃ / min, and held at 900℃ for 3h to oxidize; the temperature is raised to 1260℃ at a rate of 2℃ / min, and held at 1260℃ for 2h to sinter; after sintering, the temperature is lowered to room temperature at a rate of 5℃ / h and the porcelain pieces are removed. (10) Cement bonding: First, use 42.5 grade ordinary silicate cement, quartz sand and water in a mass ratio of 1:2:0.4 to prepare an adhesive, and add 0.6% aramid pulp composite reinforcing material to the adhesive. After stirring evenly, the cement-reinforced adhesive is obtained. The cement-reinforced adhesive is injected into the gap between the iron cap and the head of the ceramic part, and steel feet are installed at the same time. It is placed in a pressure holding device for pressure holding and curing for 24 hours. The pressure holding pressure is 0.3MPa. The preparation method of aramid pulp composite reinforcing material is the same as in Example 2.

[0031] After sintering in Example 3, the crack resistance of the porcelain head was tested with reference to GB / T 1001.1-2021 "Overhead line insulators with nominal voltage higher than 1000V - Part 1: Definition, test methods and judgment criteria for porcelain or glass insulators for AC systems". The test value was 14.1kN, and the breakdown voltage was tested with a test value of 128kV / cm. Both met the design requirements. The round-head sandblasted compression glaze suspension insulators prepared in Example 3 were subjected to pre-shipment testing: Referring to GB / T 1001.1-2021 "Insulators for Overhead Lines with Nominal Voltage Higher Than 1000V - Part 1: Definitions, Test Methods and Judgment Criteria for Porcelain or Glass Insulators for AC Systems", the tensile strength was tested at 198kN. The insulation resistance was tested using a 5000V megohmmeter and was ≥1000MΩ. The head interface was inspected using an ultrasonic flaw detector and no peeling defects were found. Referring to GB / T 4208-2017 "Degrees of Protection Provided by Enclosures (IP Code)", the sealing rating of the insulator was measured to be IP66. In addition, after the insulator was subjected to a temperature difference cycle of -40℃ to 80℃ for 50 cycles, the glaze surface showed no cracks and no sand particles fell off, indicating stable insulation performance.

[0032] Comparative Example 1 The method for preparing a round-head sandblasted compressed glaze suspension insulator provided in this comparative example differs from that in Example 2 in that the formulation ratio of the cement-reinforced adhesive is different. The cement-reinforced adhesive used in this comparative example is prepared by mixing 42.5 grade ordinary silicate cement, quartz sand, and water in a mass ratio of 1:2:0.4, and 0.4% polypropylene fiber is added to the adhesive.

[0033] The round-headed sandblasted compression glaze suspension insulator prepared in Comparative Example 1 had a tensile strength of 157 kN when tested according to GB / T 1001.1-2021 "Overhead line insulators with nominal voltage above 1000V - Part 1: Definition, test methods and judgment criteria for porcelain or glass insulators for AC systems". The sealing rating of the insulator was measured to be IP65 according to GB / T 4208-2017 "Degrees of protection provided by enclosures (IP codes)".

[0034] Comparative Example 2 The difference between the preparation method of the round-head sandblasted compression glaze suspension insulator provided in this comparative example and Example 2 is that the formulation ratio of the cement-reinforcing adhesive is different. The cement-reinforcing adhesive used in this comparative example is prepared by mixing 42.5 grade ordinary Portland cement, quartz sand, and water in a mass ratio of 1:2:0.4, and adding 0.4% composite reinforcing material to the adhesive. The composite reinforcing material is prepared by mixing 40% polypropylene, 54% 400-mesh wollastonite, 5% maleic anhydride-grafted PP, and 1% antioxidant in a mixer for 5 minutes, and then granulating by single-screw extrusion at a heating temperature of 220°C.

[0035] The round-headed sandblasted compression glaze suspension insulator prepared in Comparative Example 2 was tested according to GB / T 1001.1-2021 "Insulators for overhead lines with nominal voltage above 1000V - Part 1: Definitions, test methods and judgment criteria for porcelain or glass insulators for AC systems" and the tensile strength was 161kN.

[0036] Comparative Example 3 The method for preparing a round-head sandblasted compressed glaze suspension insulator provided in this comparative example differs from that in Example 2 in that the formulation ratio of the cement-reinforcing adhesive is different. The cement-reinforcing adhesive used in this comparative example is prepared by mixing 42.5 grade ordinary silicate cement, quartz sand, and water in a mass ratio of 1:2:0.4.

[0037] The round-headed sandblasted compression glaze suspension insulator prepared in Comparative Example 3 was tested according to GB / T 1001.1-2021 "Insulators for overhead lines with nominal voltage above 1000V - Part 1: Definitions, test methods and judgment criteria for porcelain or glass insulators for AC systems" and the tensile strength was 122kN.

[0038] Comparative Example 4 The method for preparing a round-head sandblasted compressed glaze suspension insulator provided in this comparative example differs from Example 2 in that the round-head compressed glaze sandblasting treatment of the blank in step (5) is not performed.

[0039] The round-headed sandblasted compression glaze suspension insulator prepared in Comparative Example 4 was tested according to GB / T 1001.1-2021 "Insulators for overhead lines with nominal voltage above 1000V - Part 1: Definitions, test methods and judgment criteria for porcelain or glass insulators for AC systems" and the tensile strength was 135kN.

[0040] Comparative Example 5 The method for preparing a round-head sandblasted compressed glaze suspension insulator provided in this comparative example differs from Example 2 in that the sealing treatment in step (11) is not performed.

[0041] The round-headed sandblasted compression glaze suspension insulator prepared in Comparative Example 5 was tested according to GB / T 1001.1-2021 "Insulators for overhead lines with nominal voltage above 1000V - Part 1: Definitions, test methods and judgment criteria for porcelain or glass insulators for AC systems" and the tensile strength was 167kN.

[0042] Tensile tests were conducted on the round-head sandblasted compressed glaze suspension insulators obtained in Examples 2-3 and Comparative Examples 1-5. It can be seen that the interface reliability of the round-head sandblasted compressed glaze suspension insulators prepared in Examples 2-3 is better than that of Comparative Examples 1-5. The examples use a sandblasting process to firmly bond the sand layer to the compressed glaze surface. In addition, the innovative formulation of the cement-reinforcing adhesive introduces aramid pulp composite reinforcing material on the basis of the existing cement-reinforcing adhesive, which effectively improves the interface bonding strength and avoids the interface peeling problem during long-term operation.

[0043] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A spherically shaped sandblasted and compressed enamel suspension insulator, characterized in that, The round-head sandblasted compression glaze suspension insulator uses a round-head hollow umbrella skirt integrated blank as the ceramic blank. It first undergoes round-head compression glaze application, round-head compression glaze surface sandblasting, and umbrella skirt compression glaze application, and then is sintered in sections to obtain the ceramic blank. Then, cement-reinforced adhesive is used to glue the iron cap and steel foot to the round head of the ceramic blank. After sealing and curing, it is obtained. The compressed glaze, by weight percentage, includes 15-20% potassium feldspar, 8-10% quartz, 10-15% kaolin, 10-15% magnesium feldspar powder, 24-40% cordierite powder, 8-14% talc powder, 3-5% zinc oxide, and 1-5% barium carbonate.

2. The round-headed sandblasted compressed glaze suspension insulator according to claim 1, characterized in that, The raw materials for preparing the round-headed hollow umbrella skirt integral blank include, by mass percentage, 25-30% kaolin, 35-42% low-titanium bauxite, 15-20% feldspar, 10-15% clay, and 4-8% magnesium carbonate.

3. A round-headed sandblasted compressed glaze suspension insulator according to claim 1, characterized in that, The glaze-coated sand used in the round-head compressed glaze sandblasting is obtained by uniformly mixing porcelain sand, room temperature vulcanized silicone rubber, and glaze powder in a mass ratio of 200:13:60, aging for 24 hours, and then screening through a 15-mesh sieve.

4. A round-headed sandblasted compressed glaze suspension insulator according to claim 1, characterized in that, The cement-reinforcing adhesive is prepared by mixing 42.5 grade ordinary Portland cement, quartz sand, and water in a mass ratio of 1:2:0.4, and adding 0.4-0.6% aramid pulp composite reinforcing material to the adhesive and stirring evenly.

5. A round-headed sandblasted compressed glaze suspension insulator according to claim 4, characterized in that, The aramid pulp composite reinforcing material is obtained by mixing 30% polypropylene, 54% 400-mesh wollastonite, 10% aramid pulp, 5% maleic anhydride-grafted PP, and 1% antioxidant in a mixer for 5 minutes by weight, and then granulating by single-screw extrusion at a heating temperature of 220°C.

6. A method for preparing a round-head sandblasted compression glaze suspension insulator as described in any one of claims 1-5, characterized in that, Includes the following steps: (1) After adding deionized water to the raw material for preparing the round-headed hollow umbrella skirt integrated blank, the raw material is ball-milled, iron removed, and filtered into mud cake. The mud cake is then vacuum-kneaded, and after kneading, it is extruded, molded, and dried to obtain the round-headed hollow umbrella skirt integrated blank. (2) Prepare compressed glaze. Apply compressed glaze to the inner and outer walls of the head of the round-headed hollow umbrella skirt integral blank using an automatic spraying equipment. Prepare glaze-coated sand. Suspend the round-headed hollow umbrella skirt integral blank after applying compressed glaze in a sandblasting equipment with the head facing down. Sandblast the compressed glaze surface of the inner and outer walls of the head of the round-headed hollow umbrella skirt integral blank. Apply compressed glaze to the umbrella skirt surface of the round-headed hollow umbrella skirt integral blank by immersion glaze method. (3) The glazed round-headed hollow umbrella skirt integral body is subjected to programmed heating and sintering to obtain porcelain pieces; (4) Using cement-reinforced adhesive, the iron cap, steel foot and porcelain head are glued together. After pressure curing, the gap between the iron cap and porcelain is sealed with vulcanized silicone rubber sealant. After room temperature curing, the round-head sandblasted compression glaze suspension insulator is obtained.

7. The method for preparing a round-headed sandblasted compression glaze suspension insulator according to claim 6, characterized in that, In step (1), the raw material for preparing the round-headed hollow umbrella skirt integrated blank is ball-milled with water until the particle size of ≤10μm is ≥76%. After sieving to remove iron, it is pressed and filtered into mud cake. The mud cake is then vacuum-kneaded and extruded into a round-headed hollow umbrella skirt integrated blank. It is then dried until the moisture content is ≤2% and the roundness tolerance of the head is ≤0.1mm.

8. The method for preparing a round-headed sandblasted compression glaze suspension insulator according to claim 6, characterized in that, In step (2), the thickness of the compressed glaze layer on the inner wall of the head of the round-headed hollow umbrella skirt integral blank is controlled to be 0.2-0.25mm, the thickness of the compressed glaze layer on the outer wall of the head is controlled to be 0.3-0.4mm, and the top of the head is treated to avoid glaze.

9. The method for preparing a round-headed sandblasted compression glaze suspension insulator according to claim 6, characterized in that, In step (2), the compression glaze of the umbrella skirt of the hollow umbrella skirt integral blank is controlled to be 0.15-0.25mm.

10. The method for preparing a round-headed sandblasted compression glaze suspension insulator according to claim 6, characterized in that, The heating and sintering process in step (5) is as follows: heat preservation at 250-350℃ for 0.5h to remove moisture, heat preservation at 850-1000℃ for 3h to oxidize, heat preservation at 1255-1260℃ for 2-3h to sinter, and after sintering, cooling down to room temperature at a rate of 4-7℃ / h.

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