Spinneret plate structure and method for preparing matte polyester fibers based on spinneret plate

Abstract

The invention belongs to the technical field of polyester chemical fiber preparation, and relates to a spinneret plate structure and a method for preparing matte polyester fibers based on the spinneret plate, the spinneret plate structure comprises a plurality of spinneret layers which are sequentially arranged from inside to outside along the center point of the spinneret plate structure, each spinneret layer comprises a plurality of spinneret orifice assemblies arranged at intervals in the circumferential direction of the spinneret plate structure, each spinneret orifice assembly comprises a first spinneret orifice and a second spinneret orifice, the first spinneret orifice and the second spinneret orifice are the same in structure and comprise concave cavities and rectangular cavities, and the concave cavities are located in the ends of the rectangular cavities; the first spinneret orifices and the second spinneret orifices are staggered to form a circular array, and after the circular array is staggered, one of two concave cavities of the first spinneret orifices and the second spinneret orifices is concave towards the circle center of the circle, and the other concave cavity is back to the circle center of the circle. According to the polyester fiber formed based on the structure, the matte effect of the fiber is achieved, and meanwhile the multiple properties such as the heat retention property, the moisture-conducting dry and comfortable property and the durability of the fiber are improved in a balanced mode.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester chemical fiber preparation, and particularly relates to a spinneret structure and a method for preparing matte polyester fiber based on the spinneret. Background Art

[0002] With the continuous development of textile technology, consumers' demand for comfort and functionality of fabrics is increasing. Domestic mainstream chemical fiber manufacturers have laid out differentiated fibers, among which shaped fibers occupy half of the polyester fiber market.

[0003] Special-shaped fibers are mainly produced by spinning through spinnerets with holes of special geometric shapes. This type of fiber can improve the fiber's feel, gloss, warmth retention, fluffiness, sweat conduction, and dryness.

[0004] At present, the cross-section of conventional polyester fibers is circular, and dazzling spots or lines often appear when exposed to parallel light, causing discomfort to the human eye. In order to make the luster of polyester fibers softer, titanium dioxide is often added as a matting agent during production. However, titanium dioxide not only catalyzes the degradation of polyester and affects the spinning quality, but its coagulants are difficult to dissolve in triethylene glycol, making the filter element of the melt filter difficult to clean. In addition, the design of hollow cross-section special-shaped fibers is widely used because of its enhanced warmth retention, but this design easily causes the fiber to collapse or deform when stretched or compressed, resulting in reduced warmth retention and fluffiness.

[0005] Patent CN208562614U introduces a method for producing hollow shaped polylactic acid fibers, which enhances the dyeing effect and expects to achieve a better matte effect by designing gaps in the fiber cross section. Despite this, the arc edge on the fiber surface still causes more light reflection, making the gloss improvement effect insignificant. In addition, although the support and connection parts in the design reduce the deformation of the internal cavity of the fiber when stretched, the wider support part reduces the hollowness of the fiber, and the presence of the gap also makes it easy for still air to flow. These two points result in limited improvement in the fiber's thermal insulation performance. Summary of the invention

[0006] In order to solve the above technical problems, the present application discloses a spinneret structure and a method for preparing matte polyester fiber based on the spinneret.

[0007] According to one aspect of the present application, a spinneret structure is disclosed. The spinneret structure includes multiple spinneret layers, and the multiple spinneret layers are sequentially arranged from the inside to the outside along the center point of the spinneret structure. Each spinneret layer includes a plurality of spinneret hole assemblies arranged at intervals along the circumferential direction of the spinneret structure. Each spinneret hole assembly includes a first spinneret hole and a second spinneret hole. The structures of the first spinneret hole and the second spinneret hole are the same, and both include a concave cavity and a rectangular cavity. The concave cavity is located at the end of the rectangular cavity; the first spinneret hole and the second spinneret hole are arranged in a staggered circular array, and after the staggered circular array, one of the two concave cavities of the first spinneret hole and the second spinneret hole faces the center of the circle, and the other faces away from the center of the circle.

[0008] In some embodiments, the concave cavity includes a transverse cavity and vertical cavities located at both ends of the two transverse cavities. The length of the vertical cavity is less than the length of the rectangular cavity.

[0009] In some embodiments, in each spinneret hole assembly, the total number of the vertical cavity facing away from the center of the circle and the rectangular cavity is 1.5 times the total number of spinneret holes in each spinneret hole assembly.

[0010] In some embodiments, in each spinneret hole assembly, a connection point is formed at the connection between the concave cavity and the rectangular cavity. The connection points corresponding to the plurality of spinneret holes facing the center of the circle are connected to each other to form a first ring of the spinneret hole assembly. The connection points corresponding to the plurality of spinneret holes facing away from the center of the circle are connected to each other to form a second ring of the spinneret hole assembly. The second ring is inside the first ring. The rectangular cavities of the spinneret holes corresponding to the second ring divide the second ring into a plurality of hollow cavities. The number of the hollow cavities is half of the total number of spinneret holes in the spinneret hole assembly. The suspended end faces of the rectangular cavities corresponding to the plurality of spinneret holes facing away from the center of the circle are connected to each other to form a third ring. The third ring is inside the second ring.

[0011] In some embodiments, in each spinneret hole assembly, the number of the first spinneret holes is the same as the number of the second spinneret holes, and the total number of the first spinneret holes and the second spinneret holes is an even number.

[0012] In some embodiments, the ratio of the width of the rectangular cavity of each spinneret hole to the width of the concave cavity is between 1 / 10 and 1 / 8. Wherein, the width of the rectangular cavity is the distance a between the outer walls of the rectangular cavity, and the width of the concave cavity is the distance c between the outer walls of the two vertical cavities.

[0013] In some embodiments, after the first spinneret holes and the second spinneret holes are arranged in a staggered circular array, the range of the hole slit distance e between the first spinneret holes and the second spinneret holes is 0.05 mm to 0.09 mm, and the diameter d of the third ring is between 0.1 mm and 0.14 mm. Wherein, the hole slit distance e is the point-plane vertical distance between adjacent first spinneret holes and second spinneret holes, and the point-plane vertical distance is determined based on the adjacent points of the concave cavity facing away from the spinneret layer and the adjacent surface of the concave cavity facing the spinneret layer.

[0014] In some embodiments, the total height b of the spinneret holes and the width of the rectangular cavity of the spinneret holes are respectively determined based on the diameter of the second ring and the hole slit distance.

[0015] According to another aspect of the present application, a method for preparing matte polyester fibers is also disclosed. The process flow corresponding to the method is polyester melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → metering pump → spinning pack → windless zone → ring blowing cooling system → oiling device on the nozzle → guide porcelain → guide disk I → networker → guide disk II → roller → winding and forming. Wherein, the spinning pack includes the spinneret plate structure described in any one of the above.

[0016] In some embodiments, the intrinsic viscosity of the polyester melt is 0.65 - 0.68 dl / g, the end carboxyl content ≤ 28 mol / t, the impurity particle size ≦ 20 μm, the moisture content ≦ 0.05%, the temperature of the spinning box is 290 °C - 294 °C, the height of the windless zone is between 40 mm and 65 mm, the ring blowing cooling rate is 10 Pa - 18 Pa, the network pressure is 0.4 - 0.8 Mpa, and the winding speed is 2500 m / min - 2900 m / min.

[0017] The present invention includes, but is not limited to, the following beneficial effects: (1) The spinneret design of the present invention makes the protrusions (vertical cavities and rectangular cavities) around the spinneret holes well - arranged. This design increases the surface roughness of the fiber, effectively reduces the smooth areas, thereby reducing specular reflection and increasing diffuse reflection. In addition, the irregular middle - cavity structure formed inside the fiber also promotes the multiple scattering and transmission of light. The combined effect of these two characteristics makes the fiber have a more significant extinction effect, thereby enhancing the matte effect of the formed polyester fiber to obtain matte polyester fiber; (2) Based on the spinneret structure of the present invention, when the polyester melt is extruded to form the nascent fiber, due to the swelling effect of the melt, while the middle cavity is formed inside the fiber, a cross - support part is also formed. This structure can effectively reduce the deformation of the middle cavity inside the fiber when the fiber is stretched. At the same time, the irregular middle cavity reduces the cross - sectional moment of inertia, increases the specific surface area, and the number of load - bearing positions increases. The combined effect of these two points greatly improves the stability of the fiber and ensures the long - term stability of the fiber's warmth retention; (3) The outer surface of the fiber prepared by the present invention has protrusions of different lengths. These protrusions reduce the meshing phenomenon between single filaments, resulting in a lower airtightness between single filaments, increasing the sweat moisture - conduction channels. At the same time, the protrusions of different lengths also reduce the contact area between the fiber and the skin, achieving the dry feeling of sweat conduction and point contact; (4) The spinneret cavity designed by the present invention is composed of simple structural units. While achieving various performances, compared with other spinnerets with single complex cross - sectional cavities, the processing and manufacturing difficulty is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art.

[0019] Figure 1 Schematic diagram of the structure of a single spinneret hole in an embodiment of the present invention; Figure 2 Schematic diagram of an alternating arrangement of the first spinneret hole and the second spinneret hole in an embodiment of the present invention; Figure 3 Another schematic diagram of the alternating arrangement of the first spinneret hole and the second spinneret hole in an embodiment of the present invention; Figure 4 Schematic diagram of a structure of the spinneret structure in an embodiment of the present invention; Figure 5 Schematic diagram of the structure of the spinneret structure in an embodiment of the present invention Figure 1 ; Figure 6 Schematic diagram of the structure of the spinneret structure in an embodiment of the present invention Figure 2 ; Figure 7 Schematic diagram of the structure of the spinneret structure in an embodiment of the present invention Figure 3 ; Figure 8 It is a structural schematic diagram of the spinneret structure according to an embodiment of the present invention Figure 4 ; Figure 9 It is a structural schematic diagram of the spinneret structure according to an embodiment of the present invention Figure 5 ; In the figure, 1-spinneret structure, 2-spinning layer, 3-spinning hole assembly, 31-first spinning hole, 32-second spinning hole, 4-concave cavity, 41-horizontal cavity, 42-vertical cavity, 5-rectangular cavity, 6-first ring, 7-second ring, 8-third ring. Specific embodiments

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0021] According to one aspect of the present application, a spinneret structure is disclosed. Specifically, referring to Figures 1 to 9 , the spinneret structure 1 includes multiple spinning layers 2. The multiple spinning layers 2 are arranged in sequence from the inside to the outside around the center point of the spinneret structure 1. Each spinning layer 2 includes a plurality of spinning hole assemblies 3 arranged at intervals along the circumferential direction of the spinneret structure 1. Each spinning hole assembly 3 includes a plurality of first spinning holes 31 and a plurality of second spinning holes 32. The first spinning holes 31 and the second spinning holes 32 have the same structure and each includes a concave cavity 4 and a rectangular cavity 5. The concave cavity 4 is located at the end of the rectangular cavity 5; the first spinning holes 31 and the second spinning holes 32 are arranged in a staggered circular array, and after the staggered circular array, one of the two concave cavities 4 of the first spinning holes 31 and the second spinning holes 32 faces the center of the circle, and the other faces away from the center of the circle.

[0022] In some embodiments, continue to refer to Figure 2 , the concave cavity 4 includes a horizontal cavity 41 and vertical cavities 42 located at both ends of the two horizontal cavities 41. The length of the vertical cavities 42 is less than the length of the rectangular cavity 5. It can be understood that such a structure with different lengths makes the protrusions (vertical cavities 42 and rectangular cavity 5) around the spinning holes staggered. This design increases the roughness of the fiber surface, effectively reduces the smooth area, thereby reducing specular reflection and increasing diffuse reflection. In addition, the irregular middle cavity structure formed inside the fiber also promotes the multiple scattering and transmission of light. The combined effect of these two characteristics makes the fiber have a more significant extinction effect, thereby enhancing the matte effect of the formed polyester fiber and obtaining matte polyester fiber. Further, the spinneret cavity designed by the present invention is composed of simple structural units. While achieving various performances, compared with other spinnerets with a single complex cross-sectional cavity, the processing and manufacturing difficulty is lower.

[0023] In some embodiments, in each spinneret hole component 3, the total number of the vertical cavities 42 and the rectangular cavities 5 facing away from the center of the circle is 1.5 times the total number of spinneret holes in each spinneret hole component 3.

[0024] In some embodiments, referring still to Figure 2 , in each spinneret hole component 3, connection points are formed at the junctions of the concave cavities 4 and the rectangular cavities 5. The multiple connection points corresponding to the multiple spinneret holes facing the center of the circle are connected to each other to form the first ring 6 of the spinneret hole component 3. The multiple connection points corresponding to the multiple spinneret holes facing away from the center of the circle are connected to each other to form the second ring 7 of the spinneret hole component 3. The second ring 7 is inside the first ring 6. The rectangular cavities 5 of the spinneret holes corresponding to the second ring 7 divide the second ring 7 into multiple hollow cavities. The number of the hollow cavities is half of the total number of spinneret holes in the spinneret hole component 3. The suspended end faces of the rectangular cavities 5 corresponding to the multiple spinneret holes facing away from the center of the circle are connected to each other to form the third ring 8. The third ring 8 is inside the second ring 7.

[0025] In some embodiments, in each spinneret hole component 3, the number of the first spinneret holes 31 is the same as the number of the second spinneret holes 32, and the total number of the first spinneret holes 31 and the second spinneret holes 32 is an even number.

[0026] In some embodiments, referring still to Figure 1 , for each spinneret hole, the ratio of the width of the rectangular cavity 5 to the width of the concave cavity 4 of the spinneret hole is between 1 / 10 and 1 / 8. Wherein, the width of the rectangular cavity 5 is the distance a between the outer walls of the rectangular cavity 5, and the width of the concave cavity 4 is the distance c between the outer walls of the two vertical cavities 42.

[0027] In some embodiments, after the first spinneret holes 31 and the second spinneret holes 32 are staggered, the range of the distance e of the hole slit between the first spinneret holes 31 and the second spinneret holes 32 is 0.05 mm to 0.09 mm, and the diameter d of the third ring 8 is between 0.1 mm and 0.14 mm. In one example, referring still to Figure 2 as shown, the hole slit distance e is the point-to-plane perpendicular distance e between adjacent first spinneret holes 31 and second spinneret holes 32, that is, the point-to-plane perpendicular distance is determined based on the adjacent points of the concave cavity 4 facing away from the spinneret layer 2 and the adjacent surface of the concave cavity 4 facing the spinneret layer 2.

[0028] In some embodiments, the total height b of the spinneret hole and the width of the rectangular cavity 5 of the spinneret hole are determined based on the diameter of the second ring 7 and the hole slit distance. It can be understood that the total height b of the spinneret hole and the width of the rectangular cavity 5 of the spinneret hole are determined based on the diameter of the second ring 7 and the hole slit distance, which can mean that they are determined separately. That is, when preparing polyester fibers based on the spinneret plate structure 1 of this solution, a cavity with a diameter of d is formed at the third ring 8 formed by each spinneret hole assembly 3. Therefore, when preparing polyester fibers, if a cavity with a target diameter is desired, it is necessary to first determine the diameter d of the fixed third ring 8. Therefore, when the diameter d of the third ring 8 is determined, the total height b of the spinneret hole is determined based on the diameter D of the second ring 7, and the width of the rectangular cavity 5 of the spinneret hole is determined based on the hole slit distance e. As Figure 2 and Figure 3 can be seen from the comparison diagram, in Figure 3 , the hole slit distance e is relatively wide. At this time, the hole slit distance e can be increased while ensuring that the width c of the rectangular cavity 5 is Figure 2 consistent. Further, in an implementable solution, the total height b of the spinneret hole and the width of the rectangular cavity 5 of the spinneret hole are determined based on the diameter of the second ring 7 and the hole slit distance, which can also mean that they are determined collaboratively. That is, when the diameter d of the third ring 8 is determined, by simultaneously adjusting the diameter of the second ring 7 and the hole slit distance requirements, the determination of the total height of the spinneret hole is achieved. For example, after the diameter d of the third ring 8 is determined, the diameter D of the second ring 7 can be adjusted and determined first. When D is relatively small, it means that the distance between adjacent two concave cavities 4 is relatively close. At this time, the width c of the concave cavity 4 can be further adjusted based on the hole slit distance requirements. Similarly, when D is relatively large, it means that the distance between adjacent two concave cavities 4 is relatively far. At this time, the width c of the concave cavity 4 can be further adjusted based on the hole slit distance requirements.

[0029] According to another aspect of the present application, a method for preparing matte polyester fibers is also disclosed. The corresponding process flow of the method is as follows: Polyester melt → Booster pump → Heat exchanger → Melt conveying pipeline → Spinning box → Metering pump → Spinning assembly → Windless area → Ring blowing cooling → Oil applicator → Guide porcelain → Guide disk I → Networker → Guide disk II → Roller → Winding and forming, where the spinning assembly includes the spinneret plate structure of any one of the above.

[0030] Among them, the polyester melt serves as the raw material to provide the polymer melt required for spinning. The booster pump is used to increase the pressure of the polyester melt, enabling it to have sufficient kinetic energy to pass through subsequent pipelines and components, maintaining the pressure stability during the melt transportation process, and avoiding uneven spinning thickness caused by pressure fluctuations. The heat exchanger is used to adjust the melt temperature to keep it within the optimal spinning temperature range (usually higher than the melting point but lower than the thermal decomposition temperature), preventing the melt from degrading due to excessive temperature or increasing viscosity and poor fluidity due to too low temperature through temperature control. The melt transportation pipeline is used to transport the polyester melt to the spinning box. The pipeline usually has a thermal insulation layer to prevent the melt from cooling and solidifying. The pipeline design needs to ensure smooth melt flow, reduce pressure loss and residence time, and avoid deterioration of the melt properties. The spinning box is used to provide a constant temperature environment, maintain the melt fluidity, and ensure a stable spinning process. It can integrate heating devices (such as electric heating or heat transfer oil heating) inside to further evenly distribute the melt temperature. The metering pump is used to control the flow rate of the polyester melt. The control of the flow rate determines the linear density (thickness) of the single filament and the fiber output. A relatively stable metering accuracy can improve the uniformity of fiber thickness. The spinning component includes the spinneret structure introduced above, and the melt is extruded through the spinneret holes introduced above to form a liquid thin stream (primary fiber). The windless zone is used to control the initial shape of the fiber before cooling, avoiding the interference of external airflows on the primary fiber, enabling it to be initially solidified under non-disturbed conditions, and forming a stable fiber structure. The ring blow cooling is used for annular uniform air supply to quickly cool and solidify the primary fiber to form a solid fiber structure. The oiling device on the oil nozzle is used to evenly coat the fiber surface with an oil agent, reducing the friction coefficient between fibers, preventing electrostatic accumulation and fiber adhesion. The ceramic wire guide is used to guide the fiber direction with wear-resistant ceramic materials, reducing the friction between the fiber and the wire guiding components, and avoiding fiber damage or breakage. The godet I is used to initially draw (stretch) the fiber, increasing the molecular chain orientation degree and improving the fiber strength. The networker is used to entangle multiple single filaments with each other to form network nodes using high-pressure airflows, enhancing the cohesion of the fiber bundle. The godet II is used for secondary drawing (or supplementary drawing) to further improve the orientation degree and strength of the fiber. The roller is used to control the winding speed and tension of the fiber, stabilizing the winding process. The winding and forming step is used to wind the fiber into a cheesed yarn according to certain rules through a winding and forming device, facilitating storage, transportation, and subsequent processing (such as textile and weaving).

[0031] In some embodiments, the intrinsic viscosity of the polyester melt is 0.65 - 0.68 dl / g, the terminal carboxyl group content ≤ 28 mol / t, the impurity particle size ≦ 20 μm, the moisture content ≦ 0.05%, the temperature of the spinning box is 290°C - 294°C, the height of the windless zone is between 40 mm and 65 mm, the ring blow cooling rate is 10 Pa - 18 Pa, the network pressure is 0.4 - 0.8 Mpa, and the winding speed is 2500 m / min - 2900 m / min.

[0032] It can be understood that based on the spinneret structure 1 of this solution, when the polyester melt is extruded to form the primary fiber, due to the swelling effect of the melt, a cross support part is formed while a cavity is formed inside the fiber. This structure can effectively reduce the deformation of the internal cavity of the fiber when it is stretched. At the same time, the irregular cavity also reduces the moment of inertia of the cross-section, increases the specific surface area, and increases the number of load-bearing positions. The two effects together greatly improve the stability of the fiber and ensure the long-term stability of the fiber's warmth retention. Further, the outer surface of the prepared fiber has protrusions of different lengths. These protrusions reduce the meshing phenomenon between single filaments, resulting in a decrease in the airtightness between single filaments, increase the sweat conduction channels, and at the same time, the protrusions of different lengths also reduce the contact area between the fiber and the skin, achieving the dry feeling of sweat conduction and point contact.

[0033] Specifically, for better understanding, the spinneret structure and the preparation process flow of the matte polyester fiber are taken as an example and described as follows: Example 1

[0034] The preparation process flow mainly includes: polyester melt → booster pump → heat exchanger → melt delivery pipeline → spinning box → metering pump → spinning component → windless area → ring blowing cooling system → oiling device on the nozzle → wire guiding porcelain part → wire guiding disk I → networker → wire guiding disk II → roller → winding and forming. Among them, the spinning component includes the above-mentioned spinneret structure.

[0035] Specifically, first, terephthalic acid and ethylene glycol are converted into PET melt (polyester melt) through esterification and polycondensation reactions. Subsequently, the polyester melt is transported by a booster pump and its temperature is adjusted through a heat exchanger to ensure that the melt transported through the melt delivery pipeline enters the spinning box in the best state. In the spinning box, the melt is precisely controlled by a metering pump and then passes through the spinning component containing the above-mentioned spinneret structure 1 to form fibers. The fibers are initially cooled and solidified in the windless area to avoid the influence of air flow on fiber formation. Then, the fibers are further cooled by the ring blowing cooling system and their smoothness is increased by the oiling device on the nozzle. The fibers are then guided by the wire guiding porcelain part and the wire guiding disk I, the fiber-to-fiber cohesion is increased by the networker, and then they are stretched and shaped by the wire guiding disk II and the roller. Finally, they are wound into a cake in the winding and forming device to complete the entire spinning process.

[0036] In this example, as Figure 4As shown in the figure, the spinneret hole assemblies 3 are circumferentially arranged on the spinneret structure 1 in a concentric circle pattern, forming two circles in total. There are 5 spinneret hole assemblies 3 and 7 spinneret hole assemblies 3 distributed in the inner and outer circles respectively. Each group of spinneret hole assemblies 3 in the spinneret structure 1 consists of 8 spinneret holes, including 4 first spinneret holes 31 and 4 second spinneret holes 32. The diameter D of the second ring 7 formed is 0.34 mm, the diameter d of the third ring 8 is 0.12 mm, the hole slit distance e between the first spinneret hole 31 and the second spinneret hole 32 is 0.06 mm, the total height b of the spinneret holes is 0.13 mm, the width c of the concave cavity 4 is 0.07 mm, and the width a of the rectangular cavity 5 is 0.008 mm. In this example, the total number of spinneret holes in the spinneret hole assemblies 3 is 5×8 + 7×8 = 96.

[0037] During the preparation process, control the intrinsic viscosity of the PET melt to be 0.65 - 0.68 dl / g, the end carboxyl group content ≤ 28 mol / t, the impurity particle size ≤ 20 μm, and the moisture content ≤ 0.05%.

[0038] Control the box temperature in the range of 291°C - 293°C, the height of the windless area is 50 mm - 70 mm, the ring blowing cooling air pressure is between 12 Pa - 18 Pa, the network pressure is 0.4 - 0.8 Mpa, and the spinning speed is between 2300 m / min - 2500 m / min.

[0039] The fineness of the polyester fiber monofilament finally obtained by the process is 1.25 D, the linear density deviation rate is 0.28%, the elongation at break is 118%, the cv value of the elongation at break is 2.8%, the breaking strength is 2.85 cN / dtex, the cv value of the breaking strength is 2.1%, and the oil content is 0.4%. Example 2

[0040] The preparation process mainly includes: polyester melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → metering pump → spinning component → windless area → ring blowing cooling system → oiling device on the nozzle → wire guiding porcelain part → wire guiding disc I → networker → wire guiding disc II → roller → winding and forming. Among them, the spinning component includes the above-mentioned spinneret structure.

[0041] Specifically, first, terephthalic acid and ethylene glycol are converted into PET melt (polyester melt) through an esterification polycondensation reaction. Subsequently, the polyester melt is transported by a booster pump and its temperature is adjusted through a heat exchanger to ensure that the melt enters the spinning box in an optimal state after being transported through the melt conveying pipeline. In the spinning box, the melt is precisely controlled by a metering pump and then passes through a spinning component containing the spinneret plate structure 1 described above to form fibers. The fibers are initially cooled and solidified in a windless area to avoid the influence of air flow on fiber formation. Then, the fibers are further cooled by a ring blowing cooling system and their smoothness is increased by an oiling device on the nozzle. The fibers are then guided by ceramic wire guides and godet wheel I, the cohesion between the fibers is increased by a texturing device, and then they are stretched and shaped by godet wheel II and rollers. Finally, they are wound into a bobbin in a winding forming device to complete the entire spinning process.

[0042] In this example, as Figure 5 shown, the spinneret hole assemblies 3 are circumferentially arranged on the spinneret plate structure 1 in a concentric circle pattern, forming two circles in total. There are 9 spinneret hole assemblies 3 and 15 spinneret hole assemblies 3 distributed in the inner and outer circles respectively. Each group of spinneret hole assemblies 3 in the spinneret plate structure 1 consists of 8 spinneret holes, including 4 first spinneret holes 31 and 4 second spinneret holes 32. The diameter D of the second ring 7 formed is 0.36 mm, the diameter d of the third ring 8 is 0.14 mm, the hole slit distance between the first spinneret hole 31 and the second spinneret hole 32 is 0.05 mm, the total height b of the spinneret holes is 0.14 mm, the width c of the concave cavity 4 is 0.09 mm, and the width a of the rectangular cavity 5 is 0.01 mm. In this example, the total number of spinneret holes in the spinneret hole assemblies 3 is 9×8 + 15×8 = 192.

[0043] The intrinsic viscosity of the PET melt is 0.65 - 0.68 dl / g, the end carboxyl group content is ≤28 mol / t, the particle size of impurity particles is ≦20 μm, and the moisture content is ≦0.05%; The temperature of the box is in the range of 291°C - 293°C, the height of the windless area is 50 mm - 70 mm, the ring blowing cooling air pressure is between 12 Pa - 18 Pa, the texturing pressure is 0.4 - 0.8 Mpa, and the spinning speed is between 2300 m / min - 2500 m / min; The fineness of the polyester fiber monofilament finally obtained in the process is 0.8 D, the linear density deviation rate is 0.28%, the elongation at break is 121%, the cv value of the elongation at break is 2.8%, the breaking strength is 2.73 cN / dtex, the cv value of the breaking strength is 2.1%, and the oil content is 0.38%. Example 3

[0044] The preparation process mainly includes: polyester melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → metering pump → spinning pack → windless area → ring blowing cooling system → oiling device on the nozzle → ceramic guide → godet I → texturing device → godet II → roller → winding and forming. Among them, the spinning pack includes the spinneret structure described above.

[0045] Specifically, first, terephthalic acid and ethylene glycol are converted into PET melt (polyester melt) through esterification and polycondensation reactions. Subsequently, the polyester melt is transported by a booster pump and its temperature is adjusted through a heat exchanger to ensure that the melt transported through the melt conveying pipeline enters the spinning box in an optimal state. In the spinning box, the melt is precisely controlled by a metering pump and then passes through the spinning pack containing the above-mentioned spinneret structure 1 to form fibers. The fibers are initially cooled and solidified in the windless area to avoid the influence of air flow on fiber formation. Then, the fibers are further cooled by the ring blowing cooling system and their smoothness is increased by the oiling device on the nozzle. The fibers are then guided by the ceramic guide and godet I, the bonding force between the fibers is increased by the texturing device, and then stretched and shaped through godet II and the roller. Finally, they are wound into a cake in the winding and forming device, completing the entire spinning process.

[0046] In this example, as Figure 6 shown, the spinneret hole assemblies 3 are circumferentially arranged on the spinneret structure 1 in a concentric circle manner, forming three circles in total. 6 spinneret hole assemblies 3 are arranged in the inner circle, 12 spinneret hole assemblies 3 are arranged in the middle circle, and 18 spinneret hole assemblies 3 are arranged in the outer circle. Each group of spinneret hole assemblies 3 in the spinneret structure 1 consists of 8 spinneret holes, including 4 first spinneret holes 31 and 4 second spinneret holes 32. The diameter D of the second ring 7 formed is 0.32 mm, the diameter d of the third ring 8 is 0.14 mm, the hole slit distance e between the first spinneret hole 31 and the second spinneret hole 32 is 0.05 mm, the total height b of the spinneret holes is 0.12 mm, the width c of the concave cavity 4 is 0.08 mm, and the width a of the rectangular cavity 5 is 0.009 mm. In this example, the total number of spinneret holes in the spinneret hole assemblies 3 is 6×8 + 12×8 + 18×8 = 288.

[0047] During the preparation process, control the intrinsic viscosity of the PET melt to be 0.65 - 0.68 dl / g, the end carboxyl group content ≤ 28 mol / t, the impurity particle size ≦ 20 μm, and the moisture content ≦ 0.05%.

[0048] Control the box temperature in the range of 291°C - 293°C, the height of the windless area is 50 mm - 70 mm, the ring blowing cooling air pressure is between 12 Pa - 18 Pa, the network pressure is 0.4 - 0.8 Mpa, and the spinning speed is between 2300 m / min - 2500 m / min; The fineness of the polyester fiber monofilament finally obtained by the process is 0.8 D, the linear density deviation rate is 0.28%, the elongation at break is 123%, the cv value of the elongation at break is 2.8%, the breaking strength is 2.85 cN / dtex, the cv value of the breaking strength is 2.1%, and the oil content is 0.39%. Example 4

[0049] The main preparation process flow includes: polyester melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → metering pump → spinning pack → windless area → ring blowing cooling system → oiling device on the nozzle → ceramic guide for filaments → godet I → texturing device → godet II → roller → winding and forming. Among them, the spinning pack includes the above-mentioned spinneret structure.

[0050] Specifically, first, terephthalic acid and ethylene glycol are converted into PET melt (polyester melt) through esterification polycondensation reaction. Subsequently, the polyester melt is transported by a booster pump and its temperature is adjusted through a heat exchanger to ensure that the melt transported through the melt conveying pipeline enters the spinning box in an optimal state. In the spinning box, the melt is precisely controlled by a metering pump and then passes through the spinning pack containing the above-mentioned spinneret structure 1 to form fibers. The fibers are initially cooled and solidified in the windless area to avoid the influence of air flow on fiber forming. Then, the fibers are further cooled by the ring blowing cooling system and their smoothness is increased by the oiling device on the nozzle. The fibers are then guided by the ceramic guide for filaments and godet I, the cohesion between fibers is increased by the texturing device, and then stretched and shaped through godet II and rollers. Finally, they are wound into a cake in the winding and forming device to complete the entire spinning process.

[0051] In this example, as Figure 7 shown, the spinneret hole assemblies 3 are circumferentially arranged on the spinneret structure 1 in a concentric circle manner, enclosing two circles in total. 5 spinneret hole assemblies 3 are arranged in the inner circle and 7 spinneret hole assemblies 3 are arranged in the outer circle. Each group of spinneret hole assemblies 3 in the spinneret structure 1 consists of 6 spinneret holes, including 3 first spinneret holes 31 and 3 second spinneret holes 32. The diameter D of the second ring 7 enclosed is 0.34 mm, the diameter d of the third ring 8 is 0.12 mm, the hole slit distance e between the first spinneret hole 31 and the second spinneret hole 32 is 0.06 mm, the total height b of the spinneret holes is 0.15 mm, the width c of the concave cavity 4 is 0.12 mm, and the width a of the rectangular cavity 5 is 0.012 mm. In this example, the total number of spinneret holes in the spinneret hole assemblies 3 is 5×6 + 7×6 = 72.

[0052] During the preparation process, the intrinsic viscosity of the PET melt is 0.65 - 0.68 dl / g, the end carboxyl group content is ≤28 mol / t, the particle size of impurity particles is ≦20 μm, and the moisture content is ≦0.05%.

[0053] During the preparation process, the temperature of the box body ranges from 291°C to 293°C, the height of the windless area is 50 mm - 70 mm, the air pressure of the ring blowing cooling is between 12 Pa and 18 Pa, the network pressure is 0.4 - 0.8 Mpa, and the spinning speed is between 2450 m / min and 2800 m / min.

[0054] The fineness of the polyester fiber monofilament finally obtained by the process is 1.25 D, the linear density deviation rate is 0.28%, the elongation at break is 119%, the cv value of the elongation at break is 2.8%, the breaking strength is 2.82 cN / dtex, the cv value of the breaking strength is 2.1%, and the oil content is 0.38%. Example 5

[0055] The main preparation process flow includes: polyester melt → booster pump → heat exchanger → melt conveying pipeline → spinning box body → metering pump → spinning pack → windless area → ring blowing cooling system → oiling device on the nozzle → wire guiding porcelain part → wire guiding disc I → network device → wire guiding disc II → roller → winding and forming. Among them, the spinning pack includes the above-mentioned spinneret structure.

[0056] Specifically, first, terephthalic acid and ethylene glycol are converted into PET melt (polyester melt) through an esterification polycondensation reaction. Subsequently, the polyester melt is transported by a booster pump and its temperature is adjusted through a heat exchanger to ensure that the melt transported through the melt conveying pipeline enters the spinning box body in an optimal state. In the spinning box body, the melt is precisely controlled by a metering pump and then passes through the spinning pack containing the above-mentioned spinneret structure 1 to form fibers. The fibers are initially cooled and solidified in the windless area to avoid the influence of air flow on fiber formation. Then, the fibers are further cooled by the ring blowing cooling system and their smoothness is increased by the oiling device on the nozzle. The fibers are then guided by the wire guiding porcelain part and the wire guiding disc I, the bonding force between the fibers is increased by the network device, and they are stretched and shaped through the wire guiding disc II and the roller. Finally, they are wound into a cake in the winding and forming device to complete the entire spinning process.

[0057] In this example, as Figure 8As shown, the spinneret hole assemblies 3 are circumferentially arranged on the spinneret structure 1 in a concentric circle pattern, forming two circles in total. There are 9 spinneret hole assemblies 3 and 15 spinneret hole assemblies 3 distributed in the inner and outer circles respectively. Each group of spinneret hole assemblies 3 in the spinneret structure 1 consists of 6 spinneret holes, including 3 first spinneret holes 31 and 3 second spinneret holes 32. The diameter D of the second ring 7 formed is 0.36 mm, the diameter d of the third ring 8 is 0.14 mm, the hole slit distance e between the first spinneret hole 31 and the second spinneret hole 32 is 0.05 mm, the total height b of the spinneret hole is 0.16 mm, the width c of the concave cavity 4 is 0.14 mm, and the width a of the rectangular cavity 5 is 0.017 mm. In this example, the total number of spinneret holes in the spinneret hole assemblies 3 is 9×6 + 15×6 = 144.

[0058] During the preparation process, control the intrinsic viscosity of the PET melt to be 0.65 - 0.68 dl / g, the end carboxyl content ≤ 28 mol / t, the impurity particle size ≤ 20 μm, and the moisture content ≤ 0.05%; Control the box temperature in the range of 291°C - 293°C, the height of the windless area is 50 mm - 70 mm, the ring blowing cooling air pressure is between 12 Pa - 18 Pa, the network pressure is 0.4 - 0.8 Mpa, and the spinning speed is between 2450 m / min - 2800 m / min; The polyester fiber monofilament fineness finally obtained in the process is 1.25 D, the linear density deviation rate is 0.28%, the elongation at break is 125%, the cv value of the elongation at break is 2.3%, the breaking strength is 2.86 cN / dtex, the cv value of the breaking strength is 2.3%, and the oil content is 0.38%. Example 6

[0059] The preparation process mainly includes: polyester melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → metering pump → spinning pack → windless area → ring blowing cooling system → oiling device on the nozzle → guiding porcelain part → guiding disk I → networker → guiding disk II → roller → winding and forming. Among them, the spinning pack includes the above-mentioned spinneret structure.

[0060] Specifically, first, terephthalic acid and ethylene glycol are converted into PET melt (polyester melt) through an esterification polycondensation reaction. Subsequently, the polyester melt is transported by a booster pump and its temperature is adjusted through a heat exchanger to ensure that the melt enters the spinning box in an optimal state after being transported through the melt conveying pipeline. In the spinning box, the melt is precisely controlled by a metering pump and then passes through a spinning component containing the spinneret structure 1 described above to form fibers. The fibers are initially cooled and solidified in a windless area to avoid the influence of air flow on fiber formation. Then, the fibers are further cooled by a ring blowing cooling system and their smoothness is increased by an oiling device on the nozzle. The fibers are then guided by ceramic wire guides and godet I, the cohesion between the fibers is increased by a texturing device, and then they are drawn and shaped through godet II and rollers. Finally, they are wound into a cake in a winding forming device to complete the entire spinning process.

[0061] In this example, as Figure 9 shown, the spinneret hole assemblies 3 are circumferentially arranged on the spinneret structure 1 in a concentric circle manner, forming a total of three circles. The number of spinneret hole assemblies 3 in the inner circle is 6, the number of spinneret holes in the middle circle is 12, and the number of spinneret holes in the outer circle is 18. Each group of spinneret hole assemblies 3 in the spinneret structure 1 consists of 6 spinneret holes, including 3 first spinneret holes 31 and 3 second spinneret holes 32. The diameter D of the second ring 7 formed is 0.32 mm, the diameter d of the third ring 8 is 0.14 mm, the hole slit distance e between the first spinneret hole 31 and the second spinneret hole 32 is 0.05 mm, the total height b of the spinneret holes is 0.13 mm, the width c of the concave cavity 4 is 0.12 mm, and the width a of the rectangular cavity 5 is 0.013 mm. In this example, the total number of spinneret holes in the spinneret hole assemblies 3 is 6×6 + 12×6 + 18×6 = 216.

[0062] During the preparation process, the intrinsic viscosity of the PET melt is controlled at 0.65 - 0.68 dl / g, the end carboxyl group content is ≤28 mol / t, the particle size of impurity particles is ≦20 μm, and the moisture content is ≦0.05%; The temperature of the box is controlled in the range of 291°C - 293°C, the height of the windless area is 50 mm - 70 mm, the ring blowing cooling air pressure is between 12 Pa - 18 Pa, the texturing pressure is 0.4 - 0.8 Mpa, and the spinning speed is between 2450 m / min - 2800 m / min; The polyester fiber monofilament fineness finally obtained by the process is 1.38 D, the linear density deviation rate is 0.28%, the elongation at break is 126%, the cv value of the elongation at break is 2.8%, the breaking strength is 2.79 cN / dtex, the cv value of the breaking strength is 2.3%, and the oil content is 0.41%.

[0063] Furthermore, the performance of the matte polyester fiber formed by the spinneret structure of this solution is tested as follows: The test standards and methods related to the present invention are as follows: (1) Linear density deviation rate: The linear density deviation rate of high-quality matte polyester fiber filaments is tested by using "(actual linear density - theoretical linear density) / theoretical linear density * 100%" in "GB / T 14343 Test Method for Linear Density of Chemical Fiber Filaments"; (2) Tensile strength: According to "GB / T 14343 Test Method for Tensile Properties of Chemical Fiber Filaments", a Swiss Uster-Ⅳ type tensile strength tester is used to stretch the fiber to break under the condition of constant-speed uniform tension, and the tensile strength of the specimen is obtained from the data display; (3) Tensile strength CV: According to "GB / T 14343 Test Method for Tensile Properties of Chemical Fiber Filaments", a Swiss Uster-Ⅳ type tensile strength tester is used to stretch the fiber to break under the condition of constant-speed uniform tension, and the tensile strength CV of the specimen is obtained from the data display; (4) Elongation at break: According to "GB / T 14343 Test Method for Tensile Properties of Chemical Fiber Filaments", a Swiss Uster-Ⅳ type tensile strength tester is used to stretch the fiber to break under the condition of constant-speed uniform tension, and the elongation at break of the specimen is obtained from the data display; (5) Elongation at break CV: According to "GB / T 8960-2015 Drawn Polyester Filament", a Swiss Uster-Ⅳ type tensile strength tester is used to stretch the fiber to break under the condition of constant-speed uniform tension, and the elongation at break CV of the specimen is obtained from the data display; (6) Evenness variation coefficient: According to "GB / T 8960-2015 Drawn Polyester Filament", it is measured by using a Uster-Ⅳ type evenness tester. When the filament passes through the air capacitor composed of two parallel metal plates at the detection point, due to the change in the weight per unit length of the filament, the capacitance changes accordingly. The change rate of the capacitance is linearly related to the change in the weight of the filament between the plates of the detection capacitor. The evenness variation coefficient is displayed through an automatic integrator, thereby obtaining the evenness variation coefficient of high-quality matte polyester fiber filaments; (7) Oil content rate: According to "GB / T 8960-2015 Drawn Polyester Filament", a nuclear magnetic resonance fiber oil content rate tester is used to select a section of fiber according to the nuclear magnetic resonance method to test the oil content rate of high-quality matte polyester fiber filaments; (8) Thermal stress: According to FZ / T 50051-2020 "Test Method for Dynamic Thermal Stress of Polyester Pre-oriented Yarn", under the set conditions, the specimen passes through the heating device and the drawing device at a certain speed and with a constant pre-tension using an SG635 full-automatic filament thermal stress tester, so that the specimen undergoes a certain proportion of drawing under heated conditions, and the dynamic thermal stress of the specimen during the drawing process is measured. The average value, maximum value, minimum value, and cv value of the thermal stress are automatically calculated by the computer. These indicators can directly reflect the dyeing performance of the subsequent DTY.

[0064] After testing, the performance indicators of the matte polyester fiber prepared based on this solution are as follows: The fineness of a single filament is in the range of 0.8 - 2.0 D, the linear density deviation rate ≤ 1.0%, the CV of the breaking strength ≤ 3.0%, the breaking strength ≥ 2.1 cN / dtex, the elongation at break is in the range of 113% - 128%, the CV of the elongation at break ≤ 3.5%, the unevenness rate of yarn evenness ≤ 0.9%, the cv value of the dynamic thermal stress of the pre-oriented yarn ≤ 2.0%, and the oil content is 0.43 ± 0.2%.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0066] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A spinneret structure, characterized in that, The spinneret structure (1) includes multiple spinneret layers (2). The multiple spinneret layers (2) are sequentially arranged from the inside to the outside along the center point of the spinneret structure (1). Each spinneret layer (2) includes multiple spinneret hole assemblies (3) arranged at intervals along the circumferential direction of the spinneret structure (1). Each spinneret hole assembly (3) includes a first spinneret hole (31) and a second spinneret hole (32). The structures of the first spinneret hole (31) and the second spinneret hole (32) are the same, and both include a concave cavity (4) and a rectangular cavity (5). The concave cavity (4) is located at the end of the rectangular cavity (5). The first spinneret hole (31) and the second spinneret hole (32) are arranged in a staggered circular array. After the staggered circular array, one of the two concave cavities (4) of the first spinneret hole (31) and the second spinneret hole (32) faces the center of the circle, and the other faces away from the center of the circle. The concave cavity (4) includes a transverse cavity (41) and vertical cavities (42) located at both ends of the two transverse cavities (41). The length of the vertical cavity (42) is less than the length of the rectangular cavity (5).

2. The spinneret structure according to claim 1, characterized in that, In each spinneret hole assembly (3), the total number of the vertical cavity (42) facing away from the center of the circle and the rectangular cavity (5) is 1.5 times the total number of spinneret holes in each spinneret hole assembly (3).

3. The spinneret structure according to claim 1, characterized in that, In each spinneret hole assembly (3), a connection point is formed at the connection between the concave cavity (4) and the rectangular cavity (5). The multiple connection points corresponding to the multiple spinneret holes facing the center of the circle are connected to each other to form the first ring (6) of the spinneret hole assembly (3). The multiple connection points corresponding to the multiple spinneret holes facing away from the center of the circle are connected to each other to form the second ring (7) of the spinneret hole assembly (3). The second ring (7) is inside the first ring (6). The rectangular cavities (5) of the spinneret holes corresponding to the second ring (7) divide the second ring (7) into multiple hollow cavities. The number of the hollow cavities is half of the total number of spinneret holes in the spinneret hole assembly (3). The suspended end faces of the rectangular cavities (5) corresponding to the multiple spinneret holes facing away from the center of the circle are connected to each other to form a third ring (8). The third ring (8) is inside the second ring (7).

4. The spinneret structure according to claim 1, wherein In each spinneret hole assembly (3), the number of the first spinneret holes (31) is the same as the number of the second spinneret holes (32), and the total number of the first spinneret holes (31) and the second spinneret holes (32) is an even number.

5. The spinneret structure according to claim 1, wherein The ratio of the width of the rectangular cavity (5) of each spinneret hole to the width of the concave cavity (4) is between 1 / 10 and 1 / 8. Here, the width of the rectangular cavity (5) is the distance a between the outer walls of the rectangular cavity (5), and the width of the concave cavity (4) is the distance c between the outer walls of the two vertical cavities (42).

6. The spinneret structure according to claim 3, characterized in that, After the first spinneret holes (31) and the second spinneret holes (32) are arranged in a staggered circular array, the range of the hole slit distance e between the first spinneret holes (31) and the second spinneret holes (32) is 0.05 mm to 0.09 mm, and the diameter d of the third ring (8) is between 0.1 mm and 0.14 mm. Wherein, the hole slit distance e is the point-plane vertical distance between adjacent first spinneret holes (31) and second spinneret holes (32), and the point-plane vertical distance is determined based on the adjacent point of the concave cavity (4) facing away from the spinneret layer (2) and the adjacent surface of the concave cavity (4) concave towards the spinneret layer (2).

7. The spinneret structure according to claim 6, wherein The total height b of the spinneret holes and the width of the rectangular cavity (5) of the spinneret holes are respectively determined based on the diameter of the second ring (7) and the hole slit distance.

8. A method for preparing matte polyester fiber, characterized in that, The process flow corresponding to the method is polyester melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → metering pump → spinning pack → windless zone → ring blow cooling system → oiling device on the nozzle → wire guiding porcelain part → wire guiding disc I → networker → wire guiding disc II → roller → winding and forming. Wherein, the spinning pack includes the spinneret plate structure according to any one of claims 1-7.

9. The method for preparing matte polyester fiber according to claim 8, characterized in that, The intrinsic viscosity of the polyester melt is 0.65-0.68 dl / g, the end carboxyl content ≤ 28 mol / t, the impurity particle size ≦ 20 μm, the moisture content ≦ 0.05%, the temperature of the spinning box is 290°C - 294°C, the height of the windless zone is between 40 mm and 65 mm, the ring blow cooling rate is 10 Pa - 18 Pa, the network pressure is 0.4 - 0.8 Mpa, and the winding speed is 2500 m / min - 2900 m / min.

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