An in-plane weft reinforced woven spacer fabric, composites thereof and methods of making

Abstract

The application discloses an in-layer weft reinforced machine woven spacer fabric and a preparation method thereof. The fabric comprises warp yarns, weft yarns and spacer yarns. The warp yarns comprise upper layer warp yarns and lower layer warp yarns. The weft yarns comprise upper layer weft yarns, lower layer weft yarns and in-layer weft yarns between the upper layer weft yarns and the lower layer weft yarns. The spacer yarns comprise spacer yarns (I) and spacer yarns (II). Two groups of the upper layer warp yarns are interwoven with the upper layer weft yarns to form an upper layer fabric. Two groups of the lower layer warp yarns are interwoven with the lower layer weft yarns to form a lower layer fabric. The spacer yarns (I) and the spacer yarns (II) are interwoven with the upper layer weft yarns and the lower layer weft yarns to form a spacer fabric. The in-layer weft yarns are interwoven with the spacer yarns to form an in-layer reinforced structure. In the application, the in-layer weft yarns and the spacer yarns are interwoven in a plain weave structure, the weft connection of the spacer yarns is realized, and the fabric has better bending resistance, compression resistance and impact resistance.

Description

Technical Field

[0001] This invention relates to an in-layer weft-reinforced woven spacer fabric, its composite material, and its preparation method, belonging to the field of textile technology and composite materials. Background Technology

[0002] With advancements in science and technology and industrial capabilities, higher demands are being placed on material performance. Textile structural composites, using textile structural products as reinforcement and resins, ceramics, and metals as the matrix, possess high stiffness and strength. Lightweight and high-strength are important trends in composite material development. Traditional laminated composites typically suffer from high density, easy delamination, and poor specific strength. Sandwich structure composites, represented by honeycomb and foam, consist of thin upper and lower panels and a low-density, thick core material in the middle, exhibiting lightweight and high strength characteristics, but still suffer from poor delamination resistance. Woven spacer fabric reinforced composites, connecting the upper and lower panels with spacer yarns, solve the problem of easy delamination in traditional composites. This results in a lightweight, high-strength, and delamination-resistant composite material with an integral structure, widely used in aircraft, high-speed rail, oil storage tanks, wind turbine blades, and radomes.

[0003] The mechanical properties of woven spacer fabric reinforced composites are closely related to their fabric structure, especially the structure of the spacer yarns. Existing woven spacer fabric reinforced composites are prone to instability and bending failure of the spacer yarns when subjected to external forces such as compression, bending, and impact. This is highly detrimental to the performance of their mechanical properties and significantly limits their application in various scenarios. Summary of the Invention

[0004] The technical problem solved by this application is to provide a more structurally reasonable woven spacer fabric and its preparation method.

[0005] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0006] In a first aspect, the present invention provides an in-layer weft-reinforced woven spacer fabric, comprising an in-layer weft-reinforced woven spacer fabric, characterized in that it comprises warp yarns, weft yarns, and spacer yarns, wherein the warp yarns comprise upper warp yarns and lower warp yarns; the weft yarns comprise upper weft yarns, lower weft yarns, and in-layer weft yarns located between the upper and lower weft yarns; the spacer yarns comprise spacer yarns (I) and spacer yarns (II); two sets of upper warp yarns interweave with the upper weft yarns to form an upper fabric; two sets of lower warp yarns interweave with the lower weft yarns to form a lower fabric; the spacer yarns (I) and spacer yarns (II) interweave with the upper and lower weft yarns to form a spacer fabric; and the in-layer weft yarns interweave with the spacer yarns to form an in-layer reinforcement structure.

[0007] Preferably, the warp yarns, weft yarns, and spacer yarns are selected from one or more of chemical fibers, natural fiber yarns, and inorganic fibers; the natural fiber yarns are selected from one or more of ramie, jute, and flax.

[0008] Preferably, the warp yarns, weft yarns, and spacer yarns are selected from high-performance fibers.

[0009] More preferably, the high-performance fiber is selected from one or more of aramid, carbon fiber, and high-strength, high-modulus polyethylene fiber.

[0010] More preferably, the inorganic fiber is selected from one or more of glass fiber, quartz fiber, basalt fiber, and ceramic fiber.

[0011] More preferably, the chemical fiber is selected from one or more of polypropylene fiber, polyethylene fiber, polyester and acrylic fiber.

[0012] In a second aspect, the present invention provides a composite material reinforced with an inner weft yarn reinforced woven spacer fabric, characterized in that the inner weft yarn reinforced woven spacer fabric and a resin solution form the composite material reinforced with an inner weft yarn reinforced woven spacer fabric.

[0013] Preferably, the resin solution is selected from one or more of epoxy resin, vinyl resin, polyimide resin and phenolic resin.

[0014] A third aspect of the present invention provides a method for preparing a woven spacer fabric reinforced with inner weft yarns, comprising the following steps:

[0015] Step 1: Process Preparation: Select the yarns according to the required properties of the fabric, wherein the fineness of the yarns is 100-1200 tex; determine the weave structure of the upper and lower layers of fabric as plain weave, twill weave, satin weave, or a variation thereof; warp density is 30-100 ends / 10cm; weft density is 20-150 ends / 10cm; spacer yarn density is 15-50 ends / 10cm; width is 20-200cm; spacing height is 4-30mm; weaving tension is controlled at 5-10N; prepare the corresponding reeds and heald frames.

[0016] Step 2: Threading the yarns: Thread one set of upper and lower warp yarns onto a double-heddle frame in a regular pattern; thread another set of upper and lower warp yarns onto another double-heddle frame in a regular pattern; the two double-heddle frames control the interweaving of the upper and lower fabrics; thread two sets of spacer yarns onto two single-heddle frames in a regular pattern; the two single-heddle frames control the interweaving of the spacer yarns; thread three weft yarns onto the upper, middle, and lower rapiers respectively;

[0017] Step 3: Weaving the spacer fabric structure: The upper rapier guides the weft yarn between two sets of upper warp yarns, and the lower rapier guides the weft yarn between two sets of lower warp yarns. Set the height of the spacer device to 4-30mm to control the spacing after the upper and lower yarns interweave, which is the height of the spacer fabric; beat the reed; replace the heddles on the two double-heddle frames and the two single-heddle frames respectively to form a normal machine-woven spacer fabric structure unit; repeat several times according to the fabric structure designed in Step 1;

[0018] Step 4: Weaving of the Inner Layer Weft Reinforced Structure: The middle rapier introduces the weft yarn between the upper and lower layers of fabric. The reed beats the weft, and the two single-heald frames perform a heald change, achieving one layer of interlacing of the inner layer weft yarn and the spacer yarn. The same method is used to perform another layer of interlacing of the inner layer weft yarn and the spacer yarn. Then, the upper rapier introduces the weft yarn between the two sets of upper warp yarns, and the lower rapier introduces the weft yarn between the two sets of lower warp yarns. The reed beats the weft. The two double-heald frames perform a heald change, achieving one layer of interlacing of the upper and lower layers of fabric. This forms the smallest unit of an inner layer weft reinforced structure. Based on the fabric structure designed in Step 1, this process is repeated several times.

[0019] Step 5: Weaving of the interlayer weft yarn reinforced woven spacer fabric: Steps 3 and 4 are performed alternately or in combination to obtain the interlayer weft yarn reinforced woven spacer fabric;

[0020] Preferably, the preparation method satisfies one or more of the following conditions:

[0021] Condition 1 is that in step 1, the yarn is a chemical fiber and / or natural fiber yarn;

[0022] Condition 2 is that the fabric structure, warp and weft density, spacing yarn density, width, length, spacing height, and weaving tension in step 1 are designed according to actual requirements;

[0023] Condition 3 is that in step 2, the warp threading pattern is that the nth warp of each upper layer of warp is threaded through the upper heddle eye of the nth heddle wire in its corresponding heddle frame, and the nth warp of each lower layer of warp is threaded through the lower heddle eye of the nth heddle wire in its corresponding heddle frame, wherein the rightmost warp is the first warp.

[0024] Condition 4 is that in step 2, the threading pattern of the spacer yarns is such that the nth yarn of each group of spacer yarns is threaded through the nth heddle wire of its corresponding heddle frame; the nth yarn of spacer yarn (Ⅰ) passes between the (2n-1)th and (2n-2)th heddle wires of the double heddle frame; the nth yarn of spacer yarn (Ⅱ) passes between the 2nth and (2n-1)th heddle wires of the double heddle frame; where the rightmost spacer yarn is the first yarn;

[0025] Condition 5 is that in step 4, the number of interlacing times between the weft yarn and the spacer yarn is 2n;

[0026] Condition 6 is that in step 4, the interlacing structure of the weft yarn and the spacer yarn is parallel to the upper and lower fabric layers.

[0027] Condition 7 is that in step 4, the height of the interlacing reinforcement structure between the inner weft yarn and the spacer yarn can be controlled by the tension of the upper and lower sets of spacer yarns; or it can be controlled by adding an external spacer device.

[0028] Condition 8 is that in step 4, the position of the interlacing reinforcement structure of the inner weft yarn and the spacer yarn is at the halfway point between the upper and lower fabrics;

[0029] Condition 9 is that in step 4, the minimum cycle is formed by the interlacing of the weft yarn and the spacer yarn twice within the layer; and the minimum cycle is formed by the interlacing of the upper and lower layers of fabric once.

[0030] Condition 10 is that in step 4, different layers of inner weft yarn reinforcement structural units with different combinations of cycle counts can be flexibly designed according to actual needs.

[0031] Condition 11 states that in step 5, the alternating pattern of spacer fabric structural units and in-layer weft yarn reinforcement structural units can be flexibly designed according to actual needs to form in-layer weft yarn reinforcement spacer fabrics with different structures.

[0032] More preferably, the yarn is selected from one or more of glass fiber, aramid fiber, carbon fiber, high-strength high-modulus polyethylene fiber, ramie, jute and flax.

[0033] A fourth aspect of the present invention provides a method for preparing a composite material reinforced with in-layer weft yarns and woven spacer fabric, comprising the following steps:

[0034] Step 1: Process Preparation: Select the yarns according to the required properties of the fabric, wherein the fineness of the yarns is 100-1200 tex; determine the weave structure of the upper and lower layers of fabric as plain weave, twill weave, satin weave, or a variation thereof; warp density is 30-100 ends / 10cm; weft density is 20-150 ends / 10cm; spacer yarn density is 15-50 ends / 10cm; width is 20-200cm; spacing height is 4-30mm; weaving tension is controlled at 5-10N; prepare the corresponding reeds and heald frames.

[0035] Step 2: Threading the yarns: Thread one set of upper and lower warp yarns onto a double-heddle frame in a regular pattern; thread another set of upper and lower warp yarns onto another double-heddle frame in a regular pattern; the two double-heddle frames control the interweaving of the upper and lower fabrics; thread two sets of spacer yarns onto two single-heddle frames in a regular pattern; the two single-heddle frames control the interweaving of the spacer yarns; thread three weft yarns onto the upper, middle, and lower rapiers respectively;

[0036] Step 3: Weaving the spacer fabric structure: The upper rapier guides the weft yarn between two sets of upper warp yarns, and the lower rapier guides the weft yarn between two sets of lower warp yarns. Set the height of the spacer device to 4-30mm to control the spacing after the upper and lower yarns interweave, which is the height of the spacer fabric; beat the reed; replace the heddles on the two double-heddle frames and the two single-heddle frames respectively to form a normal machine-woven spacer fabric structure unit; repeat several times according to the fabric structure designed in Step 1;

[0037] Step 4: Weaving of the Inner Layer Weft Reinforced Structure: The middle rapier introduces the weft yarn between the upper and lower layers of fabric. The reed beats the weft, and the two single-heald frames perform a heald change, achieving one layer of interlacing of the inner layer weft yarn and the spacer yarn. The same method is used to perform another layer of interlacing of the inner layer weft yarn and the spacer yarn. Then, the upper rapier introduces the weft yarn between the two sets of upper warp yarns, and the lower rapier introduces the weft yarn between the two sets of lower warp yarns. The reed beats the weft. The two double-heald frames perform a heald change, achieving one layer of interlacing of the upper and lower layers of fabric. This forms the smallest unit of an inner layer weft reinforced structure. Based on the fabric structure designed in Step 1, this process is repeated several times.

[0038] Step 5: Weaving of the interlayer weft yarn reinforced woven spacer fabric: Steps 3 and 4 are performed alternately or in combination to obtain the interlayer weft yarn reinforced woven spacer fabric;

[0039] Step 6: Resin preparation: Mix the resin at a mass fraction of 65%-85% and the curing agent at a mass fraction of 15%-35% for 5-15 minutes to ensure uniform mixing.

[0040] Step 7: Resin Impregnation: Place the fabric on a mold coated with release agent; use a dropper to evenly apply the resin solution in an "S" shape along the weft direction once, then evenly apply it in an "S" shape along the warp direction once. Let it stand for 30-300 seconds to allow it to penetrate and impregnate. Turn the fabric over and use a dropper to evenly apply the resin solution in an "S" shape along the weft direction once, then evenly apply it in an "S" shape along the warp direction once. Let it stand for 30-300 seconds to allow it to penetrate and impregnate. Repeat the above operation until the resin solution content is 30%-80% of the total mass and the fabric content is 20%-70% of the total mass.

[0041] Step 8: Composite molding: Place the resin-impregnated fabric into an oven and pre-cur it at 50-320℃ for 3-12 hours to obtain a composite material reinforced with inner weft yarns and woven spacer fabric.

[0042] More preferably, the yarn is selected from one or more of glass fiber, aramid fiber, carbon fiber, high-strength high-modulus polyethylene fiber, ramie, jute and flax.

[0043] Preferably, the preparation method satisfies one or more of the following conditions:

[0044] Condition 1 is that in step 1, the yarn is one or more of chemical fiber and / or natural fiber yarn;

[0045] Condition 2 is that the fabric structure, warp and weft density, spacing yarn density, width, length, spacing height, and weaving tension in step 1 are designed according to actual requirements;

[0046] Condition 3 is that the warp threading pattern in step 2 is that the nth warp of each group of upper warp threads is threaded through the upper heddle eye of the nth heddle wire in its corresponding heddle frame, and the nth warp of each group of lower warp threads is threaded through the lower heddle eye of the nth heddle wire in its corresponding heddle frame, wherein the rightmost warp is the first warp.

[0047] Condition 4 is that the threading pattern of the spacer yarns in step 2 is that the nth yarn of each group of spacer yarns is threaded through the nth heddle wire of its corresponding heddle frame; the nth yarn of spacer yarn (Ⅰ) passes between the (2n-1)th and (2n-2)th heddle wires of the double heddle frame; the nth yarn of spacer yarn (Ⅱ) passes between the 2nth and (2n-1)th heddle wires of the double heddle frame; where the rightmost spacer yarn is the first yarn;

[0048] Condition 5 is that the number of interlacing times of the inner weft yarn and the spacer yarn in step 4 is 2n;

[0049] Condition 6 is that in step 4, the interlacing structure of the inner weft yarn and the spacer yarn is parallel to the upper and lower fabric layers.

[0050] Condition 7 states that the height of the interlacing reinforcement structure between the inner weft yarn and the spacer yarn in step 4 can be controlled by the tension of the upper and lower sets of spacer yarns; it can also be controlled by adding an external spacer device.

[0051] Condition 8 is that the interlacing reinforcement structure of the inner weft yarn and the spacer yarn in step 4 is located at the halfway point between the upper and lower fabrics;

[0052] Condition 9 is that in step 4, the inner weft yarn and the spacer yarn interweave twice to form the minimum cycle; the upper and lower layers of fabric interweave once to form the minimum cycle.

[0053] Condition 10 is that in step 4, different layers of inner weft yarn reinforcement structure units with different combinations of cycle numbers can be flexibly designed according to actual needs;

[0054] Condition 11 is that in step 5, the alternating pattern of the spacer fabric structure unit and the in-layer weft yarn reinforcement structure unit can be flexibly designed according to actual needs to form in-layer weft yarn reinforcement spacer fabrics with different structures.

[0055] Condition 12 is that the resin mass fraction in step 6 is 65%-85% and the curing agent mass fraction is 15%-35%.

[0056] More preferably, the yarn is selected from one or more of glass fiber, aramid fiber, carbon fiber, high-strength high-modulus polyethylene fiber, ramie, jute and flax.

[0057] Compared with the prior art, the beneficial effects of the present invention are:

[0058] 1. The woven spacer fabric reinforced with in-layer weft yarns obtained by the present invention introduces in-layer weft yarns and realizes the interlacing structure of in-layer weft yarns and spacer yarns by changing the movement law of the heald frame, thereby optimizing the structure of the woven spacer fabric and effectively improving its composite mechanical properties.

[0059] 2. In this invention, the weft yarns within the layer and the spacer yarns are interwoven in a plain weave structure, which realizes the weft connection of the spacer yarns and has better bending resistance.

[0060] 3. In this invention, the inner weft yarn divides the complete spacer yarn into two spacer yarns, each with half the height, effectively shortening the height of the spacer yarn. According to the Euler bar stability formula, reducing the height of the spacer yarn can effectively improve the compression resistance and impact resistance of the spacer fabric and its composite materials.

[0061] 4. In this invention, the height position of the inner weft yarn reinforcement structure can be adjusted arbitrarily; the alternation pattern of each structural unit can be flexibly designed to obtain diverse product specifications that can meet the usage needs of different scenarios.

[0062] 5. This invention provides a weaving method for woven spacer fabrics reinforced with inner weft yarns. The method, principle, and process are simple and easy to operate, and can achieve large-scale, industrialized production.

[0063] 6. The weft-reinforced woven spacer fabric and its composite material obtained by this invention have broad application prospects in the fields of aircraft, high-speed rail, oil storage tanks, wind turbine blades, and radomes. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of one of the weft-reinforced woven spacer fabrics described in this invention.

[0065] Figure 2 This is a top view schematic diagram of one of the weft yarn reinforced woven spacer fabrics described in this invention.

[0066] Figure 3 This is a schematic diagram of the warp cross-section of one of the weft-reinforced woven spacer fabrics described in this invention.

[0067] Figure 4 This is a schematic diagram of the weft section of one of the weft-reinforced woven spacer fabrics described in this invention.

[0068] Figure reference numerals: 1. Upper layer warp yarn; 2. Lower layer warp yarn; 3. Upper layer weft yarn; 4. Lower layer weft yarn; 5. Inner layer weft yarn; 6. Spacer yarn (Ⅰ); 7. Spacer yarn (Ⅱ). Detailed Implementation

[0069] To make the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings: Embodiment 1

[0070] Step 1: Process Preparation: All yarns used are 1500D aramid produced by DuPont; the upper and lower layers of fabric are both plain weave; the warp density of both upper and lower layers is 50 yarns / 10cm; the weft density of both upper and lower layers is 75 yarns / 10cm; the spacer yarn density is 23.5 yarns / 10cm; the width is 20cm, the length is 100cm, and the spacing height is 2cm; the pretension of the upper and lower spacer yarns is 5N; prepare a steel reed with a reed size of 25.5, two double-heald frames and two single-heald frames, and set the distance between the upper and lower layers to 20mm using the spacer device.

[0071] Step 2: Threading the yarn: Using the rightmost yarn and heddle as the first yarn and heddle; thread one set of upper and lower warp yarns onto a double-heddle frame according to a pattern, and thread another set of upper and lower warp yarns onto another double-heddle frame according to a pattern. The threading pattern for the warp yarns is that the nth warp yarn of each set of upper warp yarns should be threaded through the upper heddle eye of the nth heddle in its corresponding heddle frame, and the nth warp yarn of each set of lower warp yarns should be threaded through the lower heddle eye of the nth heddle in its corresponding heddle frame; then thread the two sets of spacer yarns... The yarns are threaded onto two single-heald frames according to a specific pattern. The threading pattern for the spacer yarns is as follows: the nth yarn of each group of spacer yarns should be threaded into the nth heald of its corresponding heald frame. The nth yarn of spacer yarn (Ⅰ) should pass between the (2n-1)th and (2n-2)th healds of the double-heald frame. The nth yarn of spacer yarn (Ⅱ) should pass between the 2nth and (2n-1)th healds of the double-heald frame. The three weft yarns are then threaded onto the upper, middle, and lower rapiers respectively.

[0072] Step 3: Weaving the spacer fabric structure: The upper rapier guides the upper weft yarn between the two sets of upper warp yarns, and the lower rapier guides the lower weft yarn between the two sets of lower warp yarns. Place the spacer between the upper and lower warp yarns; beat the reed once; change the heddles once for the two double-heddle frames and the two single-heddle frames to form a normal woven spacer fabric structure unit; unwind the reed once; repeat the above operation three times.

[0073] Step 4: In-layer weft yarn reinforcement structure weaving: The middle rapier introduces the in-layer weft yarn between the upper and lower layers of fabric. The reed beats the weft once, the two single-heald frames change heddles once, and the reed unwinds the weft once, completing one layer of in-layer weft yarn and spacer yarn interlacing. The same method is used to complete another layer of in-layer weft yarn and spacer yarn interlacing. Then, the upper rapier introduces the weft yarn between the two sets of upper warp yarns, and the lower rapier introduces the weft yarn between the two sets of lower warp yarns. The reed beats the weft once. The two double-heald frames change heddles once, and the reed unwinds the weft once, completing one layer of upper and lower plain weave fabric interlacing. The same method is used to complete another layer of upper and lower plain weave fabric interlacing, forming an in-layer weft yarn reinforcement structure unit.

[0074] Step 5: Weaving of the interlayer weft-reinforced woven spacer fabric: Repeat step 3 and step 4 alternately until the fabric width reaches 100cm. The final product is the interlayer weft-reinforced woven spacer fabric.

[0075] Example 2

[0076] Step 1: Fabric preparation: Select the woven spacer fabric with in-layer weft yarn reinforcement as described in Example 1 as the reinforcing material.

[0077] Step 2: Resin Preparation: Use JL-235 bisphenol A epoxy resin and JH-242 amine curing agent (produced by Hangzhou Mojiafa New Materials (Suzhou) Co., Ltd.) as the matrix materials, and LOCTITE 55-NC release agent. Prepare two clean, flat glass plates and four 20mm high support pillars. Apply the release agent evenly to one side of each glass plate and allow it to dry at room temperature for 10-20 minutes. Mix the resin and curing agent according to a mass ratio of 100:33 (epoxy resin:curing agent). Stir the resin and curing agent mixture at 20℃ for 10 minutes to ensure uniform mixing.

[0078] Step 3: Resin Impregnation: Place 100g of fabric on a glass plate with the release agent applied to the side. Using a dropper, apply the resin-curing agent mixture described in Step 2 evenly in an "S" shape along the weft direction to the surface of the upper fabric once, then apply it evenly in an "S" shape along the warp direction once. Let it stand for 30 seconds to allow it to penetrate and impregnate. Turn the fabric over and use a dropper to apply the resin-curing agent mixture described in Step 2 evenly in an "S" shape along the weft direction to the surface of the lower fabric once, then apply it evenly in an "S" shape along the warp direction once. Let it stand for 30 seconds to allow it to penetrate and impregnate. The total amount of resin-curing agent mixture used is 334.78g. Place four supports at the four corners of the glass plate, and place another glass plate with the release agent applied to the side facing down on top of the four supports.

[0079] Step 4: Composite molding: Place the resin-impregnated fabric from Step 3 into an oven at 50°C for 1 hour for pre-curing, then turn it over and place it back into the oven for 2 hours of pre-curing at 50°C. Subsequently, raise the oven temperature to 70°C and cure for 7 hours to obtain a composite material reinforced with weft yarns in the inner layer and woven spacer fabric.

Claims

1. A method for preparing a woven spacer fabric reinforced with inner weft yarns, characterized in that, Includes the following steps: Step 1: Process preparation: Select each group of yarns according to the required properties of the fabric. The fineness of the yarns is 100-1200 tex. Determine the weave structure of the upper and lower layers to be one of plain weave, twill weave, satin weave, or variations thereof; warp density should be 30-100 ends / 10cm; weft density should be 20-150 ends / 10cm; spacer yarn density should be 15-50 ends / 10cm; width should be 20-200cm; spacer height should be 4-30mm; weaving tension should be controlled at 5-10N; prepare the appropriate reeds and heald frames. Step 2: Threading the yarns: Thread one set of upper and lower warp yarns onto a double-heddle frame in a regular pattern; thread another set of upper and lower warp yarns onto another double-heddle frame in a regular pattern; the two double-heddle frames control the interweaving of the upper and lower fabrics; thread one set of spacer yarn I and one set of spacer yarn II onto two single-heddle frames in a regular pattern; the two single-heddle frames control the interweaving of the spacer yarns; thread the three weft yarns onto the upper, middle, and lower rapiers respectively; Step 3: Weaving the spacer fabric structure: The upper rapier guides the weft yarn between two sets of upper warp yarns, and the lower rapier guides the weft yarn between two sets of lower warp yarns. Set the height of the spacer device to 4-30mm to control the spacing after the upper and lower yarns interweave, which is the height of the spacer fabric; beat the reed; replace the heddles on the two double-heddle frames and the two single-heddle frames respectively to form a normal machine-woven spacer fabric structure unit; repeat several times according to the fabric structure designed in Step 1; Step 4: Weaving of the Inner Layer Weft Reinforced Structure: The middle rapier introduces the weft yarn between the upper and lower layers of fabric. The reed beats the weft, and the two single-heald frames perform a heald change, achieving one layer of weft yarn and spacer yarn interlacing. The same method is used to perform another layer of weft yarn and spacer yarn interlacing. Then, the upper rapier introduces the weft yarn between two sets of upper warp yarns, and the lower rapier introduces the weft yarn between two sets of lower warp yarns. The reed beats the weft. The two double-heald frames perform a heald change, achieving one layer of interlacing between the upper and lower layers of fabric. This forms the smallest unit of an inner layer weft reinforced structure. Based on the fabric structure designed in Step 1, this process is repeated several times. The layer weft yarn and spacer yarn interlacing structure is parallel to the upper and lower layers of fabric. Step 5: Weaving of the interlayer weft yarn reinforced woven spacer fabric: Steps 3 and 4 are performed alternately or in different ways to weave the interlayer weft yarn reinforced woven spacer fabric.

2. The method for preparing the woven spacer fabric reinforced with in-layer weft yarns as described in claim 1, characterized in that, It meets one or more of the following conditions: Condition 1 is that the warp threading pattern in step 2 is that the nth warp of each group of upper warp threads is threaded through the upper heddle eye of the nth heddle wire in its corresponding heddle frame, and the nth warp of each group of lower warp threads is threaded through the lower heddle eye of the nth heddle wire in its corresponding heddle frame, where the rightmost warp is the first warp. Condition 2 is that the threading pattern of the spacer yarns in step 2 is as follows: the nth yarn of each group of spacer yarns is threaded through the nth heddle wire of its corresponding heddle frame; the nth yarn of spacer yarn I passes between the (2n-1)th and (2n-2)th heddle wires of the double heddle frame; the nth yarn of spacer yarn II passes between the 2nth and (2n-1)th heddle wires of the double heddle frame; where the rightmost spacer yarn is the first yarn; Condition 3 is that the number of interlacing times between the inner weft yarn and the spacer yarn in step 4 is 2n; Condition 4 is that the height of the interlacing reinforcement structure of the inner weft yarn and the spacer yarn in step 4 is controlled by the tension of the upper and lower sets of spacer yarns or by adding an external spacer device. Condition 5 is that the interlacing reinforcement structure of the inner weft yarn and the spacer yarn in step 4 is located at the halfway point between the upper and lower fabrics; Condition 6 is that in step 4, the inner weft yarn and the spacer yarn interweave twice to form the minimum cycle; the upper and lower layers of fabric interweave once to form the minimum cycle. Condition 7 is that in step 4, different layers of inner weft yarn reinforcement structural units with different combinations of cycle numbers are designed according to actual needs; Condition 8 is that in step 5, the alternating pattern of spacer fabric structural units and in-layer weft yarn reinforcement structural units is designed according to actual needs to form in-layer weft yarn reinforcement spacer fabrics with different structures.

3. A woven spacer fabric reinforced with in-layer weft yarns prepared by the method of claim 1, characterized in that, The fabric comprises warp yarns, weft yarns, and spacer yarns. The warp yarns include upper warp yarns and lower warp yarns; the weft yarns include upper weft yarns, lower weft yarns, and in-layer weft yarns located between the upper and lower weft yarns; the spacer yarns include spacer yarn I and spacer yarn II. Two sets of upper warp yarns interweave with the upper weft yarns to form an upper layer fabric; two sets of lower warp yarns interweave with the lower weft yarns to form a lower layer fabric; spacer yarn I and spacer yarn II interweave with the upper and lower weft yarns to form a spacer fabric; and the in-layer weft yarns interweave with the spacer yarns to form an in-layer weft yarn reinforcement structure.

4. The woven spacer fabric reinforced with in-layer weft yarns as described in claim 3, characterized in that, The warp, weft, and spacer yarns are one or more of chemical fibers, natural fiber yarns, and inorganic fibers; the natural fiber yarns are one or more of ramie, jute, and flax.

5. The woven spacer fabric reinforced with in-layer weft yarns as described in claim 3, characterized in that, The warp, weft, and spacer yarns are high-performance fibers.

6. The woven spacer fabric reinforced with in-layer weft yarns as described in claim 4, characterized in that, The chemical fiber is one or more of polypropylene fiber, polyethylene fiber, polyester and acrylic fiber; the inorganic fiber is one or more of glass fiber, quartz fiber, basalt fiber and ceramic fiber.

7. The woven spacer fabric reinforced with in-layer weft yarns as described in claim 5, characterized in that, The high-performance fiber is one or more of aramid, carbon fiber, and high-strength, high-modulus polyethylene fiber.

8. A composite material reinforced with woven spacer fabric and reinforced with inner weft yarns, characterized in that, It is formed by mixing an inner weft-reinforced woven spacer fabric as described in any one of claims 3-7 with a resin solution.

9. The composite material reinforced with in-layer weft yarns and woven spacer fabric as described in claim 8, characterized in that, The resin solution is one or more of epoxy resin, vinyl resin, polyimide resin and phenolic resin.

10. A method for preparing a composite material reinforced with in-layer weft yarn reinforcement woven spacer fabric as described in claim 8 or 9, characterized in that, Includes the following steps: Step 1: Process preparation: Select each group of yarns according to the required properties of the fabric. The fineness of the yarns is 100-1200 tex. Determine the weave structure of the upper and lower layers to be one of plain weave, twill weave, satin weave, or variations thereof; warp density should be 30-100 ends / 10cm; weft density should be 20-150 ends / 10cm; spacer yarn density should be 15-50 ends / 10cm; width should be 20-200cm; spacer height should be 4-30mm; weaving tension should be controlled at 5-10N; prepare the appropriate reeds and heald frames. Step 2: Threading the yarns: Thread one set of upper and lower warp yarns onto a double-heddle frame in a regular pattern; thread another set of upper and lower warp yarns onto another double-heddle frame in a regular pattern; the two double-heddle frames control the interweaving of the upper and lower fabrics; thread one set of spacer yarn I and one set of spacer yarn II onto two single-heddle frames in a regular pattern; the two single-heddle frames control the interweaving of the spacer yarns; thread the three weft yarns onto the upper, middle, and lower rapiers respectively; Step 3: Weaving the spacer fabric structure: The upper rapier guides the weft yarn between two sets of upper warp yarns, and the lower rapier guides the weft yarn between two sets of lower warp yarns. Set the parameters of the spacer device to control the spacing after the upper and lower yarns interweave, i.e., the height of the spacer fabric; beat in the reed; replace the heddles on the two double-heddle frames and the two single-heddle frames respectively to form a normal machine-woven spacer fabric structure unit; repeat several times according to the fabric structure designed in Step 1; Step 4: Weaving of the Inner Layer Weft Reinforced Structure: The middle rapier introduces the weft yarn between the upper and lower layers of fabric. The reed beats the weft, and the two single-heald frames perform a heald change, achieving one layer of weft yarn and spacer yarn interlacing. The same method is used to perform another layer of weft yarn and spacer yarn interlacing. Then, the upper rapier introduces the weft yarn between two sets of upper warp yarns, and the lower rapier introduces the weft yarn between two sets of lower warp yarns. The reed beats the weft. The two double-heald frames perform a heald change, achieving one layer of interlacing between the upper and lower layers of fabric. This forms the smallest unit of an inner layer weft reinforced structure. Based on the fabric structure designed in Step 1, this process is repeated several times. The layer weft yarn and spacer yarn interlacing structure is parallel to the upper and lower layers of fabric. Step 5: Weaving of the interlayer weft yarn reinforced woven spacer fabric: Steps 3 and 4 are performed alternately or in combination to obtain the interlayer weft yarn reinforced woven spacer fabric; Step 6: Resin preparation: Mix the resin at a mass fraction of 65%-85% and the curing agent at a mass fraction of 15%-35% for 5-15 minutes to ensure uniform mixing. Step 7: Resin Impregnation: Place the fabric on a mold coated with release agent. Using a dropper, evenly apply the resin solution in an "S" shape along the weft direction once, then evenly apply it in an "S" shape along the warp direction once. Let it stand for 30-300 seconds to allow it to penetrate. Turn the fabric over and use a dropper to evenly apply the resin solution in an "S" shape along the weft direction once, then evenly apply it in an "S" shape along the warp direction once. Let it stand for 30-300 seconds to allow it to penetrate. Repeat the above operation until the resin solution mass fraction is 30%-80% of the total mass and the fabric mass fraction is 20%-70% of the total mass. Step 8: Composite molding: Place the resin-impregnated fabric into an oven and pre-cur it at 50-320℃ for 3-12 hours to obtain a composite material reinforced with inner weft yarns and woven spacer fabric.

11. The method for preparing the composite material reinforced by in-layer weft yarn reinforcement woven spacer fabric as described in claim 10, characterized in that, It meets one or more of the following conditions: Condition 1 is that the warp threading pattern in step 2 is that the nth warp of each group of upper warp threads is threaded through the upper heddle eye of the nth heddle wire in its corresponding heddle frame, and the nth warp of each group of lower warp threads is threaded through the lower heddle eye of the nth heddle wire in its corresponding heddle frame, where the rightmost warp is the first warp. Condition 2 is that the threading pattern of the spacer yarns in step 2 is as follows: the nth yarn of each group of spacer yarns is threaded through the nth heddle wire of its corresponding heddle frame; the nth yarn of spacer yarn I passes between the (2n-1)th and (2n-2)th heddle wires of the double heddle frame; the nth yarn of spacer yarn II passes between the 2nth and (2n-1)th heddle wires of the double heddle frame; where the rightmost spacer yarn is the first yarn; Condition 3 is that the number of interlacing times between the inner weft yarn and the spacer yarn in step 4 is 2n; Condition 4 is that the height of the interlacing reinforcement structure of the inner weft yarn and the spacer yarn in step 4 is controlled by the tension of the upper and lower sets of spacer yarns or by adding an external spacer device. Condition 5 is that the interlacing reinforcement structure of the inner weft yarn and the spacer yarn in step 4 is located at the halfway point between the upper and lower fabrics; Condition 6 is that in step 4, the inner weft yarn and the spacer yarn interweave twice to form the minimum cycle; the upper and lower layers of fabric interweave once to form the minimum cycle. Condition 7 is that in step 4, different layers of inner weft yarn reinforcement structural units with different combinations of cycle numbers are designed according to actual needs; Condition 8 is that in step 5, the alternating pattern of spacer fabric structural units and in-layer weft yarn reinforcement structural units is designed according to actual needs to form in-layer weft yarn reinforcement spacer fabrics with different structures. Condition 9 is that the mass ratio of fabric to resin in step 6 is 20%:80%-70%:30%; and the stirring time is 5-15 minutes.

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