A foam sandwich structure forming apparatus

Abstract

The utility model discloses a foamed sandwich structure forming device, include: process mould, the air -guiding material of the profile of process mould is pasted, the one -way air -permeable membrane of process mould is pasted on air -guiding material and is used for foamed sandwich structure forming. The utility model solves the problem that the lower skin surrounds because the resin flow difference causes the big thickness foamed sandwich structure, forms the dry spot, simultaneously, does not destroy the integrity of sandwich structure, will not cause the decline of sandwich structure performance.

Description

Technical Field

[0001] This utility model belongs to the field of composite material technology, and specifically relates to a foam sandwich structure molding device. Background Technology

[0002] Foam sandwich structures are a common type of structure used in composite material design. They have the advantages of low density, high stiffness, and good sound insulation, so they are commonly used in various industries such as aerospace and rail transportation.

[0003] For thick foam sandwich structures, molding is difficult, and autoclave manufacturing is often used. This involves first molding the lower skin, then bonding the foam with an adhesive film and curing it together with the upper skin in an autoclave. Autoclave manufacturing is costly. Existing technologies also use VARI (Vacuum Assisted Resin Infusion) to manufacture foam sandwich structures. However, for large-sized foam sandwich structures, the resin flows quickly on the upper skin under the influence of the flow guide mesh, while the lower skin penetrates slowly, causing the lower skin to surround the foam and form dry spots. Conventionally, grooves and openings are used to create resin flow channels in the foam to prevent dry spots. However, grooving and opening both damage the structural integrity of the foam, leading to a decrease in the overall performance of the sandwich structure. The degree of performance degradation varies depending on the extent of the damage. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a foam sandwich structure molding device, which solves the problem of dry spots forming due to resin flow differences causing the lower skin to surround the thick foam sandwich structure. At the same time, it does not damage the integrity of the sandwich structure and does not cause a decrease in the performance of the sandwich structure.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: In a first aspect, a foam sandwich structure molding apparatus is provided, comprising: a process mold; an air-conducting material laid on the surface of the process mold; and a one-way breathable membrane laid on the air-conducting material for molding the foam sandwich structure.

[0006] Furthermore, the one-way breathable membrane is a one-way breathable membrane that only allows gas to flow to the side of the gas-guiding material.

[0007] Furthermore, it also includes sealing strips for sealing the joints between the process mold, the air-conducting material, and the one-way breathable membrane.

[0008] Furthermore, the specifications of the air-conducting material, the one-way breathable membrane, and the lower skin of the foam sandwich structure are the same.

[0009] Furthermore, the process mold includes a lower mold for molding the foam sandwich structure and a core mold in the combined mold.

[0010] Furthermore, the gas-conducting material is connected to the vacuum system via a gas-conducting pipeline.

[0011] Furthermore, the vacuum system includes a vacuum pump.

[0012] Furthermore, a vacuum regulating valve is installed on the gas delivery pipeline.

[0013] In a second aspect, a foam sandwich structure forming method based on the foam sandwich structure forming apparatus described in the first aspect is provided, comprising: laying an air-guiding material on the surface of a process mold; laying a one-way breathable membrane on the air-guiding material; and forming a foam sandwich structure on the one-way breathable membrane.

[0014] Furthermore, before fabricating the foam sandwich structure, sealing strips are used to seal the joints between the process mold, the air-conducting material, and the one-way breathable membrane; during the fabrication of the foam sandwich structure, a vacuum system is used to evacuate the areas where the air-conducting material and the one-way breathable membrane are laid.

[0015] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: This invention lays an air-guiding material on the surface of a process mold, then lays a one-way breathable membrane on the air-guiding material; a foam sandwich structure is then fabricated on the one-way breathable membrane. During the fabrication of the foam sandwich structure, a vacuum system is used to evacuate the area where the air-guiding material and the one-way breathable membrane are laid. As the resin permeates, the sealing system formed by the one-way breathable membrane continuously acts as a vacuum source, allowing the air trapped in the lower skin to flow into the one-way breathable membrane, which is then finally removed, preventing the formation of dry spots due to resin flow differences. This solves the problem of dry spots forming on the lower skin due to resin flow differences in thick foam sandwich structures. Simultaneously, it does not damage the integrity of the sandwich structure and does not cause a decrease in its performance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the process principle of a foam sandwich structure molding device and a method for molding a thick foam sandwich structure provided in this embodiment of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the process principle of an embodiment of the present utility model. Figure 2 ; In the diagram: 1. Sealing strip; 2. One-way breathable membrane; 3. Upper skin; 4. Foam core; 5. Air duct; 6. Air duct material; 7. Lower mold; 8. Lower skin; 9. Core mold; 10. Part preform; 11. Lower mold of the combined mold. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0018] Example 1 like Figure 1 As shown, a foam sandwich structure molding device includes: a process mold; an air-guiding material 6 laid on the surface of the process mold; and a one-way breathable membrane 2 laid on the air-guiding material 6 for foam sandwich structure molding.

[0019] In this embodiment, the process module is... Figure 1 The lower mold 7 is used for molding the foam sandwich structure. The one-way breathable membrane 2 is a one-way breathable membrane that only allows gas to flow to the side of the guide material 6. It also includes a sealing strip 1 for sealing the connection between the process mold, the guide material 6 and the one-way breathable membrane 2.

[0020] This embodiment, based on the VARI process principle, lays breathable material 6 and one-way breathable membrane 2 on the surface of the lower mold 7, and seals the one-way breathable membrane 2 at the edge of the lower mold 7. The sealed one-way breathable membrane 2 is connected to the vacuum system through the air guide pipe 5 to maintain vacuum. The arrangement of other auxiliary materials follows the basic principle of the VARI process. When the resin permeates, the sealing system formed by the one-way breathable membrane 2 can always act as a vacuum source, allowing the air wrapped in the lower skin 8 of the foam sandwich structure to flow into the one-way breathable membrane 2 and finally be removed, preventing the formation of encapsulation and causing dry spots.

[0021] The specific molding process is as follows: Before laying the dry fabric of the part, a layer of air-guiding material 6 is first laid on the surface of the lower mold 7, followed by a layer of one-way breathable membrane 2. The one-way breathable membrane 3 is sealed outside the part area using sealing strip 1. When the specifications of the air-guiding material 6, the one-way breathable membrane 2 and the lower skin of the foam sandwich structure are the same, only the connection between the lower mold 7, the air-guiding material 6 and the one-way breathable membrane 2 needs to be sealed. When the specifications of the air-guiding material 6 and the one-way breathable membrane 2 are larger than the specifications of the lower skin of the foam sandwich structure, the surface of the one-way breathable membrane 2 outside the part area needs to be sealed with an impermeable material. The air-guiding material 6 and the one-way breathable membrane 2 need to be laid flat, otherwise wrinkles will appear on the surface of the part. After the one-way breathable membrane 2 is sealed, it is connected to a vacuum system to evacuate the vacuum. The laid air-guiding material 6 and the one-way breathable membrane 2 are checked to ensure that the material surface is flat and there are no abnormalities. Then, the dry fabric and foam of the part are laid on the prepared tooling surface.

[0022] Lay out the release cloth, flow guide net, glue injection pipe and other auxiliary materials in sequence to form a vacuum bag film for sealing.

[0023] Resin is poured in as required and heated to cure, ultimately forming a foam sandwich structure with a lower skin 8, a foam core 4, and an upper skin 3.

[0024] When manufacturing the foam sandwich structure, the vacuum pump in the vacuum system is started to evacuate the area where the air-conducting material 6 and the one-way breathable membrane 2 are laid. The vacuum degree of the system is adjusted to the set value that meets the process requirements by the vacuum degree regulating valve set on the air-conducting pipeline 5. This can effectively solve the problem of dry spots on the skin under the foam sandwich structure. At the same time, it can avoid the problem of reduced performance of parts due to foam grooving and opening.

[0025] Example 2 Based on the same inventive concept as Embodiment 1 and following the same principles, this utility model can also be applied to the use scenarios of combined molds, such as... Figure 2 As shown, in the combined mold, the surface of the core mold 9 (in this embodiment, the core mold 9 is the process mold) is arranged with air guiding material 6 and one-way breathable membrane 2, and the connection between the core mold 9, the air guiding material 6 and the one-way breathable membrane 2 is sealed with sealing strip 1. Then, the sealed one-way breathable membrane 2 is connected to the vacuum system through the air guiding pipe 5. The part preform 10 is made between the lower mold 11 and the core mold 9 of the combined mold. During the manufacturing process, a vacuum is maintained to prevent the formation of dry spots.

[0026] Example 3 Based on the foam sandwich structure molding apparatus described in Embodiments 1 and 2, this embodiment provides a foam sandwich structure molding method, including: Apply air-guiding material 6 to the surface of the process mold; A one-way breathable membrane 2 is laid on the air-conducting material 6, and a sealing strip 1 is used to seal the connection between the process mold, the air-conducting material 6 and the one-way breathable membrane 2. While fabricating the foam sandwich structure on the one-way breathable membrane 2, a vacuum system is used to evacuate the area where the air-conducting material 6 and the one-way breathable membrane 2 are laid.

[0027] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A foam sandwich structure molding device, characterized in that, include: Process mold; Air-conducting material (6) is applied to the surface of the process model. A one-way breathable membrane (2) is laid on the air-conducting material (6) and used for the molding of the foam sandwich structure.

2. The foam sandwich structure molding device according to claim 1, characterized in that, The one-way breathable membrane (2) is a one-way breathable membrane that only allows gas to flow to the side of the gas-guided material (6).

3. The foam sandwich structure molding device according to claim 1, characterized in that, It also includes a sealing strip (1) for sealing the connection between the process mold, the air guiding material (6) and the one-way breathable membrane (2).

4. The foam sandwich structure molding device according to claim 1, characterized in that, The air-conducting material (6), the one-way breathable membrane (2), and the lower skin of the foam sandwich structure have the same specifications.

5. The foam sandwich structure molding device according to claim 1, characterized in that, The process mold includes a lower mold (7) for forming the foam sandwich structure and a core mold (9) in the combined mold.

6. The foam sandwich structure molding device according to claim 1, characterized in that, The gas-conducting material (6) is connected to the vacuum system through the gas-conducting pipeline (5).

7. The foam sandwich structure molding device according to claim 6, characterized in that, The vacuum system includes a vacuum pump.

8. The foam sandwich structure molding device according to claim 6, characterized in that, A vacuum regulating valve is installed on the gas guide pipe (5).

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