A high thermal conductivity composite material molding die, its manufacturing method and application

Abstract

This invention relates to a high thermal conductivity composite material molding die, its manufacturing method, and its application, belonging to the field of composite material molding technology. The die includes, from top to bottom, a gel coat layer, a transition layer, a carbon fiber thermally conductive layer, and a glass fiber structural layer. The transition layer comprises a glass fiber surface mat, and its coverage area is the same as that of the gel coat layer. The carbon fiber thermally conductive layer comprises carbon fiber fabric and molding resin, and the carbon fiber thermally conductive layer protrudes by a predetermined size outside the coverage area of ​​the gel coat layer. The glass fiber structural layer comprises chopped glass fiber mat and molding resin, and its coverage area is the same as that of the carbon fiber thermally conductive layer. Using the carbon fiber thermally conductive layer as the heat conduction structure of the die increases the local heating rate of the die covered by the composite material raw material, improving the problem of uneven temperature in the molding die during the curing process of the composite product.

Description

Technical Field

[0001] This invention belongs to the field of composite material molding technology, specifically relating to a high thermal conductivity composite material molding die, its manufacturing method, and its application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Vacuum bag molding is a common molding method for glass fiber composites. Its principle involves laying the composite material onto a molding die, then using a vacuum bag to create a vacuum system. The entire assembly, including the composite material, the mold, and the vacuum bag, is placed in an environment with set temperature and pressure to complete the curing process. VARI molding technology also uses a vacuum bag, but it adds a resin infusion process within the vacuum system.

[0004] The molding accuracy of composite materials depends on the accuracy of the mold. During the heating process, the mold temperature rises along with the ambient temperature. The mold portion covered by the composite material is located at the innermost part of the entire vacuum system, and ambient heat is conducted to the mold through the vacuum bag and the composite material raw material. Due to the poor thermal conductivity of glass fiber, the mold portion covered by the composite material heats up slowly, while the portion not covered by the composite material heats up faster. This results in significant temperature differences at different locations during the curing process, causing uneven stress release and making the product prone to deformation. The problems are particularly pronounced with molds of irregular shapes. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high thermal conductivity composite material molding die, its manufacturing method, and its application. By adding a carbon fiber thermally conductive layer to the mold, the temperature uniformity of different locations in the mold is enhanced during the product curing process.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] In a first aspect, a high thermal conductivity composite material molding die includes a gel coat layer, a transition layer, a carbon fiber thermally conductive layer, and a glass fiber structural layer arranged from top to bottom;

[0008] The transition layer includes a glass fiber surface mat, and its coverage area is the same as that of the gel coat layer;

[0009] The carbon fiber thermal conductive layer comprises carbon fiber fabric and molding resin, and the carbon fiber thermal conductive layer is exposed by a set size outside the coverage area of ​​the gel coat layer;

[0010] The glass fiber structural layer comprises chopped glass fiber mat and molding resin, and the coverage area of ​​the glass fiber structural layer is the same as that of the carbon fiber thermal conductive layer.

[0011] Optionally, the raw materials for preparing the gel coat layer include epoxy resin, and the gel coat layer includes a product molding surface.

[0012] Optionally, the transition layer has a set thickness.

[0013] Optionally, the carbon fiber in the carbon fiber thermal conductive layer is continuous carbon fiber, and the carbon fiber accounts for 60%-70% of the volume of the carbon fiber thermal conductive layer.

[0014] Optionally, the carbon fiber fabric includes carbon fibers oriented from the edge to the center.

[0015] Optionally, the glass fiber structural layer is made of glass fiber fabric, chopped glass fiber mat, and molding resin.

[0016] Optionally, the high thermal conductivity composite material molding die further includes a support frame, which is installed on the side of the glass fiber structure layer away from the carbon fiber thermal conductive layer.

[0017] Secondly, the manufacturing method of the aforementioned high thermal conductivity composite material molding die includes the following steps:

[0018] S1. Spray epoxy resin onto the product forming surface of the mold to form a gel coat layer;

[0019] S2. Lay a glass fiber surface mat on the gel coat layer to form a transition layer;

[0020] S3. Lay carbon fiber fabric on the transition layer, with the laying area being larger than the gel coat layer, to form a carbon fiber thermal conductive layer;

[0021] S4. Lay glass fiber chopped strand mat on the carbon fiber thermal conductive layer;

[0022] S5. Vacuum system is formed by wrapping the mold, transition layer, carbon fiber thermal conductive layer and chopped fiber felt in a vacuum bag.

[0023] S6. Introduce resin into a vacuum system and mold it at a set temperature and pressure. After removing the mold, obtain a high thermal conductivity composite material molding die.

[0024] Optionally, in S1, the material of the mold includes one or more of epoxy wood substitute, polyester wood substitute, and HPL board.

[0025] Optionally, step S7 is also included: installing the high thermal conductivity composite material molding die onto the support frame.

[0026] Thirdly, the application of the aforementioned high thermal conductivity composite material molding die in vacuum bag molding.

[0027] The beneficial effects of this invention are as follows:

[0028] 1. This invention provides a high thermal conductivity composite material molding die, which uses a carbon fiber thermal conductive layer as the heat conduction structure of the die. When the composite material is molded using this die, the local heating rate of the die covered by the composite material raw material is increased, thereby improving the uniformity of the die temperature at the product edge and the product center, improving the problem of uneven die temperature during the curing process of the composite material product, thereby reducing the stress caused by local temperature difference of the product and improving the overall quality of the product.

[0029] 2. This invention uses carbon fiber in the carbon fiber thermal conductive layer as the thermal conductive material, which has good plasticity and wide applicability. Moreover, the carbon fiber thermal conductive layer is exposed at the edge of the mold, which can directly absorb ambient heat through the vacuum system and conduct heat to the center of the mold along the carbon fiber orientation, reducing heat loss and realizing rapid heating of the mold. Attached Figure Description

[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0031] Figure 1 This is a schematic diagram of the high thermal conductivity composite material molding die in Example 1.

[0032] Figure 2 This is a partially enlarged schematic diagram of the high thermal conductivity composite material molding die in Example 1.

[0033] Figure 3 This is a flowchart of the manufacturing method of the high thermal conductivity composite material molding die in Example 1.

[0034] Figure 4 This is a schematic diagram of the application area of ​​the high thermal conductivity composite material molding die in Example 1.

[0035] Figure 5 This is an isometric view of the high thermal conductivity composite material molding die in Example 1.

[0036] The structure consists of: 1. gel coat layer; 2. transition layer; 3. carbon fiber thermal conductive layer; 4. glass fiber structural layer; and 5. supporting skeleton. Detailed Implementation

[0037] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0038] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0039] Example 1

[0040] A high thermal conductivity composite material molding die, such as Figure 1 As shown, it includes a gel coat layer 1, a transition layer 2, a carbon fiber thermal conductive layer 3, and a glass fiber structural layer 4 arranged from top to bottom;

[0041] The transition layer 2 includes a glass fiber surface mat, and its coverage area is the same as that of the gel coat layer 1;

[0042] like Figure 2 As shown, the carbon fiber thermal conductive layer 3 includes carbon fiber fabric and molding resin, and the carbon fiber thermal conductive layer 3 is exposed by a set size outside the coverage area of ​​the gel coat layer 1.

[0043] The glass fiber structural layer 4 includes chopped glass fiber mat and molding resin, and the coverage area of ​​the glass fiber structural layer 4 is the same as that of the carbon fiber thermal conductive layer 3.

[0044] With the above settings, ambient heat can be transferred through the carbon fiber heat-conducting layer 3. The transfer path is located below the transition layer 2, so that the mold part covered by the composite material (specifically the gel coat layer 1) receives heat from the composite material raw material while also receiving heat from the carbon fiber heat-conducting layer 3 below, thereby improving the temperature uniformity of different positions of the mold.

[0045] The raw materials for preparing gel coat layer 1 include epoxy resin. Gel coat layer 1 includes a product molding surface, which is in direct contact with the composite material raw material. The product molding surface determines the surface quality of the finished product. The temperature uniformity of the present invention is specifically reflected in the temperature uniformity of various positions of gel coat layer 1 that are in direct contact with the composite material raw material.

[0046] The transition layer 2 serves to connect the gel coat layer 1 and the carbon fiber thermal conductive layer 3. Utilizing the uniform dispersion and good plasticity of the glass fiber surface mat, it improves the density and connection strength between the gel coat layer 1 and the carbon fiber thermal conductive layer 3. It has a set thickness, which determines the thermal resistance from the carbon fiber thermal conductive layer 3 to the gel coat layer 1. Therefore, when the area of ​​the gel coat layer 1 is large and the distance between the center of the mold and the edge is far, and the thermal conductivity of the carbon fiber thermal conductive layer 3 is insufficient to achieve uniform temperature, a thinner transition layer 2 can be set at the center of the mold to reduce the thermal resistance of the transition layer 2 at the center of the mold, thereby further improving the temperature uniformity.

[0047] The carbon fiber in the carbon fiber thermal conductive layer 3 is a continuous carbon fiber, and the carbon fiber accounts for 70% of the volume of the carbon fiber thermal conductive layer 3, ensuring that the carbon fiber thermal conductive layer 3 has a high thermal conductivity.

[0048] The carbon fiber fabric includes carbon fibers oriented from the edge to the center, which aligns with the desired heat conduction path.

[0049] The glass fiber structural layer 4 is made of glass fiber fabric, glass fiber chopped strand mat and mold resin. It is the main load-bearing component of the mold and provides strength and internal deformation resistance to the mold surface.

[0050] The high thermal conductivity composite material molding die also includes a support frame 5, which is installed on the side of the glass fiber structure layer 4 away from the carbon fiber thermal conductive layer 3. It is welded with 40*40*2.5mm carbon steel square tubes, with the square tubes intersecting in a cross shape and diagonal ribs added to ensure the rigidity of the entire frame. All joint positions are beveled to ensure a reliable weld.

[0051] The manufacturing method of the above-mentioned high thermal conductivity composite material molding die, such as Figure 3 As shown, it includes the following steps:

[0052] S1. Spray 0.6-0.8mm thick epoxy resin onto the product forming surface of the mold to form gel coat layer 1. In order to reduce edge defects on the product surface, the spraying range can include part of the mold edge area.

[0053] S2. Lay a glass fiber surface mat on the gel coat layer 1 to form a transition layer 2;

[0054] S3, such as Figure 4 As shown, a 0.5mm thick carbon fiber fabric is laid on the transition layer 2, and the laying area is larger than the gel coat layer 1, including the entire mold area, to form a carbon fiber thermal conductive layer 3.

[0055] S4. A 10-15mm thick glass fiber chopped strand mat is laid on the carbon fiber thermal conductive layer 3. This mat is the raw material for the glass fiber structural layer 4 and is the main load-bearing component of the mold.

[0056] S5. A vacuum system is formed by wrapping the mold, gel coat layer 1, transition layer 2, carbon fiber thermal conductive layer 3, and chopped fiber felt in a vacuum bag.

[0057] S6. Introduce mold resin into the vacuum system and mold it under the set temperature and pressure. During the process, the mold resin impregnates the glass fiber structure layer 4, the carbon fiber thermal conductive layer 3 and the transition layer 2 to form a tightly bonded structure. After removing the mold, a high thermal conductivity composite material molding mold body is obtained.

[0058] S7. Install the main body of the high thermal conductivity composite material molding die onto the support frame 5. Bond the support frame 5 to the glass fiber structure layer 4 of the high thermal conductivity composite material mold. After bonding, spray the support frame 5 with anti-rust paint to obtain the desired result. Figure 5 The mold shown is for molding high thermal conductivity composite materials.

[0059] In S1, the mold material is epoxy-modified wood.

[0060] When the aforementioned high thermal conductivity composite material molding die is used in vacuum bag molding, the composite material raw material is laid on the area of ​​the gel coat layer 1 but does not cover the area of ​​the carbon fiber thermal conductive layer 3. During heating and curing, the gel coat layer 1 at the product edge is subjected to heat conducted by the outer composite material raw material and the inner carbon fiber thermal conductive layer 3, as well as ambient heat conducted laterally along the surface of the gel coat layer 1. The gel coat layer 1 at the center of the product experiences less ambient heat conducted laterally. Since the outer composite material raw material is mainly composed of glass fiber with poor thermal conductivity, it also experiences less heat conducted by the outer composite material raw material. Due to the low thermal resistance of the carbon fiber thermal conductive layer 3 below, heat can be conducted from the exposed carbon fibers at the edge of the mold to the gel coat layer 1 at the center of the product, thereby rapidly increasing the temperature of the gel coat layer 1 at the center of the product and improving the temperature uniformity of the molding die during the curing process of the composite material product.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high thermal conductivity composite material molding die, characterized in that, It includes a gel coat layer, a transition layer, a carbon fiber thermal conductive layer, and a glass fiber structural layer arranged from top to bottom; The transition layer includes a glass fiber surface mat, and its coverage area is the same as that of the gel coat layer; The carbon fiber thermal conductive layer comprises carbon fiber fabric and molding resin, and the carbon fiber thermal conductive layer is exposed by a set size outside the coverage area of ​​the gel coat layer; The glass fiber structural layer comprises chopped glass fiber mat and molding resin, and the coverage area of ​​the glass fiber structural layer is the same as that of the carbon fiber thermal conductive layer.

2. The high thermal conductivity composite material molding die as described in claim 1, characterized in that, The raw materials for preparing the gel coat layer include epoxy resin, and the gel coat layer includes a product molding surface.

3. The high thermal conductivity composite material molding die as described in claim 1, characterized in that, The transition layer has a set thickness.

4. The high thermal conductivity composite material molding die as described in claim 1, characterized in that, The carbon fiber in the carbon fiber thermal conductive layer is continuous carbon fiber, and the carbon fiber accounts for 60%-70% of the volume of the carbon fiber thermal conductive layer.

5. The high thermal conductivity composite material molding die as described in claim 1, characterized in that, The carbon fiber fabric includes carbon fibers oriented from the edge to the center.

6. The high thermal conductivity composite material molding die as described in claim 1, characterized in that, The glass fiber structural layer is made of glass fiber fabric, chopped glass fiber mat, and molding resin.

7. The high thermal conductivity composite material molding die as described in claim 1, characterized in that, The high thermal conductivity composite material molding die also includes a support frame, which is installed on the side of the glass fiber structure layer away from the carbon fiber thermal conductive layer.

8. The method for manufacturing a high thermal conductivity composite material molding die as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Spray epoxy resin onto the product forming surface of the mold to form a gel coat layer; S2. Lay a glass fiber surface mat on the gel coat layer to form a transition layer; S3. Lay carbon fiber fabric on the transition layer, with the laying area being larger than the gel coat layer, to form a carbon fiber thermal conductive layer; S4. Lay glass fiber chopped strand mat on the carbon fiber thermal conductive layer; S5. Vacuum system is formed by wrapping the mold, transition layer, carbon fiber thermal conductive layer and chopped fiber felt in a vacuum bag. S6. Introduce resin into a vacuum system and mold it at a set temperature and pressure. After removing the mold, obtain a high thermal conductivity composite material molding die.

9. The manufacturing method as described in claim 8, characterized in that, In S1, the material of the mold includes one or more of the following: epoxy wood substitute, polyester wood substitute, and HPL board; Optionally, step S7 is also included: installing the high thermal conductivity composite material molding die onto the support frame.

10. The application of a high thermal conductivity composite material molding die as described in any one of claims 1-7 in vacuum bag molding.

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