Aerogel felt hydrophobic method and device
By mixing the hydrolyzate with the catalyst to form a sol and spraying a hydrophobic agent in the sealed environment, the problem of large amount and high cost of hydrophobic agent in the aerogel felt hydrophobic agent is solved, and an efficient and low-cost hydrophobic effect is achieved.
Patent Information
- Application Number
- CN202510139383.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-08
- Publication Date
- 2025-05-06
AI Technical Summary
Among the existing aerogel felt hydrophobic technology, the hydrophobic agent is used in large amounts and high costs, and the liquid and gas phase hydrophobic methods have problems such as long time, complex equipment, and reverse pollution.
The hydrolyzate and the catalyst are mixed to form a sol, the substrate and the sol form a wet gel felt, and then the hydrophobic agent is sprayed evenly in the sealed environment to ensure that the hydrophobic agent and the gel react fully and reduce the amount of hydrophobic agent.
The reaction efficiency of hydrophobic agent and gel is improved, the dosage and production cost of hydrophobic agent are significantly reduced, the complexity of equipment and the risk of reverse pollution are reduced, and the production efficiency is improved.
Smart Images
Figure CN119930261A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of aerogel preparation, and in particular to an aerogel felt hydrophobic method and device. Background Art
[0002] Aerogel is a gel material whose dispersion medium is gas. It has a highly cross-linked continuous three-dimensional network nano hollow structure and a large specific surface area (500-1300m 2 / g), low density (30-150Kg / m 3 ), high porosity (85%-99%), small average pore size (2-50nm), and lower thermal conductivity than room temperature air (0.01-0.02W / m·K), etc. It is currently recognized as the solid material with the lowest thermal conductivity.
[0003] In the process of hydrophobic treatment of aerogel matrix, the commonly used method is to modify aerogel felt or gel felt using liquid phase hydrophobicity or gas phase hydrophobicity. Liquid phase hydrophobicity and gas phase hydrophobicity have the following defects: separate operation steps and equipment are required, which is time-consuming, consumes a large amount of hydrophobic agent, and there will be a large amount of unreacted hydrophobic agent residue on the surface of the finished product.
[0004] The current technology also adopts premixing the hydrophobic agent with silica sol and then adding the catalyst gel, or premixing the hydrophobic agent with the catalyst and then adding the silica sol gel; however, this treatment method has the following defects: the hydrophobic agent participates in the hydrolysis and gelation, resulting in a smaller amount of hydrophobic agent involved in the modification, requiring more hydrophobic agent, thereby increasing the amount of hydrophobic agent used and high production costs.
[0005] Based on the above content, it is necessary to study a hydrophobic method and device for aerogel felt. Summary of the invention
[0006] In view of this, the object of the present invention is to provide an aerogel felt hydrophobic method and device, which effectively solves the problem of large amount of hydrophobic agent used and high cost.
[0007] To achieve the above purpose, the technical solution adopted by the present invention is: In a first aspect, a hydrophobic method for an aerogel felt comprises the following steps: Step 1, mixing the hydrolyzate with the catalyst to obtain a sol solution; Step 2, combining the substrate with the sol solution to form a gel to obtain a wet gel felt; Step 3, adding a hydrophobic agent to the surface of the wet gel felt to obtain a hydrophobic wet gel felt; Step 4: Finally, the hydrophobic wet gel felt is dried to obtain the aerogel felt.
[0008] Beneficial effects: In view of the problem of low utilization rate of hydrophobic agent in gas phase hydrophobicity and liquid phase hydrophobicity, the present invention first mixes the hydrolyzate with the catalyst to form a sol, combines the substrate with the sol to form a wet gel felt, and then sprays or rolls the hydrophobic agent on the wet gel felt. The present invention combines the hydrophobic agent and the sol with the substrate respectively, so that the hydrophobic agent directly reacts with the gel instead of combining with the gel through a medium such as alcohol, thereby improving the group substitution efficiency, thereby reducing the amount of the hydrophobic agent used and reducing the cost.
[0009] Furthermore, in step three, the hydrophobic agent is evenly sprayed on the surface of the wet gel felt in a sealed environment by spraying.
[0010] Beneficial effects: The present invention uses a contactless spraying method to spray the hydrophobic agent on the wet gel felt in a sealed environment, thereby avoiding contact between the equipment and the wet gel felt to cause reverse contamination. The invention is easy to use and simple to operate.
[0011] Furthermore, in terms of moles, the ratio of the hydrophobic agent to the sol is (15-40):800.
[0012] Furthermore, in a sealed environment, the hydrophobic agent is sprayed on the surface of the wet gel felt multiple times at the same time intervals and in the same amount.
[0013] Furthermore, the time interval is 60-180s, and the number of spraying times is 3-5 times.
[0014] Furthermore, the time interval is 180s and the number of spraying is 3 times. Beneficial effect: The present invention sprays the hydrophobic agent on the surface of the wet gel felt multiple times at equal time intervals, to ensure that the hydrophobic agent fully reacts with the gel, to ensure hydrophobicity, to reduce the amount of the hydrophobic agent used, and to save costs.
[0015] Furthermore, the wet gel felt is driven by a conveying roller to move through a sealed environment. In the sealed environment, multiple groups of spraying elements are arranged at intervals along the forward direction of the wet gel felt. The multiple groups of spraying elements spray hydrophobic agent on the wet gel felt passing therebelow in turn.
[0016] Beneficial effects: The present invention adopts a conveying roller as a transport carrier, so that the wet gel felt can pass through a sealed environment in a moving manner, thereby realizing the continuous production of aerogel felt. At the same time, through multiple groups of fixed-position spraying parts and movable wet gel felt bodies, a spraying working mode with equal time intervals and equal amounts can be realized.
[0017] Furthermore, the hydrophobic agent is any one of dimethyldiethoxysilane, methyltriethoxysilane and propyltriethoxysilane.
[0018] In a second aspect, an aerogel felt hydrophobic device is used to implement the above-mentioned aerogel felt hydrophobic method, comprising a conveying roller, a dipping tank, a sealing box, a spraying member and a drying box; the conveying roller is driven to rotate, and is used to tension and drive the substrate to move; a front guide roller and a rear guide roller are respectively arranged at the front and rear of the dipping tank, and the substrate is inclined to enter the dipping tank through the front guide roller, so that the substrate is immersed in the sol of the dipping tank; a glue replenishing component for replenishing the sol into the dipping tank is arranged on the dipping tank; After the substrate is combined with the sol in the dipping tank, it is guided by the rear guide roller and then enters the sealing box and the drying box in turn. Multiple groups of spray parts are arranged at intervals in the sealing box to form multiple spray stations arranged at intervals in the sealing box; the drying box is used to dry the wet gel felt.
[0019] Beneficial effects: The components such as the dipping tank, sealing box, spraying parts and drying box are used to form a complete automated production line, which can produce continuously without interruption, thus improving production efficiency and product quality.
[0020] Furthermore, the spraying member includes a first spraying head and a second spraying head, and the first spraying head and the second spraying head are respectively distributed on two sides of the wet gel felt and fixed to the sealing box.
[0021] Beneficial effect: By configuring the spray heads on both sides of the wet gel felt, it is possible to ensure that the upper and lower sides of the wet gel felt are sprayed simultaneously, thereby ensuring the uniformity of the spraying.
[0022] In summary, the present invention optimizes the hydrophobic method of aerogel felt, improves the reaction efficiency of the hydrophobic agent and the gel, reduces the dosage and production cost of the hydrophobic agent, improves the production efficiency, and provides strong support for the industrial production of aerogel felt. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a flow chart of the implementation method of the present invention; Figure 2 It is a structural schematic diagram of an implementation device of the present invention; Figure 3 Another schematic diagram of the structure of the device for implementing the present invention.
[0024] Figure numerals: 1-front guide roller, 2-glue dipping tank, 3-pressure roller, 4-rear guide roller, 5-rolling roller pair, 6-material receiving tank, 7-sealing box, 8-spray head, 9-collecting tank, 10-drying box, 10-adsorption block. DETAILED DESCRIPTION
[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments: Example 1. This example aims to provide an aerogel felt hydrophobic method, which is mainly used to produce hydrophobic aerogel felt. This example optimizes the aerogel felt hydrophobic process, reduces the amount of hydrophobic agent used, reduces the cost, and provides strong support for the industrial production of aerogel felt.
[0026] like Figure 1 As shown in, a hydrophobic method for aerogel felt comprises the following steps: Step 1: Mix the hydrolyzate with the catalyst to obtain a sol solution. In the specific implementation, the hydrolyzate and the catalyst are respectively stored in storage containers, the bottoms of the two storage containers are connected to a mixing container through metering valves, and the hydrolyzate and the catalyst are transported to the mixing container in proportion through the metering valve. The hydrolyzate and the catalyst are mixed in the mixing container to form a sol solution, and the sol solution is transferred to a temporary storage container for standby use.
[0027] Step 2: Combine the substrate and the sol solution to form a gel to obtain a wet gel felt; the process of combining the gel is: continuously injecting the sol into the dipping tank to ensure the liquid level of the dipping tank, spreading the substrate on the conveyor belt, and continuously moving through the dipping tank with the conveyor belt, so that the sol covers the substrate and immerses the sol into the substrate.
[0028] During implementation, a valve and a peristaltic pump are arranged at the bottom of the temporary storage container. During operation, the peristaltic pump continuously injects the sol into the immersion tank, or quantitatively injects the sol into the immersion tank according to the liquid level in the immersion tank. The above method ensures the amount of sol in the immersion tank, ensures that the sol can immerse the substrate, and enables the sol and the substrate to be fully combined.
[0029] Step three, spray or roll-coat the hydrophobic agent on the surface of the wet gel felt to obtain a hydrophobic wet gel felt; in this embodiment, the hydrophobic agent can be distributed on the wet gel felt by rolling or spraying.
[0030] First, a roller coating method is adopted. In the specific implementation, the hydrophobic agent is placed in a sealed material tank, a brush roller evenly obtains the hydrophobic agent from the material tank, and the hydrophobic agent is roller-coated onto the surface of the wet gel felt.
[0031] Second, the hydrophobic agent can be distributed on the surface of the wet gel felt by spraying. This method avoids direct contact with the sol, thereby avoiding reverse contamination. In specific implementation, the hydrophobic agent is evenly sprayed on the surface of the wet gel felt by spraying in a sealed environment.
[0032] The spraying operation mode is to spray the hydrophobic agent on the surface of the wet gel felt in equal amounts and multiple times at the same time interval. During the implementation, the wet gel felt is tensioned and conveyed forward under the action of the conveying roller, so that the wet gel felt can move through the sealed environment. In the sealed environment, multiple groups of spraying parts are arranged at intervals along the forward direction of the wet gel felt. As the wet gel felt moves forward, the multiple groups of spraying parts spray the hydrophobic agent on the wet gel felt passing below in turn.
[0033] Step 4: Finally, the hydrophobic wet gel felt is dried to obtain the aerogel felt.
[0034] This embodiment provides multiple groups of experimental examples to illustrate the feasibility of the hydrophobic method of this embodiment. Specifically, dimethyldiethoxysilane, methyltriethoxysilane, and propyltriethoxysilane are selected as hydrophobic agents for control experiments.
[0035] The specific experimental parameters are as follows: the same number of additions, the same amount added each time, and different intervals were used for the experiment. The amount of sol added was 800 ml, and the amounts of hydrophobic agent were 15 ml, 20 ml, 25 ml, 30 ml, 40 ml, and 50 ml, respectively. The hydrophobic agent was added in equal amounts for 5 times, and the time intervals for each addition were 15s, 30s, 60s, 120s, and 180s, respectively. The hydrophobic properties of the prepared hydrophobic aerogel felts were further tested. The test method was to soak each hydrophobic aerogel felt in water for 30 minutes and then take it out, and measure the percentage of the increased weight of the hydrophobic aerogel felt after soaking. The test results are shown in Table 1.
[0036] Table 1 From the above data, it can be seen that under the same conditions, the hydrophobicity of methyltriethoxysilane and propyltriethoxysilane as hydrophobic agents is weaker than that of dimethyldiethoxysilane, and dimethyldiethoxysilane as a hydrophobic agent has a better hydrophobic effect.
[0037] The hydrophobic agent uses dimethyldiethoxysilane. When the time interval is 180s, the ratio of hydrophobic dosage to sol is 40 / 800 and the ratio of hydrophobic dosage to sol is 50 / 800, the weight gain of aerogel felt is small and the hydrophobic performance is better. For dimethyldiethoxysilane, as the hydrophobic dosage increases, the hydrophobic performance is significantly improved, and the improvement is not obvious after reaching a certain amount. Therefore, it can be seen that the optimal ratio of dimethyldiethoxysilane is 40 / 800.
[0038] In general, the longer the interval time, the more significantly the hydrophobic performance is improved, and the optimal interval time is 180s. In order to further verify the effect of adding the same amount in multiple times with different addition times on the hydrophobicity when the time interval is 180s, the following experiment was conducted in this example.
[0039] The specific experimental parameters are as follows: the amount of sol added is 800 ml, the amount of hydrophobic agent used is 15 ml, 20 ml, 25 ml, 30 ml, 40 ml, 50 ml respectively, the hydrophobic agent is added in equal amounts once, twice, three times, four times and five times, the time interval for each addition is 180 s, and the hydrophobicity at the corresponding addition time interval is calculated respectively; the specific experimental results are shown in Table 2; Table 2 From the above content, it can be seen that under the same conditions, the hydrophobicity of dimethyldiethoxysilane is better than that of methyltriethoxysilane and propyltriethoxysilane; for dimethyldiethoxysilane, equal amounts are added multiple times, and as the amount of hydrophobic agent increases, after the hydrophobic dosage is reached, the difference in hydrophobicity is not large after adding 3-5 times. Considering production cost and efficiency, therefore, adding 3 times is the best implementation method.
[0040] This embodiment optimizes and improves the hydrophobic method of aerogel felt and illustrates it through multiple groups of experiments, which can ensure the hydrophobicity of the felt body. Since the hydrophobic agent and the sol are separately combined with the substrate in this embodiment, the participation of the hydrophobic agent in the hydrolysis and gelation processes is avoided, thereby significantly reducing the amount of hydrophobic agent used and reducing the cost, providing strong support for the efficient and low-cost industrial production of aerogel felt.
[0041] Example 2 This embodiment provides an apparatus for implementing the aerogel felt hydrophobic method in Example 1.
[0042] The present embodiment provides an aerogel felt hydrophobic device, comprising a conveying roller, a dipping tank 2, a sealing box 7, a spraying member 8 and a drying box 10; the conveying roller is driven to rotate, and the conveying roller is used to tension and convey the substrate; a front guide roller 1 and a rear guide roller 4 are respectively arranged at the front and rear of the dipping tank 2, and the substrate enters the dipping tank 2 obliquely through the front guide roller, so that the substrate is immersed in the sol of the dipping tank 2; a glue replenishing component for replenishing the sol in the dipping tank 2 is arranged on the dipping tank 2, The glue filling component includes a peristaltic pump, a first storage container, a second storage container and a mixing container; the first storage container is used to store the hydrolyzate, and the second storage container is used to store the catalyst. The two are connected to the mixing container via a valve and a meter, respectively, so that the hydrolyzate and the catalyst are added to the mixing container in a specific ratio. The hydrolyzate and the catalyst added to the mixing container are mixed at a certain temperature, and then transferred to a temporary storage container after mixing. The temporary storage container is connected to the glue dipping tank 2 via a valve and a peristaltic pump, so that the sol is continuously injected into the glue dipping tank 2.
[0043] During implementation, the dipping tank 2 has a pressure roller 3, which immerses the substrate into the dipping tank 2. After the substrate comes out of the dipping tank 2, it is guided by the rear guide roller 4 and then enters the sealing box 7 and the drying box 10 in sequence. A rolling roller 5 is also arranged between the rear guide roller and the pressure roller to squeeze the surface of the sol, so that the thermal insulation slurry inside the fiber felt is evenly distributed. At the same time, the excess sol is squeezed out to control the thickness of the felt body, thereby ensuring the uniformity of the product thickness and the flatness of the surface and interior of the felt body. The extruded sol falls into the receiving tank 6 for storage or is repeatedly refluxed to the dipping tank 2 after treatment.
[0044] Multiple groups of spraying parts 8 are arranged at intervals in the sealing box 7, which are used to form multiple spraying stations arranged at intervals in the sealing box 7; in this embodiment, the spraying parts 8 are spray heads, and the multiple spray heads are connected to the pump, valve assembly and hydrophobic agent storage tank through pipelines. By forming multiple fixed spraying stations at intervals in the sealing box 7, the wet gel felt is sprayed as the wet gel felt moves, and the movement and transportation of the wet gel felt is set to be constant. By controlling the spacing between the spraying stations, the spraying time interval is controlled. At the same time, a collecting tank 9 is set at the lower part of the sealing box 7 to collect excess hydrophobic agent, and the collected hydrophobic agent is recycled after treatment and reused.
[0045] The spray part includes a first spray head and a second spray head, which are respectively relatively distributed on both sides of the wet gel felt and fixed in a sealed box. During implementation, the wet gel felt can be arranged horizontally, and the first spray head and the second spray head are distributed on the upper and lower sides of the wet gel felt, or the wet gel felt can be arranged vertically, and the first spray head and the second spray head are distributed on the left and right sides of the wet gel felt. This embodiment can avoid uneven spraying caused by the gravity of the hydrophobic agent, and ensure that both sides of the wet gel felt are sprayed evenly. This embodiment can ensure that the upper and lower sides of the wet gel felt are sprayed simultaneously by configuring spray heads on both sides of the wet gel felt, thereby ensuring the uniformity of the spraying.
[0046] Since the hydrophobic agent is volatile, in order to prevent it from diffusing into the environment, an adsorption block 11 is arranged at the inlet of the sealed box to adsorb the diffused gas at the inlet and outlet.
[0047] The drying box 10 is used to dry the wet gel felt. At present, the processes for drying aerogels include supercritical drying, atmospheric pressure drying, freeze drying, subcritical drying, etc. Among them, the process that keeps the aerogel structure most intact and is easiest to achieve industrial production is the supercritical process. Commonly used supercritical processes are supercritical carbon dioxide drying and supercritical ethanol drying, among which supercritical carbon dioxide drying is the mainstream.
[0048] This embodiment realizes the glue dipping, multi-station spraying and drying operations of the substrate through the above-mentioned device, and can carry out uninterrupted continuous production, thereby improving production efficiency and product quality.
[0049] The embodiments of the present invention described above do not constitute a limitation on the protection scope of the present invention. The basic concept of the present invention is to optimize the hydrophobic method of aerogel felt, avoid the hydrophobic agent from participating in the hydrolysis and gelation process, reduce the amount of hydrophobic agent and production cost, improve production efficiency, and provide strong support for the industrial production of aerogel felt. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.
Claims
1. A hydrophobic method for aerogel felt, characterized in that: The following steps are included Step 1, mixing the hydrolyzate with the catalyst to obtain a sol solution; Step 2, combining the substrate with the sol solution to form a gel to obtain a wet gel felt; Step 3, adding a hydrophobic agent to the surface of the wet gel felt to obtain a hydrophobic wet gel felt; Step 4: Finally, the hydrophobic wet gel felt is dried to obtain the aerogel felt.
2. The aerogel felt hydrophobic method according to claim 1, characterized in that: In step three, the hydrophobic agent is evenly sprayed on the surface of the wet gel felt in a sealed environment by spraying.
3. The aerogel felt hydrophobic method according to claim 2, characterized in that: In terms of moles, the ratio of the hydrophobic agent to the sol is (15-40):
800.
4. The hydrophobic method for aerogel felt according to claim 3, characterized in that: In a sealed environment, the hydrophobic agent is sprayed on the surface of the wet gel felt multiple times at the same time interval and in the same amount.
5. The aerogel felt hydrophobic method according to claim 4, characterized in that: The time interval is 60-180s, and the number of spraying times is 3-5 times.
6. The aerogel felt hydrophobic method according to claim 5, characterized in that: The time interval is 180s, and the number of spraying is 3 times.
7. The aerogel felt hydrophobic method according to claim 2, characterized in that: The wet gel felt is driven by a conveying roller to move through a sealed environment. In the sealed environment, multiple groups of spraying elements are arranged at intervals along the forward direction of the wet gel felt. The multiple groups of spraying elements spray hydrophobic agent on the wet gel felt passing therebelow in turn.
8. The hydrophobic method for aerogel felt according to any one of claims 1 to 7, characterized in that: The hydrophobic agent is any one of dimethyldiethoxysilane, methyltriethoxysilane and propyltriethoxysilane.
9. An aerogel felt hydrophobic device, used for implementing the aerogel felt hydrophobic method according to any one of claims 1 to 6, characterized in that: It includes a conveying roller, a glue dipping tank, a sealing box, a spraying part and a drying box; the conveying roller is driven to rotate to tension and drive the substrate to move; the front and rear guide rollers are respectively arranged at the front and rear of the glue dipping tank, and the substrate enters the glue dipping tank obliquely through the front guide roller, so that the substrate is immersed in the sol of the glue dipping tank; a glue replenishing component for replenishing the sol into the glue dipping tank is arranged on the glue dipping tank; After the substrate is combined with the sol in the dipping tank, it is guided by the rear guide roller and then enters the sealing box and the drying box in turn. Multiple groups of spray parts are arranged at intervals in the sealing box to form multiple spray stations arranged at intervals in the sealing box; the drying box is used to dry the wet gel felt.
10. The hydrophobic method for aerogel felt according to claim 9, characterized in that: The spraying member comprises a first spraying head and a second spraying head. The first spraying head and the second spraying head are respectively and relatively distributed on two sides of the wet gel felt and fixed on the sealing box.