A preparation device and method for high-strength and high-elongation polyester industrial yarn

Abstract

The present invention belongs to the field of spinning technology, and relates to a preparation device and preparation method for high-strength and high-elongation polyester industrial yarn. The preparation device includes a cooling air duct, a suction duct, an annular imperforate plate, an annular porous plate, an air supply duct and a suction duct; the cooling air duct is arranged vertically, and is composed of a first equal-diameter section, a variable-diameter section and a second equal-diameter section arranged in sequence from top to bottom and coaxial; the suction duct is arranged vertically in the second equal-diameter section and coaxial therewith, the lower end of the suction duct is flush with the lower end of the second equal-diameter section and the two are connected by an annular imperforate plate, the upper end of the suction duct is connected to the inner wall of the second equal-diameter section by an annular porous plate, the suction duct, the annular imperforate plate, the annular porous plate and the second equal-diameter section together form a suction chamber, and the second equal-diameter section is provided with a groove; the air supply duct is arranged horizontally and connected to the first equal-diameter section; the suction duct is arranged horizontally and connected to the suction chamber. The preparation method of the present invention adopts the above preparation device to prepare polyester industrial yarn with high strength and high elongation.

Description

Technical Field

[0001] The invention belongs to the technical field of spinning, and relates to a device and a method for preparing high-strength and high-elongation polyester industrial yarn. Background Art

[0002] Polyester industrial yarn boasts excellent physical and chemical properties, including high strength, high modulus, heat resistance, and acid and alkali resistance, along with low production costs. It is currently widely used as a skeleton reinforcement material in membrane structures. Membrane structures are spatial structures formed by a combination of various high-strength membrane materials and reinforcing members (steel frames, steel columns, or steel cables). They are primarily used as covering structures in venues such as large stadiums, waiting halls, and theaters.

[0003] Due to the special application areas of membrane structures, they require a certain amount of pre-tensioning stress and must also withstand certain external loads (rain, snow, strong winds, etc.). The polyester industrial yarn used as the skeleton material of membrane structures must have both strength and toughness. This requires that during the production process, the strength of the polyester industrial yarn must be maintained while the elongation at break must be increased. Therefore, a preparation method for polyester industrial yarn that balances strength and elongation at break has important application value.

[0004] The existing technology mainly improves the breaking elongation of polyester filaments from two aspects: (1) adding a modifier to the polyester melt to make the polymer chain have a certain entanglement structure after polymerization, so that the fiber can withstand a higher tensile force during the spinning process, thereby making the fiber obtain higher strength and have a larger residual elongation. For example, the patent application with patent publication number CN101880919A discloses a production method of high-elongation glossy polyester filaments, which injects ether additives with a mass content of 0.5%-0.95% into the melt. The patent application with patent publication number CN102926032A discloses a high-strength, high-elongation, easy-to-dye and wear-resistant polyester fiber and its preparation method, which adds a certain amount of monomers such as pentaerythritol and isophthalic acid during the polymerization process to copolymerize and produce (2) adding a fiber elongation improver to the polyester, which transforms from a molten state to a glassy state before the polyester, counteracts the spinning tension, inhibits the orientation of the polyester molecular chain, increases the residual elongation of the nascent fiber, and further increases the breaking elongation of the fiber. For example, the patent application with the publication number JP2000160431A discloses a high elongation polyester yarn, to which a granular fiber elongation improver with a heat deformation temperature of 105-160°C is added. The patent application with the publication number EP0047464A1 discloses an unstretched polyester yarn, which includes 0.2 to 10 weight percent of a polymer of a repeating unit structure represented by formula (I), wherein R1 and R2 represent substituents selected from C, H, N, O, S, P and halogen atoms, the sum of the molecular weights of R1 and R2 is equal to or greater than 40, n is a positive integer, and the molecular weight is equal to or greater than 1000.

[0005]

[0006] The above methods all use modifiers for chemical modification, which have the following disadvantages and shortcomings: on the one hand, the introduction of modifiers destroys the regularity of polyester molecular chains, resulting in a loss of fiber strength and failure to meet the high-strength requirements of polyester industrial yarns; on the other hand, additional components need to be added, which increases the complexity of the process and also increases the cost.

[0007] Therefore, it is necessary to study a high-strength and high-elongation polyester industrial yarn without modifier. Summary of the Invention

[0008] The purpose of the present invention is to solve the problems existing in the prior art and provide a device and method for preparing high-strength and high-elongation polyester industrial yarn.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] A device for preparing high-strength and high-strength polyester industrial yarn comprises a cooling air cylinder, a suction cylinder, an annular non-porous plate, an annular porous plate, an air supply duct and a suction duct;

[0011] The cooling air duct is open at both ends and arranged vertically. It consists of a first constant diameter section, a variable diameter section, and a second constant diameter section arranged in sequence from top to bottom and coaxially. The walls of the variable diameter section and the second constant diameter section have no holes. Each constant diameter section is cylindrical, and the variable diameter section is an inverted truncated cone. The inner diameter of the first constant diameter section = the inner diameter of the upper end of the variable diameter section > the inner diameter of the lower end of the variable diameter section = the inner diameter of the second constant diameter section;

[0012] The suction cylinder is open at both ends, has no holes in its wall, is vertically arranged in the second equal-diameter section and coaxial therewith, has a length less than that of the second equal-diameter section, has a lower end flush with the lower end of the second equal-diameter section and is connected by an annular imperforate plate, and an upper end of the suction cylinder is connected to the inner wall of the second equal-diameter section by an annular porous plate, and the suction cylinder, the annular imperforate plate, the annular porous plate, and the second equal-diameter section together form a suction chamber;

[0013] The inner wall of the second constant diameter section, located above the suction cylinder, is provided with a plurality of grooves for suppressing the separation of the boundary layer from the cooling air cylinder. The boundary layer is a fluid layer formed by viscosity when the cooling air flows over the inner wall surface of the cooling air cylinder.

[0014] The air supply duct is arranged horizontally and communicated with the first equal-diameter section; the suction duct is arranged horizontally and communicated with the suction cavity.

[0015] The principles of the present invention are as follows:

[0016] During the melt spinning process, the force distribution of the fibers during the spinning process (the force distribution during the spinning process) plays a very important role in the melt spinning process, especially in the orientation and crystallization of the fibers during the spinning process. Reference 1 (Methods for Reducing the Tension of Polyester Fiber High-Speed ​​Spinning [J]. Foreign Textile Technology, 1985, (03):17) points out that the parameters affecting fiber tension include the rheological force of the nascent fibers and the friction between the fibers and the surrounding medium. Fiber tension can promote the formation of spinning-induced crystallization in high-speed spun polyester yarns. Reference 2 (Polyester Fiber Science and Engineering [M]. Beijing: China Textile Press, 2001, 102) records that air friction plays a major role in the tension of PET spinning.

[0017] The present invention arranges the cooling duct structure, the air supply duct position, and the connection between the air supply duct and the cooling duct so that the cooling airflow direction within the second constant diameter section aligns with the direction of the filament bundle. Compared to conventional vertical blowing methods such as circular and side blowing, this method reduces the velocity difference between the air and the filament bundle, effectively reducing air friction and, consequently, lowering spinning tension. According to fiber forming theory, as filaments move through an air medium, friction is generated between their surface area and the medium due to their mutual movement. This friction is proportional to the square of the relative velocity between the filaments and the air (Reference: Principles of Polymer Material Processing [M]. Beijing: China Textile Press, 2002: 189). During the extrusion stage of the spinning melt to form nascent fibers, spinning tension increases polymer molecular orientation and induces stress-induced crystallization. Reducing spinning tension can reduce the degree of molecular orientation and the crystallinity of the nascent fibers, resulting in a higher residual elongation of the nascent fibers. Subsequent stretching by heated rollers, at the same stretch ratio, the fibers maintain both a certain strength and a high elongation.

[0018] However, such an arrangement is prone to excessive turbulence and flow separation in the second constant diameter section, which has an adverse effect on the uniformity of the yarn strands. To avoid excessive turbulence and flow separation, the present invention also makes the following improvements:

[0019] ① Set a groove on the inner wall of the second equal diameter section.

[0020] The inner wall of the cooling duct in the prior art is a smooth plane. When the cooling airflow flows through the duct, the viscosity of the airflow creates friction with the duct wall. The airflow in contact with the wall slows down, forming a very thin boundary layer. The velocity on the outside of the boundary layer changes very little, while the velocity on the inside changes dramatically. In the cross-sectional direction of the duct, the velocity on both sides close to the wall is relatively small, while the velocity in the middle is consistent with the velocity of the incoming flow and does not change much. Due to the large velocity gradient inside the boundary layer, the kinetic energy of the flow is lost due to the viscous force, and the velocity of the inner layer will become slower and slower. According to Bernoulli's theorem, the flow rate slows down and the pressure increases. As the flow continues, the flow in the boundary layer becomes increasingly difficult, and finally separates from the wall, generating a huge separation vortex. The generation of the vortex makes the cooling airflow chaotic, which will disturb the filaments and affect the cooling of the filaments.

[0021] The present invention arranges grooves on the inner wall of the second equal-diameter section, and the cooling airflow can generate small refraction vortices at the grooves to avoid the generation of huge separation vortices, thereby suppressing the separation of the boundary layer and avoiding large separation vortices. It is like applying a layer of "oil film" on the wall surface. The flow resistance of the airflow outside the "oil film" is reduced, and the overall flow velocity on the cross section of the wind tube becomes more stable and uniform, so that the cooling of the filament bundle is more uniform, and the uniformity of the filament bundle is improved.

[0022] ② Set up a suction pipe at the end of the yarn cooling.

[0023] When the filament bundle is cooled in the prior art, the cooling air flow channel at the outlet of the cooling duct suddenly increases, the cooling air flow is no longer constrained by the cooling duct, the flow rate decreases, and the pressure increases, which will cause backflow at the outlet of the cooling duct, causing disturbances to the filaments. Although the filaments have been cooled and solidified at this time, the disturbance of the filaments will be transmitted upward, which is not conducive to improving the uniformity of the filaments. The present invention sets a suction pipe at the end of the cooling of the filament bundle and adjusts the suction pressure of the suction pipe to keep the cooling air flow in a stable flow state, reduce the disturbance of the filaments, thereby improving the uniformity of the filament bundle and further improving the quality of the product.

[0024] As the preferred technical solution:

[0025] As described above, the device for preparing high-strength and high-elongation polyester industrial yarn has circular pit grooves arranged in a staggered lattice structure; the diameter of the circular pit grooves is 3-4 mm, the groove depth is 2-2.5 mm, and the center distance between any two adjacent circular pits is 9-10 mm.

[0026] The high-strength and high-elongation polyester industrial yarn production device described above has non-circular grooves divided into multiple groups, wherein the non-circular grooves in the same group are distributed along the circumferential spacing of the second equal-diameter section at a spacing of 4-6 mm, and the non-circular grooves in different groups are distributed along the axial spacing of the second equal-diameter section at a spacing of 9-10 mm.

[0027] The non-circular groove gradually decreases in size from the groove opening to the groove bottom. The groove opening is oblong, the length of the oblong is 9-20 mm and the width is 3-4 mm. The groove bottom is a line segment or a rectangle, and the groove depth is 2-2.5 mm.

[0028] When the groove bottom is rectangular, the angle θ between the groove wall and the central axis of the non-circular pit is 20-30°;

[0029] For the same non-circular pit groove, the shortest symmetrical dividing line segment of the oblong, the perpendicular bisector of the line segment, and the shortest symmetrical dividing line segment of the rectangle are all parallel to the axial direction of the second equal-diameter segment. The straight line where the center of the oblong and the midpoint of the line segment or the center of the rectangle are located is perpendicular to and intersects with the central axis of the second equal-diameter segment. The shortest symmetrical dividing line segment is the shortest line segment required to divide the figure into two symmetrical parts.

[0030] The preparation device of a high-strength and high-elongation polyester industrial yarn as described above also includes an air supply duct; the air supply duct is open at both ends, the duct wall has no holes, is arranged vertically, is sleeved on the first equal-diameter section and is coaxial with it; the upper end of the air supply duct is connected to the upper end of the first equal-diameter section through an annular non-porous plate, and the lower end of the air supply duct is connected to the lower end of the first equal-diameter section through an annular non-porous plate; the first equal-diameter section is a porous structure, and an air inlet is provided on the air supply duct, and the outlet of the air supply duct is connected to the air inlet.

[0031] As described above, the preparation device for high-strength and high-elongation polyester industrial yarn has a length of 110-150 mm and an inner diameter of 200-250 mm; the inner diameter of the air supply tube is 40-60 mm larger than the outer diameter of the first equal-diameter section; the length of the variable-diameter section is 120-160 mm; the length of the second equal-diameter section is 1000-1300 mm, and the inner diameter is 150-200 mm; the length of the suction tube is 800-1200 mm smaller than the length of the second equal-diameter section, and the outer diameter is 40-50 mm smaller than the inner diameter of the second equal-diameter section.

[0032] In the above-mentioned device for preparing high-strength and high-elongation polyester industrial yarn, the inner diameter of the air supply duct is 100-120 mm, and the inner diameter of the suction duct is 100-120 mm.

[0033] The device for preparing high-strength and high-elongation polyester industrial yarn as described above also includes a spinning manifold, which is located above the first equal-diameter section, with a slow cooling zone and a windless zone between them, and the slow cooling zone is located above the windless zone.

[0034] In the above-mentioned device for preparing high-strength and high-elongation polyester industrial yarn, the height of the slow cooling zone is 95-105 mm; the height of the windless zone is 45-55 mm.

[0035] The device for preparing high-strength and high-elongation polyester industrial yarn as described above further includes a spinning tunnel, which is located below the second equal-diameter section and connected to it.

[0036] In the above-mentioned device for preparing high-strength and high-elongation polyester industrial yarn, the length of the spinning tunnel is 600-700 mm.

[0037] The present invention also provides a method for preparing high-strength and high-elongation polyester industrial yarn, which uses the device for preparing high-strength and high-elongation polyester industrial yarn as described in any one of the above items.

[0038] As the preferred technical solution:

[0039] The above-mentioned method for preparing high-strength and high-elongation polyester industrial yarn has the following spinning process: polyester melt is extruded through a spinneret → cooled in a slow cooling zone → cooled in a windless zone → cooled in a cooling duct → oiled → stretched by five pairs of hot rollers → shaped → webbed → wound;

[0040] Spinning process parameters include: ambient temperature 35-40℃; spinning temperature 291-310℃; slow cooling zone temperature 290±20℃; cooling air temperature 20-25℃; cooling air speed 0.7-1.5m / s; suction pressure of the suction pipe 0-0.2Pa; speed of the first pair of hot rollers 430-560m / min, temperature 70-80℃; speed of the second pair of hot rollers 450-580m / min, temperature 90-100℃; speed of the third pair of hot rollers 2000-2500m / min, temperature 123-135℃; speed of the fourth pair of hot rollers 2700-3250m / min, temperature 210-250℃; speed of the fifth pair of hot rollers 2000-2500m / min, temperature 123-135℃; speed of the fifth pair of hot rollers 2000-3250m / min, temperature 210-250℃; speed of the sixth pair of hot rollers 2000-3250m / min, temperature 210-250℃; speed of the eighth ... The speed of the hot rollers is 2500-3100 m / min, the temperature is 160-200°C; the total stretching ratio is 5.50-6.20, the main stretching ratio is 3.74-4.44, the secondary stretching ratio is 1.30-1.60, the total stretching ratio = the speed of the fourth pair of hot rollers / the speed of the second pair of hot rollers, the main stretching ratio = the speed of the third pair of hot rollers / the speed of the second pair of hot rollers, the secondary stretching ratio = the speed of the fourth pair of hot rollers / the speed of the third pair of hot rollers; the winding speed is 2650-3200 m / min; the spinning tension is 100-130 cN.

[0041] The high-strength and high-elongation polyester industrial yarn has a linear density of 1100-1450 dtex, a breaking strength of ≥7.2 cN / dtex, an elongation at break of 30%-32%, a yarn unevenness CV value of <1.0%, a dry heat shrinkage rate of ≤3.2%, and a yarn degradation rate of ≤1.1%.

[0042] Beneficial effects:

[0043] (1) The present invention provides a device for preparing high-strength and high-elongation polyester industrial yarn, wherein grooves are provided on the inner wall of the cooling duct to reduce the adhesion of the cooling air flow to the wall, and suction is performed at the outlet of the duct to keep the cooling air flow in a stable state, thereby avoiding disturbance of the yarn bundle and improving the uniformity of the yarn bundle.

[0044] (2) The present invention provides a method for preparing high-strength and high-elongation polyester industrial yarn, which uses a cooling airflow in the same direction as the yarn bundle to reduce the spinning tension, so that the fiber has low orientation and crystallinity, and increases the elongation of the primary fiber, thereby preparing a polyester industrial yarn with high strength and high elongation, which meets the application requirements in the field of membrane structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a structural schematic diagram of the preparation device of the present invention;

[0046] Figure 2 It is a partial schematic diagram of the air flow at the inner wall surface of the cooling duct of the preparation device of the present invention (circular pit groove);

[0047] Figure 3 This is a partial schematic diagram of the air flow at the inner wall of the cooling duct of the preparation device of the present invention (non-circular pit groove);

[0048] Figure 4 It is a combined schematic diagram of the front view and the top view of the non-circular pit groove (V-shaped groove) on the inner wall of the cooling air duct of the preparation device of the present invention;

[0049] Figure 5 It is a combined schematic diagram of the front view and the top view of the non-circular pit groove (inverted equal-height trapezoidal groove) on the inner wall of the cooling air duct of the preparation device of the present invention;

[0050] Figure 6 This is a partial schematic diagram of the air flow at the outlet of the cooling duct of Comparative Example 1A;

[0051] Figure 7 This is a partial schematic diagram of the air flow at the inner wall of the cooling duct of Comparative Example 2A;

[0052] Figure 8 3A is a schematic structural diagram of the cooling duct;

[0053] In the figure, 1 is the spinning box, 2 is the slow cooling zone, 3 is the windless zone, 4 is the air supply tube, 5 is the air supply duct, 6 is the cooling air tube, 601 is the first equal diameter section, 602 is the variable diameter section, 603 is the second equal diameter section, 7 is the suction duct, 8 is the cooling airflow, 9 is the spinning tunnel, 10 is the suction tube, 11 is the annular non-porous plate, 12 is the annular porous plate, 13 is the suction chamber, 14 is the reverse airflow, 15 is the circular pit groove, 16 is the circular pit groove refracted flow, 17 is the non-circular pit groove, 18 is the non-circular pit groove refracted flow, and 19 is the filament bundle. DETAILED DESCRIPTION

[0054] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0055] The following are the test methods for the relevant performance indicators in each embodiment and comparative example:

[0056] (1) Linear density: The test was conducted using a YG086 length measuring instrument in accordance with GB / T 14343-2008 “Test method for linear density of chemical fiber filaments”.

[0057] (2) Breaking strength: The test was conducted using a YG023B-Ⅱ tensile tester in accordance with GB / T 14344-2022 “Test method for tensile properties of chemical fiber filaments”.

[0058] (3) Elongation at break: The test was conducted using a YG023B-Ⅱ tensile tester in accordance with GB / T 14344-2022 “Test method for tensile properties of chemical fiber filaments”.

[0059] (4) CV value of yarn unevenness: The test was conducted using USTER TESTER 5 yarn evenness meter in accordance with GB / T 14346-2015 “Test method for yarn unevenness of chemical filament yarns - Capacitance method”.

[0060] (5) Dry heat shrinkage: The test was conducted using a TST510 / 250 dry heat shrinkage tester in accordance with GB / T 16604-2017 "Polyester Industrial Filament".

[0061] (6) Downgrade rate of wool yarn: refer to the specific inspection method for appearance requirements of GB / T 16604-2017 "Polyester Industrial Filament", count the number of downgraded yarn cakes and the number of full roll yarn cakes in one day, and the percentage of downgraded yarn cakes to full roll yarn cakes is the downgrade rate of wool yarn.

[0062] Example 1A

[0063] like Figure 1 and Figure 2 The device for producing high-strength and high-elongation polyester industrial yarn shown in the figure consists of a spinning box 1, an air supply cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular non-porous plate 11, an annular porous plate 12 and a spinning tunnel 9;

[0064] The cooling air duct 6 is open at both ends and arranged vertically. It consists of a first constant diameter section 601, a reduced diameter section 602, and a second constant diameter section 603, which are arranged in sequence from top to bottom and are coaxial. The reduced diameter section 602 and the second constant diameter section 603 have no holes in their walls. Each constant diameter section is cylindrical, and the reduced diameter section 602 is an inverted frustum. The inner diameter of the first constant diameter section 601 = the inner diameter of the upper end of the reduced diameter section 602 > the inner diameter of the lower end of the reduced diameter section 602 = the inner diameter of the second constant diameter section 603.

[0065] The suction cylinder 10 is open at both ends and has no holes in its wall. It is vertically arranged in the second equal-diameter section 603 and coaxial therewith. The length of the suction cylinder 10 is less than that of the second equal-diameter section 603. The lower end of the suction cylinder 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular imperforate plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction cylinder 10, the annular imperforate plate 11, the annular porous plate 12, and the second equal-diameter section 603 together form a suction chamber 13.

[0066] The inner wall of the second equal diameter section 603, which is located above the suction cylinder 10, is provided with round pits 15 arranged in a staggered lattice structure;

[0067] like Figure 2 As shown, the function of the circular pit groove 15 is to make the cooling air flow 8 form a circular pit groove refraction flow 16 inside the cooling air cylinder 6; the diameter of the circular pit groove 15 is 3mm, the groove depth is 2.5mm, and the center distance between any two adjacent circular pits is 10mm;

[0068] The air supply cylinder 4 is open at both ends, has no holes in the cylinder wall, is arranged vertically, and is sleeved on the first equal-diameter section 601 and coaxial therewith; the upper end of the air supply cylinder 4 is connected to the upper end of the first equal-diameter section 601 by an annular imperforate plate, and the lower end of the air supply cylinder 4 is connected to the lower end of the first equal-diameter section 601 by an annular imperforate plate; the first equal-diameter section 601 is a porous structure, and the air supply cylinder 4 is provided with an air inlet. The air supply duct 5 is arranged horizontally, and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is arranged horizontally and communicates with the suction chamber 13;

[0069] The first constant diameter section 601 is 120 mm long and has an inner diameter of 200 mm. The inner diameter of the air supply tube 4 is 45 mm larger than the outer diameter of the first constant diameter section 601. The length of the reducing section 602 is 140 mm. The length of the second constant diameter section 603 is 1250 mm and the inner diameter is 130 mm. The length of the suction tube 10 is 1200 mm smaller than the length of the second constant diameter section 603, and the outer diameter is 50 mm smaller than the inner diameter of the second constant diameter section 603.

[0070] The inner diameter of the air supply duct 5 is 110 mm, and the inner diameter of the suction duct 7 is 110 mm;

[0071] The spinning manifold 1 is located above the first equal-diameter section 601, with the slow cooling zone 2 and the windless zone 3 located between them. The slow cooling zone 2 is located above the windless zone 3. The height of the slow cooling zone 2 is 100 mm, and the height of the windless zone 3 is 50 mm.

[0072] The spinning shaft 9 is located below and connected to the second constant diameter section 603. The length of the spinning shaft 9 is 650 mm.

[0073] The filament bundle 19 coming out of the spinning box 1 passes through the slow cooling zone 2 and the windless zone 3 and enters the cooling air duct 6, and then enters the spinning tunnel 9; the cooling air flow 8 enters the cooling air duct 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air duct 6, the flow direction of the cooling air flow 8 is parallel to the running direction of the filament bundle 19.

[0074] Example 1B

[0075] A method for preparing high-strength and high-elongation polyester industrial yarn, using the high-strength and high-elongation polyester industrial yarn preparation device provided in Example 1A;

[0076] The spinning process is as follows: PET polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling duct → oiled → stretched by five pairs of hot rollers → shaped → webbed → wound;

[0077] The spinning process parameters are: ambient temperature 35℃; spinning temperature 290℃; slow cooling zone temperature 290℃; cooling air temperature 25℃; cooling air speed 0.8m / s; suction pressure of the suction pipe is 0.05Pa; the speed of the first pair of hot rollers is 550m / min, and the temperature is 80℃; the speed of the second pair of hot rollers is 570m / min, and the temperature is 90℃; the speed of the third pair of hot rollers is 2130m / min, and the temperature is 135℃; the speed of the fourth pair of hot rollers is 3135m / min, and the temperature is 220℃; the speed of the fifth pair of hot rollers is 2965m / min, and the temperature is 200℃; the total stretching ratio is 5.50, the main stretching ratio is 3.74, and the secondary stretching ratio is 1.47; the winding speed is 2980m / min; and the spinning tension is 120cN.

[0078] The high-strength and high-elongation polyester industrial yarn produced has a linear density of 1100 dtex, a breaking strength of 7.2 cN / dtex, an elongation at break of 32%, a yarn unevenness CV value of 0.5%, a dry heat shrinkage rate of 3%, and a hair degradation rate of 1%.

[0079] Comparative Example 1A

[0080] A production device for polyester industrial yarn is basically the same as that of Example 1A, except that no suction pipe is provided. Figure 6 As shown, the cooling air flow 8 and the filament bundle 19 are both located in the cooling air cylinder 6 , and the cooling air flow 8 forms a reverse air flow 14 at the outlet of the cooling air cylinder 6 .

[0081] Comparative Example 1B

[0082] A method for preparing polyester industrial yarn is basically the same as that of Example 1B, except that a polyester industrial yarn preparation device provided in Comparative Example 1A is used.

[0083] The linear density of the prepared polyester industrial yarn is 1105 dtex, the breaking strength is 7.18 cN / dtex, the breaking elongation is 31.5%, the yarn unevenness CV value is 1.4%, the dry heat shrinkage rate is 3.1%, and the yarn degradation rate is 2.1%.

[0084] Comparing Comparative Example 1B with Example 1B, the linear density of the polyester industrial yarn produced in Comparative Example 1B did not change significantly, while the breaking strength decreased by 0.02 cN / dtex. The elongation at break did not change significantly, the CV value of the strand unevenness increased by 0.9%, the dry heat shrinkage did not change significantly, and the lint degradation rate increased by 1.1%. This is because the cooling duct's outlet is not equipped with a suction duct. Cooling airflow 8 forms a counterflow 14 at the outlet of cooling duct 6, causing airflow pressure fluctuations at the outlet of the cooling duct. This disturbs the filament bundle 19, causing filaments to "fight" with each other, which is then transferred to the upper filament cooling zone. This results in an increase in the CV value of the strand unevenness and an increase in lint, demonstrating the significant influence of the suction duct on strand uniformity.

[0085] Comparative Example 2A

[0086] A production device for polyester industrial yarn is basically the same as that of embodiment 1A, except that no circular pit grooves or non-circular pit grooves are provided. Figure 7 As shown, the cooling air flow 8 forms a counter-flow 14 inside the cooling air cylinder 6 .

[0087] Comparative Example 2B

[0088] A method for preparing polyester industrial yarn is basically the same as that of Example 1B, except that a polyester industrial yarn preparation device provided in Comparative Example 2A is used.

[0089] The obtained polyester industrial yarn has a linear density of 1105 dtex, a breaking strength of 7.15 cN / dtex, an elongation at break of 32%, a yarn unevenness CV value of 1.5%, a dry heat shrinkage rate of 3%, and a hair degradation rate of 1.5%.

[0090] Comparing Comparative Example 2B with Example 1B, the linear density of the polyester industrial yarn produced in Comparative Example 2B did not change significantly, the breaking strength decreased by 0.05 cN / dtex, the breaking elongation did not change significantly, the CV value of the yarn unevenness increased by 1%, the dry heat shrinkage did not change significantly, and the lint degradation rate increased by 0.5%. This is because the inner wall of the cooling duct is not grooved, and the cooling airflow 8 forms a counterflow 14 within the cooling duct 6. The cooling airflow velocity in the cross-sectional direction of the cooling duct 6 is uneven, resulting in increased differences in the degree of cooling between different filament bundles, uneven orientation and crystallization between the filament bundle molecules, resulting in reduced strength and increased CV value of the yarn unevenness. Subsequently, at the same stretching ratio, different degrees of stretching and lint appear, indicating that grooves have a significant impact on yarn uniformity.

[0091] Comparative Example 3A

[0092] A preparation device for polyester industrial yarn, such as Figure 8 As shown, the filament bundle 19 coming out of the spinning box 1 passes through the slow cooling zone 2 and the windless zone 3 and then enters the cooling air duct 6. After the cooling air flow 8 enters the cooling air duct 6 from the air supply duct 5, the flow direction of the cooling air flow 8 is perpendicular to the running direction of the filament bundle 19.

[0093] Comparative Example 3B

[0094] A method for preparing polyester industrial yarn is basically the same as that of Example 1B, except that a polyester industrial yarn preparation device provided in Comparative Example 3A is used.

[0095] The obtained polyester industrial yarn has a linear density of 1105 dtex, a breaking strength of 8 cN / dtex, an elongation at break of 16%, a yarn unevenness CV value of 0.6%, a dry heat shrinkage rate of 7%, and a hair degradation rate of 1.2%.

[0096] Comparing Comparative Example 3B with Example 1B, the linear density of the polyester industrial yarn produced in Comparative Example 3B did not change significantly, while the breaking strength increased by 0.8 cN / dtex, the elongation at break decreased by 16%, the CV value of the yarn unevenness increased by 0.1%, the dry heat shrinkage increased by 4.0%, and the lint degradation rate increased by 0.2%. The cooling method, in which the cooling airflow is perpendicular to the yarn tow's travel direction, increases the tension on the tow and the degree of molecular orientation of the spun fibers. Subsequent stretching by heated rollers further increases the overall molecular chain orientation, resulting in increased breaking strength, decreased elongation at break, and increased dry heat shrinkage.

[0097] Example 2A

[0098] like Figure 1 and Figure 2The device for producing high-strength and high-elongation polyester industrial yarn shown in the figure consists of a spinning box 1, an air supply cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular non-porous plate 11, an annular porous plate 12 and a spinning tunnel 9;

[0099] The cooling air duct 6 is open at both ends and arranged vertically. It consists of a first constant diameter section 601, a reduced diameter section 602, and a second constant diameter section 603, which are arranged in sequence from top to bottom and are coaxial. The reduced diameter section 602 and the second constant diameter section 603 have no holes in their walls. Each constant diameter section is cylindrical, and the reduced diameter section 602 is an inverted frustum. The inner diameter of the first constant diameter section 601 = the inner diameter of the upper end of the reduced diameter section 602 > the inner diameter of the lower end of the reduced diameter section 602 = the inner diameter of the second constant diameter section 603.

[0100] The suction cylinder 10 is open at both ends and has no holes in its wall. It is vertically arranged in the second equal-diameter section 603 and coaxial therewith. The length of the suction cylinder 10 is less than that of the second equal-diameter section 603. The lower end of the suction cylinder 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular imperforate plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction cylinder 10, the annular imperforate plate 11, the annular porous plate 12, and the second equal-diameter section 603 together form a suction chamber 13.

[0101] The inner wall of the second equal diameter section 603, which is located above the suction cylinder 10, is provided with round pits 15 arranged in a staggered lattice structure;

[0102] like Figure 2 As shown, the function of the circular pit groove 15 is to make the cooling air flow 8 form a circular pit groove refraction flow 16 inside the cooling air cylinder 6; the diameter of the circular pit groove 15 is 4mm, the groove depth is 2mm, and the center distance between any two adjacent circular pits is 9mm;

[0103] The air supply cylinder 4 is open at both ends, has no holes in the cylinder wall, is arranged vertically, and is sleeved on the first equal-diameter section 601 and coaxial therewith; the upper end of the air supply cylinder 4 is connected to the upper end of the first equal-diameter section 601 by an annular imperforate plate, and the lower end of the air supply cylinder 4 is connected to the lower end of the first equal-diameter section 601 by an annular imperforate plate; the first equal-diameter section 601 is a porous structure, and the air supply cylinder 4 is provided with an air inlet. The air supply duct 5 is arranged horizontally, and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is arranged horizontally and communicates with the suction chamber 13;

[0104] The first constant diameter section 601 is 110 mm long and has an inner diameter of 220 mm. The inner diameter of the air supply tube 4 is 50 mm larger than the outer diameter of the first constant diameter section 601. The length of the reducing section 602 is 160 mm. The length of the second constant diameter section 603 is 1100 mm and the inner diameter is 200 mm. The length of the suction tube 10 is 1100 mm smaller than the length of the second constant diameter section 603, and the outer diameter is 42 mm smaller than the inner diameter of the second constant diameter section 6.

[0105] The inner diameter of the air supply duct 5 is 120 mm, and the inner diameter of the suction duct 7 is 120 mm;

[0106] The spinning manifold 1 is located above the first equal-diameter section 601, with the slow cooling zone 2 and the windless zone 3 located between them. The slow cooling zone 2 is located above the windless zone 3. The height of the slow cooling zone 2 is 95 mm, and the height of the windless zone 3 is 55 mm.

[0107] The spinning shaft 9 is located below and connected to the second constant diameter section 603. The length of the spinning shaft 9 is 700 mm.

[0108] The filament bundle 19 coming out of the spinning box 1 passes through the slow cooling zone 2 and the windless zone 3 and enters the cooling air duct 6, and then enters the spinning tunnel 9; the cooling air flow 8 enters the cooling air duct 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air duct 6, the flow direction of the cooling air flow 8 is parallel to the running direction of the filament bundle 19.

[0109] Example 2B

[0110] A method for preparing high-strength and high-elongation polyester industrial yarn, using the high-strength and high-elongation polyester industrial yarn preparation device provided in Example 2A;

[0111] The spinning process is as follows: PET polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling duct → oiled → stretched by five pairs of hot rollers → shaped → webbed → wound;

[0112] The spinning process parameters are: ambient temperature 38°C; spinning temperature 310°C; slow cooling zone temperature 295°C; cooling air temperature 24°C; cooling air speed 1.2m / s; suction pressure of the suction pipe is 0.15Pa; the speed of the first pair of hot rollers is 560m / min, and the temperature is 72°C; the speed of the second pair of hot rollers is 580m / min, and the temperature is 95°C; the speed of the third pair of hot rollers is 2498m / min, and the temperature is 130°C; the speed of the fourth pair of hot rollers is 3248m / min, and the temperature is 250°C; the speed of the fifth pair of hot rollers is 3078m / min, and the temperature is 180°C; the total stretching ratio is 5.60, the main stretching ratio is 4.31, and the secondary stretching ratio is 1.30; the winding speed is 3200m / min; and the spinning tension is 100cN.

[0113] The high-strength and high-elongation polyester industrial yarn produced has a linear density of 1200 dtex, a breaking strength of 7.3 cN / dtex, an elongation at break of 31%, a yarn unevenness CV value of 0.7%, a dry heat shrinkage rate of 3.1%, and a hair degradation rate of 0.8%.

[0114] Example 3A

[0115] like Figure 1 and Figure 2 The device for producing high-strength and high-elongation polyester industrial yarn shown in the figure consists of a spinning box 1, an air supply cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular non-porous plate 11, an annular porous plate 12 and a spinning tunnel 9;

[0116] The cooling air duct 6 is open at both ends and arranged vertically. It consists of a first constant diameter section 601, a reduced diameter section 602, and a second constant diameter section 603, which are arranged in sequence from top to bottom and are coaxial. The reduced diameter section 602 and the second constant diameter section 603 have no holes in their walls. Each constant diameter section is cylindrical, and the reduced diameter section 602 is an inverted frustum. The inner diameter of the first constant diameter section 601 = the inner diameter of the upper end of the reduced diameter section 602 > the inner diameter of the lower end of the reduced diameter section 602 = the inner diameter of the second constant diameter section 603.

[0117] The suction cylinder 10 is open at both ends and has no holes in its wall. It is vertically arranged in the second equal-diameter section 603 and coaxial therewith. The length of the suction cylinder 10 is less than that of the second equal-diameter section 603. The lower end of the suction cylinder 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular imperforate plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction cylinder 10, the annular imperforate plate 11, the annular porous plate 12, and the second equal-diameter section 603 together form a suction chamber 13.

[0118] The inner wall of the second equal diameter section 603, which is located above the suction cylinder 10, is provided with round pits 15 arranged in a staggered lattice structure;

[0119] like Figure 2 As shown, the function of the circular pit groove 15 is to make the cooling air flow 8 form a circular pit groove refraction flow 16 inside the cooling air cylinder 6; the diameter of the circular pit groove 15 is 3.5 mm, the groove depth is 2.3 mm, and the center distance between any two adjacent circular pits is 9.5 mm;

[0120] The air supply cylinder 4 is open at both ends, has no holes in the cylinder wall, is arranged vertically, and is sleeved on the first equal-diameter section 601 and coaxial therewith; the upper end of the air supply cylinder 4 is connected to the upper end of the first equal-diameter section 601 by an annular imperforate plate, and the lower end of the air supply cylinder 4 is connected to the lower end of the first equal-diameter section 601 by an annular imperforate plate; the first equal-diameter section 601 is a porous structure, and the air supply cylinder 4 is provided with an air inlet. The air supply duct 5 is arranged horizontally, and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is arranged horizontally and communicates with the suction chamber 13;

[0121] The first constant diameter section 601 is 150 mm long and has an inner diameter of 240 mm. The inner diameter of the air supply tube 4 is 40 mm larger than the outer diameter of the first constant diameter section 601. The diameter-reducing section 602 is 150 mm long. The second constant diameter section 603 is 1000 mm long and has an inner diameter of 180 mm. The length of the suction tube 10 is 800 mm shorter than the length of the second constant diameter section 603, and the outer diameter is 45 mm smaller than the inner diameter of the second constant diameter section 6.

[0122] The inner diameter of the air supply duct 5 is 115 mm, and the inner diameter of the suction duct 7 is 115 mm;

[0123] The spinning manifold 1 is located above the first equal-diameter section 601, with the slow cooling zone 2 and the windless zone 3 located between them. The slow cooling zone 2 is located above the windless zone 3. The height of the slow cooling zone 2 is 105 mm, and the height of the windless zone 3 is 45 mm.

[0124] The spinning shaft 9 is located below and connected to the second constant diameter section 603. The length of the spinning shaft 9 is 650 mm.

[0125] The filament bundle 19 coming out of the spinning box 1 passes through the slow cooling zone 2 and the windless zone 3 and enters the cooling air duct 6, and then enters the spinning tunnel 9; the cooling air flow 8 enters the cooling air duct 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air duct 6, the flow direction of the cooling air flow 8 is parallel to the running direction of the filament bundle 19.

[0126] Example 3B

[0127] A method for preparing high-strength and high-elongation polyester industrial yarn, using the high-strength and high-elongation polyester industrial yarn preparation device provided in Example 3A;

[0128] The spinning process is as follows: PET polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling duct → oiled → stretched by five pairs of hot rollers → shaped → webbed → wound;

[0129] The spinning process parameters are as follows: ambient temperature 40°C; spinning temperature 300°C; slow cooling zone temperature 300°C; cooling air temperature 20°C; cooling air speed 0.7m / s; suction pressure of the suction pipe is 0.2Pa; the speed of the first pair of hot rollers is 430m / min, and the temperature is 70°C; the speed of the second pair of hot rollers is 450m / min, and the temperature is 100°C; the speed of the third pair of hot rollers is 2000m / min, and the temperature is 125°C; the speed of the fourth pair of hot rollers is 2700m / min, and the temperature is 240°C; the speed of the fifth pair of hot rollers is 2530m / min, and the temperature is 190°C; the total stretching ratio is 6.00, the primary stretching ratio is 4.44, and the secondary stretching ratio is 1.35; the winding speed is 2650m / min; and the spinning tension is 110cN.

[0130] The high-strength and high-elongation polyester industrial yarn produced has a linear density of 1300 dtex, a breaking strength of 7.5 cN / dtex, an elongation at break of 30%, a yarn unevenness CV value of 0.85%, a dry heat shrinkage rate of 3.05%, and a hair degradation rate of 0.5%.

[0131] Example 4A

[0132] like Figure 1 and Figure 2 The device for producing high-strength and high-elongation polyester industrial yarn shown in the figure consists of a spinning box 1, an air supply cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular non-porous plate 11, an annular porous plate 12 and a spinning tunnel 9;

[0133] The cooling air duct 6 is open at both ends and arranged vertically. It consists of a first constant diameter section 601, a reduced diameter section 602, and a second constant diameter section 603, which are arranged in sequence from top to bottom and are coaxial. The reduced diameter section 602 and the second constant diameter section 603 have no holes in their walls. Each constant diameter section is cylindrical, and the reduced diameter section 602 is an inverted frustum. The inner diameter of the first constant diameter section 601 = the inner diameter of the upper end of the reduced diameter section 602 > the inner diameter of the lower end of the reduced diameter section 602 = the inner diameter of the second constant diameter section 603.

[0134] The suction cylinder 10 is open at both ends and has no holes in its wall. It is vertically arranged in the second equal-diameter section 603 and coaxial therewith. The length of the suction cylinder 10 is less than that of the second equal-diameter section 603. The lower end of the suction cylinder 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular imperforate plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction cylinder 10, the annular imperforate plate 11, the annular porous plate 12, and the second equal-diameter section 603 together form a suction chamber 13.

[0135] The inner wall of the second equal diameter section 603, which is located above the suction cylinder 10, is provided with round pits 15 arranged in a staggered lattice structure;

[0136] like Figure 2 As shown, the function of the circular pit groove 15 is to make the cooling air flow 8 form a circular pit groove refraction flow 16 inside the cooling air cylinder 6; the diameter of the circular pit groove 15 is 4mm, the groove depth is 2.1mm, and the center distance between any two adjacent circular pits is 10mm;

[0137] The air supply cylinder 4 is open at both ends, has no holes in the cylinder wall, is arranged vertically, and is sleeved on the first equal-diameter section 601 and coaxial therewith; the upper end of the air supply cylinder 4 is connected to the upper end of the first equal-diameter section 601 by an annular imperforate plate, and the lower end of the air supply cylinder 4 is connected to the lower end of the first equal-diameter section 601 by an annular imperforate plate; the first equal-diameter section 601 is a porous structure, and the air supply cylinder 4 is provided with an air inlet. The air supply duct 5 is arranged horizontally, and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is arranged horizontally and communicates with the suction chamber 13;

[0138] The first constant diameter section 601 is 130 mm long and has an inner diameter of 250 mm. The inner diameter of the air supply tube 4 is 60 mm larger than the outer diameter of the first constant diameter section 601. The length of the reducing section 602 is 120 mm. The length of the second constant diameter section 603 is 1300 mm and the inner diameter is 150 mm. The length of the suction tube 10 is 900 mm shorter than the length of the second constant diameter section 603, and the outer diameter is 40 mm smaller than the inner diameter of the second constant diameter section 6.

[0139] The inner diameter of the air supply duct 5 is 100 mm, and the inner diameter of the suction duct 7 is 100 mm;

[0140] The spinning manifold 1 is located above the first equal-diameter section 601, with the slow cooling zone 2 and the windless zone 3 located between them. The slow cooling zone 2 is located above the windless zone 3. The height of the slow cooling zone 2 is 100 mm, and the height of the windless zone 3 is 50 mm.

[0141] The spinning shaft 9 is located below and connected to the second constant diameter section 603. The length of the spinning shaft 9 is 600 mm.

[0142] The filament bundle 19 coming out of the spinning box 1 passes through the slow cooling zone 2 and the windless zone 3 and enters the cooling air duct 6, and then enters the spinning tunnel 9; the cooling air flow 8 enters the cooling air duct 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air duct 6, the flow direction of the cooling air flow 8 is parallel to the running direction of the filament bundle 19.

[0143] Example 4B

[0144] A method for preparing high-strength and high-elongation polyester industrial yarn, using the high-strength and high-elongation polyester industrial yarn preparation device provided in Example 4A;

[0145] The spinning process is as follows: PET polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling duct → oiled → stretched by five pairs of hot rollers → shaped → webbed → wound;

[0146] The spinning process parameters are: ambient temperature 37°C; spinning temperature 295°C; slow cooling zone temperature 310°C; cooling air temperature 23°C; cooling air speed 1.5m / s; suction pressure of the suction pipe is 0.1Pa; the speed of the first pair of hot rollers is 500m / min, and the temperature is 76°C; the speed of the second pair of hot rollers is 520m / min, and the temperature is 98°C; the speed of the third pair of hot rollers is 2015m / min, and the temperature is 123°C; the speed of the fourth pair of hot rollers is 3224m / min, and the temperature is 210°C; the speed of the fifth pair of hot rollers is 3054m / min, and the temperature is 160°C; the total stretching ratio is 6.20, the main stretching ratio is 3.88, and the secondary stretching ratio is 1.60; the winding speed is 3200m / min; and the spinning tension is 130cN.

[0147] The linear density of the high-strength and high-elongation polyester industrial yarn produced is 1450dtex, the breaking strength is 7.6cN / dtex, the breaking elongation is 31%, the yarn unevenness CV value is 0.92%, the dry heat shrinkage rate is 3.2%, and the yarn degradation rate is 0.7%.

[0148] Example 5A

[0149] like Figure 1 、 Figure 3 and Figure 4 The device for producing high-strength and high-elongation polyester industrial yarn shown in the figure consists of a spinning box 1, an air supply cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular non-porous plate 11, an annular porous plate 12 and a spinning tunnel 9;

[0150] The cooling air duct 6 is open at both ends and arranged vertically. It consists of a first constant diameter section 601, a reduced diameter section 602, and a second constant diameter section 603, which are arranged in sequence from top to bottom and are coaxial. The reduced diameter section 602 and the second constant diameter section 603 have no holes in their walls. Each constant diameter section is cylindrical, and the reduced diameter section 602 is an inverted frustum. The inner diameter of the first constant diameter section 601 = the inner diameter of the upper end of the reduced diameter section 602 > the inner diameter of the lower end of the reduced diameter section 602 = the inner diameter of the second constant diameter section 603.

[0151] The suction cylinder 10 is open at both ends and has no holes in its wall. It is vertically arranged in the second equal-diameter section 603 and coaxial therewith. The length of the suction cylinder 10 is less than that of the second equal-diameter section 603. The lower end of the suction cylinder 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular imperforate plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction cylinder 10, the annular imperforate plate 11, the annular porous plate 12, and the second equal-diameter section 603 together form a suction chamber 13.

[0152] The second equal diameter section 603 is located above the suction cylinder 10 and has multiple groups of non-circular grooves 17 on its inner wall;

[0153] like Figure 3 As shown, the function of the non-circular pit groove 17 is to make the cooling air flow 8 form a non-circular pit groove refraction flow 18 inside the cooling air cylinder 6;

[0154] like Figure 4 As shown, the non-circular groove 17 is a V-shaped groove. The size of the non-circular groove 17 gradually decreases from the groove opening to the groove bottom. The groove opening is an oblong shape with a length of 12 mm and a width of 3 mm. The groove bottom is a line segment shape with a length of the groove bottom = a length of the oblong shape - a width of the oblong shape. The groove depth is 2 mm.

[0155] The same group of non-circular pit grooves are distributed along the circumferential spacing of the second equal diameter section 603 with a spacing of 4 mm, and different groups of non-circular pit grooves are distributed along the axial spacing of the second equal diameter section 603 with a spacing of 10 mm;

[0156] For the same non-circular groove, the shortest symmetrical dividing line segment of the oblong, the perpendicular bisector of the line segment, and the shortest symmetrical dividing line segment of the rectangle are all parallel to the axial direction of the second equal-diameter segment 603. The straight line where the center of the oblong and the midpoint of the line segment or the center of the rectangle are located is perpendicular to and intersects the central axis of the second equal-diameter segment 603. The shortest symmetrical dividing line segment is the shortest line segment required to divide the figure into two symmetrical parts.

[0157] The air supply cylinder 4 is open at both ends, has no holes in the cylinder wall, is arranged vertically, and is sleeved on the first equal-diameter section 601 and coaxial therewith; the upper end of the air supply cylinder 4 is connected to the upper end of the first equal-diameter section 601 by an annular imperforate plate, and the lower end of the air supply cylinder 4 is connected to the lower end of the first equal-diameter section 601 by an annular imperforate plate; the first equal-diameter section 601 is a porous structure, and the air supply cylinder 4 is provided with an air inlet. The air supply duct 5 is arranged horizontally, and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is arranged horizontally and communicates with the suction chamber 13;

[0158] The first constant diameter section 601 is 120 mm long and has an inner diameter of 200 mm. The inner diameter of the air supply tube 4 is 45 mm larger than the outer diameter of the first constant diameter section 601. The length of the reducing section 602 is 140 mm. The length of the second constant diameter section 603 is 1250 mm and the inner diameter is 130 mm. The length of the suction tube 10 is 1200 mm smaller than the length of the second constant diameter section 603, and the outer diameter is 50 mm smaller than the inner diameter of the second constant diameter section 6.

[0159] The inner diameter of the air supply duct 5 is 110 mm, and the inner diameter of the suction duct 7 is 110 mm;

[0160] The spinning manifold 1 is located above the first equal-diameter section 601, with the slow cooling zone 2 and the windless zone 3 located between them. The slow cooling zone 2 is located above the windless zone 3. The height of the slow cooling zone 2 is 100 mm, and the height of the windless zone 3 is 50 mm.

[0161] The spinning shaft 9 is located below and connected to the second constant diameter section 603. The length of the spinning shaft 9 is 650 mm.

[0162] The filament bundle 19 coming out of the spinning box 1 passes through the slow cooling zone 2 and the windless zone 3 and enters the cooling air duct 6, and then enters the spinning tunnel 9; the cooling air flow 8 enters the cooling air duct 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air duct 6, the flow direction of the cooling air flow 8 is parallel to the running direction of the filament bundle 19.

[0163] Example 5B

[0164] A method for preparing high-strength and high-elongation polyester industrial yarn, using the high-strength and high-elongation polyester industrial yarn preparation device provided in Example 5A;

[0165] The spinning process is as follows: PET polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling duct → oiled → stretched by five pairs of hot rollers → shaped → webbed → wound;

[0166] The spinning process parameters are: ambient temperature 35℃; spinning temperature 290℃; slow cooling zone temperature 290℃; cooling air temperature 25℃; cooling air speed 0.8m / s; suction pressure of the suction pipe is 0.05Pa; the speed of the first pair of hot rollers is 550m / min, and the temperature is 80℃; the speed of the second pair of hot rollers is 570m / min, and the temperature is 90℃; the speed of the third pair of hot rollers is 2130m / min, and the temperature is 135℃; the speed of the fourth pair of hot rollers is 3135m / min, and the temperature is 220℃; the speed of the fifth pair of hot rollers is 2965m / min, and the temperature is 200℃; the total stretching ratio is 5.50, the main stretching ratio is 3.74, and the secondary stretching ratio is 1.47; the winding speed is 2980m / min; and the spinning tension is 120cN.

[0167] The high-strength and high-elongation polyester industrial yarn produced has a linear density of 1100 dtex, a breaking strength of 7.2 cN / dtex, an elongation at break of 31%, a yarn unevenness CV value of 0.6%, a dry heat shrinkage rate of 3.1%, and a hair degradation rate of 1.1%.

[0168] Example 6A

[0169] like Figure 1 、 Figure 3 and Figure 4 The device for producing high-strength and high-elongation polyester industrial yarn shown in the figure consists of a spinning box 1, an air supply cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular non-porous plate 11, an annular porous plate 12 and a spinning tunnel 9;

[0170] The cooling air duct 6 is open at both ends and arranged vertically. It consists of a first constant diameter section 601, a reduced diameter section 602, and a second constant diameter section 603, which are arranged in sequence from top to bottom and are coaxial. The reduced diameter section 602 and the second constant diameter section 603 have no holes in their walls. Each constant diameter section is cylindrical, and the reduced diameter section 602 is an inverted frustum. The inner diameter of the first constant diameter section 601 = the inner diameter of the upper end of the reduced diameter section 602 > the inner diameter of the lower end of the reduced diameter section 602 = the inner diameter of the second constant diameter section 603.

[0171] The suction cylinder 10 is open at both ends and has no holes in its wall. It is vertically arranged in the second equal-diameter section 603 and coaxial therewith. The length of the suction cylinder 10 is less than that of the second equal-diameter section 603. The lower end of the suction cylinder 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular imperforate plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction cylinder 10, the annular imperforate plate 11, the annular porous plate 12, and the second equal-diameter section 603 together form a suction chamber 13.

[0172] The second equal diameter section 603 is located above the suction cylinder 10 and has multiple groups of non-circular grooves 17 on its inner wall;

[0173] like Figure 3 As shown, the function of the non-circular pit groove 17 is to make the cooling air flow 8 form a non-circular pit groove refraction flow 18 inside the cooling air cylinder 6;

[0174] like Figure 4 As shown, the non-circular groove 17 is a V-shaped groove. The size of the non-circular groove 17 gradually decreases from the groove opening to the groove bottom. The groove opening is an oblong shape with a length of 9 mm and a width of 3.5 mm. The groove bottom is a line segment shape with a length of the groove bottom = a length of the oblong shape - a width of the oblong shape. The groove depth is 2.5 mm.

[0175] The same group of non-circular pit grooves are distributed along the circumferential spacing of the second equal diameter section 603 at a spacing of 6 mm, and the different groups of non-circular pit grooves are distributed along the axial spacing of the second equal diameter section 603 at a spacing of 9 mm.

[0176] For the same non-circular groove, the shortest symmetrical dividing line segment of the oblong, the perpendicular bisector of the line segment, and the shortest symmetrical dividing line segment of the rectangle are all parallel to the axial direction of the second equal-diameter segment 603. The straight line where the center of the oblong and the midpoint of the line segment or the center of the rectangle are located is perpendicular to and intersects the central axis of the second equal-diameter segment 603. The shortest symmetrical dividing line segment is the shortest line segment required to divide the figure into two symmetrical parts.

[0177] The air supply cylinder 4 is open at both ends, has no holes in the cylinder wall, is arranged vertically, and is sleeved on the first equal-diameter section 601 and coaxial therewith; the upper end of the air supply cylinder 4 is connected to the upper end of the first equal-diameter section 601 by an annular imperforate plate, and the lower end of the air supply cylinder 4 is connected to the lower end of the first equal-diameter section 601 by an annular imperforate plate; the first equal-diameter section 601 is a porous structure, and the air supply cylinder 4 is provided with an air inlet. The air supply duct 5 is arranged horizontally, and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is arranged horizontally and communicates with the suction chamber 13;

[0178] The first constant diameter section 601 is 110 mm long and has an inner diameter of 220 mm. The inner diameter of the air supply tube 4 is 50 mm larger than the outer diameter of the first constant diameter section 601. The length of the reducing section 602 is 160 mm. The length of the second constant diameter section 603 is 1100 mm and the inner diameter is 200 mm. The length of the suction tube 10 is 1100 mm smaller than the length of the second constant diameter section 603, and the outer diameter is 42 mm smaller than the inner diameter of the second constant diameter section 6.

[0179] The inner diameter of the air supply duct 5 is 120 mm, and the inner diameter of the suction duct 7 is 120 mm;

[0180] The spinning manifold 1 is located above the first equal-diameter section 601, with the slow cooling zone 2 and the windless zone 3 located between them. The slow cooling zone 2 is located above the windless zone 3. The height of the slow cooling zone 2 is 95 mm, and the height of the windless zone 3 is 55 mm.

[0181] The spinning shaft 9 is located below and connected to the second constant diameter section 603. The length of the spinning shaft 9 is 700 mm.

[0182] The filament bundle 19 coming out of the spinning box 1 passes through the slow cooling zone 2 and the windless zone 3 and enters the cooling air duct 6, and then enters the spinning tunnel 9; the cooling air flow 8 enters the cooling air duct 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air duct 6, the flow direction of the cooling air flow 8 is parallel to the running direction of the filament bundle 19.

[0183] Example 6B

[0184] A method for preparing high-strength and high-elongation polyester industrial yarn, using the high-strength and high-elongation polyester industrial yarn preparation device provided in Example 6A;

[0185] The spinning process is as follows: PET polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling duct → oiled → stretched by five pairs of hot rollers → shaped → webbed → wound;

[0186] The spinning process parameters are: ambient temperature 38°C; spinning temperature 310°C; slow cooling zone temperature 295°C; cooling air temperature 24°C; cooling air speed 1.2m / s; suction pressure of the suction pipe is 0.15Pa; the speed of the first pair of hot rollers is 560m / min, and the temperature is 72°C; the speed of the second pair of hot rollers is 580m / min, and the temperature is 95°C; the speed of the third pair of hot rollers is 2498m / min, and the temperature is 130°C; the speed of the fourth pair of hot rollers is 3248m / min, and the temperature is 250°C; the speed of the fifth pair of hot rollers is 3078m / min, and the temperature is 180°C; the total stretching ratio is 5.60, the main stretching ratio is 4.31, and the secondary stretching ratio is 1.30; the winding speed is 3200m / min; and the spinning tension is 100cN.

[0187] The high-strength and high-elongation polyester industrial yarn produced has a linear density of 1200 dtex, a breaking strength of 7.4 cN / dtex, an elongation at break of 32%, a yarn unevenness CV value of 0.65%, a dry heat shrinkage rate of 3%, and a hair degradation rate of 0.66%.

[0188] Example 7A

[0189] like Figure 1 、 Figure 3 and Figure 5 The device for producing high-strength and high-elongation polyester industrial yarn shown in the figure consists of a spinning box 1, an air supply cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular non-porous plate 11, an annular porous plate 12 and a spinning tunnel 9;

[0190] The cooling air duct 6 is open at both ends and arranged vertically. It consists of a first constant diameter section 601, a reduced diameter section 602, and a second constant diameter section 603, which are arranged in sequence from top to bottom and are coaxial. The reduced diameter section 602 and the second constant diameter section 603 have no holes in their walls. Each constant diameter section is cylindrical, and the reduced diameter section 602 is an inverted frustum. The inner diameter of the first constant diameter section 601 = the inner diameter of the upper end of the reduced diameter section 602 > the inner diameter of the lower end of the reduced diameter section 602 = the inner diameter of the second constant diameter section 603.

[0191] The suction cylinder 10 is open at both ends and has no holes in its wall. It is vertically arranged in the second equal-diameter section 603 and coaxial therewith. The length of the suction cylinder 10 is less than that of the second equal-diameter section 603. The lower end of the suction cylinder 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular imperforate plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction cylinder 10, the annular imperforate plate 11, the annular porous plate 12, and the second equal-diameter section 603 together form a suction chamber 13.

[0192] The second equal diameter section 603 is located above the suction cylinder 10 and has multiple groups of non-circular grooves 17 on its inner wall;

[0193] like Figure 3 As shown, the function of the non-circular pit groove 17 is to make the cooling air flow 8 form a non-circular pit groove refraction flow 18 inside the cooling air cylinder 6;

[0194] like Figure 5 As shown, the non-circular pit groove 17 is an inverted trapezoidal groove with equal height. The size of the non-circular pit groove 17 gradually decreases from the groove opening to the groove bottom. The groove opening is an oblong shape with a length of 20 mm and a width of 4 mm. The groove bottom is a rectangle with a groove depth of 2.2 mm. The angle θ between the groove wall and the central axis of the non-circular pit groove is 30°.

[0195] The same group of non-circular pit grooves are distributed along the circumferential spacing of the second equal diameter section 603 with a spacing of 5 mm, and the different groups of non-circular pit grooves are distributed along the axial spacing of the second equal diameter section 603 with a spacing of 9.5 mm.

[0196] For the same non-circular groove, the shortest symmetrical dividing line segment of the oblong, the perpendicular bisector of the line segment, and the shortest symmetrical dividing line segment of the rectangle are all parallel to the axial direction of the second equal-diameter segment 603. The straight line where the center of the oblong and the midpoint of the line segment or the center of the rectangle are located is perpendicular to and intersects the central axis of the second equal-diameter segment 603. The shortest symmetrical dividing line segment is the shortest line segment required to divide the figure into two symmetrical parts.

[0197] The air supply cylinder 4 is open at both ends, has no holes in the cylinder wall, is arranged vertically, and is sleeved on the first equal-diameter section 601 and coaxial therewith; the upper end of the air supply cylinder 4 is connected to the upper end of the first equal-diameter section 601 by an annular imperforate plate, and the lower end of the air supply cylinder 4 is connected to the lower end of the first equal-diameter section 601 by an annular imperforate plate; the first equal-diameter section 601 is a porous structure, and the air supply cylinder 4 is provided with an air inlet. The air supply duct 5 is arranged horizontally, and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is arranged horizontally and communicates with the suction chamber 13;

[0198] The first constant diameter section 601 is 150 mm long and has an inner diameter of 240 mm. The inner diameter of the air supply tube 4 is 40 mm larger than the outer diameter of the first constant diameter section 601. The diameter-reducing section 602 is 150 mm long. The second constant diameter section 603 is 1000 mm long and has an inner diameter of 180 mm. The length of the suction tube 10 is 800 mm shorter than the length of the second constant diameter section 603, and the outer diameter is 45 mm smaller than the inner diameter of the second constant diameter section 6.

[0199] The inner diameter of the air supply duct 5 is 115 mm, and the inner diameter of the suction duct 7 is 115 mm;

[0200] The spinning manifold 1 is located above the first equal-diameter section 601, with the slow cooling zone 2 and the windless zone 3 located between them. The slow cooling zone 2 is located above the windless zone 3. The height of the slow cooling zone 2 is 105 mm, and the height of the windless zone 3 is 45 mm.

[0201] The spinning shaft 9 is located below and connected to the second constant diameter section 603. The length of the spinning shaft 9 is 650 mm.

[0202] The filament bundle 19 coming out of the spinning box 1 passes through the slow cooling zone 2 and the windless zone 3 and enters the cooling air duct 6, and then enters the spinning tunnel 9; the cooling air flow 8 enters the cooling air duct 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air duct 6, the flow direction of the cooling air flow 8 is parallel to the running direction of the filament bundle 19.

[0203] Example 7B

[0204] A method for preparing high-strength and high-elongation polyester industrial yarn, using the high-strength and high-elongation polyester industrial yarn preparation device provided in Example 7A;

[0205] The spinning process is as follows: PET polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling duct → oiled → stretched by five pairs of hot rollers → shaped → webbed → wound;

[0206] The spinning process parameters are as follows: ambient temperature 40°C; spinning temperature 300°C; slow cooling zone temperature 300°C; cooling air temperature 20°C; cooling air speed 0.7m / s; suction pressure of the suction pipe is 0.2Pa; the speed of the first pair of hot rollers is 430m / min, and the temperature is 70°C; the speed of the second pair of hot rollers is 450m / min, and the temperature is 100°C; the speed of the third pair of hot rollers is 2000m / min, and the temperature is 125°C; the speed of the fourth pair of hot rollers is 2700m / min, and the temperature is 240°C; the speed of the fifth pair of hot rollers is 2530m / min, and the temperature is 190°C; the total stretching ratio is 6.00, the primary stretching ratio is 4.44, and the secondary stretching ratio is 1.35; the winding speed is 2650m / min; and the spinning tension is 110cN.

[0207] The linear density of the high-strength and high-elongation polyester industrial yarn produced is 1300 dtex, the breaking strength is 7.5 cN / dtex, the breaking elongation is 30%, the yarn unevenness CV value is 0.76%, the dry heat shrinkage rate is 3.2%, and the yarn degradation rate is 0.62%.

[0208] Example 8A

[0209] like Figure 1 、 Figure 3 and Figure 5 The device for producing high-strength and high-elongation polyester industrial yarn shown in the figure consists of a spinning box 1, an air supply cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular non-porous plate 11, an annular porous plate 12 and a spinning tunnel 9;

[0210] The cooling air duct 6 is open at both ends and arranged vertically. It consists of a first constant diameter section 601, a reduced diameter section 602, and a second constant diameter section 603, which are arranged in sequence from top to bottom and are coaxial. The reduced diameter section 602 and the second constant diameter section 603 have no holes in their walls. Each constant diameter section is cylindrical, and the reduced diameter section 602 is an inverted frustum. The inner diameter of the first constant diameter section 601 = the inner diameter of the upper end of the reduced diameter section 602 > the inner diameter of the lower end of the reduced diameter section 602 = the inner diameter of the second constant diameter section 603.

[0211] The suction cylinder 10 is open at both ends and has no holes in its wall. It is vertically arranged in the second equal-diameter section 603 and coaxial therewith. The length of the suction cylinder 10 is less than that of the second equal-diameter section 603. The lower end of the suction cylinder 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular imperforate plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction cylinder 10, the annular imperforate plate 11, the annular porous plate 12, and the second equal-diameter section 603 together form a suction chamber 13.

[0212] The second equal diameter section 603 is located above the suction cylinder 10 and has multiple groups of non-circular grooves 17 on its inner wall;

[0213] like Figure 3 As shown, the function of the non-circular pit groove 17 is to make the cooling air flow 8 form a non-circular pit groove refraction flow 18 inside the cooling air cylinder 6;

[0214] like Figure 5 As shown, the non-circular pit groove 17 is an inverted trapezoidal groove with equal height. The size of the non-circular pit groove 17 gradually decreases from the groove opening to the groove bottom. The groove opening is an oblong shape with a length of 15 mm and a width of 3.5 mm. The groove bottom is a rectangle with a groove depth of 2.4 mm. The angle θ between the groove wall and the central axis of the non-circular pit groove is 20°.

[0215] The same group of non-circular pit grooves are distributed along the circumferential spacing of the second equal diameter section 603 at a spacing of 4 mm, and the different groups of non-circular pit grooves are distributed along the axial spacing of the second equal diameter section 603 at a spacing of 9 mm.

[0216] For the same non-circular groove, the shortest symmetrical dividing line segment of the oblong, the perpendicular bisector of the line segment, and the shortest symmetrical dividing line segment of the rectangle are all parallel to the axial direction of the second equal-diameter segment 603. The straight line where the center of the oblong and the midpoint of the line segment or the center of the rectangle are located is perpendicular to and intersects the central axis of the second equal-diameter segment 603. The shortest symmetrical dividing line segment is the shortest line segment required to divide the figure into two symmetrical parts.

[0217] The air supply cylinder 4 is open at both ends, has no holes in the cylinder wall, is arranged vertically, and is sleeved on the first equal-diameter section 601 and coaxial therewith; the upper end of the air supply cylinder 4 is connected to the upper end of the first equal-diameter section 601 by an annular imperforate plate, and the lower end of the air supply cylinder 4 is connected to the lower end of the first equal-diameter section 601 by an annular imperforate plate; the first equal-diameter section 601 is a porous structure, and the air supply cylinder 4 is provided with an air inlet. The air supply duct 5 is arranged horizontally, and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is arranged horizontally and communicates with the suction chamber 13;

[0218] The first constant diameter section 601 is 130 mm long and has an inner diameter of 250 mm. The inner diameter of the air supply tube 4 is 60 mm larger than the outer diameter of the first constant diameter section 601. The length of the reducing section 602 is 120 mm. The length of the second constant diameter section 603 is 1300 mm and the inner diameter is 150 mm. The length of the suction tube 10 is 900 mm shorter than the length of the second constant diameter section 603, and the outer diameter is 40 mm smaller than the inner diameter of the second constant diameter section 6.

[0219] The inner diameter of the air supply duct 5 is 100 mm, and the inner diameter of the suction duct 7 is 100 mm;

[0220] The spinning manifold 1 is located above the first equal-diameter section 601, with the slow cooling zone 2 and the windless zone 3 located between them. The slow cooling zone 2 is located above the windless zone 3. The height of the slow cooling zone 2 is 100 mm, and the height of the windless zone 3 is 50 mm.

[0221] The spinning shaft 9 is located below and connected to the second constant diameter section 603. The length of the spinning shaft 9 is 600 mm.

[0222] The filament bundle 19 coming out of the spinning box 1 passes through the slow cooling zone 2 and the windless zone 3 and enters the cooling air duct 6, and then enters the spinning tunnel 9; the cooling air flow 8 enters the cooling air duct 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air duct 6, the flow direction of the cooling air flow 8 is parallel to the running direction of the filament bundle 19.

[0223] Example 8B

[0224] A method for preparing high-strength and high-elongation polyester industrial yarn, using the high-strength and high-elongation polyester industrial yarn preparation device provided in Example 8A;

[0225] The spinning process is as follows: PET polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling duct → oiled → stretched by five pairs of hot rollers → shaped → webbed → wound;

[0226] The spinning process parameters are: ambient temperature 37°C; spinning temperature 295°C; slow cooling zone temperature 310°C; cooling air temperature 23°C; cooling air speed 1.5m / s; suction pressure of the suction pipe is 0.1Pa; the speed of the first pair of hot rollers is 500m / min, and the temperature is 76°C; the speed of the second pair of hot rollers is 520m / min, and the temperature is 98°C; the speed of the third pair of hot rollers is 2015m / min, and the temperature is 123°C; the speed of the fourth pair of hot rollers is 3224m / min, and the temperature is 210°C; the speed of the fifth pair of hot rollers is 3054m / min, and the temperature is 160°C; the total stretching ratio is 6.20, the main stretching ratio is 3.88, and the secondary stretching ratio is 1.60; the winding speed is 3200m / min; and the spinning tension is 130cN.

[0227] The linear density of the high-strength and high-elongation polyester industrial yarn produced is 1450dtex, the breaking strength is 7.5cN / dtex, the breaking elongation is 30%, the yarn unevenness CV value is 0.84%, the dry heat shrinkage rate is 3%, and the yarn degradation rate is 0.85%.

Claims

1. A device for preparing high-strength and high-elongation polyester industrial yarn, characterized in that: It includes a cooling air cylinder (6), a suction cylinder (10), an annular non-porous plate (11), an annular porous plate (12), an air supply duct (5) and a suction duct (7); The cooling air duct (6) is open at both ends and arranged vertically, and is composed of a first constant diameter section (601), a variable diameter section (602) and a second constant diameter section (603) which are arranged in sequence from top to bottom and are coaxial. The walls of the variable diameter section (602) and the second constant diameter section (603) have no holes. Each constant diameter section is cylindrical, and the variable diameter section (602) is inverted truncated cone shape. The inner diameter of the first constant diameter section (601) = the inner diameter of the upper end of the variable diameter section (602) > the inner diameter of the lower end of the variable diameter section (602) = the inner diameter of the second constant diameter section (603); The suction cylinder (10) is open at both ends, has no holes in the cylinder wall, is vertically arranged in the second equal-diameter section (603) and is coaxial therewith, the length of the suction cylinder (10) is less than the length of the second equal-diameter section (603), the lower end of the suction cylinder (10) is flush with the lower end of the second equal-diameter section (603) and the two are connected by an annular imperforate plate (11), the upper end of the suction cylinder (10) is connected to the inner wall of the second equal-diameter section (603) by an annular porous plate (12), and the suction cylinder (10), the annular imperforate plate (11), the annular porous plate (12), and the second equal-diameter section (603) together form a suction chamber (13); The second equal diameter section (603) is provided with a plurality of grooves on the inner wall of the length section above the suction cylinder (10) for suppressing the separation of the boundary layer and the cooling air cylinder (6), wherein the boundary layer is a fluid layer formed due to viscosity when the cooling air flow flows through the inner wall surface of the cooling air cylinder (6); The air supply duct (5) is arranged horizontally and communicates with the first equal-diameter section (601); the suction duct (7) is arranged horizontally and communicates with the suction chamber (13).

2. The device for preparing high-strength and high-elongation polyester industrial yarn according to claim 1, characterized in that: The grooves are circular pit grooves (15) and are arranged in a staggered lattice structure; the diameter of the circular pit grooves (15) is 3-4 mm, the groove depth is 2-2.5 mm, and the center distance between any two adjacent circular pits is 9-10 mm.

3. The device for preparing high-strength and high-elongation polyester industrial yarn according to claim 1, characterized in that: The grooves are non-circular grooves (17) and are divided into multiple groups. The non-circular grooves (17) of the same group are distributed along the circumferential spacing of the second equal diameter section (603) with a spacing of 4-6 mm. The non-circular grooves (17) of different groups are distributed along the axial spacing of the second equal diameter section (603) with a spacing of 9-10 mm. The non-circular pit groove (17) is gradually reduced in size from the groove opening to the groove bottom, the groove opening is oblong, the length of the oblong is 9-20 mm and the width is 3-4 mm, the groove bottom is a line segment or a rectangle, and the groove depth is 2-2.5 mm; When the groove bottom is rectangular, the angle between the groove wall and the central axis of the non-circular pit groove (17) is θ 20-30°; For the same non-circular pit groove (17), the shortest symmetrical dividing line segment of the oblong, the perpendicular bisector of the line segment, and the shortest symmetrical dividing line segment of the rectangle are all parallel to the axial direction of the second equal-diameter segment (603), and the straight line where the center of the oblong and the midpoint of the line segment or the center of the rectangle are located is perpendicular to and intersects the central axis of the second equal-diameter segment (603). The shortest symmetrical dividing line segment is the shortest line segment required to divide the figure into two symmetrical parts.

4. The device for preparing high-strength and high-elongation polyester industrial yarn according to claim 1, characterized in that: It also includes an air supply tube (4); the air supply tube (4) is open at both ends, has no holes in the tube wall, is arranged vertically, is sleeved on the first equal-diameter section (601) and is coaxial with it; the upper end of the air supply tube (4) is connected to the upper end of the first equal-diameter section (601) through an annular non-porous plate (11), and the lower end of the air supply tube (4) is connected to the lower end of the first equal-diameter section (601) through an annular non-porous plate (11); the first equal-diameter section (601) is a porous structure, and an air inlet is provided on the air supply tube (4), and the outlet of the air supply duct (5) is connected to the air inlet.

5. The device for preparing high-strength and high-elongation polyester industrial yarn according to claim 4, characterized in that: The length of the first equal-diameter section (601) is 110-150 mm, and the inner diameter is 200-250 mm; the inner diameter of the air supply tube (4) is 40-60 mm larger than the outer diameter of the first equal-diameter section (601); the length of the reducing section (602) is 120-160 mm; the length of the second equal-diameter section (603) is 1000-1300 mm, and the inner diameter is 150-200 mm; the length of the suction tube (10) is 800-1200 mm smaller than the length of the second equal-diameter section (603), and the outer diameter is 40-50 mm smaller than the inner diameter of the second equal-diameter section (603).

6. The device for preparing high-strength and high-elongation polyester industrial yarn according to claim 5, characterized in that: The inner diameter of the air supply duct (5) is 100-120 mm, and the inner diameter of the suction duct (7) is 100-120 mm.

7. The device for preparing high-strength and high-elongation polyester industrial yarn according to claim 1, characterized in that: The spinning box (1) is also included. The spinning box (1) is located above the first equal-diameter section (601). Between the two is a slow cooling zone (2) and a windless zone (3). The slow cooling zone (2) is located above the windless zone (3).

8. The device for preparing high-strength and high-elongation polyester industrial yarn according to claim 7, characterized in that: The height of the slow cooling zone (2) is 95-105 mm; the height of the windless zone (3) is 45-55 mm.

9. The device for preparing high-strength and high-elongation polyester industrial yarn according to claim 1, characterized in that: It also includes a spinning tunnel (9), which is located below the second constant diameter section (603) and connected to it.

10. The device for preparing high-strength and high-elongation polyester industrial yarn according to claim 9, characterized in that: The length of the spinning shaft (9) is 600-700 mm.

11. A method for preparing high-strength and high-elongation polyester industrial yarn, characterized in that: A device for preparing high-strength and high-elongation polyester industrial yarn according to any one of claims 1 to 10 is used.

12. The method for preparing high-strength and high-elongation polyester industrial yarn according to claim 11, characterized in that: The spinning process is as follows: polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling duct (6) → oiled → stretched by five pairs of hot rollers → shaped → networked → wound; The spinning process parameters include: ambient temperature 35-40°C; spinning temperature 291-310°C; slow cooling zone temperature 290±20°C; cooling air temperature 20-25°C; cooling air speed 0.7-1.5m / s; suction pressure of the suction pipe (7) 0-0.2Pa; speed of the first pair of hot rollers 430-560m / min, temperature 70-80°C; speed of the second pair of hot rollers 450-580m / min, temperature 90-100°C; speed of the third pair of hot rollers 2000-2500m / min, temperature 123-135°C ; The speed of the fourth pair of hot rollers is 2700-3250m / min, and the temperature is 210-250℃; the speed of the fifth pair of hot rollers is 2500-3100m / min, and the temperature is 160-200℃; the total stretching ratio is 5.50-6.20, the main stretching ratio is 3.74-4.44, and the secondary stretching ratio is 1.30-1.60; the winding speed is 2650-3200m / min; the spinning tension is 100-130cN.

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