Air-jet vortex spinning water-sensitive yarn and special core-spun yarn control device and preparation method thereof

Abstract

The application provides a jet vortex spinning water-sensitive yarn and special core-spun yarn control device and a preparation method thereof. The device guarantees stable core yarn running and uniform composite of short and long fibers through coaxial double guide rings limiting, double godets segmented tension adjusting, guide cradle deviation rectifying, multi-stage tension control and rear-end double yarn guide component stable pressure winding. Raw materials are selected by reasonably matching gradually changing segment shrinkage yarn and viscose short fiber, and after pretreatment, opening, carding and three-ways drawing, the vortex core-spun yarn is completed by using the device. Tests show that the yarn has low yarn evenness CV value, less neps and hairiness and excellent strength performance. The water-sensitive yarn has regular normal structure, can produce irregular deformation to form a bamboo joint effect when meeting water, has functionality and decoration, has good fabric stiffness, durability and dyeability, is suitable for the fields of knitted garments and household textiles, and effectively enriches the jet vortex spinning fancy yarn product system.

Description

Technical Field

[0001] This disclosure relates to the field of textile technology, and in particular to a control device for jet vortex spinning of water-sensitive yarn and special core-spun yarn, and its preparation method. Background Technology

[0002] Fancy yarns differ from traditional ordinary yarns in that their core characteristic is that the yarn structure and appearance have irregular shapes. By changing the yarn density, twist direction, splicing method, or adding heterogeneous materials, the appearance and luster of the yarn can be differentiated. Common types include slub yarn, knotted yarn, beaded yarn, chenille yarn, dotted yarn, and variegated yarn, which are widely used in various specialty textile fields.

[0003] Slub yarn is one of the most widely used fancy yarns, and its current industrial production mainly consists of two processes: ring spinning and rotor spinning. Ring spinning and rotor spinning of slub yarn primarily rely on the equipment to instantaneously adjust the fiber feed speed and change the output yarn density to form a slub structure. Rotor spinning can also produce slub yarn by setting damping materials in the spinning cup cohesion tank, but this method limits the adjustment range of parameters such as slub length, thickness, and pitch, resulting in limited product styles.

[0004] Air-jet vortex spinning is characterized by high spinning speed, high production efficiency, and high degree of automation. Its yarn formation principle relies on air vortices to cause fibers to intertwine and twist into shape. The industry has attempted to directly produce slub yarn in the vortex spinning process, referencing the control methods of ring spinning and rotor spinning. However, due to the unique yarn formation mechanism and high-speed production conditions of air-jet vortex spinning, it is difficult to achieve large-scale industrial production by directly forming regular slub structures on the vortex spinning machine. Currently, the mainstream solution in the industry is to use a core-spun method, where slub filaments are wrapped around short fibers, to produce vortex-spun slub-style yarn. However, this type of product only relies on mechanical motion to change the yarn evenness; the slub appearance is mechanically forced into shape, lacking functional characteristics, resulting in a monotonous style, and the yarn structure stability and deformation consistency need improvement.

[0005] Based on this, the present invention proposes a jet vortex spun water-sensitive yarn and its preparation process. It uses a gradually shortened filament as the core yarn and combines a special core-spun yarn tension control device with the whole spinning process to prepare a functional fancy yarn that can spontaneously generate irregular expansion deformation when exposed to water and presents a natural slub appearance. This makes up for the shortcomings of existing vortex spun slub style yarns that rely solely on mechanical forming, have no additional functions, and have a rigid shape. Summary of the Invention

[0006] In this invention, a gradient-length filament is used as the core yarn, wrapped with viscose short fibers. The invention studies jet-jet vortex-spun core-spun yarn. After being soaked in water at a certain temperature, the core-spun yarn exhibits irregular dimensional changes. Fabrics made from this yarn will display irregular fabric patterns when exposed to water. Because the yarn of this invention undergoes dimensional changes upon contact with warm or boiling water at 60-100℃, it is named water-sensitive yarn in this invention.

[0007] In a first aspect, this application provides a control device for core-spun yarn for water-sensitive air jet vortex spinning, comprising a filament unwinding structure, a guide positioning structure, a tension adjustment structure, a filament guide cradle, a drafting and conveying structure, a spinning forming machine, and a winding structure arranged sequentially along the core filament conveying direction; the filament unwinding structure is the core filament input end, used to install and uniformly release the gradually shortened filament. The guiding and positioning structure includes a first fixed guide wire ring and a second fixed guide wire ring arranged coaxially at intervals. The first fixed guide wire ring is located at the lower end of the filament unwinding structure, and the second fixed guide wire ring is located at the lower end of the first fixed guide wire ring. The tension adjusting structure is located at the lower end of the second fixed guide wire ring. The tension adjusting structure includes a first guide wire wheel and a second guide wire wheel that can slide laterally to the left and right and rotate freely. The filament guide cradle is installed at the lower yarn feeding position of the tension adjustment structure; The drafting and conveying structure is located at the lower end of the filament guide cradle. The drafting and conveying structure includes a front drafting unit. The front drafting unit includes a front upper rubber roller and a front lower roller of the drafting system arranged vertically and vertically. The front upper rubber roller and the front lower roller of the drafting system are bonded together to form a front roller jaw. The spinning forming machine is provided with needle holders and vortex yarn output positions at its front and rear ends, respectively. The needle holders are the front feeding guide parts of the spinning forming machine, and the vortex yarn output positions are the rear discharge parts of the spinning forming machine. The winding structure is located at the lower end of the spinning forming machine. The winding structure includes a first yarn feeding control component and a second yarn feeding control component, a friction tension roller and a yarn package arranged sequentially along the yarn output direction. The area between the filament guide cradle and the front roller jaws forms a mixing zone for the tapered filaments and short fiber strips. A short fiber bundle feeding channel is provided laterally at the mixing zone. The short fiber bundle feeding channel is used to continuously feed the outer short fiber strips to the drawing and conveying structure. The short fiber strips drawn by the drawing and conveying structure merge with the tapered filaments at the mixing zone next to the front roller jaws.

[0008] In a further embodiment, the drafting and conveying structure further includes a middle drafting unit and a rear drafting unit, wherein the rear drafting unit, the middle drafting unit, and the front drafting unit are arranged sequentially along the short fiber sliver's travel direction; the middle drafting unit includes a pair of upper and middle rollers, and the rear drafting unit includes a pair of upper and lower rollers; the short fiber sliver is sequentially drafted through the rear drafting unit, the middle drafting unit, and the front drafting unit, and merges with the tapered filament at the front roller nip to form a composite fiber bundle before being fed into the spinning forming machine. Secondly, this application provides a method for controlling the core-spun core of water-sensitive yarn spun using the above-described device, characterized by comprising the following steps: Step S1, Core yarn unwinding and centering guidance: The gradually shortened filament is released at a constant speed by the filament unwinding structure. After release, the gradually shortened filament is sequentially passed through the first fixed guide ring and the second fixed guide ring. The radial limit of the gradually shortened filament is achieved by the two sets of coaxially arranged guide rings, which constrain the yarn deviation and complete the yarn feeding centering positioning. Step S2, Adjustable segmented yarn feeding adjustment: According to the yarn tension requirements of the spinning process, the installation positions of the first guide wheel and the second guide wheel are adjusted laterally by sliding, changing the wrapping contact angle between the tapered section filament and the two guide wheels, as well as the actual yarn feeding stroke length. By relying on the changes in wrapping angle and yarn feeding length, the running tension of the tapered section filament is changed in segments, so as to realize the segmented yarn feeding state adjustment of the front and middle sections of the yarn. Step S3, Core filament straightening and short fiber sliver drafting: After segmented tension adjustment, the tapered section of the long filament is fed into the filament guide cradle. The filament guide cradle straightens the sliver's oscillation trajectory and then directs it into the mixing area of ​​the tapered section of the long filament and the short fiber sliver. The outer short fiber sliver is conveyed to the drafting conveying structure through the short fiber bundle feeding channel, and sequentially passes through the back drafting unit, the middle drafting unit, and the front drafting unit along the direction of the short fiber sliver's travel. Drafting is performed with a roller spacing of 42.5–45.0 mm, a main draft ratio of 24.5–42.5, a middle zone draft ratio of 1.2–1.5, a back zone draft ratio of 2.9–3.1, a back roller initialization rate of 165%–175%, a roller hardness of 76–83 HA, a feed ratio of 0.98–1.02, and a spinning speed of 445–455 m / min, so that the outer short fiber sliver forms a straight and parallel short fiber sliver; Step S4, Long and Short Fiber Confluence and Vortex Forming: The drafted short fiber sliver merges with the gradually shortened filament guided by the filament guide cradle at the mixing point next to the front roller nip, forming a composite fiber bundle with the gradually shortened filament as the core layer and the short fiber sliver as the outer layer; after the composite fiber bundle is output from the front roller nip, it is guided into the spinning forming machine by the needle seat at the front end of the spinning forming machine, and under the action of the vortex airflow, the free ends of the short fibers wrap around the outside of the gradually shortened filament, completing the core-spun twist and forming water-sensitive yarn; the processed water-sensitive yarn is drawn out from the vortex yarn output position at the rear end of the spinning forming machine. S5. Rear end pressure stabilization and finished product winding: The finished yarn drawn from the vortex yarn output position passes through the first yarn drawing control component and the second yarn drawing control component in sequence to correct the yarn output position. Then, it is subjected to rear end tension compensation and pressure stabilization by the friction tension roller. The winding ratio is 1.00 and the friction roller torque is 160mN. The stabilized finished yarn is continuously wound and stored on the yarn package.

[0009] In process S1, two sets of coaxial fixed guide rings are used to radially limit the movement of the gradually shortened filaments, preventing deviation and offset during high-speed core filament transport. This ensures the core filament remains centered throughout the spinning process, providing a reliable foundation for stable core-spun yarn. In process S2, two sets of laterally adjustable guide wheels are used to adjust the core filament wrapping angle and yarn travel distance, enabling independent tension adjustment in different segments. This adapts to varying stress requirements at different spinning stages, reducing core filament tension fluctuations and improving yarn travel stability. In process S3, the filament guide cradle constrains and regulates the core filament's oscillation trajectory, ensuring precise entry into the mixing zone where it fully adheres to and converges with the continuously fed lateral short fiber strips, forming a well-structured, core-free, and air-filled composite fiber bundle. In process S4, the drafting parameters and vortex forming process are matched to improve fiber straightness and mixing uniformity. Vortex airflow is then used to uniformly wrap and twist the short fibers, stabilizing the core-spun yarn structure. The S5 process uses a double yarn guide assembly to correct the yarn exit position, and works with a friction tension roller to compensate for the tension at the rear end, improving the problems of yarn deviation and unstable tension during the winding process, and ensuring that the finished yarn is wound evenly and tightly.

[0010] In a further embodiment, in S1, the unwinding speed of the tapered section filament is 445-455 m / min; the inner diameter of the first and second fixed guide rings is 0.2-0.4 mm larger than the outer diameter of the core wire.

[0011] In different steps, the unwinding tension of the filament is controlled at 8-12 cN; the tension of the drawing section is controlled at 8-12 cN and the tension of the winding section are both controlled at 8-12 cN, and the tension of the drawing section is greater than the tension of the winding section, and the tension of the winding section is greater than the unwinding tension of the filament.

[0012] The tension in the drawing section here refers to the main drawing zone, which is the output tension in the front zone. The tension in the rear zone is controlled at 2-4 cN, and the tension in the middle zone is controlled at 5-8 cN.

[0013] Based on the front drafting unit, a middle drafting unit and a back drafting unit are added. A stepped tension gradient, from slight tension in the back zone to a transitional tension in the middle zone and strong tension in the front zone, enables segmented, graded, and orderly drafting of the fiber bundles. The back drafting unit, with a draft ratio of 2.9–3.1 times and a slight tension of 2–4 cN, performs pre-carding and initial unbundling of the fibers. It performs low-ratio pre-drafting on the viscose short fiber slivers entering the drafting system, breaking up the clumped and buckled state of the fiber bundles and eliminating fiber entanglement, wrinkles, and disordered accumulation in advance, laying a uniform and stable foundation for subsequent fine drafting. The slivers enter the middle drafting unit, where, under a low draft ratio of 1.2–1.5 times and a moderate tension of 5–8 cN, it performs buffering and finishing functions. The tension in this zone maintains the compactness of the fiber bundle, preventing excessive dispersion and providing stress buffer for the high-ratio drafting in the front zone. Simultaneously, it fine-tunes the parallelism and evenness of the fibers, further concentrating and shifting the fiber speed change point forward, avoiding fiber breakage, slippage, and uneven drafting defects caused by excessively high drafting ratios in a single zone. In the main drafting stage of the front zone, the process uses a high drafting ratio of 24.5 to 42.5 times, with an output tension of 8 to 12 cN. This tension range ensures that the fibers are fully stretched and shaped without exceeding the fiber bundle breaking strength. The front drafting unit completes the stretching and shaping of viscose staple fiber slivers through precise clamping and constant-speed feeding via the front roller jaws. The three-stage drafting and conveying structure works in stages to conduct segmented drafting and finishing of the outer-coated viscose short fiber sliver, improving the straightness, parallelism, and evenness of the short fiber sliver. This provides conditions for the stable convergence of the short fiber sliver and the gradually shortened filament at the front roller nip, and helps to reduce yarn defects such as unevenness, strength fluctuations, hairiness, and neps.

[0014] In a further embodiment, in step S2, the total horizontal and left-right adjustable stroke of the first guide wheel and the second guide wheel is 6-18mm; the central angle of the gradually shortened filament wrapped around the surface of a single guide wheel is controlled at 75°-105°; the gradually shortened filament from the second fixed guide ring to the first guide wheel is a first-stage transition yarn feeding section, from the first guide wheel to the second guide wheel is an intermediate folding yarn feeding section, and from the second guide wheel to the filament guide cradle inlet is a rear-entry yarn feeding section; The effective yarn length of the first-stage transition yarn section is 8–16 mm, the effective yarn length of the intermediate folding yarn section is 12–20 mm, and the effective yarn length of the rear-entry yarn section is 24–32 mm, and the effective yarn lengths of the three sections satisfy the following: The effective yarn length of the first-level transition yarn section is less than the effective yarn length of the intermediate return yarn section, and the effective yarn length of the intermediate return yarn section is less than the effective yarn length of the subsequent introduction yarn section.

[0015] The effective yarn lengths of the three sections are increased sequentially according to the order of primary transition yarn section, intermediate reversal yarn section and post-entry yarn section, so as to form a differentiated increasing yarn travel, which can meet the different tension adjustment requirements in the initial introduction of core yarn, intermediate reversal and end stable introduction process respectively.

[0016] By limiting the unwinding speed of the core yarn and the three gradient tension ranges of unwinding, drafting, and winding, combined with a double guide ring limiting structure with varying apertures, full-process segmented pressure stabilization control is achieved while ensuring smooth unwinding of the filament. Utilizing a configuration where the tension in the drafting section is greater than that in the winding section, and the tension in the winding section is greater than that in the unwinding section, the resistance differences in each spinning process are matched to reduce core yarn tension fluctuations and prevent yarn slack, shaking, or excessive stretching.

[0017] Thirdly, this application provides a method for preparing air-jet vortex spun water-sensitive yarn, which is prepared using the aforementioned dedicated core-spun tension control device, and includes the following processing steps: Step 1: Select gradient section shortened filament as core yarn and 1.2D*38mm viscose staple fiber as outer packaging material; perform humidification treatment on viscose staple fiber to increase the actual moisture regain of raw material to close to the nominal moisture regain of 13%, improve fiber spinnability, and reduce fiber damage during spinning process. Step 2: The humidified viscose staple fiber is processed into a uniform and complete sliver by sequentially passing through the opening and cleaning process and the carding process. During the carding process, the cylinder licker-in speed ratio is controlled to be no less than 2.65 to optimize the fiber transfer effect and reduce neps and short fibers. Step 3: Perform three-stage merging and stretching processes on the prepared viscose sliver. Use multi-strand merging and zoned stretching optimization process to improve fiber straightness and sliver uniformity, and prepare viscose sliver with stable sliver and no sliver accumulation or sliver fraying. Step 4: Using the gradually shortened filament as the core yarn and the viscose sliver obtained in Step 3 wrapped with short fiber sliver, the yarn is fed into the mixing area through the short fiber bundle feeding channel, where it merges with the gradually shortened filament to complete the core-sleeving twisting. The gradually shortened filament is subjected to segmented gradient tension adjustment through a special core-sleeving tension control device to keep the core yarn tension in each control section stable, thus producing a jet-jet vortex spun water-sensitive yarn that can produce irregular deformation when exposed to water.

[0018] Viscose staple fibers are humidified to near their nominal moisture regain, improving fiber softness and spinnability while reducing spinning friction damage. The opening and carding processes are coordinated with a reasonable yarn speed ratio to improve fiber transfer efficiency, remove short fibers and impurities, and reduce the probability of neps formation. Multiple doubling and zoned drafting methods effectively improve sliver uniformity and fiber straightening parallelism, ensuring stable feed sliver conditions. Precisely merging the pre-treated staple fiber sliver with the gradually shortened filament, along with a dedicated tension control device, ensures stable core yarn flow throughout the process, guaranteeing uniform and stable core-spun yarn formation. Ultimately, this produces a well-structured, uniformly stable water-sensitive deformation-resistant air-jet vortex-spun water-sensitive yarn.

[0019] In a further embodiment, the core process parameters of the carding process in step 2 are as follows: the distance between the feed roller and the licker-in is 0.50-0.58 mm, the distance between the licker-in and the cylinder is 0.16-0.20 mm, the distance between the cylinder and the doffer is 0.11-0.15 mm, and the distance between the movable cover plate and the cylinder along the cotton inlet to outlet direction is 0.18-0.22 mm, 0.16-0.20 mm, 0.16-0.20 mm, 0.16-0.20 mm, and 0.18-0.22 mm, respectively.

[0020] The spacing parameters are configured progressively to achieve gradient combing of the fibers, which can fully loosen the fibers, efficiently remove short fibers and impurities, and ensure smooth fiber transfer, reduce fiber damage and neps, and make the finished sliver more uniform.

[0021] In a further embodiment, in step 3, the three drawing processes involve combining 5-7 yarns in the first and second drawing processes, and combining 7-9 yarns in the final drawing process; the yarn weight of the first drawing process is 19.80-21.00 g / 5m, the back zone draft is 1.85-2.05 times, the total draft is 7.00-8.06 times, and the output yarn speed is 400-420 m / min; the yarn weight of the second drawing process is 19.50-20.80 g / 5m, and the back zone... The draft is 1.48–1.64 times, the total draft is 5.80–6.20 times, and the output yarn speed is 400–420 m / min; the weight of the blended three-way yarn is 19.40–20.60 g / 5m, the back zone draft is 1.52–1.68 times, the total draft is 5.80–6.50 times, and the output yarn speed is 390–420 m / min; the CV value of the finished sliver is ≤2.60%, and the CV value of the finished sliver weight is ≤1.10%.

[0022] Employing a three-stage gradient doubling and drafting process, with differentiated settings for the number of fused fibers, dry weight, drafting ratio, and output speed in each stage, this technology progressively corrects sliver thickness deviations and gradually improves fiber straightening and parallelism. By combining multiple fibers, it compensates for fiber unevenness. Combined with appropriate zoned drafting parameters, it effectively eliminates fiber buckling and disorder, improves the overall uniformity of the finished sliver, and ensures stable fiber sliver conditions and no obvious yarn defects in the feeding spinning area. This lays the foundation for subsequent stable core-spun yarn formation and high-quality yarn evenness.

[0023] In a further embodiment, the three drawing roller spacings are configured as follows: the first drawing roller has a rear spacing of 11.5–12.5 mm and a front spacing of 20.0–22.0 mm; the second drawing roller has a rear spacing of 11.5–12.5 mm and a front spacing of 20.0–22.0 mm; and the last drawing roller has a rear spacing of 10.5–11.5 mm and a front spacing of 20.0–22.0 mm.

[0024] A properly matched roller spacing can be adapted to the fiber length, allowing the rollers to fully clamp the fibers and complete orderly drafting, reducing fiber slippage and buckling problems, and ensuring sliver uniformity.

[0025] Preferably, in step 2, the core process parameters of the carding process are: the distance between the feed roller and the licker-in roller is 0.54mm, the distance between the licker-in roller and the cylinder is 0.18mm, the distance between the cylinder and the doffer is 0.13mm, and the distances between the movable cover plate and the cylinder are 0.20mm, 0.18mm, 0.18mm, 0.18mm, and 0.20mm respectively.

[0026] The preferred spacing adopts a pattern of large spacing at both ends and small spacing in the middle, which can gradually comb the fibers, effectively remove short fibers and impurities, ensure smooth fiber transfer, reduce damage and knots, and improve the quality of sliver.

[0027] Preferably, in step 3, the first and second drawing processes of the three-stage drawing process use 6 strands combined, and the third and final drawing process uses 8 strands combined. The process parameters are as follows: for the first mixing process, the dry weight is 20.44 g / 5m, the subsequent draw is 1.94 times, the total draw is 8.06 times, and the output speed is 410 m / min; for the second mixing process, the dry weight is 20.16 g / 5m, the subsequent draw is 1.56 times, the total draw is 6.01 times, and the output speed is 410 m / min; for the third mixing process, the dry weight is 20.01 g / 5m, the subsequent draw is 1.60 times, the total draw is 6.09 times, and the output speed is 400 m / min. The prepared cooked strip has a CV value of 2.44% and a weight CV value of 0.97%.

[0028] Preferably, the spacing of the three drawing rollers is configured as follows: the rear spacing of the first drawing roller is 12mm and the front spacing is 21mm; the rear spacing of the second drawing roller is 12mm and the front spacing is 21mm; and the rear spacing of the last drawing roller is 11mm and the front spacing is 21mm.

[0029] In step S4, during the spinning process, an oil spraying device is configured to lubricate and clean the key spinning equipment. The grooved small flying wing is checked and replaced regularly to eliminate yarn damage and weak twist defects. At the same time, the distance between the nozzle and the back roller and the nip pressure parameters are optimized to prevent yarn leakage and ensure the quality of wrapping and forming.

[0030] Fourthly, this application provides a jet-jet vortex-spun water-sensitive yarn, which is processed by the above-mentioned preparation method. The water-sensitive yarn has a core-spun yarn structure and, by mass percentage, consists of 30%-35% gradient section shortened filaments and 65%-70% viscose staple fibers, preferably 33% gradient section shortened filaments and 67% viscose staple fibers. After being soaked in warm or boiling water, the water-sensitive yarn undergoes irregular expansion and deformation, exhibiting a natural slub appearance and possessing excellent water-sensitive deformation characteristics.

[0031] The gradient segmented filaments are manufactured using a dual-hot roller temperature and speed variable process, and have the characteristics of axial irregular segmented shrinkage and differential expansion upon contact with water; the outer viscose short fiber specification can be 1.2D*38mm, and the core filament specification can be 110D.

[0032] In a further embodiment, the water-sensitive yarn can be prepared in any count specification of 10S, 12S, 16S, 20S, 26S, and 30S, with 16S and 30S being preferred; wherein the core performance indicators of the 30S water-sensitive yarn are: yarn density 19.7 tex, yarn density deviation rate 0.6, yarn density coefficient of variation (CV) 1.3%, yarn evenness (CV) 12.9%, single yarn breaking strength 13.1 cN / tex, and hairiness (H) value 3.71.

[0033] The core yarn specification can be selected from 58D, 110D or other suitable specifications according to the target yarn linear density and core yarn weight ratio. Among them, 16S water-sensitive yarn can use 110D core yarn, and 30S water-sensitive yarn can use 58D core yarn.

[0034] The equipment is equipped with Orient model nozzles and M-type spindles. The nozzle pressure is constant, and combined with set feed ratio, back roller initiation rate, roller spacing, and full-section gradient tension parameters, multiple factors work together to prevent yarn leakage. An oil spray lubrication and cleaning device is activated throughout the process, and new, intact flyblades are replaced regularly to prevent yarn damage, yarn leakage, and weak twist. The M-type spindle compensates for the drawbacks of stiff yarn and eliminates the negative effects of increased pressure. Defective, grooved flyblades are replaced promptly to prevent yarn damage.

[0035] In a further embodiment, the water-sensitive yarn raw material can be equivalently replaced: the core yarn can be conventional polyester filament or nylon filament, and the outer short fiber can be one or more blends of polyester, lyocell, bamboo pulp fiber, and acrylic short fiber.

[0036] Beneficial effects: The core-spun yarn control device for air-jet vortex spinning water-sensitive yarn provided by this invention comprises, sequentially along the core yarn conveying direction, a filament unwinding structure, a guiding and positioning structure, a tension adjustment structure, a filament guide cradle, a drafting and conveying structure, a spinning forming machine, and a winding structure. Combined with a laterally arranged short fiber bundle feeding channel, it forms a long and short fiber confluence system. The overall structural layout is reasonable, and the process connections are smooth. The first and second fixed guide rings, coaxially arranged front and rear, can reliably limit the radial movement of the tapered filament in the gradient section, constraining deviation and radial oscillation during high-speed core yarn conveying, ensuring the core yarn stays centered throughout the entire process, and preventing defects such as off-center cores and empty cores in the core-spun yarn from the source. The first and second guide wheels, which can slide laterally and rotate freely, constitute a segmented tension adjustment structure. By changing the yarn wrapping angle and yarn travel distance, independent tension control of different sections of the core yarn can be achieved. Combined with the three-stage gradient tension settings of unwinding, drafting, and winding, tension fluctuations throughout the core yarn's operation are reduced, ensuring stable yarn movement. The filament guide cradle regulates the core filament's oscillation trajectory, ensuring its precise entry into the long and short fiber mixing area, where it adheres and converges with the continuously fed, side-mounted short fiber sliver. The drafting and conveying structure features multi-stage tension control pairs, enabling segmented, step-by-step drafting and combing of the short fiber sliver. This gradually disperses the fiber bundles, improves fiber straightening and parallelism, buffers the stress impact from high-ratio main drafting, reduces fiber breakage and uneven drafting, and enhances the uniformity of long and short fiber mixing and yarn evenness. The spinning forming machine utilizes vortex airflow to achieve uniform core-spun twisting. Combined with a rear-end winding structure consisting of a double-lead control component and friction tension rollers, it achieves yarn exit orientation correction and tension stabilization, ensuring uniform and tight winding of the finished yarn.

[0037] This device, in conjunction with its supporting processes, produces water-sensitive core-spun yarn that boasts superior properties such as high strength, low hairiness, uniform yarn evenness, and resistance to pilling. The fabrics woven from this yarn exhibit excellent stiffness, durability, and dimensional stability. Furthermore, thanks to the water-sensitive properties of the core yarn, the yarn spontaneously undergoes irregular expansion and deformation upon contact with water, forming a natural slub appearance. This is distinct from traditional mechanically formed slub yarn, resulting in a unique product style and novel category. It not only broadens the application areas of air-jet vortex spinning technology but also enriches the product types of fancy yarns. It can be widely used in textile fields such as knitwear and home textiles, possessing significant industrialization and promotion value. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the overall structure of the core-spun yarn control device for jet vortex spinning water-sensitive yarn of the present invention; Figure 2 This is a flowchart of the process for preparing water-sensitive yarn by jet vortex spinning according to the present invention. Figure 3 This is a schematic diagram of the core-spun yarn structure of the jet vortex spun water-sensitive yarn described in this invention; Figure 4 This is a photograph of the normal state of the water-sensitive yarn spun by jet vortex according to the present invention; Figure 5 This is an example photograph of the appearance of the fabric woven from the water-sensitive yarn spun by the jet vortex of the present invention after dyeing treatment.

[0040] 1. Filament unwinding structure; 2. First fixed guide ring; 3. Second fixed guide ring; 4. First guide wheel; 5. Second guide wheel; 6. Filament guide cradle; 7. Front upper roller of drafting system; 8. Front lower roller of drafting system; 9. Short fiber bundle feeding channel; 10. Spinning forming machine; 11. Needle seat; 12. Vortex yarn output position; 13. First yarn feeding control component; 14. Second yarn feeding control component; 15. Friction tension roller; 16. Yarn cone; 17. Mixing section; 18. Front roller nip; 19. Water-sensitive yarn core yarn; 20. Outer short fiber; 21. Normal section of water-sensitive yarn; 22. Thick section of water-sensitive yarn; 23. Thick section of core yarn. Detailed Implementation

[0041] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0042] A control device for core-spun yarn for water-sensitive jet vortex spinning includes a filament unwinding structure 1, a guide and positioning structure, a tension adjustment structure, a filament guide cradle 6, a drafting and conveying structure, a spinning forming machine 10, and a winding structure arranged sequentially along the core filament conveying direction; the filament unwinding structure 1 is the core filament input end, used to install and uniformly release the gradually shortened filament.

[0043] The guiding and positioning structure includes a first fixed guide ring 2 and a second fixed guide ring 3 arranged coaxially at intervals. The first fixed guide ring 2 is located at the lower end of the filament unwinding structure 1, and the second fixed guide ring 3 is located at the lower end of the first fixed guide ring 2. The tension adjustment structure is located at the lower end of the second fixed guide ring 3. The tension adjustment structure includes a first guide wheel 4 and a second guide wheel 5 that can slide laterally to the left and right and rotate freely.

[0044] The filament guide rocker 6 is installed at the lower yarn feeding position of the tension adjustment structure.

[0045] The drawing and conveying structure is located at the lower end of the filament guide cradle 6. The drawing and conveying structure includes a front upper rubber roller 7 and a front lower roller 8 of the drawing system arranged correspondingly. The front upper rubber roller 7 and the front lower roller 8 of the drawing system are bonded together to form a front roller jaw 18.

[0046] The spinning forming machine 10 has a needle seat 11 and a vortex yarn output position 12 respectively at its front and rear ends. The needle seat 11 is the front feeding guide part of the spinning forming machine 10, and the vortex yarn output position 12 is the rear discharge part of the spinning forming machine 10.

[0047] The winding structure is located at the lower end of the spinning forming machine 10. The winding structure includes a first yarn guide control component 13 and a second yarn guide control component 14, a friction tension roller 15, and a yarn package 16 arranged sequentially along the yarn output direction. The area between the filament guide rocker 6 and the front roller nip 18 forms a mixing area 17 for gradually shortened filaments and short fiber slivers. A short fiber bundle feeding channel 9 is provided laterally in the mixing area 17. The discharge end of the short fiber bundle feeding channel 9 corresponds to the input end of the rear drafting unit, which is used to continuously convey the viscose sliver to the drafting conveying structure. That is to say, the mixing area 17 is a mixing area for outer short fiber bundles and gradually shortened filaments, and the mixing area 17 is close to the front roller nip 18. The drafting and conveying structure also includes a middle drafting unit and a rear drafting unit, which are arranged sequentially along the short fiber sliver's travel direction. The front drafting unit consists of a front upper roller 7 and a front lower roller 8 of the drafting system. The middle drafting unit is composed of a middle upper roller and a middle lower roller paired together, and the rear drafting unit is composed of a rear upper roller and a rear lower roller paired together. The viscose sliver is fed into the rear drafting unit through the short fiber bundle feeding channel 9, and then sequentially undergoes drafting through the rear drafting unit, the middle drafting unit, and the front drafting unit to form a straightened and parallel viscose short fiber sliver. After drafting, the viscose short fiber sliver merges with the gradually shortened filaments guided by the filament guide cradle 6 at the mixing point 17 next to the front roller nip 18 to form a composite fiber bundle. The composite fiber bundle is output from the front roller nip 18 and fed into the spinning forming machine 10.

[0048] The yarn described in this application features high strength, low hairiness, exceptional evenness, and resistance to pilling. The fabric also exhibits good stiffness, durability, and dimensional stability, offering diverse styles suitable for producing knitted garments and home textiles, thus meeting consumer demands for comfort and aesthetics. The invention and development of this product expands the diversification of air-jet vortex spinning products.

[0049] The production process of the graded segmented shrinkage polyester filament used in this invention is described in patent publication number CN1204846A; the technical principle of the shrinkage and radial expansion of the filament under the action of water and heat has been described in detail in patent publication number CN121992550A.

[0050] Example 1 Step 1, Raw material pretreatment: 110D gradient segment shortened filament is selected as the core yarn, and 1.2D×38mm viscose staple fiber is selected as the outer wrapping material; the water-sensitive yarn prepared in this embodiment has a core-spun structure, and the raw materials are precisely proportioned by mass percentage: 33.2% gradient segment shortened filament and 66.8% viscose staple fiber. The viscose staple fiber is humidified to increase the actual moisture regain of the raw material to 13% nominal moisture regain, thereby improving the fiber spinnability and reducing fiber damage during the spinning process.

[0051] Step 2, Opening and Carding Process: After the humidified viscose staple fiber is processed by the opening process, it is fed into the carding machine to prepare a uniform sliver. The cylinder-licker-in speed ratio is controlled at 2.65; the distance between the feed roller and the licker-in is 0.50mm, the distance between the licker-in and the cylinder is 0.18mm, and the distance between the cylinder and the doffer is 0.11mm; the distance between the movable flats and the cylinder along the cotton inlet to outlet direction is 0.18mm, 0.16mm, 0.16mm, 0.16mm, and 0.18mm respectively.

[0052] Step 3, Three-pass Drafting Process: The viscose sliver undergoes a three-pass Drafting process, with 6 slivers Drafted in the first and second passes, and 8 slivers in the final pass. The yarn weight for the first pass is 21.00 g / 5m, the back zone draft is 1.85 times, the total draft is 7.50 times, and the output yarn speed is 400 m / min; the yarn weight for the second pass is 19.50 g / 5m, the back zone draft is 1.64 times, the total draft is 5.80 times, and the output yarn speed is 400 m / min; the yarn weight for the third pass is 20.00 g / 5m, the back zone draft is 1.52 times, the total draft is 6.30 times, and the output yarn speed is 390 m / min. Roller spacing configuration: First pass: back zone 12.5 mm, front zone 20.0 mm; Second pass: back zone 11.5 mm, front zone 22.0 mm; Final pass: back zone 11.0 mm, front zone 21.0 mm. Finally, a stable, non-accumulated viscose strip was obtained, with a strip CV value of 2.58% and a weight CV value of 1.08%. The short fiber bundle feeding channel 9 of the standby feeding device was used.

[0053] Step 4, S1, Core yarn unwinding and centering guidance: The 110D gradient section shrinking filament is released uniformly through the filament unwinding structure 1 at the upper end of the device at a speed of 445m / min and a filament unwinding tension of 8cN; the released core yarn is sequentially passed through the first fixed guide ring 2 and the second fixed guide ring 3 arranged coaxially at the lower end. The inner diameter of the guide ring is 0.2mm larger than the outer diameter of the core yarn. The two sets of guide rings are used to achieve radial limiting of the core yarn, constrain the yarn from running left and right, and complete the centering positioning of the yarn feed.

[0054] S2. Adjustable segmented yarn feeding adjustment: The tension adjustment structure at the lower end of the second fixed guide ring 3 allows for lateral sliding adjustment of the left and right installation positions of the first guide wheel 4 and the second guide wheel 5. The total lateral adjustable stroke of the guide wheels is 10mm. The control of the gradually shortened filament wrapping around the surface of a single guide wheel at a central angle of 75° is maintained. The first-stage transition yarn feeding segment from the second fixed guide ring 3 to the first guide wheel 4 has a stroke of 8mm. The intermediate return yarn feeding segment from the first guide wheel 4 to the second guide wheel 5 has a stroke of 12mm. The rear guide yarn feeding segment from the second guide wheel 5 to the filament guide cradle 6 inlet has a stroke of 32mm. The tension in the rear zone is 3cN, the tension in the middle zone is 6cN, and the front zone is the main drafting zone with an output tension of 10cN. That is, the running tension in the drafting zone is set to 10cN, and the tension in the winding zone is set to 9cN. By changing the core yarn wrapping angle and the yarn feeding stroke, the yarn tension can be independently adjusted segment by segment. The core yarn tension fluctuation throughout the entire running process is ≤±0.8cN.

[0055] S3. Core filament straightening and short fiber sliver drafting: After yarn feeding adjustment, the gradually shortened filaments are fed into the filament guide cradle 6 at the lower end of the tension adjustment structure. The filament guide cradle 6 straightens the oscillation trajectory of the gradually shortened filaments and guides them to the mixing area 17 next to the front roller nip 18. The prepared viscose sliver is conveyed to the drafting conveying structure through the short fiber bundle feeding channel 9, and then sequentially passes through the back drafting unit, the middle drafting unit, and the front drafting unit for drafting. The roller spacing is 45.0mm × 45.0mm, the main drafting ratio is 24.5, the middle drafting ratio is 1.3, the back drafting ratio is 3.1, the back roller initialization rate is 165%, the roller hardness is 76 HA, the feed ratio is 0.98, and the spinning speed is 455m / min, so that the viscose sliver forms straight and parallel short fiber slivers.

[0056] S4. Combination and Vortex Forming of Long and Short Fibers: After drafting, the short fiber sliver merges with the gradually shortened filament guided by the filament guide cradle 6 at the mixing point 17 next to the front roller nip 18, forming a composite fiber bundle with the gradually shortened filament as the core layer and the viscose short fiber sliver as the outer layer. The composite fiber bundle is output from the front roller nip 18 and guided into the equipment via the needle seat 11 at the front end of the spinning forming machine 10. The equipment is equipped with Orient model nozzles and M-type spindles, with the nozzle pressure maintained at 0.60 MPa. Under the action of the vortex airflow, the free end of the viscose short fiber wraps around the outside of the gradually shortened filament, completing the core-spun twisting. The formed water-sensitive yarn is drawn out from the vortex yarn output position 12 at the rear end of the spinning forming machine 10. During the spinning process, the oil spray lubrication and cleaning device is activated, and the small flying wing is replaced if in good condition.

[0057] S5. Rear end pressure stabilization and finished product winding: The finished yarn drawn from the vortex yarn output position 12 passes sequentially through the first yarn guide control component 13 and the second yarn guide control component 14 arranged at the lower end along the yarn output direction to correct the yarn output orientation and correct the yarn deviation; then it is stabilized by the friction tension roller 15 for rear end tension compensation, with a winding ratio of 1.02 and a friction roller torque of 150mN. Finally, the stabilized finished yarn is continuously wound and stored on the end yarn package 16 to prepare 16S air jet vortex spun water-sensitive yarn. After soaking in 80℃ hot water for 10 minutes, the yarn body can produce irregular expansion deformation, presenting a natural slub appearance, and has excellent water-sensitive deformation characteristics.

[0058] Example 2 I. Preparation of Short Fibers in the Initial Process Step 1, Raw material pretreatment: 58D gradient segmented polyester filament is selected as the core yarn. The water-sensitive yarn prepared in this embodiment has a core-spun structure. The raw materials are precisely proportioned by mass percentage: 32.7% gradient segmented filament and 67.3% viscose staple fiber. The moisture regain of 1.2D×38mm viscose staple fiber is increased to 13% standard moisture regain, and then set aside.

[0059] Step 2, Opening and Carding Process: Viscose staple fiber is opened and carded to prepare sliver. The cylinder-licker-in speed ratio is 2.70. The distance between the feed roller and the licker-in is 0.58mm, the distance between the licker-in and the cylinder is 0.20mm, and the distance between the cylinder and the doffer is 0.15mm. The distance between the movable flats and the cylinder along the cotton inlet to outlet direction is 0.22mm, 0.20mm, 0.20mm, 0.20mm, and 0.22mm, respectively, to ensure sufficient fiber transfer and reduce neps defects.

[0060] Step 3, Three-stage merging and drafting process: The first and second stages merge 6 yarns each, and the final stage merges 8 yarns. The yarn weight for the first merging stage is 20.40 g / 5m, the back zone draft is 2.05 times, the total draft is 7.20 times, and the output yarn speed is 420 m / min; the yarn weight for the second merging stage is 20.80 g / 5m, the back zone draft is 1.48 times, the total draft is 6.20 times, and the output yarn speed is 410 m / min; the yarn weight for the third merging stage is 19.40 g / 5m, the back zone draft is 1.68 times, the total draft is 5.90 times, and the output yarn speed is 420 m / min. Roller spacing is configured as follows: first stage back zone 12.0 mm, front zone 21.0 mm; second stage back zone 12.5 mm, front zone 20.0 mm; final stage back zone 10.5 mm, front zone 22.0 mm. The prepared sliver has a CV value of 2.51% and a weight CV value of 1.02%. The prepared sliver is stored for later use and can be continuously fed through the short fiber bundle feeding channel 9.

[0061] Step 4, S1, Core yarn unwinding and centering guidance: The gradually shortened filament is released uniformly by the long filament unwinding structure 1 at the upper end of the device at a speed of 452m / min and an unwinding tension of 9cN; the core yarn is sequentially threaded through the first fixed guide ring 2 and the second fixed guide ring 3 arranged coaxially. The inner diameter of the guide ring is 0.4mm larger than the outer diameter of the core yarn. Relying on the radial limiting structure of the double guide ring, the core yarn is accurately centered and positioned throughout the entire process, eliminating the problem of yarn deviation and offset.

[0062] S2. Adjustable segmented yarn feeding adjustment: Tension is controlled by the first guide wheel 4 and the second guide wheel 5 of the tension adjustment structure. The total horizontal adjustable stroke of the guide wheel is 18mm, and the core yarn of a single guide wheel has a wrapping center angle of 105°. The three yarn feeding segments have strokes of 16mm, 20mm, and 32mm, respectively. The tension in the back zone is 3cN, the tension in the middle zone is 7cN, the tension in the drafting zone is set to 12cN, and the tension in the winding zone is set to 10cN, which can adapt to the different tension requirements of yarn and improve tension uniformity.

[0063] S3. Core filament straightening and short fiber sliver drafting: After yarn feeding adjustment, the gradually shortened filament is fed into the filament guide cradle 6. The filament guide cradle 6 straightens the oscillation trajectory of the gradually shortened filament and guides it to the mixing area 17 next to the front roller nip 18. The outer viscose sliver is conveyed to the drafting conveying structure through the short fiber bundle feeding channel 9, and then sequentially passes through the rear drafting unit, the middle drafting unit, and the front drafting unit for drafting. The roller spacing is 43.0mm × 43.0mm, the main draft ratio is 41.2, the middle draft ratio is 1.4, the rear draft ratio is 2.9, the rear roller initialization rate is 175%, the roller hardness is 83 HA, the feed ratio is 1.02, and the spinning speed is 445m / min, so that the viscose sliver forms a straight and parallel short fiber sliver.

[0064] S4. Combination of Short and Long Fibers and Vortex Forming: After drafting, the short fiber sliver merges with the gradually shortened filaments guided by the filament guide cradle 6 at the mixing point 17 next to the front roller nip 18, forming a composite fiber bundle. The composite fiber bundle is output from the front roller nip 18 and guided into the equipment by the needle seat 11 at the front end of the spinning forming machine 10. The equipment is equipped with Orient model nozzles and M-type spindles, with the nozzle pressure maintained at 0.60 MPa. Under the action of the vortex airflow, the free ends of the viscose short fibers wrap around the outside of the gradually shortened filaments, completing the core-spun twisting. The formed yarn is stably output from the vortex yarn output position 12. During the spinning process, the nozzles are kept clean, and the nip pressure is adjusted according to the actual process.

[0065] S5. Rear end pressure stabilization and finished product winding: After the forming yarn is drawn out from the vortex yarn output position 12, it passes through the first yarn drawing control component 13 and the second yarn drawing control component 14 in sequence to correct the yarn exit angle and position. Then, it passes through the friction tension roller 15 for rear end tension compensation and pressure stabilization. The winding ratio is 0.98 and the friction roller torque is 170mN. Finally, it is evenly wound to the end bobbin 16 to prepare 30S air jet vortex spun water-sensitive yarn. It has a regular core-spun structure and good water-sensitive response characteristics. After being soaked in 80℃ hot water for 10 minutes, it can produce irregular expansion deformation and form a natural slub yarn appearance.

[0066] Example 3 Step 1, Raw material pretreatment: 58D gradient segmented polyester filament is selected as the core yarn, and 1.2D×38mm viscose staple fiber is selected as the outer wrapping material; the water-sensitive yarn prepared in this embodiment has a core-spun structure, and the raw materials are precisely proportioned by mass percentage: 33% gradient segmented polyester filament, 67% viscose staple fiber, and the standard moisture regain of viscose fiber is 13%.

[0067] Step 2, Opening and Carding Process: After humidification and reaching the required standard, the viscose staple fibers are uniformly mixed and impurities removed through the opening and cleaning process, and then fed into the carding machine to prepare a uniform and complete sliver. To accelerate efficient fiber transfer, reduce neps and short fibers, and improve the clarity of the cotton web, the cylinder-licker-in speed ratio is controlled at 2.68; the carding process adopts a distance of 0.54mm between the feed roller and the licker-in, 0.18mm between the licker-in and the cylinder, and 0.13mm between the cylinder and the doffer; the distance between the movable flats and the cylinder along the cotton inlet to outlet direction is 0.20mm, 0.18mm, 0.18mm, 0.18mm, and 0.20mm respectively, ensuring that the fibers are fully combed and uniformly transferred, significantly reducing the yarn defect base.

[0068] Step 3: Three-stage drawing and drafting process: The first and second stages combine 6 slivers, and the final stage combines 8 slivers. Fixed process parameters for each stage: Stage 1: Dry weight 20.44g / 5m, back zone draft 1.94 times, total draft 8.06 times, roller spacing 12mm×21mm, output speed 410m / min; Stage 2: Dry weight 20.16g / 5m, back zone draft 1.56 times, total draft 6.01 times, roller spacing 12mm×21mm, output speed 410m / min; Stage 3: Dry weight 20.01g / 5m, back zone draft 1.60 times, total draft 6.09 times, roller spacing 11mm×21mm, output speed 400m / min. Maintain a clean and dust-free drawing path and drafting zone throughout the process, preventing defects such as flower accumulation, flower snagging, and roller wrapping. High-quality viscose cooked strips were finally obtained. The measured CV value of the cooked strips was 2.44%, the weight CV value was 0.97%, and the strip uniformity was optimal. It can be fed smoothly and continuously through the short fiber bundle feeding channel 9.

[0069] Step 4, S1, Core yarn unwinding and centering guidance: The 58D gradient segmented polyester filament is released at a uniform speed through the filament unwinding structure 1 at the top of the device. The filament unwinding spinning speed is 450m / min and the filament unwinding tension is 10cN. After release, the core yarn is sequentially passed through the first fixed guide ring 2 and the second fixed guide ring 3 arranged coaxially at the lower end. The inner diameter of the guide ring is 0.3mm larger than the outer diameter of the core yarn. The core yarn is radially limited throughout the entire process by relying on the two sets of coaxial guide rings, which completely restrains the yarn from running or deviating to the left or right, completes the yarn feeding centering positioning, and ensures the stability of the yarn feeding reference.

[0070] S2. Adjustable segmented yarn feeding adjustment: The tension adjustment structure at the lower end of the second fixed guide ring 3 allows for precise lateral sliding adjustment of the installation positions of the first guide wheel 4 and the second guide wheel 5. The total adjustable lateral stroke of the guide wheels is fixed at 12mm. The central angle of the tapered yarn wrapping around the surface of the single guide wheel is fixed at 85°. The first-stage transition yarn feeding section is 10mm, the intermediate folding yarn feeding section is 20mm, and the rear guide yarn feeding section is 24mm. The tension in the rear zone is 3cN, the tension in the middle zone is 7cN, the tension in the drafting zone is set to 12cN, and the tension in the winding zone is set to 11cN. By matching the wrapping angle and the yarn feeding stroke, the three sections of yarn can be independently and stably controlled to ensure stable yarn feeding and lay the foundation for uniform core-spun twisting.

[0071] S3. Core filament straightening and short fiber sliver drafting: After yarn feeding adjustment, the gradually shortened filaments are fed into the filament guide cradle 6. The filament guide cradle 6 straightens the oscillation trajectory of the gradually shortened filaments and guides them to the mixing area 17 next to the front roller nip 18. The prepared viscose sliver is conveyed to the drafting conveying structure through the short fiber bundle feeding channel 9, and then sequentially passes through the back drafting unit, the middle drafting unit, and the front drafting unit for drafting. The roller spacing is 42.5mm × 45mm, the main drafting ratio is 42.3, the middle drafting ratio is 1.4, the back drafting ratio is 3.0, the back roller initialization rate is 170%, the roller hardness is 79 HA, the feed ratio is 1.00, and the spinning speed is 450m / min, so that the viscose sliver is formed into a straight, parallel, and even short fiber sliver.

[0072] S4. Combination and Vortex Forming of Long and Short Fibers: After drafting, the short fiber sliver merges with the gradually shortened filament guided by the filament guide cradle 6 at the mixing point 17 next to the front roller nip 18, forming a composite fiber bundle with the gradually shortened filament as the core layer and the viscose short fiber sliver as the outer layer. The composite fiber bundle is output from the front roller nip 18 and guided into the equipment via the needle seat 11 at the front end of the spinning forming machine 10. The equipment is equipped with Orient model nozzles and M-type spindles, with the nozzle pressure maintained at 0.60 MPa. Under the action of a stable vortex airflow, the free end of the viscose short fiber wraps around the outside of the gradually shortened filament, completing the core-spun twisting. The formed water-sensitive yarn is drawn out from the vortex yarn output position 12 at the rear end of the spinning forming machine 10. During the spinning process, the oil spray lubrication and cleaning device is activated, and the small flying wings are checked and replaced regularly.

[0073] S5. Rear-end pressure stabilization and finished product winding: The finished yarn drawn from the vortex yarn output position 12 passes sequentially through the first yarn guide control component 13 and the second yarn guide control component 14 arranged at the lower end along the yarn output direction to correct the yarn output orientation and correct the yarn deviation; then it is precisely tensioned and stabilized at the rear end by the friction tension roller 15, with a fixed winding ratio of 1.00 and a friction roller torque of 160mN. Finally, the stabilized finished yarn is continuously wound and stored on the end yarn package 16 in a flat, tight, non-overlapping, and non-loose manner to prepare 30S air-jet vortex spun water-sensitive yarn. It has a regular core-spun structure and good water-sensitive response characteristics. After being soaked in 80℃ hot water for 10 minutes, it can produce irregular expansion deformation and form a natural slub yarn appearance.

[0074] Figure 3This is a schematic diagram of the core-spun yarn structure of the air-jet vortex spun water-sensitive yarn of the present invention, consisting of a water-sensitive yarn core filament 19 and an outer short fiber 20. The water-sensitive yarn core filament 19 is a gradually shortened filament with axial irregular segmental shrinkage characteristics, and the outer short fiber 20 is a viscose short fiber uniformly covering the outside of the core filament. Together, they form a stable core-sheath composite structure. Under normal conditions, the water-sensitive yarn core filament 19 and the outer short fiber 20 are tightly bonded together, forming a uniform and dense normal portion 21 of the water-sensitive yarn, with a consistent thickness and regular structure. After soaking in warm or boiling water, the thick section 23 of the core filament 19 undergoes differential shrinkage, causing the outer short fiber 20 to locally bulge, forming a water-sensitive yarn thick section 22 with an increased diameter, giving the yarn an irregular slub-like appearance.

[0075] See Figure 4 The photo shows multiple yarns arranged in parallel, with uniform thickness and tight outer short fiber coverage. It does not exhibit the irregular thick sections and bamboo-like appearance characteristic of water-sensitive treatment, clearly demonstrating the regular structure and smooth surface of the core-spun yarn of this invention under normal conditions.

[0076] The yarn is characterized by high strength, low fuzz, exceptional evenness, and resistance to pilling. The fabric also exhibits good stiffness, durability, and dimensional stability, offering diverse styles suitable for producing knitted garments, home textiles, and more, meeting consumer demands for comfort and aesthetics. This invention expands the diversification of air-jet vortex spinning products.

[0077] Figure 5 This image shows examples of the multi-colored appearance of fabrics made from the air-jet vortex-spun water-sensitive yarn of this invention after dyeing. The image displays nine fabric samples in a nine-grid layout, covering various shades including yellow, green, blue, pink, and brown. All samples exhibit a uniform and delicate fabric texture. The dyed fabrics have a smooth surface and uniform color, without any dyeing defects such as uneven yarn, fuzz, or core-spun defects, including color variations, color differences, or streaks. This demonstrates the excellent dyeability and fabric processing adaptability of the water-sensitive yarn of this invention.

[0078] Performance tests were performed on the products from Examples 1-3, and the results are as follows: Table 1: Data from Examples 1-3

[0079] Comparative Example 1 The overall process, equipment structure, and raw material ratio of this comparative example are the same as those of Example 3. The only difference is that the coaxial limiting design of the first fixed guide ring 2 and the second fixed guide ring 3 is cancelled, and a simple single guide hole guiding method conventional in the field is adopted. This is a conventional yarn feeding and positioning process in the industry, and the core yarn is not radially bidirectionally limited.

[0080] Comparative Example 2 The remaining parameters of this comparative example are completely consistent with those of Example 3. The difference is that the adjustable segmented yarn feeding structure of the dual guide rollers of this application is cancelled. The first guide roller 4 and the second guide roller 5 adopt the traditional fixed guide roller constant tension yarn feeding method. It is impossible to change the core yarn wrapping angle and yarn feeding path by adjusting the lateral position of the guide rollers. It lacks the ability to coordinate compensation for different yarn feeding sections, resulting in increased core yarn tension fluctuation. Comparative Example 3 This comparative example was used to investigate the effect of increasing the proportion of gradient-cut short-length filament on yarn performance. Except for the core yarn specification, raw material ratio, and the amount of viscose staple fiber fed to maintain the target yarn linear density, the rest of the apparatus structure and spinning process parameters were the same as in Example 3. In Comparative Example 3, the mass ratio of gradient-cut short-length filament to viscose staple fiber was set to 50:50. To maintain the yarn linear density at approximately 19.9 tex, 90D gradient-cut short-length filament was selected as the core yarn, and the amount of viscose staple fiber fed was adjusted accordingly. Comparative Example 4 The remaining parameters of this comparative example are completely consistent with those of Example 3, except that the distance between the cylinder and the doffer is adjusted to the conventional 0.18mm, and the distance between the movable cover and the cylinder is uniformly set to 0.22mm.

[0081] Comparative Example 5 This comparative example is based on Example 3, except that the final drawing process uses 6 strands combined, the total draw ratio of the final drawing process is 5.5 times, the dry weight of the mixed second drawing is 20.16g / 5m, and the dry weight of the finished sliver output from the final drawing process is 21.9g / 5m.

[0082] Comparative Example 6 The remaining parameters of this comparative example are completely consistent with those of Example 3. The difference is that the regular yarn-running structure of the filament guide cradle 6 of this application is cancelled, and a free yarn-running method without guide constraints is adopted. Comparative Example 7 The remaining parameters of this comparative example are completely consistent with those of Example 3. The difference is that the main draft ratio of spinning is changed, and the industry-standard 22.5 times main draft ratio is adopted. The dry weight of the viscose sliver is adjusted to 10.65 g / 5m, so that the yarn linear density is maintained at about 19.7 tex. Comparative Example 8 The remaining parameters of this comparative example are completely consistent with those of Example 3. The difference is that the back zone draft ratio is changed to 2.5 times the back zone draft parameter, and the dry weight of the viscose sliver is adjusted to 16.68 g / 5m, so that the yarn linear density is maintained at about 19.7 tex. Comparative Example 9 The remaining parameters of this comparative example are completely consistent with those of Example 3, except that the spinning speed is changed to adopt the industry-standard low-speed spinning process of 420m / min. Comparative Example 10 The remaining parameters of this comparative example are completely consistent with those of Example 3, except that the first yarn feeding control component 13 and the second yarn feeding control component 14 are removed, and a simple winding guide method using a single yarn feeding roller is adopted. Comparative Example 11 The remaining parameters of this comparative example are completely consistent with those of Example 3, except that the hardness of the roller is changed, and a relatively low hardness roller of 70HA, which is common in the industry, is used. Comparative Example 12 The remaining parameters of this comparative example are completely consistent with those of Example 3, except that the core wire unwinding tension is changed and a 16cN tension unwinding process is adopted. Comparative Example 13 The remaining parameters of this comparative example are completely consistent with those of Example 3, except that the winding torque is changed, and a winding ratio of 1.2 and a high friction roller torque of 190mN are used.

[0083] Comparative Example 14 The remaining parameters of this comparative example are completely consistent with those of Example 3, except that the three-section yarn travel ratio parameters of the equipment are changed. The front, middle, and rear yarn travels are all set to an equal length of 18mm.

[0084] Comparative Example 15 The remaining parameters of this comparative example are completely consistent with those of Example 3. The difference is that the three-stage gradient tension of unwinding tension, drafting, and winding of the filament in this application is cancelled, and a uniform constant tension of 12cN is used for yarn feeding.

[0085] Comparative Example 16 The remaining parameters of this comparative example are completely consistent with those of Example 3, except that the spacing of the three drawing rollers is changed: the spacing after the first drawing is 14.0 mm and the spacing before the first drawing is 23 mm; the spacing after the second drawing is 13.0 mm and the spacing before the second drawing is 23 mm; and the spacing after the last drawing is 12.0 mm and the spacing before the last drawing is 23 mm.

[0086] Table 2. Data from Comparative Examples 1-8

[0087] Table 3. Comparative Examples 9-16

[0088] In Comparative Example 1, the coefficient of variation of yarn density, CV value of yarn evenness, number of neps, and H value of hairiness increased, while the breaking strength of single yarn decreased, and the yarn uniformity and stability deteriorated. This indicates that the double fixed guide rings achieve radial bidirectional limiting of the core yarn throughout its entire journey, constraining the tapered filaments in the high-speed yarn movement to prevent deviation and ensure that the core yarn remains at the center of the fiber bundle. After the double guide rings are removed, the single guide hole can only provide simple guidance and cannot limit the radial oscillation of the core yarn during high-speed operation, leading to core yarn deviation and positioning eccentricity. During the core-wrapping twisting process, problems such as eccentricity and local empty wrapping occur, the regularity of the composite fiber bundle decreases, and ultimately, yarn evenness and large strength fluctuations are caused. At the same time, the yarn oscillation disturbs the wrapping state of the outer short fibers 20, generating a large number of neps and hairiness defects.

[0089] In Comparative Example 2, the yarn evenness, neps, hairiness, and strength variation coefficient were inferior to those in Example 3, and the overall yarn stability was significantly reduced. This indicates that the dual guide rollers can adjust the wrapping angle and yarn travel by sliding laterally. The dual guide rollers are used to coordinately regulate the yarn path and tension stability during the core yarn feeding stage. The output and winding tension of the finished yarn are adjusted by the dual yarn guide control components and friction tension rollers to match the yarn stress requirements at different stages of spinning, ensuring minimal core yarn tension fluctuations. With the traditional fixed guide roller structure, the yarn tension is uniform throughout the entire process and cannot be adaptively adjusted in segments. Insufficient tension in the yarn feeding section easily leads to the accumulation of lint, unstable tension in the drafting section causes uneven fiber drafting, and abnormal tension in the winding section causes inconsistent yarn tightness. Tension imbalance will cause uneven core yarn stretching and deformation, large differences in the density of short fiber wrapping, ultimately resulting in poor yarn evenness, increased yarn defects, and decreased strength stability.

[0090] The breaking strength of the single yarn in Comparative Example 3 was slightly higher than that in Example 3, but its evenness CV value, number of neps, coefficient of variation of single yarn strength and hairiness H value were all increased. This indicates that although increasing the core yarn ratio can enhance the yarn strength of the core yarn, it will make the outer viscose short fiber layer relatively thinner, reduce the integrity of the outer fiber covering the core yarn and the uniformity of the yarn structure, resulting in a slight deterioration in evenness, neps, hairiness and strength stability.

[0091] After being treated with hot water under the same conditions, Comparative Example 3, due to insufficient thickness of the outer short fiber layer, struggled to form significant and stable local accumulation and radial bulges under the differential shrinkage of the core filament. Its water-sensitive slub deformation effect was significantly weaker than that of Example 3, with a decrease in the number of thick segments, the degree of prominence of the thick segments, and the stability of their morphology. This indicates that Example 3, using a mass ratio of 33% gradually shortened filament and 67% viscose short fiber, achieves a better match between the hydrothermal deformation of the core filament and the coating effect of the outer short fiber. This is beneficial for balancing yarn structure stability and water-sensitive slub deformation effect, resulting in a more obvious, uniform, and stable irregular slub morphology.

[0092] In Comparative Example 4, the evenness CV value, nipple count, and hairiness value increased significantly, while the single yarn strength decreased. This indicates that the carding process is the core process for fiber combing, impurity removal, and reduction of short fibers and nipples. The spacing configuration in Example 3 achieves progressive and fine fiber combing, ensuring sufficient fiber transfer and effective removal of impurities. After increasing the cylinder doffer spacing and unifying the flat sheet spacing, fiber combing is insufficient, and unstraightened fibers, short fibers, and impurities cannot be effectively removed, resulting in a significant decrease in fiber transfer rate and a large amount of accumulated and tangled fibers remaining in the sliver. Substandard slivers, after drawing, drafting, and twisting, directly transform into yarn nipples, thick and thin areas, and hairiness defects. Poor fiber parallelism also leads to uneven yarn stress and a significant decrease in strength, which is the core cause of the deterioration in yarn quality.

[0093] In Comparative Example 5, the uniformity of the sliver decreased, resulting in poorer yarn evenness, neps, hairiness, and strength stability. The final drawing stage is a crucial process for correcting sliver evenness and improving fiber straightness. The eight-docking method and precise drafting parameters of this application effectively offset sliver thickness variations and integrate disordered fiber states. Reducing the number of dockings significantly weakens the ability to correct sliver thickness unevenness, and lowering the total draft ratio leads to insufficient fiber straightening and parallelism, resulting in a large number of crimped and disordered fibers within the sliver. When the defective sliver enters the spinning process, the disordered fibers cannot be evenly drafted and covered, forming regular thick and thin spots and neps, ultimately leading to deterioration of yarn evenness, increased strength fluctuations, and increased hairiness.

[0094] In Comparative Example 6, the core filament was unrestrained, resulting in increased yarn evenness, hairiness, and neps, while strength decreased. This illustrates that the core function of the filament guide cradle 6 is to regulate the oscillation trajectory of the high-speed core filament, eliminating yarn jitter and deviation, and ensuring the core filament enters the fiber mixing zone smoothly and accurately. Without the guide cradle, the core filament moves freely throughout the entire process, generating irregular high-frequency jitter at high speed. This causes the core filament to continuously deviate at the mixing zone 17, leading to unstable merging of long and short fibers, sometimes resulting in core deviation and sometimes uneven coverage. Disordered fiber merging causes uneven yarn thickness, localized fiber loosening forming hairiness and neps, and irregular core-sleeving structure leading to more weak points in the yarn and reduced breaking strength.

[0095] In Comparative Example 7, insufficient drafting resulted in poor yarn evenness, hairiness, and neps, with a slight decrease in strength. The main drafting ratio in this application is matched to the fiber length and cohesion characteristics of the short fiber sliver, fully stretching disordered fibers, eliminating sliver thickness deviations, and forming a uniform and dense fiber bundle. When the main drafting ratio is too low, the composite fiber bundle is insufficiently drafted, resulting in insufficient slippage between fibers, incomplete bending, and loose fiber cohesion and disordered arrangement within the yarn. After twisting, insufficiently drafted fibers result in numerous hidden thick and thin points in the yarn, with exposed fibers forming hairiness, and uncombed fiber clumps forming small neps, leading to a decrease in overall yarn density and uniformity.

[0096] In Comparative Example 8, insufficient drafting in the back zone resulted in poor fiber pre-carding, leading to deterioration in yarn evenness and yarn defect indicators. The back zone drafting primarily serves to pre-straighten and initially evenly mix fibers, laying the foundation for the main drafting in the front zone. When the back zone drafting ratio is too low, the sliver cannot effectively separate fiber bundles in the initial drafting stage. The problems of fiber bundle clumping and bending cannot be addressed in advance, and a large number of fibers enter the main drafting zone in a bundled and bent state, exceeding the carding and adaptation capacity of the main drafting. This ultimately leads to uneven yarn evenness, localized fiber accumulation forming neps, and an increase in hairiness.

[0097] Comparative Example 9 shows that reducing the spinning speed deteriorates the overall performance of the yarn, with multiple uniformity indicators worsening and clearly detectable process defects. Specifically, compared to the optimal group, this group exhibits increased yarn evenness CV value, yarn evenness CVb value, and strength coefficient of variation, resulting in decreased overall yarn uniformity and stability; hairiness H value and hairiness HCVb value also increase, leading to a deterioration in yarn surface smoothness. The proposed optimal spinning speed of 450 m / min is the one that best matches the equipment's vortex airflow, drafting rhythm, and fiber feeding, achieving a dynamic balance between airflow twisting, fiber drafting, and forming / winding, ensuring a tight, uniform yarn body and stable twist. Reducing the spinning speed to 420 m / min causes a mismatch between the equipment's vortex airflow field and the fiber feed speed, resulting in excessively long fiber residence time in the twisting zone, which can easily lead to slight fiber twisting, localized accumulation, and uneven twist distribution. Although there are fewer serious yarn defects under low-speed conditions, they will continue to cause uneven tension in the yarn body and a decrease in fiber straightness, resulting in poor yarn evenness, increased strength fluctuations, and increased hairiness. This will disrupt the consistency of the core-spun structure of the water-sensitive yarn and reduce the appearance cleanliness and production stability of the yarn.

[0098] Comparative Example 10 exhibits significant defects in winding, with deterioration in yarn density deviation, evenness, hairiness, and strength. This demonstrates that the front and rear dual-guide yarn control components can bidirectionally correct the yarn exit orientation, eliminating yarn deviation and angular offset, and ensuring a regular yarn posture before winding. Replacing it with a single-guide roller only achieves simple yarn guide and cannot correct lateral deviation and vertical swaying of the yarn during high-speed winding. The yarn's posture is unstable when entering the tension roller and winding bobbin, leading to instantaneous fluctuations in winding tension and uneven local stretching deformation. Ultimately, this results in large yarn thickness deviations, uneven yarn, and increased friction from yarn movement, generating a large amount of new hairiness and a sharp decline in yarn strength and stability.

[0099] The clamping stability of the nip in Comparative Example 11 was insufficient, resulting in poor yarn evenness, hairiness, and neps. The hardness of the roller determines the clamping accuracy and stability of the roller nip. The roller hardness of 76-83HA in this application can ensure a tight fit between the nip and uniform clamping of the fiber bundle to achieve constant-speed drafting. Low-hardness rollers have excessive elasticity and insufficient rigidity. During high-speed drafting, the roller is prone to deformation and loose fit, leading to localized missed clamping, uneven pressure, fiber bundle slippage, and uneven drafting. Some fibers are not effectively drafted and constrained, forming hairiness and neps on the yarn surface. At the same time, fluctuations in fiber transport speed cause uneven yarn evenness.

[0100] Under a constant tension of 12cN throughout the process, the tension of the core yarn unwinding section is higher than that in Example 3, which easily causes the core yarn to be overstretched during unwinding. The tension of the finished yarn winding section is also increased from 11cN to 12cN, which easily leads to tight winding, increased internal stress of the yarn, and frictional damage to the surface fibers. The original gradient relationship between the core yarn unwinding section, the core yarn introduction section, and the finished yarn winding section disappears, making it difficult to adapt to the operational requirements of different processes, resulting in deterioration of yarn evenness, strength stability, and hairiness.

[0101] In Comparative Example 13, excessive winding tension resulted in yarn stretching damage, leading to decreased strength, evenness, and hairiness. This application's winding ratio and torque achieve stable, damage-free winding, ensuring the stability of the finished yarn structure. Increasing the friction roller torque and winding ratio results in excessive winding traction, causing continuous and intense stretching of the formed water-sensitive yarn. This tightens the yarn structure, causes excessive fiber cohesion, and generates tensile stress, not only disrupting yarn uniformity but also damaging fibers and weakening yarn strength. Furthermore, excessive friction scratches the yarn surface fibers, generating significant hairiness and fine yarn defects.

[0102] Comparative Example 14 uniformly sets the effective yarn path length of the three sections to 18mm, eliminating the length differences between the primary transition yarn path, the intermediate reversal yarn path, and the post-introduction yarn path. An excessively long primary transition yarn path hinders the core yarn from quickly and stably entering the first guide roller; an excessively short post-introduction yarn path results in insufficient post-introduction distance after the core yarn changes direction at the second guide roller, easily transmitting tension changes and lateral oscillations generated at the guide roller to the filament guide cradle and mixing area. Therefore, the equal-length yarn path configuration cannot adequately adapt to the different yarn path requirements of the initial introduction, intermediate reversal, and post-introduction stages, leading to decreased operational stability when the core yarn enters the mixing area, resulting in core-spun position fluctuations, decreased yarn evenness, and increased hairiness and neps.

[0103] In Comparative Example 15, poor tension matching at each stage resulted in deterioration of yarn evenness, stability, and yarn defect indicators. Throughout the spinning process, the yarn resistance and stress environment differ in the unwinding, drafting, and winding stages. The gradient tension in this application—drafting tension > winding tension > unwinding tension—can precisely match the resistance differences in each stage and offset tension loss. Under a constant tension mode throughout the process, excessive unwinding tension damages the core yarn, insufficient winding tension leads to loose yarn and winding defects, and unstable drafting tension causes uneven fiber drafting. The cumulative effect of tension mismatch across multiple stages ultimately results in a comprehensive decline in the overall quality of the yarn.

[0104] In Comparative Example 16, insufficient drafting precision in the drawing process resulted in poor sliver quality and increased yarn evenness and defects. Appropriate roller spacing matches fiber length, ensuring sufficient fiber straightening and orderly drafting during the drawing process. Enlarging the roller spacing before and after drawing increases the effective clamping distance of the rollers on the fibers, preventing precise clamping of short fibers. A large number of fibers slide freely in the drafting zone, failing to straighten effectively, leading to severe fiber disorder and crimping within the sliver. Inferior sliver entering subsequent spinning processes further amplifies evenness deviations, generating numerous thick and thin spots, neps, and hairiness, significantly reducing the overall quality of the yarn.

[0105] The technical solutions provided in this disclosure have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this disclosure. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this disclosure. Furthermore, those skilled in the art will recognize that, based on the ideas of this disclosure, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this disclosure.

[0106] The above are merely preferred embodiments of this disclosure and are not intended to limit this disclosure. Any modifications or equivalent substitutions made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A control device for core-spun yarn specifically for jet-jet vortex spinning of water-sensitive yarn, characterized in that, It includes a filament unwinding structure (1), a guide and positioning structure, a tension adjustment structure, a filament guide cradle (6), a drafting and conveying structure, a spinning forming machine (10), and a winding structure arranged sequentially along the core filament conveying direction; the filament unwinding structure (1) is the core filament input end, used to install and uniformly release the gradually shortened filament. The guiding and positioning structure includes a first fixed guide wire ring (2) and a second fixed guide wire ring (3) arranged coaxially at intervals. The first fixed guide wire ring (2) is located at the lower end of the filament unwinding structure (1), and the second fixed guide wire ring (3) is located at the lower end of the first fixed guide wire ring (2). The tension adjustment structure is located at the lower end of the second fixed guide wire ring (3). The tension adjustment structure includes a first guide wire wheel (4) and a second guide wire wheel (5) that can slide laterally to the left and right and rotate freely. The filament guide rocker (6) is installed at the lower end of the tension adjustment structure at the yarn feeding position; The drawing and conveying structure is located at the lower end of the filament guide cradle (6). The drawing and conveying structure includes a front drawing unit. The front drawing unit includes a front upper rubber roller (7) and a front lower roller (8) of the drawing system, which are arranged vertically and vertically respectively. The front upper rubber roller (7) and the front lower roller (8) of the drawing system are bonded together to form a front roller jaw (18). The front and rear ends of the spinning forming machine (10) are respectively provided with a needle seat (11) and a vortex yarn output position (12). The needle seat (11) is the front feeding guide part of the spinning forming machine (10), and the vortex yarn output position (12) is the rear discharge part of the spinning forming machine (10). The winding structure is located at the lower end of the spinning forming machine (10). The winding structure includes a first yarn feeding control component (13) and a second yarn feeding control component (14), a friction tension roller (15), and a yarn package (16) arranged sequentially along the yarn output direction. The area between the filament guide cradle (6) and the front roller nipper (18) forms a mixing area (17) for the tapered section long filament and short fiber strip. A short fiber bundle feeding channel (9) is provided on one side of the drawing and conveying structure. The short fiber bundle feeding channel (9) is used to continuously feed the outer short fiber strip to the drawing and conveying structure. The short fiber strip after being drawn by the drawing and conveying structure merges with the tapered section long filament at the mixing area (17) next to the front roller nipper (18). The drafting and conveying structure is further provided with a middle drafting unit and a rear drafting unit. The rear drafting unit, the middle drafting unit and the front drafting unit are arranged in sequence along the short fiber sliver travel direction. The middle drafting unit includes a middle upper roller and a middle lower roller paired together. The rear drafting unit includes a rear upper roller and a rear lower roller paired together. The short fiber sliver is drafted by passing through the rear drafting unit, the middle drafting unit and the front drafting unit in sequence. It then merges with the gradually shortened filament at the front roller nip (18) to form a composite fiber bundle, which is then fed into the spinning forming machine (10).

2. A method for controlling core-spun water-sensitive yarn using the device described in claim 1, characterized in that, Includes the following steps: Step S1, Core yarn unwinding and centering guidance: The gradually shortened filament is released at a constant speed by the filament unwinding structure (1). After release, the gradually shortened filament is sequentially passed through the first fixed guide ring (2) and the second fixed guide ring (3). The gradually shortened filament is radially limited by the two sets of coaxially arranged guide rings to constrain the yarn deviation and complete the yarn feeding centering positioning. Step S2, Adjustable segmented yarn feeding adjustment: According to the yarn tension requirements of the spinning process, the installation positions of the first guide wheel (4) and the second guide wheel (5) are adjusted laterally to change the wrapping contact angle between the tapered section filament and the two guide wheels and the actual yarn feeding stroke length. The running tension of the tapered section filament is changed segmentally by relying on the change of wrapping angle and yarn feeding length to realize the segmented yarn feeding state adjustment of the front and middle sections of the yarn. Step S3, Core filament straightening and short fiber sliver drafting: After segmented tension adjustment, the tapered section of the long filament is inserted into the filament guide cradle (6). The filament guide cradle (6) straightens the sliver's oscillation trajectory and then directs it into the mixing area (17) of the tapered section of the long filament and the short fiber sliver. The outer short fiber sliver is conveyed to the drafting conveying structure via the short fiber bundle feeding channel (9) and passes sequentially through the back drafting unit, the middle drafting unit, and the... The front drafting unit performs drafting with a roller spacing of 42.5–45.0 mm, a main drafting ratio of 24.5–42.5, a middle drafting ratio of 1.2–1.5, a rear drafting ratio of 2.9–3.1, a rear roller initialization rate of 165%–175%, a roller hardness of 76–83 HA, a feed ratio of 0.98–1.02, and a spinning speed of 445–455 m / min, so that the outer short fiber sliver forms a straight and parallel short fiber sliver; Step S4, merging of short and long fibers and vortex forming: The short fiber sliver after being drawn merges with the gradually shortened filament guided by the long filament guide cradle (6) at the mixing point (17) next to the front roller nip (18) to form a composite fiber bundle with the gradually shortened filament as the core layer and the short fiber sliver as the outer layer; After the composite fiber bundle is output from the front roller nip (18), it is guided into the spinning forming machine (10) by the needle seat (11) at the front end of the spinning forming machine (10). Under the action of the vortex airflow, the free end of the short fiber wraps around the outside of the gradually shortened filament, completing the core-spun twist and forming water-sensitive yarn; The processed water-sensitive yarn is drawn out from the vortex yarn output position (12) at the rear end of the spinning forming machine (10); S5. Rear end pressure stabilization and finished product winding: The finished yarn drawn from the vortex yarn output position (12) passes through the first yarn drawing control component (13) and the second yarn drawing control component (14) in sequence to correct the yarn output position. Then, it is subjected to rear end tension compensation and pressure stabilization by the friction tension roller (15). The winding ratio is 0.98 to 1.02 and the friction roller torque is 150 to 170 mN. The stabilized finished yarn is continuously wound and stored on the yarn package (16).

3. The method for controlling water-sensitive core-spun yarn spun by jet vortex spinning according to claim 2, characterized in that, In S1, the unwinding speed of the tapered section filament is 445-455 m / min; the inner diameter of the first fixed guide ring (2) and the second fixed guide ring (3) is 0.2-0.4 mm larger than the outer diameter of the core wire; The unwinding tension of the filament is controlled at 8-12 cN; the tension of the drawing section is controlled at 8-12 cN and the tension of the winding section are both controlled at 8-12 cN, and the tension of the drawing section is greater than the tension of the winding section, and the tension of the winding section is greater than the unwinding tension of the filament.

4. The method for controlling water-sensitive core-spun yarn spun by air jet vortex spinning according to claim 2, characterized in that, In step S2, the first guide wheel (4) and the second guide wheel (5) have a total horizontal and left-right adjustable stroke of 6-18 mm; the central angle of the tapered section of the filament wrapped around the surface of a single guide wheel is controlled at 75°-105°. The gradual reduction of the filament from the second fixed guide ring (3) to the first guide wheel (4) is the first-level transition yarn section, the first guide wheel (4) to the second guide wheel (5) is the intermediate turning yarn section, and the second guide wheel (5) to the entrance of the filament guide rocker (6) is the rear-entry yarn section.

5. A method for preparing air-jet vortex spun water-sensitive yarn, characterized in that, It is prepared using the special core-spun yarn tension control device described in claim 1, and includes the following processing steps: Step 1: Select gradient section shortened filament as core yarn and viscose staple fiber as outer packaging material; perform humidification treatment on viscose staple fiber to increase the actual moisture regain of raw material to close to the standard moisture regain of 13%, improve fiber spinnability, and reduce fiber damage during spinning process. Step 2: The humidified viscose staple fiber is processed into a uniform and complete sliver by sequentially passing through the opening and cleaning process and the carding process. During the carding process, the cylinder licker-in speed ratio is controlled to be no less than 2.65 to optimize the fiber transfer effect and reduce neps and short fibers. Step 3: Perform three-stage merging and stretching processes on the prepared viscose sliver. Use multi-strand merging and zoned stretching optimization process to improve fiber straightness and sliver uniformity, and prepare viscose sliver with stable sliver and no sliver accumulation or sliver fraying. Step 4: Using the gradually shortened filament as the core filament, the viscose sliver obtained in step 3 is fed into the drafting and conveying structure through the short fiber bundle feeding channel (9); the viscose sliver is successively drafted through the rear drafting unit, the middle drafting unit and the front drafting unit to form viscose short fiber sliver, and merges with the gradually shortened filament at the mixing point (17) next to the front roller nip (18) to complete the subsequent core-spun twisting and obtain the air-jet vortex spun water-sensitive yarn.

6. The method for preparing a jet-jet vortex-spun water-sensitive yarn according to claim 5, characterized in that, The core process parameters for the carding process in step 2 are as follows: the distance between the feed roller and the licker-in is 0.50-0.58 mm, the distance between the licker-in and the cylinder is 0.16-0.20 mm, the distance between the cylinder and the doffer is 0.11-0.15 mm, and the distance between the movable cover and the cylinder along the cotton inlet to outlet direction is 0.18-0.22 mm, 0.16-0.20 mm, 0.16-0.20 mm, 0.16-0.20 mm, and 0.18-0.22 mm, respectively.

7. The method for preparing a jet-jet vortex-spun water-sensitive yarn according to claim 5, characterized in that, In step 3, the three drawing processes involve combining 5-7 yarns in the first and second draws, and 7-9 yarns in the final draw. The first draw has a yarn weight of 19.80-21.00 g / 5m, a back zone draft of 1.85-2.05 times, a total draft of 7.00-8.06 times, and an output yarn speed of 400-420 m / min. The second draw has a yarn weight of 19.50-20.80 g / 5m and a back zone draft of 1.4... The yarn has a draft ratio of 8 to 1.64 times, a total draft ratio of 5.80 to 6.20 times, and an output yarn speed of 400 to 420 m / min; the yarn weight of the blended three-way yarn is 19.40 to 20.60 g / 5m, the back zone draft ratio is 1.52 to 1.68 times, the total draft ratio is 5.80 to 6.50 times, and the output yarn speed is 390 to 420 m / min; the CV value of the finished sliver is ≤2.60%, and the CV value of the finished sliver weight is ≤1.10%.

8. The method for preparing water-sensitive yarn by air jet vortex spinning according to claim 5, characterized in that, The three-roller spacing configuration is as follows: the rear spacing of the first rolling mill is 11.5–12.5 mm, and the front spacing is 20.0–22.0 mm; the rear spacing of the second rolling mill is 11.5–12.5 mm, and the front spacing is 20.0–22.0 mm; and the rear spacing of the last rolling mill is 10.5–11.5 mm, and the front spacing is 20.0–22.0 mm.

9. A jet-jet vortex spun water-sensitive yarn, characterized in that, The water-sensitive yarn is manufactured by the preparation method described in claim 5. The water-sensitive yarn has a core-spun yarn structure and is composed of 30-35% gradient segment shortened filaments and 65-70% viscose short fibers by mass percentage. After being soaked in warm water or boiling water, the water-sensitive yarn undergoes irregular expansion and deformation, presenting a natural slub appearance and possessing excellent water-sensitive deformation characteristics.

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