Preparation method of elastic reinforced PBT polyester fiber based on POY chemical fiber process

Abstract

This invention discloses a method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber technology, comprising the following steps: S1, preparing PBT melt: PTA and BDO are mixed uniformly in a certain proportion, and then subjected to esterification reaction, pre-condensation reaction, film stretching and final condensation reaction in sequence to obtain PBT melt; S2, preparing PBT-POY precursor yarn: The PBT melt obtained in step S1 is heat-insulated and spun, then air-cooled and shaped, bundled and oiled, and finally guided and wound to form PBT-POY precursor yarn. POY precursor yarn; S3, PBT-POY precursor yarn texturing: The PBT-POY precursor yarn obtained in step S2 is subjected to multiple heat setting processes, and then wound to obtain elastic reinforced PBT polyester fiber; The POY yarn produced by the PBT melt direct spinning process of this invention has uniform tension, good evenness, few fuzz, and large package size; and the PBT-POY precursor yarn is processed by texturing machine twisting, setting and other processes to form PBT polyester fiber with unique bulkiness, good dimensional stability and superior elasticity.

Description

Technical Field

[0001] This invention relates to the field of polyester fiber technology, specifically to a method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber technology. Background Technology

[0002] PBT production can be carried out in two ways: batch and continuous. Batch production allows for smaller-scale plants but yields smaller batches and greater flexibility. As market demand for PBT grows and production scales expand, the production method must evolve towards continuous production. On one hand, continuous production has lower reaction temperatures, faster reaction rates, shorter polymerization times, less polymer degradation, lower raw material molar ratios, less THF formation, and lower raw material consumption compared to batch production. It also makes it easier to obtain PBT resin with stable intrinsic viscosity, low end-carboxyl content, good thermal stability, and good color. On the other hand, although the application of computers and improved control systems can gradually bring batch production closer to the product quality of continuous production, it still falls short in terms of production management, production costs, and product stability and uniformity. Currently, most PBT production plants with capacities exceeding 10,000 tons utilize the continuous method.

[0003] Based on the comparison of the above process technologies, the direct esterification continuous polycondensation process of PTA is recommended. Currently, the most advanced technology in the world is the three-reactor process for direct esterification continuous polycondensation of PTA, whose product quality consistently ranks among the best internationally and has won recognition in both domestic and international markets.

[0004] Therefore, this project adopts a three-reactor process for direct esterification and continuous polycondensation of PTA to produce PBT polyester fibers. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing elastic-reinforced PBT polyester fibers based on POY chemical fiber processing.

[0006] The technical solution of this invention is: a method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber process, comprising the following steps:

[0007] S1. Preparation of PBT melt:

[0008] PTA and BDO are mixed uniformly at a mass ratio of 1:3 to 5 to obtain a mixture, and the mixture is subjected to esterification reaction, pre-condensation reaction, film stretching and final condensation reaction in sequence to obtain PBT melt;

[0009] S2. Preparation of PBT-POY precursor fibers:

[0010] The PBT melt obtained in step S1 is kept warm and spun, then air-cooled and shaped and bundled with oil, and finally guided and wound to form PBT-POY raw yarn.

[0011] S3, PBT-POY raw yarn with added texture:

[0012] The PBT-POY raw yarn obtained in step S2 is placed into the first roller of the spinning machine and subjected to tension heat setting in a deformation heat box at 240-260°C. After cooling to room temperature, PBT-POY filament is obtained. The PBT-POY filament is then placed into a false twisting machine with a twisting speed ratio of 1.65-1.75 for twisting and untwisting.

[0013] The PBT-POY filament is then placed into the second roller and subjected to additional heat setting in a setting box at 150–180°C, and then placed into a network nozzle with a pressure of 0.18–0.22 MPa.

[0014] Finally, the PBT-POY filaments are placed in the third roller and finalized in a setting box at 90-100℃. The resulting elastic-reinforced PBT polyester fibers are then obtained through winding.

[0015] The speed of the first roller is 190-200 m / min, the speed of the second roller is 250-260 m / min, and the speed of the third roller is 280-290 m / min.

[0016] Further, in step S1, the esterification reaction is as follows: a catalyst accounting for 25-45% of the mass of the mixture is added to the mixture at 35-40 kPa and 200-220 °C, wherein the catalyst is TBT, and the esterification reaction is carried out for 40-50 min.

[0017] Note: Too high a reaction temperature will cause product decomposition, while too low a reaction temperature will slow down the reaction rate; too short a reaction time will lead to incomplete reaction, while too long a reaction time will lead to a decrease in product quality; too much catalyst will lead to a decrease in product quality, while too little will lead to a slow reaction rate; TBT as a catalyst has the advantages of good catalytic activity, selectivity and mild reaction.

[0018] Further, in step S1, the pre-condensation reaction is carried out at 1.5-3.5 kPa and 255-275 °C for 25-30 min, with the stirring paddle speed adjusted to 75-80 r / min.

[0019] Note: Degradation reactions will increase when the temperature is too high, the pressure is too high, or the reaction time is too long; when the rotation speed is too high, the viscosity of the product is difficult to increase because the material surface is renewed too quickly.

[0020] Further, in step S1, the final polycondensation reaction is carried out at 140-160 Pa and 255-275 °C for 1.5-2.5 h, with the stirring paddle speed adjusted to 35-40 r / min.

[0021] Note: Excessive temperature will promote thermal degradation and the formation of cyclic polymers, exacerbating the decrease in degree of polymerization and viscosity; if the esterification rate is insufficient, the vacuum effect will remove unreacted BDO from the melt, easily resulting in low viscosity; when the rotation speed is too high, the product viscosity is difficult to increase due to the rapid turnover of the material surface.

[0022] Further, in step S1, the film stretching is performed by bidirectional stretching at 95-98°C, with longitudinal and transverse stretching occurring simultaneously, the longitudinal stretching ratio being 2-4 times and the transverse stretching ratio being 3-4 times.

[0023] Note: The thickness, pore size, and fiber fineness of the PBT melt can be controlled by setting the film stretching method and stretching ratio.

[0024] Furthermore, in step S2, the heat preservation temperature is 270–280°C, and the spinneret shear rate is 13000 s. -1 The pressure is 8-9 MPa.

[0025] Note: PBT has high melt elasticity. The spinnability of the fiber is related to the spinning temperature, spinning speed, melt viscosity and linear density. The spinnability is better when the above parameters are used.

[0026] Furthermore, in step S2, the speed of the guidewire is 3450-3480 m / min, and the temperature of the guidewire is 280-285℃.

[0027] Explanation: If the guide speed is too low, the extruded melt stream cools too quickly, making it easy for the filaments to break during stretching; if the guide speed is too high, the melt stream cannot be cooled in time, resulting in filament bundling and affecting the quality of the nonwoven fabric.

[0028] Furthermore, in steps S2 and S3, the winding tension of the winding forming is 0.06 to 0.07 CN / dtex, and the winding speed is 3150 to 3180 m / min.

[0029] Note: Excessive winding tension will cause the yarn cake to deform, affecting the unwinding rate during post-texturing; excessive winding tension will cause the paper tube to deform, and the yarn cake will not be able to be pushed out from the chuck shaft of the winding head; insufficient tension will cause the yarn to move around on the hot roller, which can easily lead to yarn breakage.

[0030] Further, in step S2, the air-cooling shaping and cluster oiling are performed as follows: first, strong cooling with an annular airflow for 45-50 seconds, with an annular air temperature of 25-30°C; after the strong cooling, a first cluster oiling is performed, with the cluster position at 900-950mm and the oil amount at 0.30-0.35%; then, weak cooling with a side airflow for 30-35 seconds, with a side air temperature of 40-45°C; after the weak cooling, a second cluster oiling is performed, with the cluster position at 800-850mm and the oil amount at 0.10-0.15%.

[0031] Explanation: By first subjecting the fiber bundle to strong annular cooling, it can be rapidly cooled and solidified, which is beneficial to improving fiber uniformity. After a certain solidification time, it is then introduced into the weak lateral cooling zone, which helps to further solidify the fiber morphology and increase fiber uniformity. Strong annular cooling can promote the rapid horizontal alignment of fibers, improve the bonding strength between fibers, and thus increase the tensile strength and abrasion resistance of the fibers. Weak lateral cooling can form a thinner outer layer on the surface of the fiber bundle, protecting the internal structure of the fibers and further improving the strength of the fibers.

[0032] Bundling at a higher position after strong cooling helps reduce spinning tension and eliminate internal stress caused by high-speed stretching of the fiber bundle; lowering the bundling position after weak cooling avoids PBT recrystallization, thereby comprehensively improving fiber shape stability and spinning speed.

[0033] The beneficial effects of this invention are:

[0034] (1) The preparation method of the present invention is to process PBT-POY raw yarn through texturing machine twisting, shaping and other processes to form elastic reinforced PBT polyester fiber with unique bulkiness, good dimensional stability and superior elasticity, which can be used for clothing.

[0035] (2) The preparation method of the present invention adopts PBT melt direct spinning process, which has the advantages of short process flow, low unit output infrastructure investment cost, low energy consumption and product cost; and the POY yarn produced by high-speed spinning and winding process has uniform tension, good evenness, less fuzz, and large package size, and the product can be stored and transported for a long time, with greater flexibility in post-processing. Detailed Implementation

[0036] The present invention will now be described in more detail with reference to specific embodiments, so as to better demonstrate the advantages of the present invention.

[0037] Example 1

[0038] The preparation method of elastic reinforced PBT polyester fiber based on POY chemical fiber process includes the following steps:

[0039] S1. Preparation of PBT melt:

[0040] PTA and BDO were mixed uniformly at a mass ratio of 1:4 to obtain a mixture, and the mixture was subjected to esterification, pre-condensation, film stretching and final condensation reactions in sequence to obtain PBT melt.

[0041] The esterification reaction is as follows: a catalyst accounting for 35% of the mass of the mixture is added to the mixture at 38 kPa and 210 °C. The catalyst is TBT, and the esterification reaction is carried out for 45 min.

[0042] The pre-condensation reaction is carried out at 2 kPa and 265°C for 28 min, with the stirring paddle speed adjusted to 78 r / min.

[0043] The membrane is stretched bidirectionally at 96°C, with longitudinal and transverse stretching occurring simultaneously. The longitudinal stretching ratio is 3 times, and the transverse stretching ratio is 3.5 times.

[0044] The final polycondensation reaction was carried out at 150 Pa and 265 °C for 2 hours, with the stirring paddle speed adjusted to 38 r / min.

[0045] S2. Preparation of PBT-POY precursor fibers:

[0046] The PBT melt obtained in step S1 is subjected to heat treatment and spinning at a temperature of 275°C and a spinneret shear rate of 13000 s⁻¹. -1 The pressure is 8.5 MPa;

[0047] Next, air cooling and shaping, and bundling and oiling are performed: first, strong air cooling is applied for 48 seconds at an air temperature of 28°C. After the strong cooling, bundling and oiling are performed once, with the bundling position at 925mm and the oil amount at 0.33%. Then, weak air cooling is applied for 33 seconds at an air temperature of 43°C. After the weak cooling, bundling and oiling are performed a second time, with the bundling position at 825mm and the oil amount at 0.13%. The oil is nylon POY oil.

[0048] Finally, the wire is guided and wound into shape at a speed of 3465 m / min and a temperature of 283℃ to obtain PBT-POY precursor fiber.

[0049] S3, PBT-POY raw yarn with added texture:

[0050] The PBT-POY raw yarn obtained in step S2 is placed into the first roller of the spinning machine and subjected to tension heat setting in a deformation heat box at 250°C. It is then cooled to room temperature to obtain PBT-POY filament. The PBT-POY filament is then placed into a false twisting machine with a twisting speed ratio of 1.70 for twisting and untwisting.

[0051] The PBT-POY filament is then placed into the second roller and subjected to additional heat setting in a 165°C setting oven, and then placed into a mesh nozzle with a pressure of 0.20 MPa.

[0052] Finally, the PBT-POY filaments are placed in the third roller and finalized in a 95°C setting oven, and then wound to obtain elastic reinforced PBT polyester fibers.

[0053] The speed of the first roller is 195 m / min, the speed of the second roller is 255 m / min, and the speed of the third roller is 285 m / min.

[0054] In steps S2 and S3, the winding tension of the winding forming is 0.065 CN / dtex, and the winding speed is 3165 m / min.

[0055] Example 2

[0056] The difference between this embodiment and Example 1 is that PTA and BDO are mixed evenly at a mass ratio of 1:3, and the catalyst accounts for 25% of the mass of the mixture.

[0057] Example 3

[0058] The difference between this embodiment and Example 1 is that PTA and BDO are mixed evenly at a mass ratio of 1:5, and the catalyst accounts for 45% of the mass of the mixture.

[0059] Example 4

[0060] The difference between this embodiment and Embodiment 1 is that in step S1, the esterification reaction is as follows: a catalyst accounting for 25% of the mass of the mixture is added to the mixture at 35 kPa and 200 °C, and the catalyst is TBT, and the esterification reaction is carried out for 40 min.

[0061] Example 5

[0062] The difference between this embodiment and Embodiment 1 is that in step S1, the esterification reaction is as follows: a catalyst accounting for 45% of the mass of the mixture is added to the mixture at 40 kPa and 220 °C, and the catalyst is TBT, and the esterification reaction is carried out for 50 min.

[0063] Example 6

[0064] The difference between this embodiment and Embodiment 1 is that, in step S1, the pre-condensation reaction is carried out at 1.5 kPa and 255°C for 25 min, with the stirring paddle speed adjusted to 75 r / min.

[0065] Example 7

[0066] The difference between this embodiment and Embodiment 1 is that, in step S1, the pre-condensation reaction is carried out at 3.5 kPa and 275°C for 30 min, with the stirring paddle speed adjusted to 80 r / min.

[0067] Example 8

[0068] The difference between this embodiment and Embodiment 1 is that in step S1, the film stretching is performed by bidirectional stretching at 95°C, and the stretching method is simultaneous longitudinal and transverse stretching, with a longitudinal stretching ratio of 2 times and a transverse stretching ratio of 3 times.

[0069] Example 9

[0070] The difference between this embodiment and Embodiment 1 is that in step S1, the film stretching is performed by bidirectional stretching at 98°C, and the stretching method is simultaneous longitudinal and transverse stretching, with a longitudinal stretching ratio of 4 times and a transverse stretching ratio of 4 times.

[0071] Example 10

[0072] The difference between this embodiment and Embodiment 1 is that in step S1, the final polycondensation reaction is carried out at 140 Pa and 255 °C for 1.5 h, and the stirring speed is adjusted to 35 r / min.

[0073] Example 11

[0074] The difference between this embodiment and Embodiment 1 is that in step S1, the final polycondensation reaction is carried out at 160 Pa and 275 °C for 2.5 h, and the stirring speed is adjusted to 40 r / min.

[0075] Example 12

[0076] The difference between this embodiment and Embodiment 1 is that, in step S2, the heat preservation temperature is 270℃ and the spinneret shear rate is 13000s. -1 The pressure is 8 MPa.

[0077] Example 13

[0078] The difference between this embodiment and Embodiment 1 is that, in step S2, the heat preservation temperature is 280℃ and the spinneret shear rate is 13000s. -1 The pressure is 9 MPa.

[0079] Example 14

[0080] The difference between this embodiment and embodiment 1 is that in step S2, the air-cooling shaping and cluster oiling are as follows: first, strong cooling with an aerosol for 45 seconds, with an aerosol temperature of 25°C; after the strong cooling, a first cluster oiling is performed, with the cluster position at 900mm and the oiling amount at 0.30%; then, weak cooling with a side air for 30 seconds, with a side air temperature of 40°C; after the weak cooling, a second cluster oiling is performed, with the cluster position at 850mm and the oiling amount at 0.10%.

[0081] Example 15

[0082] The difference between this embodiment and embodiment 1 is that in step S2, the air-cooling shaping and cluster oiling are as follows: first, strong cooling with an aerosol fan for 50 seconds, with an aerosol fan temperature of 30°C; after the strong cooling is completed, a first cluster oiling is performed, with the cluster position at 950mm and the oil amount at 0.35%; then, weak cooling with a side air fan for 35 seconds, with a side air temperature of 45°C; after the weak cooling is completed, a second cluster oiling is performed, with the cluster position at 800mm and the oil amount at 0.15%.

[0083] Example 16

[0084] The difference between this embodiment and embodiment 1 is that in step S3, the PBT-POY filament is subjected to tension heat setting under the action of a deformation heat box at 2400℃, and then cooled to room temperature to obtain PBT-POY filament. The PBT-POY filament is then placed in a false twisting machine with a twisting speed ratio of 1.65 for twisting and untwisting.

[0085] Example 17

[0086] The difference between this embodiment and embodiment 1 is that in step S3, the PBT-POY filament is subjected to tension heat setting under the action of a deformation heat box at 260°C, and then cooled to room temperature to obtain PBT-POY filament. The PBT-POY filament is then placed in a false twisting machine with a twisting speed ratio of 1.75 for twisting and untwisting.

[0087] Example 18

[0088] The difference between this embodiment and embodiment 1 is that in step S3, the PBT-POY filament is placed in the second roller, subjected to supplementary heat setting in a 150°C setting hot box, and then placed in a network nozzle with a pressure of 0.18MPa.

[0089] Example 19

[0090] The difference between this embodiment and embodiment 1 is that in step S3, the PBT-POY filament is placed in the second roller, supplemented by heat setting in a 180°C setting box, and then placed in a network nozzle with a pressure of 0.22MPa.

[0091] Example 20

[0092] The difference between this embodiment and embodiment 1 is that in step S3, the PBT-POY filament is placed in the third roller, and finally shaped by a 90°C shaping hot box, and then wound to obtain elastic reinforced PBT polyester fiber.

[0093] Example 21

[0094] The difference between this embodiment and embodiment 1 is that in step S3, the PBT-POY filament is placed in the third roller, and finally shaped in a 100°C shaping box, and then wound to obtain elastic reinforced PBT polyester fiber.

[0095] Example 22

[0096] The difference between this embodiment and embodiment 1 is that in steps S2 and S3, the winding tension of the winding forming is 0.06 CN / dtex and the winding speed is 3150 m / min.

[0097] Example 23

[0098] The difference between this embodiment and embodiment 1 is that in steps S2 and S3, the winding tension of the winding forming is 0.07 CN / dtex and the winding speed is 3180 m / min.

[0099] Example 24

[0100] The difference between this embodiment and Embodiment 1 is that the speed of the first roller is 190 m / min, the speed of the second roller is 250 m / min, and the speed of the third roller is 280 m / min.

[0101] Example 25

[0102] The difference between this embodiment and Embodiment 1 is that the speed of the first roller is 200 m / min, the speed of the second roller is 260 m / min, and the speed of the third roller is 290 m / min.

[0103] Experimental Example

[0104] For the PBT polyester fibers prepared in each embodiment, five samples from each embodiment were taken to test the performance of the PBT polyester fibers. The average value of the performance measurement results of the five samples in each embodiment was taken as the performance measurement result of that embodiment. The specific investigation is as follows:

[0105] 1. To investigate the effect of raw material ratio on the breaking strength and elongation at break of PBT polyester fiber.

[0106] Table 1. Breaking strength (cN·dtex) of PBT polyester fibers in Examples 1-3 -1 Effect of ) and elongation at break (%)

[0107] Group Example 1 Example 2 Example 3 Fracture strength 6.73 6.24 6.38 Elongation at break 149 141 144

[0108] As shown in Table 1, when the proportion of PTA in the raw material ratio is too small or too large, it will reduce the breaking strength and elongation at break of PBT polyester fiber. Therefore, the raw material ratio in Example 1 is the best.

[0109] 2. Investigate the effect of step S1 on the breaking strength and elongation at break of PBT polyester fiber.

[0110] Table 2. Breaking strength (cN·dtex) of PBT polyester fibers in Examples 4-11 -1 Effect of ) and elongation at break (%)

[0111]

[0112] As shown in Table 2, in step S1, if the parameters of the esterification reaction are too small or too large, the parameters of the pre-condensation reaction are too small or too large, the parameters of the film stretching reaction are too small or too large, and the parameters of the final condensation reaction are too small or too large, the breaking strength and elongation at break of the PBT polyester fiber will be reduced. Therefore, overall, the parameters of Example 1 are relatively better.

[0113] 3. Investigate the effect of step S2 on the breaking strength and elongation at break of PBT polyester fiber.

[0114] Table 3. Breaking strength (cN·dtex) of PBT polyester fibers in Examples 12-15 and Comparative Examples 1-3. -1 Effect of ) and elongation at break (%)

[0115]

[0116] The difference between Comparative Example 1 and Example 1 is that in step S2, only the circulating air is subjected to forced cooling;

[0117] The difference between Comparative Example 2 and Example 1 is that in step S2, only weak crosswind cooling is performed;

[0118] The difference between Comparative Example 3 and Example 1 is that in step S2, only one oiling of the bundle is performed;

[0119] As shown in Table 3, the steps in Comparative Examples 1 to 3 were missing, which significantly reduced the breaking strength and elongation at break of PBT polyester fibers compared to Examples 1 to 15.

[0120] Comparing Examples 1 and 13-15, it can be seen that if the parameters of the heat-insulating spinneret are too small or too large, and the parameters of the air-cooling setting and bundling oiling are too small or too large, the breaking strength and breaking elongation of the PBT polyester fiber will be reduced. Therefore, in summary, Example 1 is relatively better.

[0121] 4. Investigate the effect of step S3 on the breaking strength and elongation at break of PBT polyester fiber.

[0122] Table 4. Breaking strength (CN·dtex) of PBT polyester fiber in Examples 16-25 and Comparative Example 4. -1 Effect of ) and elongation at break (%)

[0123]

[0124]

[0125] The difference between Comparative Example 4 and Example 1 is that in step S3, heat setting is not performed after passing through the third roller;

[0126] As shown in Table 4, the lack of a third heat setting in Comparative Example 3 significantly reduced the breaking strength and elongation at break of PBT polyester fibers compared to Examples 1-25.

[0127] Comparing Examples 1 and 16-25, it can be seen that in step S3, if the parameters of the tension heat setting are too small or too large, the parameters of the supplementary heat setting are too small or too large, the parameters of the final setting are too small or too large, the parameters of the winding forming are too small or too large, and the speeds of the three rollers are too small or too large, the breaking strength and breaking elongation of the PBT polyester fiber will be reduced. Therefore, in summary, Example 1 has the best effect.

Claims

1. A method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber technology, characterized in that, Includes the following steps: S1. Preparation of PBT melt: PTA and BDO are mixed uniformly at a mass ratio of 1:3 to 5 to obtain a mixture, and the mixture is subjected to esterification reaction, pre-condensation reaction, film stretching and final condensation reaction in sequence to obtain PBT melt; S2. Preparation of PBT-POY precursor fibers: The PBT melt obtained in step S1 is kept warm and spun, then air-cooled and shaped and bundled with oil, and finally guided and wound to form PBT-POY raw yarn. The air-cooling shaping and cluster oiling process is as follows: First, strong air cooling is applied for 45-50 seconds, with the air temperature at 25-30°C. After the strong cooling, a first cluster oiling is performed, with the cluster position at 900-950mm and the oil amount at 0.30-0.35%. Then, weak air cooling is applied for 30-35 seconds, with the side air temperature at 40-45°C. After the weak cooling, a second cluster oiling is performed, with the cluster position at 800-850mm and the oil amount at 0.10-0.15%. S3, PBT-POY raw yarn with added texture: The PBT-POY raw yarn obtained in step S2 is placed into the first roller of the spinning machine and subjected to tension heat setting in a deformation heat box at 240-260°C. After cooling to room temperature, PBT-POY filament is obtained. The PBT-POY filament is then placed into a false twisting machine with a twisting speed ratio of 1.65-1.75 for twisting and untwisting. The PBT-POY filament is then placed into the second roller and subjected to additional heat setting in a setting box at 150–180°C, and then placed into a network nozzle with a pressure of 0.18–0.22 MPa. Finally, the PBT-POY filaments are placed in the third roller and finalized in a setting box at 90-100℃. The resulting elastic-reinforced PBT polyester fibers are then obtained through winding. The speed of the first roller is 190-200 m / min, the speed of the second roller is 250-260 m / min, and the speed of the third roller is 280-290 m / min.

2. The method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber process according to claim 1, characterized in that, In step S1, the esterification reaction is as follows: a catalyst accounting for 25-45% of the mass of the mixture is added to the mixture at 35-40 kPa and 200-220 °C, wherein the catalyst is TBT, and the esterification reaction is carried out for 40-50 min.

3. The method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber process according to claim 1, characterized in that, In step S1, the pre-condensation reaction is carried out at 1.5-3.5 kPa and 255-275°C for 25-30 min, with the stirring paddle speed adjusted to 75-80 r / min.

4. The method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber process according to claim 1, characterized in that, In step S1, the final polycondensation reaction is carried out at 140-160 Pa and 255-275 °C for 1.5-2.5 h, with the stirring paddle speed adjusted to 35-40 r / min.

5. The method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber process according to claim 1, characterized in that, In step S1, the film stretching is performed by bidirectional stretching at 95-98°C, with longitudinal and transverse stretching occurring simultaneously. The longitudinal stretching ratio is 2-4 times, and the transverse stretching ratio is 3-4 times.

6. The method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber process according to claim 1, characterized in that, In step S2, the heat preservation temperature is 270-280℃, and the spinneret shear rate is 13000s. -1 The pressure is 8-9 MPa.

7. The method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber process according to claim 1, characterized in that, In step S2, the guidewire speed is 3450-3480 m / min and the guidewire temperature is 280-285℃.

8. The method for preparing elastic-reinforced PBT polyester fiber based on POY chemical fiber process according to claim 1, characterized in that, In steps S2 and S3, the winding tension of the winding forming is 0.06 to 0.07 CN / dtex, and the winding speed is 3150 to 3180 m / min.

Images