CN114717870A

CN114717870A - High-performance inorganic fiber preform and foam forming method and application thereof

Info

Publication number: CN114717870A
Application number: CN202210384160.5A
Authority: CN
Inventors: 张春辉; 侯夫庆; 丁能鑫; 杨会康
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2022-04-13
Filing date: 2022-04-13
Publication date: 2022-07-08
Anticipated expiration: 2042-04-13
Also published as: CN114717870B

Abstract

The invention belongs to the technical field of high-performance fiber composite materials, and relates to a high-performance inorganic fiber preform, a foam forming method and application thereof. The method comprises the following steps: uniformly mixing inorganic fibers, a fiber impregnating compound, a reinforcing agent and a surfactant to obtain foaming initial liquid; transferring the foaming initial liquid into a foaming device for foaming to obtain foam slurry after foaming is finished, injecting the foam slurry into a paper sheet forming device, and performing vacuum dehydration and defoaming to obtain a foam-formed quartz fiber prefabricated body wet paper web; and squeezing and drying the wet paper web to obtain the high-performance inorganic fiber preform. The method improves the evenness of the high-performance inorganic fiber preform, keeps the characteristic of high porosity of the high-performance inorganic fiber preform, endows the high-performance inorganic fiber preform with certain structural strength and a unique fiber arrangement mode, and obtains a foam system suitable for quartz fiber dispersion forming.

Description

High-performance inorganic fiber preform and foam forming method and application thereof

Technical Field

The invention belongs to the technical field of high-performance fiber composite materials, and relates to a high-performance inorganic fiber preform, a foam forming method and application thereof.

Background

The high-performance inorganic fiber such as quartz fiber, alumina fiber, aluminum silicate fiber cotton and the like has good heat resistance and electrical insulation performance, so the high-performance inorganic fiber has wide application in the aspects of preparing light heat insulation materials, insulating materials and the like. At present, the requirements and requirements of various industries on light high-temperature-resistant materials are continuously improved, and the high-performance inorganic fiber prefabricated body is an indispensable raw material for preparing the aerogel heat-insulating material. Under various demands, foam forming technology gradually comes into the field of people due to the advantages of water consumption saving, good product forming uniformity, high bulk and the like.

At present, high-performance inorganic fibers are difficult to disperse and easy to flocculate in a water system, long fibers (larger than 6mm) cannot be used for forming, the traditional wet forming method is low in concentration and high in water consumption, formed products are poor in uniformity and high in density, and high-performance inorganic fiber preforms prepared by a dry method (needling, spunlace and the like) also have the problems of poor uniformity and single fiber orientation. At present, methods of defibering, fiber surface modification or adding a high-viscosity dispersing agent are generally adopted to improve the dispersion characteristic of the high-performance inorganic long fiber (Cao chi, research on the paper forming performance and the forming mechanism of the long fiber [ D ]. Ceilu university of industry, 2016.), but the wet forming process still has the defects that the forming concentration of the fiber is low and the long fiber cannot be used for forming, so that a new forming method is urgently needed to solve the problems that the high-performance inorganic long fiber cannot be formed and is poor in uniformity.

Disclosure of Invention

In order to solve the above disadvantages of the prior art, the primary object of the present invention is to provide a method for foam-forming a high-performance inorganic fiber preform.

Another object of the present invention is to provide a high-performance inorganic fiber preform prepared by the above method.

It is still another object of the present invention to provide use of the above high performance inorganic fiber preform.

The purpose of the invention is realized by the following technical scheme:

a high-performance inorganic fiber preform and a foam forming method and application thereof comprise the following steps:

(1) uniformly mixing inorganic fibers, a fiber impregnating compound, a reinforcing agent and a surfactant to obtain foaming initial liquid;

(2) transferring the foaming initial liquid obtained in the step (1) into a foaming device for foaming to obtain foam slurry after foaming is finished, injecting the foam slurry into a paper sheet forming device, and performing vacuum dehydration and defoaming to obtain a wet paper web of a fiber preform formed by foam;

(3) squeezing and drying the wet paper web obtained in the step (2) to obtain a high-performance inorganic fiber preform;

preferably, the high-performance inorganic fiber in the step (1) is at least one of alumina fiber, quartz fiber, glass fiber and aluminum silicate fiber cotton, and the fiber diameter is 5-14 um;

the anionic surfactant is at least one of sulfate, alkylbenzene sulfonate and alpha-olefin sulfonate; the cationic surfactant is at least one of cationic amine salt and cationic quaternary ammonium salt; the amphoteric surfactant is betaine, and the nonionic surfactant is at least one of polyvinyl alcohol, multi-branched isomeric tridecanol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, tween, alkyl glycoside and triton;

the fiber sizing agent is at least one of polyoxyethylene, anionic polyacrylamide, cationic polyacrylamide, sulfuric acid and hydrochloric acid;

the dosage of the fiber impregnating compound is 0.1-2.0% of the oven-dry mass of the high-performance inorganic fiber, and when the fiber impregnating compound is sulfuric acid or hydrochloric acid, the pH value of the foaming initial liquid is 1-5.

Preferably, the mass volume concentration of the fibers in the foaming initial liquid in the step (1) is 1-20 g/L.

Preferably, the reinforcing agent in the step (1) is at least one of polyamide polyamine-epichlorohydrin resin, silica sol, polyvinyl alcohol, aluminum sol, carboxymethyl cellulose, methyl cellulose and sodium silicate, and the amount of the reinforcing agent is 1% -30% of oven-dried mass of the high-performance inorganic fiber.

Preferably, the mass volume concentration of the surfactant in the foaming initial liquid in the step (1) is 1-5 g/L;

the foaming conditions in the step (2) are as follows: the rotating speed is 1000rpm to 2000rpm, and the foaming time is 5min to 20 min.

Preferably, the surfactant in the step (1) is dodecyl dimethyl ammonium oxide and/or amido gemini quaternary ammonium salt, and the mass volume concentration of the surfactant is 3 g/L; the inorganic fiber is quartz fiber, the fiber length is 6-36 mm, the reinforcing agent is polyvinyl alcohol, and the dosage of the reinforcing agent is 3% of the mass of the oven-dried fiber.

Preferably, the vacuum dehydration defoaming pressure in the step (2) is 0-80kPa, and the time is 0.5-3 min; the pressing pressure of the wet paper web in the step (3) is 0-50N, and the drying temperature is 65-145 ℃.

Preferably, the foaming device of step (2) comprises: the foaming device comprises a foaming barrel, a baffle and a stirring impeller, wherein the baffle which surrounds the barrel wall anticlockwise is arranged in the foaming barrel, in the stirring process, the baffle forms high-strength micro-turbulence to promote the dispersion of fibers in the barrel and the rapid generation of foam, and the stirring impeller can be adjusted freely in the three-layer gap;

the sheet forming apparatus of step (2) comprises: the upper end of the forming net is connected with the forming net through screws, sealing gaskets are added to ensure sealing, the forming net is inserted into a groove of the sealing gaskets, a water outlet at the lower part of the forming net is communicated with an external steam-water separation device and a vacuum adjusting system, the vacuum adjusting system comprises a pressure controller and a vacuum pump to carry out vacuum degree controllable dehydration defoaming forming, and liquid is discharged from the water outlet and recycled.

Preferably, the gram weight of the high-performance inorganic fiber preform prepared by the step (3) is 40g/m²-800g/m²The thickness of the high-performance inorganic fiber preform is 0.5-20mm, soThe density of the high-performance inorganic fiber preform is 0.06g/cm³-0.22g/cm³。

A foam-formed high-performance inorganic fiber preform is prepared by the method.

The high-performance inorganic fiber preform is applied to the preparation of aerogel heat insulation materials.

The invention has the following advantages and beneficial effects:

(1) according to the invention, a foam system with the bubble size radius of 20-80um is adopted to replace a water system, so that the dispersion performance of the high-performance inorganic fiber is greatly improved, and the uniformity of the high-performance inorganic fiber preform is greatly improved.

(2) The invention adopts the foam forming technology to prepare the light high-performance inorganic fiber preform with low density, high porosity and unique Z-direction orientation of partial fibers (as shown in figure 7).

(3) The invention obtains the surfactant system suitable for quartz fiber dispersion forming.

(4) The invention adopts the method of adding the reinforcing agent into the slurry, and can obviously improve the structural strength of the quartz fiber preform.

(5) And water and foam in the foam slurry are removed by a vacuum suction and contact pressing method, and the water solution sucked out by vacuum suction can be foamed again for recycling.

Drawings

FIG. 1 is a flow chart of a foam-forming process for making high performance inorganic fiber preforms.

Fig. 2 shows a foaming apparatus used in the present invention.

Fig. 3 shows a forming apparatus used in the present invention.

FIG. 4 is a photograph showing the surface formation of comparative example 6 wet-laid silica fiber preform and example 6 foam-laid silica fiber preform in accordance with the present invention.

FIG. 5 shows comparative examples of a commercially available wet-laid quartz facer felt and a commercially available needle-punched quartz felt (75 g/m) according to the invention²And 430g/m²) Surface formation pictures of foam-formed quartz fiber preforms of examples 7, 8 and 9.

FIG. 6 is a photograph showing the surface uniformity of comparative example 9 foam-formed silica fiber preform and example 6 foam-formed silica fiber preform in accordance with the present invention.

FIG. 7 shows a commercial needle-punched formed quartz felt (430 g/m) of example 10 and comparative example of the present invention²) Cross-sectional microscope pictures of (a).

Fig. 8 is a picture of a microscopic photograph of bubbles in the foam slurry processed by Image J software (fig. a is a photograph of the bubbles fibers after binarization processing, fig. b is a photograph of the bubbles after the contours of the bubbles are picked up by the software, and fig. c is a photograph of the bubbles after the particle size analysis by the software).

Detailed Description

The present invention is described in further detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto, and for process parameters not specifically noted, reference may be made to conventional techniques.

Referring to fig. 2, the foaming device comprises a foaming barrel 3 with a baffle 2 surrounding the barrel wall anticlockwise and a stirring impeller 1 with three layers of gaps adjusted at will, wherein the baffle can ensure that high-intensity micro-turbulence is formed in the stirring process, and the dispersion of fibers in the barrel and the rapid generation of foam are promoted.

Referring to fig. 3, in a foam-forming sheet-forming apparatus, the upper end 1 of the former is connected to a predetermined number of forming wires 2 by screws 4, and a sealing gasket 3 is provided to ensure sealing. The forming net 2 is clamped in a designed sealing washer groove 3, a lower water outlet 6 is communicated with an external steam-water separation device and a vacuum regulation system, the vacuum regulation system comprises a pressure controller and a vacuum pump for dehydration, defoaming and forming with controllable vacuum degree, and liquid is discharged from the water outlet 6 and can be recycled.

Example 1 foam formation:

step 1: weighing 0.2% (2g/L) of 12mm short-cut quartz fiber (the fiber diameter is 5.5um) in a defibering barrel, adding a PEO dispersing agent accounting for 1% of the fiber mass and a polyvinyl alcohol (PVA) reinforcing agent accounting for 3% of the fiber mass, then adding water to the volume of foaming initial liquid of 1.1L, setting the revolution of the defibering device to 8000 turns, adding dodecyl dimethyl ammonium oxide (OB-2) with the mass concentration of 0.3% (3g/L) into the defibering slurry, and transferring the foaming initial liquid into a container.

And 2, step: setting the foaming rotation speed at 1500rpm, setting the foaming time at 10min, filling air with the volume content of 55-80% in the slurry after the foaming process is finished, setting the bubble radius at 20-80 microns, injecting the foam slurry into a foam forming container, setting the defoaming vacuum degree at 40kPa, and dehydrating and defoaming for 0.5min to obtain the foam-formed quartz fiber preform wet paper web.

And step 3: and squeezing and drying the wet paper web of the foam-formed quartz fiber preform to obtain the quartz fiber preform, wherein the squeezing pressure is 5N, and the drying temperature is 105 ℃.

The method for testing the radius of the bubbles in the foam slurry comprises the following steps:

the sampled foam was photographed using a microscope to obtain a bubble photograph, which was processed using Iamge J software and the bubble size distribution was obtained. Using the Sauter mean radius r₃₂The average radius of the bubbles was characterized and the number of bubbles detected in each test was not less than 500.

r-detected bubble radius

Example 2 foam formation:

step 1: weighing 0.2% (2g/L) of chopped quartz fiber (the fiber diameter is 5.5um) with the length of 24mm in a defibering barrel, adding a PEO dispersant accounting for 1% of the fiber mass and polyvinyl alcohol (PVA) serving as an internal slurry reinforcing agent accounting for 3% of the fiber mass, supplementing water until the volume of a foaming initial liquid is 1.1L, setting the revolution of the defibering barrel to 8000 turns, adding an amido gemini quaternary ammonium salt (GS-A6) surfactant accounting for 0.3% (3g/L) of mass concentration into the defibered slurry, and transferring the foaming initial liquid into a foaming container. The other steps were kept as in example 1.

Example 3 foam formation:

step 1: 0.2% (2g/L) of 36 mm-long chopped quartz fiber was weighed into a fluffing barrel by mass concentration, and the other steps were kept in accordance with example 1.

Example 4 foam formation:

step 1: 0.6% (6g/L) of chopped quartz fiber with the length of 6mm is weighed into the defibering barrel according to the mass concentration, and other steps are kept consistent with the example 2.

Example 5 foam formation:

step 1: 1% (10g/L) of chopped quartz fiber with the length of 6mm is weighed in a fluffing barrel by mass concentration, and other steps are consistent with those in example 2.

Example 6 foam formation:

step 1: 1.2 percent (12g/L) of chopped quartz fiber with the length of 6mm is weighed into a fluffing barrel by mass concentration, and other steps are kept consistent with the example 1.

Comparative example 1 wet forming:

step 1: weighing 0.2% (2g/L) of 12 mm-long chopped quartz fiber (the fiber diameter is 5.5um) in a defibering barrel, adding a PEO dispersant accounting for 1% of the fiber mass and a slurry reinforcing agent polyvinyl alcohol (PVA) accounting for 3% of the fiber mass, then adding water to the volume of 1.1L of foaming initial liquid, setting the revolution of a defibering device to 8000 turns, injecting the slurry after defibering into a handsheet wet forming device, and adding water to the total volume of 8L.

Step two: and (3) filtering, pressing and drying to obtain the wet-process-formed quartz fiber preform. The pressing pressure was 5N and the drying temperature was 105 ℃.

Comparative example 2 wet forming:

step 1: 0.2% (2g/L) of 24 mm-long chopped quartz fiber (fiber diameter 5.5um) was weighed in a fluffing barrel by mass concentration, and the other steps were kept the same as in comparative example 1.

Comparative example 3 wet forming:

step 1: 0.2% (2g/L) of 36 mm-long chopped quartz fiber (fiber diameter 5.5um) was weighed in a fluffing barrel by mass concentration, and the other steps were kept the same as in comparative example 1.

Comparative example 4 wet forming:

step 1: 0.6% (6g/L) of chopped quartz fiber (fiber diameter 5.5um) with the length of 6mm is weighed in a defibering barrel by mass concentration, and other steps are consistent with those of the comparative example 1.

Comparative example 5 wet forming:

step 1: 1% (10g/L) of chopped quartz fiber (fiber diameter 5.5um) with the length of 6mm is weighed in a defibering barrel by mass concentration, and other steps are consistent with those of the comparative example 1.

Comparative example 6 wet forming:

step 1: 1.2 percent (12g/L) of chopped quartz fiber (the fiber diameter is 5.5um) with the length of 6mm is weighed in a defibering barrel by mass concentration, and other steps are consistent with those of the comparative example 1.

Product porosity the actual density of the quartz fiber, determined experimentally, was 2.4397g/cm³Then, obtaining the product through theoretical calculation; the uniformity of the product is tested by a dust uniformity meter, and the smaller the uniformity index is, the better the uniformity of the product is. The testing principle is based on the K-M theory, the change of transmitted light after light penetrates through a paper pattern is converted into the quantitative change of paper in unit area, and the evenness index F of the paper sheet can be obtained after the change is processed and calculated by a computer. Is generally expressed by the following formula:

wherein F is a formation index, T is a light transmittance, W is a mass, and C is a constant for each sheet.

The performance tests for the quartz fiber preforms prepared in examples 1-6 are shown in Table 1 below:

TABLE 1

As can be seen from the results of Table 1, the quartz fiber preforms prepared in examples 1-6 according to the present invention had a porosity of 95.0% -97.6% and a uniformity of the product of 55-130, and the products prepared in comparative examples 1-6 had a porosity of 92.9% -96.3% and a uniformity of 160-250. On the premise of the same quartz fiber preform ration, the uniformity of the foam-formed quartz fiber preform is obviously superior to that of the wet-formed quartz fiber preform, the porosity of the quartz fiber preform prepared by the foam forming technology is higher, and the loose and thick preform structure is beneficial to the application of the subsequent quartz fiber preform in preparing aerogel heat insulation materials.

Example 7 foam formation:

step 1: basis weight of 44.5g/m²Weighing chopped quartz fibers (the mass concentration is 0.68g/L, the fiber diameter is 5.5um) with the length of 18mm in a disintegration barrel under the forming condition that the forming net diameter is 14cm, adding 1% of PEO dispersant and 3% of slurry reinforcing agent polyvinyl alcohol (PVA) relative to the mass of the fibers, then supplementing water to the volume of 1.1L of foaming initial liquid, setting the revolution of a fiber disintegration device to 8000 turns, adding 0.3% of dodecyl dimethyl amine oxide (OB-2) surfactant into the slurry after disintegration, and transferring the foaming initial liquid into a foaming container.

Step 2: in keeping with example 1, step 2.

And step 3: and squeezing and drying the wet paper web of the foam-formed quartz fiber preform to obtain the quartz fiber preform. The pressing pressure is 5N, and the drying temperature is 105 ℃.

Example 8 foam formation:

step 1: basis weight of 75g/m²In the forming condition of a forming net with a diameter of 14cm, chopped quartz fibers (with a mass concentration of 1.15g/L and a fiber diameter of 5.5um) with a length of 18mm were weighed in a fluffing barrel, and the other steps were kept consistent with those of example 7.

Example 9 foam formation:

step 1: 430g/m in basis weight of sheet²In the forming condition of a forming web having a diameter of 14cm, chopped quartz fibers having a length of 12mm (mass concentration: 6.62g/L, fiber diameter: 5.5um) were weighed in a fluffing barrel, and the other steps were carried out in accordance with example 7.

Example 10 foam formation:

step 1: basis weight of 400g/m²Diameter of forming wire 20cmWeighing chopped quartz fibers (the mass concentration is 12.56g/L and the fiber diameter is 7.6um) with the length of 6mm in a fluffing barrel, adding a PEO dispersant accounting for 1 percent of the mass of the fibers and polyvinyl alcohol (PVA) serving as an internal slurry reinforcing agent accounting for 3 percent of the mass of the fibers, then supplementing water to the volume of 1.1L of foaming initial liquid, setting the revolution of the fluffing machine to 8000 turns, adding dodecyl dimethyl amine oxide (OB-2) surfactant accounting for 0.3 percent of the mass concentration of the slurry after fluffing is finished, and transferring the foaming initial liquid into a foaming container.

Step 2: setting the foaming rotation speed at 1500rpm, setting the foaming time at 10min, injecting the foam slurry into a foam forming container after the foaming process is finished, setting the defoaming vacuum degree at 0kPa (natural drainage), and obtaining the foam-formed quartz fiber preform wet paper web after the dehydration and defoaming are finished.

And 3, step 3: and squeezing and drying the wet paper web of the foam-formed quartz fiber preform to obtain the quartz fiber preform. The pressing pressure was 3N and the drying temperature was 105 ℃. The performance tests for the quartz fiber preforms prepared in examples 7-9 are shown in Table 2 below:

TABLE 2

As can be seen from the results of Table 2, the quartz fiber preforms prepared in examples 7-9 of the present invention had a porosity of between 93% and 95% and a product formation of between 36 and 102. On the premise of the same quantitative amount of the quartz fiber preform, the evenness of the foam-formed quartz fiber preform is obviously superior to that of the commercially available needle-punched quartz fiber preform and the commercially available wet-formed quartz fiber preform, and the porosity of more than 93 percent of the foam-formed quartz fiber preform can still meet the processing conditions for preparing the aerogel thermal insulation material in the following process.

Comparative example 7 foam formation:

step 1: weighing 0.6% (6g/L) of chopped quartz fiber (the fiber diameter is 5.5um) with the length of 6mm in a defibering barrel, adding a PEO dispersing agent accounting for 1% of the mass of the fiber and a polyvinyl alcohol (PVA) reinforcing agent accounting for 3% of the mass of the fiber, then supplementing water to the volume of 1.1L of foaming initial liquid, setting the revolution of the defibering device to 8000 turns, adding Sodium Dodecyl Benzene Sulfonate (SDBS) surfactant accounting for 0.3% (3g/L) of mass concentration into the defibered slurry, and transferring the foaming initial liquid into a foaming container.

Step 2: setting the foaming rotation speed at 1500rpm, setting the foaming time at 10min, injecting the foam slurry into a foam forming container after the foaming process is finished, setting the defoaming vacuum degree at 40kPa, and dehydrating and defoaming for 0.5min to obtain the foam-formed quartz fiber preform wet paper web.

Comparative example 8 foam formation:

step 1: 1% (10g/L) of chopped quartz fiber (fiber diameter 5.5um) with a length of 6mm was weighed in a fluffing barrel by mass concentration, and the other steps were kept in accordance with comparative example 7.

Comparative example 9 foam formation:

step 1: 1.2 percent (12g/L) of chopped quartz fiber (the fiber diameter is 5.5um) with the length of 6mm is weighed in a defibering barrel by mass concentration, and other steps are consistent with those of the comparative example 7.

The performance tests of the quartz fiber preforms prepared in comparative examples 7-9 are shown in Table 3 below:

TABLE 3

As can be seen from the results in Table 3, the quartz fiber preforms prepared according to comparative examples 7 to 9 of the present invention using the sodium dodecylbenzenesulfonate surfactant system in the same foam-forming process had a uniformity of between 144-226, and the quartz fiber preforms prepared according to examples 4 to 6 using the dodecyldimethylamine oxide (OB-2) and the amido gemini quaternary ammonium salt (GS-A6) surfactant system had a surface uniformity of between 71-127, and the quartz fiber preforms prepared according to the two surfactant systems had comparable densities and porosities, but had significant differences in surface uniformities. Namely, the invention obtains a foam system suitable for quartz fiber dispersion forming, and quartz fiber preforms prepared by using the foam system have better surface uniformity.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A foam forming method of a high-performance inorganic fiber preform, characterized by comprising the steps of:

the surfactant in the step (1) is at least one of an anionic surfactant, a cationic surfactant, an amphoteric surfactant and a nonionic surfactant;

the length of the inorganic fiber in the step (1) is 3-40 mm;

the air volume content of the foam slurry in the step (2) is 55-80%, and the radius of bubbles in the foam slurry is 20-80 um.

2. The foam forming method of a high performance inorganic fiber preform as claimed in claim 1, wherein the high performance inorganic fiber of step (1) is at least one of alumina fiber, quartz fiber, glass fiber, alumina silicate fiber cotton, and the fiber diameter is 5-14 um;

3. The method for foam forming of a high-performance inorganic fiber preform according to claim 1, wherein the mass volume concentration of the fibers in the foaming starting liquid in the step (1) is 1 to 20 g/L.

4. The method for foam molding of a high performance inorganic fiber preform as claimed in claim 1, wherein the reinforcing agent in step (1) is at least one of polyamide polyamine-epichlorohydrin resin, silica sol, polyvinyl alcohol, aluminum sol, carboxymethyl cellulose, methyl cellulose, sodium silicate, and the amount of the reinforcing agent is 1% -30% of the oven dry mass of the high performance inorganic fiber.

5. The foam forming method of a high performance inorganic fiber preform as claimed in claim 1, 2, 3 or 4, wherein the surfactant is present in the foaming starting liquid of step (1) at a concentration of 1 to 5g/L by mass/volume;

6. The foam forming method of a high performance inorganic fiber preform according to claim 5, wherein the surfactant in step (1) is dodecyl dimethyl ammonium oxide and/or amido gemini quaternary ammonium salt, and the mass volume concentration of the surfactant is 3 g/L; the inorganic fiber is quartz fiber, the fiber length is 6-36 mm, the reinforcing agent is polyvinyl alcohol, and the dosage of the reinforcing agent is 3% of the mass of the oven-dried fiber.

7. The method for foam-forming a high-performance inorganic fiber preform according to claim 6, wherein the vacuum dehydration defoaming pressure in the step (2) is 0 to 80kPa for 0.5 to 3 min; the pressing pressure of the wet paper web in the step (3) is 0-50N, and the drying temperature is 65-145 ℃.

8. The foam forming method of a high performance inorganic fiber preform as claimed in claim 1, wherein the foaming device of step (2) comprises: the foaming device comprises a foaming barrel, a baffle and a stirring impeller, wherein the baffle which surrounds the barrel wall anticlockwise is arranged in the foaming barrel, in the stirring process, the baffle forms high-strength micro-turbulence to promote the dispersion of fibers in the barrel and the rapid generation of foam, and the stirring impeller can be adjusted freely in the three-layer gap;

9. A high performance inorganic fiber preform prepared by the method of any one of claims 1 to 9.

10. Use of the high performance inorganic fiber preform of claim 9 in the preparation of aerogel insulation.