Fabric semi-prepreg and production process thereof

Abstract

The invention discloses a fabric semi-prepreg and a production process thereof, the fabric semi-prepreg comprises a fabric and matrix resin, and the matrix resin is uniformly impregnated in the lower half layer of the fabric in a single-side pre-impregnation mode; wherein the matrix resin permeation rate is controlled to be 30-80% while it is guaranteed that the surface layer fibers are not impregnated and the appearance and the structure of the fabric are complete. The invention relates to a production process of a fabric semi-prepreg, which comprises the following steps: taking release paper as a carrier, coating matrix resin to form a resin film with a certain mass, adhering the resin film on the release paper to the lower surface of a fabric, and pressurizing to combine the resin with the lower half layer of the fabric to form partial impregnation. According to the invention, the paving property of the fabric semi-prepreg in the production and manufacturing process can be ensured, and the exhaust type of the fabric semi-prepreg in the curing process is ensured, so that the fabric semi-prepreg can meet the requirement of vacuum bag press forming, the forming process difficulty is reduced, the production energy consumption is reduced, and the production capacity is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of composite materials, and particularly relates to a fabric semi-prepreg and a production process thereof BACKGROUND

[0002] The fabric full-prepreg is the most widely used material in the fields of aerospace and low-altitude economy, and is used in a large number of structural parts of manned aircraft, unmanned aircraft and the like, but the product has the following problems.

[0003] 1) The current production process has low production efficiency, and is prone to have high porosity and delamination.

[0004] 2) A large number of hot pressing tank devices are occupied in the actual production process, resulting in low production capacity and high energy consumption.

[0005] Therefore, in view of the above technical problems, it is necessary to provide a fabric semi-prepreg and a production process thereof.

[0006] The information disclosed in the background section of this document is only intended to increase the understanding of the overall context of the present application and should not be considered as an acknowledgment or any form of suggestion that this information constitutes prior art that is known to those skilled in the art. SUMMARY

[0007] The purpose of the present application is to provide a fabric semi-prepreg and a production process thereof, which can be produced by using a hot melt method, can ensure the stability of the resin content of the semi-prepreg and the integrity of the fabric structure, and thus can ensure the uniformity and stability of the quality of the composite product. The difference between the fabric semi-prepreg and the original fabric full-prepreg is that, while ensuring the original resin content and fabric structure, all the resin is impregnated into the lower half of 30% to 80% of the fibers by single-sided pre-impregnation, and the dry fibers in the upper half are reserved as air guide channels in the curing process, thereby improving the exhaust effect of the fabric semi-prepreg in the curing process. The present application improves the problems of high porosity and delamination in the vacuum bag pressing molding of the original fabric full-prepreg, and the fabric semi-prepreg can be used for vacuum bag pressing molding, thereby reducing the molding process difficulty, reducing the production energy consumption and improving the production capacity.

[0008] In order to achieve the above-mentioned purpose, the technical scheme provided by one embodiment of the present application is as follows:

[0009] The fabric semi-prepreg comprises a fabric and a matrix resin, and the matrix resin is uniformly impregnated into the lower half of the fabric by single-sided pre-impregnation; wherein, while ensuring the unimpregnated surface layer fibers and ensuring the appearance and structure of the fabric, the impregnation rate of the matrix resin is controlled to be 30-80%.

[0010] In one or more embodiments of the present application, the matrix resin is a thermosetting epoxy resin composition.

[0011] In one or more embodiments of the present application, the thermosetting epoxy resin composition comprises an epoxy resin, a curing agent and a toughening agent. The curing agent comprises one of diethylene triamine, m-phenylenediamine, phthalic anhydride, and the toughening agent comprises one of amino-terminated butyronitrile rubber, polyetherimide, and polyether sulfone.

[0012] In one or more embodiments of the present application, the fabric comprises one or more of carbon fiber, glass fiber, quartz fiber, aramid fiber woven into warp-knitted fabric or multi-axial fabric.

[0013] In one or more embodiments of the present application, the fabric area density is 100-1000 g / m2.

[0014] In one or more embodiments of the present application, the impregnation rate is:

[0015] Impregnation rate = b / (a+b)*100%

[0016] The thickness of the dry fiber part is a, and the thickness of the impregnated part is b.

[0017] In one or more embodiments of the present application, the matrix resin is present in the lower half of the fabric, and the matrix resin comprises an impregnated part and a dry fiber part.

[0018] The fabric half-prepreg and its production process comprise the following steps:

[0019] S1, coating a resin film; using release paper as a carrier, coating a matrix resin to form a resin film of a certain mass;

[0020] S2, paste the resin film on the release paper on the lower surface of the fabric, and combine the resin with the lower half of the fabric by pressing at 30-100°C to form partial impregnation.

[0021] In one or more embodiments of the present application, the specific steps of S2 are:

[0022] S21, sandwich the fabric between the release paper coated with the resin film and the blank release paper.

[0023] S22, heat and press the fabric and the matrix resin by heating rollers to gradually impregnate the matrix resin in the fabric, and gradually reduce the proportion of the dry fiber part and increase the proportion of the impregnated part as the heating rollers heat and press.

[0024] S33, recycle the blank release paper and cover the fabric half-prepreg with a PE film, and finally roll up the fabric half-prepreg.

[0025] In one or more embodiments of the present application, the impregnation method is lower surface pre-impregnation.

[0026] Compared with the prior art, the fabric semi-prepreg and the production process thereof have the following benefits:

[0027] 1) The fiber-reinforced thermosetting epoxy resin prepreg is used as the main material of aerospace and low-altitude economic products, so that the matrix resin is not fully immersed in the fabric of the reinforcing material, but exists in the area of 30% to 80% of the lower half layer of the fabric, to form a double-sided heterogeneous state of a dry upper half layer and a wet lower half layer, which can ensure the lay-up property of the fabric semi-prepreg in the production and manufacturing process, and ensure the exhaust type of the fabric semi-prepreg in the curing process, so that the fabric semi-prepreg can meet the demand of vacuum bag compression molding.

[0028] 2) Low porosity, no delamination defects, high work efficiency, and low energy consumption. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Figure 1 is a cross-sectional pattern diagram of the fabric semi-prepreg in an embodiment of the present application;

[0031] Figure 2 is a production process schematic diagram of the fabric semi-prepreg in an embodiment of the present application.

[0032] MAIN REFERENCE NUMERALS EXPLANATION

[0033] 1-fabric, 2-matrix resin, 3-release paper, 4-heating roller, 5-wet part, 6-dry fiber part, 7-release paper coated with resin film, 8-PE film, 9-fabric semi-prepreg. DETAILED DESCRIPTION

[0034] In order to make the person skilled in the art better understand the technical solutions in the present disclosure, the technical solutions in the embodiments of the present disclosure will be described clearly and completely below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, not all. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present disclosure.

[0035] As Figure 1As shown in the figure, in one embodiment of the present invention, a semi-prepreg fabric and its production process are described. The semi-prepreg is prepared into composite material products using a vacuum bag pressing method and produced using a hot-melt method. This ensures stable resin content and intact fabric structure, thus guaranteeing the uniformity and stability of the composite material product's quality. The difference between the semi-prepreg fabric and the original full prepreg fabric is that, while maintaining the original resin content and fabric structure, the semi-prepreg fabric uses a single-sided prepreg method to impregnate all the resin into the lower half of the 30% to 80% of the fibers, while retaining the upper half of the dry fibers as a gas-guiding channel during the curing process, thereby improving the venting effect of the semi-prepreg fabric during curing. The present invention improves upon the problems of high porosity and delamination existing in the vacuum bag pressing of the original full prepreg fabric. The semi-prepreg fabric can be vacuum bag pressed, reducing the difficulty of the molding process, reducing production energy consumption, and increasing production capacity.

[0036] The fabric semi-prepreg includes fabric 1 and matrix resin 2. The matrix resin 2 is uniformly impregnated in the lower half of fabric 1 by one-sided prepreg.

[0037] Among these measures, while ensuring that the surface fibers are not impregnated and that the appearance and structure of the fabric are intact, the resin penetration rate of the matrix is ​​controlled at 30-80%.

[0038] Furthermore, the matrix resin 2 is present in the lower half of the fabric 1, and the matrix resin 2 includes an impregnated portion 5 and a dry fiber portion 6. That is, the matrix resin 2 is present in the impregnated portion 5 of the fabric 1, and the impregnation rate of the matrix resin 2 is controlled at 30-80%, and the structural integrity of the dry fiber portion 6 needs to be ensured.

[0039] like Figure 1 As shown, specifically for semi-prepreg fabrics, the impregnation rate should be controlled within the range of 30% to 80%. This range ensures good layability and workability of the semi-prepreg fabric, and allows the dry fibers to act as air channels for effective venting during curing, ensuring stable product quality. Therefore, the resin impregnation rate will now be explained in detail. Figure 1 This is a cross-sectional schematic diagram of a semi-prepreg fabric. The matrix resin 2 is present in the lower half of the fabric 1, forming the impregnated portion 5 and the dry fiber portion 6. The thickness of the dry fiber portion 6 is a, and the thickness of the impregnated portion 5 is b.

[0040] Impregnation rate = b / (a ​​+ b) * 100%

[0041] To ensure that the semi-prepreg fabric has a moderate softness and hardness while retaining sufficient air passages, the impregnation rate of the semi-prepreg fabric is controlled within the range of 30% to 80%.

[0042] The base resin is a thermosetting epoxy resin composition. The thermosetting epoxy resin composition comprises an epoxy resin, a curing agent and a toughening agent. The curing agent comprises one of diethylene triamine, m-phenylenediamine and phthalic anhydride, and the toughening agent comprises one of amino-terminated butyronitrile rubber, polyether imide and polyether sulfone.

[0043] Preferably, the epoxy resin composition is a low-temperature curing, medium-temperature curing or high-temperature curing thermosetting epoxy resin.

[0044] The fabric comprises one or more of carbon fiber, glass fiber, quartz fiber and aramid fiber woven into a warp-knitted fabric or a multi-axial fabric.

[0045] It should be noted that the fabric area density is 100-1000 g / m2. The fabric area density is preferably 800 g / m2.

[0046] In the production of the fabric semi-prepreg, as shown in Figure 2 , a plurality of heating rollers 4 are arranged in a pair of abutting relationship on the end face of the workbench, a conveying table is arranged on one side of the workbench, the conveying table conveys the fabric 1 to pass between the pair of heating rollers 4, a plurality of material supply devices are arranged on the end faces of the conveying table, the blank release paper 3 and the release paper 7 coated with a resin film are respectively wound on the material trays of the material supply devices on the opposite end faces of the pair of heating rollers 4, and the blank release paper 3 and the PE film 8 are sequentially wound on the material trays of the material supply devices near the tail of the conveying table, and a discharging device is arranged on one side of the conveying table to discharge the finished fabric semi-prepreg 9 after winding.

[0047] As shown in Figure 2 , the fabric semi-prepreg and its production process comprise the following steps:

[0048] S1, coating a resin film; coating the base resin 2 on the release paper 3 as a carrier to form a resin film of a certain quality;

[0049] S2, pasting the resin film on the release paper 3 to the lower surface of the fabric 1, and combining the base resin 2 with the lower half of the fabric 1 to form an infiltration part 5 by pressing under the condition of room temperature 30-100℃.

[0050] Preferably, the pressing temperature is 120℃.

[0051] S21, placing the fabric 1 in the first pair of heating rollers 4, and introducing the release paper 7 coated with a resin film and the blank release paper 3 from below and above into the first pair of heating rollers 4 respectively, so as to sandwich the fabric 1 between the release paper 7 coated with a resin film and the blank release paper 3.

[0052] S22, the fabric 1 and the matrix resin 2 are heated and pressed by the heating roller 4, so that the matrix resin 2 gradually infiltrates into the fabric 1, and the proportion of the dry fiber part 6 is gradually reduced and the proportion of the infiltrated part 5 is gradually increased with the heating and pressing of the second pair of heating rollers 4 and the third pair of heating rollers 4;

[0053] S33, the blank release paper 3 is recycled and a PE film 8 is coated on the surface of the fabric half-prepreg 9, and finally the fabric half-prepreg 9 is wound up.

[0054] Example 1:

[0055] Taking the WP-3011 / 9A16 / 38%-I type 2 of our company as an example, the fabric 1 is selected as the T300 grade carbon fiber plain fabric W-3011, and the 9A16 resin is used to prepare the carbon fiber fabric half-prepreg WP-3011 / 9A16 / 38%-I type 2. The fabric 1 is placed in the first pair of heating rollers 4, and the release paper 7 coated with the resin film and the blank release paper 3 are introduced into the first pair of heating rollers 4 from below and above respectively, so as to sandwich the fabric 1 between the release paper 7 coated with the resin film and the blank release paper 3. The fabric 1 and the matrix resin 2 are heated and pressed by the heating roller 4, so that the matrix resin 2 gradually infiltrates into the fabric 1, and the proportion of the dry fiber part 6 is gradually reduced and the proportion of the infiltrated part 5 is gradually increased with the heating and pressing of the second pair and the third pair of heating rollers. Then the blank release paper 3 is recycled and a PE film 8 is coated on the surface of the fabric half-prepreg 9, and finally the fabric half-prepreg 9 is wound up.

[0056] It is apparent for those skilled in the art that the present disclosure is not limited to the details of the above-described exemplary embodiments, and the present disclosure can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present disclosure. Therefore, the embodiments should be considered in all aspects as illustrative and not restrictive, and the scope of the present disclosure is defined by the appended claims rather than the above description, and it is intended to encompass all changes falling within the meaning and range of equivalents of the elements of the claims. Any reference signs in the claims should not be considered as limiting the claims involved.

[0057] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A semi-prepreg fabric, characterized in that, It includes a fabric and a matrix resin, wherein the matrix resin is uniformly impregnated into the lower half of the fabric by a single-sided pre-impregnation method. Among these measures, while ensuring that the surface fibers are not impregnated and that the appearance and structure of the fabric are intact, the resin penetration rate of the matrix is ​​controlled at 30-80%.

2. The semi-prepreg fabric according to claim 1, characterized in that, The matrix resin is a thermosetting epoxy resin composition.

3. The semi-prepreg fabric according to claim 2, characterized in that, The thermosetting epoxy resin composition includes an epoxy resin, a curing agent, and a toughening agent. The curing agent includes one of diethylenetriamine, m-phenylenediamine, and phthalic anhydride. The toughening agent includes one of amino-terminated nitrile rubber and polyetherimide polyethersulfone.

4. The semi-prepreg fabric according to claim 3, characterized in that, The fabric includes warp-knitted or multiaxial fabrics woven from one or more of the following fibers: carbon fiber, glass fiber, quartz fiber, and aramid fiber.

5. The semi-prepreg fabric according to claim 4, characterized in that, The fabric surface density is 100-1000 g / m².

6. The semi-prepreg fabric according to claim 1 or 5, characterized in that, The impregnation rate is: Impregnation rate = b / (a ​​+ b) * 100% The thickness of the dry fiber portion is a, and the thickness of the impregnated portion is b.

7. The semi-prepreg fabric according to claim 1, characterized in that, The matrix resin is present in the lower half of the fabric, and the matrix resin includes an impregnated portion and a dry fiber portion.

8. A semi-prepreg fabric and its production process, characterized in that, It includes the following steps: S1. Coating resin film: Using release paper as a carrier, a base resin is coated to form a resin film of a certain quality. S2. Adhere the resin film on the release paper to the lower surface of the fabric, and apply pressure at 30~100℃ to make the resin bond with the lower half of the fabric to form partial impregnation.

9. The production process of the semi-prepreg fabric according to claim 8, characterized in that, The specific steps of S2 are as follows: S21. Sandwich the fabric between the release paper coated with resin film and the blank release paper; S22. The fabric and the matrix resin are heated and pressurized by the heating roller, so that the matrix resin is gradually impregnated into the fabric. As the heating roller heats and pressurizes, the proportion of dry fiber part is gradually reduced and the proportion of impregnated part is increased. S33. Recycle the blank release paper and cover the surface of the fabric semi-prepreg with PE film, and finally wind up the fabric semi-prepreg.

10. The production process of the semi-prepreg fabric according to claim 9, characterized in that, The impregnation method is pre-impregnation of the lower surface.

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