Production method of polyester FDY (fully drawn yarn)

Abstract

The invention belongs to the technical field of polyester production, and relates to a production method of polyester FDYs (fully drawn yarns), which comprises the following steps of: interlacing tows between a second hot box and a winding roller by using an interlacing device in a spinning process, and applying friction force to the tows between the second hot box and the interlacing device by using a tensioning yarn guide rod so as to counteract part of tension borne by the tows; and thus, the network pressure during network addition is reduced. On the premise that the product quality is guaranteed, the network air pressure and the air consumption in the production process of the polyester FDY are reduced during network adding.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester production and relates to a production method of polyester FDY yarn. Background Art

[0002] Polyester is the trade name of polyester fiber in my country and is an important variety of synthetic fiber. It is mainly made of terephthalic acid (PTA) or dimethyl terephthalate (DMT) and ethylene glycol (EG) as raw materials. Through esterification or transesterification and polycondensation reaction, the fiber-forming polymer, polyethylene terephthalate (PET), is obtained, and then through spinning and post-processing to make fibers. PET fiber (polyester fiber) is widely used in clothing and industrial fields because of its advantages such as high modulus, high strength, good shape retention and good barrier properties.

[0003] However, with the continuous development of society, the profit margin of ordinary polyester fiber has gradually shrunk, and energy saving and consumption reduction have become an important part of production control. In the production process of polyester FDY (fully drawn yarn), network processing is a key step, which enhances the cohesion and stability of the tow by forming cross nodes on the tow. However, in the prior art (such as patent CN110106582A), the FDY main network is usually added between the second roller and the winding roller. In this process, due to the large tension of the tow (usually around 25g), the network air pressure must also be increased accordingly to meet the needs of adding the network. However, excessive network air pressure not only increases gas consumption and production costs, but may also cause a series of problems.

[0004] Specifically, the increase in network pressure will increase the degree of entanglement between the individual filaments. Although this is beneficial to the improvement of fiber bundling performance to a certain extent, excessive network pressure can easily cause the fibers to be blown off, resulting in filaments (i.e. broken filaments). The appearance of filaments will directly reduce the mechanical properties of the fibers, affecting the quality and service life of the products. In addition, when the network pressure is too high, it may also cause serious splashing of the oil, further increasing the energy consumption and cost in the production process. At the same time, excessive network pressure may also affect the uniformity of the fibers, which will directly affect the quality of the final product.

[0005] Therefore, how to reduce the network air pressure and gas consumption in the production process of polyester FDY yarn when adding the network while ensuring product quality has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] The purpose of the invention is to solve the problems existing in the prior art and provide a production method of polyester FDY yarn.

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

[0008] A method for producing polyester FDY yarn comprises the following steps: in the spinning process, a network device is used to network a yarn bundle located between a second heat box and a winding roller, and a tensioning wire rod is used to apply friction force to the yarn bundle located between the second heat box and the network device to offset part of the tension on the yarn bundle, thereby reducing the network pressure during network addition.

[0009] As the preferred technical solution:

[0010] The above-mentioned method for producing polyester FDY yarn has the overall process flow of: melt extrusion → cooling → oiling → first hot box heating → second hot box heating → tensioning guide wire rod → network device adding network → winding roller winding, wherein the first hot box is provided with a first wire separation roller SR1 and a first hot roller GR1, and the second hot box is provided with a second wire separation roller SR2 and a second hot roller GR2.

[0011] In the production method of polyester FDY yarn as described above, the single hole flow rate during melt extrusion is 0.005-0.02g / s, cooling adopts side blowing cooling, the cooling air temperature is 23-27°C, the cooling air speed is 0.3-0.6m / s, the temperature of the first hot box is 80-93°C, the temperature of the second hot box is 120-134°C, the rotation speed of the first hot roller GR1 is 1400-1800m / min, the rotation speed of the second hot roller GR2 is 3845-5070m / min, and the rotation speed of the winding roller is 3800-5300m / min.

[0012] A method for producing polyester FDY yarn as described above, wherein the tensioning wire guide rod comprises an upper screw, a cylindrical rod, a lower screw, an upper wire guide disc, an upper nut, a lower wire guide disc, a lower nut, an aluminum tube, an upper wire guide, a lower wire guide and a fixing frame;

[0013] The upper screw, the cylindrical rod and the lower screw are coaxial and fixedly connected in sequence from top to bottom;

[0014] The upper screw rod passes through the center of the upper wire guide disc and the upper nut from bottom to top, and the lower screw rod passes through the center of the lower wire guide disc and the lower nut from top to bottom;

[0015] The aluminum tube is sleeved on the cylindrical rod and is located between the upper wire guide disk and the lower wire guide disk. The outer diameters of the upper wire guide disk and the lower wire guide disk are greater than or equal to the diameter of the cylindrical rod and smaller than the outer diameter of the aluminum tube.

[0016] There are multiple upper wire guides distributed at the edge of the upper wire guide disc, and there are multiple lower wire guides distributed at the edge of the lower wire guide disc;

[0017] The fixing frame is a U-shaped frame, one end of which is fixedly connected to the upper screw rod, and the other end is fixedly connected to the aluminum tube;

[0018] The yarn tow first passes through the upper yarn guide and is spirally wound on the aluminum tube, and then passes through the lower yarn guide.

[0019] In the production method of polyester FDY yarn as described above, the length of the aluminum tube is 15-20 cm, the outer diameter is 40-50 mm, and the surface roughness is 0.2-0.7.

[0020] In the above-mentioned method for producing polyester FDY yarn, the length L of the yarn bundle wound on the aluminum tube is 77-372 mm.

[0021] In the production method of polyester FDY yarn as described above, the tension of the yarn bundle at the inlet of the network device is 3-15 cN, and the network pressure during network addition is 2-3 bar.

[0022] The polyester FDY yarn production method as described above has a linear density of 30-167 dtex, a network degree of 6-20 filaments / meter, and a total number of end hair filaments and loop filaments of 0-3.

[0023] Beneficial effects:

[0024] The present invention aims at a series of problems caused by excessive network air pressure in the existing polyester FDY yarn production process. A tensioning wire guide rod is added between the second hot box and the network device to apply friction to the yarn bundle, thereby effectively offsetting part of the tension on the yarn bundle, thereby significantly reducing the network pressure during network addition. This improvement not only reduces gas consumption and production costs, but also effectively avoids problems such as hairy yarns, oil splashing, and decreased fiber uniformity caused by excessive network pressure, thereby improving the production efficiency and economic benefits of polyester FDY yarn while ensuring product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the yarn bundle passing through the tensioning wire guide rod and the network device in sequence; wherein, 1-tow, 2-upper wire guide, 3-upper wire guide disc, 5-fixing frame, 6-aluminum tube, 7-lower wire guide disc, 8-lower wire guide, 9-network device, 12-lower nut, 13-upper screw rod, 14-upper nut;

[0026] Figure 2 The overall process flow diagram of the production method of polyester FDY yarn of the present invention is shown in the figure; wherein SR1 is the first wire separation roller, GR1 is the first hot roller, SR2 is the second wire separation roller, and GR2 is the second hot roller. DETAILED DESCRIPTION

[0027] 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.

[0028] like Figure 1 As shown, the tensioning wire guide rod in the following embodiments includes an upper screw 13, a cylindrical rod, a lower screw, an upper wire guide disc 3, an upper nut 14, a lower wire guide disc 7, a lower nut 12, an aluminum tube 6, an upper wire guide 2, a lower wire guide 8 and a fixing frame 5;

[0029] The upper screw 13, the cylindrical rod and the lower screw are coaxial and fixedly connected in sequence from top to bottom;

[0030] The upper screw 13 passes through the center of the upper wire guide disc 3 and the upper nut 14 from bottom to top, and the lower screw passes through the center of the lower wire guide disc 7 and the lower nut 12 from top to bottom.

[0031] The aluminum tube 6 is sleeved on the cylindrical rod and is located between the upper wire guide disc 3 and the lower wire guide disc 7. The outer diameters of the upper wire guide disc 3 and the lower wire guide disc 7 are greater than or equal to the diameter of the cylindrical rod and smaller than the outer diameter of the aluminum tube 6.

[0032] There are multiple upper wire guides 2 and they are distributed at the edge of the upper wire guide disc 3, and there are multiple lower wire guides 8 and they are distributed at the edge of the lower wire guide disc 7;

[0033] The fixing frame 5 is a U-shaped frame, one end of which is fixedly connected to the upper screw rod 13, and the other end of which is fixedly connected to the aluminum tube 6;

[0034] When spinning is performed using the tensioning guide rod, the filament bundle 1 first passes through the upper guide 2 and is spirally wound around the aluminum tube 6, and then passes through the lower guide 8; during the spinning process, the upper guide disk 3 and the lower guide disk 7 can be rotated (at this time, the upper screw 13 and the upper nut 14, the lower screw and the lower nut 12 are in a loosened state) to adjust the relative position of the upper guide 2 and the lower guide 8, and then control the degree of spirality of the filament bundle 1 on the aluminum tube 6, which is not only conducive to heat dissipation, but also can effectively control and reduce the tension of the filament bundle 1 at the entrance of the network device 9; after the relative position of the upper guide 2 and the lower guide 8 is adjusted, the upper screw 13 and the upper nut 14, the lower screw and the lower nut 12 are tightened at the same time, so that the upper guide disk 3 and the lower guide disk 7 are fixed on the cylindrical rod respectively.

[0035] The following are the test methods for the relevant performance indicators in each embodiment and comparative example:

[0036] Linear density: measured in accordance with GB / T14343-2008 standard; wherein, the test temperature is 25°C, the test humidity is 65%, and the pre-tension is 0.2 cN / dtex.

[0037] Network degree: The filament network degree instrument (manufacturer: Changzhou Bafang Lishi Textile Instrument Co., Ltd., model: BF1801) was used for measurement; wherein, the test length was 1m, the test speed was 2.5m / min, the release force was 0.3cN / dtex, and the pre-tension was 0.1cN / dtex.

[0038] Total number of hairy wires and looped wires on the end surface: Inspectors use flashlights to inspect the end surface of the FDY wire (weight 7.5 kg) cake (width 86 mm). Loops less than 3 mm are ignored, and the calculation starts from the length of 3 mm or more. The total number of hairy wires and looped wires on the end surface is counted.

[0039] Example 1

[0040] A production method of polyester FDY yarn, such as Figure 2 As shown, the overall process flow is: spinning box melt extrusion → side blowing cooling → oiling → first hot box heating → second hot box heating → tensioning wire rod → network adding network → winding roller winding;

[0041] Among them, the parameters related to the tensioning wire guide rod are: the length of the aluminum tube is 15 cm, the outer diameter is 40 mm, and the surface roughness is 0.2; the length L of the wire bundle wound on the aluminum tube is 77 mm;

[0042] Process parameters: single hole flow rate during melt extrusion is 0.005g / s, cooling air temperature is 23°C, cooling air speed is 0.35m / s, temperature of the first hot box is 80°C, temperature of the second hot box is 130°C, rotation speed of GR1 is 1400m / min, rotation speed of GR2 is 4140m / min, rotation speed of winding roller is 4100m / min.

[0043] Tests show that the tension of the yarn bundle at the entrance of the network device is 3cN, and the network pressure during network addition is 2bar; the final polyester FDY yarn has a specification of 30dtex / 24f, a network degree of 20 per meter, and a total number of end hairs and loops of 0.

[0044] Comparative Example 1

[0045] A method for producing polyester FDY yarn is basically the same as that of embodiment 1, except that no tensioning wire guide rod is used.

[0046] The test shows that the tension of the yarn bundle at the entrance of the network device is 7cN, and the network pressure during network addition is 3.5bar; the network density of the polyester FDY yarn finally obtained is 16 per meter, and the total number of end hair yarns and loop yarns is 4.

[0047] Compared with Example 1, the tension of the yarn bundle at the entrance of the network device, the network pressure when adding the network, and the total number of filaments and loops of the polyester FDY yarn are significantly increased, and the network degree of the polyester FDY yarn is significantly reduced. This is because without using a tensioning wire guide rod, the tension of the yarn bundle cannot be effectively controlled, resulting in an increase in the tension of the yarn bundle at the entrance of the network device. Higher yarn bundle tension will require higher network pressure when adding the network to meet processing requirements. Excessive network pressure can easily cause the fibers to be blown off, thereby generating filaments, which increases the total number of filaments and loops. At the same time, excessive network pressure will also affect the uniformity of the fiber, thereby reducing the network degree of the fiber.

[0048] Example 2

[0049] A production method of polyester FDY yarn, such as Figure 2 As shown, the overall process flow is: spinning box melt extrusion → side blowing cooling → oiling → first hot box heating → second hot box heating → tensioning wire rod → network adding network → winding roller winding;

[0050] Among them, the parameters related to the tensioning wire guide rod are: the length of the aluminum tube is 16 cm, the outer diameter is 42 mm, and the surface roughness is 0.4; the length L of the wire bundle wound on the aluminum tube is 150 mm;

[0051] Process parameters: single hole flow rate during melt extrusion is 0.007g / s, cooling air temperature is 25℃, cooling air speed is 0.3m / s, temperature of the first hot box is 82℃, temperature of the second hot box is 120℃, rotation speed of GR1 is 1426m / min, rotation speed of GR2 is 3845m / min, and rotation speed of winding roller is 3800m / min.

[0052] Tests show that the tension of the yarn bundle at the entrance of the network device is 7cN, and the network pressure during network addition is 2.2bar; the final polyester FDY yarn has a specification of 55dtex / 72f, a network degree of 15 / m, and a total of 3 end hair yarns and loop yarns.

[0053] Example 3

[0054] A production method of polyester FDY yarn, such as Figure 2 As shown, the overall process flow is: spinning box melt extrusion → side blowing cooling → oiling → first hot box heating → second hot box heating → tensioning wire rod → network adding network → winding roller winding;

[0055] Among them, the parameters related to the tensioning wire guide rod are: the length of the aluminum tube is 17 cm, the outer diameter is 46 mm, and the surface roughness is 0.5; the length L of the wire bundle wound on the aluminum tube is 200 mm;

[0056] Process parameters: single hole flow rate during melt extrusion is 0.01g / s, cooling air temperature is 25°C, cooling air speed is 0.4m / s, temperature of the first hot box is 82°C, temperature of the second hot box is 131°C, rotation speed of GR1 is 1650m / min, rotation speed of GR2 is 4755m / min, rotation speed of winding roller is 4700m / min.

[0057] Tests show that the tension of the yarn bundle at the entrance of the network device is 10cN, and the network pressure during network addition is 2.4bar; the final polyester FDY yarn has a specification of 75dtex / 24f, a network degree of 13 / m, and a total of 1 end hair yarn and loop yarn.

[0058] Example 4

[0059] A production method of polyester FDY yarn, such as Figure 2 As shown, the overall process flow is: spinning box melt extrusion → side blowing cooling → oiling → first hot box heating → second hot box heating → tensioning wire rod → network adding network → winding roller winding;

[0060] Among them, the parameters related to the tensioning wire guide rod are: the length of the aluminum tube is 18 cm, the outer diameter is 48 mm, and the surface roughness is 0.6; the length L of the wire bundle wound on the aluminum tube is 280 mm;

[0061] Process parameters: single hole flow rate during melt extrusion is 0.015g / s, cooling air temperature is 26°C, cooling air speed is 0.45m / s, temperature of the first hot box is 92°C, temperature of the second hot box is 133°C, rotation speed of GR1 is 1800m / min, rotation speed of GR2 is 5070m / min, rotation speed of winding roller is 5300m / min.

[0062] Tests show that the tension of the yarn bundle at the entrance of the network device is 12cN, and the network pressure during network addition is 2.8bar; the final polyester FDY yarn has a specification of 111dtex / 36f, a network degree of 9 / m, and a total of 1 end hair yarn and loop yarn.

[0063] Example 5

[0064] A production method of polyester FDY yarn, such as Figure 2 As shown, the overall process flow is: spinning box melt extrusion → side blowing cooling → oiling → first hot box heating → second hot box heating → tensioning wire rod → network adding network → winding roller winding;

[0065] Among them, the parameters related to the tensioning wire guide rod are: the length of the aluminum tube is 20 cm, the outer diameter is 50 mm, and the surface roughness is 0.7; the length L of the wire bundle wound on the aluminum tube is 372 mm;

[0066] Process parameters: single hole flow rate during melt extrusion is 0.02g / s, cooling air temperature is 27°C, cooling air speed is 0.6m / s, temperature of the first hot box is 93°C, temperature of the second hot box is 134°C, rotation speed of GR1 is 1670m / min, rotation speed of GR2 is 4350m / min, rotation speed of winding roller is 4300m / min.

[0067] Tests show that the tension of the yarn bundle at the entrance of the network device is 15cN, and the network pressure during network addition is 3bar; the final polyester FDY yarn has a specification of 167dtex / 96f, a network degree of 6 / m, and a total of 2 end hair yarns and loop yarns.

Claims

1. A method for producing polyester FDY yarn, wherein a yarn bundle located between a second heat box and a winding roller is networked by a networker during the spinning process, characterized in that: A tensioning wire rod is also used to apply friction to the filament bundle between the second heat box and the network device to offset part of the tension on the filament bundle, thereby reducing the network pressure during network addition.

2. The method for producing polyester FDY yarn according to claim 1, characterized in that: The overall process flow is: melt extrusion → cooling → oiling → heating in the first hot box → heating in the second hot box → tensioning the wire guide rod → adding network to the network → winding with the winding roller, wherein the first hot box is provided with a first wire separation roller SR1 and a first hot roller GR1, and the second hot box is provided with a second wire separation roller SR2 and a second hot roller GR2.

3. The method for producing polyester FDY yarn according to claim 2, characterized in that: The single hole flow rate during melt extrusion is 0.005-0.02g / s, cooling is carried out by side blowing cooling, the cooling air temperature is 23-27°C, the cooling air speed is 0.3-0.6m / s, the temperature of the first hot box is 80-93°C, the temperature of the second hot box is 120-134°C, the rotation speed of the first hot roller GR1 is 1400-1800m / min, the rotation speed of the second hot roller GR2 is 3845-5070m / min, and the rotation speed of the winding roller is 3800-5300m / min.

4. The method for producing polyester FDY yarn according to claim 2, characterized in that: The tensioning wire guide rod comprises an upper screw rod, a cylindrical rod, a lower screw rod, an upper wire guide disc, an upper nut, a lower wire guide disc, a lower nut, an aluminum tube, an upper wire guide, a lower wire guide and a fixing frame; The upper screw, the cylindrical rod and the lower screw are coaxial and fixedly connected in sequence from top to bottom; The upper screw rod passes through the center of the upper wire guide disc and the upper nut from bottom to top, and the lower screw rod passes through the center of the lower wire guide disc and the lower nut from top to bottom; The aluminum tube is sleeved on the cylindrical rod and is located between the upper wire guide disk and the lower wire guide disk. The outer diameters of the upper wire guide disk and the lower wire guide disk are greater than or equal to the diameter of the cylindrical rod and smaller than the outer diameter of the aluminum tube. There are multiple upper wire guides distributed at the edge of the upper wire guide disc, and there are multiple lower wire guides distributed at the edge of the lower wire guide disc; The fixing frame is a U-shaped frame, one end of which is fixedly connected to the upper screw rod, and the other end is fixedly connected to the aluminum tube; The yarn tow first passes through the upper yarn guide and is spirally wound on the aluminum tube, and then passes through the lower yarn guide.

5. The method for producing polyester FDY yarn according to claim 4, characterized in that: The length of the aluminum tube is 15-20 cm, the outer diameter is 40-50 mm, and the surface roughness is 0.2-0.

7.

6. The method for producing polyester FDY yarn according to claim 5, characterized in that: The length L of the filament bundle wound on the aluminum tube is 77-372 mm.

7. The method for producing polyester FDY yarn according to claim 6, characterized in that: The tension of the tow at the entrance of the network device is 3-15cN, and the network pressure during network addition is 2-3bar.

8. The method for producing polyester FDY yarn according to claim 7, characterized in that: The linear density of polyester FDY yarn is 30-167dtex, the interlacing degree is 6-20 per meter, and the total number of end hair yarns and loop yarns is 0-3.

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