Spinneret for preparing side-by-side composite hollow elastic fiber and method for preparing side-by-side composite hollow elastic fiber

Abstract

The application discloses a spinneret for preparing side-by-side composite hollow elastic fibers and a preparation method of the side-by-side composite hollow elastic fibers. The spinneret comprises a spinneret body and a plurality of spinneret micro-holes. Each of the spinneret micro-holes comprises two symmetrically arranged asymmetric units, and each of the asymmetric units comprises a plurality of circumferentially arranged circular-arc flow channels and a side-by-side flow channel. The circular-arc flow channels and the side-by-side flow channel in each of the asymmetric units are circumferentially arranged around the same center. The application also discloses a preparation method of the side-by-side composite hollow elastic fibers. The side-by-side composite hollow elastic fibers are prepared by using two kinds of fiber-forming polymers with different intrinsic viscosity, crystallization rate and shrinkage. The prepared side-by-side composite hollow elastic fibers have potential elasticity, and the elasticity is exhibited after dyeing and finishing treatment, so that the shape-keeping elastic characteristics are obtained. In addition, the side-by-side composite hollow elastic fibers have high hollow degree and capillary grooves, and have the functions of moisture absorption, quick drying, air permeability, loftiness and light weight.

Description

Technical Field

[0001] This invention relates to the field of chemical fiber production technology, and in particular to a spinneret for preparing parallel composite hollow elastic fibers and a method for preparing parallel composite hollow elastic fibers. Background Technology

[0002] Polyester filament has become a major raw material for the textile industry in recent decades due to its large production capacity, high strength, good shape retention, and wrinkle resistance. With the improvement of people's living standards, the demand for high-end textiles using polyester filament requires polyester filament to compensate for its shortcomings and upgrade its production. Improving the inherent shortcomings of polyester materials mainly focuses on aspects such as moisture absorption and breathability, lightweight, elasticity, bulkiness, and antistatic properties.

[0003] Side-by-side composite elastic fibers are a type of chemical fiber production method developed in the 1960s, in which the fiber cross-section contains two or more components. The most common type is the bicomponent side-by-side composite elastic fiber, which is produced by feeding two fiber-forming polymer melts with different viscosities in different proportions into a composite spinning assembly equipped with a spinneret. After passing through their respective filters and channels, they can converge before or after the spinneret orifices and be extruded from the spinneret orifices of the composite spinning assembly. After rapid cooling, oiling, drawing, and winding, side-by-side composite elastic fibers are produced.

[0004] In the early 1920s, DuPont developed PET / PTT side-by-side composite elastic fiber, abbreviated as T400 elastic fiber. It has potential permanent three-dimensional crimp elasticity, so it can quickly remember mechanical deformation and has the ability to quickly disappear deformation under external stress. It has outstanding memory function and micro-elasticity effect, and is a model of high-end textile polyester filament.

[0005] Existing technologies, such as Chinese invention patent CN110565184A, disclose a method for preparing highly self-crimping PET / PTT parallel composite filaments. This method involves drying and crystallizing PET and PTT chips, then melting them separately and extruding them through parallel spinnerets. After cooling, the fibers are oiled and then subjected to 1-3 stages of drawing and heat setting. The total draw ratio is controlled at 3-3.5 times, with the first stage draw ratio at 2.8-3.0 times, and the temperature controlled at 75-80℃. This method for preparing highly self-crimping PET / PTT parallel composite filaments utilizes multi-stage drawing to increase the draw ratio, achieving improved fiber strength, a moderate decrease in breaking elongation, and a significant improvement in self-crimping performance. The fiber cross-section is similar to that of T400 elastic fibers, exhibiting a solid peanut-shaped or circular parallel structure without hollow centers or numerous capillary channels. Similarly, Chinese invention patent CN104141178A discloses a PET composite elastic fiber and its preparation method. Its fiber cross-section is the same as that of T400 elastic fiber, with a solid peanut-shaped or circular parallel structure, without hollow cores and numerous capillary channels.

[0006] Chinese invention patent CN113862827A discloses a parallel composite elastic fiber, its preparation method and application, and a composite spinneret assembly, providing a composite spinneret assembly used in composite spinning. Based on the basic principles of chemical fiber spinning, the T-shaped tooth height of the outer contour is 1–50 μm. With such a low tooth height, under the melt expansion and rounding effect, the final fiber cross-section will inevitably also be rounded, making it impossible to obtain the capillary effect groove structure. Furthermore, its center is a solid core, merely serving as a second polymer, so the resulting fiber still has a solid structure.

[0007] Therefore, there is an urgent need for a new technical solution to obtain parallel composite elastic fibers that have both hollow structures and capillary effect grooves. Summary of the Invention

[0008] In view of the above shortcomings, one object of the present invention is to provide a spinneret for preparing parallel composite hollow elastic fibers, wherein two irregularly shaped units facilitate the extrusion of two different fiber-forming polymer melts to prepare parallel composite hollow elastic fibers. Another object of the present invention is that the prepared parallel composite hollow elastic fibers possess latent elasticity, exhibit elasticity after dyeing and finishing, achieving shape-preserving elasticity characteristics, and also have high hollowness and capillary grooves, providing moisture absorption, quick-drying, breathability, fluffiness, and lightweight properties.

[0009] To achieve at least one of the above-mentioned technical objectives and meet the above-mentioned technical requirements, the technical solution adopted by the present invention is as follows:

[0010] A spinneret for preparing parallel composite hollow elastic fibers includes a spinneret body having a spinneret surface and a plurality of spinneret micro-holes disposed on the spinneret surface. Each spinneret micro-hole includes two symmetrically arranged irregularly shaped units. Each irregularly shaped unit includes a plurality of circumferentially spaced arc flow channels and parallel side flow channels disposed between two of the arc flow channels. The arc flow channels and parallel side flow channels in each irregularly shaped unit are arranged around the same central circumference. Each arc flow channel has at least one outer flow channel arranged radially on its outer side. The outer flow channel is connected to the corresponding arc flow channel. The two parallel side flow channels are arranged side by side.

[0011] As a preferred technical solution, each of the irregularly shaped units has three arc-shaped flow channels, and each arc-shaped flow channel has two outer flow channels on its outer side. The included angle between two adjacent outer flow channels is 45°, and the closest distance between the two parallel side flow channels is the closest distance at which the melt between the two irregularly shaped units can be bonded together.

[0012] As a preferred technical solution, the outer flow channel is club-shaped, and the ratio of the diameter of the head end of the outer flow channel to the width of the end end of the outer flow channel is (1.1-1.3):1.

[0013] As a preferred technical solution, the ratio of the length of the outer channel to its average width is (2-6):1.

[0014] As a preferred technical solution, an opening gap is provided between two adjacent arc flow channels, and an opening gap is provided between each end of the parallel side flow channel and the nearest arc flow channel, wherein the width of the opening gap is 0.03-0.12mm.

[0015] As a preferred technical solution, the parallel side channels are disc-shaped, and the closest distance between two adjacent parallel side channels is 0.01-0.10 mm.

[0016] As a preferred technical solution, the ratio of the sum of the areas enclosed by the inner arcs of the circular arc flow channel and the parallel side flow channels to the sum of the areas enclosed by the outer arcs of the circular arc flow channel and the outer flow channel is the theoretical hollowness, which is 50%-75%.

[0017] This invention also provides a method for preparing parallel composite hollow elastic fibers, wherein the parallel composite hollow elastic fibers are prepared by the spinneret, and the preparation method includes the following steps:

[0018] Fiber-forming polymer melt A and fiber-forming polymer melt B, which have different intrinsic viscosities, crystallization rates, and shrinkage rates, are introduced into the spinneret. Fiber-forming polymer melt A is extruded through one of the shaped units in the spinneret micro-orifice to form filament bundle A, and fiber-forming polymer melt B is extruded through another shaped unit in the same spinneret micro-orifice to form filament bundle B. Fiber bundles A and B converge and bond at the spinneret spinneret surface to form nascent fibers with a certain degree of hollowness. The nascent fibers undergo rapid cooling forming, nozzle oiling, pre-networking, stretching hot roller, setting hot roller, main network, and high-speed winding to obtain the parallel composite hollow elastic fiber with potential elasticity.

[0019] As a preferred technical solution, the weight ratio of the fiber-forming polymer melt A to the fiber-forming polymer melt B is (40-60)%:(60-40)%.

[0020] As a preferred technical solution, the fiber-forming polymer melt A is low-viscosity PET with an intrinsic viscosity of 0.45-0.55 dL / g, and the fiber-forming polymer melt B is one of high-viscosity PTT, PBT, and PET, while the crystallization rate and shrinkage rate of the two fiber-forming polymers differ by at least 30%.

[0021] When the fiber-forming polymer melt B is high-viscosity PET, its intrinsic viscosity is 0.70–0.80 dL / g;

[0022] When the fiber-forming polymer melt B is high-viscosity PTT or high-viscosity PBT, its intrinsic viscosity is 1.10 to 1.25 dL / g.

[0023] The beneficial effects of this invention are:

[0024] 1) Each spinneret has two symmetrical irregularly shaped units, so that two different fiber-forming polymer melts can be extruded and formed by the corresponding irregularly shaped units. Since the two parallel side channels are arranged tangentially, it is convenient for the two different fiber-forming polymer melts to merge and bond together after being extruded through the spinneret. Multiple arc channels are set to extrude and form hollow parallel composite hollow elastic fibers. After the adjacent outer channels extrude the fiber-forming polymer melts, capillary grooves will be formed. In this way, the parallel composite hollow elastic fibers prepared by the spinneret not only have the properties of the two fiber-forming polymer melts, but also increase the number of capillary grooves and have good hollowness.

[0025] 2) In addition to the elasticity and memory function of potential permanent three-dimensional crimping elastic deformation, the parallel composite hollow elastic fibers obtained by the preparation method also have the functions of moisture absorption, quick drying, breathability, fluffiness and lightweight. Attached Figure Description

[0026] Figure 1 This is a structural diagram of the spinneret micropores provided in one embodiment of the present invention;

[0027] Figure 2 This is a front view of a spinneret provided in one embodiment of the present invention;

[0028] Figure 3 This is a cross-sectional view of a spinneret provided in one embodiment of the present invention;

[0029] Figure 4 This is a structural diagram of the spinneret micropores provided in one embodiment of the present invention;

[0030] Figure 5 This is a structural diagram of the spinneret micropores provided in a preferred embodiment of the present invention;

[0031] Figure 6 This is a cross-sectional view of parallel composite hollow elastic fibers provided in one embodiment of the present invention.

[0032] exist Figures 1-6 In the middle, 1. Spinneret body; 101. Irregular shape unit; 1011. Arc flow channel; 1012. Outer flow channel; 1013. Parallel side flow channel; 1014. Opening gap; 102. Guide hole. Detailed Implementation

[0033] The present invention will now be further described with reference to the accompanying drawings.

[0034] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "top", "bottom", "left", "right", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0035] Please refer to Figures 1-6 An embodiment of the present invention provides a spinneret for preparing parallel composite hollow elastic fibers, comprising a spinneret body 1 having a spinneret surface and a plurality of spinneret micro-holes disposed on the spinneret surface. The spinneret micro-holes include two symmetrically arranged irregularly shaped units 101. Each irregularly shaped unit 101 includes a plurality of circumferentially spaced arc flow channels 1011 and parallel side flow channels 1013 disposed between two of the arc flow channels 1011. The arc flow channels 1011 and the parallel side flow channels 1013 in each irregularly shaped unit 101 are arranged around the same central circumference. At least one outer flow channel 1012 is radially disposed on the outer side of each arc flow channel 1011. The outer flow channel 1012 communicates with the corresponding arc flow channel 1011. The two parallel side flow channels 1013 are arranged side by side.

[0036] Each spinneret has two symmetrical irregularly shaped units 101, allowing two different fiber-forming polymer melts to be extruded and formed through their respective irregularly shaped units 101. The two parallel side channels 1013 are arranged symmetrically, facilitating the merging and bonding of the two different fiber-forming polymer melts after extrusion. Multiple arc-shaped channels 1011 are also provided for extrusion to form hollow, parallel composite hollow elastic fibers. Adjacent outer channels 1012, after extruding the fiber-forming polymer melts, form capillary grooves. Thus, the parallel composite hollow elastic fibers prepared by the spinneret possess latent elasticity. After dyeing and finishing, the elasticity becomes apparent, achieving shape-preserving elasticity characteristics. They also exhibit high hollowness and capillary grooves, providing moisture absorption, quick-drying, breathability, fluffiness, and lightweight properties.

[0037] Specifically, such as Figures 1-6As shown, the reverse side of the spinneret body 1 is the spinneret surface, and the front side is the guide surface. Multiple guide holes 102 are provided on the guide surface. The guide holes 102 are connected to the corresponding spinneret micro-holes. Each irregularly shaped unit 101 corresponds to one guide hole 102, that is, each spinneret micro-hole corresponds to one set of guide holes 102. Two guide holes 102 form a group. The two guide holes 102 in each group are symmetrically inclined. The included angle formed by the two guide holes 102 in each group is greater than 20° and less than 40°. Optimally, the included angle formed by the two guide holes 102 in each group is 34°. A tapered transition angle is provided between the guide hole 102 and the irregularly shaped unit 101. The angle of the transition angle is 45°. In this way, the fiber-forming polymer melt A and the fiber-forming polymer melt B pass through the two guide holes 102 respectively. The two guide holes 102 form a suitable included angle to facilitate the bonding and forming of the fiber-forming polymer melt A and the fiber-forming polymer melt B.

[0038] Furthermore, such as Figures 4-6 As shown, each of the irregularly shaped units 101 has three arc flow channels 1011. Each arc flow channel 1011 has one, two, or three outer flow channels 1012 on its outer side. When two outer flow channels 1012 are provided on each arc flow channel 1011, the included angle between two adjacent outer flow channels 1012 is 45°. When one outer flow channel 1012 is provided on each arc flow channel 1011, the outer flow channel 1012 is located at the center of the arc flow channel 1011, and the included angle between two adjacent outer flow channels 1012 is 90°. The closest distance between two parallel side flow channels 1013 is the closest distance between two irregularly shaped units 101.

[0039] The diameter of the arc flow channel 1011 is generally fixed, and the distance between two adjacent arc flow channels 1011 is also fixed. If the number of arc flow channels 1011 is greater than three, the fiber-forming polymer melt is easily blocked in the arc flow channels 1011, resulting in poor extrusion molding. If the number of outer flow channels 1012 on each arc flow channel 1011 is greater than two, the number of capillary grooves will be too large, and the included angle formed by two adjacent capillary grooves will be too small, which will affect the moisture absorption effect. The included angle between two outer flow channels 1012 is 45°, that is, the outer flow channels 1012 are evenly arranged around the center circumference, and the maximum arc angle formed by the outer flow channels 1012 is 225°. In this way, the capillary grooves are evenly arranged, the capillary wicking effect is good, the concentrated wicking effect is outstanding, and the water absorption, water transport, and diffusion effects of the parallel composite hollow elastic fibers are good.

[0040] like Figures 4-6As shown, the outer flow channel 1012 is club-shaped, and the ratio of the diameter of the head end of the outer flow channel 1012 to the width of the tail end of the outer flow channel 1012 is (1.1-1.3):1. The outer flow channel 1012 has a gradually changing width structure, which makes the fiber-forming polymer melt flow better during extrusion and the extrusion molding smoother. The head end of the outer flow channel 1012 is semi-circular or semi-circular, which makes it easier for the fiber-forming polymer melt to gather and form at the head end of the outer flow channel 1012. The edges of the parallel composite hollow elastic fibers formed are smoother, the "long leaves" formed by the outer flow channel are more slender, and the grooves are more obvious.

[0041] like Figures 4-6 As shown, the ratio of the channel length to the average width of the outer channel 1012 is (2-6):1. If the ratio of the channel length to the average width of the outer channel 1012 is less than 2:1, the fiber-forming polymer melt will block the outer channel 1012. Even if it is extruded, this will result in poor capillary effect of the parallel composite hollow elastic fibers and low fiber rigidity. If the ratio of the channel length to the average width of the outer channel 1012 is greater than 6:1, it will also cause the fiber-forming polymer melt to be unable to be continuously extruded and the spinnability will deteriorate.

[0042] like Figures 4-6 As shown, an opening gap 1014 is provided between two adjacent arc flow channels 1011. An opening gap 1014 is provided between each end of the parallel side flow channel 1013 and the nearest arc flow channel 1011. The width of the opening gap 1014 is 0.03-0.12mm. When the width of the opening gap 1014 is less than 0.03mm, the fiber-forming polymer melt is easy to clump together when it is bonded at the opening gap 1014. If the width of the opening gap 1014 is greater than 0.12mm, the fiber-forming polymer melt cannot be bonded together at the opening gap 1014 and cannot be extruded into shape.

[0043] like Figures 4-6 As shown, the parallel side channels 1013 are disc-shaped, and the closest distance between two adjacent parallel side channels 1013 is 0.01-0.10 mm. The two ends of the two parallel side channels 1013 bend towards the nearest arc channel 1011. The two parallel side channels 1013 are arranged in parallel. If the closest distance between the parallel side channels 1013 is less than 0.01 mm, the two different fiber-forming polymer melts are prone to lumps when they merge and bond at the parallel side channels 1013, resulting in excessive bonding and unevenness of the parallel composite hollow elastic fibers. If the closest distance between the parallel side channels 1013 is greater than 0.10 mm, the two different fiber-forming polymer melts cannot continuously merge and bond at the parallel side channels 1013, which can easily lead to fiber breakage.

[0044] like Figures 4-6As shown, the ratio of the sum of the areas of the arc flow channel 1011 and the parallel side flow channels 1013 to the sum of the areas of the outer flow channel 1012 is the theoretical hollowness. The theoretical hollowness is 50%-75%. A large theoretical hollowness not only makes the textile fabric made of parallel composite hollow elastic fibers lightweight and soft and elastic to the touch, but also enhances airflow, thereby maximizing steam cooling. Their synergistic effect can enable the textile fabric to achieve better moisture and heat comfort management.

[0045] Please see Figures 1-6 The present invention also provides a method for preparing parallel composite hollow elastic fibers, wherein the parallel composite hollow elastic fibers are prepared by the spinneret, and the preparation method includes the following steps:

[0046] Fiber-forming polymer melt A and fiber-forming polymer melt B, which have different intrinsic viscosities, crystallization rates, and shrinkage rates, are introduced into the spinneret. Fiber-forming polymer melt A is extruded through one of the profiled units 101 in the spinneret micro-orifice to form filament bundle A. Fiber-forming polymer melt B is extruded through another profiled unit 101 in the same spinneret micro-orifice to form filament bundle B. Fiber bundles A and B converge and bond at the spinneret spinneret surface to form nascent fibers with a certain degree of hollowness. The nascent fibers undergo rapid cooling forming, nozzle oiling, pre-networking, stretching hot roller, setting hot roller, main network, and high-speed winding to obtain the parallel composite hollow elastic fiber with potential elasticity.

[0047] Fiber-forming polymer melt A and fiber-forming polymer melt B can be direct-spinning melts or melts molten by a screw extruder. After passing through their respective spinning metering pumps, they enter the same parallel composite spinning assembly in a specific bicomponent spinning box. The parallel composite spinning assembly includes a spinneret.

[0048] Preferably, the weight ratio of the fiber-forming polymer melt A to the fiber-forming polymer melt B is (40-60)%:(60-40)%. The fiber-forming polymer melt A is low-viscosity PET with an intrinsic viscosity of 0.45-0.55 dL / g, and the fiber-forming polymer melt B is one of high-viscosity PTT, PBT, or PET, with the crystallization rate and shrinkage rate of the two fiber-forming polymers differing by at least 30%. When the fiber-forming polymer melt B is high-viscosity PET, its intrinsic viscosity is 0.70-0.80 dL / g; when the fiber-forming polymer melt B is high-viscosity PTT or high-viscosity PBT, its intrinsic viscosity is 1.10-1.25 dL / g. Different component combinations meet different performance requirements. Fiber-forming polymer melt A and fiber-forming polymer melt B are bonded together at a certain distance. Due to the different viscosities of fiber-forming polymer melt A and fiber-forming polymer melt B, they have strong differences in shrinkage and crystallization rates. After hydrothermal treatment, the resulting parallel composite hollow elastic fibers will generate a strong longitudinal stress difference and also undergo torsion deviating from the longitudinal axis, thus causing the parallel composite hollow elastic fibers to exhibit potentially permanent three-dimensional crimp. After dyeing and finishing, the permanent three-dimensional curl is revealed, which has good elasticity. At the same time, the hollow rudder structure gives the parallel composite hollow elastic fiber the characteristics of high hollowness and many capillary channels on the surface of the parallel composite hollow elastic fiber. The textiles made from it have memory elasticity, lightness and warmth, moisture absorption and quick drying, and fluffy and breathable effects. If the weight ratio of fiber-forming polymer melt A to fiber-forming polymer melt B is not in the range of (40-60)%:(60-40)%, the performance of the prepared parallel composite hollow elastic fiber will be worse.

[0049] Example 1

[0050] A spinneret for preparing parallel composite hollow elastic fibers includes a spinneret body 1 with a spinneret surface and a plurality of spinneret micro-holes disposed on the spinneret surface. Each spinneret micro-hole includes two symmetrically arranged irregularly shaped units 101. Each irregularly shaped unit 101 includes three circumferentially spaced arcuate flow channels 1011 and parallel side flow channels 1013 disposed between two of the arcuate flow channels 1011. The arcuate flow channels 1011 and parallel side flow channels 1013 in each irregularly shaped unit 101 are arranged around a common central circumference. Two outer flow channels 1012 are radially arranged on the outer side of each arcuate flow channel 1011, and the outer flow channels 1012 communicate with the corresponding arcuate flow channel 1011. The two parallel side flow channels 1013 are arranged side-by-side, with an included angle of 45° between two adjacent outer flow channels 1012. The closest distance between the parallel side channels 1013 is the closest distance between two of the irregularly shaped units 101. The outer channel 1012 is club-shaped, and the ratio of the diameter at the head end of the outer channel 1012 to the width at the end end of the outer channel 1012 is 1.2:1. The ratio of the channel length to the average width of the outer channel 1012 is 4:1. An opening gap 1014 is provided between two adjacent arc channels 1011. An opening gap 1014 is provided between each end of the parallel side channel 1013 and the nearest arc channel 1011. The width of the opening gap 1014 is 0.06 mm. The parallel side channels 1013 are disc-shaped, and the closest distance between two adjacent parallel side channels 1013 is 0.09 mm. The theoretical hollowness is 72%.

[0051] A method for preparing parallel composite hollow elastic fibers, wherein the parallel composite hollow elastic fibers are prepared by a spinneret, the preparation method comprising the following steps: introducing fiber-forming polymer melt A and fiber-forming polymer melt B, which have different intrinsic viscosities, crystallization rates, and shrinkage rates, into the spinneret; extruding fiber-forming polymer melt A through one of the shaped units 101 in the spinneret micro-orifices to form a fiber bundle A; and extruding fiber-forming polymer melt B through another shaped unit 101 in the same spinneret micro-orifice. The irregularly shaped unit 101 is extruded to form a filament bundle B. The filament bundles A and B are joined and bonded on the spinneret spinneret surface to form a nascent fiber with a certain degree of hollowness. The nascent fiber is subjected to rapid cooling forming, nozzle oiling, pre-networking, stretching hot roller, setting hot roller, main network, and high-speed winding forming to obtain the parallel composite hollow elastic fiber with potential elasticity. The parallel composite hollow elastic fiber is a 167dtex / 72f eight-capillary groove parallel composite hollow elastic polyester elastic FDY filament.

[0052] The weight ratio of the fiber-forming polymer melt A to the fiber-forming polymer melt B is 55%:45%. The fiber-forming polymer melt A is low-viscosity PET with an intrinsic viscosity of 0.48 dL / g, and the fiber-forming polymer melt B is high-viscosity PTT with an intrinsic viscosity of 1.12 dL / g.

[0053] Example 2

[0054] A spinneret for preparing parallel composite hollow elastic fibers includes a spinneret body 1 with a spinneret surface and a plurality of spinneret micro-orifices disposed on the spinneret surface. Each spinneret micro-orifice includes two symmetrically arranged irregularly shaped units 101. Each irregularly shaped unit 101 includes three circumferentially spaced arcuate flow channels 1011 and parallel side flow channels 1013 disposed between two of the arcuate flow channels 1011. The arcuate flow channels 1011 and parallel side flow channels 1013 in each irregularly shaped unit 101 are arranged around the same central circumference. Two outer flow channels 1012 are radially arranged on the outer side of each arcuate flow channel 1011, and the outer flow channels 1012 communicate with the corresponding arcuate flow channel 1011. The two parallel side flow channels 1013 are arranged side-by-side, with an included angle of 45° between two adjacent outer flow channels 1012. The closest distance between the parallel side channels 1013 is the closest distance between two of the irregularly shaped units 101. The outer channel 1012 is club-shaped, and the ratio of the diameter at the head end of the outer channel 1012 to the width at the end end of the outer channel 1012 is 1.25:1. The ratio of the channel length to the average width of the outer channel 1012 is 5:1. An opening gap 1014 is provided between two adjacent arc channels 1011. An opening gap 1014 is provided between each end of the parallel side channel 1013 and the nearest arc channel 1011. The width of the opening gap 1014 is 0.08 mm. The parallel side channels 1013 are disc-shaped, and the closest distance between two adjacent parallel side channels 1013 is 0.07 mm. The theoretical hollowness is 68%.

[0055] A method for preparing parallel composite hollow elastic fibers, wherein the parallel composite hollow elastic fibers are prepared by a spinneret, the preparation method comprising the following steps: introducing fiber-forming polymer melt A and fiber-forming polymer melt B, which have different intrinsic viscosities, crystallization rates, and shrinkage rates, into the spinneret; extruding fiber-forming polymer melt A through one of the shaped units 101 in the spinneret micro-orifices to form a fiber bundle A; and extruding fiber-forming polymer melt B through another shaped unit 101 in the same spinneret micro-orifice. The irregularly shaped unit 101 is extruded to form a filament bundle B. The filament bundles A and B are joined and bonded on the spinneret spinneret surface to form a nascent fiber with a certain degree of hollowness. The nascent fiber is subjected to rapid cooling forming, nozzle oiling, pre-networking, stretching hot roller, setting hot roller, main network, and high-speed winding to obtain the parallel composite hollow elastic fiber with potential elasticity. The parallel composite hollow elastic fiber is a 110dtex / 72f eight-capillary groove parallel composite hollow elastic polyester elastic FDY filament.

[0056] The weight ratio of the fiber-forming polymer melt A and the fiber-forming polymer melt B is 50%:50%. The fiber-forming polymer melt A is low-viscosity PET with an intrinsic viscosity of 0.50 L / g, and the fiber-forming polymer melt B is high-viscosity PBT with an intrinsic viscosity of 1.20 dL / g.

[0057] Example 3

[0058] A spinneret for preparing parallel composite hollow elastic fibers includes a spinneret body 1 with a spinneret surface and a plurality of spinneret micro-holes disposed on the spinneret surface. Each spinneret micro-hole includes two symmetrically arranged irregularly shaped units 101. Each irregularly shaped unit 101 includes three circumferentially spaced arc flow channels 1011 and parallel side flow channels 1013 disposed between two of the arc flow channels 1011. The arc flow channels 1011 and parallel side flow channels 1013 in each irregularly shaped unit 101 are arranged around a common central circumference. Two outer flow channels 1012 are radially arranged on the outer side of each arc flow channel 1011, and the outer flow channels 1012 communicate with the corresponding arc flow channel 1011. The two parallel side flow channels 1013 are arranged side-by-side, with an included angle of 45° between two adjacent outer flow channels 1012. The closest distance between the parallel side channels 1013 is the closest distance between two of the irregularly shaped units 101. The outer channel 1012 is club-shaped, and the ratio of the diameter at the head end of the outer channel 1012 to the width at the end end of the outer channel 1012 is 1.16:1. The ratio of the channel length to the average width of the outer channel 1012 is 3.5:1. An opening gap 1014 is provided between two adjacent arc channels 1011. An opening gap 1014 is provided between each end of the parallel side channel 1013 and the nearest arc channel 1011. The width of the opening gap 1014 is 0.10 mm. The parallel side channels 1013 are disc-shaped, and the closest distance between two adjacent parallel side channels 1013 is 0.05 mm. The theoretical hollowness is 60%.

[0059] A method for preparing parallel composite hollow elastic fibers, wherein the parallel composite hollow elastic fibers are prepared by a spinneret, the preparation method comprising the following steps: introducing fiber-forming polymer melt A and fiber-forming polymer melt B, which have different intrinsic viscosities, crystallization rates, and shrinkage rates, into the spinneret; extruding fiber-forming polymer melt A through one of the profiled units 101 in the spinneret micro-orifice to form a fiber bundle A; and extruding fiber-forming polymer melt B through another profiled unit 101 in the same spinneret micro-orifice. 01. Extrusion forms filament bundle B. Filament bundle A and filament bundle B converge and bond on the spinneret spinneret surface to form nascent fibers with a certain degree of hollowness. The nascent fibers undergo rapid cooling forming, nozzle oiling, pre-networking, stretching hot roller, setting hot roller, main network, and high-speed winding forming to obtain the parallel composite hollow elastic fiber with potential elasticity. The parallel composite hollow elastic fiber is an 83dtex / 36f eight-capillary groove parallel composite hollow polyester elastic FDY filament.

[0060] The weight ratio of the fiber-forming polymer melt A to the fiber-forming polymer melt B is 40%:60%. The fiber-forming polymer melt A is a low-viscosity PET with an intrinsic viscosity of 0.45 dL / g, and the fiber-forming polymer melt B is a high-viscosity PET with an intrinsic viscosity of 0.75 dL / g.

[0061] The performance of the parallel composite hollow elastic fibers prepared in Examples 1, 2 and 3 was tested, and the results are shown in Table 1.

[0062] Table 1

[0063]

[0064] As can be seen from the performance test results in Table 1, the parallel composite hollow elastic fibers prepared by the preparation method of the present invention not only retain the deformation elastic memory function, but also have the function of lightweighting, and the moisture absorption, quick drying and air permeability are significantly improved.

[0065] Any numerical values ​​cited herein include all values ​​ranging from a lower limit to an upper limit, increasing by one unit, with at least two units between any lower and any higher value. For example, if the quantity of a component or the value of a process variable (e.g., temperature, pressure, time, etc.) is described as being from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, the purpose is to illustrate that values ​​such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also explicitly listed in this specification. For values ​​less than 1, a unit is appropriately considered to be 0.0001, 0.001, 0.01, 0.1, etc. These are merely examples intended for explicit expression, and it can be assumed that all possible combinations of values ​​listed between the minimum and maximum values ​​are similarly explicitly stated in this specification.

[0066] Unless otherwise stated, all ranges include the endpoints and all numbers between them. The terms "approximately" or "about" used with ranges apply to both endpoints of the range. Thus, "approximately 20 to 30" is intended to cover "approximately 20 to approximately 30," including at least the specified endpoints.

[0067] All articles and references disclosed herein, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified elements, components, parts, or steps, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute included by “may” is optional.

[0068] Multiple elements, components, parts, or steps can be provided by a single integrated element, component, part, or step. Alternatively, a single integrated element, component, part, or step can be divided into multiple separate elements, components, parts, or steps. The use of "a" or "an" to describe an element, component, part, or step does not imply the exclusion of other elements, components, parts, or steps.

[0069] The above embodiments are merely descriptions for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all implementations here, and any obvious variations or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A spinneret for preparing parallel composite hollow elastic fibers, characterized in that: The product includes a spinneret body with a spinneret surface and multiple spinneret micro-orifices disposed on the spinneret surface. Each spinneret micro-orifice includes two symmetrically arranged irregularly shaped units. Each irregularly shaped unit includes multiple circumferentially spaced arcuate flow channels and parallel side flow channels disposed between two of the arcuate flow channels. The arcuate flow channels and parallel side flow channels in each irregularly shaped unit are arranged around the same central circumference. Each arcuate flow channel has at least one radially arranged outer flow channel on its outer side, and the outer flow channel communicates with the corresponding arcuate flow channel. The two parallel side flow channels... The flow channels are arranged side by side; the outer flow channel is club-shaped, and the ratio of the diameter of the head end of the outer flow channel to the width of the end end of the outer flow channel is (1.1-1.3):1; the side flow channels are disc-shaped, and the closest distance between two adjacent side flow channels is 0.01-0.10mm; the ratio of the sum of the areas enclosed by the inner arcs of the arc flow channel and the side flow channels to the sum of the areas enclosed by the outer arcs of the arc flow channel and the outer flow channel is the theoretical hollowness, which is 50%-75%.

2. A spinneret for preparing parallel composite hollow elastic fibers according to claim 1, characterized in that: Each of the irregularly shaped units has 3 arc-shaped flow channels, and each arc-shaped flow channel has 2 outer flow channels on its outer side. The included angle between two adjacent outer flow channels is 45°, and the closest distance between the two parallel side flow channels is the closest distance at which the melt between the two irregularly shaped units can be bonded together.

3. A spinneret for preparing parallel composite hollow elastic fibers according to claim 1, characterized in that: The ratio of the length of the outer channel to its average width is (2-6):

1.

4. A spinneret for preparing parallel composite hollow elastic fibers according to claim 1, characterized in that: An opening gap is provided between two adjacent arc flow channels, and an opening gap is provided between each end of the parallel side flow channel and the nearest arc flow channel. The width of the opening gap is 0.03-0.12mm.

5. A method for preparing parallel composite hollow elastic fibers, characterized in that: The parallel composite hollow elastic fibers are prepared from the spinneret described in any one of claims 1-4, and the preparation method includes the following steps: Fiber-forming polymer melt A and fiber-forming polymer melt B, which have different intrinsic viscosities, crystallization rates, and shrinkage rates, are introduced into the spinneret. Fiber-forming polymer melt A is extruded through one of the shaped units in the spinneret micro-orifice to form filament bundle A, and fiber-forming polymer melt B is extruded through another shaped unit in the same spinneret micro-orifice to form filament bundle B. Fiber bundles A and B converge and bond at the spinneret spinneret surface to form nascent fibers with a certain degree of hollowness. The nascent fibers undergo rapid cooling forming, nozzle oiling, pre-networking, stretching hot roller, setting hot roller, main network, and high-speed winding to obtain the parallel composite hollow elastic fiber with potential elasticity.

6. The method for preparing a parallel composite hollow elastic fiber according to claim 5, characterized in that: The weight ratio of the fiber-forming polymer melt A to the fiber-forming polymer melt B is (40-60)%:(60-40)%.

7. The method for preparing a parallel composite hollow elastic fiber according to claim 5, characterized in that: The fiber-forming polymer melt A is low-viscosity PET with an intrinsic viscosity of 0.45–0.55 dL / g, and the fiber-forming polymer melt B is one of high-viscosity PTT, PBT, or PET. The crystallization rate and shrinkage rate of the two fiber-forming polymers differ by at least 30%. When the fiber-forming polymer melt B is high-viscosity PET, its intrinsic viscosity is 0.70–0.80 dL / g; When the fiber-forming polymer melt B is high-viscosity PTT or high-viscosity PBT, its intrinsic viscosity is 1.10 to 1.25 dL / g.

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