A method for preparing thermosetting composite material products

Abstract

This application discloses a method for preparing thermosetting composite material products, comprising: providing fiber preforms to a pressurizing section; compressing the fiber preforms in the pressurizing section to provide compressed fiber preforms; transferring the compressed fiber preforms to a curing section; and heating the compressed fiber preforms in the curing section to a temperature greater than or equal to the curing temperature to provide the composite material product. The resulting composite material product, due to the fiber orientation of the fiber preforms being oriented in the sectional direction perpendicular to its length, exhibits improved tensile strength, compressive strength, and modulus in its sectional direction. It is particularly suitable for extrusion molding of composite material products made of rods, tubes, or other profiles with similar structures, and allows for adjustment of the extrusion length as needed, thereby improving production efficiency.

Description

Technical Field

[0001] This application relates to the field of materials technology, and in particular to a method for preparing thermosetting composite material articles. Background Technology

[0002] Composite material products in related technologies can be manufactured into various shapes such as sheets, rods, and tubes. These products are typically manufactured using processes such as pultrusion, filament winding, and compression molding. The mechanical properties of composite material products are closely related to fiber orientation; generally, the fiber orientation direction exhibits superior strength and modulus.

[0003] For composite materials such as rods and tubes, due to the characteristics of processes such as pultrusion, filament winding, and compression molding, it is difficult for fibers to be oriented in the cross-sectional direction (i.e., the direction perpendicular to the length of the rod or tube). Therefore, the tensile strength, compressive strength, and modulus in the cross-sectional direction are relatively low. Summary of the Invention

[0004] This application discloses a method for preparing thermosetting composite material products, which can solve the problem of low tensile strength, compressive strength and modulus in the cross-sectional direction of composite material products such as bars and tubes in related technologies.

[0005] To achieve the above objectives, this application discloses a method for preparing a thermosetting composite material article. The composite material article is formed in the cavity of an extrusion die. The extrusion die includes a pressure section and a curing section disposed in the cavity and arranged sequentially along the feeding direction of the cavity. The method includes:

[0006] Provide fiber preforms to the pressurization section.

[0007] The fiber preforms in the pressurization section are compressed to provide compressed fiber preforms.

[0008] The compressed fiber preforms are transferred to the curing section.

[0009] In the curing stage, the compressed fiber preform is heated to a temperature greater than or equal to the curing temperature to provide composite products.

[0010] The fiber preform comprises multiple fiber preforms stacked sequentially along its length, wherein the fiber preforms are either multidirectional fiber preforms or unidirectional fiber preforms; wherein the multidirectional fiber preform comprises a multidirectional fiber cloth and a thermosetting resin, the multidirectional fiber cloth comprising at least two types of fibers with intersecting fiber orientations; the unidirectional fiber preform comprises a unidirectional fiber cloth and a thermosetting resin, wherein the fiber orientation of the fibers within the unidirectional fiber cloth remains consistent; the curing temperature is the cross-linking curing temperature of the thermosetting resin; the fiber preform comprises a unidirectional fiber preform comprising at least two types of fibers with intersecting fiber orientations, or the fiber preform comprises a multidirectional fiber preform; the length direction is consistent with the feeding direction, and the fiber orientation is perpendicular to the length direction; the compression direction is parallel to the length direction.

[0011] Optionally, the extrusion die also includes a semi-curing section located within the die cavity and between the pressurization section and the curing section; the compressed fiber preform is transferred to the curing section to heat the compressed fiber preform to a temperature greater than the curing temperature to provide a composite material article comprising:

[0012] The compressed fiber preforms are transferred to the semi-cured section.

[0013] In the semi-curing stage, the compressed fiber preform is heated to a first preset temperature to provide a semi-cured product.

[0014] Transfer the semi-solidified product to the curing section.

[0015] In the curing stage, the semi-cured product is heated to a temperature above the curing temperature to provide a composite material product. The first preset temperature is lower than the curing temperature.

[0016] Optionally, the extrusion die further includes a cooling section disposed in the die cavity, and the pressurizing section, curing section and cooling section are arranged sequentially along the feeding direction; after transferring the compressed fiber preform to the curing section to heat the compressed fiber preform to a temperature greater than the curing temperature to provide a composite material product, the method further includes:

[0017] Transfer composite material products to the cooling section.

[0018] The composite material product is cooled to a second preset temperature in the cooling section. The second preset temperature is lower than the curing temperature.

[0019] Optionally, the method further includes, prior to providing the fiber preform to the pressurization section:

[0020] The fiber cloth is pre-impregnated in a thermosetting resin to provide a fiber preform; the fiber cloth may be a multidirectional or unidirectional fiber cloth.

[0021] Fiber preforms are stacked sequentially along their length to provide fiber preforms.

[0022] Optionally, the fibers in the fiber preform of the composite material product are organic fibers or inorganic fibers.

[0023] Optionally, the inorganic fiber is one of glass fiber cloth, carbon fiber, basalt fiber, and quartz fiber; the organic fiber is one of aramid fiber and ultra-high molecular weight polyethylene fiber.

[0024] Optionally, the thermosetting resin is one of epoxy resin, vinyl ester resin, phenolic resin, benzoxazine resin, bismaleimide resin, or cyanate ester resin.

[0025] Optionally, the unidirectional fiber preform in the fiber preform is divided into a first unidirectional fiber preform and a second unidirectional fiber preform; the first unidirectional fiber preform is fiber-oriented in a first direction, and the second unidirectional fiber preform is fiber-oriented in a second direction, with the first direction, the second direction, and the length direction intersecting each other; the fiber preform includes a first prepreg section and a second prepreg section alternately arranged along the length direction, the first prepreg section including one first unidirectional fiber preform or multiple first unidirectional fiber preforms stacked sequentially along the length direction; the second prepreg section includes one second unidirectional fiber preform or multiple second unidirectional fiber preforms stacked sequentially along the length direction.

[0026] Compared with the prior art, the beneficial effects of this application are:

[0027] The preparation method disclosed in this application is used to prepare thermosetting composite material products. The composite material products are formed in the cavity of an extrusion die. The extrusion die includes a pressure section and a curing section arranged sequentially along the feeding direction of the die cavity. The method includes:

[0028] Provide fiber preforms to the pressurization section.

[0029] The fiber preforms in the pressurization section are compressed to provide compressed fiber preforms.

[0030] The compressed fiber preforms are transferred to the curing section.

[0031] In the curing stage, the compressed fiber preform is heated to a temperature greater than or equal to the curing temperature to provide composite products.

[0032] The fiber preform comprises multiple fiber preforms stacked sequentially along its length, wherein the fiber preforms are either multidirectional fiber preforms or unidirectional fiber preforms; wherein the multidirectional fiber preform comprises a multidirectional fiber cloth and a thermosetting resin, the multidirectional fiber cloth comprising at least two types of fibers with intersecting fiber orientations; the unidirectional fiber preform comprises a unidirectional fiber cloth and a thermosetting resin, wherein the fiber orientation of the fibers within the unidirectional fiber cloth remains consistent; the fiber preform comprises a unidirectional fiber preform comprising at least two types of fibers with intersecting fiber orientations, or the fiber preform comprises a multidirectional fiber preform; the length direction is consistent with the feeding direction, and the fiber orientation is perpendicular to the length direction; the compression direction is parallel to the length direction.

[0033] The resulting composite material product, in a first aspect, improves the tensile strength, compressive strength and modulus of the composite material product in its cross-section because the fiber orientation of the fiber preform is oriented in the sectional direction (perpendicular to the length direction).

[0034] In the second aspect, using the preparation method of this application, new composite material products are continuously generated at the input end of the mold cavity (i.e., the end where the pressure section is located), while the composite material products are continuously deposited and extruded from the mold at the output end of the mold cavity (i.e., the end near the curing section). It can be seen that the preparation method of this application is more suitable for extrusion molding of composite material products with similar structures such as rods, tubes, or other profiles.

[0035] Thirdly, compared to composite material products with sheet structures, the thickness of sheet materials cannot be too large due to limitations in processing equipment, and generally does not exceed 50mm. However, the composite material products of this application are used to prepare rods or tubes, and their length can be adjusted arbitrarily as needed, such as 3000mm, 5000mm, etc., which is more advantageous than sheet materials in terms of size control.

[0036] Fourthly, for sheet materials or other types of composite material products, different processing steps often need to be carried out on different equipment. For example, compaction requires a belt press, and heating and curing require infrared heating equipment. Changes in the process require the product to be transferred between different equipment. However, the composite material product of this application is completed in the extrusion mold from feeding to final molding, eliminating the need for product transfer when connecting upstream and downstream processes, thus improving production efficiency. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a first-state diagram of the processing of composite material products disclosed in this application;

[0039] Figure 2 This is a second-state diagram of the processing of composite material products disclosed in this application;

[0040] Figure 3 This is a third-state diagram of the processing of composite material products disclosed in this application;

[0041] Figure 4 This is a fourth-state diagram of the processing of composite material products disclosed in this application;

[0042] Figure 5 This is a diagram illustrating the fabrication process of the composite material product with the tubular structure disclosed in this application;

[0043] Figure 6 This is a fabrication diagram of a composite material product with another tubular structure disclosed in this application;

[0044] Figure 7 This is a structural diagram of the first composite material product made of unidirectional fiber preforms disclosed in this application;

[0045] Figure 8 This is a structural diagram of a composite material product made of unidirectional fiber preforms, as disclosed in this application.

[0046] Figure 9 This is a structural diagram of the third type of composite material product made of unidirectional fiber preforms disclosed in this application;

[0047] Figure 10 This is a structural diagram of the composite material product made of multidirectional fiber preforms disclosed in this application;

[0048] Figure 11 This diagram illustrates the preparation method of composite material products in related technologies.

[0049] Explanation of reference numerals in the attached figures:

[0050] X - First direction, Y - Second direction, Z - Length direction

[0051] 10-Composite material products

[0052] 11-First unidirectional fiber preform, 12-Second unidirectional fiber preform, 13-Multidirectional fiber preform

[0053] 20-Mold cavity,

[0054] 21-Pressure section, 22-Semi-curing section, 23-Curing section, 24-Cooling section

[0055] 201-First extrusion mechanism, 202-Second extrusion mechanism, 203-Mandrel. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0058] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0059] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0060] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0061] For composite material products such as rods and tubes in related technologies, due to the characteristics of processes such as pultrusion molding, filament winding, and compression molding, it is difficult to orient the fibers in the cross-sectional direction (i.e., the direction perpendicular to the length of the rod or tube). Therefore, the tensile strength, compressive strength, and modulus in the cross-sectional direction are relatively low. To solve this problem, the technical solution of this application was developed. The following is a combination of... Figures 1 to 11 To elaborate.

[0062] This application discloses a method for preparing a thermosetting composite material product 10. The composite material product 10 is formed into a rod or tube in the cavity 20 of an extrusion die. The extrusion die includes a pressure section 21 and a curing section 23 arranged sequentially in the cavity 20 along the feeding direction of the cavity 20. The pressure section 21 is located near the input end of the cavity 20, and the curing section 23 is located near the output end of the cavity 20. The feeding direction is from the input end of the cavity 20 to the output end of the cavity 20. The extrusion die is movably provided with a first stacking mechanism 201 and a second stacking mechanism 202. The cavity 20 is located between the first stacking mechanism 201 and the second stacking mechanism 202. The first stacking mechanism 201 is located on the side of the cavity 20 near the pressure section 21, and the second stacking mechanism 202 is located on the side of the cavity 20 near the curing section 23. At least a portion of the first stacking mechanism 201 and the second stacking mechanism 202 are connected in the same direction. At least a portion of the extrusion mechanism 202 can enter the mold cavity 20. Here, the first extrusion mechanism 201 and the second extrusion mechanism 202 can be selected from electric push rod mechanism, cylinder piston mechanism, etc. Taking the cylinder piston mechanism as an example, the front end of the piston rod can be provided with a top plate. In this way, the top plate of the first extrusion mechanism 201 and the top plate of the second extrusion mechanism 202 can enter the mold cavity 20. At the same time, the top plates of the first extrusion mechanism 201 and the top plates of the second extrusion mechanism 202 can approach each other to form extrusion on the composite material product 10 in the mold cavity 20. During the extrusion process, the composite material product 10 is gradually compacted to fit tightly against the inner wall of the mold cavity 20 to ensure that the shape of the composite material product 10 matches the inner shape of the mold cavity 20. That is to say, the shape of the mold cavity 20 determines the shape of the composite material product 10. For example, the composite material product 10 can be a tube or bar with a cross-section of a circle, rectangle, hexagon, or other shapes.

[0063] The method for preparing the composite material article 10 of this application may include:

[0064] The feeding process involves supplying fiber preforms to the pressurizing section 21. These fiber preforms are thermosetting preforms, thus possessing the molding characteristics of thermosetting materials. Specifically, they can be cured when heated to a temperature greater than or equal to the cross-linking curing temperature of thermosetting materials, and the curing effect is irreversible. The fiber preforms comprise multiple fiber preform sheets stacked sequentially along the Z-direction. These fiber preform sheets are either multidirectional fiber preform sheets or unidirectional fiber preform sheets. The multidirectional fiber preform sheet comprises a multidirectional fiber cloth and a thermosetting resin, with the multidirectional fiber cloth comprising fibers with at least two intersecting fiber orientations. The unidirectional fiber preform sheet comprises a unidirectional fiber cloth and a thermosetting resin, with the fiber orientation of the fibers within the unidirectional fiber cloth remaining consistent. The fiber preform includes unidirectional fiber preforms with at least two intersecting fiber orientations, or the fiber preform includes multidirectional fiber preforms, for example, the fiber preform consists entirely of multidirectional fiber preforms, or the fiber preform has unidirectional fiber preforms with two or more fiber orientations, and the fiber orientations of different types of unidirectional fiber preforms intersect, or the fiber preform contains both multidirectional fiber preforms and unidirectional fiber preforms.

[0065] The compaction process is performed as follows: the first extrusion mechanism 201 and the second extrusion mechanism 202 approach each other, causing the extrusion die to compress the fiber preform in the pressurization section 21. The fiber preform is gradually compacted and pressed tightly against the inner wall of the die cavity 20 to provide the compressed fiber preform, specifically as follows: Figure 1 As shown. It can be understood that if the mold cavity 20 only contains fiber preforms, the first extrusion mechanism 201 and the second extrusion mechanism 202 directly contact the two opposite end faces of the fiber preforms to compact them; however, if the mold cavity 20 already contains composite material products 10, and the retained composite material products 10 avoid the pressing section 21 and are located between the fiber preforms and the second extrusion mechanism 202, then the first extrusion mechanism 201 directly extrudes one side of the fiber preforms, while the second extrusion mechanism 202 transmits force through the composite material products 10 to indirectly extrude the other side of the fiber preforms, thereby compacting the fiber preforms and connecting them to the end of the composite material products 10.

[0066] Execute the transfer process: Control the first extrusion mechanism 201 to continue moving in the length direction Z as described below, so as to transfer the compressed fiber preform to the curing section 23 by pushing.

[0067] Perform the curing process: In the curing section 23, the compressed fiber preform is heated to a temperature greater than or equal to the curing temperature to provide the composite material product 10, specifically as follows: Figure 2As shown. Here, curing temperature refers to the cross-linking curing temperature required for the thermosetting resin in the fiber preform to undergo a cross-linking reaction. The cross-linking reaction of thermosetting materials is irreversible. Specifically, after the cross-linking reaction, the soft fiber preform becomes a solid composite material product 10, thereby improving its strength, heat resistance, wear resistance, solvent resistance and other properties.

[0068] It should be noted that after each transfer process, it can be done as follows: Figure 3 As shown, new fiber preforms are added to the pressurization section 21, and then the newly added fiber preforms are processed as follows: Figure 4 The process involves compaction, which involves cyclically feeding and curing the newly added fiber preform. This cycle repeats continuously, causing the head section of the composite material product 10 to be continuously extruded from the output end of the mold cavity 20, and new composite material products 10 to be continuously generated at the tail section, which is the side closest to the pressure section 21. The length direction Z is consistent with the feeding direction of the mold cavity 20, and the fiber orientation is perpendicular to the length direction Z; the compression direction of the mold cavity 20 on the fiber preform is parallel to the length direction Z.

[0069] The following are examples illustrating composite material products 10 composed of several different prepreg sections:

[0070] like Figures 7-9 As shown, the fiber preform can be composed of only two unidirectional fiber preforms with different fiber orientations, and the unidirectional fiber preforms in the fiber preform are divided into a first unidirectional fiber preform 11 and a second unidirectional fiber preform 12. The first unidirectional fiber preform 11 is oriented in a first direction X, and the second unidirectional fiber preform 12 is oriented in a second direction Y. The first direction X, the second direction Y, and the length direction Z intersect each other, for example, they are perpendicular to each other.

[0071] The fiber prepreg includes a first prepreg section and a second prepreg section arranged alternately along the length direction Z. The first prepreg section includes a first unidirectional fiber prepreg 11 or a plurality of first unidirectional fiber prepregs 11 stacked sequentially along the length direction Z. The second prepreg section includes a second unidirectional fiber prepreg 12 or a plurality of second unidirectional fiber prepregs 12 stacked sequentially along the length direction Z.

[0072] like Figure 7 As shown, in the structure of the first composite material product 10, the composite material product 10 is formed by alternating superposition of the first unidirectional fiber preform 11 and the second unidirectional fiber preform 12 along the length direction Z, that is, the first prepreg section includes only one first unidirectional fiber preform 11, and the second prepreg section includes only one second unidirectional fiber preform 12.

[0073] like Figure 8As shown, in the structure of the second composite material article 10, the first prepreg section may include multiple first unidirectional fiber preforms 11, such as two first unidirectional fiber preforms 11, and the second prepreg section may include one second unidirectional fiber preform 12. The composite material article 10 thus formed is generated by alternatingly stacking the first unidirectional fiber preforms 11 and the second unidirectional fiber preforms 12 in a 2:1 ratio along the length direction Z.

[0074] like Figure 9 As shown, in the structure of the third composite material article 10, the first prepreg section may include a first unidirectional fiber preform 11, and the second prepreg section may include two second unidirectional fiber preforms 12. The composite material article 10 thus formed is generated by alternatingly stacking the first unidirectional fiber preform 11 and the second unidirectional fiber preform 12 in a 1:2 ratio along the length direction Z.

[0075] Of course, the first unidirectional fiber preform 11 and the second unidirectional fiber preform 12 can also be adjusted in other proportions to adjust the structure of the composite material product 10. By adjusting the proportions, the cross-sectional properties of the composite material product 10 in a specific direction can be adjusted. At the same time, the composite material product 10 can also be formed by stacking more fiber preforms with different fiber orientations to have better cross-sectional properties in more directions. Alternatively, the fiber preform can also be composed of three or more unidirectional fiber preforms with different fiber orientations, which will not be described in detail here.

[0076] Figure 11 Compared to the traditional compression molding methods used in related technologies for composite material products, the preparation method of this application has significant mechanical advantages in the cross-section parallel to the fiber preform, such as the first direction X and the second direction Y, as shown in the table below:

[0077]

[0078] The resulting composite material article 10, in a first aspect, improves the tensile strength, compressive strength and modulus of the composite material article 10 in its cross-section because the fiber orientation of the fiber preform therein is oriented in the cross-section (perpendicular to the length direction Z).

[0079] In the second aspect, using the preparation method of this application, new composite material articles 10 are continuously generated at the input end of the mold cavity 20 (i.e., the end where the pressure section 21 is located), and at the same time, the composite material articles 10 are continuously deposited and extruded from the mold at the output end of the mold cavity 20 (i.e., the end near the curing section 23). It can be seen that the preparation method of this application is more suitable for extrusion molding of composite material articles 10 made of rods, tubes or other profiles with similar structures.

[0080] Thirdly, Figure 11 The preparation methods disclosed in the related technologies are more suitable for composite material products 10 with sheet-like structures. Compared with composite material products 10 with sheet-like structures, the thickness of the sheet cannot be too large due to the limitations of its processing equipment, and generally will not exceed 50mm. However, the composite material product 10 of this application is used to prepare rods or tubes, and its length can be adjusted arbitrarily as needed, such as 3000mm, 5000mm, etc., which is more advantageous than sheet material in terms of size control.

[0081] Fourthly, for sheet materials or other types of composite material products, different processing steps often need to be carried out on different equipment. For example, compaction requires a belt press, and heating and curing require infrared heating equipment. Changes in the process require the product to be transferred between different equipment. However, the composite material product 10 of this application is completed in the extrusion mold from feeding to final molding, eliminating the need for product transfer when connecting upstream and downstream processes, thus improving production efficiency.

[0082] In some alternative implementations, Figure 10 This is a fiber preform prepared solely using a multidirectional fiber preform 13. The multidirectional fiber preform 13 contains both first fibers oriented in a first direction X and second fibers oriented in a second direction Y, with the first and second fibers interwoven within the multidirectional fiber preform 13, for example, the first and second fibers being perpendicular to each other. Since the fiber orientations in the multidirectional fiber preform 13 are all sectionally oriented (perpendicular to the length direction Z), this also improves the tensile strength, compressive strength, and modulus of the composite material product 10 in its sectional direction.

[0083] It should also be noted that, since the multidirectional fiber preform 13 has at least two intersecting fiber orientations, the stacking of the multidirectional fiber preform 13 can be performed as follows: Figure 10As shown, when arranging the multidirectional fiber preforms 13, some of the multidirectional fiber preforms 13 can have their first fibers facing the first direction X and their second fibers facing the second direction Y, or the first fibers of other multidirectional fiber preforms 13 can be tilted relative to the first direction X and their second fibers relative to the second direction Y. Compared to preparing the composite material product 10 using unidirectional fiber preforms, when preparing the composite material product 10 using multidirectional fiber preforms 13, there is no need to deliberately consider the fiber arrangement direction in the multidirectional fiber preforms 13; the multidirectional fiber preforms 13 can be directly stacked in the length direction Z, which can improve the preparation efficiency. Furthermore, the stacking of unidirectional fiber preforms, compared to the stacking of multidirectional fiber preforms 13, can give the fiber preforms better strength and is more suitable for the composite material product 10 of this application. Therefore, producers can consider, based on their own needs, whether the composite material product 10 is prepared by multi-directional fiber preform 13, or unidirectional fiber preform, or by mixing multi-directional fiber preform and unidirectional fiber preform in a certain proportion, which will not be described in detail here.

[0084] In some alternative embodiments, the preparation method of this application is used, in addition to being used for Figures 1-4 In addition to the preparation of the disclosed rod-type composite material product 10, it can also be used to prepare the tubular composite material product 10, for example... Figure 5 As shown, in this method, a mandrel 203 is disposed inside the cavity 20 of the extrusion die. The fiber preform is also annular and sleeved on the mandrel 203. The top plate of the first extrusion mechanism 201 and the top plate of the second extrusion mechanism 202 are also sleeved on the mandrel 203. Thus, during the compaction process, the fiber preform, under the compression action of the first extrusion mechanism 201 and the second extrusion mechanism 202, will tightly adhere to the outer periphery of the mandrel 203 and the inner wall of the cavity 20. After the curing process, a composite material product 10 with a tubular structure is obtained. Alternatively, as shown... Figure 6 As shown, the top plate of the first extrusion mechanism 201 is fitted onto the mandrel 203, and the top plate of the second extrusion mechanism 202 is located on one side of the mandrel 203 along the length direction Z, which can also realize the compression of the composite material product 10.

[0085] Optionally, the pressurizing section 21 is usually only used for pressurization, so the temperature of the pressurizing section 21 is not controlled accordingly and is generally at room temperature. However, after entering the curing section 23, the temperature of the curing section 23 is usually greater than or equal to the curing temperature. This large temperature difference between the two sections can easily cause the fiber pre-products conveyed by the pressurizing section 21 to form an adhesive surface at the contact point with the original composite material product 10 after curing in the curing section 23. This can easily lead to delamination of the composite material product 10 or even breakage during use. To solve this problem, the extrusion die may also include a semi-curing section 22 located in the die cavity 20 and between the pressurizing section 21 and the curing section 23.

[0086] Thus, the aforementioned curing process (specifically, transferring the compressed fiber preform to the curing section 23 to heat the compressed fiber preform to a temperature greater than or equal to the curing temperature, in order to provide the composite material article 10) can be further broken down as follows:

[0087] Perform the transfer process: control the movement of the first extrusion mechanism 201 to transfer the compressed fiber preforms to the semi-cured section 22.

[0088] Perform the semi-curing process: In the semi-curing section 22, the compressed fiber preform is heated to a first preset temperature to provide a semi-cured product.

[0089] Perform the transfer process: control the movement of the first extrusion mechanism 201 to transfer the semi-solidified product to the curing section 23.

[0090] Perform the curing process: In the curing section 23, the semi-cured product is heated to a temperature greater than or equal to the curing temperature to provide the composite material product 10; wherein the first preset temperature is lower than the curing temperature.

[0091] It is evident that the semi-curing section 22 is equivalent to setting up a buffer zone between the pressurizing section 21 and the curing section 23. In this way, after the fiber pre-product enters the semi-curing section 22 from the pressurizing section 21, it can be partially cured and fully fused and compacted with the original composite material product 10 located in the curing section 23 at the contact point. This ensures the fusion degree of the composite material product 10, prevents the composite material product 10 from having adhesive surfaces, avoids abnormalities such as breakage in subsequent use, and improves the quality of the composite material product 10.

[0092] It should be noted that, since the composite material product 10 is continuously formed in the extrusion die, the transfer process specifically includes: controlling the movement of the first stacking mechanism 201 to transfer the fiber preform in the pressing section 21 to the semi-curing section 22, transferring the semi-solidified product in the semi-curing section 22 to the curing section 23, transferring the composite material product 10 in the curing section 23 to the cooling section 24 (described later), and pushing the composite material product 10 in the cooling section 24 out of the die. Furthermore, after each transfer process, a feeding process can be performed, that is, a new fiber preform can be added to the pressing section 21.

[0093] After receiving their respective materials, the pressurizing section 21, semi-curing section 22, curing section 23, and cooling section 24 execute their corresponding processes. For example, the pressurizing section 21 receives fiber pre-products, the semi-curing section 22 receives compressed fiber pre-products, the curing section 23 receives semi-solidified products, and the cooling section 24 receives composite material products 10. For example, the pressurizing section 21 executes the pressurizing process, the semi-curing section 22 executes the semi-curing process, the curing section 23 executes the curing process, and the cooling section 24 executes the cooling process. These processes will not be described in detail here.

[0094] Optionally, the composite material product 10 after curing usually has a high temperature. For easy storage, the extrusion die may also include a cooling section 24 in the die cavity 20. The pressurizing section 21, the semi-curing section 22, the curing section 23 and the cooling section 24 are arranged sequentially along the feeding direction.

[0095] After transferring the compressed fiber preform to the curing section 23 to heat the compressed fiber preform to a temperature greater than or equal to the curing temperature to provide the composite material article 10, i.e. after the curing process, the preparation method of this application further includes:

[0096] Execute the transfer process: Control the first stacking mechanism 201 to perform stacking motion to transfer the composite material product 10 to the cooling section 24.

[0097] Perform the cooling process: In the cooling section 24, the composite material product 10 is cooled to a second preset temperature; wherein the second preset temperature is lower than the curing temperature and lower than the first preset temperature. Thus, after the composite material product 10 has been cured in the curing section 23, it will be transferred to the cooling section 24 for cooling in order to facilitate subsequent storage.

[0098] Optionally, the preparation method of this application may further include a demolding process: controlling the first extrusion mechanism 201 to perform extrusion motion to push the composite material product 10 in the cooling section 24 out of the mold. Furthermore, a cutting mechanism may be provided on the extrusion mold, such as a laser cutting device or a water jet cutting device located at the end of the cooling section 24, to cut the composite material product 10 after it has been extruded from the mold cavity 20 to the required length, so that the composite material product 10 can be stored according to a preset length.

[0099] Optionally, for the temperature control of the semi-curing section 22 and the curing section 23, heating can be achieved by adding an electric heating mantle or electric heating rod to the mold cavity 20 and temperature control can be achieved by assembling a temperature sensor; as for the cooling method of the cooling section 24, it can be achieved by circulating air cooling, liquid medium circulating cooling, etc., which will not be described in detail here.

[0100] The following describes a composite material product 10 made of basalt fiber and benzoxazine resin. The product is 3m long, 60mm wide (width direction is the second direction Y), and 25mm thick (thickness direction is the first direction X). Temperature settings are as follows: the pressure section 21 is controlled at 10-120℃; the semi-curing section 22 is controlled at 120-170℃ (i.e., the first preset temperature range); the curing section 23 is controlled at 170-210℃ (i.e., greater than or equal to the curing temperature); and the cooling section 24 is controlled at 10-70℃ (i.e., the second preset temperature range). This description further illustrates the specific implementation of the present invention, but does not limit the invention to the scope of the described embodiments.

[0101] Example 1

[0102] The fiber preform is formed by alternating layers of a first unidirectional fiber preform 11 oriented in the first direction X and a second unidirectional fiber preform 12 oriented in the second direction Y, in a 1:1 ratio. The ratio of benzoxazine to basalt fiber content is 40:60. The set temperatures are: 50°C for the pressurization section 21, 150°C for the semi-curing section 22, 200°C for the curing section 23, and 50°C for the cooling section 24. The performance parameters of the resulting composite material product 10 are shown in the table below.

[0103] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 720 Tensile strength (MPa) along the second direction Y 720 Bending strength (MPa) along the second direction Y 1100 Flexural modulus (GPa) 55 Compressive strength (MPa) along the second direction Y 830 Compression modulus (GPa) 70

[0104] Example 2

[0105] The difference from Example 1 is that the temperatures are set as follows: the temperature of the pressurization section 21 is 10°C, the temperature of the semi-curing section 22 is 120°C, the temperature of the curing section 23 is 180°C, and the temperature of the cooling section 24 is 10°C. The performance parameters of the resulting composite material product 10 are shown in the table below:

[0106] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 690 Tensile strength (MPa) along the second direction Y 695 Bending strength (MPa) along the second direction Y 950 Flexural modulus (GPa) 50 Compressive strength (MPa) along the second direction Y 800 Compression modulus (GPa) 65

[0107] Example 3

[0108] The difference from Example 1 is that the temperatures are set as follows: 120°C for the pressurization section 21, 170°C for the semi-curing section 22, 210°C for the curing section 23, and 70°C for the cooling section 24. The performance parameters of the resulting composite material product 10 are shown in the table below.

[0109] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 730 Tensile strength (MPa) along the second direction Y 730 Bending strength (MPa) along the second direction Y 1150 Flexural modulus (GPa) 56 Compressive strength (MPa) along the second direction Y 845 Compression modulus (GPa) 72

[0110] Example 4

[0111] The fiber preform is formed by alternating layers of a first unidirectional fiber preform 11 oriented in the first direction X and a second unidirectional fiber preform 12 oriented in the second direction Y, in a 2:1 ratio. The ratio of benzoxazine to basalt fiber content is 40:60. The set temperatures are: 50°C for the pressurization section 21, 150°C for the semi-curing section 22, 200°C for the curing section 23, and 50°C for the cooling section 24. The performance parameters of the resulting composite material product 10 are shown in the table below.

[0112] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 800 Tensile strength (MPa) along the second direction Y 670 Bending strength (MPa) along the second direction Y 900 Flexural modulus (GPa) 50 Compressive strength (MPa) along the second direction Y 750 Compression modulus (GPa) 65

[0113] Example 5

[0114] The difference from Example 4 is that the temperatures are set as follows: 20°C for the pressurization section 21, 120°C for the semi-curing section 22, 170°C for the curing section 23, and 20°C for the cooling section 24. The performance parameters of the resulting composite material product 10 are shown in the table below.

[0115] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 780 Tensile strength (MPa) along the second direction Y 660 Bending strength (MPa) along the second direction Y 870 Flexural modulus (GPa) 48 Compressive strength (MPa) along the second direction Y 740 Compression modulus (GPa) 63

[0116] Example 6

[0117] The difference from Example 4 is that the temperatures are set as follows: 120°C for the pressurization section 21, 170°C for the semi-curing section 22, 210°C for the curing section 23, and 70°C for the cooling section 24. The performance parameters of the resulting composite material product 10 are shown in the table below.

[0118] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 810 Tensile strength (MPa) along the second direction Y 675 Bending strength (MPa) along the second direction Y 910 Flexural modulus (GPa) 52 Compressive strength (MPa) along the second direction Y 760 Compression modulus (GPa) 66

[0119] Example 7

[0120] The fiber preform is formed by alternating layers of a first unidirectional fiber preform 11 oriented in the first direction X and a second unidirectional fiber preform 12 oriented in the second direction Y, in a 1:2 ratio. The ratio of benzoxazine to basalt fiber content is 40:60. The set temperatures are: 50°C for the pressurization section 21, 150°C for the semi-curing section 22, 200°C for the curing section 23, and 50°C for the cooling section 24. The performance parameters of the resulting composite material product 10 are shown in the table below.

[0121] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 670 Tensile strength (MPa) along the second direction Y 800 Bending strength (MPa) along the second direction Y 1200 Flexural modulus (GPa) 60 Compressive strength (MPa) along the second direction Y 920 Compression modulus (GPa) 74

[0122] Example 8

[0123] The difference from Example 7 is that the temperatures are set as follows: the temperature of the pressurization section 21 is 10°C, the temperature of the semi-curing section 22 is 120°C, the temperature of the curing section 23 is 170°C, and the temperature of the cooling section 24 is 20°C. The performance parameters of the resulting composite material product 10 are shown in the table below:

[0124] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 660 Tensile strength (MPa) along the second direction Y 790 Bending strength (MPa) along the second direction Y 1180 Flexural modulus (GPa) 58 Compressive strength (MPa) along the second direction Y 910 Compression modulus (GPa) 72

[0125] Example 9

[0126] The difference from Example 7 is that the temperatures are set as follows: 120°C for the pressurization section 21, 170°C for the semi-curing section 22, 210°C for the curing section 23, and 70°C for the cooling section 24. The performance parameters of the resulting composite material product 10 are shown in the table below.

[0127] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 672 Tensile strength (MPa) along the second direction Y 805 Bending strength (MPa) along the second direction Y 1210 Flexural modulus (GPa) 61 Compressive strength (MPa) along the second direction Y 924 Compression modulus (GPa) 74

[0128] Example 10

[0129] The fiber preform is composed of multi-directional fiber preforms stacked together. Each multi-directional fiber preform is formed by interlacing fibers oriented in the first direction X and fibers oriented in the second direction Y in a 1:1 ratio. The ratio of benzoxazine to basalt fiber content is 40:60. The set temperatures are: 50℃ for the pressurization section 21, 150℃ for the semi-curing section 22, 200℃ for the curing section 23, and 50℃ for the cooling section 24. The performance parameters of the resulting composite material product 10 are shown in the table below.

[0130]

[0131]

[0132] Example 11

[0133] The difference from Example 10 is that the temperatures are set as follows: the temperature of the pressurization section 21 is 10°C, the temperature of the semi-curing section 22 is 120°C, the temperature of the curing section 23 is 170°C, and the temperature of the cooling section 24 is 30°C. The performance parameters of the resulting composite material product 10 are shown in the table below:

[0134] project data Density (g / cm3) 1.90 Tensile strength (MPa) along the first direction X 675 Tensile strength (MPa) along the second direction Y 674 Bending strength (MPa) along the second direction Y 1020 Flexural modulus (GPa) 50 Compressive strength (MPa) along the second direction Y 790 Compression modulus (GPa) 64

[0135] Example 12

[0136] The difference from Example 10 is that the temperatures are set as follows: the temperature of the pressurization section 21 is 120°C, the temperature of the semi-curing section 22 is 170°C, the temperature of the curing section 23 is 210°C, and the temperature of the cooling section 24 is 70°C. The performance parameters of the resulting composite material product 10 are shown in the table below:

[0137]

[0138]

[0139] Optionally, the temperature of each section in the mold cavity 20 is selected according to the different materials of the composite material product 10. Taking the preparation of a composite material product 10 containing epoxy resin as an example, the temperature of the extrusion mold pressure section 21 is controlled at 10-30℃, the temperature of the semi-curing section 22 is controlled at 120-150℃ (i.e., the first preset temperature range), the temperature of the curing section 23 is controlled at 150-180℃ (i.e., relative to or equal to the curing temperature), and the temperature of the cooling section 24 is controlled at 10-30℃ (i.e., the second preset temperature range). Taking the preparation of a composite material product 10 containing polyimide resin as an example, the temperature of the extrusion mold pressure section 21 is controlled at 10-30℃, the temperature of the semi-curing section 22 is controlled at 250-350℃, the temperature of the curing section 23 is controlled at 350-400℃, and the temperature of the cooling section 24 is controlled at 10-50℃.

[0140] Optionally, this application also discloses a method for manufacturing fiber preforms. Specifically, before providing the fiber preforms to the pressurizing section 21, the preparation method of this application further includes:

[0141] The fiber cloth is pre-impregnated in a thermosetting resin to provide a fiber preform. The fiber cloth can be either a multidirectional or unidirectional fiber cloth as described above. Taking benzoxazine as an example, the fiber cloth is impregnated in a benzoxazine solution at room temperature, such as within the temperature range of 0–40°C, and then dried or air-dried to obtain the fiber preform.

[0142] The fiber prefabricated sheet is cut according to a preset cross-sectional shape. This can be achieved, for example, by using scissors or cutting dies.

[0143] Fiber preforms are stacked sequentially along the length direction Z to provide fiber preforms.

[0144] In this way, the thermosetting resin in liquid state can effectively encapsulate the fiber cloth and achieve good dispersion and wetting. The fiber cloth determines the fiber orientation of the fiber preform, and the preset cross-sectional shape roughly matches the cross-sectional shape of the composite material product 10. For example, the preset cross-section can be cut into circles, rectangles, hexagons, rings, etc., as needed to prepare composite material products 10 with circular, rectangular, hexagonal, or ring-shaped cross-sections. Simultaneously, the overlap between the preset cross-section and the cross-section of the composite material product 10 is greater than 95%, so that the fiber preform can smoothly enter the pressing section 21 and, after being compacted in the pressing section 21, can tightly adhere to the inner wall of the mold cavity 20 for molding.

[0145] Optionally, the fibers in the fiber preform of the composite material article 10 can be organic fibers or inorganic fibers. Specifically, the inorganic fibers can be one of glass fiber cloth, carbon fiber, basalt fiber, and quartz fiber; the organic fibers can be one of aramid fiber and ultra-high molecular weight polyethylene fiber.

[0146] Optionally, the thermosetting resin may be one of epoxy resin, vinyl ester resin, phenolic resin, benzoxazine resin, bismaleimide resin, or cyanate ester resin.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a thermosetting composite material product (10), wherein the composite material product (10) is formed in the cavity (20) of an extrusion die, the extrusion die comprising a pressure section (21) and a curing section (23) disposed in the cavity (20) and arranged sequentially along the feeding direction of the cavity (20), characterized in that, The method includes: Perform the feeding process: provide fiber preforms to the pressing section (21); Perform the compaction process: compress the fiber preform in the pressurization section (21) to provide the compressed fiber preform; Perform the transfer process: transfer the compressed fiber preform to the curing section (23); Perform the curing process: In the curing section (23), the compressed fiber preform is heated to a temperature greater than or equal to the curing temperature to provide the composite material product (10). After each transfer process, a new fiber preform is added to the pressurizing section (21), and the newly added fiber preform is cycled through the feeding process and the curing process, so that the head section of the composite material product (10) is extruded from the output end of the mold cavity (20), and a new composite material product (10) is generated at the end of the composite material product (10). The fiber preform comprises multiple fiber preforms stacked sequentially along the Z-direction, wherein the fiber preforms are one of multidirectional fiber preforms and unidirectional fiber preforms; wherein the multidirectional fiber preform comprises a multidirectional fiber cloth and a thermosetting resin, and the multidirectional fiber cloth comprises fibers with at least two intersecting fiber orientations; the unidirectional fiber preform comprises a unidirectional fiber cloth and a thermosetting resin, wherein the fiber orientation of the fibers within the unidirectional fiber cloth remains consistent; and the curing temperature is the crosslinking curing temperature of the thermosetting resin. The fiber preform comprises at least two unidirectional fiber preforms with intersecting fiber orientations, or the fiber preform comprises the multidirectional fiber preform. The length direction Z is consistent with the feeding direction, and the fiber orientation is perpendicular to the length direction Z; the compression direction of the mold cavity (20) on the fiber preform is parallel to the length direction Z.

2. The preparation method according to claim 1, characterized in that, The extrusion die also includes a semi-curing section (22) located in the die cavity (20) and disposed between the pressurizing section (21) and the curing section (23). The transfer of the compressed fiber preform to the curing section (23) to heat the compressed fiber preform to a temperature greater than the curing temperature to provide the composite material article (10) includes: The compressed fiber preform is transferred to the semi-curing section (22). In the semi-curing section (22), the compressed fiber preform is heated to a first preset temperature to provide a semi-cured product; The semi-solidified product is transferred to the curing section (23). In the curing section (23), the semi-consolidated product is heated to a temperature greater than the curing temperature to provide the composite material product (10). Wherein, the first preset temperature is lower than the curing temperature.

3. The preparation method according to claim 1, characterized in that, The extrusion die also includes a cooling section (24) disposed in the die cavity (20), and the pressurizing section (21), the curing section (23) and the cooling section (24) are arranged sequentially along the feeding direction; After transferring the compressed fiber preform to the curing section (23) to heat the compressed fiber preform to a temperature greater than the curing temperature to provide the composite material article (10), the method further includes: The composite material product (10) is transferred to the cooling section (24). The composite material product (10) is cooled to a second preset temperature in the cooling section (24); Wherein, the second preset temperature is lower than the curing temperature.

4. The preparation method according to claim 1, characterized in that, Prior to providing the fiber preform to the pressurizing section (21), the method further includes: The fiber cloth is pre-impregnated in a thermosetting resin to provide the fiber preform; the fiber cloth is the multidirectional fiber cloth or the unidirectional fiber cloth; The fiber preforms are stacked sequentially along the length direction Z to provide the fiber preform.

5. The preparation method according to claim 4, characterized in that, The fibers in the fiber preform of the composite material product (10) are organic fibers or inorganic fibers.

6. The preparation method according to claim 5, characterized in that, The inorganic fiber is one of glass fiber cloth, carbon fiber, basalt fiber, and quartz fiber; The organic fiber is one of aramid fiber and ultra-high molecular weight polyethylene fiber.

7. The preparation method according to claim 4, characterized in that, The thermosetting resin is one of epoxy resin, vinyl ester resin, phenolic resin, benzoxazine resin, bismaleimide resin, and cyanate ester resin.

8. The preparation method according to claim 1, characterized in that, The unidirectional fiber preform in the fiber preform is divided into a first unidirectional fiber preform (11) and a second unidirectional fiber preform (12); the first unidirectional fiber preform (11) is oriented in the first direction X, and the second unidirectional fiber preform (12) is oriented in the second direction Y, and the first direction X, the second direction Y and the length direction Z intersect each other; The fiber prepreg includes a first prepreg section and a second prepreg section alternately arranged along the length direction Z. The first prepreg section includes a first unidirectional fiber prepreg (11) or a plurality of first unidirectional fiber prepregs (11) stacked sequentially along the length direction Z. The second prepreg section includes a second unidirectional fiber prepreg (12) or a plurality of second unidirectional fiber prepregs (12) stacked sequentially along the length direction Z.

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