Octastar hollow polyester fiber and preparation method thereof, and preparation method of filament yarn

Abstract

This invention relates to the field of hollow polyester fiber technology, and discloses an octagonal star-shaped hollow polyester fiber and its preparation method, as well as a method for preparing filament yarn. The octagonal star-shaped hollow polyester fiber comprises a monofilament with a square ring cross-section and eight wing-like structures on its outer circumferential surface. These eight wing-like structures are evenly distributed on the four outer walls of the square ring, with unequal lengths on adjacent circumferentially adjacent outer walls. This invention uses wing-like structures of varying lengths on the outer circumference of the square ring, creating grooves of different depths on the fiber surface, forming capillary channels. Especially in the multifilament state, the special cross-section increases the gaps between monofilaments, improving bulkiness and air permeability. Furthermore, the large square space in the hollow portion facilitates mold design and processing, resulting in stable product performance, particularly maintaining the hollowness, thus providing better heat-shielding and insulation effects.

Description

Technical Field

[0001] This invention relates to the field of hollow polyester fiber technology, specifically to an octagonal star-shaped hollow polyester fiber and its preparation method, as well as a method for preparing filament yarn. Background Technology

[0002] With social development and the improvement of people's living standards, people's requirements for the comfort and functionality of textiles are gradually increasing. Hollow polyester filament is favored by consumers due to its warmth and lightweight properties. However, fabrics made from ordinary hollow polyester filament have drawbacks such as a stiff hand feel, poor touch, and poor breathability and moisture absorption, which limits their application in high-end fields. In order to improve the comfort and functionality of polyester filament, it is necessary to develop a hollow polyester filament yarn that combines the high strength, dimensional stability, and quick-drying properties of polyester fibers with the soft hand feel, breathability, and moisture absorption of cotton fibers. The prior art patent application with publication number CN 111394811 A discloses a light-sensitive octagonal polyester fiber filament and its preparation method. The cross-section of the octagonal polyester fiber filament is octagonal and has several filament holes inside. However, due to the octagonal structure of the octagonal polyester fiber filament, the gap between the monofilaments in the multifilament is too small, resulting in poor breathability of the woven fabric. In addition, because there are several filament holes inside the octagonal cross-section, it is difficult to design and process the spinneret to produce this product, resulting in low hollowness of the octagonal polyester fiber filament and failure to achieve a lightweight and warm effect.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of these embodiments, but rather as a prelude to the detailed description that follows.

[0005] This invention addresses the limitations of existing technologies by providing a more comprehensive solution: an octagonal star-shaped hollow polyester fiber and its preparation method, as well as a method for preparing filament yarn. This solves the problems of poor breathability, feel, moisture absorption and quick-drying properties, and poor warmth retention in fabrics woven from existing octagonal star-shaped polyester fiber filaments. The solution to these problems is achieved through a complex combination of techniques, including improvements to the preparation methods of the octagonal star-shaped hollow polyester fiber and filament yarn.

[0006] In some embodiments, an octagonal star-shaped hollow polyester fiber comprises: The monofilament of the fiber filament has a square ring-shaped cross-section and eight wings on the outer circumferential surface. The eight wing bodies are distributed on the four outer walls of the square ring, and the lengths of the wing bodies on adjacent circumferential outer walls are not equal.

[0007] In some embodiments, the wing body is elongated, with one end connected to the outer wall and the other end extending away from the outer wall.

[0008] In some embodiments, the other ends of the two wings on the same outer wall are arranged to be opposite each other and far apart.

[0009] In some embodiments, the square ring is rectangular, and the length of the wing body on the long side is greater than the length of the wing body on the short side.

[0010] In some embodiments, a method for preparing an octagonal star-shaped hollow polyester fiber as described above includes polyethylene terephthalate being processed by a solution spinning process through a spinneret. The spinneret includes a square ring hole and eight slots. The eight slots are evenly distributed on the outer periphery of the square ring hole, and one end of each slot is connected to the four outer sides of the square ring hole. The extension lengths of the slots on adjacent sides of the square ring hole are not equal.

[0011] In some embodiments, the square annular hole is rectangular, and the four outer sides include two long sides and two short sides; the extension length of the slot communicating with the long sides is greater than the extension length of the slot communicating with the short sides.

[0012] In some embodiments, the two slots connected on each of the outer sides extend in opposite directions, and the angle between the extension directions of the two slots connected on the short side is set as A, and the angle between the extension directions of the two slots connected on the long side is set as B, satisfying 30°≤A≤40°, 60°≤B≤70°, and A+B=90°-110°.

[0013] In some embodiments, the angle between the extending directions of the slot connected on the short side and the slot that is closer to the adjacent long side is set as C, satisfying 35°≤C≤45°.

[0014] In some embodiments, a method for preparing filament yarn includes the method for preparing octagonal star hollow polyester fiber as described above, and further includes physical modification treatment of the octagonal star hollow polyester fiber. The physical modification treatment includes twisting and feathering the octagonal star hollow polyester fiber using a ring spinning machine to obtain cotton-like octagonal star hollow polyester filament yarn. The ring spinning machine includes a front rubber roller, a spindle, a yarn tube, a sanding roller, and a ring rail. The sanding roller and the spindle are axially parallel on the ring rail. The yarn tube is sleeved on the spindle. The octagonal star-shaped hollow polyester fiber contacts the front rubber roller and the sanding roller in sequence, and finally winds onto the yarn tube. Both the front rubber roller and the sanding roller rub the outer surface of the octagonal star-shaped hollow polyester fiber, causing the outer surface of the octagonal star-shaped hollow polyester fiber to produce fuzz.

[0015] In some embodiments, the abrasive rollers are provided in multiple forms and are evenly distributed around the spindle.

[0016] The octagonal star-shaped hollow polyester fiber and its preparation method, as well as the filament yarn preparation method provided in this invention embodiment, can achieve the following technical effects: The cross-sectional structure of hollow polyester fibers is designed by using square rings with wings of different lengths on the outer periphery, which creates grooves of different depths on the fiber surface, forming capillary channels. Especially in the multifilament state, the special cross-section of the monofilament increases the gaps between the monofilaments, improving the bulkiness and air permeability. Furthermore, the hollow part uses a larger square space, which facilitates mold design and processing, resulting in stable product performance. In particular, the hollowness can be maintained, providing better heat shielding and insulation effects.

[0017] By using a ring spinning machine to twist and feather octagonal star-shaped hollow polyester fibers, cotton-like octagonal star-shaped hollow polyester filament yarn is obtained. This yarn has the characteristics of high strength, dimensional stability and quick drying of polyester fibers, as well as the soft hand feel, breathability and moisture absorption of cotton fibers.

[0018] The above general description and the description below are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0019] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein: Figure 1 This is a schematic diagram of the spinneret structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of a hollow polyester fiber monofilament provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the principle structure of a ring spinning machine provided in an embodiment of the present invention.

[0020] Figure label: 1. Spinneret; 11. Spinneret orifice; 2. Monofilament; 20. Hollow section; 21. Long side; 211. First wing body; 212. Second wing body; 22. Short side; 221. Third wing body; 222. Fourth wing body; 3. Ring spinning frame; 30. Multifilament body; 31. Cylindrical bobbin; 32. Guide roller; 33. Guide wheel; 34. Front roller; 35. Front roller; 36. Guide hook; 37. Ring rail; 38. Yarn tube; 39. Frosting roller; 40. Imitation cotton octagonal star hollow polyester filament yarn. Detailed Implementation

[0021] To provide a more detailed understanding of the features and technical content of the embodiments of the present invention, the implementation of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of the present invention. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be shown in a simplified manner to simplify the drawings.

[0022] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0023] In this embodiment of the invention, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better describing the embodiments of the invention and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the embodiments of the invention according to the specific circumstances.

[0024] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this invention according to the specific circumstances.

[0025] Unless otherwise stated, the term "multiple" means two or more.

[0026] In this embodiment of the invention, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0027] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0029] Combination Figure 1 and Figure 2 As shown, an embodiment of the present invention provides an octagonal star-shaped hollow polyester fiber, comprising: The monofilament 2 of the fiber filament has a square ring-shaped cross-section and eight wings on the outer circumferential surface. The eight wing bodies are distributed on the four outer walls of the square ring, and the lengths of the wing bodies on adjacent circumferential outer walls are not equal.

[0030] The hollow polyester fiber in this embodiment of the invention has a square ring cross-section structure, and eight wings of different lengths are provided on the outer wall of the square ring. More specifically, the eight wings are evenly distributed on the four outer walls, that is, each outer wall is provided with two wings; the eight wings form an octagonal star structure.

[0031] Because the lengths of the wings on the outer wall of the monofilament 2 are different, grooves of varying depths extending along the length of the monofilament 2 are formed on its outer periphery, constituting capillary channels. These channels can quickly absorb liquid sweat and moisture from the skin surface and diffuse and conduct it outward along the grooves to the fabric surface, accelerating evaporation and ensuring the skin remains dry and comfortable. In the multifilament 30 structure composed of multiple monofilaments 2, the distance between adjacent monofilaments 2 is relatively increased due to the difference in wing lengths, forming irregular small grooves that increase the breathability of the fabric.

[0032] The embodiments of the present invention provide, as follows Figure 2The hollow polyester fiber monofilament 2 shown in the cross section includes a square ring-shaped main body with a hollow portion 20, which allows the entire monofilament 2 to store air, improving its warmth retention and heat insulation properties, and is lightweight. In this invention, the main body is square ring-shaped, including square ring-like structures with straight outer walls and curved or arc-shaped outer walls, all of which can store air to improve the warmth retention of the monofilament 2.

[0033] Because the square ring-shaped main body has a hollow section 20 in the middle, the hollow ratio (the ratio of the area occupied by the hollow cavity in the cross section) is greater than that of traditional hollow fiber. This allows for lower precision and reduced costs in mold making, while ensuring hollow ratio, light weight and thermal insulation.

[0034] The aforementioned square ring and the wings on the four outer walls of the square ring are produced by spinning, so the fiber material structure is not fixed. The square ring is usually similar to a square, not a square ring in the strict sense. The four sides of the square ring and the eight protruding wings may be curved.

[0035] Optionally, the wing body is elongated, with one end connected to the outer wall and the other end extending away from the outer wall.

[0036] The wing body of this embodiment adopts a long strip structure, with one end connected to the outer wall of the square ring-shaped main body and the other end extending away from the outer wall. By setting the long strip wing body on the outer wall, the outer surface area of ​​the entire monofilament 2 is increased. Even in the multifilament structure, the long strip structure makes the adjacent monofilaments 2 set with a large spacing, thereby increasing the fluffiness and breathability.

[0037] The eight corresponding wing bodies are evenly distributed on the outer wall of the square ring-shaped main body, which reflect and scatter light from multiple angles. This can reflect sunlight back, reduce heat absorption, and thus achieve a heat-shading effect and reduce glare.

[0038] Optionally, the other ends of the two wings on the same outer wall are arranged to be opposite each other and far apart.

[0039] In this embodiment of the invention, the wing body is elongated and located at the other end away from the square ring-shaped main body, and is opposite to another wing body on the same outer wall. Since there are two wing bodies on the same outer wall, and the opposite end is curved, the wing body can extend more widely in space. As a result, in the structure of multiple monofilaments 2, the distance between the main bodies of adjacent monofilaments 2 is increased, and the air permeability is good.

[0040] In some embodiments, the square ring is rectangular, and the length of the wing on the long side 21 is greater than the length of the wing on the short side 22.

[0041] In this embodiment of the invention, the square ring is set as a rectangle, including a long side 21 and a short side 22. Correspondingly, the length of the wing body connected to the long side 21 needs to be greater than the length of the wing body on the short side 22, so as to ensure that a certain distance can be maintained between adjacent monofilaments 2. The length of the wing body on the long side 21 can be set to 1.5-2 times the length of the wing body on the short side 22, such as the length of the wing body on the short side 22 being 0.3mm and the length of the wing body on the long side 21 being 0.5mm.

[0042] The wing body on the long side 21 has a large length, and the distance between adjacent monofilaments 2 can be guaranteed regardless of which outer wall is close to it, thereby improving air permeability.

[0043] The specific structure of the octagonal star-shaped hollow polyester fiber is described, such as... Figure 2 As shown, the rectangular ring-shaped structure includes a hollow section 20, a long side 21, a short side 22, and wing bodies. Both the long side 21 and the short side 22 are two in number, connected end-to-end to form the ring shape. Eight wing bodies are evenly distributed along the long side 21 and the short side 22, meaning each side has two wing bodies. Each long side 21 has a first wing body 211 and a second wing body 212, and each short side 22 has a third wing body 221 and a fourth wing body 222. The first wing body 211 and the second wing body 212 are of equal length and are longer than the equal-length third wing body 221 and the fourth wing body 222.

[0044] In some embodiments, a method for preparing an octagonal star-shaped hollow polyester fiber as described above includes polyethylene terephthalate being processed by a solution spinning process through a spinneret 1; The spinneret 11 includes a square ring hole and eight slots. The eight slots are evenly distributed on the outer periphery of the square ring hole, and one end of each slot is connected to the four outer sides of the square ring hole. The extension lengths of the slots on adjacent sides of the square ring hole are not equal.

[0045] In this embodiment of the invention, a special-shaped spinneret 11 is used to produce the above-mentioned octagonal star-shaped hollow polyester fiber. The raw material of the polyester fiber can be polyethylene terephthalate, which is melted and then fed into the spinneret 1 through a spinning process for spinning treatment.

[0046] The spinneret 1 is provided with irregularly shaped spinneret holes 11, which mainly consist of two parts. The main part is a square ring hole, corresponding to the square ring body of the hollow polyester fiber, that is, the square ring body of the hollow polyester fiber is ejected from the square ring hole. A slot is also provided on the outer periphery of the square ring hole. One end of the slot is connected to the square ring hole, and the other end is a blind end, extending away from the square ring hole. The position of the slot corresponds to the wing on the hollow polyester fiber, and the wing is ejected from the slot. The extension length of the slot on the outer periphery of the square ring hole is different depending on the length of the wing.

[0047] according to Figure 1 As shown, a spinneret 1 with a diameter of 75-85 mm has several spinneret holes 11. Polyethylene terephthalate is melt-spun through the spinneret holes 11 to form hollow polyester fibers; the cross-sectional shape of each spinneret 11 is similar to that of the spinneret. Figure 2 The diagram shows a matching correspondence, meaning that the cross-sectional shape of the fiber ejected through the spinneret 11 corresponds to... Figure 2 The basic structure shown is consistent with that of the one depicted, featuring a square ring-shaped main body and eight wing-shaped bodies.

[0048] The spinneret 11 is distributed on 2-3 sets of concentric circles and is evenly arranged on the same concentric circle. The spinnerets 11 in two adjacent concentric circles are staggered with an angle of 5°~10°. The purpose of the staggered arrangement is to ensure that each monofilament 2 can be cooled evenly and fully, and to prevent the filaments from sticking together.

[0049] In some embodiments, the square annular hole is rectangular, and the four outer sides include two long sides and two short sides; the extension length of the slot communicating with the long sides is greater than the extension length of the slot communicating with the short sides.

[0050] In this embodiment of the invention, the spinneret 11 is defined in detail, and the square ring hole is restricted to be rectangular, corresponding to two long sides and two short sides. In particular, the extension length of the slot on the long side is greater than the length of the slot on the short side. This structure is configured to correspond to the cross-sectional shape of the hollow polyester fiber so that the filaments are compliant with the cross-sectional structure of the hollow polyester fiber.

[0051] More specifically, the diameter of the entire octagonal star-shaped hollow polyester fiber is approximately 1.6-1.7 mm, which is the diameter of the circumference of the outer end of the slot on the relatively long side. The diameter of the circumference of the outer end of the slot on the short side is approximately 1.4-1.5 mm. The ratio of the long side to the short side of the square ring hole is approximately 1.8-2.2:1, with lengths of 1.08-1.76 mm and 0.6-0.8 mm, respectively.

[0052] In some embodiments, the two slots connected on each of the outer sides extend in opposite directions, and the angle between the extension directions of the two slots connected on the short side is set as A, and the angle between the extension directions of the two slots connected on the long side is set as B, satisfying 30°≤A≤40°, 60°≤B≤70°, and A+B=90°-110°.

[0053] In this embodiment of the invention, the spinneret 11 can obtain such... Figure 2The monofilament 2 structure shown requires that the two slots on the short side of the spinneret 11 extend in opposite directions, with the included angle being smaller than the included angle of the two slots on the long side, to prevent the extruded filaments from sticking together during production. This hole design, on the one hand, creates more obvious grooves, enhancing the capillary wicking effect; on the other hand, it solves the problem of traditional hollow octagonal fibers being easily flattened and collapsed during production. The filaments prepared by this invention have a higher hollow ratio and a more stable hollow structure, improving the warmth retention and heat shielding properties of the fabric.

[0054] In some embodiments, the angle between the extending directions of the slot connected on the short side and the slot that is closer to the adjacent long side is set as C, satisfying 35°≤C≤45°.

[0055] In this embodiment of the invention, the extension angle of two slots that are close to each other on the short and long sides is limited to further prevent the wing bodies ejected on adjacent sides from sticking together.

[0056] The above-mentioned spinneret 11 structure, with its solid central part, ensures the formation of the hollow part 20 of the extruded fiber filament, resulting in a stable hollow structure with a hollow rate of 35%-40%. Compared to the dispersed small hole structure in traditional octagonal polyester fiber filaments, this structure makes it easier to form the hollow part 20 and simplifies the fabrication of the spinneret 1.

[0057] The method for preparing octagonal star-shaped hollow polyester fibers from polyethylene terephthalate (PET) via melt spinning through spinneret 1 includes a PET pellet intrinsic viscosity of 0.80–1.10 dL / g and a terminal carboxyl group content of 15–20 mol / t. The PET raw material is pelletized, dried at 150–155℃ for 7–8 hours, and the moisture content is less than 30 ppm.

[0058] In the spinning process, the screw temperature is 285-305℃, the box temperature is 300-305℃, the speed of the first roller GR1 hot roller is 1800-2100m / min, and the temperature is 80-90℃; the speed of the second roller GR2 hot roller is 3700-4000m / min, and the temperature is 120-127℃; the winding speed is 3650-3960m / min. The process also includes a cooling process, utilizing ring-blowing cooling technology, with a cooling temperature of 15-23℃ and a cooling air velocity of 0.20-0.35m / s, ensuring that each filament is adequately cooled.

[0059] The octagonal star-shaped hollow polyester fiber obtained by the above method has specifications of 40D~75D / 12F~36F, breaking strength ≥4.00cN / dtex, breaking elongation 15%~45%, dyeing uniformity (grey card) grade ≥4.5, and yarn evenness ≤1.5.

[0060] In some embodiments, a method for preparing a filament yarn includes the method for preparing polyester fibers in an octagonal star pattern as described above, and further includes physical modification treatment of the octagonal star hollow polyester fibers. The physical modification treatment includes twisting and feathering the octagonal star hollow polyester fibers using a ring spinning machine to obtain cotton-like octagonal star hollow polyester filament yarn. The ring spinning machine 3 includes a front rubber roller 34, a spindle, a yarn tube 38, a sanding roller 39, and a ring plate 37. The sanding roller 39 and the spindle are axially parallel on the ring plate 37, and the yarn tube 38 is sleeved on the spindle. The octagonal star-shaped hollow polyester fiber contacts the front rubber roller 34 and the sanding roller 39 in sequence, and finally winds onto the yarn tube 38. Both the front rubber roller 34 and the sanding roller 39 rub the outer surface layer of the octagonal star-shaped hollow polyester fiber, causing the outer surface layer of the octagonal star-shaped hollow polyester fiber to produce fuzz.

[0061] The ring spinning machine performs physical modification treatment on the octagonal star hollow polyester fibers, which produces fuzz on the outer layer of the octagonal star hollow polyester fibers, forming cotton-like octagonal star hollow polyester filament yarn 40, achieving a cotton-like effect and solving the problems of poor touch and poor moisture absorption and perspiration of ordinary hollow polyester fibers.

[0062] The octagonal star-shaped hollow polyester fiber includes two structures: monofilament 2 or multifilament 30. Both can be physically modified using a ring spinning machine 3 to form cotton-like octagonal star-shaped hollow polyester filament yarn 40, where the multifilament 30 is formed by bundling multiple monofilaments 2.

[0063] In this embodiment of the invention, for the octagonal star-shaped hollow polyester fiber with a multifilament structure, a special ring spinning machine 3 is used for twisting and hairiness treatment to improve the formation of fine and short hairs in the multifilament 30, thereby achieving a cotton-like effect.

[0064] like Figure 3 As shown, the ring spinning frame 3 includes a filament guide roller 33, a front roller 35, a front rubber roller 34, a yarn guide hook 36, a sanding roller 39, a ring rail 37, a traveler, a spindle, and a yarn tube 38. The octagonal star-shaped hollow polyester multifilament 30 or monofilament 2 is unwound from the yarn cake 31 and enters the guide roller 32, then passes through the filament guide roller 33, enters the nip formed by the front roller 35 and the front rubber roller 34, then passes through the guide hook 36, and finally is wound onto the yarn tube 38 in contact with the sanding roller 39. The yarn tube 38 rotates under the drive of the high-speed rotating spindle and slides and twists on the ring rail to form twist.

[0065] When the multifilament 30 or monofilament 2 sequentially contacts the front rubber roller 34 and the abrasive roller 39, it first undergoes relative motion with the front rubber roller 34, rubbing against each other to form fine fuzz. Then, when the filament with the fine fuzz passes through the abrasive roller 39 again, the high-speed rotating filament air ring fully contacts the abrasive roller 39, causing short fuzz to form on the surface of the filament. Therefore, the modified ring spinning machine 3 achieves twisting and fine, short-fuzz yarn, achieving a cotton-like effect. The resulting cotton-like octagonal star-shaped hollow polyester filament yarn 40 can be used directly for weaving without sizing, greatly shortening the processing flow and improving production efficiency.

[0066] The aforementioned multifilament 30 is formed by bundling multiple monofilaments 2. The corresponding monofilaments 2 can also be twisted and feathered using the aforementioned ring spinning machine 3.

[0067] In some embodiments, the abrasive rollers 39 are provided in multiple forms and are evenly distributed around the spindle.

[0068] In this embodiment of the invention, multiple abrasive rollers 39 are provided and distributed around the spindle. When the monofilament 2 or multifilament 30 filaments are wound onto the yarn tube 38, they will continuously rub against the surrounding abrasive rollers 39. At the same time, the abrasive rollers 39 can limit the winding position of the filaments and prevent them from coming off.

[0069] The structure of the ring spinning machine 3 described above can be configured as follows: front roller 35 with a diameter of 25~27mm, front rubber roller 34 with a diameter of 30~35mm, surface roughness Ra of 1.5~12, and hardness of 70~85 degrees.

[0070] The abrasive roller 39 is installed on the steel ring plate 37 and distributed on both sides of the steel ring. The abrasive roller 39 can rotate flexibly, and the abrasive particles on the abrasive roller 39 have a mesh size of 500~700.

[0071] The twisting degree is 10~80 twists / 10cm, and the twisting direction is S-direction or Z-direction. The spindle rotation speed is 20000~25000 rpm. The steel ring is a conical steel ring with a diameter of 40~50mm.

[0072] The steel traveler is selected from the R+F series of Sapphire Bracker. The weight of the steel traveler is 3-4 sizes lighter than that of pure cotton yarn of the same linear density. The purpose is to generate a larger air loop in the yarn, so that the air loop can expand and fully contact the abrasive roller 39 to form hair.

[0073] The present invention has the following beneficial effects: 1. Excellent moisture-wicking and quick-drying properties (capillary effect): The eight wings of different lengths create eight deep grooves on the fiber surface, forming natural capillary channels. This allows for the rapid absorption of liquid sweat and moisture from the skin's surface, which is then diffused and conducted outwards along the grooves to the fabric surface, thus accelerating evaporation and keeping the skin dry and comfortable when worn. Several fibers bundled together can combine to form irregular small grooves, increasing the fabric's breathability. This makes it an ideal choice for sports, outdoor, and summer functional fabrics.

[0074] 2. Excellent warmth retention (hollow structure): The high hollow ratio of this invention allows the hollow structure inside the fiber to lock in still air. Air is a poor conductor of heat, thus forming an effective insulation layer. It is lighter than solid fibers while maintaining the same warmth, achieving a lightweight and warm effect, making it suitable for thermal underwear.

[0075] 3. Excellent heat-shielding performance: The angular cross-section of the eight wings produces multi-angle reflection and scattering of light. Using this principle, sunlight can be reflected back and prevented from shining on us, thus reducing heat absorption and achieving a heat-shielding effect. It can be used in outdoor fabrics in summer, while also reducing glare from the aurora (specular reflection).

[0076] 4. The design of the irregularly shaped spinneret 1 is the most crucial part of the production of octagonal star-shaped hollow polyester filaments. The micro-orifice shape of the spinneret 1 features a rectangular central square ring hole, corresponding to two long sides and two short sides. In particular, the extension length of the slots on the long sides is greater than the length of the slots on the short sides. These eight slots of varying lengths create eight interlaced wings in the produced fibers, increasing the cross-sectional surface area of ​​the filament. At the same denier, the filament diameter is larger, resulting in a lightweight yet thick fabric. Furthermore, the four elongated wings contribute to the fine texture of the fibers, making the fabric fluffy and soft. Simultaneously, the flat rectangular hollow design, combined with the eight wings of varying lengths, forms a stable support structure, solving the problem of easy flattening and collapse of traditional hollow octagonal fibers during production. This invention produces filaments with a higher hollow ratio, further improving the fabric's warmth retention.

[0077] 5. It possesses a cotton-like feel. Octagonal star-shaped hollow polyester fibers are prepared through melt spinning, and then fine, short hairs are formed on the fiber surface using a modified ring spinning machine 3. These hairs give the fibers a soft and comfortable feel, achieving a cotton-like effect. This shortens the production process, significantly reduces textile costs, increases economic benefits, and simultaneously saves energy and reduces consumption. It also enhances the product's high performance and added value, effectively improving its market competitiveness and brand awareness. Furthermore, it has significant social benefits and is of great importance. This exemplifies modern textile technology's approach of "endowing materials with new functions through structural design."

[0078] 6. The design, raw material selection, and process optimization of the irregular spinneret 1 of this invention are key to the production of octagonal star-shaped hollow polyester fibers. The spun fibers have high toughness and tensile strength, which effectively guarantees the implementation of subsequent cotton-like processing.

[0079] The present invention will now be described in detail with reference to specific embodiments.

[0080] Example 1: Eight-pointed star-shaped hollow polyester fiber FDY 50D / 36F was prepared using the following melt spinning process: The shaped spinneret 1 had a diameter of 85mm; the spinneret holes 11 were distributed on three sets of concentric circles, evenly arranged on the same concentric circle, with adjacent spinneret holes 11 in two concentric circles staggered at an angle of 5°; the micro-orifice shape of the spinneret 1 included a rectangular central square ring hole, corresponding to two long sides and two short sides; the angle A between the extension directions of the two slots connected by the short sides was 40°, the angle B between the extension directions of the two slots connected by the long sides was 60°, and the angle C between the extension directions of the slots connected on the short sides and the slots closer to each other on the adjacent long sides was 40°; the processing depth of the micro-orifices in the shaped spinneret 1 was 0.60mm; the intrinsic viscosity of the PET pellets used was 0.94dL / g, and the end carboxyl group content was 18mol / t. PET pellets were dried at 155℃ for 8 hours, with a moisture content of 29ppm. The screw temperature was 285–305℃, the chamber temperature was 300–305℃, the speed of the first GR1 hot roller was 2000 m / min at 85℃, the speed of the second GR2 hot roller was 3800 m / min at 125℃, and the winding speed was 3750 m / min. Cooling was achieved using ring-blown cooling technology at 20℃ and a cooling air velocity of 0.30 m / s. The resulting octagonal star-shaped hollow polyester fiber FDY 50D / 36F had an octagonal star-shaped cross-section and was hollow inside, with a hollowness rate of 38%. It exhibited a breaking strength of 4.18 cN / dtex, an elongation at break of 18.4%, a dyeing uniformity of 5.0, and a yarn evenness of 1.4.

[0081] Octagonal star-shaped hollow polyester fiber FDY was used to prepare cotton-like octagonal star-shaped hollow polyester filament yarn 40 on a modified ring spinning machine 3. The spinning process was as follows: front roller 35 with a diameter of 25mm, front rubber roller 34 with a diameter of 32mm, surface roughness Ra of 8, hardness of 75 degrees, and a frosted roller 39 with a mesh of 600. Sapphire Bracker R+F series steel traveler model 20 / 0 was selected, the conical steel ring with a diameter of 45mm, Z twist, twist of 40 twists / 10cm, and spindle speed of 24000rpm.

[0082] Example 2: Eight-pointed star-shaped hollow polyester fiber FDY 50D / 24F was prepared using the following melt spinning process: A shaped spinneret 1 with a diameter of 75 mm was used; spinneret holes 11 were distributed on two sets of concentric circles, evenly arranged on the same concentric circle, with adjacent spinneret holes 11 staggered at an angle of 8°; the micro-orifice shape of the spinneret 1 included a rectangular central ring hole with angles A (30°), B (70°), and C (40°); the processing depth of the micro-orifices in the shaped spinneret 1 was 0.45 mm; the intrinsic viscosity of the PET pellets used was 1.1 dL / g, and the end carboxyl group content was 15 mol / t. The PET pellets were dried at 153℃ for 8 hours, with a moisture content of 28 ppm. The screw temperature is 285–305℃, the housing temperature is 300–305℃, the speed of the first GR1 hot roller is 1900 m / min, and the temperature is 80–90℃; the speed of the second GR2 hot roller is 3900 m / min, and the temperature is 125℃; the winding speed is 3820 m / min. Cooling is achieved using ring-blowing cooling technology at a temperature of 20℃ and a cooling air velocity of 0.25 m / s. The prepared octagonal star-shaped hollow polyester fiber FDY 50D / 24F has an octagonal star-shaped cross-section and is hollow inside, with a hollow rate of 40%. Its breaking strength is 4.09 cN / dtex, breaking elongation is 24.79%, dyeing uniformity reaches grade 5.0, and yarn evenness is 1.4.

[0083] Octagonal star-shaped hollow polyester fiber FDY was used to prepare cotton-like octagonal star-shaped hollow polyester filament yarn 40 on a modified ring spinning machine 3. The spinning process was as follows: front roller 35 with a diameter of 25mm, front rubber roller 34 with a diameter of 32mm, surface roughness Ra of 8, hardness of 75 degrees, and a sanding roller 39 with a mesh count of 700. Sapphire Bracker R+F series travelers, model 19 / 0, were used, with a conical ring diameter of 45mm, S-twist, twist of 60 twists / 10cm, and a spindle speed of 20,000 rpm. Example 3: Eight-pointed star-shaped hollow polyester fiber FDY 75D / 36F was prepared using the following melt spinning process: A shaped spinneret 1 with a diameter of 85 mm was used; spinneret holes 11 were distributed on three sets of concentric circles, evenly arranged on the same concentric circle, with adjacent spinneret holes 11 staggered at an angle of 5°; the micro-orifice shape of the spinneret 1 included a rectangular central ring hole with angles A, B, and C of 40°; the processing depth of the micro-orifices in the shaped spinneret 1 was 0.60 mm; the intrinsic viscosity of the PET pellets used was 0.80 dL / g, and the end carboxyl group content was 20 mol / t. The PET pellets were dried at 150℃ for 7 hours, with a moisture content of 26 ppm. The screw temperature is 285–305℃, the housing temperature is 300–305℃, the speed of the first GR1 hot roller is 2100 m / min, and the temperature is 90℃; the speed of the second GR2 hot roller is 4000 m / min, and the temperature is 127℃; the winding speed is 3960 m / min. Cooling is achieved using ring-blowing cooling technology at a temperature of 23℃ and a cooling air velocity of 0.35 m / s. The prepared octagonal star-shaped hollow polyester fiber FDY 75D / 36F has an octagonal star-shaped cross-section and is hollow inside, with a hollow rate of 35%. Its breaking strength is 4.28 cN / dtex, breaking elongation is 15%, dyeing uniformity reaches grade 4.5, and yarn evenness is 1.4.

[0084] Octagonal star-shaped hollow polyester fiber FDY was used to prepare cotton-like octagonal star-shaped hollow polyester filament yarn 40 on a modified ring spinning machine 3. The spinning process was as follows: front roller 35 with a diameter of 27mm, front rubber roller 34 with a diameter of 35mm, surface roughness Ra of 12, hardness of 85 degrees, and a frosted roller 39 with a mesh of 500. Sapphire Bracker R+F series traveler model 22 / 0 was used, with a conical ring diameter of 50mm, Z-twist, twist of 10 twists / 10cm, and a spindle speed of 20000rpm. Example 4: Eight-pointed star-shaped hollow polyester fiber FDY 70D / 24F was prepared using the following melt spinning process: A shaped spinneret 1 with a diameter of 75 mm was used; spinneret holes 11 were distributed on two sets of concentric circles, evenly arranged on the same concentric circle, with adjacent spinneret holes 11 staggered at an angle of 8°; the micro-orifice shape of the spinneret 1 included a rectangular central ring hole with an angle A of 30°, an angle B of 70°, and an angle C of 40°; the processing depth of the micro-orifices in the shaped spinneret 1 was 0.45 mm; the intrinsic viscosity of the PET pellets used was 0.85 dL / g, and the end carboxyl group content was 17 mol / t. The PET pellets were dried at 153℃ for 8 hours, with a moisture content of 28 ppm. The screw temperature is 285–305℃, the housing temperature is 300–305℃, the speed of the first GR1 hot roller is 2000 m / min, and the temperature is 80–90℃; the speed of the second GR2 hot roller is 4000 m / min, and the temperature is 120–127℃; the winding speed is 3960 m / min. Cooling is achieved using ring-blown cooling technology at a temperature of 20℃ and a cooling air velocity of 0.32 m / s. The prepared octagonal star-shaped hollow polyester fiber FDY 70D / 24F has an octagonal star-shaped cross-section and is hollow inside, with a hollow rate of 36%. Its breaking strength is 4.24 cN / dtex, breaking elongation is 35%, dyeing uniformity reaches grade 5.0, and yarn evenness is 1.3.

[0085] Octagonal star-shaped hollow polyester fiber FDY was used to prepare cotton-like octagonal star-shaped hollow polyester filament yarn 40 on a modified ring spinning machine 3. The spinning process was as follows: front roller 35 with a diameter of 27mm, front rubber roller 34 with a diameter of 35mm, surface roughness Ra of 10, hardness of 80 degrees, and a frosted roller 39 with a mesh of 500. Sapphire Bracker R+F series traveler model 21 / 0 was used, with a conical ring diameter of 50mm, Z-twist, twist of 30 twists / 10cm, and spindle speed of 22000rpm. Example 5: Eight-pointed star-shaped hollow polyester fiber FDY 40D / 12F was prepared using the following melt spinning process: A shaped spinneret 1 with a diameter of 75 mm was used; spinneret holes 11 were distributed on two sets of concentric circles, evenly arranged on the same concentric circle, with adjacent spinneret holes 11 staggered at an angle of 10°; the micro-orifice shape of the spinneret 1 included a rectangular central square ring hole with angles A (35°), B (65°), and C (40°); the processing depth of the micro-orifices in the shaped spinneret 1 was 0.50 mm; the intrinsic viscosity of the PET pellets used was 0.95 dL / g, and the end carboxyl group content was 16 mol / t. The PET pellets were dried at 155℃ for 8 hours, with a moisture content of 28 ppm. The screw temperature is 285–305℃, the housing temperature is 300–305℃, the speed of the first GR1 hot roller is 1800 m / min, and the temperature is 80–90℃; the speed of the second GR2 hot roller is 3700 m / min, and the temperature is 120℃; the winding speed is 3650 m / min. Cooling is achieved using ring-blowing cooling technology at a temperature of 15℃ and a cooling air velocity of 0.20 m / s. The prepared octagonal star-shaped hollow polyester filament FDY 40D / 12F has an octagonal star-shaped cross-section and is hollow inside, with a hollow rate of 39%. Its breaking strength is 4.09 cN / dtex, breaking elongation is 45%, dyeing uniformity reaches grade 5.0, and yarn evenness is 1.5.

[0086] Eight-pointed star hollow polyester fiber FDY was used to prepare cotton-like eight-pointed star hollow polyester filament yarn 40 on a modified ring spinning machine 3. The spinning process was as follows: front roller 35 with a diameter of 25mm, front rubber roller 34 with a diameter of 30mm, surface roughness Ra of 1.5, hardness of 70 degrees, and a sanding roller 39 with a mesh of 700. Sapphire Bracker R+F series steel traveler model 18 / 0 was selected, with a conical steel ring diameter of 40mm, Z twist, twist of 80 twists / 10cm, and spindle speed of 25000rpm.

[0087] List 1 shows the hairiness index of the octagonal star-shaped hollow polyester filaments obtained in Examples 1-5 above.

[0088] Table 1

[0089] Examples 1 and 5 illustrate the hairiness index of the prepared cotton-like octagonal star-shaped hollow polyester filament yarn. Examples 3 and 4 show relatively high 1mm hairiness indices, with Example 3 exhibiting the highest hairiness, while Example 5 shows the lowest. The amount of hairiness is directly related to the surface roughness of the selected front roller, the filament twist, and the type of traveler. Higher front roller surface roughness, lower filament twist, and lighter travelers result in higher filament yarn hairiness. High front roller surface roughness facilitates friction between the filament and the roller, forming fine hairiness; low filament twist allows fine hairiness to be exposed on the yarn surface; lighter travelers tend to form large air rings, which can fully contact the abrasive roller 39, thus forming fine, short hairiness.

[0090] The foregoing description and accompanying drawings fully illustrate embodiments of the invention to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Some portions and features of some embodiments may be included or substituted for portions and features of other embodiments. Embodiments of the invention are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from their scope. The scope of the invention is limited only by the appended claims.

Claims

1. A star-shaped hollow polyester fiber, characterized by, include: The monofilament of the fiber filament has a square ring-shaped cross-section and eight wings on the outer circumferential surface. The eight wing bodies are distributed on the four outer walls of the square ring, and the lengths of the wing bodies on adjacent circumferential outer walls are not equal.

2. The octagonal star-shaped hollow polyester fiber according to claim 1, characterized in that, The wing is elongated, with one end connected to the outer wall and the other end extending away from the outer wall.

3. The octagonal star-shaped hollow polyester fiber according to claim 2, characterized in that, The other ends of the two wings on the same outer wall are set to face away from each other.

4. The octagonal star-shaped hollow polyester fiber according to any one of claims 1-3, characterized in that, The square ring is designed to be rectangular, and the length of the wing body on the longer side is greater than the length of the wing body on the shorter side.

5. A process for the production of the hollow polyester fiber of the star polygon shape according to claims 1 to 4, characterized by, This includes polyethylene terephthalate (PET) spun through a spinneret using a solution spinning process; The spinneret includes a square ring hole and eight slots. The eight slots are evenly distributed on the outer periphery of the square ring hole, and one end of each slot is connected to the four outer sides of the square ring hole. The extension lengths of the slots on adjacent sides of the square ring hole are not equal.

6. The preparation method according to claim 5, characterized in that, The square annular hole is rectangular, and the four outer sides include two long sides and two short sides; the extension length of the slot communicating with the long side is greater than the extension length of the slot communicating with the short side.

7. The preparation method according to claim 6, characterized in that, The two slots connected on each of the outer sides extend in opposite directions and are far apart. The angle between the extension directions of the two slots connected on the short side is set as A, and the angle between the extension directions of the two slots connected on the long side is set as B, satisfying 30°≤A≤40°, 60°≤B≤70°, and A+B=90°-110°.

8. The preparation method according to claim 7, characterized in that, The angle between the extension directions of the slot connected on the short side and the slot that is closer to the adjacent long side is set as C, which satisfies 35°≤C≤45°.

9. A method of making a filament yarn, characterized by, The method includes the preparation method of the octagonal star hollow polyester fiber as described in any one of claims 5-8, and further includes physical modification treatment of the octagonal star hollow polyester fiber, wherein the physical modification treatment includes twisting and feathering the octagonal star hollow polyester fiber using a ring spinning machine to obtain cotton-like octagonal star hollow polyester filament yarn. The ring spinning machine includes a front rubber roller, a spindle, a yarn tube, a sanding roller, and a ring rail. The sanding roller and the spindle are axially parallel on the ring rail. The yarn tube is sleeved on the spindle. The octagonal star-shaped hollow polyester fiber contacts the front rubber roller and the sanding roller in sequence, and finally winds onto the yarn tube. Both the front rubber roller and the sanding roller rub the outer surface of the octagonal star-shaped hollow polyester fiber, causing the outer surface of the octagonal star-shaped hollow polyester fiber to produce fuzz.

10. The preparation method according to claim 9, characterized in that, The abrasive rollers are provided in multiple sizes and are evenly distributed around the spindle.

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