Paving unidirectional fiber prepreg and production device thereof
By introducing design-optimized fractures into the carbon fiber unidirectional prepreg, defect problems in parts with large curvature and poor mechanical properties of chopped fiber materials are solved, and a prepreg with high overlay and excellent mechanical properties is achieved.
Patent Information
- Application Number
- CN202510527612.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2025-06-06
AI Technical Summary
Existing carbon fiber unidirectional prepregs are prone to defects such as wrinkles, bridges, fiber protrusions, etc. in parts with high curvature, and short-cut carbon fiber reinforced composite materials perform poorly in mechanical properties.
By introducing multiple fractures into the unidirectional fiber prepreg, fracture length, location and number are designed to improve the overlay and mechanical properties of the material, and efficient fracture design and production are achieved through adjustable cutting devices.
The prepreg has good overlaying properties in parts with high curvature, while improving its mechanical properties, avoiding the cumbersomeness of secondary processing.
Smart Images
Figure CN120095989A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of carbon fiber composite material preparation, and in particular relates to a draping unidirectional fiber prepreg and a production device thereof. Background Art
[0002] Fiber-reinforced resin-based composite materials are currently widely used in various fields such as aerospace, rail transportation, and sports equipment. The current carbon fiber composite material market has been developing steadily and rapidly. There are many methods for forming composite parts, among which the most widely used method is the molding method using prepreg using autoclave process, molding process, and vacuum bag pressing process. Carbon fiber prepreg is divided into fabric prepreg and unidirectional prepreg. The two different prepregs have their own characteristics and are important raw materials for composite parts. Carbon fiber unidirectional prepreg has a high strength conversion rate because its reinforcing fibers are continuous and there are no interlacing points between fiber bundles. Therefore, in parts with smaller curvature, carbon fiber unidirectional prepreg is usually selected as the main composite material. Because the unidirectional carbon fiber prepreg itself has high bending stiffness, it is easy to produce wrinkles, bridges, fiber protrusions, etc. in parts with larger curvatures. Improper operation will cause defects in parts.
[0003] In the current preparation process of composite parts, in order to improve the draping ability of the material, composite materials reinforced with chopped carbon fibers (length <10 mm) are often used, but their mechanical properties are very poor. Summary of the invention
[0004] In view of the above problems existing in the prior art, the present invention provides a draping unidirectional fiber prepreg and a production device thereof, which can enable the prepreg to have good draping properties while maintaining excellent mechanical properties.
[0005] To achieve the above object, the technical solution provided by the present invention is as follows:
[0006] In the first aspect, the present application provides a draping unidirectional fiber prepreg, including a prepreg precursor, on which a plurality of fractures are created, the fracture lengths being 1 mm-10 mm, the distance between adjacent fractures along the length direction of the prepreg being not less than 30 mm, and the number of fractures in any 1 square decimeter of the prepreg is 10-500.
[0007] Optionally, the prepreg precursor includes an upper size film, a lower size film, and reinforcing fibers impregnated between the upper size film and the lower size film.
[0008] Optionally, the fiber surface density of the prepreg precursor is 20-600 g / m 2 .
[0009] Optionally, the reinforcing fiber is polyacrylonitrile-based carbon fiber, asphalt-based carbon fiber or viscose-based carbon fiber.
[0010] Optionally, the resin component in the prepreg precursor is a thermosetting resin or a thermoplastic resin.
[0011] On the other hand, the present application also provides a production device for the above-mentioned draping unidirectional fiber prepreg, characterized in that it includes a traction roller, a cutting roller and a winding device, the discharge end of the traction roller is connected to the feed end of the cutting roller, the discharge end of the cutting roller is connected to the winding device, the cutting roller assembly includes an upper roller and a lower roller, and the upper roller is detachably connected to a cutting tool.
[0012] Optionally, the gap between the upper roller and the lower roller is adjustable.
[0013] Optionally, a plurality of circular rings are sleeved side by side on the upper roller, the circular rings are fixed to the upper roller by bolts, and a cutting tool is installed on the circular rings.
[0014] Optionally, the angle between the blade of the cutting tool and the generatrix of the upper roller is -70° to 70°.
[0015] Optionally, a prepreg precursor production component is connected to the feed end of the traction roller.
[0016] Optionally, the prepreg precursor production assembly includes a first impregnation roller, a heating plate, three groups of second impregnation rollers, and a cooling plate connected in sequence; the feed end of the first impregnation roller is connected to an upper film unwinding device, a reinforcing fiber feeding device and a lower film unwinding device, the discharge end of the cooling plate is connected to the traction roller, and the discharge end of the traction roller is also provided with a release paper winding device, a PE film pressing roller is provided between the cutting roller and the winding device, and the feed end of the PE film pressing roller is also connected to a PE film unwinding roller.
[0017] Compared with the prior art, this application has at least the following beneficial effects:
[0018] The present invention introduces fractures into conventional unidirectional prepregs and designs the size and position of the fractures to ensure that the material has both high mechanical properties and high draping properties.
[0019] At the same time, a detachable cutting tool is arranged on the cutting roller, and the size, position, angle, etc. of the fracture can be conveniently adjusted by switching the tool; through the design of the fracture in this application, the port cutting is carried out simultaneously on the prepreg precursor production line, which can improve the draping performance online at high speed and avoid the tedious secondary processing. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 Schematic diagram of the structure of the draping unidirectional fiber prepreg in the embodiment of the present application;
[0021] Figure 2It is a production device for the draping unidirectional fiber prepreg in the embodiment of the present application;
[0022] Figure 3 Schematic diagram of the cutting roller structure in the embodiment of the present application;
[0023] Description of reference numerals:
[0024] 1. Reinforced fiber; 2. Fracture; 3. Distance between adjacent fractures; 4. Direction of roller generatrix; 5. Cutting roller; 51. Upper roller; 52. Lower roller; 6. Winding device; 7. PE film unwinding device; 8. Upper release paper unwinding device; 9. Cooling plate; 10. Second impregnation roller; 11. First impregnation roller; 12. Heating plate; 13. Lower film unwinding device; 14. Reinforced fiber feeding device; 15. Upper film unwinding device; 16. Traction roller. DETAILED DESCRIPTION
[0025] The present invention is further described in detail below in conjunction with the accompanying drawings:
[0026] The experimental methods used in the embodiments of the present invention are conventional methods unless otherwise specified.
[0027] The reagents and materials used in this example can all be purchased conventionally. The quantitative experiments involved in the examples were repeated at least three times, and the results were averaged.
[0028] Example 1
[0029] A production device for covering unidirectional fiber prepreg, such as Figure 2 As shown, it includes a first impregnated roller 11, a heating plate 12, three groups of second impregnated rollers 10, a cooling plate 9, a traction roller 16, a cutting roller 5 and a winding device 6 connected in sequence; the feeding end of the first impregnated roller 11 is connected to an upper film unwinding device 15, a reinforcing fiber feeding device 14 and a lower film unwinding device 16, and the discharging end of the traction roller 16 is also provided with an upper release paper unwinding device 8, a PE film pressing roller is provided between the cutting roller 5 and the winding device 6, and the feeding end of the PE film pressing roller is also connected to a PE film unwinding device 7; the cutting roller 5 includes an upper roller 51 and a lower roller 52, and the upper roller 51 is detachably connected with a cutting tool. The upper roller 51 is provided with a plurality of circular rings arranged side by side along the roller axis direction, and the circular rings are fixed to the upper roller 51 by bolts, and a cutting tool is installed on the circular ring. The angle between the blade of the cutting tool and the upper roller generatrix direction 4 is -70° to 70°. The gap between the upper roller 51 and the lower roller 52 is adjustable.
[0030] First, the upper film and the lower film are drawn out from the upper film unwinding device 15 and the lower film unwinding device 13, and are respectively compounded with the upper and lower surfaces of the reinforcing fibers, and then passed through the first impregnation roller 11. The upper film and the lower film are melted and impregnated into the reinforcing fibers by the temperature and pressure of the first impregnation roller 11, and then passed through the heating plate 12 and three groups of second impregnation rollers 10 in sequence, and then cooled by the cooling plate 9 to obtain a prepreg precursor; the prepreg precursor moves forward under the action of the traction roller 16 and enters between the cutting rollers 5. During the preparation process, the gap between the cutting tool on the upper roller 51 and the roller surface of the lower roller 52 is 0. In this embodiment, by installing a suitable cutting tool, the length of the fracture 2 is 3 mm, the angle between the length direction of the fracture 2 and the width direction of the prepreg is 0°, and the number of fractures 2 per square decimeter is 20; the distance between the fractures 2 (i.e., the distance 3 between adjacent ports) is 30 mm. The prepreg after the cutting roller 5 is rolled up with the release paper, and then the upper surface is attached to the PE film released from the PE film unwinding device 7 and rolled up after being squeezed by the PE film pressing roller to obtain a draping unidirectional fiber prepreg. The structural diagram is shown in FIG. Figure 1 As shown;
[0031] The temperature of the first impregnation roller and the second impregnation roller is 90-110°C, 100°C in this embodiment, and the roller pressure is controlled at 0.4-0.7MPa, 0.6MPa in this embodiment; the temperature of the first heating plate is 115°C, and the temperature of the first cooling plate is 18±3°C;
[0032] In Example 1, the reinforcing fiber is Hengshen HF40F-12K carbon fiber (T800 grade carbon fiber), and the resin film is Hengshen's medium temperature curing epoxy resin (EM710 resin is used in this embodiment); the resin content in the prepreg precursor used is 37%, and the fiber surface density is 150g / m 2 The width of the tape masterbatch is 1000mm.
[0033] In this embodiment, the 0° tensile strength of the prepreg precursor is 1800 MPa, and the 0° tensile modulus is 120 GPa; the 0° tensile strength of the draping unidirectional fiber prepreg obtained by the method of this application is 800 MPa, and the 0° tensile modulus is 60 GPa; while the 0° tensile strength of the composite material reinforced by the short fiber is usually ≤300MPa, and the 0° tensile modulus is ≤30 GPa. Although the composite material reinforced by the short fiber (length <10mm) has good draping properties, the mechanical properties are poor; the draping unidirectional fiber prepreg prepared by the method and equipment in this application has good draping properties, and the mechanical properties are improved, and other impurities will not be introduced.
[0034] Drapability test method: The prepreg is laid in a special mold (a hemispherical metal mold with a diameter of 200 mm). After the laying is completed, the material is vacuumed and compacted with a vacuum bag, and then the wrinkles at the layup are observed. The average value is obtained through repeated tests. The average number of wrinkles is used as an indicator to characterize the drapeability of the material. The more wrinkles there are, the lower the drapeability.
[0035] The number of wrinkles of the prepreg without fracture (other things being the same) is 8.3, and the number of wrinkles of the material with fracture introduced in the embodiment of the present application is 3.3, indicating that the introduction of fracture can greatly improve the draping property of the material.
[0036] Example 2
[0037] The difference between this embodiment and embodiment 1 is that the length of the fracture 2 is 10 mm, the distance between adjacent fractures 2 along the length direction of the prepreg is 50 mm, and the number of ports per square decimeter is 30.
[0038] The draping unidirectional fiber prepreg obtained in this embodiment has a 0° tensile strength of 650 MPa and a 0° tensile modulus of 55 GPa. The number of wrinkles of the material introduced into the fracture in the embodiment of the present application is 2.7.
[0039] Example 3
[0040] The difference between this embodiment and embodiment 1 is that the length of the fracture 2 is 5 mm, the distance between adjacent fractures 2 along the length direction of the prepreg is 80 mm, and the number of ports per square decimeter is 10.
[0041] The draping unidirectional fiber prepreg obtained in this embodiment has a 0° tensile strength of 700 MPa and a 0° tensile modulus of 62 GPa. The number of wrinkles of the material introduced into the fracture in the embodiment of the present application is 2.4.
[0042] Comparative Example 1
[0043] The difference between this comparative example and Example 1 is that the length of the fracture 2 is 20 mm, the distance between adjacent fractures 2 along the length direction of the prepreg is 10 mm, and the number of ports per square decimeter is 20.
[0044] The draping unidirectional fiber prepreg obtained in this comparative example has a 0° tensile strength of 500 MPa and a 0° tensile modulus of 41 GPa. The number of wrinkles of the material introduced into the fracture in the embodiment of the present application is 5.7.
Claims
1. A draping unidirectional fiber prepreg, characterized in that: It comprises a prepreg precursor, on which a plurality of fractures are created, the fracture length is 1mm-10mm, the distance between adjacent fractures along the length direction of the prepreg is not less than 30mm, and the number of fractures in any 1 square decimeter of the prepreg is 10-500.
2. The draping unidirectional fiber prepreg according to claim 1, characterized in that: The prepreg precursor comprises an upper glue film, a lower glue film and reinforcing fibers impregnated between the upper glue film and the lower glue film.
3. The draping unidirectional fiber prepreg according to claim 2, characterized in that: The fiber surface density of the prepreg precursor is 20-600 g / m 2 .
4. The draping unidirectional fiber prepreg according to claim 2, characterized in that: The reinforcing fiber is polyacrylonitrile-based carbon fiber, asphalt-based carbon fiber or viscose-based carbon fiber.
5. The draping unidirectional fiber prepreg according to claim 1, characterized in that: The resin component in the prepreg precursor is a thermosetting resin or a thermoplastic resin.
6. A production device for the draping unidirectional fiber prepreg according to any one of claims 1 to 5, characterized in that: It includes a traction roller, a cutting roller and a winding device, the discharge end of the traction roller is connected to the feed end of the cutting roller, the discharge end of the cutting roller is connected to the winding device, the cutting roller assembly includes an upper roller and a lower roller, and the upper roller is detachably connected with a cutting tool.
7. The production device of draping unidirectional fiber prepreg according to claim 6, characterized in that: The gap between the upper roller and the lower roller is adjustable.
8. The production device of draping unidirectional fiber prepreg according to claim 6, characterized in that: A plurality of circular rings are sleeved side by side on the upper roller, the circular rings are fixed to the upper roller by bolts, and a cutting tool is installed on the circular rings.
9. The production device of draping unidirectional fiber prepreg according to claim 6, characterized in that: The angle between the blade of the cutting tool and the generatrix of the upper roller is -70° to 70°.
10. The production device of draping unidirectional fiber prepreg according to claim 6, characterized in that: The feed end of the traction roller is connected with a prepreg precursor production component.