Process for manufacturing composite material shell structure by using thermal cutting foam mold
By using thermal cutting foam molds and vacuum curing technology to manufacture composite material shells, the problems of high processing costs and long cycles of metal molds have been solved, achieving low-cost, high-efficiency production and high-quality composite material shell manufacturing.
Patent Information
- Application Number
- CN202510876415.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-10-28
AI Technical Summary
Traditional composite material shell mold manufacturing relies on metal molds, resulting in high processing costs, long cycles, heavy weight, and inconvenience in handling, making it difficult to meet the needs of rapid iteration and cost reduction in modern manufacturing.
Composite material shell structures are manufactured using thermally cut foam molds. The composite material shell is formed by using rigid polyurethane foam molds combined with thermal cutting equipment and vacuum curing technology.
It reduced processing costs, shortened processing time, improved the quality of the processed surface, simplified the mold surface treatment process, and enhanced the structural stability and production efficiency of the shell.
Smart Images
Figure CN120840104A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aircraft wing skin manufacturing and model aircraft wing manufacturing technology, specifically a process for manufacturing composite material shell structures using thermally cut foam molds. Background Technology
[0002] In modern industry, composite material shells are widely used in a wide range of sectors, including aerospace, automotive manufacturing, shipbuilding, and sporting goods, due to their outstanding characteristics such as light weight, high strength, and corrosion resistance. In aerospace, composite material shells are extensively used in aircraft fuselages and satellite outer shells to reduce weight, thereby lowering energy consumption and improving flight performance and payload. In the automotive industry, composite material shells are being used in body panels and engine hoods of some high-end models to achieve energy conservation, emission reduction, and improved handling. In sporting goods, such as bicycle frames and golf clubs, composite material shells significantly enhance product performance and quality, meeting consumers' demands for high-performance equipment.
[0003] Traditional composite material shell mold manufacturing often relies on metal molds. While metal molds are robust and durable, they are extremely difficult to manufacture, requiring complex machining processes such as precision milling and electrical discharge machining. This not only results in high costs but also long processing cycles. For example, the cost of manufacturing a high-precision metal mold for a composite material air intake shell of an aero-engine can reach millions or even tens of millions of yuan, with a manufacturing cycle often exceeding six months. This is undoubtedly a heavy burden for modern manufacturing industries that strive for rapid iteration and cost reduction. Furthermore, the large weight of metal molds makes handling and installation extremely inconvenient during the manufacturing of large composite material shells, increasing the complexity and risk of production operations. Summary of the Invention
[0004] (1) Technical problems solved
[0005] To address the shortcomings of existing technologies, this invention provides a process for manufacturing composite material shell structures using thermally cut foam molds. This process offers advantages such as reduced costs, shorter processing time, and improved surface quality, thus solving the problem of composite material shell manufacturing.
[0006] (2) Technical solution
[0007] To achieve the aforementioned goals of shortening processing time and improving surface quality, this invention provides the following technical solution: a process for manufacturing composite material shell structures using thermally cut foam molds, comprising:
[0008] Foam board is placed on the workbench of a thermal cutting equipment for cutting and forming a foam mold body with a model pattern. The foam mold undergoes a next step of surface polishing to ensure that the first composite material is completely attached to the model pattern. The surface of the foam mold needs to be covered with a film, and the first composite material is located on the film. The film is located between the model pattern and the first composite material, and the film forms a protective layer for the foam mold and the first composite material.
[0009] A semi-finished product is placed on top of a first composite material, and a second composite material is placed on top of the semi-finished product. The semi-finished product is located between the first composite material and the second composite material, and the first composite material separates the semi-finished product from the foam mold.
[0010] The above structure is wrapped in a vacuum bag and then vacuum-cured.
[0011] Preferably, the model shape needs to be designed first, and then the foam mold is precisely cut with a heating wire to form the desired model shape.
[0012] Preferably, the foam mold is made of rigid polyurethane foam (PU), and the surface of the foam mold needs to be trimmed to remove burrs, flash, and other uneven parts after being cut by a thermal cutting device.
[0013] Preferably, the film is made of Teflon (PTFE) tape or film, and the film facilitates demolding of the composite material shell.
[0014] Preferably, the first composite material and the sandwich material are first cured on the platform to obtain a semi-finished product.
[0015] Preferably, the semi-finished product is placed in the model pattern and then bent to fit the shape of the model pattern. At this time, the first composite material is located below the semi-finished product and the second composite material is placed on top of the semi-finished product, thereby forming a complete sandwich structure.
[0016] Preferably, the first composite material and the second composite material are carbon fiber composite materials, and the first composite material and the second composite material are respectively cured on the core material.
[0017] Preferably, the vacuuming equipment is started and a vacuum is drawn inside the vacuum bag.
[0018] Preferably, after the sandwich structure is vacuumed, it needs to be cured to form a robust composite material shell. The composite material shell is then removed from the model and its edges are trimmed and its quality is inspected.
[0019] (3) Beneficial effects
[0020] Compared with the prior art, the present invention provides a process for manufacturing composite material shell structures using thermally cut foam molds, which has the following advantages:
[0021] 1. This invention utilizes inexpensive, high-hardness foam material for mold making.
[0022] 2. This invention, by employing a thermal cutting processing method, significantly shortens the processing time and achieves higher surface quality.
[0023] 3. This invention separates the composite product from the foam mold by using a film, and the mold surface only needs simple polishing, avoiding the cumbersome mold surface treatment process.
[0024] 4. This invention solves the problem of easy breakage of foam core materials and improves the surface quality of the shell by modifying the layup sequence of the composite material shell. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the system structure of the present invention;
[0026] Figure 2 This is a cross-sectional structural diagram of the housing of the present invention. Detailed Implementation
[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0028] Please see Figure 1 and 2 A process for manufacturing composite material shell structures using thermally cut foam molds, comprising:
[0029] The foam board is placed on the worktable of the thermal cutting equipment for cutting and forming a foam mold body with a model pattern. The foam mold undergoes the next step of surface polishing to ensure that the first composite material is completely attached to the model pattern. The surface of the foam mold needs to be covered with a film, and the first composite material is located on the film. The film is located between the model pattern and the first composite material, and the film forms a protective layer for the foam mold and the first composite material.
[0030] A semi-finished product is placed on top of the first composite material, and a second composite material is placed on top of the semi-finished product. The semi-finished product is located between the first composite material and the second composite material, and the first composite material separates the semi-finished product from the foam mold.
[0031] The above structure is wrapped in a vacuum bag and then vacuum-cured.
[0032] Foam molds, as a primary component in mold making, can reduce mold manufacturing costs. The foam molds are made of rigid polyurethane foam (PU), which is durable, allows for adjustable hardness according to the formula, can withstand significant pressure and external forces, and maintains structural integrity better over long-term use, making it suitable for applications requiring high strength and stability. The model shape must be designed first. Once the shape is determined, the foam mold is precisely cut with a hot wire to form the desired shape, avoiding blind cutting. After the foam mold is cut with a hot wire in a thermal cutting device, it is placed in a specialized finishing instrument to remove burrs, flash, and other uneven parts. During this process, employees processing the foam mold must wear protective clothing to prevent the inhalation of toxic gases and dust emitted during thermal cutting. Using inexpensive and high-hardness foam materials for mold making reduces the need for small-batch production components, preventing resource waste when a component is not needed. The use of thermal cutting technology and precise cutting with a hot wire reduces processing time and improves surface quality.
[0033] CNC electric hot wire cutters are used for foam mold cutting. These machines can achieve high-precision three-dimensional shape cutting, suitable for complex mold designs. For rigid polyurethane foam (PU), a cutting temperature between 300℃ and 400℃ is recommended. This temperature range ensures a smooth cut surface while avoiding overheating that could cause material deformation or combustion. The cutting speed should be adjusted according to the foam thickness. Thinner sheets (e.g., less than 10mm) can use higher speeds (several meters per minute), while thicker sheets require lower speeds (tens of centimeters per minute) to ensure complete penetration of the material and a smooth cut edge.
[0034] The film is made of Teflon (PTFE) tape or film, which has excellent non-stick properties and high-temperature resistance, making it ideal for composite materials requiring high-temperature curing. It can be used long-term in a temperature range of -180℃ to +260℃, has very low surface energy, and is virtually non-adhesive to all substances, making it easy to remove stains. Various oil stains, dirt, pastes, resins, coatings, and other adhesive substances can be easily cleaned. This film facilitates demolding of composite material shells when used in foam molds.
[0035] The first composite material and the core material are first cured on a platform to obtain a semi-finished product. The semi-finished product is then placed into a mold and bent to conform to the shape of the mold. At this point, the first composite material is positioned below the semi-finished product, and the second composite material is placed on top, forming a complete sandwich structure. Both the first and second composite materials are made of carbon fiber composites and are respectively cured onto the core material. When the semi-finished product (first composite material + foam core material) is bent, it will not break due to the zero strain of the outer carbon fiber composite material. The inner layer of the core material will also not crack under compression. The semi-finished product is carefully placed into a foam mold, ensuring its shape matches the mold. At this point, the core material is encased in the first composite material, receiving effective protection and maintaining shape stability to a certain extent.
[0036] A second composite material is then laid on top of the semi-finished product. The vacuum equipment is activated, and the inside of the vacuum bag is evacuated. The second composite material is then laid, ensuring a tight fit with the semi-finished product. The entire component is then wrapped in a vacuum bag, and the bag is evacuated again to ensure no air bubbles remain between layers and that the resin fully penetrates. The component is then placed in a heating furnace for curing, with temperature and time controlled to ensure complete resin curing, thus forming a robust composite shell.
[0037] After vacuuming, the sandwich structure needs to be cured to form a robust composite shell. The composite shell is then removed from the mold, and its edges are trimmed and quality inspected. Once cured, the composite shell is removed from the foam mold. This process is relatively easy and does not damage the product surface due to the use of a release agent or film. Necessary finishing touches are performed on the finished product, such as removing excess material, drilling holes, and sanding edges, followed by quality inspection to ensure it meets design requirements.
[0038] In summary, the film applied to the foam mold prevents adhesion, effectively isolating the composite material from the mold and avoiding direct contact that could lead to sticking, thus simplifying the demolding process. It also improves surface quality; the smooth surface of the film contributes to a higher surface finish in the final product, reducing the workload of subsequent sanding and polishing. Furthermore, it extends mold life by isolating the mold from chemicals (such as resin), reducing erosion and extending its lifespan. The benefits of pre-curing the first composite material and the core material to obtain a semi-finished product include: increased production efficiency; and improved product quality. Pre-curing the outer composite material and the core material allows for the production of a semi-finished product with sufficient strength and stability in a shorter time, facilitating subsequent processes. It also ensures product quality; curing the outer composite material on a flat surface guarantees a high surface quality, improving the final product's appearance. Finally, it enhances structural stability; the core material, protected by the outer composite material, is less prone to breakage during bending, enhancing the overall structural stability and reliability.
[0039] The relevant modules involved in this system are all hardware system modules or functional modules that combine computer software programs or protocols with hardware in the prior art. The computer software programs or protocols involved in these functional modules are technologies known to those skilled in the art and are not improvements to this system. The improvement of this system lies in the interaction or connection between the modules, that is, in improving the overall structure of the system to solve the corresponding technical problems that this system aims to address.
[0040] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. A process for manufacturing composite material shell structures using thermally cut foam molds, characterized in that, include: Foam board is placed on the workbench of a thermal cutting equipment for cutting and forming a foam mold body with a model pattern. The foam mold undergoes a next step of surface polishing to ensure that the first composite material is completely attached to the model pattern. The surface of the foam mold needs to be covered with a film, and the first composite material is located on the film. The film is located between the model pattern and the first composite material, and the film forms a protective layer for the foam mold and the first composite material. A semi-finished product is placed on top of a first composite material, and a second composite material is placed on top of the semi-finished product. The semi-finished product is located between the first composite material and the second composite material, and the first composite material separates the semi-finished product from the foam mold. The above structure is wrapped in a vacuum bag and then vacuum-cured.
2. The process for manufacturing a composite material shell structure using a thermally cut foam mold according to claim 1, characterized in that, The model style needs to be designed first, and then the foam mold is precisely cut with heating wire to form the required model style shape.
3. The process for manufacturing composite material shell structures using thermally cut foam molds according to claim 1, characterized in that, The foam mold is made of rigid polyurethane foam (PU). After the foam mold is cut by a thermal cutting device, the surface needs to be trimmed to remove burrs, flash, and other uneven parts.
4. The process for manufacturing a composite material shell structure using a thermally cut foam mold according to claim 1, characterized in that, The film is made of Teflon (PTFE) tape or film, and the film facilitates demolding of the composite material shell.
5. The process for manufacturing a composite material shell structure using a thermally cut foam mold according to claim 1, characterized in that, The first composite material and the sandwich material are first cured on the platform to obtain a semi-finished product.
6. The process for manufacturing a composite material shell structure using a thermally cut foam mold according to claim 1, characterized in that, The semi-finished product is placed into the model pattern and then bent to fit the shape of the model pattern. At this time, the first composite material is located below the semi-finished product and the second composite material is placed on top of the semi-finished product, thereby forming a complete sandwich structure.
7. A process for manufacturing a composite material shell structure using a thermally cut foam mold according to claims 1 and 5, characterized in that, The first composite material and the second composite material are carbon fiber composite materials, and the first composite material and the second composite material are respectively cured on the core material.
8. The process for manufacturing a composite material shell structure using a thermally cut foam mold according to claim 1, characterized in that, When the vacuum equipment is started, it evacuates the inside of the vacuum bag.
9. A process for manufacturing a composite material shell structure using a thermally cut foam mold according to any one of claims 1, 6, or 8, characterized in that, After being vacuumed, the sandwich structure needs to be cured to form a robust composite material shell. The composite material shell is then removed from the model and its edges are trimmed and its quality is inspected.