Pre-oriented yarn with large filament number and production equipment and method thereof

Abstract

The invention relates to a pre-oriented yarn with large filament number and production equipment and method thereof, the production equipment comprises a melt conveying system, a spinning box body, a sand cup, a spinneret plate, an annular blowing device, an oiling device and a winding device which are arranged in sequence, the height of an air duct of the annular blowing device is 39-41 cm, and the air outlet amount of the upper half part of the air duct is 65-70% of the air outlet amount of the lower half part of the air duct; a vertical circular truncated cone structure is fixedly arranged in the sand cup; three drainage devices are arranged on the circumferential surface of the upper part of the circular truncated cone; the parameters of the preparation process are as follows: the length of a windless area is 45-60mm, and the temperature of cooling air is 20-22 DEG C; the breaking strength of the product is greater than or equal to 2.30 cN / dtex, the variable coefficient CV / % of the elongation at break is less than or equal to 3.00, and the yarn unevenness CV / % is less than or equal to 1.00. According to the production equipment, the cooling device, the assembly sand cup and the oiling device are innovatively modified, and the structure is simple; the preparation method is simple; and the uniformity of the prepared pre-oriented yarn product with large filament number is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of pre-oriented yarn production, and relates to a pre-oriented yarn with large single yarn fineness and a production device and method thereof. Background Art

[0002] In the production process of melt-spun POY pre-oriented yarn, the choice of cooling method has an important influence on the product characteristics. There are two cooling methods: one is side-blowing cooling, which is mainly suitable for products with larger single-filament fineness. This is because products with larger single-filament fineness require lower cooling speed and longer cooling distance, and the side-blowing has less loss when passing through the single filament close to the air outlet, and can still have a good cooling effect on the single filament far away from the end; the other is ring-blowing cooling, which is mainly suitable for products with small single-filament fineness. Ring-blowing ensures that the cooling air blown out to the surroundings has uniform wind speed at all points in the circumferential direction, and the cooling air volume required for fine-denier products is small. Ring-blowing cooling benefits from the design of cooling air blowing inward from all directions, which greatly reduces the loss of cooling air.

[0003] Generally speaking, coarse denier products with specifications of 378~545dtex / 96f are suitable for production on side-blown air conditioners. However, due to the high uniformity requirements of customers, the defect of single-sided cooling of side-blown air conditioners restricts the improvement of product uniformity, resulting in large CV of physical indicators such as elongation, strength, thermal stress and evenness, which cannot meet customer requirements.

[0004] In order to solve the above problems, Reference 1 (Research and Development of 680dtex / 192f Bright Trilobal Polyester Filament [J]. Polyester Industry, 2011, 24(2): 20-23.) describes the cooling conditions of 680dtex / 192f bright trilobal polyester filament (single yarn density 3.54dpf) using side blowing, and increases the laminar flow effect of cooling air by adding rectification technology in the horizontal direction, thereby reducing the uniformity of physical indicators. However, Reference 2 (Equipment Transformation and Process Adjustment of Coarse Denier Polyester POY Side Blowing Spinning Production Line [J]. Synthetic Fibers, 2011, (4): 38-40.) mentions that although some auxiliary equipment such as laminar flow plates and air ducts are added to the side blowing yarn chamber, the problem of mutual interference between cooling air of different spindles has not been solved because the side blowing yarns share the same yarn chamber, so there will still be differences in physical indicators. At the same time, after changing the side blowing to the ring blowing, Document 2 mainly produces 134 dtex / 144 f porous fine denier polyester pre-oriented yarn, and cannot produce 378~545dtex / 96f coarse denier products.

[0005] Therefore, it is of great significance to study a pre-oriented yarn with large single yarn fineness and a production device and method thereof to solve the problems existing in the prior art. Summary of the invention

[0006] The purpose of the present invention is to solve the problems existing in the prior art and to provide a pre-oriented yarn with large single yarn fineness and a production device and method thereof.

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

[0008] A production equipment for pre-oriented yarns with large single-filament fineness, comprising a melt conveying system, a spinning box, a sand cup, a spinneret, a cooling device, an oiling device and a winding device arranged in sequence, wherein the cooling device is a ring-blowing device, the height of the wind tube of the ring-blowing device is 39~41cm, and the air output of the upper part of the wind tube is 65~70% of the air output of the lower part; since the ring-blowing wind tube is close to the filament bundle and the cooling wind speed is low, the fiber cooling can be achieved quickly, so the length of the general ring-blowing wind tube is relatively short. In the present invention, the wind tube is extended from the general length of 19~27cm to 39~41cm, mainly to extend the cooling distance and make its effect closer to side blowing. After the distance is extended, since the cooling rate of the ring-blowing is faster, the cooling is basically completed in the front half of the wind tube, so there is no practical significance in simply extending the length of the wind tube. Therefore, the wind pressure of the front half of the wind tube is reduced by 30~35%, that is, the air output is reduced by 30~35%, so as to prevent the cooling from being completed too early, so as to achieve the purpose of extending the cooling distance;

[0009] The spinneret diameter is 104~105mm;

[0010] The sand cup comprises a sand cup body, a vertical truncated cone structure is fixedly arranged in the sand cup body, three drainage devices are arranged on the circumference of the upper part of the truncated cone, the drainage devices are inclined arc plates, and the inner arc surface of the arc plate is in contact with the circumference of the truncated cone, and the projections of the inner arc surfaces of the three arc plates on the horizontal plane enclose a complete circle;

[0011] Considering the mutual influence between the sand cup and the spinneret in the component accessories during the production process, the sand cup structure is changed to make it more consistent with the characteristics of the spinneret. However, since the fiber variety of the present invention is a coarse denier product with a large single-filament fineness, the melt flow rate is large, which will cause uneven pressure in each area when the melt flows in the sand cup. Placing a truncated cone in the center position can match the distribution characteristics of the spinneret holes of the spinneret, but it does not effectively solve the problem of uneven pressure in each area. Therefore, through innovative design, three drainage devices are set on the upper part of the truncated cone, and the inner edge of the drainage device fits the truncated cone and has a certain inclination angle with the horizontal plane. When the melt enters the sand cup at a vertical angle, it will be changed in direction by the drainage device, so that the melts in different vertical areas will mix with each other, making the melt pressure in the sand cup more uniform.

[0012] As the preferred technical solution:

[0013] As described above, in the pre-oriented yarn production equipment with large single yarn fineness, the inner diameter of the wind cylinder of the annular blowing device is 104-105mm, and the wind pressure in the upper part of the wind cylinder is 50-60Pa.

[0014] As described above, a pre-oriented yarn production device with a large single yarn fineness, the sand cup body is a cylindrical structure with an outer diameter of 104-105 mm, an inner diameter of 92-93 mm, and a height of 69-70 mm, and a plurality of through holes are opened at the bottom of the cylinder, all of which are arranged in a circle of 5-6 circles, the diameter of the through holes is 2.0-2.5 mm, and the distance between two adjacent through holes is 9-11 mm;

[0015] Two layers of filter screens are arranged between the round table and the bottom of the sand cup body.

[0016] As described above, in the pre-oriented yarn production equipment with large single yarn fineness, the upper end diameter of the truncated cone is 8-10 mm, the lower end diameter is 38-40 mm, and the height is 40-42 mm.

[0017] As described above, in a pre-oriented yarn production equipment with large single yarn fineness, the highest point of the inner arc surface of the arc plate is 8~10mm away from the upper end of the truncated cone, and the lowest point is 20~22mm away from the lower end of the truncated cone; the arc length of the inner arc surface of the arc plate is 17~19mm, and the angle between the plane of the arc plate and the horizontal plane is 28°~30°.

[0018] As described above, a pre-oriented yarn production equipment with large single-filament fineness, the truncated cone is a hollow truncated cone that is closed at the top and bottom, and the truncated cone is made of ceramic material with a smooth surface. The present invention designs the truncated cone structure that blocks the melt to be made of ceramic material, which is small at the top and large at the bottom and has a cavity inside. The main purposes are: first, the surface of the ceramic material is smooth, the friction between the melt and it is small, and the flow rate is less affected by it; second, when the melt passes through the ceramic cylinder that is small at the top and large at the bottom, as the cross-sectional area gradually decreases, the flow rate can be gradually increased to appropriately alleviate the uneven pressure distribution in the sand cup and improve production stability; third, the characteristics of the cavity in the ceramic cylinder can reduce heat conduction and reduce heat loss of the melt. All of the above can prevent the quality of the melt from declining and improve product uniformity.

[0019] As described above, a pre-oriented yarn production equipment with large single-filament fineness is provided, wherein the oiling device comprises an oil guide pipe, an atomizing nozzle, an oil receiving device and a roller, the atomizing nozzle is connected to the oil guide pipe through a bracket I, the oil receiving device is an inverted trapezoidal structure, the oil receiving device is tiltedly placed above the roller, and the angle with the horizontal plane is 40°~50°, the bottom of the oil receiving device is 4~6mm away from the upper part of the roller, the roller is fixed by a bracket II, and the surface of the roller is in contact with the yarn bundle; a certain oiling rate is given by an oil pump, and the atomizing nozzle is connected to the oil guide pipe to oil the yarn bundle, and the excess oil is collected by the oil receiving device, and then guided to the roller by gravity to oil the yarn bundle again.

[0020] As described above, in the pre-oriented yarn production equipment with large single yarn fineness, the roller is a horizontally placed cylinder, and the roller surface is made of ceramic material.

[0021] The present invention also provides a method for preparing pre-oriented yarns with large single yarn fineness using the production equipment as described in any of the above items, and the main process parameters are: melt temperature 279~285°C, spinning box temperature 285~289°C, windless zone length 45~60mm, cooling air temperature 20~22°C, cooling air relative humidity 70~80%, oil agent concentration 9.8~10.3wt%, and winding speed 2800~3215m / min.

[0022] The present invention also provides a pre-oriented yarn with large single yarn fineness obtained by the method as described above, the specification of the pre-oriented yarn with large single yarn fineness is 378~545dtex / 96f, the breaking strength is ≥2.30cN / dtex, the breaking elongation is 128.0±3.0%, the breaking elongation variation coefficient CV / %≤3.00, the yarn unevenness CV / %≤1.00, the deviation of thermal stress and the center value is within 3%, and the center value is 80~185cN.

[0023] Principle of the invention:

[0024] In order to solve the problem in the prior art that products with large monofilament fineness are cooled by side-blowing during production, resulting in poor product uniformity, the present invention firstly combines the respective advantages of annular side-blowing through innovation, adopts annular blowing for cooling, and adopts a low wind speed and long-distance cooling method. Secondly, since the larger the diameter of the spinneret, the greater the distance between the monofilaments, the better the cooling effect of the cooling air will be, so choosing a large spinneret will help improve cooling, but this also leads to an increase in the size of the component, which in turn slows down the flow rate of the melt when passing through the large component, which is not conducive to improving product quality. Therefore, the present invention has carried out technical innovation on the component sand cup to solve this problem. Finally, the oiling design is innovated to improve the uniformity of oiling. Through these innovations, indicators such as product uniformity are improved to meet customer requirements.

[0025] In terms of cooling device. The present invention designs the cooling duct to be 39-41 mm long, and reasonably extends the cooling distance with reference to the cooling characteristics of side-blowing air, so that the cooling distance is adapted to the characteristics of large single-filament fineness of the product. At the same time, the density of the duct wire mesh duct in the upper part of the duct is increased to reduce air permeability, reaching 0.65-0.7 times the air volume of the lower part of the duct. In this way, when the filament bundle is cooled by the duct, the longer duct increases the cooling distance of the filament bundle. At the same time, because the cooling wind at the upper end of the duct is smaller, the cooling speed is slowed down, which improves the shortcomings of the original duct, such as short cooling distance and too fast cooling speed, improves cooling uniformity, and improves product uniformity.

[0026] Modification of component sand cups. The present invention fixes a truncated cone structure in the sand cup body. In this way, because of the obstruction of the central truncated cone, assuming that the sand cup is regarded as a pipe, the cross-sectional area of ​​the pipe that the melt can pass through is reduced, the melt flow rate will increase, and the residence time in the sand cup will be shortened, thereby preventing the quality of the melt from being reduced. At the same time, three drainage devices are arranged on the upper part of the truncated cone, and the inner edge of the drainage device fits the truncated cone and forms a certain inclination angle with the horizontal plane. When the melt enters the sand cup at a vertical angle, the direction will be changed by the drainage device, so that the melts in different vertical areas will mix with each other, making the melt pressure in the sand cup more uniform.

[0027] Regarding the oiling device. The oil enters the atomizing nozzle through the oil guide pipe, is atomized by the nozzle and sprayed toward the direction of the tow, and the tow is oiled in the first step. At this time, some of the oil that is not absorbed by the tow or the oil that is not atomized properly will fall to the lower position on the other side of the tow. At this time, the oil receiving device with an inverted trapezoidal structure will collect these oils and guide them to the roller with a ceramic surface. The roller has a certain speed, and the tow is close to the roller surface. At this time, the oil on the roller surface will be further absorbed by the tow, thus completing the second oiling. After two oilings, the uniformity of the oiling of the tow can be improved, and the uniformity of the product can be further improved.

[0028] Beneficial effects:

[0029] (1) The present invention provides a pre-oriented yarn production device with large single-filament fineness, in which the length of the wind tube is extended from the general length of 19-27 cm to 39-41 cm. At the same time, the component sand cup is modified, that is, three drainage devices are arranged on the upper part of the circular table, so that the melt pressure in the sand cup is more uniform, and the oil receiving device design with an inverted trapezoidal structure is simple in structure and improves the uniformity of oiling.

[0030] (2) The method of preparing pre-oriented yarn with large single yarn fineness of the present invention improves the shortcomings of the original air duct, such as short cooling distance and too fast cooling speed; at the same time, the melt pressure in the sand cup is more uniform and the oiling of the yarn bundle is more uniform, thereby improving the uniformity of the product.

[0031] (3) The present invention produces a pre-oriented yarn with large single-filament fineness, and the uniformity index of the product is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the structural diagram of the spinneret;

[0033] Figure 2 Schematic diagram of the sand cup and spinneret structure, where the dotted arrow represents the direction of melt entry;

[0034] Figure 3 It is a schematic diagram of the sand cup and the truncated table structure;

[0035] Figures 4 and 5 Schematic diagram of the structure of the truncated table and the drainage device at different angles; the dotted arrow represents the direction of melt entry;

[0036] Figure 6 is a front view of the cooling device, and the area between the two dotted lines in the figure represents the range of cooling of the tow;

[0037] Figure 7 It is the rear view of the oiling device;

[0038] Figure 8 It is the left side view of the oiling device;

[0039] Among them, 1-spinneret hole distribution area, 2-central area without spinneret holes, 3-spinneret plate, 4-sand cup, 5-drainage device, 6-truncated table, 7-air cylinder, 8-upper part of air cylinder, 9-oil guide pipe, 10-atomizing nozzle, 11-oil receiving device, 12-roller, 13-filament bundle area. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it 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 within the scope limited by the appended claims of the application equally.

[0041] The test methods involved in the performance indicators in the embodiments and comparative examples of the present invention are as follows:

[0042] Breaking strength, breaking elongation, breaking elongation variation coefficient: According to the "Test method for tensile properties of chemical fiber filaments" (GB / T 14344-2022) standard, the YG023B-Ⅱ fully automatic single yarn strength tester was used to test the breaking elongation of the yarn bundle. The specific process was as follows: first, the yarn bundle was placed in an environment with a temperature of 20±2℃ and a humidity of 65±5% for 4 hours; then, the fully automatic single yarn strength tester was used for tensile test. Before the test, the clamping length of the yarn bundle was accurately set to 500±1.0mm by the upper and lower clamps, and a pre-tension (0.05±0.005cN / dtex) was applied by the manipulator to stabilize the yarn bundle; during the test, the lower clamp stretched the yarn bundle at a set speed (500mm / min) at a uniform speed until the yarn bundle broke; during the stretching process, the force sensor recorded the data in real time, and the relationship curve between strength and elongation was drawn through the data collection system; finally, the breaking strength, breaking elongation and breaking elongation coefficient of the yarn bundle were obtained through data processing and analysis.

[0043] Yarn unevenness: According to the Test Method for Yarn Unevenness of Chemical Fiber Filament - Capacitance Method (GB / T 14346-2015), the test is carried out using USTER5 Yarn Uniformity Tester. The specific process is: first, place the yarn bundle at a temperature of 20±2℃ and a humidity of 65±5% for 2 hours, then pass the yarn bundle through the two electrodes of the capacitor at a uniform speed, and convert the mass in each equal interval into an electrical signal. The percentage of the standard deviation of all test electrical signals to the average value is the yarn unevenness; among them, the test speed is 200m / min, and the yarn bundle test time is 2.5min.

[0044] Thermal stress: According to the standard "Test Method for Dynamic Thermal Stress of Polyester Pre-oriented Yarn" (FZ / T 50051-2020), the test is carried out using a YG 367 thermal stress tester. The specific process is: first, the yarn bundle is placed in an environment with a temperature of 20±2℃ and a humidity of 65±5% for 4 hours, and then the yarn bundle is passed through a heating device and a drawing device at a specific speed and pre-tension (the specific speed and pre-tension parameter settings are in accordance with Sections 8.1 and 8.3 of the standard) to test the tensile stress (i.e. thermal stress) generated by the yarn bundle being drawn under heating conditions.

[0045] Example 1

[0046] A production device for pre-oriented yarns with large single yarn fineness, comprising a melt conveying system, a spinning box, a sand cup 4, a spinneret 3, a cooling device, an oiling device and a winding device which are arranged in sequence;

[0047] like Figure 6 As shown, the cooling device is a ring blowing device, the height of the wind tube 7 of the ring blowing device is 39 cm, the inner diameter of the wind tube is 104 mm, and the wind pressure of the upper part 8 of the wind tube is 50 Pa; the air volume of the upper part 8 of the wind tube is 65% of the air volume of the lower part;

[0048] like Figure 1~2 As shown, the diameter of the spinneret 3 is 104 mm; the spinneret 3 includes a spinneret hole distribution area 1 and a central spinneret hole-free area 2, and the diameter of the central spinneret hole-free area 2 is 35 mm;

[0049] The sand cup 4 includes a sand cup body, which is a cylindrical structure with an outer diameter of 104 mm, an inner diameter of 92 mm, and a height of 69 mm. A plurality of through holes are opened at the bottom of the cylinder, and all the through holes are arranged in 5 circles. The diameter of the through holes is 2 mm, and the distance between two adjacent through holes is 9 mm.

[0050] like Figure 3 As shown, a vertical truncated cone structure is fixedly arranged in the sand cup body. The truncated cone 6 is a hollow truncated cone which is closed at the top and bottom. The truncated cone 6 is made of ceramic and has a smooth surface. The upper end diameter of the truncated cone 6 is 8 mm, the lower end diameter is 38 mm, and the height is 40 mm. Two layers of filter screens are arranged between the truncated cone and the bottom of the sand cup body.

[0051] like Figures 4 and 5 As shown, three drainage devices 5 are arranged on the circumference of the upper part of the truncated cone 6. The drainage devices 5 are inclined arc plates, and the inner arc surface of the arc plate fits the circumference of the truncated cone 6. The projections of the inner arc surfaces of the three arc plates on the horizontal plane enclose a complete circle; the highest point of the inner arc surface of the arc plate is 8 mm away from the upper end of the truncated cone 6, and the lowest point is 22 mm away from the lower end of the truncated cone 6; the arc length of the inner arc surface of the arc plate is 17 mm, and the angle between the plane of the arc plate and the horizontal plane is 28°;

[0052] like Figure 7-8 As shown, the oiling device includes an oil guide pipe 9, an atomizing nozzle 10, an oil receiving device 11 and a roller 12. The roller 12 is a horizontally placed cylinder, and the surface of the roller is made of ceramic material. The atomizing nozzle 10 is connected to the oil guide pipe 9 through a bracket I. The oil receiving device 11 is an inverted trapezoidal structure. The oil receiving device 11 is tilted and placed above the roller 12, and the angle with the horizontal plane is 40°. The roller 12 is fixed by a bracket II, and the surface of the roller 12 is in contact with the wire bundle.

[0053] Example 2

[0054] A production device for pre-oriented yarns with large single yarn fineness, comprising a melt conveying system, a spinning box, a sand cup, a spinneret, a cooling device, an oiling device and a winding device which are arranged in sequence;

[0055] The cooling device is a ring-blowing device, the height of the wind tube of the ring-blowing device is 40cm, the inner diameter of the wind tube is 104mm, and the wind pressure in the upper part of the wind tube is 55Pa; the air volume in the upper part of the wind tube is 68% of the air volume in the lower part;

[0056] The spinneret has a diameter of 104 mm; the spinneret includes a spinneret hole distribution area and a central spinneret hole-free area, and the central spinneret hole-free area has a diameter of 38 mm;

[0057] The sand cup includes a sand cup body, which is a cylindrical structure with an outer diameter of 104 mm, an inner diameter of 92.5 mm, and a height of 69.5 mm. A plurality of through holes are opened at the bottom of the cylinder, and all the through holes are arranged in 5 circles. The diameter of the through holes is 2.25 mm, and the distance between two adjacent through holes is 10 mm.

[0058] A vertical truncated cone structure is fixedly set inside the sand cup body. The truncated cone is a hollow truncated cone that is closed up and down. The truncated cone is made of ceramic and has a smooth surface. The upper diameter of the truncated cone is 9mm, the lower diameter is 39mm, and the height is 41mm. Two layers of filter screens are set between the truncated cone and the bottom of the sand cup body.

[0059] Three drainage devices are arranged on the circumference of the upper part of the truncated table. The drainage devices are inclined arc plates, and the inner arc surface of the arc plate fits the circumference of the truncated table. The projections of the inner arc surfaces of the three arc plates on the horizontal plane form a complete circle. The highest point of the inner arc surface of the arc plate is 9mm from the upper end of the truncated table, and the lowest point is 21mm from the lower end of the truncated table. The arc length of the inner arc surface of the arc plate is 18mm, and the angle between the plane of the arc plate and the horizontal plane is 29°.

[0060] The oiling device includes an oil guide pipe, an atomizing nozzle, an oil receiving device and a roller. The atomizing nozzle is connected to the oil guide pipe through bracket I. The oil receiving device is an inverted trapezoidal structure. The oil receiving device is placed obliquely on the upper part of the roller, and the angle with the horizontal plane is 46°. The roller is fixed by bracket II, and the surface of the roller is in contact with the wire bundle.

[0061] Example 3

[0062] A production device for pre-oriented yarns with large single yarn fineness, comprising a melt conveying system, a spinning box, a sand cup, a spinneret, a cooling device, an oiling device and a winding device which are arranged in sequence;

[0063] The cooling device is a ring-blowing device, the height of the wind tube of the ring-blowing device is 41cm, the inner diameter of the wind tube is 105mm, and the wind pressure in the upper part of the wind tube is 60Pa; the air volume in the upper part of the wind tube is 70% of the air volume in the lower part;

[0064] The spinneret has a diameter of 105 mm; the spinneret includes a spinneret hole distribution area and a central spinneret hole-free area, and the central spinneret hole-free area has a diameter of 40 mm;

[0065] The sand cup includes a sand cup body, which is a cylindrical structure with an outer diameter of 105 mm, an inner diameter of 93 mm, and a height of 70 mm. A plurality of through holes are opened at the bottom of the cylinder, and all the through holes are arranged in 6 circles. The diameter of the through holes is 2.5 mm, and the distance between two adjacent through holes is 11 mm.

[0066] A vertical truncated cone structure is fixedly arranged inside the sand cup body. The truncated cone is a hollow truncated cone that is closed from top to bottom. The truncated cone is made of ceramic and has a smooth surface. The diameter of the upper end of the truncated cone is 10mm, the diameter of the lower end is 40mm, and the height is 42mm. Two layers of filter screens are arranged between the truncated cone and the bottom of the sand cup body.

[0067] Three drainage devices are arranged on the circumference of the upper part of the truncated table. The drainage devices are inclined arc plates, and the inner arc surface of the arc plate is in contact with the circumference of the truncated table. The projections of the inner arc surfaces of the three arc plates on the horizontal plane form a complete circle. The highest point of the inner arc surface of the arc plate is 10 mm from the upper end of the truncated table, and the lowest point is 20 mm from the lower end of the truncated table. The arc length of the inner arc surface of the arc plate is 19 mm, and the angle between the plane of the arc plate and the horizontal plane is 30°.

[0068] The oiling device includes an oil guide pipe, an atomizing nozzle, an oil receiving device and a roller. The atomizing nozzle is connected to the oil guide pipe through a bracket I. The oil receiving device is an inverted trapezoidal structure. The oil receiving device is tilted above the roller and the angle with the horizontal plane is 50°. The roller is fixed by bracket II, and the surface of the roller is in contact with the wire bundle.

[0069] Example 4

[0070] A method for preparing pre-oriented yarn with large single yarn fineness, the specific process is as follows

[0071] The production equipment of Example 1 is used to prepare pre-oriented yarns with large single yarn fineness;

[0072] The process parameters are: melt temperature 279°C, spinning box temperature 285°C, windless zone length 45mm, cooling air temperature 20°C, cooling air relative humidity 80%, oil concentration 9.8wt%, winding speed 2800m / min.

[0073] The final pre-oriented yarn with large single yarn fineness has a specification of 378dtex / 96f (three-leaf), a breaking strength of 2.42cN / dtex, an elongation at break of 127.5%, a coefficient of variation of elongation at break CV / % of 1.78, a yarn unevenness CV / % of 0.89, a deviation of thermal stress from the center value of 2.14%, and a center value of 80cN.

[0074] Example 5

[0075] A method for preparing pre-oriented yarn with large single yarn fineness, the specific process is as follows

[0076] The production equipment of Example 2 is used to prepare pre-oriented yarns with large single yarn fineness;

[0077] The process parameters are: melt temperature 282°C, spinning box temperature 287°C, windless zone length 52mm, cooling air temperature 21°C, cooling air relative humidity 75%, oil concentration 10wt%, winding speed 3000m / min.

[0078] The final pre-oriented yarn with large single yarn fineness has a specification of 430dtex / 96f (round hole), a breaking strength of 2.64cN / dtex, an elongation at break of 128.9%, a coefficient of variation of elongation at break CV / % of 1.41, a yarn unevenness CV / % of 0.84, a deviation of thermal stress from the center value of 2.34%, and a center value of 125cN.

[0079] Example 6

[0080] A method for preparing pre-oriented yarn with large single yarn fineness, the specific process is as follows

[0081] The production equipment of Example 3 is used to prepare pre-oriented yarns with large single yarn fineness;

[0082] The process parameters are: melt temperature 285°C, spinning box temperature 289°C, windless zone length 60mm, cooling air temperature 22°C, cooling air relative humidity 70%, oil concentration 10.3wt%, winding speed 3215m / min.

[0083] The final pre-oriented yarn with large single yarn fineness has a specification of 545dtex / 96f (round hole), a breaking strength of 2.49cN / dtex, an elongation at break of 128.4%, a coefficient of variation of elongation at break CV / % of 2.02, a yarn unevenness CV / % of 0.91, a deviation of thermal stress from the center value of 1.97%, and a center value of 185cN.

Claims

1. A pre-oriented yarn production equipment with large single-filament fineness, comprising a melt conveying system, a spinning box, a sand cup, a spinneret, a cooling device, an oiling device and a winding device arranged in sequence, characterized in that: The cooling device is a ring-blowing device, the height of the wind tube of the ring-blowing device is 39~41cm, and the air volume of the upper part of the wind tube is 65~70% of the air volume of the lower part; The spinneret diameter is 104~105mm; The sand cup includes a sand cup body, in which a vertical frustum structure is fixedly arranged, and three drainage devices are arranged on the circumference of the upper part of the frustum. The drainage device is an inclined arc plate, and the inner arc surface of the arc plate is in contact with the circumference of the frustum. The projections of the inner arc surfaces of the three arc plates on the horizontal plane enclose a complete circle.

2. The production equipment of pre-oriented yarn with large single yarn fineness according to claim 1, characterized in that: The inner diameter of the wind tube of the ring blowing device is 104~105mm, and the wind pressure in the upper part of the wind tube is 50~60Pa.

3. The production equipment of pre-oriented yarn with large single yarn fineness according to claim 1, characterized in that: The sand cup body is a cylindrical structure with an outer diameter of 104~105mm, an inner diameter of 92~93mm, and a height of 69~70mm. There are multiple through holes at the bottom of the cylinder. All through holes are arranged in 5~6 circles. The diameter of the through holes is 2.0~2.5mm, and the distance between two adjacent through holes is 9~11mm. Two layers of filter screens are arranged between the round table and the bottom of the sand cup body.

4. The production equipment of pre-oriented yarn with large single yarn fineness according to claim 3, characterized in that: The upper end diameter of the cone is 8~10mm, the lower end diameter is 38~40mm, and the height is 40~42mm.

5. The production equipment of pre-oriented yarn with large single yarn fineness according to claim 4, characterized in that: The highest point of the inner arc surface of the arc plate is 8~10mm away from the upper end of the truncated cone, and the lowest point is 20~22mm away from the lower end of the truncated cone; the arc length of the inner arc surface of the arc plate is 17~19mm, and the angle between the plane of the arc plate and the horizontal plane is 28°~30°.

6. The production equipment of pre-oriented yarn with large single yarn fineness according to claim 4, characterized in that: The truncated cone is a hollow truncated cone which is closed at the top and the bottom. The truncated cone is made of ceramic and has a smooth surface.

7. The production equipment of pre-oriented yarn with large single yarn fineness according to claim 1, characterized in that: The oiling device includes an oil guide pipe, an atomizing nozzle, an oil receiving device and a roller. The atomizing nozzle is connected to the oil guide pipe through a bracket I. The oil receiving device is an inverted trapezoidal structure. The oil receiving device is tilted above the roller and the angle with the horizontal plane is 40°~50°. The roller is fixed by bracket II, and the surface of the roller is in contact with the wire bundle.

8. The production equipment of pre-oriented yarn with large single yarn fineness according to claim 7, characterized in that: The roller is a horizontally placed cylinder, and the surface of the roller is made of ceramic material.

9. A method for preparing pre-oriented yarn with large single yarn fineness using the production equipment according to any one of claims 1 to 8, characterized in that The main process parameters are: melt temperature 279~285℃, spinning box temperature 285~289℃, windless zone length 45~60mm, cooling air temperature 20~22℃, cooling air relative humidity 70~80%, oil concentration 9.8~10.3wt%, winding speed 2800~3215m / min.

10. A pre-oriented yarn with large single-filament fineness obtained by the method according to claim 9, characterized in that: The specifications of pre-oriented yarns with large single yarn fineness are 378~545dtex / 96f, breaking strength ≥2.30cN / dtex, elongation at break is 128.0±3.0%, coefficient of variation of elongation at break CV / %≤3.00, yarn unevenness CV / %≤1.00, the deviation of thermal stress from the center value is within 3%, and the center value is 80~185cN.

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