Preparation device and preparation method of high-strength and high-elongation polyester industrial yarn

Abstract

The invention belongs to the technical field of spinning, and relates to a preparation device and a preparation method of high-strength and high-elongation polyester industrial yarn. The preparation device comprises a cooling air cylinder, a suction cylinder, an annular non-porous plate, an annular porous plate, an air supply pipeline and a suction pipeline. The cooling air duct is vertically arranged and consists of a first equal-diameter section, a variable-diameter section and a second equal-diameter section which are sequentially arranged from top to bottom and are coaxial; the suction cylinder is vertically arranged in the second equal-diameter section and is coaxial with the second equal-diameter section, the lower end of the suction cylinder is flush with the lower end of the second equal-diameter section and is connected with the second equal-diameter section through an annular non-porous plate, the upper end of the suction cylinder is connected with the inner wall of the second equal-diameter section through an annular porous plate, and the suction cylinder, the annular non-porous plate, the annular porous plate and the second equal-diameter section jointly define a suction cavity; the second equal-diameter section is provided with a groove; the air supply pipeline is horizontally arranged and is communicated with the first equal-diameter section; and the suction pipeline is horizontally arranged and is communicated with the suction cavity. The preparation device is adopted in the preparation method, and the polyester industrial yarn with high strength and high elongation can be prepared.

Description

Technical Field

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

[0002] Polyester industrial yarns have excellent physical and chemical properties such as high strength, high modulus, heat resistance, acid and alkali resistance, etc., and low production costs. At present, they are widely used as skeleton reinforcement materials in membrane structures. A membrane structure is a spatial structure formed by a variety of high-strength thin film materials and strengthening members (steel frames, steel columns or steel cables), and as a covering structure, it is mainly applied in large stadiums, waiting halls, grand theaters and other places.

[0003] Due to the special application fields of membrane structures, they require a certain pre-tensile stress and at the same time have to bear certain external loads (rain, snow, strong winds, etc.). As the skeleton material of membrane structures, polyester industrial yarns not only need to have strength but also toughness. Therefore, in the production process, it is necessary to maintain the strength of polyester industrial yarns while increasing the elongation at break. Therefore, the preparation method of polyester industrial yarns that takes into account both strength and elongation at break has important application value.

[0004] The prior art mainly improves the elongation at break of polyester filaments from two aspects: (1) adding a modifier to the polyester melt to cause a certain entanglement structure in the polymer chains after polymerization, so that during the fiber spinning process, the fiber can withstand a higher stretching force, thereby enabling the fiber to obtain higher strength and having a larger remaining elongation. For example, the patent application with the publication number CN101880919A discloses a production method for high-elongation bright polyester filaments, which injects an ether additive with a mass content of 0.5%-0.95% into the melt. The patent application with the publication number CN102926032A discloses a high-strength, high-elongation, easy-dyeing 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 obtain a modified polyester; (2) adding a fiber elongation improver to the polyester. This improver changes from a molten state to a glassy state prior to the polyester, resists the spinning tension, inhibits the orientation of polyester molecular chains, increases the remaining elongation of the nascent fiber, and thus improves the elongation at break of the fiber. For example, the patent application with the publication number JP2000160431A discloses a high-elongation polyester yarn, which adds a granular fiber elongation improver with a heat distortion temperature of 105-160°C. The patent application with the publication number EP0047464A1 discloses an unstretched polyester yarn, which includes a polymer with a repeating unit structure shown in formula (Ⅰ) in an amount of 0.2 to 10% by weight, where 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, and their disadvantages and deficiencies are as follows: on the one hand, the introduction of modifiers destroys the regularity of the polyester molecular chain, and the strength of the fiber is lost, which cannot meet the requirements of high strength for polyester industrial yarns; on the other hand, additional components need to be added, increasing the complexity of the process and also raising the cost.

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

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

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

[0010] A preparation device for high-strength and high-elongation polyester industrial yarn, comprising a cooling air cylinder, a suction cylinder, an annular non-porous plate, an annular porous plate, a air supply pipe and a suction pipe;

[0011] Both ends of the cooling air cylinder are open and are arranged vertically. It is composed of a first equal-diameter section, a variable-diameter section and a second equal-diameter section arranged coaxially from top to bottom. The barrel walls of the variable-diameter section and the second equal-diameter section are non-porous. Each equal-diameter section is cylindrical, the variable-diameter section is in the shape of an inverted frustum of a cone, the inner diameter of the first equal-diameter section = the upper inner diameter of the variable-diameter section > the lower inner diameter of the variable-diameter section = the inner diameter of the second equal-diameter section;

[0012] Both ends of the suction cylinder are open, the barrel wall is non-porous, and it is arranged vertically inside the second equal-diameter section and coaxially with it. The length of the suction cylinder is less than the length of the second equal-diameter section. The lower end of the suction cylinder is flush with the lower end of the second equal-diameter section and the two are connected by an annular non-porous plate. The upper end of the suction cylinder is connected to the inner wall of the second equal-diameter section by an annular porous plate. The suction cylinder, the annular non-porous plate, the annular porous plate and the second equal-diameter section jointly enclose a suction cavity;

[0013] A plurality of grooves for suppressing the separation of the boundary layer from the cooling air cylinder are provided on the inner wall of the length section of the second equal-diameter section above the suction cylinder. The boundary layer is a fluid layer formed due to viscous action when the cooling air flow passes through the inner wall surface of the cooling air cylinder;

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

[0015] The principle of the present invention is as follows:

[0016] During the melt spinning process, the force distribution of the fibers along the spinning path (the force distribution along the spinning path) has a very important influence on the formation of melt spinning, especially on the orientation and crystallization of the fibers formed during the spinning process. Reference 1 (Methods for Reducing the Tension of High-Speed Spun Polyester Fibers [J]. Foreign Textile Technology, 1985, (03): 17) points out that the parameters affecting the fiber tension include the rheological force of the nascent fiber and the frictional force between the fiber and the surrounding medium. The fiber tension can promote the formation of spin-induced crystallization in the high-speed spun polyester filament. It is recorded in Reference 2 (Science and Engineering of Polyester Fibers [M]. Beijing: China Textile Press, 2001, 102) that the air frictional force has a major influence on the spinning tension of PET along the spinning path.

[0017] In the present invention, the structure of the cooling air cylinder, the position of the air supply duct, the connection mode between the air supply duct and the cooling air cylinder, etc. are set so that the flow direction of the cooling air flow in the second equal-diameter section is the same as the running direction of the tow. Compared with the traditional vertical blowing methods of ring blowing and side blowing, the velocity difference between the air and the tow can be reduced, effectively reducing the air frictional force, and thus reducing the spinning tension. According to the fiber forming theory, when the filament moves in the air medium, frictional force is generated between its surface area and the medium due to mutual movement, and the frictional force is proportional to the square of the relative velocity between the filament and the air (Reference: Principles of Polymer Processing [M]. Beijing: China Textile Press, 2002: 189). In the stage of extruding the spinning melt to form the nascent fiber, the spinning tension plays a role in increasing the orientation of polymer molecules and inducing stress crystallization. Reducing the spinning tension can lower the degree of molecular orientation and the crystallinity of the nascent fiber. The nascent fiber has a higher residual elongation rate. After subsequent hot roll stretching, at the same stretching ratio, the fiber not only maintains a certain strength but also maintains a higher elongation rate.

[0018] However, such a setting is likely to cause excessive turbulence and flow separation in the second equal-diameter section, which has an adverse effect on the evenness of the tow. To avoid excessive turbulence and flow separation, the present invention also makes the following improvements:

[0019] ① Grooves are provided on the inner wall of the second equal-diameter section.

[0020] The inner wall surface of the cooling air duct in the prior art is a smooth plane. When the cooling air flow passes through the air duct, the viscous effect of the air flow generates frictional force with the wall surface of the air duct. The air flow in contact with the wall surface slows down, forming a very thin boundary layer. The velocity change of the air flow outside the boundary layer is very small, while the velocity change inside is drastic. In the cross-sectional direction of the air duct, the air flow velocities near both sides of the wall surface are relatively small, and the velocity in the middle part is the same as the incoming flow velocity with little change. Due to the large velocity gradient inside the boundary layer, the kinetic energy of the flow is lost due to the action of the viscous force, and the inner layer flow velocity will become slower and slower. According to Bernoulli's theorem, as the flow velocity slows down, the pressure increases. As the flow progresses, the flow inside the boundary layer becomes more and more difficult, and finally separates from the wall surface, generating a huge separation vortex. The generation of the vortex makes the cooling air flow become chaotic, which will disturb the filament and affect the cooling of the filament.

[0021] In the present invention, grooves are provided on the inner wall of the second equal-diameter section. The cooling air flow can generate small refraction vortices at the grooves, avoiding 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 air flow outside the "oil film" is reduced, and the overall flow velocity in the cross-section of the air duct becomes more stable and uniform, making the cooling of the filament bundle more uniform and improving the evenness of the filament bundle.

[0022] ② A suction pipe is provided at the end position where the filament bundle cooling ends.

[0023] When the cooling of the prior art filament bundle ends, the cooling air flow channel at the outlet of the cooling air duct suddenly increases. The cooling air flow is not restricted by the cooling air duct, the flow velocity decreases, and the pressure increases, resulting in a reverse flow at the outlet of the cooling air duct, disturbing the filament. Although the filament has been cooled and solidified at this time, the disturbance of the filament will conduct upward, which is not conducive to improving the evenness of the filament. In the present invention, a suction pipe is provided at the end position where the filament bundle cooling ends, and the suction pressure of the suction pipe is adjusted to keep the cooling air flow in a stable flow state all the time, reducing the disturbance of the filament, thereby improving the evenness of the filament bundle and further improving the quality of the product.

[0024] As a preferred technical solution:

[0025] For the preparation device of high-strength and high-elongation polyester industrial yarn as described above, the groove is a round pit groove and is arranged in a staggered dot matrix structure; the diameter of the round pit groove is 3 - 4 mm, the groove depth is 2 - 2.5 mm, and the center distance between any two adjacent round pits is 9 - 10 mm.

[0026] For the preparation device of high-strength and high-elongation polyester industrial yarn as described above, the groove is a non-round pit groove, which is divided into multiple groups. The non-round pit grooves in the same group are circumferentially spaced along the second equal-diameter section with a spacing of 4 - 6 mm, and the non-round pit grooves in different groups are axially spaced along the second equal-diameter section with a spacing of 9 - 10 mm;

[0027] The non-circular pit groove tapers in size from the groove opening to the groove bottom. The groove opening is oblong, with a length of 9 - 20 mm and a width of 3 - 4 mm. The groove bottom is in the shape of 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 groove is 20 - 30°;

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

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

[0031] A preparation device for high-strength and high-elongation polyester industrial yarn as described above, the length of the first equal-diameter section is 110 - 150 mm, and the inner diameter is 200 - 250 mm; the inner diameter of the air supply cylinder 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 cylinder 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] A preparation device for high-strength and high-elongation polyester industrial yarn as described above, the inner diameter of the air supply pipeline is 100 - 120 mm, and the inner diameter of the suction pipeline is 100 - 120 mm.

[0033] A preparation device for high-strength and high-elongation polyester industrial yarn as described above further includes a spinning box body, and the spinning box body is located above the first equal-diameter section, and between them are a slow-cooling area and a windless area, and the slow-cooling area is located above the windless area.

[0034] A preparation device for high-strength and high-elongation polyester industrial yarn as described above, the height of the slow-cooling area is 95 - 105 mm; the height of the windless area is 45 - 55 mm.

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

[0036] A preparation device for high-strength and high-elongation polyester industrial yarn as described above, the length of the spinning channel is 600 - 700 mm.

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

[0038] As a preferred technical solution:

[0039] A preparation method for high-strength and high-elongation polyester industrial yarn as described above, the spinning process flow is: polyester melt is extruded through a spinneret → cooled in a slow-cooling zone → cooled in a windless zone → cooled by a cooling air cylinder → oiling → stretched by five pairs of hot rollers → shaped → networked → wound;

[0040] 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 velocity 0.7 - 1.5 m / s; suction pressure of the suction pipeline 0 - 0.2 Pa; speed of the first pair of hot rollers 430 - 560 m / min, temperature 70 - 80 °C; speed of the second pair of hot rollers 450 - 580 m / min, temperature 90 - 100 °C; speed of the third pair of hot rollers 2000 - 2500 m / min, temperature 123 - 135 °C; speed of the fourth pair of hot rollers 2700 - 3250 m / min, temperature 210 - 250 °C; speed of the fifth pair of hot rollers 2500 - 3100 m / min, temperature 160 - 200 °C; total draw ratio 5.50 - 6.20, main draw ratio 3.74 - 4.44, secondary draw ratio 1.30 - 1.60, total draw ratio = speed of the fourth pair of hot rollers / speed of the second pair of hot rollers, main draw ratio = speed of the third pair of hot rollers / speed of the second pair of hot rollers, secondary draw ratio = speed of the fourth pair of hot rollers / speed of the third pair of hot rollers; winding speed 2650 - 3200 m / min; spinning tension 100 - 130 cN.

[0041] A preparation method for high-strength and high-elongation polyester industrial yarn as described above, the linear density of the high-strength and high-elongation polyester industrial yarn is 1100 - 1450 dtex, the breaking strength ≥ 7.2 cN / dtex, the breaking elongation rate is 30% - 32%, the CV value of the evenness variation < 1.0%, the dry heat shrinkage rate ≤ 3.2%, and the rate of downgrading due to hairiness ≤ 1.1%.

[0042] Beneficial effects:

[0043] (1)The preparation device of a high-strength and high-elongation polyester industrial yarn of the present invention is provided with grooves on the inner wall surface of the cooling air cylinder, which reduces the adhesion force of the cooling air flow to the wall surface, and sucks at the outlet position of the air cylinder, so that the cooling air flow is always in a stable state, avoiding the disturbance of the yarn bundle and improving the evenness of the yarn bundle's strand.

[0044] (2)The preparation method of a high-strength and high-elongation polyester industrial yarn of the present invention uses a cooling air flow in the same direction as the running direction of the yarn bundle, reduces the spinning tension, makes the fiber have low orientation and crystallinity, increases the elongation rate of the nascent fiber, and then prepares a polyester industrial yarn with both high strength and high elongation rate, meeting the application in the field of membrane structures. Brief Description of the Drawings

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

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

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

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

[0049] Figure 5 is a combined schematic diagram of the front view and top view of the non-round pit groove (inverted isosceles trapezoid groove) on the inner wall of the cooling air cylinder of the preparation device of the present invention;

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

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

[0052] Figure 8 is a schematic structural diagram of the cooling air cylinder of Comparative Example 3A;

[0053] In the figure, 1 is a spinning box, 2 is a slow cooling zone, 3 is a windless zone, 4 is a blowing cylinder, 5 is a blowing pipeline, 6 is a cooling air cylinder, 601 is a first equal-diameter section, 602 is a variable-diameter section, 603 is a second equal-diameter section, 7 is a suction pipeline, 8 is a cooling air flow, 9 is a spinning channel, 10 is a suction cylinder, 11 is an annular solid plate, 12 is an annular perforated plate, 13 is a suction cavity, 14 is a reverse air flow, 15 is a round pit groove, 16 is a refracted flow of the round pit groove, 17 is a non-round pit groove, 18 is a refracted flow of the non-round pit groove, and 19 is a yarn bundle. Detailed implementation manners

[0054] The present invention will be further described below in conjunction with specific implementation manners. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

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

[0056] (1) Linear density: Tested using a YG086 type length measuring instrument with reference to GB / T 14343-2008 "Test Method for Linear Density of Continuous Filament of Chemical Fibers".

[0057] (2) Breaking strength: Tested using a YG023B-II type tensile strength tester with reference to GB / T 14344-2022 "Test Method for Tensile Properties of Continuous Filament of Chemical Fibers".

[0058] (3) Elongation at break: Tested using a YG023B-II type tensile strength tester with reference to GB / T 14344-2022 "Test Method for Tensile Properties of Continuous Filament of Chemical Fibers".

[0059] (4) CV value of evenness variation: Tested using a USTER TESTER 5 type evenness tester with reference to GB / T 14346-2015 "Test Method for Evenness Variation of Continuous Filament of Chemical Fibers - Capacitance Method".

[0060] (5) Dry heat shrinkage rate: Tested using a TST510 / 250 type dry heat shrinkage rate tester with reference to GB / T 16604-2017 "Industrial Polyester Filament Yarns".

[0061] (6) Rate of downgrading due to hairiness: Referring to the specific inspection method of the appearance requirements in GB / T 16604-2017 "Industrial Polyester Filament Yarns", count the number of downgraded bobbins due to hairiness and the number of full bobbins in one day. The percentage of the number of downgraded bobbins due to hairiness in the number of full bobbins is the rate of downgrading due to hairiness.

[0062] Example 1A

[0063] As Figure 1 and Figure 2 shown, a preparation device for high-strength and high-elongation industrial polyester filaments is composed of a spinning box body 1, a blower cylinder 4, a blower pipeline 5, a cooling air cylinder 6, a suction cylinder 10, a suction pipeline 7, an annular solid plate 11, an annular perforated plate 12, and a spinning channel 9;

[0064] The two ends of the cooling air duct 6 are open and are vertically arranged. It is composed of a first equal-diameter section 601, a reduced-diameter section 602, and a second equal-diameter section 603 that are arranged in sequence from top to bottom and are coaxial. The barrel walls of the reduced-diameter section 602 and the second equal-diameter section 603 have no holes. Each equal-diameter section is cylindrical, the reduced-diameter section 602 is frustum-shaped, the inner diameter of the first equal-diameter section 601 = the upper inner diameter of the reduced-diameter section 602 > the lower inner diameter of the reduced-diameter section 602 = the inner diameter of the second equal-diameter section 603;

[0065] The two ends of the suction barrel 10 are open, the barrel wall has no holes, and it is vertically arranged inside the second equal-diameter section 603 and is coaxial with it. The length of the suction barrel 10 is less than the length of the second equal-diameter section 603. The lower end of the suction barrel 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular holeless plate 11. The upper end of the suction barrel 10 is connected to the inner wall of the second equal-diameter section 603 by an annular perforated plate 12. The suction barrel 10, the annular holeless plate 11, the annular perforated plate 12, and the second equal-diameter section 603 jointly enclose a suction cavity 13;

[0066] On the inner wall of the length section of the second equal-diameter section 603 above the suction barrel 10, there are round pit grooves 15 arranged in a staggered dot matrix structure;

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

[0068] The two ends of the air supply duct 4 are open, the barrel wall has no holes, and it is vertically arranged, sleeved on the first equal-diameter section 601 and coaxial with it; the upper end of the air supply duct 4 is connected to the upper end of the first equal-diameter section 601 by an annular holeless plate, and the lower end of the air supply duct 4 is connected to the lower end of the first equal-diameter section 601 by an annular holeless plate; the first equal-diameter section 601 is a porous structure, and the air supply duct 4 is provided with an air inlet. The air supply pipeline 5 is horizontally arranged and the outlet of the air supply pipeline 5 is connected to the air inlet; the suction pipeline 7 is horizontally arranged and is communicated with the suction cavity 13;

[0069] The length of the first equal-diameter section 601 is 120 mm, and the inner diameter is 200 mm; the inner diameter of the air supply duct 4 is 45 mm larger than the outer diameter of the first equal-diameter section 601; the length of the reduced-diameter section 602 is 140 mm; the length of the second equal-diameter section 603 is 1250 mm, and the inner diameter is 130 mm; the length of the suction barrel 10 is 1200 mm less than the length of the second equal-diameter section 603, and the outer diameter is 50 mm less than the inner diameter of the second equal-diameter section 603;

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

[0071] The spinning box 1 is located above the first equal-diameter section 601, with a slow cooling zone 2 and a windless zone 3 therebetween. 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 duct 9 is located below and connected to the second equal-diameter section 603, and the length of the spinning duct 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 then enters the cooling air cylinder 6, and then enters the spinning duct 9; the cooling air flow 8 enters the cooling air cylinder 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air cylinder 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 yarns uses the preparation device for high-strength and high-elongation polyester industrial yarns provided in Example 1A;

[0076] The spinning process flow is: PET polyester melt is extruded through a spinneret plate → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling air cylinder → oiling → stretched by five pairs of hot rollers → shaped → texturized → wound;

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

[0078] The prepared high-strength and high-elongation polyester industrial yarns have a linear density of 1100 dtex, a breaking strength of 7.2 cN / dtex, a breaking elongation rate of 32%, a CV value of the evenness variation rate of 0.5%, a dry heat shrinkage rate of 3%, and a downgrading rate of hairiness of 1%.

[0079] Comparative Example 1A

[0080] A preparation device for polyester industrial yarns is basically the same as that in Example 1A, and the only difference is that: no suction duct is provided. As Figure 6 shown, both the cooling air flow 8 and the filament bundle 19 are located inside 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 device for preparing polyester industrial yarn provided in Comparative Example 1A is adopted.

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

[0084] Comparing Comparative Example 1B with Example 1B, the change in the linear density of the polyester industrial yarn prepared in Comparative Example 1B is not obvious, the breaking strength is reduced by 0.02 cN / dtex, the change in the breaking elongation is not obvious, the CV value of evenness variation increases by 0.9%, the change in the dry heat shrinkage rate is not obvious, and the downgrading rate of hairiness increases by 1.1%. This is because a suction pipe is not provided at the outlet position of the cooling air cylinder, and a reverse air flow 14 is formed at the outlet of the cooling air cylinder 6. The air flow pressure at the outlet of the cooling air cylinder fluctuates, and the tow 19 is disturbed here, and the single filaments "fight" with each other, which is transmitted to the upper tow cooling area, resulting in an increase in the CV value of the evenness variation of the tow and an increase in hairiness, indicating that the suction pipe has an important influence on the evenness.

[0085] Comparative Example 2A

[0086] A device for preparing polyester industrial yarn is basically the same as that of Example 1A, except that: no round pit grooves and no non-round pit grooves are provided. As Figure 7 shown, a reverse air flow 14 is formed inside the cooling air cylinder 6 by the cooling air flow 8.

[0087] Comparative Example 2B

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

[0089] The linear density of the obtained polyester industrial yarn is 1105 dtex, the breaking strength is 7.15 cN / dtex, the breaking elongation is 32%, the CV value of evenness variation is 1.5%, the dry heat shrinkage rate is 3%, and the downgrading rate of hairiness is 1.5%.

[0090] Comparative example 2B and Example 1B were compared. For the polyester industrial yarn prepared in Comparative example 2B, the linear density change was not obvious, the breaking strength decreased by 0.05 cN / dtex, the breaking elongation change was not obvious, the CV value of evenness variation increased by 1%, the dry heat shrinkage change was not obvious, and the downgrading rate of hairiness increased by 0.5%. This is because grooves were not provided on the inner wall of the cooling air cylinder, and a reverse air flow 14 was formed in the cooling air cylinder 6 by the cooling air flow 8. The flow velocity of the cooling air flow in the cross-sectional direction of the cooling air cylinder 6 was uneven, resulting in an increased difference in the cooling degree between different tows. The orientation and crystallization between the molecules of the tow were uneven, resulting in a decrease in strength and an increase in the CV value of evenness variation. Subsequently, at the same draw ratio, different degrees of stretching and hairiness occurred, indicating that the grooves have an important influence on the evenness.

[0091] Comparative example 3A

[0092] A preparation device for polyester industrial yarn, as Figure 8 shown, the tow 19 coming out of the spinning box 1 enters the cooling air cylinder 6 after passing through the slow cooling zone 2 and the windless zone 3. After the cooling air flow 8 enters the cooling air cylinder 6 from the air supply pipe 5, the flow direction of the cooling air flow 8 is perpendicular to the running direction of the tow 19.

[0093] Comparative example 3B

[0094] A preparation method for polyester industrial yarn is basically the same as that of Example 1B, and the only difference is that: the preparation device for a polyester industrial yarn provided by Comparative example 3A is adopted.

[0095] The linear density of the polyester industrial yarn prepared is 1105 dtex, the breaking strength is 8 cN / dtex, the breaking elongation is 16%, the CV value of evenness variation is 0.6%, the dry heat shrinkage is 7%, and the downgrading rate of hairiness is 1.2%.

[0096] Comparative example 3B and Example 1B were compared. For the polyester industrial yarn prepared in Comparative example 3B, the linear density change was not obvious, the breaking strength increased by 0.8 cN / dtex, the breaking elongation decreased by 16%, the CV value of evenness variation increased by 0.1%, the dry heat shrinkage increased by 4.0%, and the downgrading rate of hairiness increased by 0.2%. By adopting a cooling method in which the flow direction of the cooling air flow is perpendicular to the running direction of the tow, the tension on the tow increases, and the orientation degree of the primary fiber molecules increases. Subsequently, after hot roll stretching, the orientation degree of the overall molecular chain further increases, resulting in an increase in the breaking strength of the fiber, a decrease in the breaking elongation, and an increase in the dry heat shrinkage.

[0097] Example 2A

[0098] As Figure 1 And Figure 2A preparation device for high-strength and high-elongation polyester industrial yarn shown in the figure is composed of a spinning box body 1, a blower cylinder 4, a blower 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 channel 9;

[0099] Both ends of the cooling air cylinder 6 are open and are arranged vertically. It is composed of a first equal-diameter section 601, a diameter-changing section 602 and a second equal-diameter section 603 which are arranged coaxially from top to bottom in sequence. The barrel walls of the diameter-changing section 602 and the second equal-diameter section 603 are non-porous. Each equal-diameter section is cylindrical. The diameter-changing section 602 is frustum-shaped with a larger top diameter and a smaller bottom diameter. The inner diameter of the first equal-diameter section 601 = the upper inner diameter of the diameter-changing section 602 > the lower inner diameter of the diameter-changing section 602 = the inner diameter of the second equal-diameter section 603;

[0100] Both ends of the suction cylinder 10 are open and the barrel wall is non-porous. It is arranged vertically inside the second equal-diameter section 603 and is coaxial with it. 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 they are connected through the annular non-porous plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 through the annular porous plate 12. The suction cylinder 10, the annular non-porous plate 11, the annular porous plate 12 and the second equal-diameter section 603 together enclose a suction cavity 13;

[0101] On the inner wall of the length section of the second equal-diameter section 603 above the suction cylinder 10, there are round pit grooves 15 arranged in a staggered dot matrix structure;

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

[0103] Both ends of the blower cylinder 4 are open and the barrel wall is non-porous. It is arranged vertically and sleeved on the first equal-diameter section 601 and is coaxial with it; the upper end of the blower cylinder 4 is connected to the upper end of the first equal-diameter section 601 through an annular non-porous plate, and the lower end of the blower cylinder 4 is connected to the lower end of the first equal-diameter section 601 through an annular non-porous plate; the first equal-diameter section 601 is a porous structure, and there is an air inlet on the blower cylinder 4. The blower duct 5 is arranged horizontally and the outlet of the blower duct 5 is connected to the air inlet; the suction duct 7 is arranged horizontally and is communicated with the suction cavity 13;

[0104] The length of the first equal-diameter section 601 is 110 mm and the inner diameter is 220 mm; the inner diameter of the blower cylinder 4 is 50 mm larger than the outer diameter of the first equal-diameter section 601; the length of the diameter-changing section 602 is 160 mm; the length of the second equal-diameter section 603 is 1100 mm and the inner diameter is 200 mm; the length of the suction cylinder 10 is 1100 mm less than the length of the second equal-diameter section 603, and the outer diameter is 42 mm less than the inner diameter of the second equal-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 box 1 is located above the first equal-diameter section 601, and between them are the slow cooling zone 2 and the windless zone 3. 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 channel 9 is located below and connected to the second equal-diameter section 603, and the length of the spinning channel 9 is 700 mm;

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

[0109] Example 2B

[0110] A method for preparing high-strength and high-elongation polyester industrial yarns uses a device for preparing high-strength and high-elongation polyester industrial yarns provided in Example 2A;

[0111] The spinning process flow is: PET polyester melt is extruded through a spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling air cylinder → oiling → stretched by five pairs of hot rollers → shaped → networked → 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 1.2 m / s; suction pressure of the suction duct 0.15 Pa; speed of the first pair of hot rollers 560 m / min, temperature 72 °C; speed of the second pair of hot rollers 580 m / min, temperature 95 °C; speed of the third pair of hot rollers 2498 m / min, temperature 130 °C; speed of the fourth pair of hot rollers 3248 m / min, temperature 250 °C; speed of the fifth pair of hot rollers 3078 m / min, temperature 180 °C; total draw ratio 5.60, primary draw ratio 4.31, secondary draw ratio 1.30; winding speed 3200 m / min; spinning tension 100 cN.

[0113] The linear density of the prepared high-strength and high-elongation polyester industrial yarns is 1200 dtex, the breaking strength is 7.3 cN / dtex, the breaking elongation rate is 31%, the CV value of the evenness of yarn count is 0.7%, the dry heat shrinkage rate is 3.1%, and the downgrading rate of hairiness is 0.8%.

[0114] Example 3A

[0115] As Figure 1 AndFigure 2 A preparation device for high-strength and high-elongation polyester industrial yarn, which is composed of a spinning box 1, a blast pipe 4, a blast 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 channel 9;

[0116] Both ends of the cooling air cylinder 6 are open and are vertically arranged, and it is composed of a first equal-diameter section 601, a diameter-changing section 602 and a second equal-diameter section 603 that are arranged in sequence from top to bottom and are coaxial. The barrel walls of the diameter-changing section 602 and the second equal-diameter section 603 are non-porous. Each equal-diameter section is cylindrical, the diameter-changing section 602 is frustum-shaped, and the inner diameter of the first equal-diameter section 601 = the upper inner diameter of the diameter-changing section 602 > the lower inner diameter of the diameter-changing section 602 = the inner diameter of the second equal-diameter section 603;

[0117] Both ends of the suction cylinder 10 are open, the barrel wall is non-porous, and it is vertically arranged inside the second equal-diameter section 603 and is coaxial with it. 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 through the annular non-porous plate 11. The upper end of the suction cylinder 10 is connected to the inner wall of the second equal-diameter section 603 through the annular porous plate 12. The suction cylinder 10, the annular non-porous plate 11, the annular porous plate 12 and the second equal-diameter section 603 together enclose a suction cavity 13;

[0118] On the inner wall of the length section of the second equal-diameter section 603 above the suction cylinder 10, there are round pit grooves 15 arranged in a staggered dot matrix structure;

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

[0120] Both ends of the blast pipe 4 are open, the barrel wall is non-porous, and it is vertically arranged, sleeved on the first equal-diameter section 601 and coaxial with it; the upper end of the blast pipe 4 is connected to the upper end of the first equal-diameter section 601 through an annular non-porous plate, and the lower end of the blast pipe 4 is connected to the lower end of the first equal-diameter section 601 through an annular non-porous plate; the first equal-diameter section 601 is a porous structure, and the blast pipe 4 is provided with an air inlet, and the blast duct 5 is horizontally arranged and the outlet of the blast duct 5 is connected to the air inlet; the suction duct 7 is horizontally arranged and communicates with the suction cavity 13;

[0121] The length of the first equal-diameter section 601 is 150 mm, and its inner diameter is 240 mm; the inner diameter of the air supply tube 4 is 40 mm larger than the outer diameter of the first equal-diameter section 601; the length of the diameter-changing section 602 is 150 mm; the length of the second equal-diameter section 603 is 1000 mm, and its inner diameter is 180 mm; the length of the suction tube 10 is 800 mm smaller than the length of the second equal-diameter section 603, and its outer diameter is 45 mm smaller than the inner diameter of the second equal-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 box 1 is located above the first equal-diameter section 601, and between them are the slow-cooling zone 2 and the windless zone 3, with the slow-cooling zone 2 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 channel 9 is located below and connected to the second equal-diameter section 603, and the length of the spinning channel 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 then enters the cooling air cylinder 6, and then enters the spinning channel 9; the cooling air flow 8 enters the cooling air cylinder 6 from the air supply duct 5 and is extracted from the suction duct 7; inside the cooling air cylinder 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 yarns uses a device for preparing high-strength and high-elongation polyester industrial yarns provided in Example 3A;

[0128] The spinning process flow is: PET polyester melt is extruded through a spinneret → cooled in the slow-cooling zone → cooled in the windless zone → cooled in the cooling air cylinder → oiled → stretched by five pairs of hot rollers → shaped → networked → wound;

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

[0130] The linear density of the prepared high-strength and high-elongation polyester industrial yarn is 1300 dtex, the breaking strength is 7.5 cN / dtex, the breaking elongation rate is 30%, the CV value of the evenness variation is 0.85%, the dry heat shrinkage rate is 3.05%, and the downgrading rate of hairiness is 0.5%.

[0131] Example 4A

[0132] As Figure 1 And Figure 2 A preparation device for high-strength and high-elongation polyester industrial yarn shown in the figure consists of a spinning box body 1, an air supply cylinder 4, an air supply pipeline 5, a cooling air cylinder 6, a suction cylinder 10, a suction pipeline 7, an annular non-porous plate 11, an annular porous plate 12, and a spinning channel 9;

[0133] Both ends of the cooling air cylinder 6 are open and are vertically arranged. It consists of a first equal-diameter section 601, a variable-diameter section 602, and a second equal-diameter section 603 that are arranged coaxially from top to bottom in sequence. The barrel walls of the variable-diameter section 602 and the second equal-diameter section 603 are non-porous. Each equal-diameter section is cylindrical. The variable-diameter section 602 is frustum-shaped. The inner diameter of the first equal-diameter section 601 = the upper inner diameter of the variable-diameter section 602 > the lower inner diameter of the variable-diameter section 602 = the inner diameter of the second equal-diameter section 603;

[0134] Both ends of the suction cylinder 10 are open, the barrel wall is non-porous, and it is vertically arranged inside the second equal-diameter section 603 and coaxially with it. 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 non-porous 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 non-porous plate 11, the annular porous plate 12, and the second equal-diameter section 603 jointly enclose a suction cavity 13;

[0135] On the inner wall of the length section of the second equal-diameter section 603 above the suction cylinder 10, there are round pit grooves 15 arranged in a staggered dot matrix structure;

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

[0137] The two ends of the air supply cylinder 4 are open, the cylinder wall has no holes, it is vertically arranged, sleeved on the first equal-diameter section 601 and coaxial with it; the upper end of the air supply cylinder 4 is connected to the upper end of the first equal-diameter section 601 through an annular holeless plate, and the lower end of the air supply cylinder 4 is connected to the lower end of the first equal-diameter section 601 through an annular holeless 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 pipeline 5 is horizontally arranged and the outlet of the air supply pipeline 5 is connected to the air inlet; the suction pipeline 7 is horizontally arranged and communicated with the suction cavity 13;

[0138] The length of the first equal-diameter section 601 is 130 mm, and the inner diameter is 250 mm; the inner diameter of the air supply cylinder 4 is 60 mm larger than the outer diameter of the first equal-diameter section 601; the length of the variable-diameter section 602 is 120 mm; the length of the second equal-diameter section 603 is 1300 mm, and the inner diameter is 150 mm; the length of the suction cylinder 10 is 900 mm smaller than the length of the second equal-diameter section 603, and the outer diameter is 40 mm smaller than the inner diameter of the second equal-diameter section 6;

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

[0140] The spinning box body 1 is located above the first equal-diameter section 601, and between them are the slow cooling zone 2 and the windless zone 3, and 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 duct 9 is located below the second equal-diameter section 603 and connected to it, and the length of the spinning duct 9 is 600 mm;

[0142] The filament bundle 19 coming out of the spinning box body 1 passes through the slow cooling zone 2 and the windless zone 3 and then enters the cooling air cylinder 6, and then enters the spinning duct 9; the cooling air flow 8 enters the cooling air cylinder 6 from the air supply pipeline 5 and is extracted from the suction pipeline 7; inside the cooling air cylinder 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 yarns, using a device for preparing high-strength and high-elongation polyester industrial yarns provided in Example 4A;

[0145] The spinning process flow is: PET polyester melt is extruded through a spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling air cylinder → oiled → stretched by five pairs of hot rollers → shaped → networked → wound;

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

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

[0148] Example 5A

[0149] As Figure 1 、 Figure 3 and Figure 4 shown, a preparation device for high-strength and high-elongation polyester industrial yarn consists of a spinning box 1, an air supply cylinder 4, an air supply pipeline 5, a cooling air cylinder 6, a suction cylinder 10, a suction pipeline 7, an annular non-perforated plate 11, an annular perforated plate 12, and a spinning channel 9;

[0150] The cooling air cylinder 6 has openings at both ends and is vertically arranged. It consists of a first equal-diameter section 601, a reduced-diameter section 602, and a second equal-diameter section 603 that are arranged coaxially from top to bottom in sequence. The barrel walls of the reduced-diameter section 602 and the second equal-diameter section 603 are non-perforated. Each equal-diameter section is cylindrical. The reduced-diameter section 602 is frustum-shaped. The inner diameter of the first equal-diameter section 601 = the upper inner diameter of the reduced-diameter section 602 > the lower inner diameter of the reduced-diameter section 602 = the inner diameter of the second equal-diameter section 603;

[0151] The suction cylinder 10 has openings at both ends, the barrel wall is non-perforated, and it is vertically arranged inside the second equal-diameter section 603 and coaxially with it. 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 they are connected by an annular non-perforated 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 perforated plate 12. The suction cylinder 10, the annular non-perforated plate 11, the annular perforated plate 12, and the second equal-diameter section 603 together enclose a suction cavity 13;

[0152] On the inner wall of the length section of the second equal-diameter section 603 above the suction cylinder 10, there are multiple groups of non-circular pit grooves 17;

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

[0154] As Figure 4 shown, the non-circular pit groove 17 is a V-shaped groove. 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 12 mm and a width of 3 mm. The groove bottom is a line segment shape, and the length of the groove bottom = the length of the oblong - the width of the oblong. The groove depth is 2 mm;

[0155] The circumferential pitch of the same group of non-circular pit grooves is distributed along the circumference of the second equal-diameter section 603 and the pitch is 4 mm. The axial pitch of different groups of non-circular pit grooves is distributed along the axis of the second equal-diameter section 603 and the pitch is 10 mm;

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

[0157] Both ends of the air supply duct 4 are open, the duct wall has no holes, and it is vertically arranged, sleeved on the first equal-diameter section 601 and coaxial with it; the upper end of the air supply duct 4 is connected to the upper end of the first equal-diameter section 601 through an annular holeless plate, and the lower end of the air supply duct 4 is connected to the lower end of the first equal-diameter section 601 through an annular holeless plate; the first equal-diameter section 601 is a porous structure, and the air supply duct 4 is provided with an air inlet. The air supply pipeline 5 is horizontally arranged and the outlet of the air supply pipeline 5 is connected to the air inlet; the suction pipeline 7 is horizontally arranged and communicates with the suction cavity 13;

[0158] The length of the first equal-diameter section 601 is 120 mm, and the inner diameter is 200 mm; the inner diameter of the air supply duct 4 is 45 mm larger than the outer diameter of the first equal-diameter section 601; the length of the variable-diameter section 602 is 140 mm; the length of the second equal-diameter section 603 is 1250 mm, and the inner diameter is 130 mm; the length of the suction cylinder 10 is 1200 mm less than the length of the second equal-diameter section 603, and the outer diameter is 50 mm less than the inner diameter of the second equal-diameter section 6;

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

[0160] The spinning box body 1 is located above the first equal-diameter section 601. Between them are the slow cooling zone 2 and the windless zone 3. 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 duct 9 is located below and connected to the second equal-diameter section 603, and the length of the spinning duct 9 is 650 mm;

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

[0163] Example 5B

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

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

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

[0167] The prepared high-strength and high-elongation polyester industrial yarns have a linear density of 1100 dtex, a breaking strength of 7.2 cN / dtex, a breaking elongation rate of 31%, a CV value of the evenness variation coefficient of 0.6%, a dry heat shrinkage rate of 3.1%, and a hairiness downgrading rate of 1.1%.

[0168] Example 6A

[0169] As Figure 1 、 Figure 3 and Figure 4 shown, a preparation device for high-strength and high-elongation polyester industrial yarns is composed of a spinning box 1, a blower cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular solid plate 11, an annular perforated plate 12, and a spinning duct 9;

[0170] The two ends of the cooling air duct 6 are open and arranged vertically. It is composed of a first equal-diameter section 601, a diameter-changing section 602, and a second equal-diameter section 603 that are arranged coaxially from top to bottom. The barrel walls of the diameter-changing section 602 and the second equal-diameter section 603 are poreless. Each equal-diameter section is cylindrical, the diameter-changing section 602 is frustum-shaped, the inner diameter of the first equal-diameter section 601 = the upper inner diameter of the diameter-changing section 602 > the lower inner diameter of the diameter-changing section 602 = the inner diameter of the second equal-diameter section 603;

[0171] The two ends of the suction barrel 10 are open, the barrel wall is poreless, and it is vertically arranged inside the second equal-diameter section 603 and coaxially with it. The length of the suction barrel 10 is less than the length of the second equal-diameter section 603. The lower end of the suction barrel 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular poreless plate 11. The upper end of the suction barrel 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction barrel 10, the annular poreless plate 11, the annular porous plate 12, and the second equal-diameter section 603 together enclose a suction cavity 13;

[0172] On the inner wall of the length section of the second equal-diameter section 603 above the suction barrel 10, multiple groups of non-circular pit grooves 17 are provided;

[0173] As Figure 3 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 duct 6;

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

[0175] The same group of non-circular pit grooves are circumferentially spaced along the second equal-diameter section 603 with a spacing of 6 mm, and different groups of non-circular pit grooves are axially spaced along the second equal-diameter section 603 with a spacing of 9 mm;

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

[0177] The two ends of the air supply tube 4 are open, the tube wall has no holes, it is vertically arranged, sleeved on the first equal-diameter section 601 and 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 holeless plate, 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 holeless plate; the first equal-diameter section 601 is a porous structure, an air inlet is provided on the air supply tube 4, the air supply duct 5 is horizontally arranged and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is horizontally arranged and communicates with the suction chamber 13;

[0178] The length of the first equal-diameter section 601 is 110 mm, and the inner diameter is 220 mm; the inner diameter of the air supply tube 4 is 50 mm larger than the outer diameter of the first equal-diameter section 601; the length of the variable-diameter section 602 is 160 mm; the length of the second equal-diameter section 603 is 1100 mm, and the inner diameter is 200 mm; the length of the suction tube 10 is 1100 mm less than the length of the second equal-diameter section 603, and the outer diameter is 42 mm less than the inner diameter of the second equal-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 box body 1 is located above the first equal-diameter section 601, and between them are the slow cooling zone 2 and the windless zone 3, and 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 channel 9 is located below the second equal-diameter section 603 and is connected to it, and the length of the spinning channel 9 is 700 mm;

[0182] The filament bundle 19 coming out of the spinning box body 1 passes through the slow cooling zone 2 and the windless zone 3 and then enters the cooling air cylinder 6, and then enters the spinning channel 9; the cooling air flow 8 enters the cooling air cylinder 6 from the air supply duct 5 and is drawn out from the suction duct 7; inside the cooling air cylinder 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 yarns, using a device for preparing high-strength and high-elongation polyester industrial yarns provided in Example 6A;

[0185] The spinning process flow is: PET polyester melt is extruded through a spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling air cylinder → oiling → stretched by five pairs of hot rollers → shaped → networked → wound;

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

[0187] The linear density of the prepared high-strength and high-elongation polyester industrial yarn is 1200 dtex, the breaking strength is 7.4 cN / dtex, the breaking elongation is 32%, the CV value of the evenness variation is 0.65%, the dry heat shrinkage rate is 3%, and the downgrading rate of hairiness is 0.66%.

[0188] Example 7A

[0189] As Figure 1 、 Figure 3 and Figure 5 shown, a preparation device for high-strength and high-elongation polyester industrial yarn is composed of a spinning box 1, a blowing cylinder 4, a blowing pipeline 5, a cooling air cylinder 6, a suction cylinder 10, a suction pipeline 7, an annular non-perforated plate 11, an annular perforated plate 12 and a spinning channel 9;

[0190] The cooling air cylinder 6 has openings at both ends and is vertically arranged. It is composed of a first equal-diameter section 601, a variable-diameter section 602 and a second equal-diameter section 603 that are arranged coaxially from top to bottom. The barrel walls of the variable-diameter section 602 and the second equal-diameter section 603 are non-perforated. Each equal-diameter section is cylindrical. The variable-diameter section 602 is frustum-shaped. The inner diameter of the first equal-diameter section 601 = the upper inner diameter of the variable-diameter section 602 > the lower inner diameter of the variable-diameter section 602 = the inner diameter of the second equal-diameter section 603;

[0191] The suction cylinder 10 has openings at both ends, the barrel wall is non-perforated, and it is vertically arranged inside the second equal-diameter section 603 and coaxially with it. 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 they are connected by an annular non-perforated 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 perforated plate 12. The suction cylinder 10, the annular non-perforated plate 11, the annular perforated plate 12 and the second equal-diameter section 603 jointly enclose a suction chamber 13;

[0192] On the inner wall of the length section of the second equal-diameter section 603 above the suction cylinder 10, multiple groups of non-circular pit grooves 17 are provided;

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

[0194] As Figure 5 shown, the non-circular pit groove 17 is an inverted equal-height trapezoidal groove. 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 circumferentially spaced along the second equal-diameter section 603 with a spacing of 5 mm, and different groups of non-circular pit grooves are axially spaced along the second equal-diameter section 603 with a spacing of 9.5 mm;

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

[0197] Both ends of the air supply duct 4 are open, the duct wall has no holes, and it is vertically arranged, sleeved on the first equal-diameter section 601 and coaxial with it; the upper end of the air supply duct 4 is connected to the upper end of the first equal-diameter section 601 through an annular holeless plate, and the lower end of the air supply duct 4 is connected to the lower end of the first equal-diameter section 601 through an annular holeless plate; the first equal-diameter section 601 is a porous structure, and the air supply duct 4 is provided with an air inlet, and the air supply pipe 5 is horizontally arranged and the outlet of the air supply pipe 5 is connected to the air inlet; the suction pipe 7 is horizontally arranged and communicated with the suction cavity 13;

[0198] The length of the first equal-diameter section 601 is 150 mm, and the inner diameter is 240 mm; the inner diameter of the air supply duct 4 is 40 mm larger than the outer diameter of the first equal-diameter section 601; the length of the variable-diameter section 602 is 150 mm; the length of the second equal-diameter section 603 is 1000 mm, and the inner diameter is 180 mm; the length of the suction duct 10 is 800 mm smaller than the length of the second equal-diameter section 603, and the outer diameter is 45 mm smaller than the inner diameter of the second equal-diameter section 6;

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

[0200] The spinning box body 1 is located above the first equal-diameter section 601, and between them are the slow cooling zone 2 and the windless zone 3. 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 duct 9 is located below and connected to the second equal-diameter section 603, and the length of the spinning duct 9 is 650 mm;

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

[0203] Example 7B

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

[0205] The spinning process flow is: PET polyester melt is extruded through a spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling air cylinder → oiling → stretched by five pairs of hot rolls → shaped → texturized → wound;

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

[0207] The prepared high-strength and high-elongation polyester industrial yarns have a linear density of 1300 dtex, a breaking strength of 7.5 cN / dtex, a breaking elongation rate of 30%, a CV value of the evenness variation of 0.76%, a dry heat shrinkage rate of 3.2%, and a defective rate of hairiness of 0.62%.

[0208] Example 8A

[0209] As Figure 1 、 Figure 3 and Figure 5 shown, a preparation device for high-strength and high-elongation polyester industrial yarns is composed of a spinning box 1, a blower cylinder 4, an air supply duct 5, a cooling air cylinder 6, a suction cylinder 10, a suction duct 7, an annular solid plate 11, an annular perforated plate 12, and a spinning duct 9;

[0210] The two ends of the cooling air duct 6 are open and arranged vertically. It is composed of a first equal-diameter section 601, a diameter-changing section 602, and a second equal-diameter section 603 that are arranged coaxially from top to bottom. The barrel walls of the diameter-changing section 602 and the second equal-diameter section 603 are poreless. Each equal-diameter section is cylindrical, the diameter-changing section 602 is frustum-shaped, the inner diameter of the first equal-diameter section 601 = the upper inner diameter of the diameter-changing section 602 > the lower inner diameter of the diameter-changing section 602 = the inner diameter of the second equal-diameter section 603;

[0211] The two ends of the suction barrel 10 are open, the barrel wall is poreless, and it is arranged vertically inside the second equal-diameter section 603 and coaxially with it. The length of the suction barrel 10 is less than the length of the second equal-diameter section 603. The lower end of the suction barrel 10 is flush with the lower end of the second equal-diameter section 603 and the two are connected by an annular poreless plate 11. The upper end of the suction barrel 10 is connected to the inner wall of the second equal-diameter section 603 by an annular porous plate 12. The suction barrel 10, the annular poreless plate 11, the annular porous plate 12, and the second equal-diameter section 603 together enclose a suction chamber 13;

[0212] On the inner wall of the length section of the second equal-diameter section 603 above the suction barrel 10, multiple groups of non-circular pit grooves 17 are provided;

[0213] As Figure 3 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 duct 6;

[0214] As Figure 5 shown, the non-circular pit groove 17 is an inverted isosceles trapezoidal groove. The size of the non-circular pit groove 17 gradually shrinks from the groove opening to the groove bottom. The groove opening is oblong, the length of the oblong is 15 mm and the width is 3.5 mm. The groove bottom is rectangular, the groove depth is 2.4 mm, and the angle θ between the groove wall and the central axis of the non-circular pit groove is 20°;

[0215] The non-circular pit grooves in the same group are circumferentially spaced along the second equal-diameter section 603 with a spacing of 4 mm, and the non-circular pit grooves in different groups are axially spaced along the second equal-diameter section 603 with a spacing of 9 mm;

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

[0217] The two ends of the air supply tube 4 are open, the tube wall has no holes, it is vertically arranged, sleeved on the first equal-diameter section 601 and 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 hole-free plate, 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 hole-free plate; the first equal-diameter section 601 is a porous structure, the air supply tube 4 is provided with an air inlet, the air supply duct 5 is horizontally arranged and the outlet of the air supply duct 5 is connected to the air inlet; the suction duct 7 is horizontally arranged and communicates with the suction chamber 13;

[0218] The length of the first equal-diameter section 601 is 130 mm, and the inner diameter is 250 mm; the inner diameter of the air supply tube 4 is 60 mm larger than the outer diameter of the first equal-diameter section 601; the length of the variable-diameter section 602 is 120 mm; the length of the second equal-diameter section 603 is 1300 mm, and the inner diameter is 150 mm; the length of the suction tube 10 is 900 mm smaller than the length of the second equal-diameter section 603, and the outer diameter is 40 mm smaller than the inner diameter of the second equal-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 box 1 is located above the first equal-diameter section 601, and between them are the slow cooling zone 2 and the non-wind zone 3, and the slow cooling zone 2 is located above the non-wind zone 3; the height of the slow cooling zone 2 is 100 mm, and the height of the non-wind zone 3 is 50 mm;

[0221] The spinning duct 9 is located below the second equal-diameter section 603 and is connected to it, and the length of the spinning duct 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 non-wind zone 3 and then enters the cooling air cylinder 6, and then enters the spinning duct 9; the cooling air flow 8 enters the cooling air cylinder 6 from the air supply duct 5 and is drawn out from the suction duct 7; inside the cooling air cylinder 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 yarns, using a device for preparing high-strength and high-elongation polyester industrial yarns provided in Example 8A;

[0225] The spinning process flow is: PET polyester melt is extruded through a spinneret → cooled in the slow cooling zone → cooled in the non-wind zone → cooled in the cooling air cylinder → oiling → stretched by five pairs of hot rollers → shaped → networked → wound;

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

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

Claims

1. A device for preparing high-strength and high-strength polyester industrial yarn, characterized in that: It comprises a cooling air cylinder (6), a suction cylinder (10), an annular imperforate plate (11), an annular porous plate (12), an air supply duct (5) and a suction duct (7); The cooling air cylinder (6) is open at both ends and is arranged vertically. It is composed of a first equal diameter section (601), a reduced diameter section (602) and a second equal diameter section (603) which are arranged in sequence from top to bottom and are coaxial. The reduced diameter section (602) and the second equal diameter section (603) have walls without holes. Each equal diameter section is cylindrical. The reduced diameter section (602) is inverted truncated cone shape. The inner diameter of the first equal 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 equal 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 via 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) via 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 located 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 is in communication with the first equal-diameter section (601); the suction duct (7) is arranged horizontally and is in communication 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 a plurality of groups. The non-circular grooves (17) of the same group are distributed at a circumferential spacing along the second equal diameter section (603) and the spacing is 4-6 mm. The non-circular grooves (17) of different groups are distributed at an axial spacing along the second equal diameter section (603) and the spacing is 9-10 mm. The non-circular pit groove (17) gradually decreases in size from the groove opening to the groove bottom, the groove opening is an oblong shape, the length of the oblong shape is 9-20 mm and the width is 3-4 mm, the groove bottom is a line segment shape 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 the first equal-diameter section (601); the upper end of the air supply tube (4) is connected to the upper end of the first equal-diameter section (601) via an annular imperforate 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) via an annular imperforate plate (11); the first equal-diameter section (601) is a porous structure, 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 variable-diameter 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: It also includes a spinning box (1), which is located above the first equal-diameter section (601), and between the two is a slow cooling zone (2) and a windless zone (3), and 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 equal-diameter section (603) and connected thereto.

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 as described in 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: the polyester melt is extruded through the spinneret → cooled in the slow cooling zone → cooled in the windless zone → cooled in the cooling air cylinder (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 multiple is 5.50-6.20, the main stretching multiple is 3.74-4.44, and the secondary stretching multiple is 1.30-1.60; the winding speed is 2650-3200m / min; the spinning tension is 100-130cN.

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