Preparation method of core yarn fracture fluffing type fine denier polyester fiber

Abstract

The invention belongs to the technical field of chemical fiber production, and relates to a preparation method of core yarn breakage fluffing type fine denier polyester fiber, which comprises the following steps: after a polyester melt enters a spinneret plate for melt extrusion, cooling, oiling, pre-interlacing, G / R1 and G / R2 hot roller drafting, main interlacing and winding are sequentially performed to obtain the core yarn breakage fluffing type fine denier polyester fiber, wherein the upper surface and the lower surface of the spinneret plate are parallel to the horizontal plane; spinneret orifices are formed in the spinneret plate; the spinneret plate is divided into inner side spinneret orifices and outer side spinneret orifices from the inner side to the outer side; the spinneret holes comprise flow guide holes and micro holes; the micropore diameter of the inner side spinneret orifices is larger than that of the outer side spinneret orifices; and the draw ratio of the G / R1 hot roller and the G / R2 hot roller is equal to the theoretical draw ratio of the extruded filaments of the outer spinneret orifices and is greater than the theoretical draw ratio of the extruded filaments of the inner spinneret orifices. The method provided by the invention can be used for producing the core yarn broken fuzzing type fine denier fiber, and the velvet fabric prepared from the core yarn broken fuzzing type fine denier fiber has better fluffiness and rebound resilience.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical fiber production and relates to a method for preparing a core yarn broken and raised fine-denier polyester fiber. Background Art

[0002] At present, there are three ways to produce wool yarn polyester fiber.

[0003] The first is that under the action of external force, the single filaments in the filament bundle that are in contact with the external force are broken and protruded to form a feathering effect. For example, in patent CN109295531A, a friction device is used to rub the outer layer of filaments during the drawing process to obtain wool-like FDY, and in patent CN114232156A, a disc with a high friction coefficient and an oil tanker are used to obtain an outer layer of broken wool yarn.

[0004] The second method is to compound the finished fibers and use the difference in shrinkage to form outer terry yarns, which has the effect of broken open fibers. For example, in patent CN110747552A, two yarns are twisted together and shrinkage is used to form terry yarn, and in patent CN101177822A, polyester ATY wool-like yarn is obtained by winding and covering the surface yarn to break.

[0005] The third method is to soften the monofilaments in polyester fibers through the action of acids or alkalis to achieve the effect of softening and opening the wool yarn. For example, in patent CN116892074A, an organic acid solution is used to open the polyester-nylon composite ultrafine fibers to obtain acidic open fiber fabrics; in patent CN110106649A, 3%~8% sodium hydroxide impregnation liquid is used to act on the fibers to form an opening process; in patent CN109629265A, yarn washing powder and soda ash are mixed to soften the fibers to form a sand washing softening opening process.

[0006] However, the wool yarn polyester fibers produced by these methods are mostly broken or aggregated outer monofilaments, and the formed hairiness is attached hairiness, which only has the velvety feel of wool yarn, and the fabric has poor bulkiness and air permeability, and the fabric does not have resilience.

[0007] Moreover, the above methods cannot be used to produce fine denier fibers. This is because the fine denier fiber monofilament is relatively thin, and the dense attached hairiness formed under the action of external force or acid and alkali is easy to scatter. In addition, the fine denier yarns prepared by the above methods all form terry yarns on the outside, which also makes the terry yarns of the fine denier yarns soft and easy to deform, thereby resulting in unstable properties of the fabric.

[0008] Therefore, it is of great significance to study a method for preparing a core yarn broken fluffy fine denier polyester fiber to solve the above problems. Summary of the invention

[0009] The purpose of the invention is to solve the problems existing in the prior art and provide a method for preparing core yarn broken and fluffed fine-denier polyester fibers.

[0010] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0011] A method for preparing a core yarn broken fluffy fine-denier polyester fiber, wherein the polyester melt enters a spinneret for melt extrusion, and then sequentially undergoes cooling, oiling, pre-internetting, G / R1 hot roller drawing, G / R2 hot roller drawing, main internetting and winding to obtain the core yarn broken fluffy fine-denier polyester fiber;

[0012] The upper surface and the lower surface of the spinneret are parallel to the horizontal plane; the spinneret is provided with n circles of spinneret holes; from the inside to the outside of the spinneret, the spinneret holes from the first circle to the n-2th circle are inner spinneret holes, and the spinneret holes of the remaining circles are outer spinneret holes;

[0013] The spinneret hole includes a guide hole and a micropore connected from top to bottom; the diameter of the guide hole of the inner spinneret hole is the same as the diameter of the guide hole of the outer spinneret hole; the diameter of the micropore of the outer spinneret hole is 0.06-0.13 mm, and the diameter of the micropore of the inner spinneret hole is larger than that of the micropore of the outer spinneret hole;

[0014] The draft ratio of the G / R1 hot roller and the G / R2 hot roller is equal to the theoretical draft ratio of the filaments extruded from the outer spinneret, and is greater than the theoretical draft ratio of the filaments extruded from the inner spinneret; the theoretical draft ratio is the draft ratio at which the filaments will not be broken at the speed of the G / R1 hot roller and the speed of the G / R2 hot roller;

[0015] After the polyester melt is extruded from the spinneret, the melt diameter will become larger (non-Newtonian expansion phenomenon), and after expansion, it will enter the cooling zone for cooling and refinement. This cooling and refinement has a stretching effect, which is called nozzle stretching; under the condition of consistent melt flow rate of each spinneret hole of the spinneret (since the guide holes are the same, the flow rate of each spinneret hole is the same), the micropore diameter of the outer spinneret hole is small, the melt expansion zone formed after the melt flows out of the outer spinneret hole is stable, and the nozzle stretching is small, while the micropore diameter of the inner spinneret hole is larger, and the melt expansion zone formed after the melt flows out of the inner spinneret hole is larger than the melt expansion zone formed after the melt flows out of the outer spinneret hole, and the nozzle stretching is large, which makes the subsequent G Under G / R1 hot roller drawing and G / R2 hot roller drawing, the monofilaments extruded from the outer spinneret holes are more resistant to pulling than those extruded from the inner spinneret holes. By reasonably setting the G / R1 hot roller speed and the G / R2 hot roller speed, the inner monofilaments are pulled apart while the outer monofilaments are not pulled apart, thereby obtaining the core yarn broken fluffy fine denier polyester fiber; the reason why the monofilaments with smaller nozzle stretching are more resistant to pulling under the subsequent G / R1 hot roller drawing and G / R2 hot roller drawing is that the monofilaments with the same fineness extruded from the same spinneret have limited and consistent relative stretching ratios, while the nozzle stretching of the outer monofilaments is smaller than that of the inner monofilaments, and the remaining stretching of the outer monofilaments is greater than that of the inner monofilaments, so the outer monofilaments are resistant to pulling.

[0016] Compared with conventional fine-denier yarn, core-yarn broken-hair-raising fine-denier fiber has the characteristics of softness and natural cotton of conventional fine-denier yarn, and has more holes and higher hairiness density under the same denier, and also has both the softness of fine-denier yarn and the fluffiness of hairiness yarn. At the same time, core-yarn broken-hair-raising fine-denier fiber forms a structure that is both soft and has bones through broken monofilaments and unbroken monofilaments (that is, unbroken single yarns form yarn bones), providing Kewei with high-quality products for the production of feather velvet, imitation cotton and imitation wool.

[0017] Theoretically, fine-denier polyester fibers can also be produced by adopting an arc-shaped spinneret. Specifically, the upper surface of the arc-shaped 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 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 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. The specific principle is: 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 different effects of the aspect ratio of the spinneret holes in different circles. The aspect ratio of the outer spinneret hole is larger than that of the inner spinneret hole. The residence time of the melt from the entrance to the exit of the outer spinneret hole is longer, and the expansion rate is reduced (the spinneret temperature is high, the residence time is long, the viscosity is reduced, the internal stress is weakened, and the expansion rate is reduced accordingly), and the nozzle stretching is reduced, so that under the subsequent G / R1 hot roller drawing and G / R2 hot roller drawing, the outer monofilament is larger than the inner monofilament. The monofilament is more resistant to pulling, and under different circles, as the aspect ratio increases, the monofilament is more resistant to pulling. By reasonably setting the speed of the G / R1 hot roller and the speed of the G / R2 hot roller, the monofilament extruded from the inner spinneret is broken, while the monofilament extruded from the outer spinneret is not broken; the reason why the monofilament with low nozzle stretching is more resistant to pulling under the subsequent G / R1 hot roller drawing and G / R2 hot roller drawing is that the monofilaments with the same fineness extruded from the same spinneret have limited and consistent relative stretching ratios, and the nozzle stretching of the outer monofilament is smaller than that of the inner monofilament, and the remaining stretching of the outer monofilament is more than that of the inner monofilament, so the outer monofilament is resistant to pulling.

[0018] However, in actual production, the arc-shaped spinneret cannot be used to produce core yarn broken fluffy fine-denier polyester fibers for the following reasons:

[0019] (1) When the aspect ratio is changed by changing the length of the spinneret hole, the spinneret plate has an arc-shaped groove on the inner side, which causes a height difference in the outlet cross section of the inner spinneret hole. This causes a slight tilt effect when the melt flows out of the spinneret hole, making it easy to break the end when producing fine denier fiber products.

[0020] (2) During the production process, the spinneret needs to be cleaned periodically to remove impurities from its surface. The difficulty of cleaning the inner arc-shaped groove is relatively large, especially when producing ultra-fine deniers. The aperture is small and the inner hole is easily blocked, which makes it difficult to extrude the melt and the production is difficult.

[0021] (3) When producing fine denier fibers, the single filaments are thinner, the spinneret hole diameter is small, and the aspect ratio is within a certain range, so its length is short and the plate surface is thin. Changing the aspect ratio by reducing the length of the inner spinneret hole will make the inner plate surface thinner, affecting the service life and easily causing the spinneret to deform;

[0022] (4) Production experience shows that if the spinneret is too thin, the production difficulty will increase accordingly. Because the melt is less squeezed before being ejected, the melt is in an amorphous state, resulting in unstable melt tension at the outlet, which in turn affects the uniformity of the fineness of a single filament bundle. In serious cases, production cannot be carried out. The literature (A Brief Analysis of the Improvement of the Spinneret Structure of Polyester Filament [J], Synthetic Fiber Industry, 2004.27) also records: From the perspective of flow performance, increasing the spinneret thickness is conducive to improving the stability of the spinneret and can reduce the unevenness of short segments caused by turbulent flow in the channel. If the thickness is too small, it will affect the stability of the spinneret.

[0023] As the preferred technical solution:

[0024] In the method for preparing a core yarn broken fluffy fine-denier polyester fiber as described above, the micropore diameter of the inner spinneret hole is 1.15 to 1.50 times the micropore diameter of the outer spinneret hole.

[0025] In the method for preparing a core yarn broken fluffy fine-denier polyester fiber as described above, the total number of spinnerets is 144 to 288, and the inner spinnerets account for 48% to 52.08% of the total number of spinnerets.

[0026] According to the method for preparing a core yarn broken fluffy fine-denier 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 comprises a tension sensor, and the tension detection device is used to detect the tension when all the monofilaments extruded from the inner spinneret holes are broken (the inner monofilament breaking tension is much greater than the stretching tension, so the tension detection sensor detects the tension when broken, rather than the overall tension of the composite yarn), and detects in real time whether all the inner monofilaments are broken; wherein, the tension when all the monofilaments extruded from the inner spinneret holes are broken = the inner monofilament fineness × the number of inner monofilaments × the breaking strength of the pre-oriented yarn of the inner monofilament, and the stretching tension can be adjusted by adjusting the speed of the G / R1 hot roller. If the tension is low, the speed of the G / R1 hot roller is reduced, the stretching ratio is increased, and the tension is increased; when the tension is low, the opposite adjustment is made.

[0027] According to the method for preparing a core yarn broken fluffy fine-denier polyester fiber as described above, an outer ring heating device is provided below the spinneret, and the outer ring heating device includes a heating shell, a heat insulation plate and a connecting plate; the heating shell and the heat insulation plate are both hollow cylindrical structures; the inner diameter of the heating shell is greater than or equal to the diameter of the spinneret, the inner diameter of the heat insulation plate is greater than the maximum diameter of the circle where the inner spinneret holes are located, and the outer diameter of the heat insulation plate is less than the minimum diameter of the circle where the outer spinneret holes are located;

[0028] The heating shell and the heat insulation plate are connected by a connecting plate, and the vertical projection of the connecting plate on the spinneret does not contact the spinneret hole;

[0029] An interlayer is provided on the heating shell, and the interlayer is connected to the heat medium furnace. The heat medium furnace is used to pass biphenyl into the interlayer to exchange heat with the melt extruded from the outer spinneret hole, thereby heating the melt extruded from the outer spinneret hole, so that the temperature of the melt extruded from the outer spinneret hole increases, the viscosity decreases accordingly, and the internal stress decreases accordingly. After cooling to form fibers, the fibers are more resistant to pulling.

[0030] The height of the outer ring heating device is the height of the windless zone, and the top of the outer ring heating device is sealed and connected to the plane where the lower surface of the spinneret is located.

[0031] In the method for preparing a core yarn broken fluffy fine-denier polyester fiber as described above, the cooling device is a ring blowing device; an aluminum plate is provided on the upper cover plate of the ring blowing device, and a through hole is provided on the aluminum plate, and the through hole is used to install an outer ring heating device, and the outer diameter of the heating shell is equal to the inner diameter of the through hole; that is, the outer wall of the heating shell is tightly attached to and fixedly connected to the inner wall of the through hole; when the top of the outer ring heating device is sealed and connected to the plane where the lower surface of the spinneret is located, the aluminum plate is sealed and connected to the lower surface of the spinning box.

[0032] The method for preparing a core yarn broken fluffy fine denier polyester fiber as described above, the preparation process parameters include: the temperature of the spinning box is 290~305℃, the temperature of the annular air is 22~24℃, the wind speed of the annular air is 0.15~0.30m / s, the speed of the oil pump is 1.70~4.80r / min, the pre-network pressure is 0.06~0.10MPa, the G / R1 hot roller speed is 1850~2000m / min, the G / R2 hot roller speed is 3400~3700m / min, and the main network pressure is 0.19~0.25MPa.

[0033] The present invention also provides a core yarn broken fluffy fine-denier polyester fiber obtained by the method as described above, which is a tow composed of multiple monofilaments, a part of which 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 outside the unbroken monofilaments;

[0034] The fineness of the core yarn broken raised fine denier polyester fiber is 22~112dtex, the total number of monofilaments is 144~288, dpf<0.5, and the number of broken monofilaments is 48%~53% of the total number of monofilaments.

[0035] As the preferred technical solution:

[0036] The core yarn broken fluffy fine-denier polyester fiber as described above has a broken hair length of 0.5±0.2cm, a hair density of 1440-3000 strands / m, a breaking strength of 4.15-4.45 cN / dtex, a breaking strength CV value ≤2.52%, a breaking elongation of 30-33.02%, a breaking elongation CV value ≤5.12%, a bulkiness ≥90%, and a resilience ≥92%; the hairiness is formed by the breaking of the inner monofilaments, and the broken monofilaments protrude from the inside to the outside (the number of the outer monofilaments is small, and the hairiness length of the inner monofilaments after the breaking is much larger than the diameter of the outer circle monofilaments, so the broken monofilaments can expose the surface of the composite yarn) and support the outer monofilaments; the outer monofilaments are supported by the hairiness to form a three-dimensional air barrier, so the fluffiness is good, because the inner monofilaments are broken and protrude around the tow, the hairiness density and length are uniform, and the external shape is not easily changed by external force, and the resilience is good.

[0037] Beneficial effects:

[0038] (1) The present invention arranges inner spinneret holes and outer spinneret holes with different micropore diameters on a spinneret plate, so that the monofilaments extruded from the outer spinneret holes are more resistant to pulling than the monofilaments extruded from the inner spinneret holes. In the subsequent hot roller drawing, the G / R1 hot roller speed and the G / R2 hot roller speed are reasonably set so that the inner monofilaments are pulled apart while the outer monofilaments are not pulled apart. In this way, a raised fine-denier polyester fiber with good resilience and non-fading hairiness can be obtained.

[0039] (2) The present invention provides an outer ring heating device under the spinneret, so that the temperature of the melt extruded from the outer spinneret hole increases, the viscosity decreases accordingly, and the internal stress decreases accordingly. After cooling to form fibers, the fibers are more resistant to pulling.

[0040] (3) The present invention can produce raised fine-denier polyester fibers with different broken hairiness numbers and densities by controlling the number of inner and outer spinneret holes, and the velvety fabrics made therefrom have good fluffiness and resilience. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the distribution of spinneret holes on the spinneret in Example 3 of the present invention;

[0042] Figure 2 It is a schematic diagram of the micropore cross section of the inner and outer spinneret holes on the spinneret of the present invention;

[0043] Figure 3 A top view of the outer ring heating device of the present invention;

[0044] Figure 4 is a cross-sectional view of the outer ring heating device of the present invention;

[0045] Figure 5 This is a schematic diagram of the use of the outer ring heating device of the present invention;

[0046] Figure 6 It is a schematic diagram of the core yarn broken and fluffed fine denier polyester fiber of the present invention;

[0047] Among them, 1-spinneret, 2-inner spinneret hole, 3-outer spinneret hole, 4-heating shell, 5-insulation layer, 6-connecting plate, 7-interlayer, 8-liquefied heat medium outlet, 9-gas phase heat medium inlet, 10-outer ring heating device, 11-aluminum plate, 12-upper cover plate, 13-liquefied heat medium reflux pipe, 14-heat medium furnace, 15-gas phase heat medium delivery pipe, 16-broken single wire, 17-unbroken single wire. DETAILED DESCRIPTION

[0048] 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 are not intended 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 fall within the scope limited by the appended claims of the application equally.

[0049] The testing methods of the relevant performance indicators in the following embodiments and comparative examples are as follows:

[0050] dpf: first refer to GB / T14343-2008 Test method for linear density of chemical fiber filaments to test the total fiber density of the core yarn broken fluffy fine denier polyester fiber prepared in the example, and then divide it by the total number of monofilaments.

[0051] Breaking strength, breaking strength CV value, breaking elongation, breaking elongation CV value: referring to the standard "GB / T 14344-2008 Test method for tensile properties of synthetic filaments", the core yarn breaking raised fine denier polyester fiber prepared in the example was tested using an imported fully automatic strength and elongation tester.

[0052] Fluffiness: The core yarn broken and raised fine denier polyester fibers prepared in each example were tested with reference to GB / T 10288-2016 Testing methods for down and feathers.

[0053] Rebound rate: with reference to the standard "FZ / T 01034-2008 Test method for tensile elasticity of woven fabrics for textiles", the core yarn broken fluffy fine denier polyester fiber prepared in the embodiment was deformed by stretching at a fixed length and a fixed force using a constant rate of elongation tester. The stretching process was stretched from an initial length of 100 mm to 115 mm at a stretching speed of 20 mm / min. After the tensile force was released, the residual elongation was measured after recovery within a specified time, and then the elastic recovery rate was calculated by the calculation formula: (L0-δL1) / (L0-δL)×100%, wherein L0 is the total length of the sample after stretching, δL is the length of the sample after pre-tensioning, and δL1 is the length of the sample after the pre-tensioning force is applied again after the sample recovers from the fixed force or fixed elongation (plastic deformation).

[0054] Example 1

[0055] A method for preparing a core yarn broken fluffy fine-denier polyester fiber, comprising the following steps:

[0056] (1) polycondensing PTA (terephthalic acid) and MEG (ethylene glycol) in a mass ratio of 2.55:1 to form a polyester melt with an intrinsic viscosity of 0.690 dl / g;

[0057] (2) After the polyester melt enters the spinneret for melt extrusion, it is sequentially cooled, oiled, pre-interlaced, G / R1 hot roller drawing, G / R2 hot roller drawing, main interlaced and wound to obtain a core yarn broken fluffy fine denier polyester fiber;

[0058] Wherein, the upper surface and the lower surface of the spinneret are parallel to the horizontal plane;

[0059] The spinneret is provided with 5 circles of spinneret holes. From the inside to the outside of the spinneret, the spinneret holes in the first to third circles are inner spinneret holes, and the spinneret holes in the remaining circles are outer spinneret holes.

[0060] The spinneret holes include guide holes and microholes connected from top to bottom; the diameter of the guide holes of the inner spinneret holes is the same as that of the guide holes of the outer spinneret holes, and the diameter of the guide holes is 0.8 mm; the diameter of the microholes of the outer spinneret holes is 0.08 mm, and the diameter of the microholes of the inner spinneret holes is 1.25 times the diameter of the microholes of the outer spinneret holes; the total number of spinneret holes is 288, the inner spinneret holes account for 52.08% of the total number of spinneret holes, and the number of spinneret holes in each circle from the inner side to the outer side of the spinneret plate is 42, 50, 58, 66, and 72 respectively;

[0061] The draft ratio of the G / R1 hot roller and the G / R2 hot roller is equal to the theoretical draft ratio of the filaments extruded from the outer spinneret, and is greater than the theoretical draft ratio of the filaments extruded from the inner spinneret; the theoretical draft ratio is the draft ratio at which the filaments will not be broken at the speed of the G / R1 hot roller and the speed of the G / R2 hot roller; a tension detection device is provided between the G / R1 hot roller and the G / R2 hot roller;

[0062] The device used for cooling is a ring blowing device; an aluminum plate is provided on the upper cover plate of the ring blowing device, and a through hole is provided on the aluminum plate;

[0063] An outer ring heating device is installed in the through hole;

[0064] When the ring blowing device is in use, the ring blowing bellows rises until the top of the outer ring heating device is sealed and connected to the plane where the lower surface of the spinneret is located, and at this time, the aluminum plate is sealed and connected to the lower surface of the spinning box body;

[0065] The outer ring heating device comprises a heating shell, a heat insulation plate and a connecting plate;

[0066] The height of the outer ring heating device is the height of the windless zone, and the height of the windless zone is 48mm;

[0067] The heating shell and the heat insulation plate are both hollow cylindrical structures; the inner diameter of the heating shell is greater than or equal to the diameter of the spinneret, the outer diameter of the heating shell is equal to the inner diameter of the through hole, the inner diameter of the heat insulation plate is greater than the maximum diameter of the circle where the inner spinneret holes are located, and the outer diameter of the heat insulation plate is less than the minimum diameter of the circle where the outer spinneret holes are located;

[0068] The heating shell and the heat insulation plate are connected by a connecting plate, and the vertical projection of the connecting plate on the spinneret does not contact the spinneret hole;

[0069] An interlayer is provided on the heating shell, and the interlayer is connected to the heat medium furnace. The heat medium furnace is used to allow the gasified biphenyl to enter the interlayer from the gas phase heat medium inlet through the gas phase heat medium conveying pipe to exchange heat with the melt extruded from the outer spinneret hole, thereby heating the melt extruded from the outer spinneret hole. After the heat exchange, the liquefied heat medium will be discharged from the liquefied heat medium outlet and re-enter the heat medium furnace through the liquefied heat medium reflux pipe.

[0070] The preparation process parameters include: the temperature of the spinning box is 305°C, the temperature of the annular air is 23°C, the wind speed of the annular air is 0.2m / s, the wind pressure of the annular air is 25Pa, the speed of the oil pump is 3.59r / min, the pre-network pressure is 0.075MPa, the temperature of the G / R1 hot roller is 77°C, the speed of the G / R1 hot roller is 1950m / min, the temperature of the G / R2 hot roller is 116°C, the speed of the G / R2 hot roller is 3560m / min, the main network pressure is 0.22MPa, the temperature of the heating shell is 255°C, and the tension of all the monofilaments extruded from the inner spinneret when they break is 108.07cN;

[0071] The core yarn broken fluffy fine denier polyester fiber finally obtained is as follows Figure 6As shown, it is a tow composed of multiple monofilaments, among which a part of the monofilaments are broken and are broken monofilaments 16, and the rest are unbroken monofilaments 17, the broken monofilaments are distributed on the inner side of the unbroken monofilaments 17, and one end of all the broken monofilaments protrudes to the outer side of the unbroken monofilaments 17; the fineness of the core yarn broken fluffy fine denier polyester fiber is 83.03 dtex, the total number of monofilaments is 288, the dpf is 0.288, and the number of broken monofilaments is 52.08% of the total number of monofilaments; the broken hairiness length of the core yarn broken fluffy fine denier polyester fiber is 0.3~0.7 cm, the hairiness density is 2990 filaments / m, the breaking strength is 4.17 cN / dtex, the breaking strength CV value is 1.72%, the breaking elongation is 33.02%, the breaking elongation CV value is 4.99%, the fluffiness is 95%, and the rebound rate is 94%.

[0072] Example 2

[0073] A method for preparing a core yarn broken fluffy fine-denier polyester fiber, comprising the following steps:

[0074] (1) polycondensing PTA and MEG in a mass ratio of 2.55:1 to form a polyester melt having an intrinsic viscosity of 0.690 dl / g;

[0075] (2) After the polyester melt enters the spinneret for melt extrusion, it is sequentially cooled, oiled, pre-interlaced, G / R1 hot roller drawing, G / R2 hot roller drawing, main interlaced and wound to obtain a core yarn broken fluffy fine denier polyester fiber;

[0076] Wherein, the upper surface and the lower surface of the spinneret are parallel to the horizontal plane;

[0077] The spinneret is provided with 5 circles of spinneret holes. From the inside to the outside of the spinneret, the spinneret holes in the first to third circles are inner spinneret holes, and the spinneret holes in the remaining circles are outer spinneret holes.

[0078] The spinneret holes include guide holes and microholes connected from top to bottom; the diameter of the guide holes of the inner spinneret holes is the same as that of the guide holes of the outer spinneret holes, and the diameter of the guide holes is 0.8 mm; the diameter of the microholes of the outer spinneret holes is 0.08 mm, and the diameter of the microholes of the inner spinneret holes is 1.25 times the diameter of the microholes of the outer spinneret holes; the total number of spinneret holes is 216, the inner spinneret holes account for 48.15% of the total number of spinneret holes, and the number of spinneret holes in each circle from the inner side to the outer side of the spinneret plate is 24, 36, 44, 52, and 60 respectively;

[0079] The draft ratio of the G / R1 hot roller and the G / R2 hot roller is equal to the theoretical draft ratio of the filaments extruded from the outer spinneret, and is greater than the theoretical draft ratio of the filaments extruded from the inner spinneret; the theoretical draft ratio is the draft ratio at which the filaments will not be broken at the speed of the G / R1 hot roller and the speed of the G / R2 hot roller; a tension detection device is provided between the G / R1 hot roller and the G / R2 hot roller;

[0080] The device used for cooling is a ring blowing device; an aluminum plate is provided on the upper cover plate of the ring blowing device, and a through hole is provided on the aluminum plate;

[0081] An outer ring heating device is installed in the through hole;

[0082] When the ring blowing device is in use, the ring blowing bellows rises until the top of the outer ring heating device is sealed and connected to the plane where the lower surface of the spinneret is located, and at this time, the aluminum plate is sealed and connected to the lower surface of the spinning box body;

[0083] The outer ring heating device comprises a heating shell, a heat insulation plate and a connecting plate;

[0084] The height of the outer ring heating device is the height of the windless zone, and the height of the windless zone is 45mm;

[0085] The heating shell and the heat insulation plate are both hollow cylindrical structures; the inner diameter of the heating shell is greater than or equal to the diameter of the spinneret, the outer diameter of the heating shell is equal to the inner diameter of the through hole, the inner diameter of the heat insulation plate is greater than the maximum diameter of the circle where the inner spinneret holes are located, and the outer diameter of the heat insulation plate is less than the minimum diameter of the circle where the outer spinneret holes are located;

[0086] The heating shell and the heat insulation plate are connected by a connecting plate, and the vertical projection of the connecting plate on the spinneret does not contact the spinneret hole;

[0087] An interlayer is provided on the heating shell, and the interlayer is connected to the heat medium furnace. The heat medium furnace is used to allow the gasified biphenyl to enter the interlayer from the gas phase heat medium inlet through the gas phase heat medium conveying pipe to exchange heat with the melt extruded from the outer spinneret hole, thereby heating the melt extruded from the outer spinneret hole. After the heat exchange, the liquefied heat medium will be discharged from the liquefied heat medium outlet and re-enter the heat medium furnace through the liquefied heat medium reflux pipe.

[0088] The preparation process parameters include: the temperature of the spinning box is 295°C, the temperature of the annular air is 23°C, the wind speed of the annular air is 0.2m / s, the wind pressure of the annular air is 20Pa, the speed of the oil pump is 2.38r / min, the pre-network pressure is 0.07MPa, the temperature of the G / R1 hot roller is 75°C, the speed of the G / R1 hot roller is 1900m / min, the temperature of the G / R2 hot roller is 116°C, the speed of the G / R2 hot roller is 3450m / min, the main network pressure is 0.21MPa, the temperature of the heating shell is 255°C, and the tension of all the monofilaments extruded from the inner spinneret when they break is 66.2cN;

[0089] The core yarn broken fluffy fine denier polyester fiber finally obtained is a tow composed of multiple monofilaments, among which a part of the monofilaments are broken and are broken monofilaments, and the rest are unbroken monofilaments, the broken monofilaments are distributed on the inner side of the unbroken monofilaments, and one end of all the broken monofilaments protrudes to the outer side of the unbroken monofilaments; the fineness of the core yarn broken fluffy fine denier polyester fiber is 55.62 dtex, the total number of monofilaments is 216, the dpf is 0.258, and the number of broken monofilaments is 48.15% of the total number of monofilaments; the broken hair length of the core yarn broken fluffy fine denier polyester fiber is 0.3~0.7 cm, the hair density is 2080 filaments / m, the breaking strength is 4.35 cN / dtex, the breaking strength CV value is 1.81%, the breaking elongation is 32.01%, the breaking elongation CV value is 5.12%, the fluffiness is 93%, and the rebound rate is 92%.

[0090] Example 3

[0091] A method for preparing a core yarn broken fluffy fine-denier polyester fiber, comprising the following steps:

[0092] (1) polycondensing PTA and MEG in a mass ratio of 2.55:1 to form a polyester melt having an intrinsic viscosity of 0.690 dl / g;

[0093] (2) After the polyester melt enters the spinneret for melt extrusion, it is sequentially cooled, oiled, pre-interlaced, G / R1 hot roller drawing, G / R2 hot roller drawing, main interlaced and wound to obtain a core yarn broken fluffy fine denier polyester fiber;

[0094] Among them, Figure 1 , Figure 2 As shown, the upper and lower surfaces of the spinneret 1 are parallel to the horizontal plane;

[0095] The spinneret 1 is provided with 5 circles of spinneret holes. From the inside to the outside of the spinneret 1, the spinneret holes in the first to third circles are the inner spinneret holes 2, and the spinneret holes in the remaining circles are the outer spinneret holes 2.

[0096] The spinneret holes include guide holes and micropores connected from top to bottom; the diameter of the guide holes of the inner spinneret hole 2 is the same as the diameter of the guide holes of the outer spinneret hole 3, and the diameter of the guide holes is 0.6 mm; the diameter of the micropores of the outer spinneret hole 3 is 0.06 mm, and the diameter of the micropores of the inner spinneret hole 2 is 1.17 times the diameter of the micropores of the outer spinneret hole 3; the total number of spinneret holes is 144, the inner spinneret hole 2 accounts for 50% of the total number of spinneret holes, and the number of spinneret holes in each circle from the inner side to the outer side of the spinneret plate is 20, 24, 28, 32, and 40 respectively;

[0097] The draft ratio of the G / R1 hot roller and the G / R2 hot roller is equal to the theoretical draft ratio of the filaments extruded from the outer spinneret, and is greater than the theoretical draft ratio of the filaments extruded from the inner spinneret; the theoretical draft ratio is the draft ratio at which the filaments will not be broken at the speed of the G / R1 hot roller and the speed of the G / R2 hot roller; a tension detection device is provided between the G / R1 hot roller and the G / R2 hot roller;

[0098] like Figure 1 , Figure 5 As shown, the cooling device is a ring blowing device; an aluminum plate 11 is provided on the upper cover plate 12 of the ring blowing device, and a through hole is provided on the aluminum plate 11;

[0099] An outer ring heating device 10 is installed in the through hole;

[0100] When the ring blowing device is in use, the ring blowing bellows rises until the top of the outer ring heating device 10 is sealed and connected to the plane where the lower surface of the spinneret 1 is located, and at this time, the aluminum plate is sealed and connected to the lower surface of the spinning box body;

[0101] like Figure 1~Figure 5 As shown, the outer ring heating device 10 includes a heating shell 4, a heat insulation plate 5 and a connecting plate 6;

[0102] The height of the outer ring heating device 10 is the height of the windless zone, and the height of the windless zone is 40 mm;

[0103] The heating shell 4 and the heat insulation plate 5 are both hollow cylindrical structures; the inner diameter of the heating shell 4 is greater than or equal to the diameter of the spinneret 1, the outer diameter of the heating shell 4 is equal to the inner diameter of the through hole, the inner diameter of the heat insulation plate 5 is greater than the maximum diameter of the circle where the inner spinneret holes 2 are located, and the outer diameter of the heat insulation plate 5 is less than the minimum diameter of the circle where the outer spinneret holes 2 are located;

[0104] The heating shell 4 and the heat insulation plate 5 are connected by a connecting plate 6, and the vertical projection of the connecting plate 6 on the spinneret 1 does not contact the spinneret hole;

[0105] like Figure 4 , Figure 5 As shown, the heating shell 4 is provided with an interlayer 7, and the interlayer 7 is connected to the heat medium furnace 14. The heat medium furnace 14 is used to allow the vaporized biphenyl to enter the interlayer 7 from the gas phase heat medium inlet 9 through the gas phase heat medium delivery pipe 15 to perform heat exchange with the melt extruded from the outer spinneret hole 2, thereby heating the melt extruded from the outer spinneret hole 2. After the heat exchange, the liquefied heat medium will be discharged from the liquefied heat medium outlet 8 and re-enter the heat medium furnace 14 through the liquefied heat medium reflux pipe 13;

[0106] The preparation process parameters include: the temperature of the spinning box is 300°C, the temperature of the annular air is 24°C, the wind speed of the annular air is 0.15m / s, the wind pressure of the annular air is 10Pa, the speed of the oil pump is 1.7r / min, the pre-network pressure is 0.06MPa, the temperature of the G / R1 hot roller is 75°C, the speed of the G / R1 hot roller is 1940m / min, the temperature of the G / R2 hot roller is 115°C, the speed of the G / R2 hot roller is 3400m / min, the main network pressure is 0.19MPa, the temperature of the heating shell is 255°C, and the tension of all the monofilaments extruded from the inner spinneret when they break is 27.5cN;

[0107] The core yarn broken fluffy fine denier polyester fiber finally obtained is a tow composed of multiple monofilaments, among which a part of the monofilaments are broken and are broken monofilaments, and the rest are unbroken monofilaments, the broken monofilaments are distributed on the inner side of the unbroken monofilaments, and one end of all the broken monofilaments protrudes to the outer side of the unbroken monofilaments; the fineness of the core yarn broken fluffy fine denier polyester fiber is 22.39 dtex, the total number of monofilaments is 144, the dpf is 0.155, and the number of broken monofilaments is 50.00% of the total number of monofilaments; the broken hair length of the core yarn broken fluffy fine denier polyester fiber is 0.3~0.7 cm, the hair density is 1440 pieces / m, the breaking strength is 4.16 cN / dtex, the breaking strength CV value is 2.52%, the breaking elongation is 30.53%, the breaking elongation CV value is 3.69%, the fluffiness is 92%, and the rebound rate is 94%.

[0108] Example 4

[0109] A method for preparing a core yarn broken fluffy fine-denier polyester fiber, comprising the following steps:

[0110] (1) polycondensing PTA and MEG in a mass ratio of 2.55:1 to form a polyester melt having an intrinsic viscosity of 0.690 dl / g;

[0111] (2) After the polyester melt enters the spinneret for melt extrusion, it is sequentially cooled, oiled, pre-interlaced, G / R1 hot roller drawing, G / R2 hot roller drawing, main interlaced and wound to obtain a core yarn broken fluffy fine denier polyester fiber;

[0112] Wherein, the upper surface and the lower surface of the spinneret are parallel to the horizontal plane;

[0113] The spinneret is provided with 5 circles of spinneret holes. From the inside to the outside of the spinneret, the spinneret holes in the first to third circles are inner spinneret holes, and the spinneret holes in the remaining circles are outer spinneret holes.

[0114] The spinneret holes include guide holes and microholes connected from top to bottom; the diameter of the guide holes of the inner spinneret holes is the same as that of the guide holes of the outer spinneret holes, and the diameter of the guide holes is 1 mm; the diameter of the microholes of the outer spinneret holes is 0.1 mm, and the diameter of the microholes of the inner spinneret holes is 1.4 times the diameter of the microholes of the outer spinneret holes; the total number of spinneret holes is 288, the inner spinneret holes account for 52.08% of the total number of spinneret holes, and the number of spinneret holes in each circle from the inner side to the outer side of the spinneret plate is 42, 50, 58, 66, and 72 respectively;

[0115] The draft ratio of the G / R1 hot roller and the G / R2 hot roller is equal to the theoretical draft ratio of the filaments extruded from the outer spinneret, and is greater than the theoretical draft ratio of the filaments extruded from the inner spinneret; the theoretical draft ratio is the draft ratio at which the filaments will not be broken at the speed of the G / R1 hot roller and the speed of the G / R2 hot roller; a tension detection device is provided between the G / R1 hot roller and the G / R2 hot roller;

[0116] The device used for cooling is a ring blowing device; an aluminum plate is provided on the upper cover plate of the ring blowing device, and a through hole is provided on the aluminum plate;

[0117] An outer ring heating device is installed in the through hole;

[0118] When the ring blowing device is in use, the ring blowing bellows rises until the top of the outer ring heating device is sealed and connected to the plane where the lower surface of the spinneret is located, and at this time, the aluminum plate is sealed and connected to the lower surface of the spinning box body;

[0119] The outer ring heating device comprises a heating shell, a heat insulation plate and a connecting plate;

[0120] The height of the outer ring heating device is the height of the windless zone, and the height of the windless zone is 52mm;

[0121] The heating shell and the heat insulation plate are both hollow cylindrical structures; the inner diameter of the heating shell is greater than or equal to the diameter of the spinneret, the outer diameter of the heating shell is equal to the inner diameter of the through hole, the inner diameter of the heat insulation plate is greater than the maximum diameter of the circle where the inner spinneret holes are located, and the outer diameter of the heat insulation plate is less than the minimum diameter of the circle where the outer spinneret holes are located;

[0122] The heating shell and the heat insulation plate are connected by a connecting plate, and the vertical projection of the connecting plate on the spinneret does not contact the spinneret hole;

[0123] An interlayer is provided on the heating shell, and the interlayer is connected to the heat medium furnace. The heat medium furnace is used to allow the gasified biphenyl to enter the interlayer from the gas phase heat medium inlet through the gas phase heat medium conveying pipe to exchange heat with the melt extruded from the outer spinneret hole, thereby heating the melt extruded from the outer spinneret hole. After the heat exchange, the liquefied heat medium will be discharged from the liquefied heat medium outlet and re-enter the heat medium furnace through the liquefied heat medium reflux pipe.

[0124] The preparation process parameters include: the temperature of the spinning box is 305°C, the temperature of the annular air is 22°C, the wind speed of the annular air is 0.3m / s, the wind pressure of the annular air is 30Pa, the speed of the oil pump is 4.8r / min, the pre-network pressure is 0.09MPa, the temperature of the G / R1 hot roller is 78°C, the speed of the G / R1 hot roller is 2000m / min, the temperature of the G / R2 hot roller is 118°C, the speed of the G / R2 hot roller is 3700m / min, the main network pressure is 0.25MPa, the temperature of the heating shell is 255°C, and the tension of all the monofilaments extruded from the inner spinneret when they break is 144.53cN;

[0125] The core yarn broken fluffy fine denier polyester fiber finally obtained is a tow composed of multiple monofilaments, among which a part of the monofilaments are broken and are broken monofilaments, and the rest are unbroken monofilaments, the broken monofilaments are distributed on the inner side of the unbroken monofilaments, and one end of all the broken monofilaments protrudes to the outer side of the unbroken monofilaments; the fineness of the core yarn broken fluffy fine denier polyester fiber is 111.05 dtex, the total number of monofilaments is 288, the dpf is 0.386, and the number of broken monofilaments is 52.08% of the total number of monofilaments; the broken hair length of the core yarn broken fluffy fine denier polyester fiber is 0.3~0.7 cm, the hair density is 2900 filaments / m, the breaking strength is 4.26 cN / dtex, the breaking strength CV value is 1.84%, the breaking elongation is 30.33%, the breaking elongation CV value is 4.63%, the fluffiness is 95%, and the rebound rate is 93%.

[0126] Example 5

[0127] A method for preparing a core yarn broken fluffy fine-denier polyester fiber, comprising the following steps:

[0128] (1) polycondensing PTA and MEG in a mass ratio of 2.55:1 to form a polyester melt having an intrinsic viscosity of 0.690 dl / g;

[0129] (2) After the polyester melt enters the spinneret for melt extrusion, it is sequentially cooled, oiled, pre-interlaced, G / R1 hot roller drawing, G / R2 hot roller drawing, main interlaced and wound to obtain a core yarn broken fluffy fine denier polyester fiber;

[0130] Wherein, the upper surface and the lower surface of the spinneret are parallel to the horizontal plane;

[0131] The spinneret is provided with 5 circles of spinneret holes. From the inside to the outside of the spinneret, the spinneret holes in the first to third circles are inner spinneret holes, and the spinneret holes in the remaining circles are outer spinneret holes.

[0132] The spinneret holes include guide holes and microholes connected from top to bottom; the diameter of the guide holes of the inner spinneret holes is the same as that of the guide holes of the outer spinneret holes, and the diameter of the guide holes is 1.3 mm; the diameter of the microholes of the outer spinneret holes is 0.13 mm, and the diameter of the microholes of the inner spinneret holes is 1.46 times the diameter of the microholes of the outer spinneret holes; the total number of spinneret holes is 144, the inner spinneret holes account for 50% of the total number of spinneret holes, and the number of spinneret holes in each circle from the inner side to the outer side of the spinneret plate is 20, 24, 28, 32, and 40 respectively;

[0133] The draft ratio of the G / R1 hot roller and the G / R2 hot roller is equal to the theoretical draft ratio of the filaments extruded from the outer spinneret, and is greater than the theoretical draft ratio of the filaments extruded from the inner spinneret; the theoretical draft ratio is the draft ratio at which the filaments will not be broken at the speed of the G / R1 hot roller and the speed of the G / R2 hot roller; a tension detection device is provided between the G / R1 hot roller and the G / R2 hot roller;

[0134] The device used for cooling is a ring blowing device; an aluminum plate is provided on the upper cover plate of the ring blowing device, and a through hole is provided on the aluminum plate;

[0135] An outer ring heating device is installed in the through hole;

[0136] When the ring blowing device is in use, the ring blowing bellows rises until the top of the outer ring heating device is sealed and connected to the plane where the lower surface of the spinneret is located, and at this time, the aluminum plate is sealed and connected to the lower surface of the spinning box body;

[0137] The outer ring heating device comprises a heating shell, a heat insulation plate and a connecting plate;

[0138] The height of the outer ring heating device is the height of the windless zone, and the height of the windless zone is 55mm;

[0139] The heating shell and the heat insulation plate are both hollow cylindrical structures; the inner diameter of the heating shell is greater than or equal to the diameter of the spinneret, the outer diameter of the heating shell is equal to the inner diameter of the through hole, the inner diameter of the heat insulation plate is greater than the maximum diameter of the circle where the inner spinneret holes are located, and the outer diameter of the heat insulation plate is less than the minimum diameter of the circle where the outer spinneret holes are located;

[0140] The heating shell and the heat insulation plate are connected by a connecting plate, and the vertical projection of the connecting plate on the spinneret does not contact the spinneret hole;

[0141] An interlayer is provided on the heating shell, and the interlayer is connected to the heat medium furnace. The heat medium furnace is used to allow the gasified biphenyl to enter the interlayer from the gas phase heat medium inlet through the gas phase heat medium conveying pipe to exchange heat with the melt extruded from the outer spinneret hole, thereby heating the melt extruded from the outer spinneret hole. After the heat exchange, the liquefied heat medium will be discharged from the liquefied heat medium outlet and re-enter the heat medium furnace through the liquefied heat medium reflux pipe.

[0142] The preparation process parameters include: the temperature of the spinning box is 290°C, the temperature of the annular air is 22°C, the wind speed of the annular air is 0.3m / s, the wind pressure of the annular air is 30Pa, the speed of the oil pump is 4.35r / min, the pre-network pressure is 0.1MPa, the temperature of the G / R1 hot roller is 80°C, the speed of the G / R1 hot roller is 1850m / min, the temperature of the G / R2 hot roller is 120°C, the speed of the G / R2 hot roller is 3520m / min, the main network pressure is 0.23MPa, the temperature of the heating shell is 255°C, and the tension of all the monofilaments extruded from the inner spinneret when they break is 85.00cN;

[0143] The core yarn broken fluffy fine denier polyester fiber finally obtained is a tow composed of multiple monofilaments, among which a part of the monofilaments are broken and are broken monofilaments, and the rest are unbroken monofilaments, the broken monofilaments are distributed on the inner side of the unbroken monofilaments, and one end of all the broken monofilaments protrudes to the outer side of the unbroken monofilaments; the fineness of the core yarn broken fluffy fine denier polyester fiber is 68.13 dtex, the total number of monofilaments is 144, the dpf is 0.473, and the number of broken monofilaments is 50.00% of the total number of monofilaments; the broken hair length of the core yarn broken fluffy fine denier polyester fiber is 0.3~0.7 cm, the hair density is 1490 filaments / m, the breaking strength is 4.41 cN / dtex, the breaking strength CV value is 0.95%, the breaking elongation is 31.26%, the breaking elongation CV value is 4.5%, the fluffiness is 90%, and the rebound rate is 92%.

Claims

1. A method for preparing a core yarn broken fluffy fine denier polyester fiber, characterized in that: After the polyester melt enters the spinneret for melt extrusion, it is sequentially cooled, oiled, pre-interlaced, G / R1 hot roller drawing, G / R2 hot roller drawing, main interlaced and wound to obtain the core yarn broken fluffy fine denier polyester fiber; The upper surface and the lower surface of the spinneret are parallel to the horizontal plane; the spinneret is provided with n circles of spinneret holes; from the inside to the outside of the spinneret, the spinneret holes from the first circle to the n-2th circle are inner spinneret holes, and the spinneret holes of the remaining circles are outer spinneret holes; The spinneret hole includes a guide hole and a micropore connected from top to bottom; the diameter of the guide hole of the inner spinneret hole is the same as the diameter of the guide hole of the outer spinneret hole; the diameter of the micropore of the outer spinneret hole is 0.06-0.13 mm, and the diameter of the micropore of the inner spinneret hole is larger than that of the micropore of the outer spinneret hole; The draft ratio of the G / R1 hot roller and the G / R2 hot roller is equal to the theoretical draft ratio of the filaments extruded from the outer spinneret, and is greater than the theoretical draft ratio of the filaments extruded from the inner spinneret; the theoretical draft ratio is the draft ratio at which the filaments will not be broken at the speed of the G / R1 hot roller and the speed of the G / R2 hot roller.

2. The method for preparing a core yarn broken and fluffed fine-denier polyester fiber according to claim 1, characterized in that: The micropore diameter of the inner spinneret hole is 1.15 to 1.50 times the micropore diameter of the outer spinneret hole.

3. The method for preparing a core yarn broken and fluffed fine-denier polyester fiber according to claim 2, characterized in that: The total number of spinnerets is 144-288, and the inner spinnerets account for 48%-52.08% of the total number of spinnerets.

4. The method for preparing a core yarn broken and fluffed fine-denier polyester fiber according to claim 3, characterized in that: A tension detection device is provided between the G / R1 heat roller and the G / R2 heat roller.

5. The method for preparing a core yarn broken and fluffed fine-denier polyester fiber according to claim 4, characterized in that: An outer ring heating device is provided below the spinneret, and the outer ring heating device includes a heating shell, a heat insulation plate and a connecting plate; the heating shell and the heat insulation plate are both hollow cylindrical structures; the inner diameter of the heating shell is greater than or equal to the diameter of the spinneret, the inner diameter of the heat insulation plate is greater than the maximum diameter of the circle where the inner spinneret holes are located, and the outer diameter of the heat insulation plate is less than the minimum diameter of the circle where the outer spinneret holes are located; The heating shell and the heat insulation plate are connected by a connecting plate, and the vertical projection of the connecting plate on the spinneret does not contact the spinneret hole; An interlayer is provided on the heating shell, and the interlayer is connected to the heat medium furnace. The heat medium furnace is used to pass biphenyl into the interlayer to exchange heat with the melt extruded from the outer spinneret hole, thereby heating the melt extruded from the outer spinneret hole; The height of the outer ring heating device is the height of the windless zone, and the top of the outer ring heating device is sealed and connected to the plane where the lower surface of the spinneret is located.

6. The method for preparing a core yarn broken and fluffed fine-denier polyester fiber according to claim 5, characterized in that: The device used for cooling is a ring blowing device; an aluminum plate is provided on the upper cover plate of the ring blowing device, and a through hole is provided on the aluminum plate. The through hole is used to install an outer ring heating device, and the outer diameter of the heating shell is equal to the inner diameter of the through hole; when the top of the outer ring heating device is sealed and connected to the plane where the lower surface of the spinneret is located, the aluminum plate is sealed and connected to the lower surface of the spinning box body.

7. The method for preparing a core yarn broken and fluffed fine-denier polyester fiber according to claim 6, characterized in that: The preparation process parameters include: the temperature of the spinning box is 290~305℃, the temperature of the ring air is 22~24℃, the wind speed of the ring air is 0.15~0.30m / s, the pre-network pressure is 0.06~0.10MPa, the G / R1 hot roller speed is 1850~2000m / min, the G / R2 hot roller speed is 3400~3700m / min, and the main network pressure is 0.19~0.25MPa.

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