A high-silica glass fiber cloth and a method for manufacturing the same

Abstract

The application provides a preparation method of high-silica glass fiber cloth, comprising the step of acid leaching treatment of the glass fiber cloth, the acid leaching treatment comprising: ultrasonic acid washing of the glass fiber cloth in multiple stages by using acid solution; wherein the ultrasonic power and the ultrasonic time of each stage are different in the ultrasonic acid washing process. In the application, in the acid leaching treatment process of the glass fiber cloth, the glass fiber cloth is mixed with the acid solution in multiple stages for ultrasonic acid washing, and the ultrasonic power and the ultrasonic time of each stage are controlled, so that the acid solution and the fibers in the glass fiber cloth can chemically react at high speed, fast and uniformly, thereby precipitating the non-silicon oxides (Na2O and B2O3) in the fibers to the acid solution, and further significantly improving the SiO2 content in the glass fiber cloth.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of glass fiber, in particular to a high-silica glass fiber cloth and a preparation method thereof. BACKGROUND

[0002] High-silica glass fiber is a kind of high-tech inorganic material, the content of SiO2 is generally greater than 96%, the softening point is close to 1500 DEG C, and it can be used for a long time in the environment of 900 DEG C. It is a kind of high-performance special glass fiber, which has excellent properties such as high temperature resistance, wave transmission, light weight, etc., and is widely used in the fields of high-temperature heat insulation protection and wave transmission, heat preservation and protection materials of spacecraft.

[0003] In order to ensure the temperature resistance of high-silica glass fiber cloth, the content of silicon dioxide of high-silica glass fiber cloth needs to be greater than 96%, and the acid leaching process directly determines the content of silicon dioxide of high-silica fiber products. Therefore, in order to improve the content of SiO2 in the glass fiber cloth, the glass fiber cloth needs to be treated by acid leaching after weaving to improve the content of SiO2 in the glass fiber cloth. However, the silicon content of the glass fiber cloth treated by acid leaching in the prior art is unstable, and the content of SiO2 in the glass fiber cloth can only reach 90% at most, which leads to that the high-temperature resistance of high-silica glass fiber cloth cannot be guaranteed.

[0004] Therefore, based on the above problems, it is necessary to provide a high-silica glass fiber cloth and a preparation method thereof. SUMMARY

[0005] The embodiment of the present application provides a high-silica glass fiber cloth and a preparation method thereof. The content of SiO2 in the high-silica glass fiber cloth obtained by the preparation method is as high as 96%, so that the high-silica glass fiber cloth has good high-temperature resistance.

[0006] In the first aspect, the present application provides a preparation method of high-silica glass fiber cloth, which comprises the step of acid leaching treatment of glass fiber cloth, characterized in that the acid leaching treatment comprises: ultrasonic acid washing of the glass fiber cloth with acid liquid in multiple stages; wherein the ultrasonic power and the ultrasonic time of each stage are different in the ultrasonic acid washing process.

[0007] Preferably, the glass fiber cloth is mixed with acid liquid for ultrasonic acid washing in four stages in turn; wherein the acid washing temperature of each stage is different in the ultrasonic acid washing process.

[0008] Preferably, in the ultrasonic acid washing process, the ultrasonic power, the ultrasonic time and the acid washing temperature increase in turn from the first stage to the fourth stage.

[0009] Preferably, in the ultrasonic acid washing process:

[0010] The ultrasonic power of the first stage is 50-70W, the ultrasonic time is 10-15min, and the pickling temperature is 60-80℃;

[0011] The ultrasonic power of the second stage is 70-85W, the ultrasonic time is 20-25min, and the pickling temperature is 80-90℃;

[0012] The ultrasonic power of the third stage is 85-90W, the ultrasonic time is 30-35min, and the pickling temperature is 90-95℃;

[0013] The ultrasonic power of the fourth stage is 90-95W, the ultrasonic time is 30-35min, and the pickling temperature is 95-100℃.

[0014] Preferably, the ultrasonic frequency of each stage in the ultrasonic pickling process is 45-50kHz.

[0015] Preferably, the fiber diameter in the glass fiber cloth is not more than 13μm;

[0016] More preferably, the fiber diameter is 6-9μm.

[0017] Preferably, the acid solution is at least one of hydrochloric acid or sulfuric acid.

[0018] Preferably, the equivalent concentration of the acid solution is 3-3.3N.

[0019] Preferably, after the ultrasonic pickling, the process further comprises the step of sequentially performing ultrasonic water washing on the ultrasonic-pickled glass fiber cloth in multiple stages; wherein the ultrasonic power, the ultrasonic frequency, the ultrasonic time and the water washing temperature of each stage in the ultrasonic water washing process are different.

[0020] Preferably, the ultrasonic-pickled glass fiber cloth is sequentially washed in two stages; wherein the ultrasonic power, the ultrasonic frequency, the ultrasonic time and the water washing temperature sequentially decrease from the first stage to the second stage in the ultrasonic pickling process.

[0021] Preferably, in the ultrasonic water washing process:

[0022] The ultrasonic power of the first stage is 250-300W, the ultrasonic frequency is 28-30kHz, the ultrasonic time is 30-35min, and the water washing temperature is 60-90℃;

[0023] The ultrasonic power of the second stage is 200-240W, the ultrasonic frequency is 25-27kHz, the ultrasonic time is 25-30min, and the water washing temperature is 25-60℃.

[0024] More preferably, after the ultrasonic water washing, the pH value of the glass fiber cloth is greater than or equal to 6.

[0025] In a second aspect, the present application provides a high-silica glass fiber cloth prepared by the method of any one of the first aspect.

[0026] Compared with the prior art, the present application has at least the following beneficial effects:

[0027] (1) In the present application, during the acid leaching treatment of the glass fiber cloth, the glass fiber cloth is mixed with the acid solution in multiple stages for ultrasonic acid washing, and the ultrasonic power and ultrasonic time of each stage are controlled, so that the acid solution and the fibers in the glass fiber cloth can react at high speed, fast and uniformly, thereby precipitating the non-silicon oxides (Na2O and B2O3) in the fibers to the acid solution, and further significantly increasing the SiO2 content in the glass fiber cloth.

[0028] (2) In some preferred embodiments of the present application, after acid leaching, the acid-leached glass fiber cloth is further subjected to ultrasonic water washing in two stages, and the fibers of the fiber cloth are repeatedly impacted by ultrasonic waves, so that the residual acid solution in the glass fiber cloth is fully washed, and the water washing time of the fiber cloth is shortened, and the production efficiency of the high-silica glass fiber cloth is improved.

[0029] (3) In the present application, during the preparation of the high-silica glass fiber cloth, the method of ultrasonic-assisted acid leaching and water washing can not only significantly increase the SiO2 content in the high-silica glass fiber cloth and ensure the high-temperature resistance of the high-silica glass fiber cloth, but also significantly improve the production efficiency of the high-silica glass fiber cloth. The acid leaching and water washing process in the present application is time-saving, efficient and quality-controllable, and is suitable for mass production. DETAILED DESCRIPTION

[0030] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] The silica content in high-silica glass fiber cloth generally determines its high-temperature resistance. In order to ensure the good high-temperature resistance of high-silica glass fiber cloth, the glass fiber cloth needs to be subjected to acid leaching treatment after weaving to increase the silica content in the high-silica glass fiber cloth and thus ensure its high-temperature resistance. However, with the development of high-silica glass fiber post-treatment technology and the increasing requirement for environmental protection, the acid tank volume of the original acid leaching treatment is reduced, resulting in low production efficiency. Moreover, after the glass fiber cloth is subjected to acid leaching treatment in the intermittent mode in the prior art, the silicon content in the obtained glass fiber cloth is unstable, and the SiO2 content in the glass fiber cloth can only reach 90% at most, which makes it impossible to ensure the high-temperature resistance of the glass fiber cloth, and the acid leaching process cannot meet the needs of large-scale, rapid and stable production.

[0032] Therefore, based on one or more of the above problems, the embodiments of the present application provide a preparation method of high-silica glass fiber cloth, which comprises the step of acid leaching treatment of the glass fiber cloth, and the acid leaching treatment comprises: ultrasonic acid washing of the glass fiber cloth in multiple stages by using acid solution; wherein the ultrasonic power and the ultrasonic time of each stage are different in the ultrasonic acid washing process.

[0033] In the acid leaching treatment process of the glass fiber cloth, the glass fiber cloth is mixed with the acid solution for ultrasonic acid washing in multiple stages, and the ultrasonic power and the ultrasonic time of each stage are controlled, so that the acid leaching process can be appropriately strengthened, the acid solution can be ensured to fully contact with the glass fiber cloth, the chemical reaction between the acid solution and the fibers in the glass fiber cloth can be high-speed, rapid and uniform, the non-silicon oxides (Na2O and B2O3) in the fibers can be precipitated into the acid solution, the SiO2 content in the glass fiber cloth is significantly increased, and the good temperature resistance of the glass fiber cloth is ensured.

[0034] According to some preferred embodiments, the glass fiber cloth is subjected to ultrasonic acid washing in four stages by using acid solution; wherein the acid washing temperature of each stage is different in the ultrasonic acid washing process.

[0035] According to some preferred embodiments, in the ultrasonic acid washing process, the ultrasonic power, the ultrasonic time and the acid washing temperature gradually increase from the first stage to the fourth stage.

[0036] In the embodiment of the present application, the present inventors consider that the concentration of acid, the temperature of acid, the ultrasonic power and the ultrasonic time will all affect the acid leaching process of the glass fiber cloth during the acid leaching process. Therefore, in the present application, the acid is used to sequentially perform ultrasonic acid washing on the glass fiber cloth in four stages, and during the ultrasonic acid washing process from the first stage to the fourth stage, the parameters such as ultrasonic power, ultrasonic time and acid washing temperature are gradually increased. In this way, not only can the fibers in the glass fiber cloth be efficiently and quickly chemically reacted with the acid, but also the reaction between the fibers and the acid in each stage can be ensured, thereby facilitating the precipitation of non-silicon oxides Na2O and B2O3 in the fibers into the acid, improving the processing efficiency of acid leaching, and ensuring the high-temperature resistance of high-silicon glass fiber cloth.

[0037] In the embodiment of the present application, the ultrasonic acid washing process is preferably divided into four stages. In this way, not only can the silicon dioxide content of the glass fiber cloth after acid washing be as high as 96% or more, but also the process processing time and waste liquid can be reduced. If the number of ultrasonic acid washing is reduced, it is not conducive to ensuring the silicon dioxide content in the glass fiber cloth. Increasing the number of ultrasonic acid washing can increase the silicon dioxide content in the glass fiber cloth to a certain extent, but with the increase of the number of ultrasonic acid washing, the silicon dioxide content in the glass fiber cloth increases very little, and a large amount of acid washing wastewater is produced, thereby increasing the process cost.

[0038] According to some preferred embodiments, in the ultrasonic acid washing process:

[0039] The ultrasonic power of the first stage is 50-70 W (for example, it can be 50 W, 55 W, 60 W, 65 W or 70 W), the ultrasonic time is 10-15 min (for example, it can be 10 min, 12 min, 13 min, 14 min or 15 min), and the acid washing temperature is 60-80℃ (for example, it can be 60℃, 65℃, 70℃, 75℃ or 80℃), more preferably 75-76℃;

[0040] The ultrasonic power of the second stage is 70-85 W (for example, it can be 70 W, 75 W, 80 W or 70 W), the ultrasonic time is 20-25 min (for example, it can be 20 min, 22 min, 23 min, 24 min or 25 min), and the acid washing temperature is 80-90℃ (for example, it can be 80℃, 82℃, 85℃, 88℃, or 90℃), more preferably 85-86℃;

[0041] The ultrasonic power of the third stage is 85-90 W (for example, it can be 85 W, 86 W, 87 W, 88 W or 90 W), the ultrasonic time is 30-35 min (for example, it can be 30 min, 32 min, 33 min, 34 min or 35 min), the pickling temperature is 90-95℃ (for example, it can be 90℃, 92℃, 93℃, 94℃ or 95℃), and more preferably 94-95℃;

[0042] The ultrasonic power of the fourth stage is 90-95 W (for example, it can be 90 W, 92 W, 93 W, 94 W or 95 W), the ultrasonic time is 30-35 min (for example, it can be 30 min, 32 min, 33 min, 34 min or 35 min), the pickling temperature is 95-100℃ (for example, it can be 95℃, 96℃, 97℃, 98℃, 99℃ or 100℃), and more preferably 97-98℃.

[0043] In the embodiment of the present application, the ultrasonic wave is used to assist the acid leaching process of the glass fiber cloth, and the ultrasonic pickling conditions of each stage are controlled. By using the cavitation effect and strong penetration ability of the ultrasonic wave and suitable temperature conditions, the acid solution can rapidly and uniformly react with the fibers of the glass fiber cloth, and Na2O and B2O3 in the fibers are precipitated into the acid solution. At the same time, the ultrasonic wave can also make the acid solution quickly pass through the pores on the surface of the fiber cloth or open the blocked micropores in the fiber cloth, thereby significantly increasing the specific surface area of the glass fiber and improving the acid leaching efficiency. If the power of the ultrasonic wave in each stage is too large or the ultrasonic time is too long, the fibers in the fiber cloth will be broken, resulting in low strength of the fiber cloth. If the power of the ultrasonic wave in each stage is too small or the ultrasonic time is too short, it is not conducive to the chemical reaction between the acid solution and the fibers in the glass fiber cloth, and it is not conducive to ensuring the acid leaching efficiency of the glass fiber cloth.

[0044] According to some preferred embodiments, in the ultrasonic pickling process, the ultrasonic frequency of each stage is 45-50 kHz (for example, it can be 45 kHz, 46 kHz, 47 kHz, 48 kHz, 49 kHz or 50 kHz).

[0045] In this embodiment of the invention, the ultrasonic frequency is controlled to be the same in each stage. Under certain temperature conditions, the ultrasonic power and ultrasonic time are continuously increased. This allows the non-silicon oxides in the glass fiber cloth to precipitate quickly and fully in the acid solution. During the ultrasonic acid washing process, the first stage can replace 5-10% of the non-silicon oxides in the glass fiber cloth, the second stage can replace 15-20% of the non-silicon oxides in the glass fiber cloth, the third stage can replace 40-45% of the non-silicon oxides in the glass fiber cloth, and the fourth stage can replace 30-35% of the non-silicon oxides in the glass fiber cloth. As a result, the silica content in the final glass fiber cloth is as high as 96% or more, thereby ensuring that the glass fiber cloth has good high temperature resistance.

[0046] According to some preferred embodiments, the fiber diameter in the glass fiber cloth is not greater than 13 μm;

[0047] According to some more preferred embodiments, the diameter of the fiber is 6 to 9 μm (e.g., it can be 6 μm, 7 μm, 8 μm or 9 μm).

[0048] In this embodiment of the invention, the glass fiber cloth is preferably woven with fiber diameters within the aforementioned diameter range. This helps to ensure a larger specific surface area of ​​the fiber cloth, which in turn facilitates the leaching of non-silicon oxides during the acid leaching process.

[0049] According to some preferred embodiments, the acid solution is at least one of hydrochloric acid or sulfuric acid;

[0050] The equivalent concentration of the acid solution is 3 to 3.3N (for example, it can be 3N, 3.1N or 3.3N).

[0051] In this embodiment of the invention, hydrochloric acid or sulfuric acid, which are relatively strong acids, are used to ultrasonically pickle the glass fiber cloth. By preferably setting the equivalent concentration of the acid solution within the range mentioned above, the pickling time can be shortened while ensuring the strength of the glass fiber cloth. This experiment has confirmed that if the equivalent concentration of the acid solution is too high, the fibers in the glass fiber cloth will break, which is not conducive to ensuring the strength of the glass fiber cloth. If the equivalent concentration of the acid solution is too low, in order to ensure the silica content in the glass fiber cloth, the pickling time will be longer and the acid leaching efficiency will be lower.

[0052] It should be noted that, since hydrochloric acid is volatile in the air and sulfuric acid is hygroscopic in the air, the ultrasonic pickling in this invention is preferably carried out in a strictly sealed environment. This helps to ensure the acid concentration during the ultrasonic pickling process, thereby ensuring the efficiency of ultrasonic pickling.

[0053] According to some preferred embodiments, after ultrasonic acid washing, the process further includes: performing ultrasonic water washing on the ultrasonically acid-washed glass fiber cloth in multiple stages; wherein, during the ultrasonic water washing process, the ultrasonic power, ultrasonic frequency, ultrasonic time, and water washing temperature are different in each stage.

[0054] According to some more preferred embodiments, the ultrasonically acid-washed glass fiber cloth is ultrasonically washed in two stages; wherein, during the ultrasonic acid washing process, the ultrasonic power, ultrasonic frequency, ultrasonic time, and water washing temperature decrease sequentially from the first stage to the second stage.

[0055] In this embodiment of the invention, after acid leaching, the glass fiber cloth is further subjected to ultrasonic washing in two stages. The shock waves generated by the sudden closure of cavitation bubbles produced by ultrasound, and the further control of parameters such as ultrasonic power, frequency, duration, and temperature in each washing stage, generate thousands of atmospheres of pressure around the fibers of the glass fiber cloth. This repeatedly and directly impacts the fiber surface. This impact force, on the one hand, breaks the adsorption force between the precipitates (non-silicon oxides) from the acid washing process and the fiber surface, thus thoroughly cleaning the residual acid and non-silicon oxides in the glass fiber cloth. On the other hand, the bubbles generated by ultrasonic cavitation can continue to penetrate into the internal gaps and voids of the glass fiber cloth, thereby improving the washing effect and efficiency, and ensuring that the silica content of the high-silica glass fiber cloth meets the standards.

[0056] According to some preferred embodiments, during the ultrasonic water washing process:

[0057] The ultrasonic power of the first stage is 250-300W (e.g., 250W, 260W, 270W, 280W, 290W or 300W), the ultrasonic frequency is 28-30kHz (e.g., 28kHz, 29kHz or 30kHz), the ultrasonic time is 30-35min (e.g., 30min, 32min, 34min or 35min), and the water washing temperature is 60-90℃ (e.g., 60℃, 70℃, 80℃ or 90℃).

[0058] The ultrasonic power of the second stage is 200–240W (e.g., 200W, 210W, 220W, 230W, or 240W), the ultrasonic frequency is 25–27kHz (e.g., 25kHz, 26kHz, or 27kHz), the ultrasonic time is 25–30min (e.g., 25min, 26min, 27min, 28min, or 30min), and the water washing temperature is 25–60℃ (e.g., 25℃, 30℃, 40℃, 50℃, or 60℃).

[0059] According to some preferred embodiments, after ultrasonic washing, the pH value of the glass fiber cloth is greater than or equal to 6.

[0060] In this embodiment of the invention, since ultrasonic acid washing will precipitate non-silicon oxides in the glass fiber cloth, thereby increasing the porosity and grooves of the glass fiber cloth, after acid washing, ultrasonic-assisted two-stage water washing of the glass fiber cloth is further adopted, and the ultrasonic power, ultrasonic frequency, ultrasonic time and water washing temperature are gradually reduced. This can accelerate the water washing efficiency of the glass fiber cloth and ensure that the acid and impurities in the glass fiber cloth are fully washed away, and achieve the standard of silica content in the glass fiber cloth.

[0061] The present invention also provides a high-silica glass fiber cloth, which is prepared by the preparation method provided in the present invention.

[0062] In the preparation of high-silica glass fiber cloth, this invention employs a staged ultrasonic-assisted acid leaching and water washing method. By controlling parameters such as ultrasonic power and frequency at each stage, and appropriately enhancing acid circulation, the fiber and acid are fully mixed, and the increased flow facilitates the diffusion of substances during the reaction, allowing the acid reaction to quickly reach equilibrium. This not only significantly increases the SiO2 content in the high-silica glass fiber cloth, ensuring its high-temperature resistance, but also significantly improves the production efficiency. The acid leaching and water washing process in this invention is time-efficient, low-cost, highly efficient, and has controllable quality, making it suitable for mass production.

[0063] Unlike existing acid washing and water washing processes, which can lead to uneven silica content in thicker glass fiber cloths, the ultrasonic acid washing and ultrasonic water washing processes in this invention have a wide range of applications. They are not only suitable for glass fiber cloths of common thicknesses currently on the market, but also for thick glass fiber cloths with a thickness of 1.2 mm or more.

[0064] To more clearly illustrate the technical solution and advantages of the present invention, the following detailed description of a high-silica glass fiber cloth and its preparation method is provided through several embodiments.

[0065] Example 1:

[0066] (1) Provide glass fiber cloth; wherein the fiber diameter of the glass fiber cloth is 9μm;

[0067] (2) The glass fiber cloth was ultrasonically pickled in four stages using acid solution (hydrochloric acid with an equivalent concentration of 3N). During the ultrasonic pickling process: the ultrasonic power of the first stage was 70W, the ultrasonic frequency was 50kHz, the ultrasonic time was 15min, and the pickling temperature was 70℃; the ultrasonic power of the second stage was 85W, the ultrasonic frequency was 50kHz, the ultrasonic time was 25min, and the pickling temperature was 80℃; the ultrasonic power of the third stage was 90W, the ultrasonic frequency was 50kHz, the ultrasonic time was 35min, and the pickling temperature was 90℃; the ultrasonic power of the fourth stage was 95W, the ultrasonic frequency was 50kHz, the ultrasonic time was 35min, and the pickling temperature was 100℃.

[0068] (3) The glass fiber cloth after ultrasonic acid pickling is subjected to ultrasonic water washing in two stages. During the ultrasonic water washing process: the ultrasonic power of the first stage is 300W, the ultrasonic frequency is 30kHz, the ultrasonic time is 35min, and the water washing temperature is 90℃; the ultrasonic power of the second stage is 240W, the ultrasonic frequency is 25kHz, the ultrasonic time is 30min, and the water washing temperature is 60℃.

[0069] Example 2:

[0070] (1) Provide glass fiber cloth; wherein the fiber diameter of the glass fiber cloth is 6μm;

[0071] (2) The glass fiber cloth was ultrasonically pickled in four stages using acid solution (hydrochloric acid with an equivalent concentration of 3.2N). During the ultrasonic pickling process: the ultrasonic power of the first stage was 50W, the ultrasonic frequency was 45kHz, the ultrasonic time was 15min, and the pickling temperature was 80℃; the ultrasonic power of the second stage was 70W, the ultrasonic frequency was 45kHz, the ultrasonic time was 20min, and the pickling temperature was 90℃; the ultrasonic power of the third stage was 85W, the ultrasonic frequency was 45kHz, the ultrasonic time was 30min, and the pickling temperature was 92℃; the ultrasonic power of the fourth stage was 90W, the ultrasonic frequency was 45kHz, the ultrasonic time was 40min, and the pickling temperature was 98℃.

[0072] (3) The glass fiber cloth after ultrasonic acid pickling is subjected to ultrasonic water washing in two stages. During the ultrasonic water washing process: the ultrasonic power of the first stage is 250W, the ultrasonic frequency is 28kHz, the ultrasonic time is 30min, and the water washing temperature is 70℃; the ultrasonic power of the second stage is 200W, the ultrasonic frequency is 25kHz, the ultrasonic time is 30min, and the water washing temperature is 30℃.

[0073] Example 3:

[0074] (1) Provide glass fiber cloth; wherein the fiber diameter of the glass fiber cloth is 10μm;

[0075] (2) The glass fiber cloth was ultrasonically pickled in four stages using acid solution (sulfuric acid with an equivalent concentration of 3.3N). During the ultrasonic pickling process: the ultrasonic power of the first stage was 60W, the ultrasonic frequency was 50kHz, the ultrasonic time was 15min, and the pickling temperature was 88℃; the ultrasonic power of the second stage was 750W, the ultrasonic frequency was 50kHz, the ultrasonic time was 25min, and the pickling temperature was 92℃; the ultrasonic power of the third stage was 88W, the ultrasonic frequency was 50kHz, the ultrasonic time was 35min, and the pickling temperature was 95℃; the ultrasonic power of the fourth stage was 92W, the ultrasonic frequency was 50kHz, the ultrasonic time was 40min, and the pickling temperature was 98℃.

[0076] (3) The glass fiber cloth after ultrasonic acid pickling is subjected to ultrasonic water washing in two stages. During the ultrasonic water washing process: the ultrasonic power of the first stage is 280W, the ultrasonic frequency is 30kHz, the ultrasonic time is 35min, and the water washing temperature is 60℃; the ultrasonic power of the second stage is 230W, the ultrasonic frequency is 26kHz, the ultrasonic time is 25min, and the water washing temperature is 25℃.

[0077] Example 4:

[0078] Example 4 is basically the same as Example 1, except that in step (1), the fiber diameter of the glass fiber cloth is 7 μm.

[0079] Example 5:

[0080] Example 5 is basically the same as Example 4, except that in step (3), the glass fiber cloth after ultrasonic acid washing is ultrasonically washed; wherein, the ultrasonic power during the ultrasonic washing process is 280W, the ultrasonic frequency is 30kHz, the ultrasonic time is 60min, and the water washing temperature is 60℃.

[0081] Example 6:

[0082] Example 6 is basically the same as Example 4, except that step (3) is removed, that is, the glass fiber cloth after ultrasonic acid washing is not ultrasonically washed.

[0083] Example 7:

[0084] Example 7 is basically the same as Example 6, except that in step (2), the glass fiber cloth is ultrasonically pickled in three stages using acid solution (sulfuric acid with an equivalent concentration of 3.3N). During the ultrasonic pickling process: the ultrasonic power of the first stage is 60W, the ultrasonic frequency is 50kHz, the ultrasonic time is 15min, and the pickling temperature is 88℃; the ultrasonic power of the second stage is 75W, the ultrasonic frequency is 50kHz, the ultrasonic time is 25min, and the pickling temperature is 92℃; the ultrasonic power of the third stage is 88W, the ultrasonic frequency is 50kHz, the ultrasonic time is 75min, and the pickling temperature is 95℃.

[0085] Example 8:

[0086] Example 8 is basically the same as Example 7, except that in step (2), the glass fiber cloth is ultrasonically pickled in two stages using acid solution (sulfuric acid with an equivalent concentration of 3.3N); wherein, in the ultrasonic pickling process: the ultrasonic power of the first stage is 60W, the ultrasonic frequency is 50kHz, the ultrasonic time is 65min, and the pickling temperature is 88℃; the ultrasonic power of the second stage is 75W, the ultrasonic frequency is 50kHz, the ultrasonic time is 65min, and the pickling temperature is 92℃.

[0087] Example 9:

[0088] Example 8 is basically the same as Example 4, except that in step (2), the equivalent concentration of the acid solution is 3.5N.

[0089] Example 10:

[0090] Example 10 is basically the same as Example 4, except that in step (1), the fiber diameter in the glass fiber cloth is 15 μm.

[0091] Example 11:

[0092] Example 11 is basically the same as Example 4, except that in step (3), the glass fiber cloth after ultrasonic acid washing is subjected to ultrasonic water washing in two stages. In the ultrasonic water washing process: the ultrasonic power of the first stage is 240W, the ultrasonic frequency is 25kHz, the ultrasonic time is 30min, and the water washing temperature is 60℃; the ultrasonic power of the second stage is 300W, the ultrasonic frequency is 30kHz, the ultrasonic time is 35min, and the water washing temperature is 90℃.

[0093] Example 12:

[0094] Example 12 is basically the same as Example 4, except that in step (2), the glass fiber cloth is ultrasonically pickled in four stages using acid solution (hydrochloric acid with an equivalent concentration of 3N). During the ultrasonic pickling process: the ultrasonic power of the first stage is 95W, the ultrasonic frequency is 50kHz, the ultrasonic time is 35min, and the pickling temperature is 100℃; the ultrasonic power of the second stage is 90W, the ultrasonic frequency is 50kHz, the ultrasonic time is 35min, and the pickling temperature is 90℃; the ultrasonic power of the third stage is 85W, the ultrasonic frequency is 50kHz, the ultrasonic time is 25min, and the pickling temperature is 80℃; and the ultrasonic power of the fourth stage is 70W, the ultrasonic frequency is 50kHz, the ultrasonic time is 15min, and the pickling temperature is 70℃.

[0095] Comparative Example 1:

[0096] Comparative Example 1 is basically the same as Example 8, except that in step (2), the glass fiber cloth is ultrasonically pickled with acid solution (sulphuric acid with an equivalent concentration of 3.3N); wherein, the ultrasonic power during the ultrasonic pickling process is 60W, the ultrasonic frequency is 50kHz, the ultrasonic time is 120min, and the pickling temperature is 88℃.

[0097] Comparative Example 2:

[0098] (1) Provide glass fiber cloth; wherein the fiber diameter of the glass fiber cloth is 9μm;

[0099] (2) The glass fiber cloth was pickled in four stages using acid solution (hydrochloric acid with an equivalent concentration of 3N); the pickling process was as follows: the pickling time in the first stage was 15 min and the pickling temperature was 70℃; the pickling time in the second stage was 25 min and the pickling temperature was 80℃; the pickling time in the third stage was 35 min and the pickling temperature was 90℃; and the pickling time in the fourth stage was 35 min and the pickling temperature was 100℃.

[0100] (3) The pickled glass fiber cloth is washed with water in two stages. During the washing process: the first stage water washing time is 35 minutes and the water washing temperature is 90℃; the second stage water washing time is 30 minutes and the water washing temperature is 60℃.

[0101] Comparative Example 3:

[0102] Comparative Example 3 is basically the same as Comparative Example 2, except that in step (3), the pickled glass fiber cloth is subjected to ultrasonic water washing in two stages. In the ultrasonic water washing process: the ultrasonic power of the first stage is 300W, the ultrasonic frequency is 30kHz, the ultrasonic time is 35min, and the water washing temperature is 90℃; the ultrasonic power of the second stage is 240W, the ultrasonic frequency is 25kHz, the ultrasonic time is 30min, and the water washing temperature is 60℃.

[0103] Comparative Example 4:

[0104] Comparative Example 4 is basically the same as Comparative Example 2, except that in step (2), the glass fiber cloth is ultrasonically pickled in four stages using acid solution (hydrochloric acid with an equivalent concentration of 3N). During the ultrasonic pickling process: the ultrasonic power of the first stage is 70W, the ultrasonic frequency is 50kHz, the ultrasonic time is 15min, and the pickling temperature is 70℃; the ultrasonic power of the second stage is 85W, the ultrasonic frequency is 50kHz, the ultrasonic time is 25min, and the pickling temperature is 80℃; the ultrasonic power of the third stage is 90W, the ultrasonic frequency is 50kHz, the ultrasonic time is 35min, and the pickling temperature is 90℃; and the ultrasonic power of the fourth stage is 95W, the ultrasonic frequency is 50kHz, the ultrasonic time is 35min, and the pickling temperature is 100℃.

[0105] Comparative Example 5:

[0106] Step 1: Fabric feeding. The greige fabric is placed into the fabric feeding machine and fed to the next process. The tension of the greige fabric is controlled at 150g by the tension regulator.

[0107] Step 2: Pickling. The fabric is fed into a pre-impregnation acid bath containing 15% acid solution via a fabric feeder for initial pre-impregnation acid treatment, with a time control of 20 minutes. After pre-impregnation acid treatment, the fabric enters the first hot acid bath for initial hot pickling, with the acid solution temperature controlled at 38℃ and the time control of 15 minutes. After initial hot pickling, the fabric enters the second hot acid bath for secondary hot pickling, with the acid solution temperature controlled at 38℃ and the time control of 15 minutes. After secondary hot pickling, the fabric enters the third hot acid bath for tertiary hot pickling, with the acid solution temperature controlled at 48℃ and the time control of 20 minutes.

[0108] Step 3: Washing. The acid-washed fabrics are sequentially placed into a primary washing tank, a secondary washing tank, and a tertiary washing tank for washing. The acid concentration in the primary washing tank is controlled at 7%, the acid concentration in the secondary washing tank is controlled at 3%, and the fabric is immersed in the tertiary washing tank with flowing water. The washing time is controlled at 20 minutes.

[0109] Step 4: Drying and leveling. After washing, the fabric enters the drying and leveling equipment for drying and leveling. The fabric is dried and flattened by a hot air pressure roller. The roller temperature is controlled at 80℃ and the drying and leveling time is controlled at 15 minutes.

[0110] Step 5: The dried and leveled fabric is wound up on the winding machine.

[0111] The high-silica glass fiber cloths obtained after treatment in Examples 1 to 12 and Comparative Examples 1 to 5 were subjected to performance tests, and the test results are shown in Table 1.

[0112] Silica content test: The test shall be conducted according to Appendix A of GJB 1873-94 "Specification for High-Silica Glass Fiber Cloth";

[0113] Tensile strength test: The test shall be conducted in accordance with GB / T 7689.5-2013 "Reinforcing materials - Test methods for woven fabrics - Part 5: Determination of tensile strength and elongation at break of glass fiber".

[0114] Table 1

[0115]

[0116]

[0117] Note: The silica content of the un-acid-leached fiberglass cloth is 68.2%;

[0118] As shown in Table 1, the conventional acid leaching and washing methods used in Comparative Example 5, due to their short processing time, resulted in uneven silica content in the high-silica glass fiber cloth, and the silica content was also lower than that in the embodiments of the present invention. In contrast, the high-silica glass fiber cloth obtained after ultrasonic acid washing and ultrasonic water washing in the embodiments of the present invention had a silica content as high as 96.8%, thus ensuring good high-temperature resistance. Furthermore, the high-silica glass fiber cloth in the embodiments of the present invention had a higher strength retention rate after acid treatment and heat sintering, reaching 50%. The acid leaching method in the present invention has high efficiency and is suitable for mass production. At the same time, the ultrasonic acid washing and ultrasonic water washing methods in the present invention are applicable to thick cloths (thickness of 1.2 mm or more), and the silica content after acid washing reaches 96.5% or more, with good uniformity of silica content in the obtained product. After ultrasonic water washing, the surface pH of the glass fiber cloth reaches 6 or more.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing a high-silica glass fiber cloth, comprising the step of subjecting a glass fiber cloth to acid leaching treatment, characterized in that, The acid leaching treatment comprises: ultrasonic acid washing the glass fiber cloth with acid liquid in multiple stages; wherein, the ultrasonic power and ultrasonic time of each stage are different in the ultrasonic acid washing process; the glass fiber cloth is mixed with acid liquid for ultrasonic acid washing in four stages in turn; wherein, the acid washing temperature of each stage is different in the ultrasonic acid washing process; the ultrasonic power, ultrasonic time and acid washing temperature increase in turn from the first stage to the fourth stage in the ultrasonic acid washing process. In the ultrasonic acid washing process: the ultrasonic power of the first stage is 50-70 W, the ultrasonic time is 10-15 min, and the acid washing temperature is 60-80℃; the ultrasonic power of the second stage is 70-85 W, the ultrasonic time is 20-25 min, and the acid washing temperature is 80-90℃; the ultrasonic power of the third stage is 85-90 W, the ultrasonic time is 30-35 min, and the acid washing temperature is 90-95℃; the ultrasonic power of the fourth stage is 90-95 W, the ultrasonic time is 35-40 min, and the acid washing temperature is 95-100℃; the equivalent concentration of the acid liquid is 3-3.3 N; the fiber diameter in the glass fiber cloth is not greater than 13 μm; and the ultrasonic frequency of each stage is 45-50 kHz in the ultrasonic acid washing process.

2. The production method according to claim 1, characterized by, The diameter of the fiber is 6-9 μm.

3. The preparation method according to claim 1, characterized in that, The acid liquid is at least one of hydrochloric acid or sulfuric acid.

4. The production method according to claim 1, characterized by, After the ultrasonic acid washing, the method further comprises: a step of sequentially performing ultrasonic water washing on the glass fiber cloth after the ultrasonic acid washing in multiple stages; wherein, the ultrasonic power, ultrasonic frequency, ultrasonic time and water washing temperature of each stage are different in the ultrasonic water washing process.

5. The preparation method according to claim 4, characterized in that, The glass fiber cloth after the ultrasonic acid washing is sequentially subjected to ultrasonic water washing in two stages; wherein, the ultrasonic power, ultrasonic frequency, ultrasonic time and water washing temperature decrease in turn from the first stage to the second stage in the ultrasonic water washing process.

6. The production method according to claim 5, wherein In the ultrasonic water washing process: the ultrasonic power of the first stage is 250-300 W, the ultrasonic frequency is 28-30 kHz, the ultrasonic time is 30-35 min, and the water washing temperature is 60-90℃; the ultrasonic power of the second stage is 200-240 W, the ultrasonic frequency is 25-27 kHz, the ultrasonic time is 25-30 min, and the water washing temperature is 25-60℃.

7. The production method according to claim 6, wherein After the ultrasonic water washing, the pH value of the glass fiber cloth is greater than or equal to 6.

8. A high-silica glass fiber cloth characterized by, The glass fiber cloth is prepared by the preparation method in any one of claims 1-7.

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