Small-aperture spinning device with concave-convex structure

Abstract

The utility model relates to the technical field of spinning equipment, and particularly discloses a small-aperture spinning device with a concave-convex structure. Comprising a spinning nozzle body, and a first protruding part, a first concave part, a second protruding part and a second concave part are arranged at the two ends of the spinning nozzle body respectively; the spinning runner is arranged in the spinning nozzle main body and penetrates through the two ends of the spinning nozzle main body; wherein the spinning nozzle main body is internally provided with a plurality of circular membrane casting liquid flow channels which are arranged in an array, and the membrane casting liquid flow channels are communicated with the spinning flow channels. The matched concave-convex positioning structures (the first / second convex part and the concave part) are arranged at the two ends of the spinning nozzle main body, so that the problem of alignment during repeated installation after maintenance of a traditional spinning nozzle is thoroughly solved. The concave-convex structures are matched in a complementary mode through physical forms, accurate butt joint of the spinneret orifices and external equipment is automatically achieved during installation, manual repeated adjustment is not needed, and the problem that fiber forming is not uniform due to dislocation is fundamentally solved.

Description

Technical Field

[0001] This utility model relates to the field of spinning equipment technology, and in particular to a small-diameter spinneret with a concave-convex structure. Background Technology

[0002] In the field of spinning equipment, particularly in the production of micron-sized hollow fibers such as hemodialysis membranes, traditional spinneret technology faces several significant challenges. First, when spinnerets require maintenance and reinstallation, the lack of standardized positioning structures forces operators to repeatedly align the micron-sized spinneret orifices manually. This process is not only time-consuming but also prone to errors, as even minor deviations can lead to misalignment or tilting of the spinneret orifices. Such deviations directly impact the quality of the final product, causing issues such as uneven fiber wall thickness, flattened fibers, or off-core fibers—problems that occur frequently in production and severely affect product quality. Second, the spinneret area, being constantly exposed, is susceptible to damage from tool impacts during handling or installation. Furthermore, traditional planar sealing structures are prone to wear after repeated disassembly and reassembly, leading to leakage of the spinning solution and the intrusion of external contaminants. These problems not only affect production continuity but also negatively impact product yield.

[0003] The patent "A Protective Device for a Multi-Hole Shaped Spinneret" (Publication No. CN202122074545.5, hereinafter referred to as Prior Art 1) discloses a spinneret protection device. The core technology of Prior Art 1 lies in achieving protection for the spinneret by attaching replaceable liners and protective plates to the main body of the spinneret. The diameter of the liner is adapted to the positioning portion of the spinneret, covering the central area; while the protective plate has a larger diameter, covering the entire surface of the spinneret and the spinneret orifices, and is fixed by mounting holes on the outer side and positioning on the inner side. Utilizing the existing mounting holes (inner / outer side) and locking holes of the spinneret, the protective plate, liner, and spinneret body are firmly connected by fixing bolts, ensuring structural stability during disassembly or storage.

[0004] However, while the spinneret protection device in prior art 1 provides a certain degree of protection, it still has some limitations. First, its protective plate design is relatively bulky, increasing the overall weight and complexity of the equipment and hindering quick disassembly and maintenance. Second, although the liner design covers the central area of ​​the spinneret, the protection for the edges of the spinneret holes is still insufficient, especially during frequent disassembly and assembly, where the edges of the spinneret holes are still easily damaged, leading to uneven fiber formation. Furthermore, the sealing structure of prior art 1 relies on multiple fixing bolts, which may lead to a decrease in sealing performance during high-frequency disassembly and assembly, increasing the risk of spinning solution leakage. Utility Model Content

[0005] In view of this, the present invention provides a small-diameter spinneret with a concave-convex structure to solve the problem that traditional spinnerets lack a standardized positioning structure and require manual alignment of the micron-level spinneret holes during maintenance and reinstallation, resulting in uneven fiber formation.

[0006] This utility model provides a small-aperture spinneret device with a concave-convex structure, characterized in that it includes: a spinneret body, wherein the two ends of the spinneret body are respectively provided with a first protrusion, a first recess, a second protrusion, and a second recess; and a spinneret channel, which is disposed in the spinneret body and extends to both ends of the spinneret body; wherein the spinneret body is provided with a plurality of casting liquid channels arranged in a circular array, and the casting liquid channels are connected to the spinneret channels.

[0007] Preferably, it also includes a core tube that can be detachably installed in the spinneret channel; the core tube includes a conveying end and a spraying end; the conveying end and the spraying end are respectively provided with a first channel and a second channel; the first channel and the second channel are connected by a variable diameter guide method.

[0008] Preferably, a guide surface is provided at the connection between the first flow channel and the second flow channel; the guide surface is provided with an inclined arc surface; the diameter of the guide surface gradually decreases from the first flow channel toward the direction closer to the second flow channel.

[0009] Preferably, the spinneret extends from the first protrusion to the second protrusion, and a mixing chamber is provided in the second protrusion.

[0010] Preferably, the media conveyed by the casting liquid channel and the core tube respectively converge and mix in the mixing chamber.

[0011] Preferably, the inner wall of the casting liquid flow channel is provided with a periodic concave-convex guiding structure; wherein, the casting liquid flow channel adopts a gradually expanding structure, and the cross-sectional area of ​​the casting liquid flow channel increases from the inlet end to the outlet.

[0012] Preferably, the casting liquid channel is configured as an inclined direct current channel.

[0013] Preferably, the casting liquid channel is configured as an inclined spiral channel.

[0014] Preferably, an "R-angle" is provided between the outlet of the spinneret channel and the outlet of the casting liquid channel, forming a gradient section for the casting liquid flow rate; wherein, the curvature of the "R-angle" increases from the inlet end of the spinneret channel to the outlet end of the spinneret channel.

[0015] Preferably, the first flow channel adopts a variable diameter reduction structure, and the diameter of the first flow channel gradually decreases from the inlet end of the first flow channel to the outlet end of the first flow channel.

[0016] The small-diameter spinneret with a concave-convex structure provided by this utility model has the following beneficial effects.

[0017] In this invention, by setting matching concave-convex positioning structures (first / second protrusions and recesses) at both ends of the spinneret body, the alignment problem during repeated installation after traditional spinneret maintenance is completely solved. Through complementary physical morphology, the concave-convex structures automatically achieve precise alignment between the spinneret orifice and external equipment during installation, eliminating the need for repeated manual adjustments and fundamentally eliminating the problem of uneven fiber formation caused by misalignment. Simultaneously, this standardized structure significantly simplifies the maintenance process, making spinneret disassembly and assembly faster and more reliable, ensuring the stability and consistency of fiber dimensions during production, and greatly improving product quality and production efficiency. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, and these are all within the protection scope of this utility model.

[0019] Figure 1 This is a schematic diagram of a small-aperture spinneret with a concave-convex structure.

[0020] Figure 2 This is a schematic diagram of the structure in Example 1;

[0021] Figure 3 This is a schematic diagram of the structure in Example 2;

[0022] Figure 4 This is a schematic diagram of the core tube structure;

[0023] Parts and component numbers in the diagram:

[0024] 100 - Spinneret body, 110 - First protrusion, 120 - First recess, 130 - Second protrusion, 140 - Second recess;

[0025] 150-Spinneret flow channel;

[0026] 160 - Casting fluid flow channel;

[0027] 170 - Mixing chamber, 180 - "R angle";

[0028] 200-Core tube, 210-Conveying end, 211-First flow channel, 220-Injection end, 221-Second flow channel, 230-Guide surface. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, in this document, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In the description of this utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Unless otherwise specified, embodiments of the present invention and the various features thereof can be combined with each other, all within the protection scope of the present invention.

[0030] Example 1

[0031] Please see Figure 1 This utility model provides a small-diameter spinneret with a concave-convex structure, specifically a small-diameter nozzle with a concave-convex structure. In daily operation, if the spinneret needs maintenance and reassembly, due to the lack of a unified positioning system, workers must manually adjust the tiny spinneret orifices multiple times. This process is time-consuming and prone to errors, as even minor errors can cause inaccurate spinneret orifice positions or angular deviations. Such deviations directly affect the final product quality, such as causing inconsistent fiber wall thickness, flattened fibers, or eccentricity, which frequently occur during production and severely damage product quality.

[0032] Therefore, the design proposed in this embodiment of the present invention aims to solve the above problems by introducing an innovative concave-convex structure, which can serve as a positioning system for the spinneret and achieve precise and rapid positioning of the spinneret orifice.

[0033] Please see Figure 1 and Figure 2In this embodiment, the nozzle includes a spinneret body 100 and a spinneret channel 150 disposed inside the spinneret body 100. The spinneret body 100 has a first protrusion 110, a first recess 120, a second protrusion 130, and a second recess 140 at its two ends. The spinneret channel 150 is disposed within the spinneret body 100 and extends through both ends of the spinneret body 100. The spinneret body 100 also has a plurality of circular casting liquid channels 160 arranged in an array, which communicate with the spinneret channel 150. The aperture of a single casting liquid channel 160 is in the range of 0.05-0.2 mm.

[0034] The first protrusion 110 is disposed in the first recess 120, and the second protrusion 130 is disposed in the second recess 140.

[0035] Furthermore, the protrusions can form a "protective wall," maintaining a safe distance (e.g., a 0.5mm gap) between the core area of ​​the spinneret body 100 (including the casting liquid flow channel 160) and the external contact surface. This reduces the impact damage rate of the casting liquid flow channel 160. The protrusions use rounded corner transitions (rounded R-angles) to disperse external impact forces through the arc-shaped surface of the protrusions, preventing stress concentration that could lead to cracking of the main body.

[0036] In practical applications, the spinneret is first connected via the first protrusion 110 and the second protrusion 130. Then, the core liquid is injected into the device through the spinneret channel 150, while the casting liquid is injected through the casting liquid channel 160. This operation ensures that the core liquid and casting liquid converge smoothly at the outlet of the spinneret channel 150. Finally, the two liquids merge at the outlet of the spinneret channel 150 and are ejected through this outlet to form the desired fiber structure.

[0037] During maintenance, the recessed part engages with a special clamp to align the spinneret body 100 with the external equipment, resulting in extremely low installation offset. The recessed part is designed as a detachable groove structure, allowing for direct operation with a quick-release wrench and eliminating the need for traditional bolt removal.

[0038] Specifically, please see Figure 1The first protrusion 110, the first recess 120, the second protrusion 130, and the second recess 140 constitute a series of protrusions and recesses on the spinneret. These protrusions and recesses are matched to each other, allowing for easy positioning when the spinneret is reinstalled by simply aligning the protrusions with the recesses, eliminating the need for repeated manual adjustments. This design not only significantly improves assembly efficiency but also substantially reduces errors caused by human factors during assembly. Furthermore, the design of this concave-convex structure also considers durability and stability, ensuring accurate positioning even during long-term use, thereby continuously guaranteeing product quality.

[0039] Further, please see Figure 4 The nozzle also includes a core tube 200 detachably disposed within the spinneret channel 150; the core tube 200 includes a conveying end 210 and a spraying end 220; the conveying end 210 and the spraying end 220 are respectively provided with a first channel 211 and a second channel 221; the first channel 211 and the second channel 221 are connected.

[0040] In the textile industry, the main function of the core tube 200 is to improve the spraying accuracy of the spinneret, ensuring the uniformity and quality of the fibers. The core tube 200 has an intricate internal structure, comprising two main flow channels. The first flow channel's primary function is to receive the core liquid from the outside; this process is precisely controlled to ensure the purity and stability of the core liquid. Once the core liquid enters the core tube 200, it flows along a well-designed internal channel to the second flow channel. This internal channel further guides the core liquid until it reaches the outlet position of the spinneret flow channel 150. At the outlet, the core liquid meets and mixes with the casting liquid, jointly forming the internal structure of the fiber. This design ensures a stable and continuous flow of the core liquid, which is essential for forming a high-quality fiber structure.

[0041] Furthermore, the detachable design of the core tube 200 greatly facilitates the maintenance and replacement of the spinneret. This design allows operators to easily remove and replace the core tube 200 without the need for complex disassembly of the entire unit. This not only improves the efficiency of maintenance work but also significantly extends the service life of the spinneret. This design significantly enhances the flexibility and durability of the device. Moreover, by precisely controlling the diameter of the second flow channel 221 at the liquid injection end 220, the thickness and precision of the fiber membrane can be further precisely controlled, which is crucial for meeting the stringent fiber quality requirements of various industrial applications.

[0042] Further, please see Figure 2A guide surface 230 is provided at the connection between the first flow channel 211 and the second flow channel 221. The guide surface 230 is an inclined arc surface. The diameter of the guide surface 230 decreases from the first flow channel 211 towards the second flow channel 221. The guide surface 230 is inclined in the flow direction, which guides the core fluid to transition more smoothly from the first flow channel 211 to the second flow channel 221, reducing resistance and turbulence during the flow process. This decreasing diameter setting allows the core fluid to gradually accelerate during flow, giving it a certain initial velocity when converging with the casting liquid, resulting in better mixing. Simultaneously, the inclined arc surface design effectively disperses fluid pressure, avoiding fluid rupture or unstable flow caused by localized high pressure. This guide surface 230 design further optimizes the flow path of the core fluid, improves the uniformity and quality of fiber formation, and provides a strong guarantee for the production of high-quality fiber products.

[0043] Further, please see Figure 2 The spinneret channel 150 extends from the first protrusion 110 and is disposed within the second protrusion 130, and a mixing chamber 170 is provided within the second protrusion 130. An "R-angle" 180 is provided between the outlet of the spinneret channel 150 and the outlet of the casting liquid channel 160, forming a gradient section for the casting liquid flow rate; wherein the curvature of the "R-angle" 180 increases from the inlet end of the spinneret channel to the outlet end of the spinneret channel 150. The "R-angle" 180 is an arc-shaped R-angle design, which facilitates smooth flow and mixing of the casting liquid in each channel, reducing energy consumption.

[0044] Furthermore, the media conveyed by the casting liquid channel 160 and the core tube 200 respectively converge and mix in the mixing chamber 170.

[0045] The mixing chamber 170 provides a space for thorough mixing of the core liquid and the casting liquid. Within this chamber 170, the core liquid and the casting liquid meet under specific pressure and flow rates, undergoing mutual penetration and diffusion to form a homogeneous mixture. This mixing process is crucial for fiber formation, as it determines the fiber's internal structure and properties. The design of the mixing chamber 170 fully considers fluid dynamics principles, ensuring uniform mixing of the two liquids and thus improving fiber quality. Simultaneously, the "R-angle" 180 design not only facilitates the smooth flow of the casting liquid but also generates a certain flow rate gradient during mixing, further promoting the uniformity of the core liquid and casting liquid mixing. This design makes fiber formation more stable, improving product quality and consistency.

[0046] In traditional small-aperture spinnerets (aperture < 0.2 mm), the inner wall of the flow channel is smooth, and residual casting solution easily forms an adhesion layer. Conventional physical cleaning tools (such as ultrasonic cleaners and high-pressure water guns) are unable to completely remove micron-sized residues, especially at the corners of the flow channel. Repeated accumulation of residues causes the flow channel roughness (Ra value) to increase from the initial 0.1 μm to over 0.8 μm, accelerating channel clogging and shortening equipment life by 50%.

[0047] Therefore, the inner wall of the casting fluid flow channel 160 is provided with a periodic concave-convex guiding structure; wherein, the casting fluid flow channel 160 is arranged in a gradually expanding manner, and the cross-sectional area of ​​the casting fluid flow channel 160 increases from the inlet end to the outlet. The height of the concave-convex structure is 10-20μm, and the spacing between adjacent concave-convex structures is 0.1-0.5mm, which is used to guide the casting fluid to form turbulence and reduce casting fluid retention.

[0048] The irregular structure induces microturbulence (increasing the Reynolds number Re by approximately 15%) during the casting liquid flow. This erosion of residues on the pore wall surface by fluid shear force reduces residue accumulation, thereby slowing down pore blockage and extending service life. The gradually widening flow channel design reduces the outlet velocity, preventing high-speed fluid impact that could cause residues to backflush to the upstream area, reducing the risk of secondary contamination after cleaning, and improving cleaning efficiency. This provides a more stable and reliable environment for fiber production.

[0049] Furthermore, the casting solution channel 160 is configured as an inclined direct-flow channel, allowing the casting solution to better adhere to the channel wall during flow, reducing dead zones and further minimizing residue accumulation. The inclined design also promotes a more uniform flow velocity distribution, preventing localized excessive wear or blockage caused by uneven flow rates. Simultaneously, the inclined direct-flow channel simplifies the channel structure, facilitating cleaning and maintenance, and ensuring the continuous stability and efficiency of the fiber production process.

[0050] Furthermore, the first flow channel 211 adopts a variable diameter reduction structure, wherein the diameter of the first flow channel 211 decreases from the inlet end to the outlet end. The first flow channel 211 is a core fluid flow channel, and the variable diameter reduction design of the core fluid flow channel improves processing performance, increases core fluid flow rate, improves membrane filament support performance, and reduces the possibility of flattened filaments and blockage.

[0051] Example 2

[0052] Please see Figure 1 This utility model provides a small-aperture spinneret device with a concave-convex structure, specifically a small-aperture nozzle with a concave-convex structure.

[0053] Traditional spinnerets face a series of technical challenges when producing fibers with small orifices, especially those smaller than 0.1 mm. First, the poor flowability of the spinning solution and core solution within the tiny channels makes them prone to residue and solidification, leading to channel blockage. Second, the inhomogeneity of the hollow fibers results in insufficient flow field stability of the core solution and casting solution within the channels, causing significant fluctuations in the hollow fiber diameter and resulting in off-center cores and flattened fibers. Furthermore, cleaning the tiny orifices is extremely difficult, as they are hard to thoroughly clean, affecting the reusability of the spinneret.

[0054] To address these issues, existing technologies have explored various solutions, such as simply reducing the orifice size or increasing the number of orifices, in an attempt to improve the performance of the spinneret. However, these methods often fail to simultaneously address both clogging prevention and fiber uniformity. In other words, while reducing the orifice size or increasing the number of orifices may solve the clogging problem to some extent, they may introduce new problems, such as affecting the uniformity of hollow fibers or increasing the complexity and cost of the manufacturing process.

[0055] Please see Figure 3 In this embodiment, the casting liquid flow channel 160 is configured as an inclined spiral flow channel.

[0056] The casting fluid flow channel 160 is designed as an inclined spiral flow channel, which is more likely to induce turbulence-induced effects. The radius of curvature and periodic concave-convex structure of the spiral flow channel work together to generate periodic secondary flows (Dean vortices) in the casting fluid during flow. The Reynolds number (Re) is increased by about 25%, effectively breaking the boundary layer viscosity effect and reducing the amount of casting fluid adhering to the flow channel wall (residual amount reduced by 55%).

[0057] Furthermore, the centrifugal effect of the spiral structure creates a velocity gradient in the radial direction of the casting fluid (center velocity > wall velocity). Combined with the gradually expanding cross-sectional area design, the outlet cross-sectional area is 1.2-1.8 times that of the inlet cross-sectional area, thus reducing the standard deviation of the shear rate.

[0058] The curved path of the spiral flow channel enhances the radial disturbance of the fluid. Combined with the periodic concave and convex guiding structure, it forms a dynamic scouring effect, which prevents micron-sized particles (such as undissolved polymers) from forming a stable deposition layer in the flow channel, resulting in low residue characteristics. Experimental comparison shows that under the same operating conditions, the residual amount of casting liquid in the spiral flow channel is only 12% of that in the direct flow channel, and the risk of solidification and blockage after shutdown is reduced by more than 50%.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A small-aperture spinneret with a concave-convex structure, characterized in that, include: The spinneret body (100) has a first protrusion (110), a first recess (120), a second protrusion (130), and a second recess (140) at its two ends respectively. The spinneret flow channel (150) is located inside the spinneret body (100) and extends to both ends of the spinneret body (100); The spinneret body (100) has multiple casting liquid channels (160) arranged in a circular array, and the casting liquid channels (160) are connected to the spinneret channels (150).

2. The small-aperture spinneret with a concave-convex structure according to claim 1, characterized in that, It also includes a core tube (200) that can be detachably installed in the spinneret channel (150); The core tube (200) includes a delivery end (210) and a spray end (220). The conveying end (210) and the spraying end (220) are respectively provided with a first flow channel (211) and a second flow channel (221); The first flow channel (211) and the second flow channel (221) are connected by a variable diameter flow guide method.

3. A small-aperture spinneret with a concave-convex structure according to claim 2, characterized in that, A guide surface (230) is provided at the connection between the first flow channel (211) and the second flow channel (221); The guide surface (230) is provided with an inclined arc surface; The diameter of the guide surface (230) gradually decreases from the first flow channel (211) toward the direction closer to the second flow channel (221).

4. A small-aperture spinneret with a concave-convex structure according to claim 2, characterized in that, The spinneret channel (150) extends from the first protrusion (110) to the second protrusion (130), and a mixing chamber (170) is provided in the second protrusion (130).

5. A small-aperture spinneret with a concave-convex structure according to claim 4, characterized in that, The media delivered by the casting liquid channel (160) and the core tube (200) respectively converge and mix in the mixing chamber (170).

6. A small-aperture spinneret with a concave-convex structure according to claim 1, characterized in that, The inner wall of the casting liquid channel (160) is provided with a periodic concave-convex guiding structure; The casting liquid flow channel (160) adopts a gradually expanding structure, and the cross-sectional area of ​​the casting liquid flow channel (160) increases from the inlet end to the outlet.

7. A small-aperture spinneret with a concave-convex structure according to claim 6, characterized in that, The casting liquid flow channel (160) is configured as an inclined direct flow channel.

8. A small-aperture spinneret with a concave-convex structure according to claim 6, characterized in that, The casting liquid channel (160) is configured as an inclined spiral channel.

9. A small-aperture spinneret with a concave-convex structure according to claim 1, characterized in that, An "R angle" (180) is provided between the outlet of the spinneret channel (150) and the outlet of the casting liquid channel (160), forming a gradient change section for the casting liquid flow rate. The curvature of the "R angle" (180) increases from the inlet end of the spinneret channel to the outlet end of the spinneret flow channel (150).

10. A small-aperture spinneret with a concave-convex structure according to claim 3, characterized in that, The first flow channel (211) adopts a variable diameter reduction structure, and the diameter of the first flow channel (211) gradually decreases from the inlet end of the first flow channel (211) to the outlet end of the first flow channel (211).

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