Production method for bright cross-shaped polyester drawn yarns

Abstract

The present invention relates to a production method for bright "cross"-shaped polyester drawn yarns. A polyester melt is extruded from a spinneret having a "cross"-shaped profiled spinneret hole, and then undergoes cooling forming, first oiling, pre-interlacing, drawing and setting, second oiling, main interlacing and winding forming in sequence to obtain the bright "cross"-shaped polyester drawn yarns; and a hot roller used for drawing and setting is a hot roller having a groove, the groove being a continuous groove and being helically distributed on the peripheral surface of the hot roller. In the present invention, a mirror-smooth structure of the hot roller is designed as a helically distributed groove, the contact area between fibers and the surface of the hot roller is increased by means of the groove design, thereby increasing the heating area, reducing the shaking of tows on the hot roller, ensuring uniform heating of the fibers during heat setting, and improving the dyeing performance of the fibers.

Description

A method for producing bright cross-cut polyester drawn yarn Technical Field

[0001] This invention belongs to the field of profiled fiber technology and relates to a method for producing bright "cross" polyester drawn yarn. Background Technology

[0002] Polyester filament is the most produced and widely used synthetic fiber, primarily used in home textiles, apparel, and industrial applications. Following rapid development in recent years, while the application of polyester fiber in traditional apparel sectors continues to grow rapidly, it is gradually shifting towards differentiated and functional fibers. Differentiated and flexible products mainly involve modifying the fiber's properties through physical and chemical modifications. Physical modification involves shaping the fiber cross-section, specifically by using spinnerets with irregularly shaped spinnerets such as flat, triangular, triangular, hollow, cross-shaped, and king-shaped nozzles.

[0003] Bright "cross" polyester drawn yarn is popular in the market due to its bright color, unique and dazzling shimmering effect, good bulkiness, and high air permeability. However, because the "cross" cross section has greater friction with the air, it generates more static electricity, which makes it prone to shaking on the hot rollers during the drawing process. Furthermore, the heated surface area is too small, especially the thicker parts of the irregularly shaped fibers, which are poorly heated during shaking. This affects the stretching effect, and consequently, its dyeing properties, coefficient of variation of breaking strength, and coefficient of variation of breaking elongation.

[0004] To address the issues of fiber bundles easily vibrating on the hot rollers and having an insufficient heating surface during the drawing process, the literature (Discussion on the Application of Crude Oil Oiling in Polyester FDY Production [J]. Polyester Industry. 2017,30(6):53-56) mentions that the stability of the filaments on the hot rollers can be improved by lowering the GR1 temperature. However, the GR1 temperature is related to fuzziness and dyeing performance. Too low a GR1 temperature can easily lead to uneven stretching, resulting in increased fiber evenness, poor dyeing, filament breakage, and increased fuzziness.

[0005] Therefore, it is of great significance to study a production method for bright "cross" polyester drawn yarn in order to solve the problems existing in the current technology. Summary of the Invention

[0006] The purpose of this invention is to solve the problems existing in the prior art and provide a method for producing bright "cross" polyester drawn yarn.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for producing bright "cross" polyester drawn yarn: after the polyester melt is extruded from a spinneret with "cross" shaped spinneret holes, it is sequentially cooled and shaped, first oiling, pre-networking, drawing and shaping, second oiling, main networking and winding to obtain bright "cross" polyester drawn yarn.

[0009] The hot roller used for drafting and setting is a hot roller with grooves. The grooves are continuous and spirally distributed on the circumference of the hot roller. The reason for the continuous grooves is that the filament bundle needs to be wound in circles. The grooves are set around the direction of the filament bundle's winding, so that the filament bundle is wound in the grooves. Each filament bundle is wound in the grooves on the hot roller 5.5±1 times.

[0010] Because the cross-section of the fiber experiences significant friction with the air, it generates substantial static electricity, leading to excessive vibration on the hot roller during the drafting process. Furthermore, the heated surface area is too small, especially the thicker sections of the irregularly shaped fiber, which are poorly heated during vibration, affecting the stretching effect and consequently impacting its dyeing performance, as well as its coefficient of variation in breaking strength and elongation at break. Therefore, this invention designs the mirror-smooth structure of the hot roller with a spirally distributed groove. This groove design increases the contact area between the fiber and the hot roller surface, thereby increasing the heated area and reducing vibration of the fiber bundle on the hot roller. This ensures uniform heating during fiber heat setting, improves the fiber's dyeing performance, and significantly improves both the coefficient of variation in breaking strength and elongation at break.

[0011] As a preferred technical solution:

[0012] The production method of a bright "cross" polyester drawn yarn as described above is characterized in that the number of grooves on the circumference of the hot roller is 120 to 168, the cross-section of the groove (the cross-section along the axial direction of the hot roller) is arc-shaped, the groove width is 0.5 to 0.8 mm, and the groove depth (referring to the maximum distance in the groove depth direction) is 1 to 1.3 mm.

[0013] The production method of a bright "cross" polyester drawn yarn as described above is characterized in that the spiral diameter of the groove on the circumferential surface of the hot roller is 220~250mm, the spiral angle is 1°~2°, and the pitch is 1.5~2mm.

[0014] The production method of a bright "cross" polyester drawn yarn as described above is characterized by the use of a one-step drawing process, which is completed by two hot rollers.

[0015] The filament bundle needs to be wound on heated rollers. Typically, two heated rollers in a heating chamber operate at the same speed. One heated roller has a fixed axial position, while the other is at a certain angle in the axial direction. This allows the filament bundle to wind continuously from the inside out. Because the filament bundle enters a glassy state after heating, and the two heated rollers operate at the same speed without stretching, the tension of the filament bundle gradually decreases from the second turn onwards. This decrease in tension causes the filament bundle to vibrate on the heated rollers. The grooved heated rollers ensure that each filament bundle corresponds to a groove. The protrusions between the grooves act as barriers. With the guiding effect of the grooves, each filament bundle only rolls within its corresponding groove, preventing collisions between filament bundles.

[0016] The production method of a bright "cross" polyester drawn yarn as described above is characterized in that the first oiling is carried out by heating the oiling agent to 55±2℃ before oiling, and the concentration of the oiling agent is 92.5±0.3wt%.

[0017] Existing technologies typically use 10-20 wt% oil emulsion to allow the hot rollers to provide greater heating, enabling the fibers to reach a glassy state before stretching. However, due to the "cross" cross-section of the fiber, the oil's penetration between the filaments is relatively poor, resulting in oil residue remaining on the hot rollers during stretching, causing vibration problems. The higher the temperature of the hot rollers, the more severe the evaporation of oil and water, leading to more residue on the rollers. Therefore, to reduce the amount of oil residue on the hot rollers and improve their heating efficiency, it is necessary to increase the oil concentration and reduce the water content. The limit for increasing the oil concentration is to use crude oil (non-emulsion) for oiling. In this invention, since the crude oil is not mixed with water, there is no problem of water evaporation carrying away heat when passing through the stretching hot rollers, which can reduce the stretching temperature and power consumption. Furthermore, during the heating process on the hot rollers, the non-emulsion oil has good thermal conductivity, allowing for more uniform heating of the monofilaments and more uniform stretching, thereby improving dyeing uniformity. However, because crude oil has a higher viscosity and poorer fluidity than emulsions, it affects the penetration of crude oil between monofilaments. Therefore, this invention requires heating the oil to 55±2℃ before applying it to the filament bundle.

[0018] The production method of a bright "cross" polyester drawn yarn as described above is characterized in that the first oiling is carried out by a spinning oil spraying device with a heating function;

[0019] The spinning oil spraying device with heating function includes a spinning oil nozzle mounting bracket, an oil supply pipe, a spinning oil nozzle, an oil heating module, an oil temperature monitoring module, a temperature controller, a wiring harness, and a power supply.

[0020] The spinning oil nozzle is connected to the oil supply pipe via a quick connector. The spinning oil nozzle is mounted on the spinning oil nozzle mounting bracket. The spinning oil nozzle is an oil nozzle with a flat orifice, the length and width of which are 2.0 mm and 0.05 mm, respectively.

[0021] The width of the filament in the spinning nozzle is 1.2mm and the length is 8mm. The filament is flat and without horizontal lines. The purpose is to control oil splashing, reduce the friction between the filament bundle and the spinning nozzle, and prevent problems such as loose filaments, fuzzy filaments, and loose loops caused by excessive spinning tension.

[0022] The oil heating module and the oil temperature monitoring module are installed on the oil supply pipe near the spinning oil nozzle. The oil heating module is used to heat the oil to the set temperature, and the oil temperature monitoring module is installed on the inner wall of the oil pipe to monitor the oil temperature in real time. When the oil temperature reaches the temperature set by the temperature controller, the oil is applied to the filament through the spinning oil nozzle.

[0023] The oil heating module includes a heating resistor, a heat-conducting material, and a heat-insulating material. The heating resistor is wound around the oil pipeline. A stainless steel container is placed around the area of ​​the oil pipeline around which the heating resistor is wound. The stainless steel container is sealed to the oil pipeline. The heat-conducting material is placed in the stainless steel container. The outer surface of the stainless steel container is wrapped with heat-insulating material. The heat-conducting material is hot kerosene, and the heat-insulating material is asbestos.

[0024] The power supply is connected to the oil heating module, the oil temperature monitoring module, and the temperature controller via a wiring harness to provide power.

[0025] The production method of a bright "cross" polyester drawn yarn as described above is characterized in that the concentration of the oil used in the second oiling is 15.0±0.3wt%, the second oiling uses an emulsion, the main purpose of the second oiling is to increase the oil content on the surface of the yarn bundle, the yarn bundle is in a clump state when passing through the oil nozzle, the round hole oil spray hole can avoid oil splashing and loss, and improve the uniformity of oil content.

[0026] The production method of a bright "cross" polyester drawn yarn as described above is characterized in that the dyeing rate (M) of the bright "cross" polyester drawn yarn is ≥98.5%.

[0027] The production method of a bright "cross" polyester drawn yarn as described above is characterized in that the bright "cross" polyester drawn yarn has a breaking strength ≥3.8cN / dtex, a breaking elongation of 30.0±3%, a breaking strength coefficient of variation ≤4.00%, a breaking elongation coefficient of variation ≤5.00%, a boiling water shrinkage rate of 6.0±0.5%, a yarn unevenness rate ≤1.5%, a network density of 18±2 pieces / m, an oil content of 1.05±0.05%, an oil agent loss rate ≤0.5%, and a superior grade rate of 97% or higher. Beneficial effects

[0028] (1) A method for producing bright “cross” polyester drawn yarn of the present invention, by designing the mirror smooth structure of the hot roller into a groove shape and the grooves being spirally distributed, the groove design can increase the contact area between the fiber and the surface of the hot roller, thereby increasing the heating area and reducing the shaking of the yarn on the hot roller, ensuring uniform heating of the fiber during heat setting, and improving the dyeing performance of the fiber.

[0029] (2) The production method of a bright "cross" polyester drawn yarn of the present invention is as follows: the first oiling is carried out by heating the crude oil to 55±2℃ through a spinning oil spraying device with heating function, which reduces the drawing temperature and power consumption, and the single filament is heated evenly and the drawing is more uniform, thereby improving the dyeing uniformity; the second oiling is carried out by using non-emulsion oiling to improve the uniformity of oil content. Attached Figure Description

[0030] Figure 1 is a schematic diagram of a hot roller structure with grooves;

[0031] Figure 2 is a schematic diagram of a spinning oil spraying device with heating function;

[0032] Figure 3 is a cross-sectional view of the oil heating module;

[0033] Figure 4 shows the nozzle installation structure.

[0034] Among them, 1-spinning oil nozzle mounting bracket, 2-spinning oil nozzle, 3-heating resistor, 4-thermal conductive material, 5-thermal insulation material, 6-wire harness, 7-oil delivery pipe, and 8-oil temperature monitoring module. Implementation

[0035] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0036] The testing / calculation methods involved in the performance indicators of this invention are as follows:

[0037] (1) Breaking strength, breaking elongation, boiling water shrinkage, network density, and oil content: refer to "Irregular Polyester Draw Yarn" (FZ / T 54039-2018).

[0038] (2) Oil loss rate = 1 - actual oil content * 100% / theoretical oil content;

[0039] Actual oil content: According to the standard "Test Method for Oil Content of Chemical Fibers" (GB / T 6504-2017), a 2g fiber sample was weighed and tested using an MQC23-10 nuclear magnetic resonance oil content analyzer.

[0040] Theoretical oil content = (oil pump speed × 1.003 × oil concentration × oil pump specifications) ÷ pump supply; where 1.003 is the oil specific gravity.

[0041] (3) Excellent rate = {Total number of pieces - (Number of pieces with broken ends and small curls + Number of pieces downgraded from wool + Number of pieces downgraded from dyeing + Number of other downgraded pieces)} × 100% / Total number of pieces.

[0042] (4) Dyeing M rate: According to the "Test Method for Dyeing Uniformity of Polyester Filament" (GB / T 6508-2015), each bright "cross" polyester drawn yarn is woven into a sock and then dyed. The dyeing uniformity grade of the sock is visually evaluated by comparing the color change with the gray sample card. Socks with a dyeing uniformity grade of 4.0 or below are considered defective socks. Dyeing M rate = (1 - number of defective socks / total number of socks) × 100%.

[0043] (5) Evenness: The evenness of the sample was tested using a USTER5 evenness tester according to the "Test Method for Evenness of Chemical Fiber Filaments - Capacitive Method" (GB / T 14346-2015). After the sample was conditioned, the sample filament passed through the two plates of a capacitor at a uniform speed. The mass within each equal interval was converted into an electrical signal. The percentage of the standard deviation to the average value of all tested electrical signals was the evenness. The test speed was 200 m / min, and the test time was 2.5 min.

[0044] In the embodiments and comparative examples of this invention, the performance index of the bright "cross" polyester drawn yarn refers to the average value of the performance index of all yarn bundles measured at one spinning station, where one spinning station produces 24 yarn bundles. Example 1

[0045] A method for producing bright "cross" polyester drawn yarn, the specific process of which is as follows:

[0046] After the polyester melt is extruded from the spinneret with "cross" shaped spinneret holes, it goes through cooling and forming, first oiling, pre-networking, stretching and setting, second oiling, main networking and winding to produce bright "cross" polyester drawn yarn.

[0047] The first oiling process involves heating the oil to 55°C using a spinning oil spraying device with a heating function before applying the oil. The concentration of the oil is 92.5 wt%.

[0048] As shown in Figures 2 and 4, the spinning oil spraying device with heating function includes a spinning oil nozzle mounting bracket 1, an oil supply pipe 7, a quick connector, a spinning oil nozzle 2, an oil heating module, an oil temperature monitoring module 8, a temperature controller 9, a wiring harness, and a power supply.

[0049] The spinning oil nozzle 2 is connected to the oil supply pipe 7 via a quick connector. The spinning oil nozzle 2 is mounted on the spinning oil nozzle mounting bracket 1. The spinning oil nozzle 2 is an oil nozzle with a flat hole, the length and width of which are 2.0 mm and 0.05 mm, respectively.

[0050] The width of the yarn path in spinning nozzle 2 is 1.2 mm and the length is 8 mm;

[0051] The oil heating module and the oil temperature monitoring module 8 are installed on the oil supply pipe 7 near the spinning oil nozzle 2. The oil heating module is used to heat the oil to the set temperature, and the oil temperature monitoring module 8 is used to monitor the temperature of the oil in real time. When the oil temperature reaches the temperature set by the temperature controller 9, the oil is applied to the filament through the spinning oil nozzle.

[0052] As shown in Figure 3, the oil heating module includes a heating resistor 3, a heat-conducting material 4, and a heat-insulating material 5. The heating resistor 3 is wound around the oil pipeline 7. A stainless steel container is set around the area of ​​the oil pipeline where the heating resistor 3 is wound. The stainless steel container is sealed to the oil pipeline. The heat-conducting material 4 is placed in the stainless steel container. The outer surface of the stainless steel container is wrapped with the heat-insulating material 5. The heat-conducting material 5 is hot kerosene, and the heat-insulating material 5 is asbestos.

[0053] The power supply is connected to the oil heating module, the oil temperature monitoring module 8 and the temperature controller via wiring harness 6 to provide power;

[0054] As shown in Figure 1, the drafting and setting process adopts a one-step drafting process, which is completed by two grooved hot rollers. The grooves are continuous grooves, and the grooves are spirally distributed on the circumference of the hot rollers. The spiral diameter of the grooves on the circumference of the hot rollers is 250 mm, the spiral angle is 1°, and the pitch is 1.5 mm. The number of turns of the grooves on the circumference of the hot rollers is 120, and each bundle of filaments is wound 4.5 times in the grooves on the hot rollers. The cross-section of the grooves is arc-shaped, the groove width is 0.8 mm, and the groove depth is 1 mm.

[0055] The concentration of the oil used in the second oiling was 14.7 wt%.

[0056] The process parameters are as follows: cooling temperature is 20℃, pre-network air pressure is 0.07MPa, main network air pressure is 0.32MPa, GR1 hot roller temperature is 91℃, GR1 hot roller speed is 2000m / min, GR2 hot roller temperature is 129℃, GR2 hot roller speed is 4450m / min, and winding speed is 4350m / min.

[0057] The final bright "cross" polyester drawn yarn has a breaking strength of 4.26 cN / dtex, a breaking strength coefficient of variation of 3.49%, a breaking elongation of 31%, a breaking elongation coefficient of variation of 4.58%, a boiling water shrinkage rate of 6.3%, a yarn evenness rate of 1.35%, a network density of 16 cells / m, an oil content of 1.04%, an oil loss rate of 0.41%, a superior grade rate of 97.1%, and a dyeing M rate of 98.8%.

[0058] Comparative Example 1

[0059] A method for producing bright "cross" polyester drawn yarn is basically the same as in Example 1, except that the hot roller has a smooth circumferential surface without grooves.

[0060] The final bright "cross" polyester drawn yarn has a breaking strength of 4.13 cN / dtex, a breaking strength coefficient of variation of 5.98%, a breaking elongation of 31.1%, a breaking elongation coefficient of variation of 6.14%, a boiling water shrinkage rate of 6.9%, a yarn evenness rate of 1.91%, a network density of 16 cells / m, an oil content of 1.04%, an oil loss rate of 0.43%, a superior grade rate of 96.3%, and a dyeing M rate of 96.5%.

[0061] Comparing Comparative Example 1 and Example 1, it can be found that the coefficient of variation of breaking strength, coefficient of variation of breaking elongation, boiling water shrinkage rate, and yarn unevenness rate of Comparative Example 1 increased, while the dyeing M rate decreased. This is because there are no grooves on the hot roller, and the heating surface of the filament bundle on the hot roller is small, resulting in an increase in boiling water shrinkage rate. At the same time, due to the greater friction between the "cross" section and the air, a larger static electricity is generated, which makes it easy for the fiber to vibrate on the hot roller during the stretching process, resulting in a poor glass transition state of the fiber. Therefore, the coefficient of variation of breaking strength and coefficient of variation of breaking elongation increase, and the dyeing M rate decreases. In addition, since the temperature of the hot roller of GR1 remains unchanged, but the heating surface of the filament bundle on the hot roller is reduced, uneven stretching is more likely to occur, resulting in an increase in yarn unevenness rate.

[0062] Comparative Example 2

[0063] A method for producing glossy "cross" polyester drawn yarn is basically the same as in Example 1, except that the spinning oil spraying device does not have a heating function.

[0064] The final bright "cross" polyester drawn yarn has a breaking strength of 4.23 cN / dtex, a breaking strength coefficient of variation of 6.71%, a breaking elongation of 30.8%, a breaking elongation coefficient of variation of 6.85%, a boiling water shrinkage rate of 6.4%, a yarn evenness rate of 1.76%, a network density of 16 cells / m, an oil content of 0.97%, an oil loss rate of 0.9%, a superior grade rate of 95.8%, and a dyeing M rate of 97%.

[0065] Comparing Comparative Example 2 with Example 1, it can be found that the coefficient of variation of breaking strength, coefficient of variation of breaking elongation, yarn unevenness, and oil loss rate increased in Comparative Example 2, while the excellent grade rate and dyeing M rate decreased. This is because the oil was not preheated during oiling, and a high-concentration oil was used, which had poor penetration and fluidity, leading to an increase in fuzzy and loose yarns, thus affecting the excellent grade rate. At the same time, the poor penetration of the oil also caused problems such as oil scraping and spraying when the yarn bundle passed through ceramic parts such as the guide hook, resulting in an increased oil loss rate. In addition, the uneven oiling caused the yarn bundle to be heated inconsistently on the hot roller, thus affecting the dyeing performance, coefficient of variation of breaking strength, coefficient of variation of breaking elongation, and yarn unevenness.

[0066] Comparative Example 3

[0067] A method for producing glossy "cross" polyester drawn yarn is basically the same as in Example 1, except that the first oiling is omitted.

[0068] The final bright "cross" polyester drawn yarn has a breaking strength of 4.08 cN / dtex, a breaking strength coefficient of variation of 8.14%, a breaking elongation of 29.8%, a breaking elongation coefficient of variation of 16.2%, a boiling water shrinkage rate of 6.3%, a yarn evenness rate of 3.04%, a network density of 16 units / m, an oil content of 1.04%, an oil loss rate of 0.45%, a superior grade rate of 87.6%, and a dyeing M rate of 93.9%.

[0069] Comparing Comparative Example 3 with Example 1, it can be found that the excellent rate and dyeing M rate of Comparative Example 3 decreased significantly, while the coefficient of variation of breaking strength, coefficient of variation of breaking elongation and evenness increased significantly. This is because the fine denier "cross" cross-section fiber has a large specific surface area of ​​the filament bundle. If it is stretched and shaped directly without the first oiling, loose loops, fuzzy fibers and broken ends are likely to occur, thus reducing the excellent rate. At the same time, because the filament bundle is not coated with the first oil, it is easy for it to shake on the hot roller, resulting in dyeing problems such as striped fibers and tough fibers, thus reducing the dyeing M rate. Also, because the filament bundle shakes a lot on the hot roller, it is easy for uneven stretching to occur, resulting in an increase in the coefficient of variation of breaking strength, coefficient of variation of breaking elongation and evenness and evenness. Example 2

[0070] A method for producing bright "cross" polyester drawn yarn, the specific process of which is as follows:

[0071] After the polyester melt is extruded from the spinneret with "cross" shaped spinneret holes, it goes through cooling and forming, first oiling, pre-networking, stretching and setting, second oiling, main networking and winding to produce bright "cross" polyester drawn yarn.

[0072] The first oiling was performed by heating the oil to 53°C using a spinning oil spraying device with a heating function, with an oil concentration of 92.3 wt%.

[0073] The spinning oil spraying device with heating function includes a spinning oil nozzle mounting bracket, oil supply pipe, quick connector, spinning oil nozzle, oil heating module, oil temperature monitoring module, temperature controller, wiring harness and power supply;

[0074] The spinning oil nozzle is connected to the oil supply pipe via a quick connector. The spinning oil nozzle is mounted on the spinning oil nozzle mounting bracket. The spinning oil nozzle is an oil nozzle with a flat orifice, the length and width of which are 2.0 mm and 0.05 mm, respectively.

[0075] The width of the yarn path in the spinning nozzle is 1.2 mm and the length is 8 mm;

[0076] The oil heating module and the oil temperature monitoring module are installed on the oil supply pipe near the spinning oil nozzle. The oil heating module is used to heat the oil to the set temperature, and the oil temperature monitoring module is used to monitor the oil temperature in real time. When the oil temperature reaches the temperature set by the temperature controller, the oil is applied to the filament through the spinning oil nozzle.

[0077] The oil heating module includes a heating resistor, a heat-conducting material, and a heat-insulating material. The heating resistor is wound around the oil pipeline. A stainless steel container is placed around the area of ​​the oil pipeline around which the heating resistor is wound. The stainless steel container is sealed to the oil pipeline. The heat-conducting material is placed in the stainless steel container. The outer surface of the stainless steel container is wrapped with heat-insulating material. The heat-conducting material is hot kerosene, and the heat-insulating material is asbestos.

[0078] The power supply is connected to the oil heating module, the oil temperature monitoring module, and the temperature controller via a wiring harness to provide power.

[0079] The drafting and setting process employs a one-step drafting technique, completed by two grooved hot rollers. The grooves are continuous and spirally distributed on the circumference of the hot rollers. The spiral diameter of the grooves on the circumference of the hot rollers is 250 mm, the spiral angle is 1.3°, and the pitch is 1.6 mm. The number of turns of the grooves on the circumference of the hot rollers is 120, and each bundle of filaments is wound 4.5 times in the grooves on the hot rollers. The cross-section of the grooves is arc-shaped, the groove width is 0.5 mm, and the groove depth is 1.1 mm.

[0080] The concentration of the oil used in the second oiling was 14.9 wt%.

[0081] The process parameters are as follows: cooling temperature is 20.5℃, pre-network air pressure is 0.08MPa, main network air pressure is 0.35MPa, GR1 hot roller temperature is 90℃, GR1 hot roller speed is 1980m / min, GR2 hot roller temperature is 130℃, GR2 hot roller speed is 4480m / min, and winding speed is 4380m / min.

[0082] The final bright "cross" polyester drawn yarn has a breaking strength of 4.28 cN / dtex, a breaking strength coefficient of variation of 3.42%, a breaking elongation of 30.7%, a breaking elongation coefficient of variation of 4.7%, a boiling water shrinkage rate of 6.1%, a yarn evenness rate of 1.28%, a network density of 17 cells / m, an oil content of 1.02%, an oil loss rate of 0.48%, a superior grade rate of 97.3%, and a dyeing M rate of 99%. Example 3

[0083] A method for producing bright "cross" polyester drawn yarn, the specific process of which is as follows:

[0084] After the polyester melt is extruded from the spinneret with "cross" shaped spinneret holes, it goes through cooling and forming, first oiling, pre-networking, stretching and setting, second oiling, main networking and winding to produce bright "cross" polyester drawn yarn.

[0085] The first oiling process involves heating the oil to 54°C using a spinning oil spraying device with a heating function before applying the oil. The concentration of the oil is 92.4 wt%.

[0086] The spinning oil spraying device with heating function includes a spinning oil nozzle mounting bracket, oil supply pipe, quick connector, spinning oil nozzle, oil heating module, oil temperature monitoring module, temperature controller, wiring harness and power supply;

[0087] The spinning oil nozzle is connected to the oil supply pipe via a quick connector. The spinning oil nozzle is mounted on the spinning oil nozzle mounting bracket. The spinning oil nozzle is an oil nozzle with a flat orifice, the length and width of which are 2.0 mm and 0.05 mm, respectively.

[0088] The width of the yarn path in the spinning nozzle is 1.2 mm and the length is 8 mm;

[0089] The oil heating module and the oil temperature monitoring module are installed on the oil supply pipe near the spinning oil nozzle. The oil heating module is used to heat the oil to the set temperature, and the oil temperature monitoring module is used to monitor the oil temperature in real time. When the oil temperature reaches the temperature set by the temperature controller, the oil is applied to the filament through the spinning oil nozzle.

[0090] The oil heating module includes a heating resistor, a heat-conducting material, and a heat-insulating material. The heating resistor is wound around the oil pipeline. A stainless steel container is placed around the area of ​​the oil pipeline around which the heating resistor is wound. The stainless steel container is sealed to the oil pipeline. The heat-conducting material is placed in the stainless steel container. The outer surface of the stainless steel container is wrapped with heat-insulating material. The heat-conducting material is hot kerosene, and the heat-insulating material is asbestos.

[0091] The power supply is connected to the oil heating module, the oil temperature monitoring module, and the temperature controller via a wiring harness to provide power.

[0092] The drafting and setting process employs a one-step drafting process, completed by two grooved hot rollers. The grooves are continuous and spirally distributed on the circumference of the hot rollers. The spiral diameter of the grooves on the circumference of the hot rollers is 230 mm, the spiral angle is 1.5°, and the pitch is 1.7 mm. The number of turns of the grooves on the circumference of the hot rollers is 144, and each bundle of filaments is wound 5.5 times in the grooves on the hot rollers. The cross-section of the grooves is arc-shaped, the groove width is 0.6 mm, and the groove depth is 1.2 mm.

[0093] The concentration of the oil used in the second oiling was 15 wt%.

[0094] The process parameters are as follows: cooling temperature is 21.5℃, pre-network air pressure is 0.09MPa, main network air pressure is 0.38MPa, GR1 hot roller temperature is 89℃, GR1 hot roller speed is 1950m / min, GR2 hot roller temperature is 131℃, GR2 hot roller speed is 4500m / min, and winding speed is 4400m / min.

[0095] The final bright "cross" polyester drawn yarn has a breaking strength of 4.3 cN / dtex, a breaking strength coefficient of variation of 3.52%, a breaking elongation of 30.8%, a breaking elongation coefficient of variation of 4.4%, a boiling water shrinkage rate of 6%, a yarn evenness of 1.45%, a network density of 18 units / m, an oil content of 1.08%, an oil loss rate of 0.39%, a superior grade rate of 97.3%, and a dyeing M rate of 99.3%. Example 4

[0096] A method for producing bright "cross" polyester drawn yarn, the specific process of which is as follows:

[0097] After the polyester melt is extruded from the spinneret with "cross" shaped spinneret holes, it goes through cooling and forming, first oiling, pre-networking, stretching and setting, second oiling, main networking and winding to produce bright "cross" polyester drawn yarn.

[0098] The first oiling was performed by heating the oil to 56°C using a spinning oil spraying device with a heating function, with an oil concentration of 92.6 wt%.

[0099] The spinning oil spraying device with heating function includes a spinning oil nozzle mounting bracket, oil supply pipe, quick connector, spinning oil nozzle, oil heating module, oil temperature monitoring module, temperature controller, wiring harness and power supply;

[0100] The spinning oil nozzle is connected to the oil supply pipe via a quick connector. The spinning oil nozzle is mounted on the spinning oil nozzle mounting bracket. The spinning oil nozzle is an oil nozzle with a flat orifice, the length and width of which are 2.0 mm and 0.05 mm, respectively.

[0101] The width of the yarn path in the spinning nozzle is 1.2 mm and the length is 8 mm;

[0102] The oil heating module and the oil temperature monitoring module are installed on the oil supply pipe near the spinning oil nozzle. The oil heating module is used to heat the oil to the set temperature, and the oil temperature monitoring module is used to monitor the oil temperature in real time. When the oil temperature reaches the temperature set by the temperature controller, the oil is applied to the filament through the spinning oil nozzle.

[0103] The oil heating module includes a heating resistor, a heat-conducting material, and a heat-insulating material. The heating resistor is wound around the oil pipeline. A stainless steel container is placed around the area of ​​the oil pipeline around which the heating resistor is wound. The stainless steel container is sealed to the oil pipeline. The heat-conducting material is placed in the stainless steel container. The outer surface of the stainless steel container is wrapped with heat-insulating material. The heat-conducting material is hot kerosene, and the heat-insulating material is asbestos.

[0104] The power supply is connected to the oil heating module, the oil temperature monitoring module, and the temperature controller via a wiring harness to provide power.

[0105] The drafting and setting process employs a one-step drafting technique, completed by two grooved hot rollers. The grooves are continuous and spirally distributed on the circumference of the hot rollers. The spiral diameter of the grooves on the circumference of the hot rollers is 220 mm, the spiral angle is 1.8°, and the pitch is 1.8 mm. The number of turns of the grooves on the circumference of the hot rollers is 144, and each bundle of filaments is wound 5.5 times in the grooves on the hot rollers. The cross-section of the grooves is arc-shaped, the groove width is 0.7 mm, and the groove depth is 1.3 mm.

[0106] The concentration of the oil used in the second oiling was 15.1 wt%.

[0107] The process parameters are as follows: cooling temperature is 22℃, pre-network air pressure is 0.08MPa, main network air pressure is 0.41MPa, GR1 hot roller temperature is 88℃, GR1 hot roller speed is 1930m / min, GR2 hot roller temperature is 132℃, GR2 hot roller speed is 4530m / min, and winding speed is 4430m / min.

[0108] The final bright "cross" polyester drawn yarn had a breaking strength of 4.32 cN / dtex, a breaking strength coefficient of variation of 3.46%, a breaking elongation of 30.1%, a breaking elongation coefficient of variation of 4.98%, a boiling water shrinkage rate of 5.8%, a yarn evenness rate of 1.33%, a network density of 19 yarns / m, an oil content of 1.04%, an oil loss rate of 0.4%, a superior grade rate of 97.2%, and a dyeing M rate of 99.1%. Example 5

[0109] A method for producing bright "cross" polyester drawn yarn, the specific process of which is as follows:

[0110] After the polyester melt is extruded from the spinneret with "cross" shaped spinneret holes, it goes through cooling and forming, first oiling, pre-networking, stretching and setting, second oiling, main networking and winding to produce bright "cross" polyester drawn yarn.

[0111] The first oiling was performed by heating the oil to 57°C using a spinning oil spraying device with a heating function, with an oil concentration of 92.8 wt%.

[0112] The spinning oil spraying device with heating function includes a spinning oil nozzle mounting bracket, oil supply pipe, quick connector, spinning oil nozzle, oil heating module, oil temperature monitoring module, temperature controller, wiring harness and power supply;

[0113] The spinning oil nozzle is connected to the oil supply pipe via a quick connector. The spinning oil nozzle is mounted on the spinning oil nozzle mounting bracket. The spinning oil nozzle is an oil nozzle with a flat orifice, the length and width of which are 2.0 mm and 0.05 mm, respectively.

[0114] The width of the yarn path in the spinning nozzle is 1.2 mm and the length is 8 mm;

[0115] The oil heating module and the oil temperature monitoring module are installed on the oil supply pipe near the spinning oil nozzle. The oil heating module is used to heat the oil to the set temperature, and the oil temperature monitoring module is used to monitor the oil temperature in real time. When the oil temperature reaches the temperature set by the temperature controller, the oil is applied to the filament through the spinning oil nozzle.

[0116] The oil heating module includes a heating resistor, a heat-conducting material, and a heat-insulating material. The heating resistor is wound around the oil pipeline. A stainless steel container is placed around the area of ​​the oil pipeline around which the heating resistor is wound. The stainless steel container is sealed to the oil pipeline. The heat-conducting material is placed in the stainless steel container. The outer surface of the stainless steel container is wrapped with heat-insulating material. The heat-conducting material is hot kerosene, and the heat-insulating material is asbestos.

[0117] The power supply is connected to the oil heating module, the oil temperature monitoring module, and the temperature controller via a wiring harness to provide power.

[0118] The drafting and setting process employs a one-step drafting process, completed by two grooved hot rollers. The grooves are continuous and spirally distributed on the circumference of the hot rollers. The spiral diameter of the grooves on the circumference of the hot rollers is 220 mm, the spiral angle is 2°, and the pitch is 2 mm. The number of turns of the grooves on the circumference of the hot rollers is 168, and each bundle of filaments is wound 6.5 times in the grooves on the hot rollers. The cross-section of the grooves is arc-shaped, the groove width is 0.8 mm, and the groove depth is 1.2 mm.

[0119] The concentration of the oil used in the second oiling was 15.3 wt%.

[0120] The process parameters are as follows: cooling temperature is 23℃, pre-network air pressure is 0.09MPa, main network air pressure is 0.44MPa, GR1 hot roller temperature is 87℃, GR1 hot roller speed is 1900m / min, GR2 hot roller temperature is 133℃, GR2 hot roller speed is 4550m / min, and winding speed is 4450m / min.

[0121] The final bright "cross" polyester drawn yarn has a breaking strength of 4.39 cN / dtex, a breaking strength coefficient of variation of 3.51%, a breaking elongation of 29.9%, a breaking elongation coefficient of variation of 3.95%, a boiling water shrinkage rate of 5.5%, a yarn evenness rate of 1.47%, a network density of 20 yarns / m, an oil content of 1.03%, an oil loss rate of 0.43%, a superior grade rate of 97.5%, and a dyeing M rate of 98.9%.

Claims

1. A method for producing bright "cross" polyester drawn yarn, characterized in that: After the polyester melt is extruded from the spinneret with "cross" shaped spinneret holes, it goes through cooling and forming, first oiling, pre-networking, stretching and setting, second oiling, main networking and winding to produce bright "cross" polyester drawn yarn. The hot roller used for stretching and setting is a hot roller with grooves. The grooves are continuous and spirally distributed on the circumference of the hot roller.

2. The method for producing a bright "cross" polyester drawn yarn according to claim 1, characterized in that, The number of grooves on the circumference of the hot roller is 120 to 168, the cross-section of the groove is arc-shaped, the groove width is 0.5 to 0.8 mm, and the groove depth is 1 to 1.3 mm.

3. The method for producing a bright "cross" polyester drawn yarn according to claim 1, characterized in that, The spiral diameter of the groove on the circumferential surface of the hot roller is 220~250mm, the spiral angle is 1°~2°, and the pitch is 1.5~2mm.

4. The method for producing a bright "cross" polyester drawn yarn according to claim 1, characterized in that, The drawing and setting process is carried out in one step by two hot rollers.

5. The method for producing a bright "cross" polyester drawn yarn according to claim 1, characterized in that, The first oiling was performed after heating the oil to 55±2℃, with an oil concentration of 92.5±0.3wt%.

6. The method for producing a bright "cross" polyester drawn yarn according to claim 5, characterized in that, The first oiling is carried out using a spinning oil spraying device with a heating function; The spinning oil spraying device with heating function includes a spinning oil nozzle mounting bracket, oil supply pipe, quick connector, spinning oil nozzle, oil heating module, oil temperature monitoring module, temperature controller, wiring harness and power supply; The spinning oil nozzle is connected to the oil supply pipe via a quick connector. The spinning oil nozzle is mounted on the spinning oil nozzle mounting bracket. The spinning oil nozzle is an oil nozzle with a flat orifice, the length and width of which are 2.0 mm and 0.05 mm, respectively. The width of the yarn path in the spinning nozzle is 1.2 mm and the length is 8 mm; The oil heating module and the oil temperature monitoring module are installed on the oil supply pipe near the spinning oil nozzle. The oil heating module is used to heat the oil to the set temperature, and the oil temperature monitoring module is used to monitor the oil temperature in real time. When the oil temperature reaches the temperature set by the temperature controller, the oil is applied to the filament through the spinning oil nozzle. The oil heating module includes a heating resistor, a heat-conducting material, and a heat-insulating material. The heating resistor is wound around the oil pipeline. A stainless steel container is placed around the area of ​​the oil pipeline around which the heating resistor is wound. The stainless steel container is sealed to the oil pipeline. The heat-conducting material is placed in the stainless steel container. The outer surface of the stainless steel container is wrapped with heat-insulating material. The heat-conducting material is hot kerosene, and the heat-insulating material is asbestos. The power supply is connected to the oil heating module, the oil temperature monitoring module, and the temperature controller via a wiring harness to provide power.

7. The method for producing a bright "cross" polyester drawn yarn according to claim 1, characterized in that, The concentration of the oil used in the second oiling was 15.0 ± 0.3 wt%.

8. The method for producing a bright "cross" polyester drawn yarn according to claim 1, characterized in that, The dyeing rate of bright "cross" polyester drawn yarn is ≥98.5%.

9. The method for producing a bright "cross" polyester drawn yarn according to claim 1, characterized in that, The bright "cross" polyester drawn yarn has a breaking strength ≥3.8cN / dtex, a breaking elongation of 30.0±3%, a breaking strength coefficient of variation ≤4.00%, a breaking elongation coefficient of variation ≤5.00%, a boiling water shrinkage rate of 6.0±0.5%, a yarn unevenness rate ≤1.5%, a network density of 18±2 pieces / m, an oil content of 1.05±0.05%, an oil loss rate ≤0.5%, and a superior grade rate of over 97%.

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