Preparation method of silicon oxide density standard floater

Abstract

The invention discloses a preparation method of a silicon oxide density standard floater, which comprises the following steps: preparation of silicon dioxide slurry: dissolving silicon dioxide powder in photosensitive resin for preliminary mixing to form a mixture, and grinding the mixture to obtain the silicon dioxide slurry; 3D printing is conducted, specifically, the silicon dioxide slurry is put into photocuring 3D printing equipment to be subjected to 3D printing, and coarse silicon dioxide pellets are obtained; and cleaning and curing: cleaning and secondarily curing the silicon dioxide pellets. According to the photocuring ceramic additive manufacturing technology, through digital design-high-precision forming-gradient material integration, the problems of efficiency, precision and structure bottlenecks in traditional glass floater preparation are thoroughly solved, a hollow thin-wall and porous gradient complex structure can be formed, the structural design limitation is broken through, the forming precision is 25 microns, and the manufacturing cost is low. The machining size precision is greatly improved, the internal stress can be eliminated through an integrated degreasing and sintering mode in the preparation process, and the mechanical stability of the standard floater is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of functional ceramics, in particular to a preparation method of a silicon oxide density standard float. BACKGROUND

[0002] Fiber reinforced polymer (FRP) is a composite material formed by reinforcing fiber material and matrix material through winding, molding or pultrusion forming process. According to the different reinforcing fiber materials, it can be divided into two categories of organic fiber and inorganic fiber, the inorganic fiber includes glass fiber, carbon fiber, boron fiber, silicon carbide fiber, etc., and the organic fiber includes aramid fiber, nylon fiber, polyolefin fiber, etc. As an important material in industrial development, the fiber reinforced composite material generally has the characteristics of small density, light weight, high pressure resistance, high hardness, high temperature resistance, corrosion resistance, etc.

[0003] The density of reinforcing fiber is an important factory index representing the physical performance of reinforcing fiber, and is also a key control index in the development and production process of reinforcing fiber. The size depends on the composition, organization form and internal defects of the biological material. During the communication with the project team, the client of Petrochemical Research Institute of China Petroleum and Natural Gas Corporation introduced that the density and melt flow rate are currently the only two important physical parameters for the factory inspection of ultra-high molecular weight polyethylene fiber. During the preparation of ultra-high molecular weight polyethylene, the composition of raw materials will change with the production process, so it is necessary to detect the density of the fiber from time to time to determine whether the key production raw materials such as decalin need to be supplemented and adjusted. There are many related enterprises of reinforcing fiber in China, so there is a large demand for on-site measurement of the density of one-dimensional and two-dimensional lightweight materials such as reinforcing fiber and its composite materials.

[0004] At present, these high-end manufacturing enterprises all use the density gradient method with the highest precision among the three measurement methods of liquid displacement method, float-sink method and density gradient method required by the standards such as GB / T 30019-2013 Carbon Fiber Density Determination, GB / T 34520.3-2017 Continuous Silicon Carbide Fiber Test Method Part 3: Linear Density and Density, GB / T 40169-2021 Ultra-high Molecular Weight Polyethylene and High Density Polyethylene, GB / T 41063-2021 Glass Fiber Density Determination, as the arbitration method for measurement, but this method needs to configure a density gradient column with a linearity better than 0.99, and needs to be matched with a corresponding high-precision calibration float. At present, only two or three foreign companies master these two aspects of technology, resulting in the need for domestic reinforcing fiber manufacturing enterprises to spend a large amount of funds to purchase density gradient measurement systems and calibration floats every year.

[0005] Currently, precision calibration floats are manufactured abroad using a manual blowing method to achieve the density range (0.8~2.0) g / cm3 glass calibration floats. This method has the following significant disadvantages: Insufficient precision: Manual operation results in uneven particle size (CV value 15%~20%), far exceeding the density gradient tube requirement of ≤5%.

[0006] Inefficiency: The preparation time of a single piece is greater than 30 minutes, and there is an obvious bottleneck in large-scale production.

[0007] Structural limitations: Traditional processes make it difficult to achieve density gradient or complex hollow thin-wall integrated forming, and the material utilization rate is less than 50%. Summary of the Invention

[0008] This invention proposes an efficient, economical method for producing density standard floats of various densities and thicknesses. This method offers several significant advantages over manual blown methods: It can produce hollow, thin-walled, porous, and gradient structures, breaking through structural design limitations. It achieves a molding accuracy resolution of 25μm, significantly improving dimensional precision. Hundreds of standard floats can be produced per hour, with a material utilization rate exceeding 95%. Integrated debinding and sintering eliminates internal stresses, improving the mechanical stability of the standard floats. Light-curing ceramic additive manufacturing technology, integrating digital design, high-precision molding, and gradient materials, completely overcomes the efficiency, precision, and structural bottlenecks in traditional glass float production.

[0009] The technical solution of the present invention is achieved as follows: A method for preparing a silicon oxide density standard float comprises: Preparation of silica slurry: The silica powder and the photosensitive resin are mixed according to the following mass parts: 1200-1500 parts of the silica powder, 100-200 parts of the oligomer, 600-900 parts of the reactive diluent, 1-20 parts of the photoinitiator, 1-5 parts of the light absorber, and 1-30 parts of the dispersant to form a mixture, and the mixture is ground to obtain silica slurry; 3D printing: The three-dimensional model is then sliced ​​using modeling software, and the silica slurry is placed into a light-curing 3D printing device for 3D printing to obtain coarse silica pellets; Cleaning and curing: Clean the silica balls and perform secondary curing to obtain fine silica balls; Degreasing and sintering: The fine silica balls are loaded into a crucible and placed together in a high-temperature sintering furnace. The fine silica balls are degreased and sintered in the high-temperature sintering furnace to produce a silica density standard float.

[0010] Preferably, in the material mixing step, the grinding device of the mixture is a three-roll grinder, the rotating speed is 300 rpm / min~500 rpm / min, the rotating speed ratio is 1:3:9, the passing frequency is 3-5 times, and the three-roll grinder can realize the sufficient mixing of the material.

[0011] Preferably, the rotating speed of the three-roll grinder is 500 rpm / min, and the passing frequency is 3 times.

[0012] Preferably, the silicon dioxide powder is one of hydrophilic type and hydrophobic type, and the primary particle size is one or more of (7~500) nm; the photosensitive resin is mixed from an oligomer, an active diluent, a photoinitiator, a light absorber, and a dispersant.

[0013] Preferably, the silicon dioxide powder and the photosensitive resin are mixed according to the following mass fraction: the silicon dioxide powder is 1200~1500 parts, the oligomer is 100~200 parts, the active diluent is 600~900 parts, the photoinitiator is 1~20 parts, the light absorber is 1~5 parts, and the dispersant is 1~30 parts.

[0014] Preferably, the oligomer is epoxy acrylate or aliphatic polyurethane acrylate. The active diluent is one or a mixture of any proportion of one or more of hydroxyethyl methacrylate, 4-hydroxybenzoic acid ester, 1,6-hexanediol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, trimethylolpropane triacrylate, or pentaerythritol triacrylate. The photoinitiator is one of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, bis(2,4,6-trimethylbenzoyl) phenyl phosphine oxide, or 2,4,6-trimethylbenzoyl phenyl phosphonic acid ethyl ester. The light absorber is one of Sudan I, Sudan orange G, or Sudan red G. The dispersant is one or a mixture of any proportion of one or more of BYK-111 dispersant, BYK-2008 dispersant, or BYK-2155 dispersant.

[0015] Preferably, in the 3D printing step, the light-curing 3D printing device is a DLP light-curing printer, the ultraviolet light wavelength is 365 nm or 405 nm, the bottom layer exposure time is 1-8 s, and the light power density is 0-72 mW / cm2. Preferably, the bottom layer exposure time is 2 s, and the light power density is 20 mW / cm2, which can completely print the rough blank and prevent the printed part from being scraped off. The diameter of the coarse silica small ball is (5-8) mm, the wall thickness of the hollow thin-walled small ball is less than 1 mm, and there are two holes with a diameter of less than 1 mm on the top and bottom. Preferably, the wall thickness is (0.3-0.5) mm, and the two holes with a diameter of (0.5-0.8) mm facilitate the outflow of the printing slurry and prevent internal blockage.

[0016] Preferably, in the cleaning and curing step, the cleaning work is to clean the coarse silica small ball 2-3 times with an ultrasonic cleaner filled with isopropyl alcohol or a cleaning agent, so that the slurry in the coarse silica small ball flows out, and then the slurry remaining on the surface and inside the coarse silica small ball is washed away, to obtain a cleaned silica small ball rough blank; the secondary curing work is to blow out the uncured slurry in the hole on the surface of the silica small ball rough blank with an air gun, to fill the hole of the small ball with the slurry, and to perform secondary curing by irradiation with an ultraviolet lamp, to obtain a fine silica small ball.

[0017] Preferably, in the debinding and sintering step, the crucible is a high-temperature-resistant alumina crucible, the debinding treatment is to heat the fine silica small ball to remove components other than silica particle powder, and the sintering treatment is to perform high-temperature bonding densification on the debound rough blank in different sintering environments.

[0018] Preferably, the sintering environment is air, vacuum, or inert atmosphere.

[0019] Preferably, in the debinding and sintering step, the sintering process of the high-temperature sintering furnace is to first increase the temperature from room temperature to 100-150°C at a rate of 0.5-1°C / min, maintain the temperature for 60 min, then increase the temperature to 250-400°C at a rate of 0.5-1°C / min, maintain the temperature for 120 min, then increase the temperature to 600-800°C at a rate of 2°C / min, maintain the temperature for 60-180 min, then increase the temperature to 1150-1300°C at a rate of 5°C / min, maintain the temperature for 120-300 min, and finally cool the furnace to room temperature and take out the product.

[0020] The silica slurry needs to have a suitable curing depth to prevent over-curing and cause the printed part to be missing and the size to be inaccurate, so a suitable amount of light absorber needs to be added to the slurry, and the addition amount is adjusted according to the set layer thickness. Preferably, the light absorber is Sudan orange G.

[0021] The silica slurry needs to have shear thinning characteristics, can be well scraped in the printing tank, the viscosity is not more than 3000 Pa·s, and can ensure the integrity of the structure and small shrinkage rate after sintering, so the volume solid content should be more than 40%. Preferably, the viscosity is 1000 Pa·s~2500 Pa·s, the volume solid content is 40%~45%, and the corresponding mass solid content is 55%~65%. Advantages

[0022] The application provides a preparation method of a silica density standard float, and compared with manual blowing technology in a traditional process, the efficient DLP photocuring 3D printing technology is adopted in the method, 25 mu m optical resolution is achieved, and batch standardization and rapid preparation of a 200 mu m hollow thin-wall density standard float are realized.

[0023] The photocuring silica slurry has good fluidity, and can improve the success rate of printing.

[0024] The application uses silica particles as raw materials to prepare the photocuring silica slurry, according to a three-dimensional model, a two-dimensional slice, a light power density and a layer thickness and other parameters are obtained in a printer to obtain an expected three-dimensional hollow small ball model, further cleaning, debinding and sintering are performed to obtain the expected silica density standard float.

[0025] The average particle size of the silica powder is (7-500) nm, and the particle size after polymerization is larger, the larger particle size can cause pores in the small ball after high-temperature sintering, and affect the indexes of the product, preferably, the average particle size of the nano-silica is (40-300) nm, and a plurality of combinations of the nano-silica are used, which is beneficial to filling of the pores between the particles and reducing the shrinkage rate. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0027] Figure 1 It is a process flow chart of a preparation method of a silica density standard float according to an embodiment of the application. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention are within the scope of protection of the present invention.

[0029] According to an embodiment of the present invention, a method for preparing a silicon oxide density standard float is provided.

[0030] like Figure 1 As shown, in this optional embodiment, the method for preparing high-purity lithium carbonate according to an embodiment of the present invention includes: Step S101, preparing silica slurry: dissolving silica powder in a photosensitive resin and preliminarily mixing to form a mixture, and grinding the mixture to obtain silica slurry; Step S103, 3D printing: placing the silica slurry into a light-curing 3D printing device for 3D printing to obtain coarse silica pellets; Step S105, cleaning and curing: cleaning the silica beads and performing secondary curing to obtain fine silica beads; Step S107, degreasing and sintering: the fine silica balls are loaded into a crucible and placed together in a high-temperature sintering furnace, and the fine silica balls are degreased and sintered in the high-temperature sintering furnace to obtain a silica density standard float.

[0031] In this optional embodiment, in the material mixing step, the grinding equipment for the mixture is a three-roll grinder, the grinding speed is 300rpm / min~500rpm / min, the speed ratio is 1:3:9, and the number of roller passes is 3-5 times.

[0032] In this optional embodiment, the silica powder is one of hydrophilic and hydrophobic, and has a primary particle size of one or more of (7~500) nm; the photosensitive resin is a mixture of oligomers, reactive diluents, photoinitiators, light absorbers, and dispersants.

[0033] In this optional embodiment, the silica powder and the photosensitive resin are mixed in the following parts by mass: 1200-1500 parts of the silica powder, 100-200 parts of the oligomer, 600-900 parts of the active diluent, 1-20 parts of the photoinitiator, 1-5 parts of the light absorber, and 1-30 parts of the dispersant.

[0034] In this optional embodiment, the oligomer is epoxy acrylate or aliphatic urethane acrylate; The active diluent is one or a mixture of any proportion of one or more of hydroxyethyl methacrylate, 4-hydroxybenzoate, 1,6-hexanediol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, trimethylolpropane triacrylate or pentaerythritol triacrylate; The photoinitiator is one of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, bis(2,4,6-trimethylbenzoyl) phenyl phosphine oxide or 2,4,6-trimethylbenzoyl ethyl phenyl phosphonate; The light absorber is one of Sudan I, Sudan orange G or Sudan red G; The dispersant is one or a mixture of any proportion of one or more of BYK-111 dispersant, BYK-2008 dispersant or BYK-2155 dispersant.

[0035] In this optional embodiment, in the 3D printing step, the light-cured 3D printing equipment is a DLP light-cured printer, the ultraviolet light wavelength is 365 nm or 405 nm, the bottom layer exposure time is 1-8 s, the light power density is 0-72 mW / cm2, the coarse silica small balls are hollow thin-walled small balls with a diameter of (5-8) mm and a wall thickness of less than 1 mm, and each has a hole with a diameter of less than 1 mm at the top and bottom.

[0036] In this optional embodiment, in the cleaning and curing step, the cleaning work is to clean the coarse silica small balls with an ultrasonic cleaner filled with isopropyl alcohol or a cleaning agent for 2-3 times to obtain cleaned silica small ball blanks; and the secondary curing work is to blow out the uncured slurry in the surface holes of the silica small ball blanks by using an air gun, and to perform hole repairing and other secondary curing on the silica small ball blanks by using an ultraviolet lamp to obtain fine silica small balls.

[0037] In this optional embodiment, in the debinding and sintering step, the crucible is a high-temperature-resistant alumina crucible.

[0038] In this optional embodiment, the debinding treatment is to heat the fine silica small balls to remove components other than silica particle powder; and the sintering treatment is to perform high-temperature bonding densification on the debound blanks in different sintering environments, such as air, vacuum or inert atmosphere.

[0039] In this optional embodiment, in the degreasing and sintering steps, the sintering process of the high-temperature sintering furnace is: first, heat up from room temperature to 100℃~150℃ at a rate of 0.5℃ / min~1℃ / min, keep warm for 60 minutes, then heat up to 250℃~400℃ at a rate of 0.5℃ / min~1℃ / min, keep warm for 120 minutes, then heat up to 600℃~800℃ at a rate of 2℃ / min, keep warm for 60 minutes~180 minutes, then heat up to 1150℃~1300℃ at a rate of 5℃ / min, keep warm for 120 minutes~300 minutes, and finally take out after cooling to room temperature as the furnace temperature.

[0040] In this optional embodiment, the separation method is centrifugal separation.

[0041] In order to facilitate understanding of the above technical solutions of the present invention, the above technical solutions of the present invention are further described below through a number of specific embodiments. Example 1

[0042] like Figure 1 As shown, in specific applications, the preparation process of the silicon oxide density standard float is as follows: Preparation of silica slurry: Hydroxyethyl methacrylate, tripropylene glycol diacrylate and trimethylolpropane triacrylate are mixed in a mass ratio of 5:3:2 to form a reactive diluent, the reactive diluent and epoxy acrylate are configured in a mass fraction ratio of 9:1 to form a preliminary mixed solution, and then 2wt% of photoinitiator is added to the preliminary mixed solution, and stirred and mixed until uniformly formed a photosensitive resin premix. Then, 60wt% of 200nm silica powder is added to the photosensitive resin premix in batches and preliminarily stirred; then, 0.5wt% of BYK-111 dispersant and 1.5wt% of BYK-2155 dispersant are added to the powder, and finally 0.2wt% of Sudan Orange G is added to the entire slurry and stirred to form a silica slurry. The silica slurry is passed through a three-roll mill at a speed of 500rpm / min for 3 times; 3D printing: the obtained silica slurry is cured and formed on a sinking DLP light-curing 3D printer platform to obtain coarse silica pellets. The light source wavelength of the light-curing 3D printer is 405nm. Cleaning and curing: Clean the silica balls and perform secondary curing to obtain fine silica balls; Degreasing and sintering: The fine silica balls are loaded into a crucible and placed together in a high-temperature sintering furnace. The high-temperature sintering furnace is first heated from room temperature to 150°C at a rate of 1°C / min and kept warm for 60 minutes. Then, the temperature is raised to 250°C at a rate of 0.5°C / min and kept warm for 120 minutes. Then, the temperature is raised to 400°C at a rate of 0.5°C / min and kept warm for 120 minutes. Then, the temperature is raised to 800°C at a rate of 1°C / min and kept warm for 120 minutes. Then, the temperature is raised to 1200°C at a rate of 5°C / min and kept warm for 180 minutes. Finally, the crucible is cooled to room temperature and then taken out to obtain a silica density standard float. Example 2

[0043] like Figure 1 As shown, in specific applications, the preparation process of the silicon oxide density standard float is as follows: Preparation of silica slurry: a mixture of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate and trimethylolpropane triacrylate in a mass ratio of 5:3:2 is mixed to form a reactive diluent, the reactive diluent and epoxy acrylate are configured in a mass fraction ratio of 9:1 to form a preliminary mixed solution, 2wt% of a photoinitiator is added to the preliminary mixed solution, and the mixture is stirred and mixed until uniformly formed into a photosensitive resin premix, then 60wt% of 200nm silica powder is added to the photosensitive resin premix in batches and preliminarily stirred; then 0.5wt% of BYK-111 dispersant and 1.5wt% of BYK-2155 dispersant are added to the powder, and finally 0.2wt% of Sudan Orange G is added to the entire slurry and stirred to form a silica slurry, and the silica slurry is passed through a three-roll mill at a speed of 500rpm / min for 3 times; 3D printing: the obtained silica slurry is cured and formed on a sinking DLP light-curing 3D printer platform to obtain coarse silica pellets. The light source wavelength of the light-curing 3D printer is 405nm. Cleaning and curing: Clean the silica balls and perform secondary curing to obtain fine silica balls; Degreasing and sintering: The fine silica balls are loaded into a crucible and placed together in a high-temperature sintering furnace. The high-temperature sintering furnace is first heated from room temperature to 150°C at a rate of 1°C / min and kept warm for 60 minutes. Then, the temperature is raised to 250°C at a rate of 0.5°C / min and kept warm for 120 minutes. Then, the temperature is raised to 400°C at a rate of 0.5°C / min and kept warm for 120 minutes. Then, the temperature is raised to 800°C at a rate of 1°C / min and kept warm for 120 minutes. Then, the temperature is raised to 1200°C at a rate of 5°C / min and kept warm for 180 minutes. Finally, the crucible is cooled to room temperature and then taken out to obtain a silica density standard float. Example 3

[0044] As Figure 1 shown, in a specific application, the preparation method of the silica density standard float is as follows: Silica slurry preparation, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate and trimethylolpropane triacrylate are mixed according to the mass ratio of 5:3:2 to form an active diluent, the active diluent and epoxy acrylate are configured into a preliminary mixed solution according to the mass fraction of 8:2, then 2wt% of the photoinitiator is added into the preliminary mixed solution, and the mixture is stirred until uniform to form a photosensitive resin premix solution, then 60wt% of 200nm silica powder is added into the photosensitive resin premix solution in batches and stirred uniformly; then 0.5wt% of BYK-111 dispersant and 1.5wt% of BYK-2155 dispersant are added, and finally 0.2wt% of Sudan orange G is added into the whole slurry and stirred uniformly to form a silica slurry, which is passed through a three-roll mill at a speed of 500rpm / min for 3 times; 3D printing, the obtained silica slurry is cured and formed on a sinking DLP photocuring 3D printer platform to obtain coarse silica beads, and the wavelength of the light source of the photocuring 3D printer is 405nm; Cleaning and curing: the silica beads are cleaned and cured again to obtain fine silica beads; Degreasing and sintering: the fine silica beads are loaded into a crucible and placed in a high-temperature sintering furnace, which is first heated from room temperature to 150℃ at a rate of 1℃ / min, and then heated to 250℃ at a rate of 0.5℃ / min, and then heated to 400℃ at a rate of 0.5℃ / min, and then heated to 800℃ at a rate of 1℃ / min, and then heated to 1200℃ at a rate of 5℃ / min, and then cooled to room temperature, and then taken out, to obtain a silica density standard float. Example four

[0045] As Figure 1 shown, in a specific application, the preparation method of the silica density standard float is as follows: Silica slurry preparation, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate and trimethylolpropane triacrylate are mixed according to the mass ratio of 5:3:2 to form an active diluent, the active diluent and epoxy acrylate are configured into a preliminary mixed solution according to the mass fraction of 8:2, then 2wt% of the photoinitiator is added into the preliminary mixed solution, and the mixture is stirred until uniform to form a photosensitive resin premix solution, then 60wt% of 200nm silica powder is added into the photosensitive resin premix solution in batches and stirred uniformly; then 0.5wt% of BYK-111 dispersant and 1.5wt% of BYK-2155 dispersant are added, and finally 0.2wt% of Sudan orange G is added into the whole slurry and stirred uniformly to form a silica slurry, and the silica slurry is passed through a three-roll mill at a speed of 500rpm / min for 3 times; 3D printing, the obtained silica slurry is cured and formed on a sinking DLP photocuring 3D printer platform to obtain coarse silica small balls, and the wavelength of the light source of the photocuring 3D printer is 405nm; Washing and curing: the silica small balls are washed and subjected to secondary curing to obtain fine silica small balls; Degreasing and sintering: the fine silica small balls are loaded into a crucible and placed in a high-temperature sintering furnace, the high-temperature sintering furnace is first heated from room temperature to 150℃ at a rate of 1℃ / min, and then heated to 250℃ at a rate of 0.5℃ / min, and kept for 120min; then heated to 400℃ at a rate of 0.5℃ / min, and kept for 120min; then heated to 800℃ at a rate of 1℃ / min, and kept for 120min; then heated to 1250℃ at a rate of 5℃ / min, and kept for 180min; finally, the furnace is cooled to room temperature, and then taken out to obtain a silica density standard float.

[0046] The above only describes the preferred embodiments of the present application and should not be used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a silicon oxide density standard float, characterized in that: include: Preparation of silica slurry: dissolving silica powder in photosensitive resin and preliminarily mixing to form a mixture, and grinding the mixture to obtain silica slurry; 3D printing: Place the silica slurry into a light-curing 3D printing device for 3D printing to obtain coarse silica pellets; Cleaning and curing: Clean the silica balls and perform secondary curing to obtain fine silica balls; Degreasing and sintering: The fine silica balls are loaded into a crucible and placed together in a high-temperature sintering furnace. The fine silica balls are degreased and sintered in the high-temperature sintering furnace to produce a silica density standard float.

2. The method for preparing a silicon oxide density standard float according to claim 1, characterized in that: In the material mixing step, the grinding equipment for the mixed material is a three-roll grinder, the grinding speed is 300 rpm / min~500 rpm / min, the speed ratio is 1:3:9, and the number of roller passes is 3-5 times.

3. The method for preparing a silicon oxide density standard float according to claim 2, characterized in that: The silicon dioxide powder is one of hydrophilic and hydrophobic, and has a primary particle size of (7-500) nm or more; the photosensitive resin is formed by mixing oligomers, active diluents, photoinitiators, light absorbers, and dispersants.

4. The method for preparing a silicon oxide density standard float according to claim 3, characterized in that: The silica powder and the photosensitive resin are mixed in the following parts by mass: 1200-1500 parts of the silica powder, 100-200 parts of the oligomer, 600-900 parts of the active diluent, 1-20 parts of the photoinitiator, 1-5 parts of the light absorber, and 1-30 parts of the dispersant.

5. The method for preparing a silicon oxide density standard float according to claim 4, characterized in that: The oligomer is epoxy acrylate or aliphatic polyurethane acrylate; The active diluent is one of hydroxyethyl methacrylate, 4-hydroxybenzoate, 1,6-hexanediol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, trimethylolpropane triacrylate or pentaerythritol triacrylate, or a mixture of any proportions thereof; The photoinitiator is one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide or ethyl 2,4,6-trimethylbenzoylphenylphosphonate; The light absorber is one of Sudan I, Sudan Orange G or Sudan Red G; The dispersant is one of BYK-111 dispersant, BYK-2008 dispersant or BYK-2155 dispersant, or a mixture of any proportions of the dispersant.

6. The method for preparing a silicon oxide density standard float according to claim 5, characterized in that: In the 3D printing step, the light-curing 3D printing device is a DLP light-curing printer, the ultraviolet light wavelength is 365nm or 405nm, the bottom exposure time is 1-8s, the light power density is 0~72mW / cm2, and the coarse silica spheres are hollow thin-walled spheres with a diameter of (5~8)mm and a wall thickness of less than 1mm, with a hole with a diameter of less than 1mm on the top and bottom.

7. The method for preparing a silicon oxide density standard float according to claim 6, characterized in that: In the cleaning and curing steps, the cleaning process includes: using an ultrasonic cleaner filled with isopropyl alcohol or a cleaning agent to clean the coarse silica spheres 2-3 times to obtain cleaned silica sphere blanks; and the secondary curing process includes: using an air gun to blow out the uncured slurry in the pores on the surface of the silica sphere blanks, and using an ultraviolet lamp to fill the pores and perform secondary curing to obtain fine silica spheres.

8. The method for preparing a silicon oxide density standard float according to claim 7, characterized in that: In the degreasing and sintering steps, the crucible is a high-temperature resistant alumina crucible.

9. The method for preparing a silicon oxide density standard float according to claim 8, characterized in that: The degreasing treatment is to heat-remove the fine silica balls to burn off the components other than the silica particle powder; the sintering treatment is to perform high-temperature bonding and densification on the degreased green blank under different sintering environments, and the sintering environment is air, vacuum or inert atmosphere.

10. The method for preparing a silicon oxide density standard float according to claim 9, characterized in that: In the degreasing and sintering steps, the sintering process of the high-temperature sintering furnace is as follows: first, the temperature is raised from room temperature to 100°C~150°C at a rate of 0.5°C / min~1°C / min, and the temperature is kept for 60 minutes. Then, the temperature is raised to 250°C~400°C at a rate of 0.5°C / min~1°C / min, and the temperature is kept for 120 minutes. Then, the temperature is raised to 600°C~800°C at a rate of 2°C / min, and the temperature is kept for 60 minutes~180 minutes. Then, the temperature is raised to 1150°C~1300°C at a rate of 5°C / min, and the temperature is kept for 120 minutes~300 minutes. Finally, the temperature is cooled to room temperature as the furnace temperature is adjusted and the material is taken out.

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