Carbon fiber multifilament pultrusion production line and carbon fiber detection sample preparation method

Abstract

The present application relates to the technical field of carbon fiber manufacturing, and particularly relates to a carbon fiber multifilament pultrusion production line and a production method. A dipping device, a primary heating and curing device, a secondary heating and curing device, a traction feeding machine, a cutting machine and a spline conveying machine are sequentially arranged on a machine table along the advancing direction of the carbon fiber multifilament. A carbon fiber original roll is loaded on the unwinding machine, and a carbon fiber bundle is released; the dipping device allows the carbon fiber bundle to be soaked in glue solution; the primary heating and curing device and the secondary heating and curing device cure the carbon fiber bundle in steps; the traction feeding machine conveys the cured carbon fiber bundle to the cutting machine; the cutting machine cuts the carbon fiber bundle to a fixed length to form a carbon fiber test spline, and the test spline is output through the spline conveying machine. In this way, the automatic production of the carbon fiber test spline is realized, the tension, straightness and curing quality of each carbon fiber test spline are ensured to be consistent, the sample preparation efficiency and quality stability are improved, and reliable support is provided for the quality evaluation of the carbon fiber multifilament.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber manufacturing technology, and in particular to a carbon fiber multifilament pultrusion production line and a method for preparing carbon fiber test strips. Background Technology

[0002] The tensile properties of carbon fiber multifilaments are a core indicator for evaluating their quality and directly determine their suitability for applications in high-end equipment, aerospace, and other fields. The quality and efficiency of the preparation of carbon fiber mechanical property test strips directly affect the accuracy of tensile property test results and the speed of the testing process. Therefore, the preparation technology of carbon fiber mechanical property test strips has become a key link in the quality control system of carbon fiber multifilaments.

[0003] Currently, the preparation of carbon fiber mechanical property testing specimens mainly relies on manual methods using specific tooling. The typical preparation process is "winding into bundles - manual impregnation - static curing," requiring operators to manually position the carbon fiber bundles, apply the adhesive, and monitor the curing process. However, this manual method has significant problems: 1) High labor costs and low efficiency. It requires a large number of operators for repetitive manual operations, and the curing process for each specimen is time-consuming, making it difficult to meet the demand for rapid specimen supply for batch testing; 2) Poor specimen quality stability. During manual winding, the tension of each carbon fiber bundle cannot be precisely controlled, leading to straightness deviations and uneven adhesive impregnation after curing. This results in inconsistent mechanical property testing benchmarks between different batches, and even within the same batch, affecting the reliability of the test results; 3) Operational standardization relies heavily on manual experience. Different operators have significantly different winding strengths and adhesive impregnation control, further exacerbating the fluctuations in specimen quality.

[0004] Therefore, it is urgent for technical personnel to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a carbon fiber multifilament pultrusion production line, which aims to solve the problems of high labor costs and low efficiency in the existing design of manual sample preparation with tooling, and difficulty in ensuring the consistency of sample tension and straightness, which leads to unstable sample quality for carbon fiber mechanical property testing and failure to meet the requirements of batch standardized sample preparation.

[0006] This invention relates to a carbon fiber multifilament pultrusion production line, wherein an unwinding machine, an impregnation device, a primary heating and curing device, a secondary heating and curing device, a traction feeding machine, a cutting machine, and a strip conveying machine are sequentially arranged on the machine platform along the travel direction of the carbon fiber multifilament. Unwinding machinery is used to carry carbon fiber rolls and release carbon fiber bundles; The impregnation device is used to impregnate the carbon fiber bundles with a resin solution; A primary heating and curing device is used for the initial curing of the impregnated carbon fiber bundles; The secondary heating and curing device is used to completely cure the carbon fiber bundles after preliminary curing. The traction feeding mechanism is used to transport the fully cured carbon fiber bundles to the cutting mechanism; Cutting machinery is used to cut fully cured carbon fiber bundles to a fixed length; The sample conveying machinery is used to transport carbon fiber test samples formed by cutting machinery.

[0007] As a further improvement to the technical solution disclosed in this invention, the unwinding machine includes a yarn unwinding device and a tension adjustment device; the yarn unwinding device is used to support and position the carbon fiber roll, and during the release of the carbon fiber bundle, it follows the release action of the carbon fiber bundle to achieve synchronous rotation with the carbon fiber roll; the tension adjustment device is linked with the yarn unwinding device, and is used to detect the tension state of the carbon fiber bundle in real time during the release process, and adjust the tension of the carbon fiber bundle according to the detected tension state.

[0008] As a further improvement to the technical solution disclosed in this invention, the yarn feeding device includes a hand-cranked slide, a machine base, a hand-operated expansion shaft, and a magnetic powder brake; the hand-cranked slide is used to carry the machine base, which is mounted on the machine base; the machine base is used to fix the magnetic powder brake; the magnetic powder brake loads the hand-operated expansion shaft and forms a transmission cooperation with the hand-operated expansion shaft.

[0009] As a further improvement to the technical solution disclosed in this invention, the tension adjustment device includes a mounting plate, an upstream guide wheel, a tension detection wheel, and a downstream guide wheel; the mounting plate is based on the machine base and provides mounting support for the upstream guide wheel, the tension detection wheel, and the downstream guide wheel; the carbon fiber bundle passes sequentially around the upstream guide wheel, the tension detection wheel, and the downstream guide wheel to form a preset direction; the tension detection wheel is used to detect the tension state during the release process of the carbon fiber bundle and feeds the tension signal back to the magnetic powder brake, so that the rotational resistance of the hand-operated expansion shaft can be adjusted.

[0010] As a further improvement to the technical solution disclosed in this invention, the one-time heating and curing device includes a base, a heating mold, a position adjustment component, and a pressure locking component; the base is mounted on the machine platform; the heating mold is placed on the base and has a threading channel; the position adjustment component is used to drive the heating mold to move in a direction close to or away from the carbon fiber filament conveying path, and the pressure locking component is used to apply downward pressure to the adjusted heating mold and lock its position, and both are mounted on the base.

[0011] As a further improvement to the technical solution disclosed in this invention, the position adjustment assembly comprises an upstream front position adjustment sub-assembly, an upstream rear position adjustment sub-assembly, a downstream front position adjustment sub-assembly, and a downstream rear position adjustment sub-assembly; the upstream front position adjustment sub-assembly, the upstream rear position adjustment sub-assembly, the downstream front position adjustment sub-assembly, and the downstream rear position adjustment sub-assembly are all fixedly fitted with the base; along the direction perpendicular to the carbon fiber filament conveying path, the upstream front position adjustment sub-assembly and the upstream rear position adjustment sub-assembly are aligned, and the two cooperate to apply force to the upstream sidewall of the heating mold; along the direction perpendicular to the carbon fiber filament conveying path, the downstream front position adjustment sub-assembly and the downstream rear position adjustment sub-assembly are aligned, and the two cooperate to apply force to the downstream sidewall of the heating mold.

[0012] As a further improvement to the technical solution disclosed in this invention, the traction feeding mechanism includes a support frame, an upper traction roller assembly, and a lower traction roller assembly; the support frame is mounted on the machine base and provides mounting support for the upper traction roller assembly; the lower traction roller assembly is mounted on the machine base and is arranged opposite to the upper traction roller assembly to form a traction channel for the fully cured carbon fiber bundle to pass through.

[0013] As a further improvement to the technical solution disclosed in this invention, the cutting machine includes a fixed blade, a moving blade, a blade holder, a guide assembly, and a power unit; the fixed blade, blade holder, guide assembly, and power unit are all mounted on a support frame; the fixed blade is correspondingly arranged on the feeding path of the carbon fiber multifilament; the moving blade is fixedly mounted on the blade holder; the power unit is connected to the blade holder in a transmission manner, and with the assistance of the guide assembly, drives the blade holder to reciprocate along a preset direction, and the moving blade and the fixed blade work together to cut the carbon fiber multifilament on the feeding path into segments.

[0014] As a further improvement to the technical solution disclosed in this invention, the sample conveying mechanism includes a conveying drive unit, a V-wheel conveying assembly, and a baffle assembly; both the drive unit and the V-wheel conveying assembly are mounted on a support frame, and the conveying drive unit and the V-wheel conveying assembly are linked; the V-wheel conveying assembly is used to receive the cut carbon fiber test sample, while the baffle assembly is used to limit the extreme conveying position of the carbon fiber test sample.

[0015] Furthermore, this invention also discloses a method for preparing carbon fiber test strips, which is achieved using the aforementioned carbon fiber multifilament pultrusion production line, and includes the following steps: S1. The unwinding mechanism carries the original carbon fiber roll and releases the carbon fiber bundle; S2. The impregnation device impregnates the released carbon fiber bundles with adhesive liquid. S3. The primary heating and curing device initially cures the impregnated carbon fiber bundles, and then the secondary heating and curing device completely cures the initially cured carbon fiber bundles. S4. The traction feeding machine transports the fully cured carbon fiber bundles to the cutting machine; S5. The cutting machine cuts the carbon fiber bundle to a fixed length to form a carbon fiber test strip; S6. The sample conveying machine transports the cut carbon fiber test sample to the designated position.

[0016] In practical applications, the carbon fiber multifilament pultrusion production line disclosed in this invention can achieve at least the following beneficial technical effects, specifically: 1) The automated production line replaces traditional manual sample preparation, ensuring the consistency of carbon fiber test strip quality from the source. The unwinding machinery stably controls the release tension of the carbon fiber bundles to avoid uneven tension caused by manual winding; the impregnation device ensures uniform impregnation of each carbon fiber bundle through a standardized impregnation process; the primary and secondary heating curing devices cure in stages, precisely controlling the curing process parameters and reducing problems such as strip straightness deviation and insufficient local curing caused by manual operation. Ultimately, this achieves a unified benchmark for the mechanical properties of each strip, providing reliable sample support for the quality evaluation of carbon fiber multifilaments. 2) The continuous pultrusion process significantly shortens the sample preparation cycle, achieving full automation of the "unwinding-impregnation-curing-cutting-transferring" process. This eliminates the need for extensive manual labor, significantly reducing labor costs and operational intensity. Furthermore, the traction feeding mechanism precisely delivers the cured carbon fiber bundles, and the sample conveying mechanism automatically transports the cut samples to the designated location, reducing manual handling and further improving overall production efficiency. This meets the demand for rapid and stable sample supply for batch testing. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0018] Figure 1 This is a three-dimensional schematic diagram of the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0019] Figure 2 This is a three-dimensional schematic diagram of the unwinding machinery in the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0020] Figure 3 This is a three-dimensional schematic diagram from one perspective of the primary heating and curing device in the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0021] Figure 4This is a three-dimensional schematic diagram from another perspective of the primary heating and curing device in the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0022] Figure 5 This is a three-dimensional schematic diagram of the traction feeding mechanism in the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0023] Figure 6 This is a three-dimensional schematic diagram from one perspective of the cutting machinery in the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0024] Figure 7 This is a three-dimensional schematic diagram from another perspective of the cutting machinery in the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0025] Figure 8 This is a three-dimensional schematic diagram from another perspective of the cutting machinery in the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0026] Figure 9 This is a three-dimensional schematic diagram of the power unit in the carbon fiber multifilament pultrusion production line disclosed in this invention (the moving blade, blade holder and guide assembly are all shown in the form of double-dotted lines).

[0027] Figure 10 This is a three-dimensional schematic diagram of the power unit in the carbon fiber multifilament pultrusion production line disclosed in this invention from another perspective (the moving blade, blade holder and guide assembly are all shown in the form of double-dotted lines).

[0028] Figure 11 yes Figure 9 The front view.

[0029] Figure 12 yes Figure 11 AA sectional view.

[0030] Figure 13 This is a three-dimensional schematic diagram from one perspective of the sample conveying machinery in the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0031] Figure 14 This is a three-dimensional schematic diagram from another perspective of the sample conveying machinery in the carbon fiber multifilament pultrusion production line disclosed in this invention.

[0032] 1-Machine base; 2-Unwinding mechanism; 21-Yarn unwinding device; 211-Hand-cranked slide table; 212-Machine base; 213-Hand-operated expansion shaft; 214-Magnetic powder brake; 22-Tension adjustment device; 221-Mounting plate; 222-Upstream guide roller; 223-Tension detection roller; 224-Downstream guide roller; 3-Impregnation device; 4-First-stage heating and curing device; 41-Base; 42-Heating mold; 421-Threading channel; 43-Position adjustment assembly; 431-Upstream front position adjustment sub-assembly; 432-Upstream rear position adjustment sub-assembly; 433-Downstream front position adjustment sub-assembly; 434-Downstream rear position adjustment sub-assembly; 44-Pressure locking assembly; 441-Upstream pressure locking sub-assembly; 4 42-Downstream pressure locking sub-assembly; 5-Secondary heating and curing device; 6-Traction feeding machinery; 61-Support frame; 62-Upper traction roller assembly; 63-Lower traction roller assembly; 7-Cutting machinery; 71-Fixed blade; 72-Moving blade; 73-Blade holder; 74-Guide assembly; 741-Guide slide rail; 742-Guide slider; 75-Power unit; 751-Gear motor; 752-Coupling; 753-Drive shaft; 754-Bearing housing; 755-Eccentric wheel; 756-Force transmission component; 757-Reset assembly; 7571-First spring; 7572-Second spring; 76-Antistatic nozzle; 8-Strip conveying machinery; 81-Conveying drive unit; 82-V-wheel conveying assembly; 83-Baffle assembly. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to specific embodiments. Figure 1 A three-dimensional schematic diagram of the carbon fiber multifilament pultrusion production line disclosed in this invention is shown. It is evident that the line mainly consists of a machine base 1, an unwinding machine 2, a resin impregnation device 3, a primary heating and curing device 4, a secondary heating and curing device 5, a traction feeding machine 6, a cutting machine 7, and a sample conveying machine 8. The unwinding machine 2, resin impregnation device 3, primary heating and curing device 4, secondary heating and curing device 5, traction feeding machine 6, cutting machine 7, and sample conveying machine 8 are arranged sequentially along the direction of carbon fiber multifilament travel to collaboratively achieve unwinding, resin impregnation, preliminary curing, complete curing, traction conveying, fixed-length cutting, and sample conveying of the carbon fiber multifilament. All components are fixed to the machine base 1 as their mounting foundation. In this way, the precise connection of each process, including unwinding, impregnation, curing, traction, cutting, and conveying, is effectively ensured, laying a good foundation for the efficient preparation of carbon fiber test strips. At the same time, the entire process of "unwinding-impregnation-curing-cutting-conveying" is fully automated, requiring no large amount of manpower, significantly reducing labor costs and operational intensity, and greatly shortening the sample preparation cycle. like Figure 2As shown, the unwinding machine 2 mainly consists of two parts: a yarn unwinding device 21 and a tension adjustment device 22. The yarn unwinding device 21 supports and positions the carbon fiber roll, and during the release of the carbon fiber bundle, it rotates synchronously with the roll, providing a stable source of fiber for subsequent processes. The tension adjustment device 22 is linked to the yarn unwinding device 21, used to detect the tension state of the carbon fiber bundle in real time during release, and adjusts the tension of the carbon fiber bundle according to the detected tension state. This avoids tension fluctuations affecting the subsequent impregnation and curing quality, preventing uneven tension caused by manual winding from the source, and ensuring the consistency of the carbon fiber test sample quality. like Figure 2 As shown, the yarn feeding device 21 includes a hand-cranked slide 211, a machine base 212, a hand-operated expansion shaft 213, and a magnetic powder brake 214. The hand-cranked slide 211 carries the machine base 212, which is mounted on the machine base 1. In practical applications, the position of the machine base 212 can be adjusted by cranking the handwheel to accommodate carbon fiber rolls of different specifications. The machine base 212 is used to fix the magnetic powder brake 214. The magnetic powder brake 214 loads the hand-operated expansion shaft 213 and forms a transmission connection with it. By adjusting the braking force of the magnetic powder brake 214, the rotation speed of the hand-operated expansion shaft 213 can be controlled, thereby adjusting the release rate and basic tension value of the carbon fiber bundle. This, combined with the tension adjustment device 22, achieves dynamic tension balance, preventing the yarn bundle from breaking due to excessive tension or becoming loose and entangled due to insufficient tension. Similarly, Figure 2 As shown, the tension adjustment device 22 includes a mounting plate 221, an upstream guide wheel 222, a tension detection wheel 223, and a downstream guide wheel 224. The mounting plate 221 uses the machine base 1 as the mounting foundation and provides mounting support for the upstream guide wheel 222, the tension detection wheel 223, and the downstream guide wheel 224. The carbon fiber bundle sequentially winds around the upstream guide wheel 222, the tension detection wheel 223, and the downstream guide wheel 224 to form a preset direction, so that the tension of the bundle is evenly transmitted to the tension detection wheel 223. The tension detection wheel 223 has a built-in tension sensor for real-time detection of the tension state of the carbon fiber bundle during the release process and feeds the tension signal back to the magnetic powder brake 214. The magnetic powder brake 214 adjusts the braking force according to the feedback signal, thereby changing the rotational resistance of the hand-operated expansion shaft 213, realizing dynamic balance adjustment of the carbon fiber bundle tension, providing a stable tension bundle for the subsequent impregnation process, and ensuring uniform impregnation of the adhesive. The impregnation device 3 internally includes an impregnation chamber, a guide roller assembly, an impregnation pressure roller assembly, and an extrusion roller assembly (not shown in the figure). The impregnation chamber stores the impregnation adhesive. The guide roller assembly guides the carbon fiber bundle smoothly into the impregnation chamber, while the impregnation pressure roller assembly fully presses the bundle into the adhesive, ensuring that each carbon fiber filament is uniformly absorbed by the adhesive. The extrusion roller assembly is used to initially remove excess adhesive from the surface of the bundle, laying a good foundation for the subsequent curing process and avoiding local defects in the cured sample due to uneven adhesive distribution. The standardized impregnation process ensures uniform adhesive impregnation for each carbon fiber bundle, further guaranteeing the consistency of carbon fiber test sample quality. like Figure 3 , Figure 4 As shown, the primary heating and curing device 4 mainly consists of a base 41, a heating mold 42, a position adjustment component 43, and a pressure locking component 44. The base 41 is mounted on the machine platform 1; the heating mold 42 rests on the base 41 and has a threading channel 421 for the carbon fiber bundles to pass through; the heating mold 42 has a built-in heating element that can achieve low-temperature constant temperature control of 50-80℃, providing a preliminary curing environment for the fiber bundles and allowing the adhesive to initially set; both the position adjustment component 43 and the pressure locking component 44 are mounted on the base 41. The position adjustment component 43 is used to drive the heating mold 42 to move along the direction close to or away from the carbon fiber filament conveying path to adapt to carbon fiber bundles of different specifications. It can complete the processing of multi-specification filament bundles without stopping the machine to change the mold, thereby improving the applicability and production efficiency of the equipment. The pressure locking component 44 is used to apply downward pressure to the heating mold 42 after it is adjusted to the position and lock the position to prevent the heating mold 42 from shifting due to vibration or filament friction during operation. It maintains the relative position stability of the heating mold and the conveying path, avoids secondary friction damage to the filament bundle due to dynamic deviation, and ensures the straightness of the sample. Similarly, Figure 3 , Figure 4As shown, the position adjustment component 43 consists of an upstream front position adjustment sub-component 431, an upstream rear position adjustment sub-component 432, a downstream front position adjustment sub-component 433, and a downstream rear position adjustment sub-component 434. All four sub-components are fixedly engaged with the base 41 to ensure stability during adjustment. Along the direction perpendicular to the carbon fiber conveying path, the upstream front position adjustment sub-component 431 and the upstream rear position adjustment sub-component 432 are aligned, working together to apply force to the upstream sidewall of the heating mold 42, thus adjusting the position of the upstream end of the heating mold 42. Similarly, along the same direction, the downstream front position adjustment sub-component 433 and the downstream rear position adjustment sub-component 434 are aligned, working together to apply force to the downstream sidewall of the heating mold 42, thus adjusting the position of the downstream end of the heating mold 42. Through the coordinated action of the upstream front position adjustment sub-assembly 431, the upstream rear position adjustment sub-assembly 432, the downstream front position adjustment sub-assembly 433, and the downstream rear position adjustment sub-assembly 434, the position adjustment and precise positioning of the heating mold 42 on the horizontal plane can be achieved, meeting the threading requirements of carbon fiber bundles with different rigidity and cross-sectional size, reducing frictional damage between the fiber bundle and the inner wall of the threading channel 421, and providing a morphologically stable fiber bundle for subsequent complete curing. like Figure 1 As shown, the secondary heating and curing device 5 adopts a high-temperature oven structure. The oven is equipped with multiple sets of heating tubes and a hot air circulation fan, enabling high-temperature constant temperature control of 120–150℃, with temperature uniformity error controlled within ±3℃. High-temperature resistant sealing curtains are installed at the oven's inlet and outlet to effectively reduce heat loss and maintain stable internal temperature. After initial curing, the carbon fiber bundles enter the oven and undergo complete curing of the adhesive under high temperature, forming structurally stable carbon fiber multifilaments, providing a solid foundation for subsequent cutting and processing. The primary heating and curing device 4 and the secondary heating and curing device 5 perform step-by-step curing, precisely controlling the curing temperature and time parameters, reducing problems such as strip straightness deviation and insufficient local curing caused by manual operation, achieving a unified benchmark for the mechanical properties of each strip, and providing reliable sample support for the quality evaluation of carbon fiber multifilaments. like Figure 5As shown, the traction feeding machine 6, as a key piece of equipment connecting the curing and cutting processes, mainly consists of a support frame 61, an upper traction roller assembly 62, and a lower traction roller assembly 63. The support frame 61 uses the machine base 1 as its mounting foundation and provides support for the upper traction roller assembly 62. The lower traction roller assembly 63 uses the machine base 1 as its mounting foundation and is positioned opposite to the upper traction roller assembly 62, working together to form a traction channel for the fully cured carbon fiber bundles to pass through. During operation, the upper traction roller assembly 62 and the lower traction roller assembly 63 rotate synchronously in opposite directions, using friction to smoothly convey the carbon fiber bundles forward. The conveying speed can be adjusted according to cutting requirements, ensuring that the carbon fiber bundles enter the cutting machine 7 at a constant speed, guaranteeing fixed-length cutting, and accurately conveying the cured carbon fiber bundles, reducing manual intervention and improving overall production efficiency. like Figures 6-8 As shown, the cutting machine 7 mainly consists of several parts, including a fixed blade 71, a moving blade 72, a blade holder 73, a guide assembly 74, and a power unit 75. The fixed blade 71, blade holder 73, guide assembly 74, and power unit 75 are all mounted on a support frame 61 to ensure that the positions of each component are relatively fixed. The fixed blade 71 is positioned on the feeding path of the carbon fiber multifilament and is fixed with bolts, forming a cutting benchmark. The moving blade 72 is fixedly mounted on the blade holder 73, and the moving blade 72 is adapted to the fixed blade 71 to achieve precise cutting. The power unit 75 is connected to the blade holder 73 and, with the assistance of the guide assembly 74, drives the blade holder 73 to reciprocate along a preset direction (perpendicular to the carbon fiber multifilament feeding direction). The moving blade 72 and the fixed blade 71 work together to cut the carbon fiber multifilament on the feeding path into segments. The cutting length can be precisely controlled by controlling the conveying distance of the traction feeding machine 6 and the operating frequency of the power unit 75, ensuring the consistency of the length of each test strip and improving the reliability of the test data. As described above, the guide assembly 74 plays a crucial role in constraining the movement trajectory of the tool holder 73. It is composed of two sets of parallel guide rails 741 and guide sliders 742. Figure 7 , 8 (As shown in the diagram). The guide rail 741 is arranged along the preset reciprocating motion direction of the cutter holder 73 and is fixed to the support frame 61 to form a stable guiding reference. The guide slider 742 corresponds one-to-one with the guide rail 741 and is in clearance sliding fit, while the guide slider 742 is fixed to the cutter holder 73. In practical applications, the precise cooperation between the guide rail 741 and the guide slider 742 effectively limits the movement direction of the cutter holder 73, preventing the cutter holder 73 from deviating or shaking during reciprocating motion, ensuring that the moving cutter 72 and the fixed cutter 71 always maintain precise alignment, further improving cutting accuracy, avoiding rough cross-section phenomena, and meeting the stringent requirements of mechanical test strips for cross-section quality. like Figures 9-12As shown, the power unit 75, serving as the power source for driving the tool holder 73, comprises several parts, including a geared motor 751, a coupling 752, a drive shaft 753, a bearing housing 754, an eccentric wheel 755, a force transmission component 756, and a reset assembly 757. The output shaft of the geared motor 751 is connected to one end of the drive shaft 753 via the coupling 752, achieving efficient power transmission. The bearing housing 754 is fixedly mounted on the support frame 61, providing stable support for the drive shaft 753. The drive shaft 753 passes through the inner hole of the bearing housing 754 and rotates with its inner bearing, and is fixedly connected to the axis of the eccentric wheel 755, ensuring that the eccentric wheel 755 rotates synchronously with the drive shaft 753. One end of the force transmission component 756 is attached to the outer circumferential surface of the eccentric wheel 755. The force transmission component 756 has a top contact point, with its other end fixedly connected to the side wall of the cutter holder 73. The top contact point of the force transmission component 756 has an arc-shaped force-bearing surface that matches the radius of curvature of the outer circumference of the eccentric wheel 755, thus increasing the contact area for force transmission and ensuring smooth force transmission. The reset component 757 is adapted to the cutter holder 73 and includes a first spring 7571 and a second spring 7572, symmetrically arranged on the upper and lower sides of the cutter holder 73. It provides reset power to the cutter holder 73 during the rotation of the eccentric wheel 755. When the reduction motor 751 performs work, the eccentric wheel 755 rotates synchronously with the transmission shaft 753. During rotation, the eccentric wheel 755 pushes the force transmission component 756, and with the reverse reset action of the reset component 757, drives the cutter holder 73 to reciprocate along a preset direction, ultimately achieving continuous cutting action, improving cutting efficiency, and meeting the demand for rapid sample supply in batch testing. The cutting machine 7 is also equipped with an anti-static nozzle 76. Figure 7 , Figure 8 (As shown in the figure). The antistatic nozzle 76 is also mounted on the support frame 61, and it is connected to an external ion air generator (not shown in the figure) through an air pipe. The nozzle is directed towards the feeding path of the carbon fiber multifilament. Since the carbon fiber multifilament is prone to static electricity due to friction during transportation, it may cause the multifilament to shift and affect the cutting accuracy. The ion air sprayed by the antistatic nozzle 76 can quickly neutralize the static electricity on the surface of the multifilament, ensuring that the multifilament always maintains a flat and straight transportation state, providing a good premise for accurate cutting, and further ensuring the cutting quality and the consistency of the strip. like Figure 13 , Figure 14As shown, the sample conveying machine 8, as a device for automatically conveying the cut samples, mainly consists of a conveying drive unit 81, a V-wheel conveying assembly 82, and a baffle assembly 83. Both the conveying drive unit 81 and the V-wheel conveying assembly 82 are mounted on a support frame 61. The conveying drive unit 81 uses a stepper motor and synchronous belt drive mechanism to achieve precise control of the conveying speed. The conveying drive unit 81 is linked with the V-wheel conveying assembly 82, providing power support for the V-wheel conveying assembly 82. The V-wheel conveying assembly 82 consists of multiple sets of V-shaped conveying wheels. The grooves of the V-shaped wheels are adapted to the cross-sectional shape of the carbon fiber test samples, ensuring that the samples do not shift during conveying and stably receiving the cut carbon fiber test samples. The baffle assembly 83 is fixedly installed at the end of the V-wheel conveying assembly 82 to limit the extreme conveying position of the carbon fiber test samples, ensuring that the samples are neatly stacked in a designated area, facilitating subsequent manual collection or automated sorting and preventing sample scattering and loss. It should also be noted that this invention discloses a method for preparing carbon fiber test strips, which is achieved using the aforementioned carbon fiber multifilament pultrusion production line, and includes the following steps: S1. The hand-operated expansion shaft 213 loads the carbon fiber roll, and the magnetic powder brake 214 is activated. Under the dynamic adjustment of the tension adjustment device 22, the carbon fiber bundle is released stably to avoid uneven tension affecting subsequent processes. S2. The released carbon fiber bundles enter the impregnation device 3. Under the guidance of the guide roller group and the action of the impregnation pressure roller, they are fully impregnated with the adhesive, and the extrusion roller assembly removes excess adhesive to ensure uniform distribution of the adhesive. S3. The impregnated carbon fiber bundles enter the threading channel 421 of the heating mold 42 and are initially cured at a low temperature of 50-80℃. Then they enter the secondary heating and curing device 5 (high temperature oven) and are fully cured at a high temperature of 120-150℃. The curing parameters are precisely controlled to avoid local curing defects. S4. The fully cured carbon fiber bundle enters the traction channel of the traction feeding machine 6. The upper traction roller assembly 62 and the lower traction roller assembly 63 rotate together to smoothly transport it to the cutting machine 7, ensuring a stable conveying speed. S5, the power unit 75 drives the moving blade 72 to reciprocate, and works with the fixed blade 71 to cut the carbon fiber bundle to a fixed length to form a carbon fiber test strip. During this process, the anti-static nozzle 76 continuously sprays ion wind to remove static electricity from the strip and ensures the cutting accuracy. S6. The cut carbon fiber test strips fall into the V-shaped wheel conveyor assembly 82 and move towards the end under the drive of the conveyor drive unit 81. Finally, they are blocked by the baffle assembly 83 and neatly stacked in the designated position, completing the preparation process. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A carbon fiber multifilament pultrusion production line, characterized in that, The unwinding machine, impregnation device, primary heating and curing device, secondary heating and curing device, traction feeding machine, cutting machine, and strip conveying machine are arranged sequentially on the machine platform along the travel direction of the carbon fiber multifilament; The unwinding mechanism is used to carry the carbon fiber roll and release the carbon fiber bundle; The impregnation device is used to impregnate the carbon fiber bundles with a resin solution. The primary heating and curing device is used for the initial curing of the impregnated carbon fiber bundles; The secondary heating and curing device is used to completely cure the carbon fiber bundles after preliminary curing. The traction feeding mechanism is used to transport the fully cured carbon fiber bundles to the cutting mechanism; The cutting machine is used to cut the fully cured carbon fiber bundles to a fixed length. The strip conveying mechanism is used to convey carbon fiber test strips formed by the cutting mechanism; The primary heating and curing device includes a base, a heating mold, a position adjustment component, and a pressure locking component. The base is mounted on the machine platform. The heating mold rests on the base and has a threading channel. The position adjustment component drives the heating mold to move towards or away from the carbon fiber filament conveying path, while the pressure locking component applies downward pressure to the adjusted heating mold and locks its position. Both components are mounted on the base. The position adjustment assembly comprises an upstream front position adjustment sub-assembly, an upstream rear position adjustment sub-assembly, a downstream front position adjustment sub-assembly, and a downstream rear position adjustment sub-assembly. Each of these sub-assemblies is fixedly fitted to the base. Along the direction perpendicular to the carbon fiber conveying path, the upstream front position adjustment sub-assembly and the upstream rear position adjustment sub-assembly are aligned, working together to apply force to the upstream sidewall of the heating mold. Similarly, along the same direction, the downstream front position adjustment sub-assembly and the downstream rear position adjustment sub-assembly are aligned, working together to apply force to the downstream sidewall of the heating mold.

2. The carbon fiber multifilament pultrusion production line according to claim 1, characterized in that, The unwinding mechanism includes a yarn unwinding device and a tension adjustment device. The yarn unwinding device is used to support and position the carbon fiber roll, and during the release of the carbon fiber bundle, it rotates synchronously with the carbon fiber roll as the carbon fiber bundle is released. The tension adjustment device is linked with the yarn unwinding device and is used to detect the tension state of the carbon fiber bundle in real time during the release process, and adjust the tension of the carbon fiber bundle according to the detected tension state.

3. The carbon fiber multifilament pultrusion production line according to claim 2, characterized in that, The yarn feeding device includes a hand-cranked slide, a machine base, a hand-operated expansion shaft, and a magnetic powder brake; the hand-cranked slide is used to carry the machine base, which is mounted on the machine base; the machine base is used to fix the magnetic powder brake; the magnetic powder brake loads the hand-operated expansion shaft and forms a transmission connection with the hand-operated expansion shaft.

4. The carbon fiber multifilament pultrusion production line according to claim 3, characterized in that, The tension adjustment device includes a mounting plate, an upstream guide wheel, a tension detection wheel, and a downstream guide wheel. The mounting plate uses the machine base as its mounting foundation and simultaneously provides mounting support for the upstream guide wheel, the tension detection wheel, and the downstream guide wheel. The carbon fiber bundle sequentially winds around the upstream guide wheel, the tension detection wheel, and the downstream guide wheel to form a preset path. The tension detection wheel is used to detect the tension state during the release of the carbon fiber bundle and feeds the tension signal back to the magnetic powder brake, thereby adjusting the rotational resistance of the hand-operated expansion shaft.

5. The carbon fiber multifilament pultrusion production line according to claim 1, characterized in that, The traction feeding mechanism includes a support frame, an upper traction roller assembly, and a lower traction roller assembly; the support frame is based on the machine base and provides installation support for the upper traction roller assembly; the lower traction roller assembly is based on the machine base and is arranged opposite to the upper traction roller assembly to form a traction channel for the fully cured carbon fiber bundle to pass through.

6. The carbon fiber multifilament pultrusion production line according to claim 5, characterized in that, The cutting machine includes a fixed blade, a moving blade, a blade holder, a guide assembly, and a power unit. The fixed blade, the blade holder, the guide assembly, and the power unit are all mounted on the support frame. The fixed blade is correspondingly arranged on the feeding path of the carbon fiber multifilament. The moving blade is fixedly mounted on the blade holder. The power unit is connected to the blade holder and, with the assistance of the guide assembly, drives the blade holder to reciprocate in a preset direction. The moving blade and the fixed blade work together to cut the carbon fiber multifilament on the feeding path into segments.

7. The carbon fiber multifilament pultrusion production line according to claim 5, characterized in that, The sample conveying mechanism includes a conveying drive unit, a V-wheel conveying assembly, and a baffle assembly; both the drive unit and the V-wheel conveying assembly are mounted on the support frame, and the conveying drive unit and the V-wheel conveying assembly are linked; the V-wheel conveying assembly is used to receive the cut carbon fiber test samples, while the baffle assembly is used to limit the extreme conveying position of the carbon fiber test samples.

8. A method for preparing carbon fiber test strips, characterized in that, This is achieved using a carbon fiber multifilament pultrusion production line as described in any one of claims 1-7, comprising the following steps: S1. The unwinding mechanism carries the original carbon fiber roll and releases the carbon fiber bundle; S2, The impregnation device impregnates the released carbon fiber bundles with a resin solution; S3. The primary heating and curing device initially cures the impregnated carbon fiber bundles, and then the secondary heating and curing device completely cures the initially cured carbon fiber bundles. S4. The traction feeding machine conveys the fully cured carbon fiber bundle to the cutting machine; S5. The cutting machine cuts the carbon fiber bundle to a fixed length to form a carbon fiber test strip; S6. The strip conveying machine transports the cut carbon fiber test strip to the designated position.

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