Production equipment and preparation method of high-density polyester pongee fibers

Abstract

The invention relates to the technical field of fiber production equipment, in particular to production equipment and a preparation method of high-density polyester pongee polyester fibers, the production equipment comprises a spinning box body, a spinning assembly and a circular blowing cooling device, spinneret orifices in a spinneret plate in the spinning assembly are distributed in n circles according to the concentric circle layout, 1 lt; nlt; 31, the total hole depths of all the spinneret holes are the same, the shapes and the hole diameters of the micropores in all the spinneret holes are the same, and the hole depths of the micropores in the spinneret holes in the same circle are the same; the n circles are numbered from 1 from outside to inside, and the ratio of the hole depth of a micropore in the spinneret orifices in the ith circle to the hole diameter of the micropore is 4.5-(i-1) / 18; i = 1, 2,..., n; according to the preparation method, the production equipment is used for producing the high-density polyester pongee fibers. According to the production equipment, the micropores of the spinneret plate are distributed in a stepped manner, and the principle that cooling air decreases layer by layer is combined, so that polyester fibers are cooled more sufficiently and uniformly, and polyester pongee fibers with excellent quality are obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of fiber production equipment, and specifically relates to production equipment for high-density polyester pongee fibers and a preparation method thereof. Background Art

[0002] Polyester pongee, commonly known as rainproof cloth or coated nylon, is a kind of fabric with a smooth and flat surface, light texture, strong and wear-resistant, excellent elasticity and glossiness, and is not easy to shrink, easy to wash, quick to dry, and feels good. At present, most of the polyester pongee fabrics used in the market are used as clothing linings, because of the high degree of contact with human skin, the comfort of the fabric is required to be high.

[0003] In the industry, the raw material specifications for developing full-stretch polyester pongee are mostly 75D, and the single-filament fineness is close to 1.0D. When the total fineness of the fiber remains unchanged, but the number of holes increases, the single-filament fineness will decrease. Such changes not only make the fabric have better wear resistance, but also reduce the surface density of the fabric, improve the air permeability, and make the fabric thinner, softer, and better in texture. However, it is difficult to develop technology for preparing fibers with lower fineness.

[0004] Patent CN110438574 discloses a polyester microfiber production equipment, spinneret and oiling device. In the polyester microfiber production equipment of the patent, two spinneret holes with different apertures are arranged on the spinneret body. The aperture of the second spinneret hole in the outer circle is larger than that of the first spinneret hole in the inner circle. Therefore, the specific surface area of ​​the fiber formed by the second spinneret hole in the outer circle is small, and a larger annular blowing volume is required for cooling. The specific surface area of ​​the fiber formed by the first spinneret hole in the inner circle is large, and a smaller annular blowing volume is required for cooling, which just makes up for the deficiency caused by the sequential decrease of the annular blowing volume during the cooling process of multiple circles of fibers. The arrangement between the layers where the spinneret holes with the same aperture are parallel, and the arrangement between the layers where the spinneret holes with different apertures are staggered. The patent improves the cooling uniformity of the fiber bundle by setting the spinneret holes in the inner and outer circles of the spinneret to different apertures. However, due to the different pore sizes, the shear rate of the melt flowing in the spinneret is greatly affected, which results in the shear rate of the porous wire having multiple data, which makes it easy for floating wires, injection heads, elbows, etc. to occur during production, which is not conducive to production.

[0005] Patent CN214142637U discloses an 8-shaped opening guide wire porcelain part, which includes a housing. Eight "T-shaped" sliding columns are slidably sleeved on the top of the housing. The sliding columns are evenly distributed on the housing. A first spring is sleeved on the sliding column, and both ends of the first spring are fixed on the housing and the sliding column respectively. A clamping component is installed inside the bottom of each sliding column. An "8-shaped opening" guide wire porcelain part is sleeved at the bottom of the sliding column. Through holes are formed in the guide wire porcelain part, and the clamping component clamps the guide wire porcelain part at the bottom of the sliding column through the through holes. An anti-collision component is installed between the guide wire porcelain parts. The anti-collision component is fixed on the inner wall of the housing through a vertical plate. The guide wire porcelain parts at both ends of the housing are tightly connected in the housing through a limiting component. The limiting component is installed at both ends of the housing. This patent can prevent the phenomenon of wire jumping during spinning and winding switching, avoid problems such as wrong wire separation and wire breakage, and solve the problem of wrong wire adjustment of the original U-shaped wire divider. However, it cannot solve the problem that the wire tension at both ends of a spinning position is much different from the wire tension in the middle.

[0006] At the same time, during the spinning process, a relatively high requirement is placed on the melt fluidity. Therefore, a relatively high spinning temperature and a good heat preservation effect are required. Otherwise, the production needs cannot be met. In the prior art, a silica gel gasket is generally selected to be arranged between the spinning box body and the ring blowing air cooling device to meet the sealing requirements, reduce heat dissipation, and improve its heat preservation effect. However, the silica gel gasket is not suitable for high-temperature production environments. During the production process, the silica gel gasket is prone to adhesion and its thickness is prone to change after long-term use, resulting in a poor sealing effect and affecting the quality of the final product.

[0007] Therefore, it is urgent to develop a new production equipment and its preparation method for high-density spring Asian spinning polyester fiber to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to overcome the deficiencies of existing equipment and technologies, and provide a production equipment and its preparation method for high-density spring Asian spinning polyester fiber.

[0009] To achieve the above purpose, the following scheme is adopted in the present invention:

[0010] A production equipment for high-density spring Asian spinning polyester fiber includes a spinning box body, a spinning component, and a ring blowing air cooling device. The spinning component contains a spinneret plate. The spinneret holes on the spinneret plate are distributed in n circles according to a concentric circle layout, where 1 < n < 31. The total hole depth of all spinneret holes (i.e., the sum of the hole depths of the guide holes, transition holes, and micro holes) is the same. The shapes of the micro holes in all spinneret holes are the same. The pore diameters of the micro holes in all spinneret holes are the same. The hole depths of the micro holes in the spinneret holes in the same circle are the same. The n circles are numbered from 1 from the outside to the inside. The ratio of the hole depth to the pore diameter of the micro hole in the spinneret hole in the i-th circle = 4.5 - (i - 1) / 18; i = 1, 2,..., n.

[0011] One of the purposes of the present invention is to solve the problems of floating yarn, injection head and elbow in the prior art which improves the cooling uniformity by changing the aperture of micropores in the spinneret.

[0012] If the spinneret holes on the same spinneret have different diameters, the shear rate of each filament bundle will be different. The greater the deviation of the shear rate (when the diameter difference between different spinneret holes is 0.01mm, the shear rate will differ by 1.24 times), the most direct manifestation in actual production is that it is easier to have injection heads and elbows, which is not conducive to production.

[0013] The formula for shear rate is:

[0014] ;

[0015] In the formula, Q is the pump supply per second per hole, d is a constant, and r is the pore size of the micropore;

[0016] The present invention can improve the cooling uniformity without changing the aperture of the micropores in the spinneret, and the principle is as follows:

[0017] During the melt spinning process, the polymer melt will swell when it is extruded from the spinneret hole, which is due to its viscoelastic properties. When the melt is squeezed from a larger space into a small hole, part of the energy is converted into elastic potential energy storage, which will cause the melt to undergo elastic deformation, and the elastic deformation is reversible. As the melt flows, the molecular chains try to return to their original state. This process takes a certain amount of time. After the melt leaves the spinneret hole, the loose stream undergoes elastic recovery, resulting in the expansion of the melt after extrusion. The storage amount of elastic potential energy is closely related to the residence time of the melt in the micropores. The longer the residence time, the less elastic energy is stored and the smaller the expansion degree; otherwise, the greater the expansion degree. The hole depth of the spinneret micropore can directly affect the residence time of the melt in the micropores, and then affect the expansion degree. Different melt expansion degrees can theoretically be analyzed as the size of the melt cross-section. When the expansion degree is large, the melt cross-section is large, the contact area with the cooling air is large, and the required cooling air volume is small.

[0018] During the cooling process, since there are a large number of fiber holes, which can reach 288 or even 360, in order to achieve uniform cooling of the filament bundle, the distribution of the cooling air volume needs to be taken into consideration; the present invention adopts a special spinneret micropore design, and the hole depth of the micropore decreases from the outside to the inside, forming a stepped distribution. This design makes the residence time of the melt in the micropore decrease from the outside to the inside, and the extrusion expansion effect increases from the outside to the inside, so that the area of ​​the filament bundle in contact with the cooling air increases from the outside to the inside layer by layer, which matches the characteristic that the annular air volume decreases from the outside to the inside layer by layer, improves the cooling efficiency, and achieves more uniform cooling.

[0019] As the preferred technical solution:

[0020] The production equipment of high-density polyester pongee fiber as described above, 5≤n≤12.

[0021] In the production equipment for high-density polyester pongee fibers as described above, the number of spinneret holes on the spinneret plate is 96-360.

[0022] In the production equipment for high-density polyester pongee fibers as described above, the transition holes in all spinnerets have the same shape and height, the guide holes in all spinnerets have the same shape, and the guide holes in all spinnerets have the same aperture.

[0023] In the production equipment of high-density polyester fiber as described above, the shape of the micropores in all spinnerets is circular, and the pore size of the micropores in all spinnerets is the diameter of the micropore cross section; or, the shape of the micropores in all spinnerets is cross-shaped, flat, trilobal or pentlobal, and the pore size of the micropores in all spinnerets is the equivalent circular diameter of the micropore cross section.

[0024] In the production equipment for high-density polyester pongee fibers as described above, the diameter of the micropores in all the spinnerets is 0.12-0.18 mm.

[0025] In the production equipment for high-density polyester pongee fibers as described above, the number of spinnerets is 2m, which are arranged in sequence along the left-right direction, and m>1.

[0026] The production equipment of high-density polyester spring fiber as described above also includes a radial wire separator located below the ring-blowing cooling device, the radial wire separator includes 2m telescopic rods and 2m wire guide porcelain parts; the 2m telescopic rods are horizontally arranged, one end of each telescopic rod is connected to a wire guide porcelain part, and the other end is fixedly connected to the same point, and the 2m telescopic rods are radially distributed around the point; m telescopic rods are located on the left side, and the lengths of the m telescopic rods decrease in order from back to front, and another m telescopic rods are located on the right side, and the lengths of the m telescopic rods decrease in order from back to front.

[0027] The second purpose of the present invention is to reduce the tension difference between the entire spinning position tows, the principle is as follows:

[0028] In the prior art winding process, the tow is rapidly reduced from the horizontal tunnel opening of about one to one and a half meters on the second floor to the wire separator of a few centimeters on the first floor (the tow is in an inverted trapezoidal shape from the tunnel opening on the second floor to the first floor). In particular, the horizontal distance of the tows at both ends of a spinning position varies greatly, which makes the angle of the wires at both ends of a spinning position vary greatly, resulting in a large difference in the tension of the wires at the two ends and the tension of the wires in the middle, and a large difference between the spindles during winding;

[0029] The radial wire separator adopted by the present invention has a wire guide porcelain piece installed at the end of each telescopic rod of the radial wire separator, and the position of the wire guide porcelain piece is the same as the position of each spinning ingot. The radial wire separator changes the tension of the wire bundle by reducing the horizontal distance difference between the upper and lower parts and affecting the running angle of the wire bundle, thereby reducing the change of the angle of the wire bundle at both ends of the spinning position, thereby reducing the tension difference between the wire bundles at both ends and between the ingots.

[0030] As described above, the production equipment for high-density spring polyester fiber has m telescopic rods on the left side and m telescopic rods on the right side which are symmetrically distributed; among the m telescopic rods on the left side, the angle between two adjacent telescopic rods is 10-20 degrees, and the angle between each telescopic rod of the radial wire divider is between 10-20 degrees, which is convenient for the extension and retraction of the wire guide porcelain parts, so that the wire guide porcelain parts can play a protective role.

[0031] As described above, the production equipment for high-density spring polyester fiber, the wire guide porcelain is an eagle hook-shaped wire guide porcelain. The yarn bundle needs to pass through a horizontal U-shaped wire divider to separate the yarn bundle of each ingot when it goes down from the corridor entrance on the second floor to the first floor. However, since the horizontal U-shaped wire divider is open and lacks a binding effect on the yarn bundle, the yarn bundle can easily jump out of the open mouth of the U-shaped porcelain, resulting in yarn jumping and mis-separation. The eagle hook-shaped porcelain can bind the yarn bundle in the porcelain to prevent yarn jumping and mis-separation.

[0032] The production equipment of high-density polyester pongee fiber as described above also includes a first wire guide disk, a network device, a second wire guide disk, a roller and a winding roller which are located below the radial wire separator and arranged in sequence along the wire feeding path.

[0033] The production equipment of high-density polyester pongee fiber as described above also includes an insulation plate and an aluminum plate located between the spinning box and the ring-blowing cooling device; the insulation plate is connected to the spinning box, the aluminum plate is connected to the bellows in the ring-blowing cooling device, and the insulation plate and the aluminum plate are meshed with each other.

[0034] The third object of the present invention is to improve the sealing between the spinning manifold and the ring-blowing cooling device, and the principle is as follows:

[0035] The spinning process has high requirements on melt fluidity, high spinning temperature, and good thermal insulation effect, otherwise it cannot meet the production needs. The existing technology generally chooses to set a silicone sealing pad between the spinning box and the ring air cooling device to meet the sealing requirements, reduce heat loss, and improve its thermal insulation effect; however, silicone sealing pads are not suitable for high-temperature production environments. During the production process, silicone sealing pads are prone to adhesion and thickness changes after long-term use, which makes the sealing effect worse and affects the quality of the final product.

[0036] The present invention arranges a heat preservation plate and an aluminum plate between the spinning box and the ring-blowing cooling device. The opposite surfaces of the heat preservation plate and the aluminum plate are both serrated and can mesh with each other to form a sealing structure similar to a labyrinth, thereby preventing the heat inside the spinning box from being dissipated outward through the heat preservation plate. This is beneficial to improving the heating efficiency and ensuring the plate surface temperature of the spinneret.

[0037] The insulation board and aluminum plate are both metal plates, which will not be squeezed and deformed during long-term use. Compared with the original silicone sealing gasket, the service life is significantly extended, avoiding the occurrence of quality problems affecting the final product due to changes in the thickness of the silicone sealing gasket during use.

[0038] In the production equipment of high-density polyester pongee fibers as described above, an air interlayer is provided in the insulation board.

[0039] The present invention also provides a method for preparing high-density polyester pongee fibers, using the production equipment for high-density polyester pongee fibers as described in any one of the above items.

[0040] As the preferred technical solution:

[0041] The preparation method of the high-density polyester fiber as described above has the overall process flow of: preparing PET melt by esterification and polycondensation of terephthalic acid and ethylene glycol → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring-blowing cooling device → oiling nozzle → radial separator → first guide disc → network device → second guide disc → roller → winding roller;

[0042] The intrinsic viscosity of PET melt is 0.63-0.65dl / g, the terminal carboxyl content is ≤25mol / t, the diethylene glycol content is ≤1.005wt%, and the number of agglomerated particles with a diameter of 5-20μm is ≤0.5N / mg;

[0043] The spinning process parameters include: windless zone height 40-70 mm, spinning speed 2200-2700 m / min, and wind pressure 10-25 Pa.

[0044] A preparation method of a high-density spring polyester fiber as described above, wherein the single yarn fineness of the high-density spring polyester fiber is 0.2-0.5D, the linear density deviation rate is ≤1.0%, the breaking strength is ≥2.2cN / dtex, the breaking strength CV value is ≤3.0%, the breaking elongation is 115%-128%, the breaking elongation CV value is ≤4.0%, the yarn unevenness rate is ≤1.3%, the thermal stress CV value is ≤3.0%, and the oil content is 0.43±0.2wt%.

[0045] Beneficial effects:

[0046] The production equipment of a high-density polyester pongee fiber of the present invention has micropores of the spinneret in a stepped distribution, and utilizes the different residence time of the melt to affect its expansion degree. The expansion degree is different, and the cooling area in contact with the ring-blown air is different. In this way, according to the principle of layer-by-layer decrease of the cooling air, the polyester fiber is cooled more fully and evenly, and the polyester pongee fiber with good quality is obtained.

[0047] The production equipment of high-density polyester pongee in the present invention adopts a radial wire separator to reduce the phenomenon of wire skipping, reduce the tension difference between the wire bundles at the entire spinning position, and improve the product quality;

[0048] The production equipment of a high-density polyester spring fiber in the present invention adopts a rigidly meshed inner and outer layer vacuum insulation sealing structure in the sealing structure between the spinning box and the ring blowing cooling device, which not only significantly improves the insulation effect of the box, effectively reduces heat dissipation, ensures the temperature stability of the spinneret, and thus improves the spinnability of the fiber; moreover, compared with the original silicone sealing method, it significantly extends the service life, avoiding the problem of affecting the final quality of the product due to the change in thickness of the silicone sealing pad during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the structure of the radial wire separator in the present invention;

[0050] Among them, 1-telescopic rod, 2-guide wire porcelain. DETAILED DESCRIPTION

[0051] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0052] The following are the detection methods of the relevant performance indicators in the embodiments:

[0053] Linear density deviation rate: The linear density deviation rate of the fiber is calculated using (actual linear density - theoretical linear density) / theoretical linear density × 100% in "GB / T 14343 Test method for linear density of chemical filaments";

[0054] Breaking strength, breaking strength CV value: According to GB / T 14343 Test method for tensile properties of chemical fiber filaments, the fiber is pulled to break under uniform tension at a constant speed using an Uster-4 tensor tester, and the breaking strength and breaking strength CV value of the sample are obtained from the data display.

[0055] Elongation at break, CV value of elongation at break: According to GB / T 14343 Test method for tensile properties of chemical filaments, the fiber is pulled to break under uniform tension at a constant speed using a Swiss Uster-Ⅳ tensile tester, and the elongation at break and CV value of the sample are obtained from the data display;

[0056] Yarn unevenness: According to GB / T 8960-2015 Polyester Drawn Yarn, the yarn is tested using the Uster-4 Yarn Evenness Tester;

[0057] Thermal stress CV value: According to FZ / T50051-2020 "Test method for dynamic thermal stress of polyester pre-oriented yarn", the test is carried out using SG635 fully automatic filament thermal stress tester;

[0058] Oil content: According to GB / T 8960-2015 Polyester Drawn Yarn, the test is carried out using a nuclear magnetic resonance fiber oil content tester;

[0059] Intrinsic viscosity of PET melt: According to GB / T 14190-2017 Test Method for Fiber-Grade Polyester Chips, the outflow time of a PET solution with a solvent at 25°C and a concentration of 0.005 g / ml is measured by a capillary viscometer method, and the intrinsic viscosity is calculated based on the measured outflow time and the sample solution concentration;

[0060] Terminal carboxyl content of PET melt: According to GB / T 14190-2017 Test Method for Fiber-Grade Polyester Chips, the volumetric titration method is adopted, that is, the sample is refluxed and dissolved in a mixed solvent, and after cooling, bromophenol blue is used as an indicator and titrated with potassium hydroxide-ethanol standard titration solution. The terminal carboxyl content is calculated based on the volume consumed by the standard titration solution;

[0061] Diethylene glycol content of PET melt: According to GB / T 14190-2017 Test Method for Fiber-Grade Polyester Chips, the methanol transesterification method is used, that is, the sample undergoes an ester exchange reaction under high temperature and methanol conditions, diethylene glycol is freed, and then the diethylene glycol content in the filtrate is detected by gas chromatography;

[0062] Number of agglomerated particles with a diameter of 5-20 μm in the PET melt: According to GB / T 14190-2017 Test method for fiber-grade polyester chips, the agglomerated particles in the sample are observed under a microscope, and the size is measured and counted.

[0063] A production equipment for high-density polyester pongee fibers, comprising a spinning box, a spinning assembly, a heat preservation plate, an aluminum plate, a ring-blowing cooling device, a radial wire separator, a first wire guide disk, a network device, a second wire guide disk, a roller and a winding roller;

[0064] The spinning assembly is provided with 2m spinnerets arranged in sequence along the left-right direction, m>1;

[0065] The total number of spinnerets on each spinneret is 96-360, which are distributed on n circles according to the layout of concentric circles. <n<31;

[0066] The total hole depth of all spinnerets (i.e. the sum of the hole depths of guide holes, transition holes, and micro holes) is the same;

[0067] The shapes of the micropores in all spinnerets are circular or irregular (cross, flat, trilobal or pentlobal). When they are circular, the pore size is the diameter of the micropore cross section. When they are irregular, the pore size is the equivalent circular diameter of the micropore cross section. The pore size of all micropores is 0.12-0.18mm.

[0068] The micropores in the same circle of spinnerets have the same depth; the n circles are numbered from 1 from the outside to the inside, and the ratio of the micropore depth to the micropore diameter in the spinneret of the i-th circle is 4.5-(i-1) / 18; i=1, 2,…, n;

[0069] The shape and height of the transition holes in all spinnerets are the same;

[0070] The shape and diameter of the guide holes in all spinnerets are the same;

[0071] The insulation plate and the aluminum plate are located between the spinning box and the ring-blowing cooling device; an air interlayer is arranged in the insulation plate; the insulation plate is connected to the spinning box, the aluminum plate is connected to the bellows in the ring-blowing cooling device, and the insulation plate and the aluminum plate are meshed with each other;

[0072] The radial wire separator is arranged below the annular air cooling device, and includes a 2m telescopic rod and a 2m wire guide porcelain piece, and the wire guide porcelain piece is an eagle hook-shaped wire guide porcelain piece;

[0073] like Figure 1 As shown, 2m telescopic rods 1 are arranged horizontally, one end of each of which is connected to an eagle hook-shaped guide wire porcelain piece, and the other end is fixedly connected to the same point, and the 2m telescopic rods 1 are radially distributed around the point; m telescopic rods 1 are located on the left side, and the lengths of the m telescopic rods 1 decrease from the back to the front, and the other m telescopic rods 1 are located on the right side, and the lengths of the m telescopic rods 1 decrease from the back to the front; the m telescopic rods 1 on the left side are symmetrically distributed with the m telescopic rods 1 on the right side; among the m telescopic rods 1 on the left side, the angle between two adjacent telescopic rods 1 is 10-20°;

[0074] The first wire guide disc, the network device, the second wire guide disc, the roller and the winding roller are arranged in sequence below the radial wire separator along the wire feeding path.

[0075] Example 1

[0076] A method for preparing high-density polyester pongee fibers, the equipment used is the above-mentioned production equipment for high-density polyester pongee fibers, and the overall process flow is: terephthalic acid and ethylene glycol are esterified and polycondensed to prepare PET melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring-blowing cooling device → oiling nozzle → radial separator → first guide wire disk → network device → second guide wire disk → roller → winding roller;

[0077] The intrinsic viscosity of the PET melt is 0.63 dl / g, the terminal carboxyl content is 10 mol / t, the diethylene glycol content is 0.8 wt%, and the number of agglomerated particles with a diameter of 5-20 μm is 0.3 N / mg;

[0078] Equipment parameters include: m is 10, the number of spinnerets on each spinneret is 360, n is 12, from the outer circle to the inner circle, the number of spinnerets in each circle is 52, 48, 44, 40, 36, 32, 28, 24, 20, 16, 12, 8, the spinnerets in each circle are arranged at equal intervals, the shape of the micropores is circular, the aperture of the micropores is 0.12 mm, the depth of the micropores from the outer circle to the inner circle is 0.540 mm, 0.533 mm, 0.527 mm, 0.520 mm, 0.513 mm, 0.507 mm, 0.500 mm, 0.493 mm, 0.487 mm, 0.480 mm, 0.473 mm, 0.467 mm, and the angle between two adjacent telescopic rods is 10°;

[0079] The spinning process parameters include: the height of the windless zone is 45 mm, the spinning speed is 2200 m / min, and the wind pressure is 10 Pa;

[0080] The final high-density spring polyester fiber has a single fiber fineness of 0.2D, a linear density deviation rate of 0.23%, a breaking strength of 2.85 cN / dtex, a breaking strength CV value of 2.2%, a breaking elongation of 122%, a breaking elongation CV value of 1.9%, a yarn unevenness rate of 0.78%, a thermal stress CV value of 0.87%, and an oil content of 0.43wt%.

[0081] Comparative Example 1

[0082] A method for preparing high-density polyester pongee is basically the same as that in Example 1, except that in the equipment used in this comparative example, the hole depths of all micropores on the spinneret are the same, all of which are 0.527 mm, that is, the hole depths of the micropores of the spinneret are not distributed in a stepped manner.

[0083] The final high-density spring polyester fiber has a single fiber fineness of 0.2D, a breaking strength of 2.45 cN / dtex, a breaking strength CV value of 4.0%, a breaking elongation CV value of 4.8%, a yarn unevenness rate of 1.6%, and a thermal stress CV value of 4.5%.

[0084] Compared with Example 1, the breaking strength CV value, breaking elongation CV value, yarn unevenness rate and thermal stress CV value of the high-density spring polyester fiber prepared in Comparative Example 1 are higher than those in Example 1. This is because Comparative Example 1 adopts a traditional spinneret, and the hole depths of all micropores on the spinneret are the same, and the contact area between the filament bundle and the cooling air is the same, but the cooling air volume decreases layer by layer from the outer circle to the inner circle, which will cause uneven cooling of the inner layer of the filament bundle, and the external manifestation is that the breaking strength CV value becomes larger, the breaking elongation CV value becomes larger, the yarn unevenness rate and the thermal stress CV value increase.

[0085] Example 2

[0086] A method for preparing high-density polyester pongee fibers, the equipment used is the above-mentioned production equipment for high-density polyester pongee fibers, and the overall process flow is: terephthalic acid and ethylene glycol are esterified and polycondensed to prepare PET melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring-blowing cooling device → oiling nozzle → radial separator → first guide wire disk → network device → second guide wire disk → roller → winding roller;

[0087] The intrinsic viscosity of the PET melt is 0.63 dl / g, the terminal carboxyl content is 10 mol / t, the diethylene glycol content is 0.9 wt%, and the number of agglomerated particles with a diameter of 5-20 μm is 0.5 N / mg;

[0088] Equipment parameters include: m is 8, the number of spinnerets on each spinneret is 96, n is 5, the number of spinnerets in each circle from the outer circle to the inner circle is 32, 24, 19, 14, and 7, the spinnerets in each circle are arranged at equal intervals, the shape of the micropores is a cross, the aperture of the micropores is 0.18 mm, the depth of the micropores from the outer circle to the inner circle is 0.810 mm, 0.800 mm, 0.790 mm, 0.780 mm, and 0.770 mm, and the angle between two adjacent telescopic rods is 10°;

[0089] The spinning process parameters include: the height of the windless zone is 70 mm, the spinning speed is 2680 m / min, and the wind pressure is 25 Pa;

[0090] The final high-density spring polyester fiber has a single fiber fineness of 0.5D, a linear density deviation rate of 0.28%, a breaking strength of 2.28 cN / dtex, a breaking strength CV value of 1.8%, a breaking elongation of 128%, a breaking elongation CV value of 1.8%, a yarn unevenness rate of 0.75%, a thermal stress CV value of 0.86%, and an oil content of 0.42wt%.

[0091] Example 3

[0092] A method for preparing high-density polyester pongee fibers, the equipment used is the above-mentioned production equipment for high-density polyester pongee fibers, and the overall process flow is: terephthalic acid and ethylene glycol are esterified and polycondensed to prepare PET melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring-blowing cooling device → oiling nozzle → radial separator → first guide wire disk → network device → second guide wire disk → roller → winding roller;

[0093] The intrinsic viscosity of the PET melt is 0.64 dl / g, the terminal carboxyl content is 15 mol / t, the diethylene glycol content is 0.8 wt%, and the number of agglomerated particles with a diameter of 5-20 μm is 0.4 N / mg;

[0094] Equipment parameters include: m is 12, the number of spinnerets on each spinneret is 288, n is 10, the number of spinnerets in each circle from the outer circle to the inner circle is 56, 48, 40, 34, 30, 24, 20, 16, 12, 8, the spinnerets in each circle are arranged at equal intervals, the shape of the micropores is flat, the pore diameter of the micropores is 0.14 mm, the pore depths of the micropores from the outer circle to the inner circle are 0.630 mm, 0.622 mm, 0.614 mm, 0.607 mm, 0.599 mm, 0.591 mm, 0.583 mm, 0.576 mm, 0.568 mm, 0.560 mm, and the angle between two adjacent telescopic rods is 20°;

[0095] The spinning process parameters include: the height of the windless zone is 50 mm, the spinning speed is 2500 m / min, and the wind pressure is 16 Pa;

[0096] The final high-density spring polyester fiber has a single fiber fineness of 0.26D, a linear density deviation rate of 0.2%, a breaking strength of 2.35 cN / dtex, a breaking strength CV value of 2.1%, a breaking elongation of 116%, a breaking elongation CV value of 2.8%, a yarn unevenness rate of 0.9%, a thermal stress CV value of 0.98%, and an oil content of 0.41wt%.

[0097] Example 4

[0098] A method for preparing high-density polyester pongee fibers, the equipment used is the above-mentioned production equipment for high-density polyester pongee fibers, and the overall process flow is: terephthalic acid and ethylene glycol are esterified and polycondensed to prepare PET melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring-blowing cooling device → oiling nozzle → radial separator → first guide wire disk → network device → second guide wire disk → roller → winding roller;

[0099] The intrinsic viscosity of the PET melt is 0.64 dl / g, the terminal carboxyl content is 15 mol / t, the diethylene glycol content is 0.9 wt%, and the number of agglomerated particles with a diameter of 5-20 μm is 0.5 N / mg;

[0100] Equipment parameters include: m is 8, the number of spinnerets on each spinneret is 144, n is 6, the number of spinnerets in each circle from the outer circle to the inner circle is 40, 34, 26, 22, 14, and 8, the spinnerets in each circle are arranged at equal intervals, the shape of the micropores is trilobal, the aperture of the micropores is 0.16 mm, the depth of the micropores from the outer circle to the inner circle is 0.720 mm, 0.711 mm, 0.702 mm, 0.693 mm, 0.684 mm, and 0.676 mm, and the angle between two adjacent telescopic rods is 20°;

[0101] The spinning process parameters include: the height of the windless zone is 65 mm, the spinning speed is 2540 m / min, and the wind pressure is 18 Pa;

[0102] The final high-density spring polyester fiber has a single fiber fineness of 0.5D, a linear density deviation rate of 0.21%, a breaking strength of 2.3cN / dtex, a breaking strength CV value of 1.9%, a breaking elongation of 123%, a breaking elongation CV value of 2.1%, a yarn unevenness rate of 0.87%, a thermal stress CV value of 1.32%, and an oil content of 0.43wt%.

[0103] Example 5

[0104] A method for preparing high-density polyester pongee fibers, the equipment used is the above-mentioned production equipment for high-density polyester pongee fibers, and the overall process flow is: terephthalic acid and ethylene glycol are esterified and polycondensed to prepare PET melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring-blowing cooling device → oiling nozzle → radial separator → first guide wire disk → network device → second guide wire disk → roller → winding roller;

[0105] The intrinsic viscosity of the PET melt is 0.65 dl / g, the terminal carboxyl content is 25 mol / t, the diethylene glycol content is 1 wt%, and the number of agglomerated particles with a diameter of 5-20 μm is 0.4 N / mg;

[0106] Equipment parameters include: m is 8, the number of spinnerets on each spinneret is 192, n is 8, from the outer circle to the inner circle, the number of spinnerets in each circle is 40, 36, 31, 27, 22, 17, 12, 7, the spinnerets in each circle are arranged at equal intervals, the shape of the micropores is five-leaf, the aperture of the micropores is 0.15 mm, from the outer circle to the inner circle, the hole depth of the micropores is 0.675 mm, 0.667 mm, 0.658 mm, 0.650 mm, 0.642 mm, 0.633 mm, 0.625 mm, 0.617 mm, and the angle between two adjacent telescopic rods is 15°;

[0107] The spinning process parameters include: the height of the windless zone is 50 mm, the spinning speed is 2480 m / min, and the wind pressure is 22 Pa;

[0108] The final high-density spring polyester fiber has a single fiber fineness of 0.34D, a linear density deviation rate of 0.25%, a breaking strength of 2.37cN / dtex, a breaking strength CV value of 2%, a breaking elongation of 119%, a breaking elongation CV value of 2.2%, a yarn unevenness rate of 0.84%, a thermal stress CV value of 1.47%, and an oil content of 0.4wt%.

[0109] Example 6

[0110] A method for preparing high-density polyester pongee fibers, the equipment used is the above-mentioned production equipment for high-density polyester pongee fibers, and the overall process flow is: terephthalic acid and ethylene glycol are esterified and polycondensed to prepare PET melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring-blowing cooling device → oiling nozzle → radial separator → first guide wire disk → network device → second guide wire disk → roller → winding roller;

[0111] The intrinsic viscosity of the PET melt is 0.65 dl / g, the terminal carboxyl content is 10 mol / t, the diethylene glycol content is 0.8 wt%, and the number of agglomerated particles with a diameter of 5-20 μm is 0.3 N / mg;

[0112] Equipment parameters include: m is 8, the number of spinnerets on each spinneret is 96, n is 5, the number of spinnerets in each circle from the outer circle to the inner circle is 32, 24, 19, 14, and 7, the spinnerets in each circle are arranged at equal intervals, the shape of the micropores is circular, the aperture of the micropores is 0.18 mm, the depth of the micropores from the outer circle to the inner circle is 0.810 mm, 0.800 mm, 0.790 mm, 0.780 mm, and 0.770 mm, and the angle between two adjacent telescopic rods is 15°;

[0113] The spinning process parameters include: the height of the windless zone is 70 mm, the spinning speed is 2700 m / min, and the wind pressure is 23 Pa;

[0114] The final high-density spring polyester fiber has a single fiber fineness of 0.42D, a linear density deviation rate of 0.26%, a breaking strength of 2.75cN / dtex, a breaking strength CV value of 1.8%, a breaking elongation of 126%, a breaking elongation CV value of 1.7%, a yarn unevenness rate of 0.62%, a thermal stress CV value of 1.21%, and an oil content of 0.41wt%.

[0115] Example 7

[0116] A method for preparing high-density polyester pongee fibers is basically the same as that in Example 1, except that in the equipment used in this embodiment, a traditional silicone sealing pad is used to replace the insulation plate and aluminum plate between the spinning box and the annular air cooling device.

[0117] The final high-density spring polyester fiber has a single fiber fineness of 0.2D, a linear density deviation rate of 0.24%, a breaking strength of 2.73cN / dtex, a breaking strength CV value of 2.7%, a breaking elongation of 118%, a breaking elongation CV value of 3.3%, a yarn unevenness rate of 1.1%, a thermal stress CV value of 2.31%, and an oil content of 0.43wt%.

[0118] Compared with Example 1, the breaking strength CV value, breaking elongation CV value, yarn unevenness rate and thermal stress CV value of the high-density spring polyester fiber prepared in Example 7 are higher than those in Example 1, and the breaking strength and breaking elongation rate are lower than those in Example 1. This is because in the equipment adopted in Example 7, traditional silicone sealing pads are used to replace the insulation plate and aluminum plate between the spinning box and the annular air cooling device. However, silicone sealing pads are not suitable for high-temperature production environments. Silicone sealing pads are prone to adhesion and thickness changes due to long-term use, resulting in poor sealing effect of the spinning box. This change increases the heat loss and reduces the insulation effect, which ultimately affects the quality of the product. The external manifestations are the increase in the breaking strength CV value, the increase in the breaking elongation CV value, the increase in the yarn unevenness rate and the thermal stress CV value, and the decrease in the breaking strength and the breaking elongation rate.

[0119] Example 8

[0120] A method for preparing high-density polyester pongee is basically the same as that in Example 1, except that a traditional wire separator (the 8-shaped open wire guide porcelain component disclosed in patent CN214142637U) is used in the equipment used in this embodiment to replace the radial wire separator.

[0121] The final high-density spring polyester fiber has a single fiber fineness of 0.2D, a linear density deviation rate of 0.25%, a breaking strength of 2.56 cN / dtex, a breaking strength CV value of 2.8%, a breaking elongation of 120%, a breaking elongation CV value of 3.5%, a yarn unevenness rate of 1.2%, a thermal stress CV value of 2.58%, and an oil content of 0.43wt%.

[0122] Compared with Example 1, the breaking strength CV value, breaking elongation CV value, yarn unevenness and thermal stress CV value of the high-density spring polyester fiber prepared in Example 8 are higher than those in Example 1, and the breaking strength and breaking elongation are lower than those in Example 1. This is because the equipment in Example 8 uses a traditional wire separator (i.e., the 8-shaped open wire guide porcelain disclosed in patent CN214142637U) to replace the radial wire separator. However, since the traditional wire separator cannot reduce the horizontal distance difference between the upper and lower bundles, and thus cannot change the tension of the bundles by affecting the running angle of the bundles, it is impossible to effectively reduce the change in the angle of the bundles at both ends of the spinning position, which leads to a greater difference in tension between the bundles at both ends and between the spindles than in Example 1, which ultimately affects the quality of the product, and the external performance is that the breaking strength CV value becomes larger, the breaking elongation CV value becomes larger, the yarn unevenness and thermal stress CV values ​​increase, and the breaking strength and breaking elongation decrease.

Claims

1. A production device for high-density spring Asian spinning polyester fiber, comprising a spinning box body, a spinning component and an annular blowing air cooling device. The spinning component contains a spinneret plate, and the spinneret holes on the spinneret plate are distributed in n circles according to a concentric circle layout, where 1 < n < 31. The total hole depth of all the spinneret holes is the same, the shapes of the micropores in all the spinneret holes are the same, and the pore diameters of the micropores in all the spinneret holes are the same. It is characterized in that, The depth of the micropores in the same circle of spinnerets is the same; the n circles are numbered from 1 from the outside to the inside, and the ratio of the depth of the micropores in the spinnerets on the i-th circle to the diameter of the micropores is 4.5-(i-1) / 18; i=1, 2,…, n.

2. The production equipment of high-density polyester pongee fiber according to claim 1, characterized in that: The number of spinneret holes on the spinneret plate is 96-360; the transition holes in all the spinneret holes have the same shape and height; the guide holes in all the spinneret holes have the same shape; and the guide holes in all the spinneret holes have the same aperture.

3. The production equipment of high-density polyester pongee fiber according to claim 1, characterized in that: The shape of the micropores in all the spinnerets is circular, and the pore size of the micropores in all the spinnerets is the diameter of the micropore cross section; alternatively, the shape of the micropores in all the spinnerets is cross-shaped, flat, trilobal or pentlobal, and the pore size of the micropores in all the spinnerets is the equivalent circular diameter of the micropore cross section; the pore size of the micropores in all the spinnerets is 0.12-0.18 mm.

4. The production equipment of high-density polyester pongee fiber according to claim 1, characterized in that: The number of spinnerets is 2m, which are arranged in sequence along the left-right direction, and m>1.

5. The production equipment of high-density polyester pongee fiber according to claim 4, characterized in that: It also includes a radial wire divider located below the ring-blowing cooling device, the radial wire divider includes 2m telescopic rods and 2m wire guide porcelain pieces; the 2m telescopic rods are horizontally arranged, one end of each telescopic rod is connected to a wire guide porcelain piece, and the other end is fixedly connected to the same point, and the 2m telescopic rods are radially distributed around the point; m telescopic rods are located on the left side, and the lengths of the m telescopic rods decrease in order from back to front, and another m telescopic rods are located on the right side, and the lengths of the m telescopic rods decrease in order from back to front.

6. The production equipment of high-density polyester pongee fiber according to claim 5, characterized in that: The m telescopic rods on the left side are symmetrically distributed with the m telescopic rods on the right side; among the m telescopic rods on the left side, the included angle between two adjacent telescopic rods is 10-20 degrees; and the guide wire porcelain piece is an eagle hook-shaped guide wire porcelain piece.

7. The production equipment of high-density polyester pongee fiber according to claim 5, characterized in that: It also includes a first wire guide disk, a network device, a second wire guide disk, a roller and a winding roller which are located below the radial wire separator and are arranged in sequence along the wire path.

8. The production equipment of high-density polyester pongee fiber according to claim 1, characterized in that: It also includes a heat preservation plate and an aluminum plate located between the spinning box and the ring-blowing cooling device; the heat preservation plate is connected to the spinning box, the aluminum plate is connected to the bellows in the ring-blowing cooling device, and the heat preservation plate and the aluminum plate are meshed with each other.

9. A method for preparing high-density polyester pongee fibers, characterized in that: A production device for high-density polyester pongee fibers as described in any one of claims 1 to 8 is used.

10. The method for preparing high-density polyester pongee fiber according to claim 9, characterized in that: The overall process flow is: PET melt is prepared by esterification and polycondensation of terephthalic acid and ethylene glycol → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring-blowing cooling device → oiling nozzle → radial wire separator → first wire guide → network device → second wire guide → roller → winding roller; The intrinsic viscosity of PET melt is 0.63-0.65dl / g, the terminal carboxyl content is ≤25mol / t, the diethylene glycol content is ≤1.005wt%, and the number of agglomerated particles with a diameter of 5-20μm is ≤0.5N / mg; The spinning process parameters include: windless zone height 40-70 mm, spinning speed 2200-2700 m / min, wind pressure 10-25 Pa; The single fiber fineness of high-density spring polyester fiber is 0.2-0.5D, the linear density deviation rate is ≤1.0%, the breaking strength is ≥2.2cN / dtex, the breaking strength CV value is ≤3.0%, the breaking elongation is 115%-128%, the breaking elongation CV value is ≤4.0%, the yarn unevenness rate is ≤1.3%, the thermal stress CV value is ≤3.0%, and the oil content is 0.43±0.2wt%.

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