A core yarn broken and fuzzed polyester fiber and its preparation method

Abstract

The present invention belongs to the technical field of chemical fiber production, and relates to a core yarn broken and fuzzed polyester fiber and a preparation method thereof. The core yarn broken and fuzzed polyester fiber is a filament bundle composed of multiple single filaments, wherein a part of the single filaments are broken, and the remaining part are unbroken single filaments. The broken single filaments are distributed inside the unbroken single filaments, and one end of all the broken single filaments protrudes to the outside of the unbroken single filaments; the preparation method is as follows: after the polyester melt is extruded from the spinneret, it successively passes through cooling, oiling, pre-networking, G / R1 hot roll drafting, G / R2 hot roll drafting, main networking and winding to obtain the core yarn broken and fuzzed polyester fiber; the spinneret is provided with n circles of spinneret holes with the same aperture; from the inside to the outside of the spinneret, it can be divided into inner and outer spinneret holes; the upper surface of the spinneret is a plane, and the lower surface is an arc-shaped bottom surface. The present invention can produce polyester fibers with different numbers and densities of broken fuzz, and the obtained products have good fluffiness and resilience performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical fiber production, and relates to a core yarn broken and fuzzed polyester fiber and a preparation method thereof. Background Art

[0002] At present, there are three production methods for wool-like polyester fibers.

[0003] The first one is that under the action of external force, the single filaments in the tow that come into contact with the external force break and protrude from the tow to form a hairiness effect. For example, in Patent CN109295531A, imitation wool FDY is prepared by rubbing the outer layer filaments with a friction device during the drawing process, and in Patent CN114232156A, the outer layer broken wool yarn is prepared by using discs and oil wheels with a high coefficient of friction.

[0004] The second one is through the compounding of finished fibers, and by using the difference in shrinkage, an outer looped yarn is formed, similar to the effect of broken and fibrillated fibers. For example, in Patent CN110747552A, two yarns are plied and shrunk to form a looped yarn, and in Patent CN101177822A, a polyester ATY imitation wool yarn is prepared by winding and covering to break the surface skin yarn.

[0005] The third one is to soften the single filaments in the polyester fiber through the action of acid or alkali to achieve the effect of softening and fibrillating the wool yarn. For example, in Patent CN116892074A, an organic acid solution is used to fibrillate a polyester-polyamide composite superfine fiber to obtain an acid-fibrillated fiber fabric; in Patent CN110106649A, a 3%-8% sodium hydroxide padding solution acts on the fiber to form a fibrillating process; in Patent CN109629265A, a sand washing softening and fibrillating process is formed by softening the fiber with a mixture of yarn washing powder and soda ash.

[0006] However, the wool-like polyester fibers produced by these methods mostly have the outer single filaments broken or aggregated, and the formed hairiness is attached hairiness. This kind of hairiness only has the fluffiness of the wool yarn, and the fabric has poor bulkiness and air permeability, and the fabric does not have resilience.

[0007] Therefore, it is of great significance to study a core yarn broken and fuzzed polyester fiber and a preparation method thereof to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to solve the problems existing in the prior art, and provide a core yarn broken and fuzzed polyester fiber and a preparation method thereof.

[0009] To achieve the above purpose, the technical scheme adopted by the present invention is as follows:

[0010] A core yarn broken and fuzzed polyester fiber is a tow composed of multiple monofilaments. Among them, a part of the monofilaments are broken, and the rest are unbroken monofilaments. The broken monofilaments are distributed inside the unbroken monofilaments, and one end of all the broken monofilaments protrudes to the outside of the unbroken monofilaments;

[0011] The fineness of the core yarn broken and fuzzed polyester fiber is 55 - 223 dtex, the total number of monofilaments is 72 - 216, dpf≥0.5, and the number of broken monofilaments is 48 - 62% of the total number of monofilaments.

[0012] As a preferred technical solution:

[0013] For the core yarn broken and fuzzed polyester fiber as described above, the broken hairiness length of the core yarn broken and fuzzed polyester fiber is 0.2 - 0.6 cm, the hairiness density is 880 - 2240 pieces / m, the breaking strength is 4.10 - 4.40 cN / dtex, the CV value of the breaking strength ≤2.90%, the breaking elongation is 28 - 33%, the CV value of the breaking elongation ≤6.50%, the bulkiness ≥85%, and the resilience rate ≥90%; for the core yarn broken and fuzzed polyester fiber of the present invention, the hairiness is formed by the breakage of the inner monofilaments, and the broken monofilaments protrude from the inside to the outside (the number of outer monofilaments is small, and the hairiness length after the breakage of the inner monofilaments is much larger than the outer circle monofilament diameter, so the broken monofilaments can expose the surface of the composite filament), and support the outer monofilaments; the outer monofilaments are supported by the hairiness to form a three-dimensional air isolation layer, so it has good bulkiness. Because the inner monofilaments break and protrude around the tow, its hairiness density and length are uniform and it is not easy to change its external form by external force, and it has good resilience performance.

[0014] The present invention also provides a preparation method of the core yarn broken and fuzzed polyester fiber as described in any one of the above. After the polyester melt enters the spinneret and is extruded, it successively passes through cooling, oiling, pre-networking, G / R1 hot roll drawing, G / R2 hot roll drawing, main networking and winding to obtain the core yarn broken and fuzzed polyester fiber;

[0015] The spinneret is provided with n circles of spinneret holes, n is 4 - 6, and the apertures of the spinneret holes are the same; from the inside to the outside of the spinneret, the spinneret holes of the 1st circle to the (n - 1)th circle or the (n - 2)th circle are the inner spinneret holes, and the spinneret holes of the remaining circles are the outer spinneret holes;

[0016] The upper surface of the spinneret is a flat surface, and the lower surface is provided with an arc-shaped groove. The vertical projection of the arc-shaped groove on the upper surface of the spinneret is circular. Along the radial direction of the circle, the depth corresponding to the arc-shaped groove gradually decreases from the inside to the outside. The output end of the inner spinneret hole is located within the arc-shaped groove, and the central axis of the arc-shaped groove coincides with the central axis of the spinneret. The output end of the outer spinneret hole is located outside the arc-shaped groove. The output end of the outer spinneret hole cannot be located within the arc-shaped groove because the outer long diameter ratio is different. Even if the outer single filaments do not break, there will still be a certain stretching difference, resulting in uneven stretching of the outer single filaments.

[0017] The aperture of the inner spinneret hole is 0.14 - 0.30 mm, the long diameter ratio of the inner spinneret hole is 1.7 - 2.3, and the long diameter ratio of the outer spinneret hole is 2.7 - 3.3. The total number of spinneret holes is 72 - 216, and the number of inner spinneret holes is 48 - 62% of the total number of spinneret holes.

[0018] The draw ratio of the G / R1 hot roll and the G / R2 hot roll is equal to the theoretical draw ratio of the filaments extruded from the outer spinneret holes and greater than the theoretical draw ratio of the filaments extruded from the inner spinneret holes. The theoretical draw ratio is the draw ratio at which the filaments will not be broken under the speeds of the G / R1 hot roll and the G / R2 hot roll.

[0019] After the polyester melt enters the spinneret, the arc-shaped groove on the lower surface of the spinneret is used to make the thickness of the spinneret gradually increase from the inside to the outside along the radial direction, so as to achieve the effect that the long diameter ratios of the spinneret holes in different circles are different. The long diameter ratio of the outer spinneret holes is larger than that of the inner spinneret holes. The residence time of the melt from the inlet to the outlet of the outer spinneret holes is long, and the bulking ratio decreases (the spinneret temperature is high, the residence time is long, the viscosity decreases, the internal stress weakens, and the bulking ratio decreases accordingly), and the spinneret draw decreases. This makes the outer single filaments more tensile-resistant than the inner single filaments under the subsequent draw of the G / R1 hot roll and the G / R2 hot roll. And in different circles, as the long diameter ratio increases, the single filaments are more tensile-resistant. By reasonably setting the speeds of the G / R1 hot roll and the G / R2 hot roll, the single filaments extruded from the inner spinneret holes are broken, while the single filaments extruded from the outer spinneret holes are not broken. The reason why the single filaments with lower spinneret draw are more tensile-resistant under the subsequent draw of the G / R1 hot roll and the G / R2 hot roll is that for the single filaments with the same extrusion fineness from the same spinneret, their relative draw ratios have finiteness and consistency. The spinneret draw of the outer single filaments is relatively smaller than that of the inner single filaments, and the remaining draw of the outer single filaments is relatively more than that of the inner single filaments, so the outer single filaments are more tensile-resistant.

[0020] As a preferred technical solution:

[0021] For the preparation method of the core yarn broken and fuzzed polyester fiber as described above, the cooling is two-way mixed cooling. The device used for two-way mixed cooling includes an annular air blowing cooling device and a micro-mist cooling device.

[0022] The ring blow cooling device is a prior art. The ring blow cooling device includes a ring blow air box and a ring blow filter element; the blow air box includes an air box body and an upper cover plate; the ring blow filter element is arranged inside the air box body, and the top of the ring blow filter element is hermetically connected to the upper cover plate through a ring blow filter element gasket; through holes are provided in the upper cover plate and the bottom of the air box, the inner diameter of the ring blow filter element is equal to the inner diameter of the through hole, and the central axis of the ring blow filter element coincides with the central axis of the through hole; the central axis of the ring blow filter element coincides with the central axis of the spinneret plate, and the inner diameter of the ring blow filter element is greater than or equal to the diameter of the spinneret plate; air enters the ring blow air box from the air supply port of the ring blow air box, then blows to the circumferential surface of the ring blow filter element, and enters the inside of the ring blow filter element from the holes on the circumferential surface, so as to cool the filaments passing through the inside of the ring blow filter element;

[0023] The micro-mist cooling device includes an atomization channel, an atomization connecting pipe, an atomization nozzle, a cooling water pipe, a cooling water solenoid valve, a micro pump, a regulating valve, a pressure detector, a temperature detector, a PLC controller, a conveying pipeline and an ultrasonic atomization system;

[0024] The ultrasonic atomization system is used to provide atomized gas; the ultrasonic atomization system is a prior art;

[0025] The atomization nozzle is a rod-shaped structure with a hollow interior; a plurality of spray holes are provided on the circumferential surface of the atomization nozzle, and the spray holes are communicated with the inside of the atomization nozzle; the atomization nozzle is vertically placed inside the ring blow air box, and the vertical projection of the atomization nozzle on the spinneret plate is located inside the first ring of spinneret holes;

[0026] The atomization channel is arranged inside the upper cover plate of the ring blow air box. One end of the atomization channel is communicated with the inside of the atomization nozzle through an atomization connecting pipe, and the other end is connected to the ultrasonic atomization system through a conveying pipeline. The ultrasonic atomization system provides atomized gas, which is ejected from the atomization nozzle to achieve micro-mist cooling; the diameter of the atomization connecting pipe is 5 mm, the distance between adjacent spinneret holes in the same ring on the spinneret plate is greater than 6 mm, and the vertical projection of the atomization connecting pipe on the spinneret plate does not contact the spinneret holes;

[0027] The number of the atomization connecting pipes, the atomization channels and the atomization nozzles is the same as the number of the ring blow filter elements, and each ring blow filter element corresponds to an atomization connecting pipe, an atomization channel and an atomization nozzle;

[0028] The cooling water pipe is connected to the ultrasonic atomization system, and a cooling water solenoid valve is provided on the cooling water pipe. The cooling water solenoid valve is used to regulate the flow rate of cold water entering the ultrasonic atomization system;

[0029] The regulating valve, the pressure detector, the temperature detector and the micro pump are arranged on the conveying pipeline; the setting position of the micro pump is closer to the ultrasonic atomization system than the positions of the regulating valve, the pressure detector and the temperature detector; the micro pump is used to pressurize the atomized gas in the conveying pipeline;

[0030] The regulating valve, pressure detector, temperature detector and cooling water solenoid valve are all electrically connected to the PLC controller;

[0031] The temperature detector is used to detect the temperature of the atomized gas in the conveying pipeline, send the measured temperature of the atomized gas to the PLC controller, and compare it with the temperature set in the PLC controller. When the absolute value of the difference between the measured temperature of the atomized gas and the set temperature exceeds 0.5 °C, the PLC controller adjusts the cooling water solenoid valve to control the flow rate of cold water, so as to stabilize the temperature of the atomized gas;

[0032] The regulating valve is used to regulate the pressure of the conveying pipeline;

[0033] The pressure detector is used to detect the pressure of the atomized gas, send the measured pressure of the atomized gas to the PLC controller, and compare it with the pressure set in the PLC controller. When the absolute value of the difference between the measured pressure of the atomized gas and the set pressure exceeds 5% of the set value, the PLC controller adjusts the regulating valve to stabilize the pressure of the atomized gas;

[0034] The two-way hybrid cooling includes micro-mist cooling and ring blowing cooling. The micro-mist cooling rapidly cools the single filaments extruded from the inner spinneret holes, and the ring blowing cooling conventionally cools the single filaments extruded from the outer spinneret holes, so that the composite filaments have the effect of being brittle inside and tough outside, making full preparations for making the inner core yarn broken and fuzzed polyester fiber (that is, at the speeds of the G / R1 hot roller and the G / R2 hot roller, the single filaments extruded from the inner spinneret holes are easier to break, while the single filaments extruded from the outer spinneret holes are less likely to break).

[0035] In the preparation method of the core yarn broken and fuzzed polyester fiber as described above, a tension detection device is provided between the G / R1 hot roller and the G / R2 hot roller. The tension detection device includes a tension sensor. The tension detection device is used to detect the tension when all the single filaments extruded from the inner spinneret holes break (the inner single filament breaking tension is much greater than the drawing tension, so the tension detection sensor detects the tension at break, rather than the overall tension of the composite filaments), and real-time detects whether all the inner single filaments break; among them, the tension when all the single filaments extruded from the inner spinneret holes break = the sum of the breaking strengths of the inner single filament fineness and the pre-oriented filaments of the inner single filaments. The drawing tension can be adjusted by adjusting the speed of the G / R1 hot roller. For example, when the tension is low, the speed of the G / R1 hot roller is reduced, the draw ratio increases, and the tension increases; when the tension is low, the opposite adjustment is made.

[0036] A preparation method of a core yarn broken and fuzzed polyester fiber as described above, the process parameters include: the temperature of the spinning box is 280 - 295 °C, the power of the micro-mist cooling pump is 10 - 15 W, the temperature of the atomizing gas is 15 - 19 °C, the pressure of the atomizing gas is 30 - 50 Pa, the temperature of the ring blowing is 19 - 22 °C, the wind speed of the ring blowing is 0.2 - 0.5 m / s, the rotation speed of the oil agent pump is 3.5 - 9.5 r / min, the pre-network pressure is 0.10 - 0.15 MPa, the speed of the G / R1 hot roller is 1900 - 2200 m / min, the tension is 84 - 290 cN, the speed of the G / R2 hot roller is 3900 - 4200 m / min, and the main network pressure is 0.25 - 0.35 MPa.

[0037] Beneficial effects:

[0038] (1) In the present invention, the aspect ratio of the inner spinneret holes on the spinneret plate is controlled to gradually increase, so that the residence time of the melt in the spinneret holes of different circles is different (the higher the spinneret plate temperature, the longer the residence time, the lower the viscosity, the weaker the internal stress, and the lower the bulking ratio), and the draw ratio will also be different. In the subsequent stretching process, the larger the aspect ratio, the more tensile-resistant the single filament. By forming this internal and external stretching difference, finally, the broken hairs in the produced polyester fiber have a gradual change level (that is, the innermost circle breaks first and most easily, and the degree of breakage gradually weakens outward compared to the innermost side, forming broken hairs with a gradual change level).

[0039] (2) In the present invention, the single filaments extruded from the inner spinneret holes are rapidly cooled by micro-mist cooling, and the single filaments extruded from the outer spinneret holes are conventionally cooled by ring blowing, so that the composite filaments have the effect of being brittle inside and tough outside. When stretching the composite filaments, the single filaments extruded from the inner spinneret holes are easier to break, while the single filaments extruded from the outer spinneret holes are more difficult to break.

[0040] (3) In the present invention, by controlling the number of the inner spinneret holes on the spinneret plate and the degree of difference in the aspect ratio (the greater the difference, the more and denser the hairs), polyester fibers with different numbers and densities of broken hairs can be produced, making the prepared product have better bulkiness and resilience. Description of the drawings

[0041] Figure 1 It is a schematic diagram of the distribution of the spinneret holes on the spinneret plate of the present invention;

[0042] Figure 2 It is a cross-sectional schematic diagram of the spinneret hole of the present invention;

[0043] Figure 3 It is a schematic diagram of the ring blowing cooling device of the present invention;

[0044] Figure 4 It is a schematic diagram of the micro-mist cooling device of the present invention;

[0045] Figure 5 Schematic diagram of the core yarn broken and fuzzed polyester fiber of the present invention;

[0046] Wherein: 1 - spinneret plate, 3 - spinneret holes, 4 - arc-shaped grooves, 5 - upper cover plate, 6 - ring blow filter gasket, 7 - ring blow filter, 8 - air supply port, 10 - atomization channel, 11 - atomization connecting pipe, 12 - atomization nozzle, 13 - cooling water pipe, 14 - cooling water solenoid valve, 15 - ultrasonic atomization system, 16 - micro pump, 17 - regulating valve, 18 - pressure detector; 19 - temperature detector, 20 - conveying pipeline, 21 - broken single filaments, 22 - unbroken single filaments. Specific embodiments

[0047] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0048] The calculation method of the aspect ratio of the inner spinneret holes on the spinneret plate of the present invention: The outlet of the inner spinneret holes is a curved surface, and the aspect ratio of the inner spinneret holes = the length of the spinneret hole / the diameter of the spinneret hole; wherein, the length of the spinneret hole is the length from point A to point B, point A is the point where the central axis of the spinneret hole intersects the plane where the top end of the spinneret hole is located, and point B is the point where the central axis of the spinneret hole intersects the curved surface where the outlet of the spinneret hole is located.

[0049] The test methods for the relevant performance indicators in the following examples and comparative examples are as follows:

[0050] dpf: First, refer to the "GB / T14343-2008 Test Method for Linear Density of Chemical Fiber Filament Yarns" to test the total linear density of the core yarn broken and fuzzed polyester fiber prepared in the example, and then divide it by the total number of single filaments.

[0051] Breaking strength, breaking strength CV value, breaking elongation, breaking elongation CV value: Refer to the standard of "GB / T 14344-2008 Test Method for Tensile Properties of Synthetic Fiber Filaments", and use an imported fully automatic strength and elongation tester to test the core yarn broken and fuzzed polyester fiber prepared in each example.

[0052] Bulkiness: Refer to the "GB / T 10288-2016 Testing Methods for Down and Feather" to test the core yarn broken and fuzzed polyester fiber prepared in the example.

[0053] Rebound rate: Referring to the standard of "FZ / T 01034-2008 Test method for tensile elasticity of woven fabrics", an isometric elongation tester is used to deform the core yarn broken and fuzzed polyester fiber prepared in the example by tensile force with fixed length and fixed force. The tensile process is from the initial length of 100 mm to 115 mm, the tensile speed is 20 mm / min. After releasing the tensile force, the residual elongation is measured after recovery within the specified time, and then the elastic recovery rate is calculated through the calculation formula: (L0 - δL1) / (L0 - δL)×100%, where L0 is the total length of the specimen after stretching, δL is the length of the specimen after applying pre-tension, and δL1 is the length of the specimen after applying pre-tension again after the fixed force or fixed elongation recovery (plastic deformation amount).

[0054] Example 1

[0055] A preparation method of core yarn broken and fuzzed polyester fiber is as follows:

[0056] (1) Polycondense PTA (terephthalic acid) and MEG (monoethylene glycol) with a mass ratio of 2.55:1 into a polyester melt with an intrinsic viscosity of 0.695±0.004 dl / g;

[0057] (2) The polyester melt enters the spinning box, and after being extruded through the spinneret, it successively passes through cooling, oiling, pre-networking, G / R1 hot roll drawing, G / R2 hot roll drawing, main networking and winding to obtain the core yarn broken and fuzzed polyester fiber;

[0058] Among them, as Figure 1 、 Figure 2 shown, the upper surface of the spinneret 1 is a plane, and the lower surface is provided with an arc-shaped groove 4. The vertical projection of the arc-shaped groove 4 on the spinneret 1 is circular. Along the radial direction of the circle, the depth of the arc-shaped groove 4 gradually decreases from inside to outside; the output end of the inner spinneret hole is located in the arc-shaped groove, and the central axis of the arc-shaped groove coincides with the central axis of the spinneret;

[0059] There are 5 circles of spinneret holes 3 on the spinneret 1, and the pore diameters of the spinneret holes 3 are the same; from the inside to the outside of the spinneret 1, the 1st to 3rd circles of spinneret holes 3 are inner spinneret holes, and the remaining circles of spinneret holes 3 are outer spinneret holes; the pore diameter of the inner spinneret hole is 0.19 mm, and the length-diameter ratios of the 1st to 3rd circles of inner spinneret holes are 1.7, 2.0, 2.3 respectively, and the length-diameter ratio of the outer spinneret hole is 2.9; the number of spinneret holes 3 is 144, and the number of inner spinneret holes is 50% of the total number of spinneret holes 3. The number of spinneret holes in each circle from the 1st to 5th circles is 20, 24, 28, 32, 40 respectively;

[0060] Cooling adopts two-way mixed cooling, and the device used for two-way mixed cooling includes a ring blowing cooling device and a micro-mist cooling device;

[0061] As Figure 3 shown, the ring blow cooling device includes a ring blow air box and a ring blow filter element 7; the blow air box includes an air box body and an upper cover plate 5; the ring blow filter element 7 is arranged inside the air box body, and the top of the ring blow filter element 7 is hermetically connected to the upper cover plate 5 through a ring blow filter element gasket 6;

[0062] As Figure 3 、 Figure 4 shown, the micro-mist cooling device includes an atomization channel 10, an atomization connecting pipe 11, an atomization nozzle 12, a cooling water pipe 13, a cooling water solenoid valve 14, an ultrasonic atomization system 15, a micro pump 16, a regulating valve 17, a pressure detector 18, a temperature detector 19, a PLC controller and a conveying pipe 20;

[0063] The ultrasonic atomization system 15 is used to provide atomized gas;

[0064] The atomization nozzle 12 is a rod-shaped structure with a hollow interior; a plurality of spray holes are provided on the circumferential surface of the atomization nozzle 12, and the spray holes communicate with the interior of the atomization nozzle 12; the atomization nozzle 12 is vertically arranged inside the ring blow air box, and the vertical projection of the atomization nozzle 12 on the spinneret plate 1 is located inside the first ring of spinneret holes 3;

[0065] The atomization channel 10 is arranged inside the upper cover plate of the ring blow air box. One end of the atomization channel 10 communicates with the interior of the atomization nozzle 12 through the atomization connecting pipe 11, and the other end is connected to the ultrasonic atomization system through the conveying pipe 20. The vertical projection of the atomization connecting pipe 11 on the spinneret plate 1 does not contact the spinneret holes 3;

[0066] The numbers of the atomization connecting pipe 11, the atomization channel 10 and the atomization nozzle 12 are the same as the number of the ring blow filter elements 7;

[0067] The cooling water pipe 13 is connected to the ultrasonic atomization system, and a cooling water solenoid valve 14 is provided on the cooling water pipe 13. The cooling water solenoid valve 14 is used to regulate the flow rate of cold water entering the ultrasonic atomization system;

[0068] The regulating valve 17, the pressure detector 18, the temperature detector 19 and the micro pump 16 are arranged on the conveying pipe 20; the setting position of the micro pump 16 is closer to the ultrasonic atomization system than the positions of the regulating valve 17, the pressure detector 18 and the temperature detector 19; the micro pump 16 is used to pressurize the atomized gas in the conveying pipe 20;

[0069] The regulating valve 17, the pressure detector 18, the temperature detector 19 and the cooling water solenoid valve 14 are all electrically connected to the PLC controller;

[0070] The temperature detector 19 is used to detect the temperature of the atomized gas in the conveying pipeline 20, send the measured temperature of the atomized gas to the PLC controller, and compare it with the set temperature in the PLC controller. When the absolute value of the difference between the measured temperature of the atomized gas and the set temperature exceeds 0.5 °C, the PLC controller adjusts the cooling water solenoid valve 14 to control the flow rate of the cold water;

[0071] The regulating valve 17 is used to regulate the pressure of the conveying pipeline 20;

[0072] The pressure detector 18 is used to detect the pressure of the atomized gas, send the measured pressure of the atomized gas to the PLC controller, and compare it with the set pressure in the PLC controller. When the absolute value of the difference between the measured pressure of the atomized gas and the set pressure exceeds 5% of the set value, the PLC controller adjusts the regulating valve 17;

[0073] A tension detection device is provided between the G / R1 hot roller and the G / R2 hot roller;

[0074] The process parameters include: the temperature of the spinning box is 285 °C, the power of the micro-mist cooling pump is 12 W, the temperature of the atomized gas is 17 °C, the pressure of the atomized gas is 40 Pa, the temperature of the ring blowing is 21 °C, the wind speed of the ring blowing is 0.3 m / s, the rotation speed of the oil agent pump is 6.5 r / min, the pre-network pressure is 0.125 MPa, the speed of the G / R1 hot roller is 2050 m / min, the tension when all the single filaments extruded from the inner spinneret holes break is 138 cN, the speed of the G / R2 hot roller is 4000 m / min, and the main network pressure is 0.29 MPa.

[0075] The finally obtained core yarn broken and hairy polyester fiber is as Figure 5 shown, which is a filament bundle composed of multiple single filaments. Among them, some single filaments are broken, and the rest are unbroken single filaments 22. The broken single filaments 21 are distributed inside the unbroken single filaments 22, and one end of all the broken single filaments 21 protrudes to the outside of the unbroken single filaments 22; the fineness of the core yarn broken and hairy polyester fiber is 112.76 dtex, the total number of single filaments is 144, the dpf is 0.783, and the number of broken single filaments is 50% of the total number of single filaments; the broken hairiness of the core yarn broken and hairy polyester fiber has a gradual change level, the length of the broken hairiness is 0.2 - 0.6 cm, the hairiness density is 1480 roots / m, the breaking strength is 4.16 cN / dtex, the CV value of the breaking strength is 1.97%, the breaking elongation is 31.3%, the CV value of the breaking elongation is 3.78%, the bulkiness is 89%, and the resilience is 90%.

[0076] Example 2

[0077] A method for preparing a core yarn broken and hairy polyester fiber, the specific process is as follows:

[0078] (1) Polycondense PTA and MEG with a mass ratio of 2.55:1 to form a polyester melt with an intrinsic viscosity of 0.695 ± 0.004 dl / g;

[0079] (2) The polyester melt enters the spinning box, and after being extruded through the spinneret plate, it successively passes through cooling, oiling, pre-networking, G / R1 hot roll drawing, G / R2 hot roll drawing, main networking, and winding to obtain a core yarn broken and fuzzed polyester fiber;

[0080] Among them, the upper surface of the spinneret plate is a plane, and the lower surface is provided with an arc-shaped groove. The vertical projection of the arc-shaped groove on the spinneret plate is circular. Along the radial direction of the circle, the depth of the arc-shaped groove gradually decreases from the inside to the outside; the output end of the inner spinneret holes is located in the arc-shaped groove, and the central axis of the arc-shaped groove coincides with the central axis of the spinneret plate;

[0081] There are 5 circles of spinneret holes on the spinneret plate, and the apertures of the spinneret holes are the same; from the inside to the outside of the spinneret plate, the 1st to 3rd circles of spinneret holes are inner spinneret holes, and the remaining circles of spinneret holes are outer spinneret holes; the aperture of the inner spinneret holes is 0.14 mm, and the length-diameter ratios of the 1st to 3rd circles of inner spinneret holes are 1.7, 2.0, and 2.3 respectively, and the length-diameter ratio of the outer spinneret holes is 2.7; the number of spinneret holes is 144, and the number of inner spinneret holes is 50% of the total number of spinneret holes. The number of spinneret holes in each circle from the 1st to 5th circles is 20, 24, 28, 32, and 40 respectively;

[0082] Cooling is carried out by two-way mixed cooling. The device used for two-way mixed cooling includes an annular blowing cooling device and a micro-mist cooling device;

[0083] The annular blowing cooling device includes an annular blowing air box and an annular blowing filter element; the blowing air box includes an air box body and an upper cover plate; the annular blowing filter element is arranged inside the air box body, and the top of the annular blowing filter element is hermetically connected to the upper cover plate through an annular blowing filter element gasket;

[0084] The micro-mist cooling device includes an atomization channel, an atomization connecting pipe, an atomization nozzle, a cooling water pipe, a cooling water solenoid valve, an ultrasonic atomization system, a micro pump, a regulating valve, a pressure detector, a temperature detector, a PLC controller, a conveying pipeline, and an ultrasonic atomization system;

[0085] The ultrasonic atomization system is used to provide atomized gas;

[0086] The atomization nozzle is a rod-shaped structure with a hollow interior; a plurality of spray holes are provided on the circumferential surface of the atomization nozzle, and the spray holes are communicated with the interior of the atomization nozzle; the atomization nozzle is vertically placed, located inside the annular blowing air box, and the vertical projection of the atomization nozzle on the spinneret plate is located inside the 1st circle of spinneret holes;

[0087] The atomization channel is arranged inside the upper cover plate of the ring blow air box. One end of the atomization channel is communicated with the inside of the atomization nozzle through an atomization connecting pipe, and the other end is connected with the ultrasonic atomization system through a conveying pipeline. The vertical projection of the atomization connecting pipe on the spinneret plate does not contact the spinneret holes;

[0088] The number of atomization connecting pipes, atomization channels and atomization nozzles is the same as the number of ring blow filters;

[0089] The cooling water pipe is connected with the ultrasonic atomization system. A cooling water solenoid valve is arranged on the cooling water pipe, and the cooling water solenoid valve is used to adjust the flow rate of cold water entering the ultrasonic atomization system;

[0090] A regulating valve, a pressure detector, a temperature detector and a micro pump are arranged on the conveying pipeline; The setting position of the micro pump is closer to the ultrasonic atomization system than the positions of the regulating valve, the pressure detector and the temperature detector; The micro pump is used to pressurize the atomization gas in the conveying pipeline;

[0091] The regulating valve, the pressure detector, the temperature detector and the cooling water solenoid valve are all electrically connected to the PLC controller;

[0092] The temperature detector is used to detect the temperature of the atomization gas in the conveying pipeline, send the measured temperature of the atomization gas to the PLC controller, and compare it with the set temperature in the PLC controller. When the absolute value of the difference between the measured temperature of the atomization gas and the set temperature exceeds 0.5°C, the PLC controller adjusts the cooling water solenoid valve to control the flow rate of cold water;

[0093] The regulating valve is used to adjust the pressure of the conveying pipeline;

[0094] The pressure detector is used to detect the atomization gas pressure, send the measured atomization gas pressure to the PLC controller, and compare it with the set pressure in the PLC controller. When the absolute value of the difference between the measured atomization gas pressure and the set pressure exceeds 5% of the set value, the PLC controller adjusts the regulating valve;

[0095] A tension detection device is arranged between the G / R1 hot roll and the G / R2 hot roll;

[0096] The process parameters include: the temperature of the spinning box is 290°C, the power of the micro mist cooling pump is 12W, the temperature of the atomization gas is 17°C, the pressure of the atomization gas is 40Pa, the temperature of the ring blow is 20°C, the wind speed of the ring blow is 0.2m / s, the rotation speed of the oil agent pump is 5r / min, the pre-network pressure is 0.1MPa, the speed of the G / R1 hot roll is 2200m / min, the tension when all the monofilaments extruded from the inner spinneret holes break is 103cN, the speed of the G / R2 hot roll is 3900m / min, and the main network pressure is 0.25MPa.

[0097] The finally obtained core yarn broken and fuzzed polyester fiber is a tow composed of multiple monofilaments. Among them, a part of the monofilaments are broken, and the remaining part are unbroken monofilaments. The broken monofilaments are distributed inside the unbroken monofilaments, and one end of all the broken monofilaments protrudes to the outside of the unbroken monofilaments; the fineness of the core yarn broken and fuzzed polyester fiber is 83.64 dtex, the total number of monofilaments is 144, the dpf is 0.581, and the number of broken monofilaments is 50% of the total number of monofilaments; the broken fuzz of the core yarn broken and fuzzed polyester fiber has a gradient layer, the length of the broken fuzz is 0.2 - 0.6 cm, the fuzz density is 1390 roots / m, the breaking strength is 4.25 cN / dtex, the CV value of the breaking strength is 2.18%, the breaking elongation is 28.6%, the CV value of the breaking elongation is 3.32%, the bulkiness is 91%, and the resilience rate is 92%.

[0098] Example 3

[0099] A preparation method of a core yarn broken and fuzzed polyester fiber is as follows:

[0100] (1) Polycondense PTA and MEG with a mass ratio of 2.55:1 to form a polyester melt with an intrinsic viscosity of 0.695 ± 0.004 dl / g;

[0101] (2) The polyester melt enters the spinning box, and after being extruded through a spinneret, it successively passes through cooling, oiling, pre-networking, G / R1 hot roll drawing, G / R2 hot roll drawing, main networking, and winding to obtain the core yarn broken and fuzzed polyester fiber;

[0102] Among them, the upper surface of the spinneret is a plane, and the lower surface is provided with an arc-shaped groove. The vertical projection of the arc-shaped groove on the spinneret is circular. Along the radial direction of the circle, the depth of the arc-shaped groove gradually decreases from the inside to the outside; the output end of the inner spinneret holes is located in the arc-shaped groove, and the central axis of the arc-shaped groove coincides with the central axis of the spinneret;

[0103] There are 5 circles of spinneret holes on the spinneret, and the apertures of the spinneret holes are the same; from the inside to the outside of the spinneret, the 1st to 3rd circles of spinneret holes are inner spinneret holes, and the remaining circles of spinneret holes are outer spinneret holes; the aperture of the inner spinneret holes is 0.29 mm, and the length-diameter ratios of the 1st to 3rd circles of inner spinneret holes are 1.7, 2.0, and 2.3 respectively, and the length-diameter ratio of the outer spinneret holes is 3; the number of spinneret holes is 216, the number of inner spinneret holes is 48% of the total number of spinneret holes, and the number of spinneret holes in each circle from the 1st to 5th circles is 24, 36, 44, 52, and 60 respectively;

[0104] Cooling is carried out by two-way mixed cooling. The device used for two-way mixed cooling includes an annular air blowing cooling device and a micro-mist cooling device;

[0105] The ring blowing cooling device includes a ring blowing air box and a ring blowing filter element; the blowing air box includes an air box body and an upper cover plate; the ring blowing filter element is arranged inside the air box body, and the top of the ring blowing filter element is hermetically connected to the upper cover plate through a ring blowing filter element gasket;

[0106] The micro mist cooling device includes an atomization channel, an atomization connecting pipe, an atomization nozzle, a cooling water pipe, a cooling water solenoid valve, an ultrasonic atomization system, a micro pump, a regulating valve, a pressure detector, a temperature detector, a PLC controller, a conveying pipeline and an ultrasonic atomization system;

[0107] The ultrasonic atomization system is used to provide atomized gas;

[0108] The atomization nozzle is a rod-shaped structure with a hollow interior; a plurality of spray holes are arranged on the circumferential surface of the atomization nozzle, and the spray holes communicate with the interior of the atomization nozzle; the atomization nozzle is vertically placed inside the ring blowing air box, and the vertical projection of the atomization nozzle on the spinneret is located inside the first ring of spinneret holes;

[0109] The atomization channel is arranged inside the upper cover plate of the ring blowing air box. One end of the atomization channel is communicated with the interior of the atomization nozzle through an atomization connecting pipe, and the other end is connected to the ultrasonic atomization system through a conveying pipeline. The vertical projection of the atomization connecting pipe on the spinneret does not contact the spinneret holes;

[0110] The number of the atomization connecting pipes, the atomization channels and the atomization nozzles is the same as the number of the ring blowing filter elements;

[0111] The cooling water pipe is connected to the ultrasonic atomization system, and a cooling water solenoid valve is arranged on the cooling water pipe. The cooling water solenoid valve is used to regulate the flow of cold water into the ultrasonic atomization system;

[0112] The regulating valve, the pressure detector, the temperature detector and the micro pump are arranged on the conveying pipeline; the setting position of the micro pump is closer to the ultrasonic atomization system than the positions of the regulating valve, the pressure detector and the temperature detector; the micro pump is used to pressurize the atomized gas in the conveying pipeline;

[0113] The regulating valve, the pressure detector, the temperature detector and the cooling water solenoid valve are all electrically connected to the PLC controller;

[0114] The temperature detector is used to detect the temperature of the atomized gas in the conveying pipeline, send the measured temperature of the atomized gas to the PLC controller, and compare it with the temperature set in the PLC controller. When the absolute value of the difference between the measured temperature of the atomized gas and the set temperature exceeds 0.5 °C, the PLC controller adjusts the cooling water solenoid valve to control the flow of cold water;

[0115] The regulating valve is used to regulate the pressure of the conveying pipeline;

[0116] The pressure detector is used to detect the atomizing gas pressure, send the measured atomizing gas pressure to the PLC controller, and compare it with the pressure set in the PLC controller. When the absolute value of the difference between the measured atomizing gas pressure and the set pressure exceeds 5% of the set value, the PLC controller adjusts the regulating valve.

[0117] A tension detection device is provided between the G / R1 hot roller and the G / R2 hot roller.

[0118] The process parameters include: the temperature of the spinning box is 295°C, the power of the micro-mist cooling pump is 15W, the temperature of the atomizing gas is 15°C, the pressure of the atomizing gas is 45Pa, the temperature of the ring blowing is 19°C, the wind speed of the ring blowing is 0.5m / s, the rotation speed of the oiling pump is 8r / min, the pre-network pressure is 0.13MPa, the speed of the G / R1 hot roller is 2100m / min, the tension when all the monofilaments extruded from the inner spinneret holes break is 201cN, the speed of the G / R2 hot roller is 4200m / min, and the main network pressure is 0.3MPa.

[0119] The finally obtained core yarn broken and fuzzed polyester fiber is a filament bundle composed of multiple monofilaments. Among them, a part of the monofilaments are broken, and the rest are unbroken monofilaments. The broken monofilaments are distributed inside the unbroken monofilaments, and one end of all the broken monofilaments protrudes to the outside of the unbroken monofilaments; the fineness of the core yarn broken and fuzzed polyester fiber is 167.18dtex, the total number of monofilaments is 216, the dpf is 0.773, and the number of broken monofilaments is 48% of the total number of monofilaments; the broken fuzz of the core yarn broken and fuzzed polyester fiber has a gradual change in level, the length of the broken fuzz is 0.2 - 0.6cm, the fuzz density is 2070 pieces / m, the breaking strength is 4.35cN / dtex, the CV value of the breaking strength is 0.49%, the breaking elongation is 32.9%, the CV value of the breaking elongation is 5.24%, the bulkiness is 87%, and the resilience rate is 92%.

[0120] Example 4

[0121] A preparation method of core yarn broken and fuzzed polyester fiber is as follows:

[0122] (1) Polycondense PTA and MEG with a mass ratio of 2.55:1 to form a polyester melt with an intrinsic viscosity of 0.695 ± 0.004 dl / g.

[0123] (2) The polyester melt enters the spinning box, and after being extruded through the spinneret plate, it successively passes through cooling, oiling, pre-network, G / R1 hot roller drafting, G / R2 hot roller drafting, main network and winding to obtain the core yarn broken and fuzzed polyester fiber.

[0124] Among them, the upper surface of the spinneret is a flat surface, and the lower surface is provided with an arc-shaped groove. The vertical projection of the arc-shaped groove on the spinneret is a circle. Along the radial direction of the circle, the depth of the arc-shaped groove gradually decreases from the inside to the outside; the output end of the inner spinneret holes is located in the arc-shaped groove, and the central axis of the arc-shaped groove coincides with the central axis of the spinneret.

[0125] There are 4 circles of spinneret holes on the spinneret, and the apertures of the spinneret holes are the same; from the inside to the outside of the spinneret, the spinneret holes in the 1st to 3rd circles are inner spinneret holes, and the spinneret holes in the remaining circles are outer spinneret holes; the aperture of the inner spinneret holes is 0.19 mm, and the aspect ratios of the inner spinneret holes in the 1st to 3rd circles are 1.7, 2.0, and 2.3 respectively, and the aspect ratio of the outer spinneret holes is 3.3; the number of spinneret holes is 72, and the number of inner spinneret holes is 61% of the total number of spinneret holes. The number of spinneret holes in each circle from the 1st to 4th circles is 8, 12, 24, and 28 respectively.

[0126] Cooling adopts two-way mixed cooling. The device used for two-way mixed cooling includes a ring blowing cooling device and a micro-mist cooling device.

[0127] The ring blowing cooling device includes a ring blowing air box and a ring blowing filter element; the blowing air box includes an air box body and an upper cover plate; the ring blowing filter element is arranged inside the air box body, and the top of the ring blowing filter element is hermetically connected to the upper cover plate through a ring blowing filter element gasket.

[0128] The micro-mist cooling device includes an atomization channel, an atomization connecting pipe, an atomization nozzle, a cooling water pipe, a cooling water solenoid valve, an ultrasonic atomization system, a micro pump, a regulating valve, a pressure detector, a temperature detector, a PLC controller, a conveying pipeline, and an ultrasonic atomization system.

[0129] The ultrasonic atomization system is used to provide atomized gas.

[0130] The atomization nozzle is a rod-shaped structure with a hollow interior; there are multiple spray holes on the circumferential surface of the atomization nozzle, and the spray holes are communicated with the interior of the atomization nozzle; the atomization nozzle is vertically placed, located inside the ring blowing air box, and the vertical projection of the atomization nozzle on the spinneret is located inside the 1st circle of spinneret holes.

[0131] The atomization channel is arranged inside the upper cover plate of the ring blowing air box. One end of the atomization channel is communicated with the interior of the atomization nozzle through an atomization connecting pipe, and the other end is connected to the ultrasonic atomization system through a conveying pipeline. The vertical projection of the atomization connecting pipe on the spinneret does not contact the spinneret holes.

[0132] The number of atomization connecting pipes, atomization channels, and atomization nozzles is the same as the number of ring blowing filter elements.

[0133] The cooling water pipe is connected to the ultrasonic atomization system. A cooling water solenoid valve is provided on the cooling water pipe, and the cooling water solenoid valve is used to regulate the flow of cold water into the ultrasonic atomization system;

[0134] A regulating valve, a pressure detector, a temperature detector, and a micro pump are arranged on the conveying pipeline; the setting position of the micro pump is closer to the ultrasonic atomization system than the positions of the regulating valve, the pressure detector, and the temperature detector; the micro pump is used to pressurize the atomized gas in the conveying pipeline;

[0135] The regulating valve, the pressure detector, the temperature detector, and the cooling water solenoid valve are all electrically connected to the PLC controller;

[0136] The temperature detector is used to detect the temperature of the atomized gas in the conveying pipeline, send the measured temperature of the atomized gas to the PLC controller, and compare it with the temperature set in the PLC controller. When the absolute value of the difference between the measured temperature of the atomized gas and the set temperature exceeds 0.5 °C, the PLC controller adjusts the cooling water solenoid valve to control the flow of cold water;

[0137] The regulating valve is used to regulate the pressure of the conveying pipeline;

[0138] The pressure detector is used to detect the pressure of the atomized gas, send the measured pressure of the atomized gas to the PLC controller, and compare it with the pressure set in the PLC controller. When the absolute value of the difference between the measured pressure of the atomized gas and the set pressure exceeds 5% of the set value, the PLC controller adjusts the regulating valve;

[0139] A tension detection device is provided between the G / R1 hot roller and the G / R2 hot roller;

[0140] The process parameters include: the temperature of the spinning box is 280 °C, the power of the micro mist cooling pump is 10 W, the temperature of the atomized gas is 19 °C, the pressure of the atomized gas is 30 Pa, the temperature of the ring blowing is 22 °C, the wind speed of the ring blowing is 0.3 m / s, the rotation speed of the oil agent pump is 3.5 r / min, the pre-network pressure is 0.12 MPa, the speed of the G / R1 hot roller is 2100 m / min, the tension when all the monofilaments extruded from the inner spinneret holes break is 84 cN, the speed of the G / R2 hot roller is 4000 m / min, and the main network pressure is 0.29 MPa.

[0141] The finally obtained core yarn broken and fuzzed polyester fiber is a tow composed of multiple monofilaments, among which a part of the monofilaments are broken, and the rest are unbroken monofilaments. The broken monofilaments are distributed inside the unbroken monofilaments, and one end of all the broken monofilaments protrudes to the outside of the unbroken monofilaments; the fineness of the core yarn broken and fuzzed polyester fiber is 56.53 dtex, the total number of monofilaments is 72, the dpf is 0.785, and the number of broken monofilaments is 61% of the total number of monofilaments; the broken fuzz of the core yarn broken and fuzzed polyester fiber has a gradient layer, the length of the broken fuzz is 0.2 - 0.6 cm, the fuzz density is 880 roots / m, the breaking strength is 4.18 cN / dtex, the CV value of the breaking strength is 2.87%, the breaking elongation is 30.2%, the CV value of the breaking elongation is 4.63%, the bulkiness is 87%, and the resilience rate is 90%.

[0142] Example 5

[0143] A preparation method of core yarn broken and fuzzed polyester fiber is as follows:

[0144] (1) Polycondense PTA and MEG with a mass ratio of 2.55:1 to form a polyester melt with an intrinsic viscosity of 0.695 ± 0.004 dl / g;

[0145] (2) The polyester melt enters the spinning box, and after being extruded through the spinneret, it successively passes through cooling, oiling, pre-networking, G / R1 hot roll drawing, G / R2 hot roll drawing, main networking and winding to obtain the core yarn broken and fuzzed polyester fiber;

[0146] Among them, the upper surface of the spinneret is a plane, and the lower surface is provided with an arc-shaped groove. The vertical projection of the arc-shaped groove on the spinneret is circular. Along the radial direction of the circle, the depth of the arc-shaped groove gradually becomes smaller from the inside to the outside; the output end of the inner spinneret holes is located in the arc-shaped groove, and the central axis of the arc-shaped groove coincides with the central axis of the spinneret;

[0147] There are 6 circles of spinneret holes on the spinneret, and the aperture of the spinneret holes is the same; from the inside to the outside of the spinneret, the 1st to 4th circles of spinneret holes are inner spinneret holes, and the remaining circles of spinneret holes are outer spinneret holes; the aperture of the inner spinneret holes is 0.25 mm, and the aspect ratios of the 1st to 3rd circles of inner spinneret holes are 1.7, 1.9, 2.1, 2.3 respectively, and the aspect ratio of the outer spinneret holes is 3.2; the number of spinneret holes is 216, and the number of inner spinneret holes is 52% of the total number of spinneret holes. The number of spinneret holes in each circle from the 1st to 6th circles is 16, 24, 32, 40, 48, 56 respectively;

[0148] Cooling adopts two-way mixed cooling. The device used for two-way mixed cooling includes an annular air blowing cooling device and a micro-mist cooling device;

[0149] The ring blowing cooling device includes a ring blowing air box and a ring blowing filter element; the blowing air box includes an air box body and an upper cover plate; the ring blowing filter element is arranged inside the air box body, and the top of the ring blowing filter element is hermetically connected to the upper cover plate through a ring blowing filter element gasket;

[0150] The micro mist cooling device includes an atomization channel, an atomization connecting pipe, an atomization nozzle, a cooling water pipe, a cooling water solenoid valve, an ultrasonic atomization system, a micro pump, a regulating valve, a pressure detector, a temperature detector, a PLC controller, a conveying pipeline and an ultrasonic atomization system;

[0151] The ultrasonic atomization system is used to provide atomized gas;

[0152] The atomization nozzle is a rod-shaped structure with a hollow interior; a plurality of spray holes are provided on the circumferential surface of the atomization nozzle, and the spray holes communicate with the interior of the atomization nozzle; the atomization nozzle is vertically placed inside the ring blowing air box, and the vertical projection of the atomization nozzle on the spinneret plate is located inside the first circle of spinneret holes;

[0153] The atomization channel is arranged inside the upper cover plate of the ring blowing air box. One end of the atomization channel is communicated with the interior of the atomization nozzle through an atomization connecting pipe, and the other end is connected to the ultrasonic atomization system through a conveying pipeline. The vertical projection of the atomization connecting pipe on the spinneret plate does not contact the spinneret holes;

[0154] The number of the atomization connecting pipes, the atomization channels and the atomization nozzles is the same as the number of the ring blowing filter elements;

[0155] The cooling water pipe is connected to the ultrasonic atomization system, and a cooling water solenoid valve is provided on the cooling water pipe. The cooling water solenoid valve is used to regulate the flow rate of cold water entering the ultrasonic atomization system;

[0156] The regulating valve, the pressure detector, the temperature detector and the micro pump are arranged on the conveying pipeline; the setting position of the micro pump is closer to the ultrasonic atomization system than the positions of the regulating valve, the pressure detector and the temperature detector; the micro pump is used to pressurize the atomized gas in the conveying pipeline;

[0157] The regulating valve, the pressure detector, the temperature detector and the cooling water solenoid valve are all electrically connected to the PLC controller;

[0158] The temperature detector is used to detect the temperature of the atomized gas in the conveying pipeline, send the measured temperature of the atomized gas to the PLC controller, and compare it with the temperature set in the PLC controller. When the absolute value of the difference between the measured temperature of the atomized gas and the set temperature exceeds 0.5 °C, the PLC controller adjusts the cooling water solenoid valve to control the flow rate of cold water;

[0159] The regulating valve is used to regulate the pressure of the conveying pipeline;

[0160] The pressure detector is used to detect the atomizing gas pressure, send the measured atomizing gas pressure to the PLC controller, and compare it with the pressure set in the PLC controller. When the absolute value of the difference between the measured atomizing gas pressure and the set pressure exceeds 5% of the set value, the PLC controller adjusts the regulating valve;

[0161] A tension detection device is provided between the G / R1 hot roll and the G / R2 hot roll;

[0162] The process parameters include: the temperature of the spinning box is 295 °C, the power of the micro-mist cooling pump is 15 W, the temperature of the atomizing gas is 15 °C, the pressure of the atomizing gas is 50 Pa, the temperature of the ring blowing is 19 °C, the wind speed of the ring blowing is 0.5 m / s, the rotation speed of the oil pump is 9.5 r / min, the pre-network pressure is 0.15 MPa, the speed of the G / R1 hot roll is 1900 m / min, the tension when all the single filaments extruded from the inner spinneret holes break is 287 cN, the speed of the G / R2 hot roll is 4100 m / min, and the main network pressure is 0.35 MPa.

[0163] The finally obtained core yarn broken and fuzzed polyester fiber is a filament bundle composed of multiple single filaments, among which some single filaments are broken, and the rest are unbroken single filaments. The broken single filaments are distributed inside the unbroken single filaments, and one end of all the broken single filaments protrudes to the outside of the unbroken single filaments; the fineness of the core yarn broken and fuzzed polyester fiber is 222.78 dtex, the total number of single filaments is 216, the dpf is 1.031, and the number of broken single filaments is 52% of the total number of single filaments; the broken fuzz of the core yarn broken and fuzzed polyester fiber has a gradual change in level, the length of the broken fuzz is 0.2 - 0.6 cm, the fuzz density is 2240 pieces / m, the breaking strength is 4.12 cN / dtex, the CV value of the breaking strength is 2.29%, the breaking elongation is 30.9%, the CV value of the breaking elongation is 5.27%, the bulkiness is 86%, and the resilience is 91%.

Claims

1. A preparation method of core yarn broken and fuzzed polyester fiber, characterized in that: After the polyester melt enters the spinneret and is extruded, it successively passes through cooling, oiling, pre-networking, G / R1 hot roll drawing, G / R2 hot roll drawing, main networking, and winding to obtain core yarn broken and fuzzed polyester fiber; The core yarn broken and fuzzed polyester fiber is a tow composed of multiple monofilaments. Among them, a part of the monofilaments are broken, and the remaining part are unbroken monofilaments. The broken monofilaments are distributed inside the unbroken monofilaments, and one end of all the broken monofilaments protrudes to the outside of the unbroken monofilaments; The fineness of the core yarn broken and fuzzed polyester fiber is 55-223 dtex, the total number of monofilaments is 72-216, dpf≥0.5, and the number of broken monofilaments is 48-62% of the total number of monofilaments; There are n circles of spinneret holes on the spinneret, n is 4-6, and the aperture diameters of all the spinneret holes are the same; from the inside to the outside of the spinneret, the spinneret holes in the 1st circle to the n-1st circle or the n-2nd circle are the inner spinneret holes, and the spinneret holes in the remaining circles are the outer spinneret holes; The upper surface of the spinneret is a plane, and the lower surface is provided with an arc-shaped groove. The vertical projection of the arc-shaped groove on the upper surface of the spinneret is a circle. Along the radial direction of the circle, the depth of the arc-shaped groove gradually becomes smaller from the inside to the outside; the output end of the inner spinneret hole is located inside the arc-shaped groove, and the central axis of the arc-shaped groove coincides with the central axis of the spinneret; the output end of the outer spinneret hole is located outside the arc-shaped groove; The aperture diameter of the inner spinneret hole is 0.14-0.30 mm, the aspect ratio of the inner spinneret hole is 1.7-2.3, and the aspect ratio of the outer spinneret hole is 2.7-3.3; the total number of spinneret holes is 72-216, and the number of inner spinneret holes is 48-62% of the total number of spinneret holes; The draw ratios of the G / R1 hot roll and the G / R2 hot roll are equal to the theoretical draw ratio of the filaments extruded from the outer spinneret holes and greater than the theoretical draw ratio of the filaments extruded from the inner spinneret holes; the theoretical draw ratio is the draw ratio at which the filaments will not be broken at the speeds of the G / R1 hot roll and the G / R2 hot roll.

2. The preparation method of a core yarn broken and fuzzed polyester fiber according to claim 1, characterized in that The broken fuzz length of the core yarn broken and fuzzed polyester fiber is 0.2-0.6 cm, the fuzz density is 880-2240 pieces / m, the breaking strength is 4.10-4.40 cN / dtex, the CV value of the breaking strength ≤2.90%, the breaking elongation is 28-33%, the CV value of the breaking elongation ≤6.50%, the bulkiness ≥85%, and the resilience ≥90%.

3. The preparation method of a core yarn broken and fuzzed polyester fiber according to claim 1, characterized in that, The cooling is two-way hybrid cooling, and the device used for two-way hybrid cooling includes an annular blowing cooling device and a micro-mist cooling device; The annular blowing cooling device includes an annular blowing air box and an annular blowing filter element (7); the blowing air box includes an air box body and an upper cover plate (5); the annular blowing filter element (7) is arranged inside the air box body, and the top of the annular blowing filter element (7) is hermetically connected to the upper cover plate (5) through an annular blowing filter element gasket (6); The micro-mist cooling device includes an atomization channel (10), an atomization connecting pipe (11), an atomization nozzle (12), a cooling water pipe (13), a cooling water solenoid valve (14), a micro pump (16), a regulating valve (17), a pressure detector (18), a temperature detector (19), a PLC controller, a conveying pipeline (20), and an ultrasonic atomization system (15); The ultrasonic atomization system (15) is used to provide atomized gas; The atomizing nozzle (12) is a rod-shaped structure with a hollow interior; a plurality of spray holes are provided on the circumferential surface of the atomizing nozzle (12), and the spray holes communicate with the interior of the atomizing nozzle (12); the atomizing nozzle (12) is vertically placed inside the annular blowing air box, and the vertical projection of the atomizing nozzle (12) on the spinneret is located inside the first circle of spinneret holes; The atomization channel (10) is arranged inside the upper cover plate of the annular blowing air box. One end of the atomization channel (10) is connected to the interior of the atomizing nozzle (12) through an atomization connecting pipe (11), and the other end is connected to the ultrasonic atomization system through a conveying pipe (20). The vertical projection of the atomization connecting pipe (11) on the spinneret does not contact the spinneret holes; The number of the atomization connecting pipes (11), the atomization channels (10) and the atomizing nozzles (12) is the same as the number of the annular blowing filters (7); The cooling water pipe (13) is connected to the ultrasonic atomization system, and a cooling water solenoid valve (14) is provided on the cooling water pipe (13). The cooling water solenoid valve (14) is used to regulate the flow rate of cold water entering the ultrasonic atomization system; A regulating valve (17), a pressure detector (18), a temperature detector (19) and a micro pump (16) are arranged on the conveying pipe (20); the setting position of the micro pump (16) is closer to the ultrasonic atomization system than the positions of the regulating valve (17), the pressure detector (18) and the temperature detector (19); the micro pump (16) is used to pressurize the atomized gas in the conveying pipe (20); The regulating valve (17), the pressure detector (18), the temperature detector (19) and the cooling water solenoid valve (14) are all electrically connected to the PLC controller; The temperature detector (19) is used to detect the temperature of the atomized gas in the conveying pipe (20), send the measured temperature of the atomized gas to the PLC controller, and compare it with the temperature set in the PLC controller. When the absolute value of the difference between the measured temperature of the atomized gas and the set temperature exceeds 0.5 °C, the PLC controller adjusts the cooling water solenoid valve (14) to control the flow rate of cold water; The regulating valve (17) is used to regulate the pressure of the conveying pipe (20); The pressure detector (18) is used to detect the atomized gas pressure, send the measured atomized gas pressure to the PLC controller, and compare it with the pressure set in the PLC controller. When the absolute value of the difference between the measured atomized gas pressure and the set pressure exceeds 5% of the set value, the PLC controller adjusts the regulating valve (17).

4. The preparation method of a core yarn broken and fuzzed polyester fiber according to claim 3, characterized in that, A tension detection device is provided between the G / R1 hot roll and the G / R2 hot roll.

5. The preparation method of a core yarn broken and fuzzed polyester fiber according to claim 4, characterized in that, The process parameters include: the temperature of the spinning box is 280 - 295 °C, the power of the micro-mist cooling pump is 10 - 15 W, the temperature of the atomizing gas is 15 - 19 °C, the pressure of the atomizing gas is 30 - 50 Pa, the temperature of the ring blowing is 19 - 22 °C, the wind speed of the ring blowing is 0.2 - 0.5 m / s, the pre-network pressure is 0.10 - 0.15 MPa, the speed of the G / R1 hot roll is 1900 - 2200 m / min, the tension is 84 - 290 cN, the speed of the G / R2 hot roll is 3900 - 4200 m / min, and the main network pressure is 0.25 - 0.35 MPa.

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