Forming method of carbon fiber product with embedded part

Abstract

The invention discloses a forming method of a carbon fiber product with an embedded part, which is used for solving the technical problem that the accuracy of the position of the embedded part cannot be ensured due to the displacement of the embedded part due to the flowability of resin in the curing process of a carbon fiber composite material product with the embedded part, and belongs to the technical field of carbon fiber products. The method comprises the following steps: step 1, blanking; step 2, primary paving, curing and forming; s21, carbon fiber prepreg is laid on the mold till the thickness of the embedded part is placed; s22, sealing the paved mold in a vacuum bag film, and vacuumizing; s23, carrying out first curing molding in the autoclave after vacuumizing; thirdly, the embedded parts are bonded; step 4, secondary paving, curing and forming; and step 5, removing the mold.

Description

Technical Field

[0001] The invention belongs to the technical field of carbon fiber products, and in particular relates to a method for forming a carbon fiber product with embedded parts. Background Art

[0002] Carbon fiber products refer to products made of carbon fiber prepreg as raw materials, which are processed into materials that meet the use requirements through different processing methods. Carbon fiber composite materials have low density and light weight, so they can be used on equipment with heavy weight to reduce weight and save a lot of energy consumption. They have the characteristics of light weight and excellent mechanical properties, so they are widely used in many fields such as aviation, aerospace, and navigation.

[0003] Due to the anisotropy of carbon fiber composite materials and the special manufacturing process, the matrix after molding should not be machined, otherwise the continuity of the matrix fiber will be destroyed and the mechanical properties will be affected. In order to ensure the installation accuracy and performance requirements of carbon fiber composite products, metal embedded parts are usually placed on the carbon fiber composite matrix in advance. The appropriate positioning size and geometric tolerance value are ensured by machining the embedded parts to ensure the accuracy of the carbon fiber composite products.

[0004] For carbon fiber composite products with metal embedded parts, some of the more complex metal embedded parts, if the autoclave molding method with one-time laying and curing is adopted, the embedded parts may be displaced due to the fluidity of the resin during the curing process, so the accuracy of the embedded parts position cannot be guaranteed, resulting in local defects in the subsequent machining of the embedded parts of the carbon fiber composite products, affecting the product performance.

[0005] During the molding and curing process of a display and control upper box with metal embedded parts of a certain model of display and control console, the one-time paving and curing molding method was used, which could not guarantee the accuracy of the embedded parts position and reduced the product qualification rate. Summary of the invention

[0006] The purpose of the present invention is to provide a method for forming a carbon fiber product with embedded parts, which is used to solve the technical problem that during the curing process of the carbon fiber composite material product with embedded parts, the embedded parts will be displaced due to the fluidity of the resin, and the accuracy of the position of the embedded parts cannot be guaranteed.

[0007] The present invention is achieved by adopting the following technical solutions: A method for forming a carbon fiber product with embedded parts comprises the following steps: Step 1: Cutting materials; S11. Place the carbon fiber prepreg on the unloading machine and mark it according to the process drawing.

[0008] Step 2: First paving and curing; S21, laying carbon fiber prepreg on the mold to a thickness sufficient to place embedded parts; S22, then sealing the paved mold in a vacuum bag film to evacuate; S23, after vacuuming, the first curing molding is carried out in the autoclave.

[0009] Step 3: Bonding embedded parts; S31, performing overall polishing without demoulding on the product formed in step 2; S32. After polishing, apply adhesive to the bonding surface of the embedded part; S33, firmly bonding the embedded parts to the product formed in step 2.

[0010] Step 4: Second paving and curing; S41, after the adhesive in step S33 is dry, continue to lay the carbon fiber prepreg on the product formed in step 2 to the thickness of the finished product; S42, sealing the mold after paving in a vacuum bag film to evacuate the mold; S43, after vacuuming, the product is cured and formed for the second time in the autoclave.

[0011] Step 5: Remove the mold; S51, after step 4 is completed, the product is demoulded; S52. Trim, grind and machine the disassembled products.

[0012] Further preferably, in S31, the position where the embedded parts are placed is polished and made smooth.

[0013] More preferably, the adhesive is an epoxy resin adhesive.

[0014] Further preferably, S21 comprises the following steps: S211, laying out the mold with the marked carbon fiber prepreg in the marked order; S212, laying the embedded parts layer by layer according to the direction and number of layers specified by the product to the embedded thickness; After laying the first layer of carbon fiber prepreg in S22, vacuum is drawn to perform vacuum compaction, and vacuum is drawn to perform vacuum compaction every 2-3 layers.

[0015] Further preferably, S23 comprises the following steps: S231, covering the paved mold with a porous isolation film, a breathable felt and a vacuum bag film to ensure good sealing; S232, perform sealing test, and after passing the test, perform molding and curing; S233, heating and pressurizing the sealed mold in an autoclave for curing.

[0016] Further preferably, S31 comprises the following steps: S311, tearing off the porous isolation film, breathable felt and vacuum bag film on the surface of the mold; S312, use a grinder to perform overall grinding on the product after curing and molding in step 1 without demoulding, requiring at least the embedded parts to be flat.

[0017] Further preferably, S41 comprises the following steps: S411, after the adhesive in step S33 is dry, the marked carbon fiber prepreg is laid on the mold cured in step 2 according to the marked order; S412. Lay the tiles layer by layer according to the direction and number of layers specified by the product until the product is cured to the required thickness; In S42, vacuum compaction is performed after every 2-3 layers are laid.

[0018] Further preferably, S43 comprises the following steps: S431, covering the paved mold with a porous isolation film, breathable felt and vacuum bag film to ensure good sealing; S432, perform sealing test, and perform molding and curing after passing the test; S433, heating and pressurizing the sealed mold in an autoclave for curing.

[0019] Further preferably, in S51, the mold solidified in step 4 is taken out from the autoclave, and after cooling, the mold is separated from the product to take out the product; In S52, the product surface is trimmed and polished, and the product is further processed.

[0020] The present invention can not only ensure the accuracy of the position of the metal embedded parts and meet the precision requirements of carbon fiber composite products, but also can greatly improve the surface smoothness and flatness of the mold surface for complex carbon fiber composite products. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0022] 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 Indicates the product blank Figure 1 .

[0024] Figure 2 Indicates the product blank Figure 2 .

[0025] Figure 3 It represents the schematic diagram of product mold.

[0026] In the figure: 1-embedded part one, 2-embedded part two, 3-embedded part three. DETAILED DESCRIPTION

[0027] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0028] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] Embodiment 1, a method for forming a carbon fiber product with embedded parts, comprising the following steps: Step 1: Cutting materials; S11. Place the carbon fiber prepreg on the unloading machine and mark it according to the process drawing.

[0032] Take out the carbon fiber prepreg from the cold storage and place it on the unloading machine after warming up. Edit and mark the materials one by one according to the product process drawings.

[0033] Step 2: First paving and curing; S21, laying carbon fiber prepreg on the mold to a thickness sufficient to place embedded parts; S211, laying out the mold with the marked carbon fiber prepreg in the marked order; S212. Lay the embedded parts layer by layer according to the direction and number of layers specified in the product to the embedded thickness.

[0034] S22, then sealing the paved mold in a vacuum bag film to evacuate; After laying the first layer of carbon fiber prepreg, vacuum is drawn and vacuum compaction is performed. Vacuum is drawn and vacuum compaction is performed every 2-3 layers.

[0035] S23, after vacuuming, perform the first curing molding in the autoclave; S231, covering the paved mold with a porous isolation film, breathable felt and vacuum bag film to ensure good sealing; S232, perform sealing test, and after passing the test, perform molding and curing; S233, heating and pressurizing the sealed mold in an autoclave for curing.

[0036] Step 3: Bonding embedded parts; S31, performing overall polishing without demoulding on the product formed in step 2; S311, tear off the porous isolation film, breathable felt and vacuum bag film on the surface of the mold; S312, use a grinder to grind the product after curing and molding in step 1 without demoulding, requiring at least the embedded parts to be flat, and ensuring that the large surface and the embedded parts are placed flat.

[0037] S32. After polishing, apply adhesive to the bonding surface of the embedded part; Apply epoxy resin adhesive (LOCTITE EA9460) on the bonding surface of the metal embedded parts and bond them according to the position requirements of the drawing to ensure the correct position of the embedded parts.

[0038] S33, firmly bonding the embedded parts to the product formed in step 2.

[0039] Step 4: Second paving and curing; S41, after the adhesive in step S33 is dry, continue to lay the carbon fiber prepreg on the product formed in step 2 to the thickness of the finished product; S411, after the adhesive in step S33 is dry, the marked carbon fiber prepreg is laid on the mold cured in step 2 according to the marked order; S412. Lay the tiles layer by layer according to the direction and number of layers specified in the product until the product is cured to the required thickness.

[0040] S42, sealing the mold after paving in a vacuum bag film to evacuate, and vacuum compacting once every 2-3 layers of paving; S43, after vacuuming, the product is cured and formed for the second time in the autoclave; S431, covering the paved mold with a porous isolation film, breathable felt and vacuum bag film to ensure good sealing; S432, perform sealing test, and perform molding and curing after passing the test; S433, heating and pressurizing the sealed mold in an autoclave for curing.

[0041] Step 5: Remove the mold; S51, after step 4 is completed, the product is demoulded; The mold solidified in step 4 is taken out from the autoclave, and after cooling, the mold is separated from the product and the product is taken out.

[0042] S52. Trim, grind and machine the disassembled products.

[0043] The product surface is trimmed and polished, and the product is further processed to make the product size meet the technical requirements.

[0044] In the second embodiment, a display and control upper box molded part of a certain model of display and control console is composed of a carbon fiber composite material matrix combined with metal embedded parts, with an overall thickness of 5 mm. The metal embedded parts included are embedded part one (quantity: 1), embedded part two (quantity: 1), and embedded part three (quantity: 4). According to actual product requirements, the selected material is carbon fiber T700 unidirectional prepreg cloth.

[0045] After the carbon fiber T700 unidirectional prepreg is laid on the mold, it goes through the procedures of heating, pressurizing, keeping warm, cooling and depressurizing in the autoclave under vacuum state, and is cured by the uniform temperature and uniform pressure provided in the autoclave, thus forming carbon fiber material products with high surface and internal quality and complex shapes.

[0046] The molding method selected by the present invention is autoclave curing molding.

[0047] During the first laying and curing process, first lay the carbon fiber T700 unidirectional prepreg on the mold to a thickness of 1 mm according to the layer design, and locally thicken it to 7.6 mm at the embedded part 3 position (4 places) (see Figure 1 , Figure 2 ), after the prepreg cloth is laid, the porous isolation film, breathable felt and vacuum bag film are laid in sequence, the mold is sealed and then vacuumed and vented, and placed in an autoclave for the first molding and curing.

[0048] After curing, the perforated isolation film, breathable felt and vacuum bag film on the mold are removed. The product after the first paving and curing is not demoulded. The mold is polished to ensure that the product is flat and has no protrusions before bonding and curing the metal embedded parts. Put the metal embedded parts in the corresponding position and apply epoxy resin adhesive (LOCTITEEA9460) on the bonding surface of the embedded parts for bonding and fixing.

[0049] After the glue is dry, the second laying and curing are carried out. According to the layer design, the carbon fiber T700 unidirectional prepreg is continued to be laid on the mold until the required thickness of the product is reached. After the prepreg is laid, the porous isolation film, breathable felt, and vacuum bag film are laid in sequence. After the mold is sealed, the vacuum exhaust treatment is carried out and it is placed in the autoclave for the second molding and curing.

[0050] After the second molding and curing, the porous isolation film, breathable felt and vacuum bag film on the mold are removed, and the cured molded product is demoulded. Figure 1 After the blank is demoulded, it is processed by CNC. CNC processing is carried out using a professional composite material CNC machine tool. After the molded product is processed by CNC, the required parts are assembled to obtain the product. The mold used for product paving is as follows Figure 3 shown.

[0051] For the molding method of carbon fiber products with embedded parts, the present invention provides a method for continuing to lay and solidify for the second time without removing the mold after the first laying and solidification to ensure the accuracy of the embedded parts position, which greatly reduces the problem of inaccurate positioning of embedded parts due to resin fluidity during the curing process. During the first molding and solidification, the thinner layer of the product is easier to fit the mold surface, reducing defects such as wrinkles and bubbles, and is easier to distribute along all surfaces of the mold, maintaining the design angle and shape, and obtaining a higher product surface quality.

[0052] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A method for forming a carbon fiber product with embedded parts, characterized in that: The steps include: Step 1: Cutting materials; S11. Place the carbon fiber prepreg on the unloading machine and mark it according to the process drawing; Step 2: First paving and curing; S21, laying carbon fiber prepreg on the mold to a thickness sufficient to place embedded parts; S22, then sealing the paved mold in a vacuum bag film to evacuate; S23, after vacuuming, perform the first curing molding in the autoclave; Step 3: Bonding embedded parts; S31, performing overall polishing without demoulding on the product formed in step 2; S32. After polishing, apply adhesive to the bonding surface of the embedded part; S33, firmly bonding the embedded parts to the product formed in step 2; Step 4: Second paving and curing; S41, after the adhesive in step S33 is dry, continue to lay the carbon fiber prepreg on the product formed in step 2 to the thickness of the finished product; S42, sealing the mold after paving in a vacuum bag film to evacuate the mold; S43, after vacuuming, the product is cured and formed for the second time in the autoclave; Step 5: Remove the mold; S51, after step 4 is completed, the product is demoulded; S52. Trim, grind and machine the disassembled products.

2. The method for forming a carbon fiber product with embedded parts according to claim 1, characterized in that: In S31, the locations where embedded parts are placed need to be polished and smooth.

3. The method for forming a carbon fiber product with embedded parts according to claim 1, characterized in that: The adhesive is epoxy resin adhesive.

4. The method for forming a carbon fiber product with embedded parts according to claim 1, characterized in that: S21 includes the following steps: S211, laying out the mold with the marked carbon fiber prepreg in the marked order; S212, laying the embedded parts layer by layer according to the direction and number of layers specified by the product to the embedded thickness; After laying the first layer of carbon fiber prepreg in S22, vacuum is drawn to perform vacuum compaction, and vacuum is drawn to perform vacuum compaction every 2-3 layers.

5. The method for forming a carbon fiber product with embedded parts according to claim 1, characterized in that: S23 includes the following steps: S231, covering the paved mold with a porous isolation film, breathable felt and vacuum bag film to ensure good sealing; S232, perform sealing test, and after passing the test, perform molding and curing; S233, heating and pressurizing the sealed mold in an autoclave for curing.

6. The method for forming a carbon fiber product with embedded parts according to claim 5, characterized in that: S31 includes the following steps: S311, tearing off the porous isolation film, breathable felt and vacuum bag film on the surface of the mold; S312, use a grinder to perform overall grinding on the product after curing and molding in step 1 without demoulding, requiring at least the embedded parts to be flat.

7. The method for forming a carbon fiber product with embedded parts according to claim 1, characterized in that: S41 includes the following steps: S411, after the adhesive in step S33 is dry, the marked carbon fiber prepreg is laid on the mold cured in step 2 according to the marked order; S412. Lay the tiles layer by layer according to the direction and number of layers specified by the product until the product is cured to the required thickness; In S42, vacuum compaction is performed after every 2-3 layers are laid.

8. The method for forming a carbon fiber product with embedded parts according to claim 1, characterized in that: S43 includes the following steps: S431, covering the paved mold with a porous isolation film, breathable felt and vacuum bag film to ensure good sealing; S432, perform sealing test, and perform molding and curing after passing the test; S433, heating and pressurizing the sealed mold in an autoclave for curing.

9. The method for forming a carbon fiber product with embedded parts according to claim 1, characterized in that: In S51, the mold solidified in step 4 is taken out from the autoclave, and after cooling, the mold is separated from the product to take out the product; In S52, the product surface is trimmed and polished, and the product is further processed.

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