A spinning tension control device and its application

Abstract

The present invention relates to the field of spinning technology, and discloses a spinning tension control device and its application. The spinning device includes a cooling device and an oiling device, and the spinning tension control device includes a hollow ring; the hollow ring is placed horizontally, and is provided with an air inlet and an air outlet; the air inlet is used to allow compressed air to enter; the air outlet is annular, and the central axis of the air outlet coincides with the central axis of the hollow ring; the hollow ring is placed between the cooling device and the oiling device, and is used for the filament bundle cooled by the cooling device to pass through the hollow ring; when the compressed air enters the hollow ring from the air inlet and exits from the air outlet, the compressed air blows toward all the monofilaments in the filament bundle above the hollow ring. The present invention brings resistance to the filament bundle through compressed air, which can increase the tension of the filament bundle and improve the uniformity of the tension, and the filament bundle is less damaged.

Description

Technical Field

[0001] The invention belongs to the technical field of spinning and relates to a spinning tension control device and application thereof. Background Art

[0002] The spinning process mainly involves the yarn being cooled by air outlet, then oiled, stretched (POY yarn is not stretched), and wound. If the tension from cooling to oiling is not well controlled, especially if the inlet tension of the oil nozzle (or oil tanker) is too high or too low, the yarn will jump on the oil nozzle (or oil tanker), resulting in uneven oiling, which in turn causes single yarn breakage, hairy yarns and broken ends, affecting product quality and production efficiency. Among them, tension is the axial tensile force on the yarn during the fiber forming process. Its essence is the mechanical balance formed by the yarn overcoming various resistances during the spinning process.

[0003] Spinning technology primarily achieves tension regulation through equipment contact. For example, in the production of FDY (spinning speeds above 1800 m / min) and POY (spinning speeds above 2500 m / min), the spinning speeds are relatively high, resulting in high tension on the tow entering the nozzle, especially at the nozzle entrance. This increases friction, necessitating tension reduction. In industrial yarn production, however, the spinning speed (i.e., the speed of the first pair of heated rollers) is 418-570 m / min, resulting in relatively low tension on the tow entering the nozzle. This causes the filaments to vibrate above the nozzle, resulting in uneven thickness and uneven oiling. This can easily lead to filament breakage during stretching, resulting in broken ends and downgraded yarns. Therefore, tension increases are necessary. Patent application number CN202023094938.4 provides a spinning tension precision adjustment device that achieves precise adjustment of the yarn tension through a specific mechanical structure design. Patent application number CN202321403988.7 provides a spinning tension adjustment device that uses a tension sensor to monitor the yarn tension in real time and adjusts the motor output through a controller to achieve precise adjustment of the tension when switching between full-wind spinning. Furthermore, in actual production, a wire pressing device is added above the oil nozzle (or oil tanker) to increase the yarn resistance, thereby increasing the yarn tension at the oil nozzle (or oil tanker) inlet.

[0004] However, the above method has the following main disadvantages:

[0005] (1) Since the tow is not oiled, increasing the resistance through equipment contact will increase the damage to the yarn and affect the mechanical properties;

[0006] (2) If Figure 1As shown, when the tow 2 contacts the wire pressing device 9, only some of the monofilaments in the tow 2 contact the wire pressing device 9, and the remaining monofilaments cannot contact the wire pressing device 9. The monofilaments in contact with the wire pressing device 9 are subjected to a large friction force, while the monofilaments not in contact with the wire pressing device 9 are subjected to a small friction force. The different friction forces lead to uneven tension of the monofilaments close to the wire pressing device 9 and far from the wire pressing device 9, resulting in uneven thickness of the monofilaments in the tow 2 during the subsequent stretching process, which in turn leads to poor uniformity of the product.

[0007] (3) Due to the contact and friction between the yarn bundle and the equipment, heat is easily generated. Since local friction heat generation occurs before stretching, the activity of macromolecules increases, thereby forming a certain amorphous area and reducing the pre-crystallization degree. Different single yarns in a yarn bundle and different areas of the same yarn are prone to generate internal stress gradients, which makes it easy for problems such as broken ends and hairy yarns to occur during the subsequent stretching process.

[0008] Therefore, it is of great significance to study a spinning tension control device and its application to solve the above problems. Summary of the Invention

[0009] The purpose of the present invention is to solve the problems in the prior art and provide a spinning tension control device and application thereof.

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

[0011] A spinning tension control device, the spinning device includes a cooling device and an oiling device, and the spinning tension control device includes a hollow ring;

[0012] The hollow ring is placed horizontally and is provided with an air inlet and an air outlet; the air inlet is used to introduce compressed air; the air outlet is in a circular shape, and the central axis of the air outlet coincides with the central axis of the hollow ring;

[0013] The hollow ring is placed between the cooling device and the oiling device, and the hollow ring is used for the filament bundle cooled by the cooling device to pass through;

[0014] When the compressed air enters the hollow ring from the air inlet and comes out from the air outlet, the compressed air blows toward all the filaments in the tow above the hollow ring;

[0015] When in use, the spinning tension control device is arranged above the oiling device, allowing the filament bundle to pass through the hollow ring of the spinning tension control device; when the compressed air moves toward the top of the center of the hollow ring, the filament bundle moves from top to bottom, so that the compressed air brings resistance to the filament bundle, thereby increasing the tension of the filament bundle; since it is air contact, the air can be blown evenly to each filament through the gaps between the monofilaments, thereby improving the uniformity of the tension; in addition, the contact between the equipment (spinning tension adjustment device) and the filament strip is mainly with a part of the surface of the filament, which is mainly one-sided contact, and when the equipment is in contact, the friction coefficient of the equipment surface is relatively high, which is easy to damage the filament; while the contact between air and filament is evenly distributed on the surface of the filament strip, and the friction coefficient of large air molecules is small. When the same resistance is generated, the damage to the filament bundle will be smaller.

[0016] As the preferred technical solution:

[0017] The spinning tension control device as described above further includes an air inlet pipe, one end of which is connected to the air inlet, and the other end of which is used for introducing compressed air.

[0018] As described above, the spinning tension control device further includes an air intake regulating valve, which is arranged on the air intake pipe and is used to control the air intake volume, thereby controlling the air outlet wind speed.

[0019] The spinning tension control device as described above further includes a temperature control device, which is used to control the temperature of the compressed air. The temperature control device is a prior art.

[0020] In the spinning tension control device as described above, the inner diameter of the hollow ring is 2.5 cm to 10 cm.

[0021] As described above, a spinning tension control device has a hollow circular ring with an air outlet, and the cross-section is a circle with a notch; the midpoint of the line connecting the two end points of the circle with the notch is point A, and the center of the circle with the notch is point B; the angle between the line connecting point A and point B and the horizontal plane where point B is located is 30°~80°. If the angle is less than 30°, and the filament bundle moves downward, driving the surrounding airflow to flow downward, then under the combined action of the airflow blown out by the device and the airflow around the filament bundle, the overall direction is almost perpendicular to the direction of the filament bundle, and the tension adjustment effect is small; while if it is greater than 80°, the airflow direction is almost parallel to the filament bundle, and it is not easy for air to enter the gap between the filament bundles, and the resistance effect on the internal filament bundle will be weakened.

[0022] In the spinning tension control device as described above, the length of the line connecting the two end points of the circle with the notch is 2 mm to 8 mm, and the diameter of the circle is 6 mm to 20 mm.

[0023] The present invention also provides an application of a spinning tension control device as described in any of the above items, wherein the polyester melt is extruded through a spinneret and cooled, passes through the hollow ring of the spinning tension control device, and then sequentially undergoes oiling, one-roller drafting, two-roller drafting, pre-networking, three-roller drafting, four-roller drafting, five-roller drafting, main networking and winding to produce polyester fiber.

[0024] As the preferred technical solution:

[0025] The application of the above-mentioned spinning tension control device, the process parameters include: melt viscosity of 0.95~1.16dL / g, spinning box temperature of 292~320℃, side blowing wind speed of 0.6~1.0m / min; oil pump speed of 12~26rpm, first roller speed of 418~570m / min, first roller temperature of 25~83℃, second roller speed of 430~590m / min, second roller temperature of 95~105℃, third roller speed of 1670~2400m / min, third roller temperature of 130~138℃, fourth roller speed of 2570~3400m / min, fourth roller temperature of 235~245℃, fifth roller speed of 25 40~3350m / min, five-roll temperature is 160~170℃, winding speed is 2500~3350m / min, pre-network pressure is 1.2~3bar, main network pressure is 3~3.8bar, wind speed at the air outlet of the tension control device is 0.05~0.3m / s, the temperature of the compressed air is 25℃~65℃, the temperature control of the compressed air is generally not lower than the ambient temperature, and the maximum is not higher than the glass transition temperature of the spun fiber. The tension control device is located 25cm~100cm above the oiling device; among them, the wind speed test method at the air outlet is: cool the anemometer to 30℃, and then close the anemometer to the air outlet of the tension control device to test the wind speed there.

[0026] By applying the spinning tension control device as described above, the polyester fiber produced has a fineness of 550dtex~1500dtex, a yarn degradation rate of no more than 0.05%, a breakage rate of no more than 0.15%, a breaking strength of no less than 8.5cN / dtex, and an elongation at break of 14.7%.

[0027] Beneficial effects:

[0028] The spinning tension control device of the present invention brings resistance to the filament bundle by compressed air, which not only increases the tension of the filament bundle but also improves the uniformity of the tension. In addition, since the friction coefficient of large air molecules is small, the filament bundle will be less damaged when the same resistance is generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the contact between the device and the tow in the prior art;

[0030] Figure 2 This is a schematic structural diagram of the spinning tension control device of the present invention when in use;

[0031] Figure 3 is a schematic diagram of a spinning tension control device according to the present invention;

[0032] Figure 4 Schematic diagram of the cross section of the hollow ring of the present invention;

[0033] Figure 5 It is a partial enlarged view of the cross section of the hollow ring of the present invention;

[0034] Figure 6 Schematic diagram of the angle between the line connecting point A and point B and the horizontal plane where point B is located;

[0035] Among them, 1-spinneret, 2-filament bundle, 3-compressed air, 4-air inlet, 5-temperature control device, 6-oil nozzle, 7-air outlet, 8-air inlet regulating valve, 9-wire pressing device. DETAILED DESCRIPTION

[0036] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0037] The testing methods for the relevant performance indicators in the following embodiments and comparative examples are as follows:

[0038] Downgrade rate of lint: The polyester fibers prepared in the Examples and Comparative Examples were used as samples. 10,000 continuously produced yarn cakes were then inspected for appearance. The percentage of downgraded yarn cakes with lint to the total number of yarn cakes was calculated, representing the downgrade rate. Downgrade criteria for lint were that no single yarn cake contained more than three lints or loops.

[0039] End breakage rate: The polyester fiber prepared in each example was used as a sample, and then 10,000 yarn cakes were continuously produced. The number of small rolls generated by end breakage was counted, and then the number was divided by the total number of yarn cakes to obtain the end breakage rate.

[0040] Breaking Strength and Elongation at Break: The polyester fibers prepared in each example were used as samples. The samples were stretched until they broke using an automatic tensor-extensometer using a STATIMAT 4U instrument under test conditions in accordance with GB / T 14344-2022. The breaking strength and elongation at break were automatically calculated by a computer. The breaking strength is the ratio of strength to linear density. The test conditions were: a nominal clamping length of 500 mm, a test speed of 500 mm / min, a preload of 0.05 cN / dtex, and five tests were performed for each sample. (The breaking strength and elongation at break of the present invention are the average values ​​after five tests.)

[0041] Example 1

[0042] A spinning tension control device, such as Figures 2 to 6 As shown, the spinning device includes a cooling device and an oiling device, and the spinning tension control device includes a hollow ring, an air inlet pipe, a temperature control device 5 and an air inlet regulating valve 8;

[0043] The hollow ring is placed horizontally and is provided with an air inlet 4 and an air outlet 7;

[0044] The air outlet 7 is annular, and the central axis of the air outlet 7 coincides with the central axis of the hollow ring;

[0045] The cross section of the hollow ring provided with the air outlet 7 is a circle with a notch; the midpoint of the line connecting the two end points of the circle with the notch is point A, and the center of the circle with the notch is point B; the angle between the line connecting point A and point B and the horizontal plane where point B is located is 20° to 80°;

[0046] The length of the line connecting the two endpoints of the circle with a notch is 2mm~8mm, and the diameter of the circle is 6mm~20mm;

[0047] The inner diameter of the hollow ring is 2.5cm~10cm;

[0048] One end of the air inlet pipe is connected to the air inlet 4, and the other end of the air inlet pipe is used to pass compressed air 3;

[0049] The temperature control device 5 is used to control the temperature of the compressed air 3;

[0050] The air intake regulating valve 8 is arranged on the air intake pipe;

[0051] The hollow ring is placed between the cooling device and the oiling device, and the hollow ring is used for the filament bundle 2 cooled by the cooling device to pass through;

[0052] When the compressed air 3 enters the hollow ring from the air inlet 4 and comes out from the air outlet 7, the compressed air 3 blows toward all the monofilaments in the filament bundle 2 above the hollow ring.

[0053] Example 2

[0054] An application of a spinning tension control device, the specific process is as follows:

[0055] like Figure 2 As shown, a polyester melt (formed by polycondensation of PTA and EG, with PTA accounting for 85.5% by mass) with a viscosity of 0.95 dL / g is extruded through a spinneret 1 and cooled. The filament bundle 2 then passes through the hollow ring of the spinning tension control device described in Example 1, is oiled through an oil nozzle 6, and then undergoes single-roller drafting, two-roller drafting, pre-intertwining, three-roller drafting, four-roller drafting, five-roller drafting, main intertwining, and winding to produce a polyester fiber. The angle between the line connecting points A and B of the spinning tension control device and the horizontal plane where point B is located is 80°, the length of the line connecting the two endpoints of the notched circle is 2 mm, the diameter of the circle is 6 mm, and the inner diameter of the hollow ring is 2.5 cm.

[0056] The process parameters include: the temperature of the spinning box is 292°C, the side blowing speed is 0.6m / min; the oil pump speed is 12rpm, the speed of one roller is 570m / min, the temperature of one roller is 25°C, the speed of two rollers is 590m / min, the temperature of two rollers is 95°C, the speed of three rollers is 2400m / min, the temperature of three rollers is 130°C, the speed of four rollers is 3400m / min, the temperature of four rollers is 235°C, the speed of five rollers is 3350m / min, the temperature of five rollers is 160°C, the winding speed is 3350m / min, the pre-network pressure is 1.2bar, the main network pressure is 3.5bar, the wind speed of the air outlet of the tension control device is 0.05m / s, the temperature of the compressed air is 25°C, and the tension control device is located 25cm above the oiling device.

[0057] The final polyester fiber has a fineness of 550 dtex, a hair degradation rate of 0.042%, a breakage rate of 0.08%, a breaking strength of 8.52 cN / dtex, and an elongation at break of 14.8%.

[0058] Comparative Example 1

[0059] An application of a spinning tension control device is basically the same as that of Example 2, except that the spinning tension control device described in Example 1 is not used.

[0060] The polyester fiber finally produced had a yarn degradation rate of 0.12%, a breakage rate of 1.77%, a breaking strength of 8.45 cN / dtex, and a breaking elongation of 14.2%.

[0061] By comparing Comparative Example 1 with Example 2, it can be seen that the polyester fiber prepared in this comparative example has increased filament degradation and end breakage rates, while decreased breaking strength and elongation at break. This is because when the spinning speed is low in the production process of polyester fibers, the tension of the filament bundle is relatively small when entering the oil nozzle, which leads to severe vibration of the single fiber, resulting in uneven thickness and uneven oiling of the single fiber, making the single fiber with severe vibration more likely to be broken in the subsequent drawing process, which leads to increased filament degradation and end breakage rates, and ultimately leads to decreased breaking strength and elongation at break due to the breakage of the single fiber during the test process.

[0062] Comparative Example 2

[0063] An application of a spinning tension control device is basically the same as that in Example 2, except that the spinning tension control device described in Example 1 is replaced with a wire pressing rod, and the wire pressing rod is installed above the oil nozzle to apply pressure to the yarn bundle to increase the tension of the yarn bundle when it enters the oil nozzle, and ultimately the resistance generated by the wire pressing rod to the yarn bundle is the same as that in Example 2.

[0064] The final polyester fiber had a hair degradation rate of 0.08%, a breakage rate of 1.36%, a breaking strength of 8.47 cN / dtex, and a breaking elongation of 14.4%.

[0065] By comparing Comparative Example 2 with Example 2, it can be seen that the polyester fiber prepared in this comparative example has increased filament degradation and breakage rates, while decreased breaking strength and breaking elongation. This is because the wire pressing rod generates a certain resistance to the filament bundle, increases the tension of the filament bundle when entering the oil nozzle, and improves the uniformity of oiling. However, the wire pressing rod only contacts a part of the monofilament during the pressure application process, resulting in inconsistent tension between the contact part and the non-contact part, and the wire guide rod directly contacts the filament bundle and also damages the surface of the monofilament to a certain extent, making the monofilament more easily broken during the subsequent drawing process, ultimately leading to increased filament degradation and breakage rates, and due to the breakage of the monofilament during the test, the final breaking strength and breaking elongation decrease.

[0066] Example 3

[0067] An application of a spinning tension control device, the specific process is as follows:

[0068] A polyester melt (formed by polycondensation of PTA and EG, with PTA accounting for 85.5% by weight) with a viscosity of 0.95 dL / g was extruded through a spinneret and cooled, then passed through the hollow ring of the spinning tension control device described in Example 1, and then underwent oiling, one-roll drafting, two-roll drafting, pre-intertwining, three-roll drafting, four-roll drafting, five-roll drafting, main intertwining, and winding to produce a polyester fiber. The angle between the line connecting points A and B of the spinning tension control device and the horizontal plane containing point B was 60°, the length of the line connecting the two endpoints of the notched circle was 4 mm, the diameter of the circle was 12 mm, and the inner diameter of the hollow ring was 6.5 cm.

[0069] The process parameters include: the temperature of the spinning box is 298°C, the side wind speed is 0.8m / min; the oil pump speed is 17rpm, the speed of one roller is 550m / min, the temperature of one roller is 32°C, the speed of two rollers is 570m / min, the temperature of two rollers is 96°C, the speed of three rollers is 2350m / min, the temperature of three rollers is 135°C, the speed of four rollers is 3200m / min, the temperature of four rollers is 242°C, the speed of five rollers is 3060m / min, the temperature of five rollers is 165°C, the winding speed is 3000m / min, the pre-network pressure is 1.8bar, the main network pressure is 3.2bar, the wind speed of the air outlet of the tension control device is 0.1m / s, the temperature of the compressed air is 30°C, and the tension control device is located 40cm above the oiling device.

[0070] The final polyester fiber has a fineness of 840 dtex, a hair degradation rate of 0.035%, a breakage rate of 0.11%, a breaking strength of 8.57 cN / dtex, and an elongation at break of 14.7%.

[0071] Example 4

[0072] An application of a spinning tension control device, the specific process is as follows:

[0073] A polyester melt (formed by polycondensation of PTA and EG, with PTA accounting for 85.5% by weight) with a viscosity of 1.12 dL / g was extruded through a spinneret and cooled, then passed through the hollow ring of the spinning tension control device described in Example 1, and then underwent oiling, one-roll drafting, two-roll drafting, pre-intertwining, three-roll drafting, four-roll drafting, five-roll drafting, main intertwining, and winding to produce a polyester fiber. The angle between the line connecting points A and B of the spinning tension control device and the horizontal plane containing point B was 50°, the length of the line connecting the two endpoints of the notched circle was 5 mm, the diameter of the circle was 12 mm, and the inner diameter of the hollow ring was 6.5 cm.

[0074] The process parameters include: the temperature of the spinning box is 300℃, the side blowing speed is 0.8m / min; the oil pump speed is 20rpm, the speed of the first roller is 477m / min, the temperature of the first roller is 35℃, the speed of the second roller is 489m / min, the temperature of the second roller is 98℃, the speed of the third roller is 1870m / min, the temperature of the third roller is 133℃, the speed of the fourth roller is 2800m / min, the temperature of the fourth roller is 238℃, the speed of the fifth roller is 2787m / min, the temperature of the fifth roller is 165℃, the winding speed is 2700m / min, the pre-network pressure is 2.6bar, the main network pressure is 3bar, the wind speed of the tension control device at the air outlet is 0.2m / s, the temperature of the compressed air is 45℃, and the tension control device is located 40cm above the oiling device.

[0075] The final polyester fiber has a fineness of 1100 dtex, a hair degradation rate of 0.03%, a breakage rate of 0.08%, a breaking strength of 8.58 cN / dtex, and an elongation at break of 14.9%.

[0076] Example 5

[0077] An application of a spinning tension control device, the specific process is as follows:

[0078] A polyester melt (formed by polycondensation of PTA and EG, with PTA accounting for 85.5% by weight) with a viscosity of 1.12 dL / g was extruded through a spinneret and cooled, then passed through the hollow ring of the spinning tension control device described in Example 1, and then underwent oiling, one-roll drafting, two-roll drafting, pre-intertwining, three-roll drafting, four-roll drafting, five-roll drafting, main intertwining, and winding to produce a polyester fiber. The angle between the line connecting points A and B of the spinning tension control device and the horizontal plane containing point B was 45°, the length of the line connecting the two endpoints of the notched circle was 8 mm, the diameter of the circle was 20 mm, and the inner diameter of the hollow ring was 10 cm.

[0079] The process parameters include: the temperature of the spinning box is 315℃, the side wind speed is 0.9m / min; the oil pump speed is 24rpm, the speed of the first roller is 448m / min, the temperature of the first roller is 75℃, the speed of the second roller is 460m / min, the temperature of the second roller is 100℃, the speed of the third roller is 1780m / min, the temperature of the third roller is 135℃, the speed of the fourth roller is 2680m / min, the temperature of the fourth roller is 242℃, the speed of the fifth roller is 2645m / min, the temperature of the fifth roller is 170℃, the winding speed is 2600m / min, the pre-network pressure is 3bar, the main network pressure is 3.5bar, the wind speed of the tension control device at the air outlet is 0.3m / s, the temperature of the compressed air is 60℃, and the tension control device is located 100cm above the oiling device.

[0080] The final polyester fiber has a fineness of 1300 dtex, a hair degradation rate of 0.038%, a breakage rate of 0.14%, a breaking strength of 8.56 cN / dtex, and an elongation at break of 14.9%.

[0081] Example 6

[0082] An application of a spinning tension control device, the specific process is as follows:

[0083] A polyester melt (formed by polycondensation of PTA and EG, with PTA accounting for 85.5% by weight) with a viscosity of 1.16 dL / g was extruded through a spinneret and cooled, then passed through the hollow ring of the spinning tension control device described in Example 1, and then underwent oiling, one-roll drafting, two-roll drafting, pre-intertwining, three-roll drafting, four-roll drafting, five-roll drafting, main intertwining, and winding to produce a polyester fiber. The angle between the line connecting points A and B of the spinning tension control device and the horizontal plane where point B lies was 30°, the length of the line connecting the two endpoints of the notched circle was 8 mm, the diameter of the circle was 20 mm, and the inner diameter of the hollow ring was 10 cm.

[0084] The process parameters include: the temperature of the spinning box is 320℃, the side blowing speed is 1m / min; the oil pump speed is 26rpm, the speed of the first roller is 418m / min, the temperature of the first roller is 83℃, the speed of the second roller is 430m / min, the temperature of the second roller is 105℃, the speed of the third roller is 1670m / min, the temperature of the third roller is 138℃, the speed of the fourth roller is 2570m / min, the temperature of the fourth roller is 245℃, the speed of the fifth roller is 2540m / min, the temperature of the fifth roller is 168℃, the winding speed is 2500m / min, the pre-network pressure is 3bar, the main network pressure is 3.8bar, the wind speed of the tension control device at the air outlet is 0.3m / s, the temperature of the compressed air is 65℃, and the tension control device is located 80cm above the oiling device.

[0085] The final polyester fiber has a fineness of 1500 dtex, a hair degradation rate of 0.048%, a breakage rate of 0.13%, a breaking strength of 8.67 cN / dtex, and a breaking elongation of 14.9%.

Claims

1. A spinning tension control device, the spinning device includes a cooling device and an oiling device, characterized in that: The spinning tension control device includes a hollow ring; The hollow ring is placed horizontally and is provided with an air inlet and an air outlet; the air inlet is used to introduce compressed air; the air outlet is in a circular shape, and the central axis of the air outlet coincides with the central axis of the hollow ring; The hollow ring is placed between the cooling device and the oiling device, and the hollow ring is used for the filament bundle cooled by the cooling device to pass through; When the compressed air enters the hollow ring from the air inlet and comes out from the air outlet, the compressed air blows toward all the filaments in the tow above the hollow ring; The hollow ring is a hollow ring provided with an air outlet, and its cross section is a circle with a notch; the midpoint of the line connecting the two end points of the circle with the notch is point A, and the center of the circle with the notch is point B; the angle between the line connecting point A and point B and the horizontal plane where point B is located is 30°~80°.

2. A spinning tension control device according to claim 1, characterized in that: The spinning tension control device also includes an air inlet pipe, one end of which is connected to the air inlet, and the other end of which is used for introducing compressed air.

3. A spinning tension control device according to claim 2, characterized in that: The spinning tension control device also includes an air intake regulating valve, which is arranged on the air intake pipe.

4. A spinning tension control device according to claim 3, characterized in that: The spinning tension control device also includes a temperature control device, which is used to control the temperature of the compressed air.

5. A spinning tension control device according to claim 4, characterized in that: The inner diameter of the hollow ring is 2.5cm~10cm.

6. A spinning tension control device according to claim 5, characterized in that: The length of the line connecting the two end points of the circle with the notch is 2 mm to 8 mm, and the diameter of the circle is 6 mm to 20 mm.

7. Use of a spinning tension control device according to any one of claims 1 to 6, characterized in that: After the polyester melt is extruded through the spinneret and cooled, it passes through the hollow ring of the spinning tension control device, and then goes through oiling, one-roller drawing, two-roller drawing, pre-network, three-roller drawing, four-roller drawing, five-roller drawing, main network and winding in sequence to produce polyester fiber.

8. Application of a spinning tension control device according to claim 7, characterized in that: The process parameters include: melt viscosity of 0.95~1.16dL / g, spinning box temperature of 292~320℃, side blowing wind speed of 0.6~1.0m / min; oil pump speed of 12~26rpm, first roller speed of 418~570m / min, first roller temperature of 25~83℃, second roller speed of 430~590m / min, second roller temperature of 95~105℃, third roller speed of 1670~2400m / min, third roller temperature of 130~138℃, fourth roller speed of 2 570~3400m / min, four-roll temperature is 235~245℃, five-roll speed is 2540~3350m / min, five-roll temperature is 160~170℃, winding speed is 2500~3350m / min, pre-network pressure is 1.2~3bar, main network pressure is 3~3.8bar, the wind speed of the air outlet of the tension control device is 0.05~0.3m / s, the temperature of the compressed air is 25℃~65℃, and the tension control device is located 25cm~100cm above the oiling device.

9. Application of the spinning tension control device according to claim 8, characterized in that: The fineness of the prepared polyester fiber is 550dtex~1500dtex, the fiber degradation rate is not more than 0.05%, the breakage rate is not more than 0.15%, the breaking strength is not less than 8.5cN / dtex, and the breaking elongation is 14.7%~14.9%.

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