Preparation method of carbon fiber composite material

Abstract

The invention relates to a preparation method of a carbon fiber composite material, which is characterized in that a connecting line is arranged in the Z direction of a carbon fiber laminated plate, so that the interlayer toughness of the carbon fiber plate is obviously enhanced, and the problems that the interlayer toughness between layers of the existing carbon fiber composite material is weak, and the layers are easy to separate under an impact load are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials science and technology, and relates to a preparation method of carbon fiber composite materials. Background Art

[0002] Existing carbon fiber composite materials are generally laminated structures. The interlayer properties of carbon fiber composite materials, such as mechanical, electrical, and thermal properties between layers, are not excellent. Because the middle layer is not fiber-reinforced and can only rely on the epoxy matrix to bear the bonding and load transfer functions, its interlayer toughness is weak. Especially under impact loads, delamination between layers is more likely to occur, which also limits the application of carbon fiber composite materials.

[0003] To overcome the problem of weak interlayer toughness of carbon fiber composite materials, the existing technology generally solves it by changing the components of the resin matrix for manufacturing carbon fiber prepregs. Chinese invention patent CN104945852B discloses a preparation method of a multi-scale micro-nano particle interlayer toughened composite material. First, a mixed solution of micro-nano particles (all inorganic particles) is evenly sprayed on the fibers, then placed in an oven for drying treatment. After the solvent has completely evaporated, it is compounded with a thermosetting resin to obtain a composite material with micro-nano particle interlayer toughening. The modified micron particles and nano particles coexist in the interlayer of the composite material to synergistically toughen the composite material. Although this method significantly improves the interlayer fracture toughness GIC of the composite material, the forming process is relatively complex and not suitable for popularization and application. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of carbon fiber composite materials, which solves the problem of weak interlayer toughness between layers of existing carbon fiber composite materials and easy delamination between layers under impact loads.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] A preparation method of carbon fiber composite materials, comprising the following steps,

[0007] Step 1, layering and placing multiple carbon fiber prepregs to make a carbon fiber laminate;

[0008] Step 2, threading connecting lines through the carbon fiber laminate, and multiple carbon fiber prepregs are connected by the connecting lines;

[0009] Step 3, transferring the carbon fiber laminate completed in Step 2 to a mold, and performing pre-pressing, heating, and curing to obtain a carbon fiber composite material.

[0010] The carbon fiber prepreg in Step 1 is a plain weave fabric, or a unidirectional fabric, or an expanded tow.

[0011] The connecting line in Step 2 is made of carbon fiber, or glass fiber, or aramid, or nylon.

[0012] The connecting line is threaded between carbon fiber laminates by a sewing machine.

[0013] Step 3: First, cover one carbon fiber prepreg on each of the upper and lower surfaces of the carbon fiber laminate completed in Step 2, and then transfer it to a mold for pre-pressing, heating, and curing to obtain a carbon fiber composite material.

[0014] A method for preparing a carbon fiber composite material, comprising the following steps:

[0015] Step 1: Lay multiple carbon fiber plates to form a carbon fiber laminate.

[0016] Step 2: Thread a connecting line through the carbon fiber laminate, and the multiple carbon fiber plates are connected by the connecting line to form a carbon fiber laminate.

[0017] Step 3: Transfer the carbon fiber laminate completed in Step 2 to a resin matrix to make a carbon fiber prepreg, and then transfer the carbon fiber prepreg to a mold for pre-pressing, heating, and curing to obtain a carbon fiber composite material; or transfer the carbon fiber laminate completed in Step 2 to a mold, inject a resin matrix into the mold, and then cure it to obtain a carbon fiber composite material.

[0018] The carbon fiber plate in Step 1 is a plain weave fabric or a unidirectional fabric.

[0019] The connecting line in Step 2 is made of carbon fiber, or glass fiber, or aramid, or nylon.

[0020] The connecting line is threaded between carbon fiber laminates by a sewing machine.

[0021] Step 3: First, cover one carbon fiber plate on each of the upper and lower surfaces of the carbon fiber laminate completed in Step 2 and then transfer it to a resin matrix to make a carbon fiber prepreg, and then transfer the carbon fiber prepreg to a mold for pre-pressing, heating, and curing to obtain a carbon fiber composite material.

[0022] Or, first cover one carbon fiber plate on each of the upper and lower surfaces of the carbon fiber laminate completed in Step 2 and then transfer it to a mold, inject a resin matrix into the mold, and then cure it to obtain a carbon fiber composite material.

[0023] The advantages of the present invention are as follows: There is no need to improve the existing carbon fiber plates, nor to change the type or components of the resin matrix between the existing carbon fiber plates. Connecting lines are arranged between the carbon fiber plates, enabling the connecting lines to combine with the resin matrix. The connecting lines are similar to the steel bars combined with cement in reinforced concrete, greatly enhancing the adhesion between the layers of the carbon fiber plates. The layers are no longer easily separated under impact loads, significantly enhancing the interlayer toughness of the carbon fiber composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the structure of a plain weave carbon fiber composite material using the method of the present invention;

[0025] Figure 2 is a schematic diagram of the structure of a unidirectional fabric carbon fiber composite material using the method of the present invention.

[0026] In the figure: 1 - carbon fiber plate; 2 - connecting line. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present invention will be further described below with reference to the accompanying drawings. The accompanying drawings are only for illustrative purposes and should not be construed as a limitation of this patent.

[0028] For the sake of more concise description of this embodiment, some components that are well-known to those skilled in the art but not relevant to the main content of this creation will be omitted in the drawings or description. Additionally, for the convenience of expression, some components in the drawings will be omitted, enlarged, or reduced, but this does not represent the dimensions or the entire structure of the actual product.

[0029] The present invention discloses a preparation method of a carbon fiber composite material. The carbon fiber composite material is as Figure 1 , Figure 2 shown, and includes the following steps:

[0030] Step 1, lay multiple carbon fiber plate 1 prepregs, and stack them into a carbon fiber laminate; the carbon fiber plate 1 can be a plain weave fabric, or a unidirectional fabric, or an unfolded tow.

[0031] Step 2, insert a connecting line 2 through the carbon fiber laminate, and the multiple carbon fiber plate 1 prepregs are connected by the connecting line 2; the connecting line 2 can be selected to be made of carbon fiber, or glass fiber, or aramid, or nylon.

[0032] Step 3, transfer the carbon fiber laminate completed in Step 2 to a mold, and perform pre-pressing, heating, and curing to obtain the carbon fiber composite material.

[0033] In step 2, the connecting line 2 can be manually passed from the top layer to the bottom layer with a needle, and then cut from the upper and lower surfaces. The purpose is to make the carbon fiber laminate have wires or fibers in the Z direction to connect and pull the carbon fiber plates 1 layer by layer, similar to driving steel bars in the Z direction. In this way, during the process of melting and then solidifying the prepreg of the carbon fiber plate 1 in the mold, the resin matrix and the connecting line 2 are firmly combined together, so that the adhesion of the carbon fiber laminate in the Z direction is greatly enhanced, and the stacked carbon fiber plates 1 are firmly combined together by the combination of the connecting line 2 and the resin matrix. When encountering impact loads, because the stacked carbon fiber plates 1 are strongly attached and pulled by the connecting line 2 and the resin matrix combination, the carbon fiber plates 1 will not separate, so that the firmness of the carbon fiber composite material is greatly enhanced.

[0034] The connecting line 2 can also be inserted between the carbon fiber laminates using a sewing machine.

[0035] Furthermore, for the sake of aesthetics and scene requirements, there should be no thread ends on the surface of the carbon fiber composite material. In step three, first cover the upper and lower surfaces of the carbon fiber laminate completed in step two with a carbon fiber board 1 prepreg, then transfer it to the mold, pre-press, heat, and cure to obtain the carbon fiber composite material.

[0036] The results of the experiment using the unidirectional woven carbon fiber plate 1 are as follows:

[0037]

[0038] The above experiments show that by using the method of the present invention, the interlayer toughness is significantly improved by arranging connecting lines 2 between carbon fiber laminates.

[0039] A method for preparing a carbon fiber composite material comprises the following steps:

[0040] Step 1: Lay a plurality of carbon fiber plates 1 in layers to form a carbon fiber laminate; the carbon fiber plates 1 may be plain weave fabrics or unidirectional fabrics.

[0041] Step 2: a connecting line 2 is passed through the carbon fiber laminate, and a plurality of carbon fiber plates 1 are connected by the connecting line 2 to form a carbon fiber laminate; the connecting line 2 can be made of carbon fiber, glass fiber, aramid or nylon.

[0042] Step three, transferring the carbon fiber laminate completed in step two to a resin matrix to make a carbon fiber board 1 prepreg, and then transferring the carbon fiber board 1 prepreg to a mold, pre-pressing, heating, and curing to obtain a carbon fiber composite material; or, transferring the carbon fiber laminate completed in step two to a mold, injecting a resin matrix into the mold, and then curing to obtain a carbon fiber composite material.

[0043] In Step 2, the connecting line 2 can be manually passed from the top layer to the bottom layer with a needle and then cut from the upper and lower surfaces. The purpose is to have wires or fibers in the Z direction to connect and pull the carbon fiber laminates layer by layer, similar to driving steel bars in the Z direction. In this way, when the carbon fiber laminate is placed into the resin matrix, the resin matrix will firmly bond with the connecting line 2. Then, it is melted and cured in the mold, greatly enhancing the adhesive force of the carbon fiber laminate in the Z direction. The stacked carbon fiber plates 1 are firmly bonded together by the combination of the connecting line 2 and the resin matrix. When encountering impact loads, since there is a strong attachment and pulling of the combination of the connecting line 2 and the resin matrix between the stacked carbon fiber plates 1, the carbon fiber plates 1 will not separate, greatly enhancing the firmness of the carbon fiber composite material.

[0044] The connecting line 2 can also be sewn between the carbon fiber laminates with a sewing machine.

[0045] Furthermore, for aesthetic and application requirements, there should be no wire ends on the surface of the carbon fiber composite material. In Step 3, first, cover one carbon fiber plate 1 on each of the upper and lower surfaces of the carbon fiber laminate after Step 2 is completed, and then transfer it to the resin matrix to make a carbon fiber plate 1 prepreg. Then, transfer the carbon fiber plate 1 prepreg to the mold and perform pre-pressing, heating, and curing to obtain the carbon fiber composite material; or, first, cover one carbon fiber plate 1 on each of the upper and lower surfaces of the carbon fiber laminate after Step 2 is completed, then transfer it to the mold, inject the resin matrix into the mold, and then perform curing to obtain the carbon fiber composite material.

[0046] This method is not applicable to spreading tows.

[0047] The method of the present invention does not change the structure of the carbon fiber plate 1, nor does it change the type or components of the resin matrix. It only adds the setting of the connecting line 2 in the original carbon fiber composite material preparation process. The connecting line 2 can be sewn manually or with a sewing machine, and a carbon fiber composite material with greater interlayer toughness, higher firmness, and more stable quality can be produced on the original production equipment or production line.

[0048] The above is only the preferred embodiment of the present invention and is not used to limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made according to the content of the patent application scope of the present invention should fall within the technical scope of the present invention.

Claims

1. A method for preparing a carbon fiber composite material, characterized in that: The following steps are included: Step 1, laying out a plurality of carbon fiber board (1) prepregs to form a carbon fiber laminate; Step 2: a connecting line (2) is inserted into the carbon fiber laminate, and a plurality of carbon fiber plates (1) prepregs are connected by the connecting line (2); Step three, transferring the carbon fiber laminated plate obtained in step two to a mold, performing pre-pressing, heating, and curing to obtain a carbon fiber composite material.

2. The method for preparing a carbon fiber composite material according to claim 1, characterized in that: The carbon fiber sheet (1) in step 1 is a plain woven fabric, or a unidirectional fabric, or a spread tow.

3. The method for preparing a carbon fiber composite material according to claim 1, characterized in that: The connecting wire (2) in step 2 is made of carbon fiber, glass fiber, aramid or nylon.

4. The method for preparing a carbon fiber composite material according to claim 3, characterized in that: The connecting line (2) is inserted between the carbon fiber laminate plates by a sewing machine.

5. The method for preparing a carbon fiber composite material according to claim 4, characterized in that: Step three, firstly, a carbon fiber plate (1) prepreg is coated on the upper surface and the lower surface of the carbon fiber laminated plate completed in step two, and then transferred to a mold, and pre-pressed, heated, and cured to obtain a carbon fiber composite material.

6. A method for preparing a carbon fiber composite material, characterized in that: The following steps are included: Step 1, laying a plurality of carbon fiber plates (1) to form a carbon fiber laminate; Step 2: a connecting line (2) is inserted into the carbon fiber laminate, and a plurality of carbon fiber plates (1) are connected by the connecting line (2) to form a carbon fiber laminate; Step 3, transferring the carbon fiber laminate obtained in step 2 into a resin matrix to prepare a carbon fiber plate (1) prepreg, and then transferring the carbon fiber plate (1) prepreg into a mold, performing pre-pressing, heating, and curing to obtain a carbon fiber composite material; Alternatively, the carbon fiber laminated plate after step 2 is transferred to a mold, a resin matrix is ​​injected into the mold, and then cured to obtain a carbon fiber composite material.

7. The method for preparing a carbon fiber composite material according to claim 6, characterized in that: The carbon fiber sheet (1) in step 1 is a plain weave or a unidirectional weave.

8. The method for preparing a carbon fiber composite material according to claim 6, characterized in that: The connecting wire (2) in step 2 is made of carbon fiber, glass fiber, aramid or nylon.

9. The method for preparing a carbon fiber composite material according to claim 8, characterized in that: The connecting line (2) is inserted between the carbon fiber laminate plates by a sewing machine.

10. The method for preparing a carbon fiber composite material according to claim 6, characterized in that: Step 3: first, a carbon fiber sheet (1) is coated on the upper surface and the lower surface of the carbon fiber laminate obtained in step 2, and then the carbon fiber sheet (1) is transferred to a resin matrix to form a carbon fiber sheet (1) prepreg, and then the carbon fiber sheet (1) prepreg is transferred to a mold, and pre-pressed, heated, and cured to obtain a carbon fiber composite material; Alternatively, a carbon fiber plate (1) is firstly covered on the upper surface and the lower surface of the carbon fiber laminated plate completed in step 2, and then transferred to a mold, and a resin matrix is ​​injected into the mold, and then cured to obtain a carbon fiber composite material.

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