Preparation method of fiber reinforced composite material profile with flanging structure

Abstract

The invention relates to the technical field of fiber reinforced composite material special-shaped profiles, in particular to a preparation method of a fiber reinforced composite material profile with a flanging structure. The method comprises the following steps: a) providing a laminated board which is obtained by carrying out mould pressing on a prepreg obtained by processing a plurality of layers of fiber materials through thermoplastic resin, and cutting a part, which needs to be flanged, of the laminated board to form a gap so as to form a plurality of petal-shaped structures and a central structure surrounded by the petal-shaped structures; b) providing a profile mold cavity of which the inner surface is pre-coated with a release agent, wherein the profile mold cavity comprises a lower mold concave table and an upper mold convex table which can be sleeved in the lower mold concave table; the laminated board is placed in the profile die cavity without being preheated, the upper surface of the center structure makes contact with the upper die boss, and the lower surfaces of the petal-shaped structures make contact with the lower die concave table; heating the profile die cavity to soften the laminated board and carrying out die pressing; and c) cooling and demolding to obtain the profile.

Description

Technical Field

[0001] The present invention relates to the technical field of fiber-reinforced composite material special-shaped profiles, and in particular to a method for preparing a fiber-reinforced composite material profile with a flanging structure. Background Art

[0002] Carbon fiber prepregs are widely used in many fields such as fishing tackle, sports equipment, sporting goods, aerospace and transportation vehicles. Especially in the context of the increasing demand for lightweighting in the aviation industry, its application range continues to expand. Carbon fiber prepregs are intermediate materials formed by impregnating carbon fibers with resins. They are environmentally friendly, have stable resin content, high surface quality and simple process. Prepregs can be formed into composite products through autoclaves, vacuum-assisted or molding processes, among which the production efficiency of prepreg molding processes is particularly outstanding. For simple thermoplastic profiles, such as flat plates, the molding method has become increasingly mature, but for some complex three-dimensional structure profiles such as profiles with flanging structures, the molding process has problems such as difficult molding and difficult quality control. Therefore, a new molding method is needed to complete the molding of complex structural profiles. Summary of the Invention

[0003] The present invention relates to the following technical solutions:

[0004] A method for preparing a fiber-reinforced composite material profile with a flanging structure, comprising:

[0005] a) providing a laminated board formed by molding multiple layers of fiber material prepreg treated with thermoplastic resin, and cutting out notches in portions of the laminated board to be flanged to form a plurality of petal-like structures and a central structure surrounded by the petal-like structures;

[0006] b) providing a profile mold cavity with an inner surface of the mold cavity pre-coated with a release agent, the profile mold cavity comprising a lower mold concave platform and an upper mold protrusion capable of being sleeved within the lower mold concave platform;

[0007] The laminate is placed in the profile mold cavity without preheating, with the upper surface of the central structure in contact with the upper mold protrusion and the lower surfaces of the petal-shaped structures in contact with the lower mold concave platform;

[0008] heating the profile mold cavity to soften and mold the laminate;

[0009] c) cooling and demoulding to obtain the profile.

[0010] The inventor unexpectedly discovered that this method can effectively improve various parameters of the obtained special-shaped profiles, thereby achieving better yield and performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 A schematic diagram of a laminate structure with a petal-like structure provided by one embodiment of the present invention.

[0013] Figure 2 This is a schematic diagram of the laminate structure with a petal-shaped structure provided in Example 1 of the present invention.

[0014] Figure 3 This is a schematic diagram of the laminate structure with a petal-like structure provided in Example 4 of the present invention. DETAILED DESCRIPTION

[0015] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are described below. Each example is provided to illustrate, not to limit, the present invention. Indeed, it will be apparent to those skilled in the art that various modifications and variations may be made to the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment may be used in another embodiment to produce further embodiments.

[0016] Unless otherwise indicated, all terms (including technical and scientific terms) used to disclose the present invention have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. By way of further guidance, the following definitions are provided to better understand the teachings of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0017] In the present invention, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art.

[0018] The terms "and / or", "or / and", and "and / or" used herein include any one of two or more related listed items, and also include any and all combinations of the related listed items, wherein the any and all combinations include any combination of two related listed items, any more related listed items, or all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or", "or / and", and "and / or", it should be understood that in the present invention, the technical solution undoubtedly includes technical solutions connected by "logical and" and also undoubtedly includes technical solutions connected by "logical or". For example, "A and / or B" includes three parallel solutions of A, B and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, the technical solution of all being connected by "logical OR"), and also includes any and all combinations of A, B, C, and D, that is, the combination of any two or any three of A, B, C, and D, and also includes the four-item combination of A, B, C, and D (that is, the technical solution of all being connected by "logical AND").

[0019] As used herein, the terms "comprising," "including," and "comprising" are synonymous and are inclusive or open-ended and do not exclude additional, unrecited members, elements, or method steps.

[0020] The recitation of numerical ranges herein by endpoints includes all numbers and fractions subsumed within the range, as well as the recited endpoints.

[0021] The term "about" or "approximately" used in the present invention means within 20% of a given value or range, preferably within 10%, more preferably within 5%. It also includes specific numbers, for example, about 20 includes 20.

[0022] In addition, when describing representative embodiments of the present invention, this specification may present the method and / or process of the present invention as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of steps set forth herein, the method or process should not be limited to the specific order of steps described. As one of ordinary skill in the art will appreciate, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be interpreted as limiting the claims. In addition, claims to the method and / or process of the present invention should not be limited to the execution of the steps in the order in which they are written, and those skilled in the art will readily recognize that the sequence can be changed and still remain within the spirit and scope of the present invention.

[0023] As used herein, the singular articles "a," "an," and "the" include plural referents unless otherwise indicated.

[0024] In the present invention, descriptions such as "plurality" and "multiple" refer to quantities greater than or equal to 2 unless otherwise specified.

[0025] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0026] In the present invention, "preferably", "better", "more preferably", and "suitably" are merely descriptions of preferred implementation methods or examples, and should be understood to not limit the scope of protection of the present invention. In the present invention, "optionally", "optional", and "optional" refer to being optional, that is, to being selected from either of the two parallel options of "with" or "without". If multiple "options" appear in a technical solution, unless otherwise specified and without contradiction or mutual restriction, each "optional" is independent.

[0027] The present invention relates to a method for preparing a fiber-reinforced composite material profile with a flanging structure, comprising:

[0028] a) providing a laminated board formed by molding multiple layers of fiber material prepreg treated with thermoplastic resin, and cutting out notches in portions of the laminated board to be flanged to form a plurality of petal-like structures and a central structure surrounded by the petal-like structures;

[0029] b) providing a profile mold cavity with an inner surface of the mold cavity pre-coated with a release agent, the profile mold cavity comprising a lower mold concave platform and an upper mold protrusion capable of being sleeved within the lower mold concave platform;

[0030] The laminate is placed in the profile mold cavity without preheating, with the upper surface of the central structure in contact with the upper mold protrusion and the lower surfaces of the petal-shaped structures in contact with the lower mold concave platform;

[0031] heating the profile mold cavity to soften and mold the laminate;

[0032] c) cooling and demoulding to obtain the profile.

[0033] The present invention processes the laminate into a special-shaped shape with a petal-like structure, and uses a mold to mold the petal-like structures on all sides into a flange structure; preferably, the flange structure is substantially perpendicular to the central structure. The laminate preheating process does not adopt the traditional heating table preheating method. The laminate is preheated by the upper and lower molds of the mold, that is, the central structure of the laminate is in contact with the upper mold of the mold, and the petal-like structure is in contact with the lower mold of the mold. The laminate is heated together with the mold, and the mold is closed and molded when the temperature reaches above the melting point of the resin. This solution preheats in the mold, eliminating the step of using a heating table for preheating, and avoids the problem of the laminate suddenly cooling during the transfer process after preheating, causing the system to harden. More importantly, the inventor unexpectedly discovered that this method can effectively improve the various parameters of the obtained special-shaped profile, and obtain better yield and performance.

[0034] The mold used in the present invention is more advantageous in that the upper surface of the central structure is in complete contact and fit with the upper mold boss, and the lower surface of the petal-shaped structure is in complete contact and fit with the lower mold concave; this can achieve as uniform heating as possible.

[0035] The cross-sectional shape of the petal-like structure is a triangle (simple shape, easy to cut and fold), a trapezoid (increases the edge coverage area after folding), a semicircle or a semi-ellipse (suitable for flexible flanging, enhancing fit), a polygon or an irregular shape such as a petal. Those skilled in the art can choose according to the purpose of the flanging. The number of the petal-like structures can be set to 3 to 20 petals, or more (such as 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16 or 18 petals) according to actual needs, preferably arranged symmetrically so that an edge around the central structure is uniformly formed after folding. More advantageously, the petal-like structures have the same shape; further, the petal-like structures are evenly distributed around the central structure, and the notch depth is consistent, so that the petal-like structures can be evenly closed after molding; more preferably, the petal-like structures are seamlessly spliced ​​after molding.

[0036] In some embodiments, the thickness of the laminate is 100% to 110% of the depth of the profile mold cavity; for example, 101%, 102%, 103%, 104%, 105%, 106%, 107%, 108%, or 109%. The present invention has found that when the thickness difference is within 10%, the internal quality of the profile gradually improves as the thickness difference increases. However, when the thickness difference exceeds 10%, the profile is prone to poor appearance due to factors such as excessive extrusion of prepreg.

[0037] In some embodiments, the laminate has a thickness of 1.8 mm to 2.2 mm, for example, 1.9 mm, 2.0 mm, or 2.1 mm.

[0038] In some embodiments, when the laminate is softened, the temperature of the concave portion of the lower mold is 8°C to 12°C higher than that of the convex portion of the upper mold, for example, 9°C, 10°C, or 11°C. The present invention unexpectedly discovered that within the aforementioned temperature difference range between the upper and lower molds, as the temperature difference increases, the appearance of the profile gradually improves, but when the temperature difference exceeds the aforementioned temperature difference range, the surface quality of the profile deteriorates.

[0039] In some embodiments, the temperature of the upper mold boss is 385°C to 395°C, for example, 387°C, 390°C, or 393°C.

[0040] In some embodiments, the temperature during the molding in step b) is 310°C to 330°C, such as 315°C, 320°C, or 325°C.

[0041] In some embodiments, the number of layers of the prepreg is ≥12 layers, preferably ≥14 layers, for example 15, 16, 17, 18, 19, or 20 layers.

[0042] In some embodiments, the laminate is molded at a temperature of 380°C to 400°C (e.g., 385°C, 390°C, 395°C), the temperature of the lower mold concave platform and the upper mold convex platform are consistent during mold closing, and is naturally cooled to 20°C to 40°C (e.g., 25°C, 30°C, 35°C) after mold closing.

[0043] In some embodiments, in step c), demolding is completed by naturally cooling to 20°C to 40°C (eg, 25°C, 30°C, 35°C).

[0044] In some embodiments, the central structure is circular, elliptical, or polygonal, such as a triangle, quadrilateral, pentagon, hexagon, heptagon, octagon, nonagon, or decagon; preferably, the polygon is a regular polygon.

[0045] In the present invention, "fibrous material" refers to an aggregate of fibers. Before it is pre-impregnated and formed, it takes the form of strands. After forming and impregnation (particularly impregnation into the core), it has the form of a layer. When the reinforcing fibers are continuous, their aggregate can constitute a fabric or a non-woven fabric (NCF). When the fibers are short, their aggregate can constitute a felt or a fiber mat. In some embodiments, the fibrous material comprises one or more of fibers, organic fibers or plant fibers; preferably, mineral fibers include one or more of carbon fibers, glass fibers, basalt fibers, silica fibers and silicon carbide fibers; preferably, organic fibers include fibers based on thermoplastic or thermosetting polymers, such as semi-aromatic polyamide fibers, aramid fibers or polyolefin fibers; plant fibers include natural flax fibers, hemp fibers, lignin fibers, bamboo fibers, silk fibers, in particular spider silk fibers, sisal fibers and other cellulose fibers, in particular viscose fibers. In order to promote adhesion and impregnation of the thermoplastic polymer matrix, these plant fibers can be used in pure, treated or coated forms.

[0046] The fibrous material can also be a woven fabric, a textile, or a braid with fibers. It can also correspond to fibers with supporting threads.

[0047] These constituent fibers can be used individually or in the form of a mixture.Thus, organic fibers can be mixed with mineral fibers in order to be pre-impregnated with the thermoplastic polymer powder and to form a pre-impregnated fibrous material.

[0048] In some embodiments, the thermoplastic resin is selected from the group consisting of: polyaryletherketone (PAEK); polyaryletherketoneketone (PAEKK); aromatic polyetherimide (PEI); polyarylsulfone; polyarylsulfide; polyamide (PA); PEBA, polyacrylate; polyolefins, polylactic acid (PLA), polyvinyl alcohol (PVA), and fluorinated polymers; and mixtures thereof.

[0049] As the fluorinated polymer, a homopolymer of vinylidene fluoride (VDF having the formula CH₂═CF₂) or a copolymer of VDF can be used, the copolymer comprising at least 50% by weight of VDF and at least one other monomer copolymerizable with VDF. The VDF level must exceed 80% by weight, or even better, 90% by weight, to provide the structural component with good mechanical strength, especially when subjected to thermal and chemical stresses. The comonomer must be a fluorinated monomer, such as vinyl fluoride.

[0050] For structural components that must withstand high temperatures, in addition to fluorinated polymers, PAEK (polyaryletherketone) such as poly(etherketone) PEK, poly(etheretherketone) PEEK, poly(etherketoneketone) PEKK, poly(etherketoneetherketoneketone) PEKEKK or PA with a high glass transition temperature Tg is advantageously used according to the present disclosure. Advantageously, the thermoplastic polymer is a polymer having a glass transition temperature Tg ≥ 80°C or a semi-crystalline polymer having a melting temperature Tm ≥ 150°C.

[0051] The embodiments of the present invention will be described in detail below with reference to the examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. For experimental methods in the following examples where specific conditions are not specified, reference is made to the guidance provided in the present invention, and may also be made to experimental manuals or conventional conditions in the art, other experimental methods known in the art, or conditions recommended by the manufacturer.

[0052] In the following specific examples, the measured parameters of raw material components may have slight deviations within the range of weighing accuracy unless otherwise specified. For temperature and time parameters, acceptable deviations caused by instrument testing accuracy or operational accuracy are allowed.

[0053] In the following examples:

[0054] Petal-like structures Figure 1 As shown;

[0055] The prepreg used is made of carbon fiber; the thermoplastic resin is polyetheretherketone; the thickness of each layer is 0.145mm±0.05mm; the impregnation method is powder impregnation:

[0056] Example 1

[0057] 1. Clean the flat mold with anhydrous ethanol. After cleaning, evenly apply a layer of release agent on the inner surface of the mold. The release agent is a high-temperature water-based release agent.

[0058] 2. Lay out 14 layers of quasi-isotropic prepreg, place them in a 2mm thick flat mold cavity, and close the mold.

[0059] 3. The flat mold temperature on the hot press is maintained at 390°C and the molding pressure is maintained at 3 MPa. 14 layers of quasi-isotropic prepreg are molded into a flat laminate with a thickness of 2 mm.

[0060] 4. Wait for the temperature of the flat mold to cool naturally to 30°C (the cooling rate on both sides of the flat mold remains consistent) and complete demoulding;

[0061] 5. Use an engraving machine to shape the flat plate into petals;

[0062] 6. Clean the profile mold cavity with anhydrous ethanol and evenly apply a layer of release agent on the inner surface of the mold cavity. The release agent is a high-temperature water-based release agent;

[0063] 7. Place the laminated board machined as above in the profile mold cavity, close the mold so that the upper surface of the laminated board contacts the upper mold boss, and the lower surface of the petal part of the laminated board contacts the lower mold, set the hot press program to raise the profile mold temperature to 390℃ and maintain it for 20 minutes to soften the laminated board, set the hot press program to close the mold and start molding, that is, the temperature is 320℃, the pressure is 3MPa, after isothermal for 20 minutes, naturally cool to 30℃ under a pressure of 3MPa to complete demoulding.

[0064] Example 2

[0065] 1. Clean the flat mold with anhydrous ethanol. After cleaning, evenly apply a layer of release agent on the inner surface of the mold. The release agent is a high-temperature water-based release agent.

[0066] 2. Lay out 14 layers of quasi-isotropic prepreg, place them in a 2mm thick flat mold cavity, and close the mold.

[0067] 3. The flat mold temperature on the hot press is maintained at 390°C and the molding pressure is maintained at 3 MPa. 14 layers of quasi-isotropic prepreg are molded into a flat laminate with a thickness of 2 mm.

[0068] 4. Wait for the temperature of the flat mold to cool naturally to 30°C (the cooling rate on both sides of the flat mold remains consistent) and complete demoulding;

[0069] 5. Use an engraving machine to shape the flat plate into petals;

[0070] 6. Clean the profile mold cavity with anhydrous ethanol and evenly apply a layer of release agent on the inner surface of the mold cavity. The release agent is a high-temperature water-based release agent;

[0071] 7. Place the laminated board machined as above in the profile mold cavity, close the mold so that the upper surface of the laminate contacts the upper mold boss, and the lower surface of the petal part of the laminate contacts the lower mold, set the hot press program to make the upper mold temperature of the profile mold 390℃ and the lower mold temperature 400℃, wait for the mold temperature to rise to the specified temperature and maintain it for 20 minutes to soften the laminate, set the hot press program to close the mold and start molding, that is, the temperature is 320℃ and the pressure is 3MPa. After isothermal for 20 minutes, naturally cool to 30℃ under a pressure of 3MPa to complete demolding.

[0072] Example 3

[0073] 1. Clean the flat mold with anhydrous ethanol. After cleaning, evenly apply a layer of release agent on the inner surface of the mold. The release agent is a high-temperature water-based release agent.

[0074] 2. Lay out 15 layers of quasi-isotropic prepreg, place them in a 2.2mm thick flat mold cavity, and close the mold.

[0075] 3. The flat mold temperature on the hot press is maintained at 390°C and the molding pressure is maintained at 3 MPa. 14 layers of quasi-isotropic prepreg are molded into a flat laminate with a thickness of 2.2 mm.

[0076] 4. Wait for the temperature of the flat mold to cool naturally to 30°C (the cooling rate on both sides of the flat mold remains consistent) and complete demoulding;

[0077] 5. Use an engraving machine to shape the flat plate into petals;

[0078] 6. Clean the 2mm profile cavity mold with anhydrous ethanol and evenly apply a layer of release agent on the inner surface of the cavity. The release agent is a high-temperature water-based release agent.

[0079] 7. Place the laminated board machined as above in the profile mold cavity, close the mold so that the upper surface of the laminated board contacts the upper mold boss, and the lower surface of the petal part of the laminated board contacts the lower mold, set the hot press program to raise the profile mold temperature to 390℃ and maintain it for 20 minutes to soften the laminated board, set the hot press program to close the mold and start molding, that is, the temperature is 320℃, the pressure is 3MPa, after isothermal for 20 minutes, naturally cool to 30℃ under a pressure of 3MPa to complete demoulding.

[0080] Example 4

[0081] 1. Clean the flat mold with anhydrous ethanol. After cleaning, evenly apply a layer of release agent on the inner surface of the mold. The release agent is a high-temperature water-based release agent.

[0082] 2. Lay out 15 layers of quasi-isotropic prepreg, place them in a 2.2mm thick flat mold cavity, and close the mold.

[0083] 3. The flat mold temperature on the hot press is maintained at 390°C and the molding pressure is maintained at 3 MPa. 14 layers of quasi-isotropic prepreg are molded into a flat laminate with a thickness of 2.2 mm.

[0084] 4. Wait for the temperature of the flat mold to cool naturally to 30°C (the cooling rate on both sides of the flat mold remains consistent) and complete demoulding;

[0085] 5. Use an engraving machine to shape the flat plate into petals;

[0086] 6. Clean the 2mm profile cavity mold with anhydrous ethanol and evenly apply a layer of release agent on the inner surface of the cavity. The release agent is a high-temperature water-based release agent.

[0087] 7. Place the laminated board machined as above in the profile mold cavity, close the mold so that the upper surface of the laminated board contacts the upper mold boss, and the lower surface of the petal part of the laminated board contacts the lower mold. Set the hot press program to make the upper mold temperature of the profile mold 390℃ and the lower mold temperature 400℃. Wait until the mold temperature rises to the specified temperature and maintains it for 20 minutes to soften the laminated board. Set the hot press program to close the mold and start molding, that is, the temperature is 320℃ and the pressure is 3MPa. After isothermal for 20 minutes, naturally cool to 30℃ under a pressure of 3MPa to complete demoulding.

[0088] Comparative Example

[0089] 1. Clean the flat mold with anhydrous ethanol. After cleaning, evenly apply a layer of release agent on the inner surface of the mold. The release agent is a high-temperature water-based release agent.

[0090] 2. Lay out 14 layers of quasi-isotropic prepreg, place them in a 2mm thick flat mold cavity, and close the mold.

[0091] 3. The flat mold temperature on the hot press is maintained at 390°C and the molding pressure is maintained at 3 MPa. 14 layers of quasi-isotropic prepreg are molded into a flat laminate with a thickness of 2 mm.

[0092] 4. Wait for the temperature of the flat mold to cool naturally to 30°C (the cooling rate on both sides of the flat mold remains consistent) and complete demoulding;

[0093] 5. Use an engraving machine to shape the flat plate into petals;

[0094] 6. Clean the 2mm profile cavity mold with anhydrous ethanol and evenly apply a layer of release agent on the inner surface of the cavity. The release agent is a high-temperature water-based release agent.

[0095] 7. Preheat the machined laminate on a copper heating table at 380°C for 30 minutes. To prevent the laminate from cooling and hardening during the transfer process, place a thick steel plate under the laminate to assist in heat preservation transfer. Transfer the softened laminate to the mold and close the mold to start molding. That is, the temperature is 320°C and the pressure is 3 MPa. After isothermal for 20 minutes, naturally cool to 30°C under a pressure of 3 MPa to complete demolding.

[0096] The examples of the present disclosure were compared with the comparative examples, and the results are shown in the following table:

[0097]

[0098] In the comparative example, the preheating method of preheating on a heating table is adopted. Since the melting point of thermoplastic resin is relatively high, it will harden when transferred to the mold after preheating, which will cause quality problems during the molding process. In the embodiment, direct preheating in the mold can avoid this problem. On the one hand, it reduces the difficulty of operation and eliminates the cost of purchasing a heating table. On the other hand, it can reduce the porosity of the finished product from more than 7% to between 2% and 7%, and the profile delamination defects are also greatly improved. The profile surface roughness is reduced from more than 6.3 to within 2.1, and the bearing capacity is increased from 300MPa to 700MPa. In Example 4, the preheating process sets the temperature of the lower mold to be 10°C higher than the temperature of the upper mold, and the thickness of the laminate is slightly larger than the depth of the mold, so that the petal structure of the laminate can be more fully preheated. It was unexpectedly found that it is conducive to further flanging molding, and can reduce the porosity of the finished product to within 1%, the surface roughness of the profile to within 1.5, and the bearing capacity can reach 837MPa. The cross-sectional structure of the profile is as follows Figure 2 and Figure 3 shown.

[0099] The above-described embodiments merely represent several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art may make several modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be based on the appended claims, and the description and drawings may be used to interpret the content of the claims.

Claims

1. A method for preparing a fiber-reinforced composite material profile with a flanging structure, characterized in that: include: a) providing a laminated board formed by molding multiple layers of fiber material prepreg treated with thermoplastic resin, and cutting out notches in portions of the laminated board to be flanged to form a plurality of petal-like structures and a central structure surrounded by the petal-like structures; b) providing a profile mold cavity with an inner surface of the mold cavity pre-coated with a release agent, the profile mold cavity comprising a lower mold concave platform and an upper mold protrusion capable of being sleeved within the lower mold concave platform; The laminate is placed in the profile mold cavity without preheating, with the upper surface of the central structure in contact with the upper mold protrusion and the lower surfaces of the petal-shaped structures in contact with the lower mold concave platform; heating the profile mold cavity to soften and mold the laminate; c) cooling and demoulding to obtain the profile.

2. The preparation method according to claim 1, characterized in that The thickness of the laminate is 100% to 110% of the depth of the profile mold cavity; Optionally, the thickness of the laminate is 1.8 mm to 2.2 mm.

3. The preparation method according to claim 1, characterized in that When the laminate is softened, the temperature of the lower die concave portion is 8° C. to 12° C. higher than that of the upper die convex portion; Optionally, the temperature of the upper die boss is 385°C to 395°C.

4. The preparation method according to claim 3, characterized in that The temperature during the molding in step b) is 310°C to 330°C.

5. The preparation method according to any one of claims 1 to 4, characterized in that The number of layers of the prepreg is ≥12, preferably ≥14.

6. The preparation method according to claim 5, characterized in that The laminate is molded at a temperature of 380° C. to 400° C., and the temperature of the lower mold concave platform and the upper mold convex platform are consistent during the mold closing process. After the mold closing, the laminate is naturally cooled to 20° C. to 40° C.

7. The preparation method according to any one of claims 1 to 4 and 6, characterized in that: In step c), the mold is demoulded by naturally cooling to 20° C. to 40° C.

8. The preparation method according to any one of claims 1 to 4 and 6, characterized in that: The central structure is circular, elliptical or polygonal, preferably a regular polygon.

9. The preparation method according to any one of claims 1 to 4 and 6, characterized in that: The fiber material includes one or more of mineral fibers, organic fibers or plant fibers; preferably, the mineral fibers include one or more of carbon fibers, glass fibers, basalt fibers, silicon oxide fibers and silicon carbide fibers; preferably, the organic fibers include fibers based on thermoplastic or thermosetting polymers, such as at least one of semi-aromatic polyamide fibers, aramid fibers or polyolefin fibers; preferably, the plant fibers include at least one of natural flax fibers, hemp fibers, lignin fibers, bamboo fibers, silk fibers, especially spider silk fibers, and sisal fibers.

10. The preparation method according to any one of claims 1 to 4 and 6, characterized in that: The thermoplastic resin is selected from the group consisting of: polyaryletherketone (PAEK); polyaryletherketoneketone (PAEKK); aromatic polyetherimide (PEI); polyarylsulfone; polyarylsulfide; polyamide (PA); PEBA, polyacrylate; polyolefin, polylactic acid (PLA), polyvinyl alcohol (PVA), and fluorinated polymers; and mixtures thereof.

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