An apparatus and method for producing a prepreg

Abstract

The present disclosure provides a kind of preparation device and method of prepreg.The preparation device includes withdrawal frame, yarn spreading mechanism, impregnation mechanism and forming mechanism arranged in sequence along the direction of fiber tow, wherein the impregnation mechanism includes: fiber opening assembly, fiber opening assembly includes a plurality of first fiber opening roller and a plurality of second fiber opening roller, the first fiber opening roller is used to scatter the fiber tow after widening, the second fiber opening roller is used to turn over the fiber tow after widening;Material loading assembly, material loading assembly is used to set impregnating material to the fiber tow running on the fiber opening assembly.The preparation device of prepreg provided by the present disclosure can uniformly disperse the impregnating material into the surface and internal gap of the fiber tow, realize the deep impregnation of the impregnating material to the fiber tow, improve the mechanical properties of the prepreg, and also avoid the agglomeration of the impregnating material and the fiber tow, so as to effectively improve the flexibility of the prepreg, facilitate the laying of the prepreg, and improve the production yield of the prepreg product.

Description

Technical Field

[0001] This disclosure relates to the field of composite materials technology, and in particular to an apparatus and method for preparing prepreg. Background Technology

[0002] Thermoplastic prepregs are widely used in aerospace, new energy vehicles, and rail transportation due to their advantages such as short processing cycles, recyclability, and stable mechanical properties. However, prepregs made from traditional thermoplastic prepregs suffer from poor mechanical properties, insufficient flexibility, and difficulty in processing, resulting in a high scrap rate for prepreg products. Summary of the Invention

[0003] To address the problems existing in related technologies, this disclosure provides an apparatus and method for preparing prepreg.

[0004] According to a first aspect of the present disclosure, an apparatus for preparing a prepreg is provided. The apparatus includes a yarn unwinding frame, a yarn spreading mechanism, an impregnation mechanism, and a forming mechanism arranged sequentially along the travel direction of a fiber bundle. The yarn unwinding frame is used to unwind the fiber bundle, the yarn spreading mechanism is used to spread the fiber bundle, the impregnation mechanism is used to apply an impregnation material to the surface of the fiber bundle, and the forming mechanism is used to form the fiber bundle having the impregnation material into a prepreg. The impregnation mechanism includes: The fiber opening assembly includes a plurality of first fiber opening rollers and a plurality of second fiber opening rollers. The first fiber opening rollers and the second fiber opening rollers are alternately distributed along the traveling direction of the fiber bundle. The fiber bundle passes through each of the first fiber opening rollers and each of the second fiber opening rollers in sequence. The first fiber opening rollers are used to break up the broadened fiber bundles, and the second fiber opening rollers are used to turn over the broadened fiber bundles. A feeding assembly is used to apply the impregnation material to the fiber bundle passing through the fiber opening assembly.

[0005] In some embodiments of this disclosure, the outer surface of the first fiber opening roller includes a plurality of arc-shaped protrusions and a plurality of arc-shaped grooves, and each of the arc-shaped protrusions and each of the arc-shaped grooves extends along the circumference of the first fiber opening roller. The arc-shaped protrusions and the arc-shaped grooves are alternately arranged along the axial direction of the first fiber opening roller and connected end to end in sequence, so that the outer surface of the first fiber opening roller has a wavy structure. The outer surface of the second fiber-opening roller is provided with a plurality of protrusion structures, which are used to insert into the fiber bundle.

[0006] In some embodiments of this disclosure, multiple convex structures are spaced apart in multiple rows along the circumference of the second fiber opening roller. Each row of convex structures includes multiple convex structures that are spaced apart sequentially in the axial direction of the second fiber opening roller, and adjacent rows of convex structures are staggered in the axial direction of the second fiber opening roller.

[0007] In some embodiments of this disclosure, the first fiber-opening roller along the direction of travel of the fiber bundle is the first fiber-opening roller.

[0008] In some embodiments of this disclosure, the impregnation mechanism further includes: The container is provided with a yarn inlet and a yarn outlet for the fiber bundle to pass through. A temperature control component, the temperature control component being used to control the temperature inside the containment box; The vibration assembly includes vibration elements that correspond one-to-one with a plurality of first fiber-opening rollers and a plurality of second fiber-opening rollers.

[0009] In some embodiments of this disclosure, the molding mechanism includes: A hot press roller is used to heat-press and shape the fiber bundles having the impregnated material into a prepreg.

[0010] In some embodiments of this disclosure, the impregnating material is in powder form, and the prepreg preparation apparatus further includes: An oven is disposed between the impregnation mechanism and the forming mechanism, and the oven is used to melt the powdered impregnation material.

[0011] According to a second aspect of the present disclosure, a method for preparing a prepreg is provided, the method being applied to a prepreg preparation apparatus as described above, the method comprising: Control the unwinding frame to unwind the fiber bundles; The control yarn spreading mechanism spreads the unwound fiber bundles; The first fiber-opening roller of the impregnation mechanism disperses the broadened fiber bundle, the second fiber-opening roller of the impregnation mechanism flips the broadened fiber bundle, and the feeding assembly forms impregnation material on the fiber bundle passing through the first and second fiber-opening rollers. The forming mechanism is controlled to form the fiber bundles with impregnated material to obtain a prepreg.

[0012] In some embodiments of this disclosure, the method for preparing the prepreg further includes: The temperature control component of the impregnation mechanism adjusts the temperature inside the impregnation chamber, and the temperature range of the chamber is 100°C to 130°C. The vibrating element of the impregnation mechanism is controlled to vibrate each of the first and second fiber-opening rollers.

[0013] In some embodiments of this disclosure, the method for preparing the prepreg further includes: The oven is controlled to heat the fiber bundles containing the impregnated material at a preset temperature for a preset duration. The preset temperature is 10°C to 30°C higher than the melting point of the powdered impregnation material, and the preset duration is 30s to 60s.

[0014] The beneficial effects of this disclosure include, but are not limited to: the prepreg preparation apparatus provided by this disclosure is equipped with a composite fiber-opening assembly including a first fiber-opening roller and a second fiber-opening roller. After the fiber bundle is widened by the yarn-spreading mechanism, the first fiber-opening roller further disperses the widened fiber bundle, while the second fiber-opening roller simultaneously tumbles the widened fiber bundle to achieve deep fiber opening, increase the gap space between the fibers in the fiber bundle, and prevent agglomeration between the fibers. Thus, during the process of feeding the impregnation material onto the fiber bundle passing through the fiber-opening assembly via the feeding assembly, the impregnation material can be more evenly filled into the surface and internal gaps of the fiber bundle, avoiding the problem of impregnation material not being able to reach or penetrate due to fiber tufting or agglomeration. Furthermore, the prepreg prepared by this preparation device can not only improve its quality and mechanical properties, but also improve its flexibility by avoiding the use of impregnating materials. This facilitates the laying of the prepreg and avoids problems such as wrinkles and delamination caused by uneven distribution of impregnating materials during the laying process. As a result, it not only helps to improve the production yield of prepreg products, but also makes the prepreg suitable for laying on complex curved surfaces such as arcs and irregular shapes, thus improving the flexibility of the prepreg in use.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of these embodiments. In these drawings, similar reference numerals are used to denote similar elements. The drawings described below are some embodiments of the present disclosure, but not all embodiments. Other drawings will be readily available to those skilled in the art based on these drawings without inventive effort.

[0017] Figure 1This is a schematic diagram of a prepreg preparation apparatus according to an exemplary embodiment of the present disclosure; Figure 2 This is a top view of a fiber-opening assembly according to an exemplary embodiment of the present disclosure; Figure 3 This is a front view of a fiber-opening assembly according to an exemplary embodiment of this disclosure; Figure 4 A top view of a fiber-opening assembly, as shown in another exemplary embodiment of this disclosure; Figure 5 A schematic diagram of a prepreg preparation apparatus according to another exemplary embodiment of this disclosure; Figure 6 This is a schematic flowchart of a method for preparing a prepreg according to an exemplary embodiment of the present disclosure; Figure 7 This is a schematic flowchart of a method for preparing a prepreg according to another exemplary embodiment of the present disclosure; Figure 8 This is a schematic cross-sectional view of a prepreg, which is another exemplary embodiment of this disclosure. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of this disclosure will be clearly and completely described below in conjunction with the embodiments of this disclosure. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this disclosure can be arbitrarily combined with each other.

[0019] In related technologies, thermoplastic prepregs suffer from the following technical challenges during preparation: First, insufficient fiber opening. Existing fiber opening equipment often uses a single smooth roller or comb roller, which can only disperse the fiber bundles on the surface, making it difficult for the internal monofilaments to be turned out. This results in the resin only adhering to the fiber surface, and the internal "dry yarn" or resin accumulation phenomenon easily occurs, which seriously affects the mechanical properties of the prepreg. Second, poor uniformity of resin powder impregnation. During the powdering process, the powder is prone to agglomeration and cannot uniformly fill the fiber gaps, further aggravating the performance fluctuations of the prepreg. Third, insufficient flexibility of the prepreg. In order to pursue the interfacial bonding strength, traditional processes often adopt a design of continuous resin coating on fibers, resulting in high rigidity and poor bending performance of the prepreg. It is difficult to adapt to the stacking of complex curved surface products such as arcs and irregular shapes. Wrinkles and debonding are prone to occur during the laying process, increasing the production scrap rate.

[0020] Based on this, this disclosure provides a prepreg preparation apparatus, which includes a composite fiber-opening assembly comprising a first fiber-opening roller and a second fiber-opening roller. After the fiber bundle is broadened by the yarn-spreading mechanism, the first fiber-opening roller further disperses the broadened fiber bundle, while the second fiber-opening roller simultaneously tumbles the broadened fiber bundle to achieve deep fiber opening, increasing the gap space between the fibers and preventing agglomeration. Thus, during the process of feeding the impregnation material onto the fiber bundle passing through the fiber-opening assembly via the feeding assembly, the impregnation material can more evenly fill the surface and internal gaps of the fiber bundle, avoiding the problem of impregnation material failing to reach or penetrate due to fiber tufting or agglomeration. Furthermore, the prepreg prepared by this preparation device can not only improve its quality and mechanical properties, but also improve its flexibility by avoiding the use of impregnating materials. This facilitates the laying of the prepreg and avoids problems such as wrinkles and delamination caused by uneven distribution of impregnating materials during the laying process. As a result, it not only helps to improve the production yield of prepreg products, but also makes the prepreg suitable for laying on complex curved surfaces such as arcs and irregular shapes, thus improving the flexibility of the prepreg in use.

[0021] An exemplary embodiment of this disclosure provides an apparatus for preparing prepreg, such as... Figure 1 As shown, the preparation apparatus 100 includes a yarn unwinding frame 10, a yarn spreading mechanism 20, an impregnation mechanism 30, and a forming mechanism 40 arranged sequentially along the direction of fiber bundle travel.

[0022] The unwinding frame 10 is used to unwind the fiber bundle. Before the prepreg is prepared, the fiber roll is first installed on the unwinding frame 10. The fiber bundle is unwound and unwound by the unwinding frame 10. The unwinding speed can be adjusted according to the requirements of subsequent processes. For example, the unwinding speed can be adjusted from 0.5m / min to 2m / min. For example, the unwinding speed can be 0.5m / min, 1m / min or 2m / min. The unwinding speed can also be any value between the exemplary speeds. For example, the unwinding speed can be any value between 0.8m / min and 1.5m / min.

[0023] The yarn spreading mechanism 20 is used to spread the fiber bundle. Exemplarily, the yarn spreading mechanism 20 can be at least one set of spreading rollers, such as one, two, three, or four sets of spreading rollers. The rotation direction of the spreading rollers in the yarn spreading mechanism 20 is opposite to the travel direction of the fiber bundle to apply lateral tension to the fiber bundle, remove loose fibers from the surface of the fiber bundle, and achieve initial spreading of the fiber bundle, preventing the fiber bundle from agglomerating before entering the impregnation mechanism 30. The axial distance between two adjacent sets of spreading rollers can be 15cm to 25cm, which can ensure that the fiber bundle has stable tension and prevent the overhang section of the fiber bundle between adjacent sets of spreading rollers from being too long. For example, the axial distance between two adjacent sets of spreading rollers can be 15cm, 20cm, or 25cm, or it can be any value between the exemplary axial distances, such as any value between 18cm and 22cm. The spreading roller has a smooth surface and is coated with a wear-resistant coating, such as chromium nitride, which reduces frictional losses during the initial widening of the fiber bundle by the reverse rotation of the spreading roller. The spreading mechanism 20 applies a transverse tension of 5N to 20N to the fiber bundle. Within this range, the fiber bundle can be stretched and spread laterally, while avoiding excessive tension that could cause tensile damage. For example, the transverse tension applied by the spreading mechanism 20 to the fiber bundle can be 50N, 10N, or 20N. The transverse tension applied by the spreading mechanism 20 to the fiber bundle can also be any value between these exemplary tensions, such as any value between 8N and 15N.

[0024] The impregnation mechanism 30 is used to apply an impregnation material to the surface of the fiber bundle, so that the impregnation material fills the surface and gaps of the fiber bundle.

[0025] The forming mechanism 40 is used to form fiber bundles with impregnated material into prepreg. In the forming mechanism 40, the fiber bundles and the impregnated material are combined to obtain the prepreg. For example, the forming mechanism 40 can be two sets of upper and lower pressing hot rollers, which flatten and cure the prepreg by rolling. Alternatively, it can be a platform and a liftable flattening structure, which can also form the prepreg by pressing against the prepreg. Of course, the forming mechanism 40 can also be in other configurations, which will not be listed here.

[0026] Combination Figure 1 and Figure 2 As shown, the impregnation mechanism 30 includes a fiber opening assembly 31 and a feeding assembly (not shown in the figure), as... Figure 2 As shown, the fiber opening assembly 31 includes a plurality of first fiber opening rollers 311 and a plurality of second fiber opening rollers 312, which are alternately distributed along the direction of fiber bundle travel, for example... Figure 2The diagram shows a fiber opening assembly 31 comprising three first fiber opening rollers 311 and three second fiber opening rollers 312. Alternatively, the fiber opening assembly 31 may also comprise two first fiber opening rollers 311 and two second fiber opening rollers 312, or four first fiber opening rollers 311 and four second fiber opening rollers 312.

[0027] like Figure 3 As shown, the fiber bundles pass sequentially through each first fiber-opening roller 311 and each second fiber-opening roller 312. The first fiber-opening rollers 311 and 312 repeatedly mechanically open the fiber bundles. The first fiber-opening roller 311 is used to disperse the broadened fiber bundles, and the second fiber-opening roller 312 is used to tumble the broadened fiber bundles, so that the fiber bundles are deeply opened. It should be noted that the first fiber-opening roller along the direction of fiber bundle travel can be the first fiber-opening roller 311, that is, the order in which the fiber bundles pass through the fiber-opening rollers can be the first fiber-opening roller 311, the second fiber-opening roller 312, and so on. The first fiber-opening roller along the direction of fiber bundle travel can also be the second fiber-opening roller 312, that is, the order in which the fiber bundles pass through the fiber-opening rollers can be the second fiber-opening roller 312, the first fiber-opening roller 311, and so on. This ensures the continuity of the fiber bundle opening state and prevents the fiber bundle from agglomerating again after being opened by the previous opening roller and before reaching the next opening roller.

[0028] The axial spacing between adjacent fiber opening rollers is 8cm to 12cm. For example, the axial spacing between adjacent fiber opening rollers can be 8cm, 10cm or 12cm. The axial spacing between adjacent fiber opening rollers can also be any value between the exemplary axial spacings, such as any value between 9cm and 11cm.

[0029] The feeding assembly is used to apply impregnation material to the fiber bundle passing through the fiber opening assembly. The feeding assembly refers to the component that applies impregnation material to the fiber bundle. For example, the feeding assembly includes an impregnation material storage bin, a metering feeder, and multiple feeding nozzles symmetrically arranged on the upper and lower sides of the fiber bundle. Two feeding nozzles can be arranged directly above and two directly below each fiber opening roller, for a total of four nozzles on each fiber opening roller. The two feeding nozzles on each side can be positioned at one-quarter and three-quarters of the length of the fiber opening roller, respectively. If the fiber bundle width is large, six feeding nozzles can be arranged on each fiber opening roller, ensuring that the positions of the three feeding nozzles on each side are uniform relative to the length of the fiber opening roller. The distance between the feeding nozzle and the fiber bundle can be 10cm to 15cm. For example, the distance between the feeding nozzle and the fiber bundle can be 10cm, 12cm, or 15cm. The distance between the feeding nozzle and the fiber bundle can also be any value between these exemplary distances, such as any value between 11cm and 13cm. The feeding component can apply the impregnation material to the fiber bundle by spraying or coating. The feeding rate of the feeding component can be 5g / min to 30g / min. Within this range, excessive feeding can prevent the impregnation material from being unable to disperse in time, while insufficient feeding can prevent the prepreg from failing to meet the required resin content. For example, the feeding rate of the feeding component can be 5g / min, 15g / min, or 30g / min. The feeding rate of the feeding component can also be any value between these exemplary distances, such as any value between 10g / min and 20g / min.

[0030] For example, the rubber content of the prepreg can be from 10% to 40%, where rubber content is the mass ratio of the impregnating material in the prepreg. Within this rubber content range, the flexibility and rigidity of the prepreg can be balanced. For example, the rubber content of the prepreg can be 10%, 25%, or 40%, or any value between the exemplary rubber contents, such as any value between 20% and 30%.

[0031] The prepreg preparation apparatus provided in this embodiment is equipped with a composite fiber-opening assembly including a first fiber-opening roller 311 and a second fiber-opening roller 312. After the fiber bundle is widened by the yarn spreading mechanism, the first fiber-opening roller further disperses the widened fiber bundle, and at the same time, the second fiber-opening roller turns the widened fiber bundle over to achieve deep fiber opening, increase the gap space between the fibers in the fiber bundle, and avoid agglomeration between the fibers.

[0032] In this way, during the process of feeding the fiber bundle through the feeding component to apply the impregnation material, the impregnation material can be more evenly filled into the surface and internal gaps of the fiber bundle, achieving deep impregnation of the fiber bundle. For example, the uniformity of the impregnation material distribution in the cross section is increased to more than 90%, avoiding the problem that the impregnation material cannot reach or penetrate due to fiber bundle aggregation or agglomeration in the fiber bundle.

[0033] Furthermore, the prepreg prepared by this equipment not only improves its quality and mechanical properties, such as achieving an interlaminar shear strength of over 60 MPa, but also enhances its flexibility by avoiding the use of impregnating materials. For instance, the bending radius of the prepreg at room temperature can reach 5 to 10 times its thickness, facilitating its application and preventing problems such as wrinkles and delamination caused by uneven distribution of impregnating materials during the application process. This not only improves the production yield of prepreg products, reducing the scrap rate to below 5%, but also makes the prepreg suitable for complex curved surfaces such as arcs and irregular shapes, thus increasing the flexibility of its use.

[0034] Furthermore, the prepreg prepared by the preparation apparatus of this embodiment has an impregnation material that only fills the gaps in the fiber bundles rather than completely covers the fibers in the fiber bundles. This can ensure the interfacial bonding strength between the fibers and the impregnation material while giving the prepreg better flexibility.

[0035] For example, the fiber in the exemplary embodiments of this disclosure may be one or more mixed fibers selected from carbon fiber, glass fiber, and aramid fiber.

[0036] Exemplarily, the impregnation material in the exemplary embodiments of this disclosure includes a resin, such as at least one selected from polyphenylene sulfide, polyamide 6, and polyetheretherketone. The impregnation material can be a resin powder or a resin liquid. When the impregnation material is a resin powder, the particle size of the resin powder is between 5 μm and 20 μm. Within this particle size range, the resin powder can easily penetrate into the internal gaps of the fiber bundle without agglomeration due to excessively small particle size and strong van der Waals forces. For example, the particle size of the resin powder can be 5 μm, 10 μm, or 20 μm, or any value between the exemplary particle sizes, such as any value between 8 μm and 15 μm.

[0037] In one exemplary embodiment, such as Figure 2As shown, the outer surface of the first fiber opening roller 311 includes multiple arc-shaped protrusions 3121 and multiple arc-shaped grooves 3122, and each arc-shaped protrusion 3121 and each arc-shaped groove 3122 extends along the circumference of the first fiber opening roller 311. The arc-shaped protrusions 3121 and the arc-shaped grooves 3122 are alternately arranged along the axial direction of the first fiber opening roller 311 and connected end to end in sequence, so that the outer surface of the first fiber opening roller 311 has a wave-shaped structure.

[0038] The wavy structure on the outer surface of the first fiber-opening roller 311 can generate a lateral pulling force on the fiber bundle passing through the first fiber-opening roller 311, breaking up the broadened fiber bundle. By setting the first fiber-opening roller 311 in the above form, the structure of the first fiber-opening roller 311 is simple, making it easy to produce and process. At the same time, the arc-shaped protrusion structure 3121 and the arc-shaped groove structure 3122 can also improve the smoothness of the fiber bundle during passage, avoiding scratches, abrasions and other damage to the fiber bundle, thereby helping to further improve the quality of the prepreg.

[0039] For example, the protrusion height of the arc-shaped protrusion structure 3121 in the radial direction of the first fiber opening roller 311 can be from 2 mm to 4 mm. For example, the protrusion height of the arc-shaped protrusion structure 3121 in the radial direction of the first fiber opening roller 311 can be 2 mm, 3 mm or 4 mm. The protrusion height of the arc-shaped protrusion structure 3121 in the radial direction of the first fiber opening roller 311 can also be any value between the exemplary protrusion heights. For example, the protrusion height of the arc-shaped protrusion structure 3121 in the radial direction of the first fiber opening roller 311 can be any value between 2.5 mm and 4.5 mm. The length of the arc-shaped protrusion structure 3121 along the axial direction of the first fiber-opening roller 311 can be from 8 mm to 12 mm. For example, the length of the arc-shaped protrusion structure 3121 along the axial direction of the first fiber-opening roller 311 can be 8 mm, 10 mm, or 12 mm. The length of the arc-shaped protrusion structure 3121 along the axial direction of the first fiber-opening roller 311 can also be any value between the exemplary lengths, such as any value between 8.5 mm and 10.5 mm. By limiting the protrusion height of the arc-shaped protrusion structure 3121 and its length along the axial direction of the first fiber-opening roller 311 to the above ranges, it can be ensured that the crest of the wave-shaped structure can lift the fiber bundle to apply a lateral tensile force to it, thus breaking up the broadened fiber bundle. For example, the first fiber-opening roller 311 can be made of 304 stainless steel, which has high strength and strong corrosion resistance. The roughness Ra of the outer surface of the first fiber-opening roller 311 is ≤0.8μm, which can avoid the generation of fuzz due to excessive friction during the fiber bundle dispersal process, thus affecting the quality of the fiber bundle.

[0040] In one exemplary embodiment, such as Figure 2 As shown, the outer surface of the second fiber-opening roller 312 is provided with multiple protrusion structures 3111, which are used to insert into the fiber bundle. For example, the protrusion structure 3111 can be a conical structure with a sharp vertex. When the fiber bundle passes through the second fiber-opening roller 312, the protrusion structures 3111 on the outer surface of the second fiber-opening roller 312 insert into the fiber bundle, turning out the individual fiber filaments inside the fiber bundle, thus opening the fiber bundle and spreading it into a larger area. This allows the feeding component to more evenly distribute the impregnation material onto the fiber bundle, enabling the impregnation material to be dispersed on the surface and in the internal gaps of the fiber bundle. This design makes the structure of the second fiber-opening roller 312 simple and easy to produce and process.

[0041] In one exemplary embodiment, such as Figure 2 As shown, multiple convex structures 3111 are arranged in multiple rows circumferentially along the second fiber-opening roller 312. Each row of convex structures 3111 includes multiple convex structures 3111 arranged sequentially at intervals along the axial direction of the second fiber-opening roller 312, and adjacent rows of convex structures 3111 are staggered along the axial direction of the second fiber-opening roller 312. The staggered arrangement of adjacent rows of convex structures 3111, that is, the convex structure 3111 of the later row is located at the interval of the convex structure 3111 of the previous row, allows the convex structures 3111 to form an irregular gap network when inserted into the fiber bundle, ensuring the uniformity of fiber opening.

[0042] For example, the height of the protrusion structure 3111 on the outer surface of the second fiber opening roller 312 can be from 1.5 mm to 3 mm. For example, the height of the protrusion structure 3111 can be 1.5 mm, 2 mm or 3 mm. The height of the protrusion structure 3111 can also be any value between the exemplary heights. For example, the height of the protrusion structure 3111 can be any value between 1.8 mm and 2.5 mm.

[0043] The spacing between adjacent protrusion structures 3111 on the outer surface of the second fiber opening roller 312 can be, for example, 3mm to 5mm. For example, the spacing between adjacent protrusion structures 3111 can be 3mm, 4mm or 5mm. The spacing between adjacent protrusion structures 3111 can also be any value between the exemplary spacings. For example, the spacing between adjacent protrusion structures 3111 can be any value between 3.5mm and 4.5mm.

[0044] By setting the protrusion structure 3111 on the outer surface of the second fiber opening roller 312 within the above-mentioned height and spacing range, it can be ensured that the protrusion structure 3111 can penetrate the fiber bundle and form a sparse gap network to achieve the fiber opening effect.

[0045] Furthermore, the material of the raised dot structure 3111 on the outer surface of the second fiber-opening roller 312 can be the same as the material of the roller body, such as 304 stainless steel, which has high strength and strong corrosion resistance. The raised dot structure 3111 on the outer surface of the second fiber-opening roller 312 is integrally formed with the roller body, ensuring the connection strength between the raised dot structure 3111 and the roller body, thereby guaranteeing the service life and reliability of the second fiber-opening roller 312. Of course, the material of the raised dot structure 3111 can also be other materials; no specific limitation is made here, and it can be set according to actual needs.

[0046] In one exemplary embodiment, such as Figure 4 As shown, the first fiber-opening roller along the fiber bundle's travel direction 50 is the first fiber-opening roller 311, followed by the second fiber-opening roller 312, and so on. The wavy structure on the outer surface of the first fiber-opening roller 311 can generate a lateral pulling force on the fiber bundle passing through it, breaking up the broadened fiber bundle. The protruding structure 3111 on the outer surface of the second fiber-opening roller 312 inserts into the fiber bundle, turning over the internal fiber filaments, thus opening the fiber bundle and spreading it to a larger area. At the same time, it can expose the internal fiber filaments to the surface, thereby turning over the fiber bundle and allowing for deep fiber opening.

[0047] After the fiber bundle enters the spreading mechanism 20, it first passes through the first fiber-opening roller 311 with a wavy structure. The fiber bundle is dispersed into a plane with a relatively uniform width and thickness. The feeding components on the upper and lower sides of the fiber bundle apply impregnation material to the fiber bundle, which can be evenly distributed on the upper and lower surfaces of the fiber bundle. Subsequently, the fiber bundle covered with impregnation material passes through the second fiber-opening roller 312 with a protruding structure 3111. The protruding structure 3111 inserts into the interior of the fiber bundle, turning out the individual fiber filaments inside the fiber bundle, thereby turning the fiber bundle. As a result, the impregnation material covering the surface of the fiber bundle is stirred into the interior of the fiber bundle, thus achieving uniform dispersion and penetration of the impregnation material into the fiber bundle.

[0048] In one exemplary embodiment, the impregnation mechanism further includes a housing, a temperature control component, and a vibration assembly. Both the fiber opening assembly and the feeding assembly are disposed within the housing, which has an inlet and an outlet for the fiber bundles to pass through. The temperature control component controls the temperature within the housing. The vibration assembly includes vibrating elements corresponding one-to-one with a plurality of first fiber opening rollers and a plurality of second fiber opening rollers.

[0049] For example, the impregnation chamber can be a sealed impregnation cavity made of stainless steel. The fiber bundle enters the chamber through the yarn inlet and exits through the yarn outlet after impregnation to enter the downstream process. The fiber opening and feeding components are both located inside the chamber to open and feed the fiber bundles, which can avoid splashing of impregnation material and facilitate the collection of residual impregnation material in the device.

[0050] For example, the temperature control component includes a heating element and a temperature sensor. The temperature sensor monitors the temperature inside the container in real time. The heating element is evenly arranged on the inner wall of the container to ensure that the temperature of the impregnation mechanism is stable between 100°C and 130°C. Within this temperature range, the flowability of the impregnation material is enhanced, which is beneficial to the dispersion and penetration of the impregnation material on the surface and internal gaps of the fiber bundle. Within this temperature range, the sizing agent on the fiber surface softens and becomes sticky, which helps the fiber bundle disperse and open, and enhances the adhesion between the impregnation material and the fiber bundle.

[0051] In addition, heating tubes can also be installed inside the first and second fiber-opening rollers to control the temperature of the fiber-opening rollers, thereby controlling the temperature of the fiber bundle passing through the fiber-opening rollers to be stable between 100°C and 130°C.

[0052] The vibration assembly includes vibrating elements corresponding one-to-one with multiple first and second fiber-opening rollers. For example, each set of vibrating elements includes a vibration drive mechanism and a vibration generator. The vibrating elements can control the first and second fiber-opening rollers to vibrate synchronously at a vibration frequency of 50Hz to 200Hz, promoting the uniform filling of the gaps inside the fiber bundle by the impregnating material. For example, the vibration frequency of the first and second fiber-opening rollers can be 50Hz, 100Hz, or 200Hz, or any value between exemplary frequencies, such as any value between 100Hz and 150Hz. By vibrating the first and second fiber-opening rollers with each vibrating element, on the one hand, the dispersion of the fiber bundles passing through the first and second fiber-opening rollers can be improved under the action of vibration, achieving deep fiber opening of the fiber bundles. On the other hand, it can also allow the impregnating material to penetrate into the interior of the fiber bundles under the action of vibration, further improving the penetration effect of the impregnating material into the fiber bundles.

[0053] In one exemplary embodiment, the forming mechanism includes hot press rollers for hot-pressing and shaping fiber bundles with impregnated material into a prepreg. Exemplarily, the hot press rollers may be two sets of opposing hot rollers, the surfaces of which are coated with a Teflon coating to prevent the impregnated material from sticking together.

[0054] Hot rollers flatten and solidify the impregnated material on the fiber bundles through rolling pressure, while simultaneously performing compression shaping to ensure uniform prepreg thickness. The hot pressing temperature of the hot rollers is 0°C to 30°C higher than the glass transition temperature of the impregnated material. Within this temperature range, the impregnated material is neither as fluid as in a molten state nor does it retain excessive fluidity, thus maintaining a certain degree of flowability to fill the gaps between the fiber bundles and forming a dense prepreg. For example, the hot pressing temperature of the hot rollers can be comparable to, or 20°C or 30°C higher than, the glass transition temperature of the impregnated material. The difference between the hot pressing temperature of the hot rollers and the glass transition temperature of the impregnated material can also be any of the exemplary temperature differences, such as any value between 5°C and 25°C higher than the glass transition temperature of the impregnated material. The compression pressure between the upper and lower hot rollers is 0.5MPa to 2MPa, ensuring uniform prepreg thickness, such as a thickness deviation of ≤±0.05mm. For example, the pressure between the upper and lower hot rollers can be 0.5MPa, 1MPa or 2MPa, and the pressure between the upper and lower hot rollers can also be any value between the exemplary pressures, such as any value between 1MPa and 1.8MPa.

[0055] In an exemplary embodiment, the prepreg preparation apparatus further includes a winding mechanism for winding the prepreg after hot pressing and shaping by the forming mechanism to obtain a flexible thermoplastic prepreg. The winding speed of the winding mechanism is matched with the unwinding speed of the unwinding creel. The tension applied to the prepreg by the winding mechanism can be from 5N to 20N. Within this tension range, sufficient tension can be ensured to allow the prepreg to be tightly and neatly wound on the winding core, and to prevent the prepreg from stretching and deforming during the winding process. For example, the tension applied to the prepreg by the winding mechanism can be 5N, 10N, or 20N, or any value between the exemplary tensions, such as any value between 10N and 15N.

[0056] In one exemplary embodiment, the impregnating material is in powder form, such as... Figure 5As shown, the prepreg preparation apparatus 100 also includes an oven 60, which is disposed between the impregnation mechanism 30 and the forming mechanism 40. The oven 60 is used to melt the powdered impregnation material. For example, multiple sets of heating plates and a hot air circulation system can be uniformly arranged inside the oven 60. The temperature of the heating plates is adjustable to ensure that the temperature inside the oven is stably 10°C to 30°C higher than the melting point of the impregnation material. The fiber bundles with the impregnation material stay in the oven for 30s to 60s. Within this temperature range and residence time range, the powdered impregnation material on the fiber bundles can be fully melted, uniformly impregnating the gaps between the fiber bundles. For example, the stable temperature inside the oven can be 10°C, 20°C, or 30°C higher than the melting point of the impregnation material. The difference between the temperature inside the oven and the melting point of the impregnation material can also be any value between exemplary temperature differences, such as any value between 15°C and 25°C higher than the melting point of the impregnation material. For example, the residence time of the fiber bundle with impregnated material in the oven can be 30s, 50°C or 60s. The residence time of the fiber bundle with impregnated material in the oven can also be any value between the exemplary durations, such as any value between 40s and 50s.

[0057] An exemplary embodiment of this disclosure provides a method for preparing a prepreg, which is applied to the prepreg preparation apparatus described above, i.e., the prepreg preparation apparatus described above uses the preparation method of this embodiment to prepare the prepreg.

[0058] Combination Figure 1 and Figure 6 As shown, the preparation method includes the following steps: S100, control the unwinding frame to unwind the fiber bundle.

[0059] In this step, the unwinding frame 10 is controlled to unwind the fiber bundle at an unwinding speed of 0.5 m / min to 2 m / min. For example, the unwinding speed can be 0.5 m / min, 1 m / min or 2 m / min. The unwinding speed can also be any value between the exemplary speeds, for example, any value between 0.8 m / min and 1.5 m / min.

[0060] S200, the control yarn spreading mechanism spreads the unwound fiber bundles.

[0061] In this step, the yarn spreading mechanism 20 can be at least one set of yarn spreading rollers. The rotation direction of the yarn spreading rollers in the yarn spreading mechanism 20 is controlled to be opposite to the direction of travel of the fiber bundle, so as to apply transverse tension to the fiber bundle, remove loose fibers on the surface of the fiber bundle, and achieve the initial widening of the fiber bundle, so as to avoid the fiber bundle from agglomerating before entering the impregnation mechanism 30.

[0062] S300, the first fiber-opening roller of the impregnation mechanism disperses the broadened fiber bundle, the second fiber-opening roller of the impregnation mechanism flips the broadened fiber bundle, and the feeding assembly forms impregnation material on the fiber bundle passing through the first and second fiber-opening rollers.

[0063] In this step, the broadened fiber bundle enters the impregnation mechanism 30. The first fiber-opening roller 311 of the impregnation mechanism 30 is controlled to disperse the broadened fiber bundle. Specifically, the wavy structure on the outer surface of the first fiber-opening roller 311 is controlled to create a lateral pulling force on the fiber bundle passing through the first fiber-opening roller 311, thus dispersing the broadened fiber bundle. At the same time, the protrusion structure 3111 on the outer surface of the second fiber-opening roller 312 is controlled to insert into the interior of the fiber bundle, turning out the individual fiber filaments inside the fiber bundle, thereby opening the fiber bundle and spreading it out to a larger area. While controlling the first fiber-opening roller 311 to disperse the fiber bundle and controlling the second fiber-opening roller 312 to turn the fiber bundle, the feeding component is controlled to form an impregnation material on the fiber bundle passing through the first fiber-opening roller 311 and the second fiber-opening roller 312. The impregnation material can be evenly dispersed on the surface and in the internal gaps of the opened fiber bundle.

[0064] S400: The forming mechanism controls the forming process of fiber bundles with impregnated material to obtain prepreg.

[0065] In this step, the forming mechanism 40 can be, for example, two sets of opposing hot rollers. By controlling the opposing hot rollers, the fiber bundles with impregnated material are flattened and cured through roller pressing to obtain the prepreg.

[0066] The prepreg preparation method provided in this embodiment achieves deep fiber opening by controlling the dual fiber opening of the fiber bundle by the first fiber opening roller 311 and the second fiber opening roller 312. This disperses and tumbles the fiber bundle during its passage, thereby increasing the gap space within the fiber bundle and preventing agglomeration between the fibers. During the dispersion and tumbling of the fiber bundle, the feeding component is controlled to apply impregnation material to the fiber bundle. The impregnation material can more evenly fill the surface and internal gaps of the fiber bundle, achieving deep impregnation of the fiber bundle and avoiding the problem of impregnation material not reaching or penetrating due to fiber clumping or agglomeration. Furthermore, the prepreg prepared by this method not only improves its quality and mechanical properties, but also enhances its flexibility by avoiding the use of impregnating materials. This facilitates the laying of the prepreg and avoids problems such as wrinkles and delamination caused by uneven distribution of impregnating materials during the laying process. As a result, it not only improves the production yield of prepreg products, but also makes the prepreg suitable for laying on complex curved surfaces such as arcs and irregular shapes, thus improving the flexibility of the prepreg in use.

[0067] In one exemplary embodiment, such as Figure 7 As shown, the preparation method of prepreg also includes the following steps: S310. The temperature control component of the impregnation mechanism adjusts the temperature inside the impregnation chamber, with the temperature range of the chamber being 100°C to 130°C.

[0068] In this step, for example, the temperature control component includes heating tubes and temperature sensors uniformly arranged on the inner wall of the container. The temperature sensor monitors the temperature inside the container in real time, and the heating tubes operate according to the temperature monitored by the temperature sensor, ensuring that the temperature of the impregnation mechanism is stable between 100°C and 130°C. Within this temperature range, the flowability of the impregnation material is enhanced, which is beneficial for the dispersion and penetration of the impregnation material on the surface and internal gaps of the fiber bundle. Furthermore, within this temperature range, the sizing agent on the fiber surface softens and becomes sticky, assisting in the dispersion and opening of the fiber bundle and enhancing the adhesion between the impregnation material and the fiber bundle. For example, when the temperature inside the container monitored by the temperature sensor gradually decreases and approaches 100°C, the heating tubes are controlled to start working or increase their power to heat the container; when the temperature inside the container monitored by the temperature sensor gradually increases and approaches 130°C, the heating tubes are controlled to stop working or decrease their power to stop or slow down the heating of the container.

[0069] S320, The vibrating component of the control impregnation mechanism vibrates each of the first and second fiber-opening rollers.

[0070] In this step, each set of vibrating components may include, for example, a vibration drive mechanism and a vibration generator, which control the vibrating components to synchronously vibrate the first and second fiber opening rollers at a vibration frequency of 50Hz to 200Hz, thereby promoting the uniform filling of the internal gaps of the fiber bundle by the impregnating material.

[0071] The prepreg preparation method in this embodiment, the temperature control component adjusting the temperature inside the container, and the vibration component controlling the vibration of each first and second fiber-opening roller, can all promote the dispersion and filling of the impregnating material on the surface and internal gaps of the fiber bundle.

[0072] It should be noted that steps S310 and S320 are not sequential; they are performed simultaneously. That is, controlling the temperature control component of the impregnation mechanism to adjust the temperature inside the impregnation mechanism's container, and controlling the vibration component of the impregnation mechanism to vibrate each of the first and second fiber-opening rollers are performed at the same time.

[0073] In one exemplary embodiment, the method for preparing the prepreg further includes the following steps: The oven is controlled to heat the fiber bundles with impregnated material at a preset temperature for a preset duration. The preset temperature is 10°C to 30°C higher than the melting point of the powdered impregnated material, and the preset duration is 30s to 60s.

[0074] When the impregnating material is in powder form, before the fiber bundles containing the impregnating material enter the forming mechanism, the oven is controlled to heat the fiber bundles containing the impregnating material at a temperature 10°C to 30°C higher than the melting point of the powdered impregnating material, and this heating is continued for 30 to 60 seconds. Within this preset temperature and duration range, the powdered impregnating material on the fiber bundles can be fully melted, uniformly impregnating the gaps between the fiber bundles. For example, the oven is controlled to heat the fiber bundles containing the impregnating material at a preset temperature of 10°C, 20°C, or 30°C higher than the melting point of the powdered impregnating material. For example, the preset duration of the oven heating the fiber bundles containing the impregnating material at the preset temperature can be 30 seconds, 50 seconds, or 60 seconds. The preset duration of the oven heating the fiber bundles containing the impregnating material at the preset temperature can also be any value between the exemplary durations, such as any value between 40 seconds and 50 seconds.

[0075] The prepreg preparation apparatus provided in this exemplary embodiment allows for parameter adjustment of each component, thereby enabling adaptation to different types of fibers and impregnation materials. Furthermore, the continuous operation of the production process improves the prepreg preparation efficiency, achieving a production speed of 0.5 m / min to 2 m / min, representing an efficiency increase of over 30% compared to traditional intermittent processes. Simultaneously, the parameters of each process are precisely controlled through automation, resulting in minimal fluctuations in prepreg performance and excellent batch stability.

[0076] The prepreg preparation apparatus and method provided in the exemplary embodiments of this disclosure can be used for complex structural components in the aerospace field (such as satellite brackets and aircraft window frames), battery pack housings in the new energy vehicle field, and interior parts in the rail transit field. They are particularly suitable for scenarios with high requirements for the flexibility and layability of prepregs, thus expanding the application range of thermoplastic prepregs.

[0077] To more clearly explain the technical solutions provided by the exemplary embodiments of this disclosure, in conjunction with... Figure 2 and Figure 5 As shown, two examples of preparing prepregs using the prepreg preparation apparatus and method disclosed herein are presented.

[0078] Example 1 A flexible thermoplastic prepreg with a resin content of 30% was prepared using T700 grade carbon fiber (12K) as the reinforcing fiber and polyphenylene sulfide powder (melting point 280℃, glass transition temperature 100℃, particle size 10-15μm) as the impregnating material, as detailed below: The T700 grade carbon fiber roll is installed on the unwinding frame 10, and the unwinding speed is set to 1m / min. The unwinding frame 10 is controlled to unwind the fiber bundle.

[0079] The fiber bundle enters the spreading mechanism 20. The center distance between the two sets of spreading rollers is 20cm, and the reverse rotation speed is 1.2m / min. The spreading mechanism 20 is controlled to spread the unwound fiber bundle and apply a 10N transverse tension to the fiber bundle to achieve initial spreading.

[0080] The temperature control component of the impregnation mechanism 30 adjusts the temperature inside the impregnation chamber, with a temperature range of 120℃. The vibration component of the impregnation mechanism vibrates each of the first and second fiber-opening rollers at a frequency of 100Hz. The first fiber-opening roller 311 (with an arc-shaped protrusion structure 3121 having a radial protrusion height of 3mm and an axial length of 10mm along the first fiber-opening roller 311) of the impregnation mechanism 30 disperses the broadened fiber bundles. The second fiber-opening roller 312 (with a protrusion height of 2mm and a spacing of 4mm) of the impregnation mechanism tumbles the broadened fiber bundles. The feeding component forms polyphenylene sulfide powder onto the fiber bundles passing through the first and second fiber-opening rollers 311 and 312. The feeding rate of the feeding component is 15g / min, and the distance between the feeding nozzle and the fiber bundle is 12cm.

[0081] The fiber bundle containing polyphenylene sulfide powder is heated in oven 60 at 300℃ (20℃ higher than the melting point of polyphenylene sulfide). The fiber bundle stays in oven 60 for 45 seconds, and the polyphenylene sulfide powder is fully melted.

[0082] The temperature of the hot roller in the forming mechanism 40 is set to 120°C (20°C higher than the glass transition temperature of polyphenylene sulfide powder), and the pressure is set to 1MPa. The forming mechanism 40 is controlled to form the fiber bundle containing polyphenylene sulfide powder to obtain prepreg.

[0083] The tension of the winding mechanism is set to 10N and the winding speed is 1m / min. The winding mechanism is controlled to wind the prepreg, and finally a flexible thermoplastic prepreg with a thickness of 0.2mm is obtained.

[0084] Performance tests were conducted on the prepreg: its room temperature bending radius was 1.5 mm (7.5 times its thickness), interlaminar shear strength was 85 MPa, resin distribution uniformity was 92%, and when laid on an arc-shaped mold (10 mm radius of curvature), it showed no wrinkles or delamination, demonstrating excellent laying performance. Figure 8 The cross-sectional view of the prepreg 80 shown shows the discontinuous distribution of resin (polyphenylene sulfide powder) 81 inside the fiber bundle 82. That is, the resin 81 fills the gaps between the fiber bundle 82 rather than completely covers it. This can ensure the interfacial bonding strength between the fiber and the resin 81 while giving the prepreg 80 excellent flexibility.

[0085] Example 2 A flexible thermoplastic prepreg with a resin content of 25% was prepared using glass fiber (2400 tex) as the reinforcing fiber and polyamide 6 resin powder (melting point 220℃, glass transition temperature 50℃, particle size 5-10 μm) as the impregnating material, as detailed below: The fiberglass roll is installed on the unwinding frame 10, and the unwinding speed is set to 1.5 m / min. The unwinding frame 10 is controlled to unwind the fiber bundle.

[0086] The fiber bundle enters the spreading mechanism 20. The center distance between the two sets of spreading rollers is 25cm, and the reverse rotation speed is 1.8m / min. The spreading mechanism 20 is controlled to spread the unwound fiber bundle and apply a lateral tension of 15N to the fiber bundle to achieve initial spreading.

[0087] The temperature control component of the impregnation mechanism 30 adjusts the temperature inside the impregnation chamber, with a temperature range of 110°C. The vibration component of the impregnation mechanism is controlled to vibrate each of the first fiber-opening rollers 311 and each of the second fiber-opening rollers 312 at a frequency of 150Hz. The first fiber-opening roller 311 of the impregnation mechanism 30 (with an arc-shaped protrusion structure 3121 having a radial protrusion height of 2mm and an axial length of 8mm along the first fiber-opening roller 311) is controlled to disperse the broadened fiber bundles, and the second fiber-opening roller 312 of the impregnation mechanism (with a protrusion height of 1.5mm and a spacing of 3mm) is controlled to tumble the broadened fiber bundles. The feeding component is also controlled to form polyamide 6 powder on the fiber bundles passing through the first and second fiber-opening rollers 311 and 312. The feeding component has a feeding rate of 20g / min and a distance of 10cm between the feeding nozzle and the fiber bundle.

[0088] The fiber bundle containing polyamide 6 powder is heated in oven 60 at 240℃ (20℃ higher than the melting point of polyamide 6). The fiber bundle stays in oven 60 for 30 seconds, and the polyamide 6 powder is fully melted.

[0089] The temperature of the hot roller in the molding mechanism 40 is set to 65°C (15°C higher than the glass transition temperature of polyamide 6), and the pressure is set to 1.5 MPa. The molding mechanism 40 is controlled to mold the fiber bundle containing polyamide 6 powder to obtain prepreg.

[0090] The tension of the winding mechanism is set to 15N and the winding speed is 1.5m / min. The winding mechanism is controlled to wind the prepreg, and finally a flexible thermoplastic prepreg with a thickness of 0.3mm is obtained.

[0091] The performance of the prepreg was tested: the bending radius at room temperature was 2mm (6.7 times the thickness), the tensile strength was 650MPa, the resin distribution uniformity was 90%, and when laid on irregular molds (including R2mm corners), there was no exposed white or missing material at the corners, indicating good fit.

[0092] The above-described contents can be implemented individually or in various combinations, and all such variations are within the scope of this disclosure.

[0093] Finally, it should be noted that in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0094] The above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure.

Claims

1. An apparatus for preparing prepreg, characterized in that, The preparation apparatus includes a yarn unwinding frame, a yarn spreading mechanism, an impregnation mechanism, and a forming mechanism arranged sequentially along the travel direction of the fiber bundle. The yarn unwinding frame is used to unwind the fiber bundle, the yarn spreading mechanism is used to spread the fiber bundle, the impregnation mechanism is used to apply an impregnation material to the surface of the fiber bundle, and the forming mechanism is used to form the fiber bundle with the impregnation material into a prepreg. The impregnation mechanism includes: The fiber opening assembly includes a plurality of first fiber opening rollers and a plurality of second fiber opening rollers. The first fiber opening rollers and the second fiber opening rollers are alternately distributed along the traveling direction of the fiber bundle. The fiber bundle passes through each of the first fiber opening rollers and each of the second fiber opening rollers in sequence. The first fiber opening rollers are used to break up the broadened fiber bundles, and the second fiber opening rollers are used to turn over the broadened fiber bundles. A feeding assembly is used to apply the impregnation material to the fiber bundle passing through the fiber opening assembly.

2. The prepreg preparation apparatus according to claim 1, characterized in that, The outer surface of the first fiber opening roller includes multiple arc-shaped protrusions and multiple arc-shaped grooves. Each arc-shaped protrusion and each arc-shaped groove extends along the circumference of the first fiber opening roller. The arc-shaped protrusions and the arc-shaped grooves are alternately arranged along the axial direction of the first fiber opening roller and connected end to end in sequence, so that the outer surface of the first fiber opening roller has a wavy structure. The outer surface of the second fiber-opening roller is provided with a plurality of protrusion structures, which are used to insert into the fiber bundle.

3. The prepreg preparation apparatus according to claim 2, characterized in that, Multiple convex structures are spaced apart in multiple rows along the circumference of the second fiber opening roller. Each row of convex structures includes multiple convex structures that are spaced apart in sequence along the axial direction of the second fiber opening roller, and adjacent rows of convex structures are staggered in the axial direction of the second fiber opening roller.

4. The prepreg preparation apparatus according to claim 2, characterized in that, The first fiber-opening roller along the direction of travel of the fiber bundle is the first fiber-opening roller.

5. The prepreg preparation apparatus according to claim 1, characterized in that, The impregnation mechanism also includes: The container is provided with a yarn inlet and a yarn outlet for the fiber bundle to pass through. A temperature control component, the temperature control component being used to control the temperature inside the containment box; The vibration assembly includes vibration elements that correspond one-to-one with a plurality of first fiber-opening rollers and a plurality of second fiber-opening rollers.

6. The prepreg preparation apparatus according to claim 1, characterized in that, The molding mechanism includes: A hot press roller is used to heat-press and shape the fiber bundles having the impregnated material into a prepreg.

7. The apparatus for preparing prepreg according to any one of claims 1 to 6, characterized in that, The impregnation material is in powder form, and the prepreg preparation apparatus further includes: An oven is disposed between the impregnation mechanism and the forming mechanism, and the oven is used to melt the powdered impregnation material.

8. A method for preparing a prepreg, characterized in that, The preparation method is applied to the prepreg preparation apparatus according to any one of claims 1 to 7, the preparation method comprising: Control the unwinding frame to unwind the fiber bundles; The control yarn spreading mechanism spreads the unwound fiber bundles; The first fiber-opening roller of the impregnation mechanism disperses the broadened fiber bundle, the second fiber-opening roller of the impregnation mechanism flips the broadened fiber bundle, and the feeding assembly forms impregnation material on the fiber bundle passing through the first and second fiber-opening rollers. The forming mechanism is controlled to form the fiber bundles with impregnated material to obtain a prepreg.

9. The method for preparing the prepreg according to claim 8, characterized in that, The method for preparing the prepreg further includes: The temperature control component of the impregnation mechanism adjusts the temperature inside the impregnation chamber, and the temperature range of the chamber is 100°C to 130°C. The vibrating element of the impregnation mechanism is controlled to vibrate each of the first and second fiber-opening rollers.

10. The method for preparing the prepreg according to claim 8, characterized in that, The method for preparing the prepreg further includes: The oven is controlled to heat the fiber bundles containing the impregnated material at a preset temperature for a preset duration. The preset temperature is 10°C to 30°C higher than the melting point of the powdered impregnation material, and the preset duration is 30s to 60s.

Images