Three-dimensional woven modified glass fiber structure and preparation method thereof

Abstract

The invention relates to the technical field of composite materials, and discloses a three-dimensional woven modified glass fiber structure and a preparation method thereof.The three-dimensional woven modified glass fiber structure comprises two fiber layers formed by weaving glass fibers and a supporting layer, and the surfaces of the glass fibers are modified to form interface layers; the glass fiber is combined with the resin structure layer wrapping the outer side of the glass fiber through the interface layer. The interface layer can improve the bonding capacity of the glass fibers and resin, the resin structure layer adopts epoxy resin and has high tensile strength and rigidity and high electrical performance and chemical resistance, the structure formed by weaving the glass fibers serves as a reinforcing phase, the epoxy resin serves as a matrix, and the composite material structure is formed. Better mechanical properties are realized; the epoxy resin is filled in gaps of the three-dimensional braided structure in a foaming mode and wraps the outer side of the glass fiber to form a resin structure layer, and the formed composite material structure can bear certain external force and has the effects of shock absorption, noise reduction and heat preservation.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and more particularly to a three-dimensional woven modified glass fiber structure and a preparation method thereof. Background Art

[0002] With the continuous development and progress of the engineering field, the requirements for engineering materials are constantly increasing, which require both lightweight and good mechanical properties. In industries such as aerospace, rail passenger cars, construction engineering, and medical equipment, external structures that can withstand certain external forces, have shock absorption capabilities, and have thermal insulation effects are usually required. In the existing technology, external structures with the above functions usually require complex structures to achieve, and complex structures usually mean that they cannot be lightweight.

[0003] Therefore, it is necessary to propose a three-dimensional woven modified glass fiber structure and a preparation method thereof to at least partially solve the problems existing in the prior art. Summary of the invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0005] In order to at least partially solve the above problems, the present invention provides a three-dimensional woven modified glass fiber structure, including: two fiber layers and a support layer formed by weaving glass fibers, the surface of the glass fibers is modified to form an interface layer, and the glass fibers are combined with a resin structure layer wrapped around the outside of the glass fibers through the interface layer.

[0006] Preferably, the gaps between the fiber layer and the support layer are filled with foamed epoxy resin.

[0007] Preferably, the support layer comprises: a plurality of first support bodies and a plurality of second support bodies connected between two fiber layers, and the first support bodies and the second support bodies are arranged alternately.

[0008] Preferably, the first support body is S-shaped, and the second support body is S-shaped and symmetrically arranged with the first support body.

[0009] Preferably, the fiber layer is formed by weaving warp fibers and weft fibers, and the support layer is formed by weaving bonding fibers and weft fibers of the two fiber layers.

[0010] A method for preparing a three-dimensional woven modified glass fiber structure, comprising:

[0011] A three-dimensional woven structure having two fiber layers and a support layer is formed by weaving glass fibers;

[0012] The three-dimensional braided structure is subjected to a heating treatment and a modification treatment in sequence, so that an interface layer is formed on the surface of the glass fiber, thereby obtaining a treated three-dimensional braided structure;

[0013] forming the processed three-dimensional braided structure into a desired three-dimensional skeleton;

[0014] filling the prepared epoxy resin foam solution into the three-dimensional skeleton;

[0015] The three-dimensional skeleton filled with epoxy resin foam solution is heated to foam the epoxy resin foam solution, and then solidified to form a shape.

[0016] Preferably, the temperature for heating the three-dimensional skeleton filled with the epoxy resin foam solution is 110 degrees Celsius and the heating time is 40 minutes.

[0017] Preferably, the modification process of the three-dimensional woven structure comprises:

[0018] The silane coupling agent and the ethanol solution are uniformly dispersed in a stirrer to obtain a mixed solution; wherein the pH value of the ethanol solution is 5;

[0019] The three-dimensional braided structure after the heating treatment is placed in a mixed solution for modification treatment, and after reaching a first set time, it is taken out and dried to obtain a three-dimensional braided structure after the treatment.

[0020] Preferably, the preparation of the epoxy resin foam solution comprises:

[0021] 20.8% of the curing agent and 3.5% of the foaming agent were mixed and ultrasonically shaken for 30 minutes to obtain solution A;

[0022] 1% of the foam stabilizer and 1% of the emulsifier were mixed and magnetically stirred for 30 minutes to obtain solution B;

[0023] Mix solution A and solution B evenly;

[0024] 3.5% of curing agent, 69.2% of epoxy resin and 1% of accelerator were mixed, magnetically stirred for 10 minutes, and then placed in a 60°C oven for pre-curing for 10 minutes to obtain solution C;

[0025] The mixed solution of solution A and solution B was added to solution C and magnetically stirred for 10 minutes to obtain an epoxy resin foam solution.

[0026] Preferably, filling the prepared epoxy resin foam solution into the three-dimensional skeleton comprises:

[0027] The three-dimensional skeleton is placed in a matching mold, and the mold is provided with a liquid inlet and an exhaust port;

[0028] The epoxy resin foam solution is delivered into the mold through the liquid inlet, and the gas in the mold is discharged through the exhaust port, and the filling amount of the epoxy resin foam solution is detected in real time;

[0029] When the filling amount of the epoxy resin foam solution reaches the set amount, the exhaust port is closed, the epoxy resin foam solution continues to be transported into the mold through the liquid inlet, and the pressure in the mold is detected in real time;

[0030] When the pressure in the mold reaches the set pressure, the pressure in the mold is controlled to be maintained within the pressure setting range, and after reaching the second set time, the liquid inlet is closed.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] The three-dimensional woven modified glass fiber structure and preparation method thereof described in the present invention form a fiber layer and a support layer by weaving glass fibers, and then modify the formed three-dimensional woven structure so that an interface layer is formed on the surface of the glass fibers. The interface layer can enhance the bonding ability between the glass fibers and the resin, and the resin structure layer adopts epoxy resin, which has high tensile strength and rigidity, and high electrical properties and chemical resistance. Therefore, the present invention adopts a structure formed by weaving glass fibers as a reinforcing phase and adopts epoxy resin as a matrix to form a composite material structure, which can have better mechanical properties; the epoxy resin can be filled in the gaps of the three-dimensional woven structure in a foamed form, and the foamed epoxy resin is wrapped around the outside of the glass fibers to form a resin structure layer. The composite material structure formed in this form can withstand a certain external force and has the effects of shock absorption, noise reduction and heat preservation.

[0033] The three-dimensional woven modified glass fiber structure and preparation method thereof described in the present invention, and other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by technicians in this field through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 This is a schematic diagram of the internal structure of the three-dimensional woven modified glass fiber structure of the present invention;

[0036] Figure 2 This is a schematic structural diagram of the connection between the glass fiber and the resin structure layer in the three-dimensional woven modified glass fiber structure of the present invention;

[0037] Figure 3 A schematic diagram of a three-dimensional woven structure formed by a fiber layer and a support layer in the three-dimensional woven modified glass fiber structure of the present invention;

[0038] Figure 4 for Figure 3 A side view schematic diagram of the structure;

[0039] Figure 5 This is a flow chart of a method for preparing a three-dimensional woven modified glass fiber structure according to the present invention;

[0040] Figure 6 This is a flow chart of step S2 in the method for preparing a three-dimensional woven modified glass fiber structure according to the present invention;

[0041] Figure 7 This is a flow chart of step S4 in the method for preparing the three-dimensional woven modified glass fiber structure of the present invention. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description.

[0043] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0044] like Figure 1-Figure 2 As shown, the present invention provides a three-dimensional woven modified glass fiber structure, including: two fiber layers 4 and a support layer 5 woven from glass fibers 1, the surface of the glass fibers 1 being modified to form an interface layer 2, and the glass fibers 1 being combined with a resin structure layer 3 wrapped around the outside of the glass fibers 1 through the interface layer 2.

[0045] The glass fiber 1 is woven into a Figure 1 The fiber layer 4 and the support layer 5 shown are then modified to form a three-dimensional woven structure, so that an interface layer 2 is formed on the surface of the glass fiber 1. The interface layer 2 can enhance the bonding ability between the glass fiber 1 and the resin, and the resin structure layer 3 is made of epoxy resin, which has high tensile strength and rigidity, and high electrical properties and chemical resistance. Therefore, the present invention uses the structure formed by weaving the glass fiber 1 as a reinforcing phase and uses epoxy resin as a matrix to form a composite material structure, so that it has better mechanical properties;

[0046] The resin structure layer 3 is realized in the form of epoxy resin being filled in the gap of the three-dimensional woven structure in a foamed form, and then the foamed epoxy resin is wrapped around the outside of the glass fiber 1 to form the resin structure layer 3. The composite material structure formed in this form can withstand a certain external force and has the effects of shock absorption, noise reduction and heat preservation; or, the three-dimensional woven structure is soaked in epoxy resin, so that the surface of the glass fiber 1 is evenly wrapped with epoxy resin to form the resin structure layer 3, which does not have a heat preservation effect compared with the above-mentioned form; the specific preparation can be selected according to the actual situation;

[0047] Since the glass fiber 1 and the resin matrix are prone to damage, such as premature failure due to interface debonding, microcracks and delamination, which affects the mechanical properties of the formed composite material, it is necessary to modify the glass fiber 1 so that it has better bonding ability with the epoxy resin, thereby preventing damage to the glass fiber 1 and the epoxy resin, ensuring the mechanical properties of the formed structure, improving the load transfer efficiency, reducing interface stress concentration, and further improving the overall performance.

[0048] In one embodiment, the gaps between the fiber layer 4 and the support layer 5 are filled with foamed epoxy resin 6 .

[0049] The foamed epoxy resin 6 can be combined with the interface layer 2 of the glass fiber 1 of the fiber layer 4 and the support layer 5. The foamed epoxy resin 6 has many air bubbles. The glass fiber 1 can relax local stress by utilizing the spatial deformation of the air bubbles. That is, after the fiber layer 4 and the support layer 5 are subjected to force, they can transfer the load to the foamed epoxy resin 6. The foamed epoxy resin 6 plays an elastic supporting role for the glass fiber 1. When vibration occurs, the foamed epoxy resin 6 can withstand impact vibration loads, has better bearing capacity, and absorbs vibrations, thereby achieving the purpose of vibration reduction and noise reduction. Moreover, the epoxy resin itself also has a thermal insulation effect. Therefore, the combination of the fiber layer 4 and the support layer 5 with the foamed epoxy resin 6 can simultaneously have the effects of vibration reduction, noise reduction and thermal insulation, and can be applied to more working conditions.

[0050] like Figure 3 and Figure 4 As shown, in one embodiment, the support layer 5 includes: a plurality of first support bodies 51 and a plurality of second support bodies 52 connected between two fiber layers 4, and the first support bodies 51 and the second support bodies 52 are arranged alternately.

[0051] Furthermore, the support layer 5 also includes: a space region, such as Figure 3 The hollow part shown; the supporting layer 5 adopts a bionic structure, which can have a better bearing capacity.

[0052] Further, the first support body 51 is S-shaped, and the second support body 52 is S-shaped and symmetrically arranged with the first support body 51 .

[0053] The first support body 51 and the second support body 52 form an "8" shape, which can absorb vibration when subjected to vibration impact. In addition, the first support body 51 and the second support body 52 can cooperate with the foamed epoxy resin 6 to further improve the bearing capacity and vibration reduction effect.

[0054] like Figure 3 and Figure 4 As shown, in one embodiment, the fiber layer 4 is formed by weaving warp fibers and weft fibers, and the support layer 5 is formed by weaving bonding fibers and weft fibers of the two fiber layers 4 .

[0055] like Figure 3 and Figure 4 The first support body 51 and the second support body 52 are formed by weaving bonding fibers, and the fiber layer 4 is formed by weaving warp fibers and weft fibers.

[0056] like Figure 5 As shown, the present invention also provides a method for preparing a three-dimensional woven modified glass fiber structure, comprising:

[0057] S1, a three-dimensional woven structure having two fiber layers 4 and a support layer 5 is formed by weaving glass fibers 1;

[0058] S2, sequentially performing a heating treatment and a modification treatment on the three-dimensional braided structure, so that an interface layer 2 is formed on the surface of the glass fiber 1, and a three-dimensional braided structure after treatment is obtained; wherein the temperature of the heating treatment on the three-dimensional braided structure is 250 degrees Celsius;

[0059] In this step, the three-dimensional woven structure is heated at 250 degrees Celsius to remove the surface sizing agent, and then subjected to a modification treatment, wherein the modifier used in the modification treatment is hydrolyzed and polymerized, and grows on the surface of the glass fiber 1 through chemical bonding to form an interface layer 2;

[0060] S3, forming the processed three-dimensional braided structure into a required three-dimensional skeleton;

[0061] S4, filling the prepared epoxy resin foam solution into the three-dimensional skeleton;

[0062] S5. The three-dimensional skeleton filled with the epoxy resin foam solution is heated to foam the epoxy resin foam solution, and then the epoxy resin foam solution is solidified and formed.

[0063] The three-dimensional skeleton in step S3 may be any structural form, depending on actual needs; for example, the three-dimensional skeleton may be a multi-layer three-dimensional woven structure, and when the epoxy resin foam solution is filled, the multi-layer three-dimensional woven structure may be placed in a container and then filled;

[0064] The prepared epoxy resin foam solution has not yet foamed. In order to prevent defoaming during the filling process, it is first filled into the three-dimensional skeleton and then foamed after filling. In this way, the foaming process of the epoxy resin foam solution can be carried out evenly and stably, and will not be affected by the filling process. After curing, a foamed epoxy resin 6 combined with the glass fiber 1 is formed.

[0065] Furthermore, the three-dimensional skeleton filled with the epoxy resin foam solution was heated at a temperature of 110 degrees Celsius for a heating time of 40 minutes.

[0066] Organic microspheres D31DU40 are used for foaming in the epoxy resin foam solution. They can expand when heated in liquid epoxy resin to form a foamed pore structure. The pore size formed is uniform. The shell wall material of the organic microspheres D31DU40 is composed of a thermoplastic polymer generated by polymerization of acrylonitrile, 1,1-dichloroethylene or acrylic acid monomers and a cross-linking agent under the action of an initiator. At a temperature of 80 degrees Celsius to 130 degrees Celsius, the liquid low-boiling point core material of the microspheres vaporizes and expands, generating pressure on the outer capsule membrane, causing the heat-softened capsule membrane to expand to form expanded microspheres filled with epoxy resin. In this embodiment, the heating temperature is selected to be 110 degrees Celsius, and the mechanical properties of the formed foamed pore structure are better.

[0067] like Figure 6 As shown, in one embodiment, modifying the three-dimensional woven structure includes:

[0068] S21, uniformly dispersing the silane coupling agent and the ethanol solution in a stirrer to obtain a mixed solution; wherein the pH value of the ethanol solution is 5;

[0069] The uniform dispersion is carried out in a magnetic stirrer for 3 hours; the concentration of the silane coupling agent is 1.3% to 3%, and the ethanol solution is 70% ethanol solution;

[0070] S22, placing the three-dimensional braided structure after the heating treatment into the mixed solution for modification treatment, taking it out after a first set time and performing a drying treatment to obtain a three-dimensional braided structure after the treatment;

[0071] Specifically, the first set time is 1 hour; the three-dimensional woven structure is placed in the mixed solution for hydrolysis for 1 hour, and then taken out and placed in an oven for drying at a drying temperature of 50 degrees Celsius.

[0072] The silane coupling agent undergoes a hydrolysis reaction in a weakly acidic ethanol aqueous solution, and the hydrolyzed group generates a silanol group, and then the product generated by further hydrolysis undergoes a polycondensation reaction to generate a long molecular chain to become an oligomer. After drying, the oligomer can react with the surface hydroxyl group of the glass fiber 1 in the form of hydrogen bonds, so that the modifier grows on the surface of the glass fiber 1;

[0073] After the modification, the surface of the glass fiber 1 changes from smooth to rough, which increases the mechanical bonding ability of the interface layer 2 and improves the bonding ability with the epoxy resin; the glass fibers 1 before and after the modification are tested, and the 2 mm long ends of the two glass fibers 1 are soaked in the epoxy resin. When the epoxy resin is semi-cured, the two glass fibers 1 are pulled out, and then the change of the load with time is recorded, and the interface strength of the two glass fibers can be obtained. The results show that the interface strength of the glass fiber 1 after modification is improved by 46.8% compared with that before modification, indicating that the modified glass fiber 1 has a stronger bonding ability with the epoxy resin; the glass fiber 1 is modified with a silane coupling agent, which causes less damage to the glass fiber 1 and significantly improves the interface performance.

[0074] In one embodiment, the preparation of the epoxy resin foam solution includes:

[0075] 20.8% of the curing agent and 3.5% of the foaming agent were mixed and ultrasonically shaken for 30 minutes to obtain solution A;

[0076] Ultrasonic vibration can make the foaming agent evenly distributed in the curing agent;

[0077] 1% of the foam stabilizer and 1% of the emulsifier were mixed and magnetically stirred for 30 minutes to obtain solution B;

[0078] The foam stabilizer can make the foaming pore structure formed later more stable and more uniform in size, and the emulsifier can emulsify the foam stabilizer which is difficult to dissolve in the curing agent and epoxy resin, so that it is evenly distributed in the curing agent and epoxy resin;

[0079] Mix solution A and solution B evenly;

[0080] 3.5% of curing agent, 69.2% of epoxy resin and 1% of accelerator were mixed, magnetically stirred for 10 minutes, and then placed in a 60°C oven for pre-curing for 10 minutes to obtain solution C;

[0081] The mixed solution of solution A and solution B was added to solution C and magnetically stirred for 10 minutes to obtain an epoxy resin foam solution.

[0082] Furthermore, the foaming agent is organic microsphere D31DU40, the curing agent is DM230, the foam stabilizer is dimethyl silicone oil, the emulsifier is Tween-80, and the accelerator is DMP.

[0083] In the above scheme, the epoxy resin and a part of the curing agent are pre-cured in advance, which can make the epoxy resin partially cross-linked and pre-polymerized, dissipate part of the heat, reduce the heat concentration during the curing process, and avoid burning; and the pre-curing can reach a certain viscosity, provide certain support for the subsequent foaming agent when foaming, so that the formed foaming pore structure is more uniform and stable.

[0084] like Figure 7 As shown, in one embodiment, filling the prepared epoxy resin foam solution into the three-dimensional skeleton includes:

[0085] S41, placing the three-dimensional skeleton in a matching mold, wherein the mold is provided with a liquid inlet and an exhaust port;

[0086] Wherein, the liquid inlet and the exhaust port can be respectively arranged on two opposite sides of the mold;

[0087] S42, delivering the epoxy resin foam solution into the mold through the liquid inlet, and at the same time exhausting the gas in the mold through the exhaust port, and detecting the filling amount of the epoxy resin foam solution in real time;

[0088] Wherein, the filling amount of the epoxy resin foam solution can be obtained by detecting the total flow rate of the epoxy resin foam solution at the liquid inlet;

[0089] S43, when the filling amount of the epoxy resin foam solution reaches the set amount, the exhaust port is closed, the epoxy resin foam solution continues to be transported into the mold through the liquid inlet, and the pressure in the mold is detected in real time;

[0090] The set amount is designed so that the epoxy resin foam solution will not be discharged from the exhaust port before the filling amount of the epoxy resin foam solution reaches the set amount;

[0091] S44, when the pressure in the mold reaches the set pressure, the pressure in the mold is controlled to be maintained within the pressure setting range, and after reaching the second set time, the liquid inlet is closed;

[0092] The design of the set pressure is related to the viscosity of the epoxy resin foam solution and the minimum void size of the three-dimensional skeleton. Before filling, the set pressure is determined according to the minimum void size and viscosity of the three-dimensional skeleton, and then filling is performed, that is, the set pressure is: the product of the reference pressure and the filling coefficient; the filling coefficient is: the product of the viscosity of the epoxy resin foam solution and its influence coefficient on the filling pressure, and the sum of the product of the minimum void size of the three-dimensional skeleton and its influence coefficient on the filling pressure, where the two influence coefficients can be obtained through experience;

[0093] The second setting time is 5 minutes. The pressure setting range has an upper limit and a lower limit, and the set pressure is the lower limit of the pressure setting range; that is, it is necessary to control the delivery of the epoxy resin foam solution to maintain the pressure in the mold, so that the epoxy resin foam solution can be fully filled into the gaps in the three-dimensional skeleton under this pressure to ensure the uniformity and integrity of the filling.

[0094] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “meridional”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0095] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0096] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the present invention, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A three-dimensional woven modified glass fiber structure, characterized in that: include: Two fiber layers (4) and a support layer (5) are formed by weaving glass fibers (1); the surface of the glass fibers (1) is modified to form an interface layer (2); and the glass fibers (1) are combined with a resin structure layer (3) wrapped around the outside of the glass fibers (1) via the interface layer (2).

2. The three-dimensional woven modified glass fiber structure according to claim 1, characterized in that: The gaps between the fiber layer (4) and the support layer (5) are filled with foamed epoxy resin (6).

3. The three-dimensional woven modified glass fiber structure according to claim 1, characterized in that: The support layer (5) comprises: a plurality of first support bodies (51) and a plurality of second support bodies (52) connected between two fiber layers (4), wherein the first support bodies (51) and the second support bodies (52) are arranged in a staggered manner.

4. The three-dimensional woven modified glass fiber structure according to claim 3, characterized in that: The first support body (51) is S-shaped, and the second support body (52) is S-shaped and is symmetrically arranged with the first support body (51).

5. The three-dimensional woven modified glass fiber structure according to claim 1, characterized in that: The fiber layer (4) is formed by weaving warp fibers and weft fibers, and the support layer (5) is formed by weaving bonding fibers and weft fibers of the two fiber layers (4).

6. A method for preparing a three-dimensional woven modified glass fiber structure, characterized in that: include: A three-dimensional woven structure having two fiber layers (4) and a supporting layer (5) is formed by weaving glass fibers (1); The three-dimensional braided structure is subjected to a heating treatment and a modification treatment in sequence, so that an interface layer (2) is formed on the surface of the glass fiber (1), thereby obtaining a three-dimensional braided structure after treatment; forming the processed three-dimensional braided structure into a desired three-dimensional skeleton; filling the prepared epoxy resin foam solution into the three-dimensional skeleton; The three-dimensional skeleton filled with epoxy resin foam solution is heated to foam the epoxy resin foam solution, and then solidified to form a shape.

7. The method for preparing a three-dimensional woven modified glass fiber structure according to claim 6, characterized in that: The three-dimensional skeleton filled with the epoxy resin foam solution is heated at a temperature of 110 degrees Celsius for a heating time of 40 minutes.

8. The method for preparing a three-dimensional woven modified glass fiber structure according to claim 6, characterized in that: Modifications to 3D braided structures include: The silane coupling agent and the ethanol solution are uniformly dispersed in a stirrer to obtain a mixed solution; wherein the pH value of the ethanol solution is 5; The three-dimensional braided structure after the heating treatment is placed in a mixed solution for modification treatment, and after reaching a first set time, it is taken out and dried to obtain a three-dimensional braided structure after the treatment.

9. The method for preparing a three-dimensional woven modified glass fiber structure according to claim 6, characterized in that: The preparation of epoxy resin foam solution includes: 20.8% of the curing agent and 3.5% of the foaming agent were mixed and ultrasonically shaken for 30 minutes to obtain solution A; 1% of the foam stabilizer and 1% of the emulsifier were mixed and magnetically stirred for 30 minutes to obtain solution B; Mix solution A and solution B evenly; 3.5% of curing agent, 69.2% of epoxy resin and 1% of accelerator were mixed, magnetically stirred for 10 minutes, and then placed in a 60°C oven for pre-curing for 10 minutes to obtain solution C; The mixed solution of solution A and solution B was added to solution C and magnetically stirred for 10 minutes to obtain an epoxy resin foam solution.

10. The method for preparing a three-dimensional woven modified glass fiber structure according to claim 6, characterized in that: Filling the three-dimensional skeleton with the prepared epoxy resin foam solution, including: The three-dimensional skeleton is placed in a matching mold, and the mold is provided with a liquid inlet and an exhaust port; The epoxy resin foam solution is delivered into the mold through the liquid inlet, and the gas in the mold is discharged through the exhaust port, and the filling amount of the epoxy resin foam solution is detected in real time; When the filling amount of the epoxy resin foam solution reaches the set amount, the exhaust port is closed, the epoxy resin foam solution continues to be transported into the mold through the liquid inlet, and the pressure in the mold is detected in real time; When the pressure in the mold reaches the set pressure, the pressure in the mold is controlled to be maintained within the pressure setting range, and after reaching the second set time, the liquid inlet is closed.

Images