A melt distribution and annealing spinning apparatus for composite fibers

Abstract

This utility model discloses a melt distribution and slow-cooling spinning device for composite fibers, specifically relating to the technical field of chemical fiber production equipment. It includes a melt extruder, an optimized melt distribution pipeline system, a spinning box, a slow-cooling device, a cooling air blowing device, and a fiber bundle. The optimized melt distribution pipeline system is located on one side of the melt extruder. This system includes a main pipeline fixedly connected to the melt extruder, and branch pipelines on the outer wall of the main pipeline, all fixedly connected to the melt extruder. The spinning box is located on one side of the optimized melt distribution pipeline system. A slow-cooling device is located at the bottom of the spinning box, and a cooling air blowing device is fixedly connected to the bottom of the slow-cooling device. A fiber bundle is threaded through the top of the slow-cooling device. Through the synergistic effect of the flow channel and the static mixer, the pressure and temperature gradients of the melt during the conveying process are eliminated, thereby ensuring the uniformity and stability of the performance of the entire batch of fiber products.

Description

Technical Field

[0001] This utility model relates to the technical field of chemical fiber production equipment, and more specifically, to a melt distribution and slow cooling spinning device for composite fibers. Background Technology

[0002] In the production of high-performance composite fibers, especially carbon nanotube-reinforced nylon 6 (CNT / PA6) fibers, the uniformity of the melt from the extruder to each spinning station is crucial to the final fiber quality. Traditional melt distribution piping systems, due to factors such as pipe design, bends, and valves, are prone to differences in melt pressure, temperature, and residence time at different spinning stations, resulting in large fluctuations in product performance and low yield between spinning stations. Furthermore, the CNT / PA6 composite melt, due to its high thermal conductivity carbon nanotubes, cools very rapidly after extrusion from the spinneret. This rapid cooling leads to an early and excessively high melt solidification point, causing two problems: first, the excessively rapid cooling rate generates significant internal stress within the fiber; second, the upward shift of the solidification point necessitates applying greater nozzle tensile tension during the stretching process, thus increasing the pre-orientation of the nascent fiber. Excessive pre-orientation consumes some of the stretching potential of the molecular chains, making it difficult to achieve high-ratio stretching in subsequent drawing processes, ultimately limiting the improvement of fiber mechanical properties (such as strength and modulus).

[0003] Therefore, a melt distribution and slow cooling spinning device for composite fibers is proposed to address the above problems. Utility Model Content

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a melt distribution and slow cooling spinning device for composite fibers to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a melt distribution and slow-cooling spinning device for CNT / PA composite fibers, comprising a melt extruder, an optimized melt distribution pipeline system, a spinning box, a slow-cooling device, a cooling air blowing device, and a fiber bundle. The optimized melt distribution pipeline system is provided on one side of the melt extruder. The optimized melt distribution pipeline system includes a main pipeline fixedly connected to the melt extruder. Several branch pipelines are provided on the outer wall of the main pipeline, and each of the branch pipelines is fixedly connected to the melt extruder. A spinning box is provided on the side of the optimized melt distribution pipeline system away from the melt extruder. A slow-cooling device is provided at the bottom of the spinning box. A cooling air blowing device is fixedly connected to the bottom of the slow-cooling device. A fiber bundle is permeated through the top of the slow-cooling device.

[0006] Preferably, a static mixer is fixedly connected to the inside of both the main pipe and the branch pipe on the side closest to the melt extruder, and the static mixer adopts a high-efficiency spiral blade structure.

[0007] By adopting the above technical solution, the static mixer uses a highly efficient spiral blade structure. When the melt flows through the static mixer, it is forcibly cut, rotated and recombined, achieving full mixing at the micro level and ensuring high uniformity of melt pressure, temperature and CNT dispersion state.

[0008] Preferably, the side of the main pipe and branch pipe away from the melt extruder is fixedly connected to the spinning box, and a spinneret is fixedly connected to the bottom of the spinning box.

[0009] By adopting the above technical solution, the homogenized melt is then transported to the spinning box and extruded through the spinneret to form multiple fine filament bundles.

[0010] Preferably, the bottom of the spinneret is fixedly connected to the slow cooling device via a flange, and a heating element is fixedly connected to the inner wall of the slow cooling device.

[0011] By adopting the above technical solution, the fine bundle is slowly cooled by a slow cooling device.

[0012] Preferably, a temperature sensor is embedded in the surface of the heating element, and an insulating shell is fixedly connected to the outer wall of the slow cooling device.

[0013] By adopting the above technical solution, the external temperature control system can accurately control the power of the heating element based on the feedback from the temperature sensor, maintain the temperature of the slow cooling zone inside the slow cooling device at 120℃, and reduce heat loss by keeping the heat insulation shell in place.

[0014] Preferably, the heating element is composed of an electric heating band, and the temperature sensor is composed of a thermocouple.

[0015] By adopting the above technical solution, the heating element adopts a combination design of electric heating strip and embedded thermocouple, which has the advantages of strong heating uniformity, high temperature measurement accuracy, energy saving and long service life.

[0016] The technical effects and advantages of this utility model are as follows: 1. Compared with the prior art, this melt distribution and slow cooling spinning equipment for composite fibers effectively eliminates the pressure and temperature gradient of the melt during the conveying process through the synergistic effect of the optimized flow channel and static mixer, ensuring that the melt conditions reaching each spinning position are highly consistent, thereby ensuring the performance uniformity and stability of the entire batch of fiber products.

[0017] 2. Compared with existing technologies, this melt distribution and slow-cooling spinning equipment for composite fibers provides a mild cooling environment for nascent fibers through a slow-cooling device, significantly reducing the cooling rate, extending the molten zone, and lowering the solidification point. This directly reduces the tension required for nozzle stretching, thereby reducing the pre-orientation of nascent fibers and creating conditions for achieving higher effective draft ratios in subsequent processes.

[0018] 3. Compared with the existing technology, this melt distribution and slow cooling spinning equipment for composite fibers improves the fiber macromolecular chains by increasing the post-drawing ratio, allowing them to be more fully oriented and crystallized along the axial direction, resulting in a significant improvement in key mechanical properties such as tensile strength and Young's modulus of the final finished fiber.

[0019] 4. Compared with the existing technology, this melt distribution and slow cooling spinning equipment for composite fibers improves the existing spinning equipment through modularization. The melt distribution pipeline system and slow cooling device can be manufactured and integrated as independent components, the transformation cost is controllable, and it is easy to promote and apply on existing production lines. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the melt extruder of this utility model.

[0021] Figure 2 This is a three-dimensional cross-sectional structural diagram of the main pipeline of this utility model.

[0022] Figure 3 This is a three-dimensional structural diagram of the filament bundle of this utility model.

[0023] Figure 4 This is a three-dimensional cross-sectional structural diagram of the slow cooling device of this utility model.

[0024] Figure 5 This is a three-dimensional structural diagram of the spinneret of this utility model.

[0025] The attached figures are labeled as follows: 1. Melt extruder; 2. Optimized melt distribution piping system; 21. Main pipe; 22. Branch pipe; 23. Static mixer; 3. Spinning box; 31. Spinneret; 4. Slow cooling device; 41. Heating element; 42. Temperature sensor; 43. Insulation shell; 5. Cooling blower; 6. Fiber bundle. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] Example 1 As attached Figures 1 to 5 The illustrated melt distribution and slow-cooling spinning equipment for composite fibers includes a melt extruder 1, an optimized melt distribution piping system 2, a spinning box 3, a slow-cooling device 4, a cooling air blowing device 5, and a fiber bundle 6. The optimized melt distribution piping system 2 is provided on one side of the melt extruder 1. The optimized melt distribution piping system 2 includes a main pipe 21 fixedly connected to the melt extruder 1. Several branch pipes 22 are provided on the outer wall of the main pipe 21. The branch pipes 22 are all fixedly connected to the melt extruder 1. The spinning box 3 is provided on the side of the optimized melt distribution piping system 2 away from the melt extruder 1. The slow-cooling device 4 is provided at the bottom of the spinning box 3. The cooling air blowing device 5 is fixedly connected to the bottom of the slow-cooling device 4. The fiber bundle 6 is provided through the top of the slow-cooling device 4. Static mixers 23 are fixedly connected to the inside of the main pipe 21 and the branch pipes 22 on the side close to the melt extruder 1. The static mixer 23 adopts a high-efficiency spiral blade structure.

[0028] In operation, the fully mixed composite melt is extruded by the melt extruder 1 and enters the optimized melt distribution pipeline system 2. When the melt flows through the static mixer 23 inside the main pipeline 21 and the branch pipeline 22, it is forcibly cut, rotated and recombined, achieving full mixing at the microscopic level. This ensures a high degree of uniformity in melt pressure, temperature and CNT dispersion. The diameter, length and bends of the entire pipeline are optimized by computer fluid dynamics simulation to achieve automatic balance of flow and pressure at the end of each branch. The homogenized melt is then transported to the spinning box 3, where it forms multiple fine filament bundles 6. The filament bundles 6 then enter the slow cooling device 4 for slow cooling. After leaving the slow cooling device 4, the filament bundles 6 enter the conventional cooling blower 5 for rapid cooling and shaping, and then proceed to the subsequent winding and drawing processes.

[0029] Example 2 Based on Example 1, the solution in Example 1 will be further described in detail below with reference to the specific working method, such as... Figures 1 to 5 As shown below, see details: In a preferred embodiment, the bottom of the spinneret 31 is fixedly connected to the slow cooling device 4 via a flange. A heating element 41 is fixedly connected to the inner wall of the slow cooling device 4, and a temperature sensor 42 is embedded in the surface of the heating element 41. An insulation shell 43 is fixedly connected to the outer wall of the slow cooling device 4. In use, the external temperature control system precisely controls the power of the heating element 41 based on the feedback from the temperature sensor 42, maintaining the temperature of the slow cooling zone inside the slow cooling device 4 at 120°C. At the same time, the insulation shell 43 covering the outer layer of the slow cooling device 4 can reduce heat loss.

[0030] As a preferred embodiment, the heating element 41 is composed of an electric heating band, and the temperature sensor 42 is composed of a thermocouple. In use, the heating element 41 adopts a combination design of electric heating band and embedded thermocouple, which has the advantages of strong heating uniformity, high temperature measurement accuracy, energy saving and long service life.

[0031] In this embodiment, the melt extruder 1, spinning box 3, slow cooling device 4, and cooling blowing device 5 are all commercially available equipment known to those skilled in the art. They can be customized or selected according to actual needs. Here, we are only using them without making any structural or functional improvements, and we will not go into detail about them here.

[0032] The working process of this utility model is as follows: First, the fully mixed composite melt is extruded by the melt extruder 1 and enters the optimized melt distribution pipeline system 2. When the melt flows through the static mixer 23 inside the main pipeline 21 and the branch pipeline 22, it is forcibly cut, rotated and recombined, realizing full mixing at the micro level and ensuring high uniformity of melt pressure, temperature and CNT dispersion state. The pipe diameter, length and bend angle of the entire pipeline are optimized by computer fluid dynamics simulation to achieve automatic balance of flow and pressure at the end of each branch. Then, the uniformized melt is transported to the spinning box 3 and extruded through the spinneret 31 to form multiple fine filament bundles 6. Then, the filament bundles 6 enter the slow cooling device 4 for slow cooling.

[0033] At this time, the external temperature control system, based on the feedback from the temperature sensor 42, precisely controls the power of the heating element 41 to maintain the temperature of the slow cooling zone inside the slow cooling device 4 at 120°C. Meanwhile, the heat-insulating shell 43 covering the outer layer of the slow cooling device 4 can reduce heat loss. The solidification point moves down from the spinneret 31 in the traditional process to near the outlet of the slow cooling device 4. This process greatly reduces the tensile tension of the nozzle, resulting in a significant reduction in the pre-orientation of the nascent fiber. Subsequently, the fiber bundle 6 leaves the slow cooling device 4 and enters the conventional cooling air blowing device 5, where it is rapidly cooled and shaped by cold air. Then, it enters the subsequent winding and drawing processes. Due to the low pre-orientation, the fiber bundle 6 can easily achieve a high drawing ratio of more than 5 times in the subsequent drawing process. The final CNT / PA6 fiber has a tensile strength that is more than 20% higher than that of the traditional process. The above is the working principle of this melt distribution and slow cooling spinning equipment for composite fibers.

Claims

1. A melt distribution and slow-cooling spinning device for composite fibers, comprising a melt extruder (1), an optimized melt distribution piping system (2), a spinning box (3), a slow-cooling device (4), a cooling blowing device (5), and a fiber bundle (6), characterized in that: An optimized melt distribution pipeline system (2) is provided on one side of the melt extruder (1). The optimized melt distribution pipeline system (2) includes a main pipeline (21) fixedly connected to the melt extruder (1). Several branch pipelines (22) are provided on the outer wall of the main pipeline (21). Several branch pipelines (22) are fixedly connected to the melt extruder (1). A spinning box (3) is provided on the side of the optimized melt distribution pipeline system (2) away from the melt extruder (1). A slow cooling device (4) is provided at the bottom of the spinning box (3). A cooling blower (5) is fixedly connected to the bottom of the slow cooling device (4). A filament bundle (6) is provided through the top of the slow cooling device (4).

2. The melt distribution and slow cooling spinning equipment for composite fibers according to claim 1, characterized in that: The main pipe (21) and the branch pipe (22) are both fixedly connected to a static mixer (23) on the side of the melt extruder (1). The static mixer (23) adopts a high-efficiency spiral blade structure.

3. The melt distribution and slow cooling spinning equipment for composite fibers according to claim 2, characterized in that: The main pipe (21) and the branch pipe (22) are fixedly connected to the spinning box (3) on the side away from the melt extruder (1), and a spinneret (31) is fixedly connected to the bottom of the spinning box (3).

4. The melt distribution and slow cooling spinning equipment for composite fibers according to claim 3, characterized in that: The bottom of the spinneret (31) is fixedly connected to the slow cooling device (4) via a flange, and a heating element (41) is fixedly connected to the inner wall of the slow cooling device (4).

5. The melt distribution and slow cooling spinning equipment for composite fibers according to claim 4, characterized in that: A temperature sensor (42) is fitted onto the surface of the heating element (41), and an insulation shell (43) is fixedly connected to the outer wall of the slow cooling device (4).

6. The melt distribution and slow cooling spinning equipment for composite fibers according to claim 5, characterized in that: The heating element (41) is composed of an electric heating band, and the temperature sensor (42) is composed of a thermocouple.

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