Preparation method of small-batch unidirectional resin-based carbon fiber prepreg
By using cutting, laying, vacuuming and heating and wetting treatment methods to control the fiber surface density in small batches, the problem of waste of materials and time in small batches is solved, and efficient and low-cost prepreg preparation and rapid evaluation capabilities are improved.
Patent Information
- Application Number
- CN202510101772.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2025-04-08
AI Technical Summary
In the prior art, when preparing resin-based composite prepregs in small batches, there is a problem of waste of material and time costs, and there is a lack of efficient and low-cost preparation methods and index characterization.
A small batch unidirectional resin-based carbon fiber prepreg is adopted, including cutting carbon fiber tows, laying them onto resin films, vacuuming, assembling auxiliary materials and heating and wetting treatment, controlling the fiber surface density to achieve efficient and low-cost preparation.
This method solves the problem of waste of material and time when preparing prepregs with uncertain performance in large batches, realizes efficient and low-cost prepreg preparation, and improves the rapid evaluation ability of new prepregs.
Smart Images
Figure CN119773105A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of composite materials, and in particular relates to a method for preparing a small batch of unidirectional resin-based carbon fiber prepreg. Background Art
[0002] A large number of resin-based composite materials are used in advanced aircraft structures, and the basic performance of composite materials has become an important indicator for measuring a new type of resin or fiber. Carbon fiber prepreg is currently a key material in advanced aircraft, and is generally obtained by the preparation process of "two films and one dip" or "four films and two dips". However, the minimum standard for prepreg preparation equipment is 20m 2 , consuming a lot of manpower and material resources, and causing waste of materials, making the basic performance verification of new prepregs complicated and costly. At the same time, there are relatively few reports on the preparation of small batches of experimental prepregs in the prepreg molding process.
[0003] Since the sample for verifying the basic performance of composite materials is small, the required prepreg area is only 5m 2 There are certain requirements for the surface density accuracy of prepreg. Prepreg equipment can well control various parameters of prepreg, but the preparation of prepreg by prepreg equipment needs to meet quality requirements. The preparation of small batch test-level prepreg requires an efficient and low-cost preparation method. For this reason, a small batch prepreg preparation method is needed, which can be controlled by the fiber surface density of the prepreg to reduce the waste of financial and material resources, thereby improving the rapid evaluation capability of new prepregs.
[0004] At present, there is no standard for the preparation method of small batch composite prepregs, and there is little research on related characterization. There is no efficient and low-cost preparation method and index characterization for composite material testing at home and abroad. Summary of the invention
[0005] The purpose of the present invention is to provide a method for preparing a small batch of unidirectional resin-based carbon fiber prepregs, so as to solve the problem of waste of material and time costs that may be caused when preparing prepregs with uncertain performance in large quantities.
[0006] To achieve the above object, the present invention adopts the following technical solutions:
[0007] A method for preparing a small batch of unidirectional resin-based carbon fiber prepreg comprises the following steps:
[0008] 1) preparing a resin film;
[0009] 2) cutting the carbon fiber tow according to the preset prepreg length;
[0010] 3) Laying one side of the cut carbon fiber tow onto the adhesive film to obtain a single-sided adhesive film prepreg;
[0011] 4) Cover the single-sided prepreg with the same adhesive film and perform vacuum treatment;
[0012] 5) Assembling the vacuum treated prepreg with auxiliary materials in a preset order and placing it in an oven for heating and impregnation treatment;
[0013] 6) After the treatment is completed, the prepreg is taken out from the oven and cooled at room temperature to obtain a small batch of unidirectional resin-based carbon fiber prepreg.
[0014] Furthermore, in step 3), the fiber tows are laid according to a preset fiber surface density, and the width of the single-sided adhesive film prepreg is measured every 10 tows to calibrate the fiber surface density.
[0015] Furthermore, the vacuum degree of the vacuum extraction in step 4) is not less than 0.085 MPa.
[0016] Furthermore, during the heating and infiltration treatment in step 5), the heating temperature is selected according to the rheological properties of the resin, and the resin does not solidify during the heating process.
[0017] Furthermore, in step 5), the vacuum-treated prepreg is assembled with auxiliary materials in a preset order, which means that the non-porous template, prepreg, non-porous isolation membrane, equalizing plate, porous isolation membrane, breathable felt and vacuum bag are assembled in a bottom-up order.
[0018] Furthermore, a release cloth is attached to the non-porous template, and the size of the release cloth is greater than or equal to the prepreg.
[0019] Furthermore, a release cloth is attached to the pressure equalizing plate, and the size of the release cloth is smaller than, larger than or equal to the prepreg.
[0020] Furthermore, the size of the porous separator is larger than that of the prepreg.
[0021] The beneficial effects achieved by the present invention are as follows:
[0022] 1. The present invention provides a method for preparing a small batch of unidirectional resin-based carbon fiber prepregs, which can establish a basic performance database for new prepreg composite materials.
[0023] 2. The present invention can guide the optimization of the prepreg process of the test piece, ensure the dimensional accuracy and quality requirements of the product, and meet the test requirements for the use of prepreg.
[0024] 3. The present invention solves the problem of waste of material and time costs that may be caused when preparing prepregs with uncertain properties in large quantities through this method.
[0025] 4. In view of the current status of fiber prepreg preparation, the present invention has developed a small-batch prepreg preparation method, filling the gap in small-batch composite material prepreg preparation methods.
[0026] 5. The present invention achieves efficient and low-cost preparation by controlling the surface density of prepreg fibers, reduces resource waste, and improves the high-speed evaluation capability of the new prepreg.
[0027] 6. While ensuring the quality and dimensional accuracy of the prepreg, the present invention reduces the standard requirements and costs of the preparation equipment and improves the economy of small-batch preparation. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 It is a schematic diagram of the close arrangement of fiber bundles in the embodiment.
[0029] Figure 2 Schematic diagram of the structure of the prepreg in the embodiment before entering the oven for assembly.
[0030] In the figure: 201-vacuum pump; 202-vacuum tube; 203-vacuum nozzle; 204-vacuum bag; 205-air supply felt; 206-demolding cloth; 207-unheated prepreg; 208-porous isolation film; 209-equalizing plate; 210-vacuum sealing tape. DETAILED DESCRIPTION
[0031] In order to make the various technical features and advantages or technical effects in the above technical solutions of the present invention more obvious and easy to understand, they are described in detail below in conjunction with embodiments.
[0032] Example 1
[0033] High temperature epoxy T800 grade carbon fiber unidirectional prepreg AC528 / CCF800H-35% small batch prepreg preparation test.
[0034] First, cut the AC528 resin film into two pieces with a size of 100cm*100cm. The surface density of the prepreg is calculated to be 205g / m 2 The width of every 10 fiber bundles is calculated. The fibers are pulled and straightened in a way that they are closely arranged and adhered to an AC528 resin film. The width is measured every 10 fiber bundles and adjusted by comparing the calculated results. Figure 1 As shown, the numbers in the figure are the serial numbers of the fiber bundles, and the translucent rectangular shadow parts are two layers of film, which are respectively located above and below the fiber bundles.
[0035] After the prepreg fiber bundles of the predetermined width are bonded, another AC528 resin film is attached to the prepreg obtained above and vacuumized, with the vacuum degree not less than 0.085MPa. The state of the prepreg before entering the oven for assembly is as follows: Figure 2Then, on the oven platform, assemble from bottom to top in the order of non-porous template → non-porous isolation membrane → prepreg laminate → non-porous isolation membrane → pressure balancing plate with porous isolation membrane → breathable felt → vacuum bag, heat up to 80°C, and keep warm for 20 minutes.
[0036] After the treatment is completed, the prepreg is taken out from the oven and cooled at room temperature to obtain a small batch of unidirectional resin-based carbon fiber prepreg.
[0037] Example 2
[0038] High temperature epoxy T800 grade carbon fiber unidirectional prepreg AC21CCF800-35% small batch weight prepreg preparation test formula.
[0039] First, cut the AC521 resin film into two pieces with a size of 100cm*100cm. The surface density of the prepreg is calculated to be 210g / m 2 The width of the prepreg for every 10 fiber bundles is . The fibers are pulled and straightened in a way that the fibers are closely arranged and adhered to a sheet of AC521 resin film. The width is measured every 10 fiber bundles and adjusted by comparing with the calculated results. Figure 1 As shown, the numbers in the figure are the serial numbers of the fiber bundles.
[0040] After the prepreg fiber bundles of the predetermined width are bonded, another AC521 resin film is attached. The prepreg obtained above is vacuumed, and the vacuum degree is not less than 0.085MPa. The state of the prepreg before entering the oven for assembly is as follows: Figure 2 Then, on the oven platform, assemble from bottom to top in the order of non-porous template → non-porous isolation membrane → prepreg laminate → non-porous isolation membrane → pressure balancing plate with porous isolation membrane → breathable felt → vacuum bag, heat up to 80°C, and keep warm for 20 minutes.
[0041] After the treatment is completed, the prepreg is taken out from the oven and cooled at room temperature to obtain a small batch of unidirectional resin-based carbon fiber prepreg.
[0042] The surface density of the obtained small batch of unidirectional resin-based carbon fiber prepreg was measured, and 9 random points of 1 cm*1 cm prepreg were determined and the load-bearing records were shown in Tables 1 and 2 below.
[0043] Table 1AC528 / CCF800H-35% prepreg surface density test results
[0044]
[0045] Table 2 AC521 / CCF800H-35% prepreg surface density test results
[0046]
[0047] It can be seen from Table 1 and Table 2 that the measured value / theoretical value of the surface density of the prepreg prepared by the method of the present invention reaches 99.9%, which shows that the desired prepreg can be prepared by the method of the present invention.
[0048] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Appropriate modifications or equivalent substitutions of the technical solutions of the present invention made by ordinary technicians in the field should all be included in the protection scope of the present invention. The protection scope of the present invention shall be based on what is defined in the claims.
Claims
1. A method for preparing a small batch of unidirectional resin-based carbon fiber prepreg, characterized in that: The following steps are involved: 1) preparing a resin film; 2) cutting the carbon fiber tow according to the preset prepreg length; 3) Laying one side of the cut carbon fiber tow onto the adhesive film to obtain a single-sided adhesive film prepreg; 4) Cover the single-sided prepreg with the same adhesive film and perform vacuum treatment; 5) Assembling the vacuum treated prepreg with auxiliary materials in a preset order and placing it in an oven for heating and impregnation treatment; 6) After the treatment is completed, the prepreg is taken out from the oven and cooled at room temperature to obtain a small batch of unidirectional resin-based carbon fiber prepreg.
2. The preparation method according to claim 1, characterized in that In step 3), the fiber tows are laid out according to the preset fiber surface density, and the width of the single-sided adhesive film prepreg is measured every 10 tows to calibrate the fiber surface density.
3. The preparation method according to claim 1, characterized in that: The vacuum degree of the vacuum pumping in step 4) is not less than 0.085 MPa.
4. The preparation method according to claim 1, characterized in that: During the heating and infiltration treatment in step 5), the heating temperature is selected according to the rheological properties of the resin, and the resin does not solidify during the heating process.
5. The preparation method according to claim 1, characterized in that: In step 5), the vacuum-treated prepreg is assembled with auxiliary materials in a preset order, which means that the non-porous template, prepreg, non-porous isolation membrane, equalizing plate, porous isolation membrane, breathable felt and vacuum bag are assembled in a bottom-up order.
6. The preparation method according to claim 5, characterized in that: A release cloth is attached to the non-porous template, and its size is greater than or equal to the prepreg.
7. The preparation method according to claim 5, characterized in that: A release cloth is attached to the pressure equalizing plate, and the size of the release cloth is smaller than, larger than or equal to the prepreg.
8. The preparation method according to claim 5, characterized in that: The size of the perforated release film is larger than that of the prepreg.