A regenerated polyester-polyamide composite ultrafine fiber and a method for manufacturing the same

Abstract

The present application relates to the technical field of superfine fiber production, and particularly relates to a manufacturing method of regenerated polyester and nylon composite superfine fiber. The manufacturing method of the regenerated polyester and nylon composite superfine fiber adopts a two-step method to spin the regenerated polyester and nylon composite superfine fiber, the first step adopts the edge polyester and nylon waste silk generated in the fiber production or use process, and the regenerated polyester and nylon chips are obtained after the edge polyester and nylon waste silk is washed, dried and melt chain extended, the second step adopts a composite spinning method to obtain the composite superfine fiber, the feasibility and the adaptability of the regenerated polyester and nylon waste silk after melt chain extension for the composite are improved, and the prepared regenerated polyester fiber has excellent mechanical properties. The single fiber linear density of the regenerated polyester and nylon fiber is less than 0.3 dtex, and the fiber product belongs to the superfine fiber, after the fiber product is subjected to the pulling wool or the sanding wool treatment, the formed velvet fabric has delicate and full wool feeling, and can be used for manufacturing the cleaning products such as the towel and the wiping cloth.

Description

Technical Field

[0001] This invention relates to the field of microfiber production technology, and in particular to a recycled polyester-nylon microfiber and its manufacturing method. Background Technology

[0002] Polyester-nylon composite fiber is a bicomponent composite fiber material containing both polyester and polyamide within the same cross-section. The fiber possesses the high strength and modulus of polyester and the abrasion resistance and high elasticity of nylon. Simultaneously, nylon's excellent moisture absorption compensates for polyester's poor moisture absorption. In the production of polyester-nylon composite fibers, through special spinning processes and the combination of spinning components, the two components are distributed in a specific arrangement on the same cross-section of the fiber. After fibrillation treatment, the original single fiber splits into 9 or 16 individual fibers, and the linear density of the individual fibers decreases accordingly, thus obtaining polyester-nylon microfiber with superior performance and a wider range of applications.

[0003] Since most synthetic fibers cannot be biodegradable, the disposal of polyester / nylon fibers after their lifespan is quite difficult. Currently, the main disposal methods include incineration and landfill, which undoubtedly damage the natural environment. Therefore, recycling is receiving increasing attention within the industry. For example, some individuals collect waste polyester / nylon fibers from textile mills and sell them to bedding factories for reuse. However, this product has low added value and limited market application. Regenerated polyester / nylon fibers are produced by secondary melt spinning of waste polyester / nylon textiles. However, the fibers produced by this method have significantly lower strength, elasticity, and open fiber rate compared to virgin polyester / nylon fibers. This is because during the initial melt spinning, the polymer, after being melted at high temperatures, undergoes changes in its crystal structure, and the precipitation of oligomers and monomers reduces the melt viscosity. During the second spinning, the spinnability and intrinsic viscosity of the recycled chips are reduced to varying degrees due to the influence of the initial spinning.

[0004] Chinese patent application CN201911122101.5 discloses a method for separating polyester and nylon depolymers from waste polyester materials containing nylon. The method includes the following steps: 1) Pre-treating recycled polyester-nylon fabric and / or polyester-nylon composite yarns, then forming them into foam using a friction molding process; 2) Adding waste polyester and ethylene glycol together in a reaction vessel in a specific ratio and depolymerizing for 1-3 hours under the action of a catalyst. After depolymerization, the depolymerization liquid is filtered, and the filtrate contains BHET and oligomers; 3) Adding the filtered nylon to the depolymerization vessel, adding a certain amount of ethylene glycol to continue depolymerizing the nylon, thereby obtaining a depolymerization product containing low molecular weight polyamide. This two-stage depolymerization method effectively depolymerizes and separates waste polyester containing nylon. Although it achieves effective separation of nylon and polyester, the simultaneous depolymerization of nylon and polyester leads to difficulties in subsequent recycling stages, increasing recycling costs. Summary of the Invention

[0005] In view of this, the purpose of this invention is to propose a recycled polyester-nylon microfiber and its manufacturing method to solve the problem of effective recycling of waste polyester-nylon fibers.

[0006] To achieve the above objectives, the present invention provides a method for manufacturing recycled polyester-nylon composite microfiber, comprising the following preparation steps: S1: Using waste polyester filaments or waste polyester fabrics as raw materials, the materials are first sorted and washed to remove impurities, then dehydrated and dried before being crushed in a fiber shredder to obtain a mixture of waste polyester filaments. S2: Polyester waste filament mixture and bisoxazoline chain extender A are fed into a single screw extruder for melting. The resulting melt exits the screw extruder and enters a vertical melt double-stage pre-filter for two-stage filtration. The resulting recycled polyester melt is extruded, cooled in a water bath, solidified, and pelletized to obtain recycled polyester chips. S3: Using waste nylon yarn or waste nylon fabric as raw material, it is first sorted and washed to remove impurities, and then crushed in a fiber shredder after dehydration and drying to obtain a mixture of waste nylon yarn. S4: The nylon waste filament mixture and bisoxazoline chain extender B are fed into a single screw extruder for melting. The resulting melt exits the screw extruder and enters a vertical melt double-stage pre-filter for two-stage filtration. The resulting recycled nylon melt is extruded, cooled in a water bath, solidified, and pelletized to obtain recycled nylon chips. S5: Recycled polyester chips and recycled nylon chips are melted and fed into a spinning box for compound extrusion to obtain nascent yarn; S6: The nascent filaments are cooled by side blowing, bundled and oiled, drawn and wound to form pre-oriented filaments; S7: The pre-oriented yarn is sequentially washed with water, opened, washed with cold water, acid washed, washed with cold water, and dried to form recycled polyester-nylon microfiber; Preferably, in step S2, the bisoxazoline chain extender A is prepared by a click reaction of 2-isopropenyl-2-oxazoline and mercapto-polyethylene glycol-mercapto with a molecular weight of 200 in a molar ratio of 2.1:1.

[0007] Preferably, in step S4, the bisoxazoline chain extender B is prepared by a click reaction of 2-isopropenyl-2-oxazoline and mercapto-polyethylene glycol-mercapto with a molecular weight of 400 in a molar ratio of 2.1:1.

[0008] Preferably, in step S2, the temperature control of the screw extruder is 260-265℃ in the feeding section, 270-280℃ in the compression section, and 281-283℃ in the metering section.

[0009] Preferably, in step S4, the temperature control of the screw extruder is 255-260℃ in the feeding section, 262-267℃ in the compression section, and 270-273℃ in the metering section.

[0010] Preferably, the filter element of the vertical dual-stage melt filter in steps S2 and S4 is a pleated multi-layer metal mesh.

[0011] Preferably, the intrinsic viscosity of the recycled polyester chips in step S2 is 0.73-0.76 dL / g.

[0012] Preferably, the intrinsic viscosity of the recycled nylon chips in step S4 is 0.83-0.86 dL / g.

[0013] Preferably, the amount of bioxazoline chain extender A added in step S2 is 0.4wt%-0.6wt%; Preferably, the amount of bioxazoline chain extender B added in step S4 is 0.4wt%-0.6wt%.

[0014] Preferably, the specific preparation method of the bisoxazoline chain extender A in step S2 is as follows: under a nitrogen atmosphere, 2-isopropenyl-2-oxazoline, mercapto-polyethylene glycol-mercapto with a molecular weight of 200 and photoinitiator 500 are added to DMF solvent, reacted under ultraviolet light for 12 hours, purified, and vacuum dried to obtain bisoxazoline chain extender A.

[0015] Preferably, the specific preparation method of the bisoxazoline chain extender B in step S4 is as follows: Under a nitrogen atmosphere, 2-isopropenyl-2-oxazoline, mercapto-polyethylene glycol-mercapto with a molecular weight of 400 and photoinitiator 500 are added to DMF solvent, reacted under ultraviolet light for 12 hours, purified, and vacuum dried to obtain bisoxazoline chain extender B.

[0016] Preferably, in step S5, the spinning speed is 2900-3100 m / min, and the mass ratio of recycled polyester chips to recycled nylon chips is 70-88:30-12.

[0017] Preferably, in step S6, the side-blowing wind speed is 0.4-0.6 m / s, the wind temperature is 22±2℃, and the humidity is 85%±3%.

[0018] Preferably, in step S6, the linear speed of GR1 during stretching and winding is 3100 m / min, and the linear speed of GR2 is 3118 m / min.

[0019] The beneficial effects of this invention are: This invention employs a two-step method to spin recycled polyester-nylon composite microfiber. The first step utilizes waste polyester and nylon fibers generated during fiber production or usage processes. After washing and drying, these fibers are melt-extended to obtain recycled polyester and recycled nylon chips. The second step uses a composite spinning method, where the two types of recycled chips are melt-extruded by two independent screws. Considering the viscosity differences in the recycled chips, the spinning process has been optimized. The resulting recycled polyester-nylon composite fiber can be used in the manufacture of products such as towels, cleaning cloths, and carpets.

[0020] In the first step, this invention recycles waste polyester and nylon fibers from the textile process. After washing and impurity removal, and melt chain extension, recycled polyester chips and recycled nylon chips are obtained. A novel bisoxazoline chain extender is used, which can effectively adjust the viscosity of the recycled polyester and nylon chips, improving the feasibility and compatibility of compounding. The compound spinning of the two improves the mechanical properties of textile waste fiber products and effectively utilizes resources.

[0021] In the second step, this invention performs fibrillation treatment on the recycled polyester-nylon composite fibers. After washing, fiber opening, cold washing, acid washing, cold washing, and drying, the resulting recycled polyester-nylon fibers have a dpf of less than 0.3 dtex, classifying them as ultrafine fibers. After napping or brushing, the resulting fabrics have a delicate and full texture, suitable for making cleaning products such as towels and wiping cloths. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0023] Preparation Example A method for manufacturing a bisoxazoline chain extender A includes the following steps: under a nitrogen atmosphere, 2.3 kg of 2-isopropenyl-2-oxazoline, 2 kg of mercapto-polyethylene glycol-mercapto with a molecular weight of 200 and 0.13 kg of photoinitiator 500 are added to 10 kg of DMF solvent, and then reacted under ultraviolet light for 12 h. After purification and vacuum drying, bisoxazoline chain extender A is obtained. A method for manufacturing a bisoxazoline chain extender B includes the following steps: under a nitrogen atmosphere, 2.3 kg of 2-isopropenyl-2-oxazoline, 4 kg of mercapto-polyethylene glycol-mercapto with a molecular weight of 400 and 0.19 kg of photoinitiator 500 are added to 15 kg of DMF solvent, and then reacted under ultraviolet light for 12 h. After purification and vacuum drying, bisoxazoline chain extender B is obtained. Example

[0024] A method for manufacturing recycled polyester-nylon composite microfiber includes the following steps: S1: Using 222dtex / 96f polyester waste yarn as raw material, after sorting, it is washed with 50℃ warm water for 60 minutes, the dewatering machine speed is 750 rpm, the oven temperature is 105℃, the wind speed is 1.8m / s, and after being crushed by a shredder, a clean polyester waste yarn mixture is obtained. S2: The polyester waste filament mixture and bisoxazoline chain extender A are fed into the screw extruder. The amount of bisoxazoline chain extender added is 0.42% of the polyester waste filament mixture. The temperature control of each section is 267℃ in the feeding section, 278℃ in the compression section, and 290℃ in the metering section. After the melt exits the screw extruder, it enters the vertical melt double-stage pre-filter for two-stage filtration. After the melt is extruded through the casting head, it is solidified and pelletized to obtain recycled polyester chips. S3: Using 78dtex / 24f nylon waste yarn as raw material, a clean nylon waste yarn mixture is prepared, the process is the same as S1; S4: The nylon waste filament mixture and bisoxazoline chain extender B are fed into the screw extruder for melting. The amount of bisoxazoline chain extender added is 0.41 wt% of the nylon waste filament mixture. The temperature control of each section is 258℃ in the feeding section, 265℃ in the compression section, and 270℃ in the metering section. After the melt exits the screw extruder, it is filtered in two stages by a vertical melt double-stage pre-filter, and then cooled and solidified in a water bath and granulated to obtain recycled nylon chips.

[0025] S5: Recycled polyester chips and recycled nylon chips are fed into the spinning box at a mass ratio of 80:20, and compound extrusion is performed. The temperature of the spinning box is controlled at 285℃, the spinning speed is 3000m / min, the cross section is "orange petal" shaped, the number of spinneret holes is 72, and the fineness is 170dtex to obtain nascent yarn. S6: The nascent filament is cooled by side blowing, bundled and oiled, and drawn and wound to form a pre-oriented filament. The side blowing cooling wind speed is 0.4 m / s, the wind temperature is 22℃, the humidity is 75%, the bundled oiling rate is 1.5%, and the linear speed of GR1 in the drawing and winding process is 3000 m / min and the linear speed of GR2 is 3018 m / min, thus obtaining the pre-oriented filament. S7: The pre-oriented yarn is sequentially washed with water, opened, cold washed with water, acid washed, cold washed with water, and dried to obtain a regenerated ultrafine polyester-nylon fiber with a single fiber linear density of 0.146 dtex. Example

[0026] A method for manufacturing recycled polyester-nylon composite microfiber includes the following steps: S1: Using 333dtex / 96f polyester waste yarn as raw material, after sorting, it is washed with water at 50℃ for 60 minutes, the dewatering machine speed is 700 rpm, the oven air temperature is 105℃, the air speed is 1.8m / s, and after being crushed by a shredder, a clean polyester waste yarn mixture is obtained. S2: The polyester waste filament mixture and bisoxazoline chain extender A are fed into the screw extruder. The amount of bisoxazoline chain extender added is 0.51 wt% of the polyester waste filament mixture. The temperature control of each section is 268℃ in the feeding section, 279℃ in the compression section, and 288℃ in the metering section. After the melt exits the screw extruder, it enters the vertical melt double-stage pre-filter for two-stage filtration. After the melt is extruded through the casting head, it is cooled and solidified in a water bath and granulated to obtain recycled polyester chips. S3: Using 50dtex / 48f nylon waste yarn as raw material, the washing and shredding process is the same as S1; S4: The nylon waste filament mixture and bisoxazoline chain extender B are fed into the screw extruder for melting. The amount of bisoxazoline chain extender added is 0.49 wt% of the nylon waste filament mixture. The temperature control of each section is 258℃ in the feeding section, 266℃ in the compression section, and 272℃ in the metering section. The melt filtration device is configured the same as the recycled polyester melt filtration device to obtain recycled nylon chips. S5: Recycled polyester chips and recycled nylon chips are fed into the spinning box at a mass ratio of 88:12, and compound extrusion is performed. The temperature of the spinning box is controlled at 290℃, the spinning speed is 3000m / min, the cross section is "orange petal" shaped, the number of spinneret holes is 72, and the fineness is 208dtex to obtain nascent yarn. S6: The nascent filament is cooled by side blowing, bundled and oiled, and drawn and wound to form a pre-oriented filament. The side blowing cooling wind speed is 0.4 m / s, the wind temperature is 22℃, the humidity is 80%, the bundled oiling rate is 1.5%, and the linear speed of GR1 in the drawing and winding process is 3000 m / min and the linear speed of GR2 is 3015 m / min, thus obtaining the pre-oriented filament. S7: The pre-oriented yarn is sequentially washed with water, opened, cold washed with water, acid washed, cold washed with water, and dried to obtain a regenerated ultrafine polyester-nylon fiber with a single fiber linear density of 0.158 dtex. Example

[0027] A method for manufacturing recycled polyester-nylon composite microfiber includes the following steps: S1: Using 111dtex / 96f polyester waste yarn as raw material, after sorting, it is washed with water at 50℃ for 60 minutes, the dewatering machine speed is 800 rpm, the oven air temperature is 110℃, the air speed is 1.5m / s, and after being crushed by a shredder, a clean polyester waste yarn mixture is obtained. S2: The polyester waste filament mixture and bisoxazoline chain extender A are fed into the screw extruder. The amount of bisoxazoline chain extender added is 0.59 wt% of the polyester waste filament mixture. The temperature control of each section is 269℃ for the feeding section, 281℃ for the compression section, and 288℃ for the metering section. After the melt exits the screw extruder, it enters the vertical melt double-stage pre-filter for two-stage filtration. After being extruded through the casting head, it is cooled and solidified in a water bath and granulated to obtain recycled polyester chips. S3: Using 78dtex / 24f nylon waste yarn as raw material, the washing and shredding process is the same as S1; S4: The nylon waste filament mixture and bisoxazoline chain extender B are fed into the screw extruder for melting. The amount of bisoxazoline chain extender added is 0.58 wt% of the nylon waste filament mixture. The temperature control of each section is 258℃ in the feeding section, 266℃ in the compression section, and 273℃ in the metering section. The melt filtration is configured the same as the recycled polyester melt filtration device to obtain recycled nylon chips. S5: Recycled polyester chips and recycled nylon chips are fed into the spinning box at a mass ratio of 70:30 for compound extrusion. The temperature of the spinning box is controlled at 292℃, and the spinning speed is 3100m / min. The cross-section is "X" shaped, the number of spinneret holes is 72, and the fineness is 111dtex, resulting in nascent yarn. S6: The nascent filament is cooled by side blowing, bundled and oiled, and drawn and wound to form a pre-oriented filament. The side blowing cooling wind speed is 0.4 m / s, the wind temperature is 22℃, the humidity is 75%, the bundled oiling rate is 1.2%, and the linear speed of GR1 in the drawing and winding process is 3100 m / min and the linear speed of GR2 is 3000 m / min, thus obtaining the pre-oriented filament. S7: The pre-oriented yarn is sequentially washed with water, opened, cold washed with water, acid washed, cold washed with water, and dried to obtain recycled ultrafine polyester-nylon fiber with a single fiber linear density of 0.154 dtex.

[0028] Comparative Example 1 A method for manufacturing a fiber differs from Example 2 in that: in step S2, polyester waste yarn is directly fed into a screw extruder without the addition of bisoxazoline chain extender A.

[0029] Comparative Example 2 A method for manufacturing a fiber differs from Example 2 in that: in step S4, nylon waste yarn is directly fed into a screw extruder without the addition of bisoxazoline chain extender B.

[0030] Comparative Example 3 A method for manufacturing a fiber differs from Example 2 in that: in step S2, polyester waste yarn is directly fed into the screw extruder without adding bisoxazoline chain extender A; and in step S4, nylon waste yarn is directly fed into the screw extruder without adding bisoxazoline chain extender B.

[0031] Comparative Example 4 A method for manufacturing a fiber differs from Example 2 in that: in step S2, bisoxazoline chain extender A is replaced with 2,2'-bis(2-oxazoline), and the amount added is 0.23 wt% of the polyester waste yarn mixture; in step S4, bisoxazoline chain extender B is replaced with 2,2'-bis(2-oxazoline), and the amount added is 0.14 wt% of the nylon waste yarn mixture.

[0032] Performance testing Fiber mechanical properties: The prepared fibers were tested on a universal testing machine to determine their breaking strength and elongation at break. The test results are shown in Table 1. Table 1 Performance test results of fibers prepared in the examples and comparative examples

[0033] Data Analysis: As can be seen from Examples 1-3, the linear density of the single fiber of the recycled polyester-nylon composite fiber manufactured by the method of the present invention is less than 0.3 dtex after opening, which belongs to ultrafine fiber. Its breaking strength and breaking elongation are comparable to those of polyester-nylon composite fibers prepared directly using raw materials. Furthermore, by adjusting the molecular weight of the ether chain in the bisoxazoline chain extender prepared by the present invention, the intrinsic viscosity of recycled polyester-nylon chips can be effectively recycled, making the intrinsic viscosity of recycled polyester chips and recycled nylon chips suitable for existing processes and equipment without the need to rematch new processes and equipment. It has excellent composite feasibility and compatibility. As can be seen from Examples 2 and Comparative Examples 1-3, when the designed fineness and composite ratio are the same, the simultaneous use of bisoxazoline chain extender A and bisoxazoline chain extender B in the examples causes a chain extension reaction during the melting of the recycled chips. This increases the relative molecular weight of the polymer and significantly increases the viscosity compared to ordinary recycled chips without added chain extenders. The resulting microfibers exhibit higher breaking strength and elongation at break. Examples 2 and Comparative Example 4 show that, compared to existing bisoxazoline chain extenders, the bisoxazoline chain extender A and bisoxazoline chain extender B prepared in this invention can more effectively improve the intrinsic viscosity of the recycled chips, resulting in higher breaking strength and elongation at break in the final microfibers. This may be due to the introduction of ether chains, which improves the entanglement of polyester and nylon molecular chains, ultimately leading to increased breaking strength and elongation at break in the microfibers.

[0034] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0035] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for manufacturing recycled polyester-nylon composite microfiber, characterized in that, The preparation steps include the following: S1: Using waste polyester filaments or waste polyester fabrics as raw materials, the materials are first sorted and washed to remove impurities, then dehydrated and dried before being crushed in a fiber shredder to obtain a mixture of waste polyester filaments. S2: Polyester waste filament mixture and bisoxazoline chain extender A are fed into a single-screw extruder for melting. The resulting melt exits the screw extruder and enters a vertical melt dual-stage pre-filter for two-stage filtration. The resulting recycled polyester melt is extruded, cooled in a water bath, solidified, and pelletized to obtain recycled polyester chips. The amount of bisoxazoline chain extender A added is 0.4wt%-0.6wt%, and the intrinsic viscosity of the recycled polyester chips is 0.73-0.76dL / g. S3: Using waste nylon yarn or waste nylon fabric as raw material, it is first sorted and washed to remove impurities, and then crushed in a fiber shredder after dehydration and drying to obtain a mixture of waste nylon yarn. S4: The nylon waste filament mixture and bisoxazoline chain extender B are fed into a single-screw extruder for melting. The resulting melt exits the screw extruder and enters a vertical melt double-stage pre-filter for two-stage filtration. The resulting recycled nylon melt is extruded, cooled in a water bath, solidified, and pelletized to obtain recycled nylon chips. The amount of bisoxazoline chain extender B added is 0.4wt%-0.6wt%, and the intrinsic viscosity of the recycled nylon chips is 0.83-0.86dL / g. S5: Recycled polyester chips and recycled nylon chips are melted at a mass ratio of 70-88:30-12 and then fed into a spinning box. They are then extruded together at a spinning speed of 2900-3100 m / min to obtain nascent yarn. S6: The nascent filaments are cooled by side blowing, bundled and oiled, drawn and wound to form pre-oriented filaments; S7: The pre-oriented yarn is sequentially washed with water, opened, washed with cold water, acid washed, washed with cold water, and dried to form recycled polyester-nylon microfiber with a single fiber linear density of 0.146-0.158 dtex; The specific preparation method of bisoxazoline chain extender A in step S2 is as follows: Under a nitrogen atmosphere, 2-isopropenyl-2-oxazoline, mercapto-polyethylene glycol-mercapto with a molecular weight of 200 and photoinitiator 500 are added to DMF solvent, reacted under ultraviolet light for 12 hours, purified, and vacuum dried to obtain bisoxazoline chain extender A. The specific preparation method of the bisoxazoline chain extender B in step S4 is as follows: Under a nitrogen atmosphere, 2-isopropenyl-2-oxazoline, mercapto-polyethylene glycol-mercapto with a molecular weight of 400 and photoinitiator 500 are added to DMF solvent, reacted under ultraviolet light for 12 hours, purified, and vacuum dried to obtain bisoxazoline chain extender B.

2. The method for manufacturing recycled polyester-nylon composite microfiber according to claim 1, characterized in that, In step S2, the temperature control of the screw extruder is 267°C for the feeding section, 278°C for the compression section, and 290°C for the metering section; in step S4, the temperature control of the screw extruder is 258°C for the feeding section, 265°C for the compression section, and 270°C for the metering section.

3. The method for manufacturing recycled polyester-nylon composite microfiber according to claim 1, characterized in that, In steps S2 and S4, the filter element of the vertical melt dual-stage pre-filter is a pleated multi-layer metal mesh.

4. The method for manufacturing recycled polyester-nylon composite microfiber according to claim 1, characterized in that, In step S6, the side-blowing wind speed is 0.4-0.6 m / s, the wind temperature is 22±2℃, and the humidity is 85%±3%.

5. The method for manufacturing recycled polyester-nylon composite microfiber according to claim 1, characterized in that, In step S6, the linear speed of GR1 during drawing and winding is 3100 m / min, and the linear speed of GR2 is 3118 m / min.

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