Continuous carbon fiber reinforced polyaryletherketone rod-shaped structural member, reinforced screw and preparation method of continuous carbon fiber reinforced polyaryletherketone rod-shaped structural member

Abstract

The invention provides a continuous carbon fiber reinforced polyaryletherketone rod-like structural member, a reinforced screw and a preparation method thereof, belongs to the technical field of engineering plastics, and mainly develops post-treatment of annealing a hot-press molded rod in a vacuum rotating state, so that overall uniform heating can be realized, internal stress can be effectively eliminated, and the service life of the reinforced screw is prolonged. According to the preparation method of the reinforced screw, the continuous carbon fibers are laid in a partitioned and multi-layer mode in the internal structure of the screw and are combined with vacuum rotation synergistic annealing, the prepared screw has the advantage of being excellent in comprehensive mechanical property, and the service life of the screw is prolonged. The torsional strength is greater than or equal to 6.0 N.m, the cyclic fatigue is greater than or equal to 6 million times, and the bending strength is greater than or equal to 900 N.

Description

Technical Field

[0001] This invention belongs to the field of engineering plastics technology, specifically relating to a continuous carbon fiber reinforced polyaryletherketone rod structure, a reinforcing screw, and a method for preparing the same. Background Technology

[0002] Currently, continuous carbon fiber reinforced thermoplastic composites, while inheriting the excellent properties of thermoset carbon fiber composites such as corrosion resistance, high specific strength, and low density, further integrate outstanding characteristics such as recyclability and efficient molding. This makes them show broad application prospects in many cutting-edge fields, such as aerospace, medical and health, and electronics and electrical industries. However, due to the core technological barriers in material preparation and molding processing, the promotion and application of this material in China still faces many constraints. Among them, the medical field, with its specific performance requirements and technological acceptance, has become a relatively mature and concentrated application area in China.

[0003] In clinical medicine, traditional screws are mostly made of titanium alloy or stainless steel, but these metal materials have the following drawbacks: 1. Their elastic modulus is much higher than that of human bone tissue, which can easily cause stress shielding effect, leading to bone resorption and screw loosening; 2. They produce obvious artifacts in medical images such as CT and MRI, affecting postoperative evaluation; 3. There is a risk of metal ion release with long-term implantation.

[0004] Polyetheretherketone (PEEK) and its derivative orthopedic materials possess excellent image transmittance and an elastic modulus close to that of human bone tissue, leading to their gradual development and application in clinical practice. However, existing carbon fiber composite screws are mostly based on chopped carbon fiber reinforced PEEK. For example, patent CN116533550A discloses a processing technology for a vertebral body shaping screw based on carbon fiber reinforced PEEK material. This involves uniformly mixing and granulating chopped carbon fiber with PEEK powder to obtain a composite powder, which is then injection molded and hot-pressed to obtain the semi-finished components of the vertebral body shaping screw. Furthermore, some clinical medical screws still use metal mandrels. For instance, patent CN113209389A discloses a medical orthopedic bone nail comprising a mandrel and carbon fiber reinforced PEEK wrapped around the mandrel. The mandrel is made of Ti6Al4V titanium alloy. Moreover, there are few reports on post-processing techniques for screw forming.

[0005] In summary, existing carbon fiber reinforced thermoplastic composites still have problems such as insufficient mechanical properties, and there is a need to develop a continuous carbon fiber reinforced polyaryletherketone rod structure, a reinforcing screw, and its preparation method. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention provides a continuous carbon fiber reinforced polyaryletherketone rod structure, a reinforced screw, and a method for preparing the same. The key development is the post-treatment of annealing the hot-pressed rod under vacuum rotation, which can achieve uniform heating, effectively eliminate internal stress, and enhance the interfacial bonding between the continuous carbon fiber and the polyaryletherketone matrix, thereby significantly improving pull-out force, bending strength, and fatigue life. The method for preparing the reinforced screw combines the multi-layer laying of continuous carbon fiber in the internal structure of the screw with vacuum rotation synergistic annealing. The resulting screw has excellent comprehensive mechanical properties, with a torsional strength ≥6.0 Nm, cyclic fatigue ≥6 million cycles, and bending strength ≥900 N.

[0007] To achieve this objective, the present invention adopts the following technical solution: One objective of this invention is to provide a method for preparing a continuous carbon fiber reinforced polyaryletherketone rod structure, the method comprising the following steps: (1) In-situ impregnation of continuous carbon fiber with molten polyaryletherketone to form a continuous carbon fiber / polyaryletherketone prepreg tape; (2) Lay the continuous carbon fiber / polyaryletherketone prepreg tape described in step (1) at 0° axial angle and hot press it to form a continuous carbon fiber reinforced polyaryletherketone board. (3) The continuous carbon fiber reinforced polyaryletherketone sheet described in step (2) is machined at 0° along the axial direction, and the resulting rod is annealed under vacuum rotation to form a continuous carbon fiber reinforced polyaryletherketone rod structure.

[0008] The method for preparing continuous carbon fiber reinforced polyaryletherketone rod structure of the present invention involves annealing the hot-pressed and machined rod under vacuum rotation. This achieves uniform heating, effectively eliminates internal stress, promotes secondary fusion and interfacial rearrangement of the continuous carbon fiber and the polyaryletherketone matrix, thereby enhancing the interfacial bonding between the two and significantly improving pull-out resistance, bending strength and fatigue life.

[0009] As a preferred technical solution of the present invention, in step (1), the continuous carbon fiber is a high-modulus carbon fiber or a medium-modulus carbon fiber, which meets the performance requirements of aerospace, medical devices and other fields.

[0010] As a preferred technical solution of the present invention, in step (1), the volume fraction of continuous carbon fiber in the continuous carbon fiber / polyaryletherketone prepreg tape is 40-65%, such as 40%, 45%, 50%, 55%, 60% or 65%, etc., but not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0011] And / or, in step (1), the polyaryletherketone includes any one or a combination of at least two of polyetheretherketone, polyetherketoneketone, polyetherketone, polyetheretherketoneketone or polyetherketoneetherketoneketone, preferably polyetheretherketone.

[0012] As a preferred technical solution of the present invention, in step (2), the temperature of the hot pressing is 350-400℃, such as 350℃, 360℃, 370℃, 380℃, 390℃ or 400℃, etc., the pressure of the hot pressing is 13-18MPa, such as 13MPa, 14MPa, 15MPa, 16MPa, 17MPa or 18MPa, etc., and the time of the hot pressing is 3-8min, such as 3min, 4min, 5min, 6min, 7min or 8min, etc., but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0013] As a preferred technical solution of the present invention, in step (3), the annealing is carried out in a vacuum drum dryer.

[0014] And / or, in step (3), the vacuum degree of the annealing is ≤100Pa.

[0015] And / or, in step (3), the rotational speed of the annealing is 5-25 rpm, such as 5 rpm, 8 rpm, 10 rpm, 11 rpm, 13 rpm, 15 rpm, 18 rpm, 20 rpm, 22 rpm or 25 rpm, but not limited to the listed values. Other unlisted values ​​within the above range are also applicable, preferably 10-15 rpm.

[0016] As a preferred technical solution of the present invention, in step (3), the annealing includes a low-temperature stress relief stage, a high-temperature crystal region rearrangement stage, and a slow cooling and shaping stage performed sequentially.

[0017] Preferably, the temperature of the low-temperature stress relief stage is 180-220℃, such as 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃, 215℃ or 220℃, and the holding time is 1-2h, such as 1h, 1.1h, 1.3h, 1.5h, 1.6h, 1.8h or 2h, but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0018] Preferably, the temperature of the high-temperature crystal region rearrangement stage is 280-340℃, such as 280℃, 290℃, 300℃, 310℃, 320℃, 330℃ or 340℃, and the holding time is 1-3h, such as 1h, 1.3h, 1.5h, 1.7h, 2h, 2.3h, 2.5h, 2.8h or 3h, but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0019] Preferably, the cooling rate during the slow cooling and shaping stage is ≤2℃ / min.

[0020] The low-temperature stress relief stage, high-temperature crystal region rearrangement stage, and slow cooling and shaping stage that are carried out sequentially in the annealing process described in this invention are processes of gradual crystal improvement, which help to make the molecular structure crystal tend to be perfect.

[0021] As a preferred technical solution of the present invention, in step (3), the annealing is accompanied by microwave vibration treatment, which can further remove the gas at the interface between the continuous carbon fiber and the polyaryletherketone matrix by microwave vibration under vacuum rotation, which can further eliminate internal stress, promote the secondary fusion and interface rearrangement of the continuous carbon fiber and the polyaryletherketone matrix, thereby enhancing the interface bonding between the two, and further significantly improving the pull-out resistance, bending strength and fatigue life.

[0022] Preferably, the microwave vibration frequency of the microwave vibration treatment is 20-80Hz, such as 20Hz, 30Hz, 40Hz, 50Hz, 53Hz, 55Hz, 58Hz, 60Hz, 70Hz or 80Hz, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable, preferably 50-60Hz.

[0023] A second objective of this invention is to provide a continuous carbon fiber reinforced polyaryletherketone rod-shaped structural component, which is prepared using the preparation method described in one objective.

[0024] A third objective of this invention is to provide a reinforcing screw, the reinforcing screw comprising a central core rod, a threaded layer located on the side surface of the central core rod, and a screw tail located at the tip of the central core rod; wherein, the central core rod comprises a continuous carbon fiber reinforced polyaryletherketone rod-shaped structure prepared by the preparation method described in the first objective, or, the central core rod comprises a continuous carbon fiber reinforced polyaryletherketone rod-shaped structure described in the second objective.

[0025] The fourth objective of this invention is to provide a method for preparing the reinforcing screw described in the third objective, the method comprising the following steps: S1: In-situ impregnation of continuous carbon fibers with molten polyaryletherketone (PREE) to form continuous carbon fiber / PREE prepreg yarn and continuous carbon fiber / PREE prepreg tape. S2: The continuous carbon fiber / polyaryletherketone prepreg tape described in S1 is laid at 0° axial direction and hot-pressed. The resulting plate is machined into a cylindrical shape at 0° axial direction to obtain the screw core rod. S3: The continuous carbon fiber / polyaryletherketone prepreg tape described in S1 is cut into narrow strips at 0° along the axial direction. The narrow strips are then interlaced and hot-pressed on the side surface of the screw mandrel described in S2 to form the threaded processing area. S4: The continuous carbon fiber / polyaryletherketone prepreg yarn described in S1 is interwoven to form a carbon fiber cloth, which is then wrapped around the tail of the rod obtained in S3 and hot-pressed to form the screw tail. S5: Place the screw blank obtained in S4 into a screw mold and hot press it to obtain a shaped screw; S6: Anneal the formed screw described in S5 under vacuum rotation to form a reinforced screw.

[0026] The method for preparing the reinforced screw described in this invention involves, on the one hand, laying continuous carbon fibers in multiple layers within the screw's internal structure to achieve a zoned, directional reinforcement design; on the other hand, annealing the integrally hot-pressed screw under vacuum rotation allows for uniform heating, releasing internal residual stress and promoting secondary fusion and interfacial rearrangement between the continuous carbon fibers and the polyaryletherketone matrix. This enhances the interfacial bonding between the two, significantly improving the screw's pull-out force, bending strength, and fatigue life, reducing the risk of fracture initiation, and improving implantation safety and reliability. The reinforced screw prepared by this invention not only effectively overcomes the stress shielding and image artifact problems of metal screws but also possesses excellent comprehensive mechanical properties, significantly improving the screw's pull-out force, bending strength, and fatigue life while reducing internal residual stress and interfacial defects.

[0027] It should be noted that the continuous carbon fiber partitioned directional reinforcement design in the reinforcing screw of the present invention includes: the core rod of the reinforcing screw adopts a 0° axial continuous carbon fiber reinforcement structure, which can improve bending stiffness; the thread layer of the reinforcing screw adopts continuous carbon fiber prepreg tape interlaced with a helical angle of ±20°-±40°, which can improve pull-out resistance and fatigue resistance; the tail of the reinforcing screw is covered with a continuous carbon fiber cloth with an interlaced braided structure, which can suppress crack propagation and improve fracture toughness.

[0028] As a preferred technical solution of the present invention, in step S3, the width of the narrow band is 1.5-2.5mm, such as 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm or 2.5mm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0029] And / or, in step S3, the helical angle of the interlaced winding is ±20°-±40°, such as ±20°, ±25°, ±30°, ±35° or ±40°, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0030] And / or, in step S4, the weaving angle of the carbon fiber cloth is ±40-±50°, such as ±40°, ±41°, ±43°, ±45°, ±47°, ±49° or ±50°, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0031] And / or, in steps S2-S5, the hot pressing temperature is independently 350-400℃, for example 350℃, 360℃, 370℃, 380℃, 390℃ or 400℃, etc., the hot pressing pressure is independently 13-18MPa, for example 13MPa, 14MPa, 15MPa, 16MPa, 17MPa or 18MPa, etc., and the hot pressing time is independently 3-8min, for example 3min, 4min, 5min, 6min, 7min or 8min, etc., but is not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0032] And / or, in step S6, the annealing is performed in a vacuum drum dryer.

[0033] And / or, in step S6, the vacuum degree of the annealing is ≤100Pa.

[0034] And / or, in step S6, the rotational speed of the annealing is 5-25 rpm, such as 5 rpm, 8 rpm, 10 rpm, 11 rpm, 13 rpm, 15 rpm, 18 rpm, 20 rpm, 22 rpm or 25 rpm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable, preferably 10-15 rpm.

[0035] And / or, in step S6, the annealing includes a low-temperature stress relief stage, a high-temperature crystal region rearrangement stage, and a slow cooling and shaping stage performed sequentially; the temperature of the low-temperature stress relief stage is 180-220℃, for example, 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃, 215℃, or 220℃, etc., and the holding time is 1-2 hours, for example, 1 hour, 1.1 hours, 1.3 hours, 1.5 hours, or 1 hour. The temperature of the high-temperature crystal rearrangement stage is 280-340℃, such as 280℃, 290℃, 300℃, 310℃, 320℃, 330℃ or 340℃, etc., and the holding time is 1-3h, such as 1h, 1.3h, 1.5h, 1.7h, 2h, 2.3h, 2.5h, 2.8h or 3h, etc., and the cooling rate of the slow cooling and shaping stage is ≤2℃ / min.

[0036] And / or, in step S6, the annealing is also accompanied by microwave vibration treatment; the microwave vibration frequency of the microwave vibration treatment is 20-80Hz, such as 20Hz, 30Hz, 40Hz, 50Hz, 53Hz, 55Hz, 58Hz, 60Hz, 70Hz or 80Hz, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable, preferably 50-60Hz.

[0037] Compared with existing technical solutions, the present invention has at least the following beneficial effects: (1) This invention provides a method for preparing continuous carbon fiber reinforced polyaryletherketone rod structure. The key development is the post-treatment of annealing the rod after hot pressing in a vacuum rotation state, which can achieve uniform heating of the whole, effectively eliminate internal stress, enhance the interfacial bonding between continuous carbon fiber and polyaryletherketone matrix, and thus significantly improve pull-out resistance, bending strength and fatigue life.

[0038] (2) The method for preparing the reinforced screw described in this invention adopts a continuous carbon fiber directional reinforcement structure, which effectively improves the bending resistance, pull-out resistance and fatigue resistance.

[0039] (3) The preparation method of the reinforcing screw described in this invention achieves optimal matching of performance in different parts through a zoned laying design.

[0040] (4) The method for preparing the reinforcing screw of the present invention preferably uses a rotary drum vacuum microwave synergistic annealing process, which can significantly reduce residual stress and improve interface density.

[0041] (5) The reinforced screw prepared by the present invention can not only effectively overcome the stress shielding and image artifact problems of metal screws, but also has excellent image transmittance and biocompatibility, reducing the risk of postoperative complications. It also has excellent comprehensive mechanical properties, with torsional strength ≥6.0Nm, cyclic fatigue ≥6 million times, and bending strength ≥900N. It can significantly improve the screw's pull-out force, bending strength and fatigue life, and reduce the residual stress and interface defects inside the screw. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the fabrication process of a reinforced screw containing a continuous carbon fiber reinforced polyaryletherketone rod structure; In the diagram: 1-Screw core bar; 2-Threaded area to be machined; 3-Screw tail. Detailed Implementation

[0043] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0044] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows: The continuous carbon fiber is grade T700, and the polyetheretherketone (PEEK) is grade Vigers PEEK 450G.

[0045] Example 1 This embodiment provides a method for preparing a continuous carbon fiber reinforced polyaryletherketone rod structure, the method comprising the following steps: (1) Prepreg preparation: High-modulus continuous carbon fiber (T700 grade) and molten polyether ether ketone (PEEK) resin are impregnated in situ using a hot melt impregnation device to form a continuous carbon fiber / PEEK prepreg tape. The volume fraction of continuous carbon fiber in the continuous carbon fiber / PEEK prepreg tape is controlled to be 60%, the width is 100 mm, and the unit area mass is 200 g / m. 2 ; (2) Laying and hot pressing: The continuous carbon fiber / polyetheretherketone prepreg tape is laid unidirectionally in the axial direction (0° direction) for a total of 20 layers. The laminated layers are placed in a hot press and hot pressed for 5 minutes at a temperature of 380 ℃ and a pressure of 15 MPa to allow the resin to fully melt and impregnate the fiber. After curing, a continuous carbon fiber reinforced PEEK board with a thickness of about 5.0 mm is obtained. (3) Machining and Vacuum Rotary Annealing: The continuous carbon fiber reinforced PEEK sheet is machined along the axial direction (0° direction) using a precision lathe to obtain a smooth cylindrical rod with the following specifications: diameter 5.0 mm and length 100.0 mm. The machined rod is placed in a vacuum drum dryer for synergistic annealing. The specific process is as follows: Vacuum is drawn until the system vacuum degree is ≤100 Pa, the drum is started to rotate, the rotation speed is controlled at 15 rpm, and the microwave vibration device is started simultaneously, with the vibration frequency set to 50 Hz. Annealing is carried out according to the following temperature program: the temperature is increased to 190 ℃ at a rate of 5 ℃ / min, and held for 2 h to complete the low-temperature stress relief stage; the temperature is further increased to 330 ℃ at a rate of 5 ℃ / min, and held for 2 h to complete the high-temperature crystal region rearrangement stage; finally, the temperature is increased to 1.5 ℃ / min. The temperature is programmed to decrease to room temperature (approximately 25°C) at a rate of ℃ / min to complete the slow cooling and shaping stage; after annealing, all devices are turned off, the rod is removed, and a continuous carbon fiber reinforced polyether ether ketone cylindrical rod structure is obtained.

[0046] Comparative Example 1 This comparative example provides a method for preparing a continuous carbon fiber reinforced polyaryletherketone rod structure. Compared with Example 1, the only difference is that the annealing step in step (3) is completely omitted, that is, the smooth cylindrical rod obtained by machining (specification: diameter 5.0 mm, length 100.0 mm) is used as the final product.

[0047] Comparative Example 2 This comparative example provides a method for preparing a continuous carbon fiber reinforced polyaryletherketone rod structure. Compared with Example 1, the only difference is that during annealing in step (3), the drum rotation is stopped, so that the drum is in a static state and accompanied by microwave vibration to perform the corresponding annealing step.

[0048] According to the test methods disclosed in ASTM F1717 and ASTM F543, the cylindrical rod-shaped structural members obtained in the above embodiments and comparative examples were tested for bending strength, interlaminar shear, and axial tension, respectively. The relevant test results are summarized in Table 1.

[0049] Table 1 For reinforced screws containing continuous carbon fiber reinforced polyaryletherketone rod-shaped structures, the preparation process is as follows: Figure 1As shown, continuous carbon fiber / polyetheretherketone prepreg filaments and continuous carbon fiber / polyetheretherketone prepreg tapes are obtained by in-situ impregnation. The continuous carbon fiber / polyetheretherketone prepreg tapes are sequentially laid, hot-pressed, and machined to obtain a cylindrical screw core rod 1. Then, the continuous carbon fiber / polyetheretherketone prepreg tapes are cut into narrow strips, which are sequentially interlaced and hot-pressed to obtain the threaded processing area 2. Subsequently, the continuous carbon fiber / polyetheretherketone prepreg filaments are sequentially interlaced, wrapped, and hot-pressed to obtain the screw tail 3. Finally, the screw is placed in a screw mold and sequentially hot-pressed and annealed under vacuum rotation to obtain a reinforced screw.

[0050] Application Example 1 This application example provides a method for preparing a reinforced screw, the method comprising the following steps: S1: High-modulus continuous carbon fiber (T700 grade) is impregnated in situ with molten polyetheretherketone (PEEK) resin using a hot-melt impregnation device to form continuous carbon fiber / PEEK prepreg yarn and continuous carbon fiber / PEEK prepreg tape. The volume fraction of continuous carbon fiber in the continuous carbon fiber / PEEK prepreg tape is controlled to be 60%, the width is 100 mm, and the unit area mass is 200 g / m. 2 ; S2: The continuous carbon fiber / polyetheretherketone prepreg tape described in S1 is laid unidirectionally along the axial direction (0° direction) for a total of 20 layers. The laminated layers are placed in a hot press and hot-pressed for 5 minutes at a temperature of 380 ℃ and a pressure of 15 MPa to fully melt the resin and impregnate the fiber. After curing, a continuous carbon fiber reinforced PEEK sheet with a thickness of about 3.0 mm is obtained. The continuous carbon fiber reinforced PEEK sheet is machined along the axial direction (0° direction) using a precision lathe to obtain a smooth cylindrical rod with a diameter of 3.0 mm and a length of 10.0 mm, which is used to obtain a screw core rod. S3: The continuous carbon fiber / polyetheretherketone prepreg tape described in S1 is cut into narrow strips with a width of 2mm at 0° along the axial direction. Then, on the side surface of the screw core rod described in S2, it is interlaced and wound at a helical angle of ±30°, laying 2 layers. The laminated layers are placed in a hot press and hot-pressed for 5 minutes at a temperature of 380 ℃ and a pressure of 15 MPa to allow the resin to fully melt and impregnate the fiber. After curing, the threaded area to be processed is formed. S4: Using the continuous carbon fiber / polyetheretherketone prepreg described in S1, weave a 2mm wide carbon fiber cloth at a weaving angle of ±45°. Then, wrap two layers around the tail of the screw core rod obtained in S3 and place the whole thing in a hot press. Hot press for 5 minutes at a temperature of 380 ℃ and a pressure of 15 MPa to allow the resin to fully melt and impregnate the fiber. After curing, the screw tail is formed. S5: Place the screw blank obtained in S4 into the corresponding screw mold and put it into a hot press. Hot press for 5 min at a temperature of 380 ℃ and a pressure of 15 MPa to obtain the shaped screw. S6: Place the formed screw described in S5 into a vacuum drum dryer for synergistic annealing. The specific process is as follows: Evacuate the system to a vacuum degree ≤100 Pa, start the drum rotation, control the speed at 15 rpm, and simultaneously start the microwave vibration device, setting the vibration frequency to 50 Hz; perform annealing according to the following temperature program: heat up to 190 ℃ at a rate of 5 ℃ / min, hold for 2 h to complete the low-temperature stress relief stage; continue to heat up to 330 ℃ at a rate of 5 ℃ / min, hold for 2 h to complete the high-temperature crystal region rearrangement stage; finally, cool down to room temperature (approximately 25°C) at a rate of 1.5 ℃ / min to complete the slow cooling and shaping stage; after annealing, turn off all devices and remove the reinforced screw.

[0051] Application Example 2 This application example provides a method for preparing a reinforced screw, the method comprising the following steps: S1: High-modulus continuous carbon fiber (T700 grade) is impregnated in situ with molten polyetheretherketone (PEEK) resin using a hot-melt impregnation device to form continuous carbon fiber / PEEK prepreg yarn and continuous carbon fiber / PEEK prepreg tape. The volume fraction of continuous carbon fiber in the continuous carbon fiber / PEEK prepreg tape is controlled to be 40%, the width is 100 mm, and the unit area mass is 200 g / m. 2 ; S2: The continuous carbon fiber / polyetheretherketone prepreg tape described in S1 is laid unidirectionally along the axial direction (0° direction) for a total of 20 layers. The laminated layers are placed in a hot press and hot-pressed for 3 minutes at a temperature of 350 ℃ and a pressure of 13 MPa to fully melt the resin and impregnate the fiber. After curing, a continuous carbon fiber reinforced PEEK sheet with a thickness of about 3.0 mm is obtained. The continuous carbon fiber reinforced PEEK sheet is machined along the axial direction (0° direction) using a precision lathe to obtain a smooth cylindrical rod with a diameter of 3.0 mm and a length of 10.0 mm, which is used to obtain a screw core rod. S3: The continuous carbon fiber / polyetheretherketone prepreg tape described in S1 is cut into narrow strips with a width of 1.5 mm at 0° along the axial direction. Then, on the side surface of the screw mandrel described in S2, it is interlaced and wound at a helical angle of ±20°, laying 2 layers. The laminated layers are placed in a hot press and hot-pressed for 3 minutes at a temperature of 350 ℃ and a pressure of 13 MPa to allow the resin to fully melt and impregnate the fiber. After curing, the threaded area to be processed is formed. S4: Using the continuous carbon fiber / polyetheretherketone prepreg described in S1, weave a carbon fiber cloth with a width of 1.5 mm at a weaving angle of ±40°. Then, wrap two layers around the tail of the screw core rod obtained in S3 and place the whole in a hot press. Hot press for 3 minutes at a temperature of 350 ℃ and a pressure of 13 MPa to fully melt the resin and impregnate the fiber. After curing, the screw tail is formed. S5: Place the screw blank obtained in S4 into the corresponding screw mold and put it into a hot press. Hot press for 3 min at a temperature of 350 ℃ and a pressure of 13 MPa to obtain the shaped screw. S6: Place the formed screw described in S5 into a vacuum drum dryer for synergistic annealing. The specific process is as follows: Evacuate the system to a vacuum degree ≤100 Pa, start the drum rotation, control the speed at 10 rpm, and simultaneously start the microwave vibration device, setting the vibration frequency to 50 Hz; perform annealing according to the following temperature program: heat up to 180 ℃ at a rate of 5 ℃ / min, hold for 1 h to complete the low-temperature stress relief stage; continue to heat up to 280 ℃ at a rate of 5 ℃ / min, hold for 1 h to complete the high-temperature crystal region rearrangement stage; finally, cool down to room temperature (approximately 25°C) at a rate of 1.5 ℃ / min to complete the slow cooling and shaping stage; after annealing, turn off all devices and remove the reinforced screw.

[0052] Application Example 3 This application example provides a method for preparing a reinforced screw, the method comprising the following steps: S1: High-modulus continuous carbon fiber (T700 grade) is impregnated in situ with molten polyetheretherketone (PEEK) resin using a hot-melt impregnation device to form continuous carbon fiber / PEEK prepreg yarn and continuous carbon fiber / PEEK prepreg tape. The volume fraction of continuous carbon fiber in the continuous carbon fiber / PEEK prepreg tape is controlled to be 65%, the width is 100 mm, and the unit area mass is 200 g / m. 2 ; S2: The continuous carbon fiber / polyetheretherketone prepreg tape described in S1 is laid unidirectionally along the axial direction (0° direction) for a total of 20 layers. The laminated layers are placed in a hot press and hot-pressed for 8 minutes at a temperature of 400 ℃ and a pressure of 18 MPa to fully melt the resin and impregnate the fiber. After curing, a continuous carbon fiber reinforced PEEK sheet with a thickness of about 3.0 mm is obtained. The continuous carbon fiber reinforced PEEK sheet is machined along the axial direction (0° direction) using a precision lathe to obtain a smooth cylindrical rod with a diameter of 3.0 mm and a length of 10.0 mm, which is used to obtain a screw core rod. S3: The continuous carbon fiber / polyetheretherketone prepreg tape described in S1 is cut into narrow strips with a width of 2.5 mm at 0° along the axial direction. Then, on the side surface of the screw mandrel described in S2, it is interlaced and wound at a helical angle of ±40°, laying 2 layers. The laminated layers are placed in a hot press and hot-pressed for 8 minutes at a temperature of 400 ℃ and a pressure of 18 MPa to allow the resin to fully melt and impregnate the fiber. After curing, the threaded area to be processed is formed. S4: Using the continuous carbon fiber / polyetheretherketone prepreg described in S1, weave a carbon fiber cloth with a width of 2.5 mm at a weaving angle of ±50°. Then, wrap two layers around the tail of the screw core rod obtained in S3 and place the whole in a hot press. Hot press for 8 minutes at a temperature of 400 ℃ and a pressure of 18 MPa to fully melt the resin and impregnate the fiber. After curing, the screw tail is formed. S5: Place the screw blank prepared in S4 into the corresponding screw mold and put it into a hot press. Hot press for 8 minutes at a temperature of 400 ℃ and a pressure of 18 MPa to obtain the shaped screw. S6: Place the formed screw described in S5 into a vacuum drum dryer for synergistic annealing. The specific process is as follows: Evacuate the system to a vacuum degree ≤100 Pa, start the drum rotation, control the speed at 10 rpm, and simultaneously start the microwave vibration device, setting the vibration frequency to 60 Hz; perform annealing according to the following temperature program: heat up to 220 ℃ at a rate of 5 ℃ / min, hold for 2 h to complete the low-temperature stress relief stage; continue to heat up to 340 ℃ at a rate of 5 ℃ / min, hold for 2 h to complete the high-temperature crystal region rearrangement stage; finally, cool down to room temperature (approximately 25°C) at a rate of 1.5 ℃ / min to complete the slow cooling and shaping stage; after annealing, turn off all devices and remove the reinforced screw.

[0053] Application Example 4 This application example provides a method for preparing a reinforced screw, which differs from Application Example 1 only in that the microwave vibration in step S6 is completely omitted.

[0054] Comparative Application Example 1 This comparative application example provides a method for preparing a screw. Compared with Application Example 1, the only difference is that step S4 is completely omitted, that is, the tail of the mandrel in the screw is no longer covered with carbon fiber cloth.

[0055] Comparative Application Example 2 This comparative application example provides a method for preparing a screw, which differs from Application Example 1 only in that the rotation in step S6 is stopped, and vacuum microwave vibration-assisted annealing is performed in a static state.

[0056] Comparative Application Example 3 This comparative application example provides a method for preparing a screw, which differs from Application Example 1 only in that the vacuum condition in step S6 is completely omitted, that is, annealing with rotational microwave vibration synergy is performed under normal pressure.

[0057] According to the test methods disclosed in ASTM F1717 and ASTM F543, the screws obtained in the above examples and comparative examples were tested for torsional strength, cyclic fatigue and bending strength, respectively. The relevant test results are summarized in Table 2.

[0058] Table 2 This invention provides a continuous carbon fiber reinforced polyaryletherketone (PAEK) rod structure, a reinforced screw, and a method for preparing the same. The key development focuses on the post-treatment of annealing the hot-pressed rod under vacuum rotation, which achieves uniform heating, effectively eliminates internal stress, and enhances the interfacial bonding between the continuous carbon fiber and the PAEK matrix. This significantly improves pull-out strength, bending strength, and fatigue life. The method for preparing the reinforced screw combines multi-layered continuous carbon fiber layering within the screw's internal structure with vacuum rotation synergistic annealing. The resulting screw exhibits excellent comprehensive mechanical properties, including a torsional strength ≥6.0 Nm, cyclic fatigue strength ≥6 million cycles, and bending strength ≥900 N.

[0059] The present invention has been illustrated with the above embodiments to illustrate its detailed structural features. However, the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0060] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0061] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0062] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing a continuous carbon fiber reinforced polyaryletherketone rod-shaped structural component, characterized in that, The preparation method includes the following steps: (1) In-situ impregnation of continuous carbon fiber with molten polyaryletherketone to form a continuous carbon fiber / polyaryletherketone prepreg tape; (2) Lay the continuous carbon fiber / polyaryletherketone prepreg tape described in step (1) at 0° axial angle and hot press it to form a continuous carbon fiber reinforced polyaryletherketone board. (3) The continuous carbon fiber reinforced polyaryletherketone sheet described in step (2) is machined at 0° along the axial direction, and the resulting rod is annealed under vacuum rotation to form a continuous carbon fiber reinforced polyaryletherketone rod structure.

2. The preparation method according to claim 1, characterized in that, In step (1), the volume fraction of continuous carbon fiber in the continuous carbon fiber / polyaryletherketone prepreg tape is 40-65%; In step (1), the polyaryletherketone includes any one or a combination of at least two of polyetheretherketone, polyetherketoneketone, polyetherketone, polyetheretherketoneketone or polyetherketoneetherketoneketone.

3. The preparation method according to claim 1, characterized in that, In step (2), the hot pressing temperature is 350-400℃, the hot pressing pressure is 13-18MPa, and the hot pressing time is 3-8min.

4. The preparation method according to claim 1, characterized in that, In step (3), the annealing is carried out in a vacuum drum dryer; the vacuum degree of the annealing is ≤100Pa; the rotation speed of the annealing is 5-25rpm.

5. The preparation method according to claim 1 or 4, characterized in that, In step (3), the annealing includes a low-temperature stress relief stage, a high-temperature crystal region rearrangement stage, and a slow cooling and shaping stage performed sequentially.

6. The preparation method according to claim 1 or 4, characterized in that, In step (3), the annealing is accompanied by microwave vibration treatment; the microwave vibration frequency of the microwave vibration treatment is 20-80Hz.

7. A continuous carbon fiber reinforced polyaryletherketone rod-shaped structural component, characterized in that, It is prepared by the preparation method described in any one of claims 1-6.

8. A reinforcing screw, characterized in that, The reinforcing screw includes a central core, a threaded layer on the side surface of the central core, and a screw tail at the tip of the central core. The core rod comprises a continuous carbon fiber reinforced polyaryletherketone rod structure prepared by the preparation method according to any one of claims 1-6, or the core rod comprises the continuous carbon fiber reinforced polyaryletherketone rod structure according to claim 7.

9. A method for preparing the reinforcing screw according to claim 8, characterized in that, The preparation method includes the following steps: S1: In-situ impregnation of continuous carbon fibers with molten polyaryletherketone (PREE) to form continuous carbon fiber / PREE prepreg yarn and continuous carbon fiber / PREE prepreg tape. S2: The continuous carbon fiber / polyaryletherketone prepreg tape described in S1 is laid at 0° axial direction and hot-pressed. The resulting plate is machined into a cylindrical shape at 0° axial direction to obtain the screw core rod. S3: The continuous carbon fiber / polyaryletherketone prepreg tape described in S1 is cut into narrow strips at 0° along the axial direction. The narrow strips are then interlaced and hot-pressed on the side surface of the screw mandrel described in S2 to form the threaded processing area. S4: The continuous carbon fiber / polyether ether ketone prepreg yarn described in S1 is interwoven to form a carbon fiber cloth, which is then wrapped around the tail of the rod obtained in S3 and hot-pressed to form the screw tail. S5: Place the screw blank obtained in S4 into a screw mold and hot press it to obtain a shaped screw; S6: Anneal the formed screw described in S5 under vacuum rotation to form a reinforced screw.

10. The preparation method according to claim 9, characterized in that, In step S3, the width of the narrow strip is 1.5-2.5 mm; the spiral angle of the interlaced winding is ±20°-±40°.

11. The preparation method according to claim 9, characterized in that, In step S4, the weaving angle of the carbon fiber cloth is ±40-±50°.

12. The preparation method according to claim 9, characterized in that, In steps S2-S5, the hot pressing temperature is independently 350-400℃, the hot pressing pressure is independently 13-18MPa, and the hot pressing time is independently 3-8min.

13. The preparation method according to claim 9, characterized in that, In step S6, the annealing is carried out in a vacuum drum dryer; the vacuum degree of the annealing is ≤100Pa; the rotation speed of the annealing is 5-25rpm.

14. The preparation method according to claim 9, characterized in that, In step S6, the annealing includes a low-temperature stress relief stage, a high-temperature crystal region rearrangement stage, and a slow cooling and shaping stage performed sequentially; the temperature of the low-temperature stress relief stage is 180-220℃, and the holding time is 1-2h; the temperature of the high-temperature crystal region rearrangement stage is 280-340℃, and the holding time is 1-3h; the cooling rate of the slow cooling and shaping stage is ≤2℃ / min.

15. The preparation method according to claim 9, characterized in that, In step S6, the annealing is also accompanied by microwave vibration treatment; the microwave vibration frequency of the microwave vibration treatment is 20-80Hz.

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