A kind of production equipment and preparation method of high-density polyester pongee fiber

Abstract

The present invention relates to the technical field of fiber production equipment, and relates to a production equipment for high-density polyester fiber of spring Asian spinning and a preparation method thereof. The production equipment includes a spinning box body, a spinning component and an annular air blowing cooling device. The spinneret holes on the spinneret plate in the spinning component 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 and pore 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 the outside to the inside. The ratio of the hole depth to the pore diameter of the micropores in the spinneret holes in the i-th circle = 4.5 - (i - 1) / 18; i = 1, 2,..., n; the preparation method is to use this production equipment to produce high-density polyester fiber of spring Asian spinning. In the production equipment of the present invention, the micropores of the spinneret plate are distributed in a stepped manner, combined with the principle of gradually decreasing cooling air layer by layer, so that the polyester fiber is cooled more fully and evenly, and high-quality polyester fiber of spring Asian spinning is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of fiber production equipment, and particularly relates to a production equipment for high-density polyester fiber of spring sub-fabric and a preparation method thereof. Background Art

[0002] Spring sub-fabric, commonly known as rainproof cloth or coated nylon fabric, is a kind of fabric with a flat and smooth surface, light texture, firm and wear-resistant, excellent elasticity and gloss, not easy to shrink, easy to wash, quick-drying, and good hand feeling. At present, most of the spring sub-fabric used in the market is used as the lining of clothing, and because of the high contact with the human skin, the comfort requirement for the fabric is relatively high.

[0003] In the industry, the raw material specifications of fully elastic spring sub-fabric 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 a change not only makes the fabric have better wear resistance, but also makes the surface density of the fabric smaller, the air permeability better, the fabric thinner, softer and with better texture. However, the development of the technology for preparing fibers with lower fineness is more difficult.

[0004] Patent CN110438574 discloses a production equipment, a spinneret plate and an oiling device for polyester microfibers. In the production equipment for polyester microfibers of this patent, two kinds of spinneret holes with different apertures are arranged on the spinneret plate body. The aperture of the second spinneret holes in the outer circle is larger than that of the first spinneret holes in the inner circle. Therefore, the specific surface area of the fibers formed by the second spinneret holes in the outer circle is small and requires a large amount of ring blowing air volume for cooling, while the specific surface area of the fibers formed by the first spinneret holes in the inner circle is large and requires a small amount of ring blowing air volume for cooling, which just makes up for the deficiency brought by the sequential decrease of the air volume during the cooling process of multi-layer fibers by the ring blowing air volume. The arrangement between layers where the spinneret holes have the same aperture is parallel arrangement, and the arrangement between layers where the spinneret holes have different apertures is staggered arrangement. This patent improves the cooling uniformity of the filament bundle by setting the spinneret holes in the inner and outer circles of the spinneret plate to have different apertures. However, due to the different apertures, the shear rate of the melt during its flow in the spinneret plate is greatly affected, which results in multiple data for the shear reduction rate of the multi-hole filaments, and thus it is easy to occur situations such as floating filaments, injection heads, bends, etc. 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 on the bottom of the sliding column. A through hole is opened on 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 hole. 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 tension of the wires at both ends of a spinning position is quite different from that of the wires 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 deterioration of the sealing effect and affecting the quality of the final product.

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

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

[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 of improving cooling uniformity by changing the aperture of micropores in the spinneret.

[0012] If the diameters of the spinnerets on the same spinneret are different, the shear rate of each filament bundle will be different. The greater the deviation of the shear rate (when the diameter difference between different spinnerets 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] Where 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 thin stream that loses its constraints recovers elastically, causing the melt to swell after extrusion. The amount of elastic potential energy stored 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 degree of swelling; otherwise, the greater the amount of swelling. The depth of the spinneret micropores can directly affect the residence time of the melt in the micropores, and thus affect the degree of swelling. Different degrees of melt expansion can theoretically be analyzed as the size of the melt cross-section. When the degree of expansion 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, due to the 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, 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, which matches the characteristic that the air volume of the annular air decreases from the outside to the inside, improves the cooling efficiency, and achieves more uniform cooling.

[0019] As the preferred technical solution:

[0020] A production device for high-density spring sub-polyester fiber as described above, where 5 ≤ n ≤ 12.

[0021] A production device for high-density spring sub-polyester fiber as described above, the number of spinneret holes on the spinneret plate is 96 - 360.

[0022] A production device for high-density spring sub-polyester fiber as described above, the shapes and heights of the transition holes in all the spinneret holes are the same, the shapes of the guide holes in all the spinneret holes are the same, and the diameters of the guide holes in all the spinneret holes are the same.

[0023] A production device for high-density spring sub-polyester fiber as described above, the shapes of the micro-holes in all the spinneret holes are circular, and the diameters of the micro-holes in all the spinneret holes are the diameters of the cross-sections of the micro-holes; or, the shapes of the micro-holes in all the spinneret holes are cross-shaped, flat-shaped, three-leaf-shaped or five-leaf-shaped, and the diameters of the micro-holes in all the spinneret holes are the equivalent circular diameters of the cross-sections of the micro-holes.

[0024] A production device for high-density spring sub-polyester fiber as described above, the diameters of the micro-holes in all the spinneret holes are 0.12 - 0.18 mm.

[0025] A production device for high-density spring sub-polyester fiber as described above, the number of spinneret plates is 2m, arranged in sequence along the left-right direction, where m > 1.

[0026] A production device for high-density spring sub-polyester fiber as described above, further comprising a radial wire distributor located below the ring blow cooling device. The radial wire distributor includes 2m telescopic rods and 2m wire guiding porcelain parts; the 2m telescopic rods are horizontally arranged, one end of each is connected to a wire guiding porcelain part, and the other end is fixedly connected to the same point. The 2m telescopic rods are radially distributed around this 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. The other 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 object of the present invention is to reduce the tension difference between the tows of the entire spinning position. The principle is as follows:

[0028] During the winding process of the prior art, the tow descends from the horizontal passage opening on the second floor, about one meter to one and a half meters, to the first floor and quickly shrinks into a wire distributor within a few centimeters (the tow descends from the passage opening on the second floor in an inverted trapezoid shape to the first floor). Especially for the tows at both ends within a spinning position, the horizontal distance changes greatly, resulting in a large change in the angles of the tows at both ends, leading to a large difference in the tension between the tows at both ends and the tows in the middle. When winding, the difference between the spindles is also large;

[0029] The radial wire distributor adopted by the present invention has a wire guiding porcelain part installed at the end of each telescopic rod of the radial wire distributor. The position of the wire guiding porcelain part is the same as that of each spinning spindle. By reducing the horizontal distance gap between the upper and lower parts, the radial wire distributor affects the angle of the filament bundle movement to change the tension of the filament bundle, reduces the change in the filament bundle angle at both ends of the spinning position, and thus reduces the tension difference between the filament bundles at both ends and between the spindles.

[0030] For the production equipment of high-density spring suede polyester fiber as described above, the m telescopic rods on the left and the m telescopic rods on the right are symmetrically distributed; among the m telescopic rods on the left, the included angle between two adjacent telescopic rods is 10 - 20°, and the included angle of each telescopic rod of the radial wire distributor is between 10 - 20 degrees, which is convenient for the expansion and contraction of the wire guiding porcelain part, so that the wire guiding porcelain part can play a protective role.

[0031] For the production equipment of high-density spring suede polyester fiber as described above, the wire guiding porcelain part is a hawk-hook type wire guiding porcelain part. When the filament bundle descends from the second-floor aisle opening to the first floor, it needs to pass through a horizontal U-shaped wire distributor to separate the filament bundle of each spindle. However, since the horizontal U-shaped wire distributor is open-mouthed and lacks the binding effect on the filament bundle, the filament bundle is easy to jump out of the open mouth of the U-shaped porcelain part, resulting in wire jumping and mis-wiring phenomena. The hawk-hook type porcelain part can bind the filament bundle inside the porcelain part to prevent the phenomena of wire jumping and mis-wiring of the filament bundle.

[0032] For the production equipment of high-density spring suede polyester fiber as described above, it further includes a first wire guiding disc, a networker, a second wire guiding disc, a roller and a winding roller which are arranged in sequence along the wire path below the radial wire distributor.

[0033] For the production equipment of high-density spring suede polyester fiber as described above, it further includes a heat preservation board and an aluminum plate between the spinning box body and the ring blowing air cooling device; the heat preservation board is connected to the spinning box body, the aluminum plate is connected to the air box in the ring blowing air cooling device, and the heat preservation board and the aluminum plate are meshed with each other.

[0034] The third object of the present invention is to improve the sealing performance between the spinning box body and the ring blowing air cooling device. The principle is as follows:

[0035] During the spinning process, a higher melt fluidity is required, a higher spinning temperature and a better heat preservation effect are needed, otherwise the production requirements cannot be met. In the prior art, a silica gel sealing gasket is generally selected between the spinning box body and the ring blowing air cooling device to meet the sealing requirements, reduce the heat dissipation and improve its heat preservation effect; however, the silica gel sealing gasket is not suitable for high-temperature production environments. During the production process, the silica gel sealing gasket is easy to adhere and its thickness is easy to change after long-term use, resulting in a poor sealing effect and affecting the quality of the final product.

[0036] The present invention provides a heat-insulating board and an aluminum plate between the spinning box and the ring blowing cooling device. The opposite surfaces of the heat-insulating board and the aluminum plate are both serrated, and they can be meshed with each other to form a sealing structure similar to a maze, preventing the heat inside the spinning box from dissipating outward through the heat-insulating board. This is beneficial to improving its heating efficiency and ensuring the temperature of the spinneret plate surface.

[0037] Both the heat-insulating board and the aluminum plate are metal plates, and they will not be extruded and deformed after long-term use. Compared with the original silicone gasket, the service life is significantly extended, avoiding the problem that the change in the thickness of the silicone gasket during use affects the final quality of the product.

[0038] For the production equipment of high-density spring suede polyester fiber as described above, an air interlayer is provided inside the heat-insulating board.

[0039] The present invention also provides a preparation method of high-density spring suede polyester fiber, which adopts the production equipment of high-density spring suede polyester fiber described in any one of the above.

[0040] As a preferred technical solution:

[0041] For the preparation method of high-density spring suede polyester fiber as described above, the overall process flow is: 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 on the nozzle → radial filament distributor → first godet wheel → networker → second godet wheel → roller → winding roller;

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

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

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

[0045] Beneficial effects:

[0046] A production device for high-density spring sub-polyester fiber in the present invention has the micropores of the spinneret plate distributed in a stepped manner. By using the different residence times of the melt, the bulking degree is affected. Different bulking degrees result in different cooling areas when contacting the ring blowing air. Then, according to the principle of gradually decreasing cooling air layer by layer, the polyester fiber can be cooled more fully and evenly, and high-quality spring sub-polyester fiber can be obtained.

[0047] A production device for high-density spring sub-polyester fiber in the present invention adopts a radial wire distributor to reduce the wire skipping phenomenon, reduce the tension difference between the filament bundles of the entire spinning position, and improve the product quality.

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

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

[0050] Among them, 1 - telescopic rod, 2 - wire guiding porcelain part. DETAILED DESCRIPTION OF THE INVENTION

[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 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.

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

[0053] Linear density deviation rate: It is calculated by (actual linear density - theoretical linear density) / theoretical linear density × 100% in "GB / T 14343 Test Method for Linear Density of Chemical Fiber Filament Yarns" to calculate the linear density deviation rate of the fiber;

[0054] Breaking strength, breaking strength CV value: According to "GB / T 14343 Test Method for Tensile Properties of Chemical Fiber Filaments", use a Uster Uster-4 tensile strength tester to pull the fiber to break under the condition of constant speed and uniform tension, and obtain the breaking strength and breaking strength CV value of the sample 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 Fiber Filaments", using a Swiss Uster-Ⅳ type tensile strength and elongation tester, the fiber is pulled to break under a constant uniform tensile force, and the elongation at break and the CV value of elongation at break of the specimen are obtained from the data display;

[0056] Evenness variation coefficient: According to "GB / T 8960-2015 Drawn Polyester Yarn", it is detected using an Uster-4 type evenness tester;

[0057] CV value of thermal stress: According to FZ / T50051-2020 "Test Method for Dynamic Thermal Stress of Polyester Preoriented Yarn", it is detected using an SG635 full-automatic filament thermal stress tester;

[0058] Oil content: According to "GB / T 8960-2015 Drawn Polyester Yarn", it is detected using a nuclear magnetic resonance fiber oil content detector;

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

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

[0061] Diethylene glycol content of PET melt: According to "GB / T 14190-2017 Test Methods for Fiber Grade Polyester Chips", using the methanol transesterification method, that is, the sample undergoes a transesterification reaction under high temperature and the presence of methanol, and diethylene glycol is liberated, and then the content of diethylene glycol in the filtrate is detected by gas chromatography;

[0062] Number of coagulated particles with a diameter of 5-20μm in PET melt: According to "GB / T 14190-2017 Test Methods for Fiber Grade Polyester Chips", the coagulated particles in the sample are observed under a microscope, and their sizes are measured and counted.

[0063] A production device for high-density spring suede polyester fiber, including a spinning box, a spinning component, a heat preservation board, an aluminum plate, an annular air blowing cooling device, a radial yarn distributor, a first godet, a texturing device, a second godet, rollers, and a winding roller;

[0064] There are 2m spinnerets arranged in sequence in the left - right direction inside the spinning component, where m > 1;

[0065] The total number of spinneret holes on each spinneret is 96 - 360, and they are distributed in n circles according to a concentric - circle layout, where 1 < n < 31;

[0066] 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;

[0067] The shapes of the micro - holes in all spinneret holes are all circular or all special - shaped (cross - shaped, flat - shaped, three - leaf - shaped, or five - leaf - shaped). When they are circular, the pore diameter of the micro - hole is the diameter of the cross - section of the micro - hole; when they are special - shaped, the pore diameter of the micro - hole is the equivalent - circle diameter of the cross - section of the micro - hole; the pore diameters of all micro - holes are 0.12 - 0.18 mm;

[0068] Among the spinneret holes in the same circle, the hole depths of the micro - holes are the same; the n circles are numbered from 1 from the outside to the inside. The ratio of the hole depth of the micro - hole to the pore diameter of the micro - hole in the spinneret holes on the i - th circle = 4.5-(i - 1) / 18; i = 1, 2,…, n;

[0069] The shapes and heights of the transition holes in all spinneret holes are the same;

[0070] The shapes and pore diameters of the guide holes in all spinneret holes are the same;

[0071] The heat - insulating board and the aluminum plate are located between the spinning box and the ring - blowing air cooling device; there is an air interlayer inside the heat - insulating board; the heat - insulating board is connected to the spinning box, the aluminum plate is connected to the air box in the ring - blowing air cooling device, and the heat - insulating board and the aluminum plate are meshed with each other;

[0072] The radial wire distributor is arranged below the ring - blowing air cooling device and includes 2m telescopic rods and 2m wire - guiding porcelain parts. The wire - guiding porcelain parts are eagle - hook - shaped wire - guiding porcelain parts;

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

[0074] The first wire - guiding disk, the networker, the second wire - guiding disk, the roller, and the winding roller are arranged in sequence along the wire - passing path below the radial wire distributor.

[0075] Example 1

[0076] A preparation method of high-density polyester fiber for spring Asian spinning, using the above-mentioned production equipment for high-density polyester fiber for spring Asian spinning. The overall process flow is as follows: terephthalic acid and ethylene glycol are esterified and polycondensed to obtain PET melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring blowing cooling device → oiling at the nozzle → radial filament distributor → first godet wheel → networker → second godet wheel → roller → winding roller;

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

[0078] The equipment parameters include: m is 10, the number of spinneret holes on each spinneret plate is 360, n is 12, from the outer ring to the inner ring, the number of spinneret holes in each ring is 52, 48, 44, 40, 36, 32, 28, 24, 20, 16, 12, 8 in turn. The spinneret holes in each ring are arranged at equal intervals, the shape of the micropores is circular, the pore diameter of the micropores is 0.12 mm, from the outer ring to the inner ring, the pore depth of the micropores 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 in turn, and the included angle between adjacent two 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 single filament fineness of the finally obtained high-density polyester fiber for spring Asian spinning is 0.2 D, the linear density deviation rate is 0.23%, the breaking strength is 2.85 cN / dtex, the CV value of the breaking strength is 2.2%, the breaking elongation is 122%, the CV value of the breaking elongation is 1.9%, the evenness variation coefficient is 0.78%, the CV value of the thermal stress is 0.87%, and the oil content is 0.43 wt%.

[0081] Comparative Example 1

[0082] A preparation method of high-density polyester fiber for spring Asian spinning is basically the same as that of Example 1, except that: in the equipment used in this comparative example, the pore depth of all micropores on the spinneret plate is the same, all 0.527 mm, that is, the pore depth of the micropores on the spinneret plate does not adopt a stepped distribution.

[0083] The single filament fineness of the finally obtained high-density polyester fiber for spring Asian spinning is 0.2 D, the breaking strength is 2.45 cN / dtex, the CV value of the breaking strength is 4.0%, the CV value of the breaking elongation is 4.8%, the evenness variation coefficient is 1.6%, and the CV value of the thermal stress is 4.5%.

[0084] Comparing Comparative Example 1 with Example 1, the CV value of the breaking strength, the CV value of the elongation at break, the evenness variation rate, and the CV value of the thermal stress of the high-density spring suede polyester fiber prepared in Comparative Example 1 are all higher than those in Example 1. This is because in Comparative Example 1, a traditional spinneret is used, where the hole depth of all micropores on the spinneret is the same, and the area of the filament bundle in contact with the cooling air is the same. However, the cooling air volume decreases layer by layer from the outer circle to the inner circle, which leads to uneven cooling of the inner layer of the filament bundle. The external manifestation is an increase in the CV value of the breaking strength, the CV value of the elongation at break, the evenness variation rate, and the CV value of the thermal stress.

[0085] Example 2

[0086] A preparation method of high-density spring suede polyester fiber uses the above-mentioned production equipment for high-density spring suede polyester fiber. The overall process flow is as follows: 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 on the nozzle → radial wire distributor → first godet wheel → texturing device → second godet wheel → roller → winding roller;

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

[0088] The equipment parameters include: m is 8, the number of spinneret holes on each spinneret is 96, n is 5, and from the outer circle to the inner circle, the number of spinneret holes in each circle is 32, 24, 19, 14, 7 in sequence. The spinneret holes in each circle are arranged at equal intervals, the shape of the micropores is all cross-shaped, the pore diameter of the micropores is all 0.18 mm, and from the outer circle to the inner circle, the hole depth of the micropores is 0.810 mm, 0.800 mm, 0.790 mm, 0.780 mm, 0.770 mm in sequence, and the included angle between adjacent two telescopic rods is 10°;

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

[0090] The finally prepared high-density spring suede polyester fiber has a single filament fineness of 0.5 D, a linear density deviation rate of 0.28%, a breaking strength of 2.28 cN / dtex, a CV value of the breaking strength of 1.8%, an elongation at break of 128%, a CV value of the elongation at break of 1.8%, an evenness variation rate of 0.75%, a CV value of the thermal stress of 0.86%, and an oil content of 0.42 wt%.

[0091] Example 3

[0092] A preparation method of high-density spring sub-polyester fiber, using the above-mentioned production equipment for high-density spring sub-polyester fiber. The overall process flow is: 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 on the nozzle → radial wire distributor → first godet wheel → networker → second godet wheel → roller → winding roller;

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

[0094] The equipment parameters include: m is 12, the number of spinneret holes on each spinneret plate is 288, n is 10. From the outer circle to the inner circle, the number of spinneret holes in each circle is 56, 48, 40, 34, 30, 24, 20, 16, 12, 8 in turn. The spinneret holes 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, and from the outer circle to the inner circle, the pore depth of the micropores is 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 in turn. The included angle between adjacent two telescopic rods is 20°;

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

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

[0097] Example 4

[0098] A preparation method of high-density spring sub-polyester fiber, using the above-mentioned production equipment for high-density spring sub-polyester fiber. The overall process flow is: 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 on the nozzle → radial wire distributor → first godet wheel → networker → second godet wheel → roller → winding roller;

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

[0100] The equipment parameters include: m is 8, the number of spinneret holes on each spinneret plate is 144, n is 6, from the outer circle to the inner circle, the number of spinneret holes in each circle is 40, 34, 26, 22, 14, 8 in sequence, the spinneret holes in each circle are arranged at equal intervals, the shape of the micropores is all three - leaf - shaped, the aperture of the micropores is all 0.16 mm, from the outer circle to the inner circle, the depth of the micropores is 0.720 mm, 0.711 mm, 0.702 mm, 0.693 mm, 0.684 mm, 0.676 mm in sequence, and the included angle between adjacent two 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 single - filament fineness of the finally prepared high - density spring - like polyester fiber is 0.5 D, the linear density deviation rate is 0.21%, the breaking strength is 2.3 cN / dtex, the CV value of the breaking strength is 1.9%, the breaking elongation is 123%, the CV value of the breaking elongation is 2.1%, the evenness variation coefficient is 0.87%, the CV value of the thermal stress is 1.32%, and the oil content is 0.43 wt%.

[0103] Example 5

[0104] A preparation method of high - density spring - like polyester fiber uses the above - mentioned production equipment of high - density spring - like polyester fiber. The overall process flow is: using terephthalic acid and ethylene glycol for esterification and polycondensation to obtain PET melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring blow cooling device → oiling at the oil nozzle → radial filament distributor → first godet wheel → networker → second godet wheel → roller → winding roller;

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

[0106] The equipment parameters include: m is 8, the number of spinneret holes on each spinneret is 192, n is 8. From the outer circle to the inner circle, the number of spinneret holes in each circle is 40, 36, 31, 27, 22, 17, 12, 7 in sequence. The spinneret holes in each circle are arranged at equal intervals. The shape of the micropores is pentafoil, the pore diameter of the micropores is 0.15 mm, and from the outer circle to the inner circle, the pore 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 in sequence. The included 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 single fiber fineness of the finally prepared high-density spring Asian spinning polyester fiber is 0.34 D, the linear density deviation rate is 0.25%, the breaking strength is 2.37 cN / dtex, the CV value of the breaking strength is 2%, the breaking elongation is 119%, the CV value of the breaking elongation is 2.2%, the unevenness rate of yarn evenness is 0.84%, the CV value of the thermal stress is 1.47%, and the oil content is 0.4 wt%.

[0109] Example 6

[0110] A preparation method of high-density spring Asian spinning polyester fiber uses the above-mentioned production equipment for high-density spring Asian spinning polyester fiber. The overall process flow is: using terephthalic acid and ethylene glycol for esterification and polycondensation to obtain PET melt → booster pump → heat exchanger → melt conveying pipeline → spinning box → ring blowing cooling device → oiling on the oil nozzle → radial wire distributor → first godet wheel → networker → second godet wheel → roller → winding roller;

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

[0112] The equipment parameters include: m is 8, the number of spinneret holes on each spinneret is 96, n is 5. From the outer circle to the inner circle, the number of spinneret holes in each circle is 32, 24, 19, 14, 7 in sequence. The spinneret holes in each circle are arranged at equal intervals. The shape of the micropores is circular, the pore diameter of the micropores is 0.18 mm, and from the outer circle to the inner circle, the pore depth of the micropores is 0.810 mm, 0.800 mm, 0.790 mm, 0.780 mm, 0.770 mm in sequence. The included 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 fineness of the single filament of the finally obtained high-density polyester pongee fiber is 0.42 D, the linear density deviation rate is 0.26%, the breaking strength is 2.75 cN / dtex, the CV value of the breaking strength is 1.8%, the breaking elongation is 126%, the CV value of the breaking elongation is 1.7%, the unevenness rate of yarn evenness is 0.62%, the CV value of the thermal stress is 1.21%, and the oil content is 0.41 wt%.

[0115] Example 7

[0116] A preparation method of high-density polyester pongee fiber is basically the same as that of Example 1, except that: in the equipment used in this example, a traditional silica gel gasket is used to replace the heat insulation board and aluminum plate between the spinning box and the ring blow cooling device.

[0117] The fineness of the single filament of the finally obtained high-density polyester pongee fiber is 0.2 D, the linear density deviation rate is 0.24%, the breaking strength is 2.73 cN / dtex, the CV value of the breaking strength is 2.7%, the breaking elongation is 118%, the CV value of the breaking elongation is 3.3%, the unevenness rate of yarn evenness is 1.1%, the CV value of the thermal stress is 2.31%, and the oil content is 0.43 wt%.

[0118] Compared with Example 1, for the high-density polyester pongee fiber obtained in Example 7, the CV value of the breaking strength, the CV value of the breaking elongation, the unevenness rate of yarn evenness, and the CV value of the thermal stress are all higher than those in Example 1, while the breaking strength and the breaking elongation are lower than those in Example 1. This is because in the equipment used in Example 7, a traditional silica gel gasket is used to replace the heat insulation board and aluminum plate between the spinning box and the ring blow cooling device. However, the silica gel gasket is not suitable for high-temperature production environments. Due to long-term use, the silica gel gasket is prone to adhesion and its thickness changes, resulting in a poor sealing effect of the spinning box. This change causes an increase in heat loss and a decrease in the heat insulation effect, ultimately affecting the quality of the product. The external manifestations are an increase in the CV value of the breaking strength, an increase in the CV value of the breaking elongation, an increase in the unevenness rate of yarn evenness, an increase in the CV value of the thermal stress, and a decrease in the breaking strength and the breaking elongation.

[0119] Example 8

[0120] A preparation method of high-density polyester pongee fiber is basically the same as that of Example 1, except that: in the equipment used in this example, a traditional filament separator (the 8-shaped opening wire guiding porcelain part disclosed in Chinese Patent CN214142637U) is used to replace the radial filament separator.

[0121] The fineness of the single filament of the finally obtained high-density polyester pongee is 0.2 D, the linear density deviation rate is 0.25%, the breaking strength is 2.56 cN / dtex, the CV value of the breaking strength is 2.8%, the breaking elongation is 120%, the CV value of the breaking elongation is 3.5%, the unevenness rate of yarn evenness is 1.2%, the CV value of the thermal stress is 2.58%, and the oil content is 0.43 wt%.

[0122] Compared with Example 1, in Example 8, the CV value of the breaking strength, the CV value of the breaking elongation, the unevenness rate of yarn evenness, and the CV value of the thermal stress of the high-density polyester pongee obtained in Example 8 are all higher than those in Example 1, while the breaking strength and the breaking elongation are lower than those in Example 1. This is because a traditional filament separator (i.e., the figure-eight opening wire guiding porcelain part disclosed in Patent CN214142637U) is used in the equipment of Example 8 to replace the radial filament separator. However, since the traditional filament separator cannot reduce the horizontal distance gap between the upper and lower parts of the filament bundle, and thus cannot change the tension of the filament bundle by affecting the running angle of the filament bundle, it is unable to effectively reduce the change in the filament bundle angle at both ends of the spinning position. This results in a larger tension difference between the filament bundles at both ends and between the spindle positions than in Example 1, ultimately affecting the product quality, which is externally manifested as an increase in the CV value of the breaking strength, an increase in the CV value of the breaking elongation, an increase in the unevenness rate of yarn evenness, an increase in the CV value of the thermal stress, and a decrease in the breaking strength and the breaking elongation.

Claims

1. A production device for high-density spring Asian spinning polyester fiber, comprising a spinning box body, a spinning component and an annular air blowing cooling device. The spinning component contains a spinneret plate, and the spinneret holes on the spinneret plate are distributed in n circles according to the layout of concentric circles, 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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