Process for the production of a spiral-like wool-like polyamide fibre

Abstract

The present application relates to a kind of preparation method of spiral wool-like polyamide fiber, comprising the following steps: step S1: full-extinction PA6 chip is melted extruded by screw extruder, after passing through melt pipeline, metering pump enters the assembly with comb-shaped spinneret hole, and the melt of plane type sawtooth section is obtained;Step S2: high wind speed side blowing wind window is fixed with the vortex disrupter of multiple semicircular structure slot, and the bottom of vortex disrupter has 6 nitrogen interfaces, and the melt is cooled after the high-speed vortex air mass formed by nitrogen and high wind speed side blowing wind mixture is gathered and oiled;Step S3: after the oiling of the yarn bundle is passed through spinning duct, by cold roll, hot roll stretching setting, after the relaxation of wire reel internal stress, by winding machine, the spiral wool-like polyamide fiber FDY of winding formation is obtained.The spiral wool-like fiber prepared by the present application is more fluffy, warm, and more comfortable in hand feeling, which can become a better wool substitute fiber.

Description

Technical Field

[0001] This invention relates to the field of wool-like fiber production technology, and in particular to a method for preparing spiral-shaped wool-like polyamide fibers. Background Technology

[0002] Rabbit hair sweaters, sherpa sweaters, lambskin sweaters, and many others belong to the large family of sweaters. Sweater apparel is developing towards becoming more like outerwear, more serialized, more fashionable, more artistic, more upscale, and more branded. Sweater tops are popular for their warmth, smooth feel, and comfortable wear; while double-faced wool coats, with their delicate and smooth feel, dense texture, crisp yet elastic feel, and vibrant, diverse colors, are suitable for different age groups, showcasing the unique charm of urban women's elegance, sophistication, and fashionable individuality.

[0003] However, because they are made of natural fibers, they do not have antibacterial and insect-repellent properties, and the fabrics will turn yellow after being stored for a long time. High-end clothing made of wool generally needs to be dry cleaned because wool will shrink, shed, and pill after washing, so wool fabrics are more troublesome to care for. Wool is relatively expensive, with many starting at tens of thousands of yuan. In order to improve the shortcomings of natural fibers and reduce costs, wool can be blended with other chemical fibers or chemical fibers can be used as substitutes.

[0004] In natural fibers, wool naturally exhibits a periodic crimp along its length, a natural crimp caused by the asymmetry of the fiber's cross-section. Typically, a single cross-section of wool contains both cortical and paracortical cells. These two types of cells have different structures and proportions, and are arranged bilaterally, causing the fiber to twist or spiral around its axis, resulting in a helical, three-dimensional crimp. Currently, many commercially available helical wool-like fibers are produced using composite spinning. Two or more polymers with different viscosities or shrinkage rates are passed through their respective melt channels, converge at the spinneret, and form a composite melt that is extruded through a single spinneret to form a single fiber. Due to the different shrinkage rates of the polymers, the relaxed fiber exhibits high bulk and crimp. However, the composite spinning method requires composite spinning equipment with a twin-screw system. Furthermore, in the preparation process of wool-like polyamide fiber FDY, most of the produced fibers are straight filaments with only slight fluffiness, which is quite different from the fluffiness of real wool / cashmere. Currently, the fabrics produced by conventional wool-like FDY have a similar appearance to wool sweaters, but the softness and fullness of the fabric are still quite different. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing spiral-shaped wool-like polyamide fibers, which can be produced on a single-screw extruder and make the wool-like fibers stand up naturally when woven into fabrics, with a style and curl similar to natural fibers such as wool, thus solving the problem that wool-like polyamide fibers are significantly different from real wool.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing helical wool-like polyamide fibers, comprising the following steps:

[0007] Step S1: After the full-dull PA6 chips are melted and extruded by a screw extruder, they enter the spinneret assembly through the melt pipeline and metering pump to obtain a melt with a planar serrated cross section.

[0008] Step S2: A vortex disruptor with multiple semi-circular slots is fixed at the blowing window of the high-speed side blowing. The bottom of the vortex disruptor has 6 nitrogen ports. After the melt is cooled by the high-speed vortex airflow formed by the mixing of nitrogen and high-speed side blowing, it is bundled and oiled.

[0009] Step S3: After oiling, the filament bundle passes through the spinning tunnel, is stretched and shaped by cold rollers and hot rollers, and after the internal stress is relaxed by the guide disc, it reaches the winding machine to obtain the spiral-shaped wool-like polyamide fiber FDY.

[0010] Furthermore, in step S1, the diameter of the spinneret is 80-95mm, the number of spinneret holes on the spinneret is 5-12, and the cross-section of the spinneret holes is a horizontal comb shape.

[0011] Furthermore, in step S1, the nozzles are evenly distributed in a circular pattern on the spray plate, with a nozzle height of 0.6-0.7 mm, a nozzle length of 1.4-1.9 mm, a nozzle width of 0.1-0.2 mm at the narrower part, and a nozzle width of 0.3-0.6 mm at the wider part. The angle between the direction of the spinneret and the side blowing air is 0-11°.

[0012] Furthermore, in step S2, the frame width of the eddy current jammer is 400-410mm, the frame thickness is 85-95mm, and the diameter of the semi-circular structure is 105-115mm.

[0013] Furthermore, the eddy current jammer frame in step 2 includes a base plate, side plates, a top plate, guide plates, and stainless steel pipes; multiple guide plates are fixed on the side plates, a top plate is fixed above the guide plates, and a base plate is fixed below the guide plates. The nitrogen inlet is located on the base plate. The base plate, top plate, and guide plates are all provided with multiple semi-circular opening slots arranged in a straight line. The nitrogen inlet is connected to multiple stainless steel pipes, which penetrate the guide plates. Circular nozzles are provided in the gaps between the guide plates.

[0014] Furthermore, in step S2, rectangular fixing plates are fixed at the four corners of the eddy current jammer. The eddy current jammer is fixed to the air blowing window by the rectangular fixing plates and is completely perpendicular to the side air blowing net. The eddy current jammer is installed flush with the top of the side air blowing net.

[0015] Furthermore, in step S2, the wind speed range of the high-speed vortex wind mass is 0.70-0.90 m / s, the wind temperature of the high-speed vortex wind mass is 14-18℃, the humidity of the high-speed vortex wind mass is 88%-99%, the cooling distance of the high-speed vortex wind mass is 1000mm-1800mm, and the nitrogen pressure is 0.02 MPa.

[0016] Furthermore, in step S3, the winding speed of the winding machine is 3250-3800 m / min, the speed of the cold roller is 1800-2500 m / min, the speed of the hot roller is 3300-3900 m / min, the setting temperature of the hot roller is 130-155℃, the stretching ratio of the cold roller and the hot roller is between 1.32 and 2.16, and the speed of the guide disc is 3200-3950 m / min.

[0017] Furthermore, in step S3, the winding speed of the winding machine is 3250-3800 m / min, the speed of the cold roller is 1800-2500 m / min, the speed of the hot roller is 3300-3900 m / min, the setting temperature of the hot roller is 130-155℃, the stretching ratio of the cold roller and the hot roller is between 1.32 and 2.16, and the speed of the guide disc is 3200-3950 m / min.

[0018] The beneficial effects of this invention are:

[0019] 1) The present invention uses an asymmetric cooling molding method, which can realize production on a single screw machine, with lower equipment requirements, and can meet the large-scale application of spiral wool-like polyamide fibers;

[0020] 2) This invention provides a method for preparing helical wool-like polyamide fibers using an asymmetric cooling process. A planar sawtooth melt is obtained by using a spinneret with a comb-shaped cross-section. A nitrogen-plus-side-blowing rapid vortex cooling method is employed in conjunction with the planar sawtooth melt to create an asymmetric cooling effect, resulting in differences in the fiber cortex structure and thus producing helical wool-like polyamide fibers. Helical wool-like fibers exhibit a memory effect, maintaining their crimp shape. While the number of crimps decreases when the fiber is damp, they can recover after drying. Helical wool-like fibers have superior bulkiness, warmth retention, and a more comfortable feel, making them a better alternative to wool. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the spinneret structure of the present invention;

[0022] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0023] Figure 3 This is a schematic diagram of the eddy current jammer.

[0024] Figure 4 This is a schematic diagram of the structure of the product of the present invention;

[0025] Figure 5 This is an enlarged view of the product appearance of the present invention;

[0026] Figure 6 This is an enlarged cross-sectional view of the product of the present invention;

[0027] Figure 7 This is a schematic diagram showing the location of the eddy current jammer of the present invention.

[0028] 1. Top plate, 2. Fixing plate, 3. Side plate, 4. Guide plate, 5. Nitrogen port, 6. Side blowing net, 7. Vortex jammer, 8. Wind window. Detailed Implementation

[0029] The invention will now be further described with reference to the accompanying drawings.

[0030] Please see Figures 1 to 6 The present invention provides an embodiment: a method for preparing helical wool-like polyamide fibers, comprising the following steps:

[0031] Step S1: After being melted and extruded by a screw extruder, the fully matte PA6 chips enter the spinneret assembly through the melt pipeline and metering pump to obtain a melt with a planar sawtooth cross section. The fully matte PA6 chips make the imitation wool effect more realistic because the luster of wool is matte, and the fully matte effect can achieve a completely matte finish.

[0032] Step S2: A vortex disruptor 7 with multiple semi-circular slots is fixed at the air vent 8 of the high-speed side-blowing airflow. The bottom of the vortex disruptor 7 has six nitrogen inlets 5. After the melt is cooled by the high-speed vortex airflow formed by the mixture of nitrogen and the high-speed side-blowing airflow, it is bundled and oiled. The serrated melt is wider, thicker, and irregularly shaped than that produced by conventional spray plates. During the cooling process, because of the high speed of the high-speed vortex airflow, the side closer to the side-blowing airflow cools more thoroughly, while the opposite side cools more slowly, thus forming an asymmetrical cooling method. Simultaneously, the guide plate can change the direction of the side-blowing airflow. The direction of the side-blowing airflow is as follows... Figure 1 and Figure 2 As shown. Because the vortex disruptor 7 is installed below the spinneret and is combined with a high-speed side-blowing airflow, after installation, the mixed high-speed vortex airflow can cause vibration at the melt root of the spinneret, which helps the yarn form a spiral structure. The more vibrating, the better the spiral effect and the better the product's bulkiness, but the spinning conditions will deteriorate. To ensure stable spinning conditions, a spinning speed of 3200-3800 m / min is recommended.

[0033] Step S3: After oiling, the filament bundle passes through the spinning tunnel, is stretched and shaped by cold and hot rollers, and after the internal stress is relaxed by the guide disc, it reaches the winding machine to obtain a spiral-shaped wool-like polyamide fiber FDY. For example... Figure 4 As shown, the spiral shape is three-dimensional, achieving both process convenience and cost savings.

[0034] Please continue reading. Figures 1 to 2 As shown, in one embodiment of the present invention, the diameter of the spinneret in step S1 is 80-95mm, the number of spinneret holes on the spinneret is 5-12, and the cross-section of the spinneret holes is a horizontal comb shape.

[0035] Please continue reading. Figures 1 to 2 As shown, in one embodiment of the present invention, the nozzles in step S1 are evenly distributed in a circular pattern on the spray plate. The height of the nozzles is 0.6-0.7 mm, preferably 0.65 mm, the length of the nozzles is 1.4-1.9 mm, preferably 1.6 mm, the narrowest part of the nozzle width is 0.1-0.2 mm, preferably 0.15 mm, the widest part of the nozzle width is 0.3-0.6 mm, preferably 0.4 mm, and the angle between the direction of the spinneret and the side blowing air is 0-11°.

[0036] Please continue reading. Figure 3 As shown, in one embodiment of the present invention, the frame width of the eddy current jammer 7 in step S2 is 400-410mm, preferably 405mm, the frame thickness of the eddy current jammer 7 is 85-95mm, preferably 90mm, and the diameter of the semi-circular structure is 105-115mm, preferably 110mm.

[0037] Please continue reading. Figure 3 , Figure 7 As shown, in one embodiment of the present invention, the eddy current disruptor 7 frame in step 2 includes a base plate, side plates 3, a top plate 1, guide plates 4, and stainless steel tubes. Multiple guide plates 4 are fixed on the side plates 3. The top plate 1 is fixed above the guide plates 4, and the base plate is fixed below the guide plates 4. The nitrogen inlet 5 is disposed on the base plate. Multiple semi-circular openings are formed in a straight line on the base plate, top plate 1, and guide plates 4. The nitrogen inlet 5 is connected to multiple stainless steel tubes, which penetrate the guide plates 4. Circular nozzles are formed in the gaps between the guide plates 4 and the guide plates 4. The number of guide plates 4 is 40, and the number of stainless steel tubes is 6, the same as the number of nitrogen inlets 5. The diameter φ of the stainless steel tubes is 15mm, and the diameter φ of the circular nozzles is 5mm.

[0038] Please continue reading. Figure 3 , Figure 7As shown, in one embodiment of the present invention, the eddy current jammer 7 in step S2 has rectangular fixing plates 2 fixed at its four corners. The eddy current jammer 7 is fixed to the side-blowing window 8 by the rectangular fixing plates 2 and is completely perpendicular to the side-blowing net 6. The eddy current jammer 7 is installed flush with the top of the side-blowing net 6.

[0039] Please continue reading. Figures 1 to 6 As shown, in one embodiment of the present invention, the wind speed range of the high-speed vortex airflow in step S2 is 0.70-0.90 m / s, preferably 0.8 m / s; the wind temperature of the high-speed vortex airflow is 14-18℃, preferably 16℃; the humidity of the high-speed vortex airflow is 88%-99%, preferably 96%; the cooling distance of the high-speed vortex airflow is 1000mm-1800mm, preferably 1400mm; and the nitrogen pressure is 0.02 MPa. Because the overall wind speed effect needs to ensure rapid cooling, the nitrogen pressure is 0.02 MPa. Since the nitrogen direction is 90° to the side-blowing air, it will form a vortex with changing wind direction, causing the melt to vibrate irregularly after being ejected from the nozzle, resulting in uneven internal and external cooling, thus causing the product to exhibit a spiral curling shape, such as... Figure 4 , Figure 5 , Figure 6 As shown.

[0040] Please continue reading. Figures 1 to 4 As shown, in one embodiment of the present invention, the winding speed of the winding machine in step S3 is 3250-3800 m / min, the cold roller speed is 1800-2500 m / min, preferably 3150 m / min, the hot roller speed is 3300-3900 m / min, preferably 3600 m / min, the setting temperature of the hot roller is 130-155℃, preferably 142℃, the stretching ratio of the cold roller and the hot roller is between 1.32 and 2.16, preferably 1.7, and the speed of the guide disc is 3200-3950 m / min, preferably 3600 m / min. The spinning speed setting range matches the yarn output speed, improving the stability of the spinning process.

[0041] Please continue reading. Figure 4 As shown, in one embodiment of the present invention, the spiral-shaped wool-like polyamide fiber FDY obtained in step S3 has a fineness of 40-70D, a pore number of 5-12F, a breaking strength of 2.8-3.8CN / dtex, a breaking elongation of 28%-35%, a boiling water shrinkage rate of 8%-11%, an oil content of 0.7%-1.0%, and a needle-punched network number of 0-2.

[0042] Example 1:

[0043] A method for preparing helical wool-like polyamide fibers includes the following steps:

[0044] Fully matte PA6 chips are fed into a feeding tank, pass through a pipeline, and enter a screw extruder. The screw extruder pressure is set to 12 MPa, and the temperatures for zones 1-6 are set to 250, 254, 256, 257, 258, and 259°C, respectively. After melt extrusion, the fully matte PA6 chips are transported through a melt pipeline, accurately metered by a metering pump, and then enter the spinneret assembly to obtain a serrated melt. The initial pressure of the assembly is 14.5 MPa, and the spinneret has 5 orifices. The melt is then processed by an eddy current disruptor 7. After the vortex airflow, the filament bundle starts from the spinneret and generates incomplete and irregular shaking, resulting in an incompletely cooled and deformed filament bundle. The shaking frequency is 20-40 times / min, and the shaking amplitude is about 0.2-0.7mm. The vortex airflow consists of mutually perpendicular side blowing air at 0.75m / s and nitrogen airflow at 0.02Mpa. The incompletely cooled and deformed filament bundle is bundled and oiled, stretched by hot and cold rollers, relaxed by guide plate, and wound into shape to obtain the spiral wool-like polyamide fiber.

[0045] The following are the results of physical property testing and appearance observation of the spiral-shaped wool-like polyamide fiber (50D / 5F) obtained through the above process steps:

[0046] Physical property testing showed a fineness of 55.2 dtex, a breaking strength of 2.98 CN / dtex, a breaking strength coefficient of variation (CV) of 4.64%, a breaking elongation of 30.25%, a breaking elongation coefficient of variation of 5.20%, and a dyeing uniformity grade ≥4.0.

[0047] Upon visual inspection, the cross-section of the yarn cake exhibits a slightly fuzzy feel, and the overall yarn cake feels slightly soft to the touch. When the yarn is pulled out and laid flat, the yarn bundle is loose and presents a distinct spiral shape. When the yarn is cut into short fibers of about 0.5-2cm, the shape is curly and similar to animal hair. This method yields spiral-shaped wool-like polyamide fibers.

[0048] Example 2:

[0049] A method for preparing helical wool-like polyamide fibers includes the following steps:

[0050] Fully matte PA6 chips are fed into a feeding tank, pass through a pipeline, and enter a screw extruder. The screw extruder pressure is set to 14 MPa, and the temperatures for zones 1-6 are set to 252, 254, 256, 257, 258, and 260 °C, respectively. After melt extrusion, the fully matte PA6 chips are transported through a melt pipeline, accurately metered by a metering pump, and then enter the spinneret assembly to obtain a serrated melt. The initial pressure of the assembly is 15.0 MPa, and the spinneret has 7 orifices. The melt is then processed by an eddy current disruptor 7. After the vortex airflow, the filament bundle starts from the spinneret and generates incomplete and irregular shaking, resulting in an incompletely cooled and deformed filament bundle. The shaking frequency is 20-30 times / min, and the shaking amplitude is about 0.2-0.5mm. The vortex airflow consists of mutually perpendicular side blowing air at 0.85m / s and nitrogen airflow at 0.02Mpa. The incompletely cooled and deformed filament bundle is bundled and oiled, stretched by hot and cold rollers, relaxed by guide plate, and wound into shape to obtain the spiral wool-like polyamide fiber.

[0051] The following are the results of physical property testing and appearance observation of the spiral-shaped wool-like polyamide fiber (70D / 7F) obtained through the above process steps:

[0052] Physical property testing showed a fineness of 78.5 dtex, a breaking strength of 3.12 CN / dtex, a breaking strength coefficient of variation (CV) of 3.25%, a breaking elongation of 33.55%, a breaking elongation coefficient of variation (CV) of 4.12%, and a dyeing uniformity grade ≥ 4.0.

[0053] Upon visual inspection, the cross-section of the yarn cake exhibits a slightly fuzzy feel, and the overall yarn cake feels slightly soft to the touch. When the yarn is pulled out and laid flat, the yarn bundle is loose and presents a distinct spiral shape. When the yarn is cut into short fibers of about 0.5-2cm, the shape is curly and similar to animal hair. This method yields spiral-shaped wool-like polyamide fibers.

[0054] Example 3:

[0055] A method for preparing helical wool-like polyamide fibers includes the following steps:

[0056] Fully matte PA6 chips are fed into a feeding tank, pass through a pipeline, and enter a screw extruder. The screw extruder pressure is set to 11 MPa, and the temperatures for zones 1-6 are set to 252, 254, 256, 257, 258, and 259°C, respectively. After melt extrusion, the fully matte PA6 chips are transported through a melt pipeline, accurately metered by a metering pump, and then enter the spinneret assembly to obtain a serrated melt. The initial pressure of the assembly is 16.2 MPa, and the spinneret has 10 orifices. The melt is then processed by an eddy current disruptor 7. After the vortex airflow, the filament bundle starts from the spinneret and generates incomplete and irregular vibrations, resulting in an incompletely cooled and deformed filament bundle. The vibration frequency is 30-45 times / min, and the vibration amplitude is about 0.2-0.7mm. The vortex airflow consists of mutually perpendicular side airflows at 0.70m / s and nitrogen airflow at 0.02Mpa. The incompletely cooled and deformed filament bundle is bundled and oiled, stretched by hot and cold rollers, relaxed by guide plate, and wound to obtain the spiral wool-like polyamide fiber.

[0057] The following are the results of physical property testing and appearance observation of the spiral-shaped wool-like polyamide fiber (70D / 10F) obtained through the above process steps:

[0058] Physical property testing showed a fineness of 78.9 dtex, a breaking strength of 2.85 CN / dtex, a breaking strength coefficient of variation (CV) of 3.64%, a breaking elongation of 29.65%, a breaking elongation coefficient of variation of 5.80%, and a dyeing uniformity grade ≥4.0.

[0059] Upon visual inspection, the cross-section of the yarn cake exhibits a slightly fuzzy feel, and the overall yarn cake feels slightly soft to the touch. When the yarn is pulled out and laid flat, the yarn bundle is loose and presents a distinct spiral shape. When the yarn is cut into short fibers of about 0.5-2cm, the shape is curly and similar to animal hair. This method yields spiral-shaped wool-like polyamide fibers.

[0060] In summary, this invention, after obtaining a planar sawtooth melt using a spinneret of a specific shape, employs a vortex disruptor to create vortex air currents perpendicular to each other, causing the fiber bundle to vibrate irregularly and achieve incomplete cooling. This results in spiral-shaped wool-like polyamide fibers, which can be produced on a single-screw extruder, reducing the dependence of wool-like fiber production on equipment.

[0061] The above description is only a preferred embodiment of the present invention and should not be construed as a limitation of this application. All equivalent changes and modifications made in accordance with the scope of the patent application of the present invention should be covered by the present invention.

Claims

1. A process for the production of a spiral-like wool-like polyamide fiber, characterized by, Comprise the following steps: Step S1: After the full extinction PA6 chip is melted and extruded by the screw extruder, it is sent into the spinneret assembly through the melt pipeline and the metering pump to obtain the melt with the plane sawtooth cross section; Step S2: A vortex disrupter with multiple semicircular structure slotting is fixed at the air window of the high wind speed side blowing, and the bottom of the vortex disrupter has six nitrogen gas interfaces; after the melt is cooled by the high wind speed vortex air mass formed by the mixed nitrogen gas and high wind speed side blowing, the melt is oil collected; Step S3: After the oil collected yarn passes through the spinning duct, it is stretched and shaped by the cold roller and the hot roller, and then the internal stress is relaxed by the godet, and finally reaches the winding machine to obtain the spiral-shaped wool-like polyamide fiber FDY; The frame of the vortex disrupter in the step S2 comprises a bottom plate, a side plate, a top plate, a guide plate and a stainless steel pipe; a plurality of guide plates are fixed on the side plate, a top plate is fixed above the guide plate, a bottom plate is fixed below the guide plate, the nitrogen gas interface is arranged on the bottom plate, the bottom plate, the top plate and the guide plate are all provided with multiple semicircular opening slots arranged in a straight line, the nitrogen gas interface is connected with multiple stainless steel pipes, the stainless steel pipes penetrate through the guide plate, and the stainless steel pipes are provided with circular nozzles in the gap between the guide plate and the guide plate; The vortex disrupter in the step S2 is fixed at the air window of the high wind speed side blowing through the rectangular fixed plate, and is completely vertically attached to the side blowing net, and the vortex disrupter is installed flush with the top of the side blowing net.

2. The process for preparing a spiral-like wool-like polyamide fiber according to claim 1, characterized by: The diameter of the spinneret in the step S1 is 80-95mm, the number of the spinneret holes on the spinneret is 5-12, and the cross section of the spinneret hole is a lying comb shape.

3. The process for the production of a spiral-like wool-like polyamide fibre according to claim 2, characterized in that: The spinneret holes in the step S1 are uniformly distributed in a circular shape on the spinneret, the height of the spinneret hole is 0.6-0.7mm, the length of the spinneret hole is 1.4-1.9mm, the width of the spinneret hole is 0.1-0.2mm at the narrow part, the width of the spinneret hole is 0.3-0.6mm at the wide part, and the angle between the direction of the spinneret hole and the side blowing is 0-11°.

4. The process for preparing a spiral-like wool-like polyamide fiber according to claim 1, characterized by: The frame width of the vortex disrupter in the step S2 is 400-410mm, the frame thickness of the vortex disrupter is 85-95mm, and the diameter of the semicircular structure is 105-115mm.

5. The process for preparing a spiral-like wool-like polyamide fiber according to claim 1, characterized by: The wind speed of the high wind speed vortex air mass in the step S2 is 0.70-0.90m / s, the wind temperature of the high wind speed vortex air mass is 14-18℃, the humidity of the high wind speed vortex air mass is 88%-99%, the cooling distance of the high wind speed vortex air mass is 1000mm-1800mm, and the pressure of the nitrogen gas is 0.02Mpa.

6. The process for preparing a spiral-like wool-like polyamide fiber according to claim 1, characterized by: The winding speed of the winding machine in the step S3 is 3250-3800m / min, the speed of the cold roller is 1800-2500m / min, the speed of the hot roller is 3300-3900m / min, the setting temperature of the hot roller is 130-155℃, the stretching multiple of the cold roller and the hot roller is between 1.32 and 2.16, and the speed of the godet is 3200-3950m / min.

7. The process for preparing a spiral-like wool-like polyamide fiber according to claim 1, characterized by: The spiral-like wool-like polyamide fiber FDY obtained in the step S3 has a fineness of 40-70D, a number of pores of 5-12F, a breaking strength of 2.8-3.8CN / dtex, an elongation at break of 28%-35%, a boiling water shrinkage of 8%-11%, and an oil content of 0.7%-1.0%.

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