Preparation method of lustrous polyester-nylon superfine fiber

Abstract

The invention relates to the technical field of preparation of lustrous polyester-nylon superfine fibers, in particular to a preparation method of lustrous polyester-nylon superfine fibers, which comprises the following steps: step S1, raw material preparation, step S2, polyester melt extrusion, step S3, nylon melt extrusion, step S4, composite spinning, step S5, primary stretching, step S6, secondary stretching, step S7, heat setting, and step S8, winding. An existing preparation method of the lustrous polyester-nylon superfine fiber is improved, a special distribution plate structure is used for filtering a polyester melt and a nylon melt in the flow dividing process, impurities in the polyester melt and the nylon melt are removed, the gloss and brightness of the prepared lustrous polyester-nylon superfine fiber are effectively improved, and the lustrous polyester-nylon superfine fiber has a good application prospect. The quality of the lustrous polyester-nylon superfine fiber is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of bright polyester and nylon ultrafine fibers, and in particular to a preparation method of bright polyester and nylon ultrafine fibers. Background Art

[0002] Bright polyester-nylon composite yarn is a composite fiber. It is made of polyester and nylon through a special composite process. Bright polyester makes it have good wrinkle resistance, shape retention and wear resistance, and is not easy to pilling; bright nylon has excellent strength, elasticity and wear resistance, and its moisture absorption and dyeability are also better than polyester. The combination of the two can give full play to their respective advantages, and "bright" means that the fiber has a higher gloss, which is usually because the surface of the fiber is relatively smooth and has a strong ability to reflect light.

[0003] The production of polyester-nylon composite yarn generally adopts composite spinning technology. This process is to melt or dissolve the spinning raw materials of polyester and nylon respectively, and then use a special spinneret to combine the two melts or solutions at the spinneret hole to form a composite fiber. In this process, the design of the spinneret and the control of process parameters are very critical, which will affect the structure and performance of the composite yarn. For example, different composite ratios and composite methods will give the composite yarn different characteristics.

[0004] For example, a Chinese patent with patent application number CN201410059805.3 discloses a bright polyester-nylon composite fiber, which is prepared by composite spinning of polyester bright slices and nylon bright slices, wherein the composite ratio is 15% to 85%. The present invention also designs a method for producing a bright polyester-nylon composite fiber, which adopts a one-step spinning method, characterized in that the composite fiber is prepared by composite spinning of polyester bright slices and nylon bright slices, wherein the composite ratio is 15% to 85%. The bright polyester-nylon composite fiber prepared by this method has the characteristics of good gloss and hand feel. In addition, this method belongs to one-step spinning, with simple process and low consumption, which can effectively reduce production costs. Composite spinning of polyester bright slices and nylon bright slices can improve spinnability and reduce the generation of hair. In the production process, by adjusting the ratio of polyester and nylon, the hand feel of the fiber can be changed to achieve the best.

[0005] However, in the above-mentioned method for preparing the bright polyester-nylon composite fiber, impurities in the polyester melt and the nylon melt cannot be filtered, resulting in that the gloss and brightness of the formed bright polyester-nylon composite fiber cannot be further improved. Summary of the invention

[0006] In view of the above problems, the present invention provides a method for preparing shiny polyester and nylon superfine fibers. By improving the existing method for preparing shiny polyester and nylon superfine fibers, a special distribution plate structure is used to filter the polyester melt and the nylon melt during the diversion process to remove impurities in the polyester melt and the nylon melt. The gloss and brightness of the prepared shiny polyester and nylon superfine fibers are effectively improved, thereby further improving the quality of the shiny polyester and nylon superfine fibers.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing a bright polyester-nylon ultrafine fiber comprises the following steps:

[0009] Step S1, raw material preparation, heating and drying the selected bright polyester slices and bright nylon slices to a moisture content of less than 0.05% to ensure good melting performance;

[0010] Step S2, polyester melt extrusion, adding the dried shiny polyester slices into a first screw extruder for heating and melting, wherein the heating temperature of the first zone of the first screw extruder is 280-290° C., the heating temperature of the second zone is 290-300° C., the heating temperature of the third zone is 300-310° C., and the screw speed is 30-40 r / min, so as to obtain a fully melted and uniform polyester melt;

[0011] Step S3, nylon melt extrusion, adding the dried shiny nylon slices into a second screw extruder for heating and melting, wherein the heating temperature of the first zone of the second screw extruder is 240-250° C., the heating temperature of the second zone is 250-260° C., the heating temperature of the third zone is 260-270° C., and the screw speed is 25-35 r / min, to obtain a nylon melt with good fluidity;

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

[0013] Step S5, primary stretching, after the bright polyester and nylon microfibers are solidified, primary stretching is performed, the stretching temperature is 70-80°C, the stretching multiple is 2.0-2.5 times, and the stretching speed is 1000-1200m / min, so that the bright polyester and nylon microfiber macromolecules are initially oriented;

[0014] Step S6, secondary stretching, the bright polyester nylon ultrafine fiber after the treatment in step S5 is subjected to secondary stretching, the stretching temperature is 120-130° C., the stretching multiple is 1.3-1.5 times, and the stretching speed is 1200-1400 m / min, so as to further improve the orientation and strength of the fiber;

[0015] Step S7, heat setting: after the treatment in step S6, the heat setting temperature of the bright polyester and nylon microfiber is 180-200°C, the time is 30-40s, and the tension is controlled to be 0.08-0.12cN / dtex, so as to stabilize the fiber structure, eliminate internal stress, and improve the dimensional stability and glossiness of the fiber;

[0016] Step S8, winding, the shiny polyester-nylon ultrafine fiber that has been heat-set in step S7 is neatly wound on a bobbin at a winding speed of 3000-3500 m / min.

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

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

[0019] As an improvement, in step S4, the polyester melt and the nylon melt are sequentially passed through the first distribution plate, the second distribution plate, the third distribution plate and the fourth distribution plate from top to bottom for diversion processing;

[0020] When the polyester melt and the nylon melt are divided in the second distribution plate, they are divided and filtered by the first and second flow-dividing filter nets that are rotatably arranged inside.

[0021] As an improvement, the second distribution plate includes an upper plate, a middle plate and a lower plate from top to bottom;

[0022] The first diversion filter and the second diversion filter are coaxially rotated on the lower plate respectively, and the polyester melt and the nylon melt flowing obliquely downward through the first flow channel and the second flow channel on the middle plate respectively impact the corresponding first diversion filter and the second diversion filter, so that the first diversion filter and the second diversion filter are rotated.

[0023] As an improvement, the first diversion filter screen and the second diversion filter screen both include a plurality of partitions equidistantly arranged in a circle, the partitions are connected by a filter screen, and arc-shaped filter grooves are arranged on the filter screen.

[0024] As an improvement, the first flow channel and the second flow channel are respectively arranged tangentially and inclined along the rotation direction of the corresponding first diversion filter and second diversion filter, and multiple groups of the first flow channel and the second flow channel are arranged, and the first flow channel and the second flow channel are respectively arranged equidistantly around the central axis of the middle plate.

[0025] As an improvement, a third flow channel and a fourth flow channel are respectively provided at intervals between adjacent first flow channels, and the third flow channel and the fourth flow channel are arranged in a staggered manner;

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

[0027] As an improvement, a fifth flow channel and a sixth flow channel are respectively provided at intervals between adjacent second flow channels, and the fifth flow channel and the sixth flow channel are arranged in a staggered manner;

[0028] The fifth flow channel is arranged to be inclined outward along the radial direction of the middle plate, and the sixth flow channel is arranged to be inclined inward along the radial direction of the middle plate. The fifth flow channel and the sixth flow channel output the nylon melt at an angle, so that the nylon melt at the second diversion 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 to the upper plate and the lower plate are arranged in a staggered manner of concave and convex.

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

[0031] (1) The present invention improves the existing method for preparing bright polyester and nylon ultrafine fibers, and uses a special distribution plate structure to filter the polyester melt and the nylon melt during the diversion process to remove impurities in the polyester melt and the nylon melt. The gloss and brightness of the prepared bright polyester and nylon ultrafine fibers are effectively improved, and the quality of the bright polyester and nylon ultrafine fibers is further improved. The gloss value of the prepared bright polyester and nylon ultrafine fibers is greater than 120GU, the dynamic friction coefficient is 0.1-0.3, and the static friction coefficient is 0.25-0.45;

[0032] (2) The present invention separates the upper plate, the middle plate and the lower plate of the second distribution plate in the composite spinneret assembly, and then connects the upper plate, the middle plate and the lower plate as a whole through diffusion welding to form the second distribution plate. Before the upper plate, the middle plate and the lower plate are connected, a first diversion filter and a second diversion filter are placed between the lower plate and the middle plate. The first diversion filter and the second diversion filter are used to filter the polyester melt and the nylon melt respectively, so as to achieve the purpose of filtering and diverting the polyester melt and the nylon melt by the distribution plate;

[0033] (3) When the first diverter filter and the second diverter filter are provided, the polyester melt and the nylon melt flowing obliquely downward impact the partitions on the first diverter filter and the second diverter filter through the inclined first flow channel and the second flow channel provided on the middle plate, so that the first diverter filter and the second diverter filter obtain rotational power, thereby enabling the first diverter filter and the second diverter filter to perform continuous diverting filtration on the polyester melt and the nylon melt respectively, thereby ensuring the quality of the prepared bright polyester-nylon ultrafine fiber;

[0034] (4) The present invention adjusts the inclination direction of the third flow channel, the fourth flow channel, the fifth flow channel and the sixth flow channel so that the polyester melt and the nylon melt flow in a wave shape on the second distribution plate, thereby making the diversion more delicate. At the same time, the second distribution plate is selected as a carrier of the first diversion filter and the second diversion filter, so that the polyester melt and the nylon melt are filtered without affecting the pressure at the spinneret, thereby ensuring the fluctuation stability of the spinneret.

[0035] In summary, the present invention has the advantages of good brightness, high gloss, smooth surface, high strength, good wear resistance, etc. for forming bright polyester and nylon ultrafine fibers, and is particularly suitable for the technical field of preparation of bright polyester and nylon ultrafine fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the process of the invention preparation method;

[0037] Figure 2 It is a schematic diagram of the three-dimensional structure of the composite spinneret assembly of the present invention;

[0038] Figure 3 The three-dimensional cross-sectional structure diagram of the composite spinneret assembly of the present invention is shown in FIG. Figure 1 ;

[0039] Figure 4 The three-dimensional cross-sectional structure diagram of the composite spinneret assembly of the present invention is shown in FIG. Figure 2 ;

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

[0041] Figure 6This is a schematic diagram of the three-dimensional structure of the first distribution plate of the present invention;

[0042] Figure 7 This is a schematic cross-sectional structural diagram of the first distribution plate of the present invention;

[0043] Figure 8 This is a schematic diagram of the top view of the middle plate structure of the present invention;

[0044] Fig. 9 for Figure 8 The enlarged structural diagram at a in the middle;

[0045] Fig.10 for Figure 8 The enlarged structural diagram at b in the middle;

[0046] Fig.11 This is a schematic diagram of the cross-sectional structure of the lower plate of the present invention;

[0047] Fig.12 This is a schematic diagram of the three-dimensional structure of the lower plate of the present invention;

[0048] Fig.13 It is a schematic diagram of the three-dimensional structure of the first diverter filter and the second diverter filter of the present invention;

[0049] Fig.14 This is a schematic diagram of the top view of the structure of the third distribution plate of the present invention;

[0050] Fig.15 This is a schematic diagram of the three-dimensional structure of the fourth distribution plate of the present invention;

[0051] Fig.16 This is a schematic diagram of the spinneret structure of the present invention when viewed from above;

[0052] Fig.17 for Fig.16 The enlarged structural diagram at c in the middle;

[0053] Fig.18 It is a schematic diagram of the top view of the spinneret structure of the present invention.

[0054] In the figure: composite spinneret assembly I, spinneret hole 10, first distribution plate 1, flow hole A11, flow hole B12, second distribution plate 2, first diversion filter 21, partition 211, filter 212, filter slot 213, second diversion filter 22, upper plate 23, distribution slot A231, distribution slot B232, flow hole A233, flow 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, diverter groove E31, diverter groove F32, connecting hole A33, connecting hole B34, fourth distribution plate 4, diverter groove G41, diverter groove H42, diverter hole A43, diverter hole B44, feed connector 6, first feed channel 61, second feed channel 62, spinneret plate 7, confluence groove 71, lower box body 8. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0057] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0058] Embodiment 1:

[0059] like Figure 1 As shown, a method for preparing a bright polyester-nylon ultrafine fiber comprises the following steps:

[0060] Step S1, raw material preparation, heating and drying the selected bright polyester slices and bright nylon slices to a moisture content of less than 0.05%. Reducing the moisture content of the slices helps to improve the strength, toughness and glossiness of the prepared bright polyester and nylon ultrafine fibers, and also helps to improve the chemical stability;

[0061] Step S2, polyester melt extrusion, adding the dried shiny polyester slices into a first screw extruder for heating and melting, wherein the heating temperature of the first zone of the first screw extruder is 280-290° C., the heating temperature of the second zone is 290-300° C., the heating temperature of the third zone is 300-310° C., and the screw speed is 30-40 r / min, so as to obtain a fully melted and uniform polyester melt;

[0062] Step S3, nylon melt extrusion, adding the dried shiny nylon slices into a second screw extruder for heating and melting, wherein the heating temperature of the first zone of the second screw extruder is 240-250° C., the heating temperature of the second zone is 250-260° C., the heating temperature of the third zone is 260-270° C., and the screw speed is 25-35 r / min, to obtain a nylon melt with good fluidity;

[0063] The first screw extruder and the second screw extruder adopt zone heating. In zone one, the material just enters the extruder and the temperature is low. It needs to be heated quickly to achieve the transformation from glass state to viscous flow state. Zone heating can provide strong external heat in this area, so that the material can quickly reach the initial plasticization temperature, avoiding the material "bridging" at the feed port or "sticking to the wall" in the machine;

[0064] In the second zone, the material is subjected to strong shearing and compression by the screw, which will generate a certain amount of shear heat. Properly increasing the heating temperature of the zone will help reduce the viscosity of the material, speed up its fluidity, and allow the material to be better compressed and transported. At the same time, it can also reduce the harm of shear heat to the equipment.

[0065] For the third zone, the material is basically in a molten state at this stage. Due to the change in the screw channel volume, the melt pressure will drop suddenly. Maintaining the temperature consistent with 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.

[0066] 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 evenly compounded at the spinneret hole 10, and extruded to form a bright polyester-nylon ultrafine fiber with a core layer of nylon melt and a skin layer of polyester melt;

[0067] Step S5, primary stretching, after the bright polyester nylon ultrafine fiber is solidified, primary stretching is performed, the stretching temperature is 70-80°C, the stretching multiple is 2.0-2.5 times, and the stretching speed is 1000-1200m / min;

[0068] Step S6, secondary stretching, the bright polyester and nylon ultrafine fibers after the treatment in step S5 are subjected to secondary stretching, the stretching temperature is 120-130° C., the stretching multiple is 1.3-1.5 times, and the stretching speed is 1200-1400 m / min;

[0069] Step S7, heat setting: after the treatment in step S6, the heat setting temperature of the bright polyester and nylon microfiber is 180-200°C, the time is 30-40s, and the tension is controlled to be 0.08-0.12cN / dtex;

[0070] Step S8, winding, the shiny polyester-nylon ultrafine fiber that has been heat-set in step S7 is neatly wound on a bobbin at a winding speed of 3000-3500 m / min.

[0071] Wherein, in the step S1, the bright polyester chips are polyester chips, the intrinsic viscosity of the bright polyester chips is 0.64-0.68 dL / g, the terminal carboxyl content is ≤30 mol / t, and the titanium dioxide content is 0.3%-0.5%.

[0072] Furthermore, in step S1, the shiny nylon slice is a polyamide 6 slice, and the relative viscosity of the shiny nylon slice is 2.4-2.8.

[0073] It should be noted that the present invention preferably uses the bright polyester chips as polyester chips and the bright nylon chips as polyamide 6 chips, and utilizes the characteristic that the apparent viscosity of the polyester melt and the nylon melt should be similar to improve the stability of the composite fiber.

[0074] like Figure 2-Figure 18 As shown, it is further explained that in the step S4 of the present invention, the polyester melt and the nylon melt are 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 in sequence, and different distribution plates assume different distribution and combination functions, from the initial preliminary diversion of components to gradual refinement and adjustment, and finally realize the precise compounding of the two components at the microscopic level.

[0075] The composite spinneret assembly I further includes a feed connector 6 connected to the first distribution plate 1, a spinneret plate 7 and a lower box 8, the spinneret plate 7 is evenly distributed with spinneret holes 10, and the lower box 8 surrounds the first distribution plate 1, the second distribution plate 2, the third distribution plate 3 and the fourth distribution plate 4;

[0076] The feed connector 6 is provided with a first feed channel 61 for inputting polyester melt, and a second feed channel 62 for inputting nylon melt. The outlet of the first feed channel 61 is located at the center of the feed connector 6, and the second feed channel 62 is located on one side of the feed connector 6. The first distribution plate 1 is arranged in cooperation with the feed connector 6. The first distribution plate 1 is provided with a flow hole A11 and a flow hole B12. The flow hole A11 is connected to the first feed channel 61 for conveying the polyester melt to the second distribution plate 2, and the flow hole B12 is connected to the second feed channel 62 for conveying the nylon melt to the second distribution plate 2.

[0077] When the polyester melt and the nylon melt are diverted in the second distribution plate 2, they are diverted and filtered by the first diversion filter 21 and the second diversion filter 22 which are rotated inside to filter out impurities in the melt, thereby further improving the gloss and smoothness of the prepared shiny polyester and nylon ultrafine fibers.

[0078] The second distribution plate 2 includes an upper plate 23, a middle plate 24 and a lower plate 25 from top to bottom;

[0079] The biggest difference from the structure of the existing composite spinneret assembly is that the present invention divides the existing integrated second distribution plate into a split type, so that the first diversion filter 21 and the second diversion filter 22 can be placed on the lower plate 25, and the lower plate 25 is provided with a first annular filter groove 251 and a second annular filter groove 252 for filtering polyester melt and nylon melt respectively. The first annular filter groove 251 and the second annular filter groove 252 are concentrically arranged, the first diversion filter 21 is placed in the first annular filter groove 251, and the second diversion filter 22 is placed in the second annular filter groove 252.

[0080] After the first diversion filter 21 and the second diversion filter 22 are placed in the second distribution plate 2, the split second distribution plate 2 is connected to form an integral setting through diffusion welding, so that the first diversion filter 21 and the second diversion filter 22 are sealed in the second distribution plate 2 to prevent leakage of the polyester melt and the nylon melt when they are diverted and filtered in the second distribution plate 2.

[0081] The end of the upper plate 23 that cooperates with the first distribution plate 1 is provided with a distribution groove A231 for diverting the polyester melt, and a distribution groove B232 for diverting the nylon melt. The distribution groove A231 is located at the center of the upper plate 23, and the distribution groove A231 is connected to the flow hole A11. The distribution groove B232 is arranged around the distribution groove A231 on the outside of the distribution groove A231, and the distribution groove B232 is connected to the flow hole B12. The distribution groove A231 is provided with flow holes A233 that are equidistantly arranged around the central axis of the first distribution plate 1. The flow holes A233 are connected to the first flow channel 241 on the middle plate 24. The distribution groove B232 is provided with flow holes B234 that are equidistantly arranged around the central axis of the first distribution plate. The flow holes B234 are connected to the second flow channel 242 on the middle plate 24. The first The flow channel 241 and the second flow channel 242 are respectively arranged tangentially and inclined along the rotation direction of the corresponding first diverter filter 21 and the second diverter filter 22, and the inclination angles of the first flow channel 241 and the second flow channel 242 are arranged in an arithmetic progression. For example, the inclination angles of the first flow channel 241 and the second flow channel 242 in the first position are α, α is an integer greater than 8, and the inclination angles of the first flow channel 241 and the second flow channel 242 in the second position are α+n, n is an integer greater than 2, and so on; the polyester melt and the nylon melt flowing out of the first flow channel 241 and the second flow channel 242 respectively obliquely downward impact the corresponding first diverter filter 21 and the second diverter filter 22, so that the first diverter filter 21 and the second diverter filter 22 are rotated.

[0082] Specifically, the first diversion filter 21 and the second diversion filter 22 each include a plurality of partitions 211 equidistantly arranged 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. When the polyester melt or the nylon melt is obliquely sprayed onto the first diversion filter 21 and the second diversion filter 22, the melt will impact the partition 211, thereby causing the first diversion filter 21 and the second diversion filter 22 to rotate, and the filter screen 212 will filter and retain impurities on the filter screen 212, and since the first diversion filter 21 and the second diversion filter 22 are always in a rotating state, the filter screen 212 will not be blocked by the retained impurities.

[0083] The first annular filter groove 251 and the second annular filter groove 252 are coaxially arranged, and the first annular filter groove 251 is located in the inner circle of the second annular filter groove 252. The longitudinal sections of the first annular filter groove 251 and the second annular filter groove 252 are arranged in a contour with the partition 211. The first annular filter groove 251 is connected with the first flow channel 241, the third flow channel 243 and the fourth flow channel 244 for diverting the polyester melt, and the second annular filter groove 252 is connected with the second flow channel 242, the fifth flow channel 245 and the sixth flow channel 246 for diverting the nylon melt, and a plurality of through holes A253 are evenly distributed at the bottom of the first annular filter groove 251, and a plurality of through holes B254 are evenly distributed at the bottom of the second annular filter groove 252. The through holes A253 and the through holes B254 are both connected to the third distribution plate 3.

[0084] The end of the third transfer plate 3 that cooperates with the lower plate 25 is provided with a diverter groove E31 corresponding to the through hole A253, and a diverter groove F32 corresponding to the through hole B254. The diverter groove E31 and the diverter groove F32 are both arranged along the radial direction of the third distribution plate 3, and the diverter groove E31 and the diverter groove F32 are also arranged equidistantly around the central axis of the third distribution plate 3. The diverter groove E31 is used to divert the polyester melt, and the diverter groove F32 is used to divert the nylon melt. The bottom of the diverter groove E31 is arranged with connecting holes A33 along its setting direction, and the bottom of the diverter groove F32 is arranged with connecting holes B34 along its setting direction. The connecting hole A33 transports the polyester melt to the fourth distribution plate 4, and the connecting hole B34 transports the nylon melt to the fourth distribution plate 4.

[0085] The fourth distribution plate 4 and the third distribution plate 3 cooperate with the end surface on which the diverter grooves G41 and the diverter grooves H42 are alternately arranged. The diverter grooves G41 and the diverter grooves H42 are coaxially sleeved with each other, and the diverter grooves G41 are connected to the connecting holes A33 located in the same annular direction, and the diverter grooves H42 are connected to the connecting holes B34 located in the same annular direction. The bottom of each group of diverter grooves G41 is evenly spaced with a number of diverter holes A43, and the bottom of each group of diverter grooves H42 is evenly spaced with a number of diverter holes B44. The diverter holes A43 guide the polyester melt to the spinneret 7, and the diverter holes B44 guide the nylon melt to the spinneret 7.

[0086] The end surface of the spinneret 7 cooperating with the fourth distribution plate 4 is provided with a converging groove 71, which connects the diversion hole A43 and the diversion hole B44. A number of spinneret holes 10 are evenly distributed at the bottom of the converging groove 71. The spinneret holes 10 are arranged corresponding to the diversion holes B44. The spinneret holes 10 are arranged in a cross shape, and the diversion hole B44 is located at the center of the spinneret hole 10.

[0087] 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 to the upper plate 23 and the lower plate 25 are all arranged in a staggered manner, so that when the second distribution plate 2 arranged in a split manner is compounded, there will be no cross-flow between the polyester melt and the nylon melt flowing in the internal distribution grooves C253 and D254.

[0088] In addition, in addition to being formed as an integral unit by diffusion welding, the second distribution plate 2 of the present invention can also be connected as an integral unit by means of threaded fastening. The anti-leakage effect of the second distribution plate 2 formed as an integral unit by threaded fastening is not as good as that of the second distribution plate diffused by welding, but it is easy to disassemble and assemble, and can facilitate the inspection of the first diversion filter 21 and the second diversion filter 22 inside.

[0089] Example 2

[0090] The difference between Example 2 of the present invention and Example 1 described with reference to Example 1 is that:

[0091] like Figure 8-10 As shown, the intervals between the adjacent first flow channels 241 on the middle plate are respectively provided with a third flow channel 243 and a fourth flow channel 244, and the third flow channel 243 and the fourth flow channel 244 are arranged in a staggered interval;

[0092] The third flow channel 243 is arranged to be tilted outward along the radial direction of the middle plate 24, and the fourth flow channel 244 is arranged to be tilted inward along the radial direction of the middle plate 24. The third flow channel 243 and the fourth flow channel 244 output the polyester melt at an angle, so that the polyester melt at the first diversion filter 21 flows in a wave shape.

[0093] Correspondingly, the intervals between the adjacent second flow channels 242 on the middle plate are respectively provided with a fifth flow channel 245 and a sixth flow channel 246, and the fifth flow channel 245 and the sixth flow channel 246 are arranged in a staggered interval;

[0094] The fifth flow channel 245 is arranged to be inclined outward along the radial direction of the middle plate 24, and the sixth flow channel 246 is arranged to be inclined inward along the radial direction of the middle plate 24. The fifth flow channel 245 and the sixth flow channel 246 output the nylon melt at an angle, so that the nylon melt at the second diversion filter 22 flows in a wave shape.

[0095] 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 the spinneret hole can be more complex and diversified, which is conducive to forming special profiled cross-sectional structures, such as the common orange segment shape and the cross-shaped cross-sectional structure; these profiled cross-sectional structures can increase the specific surface area of ​​the fiber, giving the fiber better moisture absorption, moisture conduction, breathability and other properties; 2. When the upstream melt pressure fluctuates, the wave-shaped flow can absorb and alleviate this pressure change to a certain extent, making the melt pressure more stable before reaching the spinneret hole, ensuring the stability of the spinning process, and reducing the problems of broken wires and uneven thickness caused by pressure fluctuations; 3. In actual production, polyester and nylon melts may have uneven flow due to differences in physical properties. The wave-shaped flow can fine-tune the flow 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 product quality.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing bright polyester and nylon ultrafine fibers, characterized in that: The following steps are involved: Step S1, raw material preparation, heating and drying the selected shiny polyester slices and shiny nylon slices to a moisture content of <0.05%; Step S2, polyester melt extrusion, adding the dried shiny polyester slices into a first screw extruder for heating and melting, wherein the heating temperature of the first zone of the first screw extruder is 280-290° C., the heating temperature of the second zone is 290-300° C., the heating temperature of the third zone is 300-310° C., and the screw speed is 30-40 r / min, so as to obtain a fully melted and uniform polyester melt; Step S3, nylon melt extrusion, adding the dried shiny nylon slices into a second screw extruder for heating and melting, wherein the heating temperature of the first zone of the second screw extruder is 240-250° C., the heating temperature of the second zone is 250-260° C., the heating temperature of the third zone is 260-270° C., and the screw speed is 25-35 r / min, so as 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 input into the composite spinning assembly (I), the polyester melt and the nylon melt are evenly composited at the spinneret hole (10), and extruded to form a bright polyester-nylon ultrafine fiber with a core layer of nylon melt and a skin layer of polyester melt; Step S5, primary stretching, after the bright polyester nylon ultrafine fiber is solidified, primary stretching is performed, the stretching temperature is 70-80°C, the stretching multiple is 2.0-2.5 times, and the stretching speed is 1000-1200m / min; Step S6, secondary stretching, the bright polyester and nylon ultrafine fibers after the treatment in step S5 are subjected to secondary stretching, the stretching temperature is 120-130° C., the stretching multiple is 1.3-1.5 times, and the stretching speed is 1200-1400 m / min; Step S7, heat setting: after the treatment in step S6, the heat setting temperature of the bright polyester and nylon microfiber is 180-200°C, the time is 30-40s, and the tension is controlled to be 0.08-0.12cN / dtex; Step S8, winding, the shiny polyester-nylon ultrafine fiber that has been heat-set in step S7 is neatly wound on a bobbin at a winding speed of 3000-3500 m / min.

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

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

8.

4. The method for preparing a bright polyester-nylon ultrafine fiber according to claim 1, characterized in that: In the step S4, the polyester melt and the nylon melt are sequentially passed 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) from top to bottom for diversion processing; When the polyester melt and the nylon melt are divided in the second distribution plate (2), they are divided and filtered by a first flow dividing filter (21) and a second flow dividing filter (22) which are rotatably arranged inside.

5. The method for preparing a bright polyester-nylon ultrafine fiber according to claim 4, characterized in that: The second distribution plate (2) comprises, 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 respectively coaxially rotated on the lower plate (25), and the polyester melt and the 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 the second diversion filter (22), so that the first diversion filter (21) and the second diversion filter (22) are rotated.

6. The method for preparing a bright polyester-nylon ultrafine fiber according to claim 5, characterized in that: The first flow-dividing filter screen (21) and the second flow-dividing filter screen (22) both comprise a plurality of partitions (211) arranged equidistantly in a circumference, the partitions (211) being connected via a filter screen (212), and arc-shaped filter grooves (213) are arranged on the filter screen (212).

7. The method for preparing bright polyester-nylon ultrafine fiber according to claim 5, characterized in that: Features: The first flow channel (241) and the second flow channel (242) are respectively arranged tangentially and inclined along the rotation direction of the corresponding first flow diversion filter (21) and second flow diversion filter (22), and multiple groups of the first flow channel (241) and the second flow channel (242) are arranged, and the first flow channel (241) and the second flow channel (242) are respectively arranged at equal distances around the central axis of the middle plate (24).

8. The method for preparing a bright polyester-nylon ultrafine fiber according to claim 7, characterized in that: A third flow channel (243) and a fourth flow channel (244) are respectively arranged at intervals between adjacent first flow channels (241), and the third flow channel (243) and the fourth flow channel (244) are arranged in a staggered manner; The third flow channel (243) is arranged to be inclined outward along the radial direction of the middle plate (24), and the fourth flow channel (244) is arranged to be inclined inward along the radial direction of the middle plate (24). The third flow channel (243) and the fourth flow channel (244) output the polyester melt at an angle, so that the polyester melt at the first diversion filter (21) flows in a wave shape.

9. The method for preparing a bright polyester-nylon ultrafine fiber according to claim 7, characterized in that: A fifth flow channel (245) and a sixth flow channel (246) are respectively arranged at intervals between adjacent second flow channels (242), and the fifth flow channel (245) and the sixth flow channel (246) are arranged in a staggered manner; The fifth flow channel (245) is arranged to be inclined outward along the radial direction of the middle plate (24), and the sixth flow channel (246) is arranged to be inclined inward along the radial direction of the middle plate (24). The fifth flow channel (245) and the sixth flow channel (246) output the nylon melt at an angle, so that the nylon melt at the second diversion filter (22) flows in a wave shape.

10. The method for preparing bright polyester-nylon ultrafine fiber according to claim 5, characterized in that: The upper plate (23), the middle plate (24) and the lower plate (25) are integrally connected by diffusion welding, and the end surfaces of the middle plate (24) connected to the upper plate (23) and the lower plate (25) are arranged in a staggered manner with concave and convex shapes.

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