Double-layered lattice woven fabric, weaving method thereof and modified rapier loom

Abstract

The application discloses a double-layer grating machine woven fabric, a weaving method thereof and a modified rapier loom. Warp fiber bundles, weft fiber bundles and binding fiber bundles are woven in the same surface layer fabric of the double-layer grating machine woven fabric; the connecting fiber bundles are located between the upper layer fabric and the lower layer fabric and are in the thickness direction of the double-layer grating machine woven fabric. In one weaving unit, the connecting fiber bundles are located between two warp fiber bundles, and the binding fiber bundles are located outside the warp fiber bundles; the two warp fiber bundles and one weft fiber bundle are woven to float or sink in the warp direction to clamp the weft fiber bundle, and are bound by the binding fiber bundles between the two weft fiber bundles; the binding fiber bundles only sink in the weft fiber bundle after being cross-bound. The double-layer grating machine woven fabric woven by the method has stable fabric structure in the warp direction, does not come off and does not slip.

Description

Technical Field

[0001] This invention relates to woven fabrics used in fiber-reinforced composite materials as a reinforcing phase; more particularly, it refers to a double-layer grid woven fabric obtained by combining a three-dimensional multi-rapier loom with a warp knitting machine. Background Technology

[0002] Currently, the formation principle of fabrics is seen in Figure 1 As shown in the diagram, the warp yarns are drawn out from the warp beam and inserted into the heddle holes of the warp stop and heddle frame before reaching the reed teeth. Then, the weft yarns are inserted onto the warp yarns by the weft inserter to form weft points, and finally, they are taken up by the take-up roller and the take-up roller.

[0003] Three-dimensional woven fabrics, as the reinforcing phase in fiber-reinforced composite materials, have been widely used in many fields such as aerospace, automotive, and shipbuilding due to their numerous advantages, including light weight, good integrity and conformability, and excellent mechanical properties. However, the production of three-dimensional woven fabrics is technically challenging, costly, and has low output. Moreover, it sometimes fails to meet the requirements of the fabric structure. Therefore, how to weave integral woven fabrics with a three-dimensional interwoven structure has become one of the important research topics in the field of composite materials science in recent years.

[0004] Three-dimensional woven fabrics refer to spatial networks in which yarns interweave and intertwine in three directions to form a specific geometric shape. Different weaving methods will result in woven fabrics with different structures.

[0005] The book *Weaving Machinery*, edited by Chen Ge, published by China Textile Press in Beijing in May 2009, pp. 220-225, introduces the structure of a three-dimensional rapier loom. A three-dimensional rapier loom includes a shedding mechanism, weft insertion mechanism, selvage mechanism, beat-up mechanism, warp feed mechanism, and take-up mechanism. The weaving principle of a three-dimensional rapier loom is as follows: Figure 2 As shown.

[0006] Warp knitting is a type of knitting method that uses one or more groups of parallel yarns fed into all the working needles of a knitting machine in the warp direction to form loops and create a knitted fabric. This type of knitted fabric is called warp-knitted fabric, and the knitting machine used to complete this process is called a warp knitting machine. The structure of warp-knitted fabric is a comprehensive reflection of the influence of a series of factors on its appearance, structure, and performance. These factors include the warp knitting machine size, number of needle beds, number of guide bars, warp threading, the correspondence (yarn or guide bar) of each guide bar, the type, color, and count of the yarn used, the lateral movement of the guide needles in a complete structure, the average warp feed per row, the fabric density, and additional yarns. Among these, the lateral movement of the guide needles, that is, the sequential lateral movement direction and magnitude of the guide needles before and after the needles, directly affects the structural shape of the loops, making the design of the warp knitting process of great significance. Summary of the Invention

[0007] One objective of this invention is to provide a double-layer grid fabric with warp-bound binding, the double-layer grid fabric comprising at least warp fiber bundles, weft fiber bundles, binding fiber bundles, and connecting fiber bundles. The warp fiber bundles, weft fiber bundles, and binding fiber bundles are woven in the same surface layer fabric; the connecting fiber bundles are located between the upper fiber bundle weaving unit and the lower fiber bundle weaving unit, and are in the thickness direction of the double-layer grid fabric. In one weaving unit of the double-layer grid fabric (e.g., ... Figure 5 As shown, the connecting fiber bundle is located between two warp fiber bundles, and the binding fiber bundle is located outside the warp fiber bundle. The two warp fiber bundles and one weft fiber bundle float or sink in the warp direction, weaving to hold the weft fiber bundle, and are bound between the two weft fiber bundles by the binding fiber bundle. After the binding fiber bundle is cross-bound, it only sinks to the weft fiber bundle. The binding point and the weaving point do not coincide in the warp direction. The binding point and weaving point of the upper fiber bundle weaving unit are parallel to the binding point and weaving point of the lower fiber bundle weaving unit in the thickness direction. This double-layer grid fabric with warp binding exhibits a stable fabric structure after tensile testing, without loosening or slipping. In the calibration of the double-layer grid fabric, the length of the grid is a, the width is b, and the height is C, in cm; preferably, dimensions a, b, and C are the same.

[0008] The second objective of this invention is to provide an improved three-dimensional double rapier loom, see [link to related document]. Figure 3 As shown, in terms of the distribution of warp fiber bundles, guide bars, and hem frames, guide bars are added between the hem frames and the reed. The number of guide bars and hem frames is related to the configuration of the grating fabric; that is, the number of hem frames is the same as the number of warp fiber bundles, and the number of guide bars is the same as the number of warp bundles. The function of the guide bar mechanism is to enable the guide bars to move in four directions (up, down, left, and right) according to different fabric structure requirements. It can act on one or more guide bars and coordinate with the oscillation. This invention's improved three-dimensional double rapier loom can weave large-size double-layer grating fabrics with a width of 100cm to 300cm (e.g., Figure 9 The length of B), and the thickness is 2mm to 10cm (e.g., Figure 9 (the length of C), and a and b can have the same dimensions as C.

[0009] A third objective of this invention is to propose an improved warp knitting method that enables the weaving of large-sized double-layer grid fabrics on an improved rapier loom. The method for weaving a double-layer grid fabric with warp binding includes the following steps: selecting raw materials containing the fibers required for weaving the grid three-dimensional fabric; warping on an improved warp knitting machine, using two types of warp heads: one type warps the warp fiber bundles and connecting fiber bundles, then threading the warped warp fiber bundles onto the connecting fiber bundle heads through the eyelets of the hem frame; the other type warps and binds the fiber bundles, then threading the bound fiber bundles onto the guide needle eyelets of the guide bar; and then performing warp knitting on the improved warp knitting machine. The double-layer grid fabric with warp binding obtained by this invention exhibits low elongation in both the warp and weft directions, indicating a stable fabric structure. Attached Figure Description

[0010] Figure 1 A simplified diagram illustrating the fabric formation principle of traditional woven fabrics.

[0011] Figure 2 Diagram illustrating the weaving principle of a traditional three-dimensional multi-rapier loom.

[0012] Figure 3 This is a diagram showing the distribution structure of the warp fiber bundles, combs, and hem frames in the improved three-dimensional double rapier loom of this invention.

[0013] Figure 3A This is a schematic diagram of the movement of the brown frame.

[0014] Figure 3B This is a schematic diagram of the comb's movement.

[0015] Figure 4 This is a three-dimensional structural diagram of a grid fabric with warp binding obtained by the method of the present invention.

[0016] Figure 4A These are photos of the actual product.

[0017] Figure 4B yes Figure 4A A bird's-eye view photo.

[0018] Figure 4C yes Figure 4A A front-view photo.

[0019] Figure 4D yes Figure 4A A photo taken from the left side.

[0020] Figure 5 This is a three-dimensional structural diagram of a grid fabric with an independent unit in the warp direction, obtained by the method of the present invention.

[0021] Figure 5A These are photos of the actual product.

[0022] Figure 6 yes Figure 5 A three-dimensional structural photograph of the middle and upper layers of fabric and the connecting fiber bundles.

[0023] Figure 7 yes Figure 5 A three-dimensional structural photograph of the middle and lower layers of fabric and the connecting fiber bundles.

[0024] Figure 8 It is a three-dimensional structural diagram of the connection between the fiber bundle and the latitudinal fiber bundle.

[0025] Figure 9 This is a schematic diagram of the geometric calibration of the grid in a grid woven fabric.

[0026] Figure 10 This is a structural diagram of a fixture designed for tensile testing of the grid fabric of the present invention.

[0027] Figure 10A This is a diagram of the fixture structure without the pull plate assembled.

[0028] Figure 11 The present invention is a cut-out of a test sample size diagram of a double-layer grid fabric bound in the warp direction.

[0029] Figure 11A This is a schematic diagram of placing the sample radially on the fixture.

[0030] Figure 11B This is a schematic diagram of placing the sample in the latitudinal direction on the fixture.

[0031] Figure 12 These are diagrams showing the warp tensile mechanical properties of double-layer grid fabrics with different grid sizes.

[0032] Figure 13 These are diagrams showing the weft tensile mechanical properties of double-layer grid woven fabrics with different grid sizes.

[0033] Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. The examples of the parameters listed are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0035] Part 1: Improved Three-Dimensional Double Rapier Loom

[0036] See Figure 3The improved three-dimensional double rapier loom of the present invention, as shown, produces a double-layer grid fabric. Looking at the distribution of warp fiber bundles, guide bars, and hem frames in a weaving unit, the improvement lies in the addition of guide bars between the hem frames and the reed. See also... Figure 3A , Figure 3B As shown, the guide bars are used to achieve movement in four directions (up, down, left, and right) of the bundled fiber bundles; the palm frames are used, on the one hand, to insert and connect warp fiber bundles through the palm holes, and on the other hand, to achieve movement in the up and down directions of the warp fiber bundles and connecting fiber bundles. The number of guide bars and palm frames is related to the configuration of the grid fabric, that is, the number of palm frames is the same as the number of warp fiber bundles, and the number of guide bars is the same as the number of warp bundles. The function of the guide bar mechanism is to enable the guide bars to move in four directions (up, down, left, and right) according to different fabric structure requirements. It can operate on one or more guide bars and coordinate with the oscillation.

[0037] In this invention, if the weaving results in the following: Figure 4 , Figure 4A , Figure 5 , Figure 5A The double-layer grating fabric shown has two guide bars and three heald frames in the upper fabric structure 1 and three heald frames in the lower fabric structure 2 within one weaving unit. The number of guide bars and heald frames is set according to the number of weaving units. Specifically, guide bars B and D are installed after the reed, followed by guide bars A and C. Multiple heald frames are then installed after guide bars A and C.

[0038] A comb is used to control the movement of AA-bound fiber bundle 1C and the upper weft fiber bundle in the warp direction during the warp knitting process, so that AA-bound fiber bundle 1C crosses with AB-bound fiber bundle 1D.

[0039] B comb is used to control the movement of AB-bound fiber bundle 1D in the upper fabric structure 1 and the upper weft fiber bundle in the warp direction during the warp knitting process, so that AA-bound fiber bundle 1C and AB-bound fiber bundle 1D cross.

[0040] The C comb is used to control the movement of the BA-bound fiber bundle 2C in the lower layer fabric structure 2 and the lower layer weft fiber bundle in the warp direction during the warp knitting process, so that the BA-bound fiber bundle 2C and the BB-bound fiber bundle 2D cross.

[0041] The D comb is used to control the movement of the BB-bound fiber bundle 3D in the lower layer fabric structure 2 and the lower layer weft fiber bundle in the warp direction during the warp knitting process, so that the BA-bound fiber bundle 2C and the BB-bound fiber bundle 2D cross.

[0042] A heald frame is used to control the movement of the warp fiber bundle 1A in the upper layer fabric structure 1 and the upper layer weft fiber bundle in the warp direction during the warp knitting process.

[0043] The B heald frame is used to control the movement of the AB warp fiber bundle 1B in the upper fabric structure 1 in the warp direction during the warp knitting process, together with the upper weft fiber bundle.

[0044] The C-heal frame is used to control the movement of the CA connecting fiber bundle 3A in the warp direction with the upper and lower weft fiber bundles during the warp knitting process in the thickness direction.

[0045] The D heald frame is used to control the movement of the BA warp fiber bundle 2A in the lower layer fabric structure 2 in the warp direction during the warp knitting process with the lower layer weft fiber bundle.

[0046] The E heald frame is used to control the movement of the BB warp fiber bundle 2B in the lower layer fabric structure 2 in the warp direction during the warp knitting process, together with the lower layer weft fiber bundle.

[0047] The F heald frame is used to control the movement of the CB connecting fiber bundle 3B in the warp direction with the lower weft fiber bundle and the lower weft fiber bundle in the warp direction during the warp knitting process.

[0048] Part Two: Improved Warp Knitting Methods

[0049] Fiber-reinforced composite materials are composite materials in which various forms of fibers or fiber assemblies serve as the reinforcing phase, and materials such as rubber, resin, ceramics, metals, cement, mortar, and concrete serve as the matrix phase. In these composite materials, the fibers or fiber assemblies act as a skeleton. Fabric-reinforced materials can be further classified into woven fabrics, knitted fabrics, three-dimensional braided fabrics, and nonwoven fabric-reinforced composite materials, depending on the structure of the textile fibers and the weaving method (woven or knitted).

[0050] Currently, warp knitting machines use chain stitches and weft stitches to form fabrics through loops. The raw materials used must be organic fibers with a certain degree of elasticity, while inorganic fibers are too brittle and easily broken to be used on warp knitting machines. The double-layer grid fabric produced by this invention is woven from inorganic fibers (such as basalt fiber, carbon fiber, glass fiber, silicon carbide fiber, aramid fiber, etc.), thus requiring improvements to the warp knitting machine process.

[0051] This invention relates to an improved warp knitting machine (such as...) Figure 3 The improved warp knitting process was applied to the fabric (as shown) to achieve the following results: Figure 4 , Figure 4A , Figure 11 The method for weaving the double-layered grid three-dimensional fabric with bound warp direction, as shown, includes the following steps:

[0052] Step 1: Select the raw materials for the fibers needed to weave the grid three-dimensional fabric;

[0053] Since the present invention requires the weaving of large-size grid three-dimensional fabrics for use in fiber-reinforced composite materials, from the geometric calibration structure (such as...) Figure 9 As shown in the diagram, the length of the grid is denoted as a (in cm), the width as b (in cm), and the thickness as C (in cm). The larger dimensions refer to a, b, and C varying within the range of 2 mm to 10 cm. The length and width of the double-layer grid three-dimensional fabric with warp binding obtained by the method of this invention meet the size limitations of the warp knitting machine.

[0054] Because the raw materials used to weave large-sized double-layer grid three-dimensional fabrics can be basalt fiber, carbon fiber, glass fiber, silicon carbide fiber, aramid fiber, etc.

[0055] Each fiber bundle arranged on the improved warp knitting machine contains 600–1200 monofilament fibers. (In terms of volume per cubic meter) The weight of the double-layer grid three-dimensional fabric is estimated to be 600g to 850g.

[0056] Step two: Warping on the improved warp knitting machine;

[0057] Warping is a preparatory step in weaving, which involves winding a certain number of warp yarns onto a warp beam with uniform and appropriate tension, according to the required length and width.

[0058] In this invention, the warping process uses two types of warping heads. One type of warping head warps the warp fiber bundles and connecting fiber bundles, and then the fiber bundles on the warped warp fiber bundle warping head and connecting fiber bundle warping head are threaded through the eyelets of the brown frame. The other type of warping head warps and binds the fiber bundles, and then the fiber bundles on the warped and bound fiber bundle warping head are threaded through the eyelets of the guide bar needles.

[0059] In this invention, due to the weaving of large-sized double-layer grid three-dimensional fabric, the warping speed is 10 mm / min to 50 mm / min, and the tension is 0.09 cN / dtex to 0.13 cN / dtex. The spacing between the heddle wires is set to 10 mm to 50 mm by adjusting the grid size. Each fiber bundle needs to pass through the heddle eye on the heddle frame.

[0060] The warping machine is a GA163H type manufactured by Jiangyin No.4 Textile Machinery, with a warping line speed of up to 1000m / min and warp beam diameters of 800mm and 1000mm. It adopts an automatic displacement detection system with laser technology, which makes the yarn positioning very accurate.

[0061] Step 3: Perform warp knitting on the improved warp knitting machine;

[0062] The task of weaving is to weave the fiber bundles in the warp, weft, and thickness directions after the warping process into finished fabric products according to the fabric specifications using the improved warp knitting machine of this invention.

[0063] In a weaving unit of a double-layer grid fabric, the upper fabric structure 1 uses 2 guide bars and 3 sets of heddle frames, while the lower fabric structure 2 uses 2 guide bars and 3 sets of heddle frames. The number of guide bars and heddle frames is set according to the number of weaving units. See also Figure 3 , Figure 3A , Figure 3B As shown, the up-and-down movement of heald frames A, B, and C, combined with the up-and-down and left-and-right movement of combs A and B, causes the AA binding fiber bundle 1C to cross with the AB binding fiber bundle 1D, thereby binding the AA warp fiber bundle 1A and AB warp fiber bundle 1B in the upper fabric structure 1, as well as the CA connecting fiber bundle 3A or CB connecting fiber bundle 3B.

[0064] See Figure 3 , Figure 3A , Figure 3B As shown, the up-and-down movement of heald frames D, E, and F, combined with the up-and-down and left-and-right movement of combs C and D, causes the BA binding fiber bundle 2C and the BB binding fiber bundle 2D to cross, thereby binding the BA warp fiber bundle 2A and the BB warp fiber bundle 2B in the lower layer fabric structure 2, as well as the CA connecting fiber bundle 3A or the CB connecting fiber bundle 3B.

[0065] Part Three: Double-Layer Grid Three-Dimensional Fabric Applied to Fiber-Reinforced Composites

[0066] See Figure 4 , Figure 4A , Figure 4B , Figure 4C , Figure 4D , Figure 5 , Figure 5A , Figure 6 , Figure 7 , Figure 8 As shown, the double-layer grid fabric with warp binding of the present invention is composed of an upper fabric structure 1, a lower fabric structure 2, and a thickness direction structure 3. The upper fabric structure 1 and the lower fabric structure 2 have the same structure. The upper fabric structure 1 is composed of multiple upper fiber bundle weaving units 10. The lower fabric structure 2 is composed of multiple lower fiber bundle weaving units 20.

[0067] The binding points and knots in the upper fiber bundle weaving unit 10 do not coincide in the warp direction. In one upper fiber bundle weaving unit 10, the connecting fiber bundles (3A, 3B) are located between two warp fiber bundles (1A, 1B), and the binding fiber bundles (1C, 1D) are located outside the warp fiber bundles (1A, 1B). The two warp fiber bundles (1A, 1B) and one weft fiber bundle float or sink in the warp direction to hold the weft fiber bundle, and the binding fiber bundles (1C, 1D) bind the weft fiber bundle between the two weft fiber bundles (4B, 4C) to form binding points. After the binding fiber bundles (1C, 1D) are cross-bound, they only sink to the weft fiber bundle.

[0068] In the lower fiber bundle weaving unit 20, the binding points and knot points do not coincide in the warp direction. In a lower fiber bundle weaving unit 20, the connecting fiber bundles (3A, 3B) are located between two warp fiber bundles (2A, 2B), and the binding fiber bundles (2C, 2D) are located outside the warp fiber bundles (2A, 2B). The two warp fiber bundles (2A, 2B) and one weft fiber bundle float or sink in the warp direction to hold the weft fiber bundle, and the binding fiber bundles (2C, 2D) bind the two weft fiber bundles to form binding points. After the binding fiber bundles (2C, 2D) are cross-bound, they only sink to the weft fiber bundle.

[0069] The binding points and knots of the upper fiber bundle weaving unit 10 are parallel to the binding points and knots of the lower fiber bundle weaving unit 20 in the thickness direction.

[0070] Upper fabric structure 1

[0071] See Figure 4 , Figure 4A , Figure 4B , Figure 4C , Figure 4D , Figure 5 , Figure 5A , Figure 6 , Figure 8 As shown, the upper fabric structure 1 is woven by warp knitting of the upper warp fiber bundle, the upper binding fiber bundle, and the upper weft fiber bundle.

[0072] In this invention, AA warp fiber bundle 1A, AB warp fiber bundle 1B, AA bundled fiber bundle 1C, and AB bundled fiber bundle 1D, together with the upper weft fiber bundle, are warp-knitted to form an upper fiber bundle weaving unit 10, such as... Figure 6 As shown. The starting fiber bundle of the upper fiber bundle weaving unit 10 along the winding direction is configured as follows:

[0073] Step 101: AA warp fiber bundle 1A sinks below DA weft fiber bundle 4A, then AB warp fiber bundle 1B floats above DA weft fiber bundle 4A; AA binding fiber bundle 1C and AB binding fiber bundle 1D sink simultaneously below DA weft fiber bundle 4A, with AA binding fiber bundle 1C located outside AA warp fiber bundle 1A and AB binding fiber bundle 1D located outside AB warp fiber bundle 1B; CA connecting fiber bundle 3A floats above DA weft fiber bundle 4A and is located between AA warp fiber bundle 1A and AB warp fiber bundle 1B.

[0074] Step 102: AA binding fiber bundle 1C and AB binding fiber bundle 1D cross between DA weft fiber bundle 4A and DB weft fiber bundle 4B, and float above AA warp fiber bundle 1A and AB warp fiber bundle 1B to form upper layer IA warp binding node 10A.

[0075] Step 103: AA warp fiber bundle 1A floats above DB weft fiber bundle 4B, then AB warp fiber bundle 1B sinks below DB weft fiber bundle 4B; AA binding fiber bundle 1C and AB binding fiber bundle 1D sink simultaneously below DB weft fiber bundle 4B, with AA binding fiber bundle 1C located outside AB warp fiber bundle 1B and AB binding fiber bundle 1D located outside AA warp fiber bundle 1A; CB connecting fiber bundle 3B floats above DB weft fiber bundle 4B and is located between AA warp fiber bundle 1A and AB warp fiber bundle 1B.

[0076] Step 104: AA binding fiber bundle 1C and AB binding fiber bundle 1D cross between DB weft fiber bundle 4B and DC weft fiber bundle 4C, and float above AA warp fiber bundle 1A and AB warp fiber bundle 1B to form upper layer IB warp binding node 10B.

[0077] Step 105: AA warp fiber bundle 1A sinks into DC weft fiber bundle 4C, then AB warp fiber bundle 1B floats into DC weft fiber bundle 4C; AA binding fiber bundle 1C and AB binding fiber bundle 1D sink into DC weft fiber bundle 4C simultaneously, with AA binding fiber bundle 1C located outside AA warp fiber bundle 1A and AB binding fiber bundle 1D located outside AB warp fiber bundle 1B; CA connecting fiber bundle 3A floats into DC weft fiber bundle 4C and is located between AA warp fiber bundle 1A and AB warp fiber bundle 1B.

[0078] Step 106: AA binding fiber bundle 1C and AB binding fiber bundle 1D cross between DC weft fiber bundle 4C and DD weft fiber bundle 4D, and float above AA warp fiber bundle 1A and AB warp fiber bundle 1B to form upper IC warp binding node 10C.

[0079] Step 107: AA warp fiber bundle 1A floats above DD weft fiber bundle 4D, then AB warp fiber bundle 1B sinks below DD weft fiber bundle 4D; AA binding fiber bundle 1C and AB binding fiber bundle 1D sink simultaneously below DD weft fiber bundle 4D, with AA binding fiber bundle 1C located outside AB warp fiber bundle 1B and AB binding fiber bundle 1D located outside AA warp fiber bundle 1A; CB connecting fiber bundle 3B floats above DD weft fiber bundle 4D and is located between AA warp fiber bundle 1A and AB warp fiber bundle 1B.

[0080] Lower layer fabric structure 2

[0081] See Figure 4 , Figure 4A , Figure 4B , Figure 4C , Figure 4D , Figure 5 , Figure 5A , Figure 7 , Figure 8 As shown, the lower fabric structure 2 is woven by warp knitting of the lower warp fiber bundle, the lower binding fiber bundle and the lower weft fiber bundle.

[0082] In this invention, BA warp fiber bundle 2A, BB warp fiber bundle 2B, BA bundled fiber bundle 2C, and BB bundled fiber bundle 2D, together with the lower weft fiber bundle, are warp-knitted to form a lower fiber bundle weaving unit 20, such as... Figure 7 As shown. The starting fiber bundle configuration of the lower fiber bundle weaving unit 20 along the winding direction is as follows:

[0083] Step 201: BA warp fiber bundle 2A sinks below EA weft fiber bundle 5A, then BB warp fiber bundle 2B floats above EA weft fiber bundle 5A; BA binding fiber bundle 2C and BB binding fiber bundle 2D sink simultaneously below EA weft fiber bundle 5A, with BA binding fiber bundle 2C located outside BA warp fiber bundle 2A and BB binding fiber bundle 2D located outside BB warp fiber bundle 2B; CB connecting fiber bundle 3B sinks below EA weft fiber bundle 5A and is located between BA warp fiber bundle 2A and BB warp fiber bundle 2B.

[0084] Step 202: BA binding fiber bundle 2C and BB binding fiber bundle 2D cross between EA weft fiber bundle 5A and EB weft fiber bundle 5B, and float above BA warp fiber bundle 2A and BB warp fiber bundle 2B to form upper JA warp binding node 20A;

[0085] Step 203: BA warp fiber bundle 2A floats above EB weft fiber bundle 5B, while BB warp fiber bundle 2B sinks below EB weft fiber bundle 5B; BA binding fiber bundle 2C and BB binding fiber bundle 2D sink simultaneously below EB weft fiber bundle 5B, with BA binding fiber bundle 2C located outside BB warp fiber bundle 2B and BB binding fiber bundle 2D located outside BA warp fiber bundle 2A; CA connecting fiber bundle 3A floats above EB weft fiber bundle 5B and is located between BA warp fiber bundle 2A and BB warp fiber bundle 2B.

[0086] Step 204: BA binding fiber bundle 2C and BB binding fiber bundle 2D cross between EB weft fiber bundle 5B and EC weft fiber bundle 5C, and float above BA warp fiber bundle 2A and BB warp fiber bundle 2B to form upper JB warp binding node 20B.

[0087] Step 205: BA warp fiber bundle 2A sinks into EC weft fiber bundle 5C, then BB warp fiber bundle 2B floats into EC weft fiber bundle 5C; BA binding fiber bundle 2C and BB binding fiber bundle 2D sink into EC weft fiber bundle 5C simultaneously, with BA binding fiber bundle 2C located outside BA warp fiber bundle 2A and BB binding fiber bundle 2D located outside BB warp fiber bundle 2B; CB connecting fiber bundle 3B sinks into EC weft fiber bundle 5C and is located between BA warp fiber bundle 2A and BB warp fiber bundle 2B.

[0088] Step 206: BA binding fiber bundle 2C and BB binding fiber bundle 2D cross between EC weft fiber bundle 5C and ED weft fiber bundle 5D, and float above BA warp fiber bundle 2A and BB warp fiber bundle 2B to form upper JC warp binding node 20C;

[0089] Step 207: BA warp fiber bundle 2A floats above ED weft fiber bundle 5D, while BB warp fiber bundle 2B sinks below ED weft fiber bundle 5D; BA binding fiber bundle 2C and BB binding fiber bundle 2D sink simultaneously below ED weft fiber bundle 5D, with BA binding fiber bundle 2C located outside BB warp fiber bundle 2B and BB binding fiber bundle 2D located outside BA warp fiber bundle 2A; CA connecting fiber bundle 3A floats above ED weft fiber bundle 5D and is located between BA warp fiber bundle 2A and BB warp fiber bundle 2B.

[0090] Thickness direction tissue structure

[0091] See Figure 4 , Figure 4A , Figure 4B , Figure 4C , Figure 4D , Figure 5 , Figure 5A , Figure 6 , Figure 7 , Figure 8 As shown, the thickness direction structure 3 is woven using a warp knitting method, consisting of two connecting fiber bundles (3A, 3B) and upper weft fiber bundles (4A, 4B, 4C, 4D) and lower weft fiber bundles (5A, 5B, 5C, 5D), respectively. The starting fiber bundles along the winding direction are configured as follows:

[0092] Step 301: CA connecting fiber bundle 3A floats above DA weft fiber bundle 4A, and CB connecting fiber bundle 3B sinks below EA weft fiber bundle 5A.

[0093] Step 302: After CA connecting fiber bundle 3A passes through DA weft fiber bundle 4A, CA connecting fiber bundle 3A sinks into EB weft fiber bundle 5B, floats into DC weft fiber bundle 4C, and sinks into ED weft fiber bundle 5D.

[0094] Step 303: After the CB connecting fiber bundle 3B passes through the EA weft fiber bundle 5A, the CB connecting fiber bundle 3B floats up to the DB weft fiber bundle 4B, sinks down to the EC weft fiber bundle 5C, and floats up to the DD weft fiber bundle 4D.

[0095] Step 304: During the warp knitting process, CA connecting fiber bundle 3A and CB connecting fiber bundle 3B meet and intersect in the thickness direction, that is, they are located between two weft fiber bundles.

[0096] The fiber bundles used in the double-layer grid three-dimensional fabric with warp binding obtained by the warp knitting process of this invention are basalt fiber, carbon fiber, glass fiber, silicon carbide fiber, or aramid fiber, or a combination of two or three fiber bundles. For example, carbon fiber is used to connect the fiber bundles, while glass fiber is used for the warp, weft, and binding fiber bundles. Alternatively, carbon fiber can be used to connect the fiber bundles, while glass fiber is used for the warp and weft fiber bundles, and basalt fiber is used to bind the fiber bundles.

[0097] Part Four: Tensile Testing and Analysis

[0098] The double-layer grid three-dimensional fabric with warp binding obtained by the warp knitting method of the present invention, on the one hand, the warp and weft fiber bundles of the same surface layer fabric cooperate with the binding fiber bundles to constrain the elongation of the fabric in the warp direction, and also to stabilize the grid distributed along the warp direction; on the other hand, the connecting fiber bundle in the thickness direction of the grid three-dimensional fabric is located between the two warp fiber bundles and cooperates with the binding fiber bundle located outside the warp fiber bundle to constrain the elongation of the fabric in the thickness direction, and also to stabilize the grid distributed along the thickness; furthermore, the binding fiber bundle sinks into the weft fiber bundle and clamps the weft fiber bundle with the warp fiber bundle to constrain the elongation of the fabric in the weft direction, and also to stabilize the grid distributed along the weft direction.

[0099] Preparation of test samples

[0100] Tensile testing equipment: S2 series electronic universal testing machine (maximum output load 5KN), Stema (Shanghai) Industrial Co., Ltd.

[0101] Homemade test fixtures (such as) Figure 10 , 10A (As shown): The detachable U-shaped frame fixture consists of an upper fixture, a lower fixture, an upper pull plate, and a lower pull plate. Screws and nuts are used to secure the fixtures together and to the sample. The measurement area of ​​the detachable U-shaped frame fixture is... The fixed dimensions facilitate the calibration of tensile mechanical properties in the processor of the electronic universal testing machine, making the calculation of tensile displacement and fabric elongation more accurate.

[0102] Tensile test specimen: Shear dimensions of the specimen to be tested ,like Figure 11 As shown. The specimen placed radially is designated as type I specimen (e.g., ...). Figure 11A ), samples placed in the latitudinal direction are denoted as type II samples (e.g. Figure 11B Five samples of each type are typically cut, and 40 valid values ​​are measured for each sample. The average value is then taken.

[0103] Grid dimensions of specimens A and E The grid dimensions of specimens B and F The grid dimensions of samples C and G Grid dimensions of specimens D and H Eight different specifications of specimens were selected for tensile testing. Four specifications (A, B, C, and D) were measured in the warp direction, and the other four specifications (E, F, G, and H) were measured in the weft direction. Five specimens of each specification were cut, and 40 valid values ​​were measured for each specimen during the tensile test, with the average value taken. Because the grid three-dimensional fabric is flexible, the cut edges are prone to loosening and slippage, which can lead to inaccurate test results reflecting the fabric's properties and make tensile mechanical property measurements difficult. Therefore, a 20% reduction in the quantity of specimens was used for tensile mechanical property analysis to ensure the accuracy of parameters in the measurement area. The fiber weight per cubic meter was 835g for specimens A and E (error not exceeding 5g), 750g for specimens B and F (error not exceeding 5g), 675g for specimens C and G (error not exceeding 5g), and 610g for specimens D and H (error not exceeding 5g).

[0104] Installation of the test specimen on the fixture: (A) Place the warp direction of the specimen in the opening of the lower fixture, and then lay it flat in the groove of the lower fixture; (B) Cover with the upper fixture, and if the fabric thickness is lower than the clamping area, fill it with fabric of the same material; (C) Connect the nuts by passing screws through the through holes on the upper and lower fixtures; (D) Clamp the fabric at the opening with the upper and lower pull plates, and connect the nuts by passing screws through the through holes on the upper and lower pull plates; (E) Install the installed specimen and fixture on the worktable of the universal testing machine. Complete three warp direction tensile specimens according to steps (A) to (E). For the weft direction tensile specimen, simply place the weft direction of the specimen at the opening of the lower fixture in step (A), and the rest of the steps are the same.

[0105] After the sample is installed with the detachable U-shaped frame fixture, the central area of ​​the detachable U-shaped frame fixture is the actual measurement area of ​​the fabric, and the size of the actual measurement area is exactly the same. .

[0106] The tensile measurement conditions were: tensile speed 1 mm / min, spacing length 20 mm, and sample pre-tension 2 N; the tensile stopping conditions were: maximum load 2 kN; and the test environment temperature was 22 ℃ and the humidity was 65%.

[0107] See Figure 12 The warp-direction tensile displacement curve shown indicates that the sample is no longer stretched and the fabric structure remains stable at an average of 800 N.

[0108] See Figure 13 The weft-direction tensile displacement curve shown indicates that the sample is no longer stretched at an average of 900 N, and the fabric structure remains stable.

[0109] Analysis of the obtained parameters shows that under a maximum load of 2KN, the warp and weft directions no longer elongate and remain stable. This is because the connecting fiber bundle and the binding fiber bundle cooperate to achieve a balance of forces.

[0110] Average elongation , This represents the length (mm) of the unstretched specimen. This represents the length (mm) of the specimen after tension. The tensile specimen is measured, and the average value is taken.

[0111] Table 1 Elongation under meridional tension

[0112]

[0113] Table 2 Elongation under weft tension

[0114]

[0115] Analysis of the data in Tables 1 and 2 shows that, under the same load conditions, the elongation of double-layer grid fabrics with different grid sizes and warp-bound binding, woven using the method of this invention, increases with increasing grid size. Because the displacement of the samples after stretching is relatively small, this indicates that the double-layer grid fabric with warp-bound binding has a more stable three-dimensional grid structure.

Claims

1. A double-layer grid woven fabric, wherein the woven fabric includes at least warp fiber bundles and weft fiber bundles; characterized in that: It also includes bundled fiber bundles and connecting fiber bundles; Warp fiber bundles, weft fiber bundles, and bundled fiber bundles are woven in the same surface layer fabric; The connecting fiber bundle is located between the upper fiber bundle weaving unit (10) and the lower fiber bundle weaving unit (20), and is in the thickness direction of the double-layer grid fabric; In a weaving unit of a double-layer grid fabric, the connecting fiber bundle is located between two warp fiber bundles, and the binding fiber bundle is located outside the warp fiber bundle; the two warp fiber bundles and one weft fiber bundle float or sink in the warp direction to hold the weft fiber bundle, and are bound by the binding fiber bundle between the two weft fiber bundles; after the binding fiber bundle is cross-bound, it only sinks to the weft fiber bundle. The binding points and knots in the upper fiber bundle weaving unit (10) do not coincide in the warp direction; the binding points and knots in the lower fiber bundle weaving unit (20) do not coincide in the warp direction. The binding points and knots of the upper fiber bundle weaving unit (10) are parallel to the binding points and knots of the lower fiber bundle weaving unit (20) in the thickness direction; Multiple weaving units are arranged in an array along the weft direction of the double-layer grid fabric.

2. The double-layer grid fabric according to claim 1, characterized in that: The fiber bundle is an inorganic fiber material.

3. The double-layer grid fabric according to claim 2, characterized in that: The fiber bundles are basalt fibers, carbon fibers, glass fibers, silicon carbide fibers and / or aramid fibers.

4. The double-layer grid fabric according to claim 1, characterized in that: The grid size in double-layer grid woven fabric is 2mm to 10cm.

5. The double-layer grid fabric according to claim 1, characterized in that: The double-layer grid fabric consists of an upper fabric structure (1), a lower fabric structure (2), and a thickness direction structure (3); wherein, the upper fabric structure (1) and the lower fabric structure (2) have the same structure; the upper fabric structure (1) is composed of multiple upper fiber bundle weaving units (10); the lower fabric structure (2) is composed of multiple lower fiber bundle weaving units (20); The upper fabric structure (1) is obtained by warp knitting of the upper warp fiber bundle, the upper binding fiber bundle and the upper weft fiber bundle; The AA warp fiber bundle (1A), AB warp fiber bundle (1B), AA bundled fiber bundle (1C), and AB bundled fiber bundle (1D) are combined with the upper weft fiber bundle using a warp knitting process to form an upper fiber bundle weaving unit (10); the starting fiber bundle of the upper fiber bundle weaving unit (10) along the winding direction is configured as follows: Step 101: The AA warp fiber bundle (1A) sinks into the DA weft fiber bundle (4A), and the AB warp fiber bundle (1B) floats into the DA weft fiber bundle (4A); the AA binding fiber bundle (1C) and the AB binding fiber bundle (1D) sink into the DA weft fiber bundle (4A) at the same time, and the AA binding fiber bundle (1C) is located outside the AA warp fiber bundle (1A), and the AB binding fiber bundle (1D) is located outside the AB warp fiber bundle (1B); the CA connecting fiber bundle (3A) floats into the DA weft fiber bundle (4A) and is located between the AA warp fiber bundle (1A) and the AB warp fiber bundle (1B); Step 102: AA binding fiber bundle (1C) and AB binding fiber bundle (1D) intersect between DA weft fiber bundle (4A) and DB weft fiber bundle (4B), and float above AA warp fiber bundle (1A) and AB warp fiber bundle (1B) to form upper layer IA warp binding node (10A). Step 103: The AA warp fiber bundle (1A) floats above the DB weft fiber bundle (4B), and the AB warp fiber bundle (1B) sinks below the DB weft fiber bundle (4B); the AA binding fiber bundle (1C) and the AB binding fiber bundle (1D) sink below the DB weft fiber bundle (4B) simultaneously, with the AA binding fiber bundle (1C) located outside the AB warp fiber bundle (1B) and the AB binding fiber bundle (1D) located outside the AA warp fiber bundle (1A); the CB connecting fiber bundle (3B) floats above the DB weft fiber bundle (4B) and is located between the AA warp fiber bundle (1A) and the AB warp fiber bundle (1B). Step 104: AA binding fiber bundle (1C) and AB binding fiber bundle (1D) intersect between DB weft fiber bundle (4B) and DC weft fiber bundle (4C), and float above AA warp fiber bundle (1A) and AB warp fiber bundle (1B) to form upper IB warp binding node (10B). Step 105: The AA warp fiber bundle (1A) sinks into the DC weft fiber bundle (4C), and the AB warp fiber bundle (1B) floats into the DC weft fiber bundle (4C); the AA binding fiber bundle (1C) and the AB binding fiber bundle (1D) sink into the DC weft fiber bundle (4C) at the same time, and the AA binding fiber bundle (1C) is located outside the AA warp fiber bundle (1A), and the AB binding fiber bundle (1D) is located outside the AB warp fiber bundle (1B); the CA connecting fiber bundle (3A) floats into the DC weft fiber bundle (4C) and is located between the AA warp fiber bundle (1A) and the AB warp fiber bundle (1B); Step 106: The AA binding fiber bundle (1C) and the AB binding fiber bundle (1D) intersect between the DC weft fiber bundle (4C) and the DD weft fiber bundle (4D), and float above the AA warp fiber bundle (1A) and the AB warp fiber bundle (1B) to form the upper IC warp binding node (10C). Step 107: The AA warp fiber bundle (1A) floats above the DD weft fiber bundle (4D), and the AB warp fiber bundle (1B) sinks below the DD weft fiber bundle (4D); the AA binding fiber bundle (1C) and the AB binding fiber bundle (1D) sink below the DD weft fiber bundle (4D) simultaneously, with the AA binding fiber bundle (1C) located outside the AB warp fiber bundle (1B) and the AB binding fiber bundle (1D) located outside the AA warp fiber bundle (1A); the CB connecting fiber bundle (3B) floats above the DD weft fiber bundle (4D) and is located between the AA warp fiber bundle (1A) and the AB warp fiber bundle (1B). The lower layer fabric structure (2) is woven by warp knitting of the lower layer warp fiber bundle, the lower layer binding fiber bundle and the lower layer weft fiber bundle; The BA warp fiber bundle (2A), BB warp fiber bundle (2B), BA bundled fiber bundle (2C), and BB bundled fiber bundle (2D) are combined with the lower weft fiber bundle using a warp knitting process to form a lower fiber bundle weaving unit (20); the starting fiber bundle of the lower fiber bundle weaving unit (20) along the winding direction is configured as follows: Step 201: The BA warp fiber bundle (2A) sinks below the EA weft fiber bundle (5A), and the BB warp fiber bundle (2B) floats above the EA weft fiber bundle (5A); the BA binding fiber bundle (2C) and the BB binding fiber bundle (2D) sink below the EA weft fiber bundle (5A) simultaneously, with the BA binding fiber bundle (2C) located outside the BA warp fiber bundle (2A) and the BB binding fiber bundle (2D) located outside the BB warp fiber bundle (2B); the CB connecting fiber bundle (3B) sinks below the EA weft fiber bundle (5A) and is located between the BA warp fiber bundle (2A) and the BB warp fiber bundle (2B). Step 202: The BA binding fiber bundle (2C) and the BB binding fiber bundle (2D) cross between the EA weft fiber bundle (5A) and the EB weft fiber bundle (5B), and float above the BA warp fiber bundle (2A) and the BB warp fiber bundle (2B) to form the upper JA warp binding node (20A). Step 203: The BA warp fiber bundle (2A) floats above the EB weft fiber bundle (5B), and the BB warp fiber bundle (2B) sinks below the EB weft fiber bundle (5B); the BA binding fiber bundle (2C) and the BB binding fiber bundle (2D) sink below the EB weft fiber bundle (5B) simultaneously, with the BA binding fiber bundle (2C) located outside the BB warp fiber bundle (2B) and the BB binding fiber bundle (2D) located outside the BA warp fiber bundle (2A); the CA connecting fiber bundle (3A) floats above the EB weft fiber bundle (5B) and is located between the BA warp fiber bundle (2A) and the BB warp fiber bundle (2B). Step 204: The BA binding fiber bundle (2C) and the BB binding fiber bundle (2D) cross between the EB weft fiber bundle (5B) and the EC weft fiber bundle (5C), and float above the BA warp fiber bundle (2A) and the BB warp fiber bundle (2B) to form the upper JB warp binding node (20B). Step 205: The BA warp fiber bundle (2A) sinks into the EC weft fiber bundle (5C), and the BB warp fiber bundle (2B) floats into the EC weft fiber bundle (5C); the BA binding fiber bundle (2C) and the BB binding fiber bundle (2D) sink into the EC weft fiber bundle (5C) at the same time, and the BA binding fiber bundle (2C) is located outside the BA warp fiber bundle (2A), and the BB binding fiber bundle (2D) is located outside the BB warp fiber bundle (2B); the CB connecting fiber bundle (3B) sinks into the EC weft fiber bundle (5C) and is located between the BA warp fiber bundle (2A) and the BB warp fiber bundle (2B); Step 206: BA bundle (2C) and BB bundle (2D) intersect between EC weft bundle (5C) and ED weft bundle (5D), and float above BA warp bundle (2A) and BB warp bundle (2B) to form upper JC warp bundle node (20C). Step 207: The BA warp fiber bundle (2A) floats above the ED weft fiber bundle (5D), and the BB warp fiber bundle (2B) sinks below the ED weft fiber bundle (5D); the BA binding fiber bundle (2C) and the BB binding fiber bundle (2D) sink below the ED weft fiber bundle (5D) simultaneously, with the BA binding fiber bundle (2C) located outside the BB warp fiber bundle (2B) and the BB binding fiber bundle (2D) located outside the BA warp fiber bundle (2A); the CA connecting fiber bundle (3A) floats above the ED weft fiber bundle (5D) and is located between the BA warp fiber bundle (2A) and the BB warp fiber bundle (2B). The thickness direction structure (3) is woven by warp knitting using two connecting fiber bundles (3A, 3B) and the upper weft fiber bundles (4A, 4B, 4C, 4D) and the lower weft fiber bundles (5A, 5B, 5C, 5D), respectively; the starting fiber bundles along the winding direction are set as follows: Step 301: CA connecting fiber bundle (3A) floats above DA weft fiber bundle (4A), and CB connecting fiber bundle (3B) sinks below EA weft fiber bundle (5A). Step 302: After the CA connecting fiber bundle (3A) passes through the DA weft fiber bundle (4A), the CA connecting fiber bundle (3A) sinks into the EB weft fiber bundle (5B), floats up into the DC weft fiber bundle (4C), and sinks into the ED weft fiber bundle (5D). Step 303: After the CB connecting fiber bundle (3B) passes through the EA weft fiber bundle (5A), the CB connecting fiber bundle (3B) floats on the DB weft fiber bundle (4B), sinks on the EC weft fiber bundle (5C), and floats on the DD weft fiber bundle (4D). Step 304: During the warp knitting process, the CA connecting fiber bundle (3A) and the CB connecting fiber bundle (3B) meet and intersect in the thickness direction, that is, they are located between the two weft fiber bundles.

6. The double-layer grid fabric according to claim 1 or 5, characterized in that: Double-layer grid woven fabric is used as a reinforcing phase in fiber-reinforced composites.

7. A modified rapier loom used for weaving the double-layer grating fabric of claim 1, wherein the rapier loom is a three-dimensional double rapier loom; characterized in that: A comb was added between the brown frame and the reed; Combs are used to enable the binding of fiber bundles to move in four directions: up, down, left, and right. The brown frame is used for two purposes: firstly, to insert and connect warp fiber bundles in the brown eyelets; and secondly, to enable the warp fiber bundles and connecting fiber bundles to move in both the up and down directions. In a weaving unit of a double-layer grid fabric, the upper fabric structure (1) uses 2 combs and 3 heddle frames, and the lower fabric structure (2) uses 2 combs and 3 heddle frames.

8. A method for weaving the double-layer grid fabric of claim 1, characterized in that... It includes the following steps: Step 1: Select the raw materials for the fibers needed to weave the grid three-dimensional fabric; Fiber material is selected based on the application requirements of double-layer grid three-dimensional fabric. The grid size is set according to the application scenario requirements of the double-layer grid three-dimensional fabric; the grid length is denoted as a, the width as b, and the thickness as C, with the values ​​of a, b, and C ranging from 2mm to 10cm. Step two: Warping on the improved warp knitting machine; The warping process uses two types of warping heads. One type of warping head warps the warp fiber bundles and connecting fiber bundles, and then the fiber bundles on the warped warp fiber bundle warping head and connecting fiber bundle warping head are threaded into the eyelets of the brown frame. The other type of warping head warps and binds the fiber bundles, and then the fiber bundles on the warped and bound fiber bundle warping head are threaded into the eyelets of the guide bar needles. Step 3: Perform warp knitting on the improved warp knitting machine; The number of guide bars and heald frames are set according to the number of weaving units; In a weaving unit of a double-layer grid fabric, the upper fabric structure (1) uses 2 combs and 3 heddle frames, and the lower fabric structure (2) uses 2 combs and 3 heddle frames. The up-and-down movement of heddle frames A, B, and C, combined with the up-and-down and left-and-right movement of combs A and B, causes the AA binding fiber bundle (1C) to cross with the AB binding fiber bundle (1D), thereby binding the AA warp fiber bundle (1A) and AB warp fiber bundle (1B) in the upper fabric structure (1), as well as the CA connecting fiber bundle (3A) or CB connecting fiber bundle (3B). The up-and-down movement of heddle frames D, E, and F, combined with the up-and-down and left-and-right movement of combs C and D, causes the BA binding fiber bundle (2C) and BB binding fiber bundle (2D) to cross, thereby binding the BA warp fiber bundle (2A) and BB warp fiber bundle (2B) in the lower fabric structure (2), as well as the CA connecting fiber bundle (3A) or CB connecting fiber bundle (3B).

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