Hollow fabric composite material and forming method thereof

Abstract

The invention provides a hollow fabric composite material and a forming method thereof. The forming method comprises the following steps: (1) acquiring characteristic parameters of a hollow fabric; wherein the characteristic parameters comprise the profile type, the boundary dimension and the cavity form of the hollow fabric; (2) determining characteristic parameters of the fixed core plate according to the characteristic parameters of the hollow fabric; wherein the characteristic parameters comprise the size, the material and the number of the fixed core plates; (3) inserting a fixed core plate between adjacent pile warp cavities in the hollow fabric core layer, so that the upper and lower surfaces of the fixed core plate are completely attached to the upper and lower surface layers of the hollow fabric; (4) putting the hollow fabric in the step (3) into a forming tool, and performing composite forming on the hollow fabric in combination with a resin composite forming process to obtain a hollow fabric composite material; wherein the hollow fabrics with different molded surface types correspond to different forming tools respectively. According to the invention, high-precision forming of the large-size hollow fabric composite material can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to a hollow fabric composite material and a molding method thereof. Background Art

[0002] The hollow fabric is compounded with the resin matrix to obtain the hollow sandwich fabric composite material. Due to its light weight, high strength, sound insulation, flame retardancy, wave transmission, integral molding and other characteristics, it overcomes the shortcomings of easy delamination and poor impact resistance of traditional sandwich composite materials such as honeycomb and foam. The forming height of the hollow fabric composite mainly depends on the standing height of the core layer velvet warp column, and the standing of the velvet warp mainly depends on its capillary action and automatically stands to a certain height. However, the standing height of the velvet warp has random uncertainty, and the height of the finished product often cannot meet the ideal set value.

[0003] In the related art, the height is generally controlled by external tooling. For example, Patent 202311243855.2 provides a height control device and method for a hollow fabric composite material, which uses a height limit block to limit the height and a pulling component to pull the upper surface of the hollow fabric to fit the upper cover. The operation method is simple, but in actual production, the fabric (including the fabric after adsorption of resin) is affected by gravity, and there is no pulling point in the middle area. The fabric will not fit completely with the upper cover, and the thickness of the non-fitting part is not completely controllable. It is not suitable for the molding of larger-sized or curved hollow fabrics. At the same time, the precision range of the molding control method is relatively low, which is not suitable for high-precision hollow fabric composite molding preparation.

[0004] Patent 202210537100.2 discloses a method for preparing hollow fabric composite materials using a three-axis forming tool. Although the forming tool can achieve the purpose of controlling the height of the overall hollow composite material, the cost of the tooling equipment is relatively high, and the fixed tooling size is not adaptable to different sizes of hollow fabrics. It does not have the ability to prepare multiple varieties at low cost, efficiently and accurately, and is also not suitable for curved surface preparation, which is not conducive to actual production application and promotion.

[0005] Patent 201410696060.1 assists the hollow fabric to stand up by pulling with metal wire and magnetic field. Since both the metal wire and the fabric are flexible materials, it is difficult to control them after they are introduced into the hollow fabric. In addition, the strength of the metal wire is relatively low, and it cannot be demolded after forming and curing, which easily causes excess residue. At the same time, the height and uniformity of the board after forming depend on the state of the hollow fabric body. The overall forming thickness of the board is relatively random, and the actual operability is not strong.

[0006] Patent 201510955677.5 design uses warp profiles and weft profiles, which are connected by slots and embedded in the hollow floor for integrated formation, thereby achieving hollow fabric-assisted standing. However, the final product includes embedded profiles and is not a simple hollow fabric composite board. The final thickness, thickness accuracy and surface flatness of the hollow composite board are related to the state of the brushed hollow fabric, and cannot be precisely controlled. It is also not suitable for curved surface forming.

[0007] Therefore, based on the above problems, there is an urgent need to provide a hollow fabric composite material and a molding method thereof. Summary of the invention

[0008] The embodiment of the present invention provides a hollow fabric composite material and a molding method thereof, which can solve the problem that the molding method of the traditional hollow fabric composite material has poor molding accuracy and cannot realize one-time molding of a larger size and multifunctional hollow fabric composite material.

[0009] In a first aspect, the present invention provides a hollow fabric composite material and a molding method thereof, the molding method comprising:

[0010] (1) Obtaining characteristic parameters of the hollow fabric; wherein the characteristic parameters include the profile type, external dimensions and cavity shape of the hollow fabric;

[0011] (2) determining characteristic parameters of the fixed core plate according to the characteristic parameters of the hollow fabric; wherein the characteristic parameters include the size, material and quantity of the fixed core plate;

[0012] (3) inserting the fixed core plate between adjacent pile warp cavities in the hollow fabric core layer so that the upper and lower surfaces of the fixed core plate are completely in contact with the upper and lower layers of the hollow fabric;

[0013] (4) placing the hollow fabric in step (3) in a molding tool, and performing composite molding on it in combination with a resin composite molding process to obtain the hollow fabric composite material; wherein the hollow fabrics of different profile types correspond to different molding tools.

[0014] Preferably, the profile types of the hollow fabric include a flat surface type and a curved surface type;

[0015] The material of the fixed core plate is determined based on the surface type of the hollow fabric; preferably, when the hollow fabric is planar, the fixed core plate is a rigid fixed core plate, and when the hollow fabric is curved, the fixed core plate is a flexible fixed core plate.

[0016] Preferably, the width of the fixed core plate is not greater than the width of the velvet warp cavity in the hollow fabric core layer, the height is not greater than the height of the velvet warp cavity in the hollow fabric core layer, and the length is not less than the overall width / length of the hollow fabric.

[0017] Preferably, the number of the fixed core plates is determined by the following formula:

[0018]

[0019] Wherein, M is the number of the fixed core plates, W i is the overall width of the flat hollow fabric or the overall arc length of the curved hollow fabric, and w is the width of the adjacent pile warp cavities in the core layer of the hollow fabric.

[0020] Preferably, when the hollow fabric is planar, the forming tooling comprises two upper and lower rigid plates; wherein the rigid plates are respectively located on the surfaces of the upper and lower layers of the hollow fabric, and are used to control the height and overall thickness of the hollow fabric composite material formed.

[0021] Preferably, the forming tool further comprises a plurality of rigid contour blocks, which are evenly placed around the hollow fabric and have upper surfaces respectively fitted with the rigid flat plates, for further controlling the overall thickness of the hollow fabric composite material.

[0022] More preferably, the height of the rigid contour blocks is the same as the overall height of the hollow fabric.

[0023] Preferably, when the hollow fabric is curved, the molding tool is composed of a metal male mold and a metal female mold; wherein the shapes of the metal male mold and the metal female mold respectively correspond to the shapes of the upper and lower surfaces of the hollow fabric, and are used to control the molding height and overall thickness of the hollow fabric composite material.

[0024] Preferably, before inserting the fixed core plate between adjacent pile warp cavities in the hollow fabric core layer, the method further includes applying a release agent on the surface of the fixed core plate.

[0025] Preferably, before placing the hollow fabric in step (3) in a forming tool, the method further includes laying a functional layer or a skin layer on the upper and lower surfaces of the hollow fabric.

[0026] In a second aspect, the present invention provides a hollow fabric composite material, which is formed by using any of the forming methods described in the first aspect.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] (1) In the present invention, a fixed core plate is introduced into the forming process of the hollow fabric composite material, and the characteristic parameters of the fixed core plate (such as size, material or quantity) are determined according to the characteristic parameters of the hollow fabric, and then the fixed core plate is inserted between the adjacent velvet warp cavities in the core layer of the hollow fabric, so that the upper and lower surfaces of the fixed core plate are completely in contact with the upper and lower layers of the hollow fabric, thereby accurately fixing the core layer of the hollow fabric, and finally placing the whole in a forming tool, and using a resin composite forming process for composite forming, so as to obtain a hollow fabric composite material. In this way, by accurately combining the quantitative control points formed by combining the fixed core plate and the forming tool, and interlocking the forming tool with the operating process details, it is possible to achieve precise control of the hollow fabric forming cavity size, surface layer thickness size, product overall thickness size and overall profile flatness accuracy / dimensional fluctuation (dimensional error ≤ 0.1mm, dimensional fluctuation ≤ 0.1mm).

[0029] (2) The molding method of the present invention is easy to implement and has strong operability. The fixed core plate and molding tooling are highly adaptable to the hollow fabric composite molding process, and can realize one-time high-precision, high-quality batch production of hollow fabric composite materials with different surface types, different interlayers, and different functional layers + hollow combinations. For the preparation of hollow fabric composite products with high precision requirements, the above method will greatly improve the product preparation efficiency and the one-time pass rate, and effectively reduce the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 This is a flow chart of a hollow fabric composite material and a molding method thereof provided by one embodiment of the present invention;

[0032] Figure 2 It is a weft plan view of a flat hollow fabric provided by one embodiment of the present invention after being inserted into a fixed core plate;

[0033] Figure 3 It is a weft plan view of a curved (single curvature) hollow fabric provided by one embodiment of the present invention after being inserted into a fixed core plate;

[0034] Figure 4 It is a warp plan view of a flat hollow fabric provided by one embodiment of the present invention after being inserted into a fixed core plate;

[0035] Figure 5It is a warp plan view of a curved surface type (single curvature) hollow fabric provided by one embodiment of the present invention after being inserted into a fixed core plate;

[0036] Figure 6 It is a top view of a planar hollow fabric provided by one embodiment of the present invention after being inserted into a fixed core plate and placed into a forming tool (the rigid flat plate is not shown);

[0037] Figure 7 It is a side view of a planar hollow fabric provided by one embodiment of the present invention after being inserted into a fixed core plate and placed into a forming tool;

[0038] In the figure, C1 is the upper layer of the hollow fabric; C2 is the core layer (flannel warp layer) of the hollow fabric; C3 is the lower layer of the hollow fabric; C4 is the fixed core plate; A1 is the rigid equal height block; A3 is the interweaving point of the hollow fabric flannel warp on the upper layer; A2 is the rigid flat plate. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] like Figure 1 As shown, the embodiment of the present invention first provides a hollow fabric composite material and a molding method thereof, the molding method comprising:

[0041] (1) Obtaining characteristic parameters of the hollow fabric; wherein the characteristic parameters include the profile type, external dimensions and cavity shape of the hollow fabric;

[0042] (2) determining characteristic parameters of the fixed core plate according to the characteristic parameters of the hollow fabric; wherein the characteristic parameters include the size, material and quantity of the fixed core plate;

[0043] (3) inserting the fixed core plate between adjacent pile warp cavities in the hollow fabric core layer so that the upper and lower surfaces of the fixed core plate are completely in contact with the upper and lower layers of the hollow fabric;

[0044] (4) placing the hollow fabric in step (3) in a molding tool, and performing composite molding on it in combination with a resin composite molding process to obtain the hollow fabric composite material; wherein the hollow fabrics of different profile types correspond to different molding tools.

[0045] In the embodiment of the present invention, a fixed core plate is introduced in the forming process of the hollow fabric composite material, and the characteristic parameters of the fixed core plate (such as size, material or quantity) are determined according to the characteristic parameters of the hollow fabric, and then the fixed core plate is inserted between the adjacent velvet warp cavities in the core layer of the hollow fabric, so that the upper and lower surfaces of the fixed core plate are completely in contact with the upper and lower layers of the hollow fabric, thereby accurately fixing the core layer of the hollow fabric, and finally placing the whole in a forming tool, and using a resin composite forming process for composite forming, so as to obtain a hollow fabric composite material. In this way, by accurately combining the quantitative control points formed by combining the fixed core plate and the forming tool, and interlocking the forming tool with the operating process details, it is possible to achieve precise control of the hollow fabric forming cavity size, surface layer thickness size, product overall thickness size and overall profile flatness accuracy / dimensional fluctuation (dimensional error ≤ 0.1mm, dimensional fluctuation ≤ 0.1mm).

[0046] According to some preferred embodiments, the surface types of the hollow fabric include flat type and curved type; the material of the fixed core plate is determined based on the surface type of the hollow fabric; when the hollow fabric is flat, the fixed core plate is a rigid fixed core plate, and when the hollow fabric is curved, the fixed core plate is a flexible fixed core plate.

[0047] Considering that there are various types of hollow fabrics (such as flat and curved), in the embodiments of the present invention, Figure 2 As shown in FIG. 1 , when the hollow fabric is planar, a rigid fixed core plate is used to support the core layer of the hollow fabric, such as Figure 3 As shown, when the hollow fabric is a curved surface type (single curvature type, double curvature type, etc.), a flexible fixed core plate is used to support the core layer of the hollow fabric. In this way, the fixed core plate can fit with the upper and lower layers of the hollow fabric and support the velvet cavity of the core layer, thereby achieving high-precision molding of hollow fabric composite materials with various surface types.

[0048] According to some preferred embodiments, the width of the fixed core plate is not greater than the width of the velvet warp cavity in the hollow fabric core layer, the height is not greater than the height of the velvet warp cavity in the hollow fabric core layer, and the length is not less than the overall width / length of the hollow fabric.

[0049] In the embodiment of the present invention, the size (such as thickness, height and length, etc.) of the fixed core plate is determined according to the outer dimensions of the hollow fabric. Figure 4Or as shown in 5, when each column of pile warps in the hollow fabric core layer is evenly arranged along the length direction of the hollow fabric, the width of each fixed core plate is not greater than the width of the cavity formed between two adjacent columns of pile warps, the height is not greater than the height of the cavity formed between two adjacent columns of pile warps, and the length is not less than the overall length of the hollow fabric; by further controlling the size of the fixed core plate, not only the fixed core plate and the pile warp cavity of the hollow fabric are better fitted, thereby further ensuring the high-precision molding of the hollow fabric composite material, but also it is conducive to better fixing and demolding of the fixed core plate.

[0050] According to some preferred embodiments, the number of the fixed core plates is determined by the following formula:

[0051]

[0052] Wherein, M is the number of the fixed core plates, W i is the overall width / length of the flat hollow fabric or the overall arc length of the curved hollow fabric, and w is the width of the pile warp cavity in the core layer of the hollow fabric.

[0053] The fixed core plate can be arranged in the entire area of ​​the hollow fabric or in several local areas of the hollow fabric. For example, the fixed core plate is arranged in the velvet warp cavities at the left and right ends of the hollow fabric and the velvet warp cavities in the central area. In the embodiment of the present invention, it is preferred to arrange a fixed core plate in each velvet warp cavity of the hollow fabric, and the number of fixed core plates is accurately calculated according to the overall size of the hollow fabric. In this way, it can be ensured that the height dimension of the velvet warp cavity of the hollow fabric meets the product design requirements, and the outer dimensions of the core layer area are accurately controlled to meet the final cavity area dimension requirements of the product, thereby realizing the net size molding of the hollow fabric composite material and facilitating the one-time overall molding of multi-layer hollow fabric composite materials.

[0054] Different types of hollow fabric profiles require different types of forming tooling;

[0055] According to some preferred embodiments, Figures 6 to 7 As shown in , when the hollow fabric is planar, the forming tooling includes two upper and lower rigid plates; wherein the rigid plates are respectively located on the surfaces of the upper and lower layers of the hollow fabric, and are used to control the height and overall thickness of the hollow fabric composite material formed.

[0056] According to some preferred embodiments, the forming tooling further comprises a plurality of rigid contour blocks, which are evenly placed around the hollow fabric, and whose upper surfaces are respectively in contact with the rigid flat plates, so as to further control the overall thickness of the hollow fabric composite material; preferably, the height of the rigid contour blocks is the same as the overall height of the hollow fabric.

[0057] In an embodiment of the present invention, during the molding process of a planar hollow fabric composite material, the method of using the molding tooling is as follows: first, a fixed core plate is inserted between each velvet warp cavity of the hollow fabric and is soaked in resin, so that the upper and lower layers of the hollow fabric are completely adhered to the upper / lower surfaces of the rigid fixed core plate, and the fixed core plate provides support to allow the velvet warp to be naturally stretched in the Z direction. Then, a number of rigid equal-height plates are evenly placed around the hollow fabric. Finally, rigid flat plates are placed on the upper and lower surface of the hollow fabric, respectively, and the size of the rigid flat plates is larger than the size of the upper and lower layers of the hollow fabric. In this way, direct and precise control of the core layer velvet warp cavity height and the overall thickness during the molding process of the hollow fabric composite material can be achieved, and indirect precision control of the thickness of the upper and lower layers of the hollow fabric composite material, as well as precise control of the flatness of the upper and lower surfaces can be achieved.

[0058] It should be noted that in the embodiment of the present invention, the height of the rigid contour blocks is the same as the height of the entire product, so that the overall thickness of the product can meet the design requirements. In addition, there is no specific restriction on the number of rigid contour blocks in the embodiment of the present invention, which can be set according to actual needs, but at least several key positions of the hollow fabric (such as the four sides, the center of each edge, etc.) should be covered.

[0059] According to some preferred embodiments, when the hollow fabric is a curved surface, the molding tool is composed of a metal male mold and a metal female mold; wherein the shapes of the metal male mold and the metal female mold respectively correspond to the shapes of the upper and lower surfaces of the hollow fabric, and are used to control the molding height and overall thickness of the hollow fabric composite material.

[0060] In the embodiment of the present invention, during the molding process of the curved hollow fabric composite material, the molding tool is used as follows: first, a fixed core plate is inserted between each pile warp cavity of the hollow fabric, so that the upper and lower layers of the hollow fabric are completely attached to the upper / lower surfaces of the flexible fixed core plate, and the fixed core plate provides support to make the pile warp naturally straight in the Z direction (such as Figure 5 As shown), it is then spread on the surface of the male mold of the metal mold, and the metal female mold is used for mold closing and pressurization, so that the upper and lower layers of the hollow fabric preform are completely conformed to the rigid mold as a whole, thereby realizing the shaping treatment of the preform before composite molding; the preform is then impregnated with resin in the metal mold, and the overall height is controlled by limiting the metal mold closing (equivalent to a rigid flat plate + a rigid equal-height block) or performing overall bag pressure on the metal male mold, thereby realizing direct precision control of the core layer fleece cavity height and the overall thickness during the hollow fabric composite material molding process, and indirect precision control of the thickness of the upper and lower layers of the hollow fabric.

[0061] Specifically, there are many options for the molding process of single-curvature hollow fabric composite materials. For example, the hollow fabric can be first impregnated with resin and then inserted into a fixed core plate along the velvet warp cavity channel. The fixed core plate can also be inserted into the fixed core plate along the velvet warp cavity channel and then impregnated with resin as a whole. After that, it can be individually bagged on the surface of a metal male mold or a metal female mold, or bagged after the metal mold is closed. Considering that the profile of the double-curvature hollow fabric is relatively complex, in the molding process of the double-curvature hollow fabric composite material, it is necessary to first insert the fixed core plate along the velvet warp cavity channel to support the velvet warp of the hollow fabric, and then use the metal mold to close the mold and pressurize to pre-shape the hollow fabric. Finally, the preform is impregnated with resin in the metal mold, and after curing, a double-curvature hollow fabric composite material is obtained.

[0062] It should be noted that when forming a planar hollow fabric composite material, in order to further control the overall thickness of the hollow fabric composite material and the quality of the upper and lower layers, additional pressure can be applied to the rigid plate, or a vacuum bag can be placed on the outer contour of the rigid plate for overall bag pressing, or the plate can be put into an autoclave for overall molding to ensure that the rigid plate's pressure function is stable and reliable; at the same time, the specific parameters of the resin composite molding process (such as curing temperature and pressure and other parameters) can be selected according to actual needs.

[0063] According to some preferred embodiments, before inserting the fixed core plate between the cavities along the pile in the hollow fabric core layer, the step of applying a release agent on the surface of the fixed core plate is also included.

[0064] In an embodiment of the present invention, a release agent is evenly applied to the surface of the fixed core plate, which facilitates the removal of the fixed core plate after the resin and the hollow fabric are composited and formed, thereby avoiding damage to the structure of the hollow fabric during the demoulding process and achieving effective forming of the hollow fabric composite material.

[0065] According to some preferred embodiments, before placing the hollow fabric in step (3) in a forming tool, the process further includes laying a functional layer or a skin layer on the upper and lower surfaces of the hollow fabric.

[0066] In an embodiment of the present invention, during the composite material molding process, the upper and lower layers of the hollow fabric can be further designed according to the performance requirements of the composite material. For example, before the hollow fabric is impregnated with resin, a functional layer and / or a skin layer can be positioned and laid on the upper and lower layers of the hollow fabric, thereby giving the hollow fabric different properties and realizing further design of the thickness and function of the surface layer of the hollow fabric composite material; for example, the edges or four sides of the preset size of the hollow fabric can be de-linted, and then the solid flange prepared in advance can be placed between the upper and lower layers of the de-linted area, and the solid flange can be fit with the side wall of the fixed core plate, thereby realizing a one-time integral composite molding of the hollow fabric and the solid flange material.

[0067] Similarly, the embodiments of the present invention can also implement the design of the interlayer of the hollow fabric composite material. For example, the hollow fabric composite material can be stacked using the above method to obtain a three-layer or multi-layer hollow fabric composite material.

[0068] It should be noted that the type of resin can be selected according to molding requirements, for example, it can be epoxy resin, unsaturated resin, phenolic resin or aromatic acetylene resin.

[0069] An embodiment of the present invention further provides a hollow fabric composite material, which is formed by any of the above-mentioned forming methods.

[0070] In the embodiment of the present invention, by accurately combining the quantitative control points formed by the fixed core plate and the molding tooling, the fixed core plate, the molding tooling design and the operation process detail settings are closely linked, so as to achieve precise control of the cavity size of the hollow fabric composite material forming velvet warp, the thickness size of the surface layer, the overall thickness size of the product and the overall surface flatness accuracy / dimensional fluctuation (dimensional error ≤ 0.1mm, dimensional fluctuation ≤ 0.1mm).

[0071] The above-mentioned molding method is easy to implement, has strong operability, and has high control precision during the operation process. The molding tooling and fixed core plate have strong adaptability to the hollow fabric composite molding process, and can achieve high-precision molding of hollow fabric composite materials with different shapes. It is extremely suitable for one-time high-precision and high-quality batch production of hollow fabric composite materials with different profiles, different interlayers, and solid + hollow combinations. At the same time, the above-mentioned molding method can improve product preparation efficiency and one-time pass rate, and effectively reduce production costs.

[0072] In order to more clearly illustrate the technical solution and advantages of the present invention, a hollow fabric composite material and a forming method thereof are described in detail below through several embodiments.

[0073] Embodiment 1:

[0074] A wave-transmitting composite material with a hollow fabric and solid flange structure, including two solid flanges at the ends and a hollow fabric wave-transmitting area connecting the two solid flanges. The two solid flanges are 40 mm wide, the hollow wave-transmitting area is 720 mm wide, and the length is 650 mm. The overall layer is: 0.2 mm quartz fiber fabric + 11.5 mm hollow fabric + 0.2 mm quartz fiber fabric, wherein the thickness of the whole board is required to be 11.9 ± 0.1 mm, and the height of the cavity of the hollow wave-transmitting area is required to be (10.9 ± 0.05) mm.

[0075] (1) Determine the characteristic parameters of the hollow fabric: The hollow fabric used (Nanjing Glass Fiber Research and Design Institute Co., Ltd.) is a quartz fiber flat hollow fabric with a thickness of 11.5 mm; the core layer pile warp height is 10.9 mm, and the thickness of the upper and lower layers is 0.3 mm;

[0076] (2) Determine the characteristic parameters of the fixed core plate based on the hollow fabric:

[0077] Fixed core plate material: Aluminum alloy rigid fixed core plate; Fixed core plate size: The hollow fabric velvet cavity size is (4 (width) * 10.9 (height) * 650 (length)) mm, therefore, the fixed core plate size is designed to be (4 (width) * 10.9 (height) * 1200 (length)) mm, and the front end of the fixed core plate is rounded, and the tail end is punched or threaded; Number of core rods: The width of the hollow wave-transmitting area is 720 mm, and the width of a single fixed core plate is 4 mm. According to calculations, the required number of fixed core plates is 180;

[0078] (3) Clean the foreign matter and glue residue on the surface of the fixed core board, and use acetone and alcohol to scrub the surface of the core board in turn to ensure the surface is clean; after the alcohol evaporates, apply a release agent on the entire surface of the fixed core board, and finally wipe it with release wax. According to the thickness and size of the whole board, cut a piece of hollow fabric with a size of (1000*800) mm, and insert the fixed core board along the velvet cavity channel in the middle area of ​​the hollow fabric with a width of 720 mm, so that the upper and lower surfaces of the fixed core board are completely in contact with the upper and lower layers of the hollow fabric. Except for this area, the areas with a width of 140 mm at both ends are de-velveted, and only the upper and lower layers are retained;

[0079] (4) The hollow fabric obtained in step (3) is placed on the upper surface of a rigid flat plate, and is impregnated with resin using a vacuum drainage-vacuum breaking process or a hand lay-up process, and a solid flange (200g / m2) with a size of (140*650) mm is placed between the upper and lower layers of the de-linting area. 2 and 400g / m 2 High-strength cloth), make the solid flange side wall close to the fleece layer at the edge of the wave-transmitting area, and the upper and lower surfaces of the solid flange are flat and in contact with the upper and lower surfaces of the hollow fabric respectively; 2The quartz cloth is stacked on the upper and lower surfaces of the hollow fabric according to the designed layering, and a layer of demoulding cloth is covered on the top as a whole; then, several rigid contour blocks (designed according to the product size requirements, size (10*11.9*30) mm) are evenly placed on the rigid flat plate, and the rigid contour blocks are evenly distributed around the hollow fabric; then another rigid flat plate is placed parallel to the hollow fabric and the upper side of the rigid contour blocks, so that the rigid flat plate and the upper layer of the hollow fabric and the rigid contour blocks fit tightly. The outer contour of the rigid flat plate is vacuum bagged and the overall bag is pressed to ensure that the pressure function of the rigid upper cover plate is stable and reliable. Finally, it is heated and cured according to the preset process, and a high-precision hollow fabric with a solid flanging structure wave-transmitting composite material blank is obtained after demoulding. According to the product size, the outer contour size (800*650) mm is cut to obtain a high-precision hollow fabric with a solid flanging structure wave-transmitting composite material product.

[0080] After testing, the overall dimensions of the composite material product, the overall dimensions of the wave-transmitting area, the dimensions of the solid flange, the thickness of the entire plate, the height dimensions of the hollow wave-transmitting area cavity, etc. in this embodiment all meet the accuracy requirement of ±0.1mm.

[0081] Embodiment 2:

[0082] A curved hollow fabric composite material, the overall ply is: 0.2mm quartz fiber fabric + 11.5mm hollow fabric + 0.2mm quartz fiber fabric, wherein the arc length of the hollow wave-transmitting area is 720mm and the length is 650mm. The thickness of the whole board is required to be 11.9±0.1mm, and the height of the hollow core layer fleece cavity is required to be (10.9±0.05)mm.

[0083] (1) Determine the characteristic parameters of the hollow fabric: The hollow fabric used is a quartz fiber hollow fabric with a thickness of 11.5 mm; the core layer pile warp height is 10.9 mm, and the thickness of the upper and lower layers is 0.3 mm;

[0084] (2) Determine the characteristic parameters of the fixed core plate based on the hollow fabric:

[0085] Fixed core board material: flexible fixed core board; Fixed core board size: The hollow fabric velvet cavity size is (4 (width) * 10.9 (height) * 650 (length)) mm, therefore, the fixed core board size is designed to be (4 (width) * 10.9 (height) * 1200 (length)) mm, and the front end of the fixed core board is rounded, and the tail end is punched or threaded; Number of core rods: The arc length of the hollow area is 720 mm, and the width of a single fixed core board is 4 mm. According to calculations, the required number of fixed core boards is 180;

[0086] (3) Clean the foreign matter and glue residue on the surface of the fixed core board, and use acetone and alcohol to scrub the surface of the core board in turn to ensure the surface is clean; after the alcohol evaporates, apply a release agent on the entire surface of the fixed core board, and finally wipe it with release wax. According to the thickness and size of the whole board, cut a piece of hollow fabric with a size of (1000*800) mm, and insert the fixed core board along the velvet cavity channel in the middle area of ​​the hollow fabric with an arc length of 720 mm, so that the upper and lower surfaces of the fixed core board are completely in contact with the upper and lower layers of the hollow fabric;

[0087] (4) The hollow fabric preform obtained in step (3) is impregnated with resin by a vacuum drainage-vacuum breaking process, and is laid on the surface of the male mold of the metal mold, so that the hollow fabric preform as a whole is completely conformed to the single curvature rigid mold, and the 100 g / m 2 The quartz cloth is stacked on the upper and lower surfaces of the hollow fabric according to the designed layering, and a layer of demoulding cloth is covered on the upper surface; then the metal female mold is pressed and pressed, and finally, it is heated and cured according to the preset process, and the high-precision hollow fabric composite material blank is obtained after demoulding. According to the product size, the outer contour size (720*650) mm is cut to obtain a high-precision single-curvature hollow fabric composite material product.

[0088] After testing, the overall dimensions of the composite material product, the overall dimensions of the wave-transmitting area, the thickness of the entire plate, the height dimensions of the hollow wave-transmitting area cavity, etc. in this embodiment all meet the accuracy requirement of ±0.1mm.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for forming a hollow fabric composite material, characterized in that: The molding method comprises: (1) Obtaining characteristic parameters of the hollow fabric; wherein the characteristic parameters include the profile type, external dimensions and cavity shape of the hollow fabric; (2) determining characteristic parameters of the fixed core plate according to the characteristic parameters of the hollow fabric; wherein the characteristic parameters include the size, material and quantity of the fixed core plate; (3) inserting the fixed core plate between adjacent pile warp cavities in the hollow fabric core layer so that the upper and lower surfaces of the fixed core plate are completely in contact with the upper and lower layers of the hollow fabric; (4) placing the hollow fabric in step (3) in a molding tool, and performing composite molding on it in combination with a resin composite molding process to obtain the hollow fabric composite material; wherein the hollow fabrics of different profile types correspond to different molding tools.

2. The molding method according to claim 1, characterized in that: The profile types of the hollow fabric include flat type and curved type; The material of the fixed core plate is determined based on the surface type of the hollow fabric; preferably, when the hollow fabric is planar, the fixed core plate is a rigid fixed core plate, and when the hollow fabric is curved, the fixed core plate is a flexible fixed core plate.

3. The molding method according to claim 1 or 2, characterized in that: The width of the fixed core plate is not greater than the width of the velvet warp cavity in the hollow fabric core layer, the height is not greater than the height of the velvet warp cavity in the hollow fabric core layer, and the length is not less than the overall width / length of the hollow fabric.

4. The molding method according to claim 2, characterized in that: The number of fixed core plates is determined by the following formula: Wherein, M is the number of the fixed core plates, W i is the overall width of the flat hollow fabric or the overall arc length of the curved hollow fabric, and w is the width of the adjacent pile warp cavities in the core layer of the hollow fabric.

5. The molding method according to claim 2, characterized in that: When the hollow fabric is planar, the molding tool includes two upper and lower rigid plates; wherein the rigid plates are respectively located on the surfaces of the upper and lower layers of the hollow fabric, and are used to control the height and overall thickness of the hollow fabric composite material formed.

6. The molding method according to claim 5, characterized in that: The molding tool also includes a plurality of rigid equal-height blocks, which are evenly placed around the hollow fabric, and the upper surfaces of which are respectively in contact with the rigid flat plates, so as to further control the overall thickness of the hollow fabric composite material; Preferably, the height of the rigid contour blocks is the same as the overall height of the hollow fabric.

7. The molding method according to claim 2, characterized in that: When the hollow fabric is a curved surface, the molding tool is composed of a metal male mold and a metal female mold; wherein the shapes of the metal male mold and the metal female mold respectively correspond to the shapes of the upper and lower surfaces of the hollow fabric, and are used to control the molding height and overall thickness of the hollow fabric composite material.

8. The molding method according to claim 1, characterized in that: Before inserting the fixed core plate between adjacent pile warp cavities in the hollow fabric core layer, the method further includes applying a release agent on the surface of the fixed core plate.

9. The molding method according to claim 1, characterized in that: Before placing the hollow fabric in step (3) in a forming tool, the method further includes laying a functional layer or a skin layer on the upper and lower surfaces of the hollow fabric.

10. A hollow fabric composite material, characterized in that: The product is obtained by molding using the molding method described in any one of claims 1 to 9.

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