Composite fiber, method for producing the same, elastic profiled fiber, and textile

Abstract

The present application discloses a kind of composite fibers, elastic profiled fiber and its preparation method and textile, first component, second component and third component are used as raw material, the shrinkage is different when the first component and second component solidify, the phase separation phenomenon appears when the third component respectively and first component, second component melt contact;Specific jetting assembly can be continuously and stably jetting extruding composite fiber, the distribution channel is uniquely designed in the jetting assembly, can make the three components with different properties easy to control pressure and flow state in flow process, reduce the influence between each other, and then ensure excellent continuous productivity, at the same time, the composite fiber prepared by the method of the present application can be split into a specific structure fiber, the fiber not only can have ultra-fine radial dimension, but also simultaneously in elasticity, gloss, strength such as tear strength has achieved significant further, it is beneficial to prepare high-quality textile.

Description

Technical Field

[0001] This invention relates to the field of spinning technology, specifically to a composite fiber, an elastic profiled fiber, a method for preparing the same, and textiles thereof. Background Technology

[0002] Currently, the textile industry generally defines fibers with a single filament fineness of less than 0.44 dtex as microfibers. The main characteristics of microfibers include a soft and delicate feel and good flexibility. There are various methods for producing microfibers, such as direct spinning and bicomponent spinning. Direct spinning is relatively simple, but it is difficult to spin fibers below 0.44 dtex in practical applications, making it difficult to scale up production. Bicomponent spinning is currently the most widely used and researched method, which can be roughly divided into composite spinning and blend spinning. Among them, composite spinning is the most widely used. The specific operation involves spinning two or more fiber-forming polymers into composite fibers, and then dissolving and removing one component of the composite fiber to separate the components and obtain microfibers. For example, non-adhesive melt polyester and polyamide can be made into composite fibers, and then microfibers can be obtained after peeling. A common method is to first prepare island-type fibers, in which one component is a dispersed phase (i.e., island component) and the other is a continuous phase (i.e., sea component). The island component is contained in the sea component in the shape of microfibers, and the cross-section of the microfibers is distributed in an island shape, with its long axis parallel to the composite fiber. Dissolving and removing the sea component yields microfibers generated from the island components. However, the microfibers currently being prepared still have defects such as insufficient elasticity, poor luster, and relatively poor strength, such as tear strength, which limits their applicability to various scenarios.

[0003] It should be noted that the information disclosed in the background section above is only for understanding the background of this application. Therefore, the background section of this invention may include background information about the problems or environment of this invention, and is not necessarily a description of the prior art. Thus, the content included in the background section does not constitute an admission of the prior art by the applicant. Summary of the Invention

[0004] The purpose of this invention is to overcome one or more deficiencies in the prior art and to provide an improved composite fiber and elastic profiled fiber, with the aim of achieving improvements in at least one aspect of elasticity, gloss, and strength, such as tear strength, in the prepared microfiber.

[0005] The present invention also provides a textile comprising the above-mentioned composite fiber and elastic profiled fiber.

[0006] To achieve the above objectives, the present invention provides a technical solution: a method for preparing composite fibers, the preparation method comprising:

[0007] Using a first component, a second component, and a third component as raw materials, the first component and the second component have different shrinkage rates during solidification, and the third component exhibits phase separation when it melts and comes into contact with the first component and the second component, respectively.

[0008] The composite fibers are spun and extruded using a spinneret assembly;

[0009] The spinneret assembly includes a distribution plate and a spinneret plate with spinneret holes. The distribution plate includes a first flow channel for simultaneously introducing the first component and the second component into the spinneret holes, and a second flow channel for introducing the third component into the spinneret holes. The axis of the first flow channel is perpendicular to the axis of the second flow channel.

[0010] The area of ​​the cross-section of the first flow channel perpendicular to its length is S1, and the length of the first flow channel is denoted as L1, satisfying the following condition:

[0011] And 5≤a≤20;

[0012] The area of ​​the cross-section of the second flow channel perpendicular to its length is S2, and the length of the second flow channel is denoted as L2, satisfying the following condition:

[0013] Where, and 1≤b≤10;

[0014] The first flow channel and the second flow channel each have multiple channels, and each pair of adjacent first flow channels is separated by a second flow channel. The multiple second flow channels are independent of each other or their respective axis lines intersect at the same point. The orthographic projections of the first flow channel and the second flow channel are both located within the orthographic projection range of the inlet of the spinneret.

[0015] According to some preferred aspects of the present invention, the outlets of a plurality of first flow channels are respectively distributed on the circumference of a first circle, and the inlets of a plurality of second flow channels are respectively distributed on the circumference of a second circle;

[0016] The center of the first circle coincides with the center of the second circle, or the straight line containing the centers of the two circles is parallel to the axis of the first flow channel.

[0017] Furthermore, the diameter of the first circle is 1 / 3 to 3 / 4 of the diameter of the second circle.

[0018] In some preferred embodiments of the present invention, the cross-section of the first flow channel perpendicular to the length direction is circular.

[0019] In some preferred embodiments of the present invention, the cross-section of the second flow channel perpendicular to the length direction is square.

[0020] In some preferred embodiments of the present invention, a fan-shaped region is formed between two adjacent second channels, and the first channel is located at the centroid of the fan-shaped region.

[0021] In some preferred embodiments of the present invention, the cross-section of the spinneret orifice perpendicular to the length direction is circular.

[0022] According to some preferred aspects of the invention, the distribution plate further includes a third flow channel that surrounds the outer periphery of the plurality of second flow channels and communicates with the plurality of second flow channels respectively.

[0023] Furthermore, the distribution plate also includes at least one fourth flow channel and a plurality of fifth flow channels, wherein the at least one fourth flow channel is connected to the third flow channel respectively, and the fifth flow channels are connected to the first flow channels in a one-to-one correspondence.

[0024] Furthermore, the fourth flow channel includes a first sub-flow channel and a second sub-flow channel that are interconnected. The centerlines of the first sub-flow channel, the fifth flow channel, and the first flow channel are all parallel. The second sub-flow channel is connected to the third flow channel, and its outlet is offset from the inlet of the second flow channel.

[0025] According to some preferred aspects of the present invention, L1, L2, S1, and S2 satisfy the following conditions:

[0026] And 1.5≤c≤5.

[0027] In some preferred embodiments of the present invention, the difference in intrinsic viscosity between the first component and the second component is 0.15-0.7 dL / g.

[0028] In some preferred embodiments of the present invention, the mass ratio of the first component to the second component is 10:90 to 90:10.

[0029] In some preferred embodiments of the present invention, the ratio of the total mass of the first component and the second component to the mass of the third component is 90:10 to 50:50.

[0030] According to certain aspects of the present invention, the first component and the second component are independently selected from PET (polyethylene terephthalate), PBT (polybutylene terephthalate), or PTT (polypropylene terephthalate), and the third component is PA6 (nylon 6), COPET (polyethylene terephthalate copolymer, alkali-soluble polyester), PE (polyethylene), or PP (polypropylene).

[0031] In some preferred embodiments of the present invention, the preparation method is carried out using the FDY process, wherein the parameters of the FDY process are as follows: the spinning temperature of the first component box is 240-295℃, the spinning temperature of the second component box is 240-295℃, the spinning temperature of the third component box is 240-285℃, the cooling temperature is 19-23℃, the cooling air pressure is 15-35Pa, the network pressure is 0.25-0.4MPa, the speed of the first roller is 1600-2800m / min, the temperature of the first roller is 60-92℃, the speed of the second roller is 4000-6000m / min, the temperature of the second roller is 95-155℃, and the winding speed is 3900-5800m / min.

[0032] Another technical solution provided by the present invention: a composite fiber prepared by the above-described method for preparing composite fibers.

[0033] According to the present invention, the tensile strength of the composite fiber, as determined according to GB / T 14344-2008, is greater than or equal to 2.4 cN / dtex. In some embodiments, the tensile strength is 2.6-3.5 cN / dtex.

[0034] In some embodiments of the present invention, the elongation at break of the composite fiber is 10%-30% as determined according to GB / T 14344-2008.

[0035] In some embodiments of the present invention, the linear density of the composite fiber is 20-200 dtex, as determined according to GB / T 14343-2008.

[0036] In some embodiments of the present invention, the dyeing uniformity of the composite fiber is greater than or equal to grade 4.5, as determined according to GB / T 6508-2015.

[0037] In some embodiments of the present invention, the boiling water shrinkage rate of the composite fiber is 6%-12%, as determined according to GB / T 6505-2017.

[0038] In some embodiments of the present invention, the crimp shrinkage rate of the composite fiber is 20%-40% as determined according to GB / T 6506-2017.

[0039] Another technical solution provided by the present invention: a composite fiber, the composite fiber comprising a first component, a second component and a third component, wherein the first component and the second component have different shrinkage rates during curing, and the third component exhibits phase separation when mixed and melted with the first component and the second component respectively;

[0040] The cross section of the composite fiber perpendicular to its length direction includes multiple single-component regions and two-component regions, with each pair of adjacent two-component regions separated by a single-component region. The single-component regions occupy at most 50% of the area of ​​the cross section perpendicular to its length direction, and the multiple single-component regions are either separate from each other or connected to each other at the center of the cross section perpendicular to its length direction.

[0041] The single-component region is composed of the third component, and the two-component region comprises the first component and the second component. The first component and the second component are arranged side by side, and both the first component and the second component are in contact with the third component.

[0042] According to some preferred and specific aspects of the invention, the bicomponent region has a fan-shaped structure.

[0043] According to some preferred and specific aspects of the invention, the cross-section perpendicular to the length direction has a hollow structure, and the two-component region is the structure remaining after removing a portion of the adjacent center of the fan-shaped structure.

[0044] According to some preferred aspects of the invention, in the two-component region, the portion of the first component that contacts the second component is arc-shaped.

[0045] Another technical solution provided by the present invention: an elastic irregular fiber, wherein the elastic irregular fiber is obtained by removing the third component from the composite fiber described above.

[0046] In some embodiments of the present invention, the removal method includes mechanical peeling, alkaline peeling, or dissolution removal.

[0047] In some embodiments of the present invention, the removal method is alkaline solution dissolution treatment or alkaline stripping, for example, an aqueous solution of sodium hydroxide can be used, and the treatment can be carried out at 80-100°C for a period of time, which can be 10-30 minutes.

[0048] Another technical solution provided by the present invention is a textile, which comprises at least a portion of the composite fibers described above, or the elastic irregular fibers described above.

[0049] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0050] The inventors of this invention, recognizing that existing microfibers still suffer from insufficient elasticity, poor gloss, and relatively poor strength (e.g., tear strength), have innovatively provided a composite fiber and its preparation method. Using the composite fiber of this invention, microfibers with significantly reduced radial dimensions can be produced. Furthermore, this microfiber achieves significant improvements in at least one aspect of elasticity, gloss, and strength (e.g., tear strength). More specifically, this invention achieves excellent overall performance enhancement; for example, the prepared microfiber simultaneously possesses excellent elasticity, gloss, and strength. In addition, the composite fiber of this invention can be used directly, allowing the product to possess the properties of both microfiber elastic fibers and a third component. Alternatively, the third component can be dissolved and removed after the composite fiber is made into a fabric, directly obtaining a product made from microfiber elastic fibers. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the spinneret assembly in an embodiment of the present invention;

[0052] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0053] Figure 3 This is a schematic diagram of the distribution plate in an embodiment of the present invention;

[0054] Figure 4 for Figure 3 Enlarged view of point B in the middle;

[0055] Figure 5 for Figure 4 Another schematic diagram of the distribution channel is shown;

[0056] Figure 6 This is a schematic diagram of the internal flow channels of the distribution plate after it has been cut open in an embodiment of the present invention;

[0057] Figure 7 for Figure 6 Enlarged view of point C in the middle;

[0058] Figure 8 This is a schematic diagram of the internal flow channel of the spinneret assembly after it has been cut open in an embodiment of the present invention;

[0059] Figure 9 for Figure 8 Enlarged view of point D in the middle;

[0060] Figure 10 This is a partial schematic diagram of the first and second flow channels;

[0061] Figure 11 This is a schematic diagram of another feeding structure for the three components in an embodiment of the present invention;

[0062] Figure 12 This is one of the cross-sectional schematic diagrams of the composite fiber, the elastic profiled fiber, and the single-component fiber formed from the third component in an embodiment of the present invention; wherein, Figure 12 (a) is a schematic diagram of the cross-section of the composite fiber. Figure 12 (b) is a schematic diagram of the cross-section of the elastic profiled fiber. Figure 12 (c) is a schematic cross-sectional view of the fiber formed by the third component;

[0063] Figure 13 This is a second schematic cross-sectional view of the composite fiber, the elastic profiled fiber, and the single-component fiber formed from the third component in an embodiment of the present invention; wherein, Figure 13 (a) is a schematic diagram of the cross-section of the composite fiber. Figure 13 (b) is a schematic diagram of the cross-section of the elastic profiled fiber. Figure 13 (c) is a schematic cross-sectional view of the fiber formed by the third component;

[0064] Figure 14 This is the third cross-sectional schematic diagram of the composite fiber, the elastic profiled fiber, and the single-component fiber formed from the third component in the embodiments of the present invention; wherein, Figure 14 (a) is a schematic diagram of the cross-section of the composite fiber. Figure 14 (b) is a schematic diagram of the cross-section of the elastic profiled fiber. Figure 14 (c) is a schematic cross-sectional view of the fiber formed by the third component;

[0065] Figure 15 This is the fourth cross-sectional schematic diagram of the composite fiber, elastic profiled fiber, and single-component fiber formed from the third component in the embodiments of the present invention; wherein, Figure 15 (a) is a schematic diagram of the cross-section of the composite fiber. Figure 15 (b) is a schematic diagram of the cross-section of the elastic profiled fiber. Figure 15 (c) is a schematic cross-sectional view of the fiber formed by the third component;

[0066] In the attached figures, the following are the reference numerals: 10, first component; 20, second component; 30, third component; 40, spinneret assembly; 41, distribution plate; 411, first flow channel; 412, second flow channel; 413, third flow channel; 414, fourth flow channel; 4141, first sub-flow channel; 4142, second sub-flow channel; 415, fifth flow channel; 416, first component inlet channel; 417, second component inlet channel; 418, third component inlet channel; 419, solid center; 42, spinneret; 421, spinneret orifice; 50, composite fiber; 51, single-component region; 52, two-component region; 53, hollow structure; 60, elastic profiled fiber; 70, single-component fiber. Detailed Implementation

[0067] Currently, the main method for preparing microfibers is to first prepare island-type fibers, and then dissolve and remove the island component to obtain microfibers generated from the island component. In practice, the inventors of this invention used this approach to try to produce elastic microfibers by replacing the island component with, for example, a two-component PET with a high-low viscosity difference. The elasticity of the microfibers was achieved by using the different curing shrinkage rates of the two components. However, experiments have shown that using conventional spinnerets results in significant fluctuations during the spinning process, such as uneven spinneret pressure and spinning failures, leading to a low spinning success rate, which is not conducive to large-scale industrial production. In addition, even if microfibers are successfully prepared, their strength, such as tear strength and gloss, is poor, or they are prone to uneven yarn count and dyeing abnormalities, which greatly limits their practical application.

[0068] Based on this, the present invention provides an improved spinneret assembly, which can be used to continuously and stably produce composite fibers. The composite fibers have the radial size of normal fibers. By removing the single-component fibers formed by the third component from the composite fibers, ultrafine fibers with excellent effects in terms of elasticity, gloss, and strength such as tear strength can be obtained. The ultrafine fibers are composed of a first component and a second component. The first component and the second component have different shrinkage rates during curing. The third component separates from the first component and the second component when they are in molten contact. The third component can be removed by means of dissolution removal, alkaline peeling (non-dissolution), mechanical peeling, etc. Furthermore, the third component can be, for example, alkali-soluble fibers, water-soluble fibers, etc. The single-component fibers obtained by separation can also have special morphologies, such as "X" shape, "I" shape, etc. The "X" shape fibers have a large specific surface area and strong moisture absorption.

[0069] In this embodiment of the invention, the first component and the second component are independently selected from PET (polyethylene terephthalate), PBT (polybutylene terephthalate), or PTT (polypropylene terephthalate), and the third component may include, but is not limited to, PA6 (nylon 6), COPET (polyethylene terephthalate copolymer), PE (polyethylene), PP (polypropylene), etc. Furthermore, the difference in intrinsic viscosity between the first component and the second component is 0.15-0.7 dL / g, for example, it can be 0.15 dL / g, 0.2 dL / g, 0.25 dL / g, 0.3 dL / g, 0.35 dL / g, 0.4 dL / g, 0.45 dL / g, 0.5 dL / g, 0.55 dL / g, 0.6 dL / g, 0.65 dL / g, 0.7 dL / g, etc.; the mass ratio of the first component to the second component is 10:90 to 90:10, for example, it can be... The ratios of the total mass of the first component to the second component and the mass of the third component are 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, etc.; the ratio of the total mass of the first component to the second component and the mass of the third component is 90:10 to 50:50, for example, 50:50, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, etc.

[0070] The composite fiber of this invention can be prepared using the FDY process. The parameters of the FDY process are as follows: the spinning temperature of the first component box is 240-295℃, the spinning temperature of the second component box is 240-295℃, the spinning temperature of the third component box is 240-285℃, the cooling temperature is 19-23℃, the cooling air pressure is 15-35Pa, the network pressure is 0.25-0.4MPa, the speed of the first roller is 1600-2800m / min, the temperature of the first roller is 60-92℃, the speed of the second roller is 4000-6000m / min, the temperature of the second roller is 95-155℃, and the winding speed is 3900-5800m / min.

[0071] In practice, it has been found that because the three components introduced in this invention have different properties, using the conventional melt distribution method, i.e., the conventional through-hole melt distribution method, easily leads to uneven melt distribution during the spinning process, resulting in significant differences from the expected component content, and even slurry leakage, making normal spinning impossible. Even if composite fibers are accidentally spun, the properties of the resulting ultrafine fibers are still unsatisfactory. Based on this, this invention features a unique design for the spinneret assembly:

[0072] The spinneret assembly includes a distribution plate and a spinneret plate having spinneret orifices. The distribution plate includes a first flow channel for simultaneously introducing a first component and a second component into the spinneret orifices, and a second flow channel for introducing a third component into the spinneret orifices. The axis of the first flow channel is perpendicular to the axis of the second flow channel.

[0073] The area of ​​the cross-section of the first flow channel perpendicular to its length is S1, and the length of the first flow channel is denoted as L1, satisfying the following condition:

[0074] And 5≤a≤20;

[0075] The area of ​​the cross-section of the second flow channel perpendicular to its length is S2, and the length of the second flow channel is denoted as L2, satisfying the following condition:

[0076] And 1≤b≤10;

[0077] The first flow channel and the second flow channel each have multiple channels, and each pair of adjacent first flow channels is separated by a second flow channel. The multiple second flow channels are independent of each other or their respective axis lines intersect at the same point. The orthographic projections of the first flow channel and the second flow channel are both located within the orthographic projection range of the spinneret inlet.

[0078] The following is combined with Figures 1 to 15 The technical solution of the present invention will be further described below. A schematic diagram of the spinneret assembly used in the preparation process of the composite fiber of the present invention is shown below. Figures 1 to 11 Cross-sectional schematic diagrams of the composite fibers, elastic profiled fibers, and single-component fibers formed from the third component are shown in [reference 1]. Figures 12 to 15 .

[0079] The spinneret assembly 40 includes a distribution plate 41 and a spinneret 42 stacked together from top to bottom. The distribution plate 41 is used to introduce various components, and the spinneret 42 has spinneret holes 421 formed on it. The spinneret holes 421 are used to receive the various components introduced by the distribution plate 41 and then spin them out to form composite fibers 50.

[0080] Figures 1 to 2A schematic diagram of the distribution channels for the first, second, and third components initially introduced onto the distribution plate 41 is provided. Only one example is shown to illustrate this, illustrating one form of composite fiber. Specifically, the first component is introduced into the fifth channel 415 via the first component introduction groove 416, and the second component is introduced into the fifth channel 415 via the second component introduction groove 417. The first component introduction groove 416 and the second component introduction groove 417 are respectively connected to the fifth channel 415, and the two form an angle between them. This angle is acute, and the acute angle can be between 10° and 75°. One first component introduction groove 416, one second component introduction groove 417, and one fifth channel 415 constitute a channel for introducing... The combination of the two components has multiple components arranged in a roughly circular pattern. The fifth flow channel 415 is located in the middle of the circle. The first component introduction groove 416 and the second component introduction groove 417 extend from the outside to the inside. At the same time, multiple third component introduction grooves 418 are also provided on the distribution plate 41. The third component introduction grooves 418 are arranged in a ring. One third component introduction groove 418 can be provided on each side of the aforementioned circle. The two third component introduction grooves 418 surround the aforementioned circle in the middle. In this way, the third component can be introduced at both ends. This not only ensures that the third component can be introduced in a sufficient amount, but also helps to disperse the pressure of the third component introduction and avoids excessive pressure caused by the introduction from a single position.

[0081] Further, see Figures 3 to 4 With the bottom of the distribution plate 41 facing upwards, a schematic diagram of the distribution channels at the bottom of the distribution plate 41 can be seen. It has multiple first channels 411 and multiple second channels 412. Each pair of adjacent first channels 411 is separated by a second channel 412, and vice versa. Figure 4Multiple second channels 412 converge at a central point (region), thus forming a monocomponent fiber that is a single unit with a distinct irregular structure. The first and second components introduced simultaneously by the first channel 411 will flow side-by-side to the spinneret. In this way, the bicomponent fiber formed by the first and second components will be confined within the gaps between the monocomponent fibers. The third channel 413 is annularly arranged, meaning that the third component within the third channel 413 can be simultaneously supplied to multiple second channels 412 through this annular arrangement, forming an annular flow channel. The third component in the current third channel 413 flows in sequentially through the first sub-channel 4141 and the second sub-channel 4142 of the fourth channel. Two fourth channels can be symmetrically arranged, allowing the third component to be introduced into the third channel 413 from both ends simultaneously. This facilitates the rapid filling of the third component into each position of the third channel 413, enabling each second channel 412 to receive the third component almost simultaneously and uniformly. This also facilitates the simultaneous introduction of the third component into the spinneret by multiple second channels 412, further ensuring the stable and continuous preparation of the composite fiber.

[0082] Figure 5 The structure shown is basically the same Figure 4 The difference lies only in that each of the second channels 412 is set separately from each other and cannot converge in the middle. Specifically, the middle is made solid, and it is set in the form of a solid middle channel 419. In this way, the preparation of hollow composite fibers can be achieved.

[0083] Figure 6 and Figure 7 The internal flow channels of the distribution plate 41 are revealed by cutting it open. Figure 8 and Figure 9The internal flow channels of the spinneret assembly 40, including the distribution plate 41 and the spinneret plate, are exposed by cutting open a portion of the assembly. Specifically, the first component and the second component, introduced from the first component inlet groove and the second component inlet groove respectively, flow together into the first flow channel 411 through the fifth flow channel 415. The outlet of the first flow channel 411 is directly opposite the inlet of the spinneret orifice 421. The third component, introduced from the third component inlet groove, flows sequentially through the first sub-flow channel 4141 and the second sub-flow channel 4142 of the fourth flow channel and enters the third flow channel 413. The centerlines of the first sub-flow channel 4141, the fifth flow channel 415, and the first flow channel 411 are all parallel. The second sub-flow channel 4142 is connected to the third flow channel 413, and its outlet is offset from the inlet of the second flow channel 412. The third flow channel 413 simultaneously and evenly distributes the third component to multiple second flow channels 412, allowing the third component to quickly fill the second flow channels 411. 2. The first flow channel 411 and the second flow channel 412 enter the spinneret 421 through the lower opening of the second flow channel 412. The orthographic projections of the first flow channel 411 and the second flow channel 412 are both located within the orthographic projection range of the inlet of the spinneret 421. The axis of the first flow channel 411 is perpendicular to the axis of the second flow channel 412. Here, the present invention designs the structure of the first flow channel 411 and the second flow channel 412. The purpose of the design is to ensure that the first component, the second component and the third component are in a suitable pressure state and flow state when they are distributed and introduced. Further, the area of ​​the cross-section of the first flow channel 411 perpendicular to the length direction is S1, and the cross-section of the first flow channel 411 perpendicular to the length direction can be circular. The area of ​​the cross-section of the second flow channel 412 perpendicular to the length direction is S2, and the cross-section of the second flow channel 412 perpendicular to the length direction is square. At the same time, they each satisfy the following conditions (see further details). Figure 10 Let L1 be the length of the first flow channel 411, and let it satisfy the following condition: S1 = π × (L1 / 2a) 2 And 5≤a≤20; The length of the second flow channel 412 is denoted as L2, and satisfies the following condition: S2=π×( L2 / 2b) 2 And 1≤b≤10; more preferably, L1, L2, S1, and S2 can satisfy the following conditions:

[0084] And 1.5≤c≤5;

[0085] The first flow channel 411 and the second flow channel 412 are the final distribution parts of the distribution plate 41. The three components will then enter the spinneret and be ejected through the spinneret. Experiments of this invention have shown that by limiting the structure of the first flow channel 411 and the second flow channel 412 as described above, it is possible to better ensure that the three components have appropriate pressure and flow states when they are distributed into the flow channel. This allows for the stable and continuous preparation of composite fibers, reducing or even avoiding uneven distribution caused by the interaction between the components and the possible leakage of slurry.

[0086] Furthermore, the outlets of multiple first flow channels 411 are distributed on the circumference of the first circle, and the inlets of multiple second flow channels 412 are distributed on the circumference of the second circle; the center of the first circle coincides with the center of the second circle, or the straight line containing the two centers is parallel to the axis of the first flow channel 411. Further, the diameter of the first circle is 1 / 3 to 3 / 4 of the diameter of the second circle; in this embodiment, approximately 1 / 2 can be used. A fan-shaped region is formed between pairs of adjacent second flow channels 412, with the first flow channel 411 located at the centroid of the fan-shaped region. The cross-section of the spinneret 421 perpendicular to its length direction is circular.

[0087] See Figure 11 As shown, this is a schematic diagram of another feeding structure for the three components of the present invention, which is different from... Figure 2 In contrast, this will result in a composite fiber with a different structure; the main difference lies in the arrangement of the first and second components, while the subsequent spinneret structure remains the same. Figure 2 The feeding structure shown will obtain Figure 13 or Figure 15 The structure shown is arranged in a left-right pattern. Figure 11 The feeding structure shown will obtain Figure 12 or Figure 14 The structure shown is arranged vertically (inner and outer); further, Figure 11 In the middle, the position of the fourth flow channel 414' is the same as Figure 2 The first component inlet channel 416' and the second component inlet channel 417' are arranged opposite to each other, while the fifth flow channel 415' is located in the middle of the first component inlet channel 416' and the second component inlet channel 417'. In particular, only one second component inlet channel 417' is provided, which corresponds to multiple first component inlet channels 416'. This feeding method is conducive to forming Figure 12 or Figure 14 The first and second components are arranged vertically as shown.

[0088] Cross-sectional schematic diagrams of the composite fiber, elastic profiled fiber, and single-component fiber formed from the third component of the present invention are shown below. Figures 12 to 15 As shown;

[0089] in, Figure 12and Figure 13 In the composite fiber 50, the overall cross-section is basically circular. The single-component region 51 is composed of the third component 30, and the two-component region 52 is composed of the first component 10 and the second component 20. The third component 30 forms the single-component fiber 70, specifically a "cross" shaped fiber with a very large specific surface area. The elastic irregular fiber 60 composed of the first component 10 and the second component 20... Figure 12 and Figure 13 The differences lie in the distribution patterns of the first component 10 and the second component 20. These distribution patterns can be achieved by adjusting the feeding direction of the first component 10 and the second component 20 on the distribution plate. Figure 12 It can be adopted Figure 11 The three-component feeding directions are shown. Figure 13 It can be adopted Figure 2 (The three-component feeding direction is shown), and the elastic shaped fiber 60 composed of the first component 10 and the second component 20 has been tested and its strength, such as tear strength and gloss, has shown excellent performance.

[0090] Figure 14 and Figure 15 In the composite fiber 50, the entire composite fiber is hollow, and its cross-section has a hollow structure 53, which can be used to... Figure 5 The distribution plate structure shown achieves this, and the construction of the elastic irregular fiber 60 thus made is similar to... Figure 12 , Figure 13 While there are slight differences, tests have shown that both have essentially the same performance. One has a hollow structure, while the other is solid, resulting in differences in the stress resistance during disassembly and peeling. Furthermore, the single-component fibers obtained after mechanical disassembly of the hollow composite fiber appear in multiple "I" shapes, possessing a unique touch and luster, primarily used in sun-protective clothing. In addition, hollow composite fibers can be used in high-end skin-protective clothing, down jackets, and other similar garments.

[0091] The composite fiber prepared by this invention has a linear density of 20-200 dtex; a breaking elongation of 10%-30%; a breaking strength of 2.6-3.5 cN / dtex; a dyeing uniformity of grade 4.5 or higher; a boiling water shrinkage rate of 6%-12%; and a crimp shrinkage rate of 20%-40%.

[0092] The above-mentioned solution will be further described below with reference to specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions used in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0093] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared by conventional methods in the art.

[0094] Example 1:

[0095] This example provides a composite fiber, an elastic profiled fiber, and a method for preparing them, using a spinneret with the structure shown in the above figures, and following the FDY process, particularly using... Figure 11 The three-component feeding method shown is as follows: Low-viscosity PET (intrinsic viscosity 0.58 dL / g) is used as the first component, high-viscosity PTT (intrinsic viscosity 1.2 dL / g) as the second component, and PA6 (purchased from Wuxi Chang'an Polymer, grade 1600-1, relative viscosity 2.7) as the third component; the mass ratio of the first component to the second component is 50:50; the total mass ratio of the first and second components to the third component is 80:20; in the first flow channel, a=5; in the second flow channel, b=1; After each component is melted and metered, it is fed into the above-mentioned spinneret assembly and then spun out. The parameters of the FDY process are as follows: the spinning temperature of the first component box is 268℃, the spinning temperature of the second component box is 258℃, the spinning temperature of the third component box is 265℃, the cooling temperature is 23℃, the cooling air pressure is 20Pa, the network pressure is 0.3MPa, the speed of the first roller is 1750m / min, the temperature of the first roller is 80℃, the speed of the second roller is 3920m / min, the temperature of the second roller is 120℃, and the winding speed is 3800m / min, resulting in composite fibers.

[0096] The composite fiber formed Figure 12 The structure shown has a linear density of 33 dtex, an elongation at break of 25%, and a breaking strength of 3.05 cN / dtex.

[0097] The composite fiber was peeled in an aqueous sodium hydroxide solution (solution concentration approximately 2%, temperature approximately 100℃, residence time approximately 20 min) to obtain elastic profiled fibers and "X" shaped fibers. The performance test results of the elastic profiled fibers are shown in Table 1.

[0098] Example 2:

[0099] This example provides a composite fiber, an elastic profiled fiber, and a method for preparing them, using a spinneret with the structure shown in the above figures, and following the FDY process, particularly using... Figure 2The three-component feeding method shown is as follows: low-viscosity PET (intrinsic viscosity 0.58 dL / g) is used as the first component, high-viscosity PBT (intrinsic viscosity 1.28 dL / g) as the second component, and PA6 (purchased from Wuxi Chang'an Polymer, grade 1600-1, relative viscosity 2.7) as the third component; the mass ratio of the first component to the second component is 50:50; the total mass ratio of the first component to the second component and the mass ratio of the third component are 80:20; in the first flow channel, a=12; in the second flow channel, b=7. After the components are melted and metered, they are fed into the above-mentioned spinneret assembly and then extruded. The parameters of the FDY process are as follows: the spinning temperature of the first component box is 266℃, the spinning temperature of the second component box is 260℃, the spinning temperature of the third component box is 264℃, the cooling temperature is 23℃, the cooling air pressure is 25Pa, the network pressure is 0.35MPa, the speed of the first roller is 1820m / min, the temperature of the first roller is 82℃, the speed of the second roller is 4080m / min, the temperature of the second roller is 125℃, and the winding speed is 4000m / min, resulting in composite fibers.

[0100] The composite fiber formed Figure 13 The structure shown has a linear density of 55 dtex, an elongation at break of 25%, and a breaking strength of 3.15 cN / dtex.

[0101] The composite fiber was peeled in an aqueous sodium hydroxide solution (solution concentration approximately 2%, temperature 100℃, residence time approximately 20 min) to obtain elastic profiled fibers and "X" shaped fibers. The performance test results of the elastic profiled fibers are shown in Table 1.

[0102] Example 3:

[0103] This example provides a composite fiber, an elastic profiled fiber, and a method for preparing them, using a spinneret with the structure shown in the above figures, and following the FDY process, particularly using... Figure 11The three-component feeding method shown is as follows: Low-viscosity PET (intrinsic viscosity 0.58 dL / g) is used as the first component, high-viscosity PBT (intrinsic viscosity 1.28 dL / g) as the second component, and COPET (intrinsic viscosity 0.64 dL / g) as the third component; the mass ratio of the first component to the second component is 50:50; the total mass ratio of the first and second components to the third component is 75:25; in the first flow channel, a=15; in the second flow channel, b=8; the components are melted... After being fused and metered, the solution is fed into the aforementioned spinneret assembly and then ejected. The parameters of the FDY process are as follows: the spinning temperature of the first component box is 268℃, the spinning temperature of the second component box is 262℃, the spinning temperature of the third component box is 272℃, the cooling temperature is 23℃, the cooling air pressure is 28Pa, the network pressure is 0.3MPa, the speed of the first roller is 1750m / min, the temperature of the first roller is 85℃, the speed of the second roller is 4065m / min, the temperature of the second roller is 125℃, and the winding speed is 4000m / min, resulting in composite fibers.

[0104] The composite fiber forms Figure 14 The structure shown has a linear density of 83 dtex, an elongation at break of 21%, and a breaking strength of 2.7 cN / dtex.

[0105] The composite fiber was subjected to alkaline hydrolysis (using an aqueous sodium hydroxide solution with a concentration of approximately 2.5%, at a temperature of 100°C, for approximately 25 minutes), which dissolved the COPET, yielding elastic profiled fibers. The performance test results of the elastic profiled fibers are shown in Table 1.

[0106] Example 4:

[0107] This example provides a composite fiber, an elastic profiled fiber, and a method for preparing them, using a spinneret with the structure shown in the above figures, and following the FDY process, particularly using... Figure 2The three-component feeding method shown is as follows: Low-viscosity PET (intrinsic viscosity 0.58 dL / g) is used as the first component, high-viscosity PBT (intrinsic viscosity 1.28 dL / g) as the second component, and PA6 (purchased from Wuxi Chang'an Polymer, grade 1600-1, relative viscosity 2.7) as the third component; the mass ratio of the first component to the second component is 60:40; the total mass ratio of the first and second components to the third component is 80:20; in the first flow channel, a=20; in the second flow channel, b=10; after melting and metering each component, it is fed into the above-mentioned spinneret assembly and then extruded. The parameters of the FDY process are: the spinning temperature of the first component in the spinning chamber is 266℃, and the spinning temperature of the second component in the spinning chamber is 262℃. The third component's spinning temperature was 258℃, cooling temperature was 20℃, cooling air pressure was 35Pa, network pressure was 0.3MPa, first roller speed was 1950m / min, first roller temperature was 88℃, second roller speed was 4260m / min, second roller temperature was 135℃, and winding speed was 4200m / min, resulting in composite fibers.

[0108] The composite fiber forms Figure 15 The structure shown has a linear density of 110 dtex, an elongation at break of 22%, and a breaking strength of 3.2 cN / dtex.

[0109] The composite fiber was peeled in a sodium hydroxide solution (solution concentration 1.5-2.5%, temperature 100℃, residence time 15-25 min) to obtain elastic profiled fibers and "I" shaped fibers. The performance tests of the elastic profiled fibers are shown in Table 1.

[0110] Comparative Example 1:

[0111] The design is basically the same as in Example 1, except that in the first flow channel, a=30; and in the second flow channel, b=15. After practical testing, it was found that the spinneret assembly stuck to the plate at the outlet, preventing normal spinning.

[0112] Comparative Example 2:

[0113] The design is basically the same as in Example 1, except that a=1 in the first flow channel and b=0.5 in the second flow channel. After trying this design, it was found that it could not produce fibers normally, and the fibers were discontinuous and intermittent.

[0114] Performance testing:

[0115] The composite fibers obtained in Examples 1-4 above were subjected to the following performance tests, in which: (1) the linear density was measured in accordance with GB / T 14343-2008; (2) the elongation at break was measured in accordance with GB / T 14344-2008; (3) the tensile strength was measured in accordance with GB / T 14344-2008; (4) the grey level was measured in accordance with GB / T 6508-2015; (5) the boiling water shrinkage was measured in accordance with GB / T 6505-2017; and (6) the crimp shrinkage was measured in accordance with GB / T 6506-2017.

[0116] Table 1

[0117]

[0118] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

[0119] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. A method for preparing composite fibers, characterized in that, The preparation method includes: Using a first component, a second component, and a third component as raw materials, the first component and the second component have different shrinkage rates during solidification, and the third component exhibits phase separation when it melts and comes into contact with the first component and the second component, respectively. The composite fibers are spun and extruded using a spinneret assembly; The spinneret assembly includes a distribution plate and a spinneret plate with spinneret holes. The distribution plate includes a first flow channel for simultaneously introducing the first component and the second component into the spinneret holes, and a second flow channel for introducing the third component into the spinneret holes. The axis of the first flow channel is perpendicular to the axis of the second flow channel. The area of ​​the cross-section of the first flow channel perpendicular to its length is S1, and the length of the first flow channel is denoted as L1, satisfying the following condition: And 5≤a≤20; The area of ​​the cross-section of the second flow channel perpendicular to its length is S2, and the length of the second flow channel is denoted as L2, satisfying the following condition: And 1≤b≤10; The first flow channel and the second flow channel each have multiple channels, and each pair of adjacent first flow channels is separated by a second flow channel. The multiple second flow channels are independent of each other or their respective axis lines intersect at the same point. The orthographic projections of the first flow channel and the second flow channel are both located within the orthographic projection range of the inlet of the spinneret.

2. The method for preparing composite fibers according to claim 1, characterized in that, The outlets of the multiple first flow channels are respectively distributed on the circumference of the first circle, and the inlets of the multiple second flow channels are respectively distributed on the circumference of the second circle; The center of the first circle coincides with the center of the second circle, or the straight line containing the centers of the two circles is parallel to the axis of the first flow channel.

3. The method for preparing composite fibers according to claim 2, characterized in that, The diameter of the first circle is 1 / 3 to 3 / 4 of the diameter of the second circle.

4. The method of producing a composite fiber according to claim 1 or 2, characterized by, The first flow channel has a circular cross-section perpendicular to its length; and / or, the second flow channel has a square cross-section perpendicular to its length; and / or, a fan-shaped region is formed between two adjacent second flow channels, and the first flow channel is located at the centroid of the fan-shaped region; and / or, the spinneret orifice has a circular cross-section perpendicular to its length.

5. The method of producing a composite fiber according to claim 1, characterized by, The distribution plate further includes a third flow channel, which surrounds the periphery of the plurality of second flow channels and is respectively connected to the plurality of second flow channels.

6. The method of producing a composite fiber according to claim 5, characterized by, The distribution plate further includes at least one fourth flow channel and multiple fifth flow channels. The at least one fourth flow channel is connected to the third flow channel, and the fifth flow channels are connected to the first flow channels in a one-to-one correspondence.

7. The method of producing a composite fiber according to claim 6, characterized by, The fourth flow channel includes a first sub-flow channel and a second sub-flow channel that are interconnected. The centerlines of the first sub-flow channel, the fifth flow channel, and the first flow channel are all parallel. The second sub-flow channel is connected to the third flow channel, and its outlet is offset from the inlet of the second flow channel.

8. The method of producing a composite fiber according to claim 1, characterized by, L1, L2, S1, S2 satisfy the following conditions: and 1.5 ≤ c ≤ 5; And / or, the difference in intrinsic viscosity between the first component and the second component is 0.15-0.7 dL / g; and / or, the mass ratio of the first component to the second component is 10:90 to 90:10; and / or, the total mass ratio of the first component to the second component and the mass ratio of the third component is 90:10 to 50:

50.

9. The method of producing a composite fiber according to claim 1, characterized by, The first component and the second component are independently selected from PET, PBT or PTT, and the third component is PA6, COPET, PE or PP.

10. The method of producing a composite fiber according to claim 1, characterized by, The preparation method adopts the FDY process, and the parameters of the FDY process are as follows: the spinning temperature of the first component box is 240-295℃, the spinning temperature of the second component box is 240-295℃, the spinning temperature of the third component box is 240-285℃, the cooling temperature is 19-23℃, the cooling air pressure is 15-35Pa, the network pressure is 0.25-0.4MPa, the speed of the first roller is 1600-2800m / min, the temperature of the first roller is 60-92℃, the speed of the second roller is 4000-6000m / min, the temperature of the second roller is 95-155℃, and the winding speed is 3900-5800m / min.

11. A composite fiber prepared by the method of preparing the composite fiber according to any one of claims 1-10.

12. The conjugated fiber according to claim 11, characterized by The tensile strength of the composite fiber is greater than or equal to 2.4 cN / dtex.

13. The conjugated fiber according to claim 11, wherein The composite fiber has a breaking elongation of 10%-30% and a linear density of 20-200 dtex; and / or, the composite fiber has a dyeing uniformity of grade 4.5 or higher; and / or, the composite fiber has a boiling water shrinkage of 6%-12%; and / or, the composite fiber has a crimping shrinkage of 20%-40%.

14. A composite fiber, characterized by, The composite fiber is made by the method of preparing composite fiber according to any one of claims 1-10; the composite fiber comprises a first component, a second component and a third component, wherein the first component and the second component have different shrinkage rates during curing, and the third component exhibits phase separation when mixed and melted with the first component and the second component respectively; The cross section of the composite fiber perpendicular to its length direction includes multiple single-component regions and two-component regions, with each pair of adjacent two-component regions separated by a single-component region. The single-component regions occupy at most 50% of the area of ​​the cross section perpendicular to its length direction, and the multiple single-component regions are either separate from each other or connected to each other at the center of the cross section perpendicular to its length direction. The single-component region is composed of the third component, and the two-component region comprises the first component and the second component. The first component and the second component are arranged side by side, and both the first component and the second component are in contact with the third component.

15. The conjugated fiber according to claim 14, wherein The two-component region has a fan-shaped structure.

16. The conjugated fiber according to claim 14, wherein The cross-section perpendicular to the length direction has a hollow structure, and the two-component region is the structure remaining after removing a portion of the adjacent center of the fan-shaped structure.

17. The conjugated fiber according to claim 14, wherein In the two-component region, the portion where the first component and the second component come into contact is arc-shaped.

18. An elastic profiled fiber, characterized by, The elastic shaped fiber is obtained by removing the third component from the composite fiber described in any one of claims 11-17.

19. The elastic profiled fiber according to claim 18, characterized in that, The removal methods include mechanical peeling, alkaline peeling, or dissolution removal.

20. A textile, characterized in that, It consists of at least a portion of the composite fiber as described in any one of claims 11-17, or the elastic shaped fiber as described in any one of claims 18-19.

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