Asymmetric gradient multi-layer textile dot matrix interlayer composite material and preparation method thereof

Abstract

The invention discloses an asymmetric gradient multi-layer textile dot matrix interlayer composite material and a preparation method thereof, and belongs to the technical field of composite materials, the asymmetric gradient multi-layer textile dot matrix interlayer composite material comprises N + 1 layers of panels, N layers of dot matrix interlayers and (polyurethane foam), the dot matrix interlayers are 2 mm, 3 mm, 5 mm, 8 mm, 10 mm, 12 mm, 15 mm, 18 mm, 20 mm and the like in thickness, therefore, the asymmetric gradient multilayer textile dot matrix interlayer composite material is formed by combining the dot matrix interlayers with different thicknesses and multiple layers in the warp and weft directions. The preparation method comprises the following steps: preparing single-layer spinning dot matrix interlayer composite materials with different thicknesses through vacuum flow guide perfusion resin; and carrying out secondary cementing molding on the asymmetric gradient structure prefabricated member through a composite material cementing process (filling polyurethane foam into gaps of a certain layer or certain layers of core layers of the cured asymmetric gradient multi-layer textile lattice sandwich structure), wherein the polyurethane foam is filled into the gaps of the core layers of the one or more layers of the cured asymmetric gradient multi-layer textile lattice sandwich structure or the gaps of the core layers of the cured asymmetric gradient multi-layer textile lattice sandwich structure. According to the composite material structure, the complementarity of the performance of the core layers with different thicknesses can be effectively utilized, and the requirements for structural strength and rigidity and the impact resistance (and the multifunctionality of heat preservation, heat insulation, flame retardance and thinness) can be efficiently met.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to an asymmetric gradient multilayer textile lattice sandwich composite material and a preparation method thereof. Background Art

[0002] Composite sandwich structures are characterized by light weight, high specific strength and high specific modulus. Traditional composite sandwich structures are generally composed of three parts. The outermost parts are the upper and lower panels, which mainly bear the normal stress and are generally fiber-reinforced composite materials such as glass fiber and carbon fiber; the middle layer is the core material, which mainly bears the shear stress and is generally made of foam, balsa wood or honeycomb.

[0003] Compared with traditional honeycomb foam sandwich, textile lattice sandwich structure shows better characteristics in anti-delamination and impact resistance, and has broad application prospects in rail transportation, ships, aerospace, etc. The tensile strength of textile lattice sandwich single-layer boards with different thicknesses from thin to thick shows an increasing trend, while the shear strength shows a decreasing trend.

[0004] The current textile lattice sandwich multilayer board forming process usually solidifies a single-layer board first, and then uses glue or resin to bond multiple single-layer boards. Due to the high surface stiffness of the single-layer board after solidification, the adhesive surface cannot fit well, and there are many pores, which reduces the interlayer shear strength, is prone to delamination defects, and is prone to peeling damage when bearing. Summary of the invention

[0005] The present invention provides an asymmetric gradient multilayer textile lattice sandwich composite material and a preparation method thereof. While utilizing the multilayer structure to improve the performance of a single-layer board, the asymmetric gradient plying fully utilizes the complementarity of the performance of core layers of different thicknesses and enhances the interlayer bonding force.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions:

[0007] The present invention relates to an asymmetric gradient multilayer textile lattice sandwich composite material and a preparation method thereof.

[0008] The asymmetric gradient multilayer textile lattice sandwich composite material comprises an upper panel, an N-1 layer interlayer panel, an N layer lattice core layer, and a lower panel; each panel is bonded to the lattice core layer by a resin adhesive; and the lattice core layer is filled with polyurethane foam.

[0009] When the upper and lower panels need to be thickened, 3 to 5 additional layers of glass fiber plain cloth can be laid. When the interlayer panel needs to be thickened, 1 to 2 additional layers of glass fiber plain cloth can be laid. When laying additional glass fiber plain cloth, the problem of matching the number of laying layers with the mechanical properties of the core needs to be considered.

[0010] The single-layer board of the textile lattice sandwich composite material is a three-dimensional hollow fabric, the surface layer and the core layer are woven from continuous fibers as a whole, the warp yarn and the weft yarn constitute the surface layer, and the core Z-direction fibers connect the two surface layers. The core Z-direction fibers appear as discrete core piles; the core piles present different lattice periodic structural forms in the warp and weft directions, the spacing between the core piles in the warp direction is greater than the spacing between the core piles in the weft direction, the core piles in the warp direction appear as an "8" shape, and the core piles in the weft direction appear as a "1" shape.

[0011] The thicknesses of the N lattice core layers are not completely the same.

[0012] The resin is unsaturated polyester, vinyl resin, epoxy resin or phenolic resin.

[0013] The polyurethane foam adopts a two-component foaming type rigid polyurethane foam.

[0014] The preparation method comprises the following steps:

[0015] (1) A single-layer board is prepared, a resin glue is prepared, and a three-dimensional hollow fabric of corresponding size is cut according to design requirements. The cut three-dimensional hollow fabric is infiltrated with the resin glue by vacuum induction, and a single-layer textile lattice sandwich composite material is obtained after curing.

[0016] (2) Grind the bonding surface of the board and clean it with solvent.

[0017] (3) Prepare a multilayer board, prepare a resin adhesive, cut a three-dimensional hollow fabric of corresponding size according to design requirements, use vacuum induction to soak the cut hollow fabric with the resin adhesive, brush an appropriate amount of resin adhesive on the surface to be bonded of the cured board, and before curing, lay the hollow fabric soaked with the resin adhesive on the surface to be bonded brushed with the resin adhesive, and trim the hollow fabric to ensure that the bonding surface is tightly fitted. After curing, a multilayer asymmetric gradient textile lattice sandwich structure composite material is obtained.

[0018] (4) Repeat steps (2) to (3) to obtain an asymmetric gradient multilayer textile lattice sandwich structure composite material. After repeating N-2 times, an N-layer asymmetric gradient textile lattice sandwich structure composite material is obtained.

[0019] (5) preparing the prepolymer required for the polyurethane foam, quickly stirring it and then pouring it into the gaps in the core layer of the N-layer textile lattice sandwich composite material obtained in step (4);

[0020] (6) After the polyurethane foam in step (5) is foamed, the excess foam is cleaned to obtain a foam-filled asymmetric gradient multilayer textile lattice sandwich composite material.

[0021] On the basis of the above scheme and as a preferred scheme of the above scheme: fiber woven cloth can be additionally covered between layers and on the surface of the board to enhance the bonding between layers and the strength of the panel.

[0022] On the basis of the above scheme and as a preferred scheme of the above scheme: the resin curing environment of steps (1) and (3) is selected according to the characteristics of different resins, namely, room temperature curing or high temperature curing.

[0023] On the basis of the above solution and as a preferred solution of the above solution: the additional fabrics laid between the layers of the multi-layer textile lattice sandwich structure composite material are made of different materials.

[0024] On the basis of the above scheme and as a preferred scheme of the above scheme: the additional fabrics laid between the layers of the multi-layer textile lattice sandwich structure composite material have different thicknesses or numbers of layers.

[0025] On the basis of the above scheme and as a preferred scheme of the above scheme: the selected textile lattice core layer material is glass fiber, carbon fiber or other fiber-reinforced materials.

[0026] On the basis of the above scheme and as a preferred scheme of the above scheme: the directions of the textile lattice core layers with different numbers of layers can be selected as warp direction, weft direction or other directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of an asymmetric gradient multilayer textile lattice sandwich composite material in an embodiment of the present invention;

[0028] Figure 2 A physical diagram of the composite material structure involved in the embodiment;

[0029] Figure 3 This is a physical picture of the raw material of the three-dimensional hollow fabric;

[0030] Figure 4 Schematic diagram of the manufacturing process. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0032] The present invention relates to an asymmetric gradient multilayer textile lattice sandwich composite material structure, which has three layers in the example, with thicknesses of 2mm, 8mm, and 5mm respectively, and includes a panel 1, a panel 2, an interlayer panel 3, a panel 4, a lattice core layer 5, a lattice core layer 6, a lattice core layer 7, and a polyurethane foam 8. The panel is 200g / m 2 The structure is a hybrid of E-grade glass fiber plain weave and a single-layer textile lattice sandwich composite material surface layer. The lattice core layer is a three-dimensional hollow fabric Z-direction fiber. The upper panel 1 and the lower panel 4 are covered with three layers of 200g / m2 E-grade glass fiber plain weave cloth thickened, interlayer panel 2 and interlayer panel 3 covered with a layer of 200g / m 2 E-grade glass fiber plain cloth is thickened. The co-bonding process is used for molding and cured at room temperature. The polyurethane foam is filled into the middle layer of the composite material structure through the prepolymer foaming process, and the excess foam is cleaned to obtain a foam-filled asymmetric gradient multi-layer textile lattice sandwich composite material.

[0033] The specific steps of this embodiment are as follows:

[0034] (1) Before each vacuum infusion, epoxy resin glue was prepared according to the mass ratio of resin to curing agent of 10:3 and mechanically stirred evenly;

[0035] (2) Cut three-dimensional hollow fabrics with a plane size of 300×300 mm and thicknesses of 2 mm, 5 mm, and 8 mm and eight sheets of 200 g / m 2 E-grade glass fiber plain weave cloth;

[0036] (3) vacuum induction was used to treat the 2 mm thick three-dimensional hollow fabric obtained in step (2) and three 200 g / m 2 The epoxy resin glue solution of step (1) is poured into the E-grade glass fiber plain weave fabric, and after soaking, the surface of the fabric and the plain weave fabric is trimmed to make them as flat as possible, and three layers of plain weave fabric and one layer of 2 mm hollow fabric are laid from bottom to top, and a single-layer textile lattice sandwich composite material is obtained after curing;

[0037] (4) polishing and cleaning the upper surface of the single-layer textile lattice sandwich composite material obtained in step (3) with a solvent as the bonding surface, drying it for later use;

[0038] (5) vacuum induction was used to treat the 8 mm thick three-dimensional hollow fabric obtained in step (2) and a 200 g / m 2 The epoxy resin glue obtained in step (1) is poured into the E-grade glass fiber plain weave cloth, and after impregnation, the surface of the fabric and the plain weave cloth is trimmed to make them as flat as possible, and then laid on the surface to be bonded of the single-layer textile lattice sandwich composite material obtained in step (4) in the order of a layer of plain weave cloth and a layer of 2 mm hollow fabric from bottom to top, and after curing, a double-layer textile lattice sandwich composite material is obtained;

[0039] (6) polishing and cleaning the upper surface of the double-layer textile lattice sandwich composite material obtained in step (5) with a solvent as the bonding surface, drying it for later use;

[0040] (7) vacuum induction was used to treat the 5 mm thick three-dimensional hollow fabric obtained in step (2) and four 200 g / m 2The epoxy resin glue obtained in step (1) is poured into the E-grade glass fiber plain weave cloth, and after impregnation, the surface of the fabric and the plain weave cloth is trimmed to make them as flat as possible, and then laid on the surface to be bonded of the double-layer textile lattice sandwich composite material obtained in step (6) in the order of one layer of plain weave cloth, one layer of 2 mm hollow fabric, and three layers of plain weave cloth from bottom to top, and after curing and trimming, an asymmetric gradient three-layer textile lattice sandwich composite material is obtained;

[0041] (8) preparing polyurethane foam in a mass ratio of material A to material B of 1:1, quickly stirring and then pouring it into the gaps in the lattice core layer 6 of the three-layer textile lattice sandwich composite material described in step (7);

[0042] (9) After the polyurethane foam is foamed in step (8), the excess foam is cleaned to obtain a foam-filled asymmetric gradient three-layer textile lattice sandwich composite material;

[0043] The above description is only a specific implementation of the present invention and does not limit the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. An asymmetric gradient multilayer textile lattice sandwich composite material, characterized in that: The composite material is prepared by compositely preparing N layers of single-layer boards, including N+1 layers of panels and N layers of lattice core layers (and polyurethane foam); the lattice core layers are respectively distributed between the N+1 layers of panels; the N layers of lattice core layers have different thicknesses; the lattice core layer includes two fiber textile directions, warp and weft; (the gaps between the panels are filled with polyurethane foam) the lattice core layer is composed of discrete core piles; the core piles present different lattice periodic structural forms in the warp and weft directions, the spacing between the core piles in the warp direction is greater than the spacing between the core piles in the weft direction, the core piles in the warp direction are in the shape of "8", and the core piles in the weft direction are in the shape of "1".

2. The asymmetric gradient multilayer textile lattice sandwich composite material according to claim 1, characterized in that: The surface layer and the core layer of the single-layer board are three-dimensional fabrics woven from glass fibers.

3. The asymmetric gradient multilayer textile lattice sandwich composite material according to claims 1 and 2, characterized in that: The panel is composed of glass fiber cloth and the three-dimensional fabric surface layer.

4. The asymmetric gradient multilayer textile lattice sandwich composite material according to claim 3, characterized in that: The panel is divided into an upper panel, an interlayer panel and a lower panel.

5. The asymmetric gradient multilayer textile lattice sandwich composite material according to claim 4, characterized in that: When the upper and lower panels are thickened, three layers of glass fiber cloth are used; when the interlayer panel is thickened, one or two layers of glass fiber cloth are used.

6. A method for preparing an asymmetric gradient multilayer textile lattice sandwich composite material, characterized in that: The following steps are involved: (1) Clean the mold to ensure that the mold molding surface is smooth, dust-free, water-free and oil-free, and apply a release agent on the mold; (2) Cutting three-dimensional fabrics of corresponding sizes and auxiliary bag-making materials such as peelable fabrics, guide nets, vacuum bags, and sealing tapes according to design requirements; (3) The pre-cut materials obtained in step (2) are laid in the order of guide net, peelable cloth, three-dimensional fabric, guide net, and vacuum bag starting from the mold layer, and then sealed with sealing tape, and a glue inlet and vacuum exhaust port are reserved, and an air tightness test is performed; (4) Prepare resin glue according to resin technical requirements; (5) using vacuum induction to allow the resin glue obtained in step (4) to enter the mold encapsulated in step (3) to fully infiltrate the three-dimensional fabric; (6) removing the auxiliary bag-making materials and curing the three-dimensional fabric single-layer board according to the resin curing parameters; (7) Cutting a two-dimensional glass fiber cloth of corresponding size according to design requirements, and impregnating the two-dimensional glass fiber cloth with a resin of the same system as steps (2) to (5); (8) combining the resin-impregnated two-dimensional glass fiber cloth obtained in step (7) and the single-layer textile lattice sandwich composite material of different thicknesses described in step (6) and curing them under a certain pressure to obtain an asymmetric gradient multilayer textile lattice sandwich composite material; (9)-Foam.

7. The method for preparing an asymmetric gradient multilayer textile lattice sandwich composite material according to claim 6, characterized in that: The mold material in step (1) is a hard material such as metal, glass, or composite material.

8. The method for preparing an asymmetric gradient multilayer textile lattice sandwich composite material according to claim 6, characterized in that: The air tightness test in step (3) is to close the glue inlet, turn on the vacuum pump connected to the vacuum exhaust port, until the vacuum degree is ≥0.85 bar, turn off the vacuum pump, and if the vacuum degree drops by ≤25 mbar within 1 minute, the air tightness test is qualified.

9. The method for preparing an asymmetric gradient multilayer textile lattice sandwich composite material according to claim 6, characterized in that: The pressure in step (8) is 0.8 bar to 3 bar.

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