Preparation method of light polyester and nylon super fine fiber

Abstract

The present application relates to the technical field of preparation of bright polyester-polyamide super fine fiber, and particularly relates to a preparation method of bright polyester-polyamide super fine fiber, which comprises the following steps: step S1, raw material preparation, step S2, polyester melt extrusion, step S3, polyamide melt extrusion, step S4, composite spinning, step S5, primary stretching, step S6, secondary stretching, step S7, heat setting, and step S8, winding. The present application improves the existing preparation method of bright polyester-polyamide super fine fiber, and utilizes a special distribution plate structure to filter the polyester melt and the polyamide melt in the distribution process, so as to remove the impurities in the polyester melt and the polyamide melt. The prepared bright polyester-polyamide super fine fiber has improved gloss and brightness, and the quality of the bright polyester-polyamide super fine fiber is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of preparation of lustrous polyester-nylon super fine fiber, and particularly relates to a preparation method of lustrous polyester-nylon super fine fiber. BACKGROUND

[0002] Lustrous polyester-nylon composite yarn is a kind of composite fiber. It is made of polyester and nylon through special composite process. The lustrous polyester has good wrinkle resistance, shape retention and wear resistance, and is not easy to generate fuzz and pilling; the lustrous nylon has excellent strength, elasticity and wear resistance, and better moisture absorption and dyeing than polyester, and the combination of the two can exert their respective advantages, and the "luster" means that the fiber has high gloss, which is usually because the surface of the fiber is relatively smooth and has strong light reflection ability.

[0003] The production of polyester-nylon composite yarn generally adopts composite spinning technology. In this process, the spinning raw materials of polyester and nylon are respectively treated by melting or dissolving, and then the two melts or solutions are combined together at the spinning hole through a special spinning pack to form a composite fiber. In this process, the design of the spinning pack and the control of the process parameters are very critical, which will affect the structure and performance of the composite yarn. For example, different composite proportions and composite methods will make the composite yarn have different characteristics.

[0004] For example, a lustrous polyester-nylon composite fiber is disclosed in Chinese patent application No. CN201410059805.3, which is made of lustrous polyester chip and lustrous nylon chip through composite spinning, and the composite proportion is 15% to 85%. The present application also designs a production method of lustrous polyester-nylon composite fiber, which adopts one-step spinning method, and is characterized in that the composite fiber is made of lustrous polyester chip and lustrous nylon chip through composite spinning, and the composite proportion is 15% to 85%. The lustrous polyester-nylon composite fiber made by this method has the characteristics of good luster and hand feeling. In addition, this method belongs to one-step spinning, and the process is simple and low in consumption, which can effectively reduce the production cost. The use of lustrous polyester chip and lustrous nylon chip for composite spinning can improve the spinnability and reduce the generation of fuzz. In the production process, by adjusting the proportion of polyester and nylon, the hand feeling of the fiber can be changed to the best.

[0005] However, in the above-mentioned preparation method of lustrous polyester-nylon composite fiber, the impurities in the polyester melt and the nylon melt cannot be filtered, so that the luster and brightness of the formed lustrous polyester-nylon composite fiber cannot be further improved. SUMMARY

[0006] In order to solve the above problems, the present application provides a preparation method of lustrous polyester-polyamide superfine fiber, which improves the existing preparation method of lustrous polyester-polyamide superfine fiber, filters the polyester melt and the polyamide melt in the distribution process by using a special distribution plate structure, removes the impurities in the polyester melt and the polyamide melt, effectively improves the gloss and brightness of the prepared lustrous polyester-polyamide superfine fiber, and further improves the quality of the lustrous polyester-polyamide superfine fiber.

[0007] To achieve the above object, the present application provides the following technical scheme:

[0008] A preparation method of lustrous polyester-polyamide superfine fiber, comprising the following steps:

[0009] Step S1, raw material preparation, the selected lustrous polyester chip and lustrous polyamide chip are heated and dried to a water content of <0.05% to ensure good melting performance;

[0010] Step S2, polyester melt extrusion, the dried lustrous polyester chip is added to a first screw extruder for heating and melting, the heating temperature of the first screw extruder is 280-290℃ in the first zone, 290-300℃ in the second zone, and 300-310℃ in the third zone, and the screw rotation speed is 30-40r / min, to obtain fully melted and uniform polyester melt;

[0011] Step S3, polyamide melt extrusion, the dried lustrous polyamide chip is added to a second screw extruder for heating and melting, the heating temperature of the second screw extruder is 240-250℃ in the first zone, 250-260℃ in the second zone, and 260-270℃ in the third zone, and the screw rotation speed is 25-35r / min, to obtain good flowability of the polyamide melt;

[0012] Step S4, composite spinning, the polyester melt in step S2 and the polyamide melt in step S3 are respectively input into a composite spinning pack, the polyester melt and the polyamide melt are uniformly compounded at the spinning hole, and the lustrous polyester-polyamide superfine fiber with the core layer of polyamide melt and the skin layer of polyester melt is extruded, the diameter of the spinning hole is 0.3-0.4mm, the ratio of the skin layer to the core layer is 70:30, which can be adjusted according to product requirements, and the pressure of the polyester melt and the polyamide melt in the spinning pack is controlled at 8-10MPa, the melt is uniformly compounded at the spinning hole by the precisely designed distribution plate, and the extrusion speed is 800-1000m / min;

[0013] Step S5, primary stretching, after the lustrous polyester-polyamide superfine fiber is solidified, primary stretching is performed, the stretching temperature is 70-80℃, the stretching multiple is 2.0-2.5 times, and the stretching speed is 1000-1200m / min, to preliminarily orient the macromolecules of the lustrous polyester-polyamide superfine fiber;

[0014] Step S6, secondary stretching, the lustrous polyester-nylon super fine fiber after step S5 is treated to be secondarily stretched, the stretching temperature is 120-130℃, the stretching multiple is 1.3-1.5 times, the stretching speed is 1200-1400m / min, the orientation degree and the strength of the fiber are further improved;

[0015] Step S7, heat setting, the lustrous polyester-nylon super fine fiber after step S6 is treated to be heat set, the heat setting temperature is 180-200℃, the time is 30-40s, the tension control is 0.08-0.12cN / dtex, the fiber structure is stable, the internal stress is eliminated, and the size stability and the gloss of the fiber are improved;

[0016] Step S8, winding, the lustrous polyester-nylon super fine fiber after step S7 is completed to be heat set is wound on the bobbin, and the winding speed is 3000-3500m / min.

[0017] As an improvement, in the step S1, the lustrous polyester chip is polyester chip, the intrinsic viscosity of the lustrous polyester chip is 0.64-0.68dL / g, the carboxyl end group content is ≤30mol / t, and the titanium dioxide content is 0.3%-0.5%, and the titanium dioxide is used to increase the whiteness and the gloss of the fiber.

[0018] As an improvement, in the step S1, the lustrous nylon chip is polyamide 6 chip, and the relative viscosity of the lustrous nylon chip is 2.4-2.8.

[0019] As an improvement, in the step S4, the polyester melt and the nylon melt pass through the first distribution plate, the second distribution plate, the third distribution plate and the fourth distribution plate from top to bottom in sequence for shunting treatment.

[0020] And when the polyester melt and the nylon melt are shunted in the second distribution plate, they are shunted and filtered by the first shunt filter screen and the second shunt filter screen arranged inside and rotating.

[0021] As an improvement, the second distribution plate comprises an upper plate, a middle plate and a lower plate from top to bottom in sequence.

[0022] The first shunt filter screen and the second shunt filter screen are coaxially rotating on the lower plate, and the polyester melt and the nylon melt flowing out from the first flow channel and the second flow channel on the middle plate impact the corresponding first shunt filter screen and second shunt filter screen, so that the first shunt filter screen and the second shunt filter screen are arranged to rotate.

[0023] As an improvement, the first shunt filter screen and the second shunt filter screen each comprise a plurality of partition plates arranged at equal distances in a circle, the partition plates are connected by filter screens, and arc-shaped filter grooves are arranged on the filter screens.

[0024] As an improvement, the first flow channel and the second flow channel are respectively inclined along the tangential direction of the rotation direction of the corresponding first shunt filter screen and second shunt filter screen, a plurality of groups of the first flow channel and the second flow channel are provided, and the first flow channel and the second flow channel are respectively circumferentially equidistantly arranged around the central axis of the middle plate.

[0025] As an improvement, the third flow channel and the fourth flow channel are respectively arranged at the interval between adjacent first flow channels, and the third flow channel and the fourth flow channel are staggered and arranged.

[0026] The third flow channel is inclined outward along the radial direction of the middle plate, the fourth flow channel is inclined inward along the radial direction of the middle plate, and the third flow channel and the fourth flow channel are inclined to output the polyester melt, so that the polyester melt at the first shunt filter screen flows in a wave shape.

[0027] As an improvement, the fifth flow channel and the sixth flow channel are respectively arranged at the interval between adjacent second flow channels, and the fifth flow channel and the sixth flow channel are staggered and arranged.

[0028] The fifth flow channel is inclined outward along the radial direction of the middle plate, the sixth flow channel is inclined inward along the radial direction of the middle plate, and the fifth flow channel and the sixth flow channel are inclined to output the polyamide melt, so that the polyamide melt at the second shunt filter screen flows in a wave shape.

[0029] As an improvement, the upper plate, the middle plate and the lower plate are integrally connected by diffusion welding, and the end faces of the middle plate connected with the upper plate and the lower plate are concave-convex staggered.

[0030] The beneficial effects of the present application are:

[0031] (1) The present application improves the preparation method of the existing bright polyester-polyamide superfine fiber, uses a special distribution plate structure to filter the polyester melt and polyamide melt during the shunt process, removes impurities in the polyester melt and polyamide melt, effectively improves the gloss and brightness of the prepared bright polyester-polyamide superfine fiber, further improves the quality of the bright polyester-polyamide superfine fiber, and the prepared bright polyester-polyamide superfine fiber has a gloss value > 120GU, a dynamic friction coefficient of 0.1-0.3, and a static friction coefficient of 0.25-0.45.

[0032] (2) The second distribution plate of the composite spinning pack is first provided in a split manner, and then the upper plate, the middle plate and the lower plate are integrally connected by diffusion welding to form the second distribution plate, and before the upper plate, the middle plate and the lower plate are connected, the first shunt filter screen and the second shunt filter screen are arranged between the lower plate and the middle plate, the first shunt filter screen and the second shunt filter screen are used for filtering the polyester melt and the nylon melt respectively, and the purpose of filtering and shunting the polyester melt and the nylon melt by the distribution plate is realized;

[0033] (3) When the first shunt filter screen and the second shunt filter screen are arranged, the inclined first flow channel and the second flow channel arranged on the middle plate are used, the polyester melt and the nylon melt flowing obliquely downward impact the partition plate on the first shunt filter screen and the second shunt filter screen, so that the first shunt filter screen and the second shunt filter screen obtain the power of rotation, and then the first shunt filter screen and the second shunt filter screen can continuously filter and shunt the polyester melt and the nylon melt respectively, and the quality of the prepared bright polyester-nylon superfine fiber is ensured;

[0034] (4) The inclined directions of the third flow channel, the fourth flow channel, the fifth flow channel and the sixth flow channel are adjusted, so that the polyester melt and the nylon melt flow in a wave shape on the second distribution plate, and then the shunting is more detailed, and the second distribution plate is selected as the carrier of the first shunt filter screen and the second shunt filter screen, so that the polyester melt and the nylon melt are filtered at the same time, and the pressure at the spinning hole is not affected, and the fluctuation stability of the spinning hole is ensured.

[0035] In summary, the bright polyester-nylon superfine fiber prepared by the method has the advantages of good brightness, high gloss, smooth surface, high strength, good wear resistance and the like, and is especially suitable for the technical field of preparing bright polyester-nylon superfine fiber. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a preparation method flowchart of the invention;

[0037] Figure 2 It is a three-dimensional structure schematic diagram of the composite spinning pack of the invention;

[0038] Figure 3 It is a three-dimensional structure schematic diagram of the composite spinning pack of the invention; Figure 1

[0039] Figure 4 It is a three-dimensional structure schematic diagram of the composite spinning pack of the invention; Figure 2

[0040] Figure 5 It is a first distribution plate cross-sectional view schematic diagram of the invention;

[0041] Figure 6 ​​A schematic view of the three-dimensional structure of the first distribution plate of the present application;

[0042] Figure 7 A schematic view of the sectional structure of the first distribution plate of the present application;

[0043] Figure 8 A schematic view of the top structure of the middle plate of the present application;

[0044] Figure 9 A schematic view of the sectional structure of the middle plate of the present application; Figure 8 A schematic view of the enlarged structure at a of the middle plate of the present application;

[0045] Figure 10 A schematic view of the sectional structure of the lower plate of the present application; Figure 8 A schematic view of the enlarged structure at b of the lower plate of the present application;

[0046] Figure 11 A schematic view of the sectional structure of the lower plate of the present application;

[0047] Figure 12 A schematic view of the three-dimensional structure of the lower plate of the present application;

[0048] Figure 13 A schematic view of the three-dimensional structure of the first and second distribution plates of the present application;

[0049] Figure 14 A schematic view of the top structure of the third distribution plate of the present application;

[0050] Figure 15 A schematic view of the three-dimensional structure of the fourth distribution plate of the present application;

[0051] Figure 16 A schematic view of the bottom structure of the spinneret of the present application;

[0052] Figure 17 A schematic view of the enlarged structure at c of the spinneret of the present application; Figure 16 A schematic view of the top structure of the spinneret of the present application;

[0053] Figure 18 A schematic view of the top structure of the spinneret of the present application.

[0054] In the figure: composite spinning assembly I, spinneret hole 10, first distribution plate 1, flow-through hole A11, flow-through hole B12, second distribution plate 2, first shunt filter screen 21, partition 211, filter screen 212, filter groove 213, second shunt filter screen 22, upper plate 23, distribution groove A231, distribution groove B232, flow-through hole A233, flow-through hole B234, middle plate 24, first flow channel 241, second flow channel 242, third flow channel 243, fourth flow channel 244, fifth flow channel 245, sixth flow channel 246, lower plate 25, first annular filter groove 251, second annular filter groove 252, through hole A253, through hole B254, third distribution plate 3, shunt groove E31, shunt groove F32, communication hole A33, communication hole B34, fourth distribution plate 4, shunt groove G41, shunt groove H42, shunt hole A43, shunt hole B44, feed connector 6, first feed channel 61, second feed channel 62, spinneret plate 7, confluence groove 71, lower box 8. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0056] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0057] Example 1:

[0058] As Figure 1 shown, a method for preparing a light polyester nylon superfine fiber includes the following steps:

[0059] Step S1, raw material preparation, the selected bright polyester chip and bright nylon chip are heated and dried to a water content <0.05%, reducing the water content of the chip helps to improve the strength, toughness and gloss of the prepared bright polyester-nylon ultra-fine fiber, and also helps to improve the chemical stability;

[0060] Step S2, polyester melt extrusion, the dried bright polyester chip is added to the first screw extruder for heating and melting, the first screw extruder has a one-zone heating temperature of 280-290℃, a two-zone heating temperature of 290-300℃, and a three-zone heating temperature of 300-310℃, and the screw rotation speed is 30-40r / min, to obtain a fully melted and uniform polyester melt;

[0061] Step S3, nylon melt extrusion, the dried bright nylon chip is added to the second screw extruder for heating and melting, the second screw extruder has a one-zone heating temperature of 240-250℃, a two-zone heating temperature of 250-260℃, and a three-zone heating temperature of 260-270℃, and the screw rotation speed is 25-35r / min, to obtain a good flowability of the nylon melt;

[0062] The first screw extruder and the second screw extruder are partitioned and heated, in the one-zone, the material just enters the extruder, the temperature is low, and rapid heating is needed to realize the transformation from glass state to viscous flow state. Partitioned heating can provide strong external heat in this area, so that the material can quickly reach the initial plasticizing temperature, avoiding the material "bridging" at the feeding port or "sticking to the wall" in the machine;

[0063] In the two-zone, the material is subjected to strong shearing and compression by the screw, and generates certain shearing heat, so appropriate increase of the partitioned heating temperature helps to reduce the material viscosity, speed up its flowability, make the material better compressed and transported, and also reduce the damage of shearing heat to the equipment;

[0064] For the three-zone, the material is basically in a molten state, due to the change of screw groove volume, the melt pressure will suddenly decrease, maintaining the same temperature as the compression section can prevent the melt from cooling down, so that the material can be fully melted and homogenized at a relatively stable temperature;

[0065] Step S4, composite spinning, the polyester melt in step S2 and the nylon melt in step S3 are respectively input into the composite spinning assembly I, the polyester melt and the nylon melt are uniformly compounded at the spinning hole 10, and the bright polyester-nylon ultra-fine fiber with a core layer of nylon melt and a skin layer of polyester melt is formed by extrusion;

[0066] Step S5, primary stretching, after the bright polyester-nylon ultra-fine fiber is solidified, primary stretching is carried out, the stretching temperature is 70-80℃, the stretching ratio is 2.0-2.5 times, and the stretching speed is 1000-1200m / min;

[0067] Step S6, Secondary stretching: The bright polyester-nylon microfiber after step S5 is subjected to secondary stretching. The stretching temperature is 120-130℃, the stretching ratio is 1.3-1.5 times, and the stretching speed is 1200-1400m / min.

[0068] Step S7, heat setting: After step S6, the heat setting temperature of the bright polyester-nylon microfiber is 180-200℃, the time is 30-40s, and the tension is controlled at 0.08-0.12cN / dtex.

[0069] Step S8: Winding. The bright polyester-nylon microfiber that has been heat-set in step S7 is neatly wound onto the bobbin at a winding speed of 3000-3500 m / min.

[0070] In step S1, the bright polyester chips are polyester chips with an intrinsic viscosity of 0.64-0.68 dL / g, a terminal carboxyl group content of ≤30 mol / t, and a titanium dioxide content of 0.3%-0.5%.

[0071] Furthermore, in step S1, the bright nylon chip is a polyamide 6 chip, and the relative viscosity of the bright nylon chip is 2.4-2.8.

[0072] It should be noted that the present invention preferably uses bright polyester chips as polyester chips and bright nylon chips as polyamide 6 chips, taking advantage of the fact that the apparent viscosity of polyester melt and nylon melt should be similar to improve the stability of composite fibers.

[0073] like Figures 2-18 As shown, in step S4 of the present invention, the polyester melt and the nylon melt are sequentially passed from top to bottom through the first distribution plate 1, the second distribution plate 2, the third distribution plate 3 and the fourth distribution plate 4 in the composite spinneret assembly I for diversion processing. Different distribution plates undertake different distribution and combination functions, from the initial component diversion to gradual refinement and adjustment, and finally achieve precise composite of the two components at the microscopic level.

[0074] The composite spinneret I also includes a feed connector 6, a spinneret 7, and a lower housing 8 connected to the first distribution plate 1. Spinneret 7 has evenly distributed spinneret holes 10, and the lower housing 8 surrounds the first distribution plate 1, the second distribution plate 2, the third distribution plate 3, and the fourth distribution plate 4.

[0075] The first feeding channel 61 for inputting polyester melt and the second feeding channel 62 for inputting nylon melt are arranged on the feeding joint 6, the outlet of the first feeding channel 61 is located at the center position of the feeding joint 6, and the second feeding channel 62 is located at one side of the feeding joint 6; the first distribution plate 1 is arranged in cooperation with the feeding joint 6, and the flow-through hole A11 and the flow-through hole B12 are arranged on the first distribution plate 1, the flow-through hole A11 is communicated with the first feeding channel 61 and used for conveying the polyester melt to the second distribution plate 2, and the flow-through hole B12 is communicated with the second feeding channel 62 and used for conveying the nylon melt to the second distribution plate 2.

[0076] When the polyester melt and the nylon melt are distributed in the second distribution plate 2, the first distribution filter screen 21 and the second distribution filter screen 22 arranged in the interior are used for distribution and filtration treatment, so that impurities in the melt are filtered out, and the glossiness and smoothness of the prepared lustrous polyester-nylon superfine fiber are further improved.

[0077] The second distribution plate 2 sequentially comprises an upper plate 23, a middle plate 24 and a lower plate 25 from top to bottom.

[0078] The biggest difference between the composite spinning nozzle assembly and the prior art is that the second distribution plate of the prior art is split type, so that the first distribution filter screen 21 and the second distribution filter screen 22 can be arranged on the lower plate 25, the first annular filter groove 251 and the second annular filter groove 252 for filtering the polyester melt and the nylon melt are arranged on the lower plate 25, the first annular filter groove 251 and the second annular filter groove 252 are concentrically arranged, the first distribution filter screen 21 is arranged in the first annular filter groove 251, and the second distribution filter screen 22 is arranged in the second annular filter groove 252.

[0079] After the first distribution filter screen 21 and the second distribution filter screen 22 are arranged in the second distribution plate 2, the split type second distribution plate 2 is integrally connected by diffusion welding, so that the first distribution filter screen 21 and the second distribution filter screen 22 are sealed in the second distribution plate 2, and leakage of the polyester melt and the nylon melt during distribution and filtration in the second distribution plate 2 is avoided.

[0080] The end of the upper plate 23 matched with the first distribution plate 1 is provided with a distribution groove A231 for distributing polyester melt, and a distribution groove B232 for distributing nylon melt. The distribution groove A231 is located at the center of the upper plate 23, and is communicated with the flow-through hole A11. The distribution groove B232 is arranged outside the distribution groove A231 around the distribution groove A231, and is communicated with the flow-through hole B12. The distribution groove A231 is provided with flow-through holes A233 arranged equidistantly around the central axis of the first distribution plate 1. The flow-through holes A233 are communicated with the first flow channels 241 on the middle plate 24. The distribution groove B232 is provided with flow-through holes B234 arranged equidistantly around the central axis of the first distribution plate. The flow-through holes B234 are communicated with the second flow channels 242 on the middle plate 24. The first flow channels 241 and the second flow channels 242 are respectively arranged obliquely along the tangential direction of the rotation direction of the first distribution filter screen 21 and the second distribution filter screen 22. The inclination angles of the first flow channels 241 and the second flow channels 242 are arranged in an arithmetic progression, for example, the inclination angles of the first flow channels 241 and the second flow channels 242 at the first position are α, and α is an integer greater than 8. The inclination angles of the first flow channels 241 and the second flow channels 242 at the second position are α+n, and n is an integer greater than 2. The polyester melt and the nylon melt flowing out obliquely from the first flow channels 241 and the second flow channels 242 impact the first distribution filter screen 21 and the second distribution filter screen 22, so that the first distribution filter screen 21 and the second distribution filter screen 22 are arranged to rotate.

[0081] Specifically, the first distribution filter screen 21 and the second distribution filter screen 22 each include a plurality of partition plates 211 arranged equidistantly in a circle. The partition plates 211 are connected by filter screens 212. The filter screens 212 are provided with arc-shaped filter grooves 213. When the polyester melt or the nylon melt is obliquely sprayed onto the first distribution filter screen 21 and the second distribution filter screen 22, the melt impacts the partition plates 211, so that the first distribution filter screen 21 and the second distribution filter screen 22 rotate. The filter screens 212 filter and retain impurities on the filter screens 212. Since the first distribution filter screen 21 and the second distribution filter screen 22 are always in a rotating state, the filter screens 212 will not be blocked by the retained impurities.

[0082] The first annular filter groove 251 and the second annular filter groove 252 are coaxially arranged, the first annular filter groove 251 is located at the inner ring of the second annular filter groove 252, the longitudinal section of the first annular filter groove 251 and the second annular filter groove 252 is shaped with the partition plate 211, the first annular filter groove 251 is in communication with the first flow channel 241, the third flow channel 243 and the fourth flow channel 244, for distributing the polyester melt, and the second annular filter groove 252 is in communication with the second flow channel 242, the fifth flow channel 245 and the sixth flow channel 246, for distributing the nylon melt, and a plurality of through holes A 253 are uniformly distributed at the bottom of the first annular filter groove 251, and a plurality of through holes B 254 are uniformly distributed at the bottom of the second annular filter groove 252, and the through holes A 253 and the through holes B 254 are in communication with the third distribution plate 3.

[0083] The end of the third distribution plate 3 matched with the lower plate 25 is provided with a distribution groove E31 corresponding to the through hole A 253 and a distribution groove F32 corresponding to the through hole B 254, the distribution groove E31 and the distribution groove F32 are arranged along the radial direction of the third distribution plate 3, and the distribution groove E31 and the distribution groove F32 are also arranged at equal intervals around the central axis of the third distribution plate 3, the distribution groove E31 is used for distributing the polyester melt, the distribution groove F32 is used for distributing the nylon melt, the bottom of the distribution groove E31 is arranged with a communication hole A 33 along the arrangement direction, the bottom of the distribution groove F32 is arranged with a communication hole B 34 along the arrangement direction, the communication hole A 33 delivers the polyester melt to the fourth distribution plate 4, and the communication hole B 34 delivers the nylon melt to the fourth distribution plate 4.

[0084] The end surface of the fourth distribution plate 4 matched with the third distribution plate 3 is arranged with a distribution groove G41 and a distribution groove H42, the distribution groove G41 and the distribution groove H42 are coaxially arranged, the distribution groove G41 is in communication with the communication hole A 33 located at the same ring direction, and the distribution groove H42 is in communication with the communication hole B 34 located at the same ring direction, the bottom of each group of distribution grooves G41 is arranged with a plurality of distribution holes A 43 at equal intervals, the bottom of each group of distribution grooves H42 is arranged with a plurality of distribution holes B 44 at equal intervals, the distribution hole A 43 guides the polyester melt to the spinneret 7, and the distribution hole B 44 guides the nylon melt to the spinneret 7.

[0085] The end surface of the spinneret 7 matched with the fourth distribution plate 4 is provided with a merging groove 71, the merging groove 71 is in communication with the distribution hole A 43 and the distribution hole B 44, the bottom of the merging groove 71 is uniformly arranged with a plurality of spinning holes 10, the spinning hole 10 is arranged corresponding to the distribution hole B 44, the spinning hole 10 is arranged in a cross shape, and the distribution hole B 44 is located at the center position of the spinning hole 10.

[0086] As a preferred embodiment, the upper plate 23, the middle plate 24 and the lower plate 25, and the end faces of the middle plate 24 connected with the upper plate 23 and the lower plate 25 are all staggered with concaves and protrusions, so that when the second distribution plate 2 is combined, the polyester melt and the nylon melt flowing in the distribution groove C253 and the distribution groove D254 will not appear to be mixed.

[0087] In addition, the second distribution plate 2 of the present application can be integrally connected by screw fastening in addition to diffusion welding, so that the second distribution plate 2 is integrally connected. The anti-leakage effect of the second distribution plate 2 formed by screw fastening is not as good as that of the second distribution plate formed by diffusion welding, but it is convenient to disassemble and can facilitate the maintenance of the first shunt filter screen 21 and the second shunt filter screen 22.

[0088] Example 2

[0089] Example 2 of the present application is different from Example 1 in that:

[0090] As shown in Figures 8-10 , the third flow channel 243 and the fourth flow channel 244 are respectively arranged at the intervals of the adjacent first flow channels 241 on the middle plate, and the third flow channel 243 and the fourth flow channel 244 are staggered and spaced apart;

[0091] The third flow channel 243 is inclined outward along the radial direction of the middle plate 24, the fourth flow channel 244 is inclined inward along the radial direction of the middle plate 24, and the third flow channel 243 and the fourth flow channel 244 are inclined to output the polyester melt, so that the polyester melt at the first shunt filter screen 21 flows in a wave shape.

[0092] Correspondingly, the fifth flow channel 245 and the sixth flow channel 246 are respectively arranged at the intervals of the adjacent second flow channels 242 on the middle plate, and the fifth flow channel 245 and the sixth flow channel 246 are staggered and spaced apart;

[0093] The fifth flow channel 245 is inclined outward along the radial direction of the middle plate 24, the sixth flow channel 246 is inclined inward along the radial direction of the middle plate 24, and the fifth flow channel 245 and the sixth flow channel 246 are inclined to output the nylon melt, so that the nylon melt at the second shunt filter screen 22 flows in a wave shape.

[0094] When the polyester melt and the nylon melt flow in a wave shape on the lower plate 25, 1, the flow rate and pressure distribution of the melt at different positions when extruding from the spinneret hole are more complex and diversified, which is beneficial to form special shaped cross-section structures, such as the common orange petal shape, rice character shape, etc. These shaped cross-sections can increase the specific surface area of the fiber and give the fiber better moisture absorption, moisture conduction, air permeability and other properties; 2, when the upstream melt pressure fluctuates, the wave-shaped flow can absorb and relieve this pressure change to some extent, so that the melt pressure is more stable before reaching the spinneret hole, ensuring the stability of the spinning process and reducing the problems of broken filaments, uneven thickness, etc. caused by pressure fluctuations; 3, in actual production, due to the differences in physical properties and other reasons, the flow rates of the polyester and nylon melts may be unbalanced. The wave-shaped flow can fine-tune the flow rates of different melts by changing the shape and length of the flow, so that the two melts can enter the spinneret hole in a more accurate ratio, ensuring the stability of the ratio of the two components in the composite fiber and improving the stability of the product quality.

[0095] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing bright polyester-nylon microfiber, characterized in that, Includes the following steps: Step S1: Raw material preparation. The selected bright polyester chips and bright nylon chips are heated and dried until the moisture content is <0.05%. Step S2: Polyester melt extrusion. The dried bright polyester chips are added into the first screw extruder and heated to melt. The heating temperature of the first screw extruder is 280-290℃ in the first zone, 290-300℃ in the second zone, and 300-310℃ in the third zone. The screw speed is 30-40 r / min to obtain a fully melted and uniform polyester melt. Step S3: Nylon melt extrusion. The dried bright nylon chips are added to the second screw extruder and heated to melt. The heating temperature of the first zone of the second screw extruder is 240-250℃, the heating temperature of the second zone is 250-260℃, the heating temperature of the third zone is 260-270℃, and the screw speed is 25-35 r / min to obtain a nylon melt with good fluidity. Step S4, Composite spinning: The polyester melt in step S2 and the nylon melt in step S3 are respectively fed into the composite spinneret (I). The polyester melt and the nylon melt are uniformly composited at the spinneret hole (10) and extruded to form a bright polyester-nylon microfiber with a core layer of nylon melt and a skin layer of polyester melt. The polyester melt and nylon melt are sequentially diverted from top to bottom through the first distribution plate (1), the second distribution plate (2), the third distribution plate (3) and the fourth distribution plate (4) in the composite spinneret assembly (I); When the polyester melt and the nylon melt are separated in the second distribution plate (2), they are separated and filtered by the first diversion filter (21) and the second diversion filter (22) respectively, which are internally rotated. The second distribution plate (2) includes, from top to bottom, an upper plate (23), a middle plate (24) and a lower plate (25); The first diversion filter (21) and the second diversion filter (22) are coaxially rotated on the lower plate (25). The polyester melt and nylon melt flowing obliquely downward through the first flow channel (241) and the second flow channel (242) on the middle plate (24) impact the corresponding first diversion filter (21) and second diversion filter (22), so that the first diversion filter (21) and the second diversion filter (22) are rotated. The first diversion filter (21) and the second diversion filter (22) each include a plurality of partitions (211) arranged equidistantly in a circle. The partitions (211) are connected by a filter screen (212), and the filter screen (212) is provided with arc-shaped filter grooves (213). The first flow channel (241) and the second flow channel (242) are respectively inclined tangentially along the rotation direction of the corresponding first diversion filter (21) and second diversion filter (22). Multiple sets of the first flow channel (241) and the second flow channel (242) are provided, and the first flow channel (241) and the second flow channel (242) are respectively equidistantly arranged around the central axis of the middle plate (24). Step S5: First-stage stretching. After the bright polyester-nylon microfiber solidifies, it undergoes first-stage stretching at a temperature of 70-80℃, a stretching ratio of 2.0-2.5 times, and a stretching speed of 1000-1200m / min. Step S6, Secondary stretching: The bright polyester-nylon microfiber after step S5 is subjected to secondary stretching. The stretching temperature is 120-130℃, the stretching ratio is 1.3-1.5 times, and the stretching speed is 1200-1400m / min. Step S7, heat setting: After step S6, the heat setting temperature of the bright polyester-nylon microfiber is 180-200℃, the time is 30-40s, and the tension is controlled at 0.08-0.12cN / dtex. Step S8: Winding. The bright polyester-nylon microfiber that has been heat-set in step S7 is neatly wound onto the bobbin at a winding speed of 3000-3500 m / min.

2. The method for preparing a bright polyester-nylon microfiber according to claim 1, characterized in that: In step S1, the bright polyester chips are polyester chips with an intrinsic viscosity of 0.64-0.68 dL / g, a terminal carboxyl group content of ≤30 mol / t, and a titanium dioxide content of 0.3%-0.5%.

3. The method for preparing a bright polyester-nylon microfiber according to claim 1, characterized in that: In step S1, the bright nylon chips are polyamide 6 chips, and the relative viscosity of the bright nylon chips is 2.4-2.

8.

4. The method for preparing a bright polyester-nylon microfiber according to claim 1, characterized in that: A third flow channel (243) and a fourth flow channel (244) are respectively provided at the interval between adjacent first flow channels (241), and the third flow channel (243) and the fourth flow channel (244) are arranged alternately; The third flow channel (243) is arranged outward at an angle along the radial direction of the middle plate (24), and the fourth flow channel (244) is arranged inward at an angle along the radial direction of the middle plate (24). The third flow channel (243) and the fourth flow channel (244) output polyester melt at an angle, so that the polyester melt at the first diversion filter screen (21) flows in a wave-like shape.

5. The method for preparing a bright polyester-nylon microfiber according to claim 1, characterized in that: A fifth flow channel (245) and a sixth flow channel (246) are respectively provided at the interval between adjacent second flow channels (242), and the fifth flow channel (245) and the sixth flow channel (246) are arranged alternately; The fifth flow channel (245) is arranged outward at an angle along the radial direction of the middle plate (24), and the sixth flow channel (246) is arranged inward at an angle along the radial direction of the middle plate (24). The fifth flow channel (245) and the sixth flow channel (246) output nylon melt at an angle, so that the nylon melt at the second diversion filter screen (22) flows in a wave-like manner.

6. The method for preparing a bright polyester-nylon microfiber according to claim 1, characterized in that: The upper plate (23), middle plate (24) and lower plate (25) are integrally connected by diffusion welding, and the end faces of the middle plate (24) connected to the upper plate (23) and lower plate (25) are arranged in an alternating concave-convex pattern.

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