Preparation method of core yarn broken and fuzzing type fine denier polyester fiber

Abstract

The present invention belongs to the technical field of chemical fiber production, and relates to a preparation method of a core yarn broken and fuzzed fine denier polyester fiber. The preparation method is as follows: after the polyester melt enters the spinneret and is melt-extruded, it successively passes through cooling, oiling, pre-networking, G / R1 and G / R2 hot roller drafting, main networking and winding to obtain the core yarn broken and fuzzed fine denier polyester fiber; wherein, the upper and lower surfaces of the spinneret are parallel to the horizontal plane; the spinneret is provided with spinneret holes; from the inner side to the outer side of the spinneret, it is divided into inner spinneret holes and outer spinneret holes; the spinneret holes include flow guiding holes and micropores; the micropore diameter of the inner spinneret holes is larger than that of the outer spinneret holes; the drafting ratio of the G / R1 and G / R2 hot rollers is equal to the theoretical drafting ratio of the filaments extruded from the outer spinneret holes and is greater than the theoretical drafting ratio of the filaments extruded from the inner spinneret holes. The method of the present invention can produce core yarn broken and fuzzed fine denier fibers, and the fluffiness and resilience of the velvet-like fabric prepared therefrom are relatively good.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical fiber production, and relates to a preparation method of core yarn broken and fuzzed fine denier polyester fiber. 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 contact the external force break and protrude from the tow to form a fuzz effect. For example, in patent CN109295531A, imitation wool FDY is prepared by using a friction device to rub the outer layer of filaments during the drawing process, and in patent CN114232156A, the outer broken wool yarn is prepared by using discs and oil wheels with a high coefficient of friction.

[0004] The second one is to form outer looped filaments by compounding the finished fibers and utilizing the shrinkage difference, similar to the effect of broken and fibrillated fibers. For example, in patent CN110747552A, two yarns are plied and looped yarns are formed by shrinkage, and in patent CN101177822A, 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 by the action of acid or alkali to achieve the effect of wool yarn softening and fibrillating. For example, in patent CN116892074A, an organic acid solution is used to fibrillate the 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 sand 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 fuzz is attached fuzz. This kind of fuzz only has the fluffiness of wool yarn, and the fabric has poor bulkiness and air permeability, and the fabric does not have elastic recovery performance.

[0007] Moreover, the above methods cannot be used to produce fine denier fibers. This is because the single filaments of fine denier fibers are relatively thin, and the attached fuzz formed under the action of external force or acid-base is dense and easy to scatter. And the fine denier filaments prepared by the above methods all form looped yarns on the outside, which also makes the looped yarns of the fine denier filaments soft and easy to deform, thus resulting in unstable fabric properties.

[0008] Therefore, it is of great significance to study a preparation method of core yarn broken and fuzzed fine denier polyester fiber to solve the above problems. Summary of the Invention

[0009] The object of the present invention is to solve the problems existing in the prior art and provide a preparation method for core yarn broken and fuzzed fine denier polyester fiber.

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

[0011] A preparation method for core yarn broken and fuzzed fine denier polyester fiber. After the polyester melt enters the spinneret and is melt-extruded, it successively undergoes 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 fine denier polyester fiber.

[0012] The upper surface and the lower surface of the spinneret are both parallel to the horizontal plane; there are n circles of spinneret holes on the spinneret; from the inside to the outside of the spinneret, the spinneret holes in the 1st to the (n - 2)th circles are inner spinneret holes, and the spinneret holes in the remaining circles are outer spinneret holes.

[0013] The spinneret holes include a diversion hole and a micropore connected from top to bottom; the aperture of the diversion hole of the inner spinneret holes is the same as that of the diversion hole of the outer spinneret holes; the aperture of the micropore of the outer spinneret holes is 0.06 - 0.13 mm, and the aperture of the micropore of the inner spinneret holes is larger than that of the outer spinneret holes.

[0014] 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 under the speeds of the G / R1 hot roll and the G / R2 hot roll.

[0015] After the polyester melt is extruded from the spinneret, the diameter of the melt will increase (the swelling phenomenon of non-Newtonian fluid), and after swelling, it enters the cooling zone for cooling and refinement. This cooling and refinement has a stretching effect, which is called spinneret stretching. Under the condition that the melt flow rate of each spinneret hole of the spinneret is the same (since the diversion holes are the same, the flow rate of each spinneret hole is the same), the aperture of the micropore of the outer spinneret holes is small, the melt swelling area formed after the melt flows out of the outer spinneret holes is stable, and the spinneret stretching is small. While the aperture of the micropore of the inner spinneret holes is relatively large, the melt swelling area formed after the melt flows out of the inner spinneret holes is larger than the melt swelling area formed after the melt flows out of the outer spinneret holes, and the spinneret stretching is large. This makes the single filaments extruded from the outer spinneret holes more tensile-resistant than the single filaments extruded from the inner spinneret holes under the subsequent G / R1 hot roll drawing and G / R2 hot roll drawing. By reasonably setting the speeds of the G / R1 hot roll and the G / R2 hot roll, the inner single filaments are broken, while the outer single filaments are not broken, thereby obtaining the core yarn broken and fuzzed fine denier polyester fiber. The reason why the filaments with smaller spinneret stretching are more tensile-resistant under the subsequent G / R1 hot roll drawing and G / R2 hot roll drawing is that for single filaments with the same extrusion fineness from the same spinneret, their relative draw ratios have finiteness and consistency. The spinneret stretching of the outer single filaments is relatively smaller than that of the inner single filaments, and the remaining stretching of the outer single filaments is relatively more than that of the inner single filaments, so the outer single filaments are tensile-resistant.

[0016] Compared with conventional fine denier filaments, the core yarn broken and fuzzed fine denier fiber has the characteristics of softness and natural cotton of conventional fine denier filaments. At the same time, under the same denier, the fine denier fiber has more holes and a larger hairiness density. It also combines the softness of fine denier filaments and the fluffiness of hairiness yarn. Meanwhile, the core yarn broken and fuzzed fine denier fiber forms a structure that is both soft and has a backbone through broken single filaments and unbroken single filaments (i.e., the unbroken single yarn forms the yarn backbone), which can provide high-quality products for post-spinning production of feather velvet, cotton-like, and wool-like products.

[0017] In theory, fine denier polyester fibers can also be produced by using 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 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 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 as follows: 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 aspect ratios of the spinneret holes in different circles are different. The aspect ratio of the outer spinneret holes is larger than that of the inner spinneret holes. The residence time of the melt from the entrance to the exit of the outer spinneret hole is long, and the swelling ratio decreases (the spinneret temperature is high, the residence time is long, the viscosity decreases, the internal stress weakens, and the swelling ratio decreases accordingly), and the spinneret drawdown decreases. As a result, under the subsequent G / R1 hot roll drafting and G / R2 hot roll drafting, the outer single filaments are more tensile-resistant than the inner single filaments. In different circles, as the aspect 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 spinneret drawdown is low and the filaments are more tensile-resistant under the subsequent G / R1 hot roll drafting and G / R2 hot roll drafting is that for the single filaments extruded from the same spinneret with the same fineness, 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. Therefore, the outer single filaments are tensile-resistant.

[0018] However, in the actual production process, the above arc-shaped spinneret cannot be used to produce core yarn broken and fuzzed fine denier polyester fibers. The specific reasons are as follows:

[0019] (1) When changing the aspect ratio by changing the length of the spinneret hole, due to the inner arc-shaped groove of the spinneret, there is a height difference in the outlet cross-section of the inner spinneret hole, resulting in a slight inclination effect when the melt flows out of the spinneret hole, and it is easy to break the head when producing fine denier fiber products;

[0020] (2)During the production process, the spinneret plate needs to be periodically cleaned of impurities on its surface. The cleaning of the inner arc-shaped groove is relatively difficult, especially when producing superfine denier fibers. The pore diameter is small, and the inner holes are prone to blockage, resulting in difficult melt extrusion and high production difficulty.

[0021] (3)When producing fine denier fibers, the single filaments are relatively thin, the spinneret hole diameter is small, and the aspect ratio is within a certain range, so its length is small and the plate surface is thin. Reducing the length of the inner spinneret holes to change the aspect ratio will result in an even thinner inner plate surface, affecting the service life and easily causing deformation of the spinneret plate.

[0022] (4)Based on production experience, when the spinneret plate is too thin, the production difficulty increases accordingly. Because the melt is less squeezed before ejection and is in an amorphous state, the melt tension at the outlet is unstable, which in turn affects the uniformity of the fineness of a single filament bundle. In severe cases, production cannot be carried out. The literature (Analysis of the Structural Improvement of Polyester Filament Spinneret Plates [J], Synthetic Fiber Industry, 2004.27) also records that in terms of fluidity, increasing the thickness of the spinneret plate is beneficial to improving the stability of spinning, which can reduce the non-uniformity of short segments caused by channel turbulence. If the thickness is too small, it will affect the spinning stability.

[0023] As a preferred technical solution:

[0024] For the preparation method of the core yarn broken and fuzzed fine denier polyester fiber as described above, the micropore diameter of the inner spinneret holes is 1.15 - 1.50 times that of the outer spinneret holes.

[0025] For the preparation method of the core yarn broken and fuzzed fine denier polyester fiber as described above, the total number of spinneret holes is 144 - 288, and the inner spinneret holes account for 48% - 52.08% of the total number of spinneret holes.

[0026] For the preparation method of the core yarn broken and fuzzed 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 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 breakage tension is much greater than the drawing tension. Therefore, the tension detection sensor detects the tension at break, rather than the overall tension of the composite filament), 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 fineness of the inner single filament × the number of inner single filaments × the breaking strength of the pre-oriented yarn of the inner single filament. The drawing tension can be adjusted by adjusting the speed of the G / R1 hot roller. For example, if the tension is low, reduce the speed of the G / R1 hot roller, the draw ratio increases, and the tension increases; when the tension is low, the opposite adjustment is made.

[0027] A preparation method of a core yarn broken and fuzzed fine denier polyester fiber as described above, an outer ring heating device is provided below the spinneret. The outer ring heating device includes a heating outer shell, a heat insulation plate and a connecting plate; both the heating outer shell and the heat insulation plate are hollow cylindrical structures; the inner diameter of the heating outer 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 outer shell and the heat insulation plate are connected by the connecting plate, and the vertical projection of the connecting plate on the spinneret does not contact the spinneret holes;

[0029] A sandwich layer is provided on the heating outer shell, and the sandwich layer is communicated with a heat medium furnace. The heat medium furnace is used to introduce diphenyl into the sandwich layer to exchange heat with the melt extruded from the outer spinneret holes, so as to heat the melt extruded from the outer spinneret holes, increase the temperature of the melt extruded from the outer spinneret holes, reduce the viscosity accordingly, and reduce the internal stress accordingly. After cooling to form fibers, they are more tensile.

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

[0031] A preparation method of a core yarn broken and fuzzed fine denier polyester fiber as described above, the device used for cooling is an annular blowing device; an aluminum plate is provided on the upper cover plate of the annular blowing device, and through holes are provided on the aluminum plate. The through holes are used to install the outer ring heating device, and the outer diameter of the heating outer shell is equal to the inner diameter of the through holes; that is, the outer wall of the heating outer shell is closely attached to and fixedly connected to the inner wall of the through holes; when the top of the outer ring heating device is hermetically connected to the plane where the lower surface of the spinneret is located, the aluminum plate is hermetically connected to the lower surface of the spinning box.

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

[0033] The present invention also provides a core yarn broken and fuzzed fine denier polyester fiber prepared by the method as described above, which is a tow composed of multiple single filaments. Among them, 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;

[0034] The fineness of the core yarn broken and fuzzed fine denier polyester fiber is 22~112 dtex, 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 a preferred technical solution:

[0036] For a core yarn broken and fuzzed fine denier polyester fiber as described above, the broken fuzz length of the core yarn broken and fuzzed fine denier polyester fiber is 0.5 ± 0.2 cm, the fuzz density is 1440~3000 pieces / m, the breaking strength is 4.15~4.45 cN / dtex, the CV value of the breaking strength ≤ 2.52%, the breaking elongation is 30~33.02%, the CV value of the breaking elongation ≤ 5.12%, the bulkiness ≥ 90%, and the resilience rate ≥ 92%; the fuzz 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 fuzz length after the breakage of the inner monofilaments is much larger than the outer 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 fuzz to form a three-dimensional air isolation layer, so it has good bulkiness. Because the inner monofilaments break and protrude around the filament bundle, its fuzz density and length are uniform and it is not easy to change its external shape by external force, and it has good resilience performance.

[0037] Beneficial effects:

[0038] (1) By setting inner spinneret holes and outer spinneret holes with different micropore diameters on the spinneret plate in the present invention, the monofilaments extruded from the outer spinneret holes are more tensile-resistant than those extruded from the inner spinneret holes. During subsequent hot roll drafting, by reasonably setting the G / R1 hot roll speed and the G / R2 hot roll speed, the inner monofilaments are broken while the outer monofilaments are not broken. In this way, a fuzzed fine denier polyester fiber with good resilience and not easy to shed fuzz can be prepared.

[0039] (2) An outer ring heating device is provided below the spinneret plate in the present invention, so that the melt temperature extruded from the outer spinneret holes increases, the viscosity decreases accordingly, and the internal stress decreases accordingly. After cooling to form fibers, it is more tensile-resistant.

[0040] (3) By controlling the number of inner spinneret holes and outer spinneret holes in the present invention, fuzzed fine denier polyester fibers with different numbers and densities of broken fuzz can be produced, and the flannelette fabrics made from them have good bulkiness and resilience performance. Description of the Drawings

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

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

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

[0045] Figure 5 Schematic diagram of the use of the outer ring heating device of the present invention;

[0046] Figure 6 Schematic diagram of the core yarn broken and fuzzed fine denier polyester fiber of the present invention;

[0047] Wherein, 1 - spinneret plate, 2 - inner spinneret holes, 3 - outer spinneret holes, 4 - heating shell, 5 - heat insulation layer, 6 - connecting plate, 7 - sandwich layer, 8 - liquefied heat medium outlet, 9 - gaseous heat medium inlet, 10 - outer ring heating device, 11 - aluminum plate, 12 - upper cover plate, 13 - liquefied heat medium return pipe, 14 - heat medium furnace, 15 - gaseous heat medium delivery pipe, 16 - broken single filaments, 17 - unbroken single filaments. Specific embodiments

[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 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.

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

[0050] dpf: First, refer to "GB / T14343 - 2008 Chemical Fiber - Filament Linear Density Test Method" to test the total fiber linear density of the core yarn broken and fuzzed fine denier polyester fiber prepared in the examples, 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 Synthetic Fibers - Filament Tensile Properties Test Method", and use an imported fully automatic strength and elongation tester to test the core yarn broken and fuzzed fine denier polyester fiber prepared in the examples.

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

[0053] Rebound rate: Referring to the standard of "FZ / T 01034-2008 Textiles - Test method for tensile elasticity of woven fabrics", an isometric elongation tester is used to deform the core yarn broken and fuzzed fine denier 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 and recovering within the specified time, the residual elongation is measured, 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 tension, δL is the length of the specimen after applying pre-tension, and δL1 is the length (plastic deformation amount) of the specimen after applying pre-tension again after the fixed force or fixed elongation recovery.

[0054] Example 1

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

[0056] (1) Polycondense PTA (terephthalic acid) and MEG (ethylene glycol) with a mass ratio of 2.55:1 into a polyester melt with an intrinsic viscosity of 0.690 dl / g.

[0057] (2) After the polyester melt enters the spinneret and is melt-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 fine denier polyester fiber;

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

[0059] There are 5 circles of spinneret holes on the spinneret. 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;

[0060] The spinneret holes include a diversion hole and a micropore connected from top to bottom; the aperture of the diversion hole of the inner spinneret hole is the same as that of the outer spinneret hole, and the aperture of the diversion hole is 0.8 mm; the aperture of the micropore of the outer spinneret hole is 0.08 mm, and the aperture of the micropore of the inner spinneret hole is 1.25 times that of the outer spinneret hole; the total number of spinneret holes is 288, and the inner spinneret holes account for 52.08% of the total number of spinneret holes. The number of spinneret holes in each circle from the inside to the outside of the spinneret is 42, 50, 58, 66, 72 respectively;

[0061] 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 under the speeds of the G / R1 hot roll and the G / R2 hot roll; a tension detection device is provided between the G / R1 hot roll and the G / R2 hot roll;

[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 through holes are provided on the aluminum plate;

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

[0064] When the ring blowing device is in use, the ring blowing air box rises until the top of the outer ring heating device is hermetically connected to the plane where the lower surface of the spinneret is located. At this time, the aluminum plate is hermetically connected to the lower surface of the spinning box;

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

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

[0067] Both the heating outer shell and the heat insulation plate are hollow cylindrical structures; the inner diameter of the heating outer shell is greater than or equal to the diameter of the spinneret, the outer diameter of the heating outer 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 side 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 side spinneret holes are located;

[0068] The heating outer 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 holes;

[0069] A sandwich layer is provided on the heating outer shell, and the sandwich layer is communicated with a heat medium furnace. The heat medium furnace is used to convey the vaporized diphenyl through a vapor-phase heat medium delivery pipe and enter the sandwich layer from the vapor-phase heat medium inlet to exchange heat with the melt extruded from the outer side spinneret holes, so as to heat the melt extruded from the outer side spinneret holes. The liquefied heat medium after heat exchange will be discharged from the liquefied heat medium outlet and re-enter the heat medium furnace through the liquefied heat medium return pipe;

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

[0071] The finally prepared core yarn broken and fuzzed fine denier polyester fiber is as Figure 6As shown, it is a tow composed of multiple monofilaments, among which some monofilaments are broken into broken monofilaments 16, and the rest are unbroken monofilaments 17. The broken monofilaments are distributed inside the unbroken monofilaments 17, and one end of all the broken monofilaments protrudes outside the unbroken monofilaments 17; the fineness of the core-yarn broken and fuzzed 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 fuzz length of the core-yarn broken and fuzzed fine denier polyester fiber is 0.3 - 0.7 cm, the fuzz density is 2990 pieces / m, the breaking strength is 4.17 cN / dtex, the CV value of the breaking strength is 1.72%, the breaking elongation is 33.02%, the CV value of the breaking elongation is 4.99%, the bulkiness is 95%, and the resilience rate is 94%.

[0072] Example 2

[0073] A preparation method of a core-yarn broken and fuzzed fine denier polyester fiber is as follows:

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

[0075] (2) After the polyester melt enters the spinneret and is melt-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 fine denier polyester fiber;

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

[0077] There are 5 circles of spinneret holes on the spinneret. 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;

[0078] The spinneret holes include a flow guide hole and a micropore connected from top to bottom; the aperture of the flow guide hole of the inner spinneret holes is the same as that of the outer spinneret holes, and the aperture of the flow guide hole is 0.8 mm; the aperture of the micropore of the outer spinneret holes is 0.08 mm, and the aperture of the micropore of the inner spinneret holes is 1.25 times that of the outer spinneret holes; the total number of spinneret holes is 216, and the inner spinneret holes account for 48.15% of the total number of spinneret holes. The number of holes in each circle of spinneret holes from the inside to the outside of the spinneret is 24, 36, 44, 52, and 60 respectively;

[0079] 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 under the speeds of the G / R1 hot roll and the G / R2 hot roll; a tension detection device is provided between the G / R1 hot roll and the G / R2 hot roll;

[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 through holes are 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 air box rises until the top of the outer ring heating device is hermetically connected to the plane where the lower surface of the spinneret plate is located. At this time, the aluminum plate is hermetically connected to the lower surface of the spinning box body;

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

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

[0085] Both the heating outer shell and the heat insulation plate are hollow cylindrical structures; the inner diameter of the heating outer shell is greater than or equal to the diameter of the spinneret plate, the outer diameter of the heating outer 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 outer shell and the heat insulation plate are connected by a connecting plate, and the vertical projection of the connecting plate on the spinneret plate does not contact the spinneret holes;

[0087] A sandwich layer is provided on the heating outer shell, and the sandwich layer is communicated with a heat medium furnace. The heat medium furnace is used to send the vaporized diphenyl through a gas-phase heat medium delivery pipe into the sandwich layer from the gas-phase heat medium inlet to exchange heat with the melt extruded from the outer spinneret holes, so as to heat the melt extruded from the outer spinneret holes. The liquefied heat medium after heat exchange will be discharged from the liquefied heat medium outlet and re-enter the heat medium furnace through the liquefied heat medium return pipe;

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

[0089] The finally obtained core yarn broken and fuzzed fine denier polyester fiber is a tow composed of multiple monofilaments. Among them, a part of the monofilaments are broken into broken monofilaments, 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 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 hairiness length of the core yarn broken and fuzzed fine denier polyester fiber is 0.3 - 0.7 cm, the hairiness density is 2080 roots / m, the breaking strength is 4.35 cN / dtex, the CV value of the breaking strength is 1.81%, the breaking elongation is 32.01%, the CV value of the breaking elongation is 5.12%, the bulkiness is 93%, and the resilience rate is 92%.

[0090] Example 3

[0091] A preparation method of a core yarn broken and fuzzed fine denier polyester fiber is as follows:

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

[0093] (2) After the polyester melt enters the spinneret and is melt-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 fine denier polyester fiber;

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

[0095] There are 5 circles of spinneret holes on the spinneret 1. From the inside to the outside of the spinneret 1, the spinneret holes in the 1st to 3rd 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 a diversion hole and a micropore connected from top to bottom; the aperture of the diversion hole of the inner spinneret hole 2 is the same as that of the diversion hole of the outer spinneret hole 3, and the aperture of the diversion hole is 0.6 mm; the aperture of the micropore of the outer spinneret hole 3 is 0.06 mm, and the aperture of the micropore of the inner spinneret hole 2 is 1.17 times that of the micropore of the outer spinneret hole 3; the total number of spinneret holes is 144, and the inner spinneret holes 2 account for 50% of the total number of spinneret holes. The number of spinneret holes in each circle from the inside to the outside of the spinneret is 20, 24, 28, 32, and 40 respectively;

[0097] 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; a tension detection device is provided between the G / R1 hot roll and the G / R2 hot roll;

[0098] As Figure 1 、 Figure 5 shown, the device used for cooling is an annular blowing device; an aluminum plate 11 is provided on the upper cover plate 12 of the annular blowing device, and through holes are provided on the aluminum plate 11;

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

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

[0101] As Figures 1 to 5 shown, the outer ring heating device 10 includes a heating outer 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 area, and the height of the windless area is 40 mm;

[0103] Both the heating outer shell 4 and the heat insulation plate 5 are hollow cylindrical structures; the inner diameter of the heating outer shell 4 is greater than or equal to the diameter of the spinneret plate 1, the outer diameter of the heating outer 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 outer shell 4 and the heat insulation plate 5 are connected by the connecting plate 6, and the vertical projection of the connecting plate 6 on the spinneret plate 1 does not contact the spinneret holes;

[0105] As Figure 4 、 Figure 5 shown, a sandwich layer 7 is provided on the heating outer shell 4, and the sandwich layer 7 is communicated with a heat medium furnace 14. The heat medium furnace 14 is used to send the vaporized diphenyl through the gas-phase heat medium conveying pipe 15 into the sandwich layer 7 from the gas-phase heat medium inlet 9 to exchange heat with the melt extruded from the outer spinneret holes 2, so as to heat the melt extruded from the outer spinneret holes 2. The liquefied heat medium after heat exchange will be discharged from the liquefied heat medium outlet 8 and re-enter the heat medium furnace 14 through the liquefied heat medium return pipe 13;

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

[0107] The finally prepared core yarn broken and fuzzed fine denier polyester fiber is a filament bundle composed of multiple single filaments. Among them, some single filaments are broken into broken single filaments, 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 fine denier polyester fiber is 22.39 dtex, the total number of single filaments is 144, the dpf is 0.155, and the number of broken single filaments is 50.00% of the total number of single filaments; the broken fuzz length of the core yarn broken and fuzzed fine denier polyester fiber is 0.3 - 0.7 cm, the fuzz density is 1440 pieces / m, the breaking strength is 4.16 cN / dtex, the CV value of the breaking strength is 2.52%, the breaking elongation is 30.53%, the CV value of the breaking elongation is 3.69%, the bulkiness is 92%, and the resilience rate is 94%.

[0108] Example 4

[0109] A preparation method of a core yarn broken and fuzzed fine denier polyester fiber is as follows:

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

[0111] (2) After the polyester melt enters the spinneret plate and is melt-extruded, it successively passes through cooling, oiling, pre-network, G / R1 hot roller drawing, G / R2 hot roller drawing, main network, and winding to obtain the core yarn broken and fuzzed fine denier polyester fiber;

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

[0113] There are 5 circles of spinneret holes on the spinneret plate. From the inside to the outside of the spinneret plate, 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;

[0114] The spinneret holes include a flow guide hole and a micro hole connected from top to bottom; the aperture of the flow guide hole of the inner spinneret holes is the same as that of the flow guide hole of the outer spinneret holes, and the aperture of the flow guide hole is 1 mm; the aperture of the micro hole of the outer spinneret holes is 0.1 mm, and the aperture of the micro hole of the inner spinneret holes is 1.4 times that of the micro hole of the outer spinneret holes; the total number of spinneret holes is 288, and the inner spinneret holes account for 52.08% of the total number of spinneret holes. 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 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 under the speeds of the G / R1 hot roll and the G / R2 hot roll; a tension detection device is provided between the G / R1 hot roll and the G / R2 hot roll;

[0116] The device used for cooling is an annular blowing device; an aluminum plate is provided on the upper cover plate of the annular blowing device, and through holes are provided on the aluminum plate;

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

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

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

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

[0121] Both the heating outer shell and the heat insulation plate are hollow cylindrical structures; the inner diameter of the heating outer shell is greater than or equal to the diameter of the spinneret plate, the outer diameter of the heating outer 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 outer shell and the heat insulation plate are connected by a connecting plate, and the vertical projection of the connecting plate on the spinneret plate does not contact the spinneret holes;

[0123] A sandwich layer is provided on the heating outer shell, and the sandwich layer is communicated with a heat medium furnace. The heat medium furnace is used to transport the vaporized diphenyl through a vapor-phase heat medium delivery pipe from a vapor-phase heat medium inlet into the sandwich layer to exchange heat with the melt extruded from the outer spinneret holes, thereby heating the melt extruded from the outer spinneret holes. The liquefied heat medium after heat exchange will be discharged from a liquefied heat medium outlet and re-enter the heat medium furnace through a liquefied heat medium return pipe;

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

[0125] The finally prepared core yarn broken and fuzzed fine denier polyester fiber is a filament bundle composed of multiple single filaments. Among them, a part of the single filaments are broken into broken single filaments, 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 fine denier polyester fiber is 111.05 dtex, the total number of single filaments is 288, the dpf is 0.386, and the number of broken single filaments is 52.08% of the total number of single filaments; the broken hairiness length of the core yarn broken and fuzzed fine denier polyester fiber is 0.3 - 0.7 cm, the hairiness density is 2900 roots / m, the breaking strength is 4.26 cN / dtex, the CV value of the breaking strength is 1.84%, the breaking elongation is 30.33%, the CV value of the breaking elongation is 4.63%, the bulkiness is 95%, and the resilience rate is 93%.

[0126] Example 5

[0127] A preparation method of a core yarn broken and fuzzed fine denier polyester fiber is as follows:

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

[0129] (2) After the polyester melt enters the spinneret plate and is melt-extruded, it successively passes through cooling, oiling, pre-network, G / R1 hot roller drawing, G / R2 hot roller drawing, main network, and winding to obtain the core yarn broken and fuzzed fine denier polyester fiber;

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

[0131] There are 5 circles of spinneret holes on the spinneret plate. From the inside to the outside of the spinneret plate, 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;

[0132] The spinneret holes include a flow guiding hole and a micro hole connected from top to bottom; the aperture of the flow guiding hole of the inner spinneret holes is the same as that of the flow guiding hole of the outer spinneret holes, and the aperture of the flow guiding hole is 1.3 mm; the aperture of the micro hole of the outer spinneret holes is 0.13 mm, and the aperture of the micro hole of the inner spinneret holes is 1.46 times that of the micro hole of the outer spinneret holes; the total number of spinneret holes is 144, and the inner spinneret holes account for 50% of the total number of spinneret holes. 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 draw ratios of the G / R1 hot roller and the G / R2 hot roller 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 roller and 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 an annular blowing device; an aluminum plate is provided on the upper cover plate of the annular blowing device, and through holes are provided on the aluminum plate;

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

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

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

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

[0139] Both the heating outer shell and the heat insulation plate are hollow cylindrical structures; the inner diameter of the heating outer shell is greater than or equal to the diameter of the spinneret plate, the outer diameter of the heating outer 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 outer shell and the heat insulation plate are connected by a connecting plate, and the vertical projection of the connecting plate on the spinneret plate does not contact the spinneret holes;

[0141] A sandwich layer is provided on the heating outer shell, and the sandwich layer is communicated with a heat medium furnace. The heat medium furnace is used to convey the vaporized diphenyl through a gas-phase heat medium conveying pipe from a gas-phase heat medium inlet into the sandwich layer to exchange heat with the melt extruded from the outer spinneret holes, so as to heat the melt extruded from the outer spinneret holes. The liquefied heat medium after heat exchange will be discharged from a liquefied heat medium outlet and re-enter the heat medium furnace through a liquefied heat medium return pipe;

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

[0143] The finally obtained core yarn broken and fuzzed fine denier polyester fiber is a filament bundle composed of multiple single filaments. Among them, a part of the single filaments are broken into broken single filaments, 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 fine denier polyester fiber is 68.13 dtex, the total number of single filaments is 144, the dpf is 0.473, and the number of broken single filaments is 50.00% of the total number of single filaments; the broken fuzz length of the core yarn broken and fuzzed fine denier polyester fiber is 0.3 - 0.7 cm, the fuzz density is 1490 pieces / m, the breaking strength is 4.41 cN / dtex, the CV value of the breaking strength is 0.95%, the breaking elongation is 31.26%, the CV value of the breaking elongation is 4.5%, the bulkiness is 90%, and the resilience is 92%.

Claims

1. A preparation method of a core yarn broken and fuzzed fine denier polyester fiber, characterized in that: After the polyester melt enters the spinneret plate and is extruded by melting, 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 fine denier polyester fiber; The upper surface and the lower surface of the spinneret plate are both parallel to the horizontal plane; there are n circles of spinneret holes on the spinneret plate; from the inside to the outside of the spinneret plate, the spinneret holes in the 1st to the n-2nd circles are inner spinneret holes, and the spinneret holes in the remaining circles are outer spinneret holes; The spinneret holes include a diversion hole and a micropore connected from top to bottom; the aperture of the diversion hole of the inner spinneret holes is the same as that of the diversion hole of the outer spinneret holes; the aperture of the micropore of the outer spinneret holes is 0.06 - 0.13 mm, and the aperture of the micropore of the inner spinneret holes is larger than that of the outer 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 under 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 fine denier polyester fiber according to claim 1, characterized in that, The aperture of the micropore of the inner spinneret holes is 1.15 - 1.50 times that of the micropore of the outer spinneret holes.

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

4. The preparation method of a core yarn broken and fuzzed fine denier 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 fine denier polyester fiber according to claim 4, characterized in that, An outer ring heating device is provided below the spinneret plate. The outer ring heating device includes a heating outer shell, a heat insulation plate, and a connecting plate; both the heating outer shell and the heat insulation plate are hollow cylindrical structures; the inner diameter of the heating outer shell is greater than or equal to the diameter of the spinneret plate, 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 outer shell and the heat insulation plate are connected by the connecting plate, and the vertical projection of the connecting plate on the spinneret plate does not contact the spinneret holes; A sandwich layer is provided on the heating outer shell, and the sandwich layer is communicated with a heat medium furnace. The heat medium furnace is used to introduce diphenyl into the sandwich layer to exchange heat with the melt extruded from the outer spinneret holes, so as to heat the melt extruded from the outer spinneret holes; The height of the outer ring heating device is the height of the windless area, and the top of the outer ring heating device is hermetically connected to the plane where the lower surface of the spinneret plate is located.

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

7. The preparation method of a core yarn broken and fuzzed 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 °C, the temperature of the annular blowing air is 22 - 24 °C, the wind speed of the annular blowing air is 0.15 - 0.30 m / s, the pre-network pressure is 0.06 - 0.10 MPa, the speed of the G / R1 hot roll is 1850 - 2000 m / min, the speed of the G / R2 hot roll is 3400 - 3700 m / min, and the main network pressure is 0.19 - 0.25 MPa.

Images