A method for preparing a dynamic profiled yarn

Abstract

The application belongs to the technical field of profiled yarn and discloses a preparation method of dynamic profiled yarn, which comprises the following steps: firstly, the polyester melt is sprayed from a spinneret, and then the polyester melt is preliminarily cooled to 200-240 DEG C in a spinning channel to obtain a preliminarily formed single yarn; secondly, the preliminarily formed single yarn is subjected to periodic cold air impact of 0-20 DEG C in the spinning channel, so that the temperature of the impacted area is reduced to 70-80 DEG C within 5-50 ms; and finally, the single yarn is sequentially subjected to bundling, drawing and setting, oiling and winding to obtain the dynamic profiled yarn; and the cross-sectional shape of the single yarn of the dynamic profiled yarn periodically changes along the length direction. According to the application, the single yarn dynamic profiled nozzle system is installed in the spinning channel during the polyester filament spinning stage, and the local quenching of the single yarn is accurately controlled, so that the single yarn with the dynamic profiled shape which changes along the length direction can be finally formed, and the method is simple and easy to implement.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of profiled yarns, and relates to a preparation method of dynamic profiled yarns. BACKGROUND

[0002] Profiled yarns break through the limitations of traditional round fibers in performance by changing cross-sectional shapes (such as triangular, trilobal, Y-shaped, hollow-shaped, etc.), thereby strengthening physical properties, increasing functional expansion, and meeting the needs of different fields.

[0003] In the prior art, profiled yarns are usually prepared by the following two methods:

[0004] One method is to use fixed-shaped spinning holes (such as triangular, cross-shaped, etc.) on the spinneret to make the melt directly form a single fixed cross-section when spinning. However, the cross-section of the single yarn prepared by this method is constant throughout, and after being combined into a yarn bundle, the single yarn is arranged loosely, and the whole still appears round, which cannot achieve the purpose of "dynamic change of the shape of the same single yarn in different sections". For example, the patent with the authorization announcement number CN110938889B discloses a profiled nylon 6 filament and a preparation method thereof. The preparation method prepares a profiled nylon 6 filament by improving the structure of the spinneret and cooperating with the method of coloring the original solution of nylon 6 filament.

[0005] Another method is to use a yarn bundle mechanical embossing technology in the post-processing stage to apply mechanical pressure to the combined yarn bundle (a collection of multiple single yarns) to forcibly change the overall cross-sectional shape. However, although the profiled yarn prepared by this technology can have an overall profiled shape, the single yarns are squeezed and rubbed against each other, resulting in a significant decrease in strength, uneven stress on the single yarns, low profiled precision, and difficulty in achieving functional design and precise control of the local shape of the single yarn. For example, the patent application with the application publication number CN104452070A discloses a concave-convex three-dimensional embossed knitted fabric. The fabric is fixed between the upper and lower dies of an embossing machine, then the upper and lower dies are heated to 165-175 DEG C, and the upper and lower dies are pressed and squeezed. After embossing, pressure cooling is performed, and the fabric is taken out after it cools to room temperature.

[0006] Therefore, it is necessary to provide a preparation method of dynamic profiled yarns to solve the above problems, which is of great significance. SUMMARY

[0007] The purpose of the application is to solve the problems existing in the prior art and provide a preparation method of dynamic profiled yarns.

[0008] To achieve the above purpose, the technical scheme adopted by the application is as follows:

[0009] The application relates to a preparation method of dynamic profiled yarn, wherein polyester melt is sprayed from a spinneret, is preliminarily cooled to 200-240 DEG C in a spinning duct to obtain preliminarily shaped filaments, and then the preliminarily shaped filaments are subjected to periodic cold air impact of 0-20 DEG C in the spinning duct to reduce the temperature of the impacted area to 70-80 DEG C within 5-500 ms, and then the filaments are sequentially subjected to bundling, drawing, oiling and winding to obtain the dynamic profiled yarn.

[0010] The cross-sectional shape of the filaments of the dynamic profiled yarn periodically changes along the length direction.

[0011] As a preferred technical scheme,

[0012] According to the preparation method of the dynamic profiled yarn, the cold air impact pressure is 0.2-0.5 MPa, the cold air impact pressure determines the cooling rate and the uniformity of the cooling, the pressure is too high to break the yarn, and the pressure is too low to cause poor cooling effect, and the cold air impact is applied every 50-100 ms, and each application lasts for 5-500 ms.

[0013] According to the preparation method of the dynamic profiled yarn, the cold air impact is realized through a filament cold air dynamic profiled nozzle system installed in the spinning duct, and the nozzle system is integrally installed in the spinning duct through a support.

[0014] The nozzle system comprises a nozzle module and a control system, the control system is used for controlling the position, time and interval of the opening / closing of the nozzle according to a preset program, the control system comprises electromagnetic valves, a nozzle switch controller and a cold air pressure regulating valve, the nozzle module is composed of multiple nozzles, each nozzle is used for applying cold air impact to one filament, each nozzle is provided with multiple annularly and uniformly distributed air outlets, and the air outlets are directed to the peripheral surface of the filament, one electromagnetic valve is installed on the pipeline corresponding to each air outlet, all the electromagnetic valves are connected to the nozzle switch controller through a cable, the opening / closing of the electromagnetic valves is controlled by the nozzle switch controller, so that whether the air outlets emit air and the air flow rate are controlled, and the nozzles are commonly connected to a total air inlet pipeline through air pipes, the cold air pressure regulating valve is installed at the inlet of the total air inlet pipeline, and the air outlet temperature and pressure of the nozzle are adjusted through the cold air pressure regulating valve.

[0015] According to the preparation method of the dynamic profiled yarn, the number of the air outlets on each nozzle is 2-8, the aperture is 0.05-0.3 mm, and the aperture of the yarn inlet hole of the nozzle through which the filament passes is 0.06-0.6 mm.

[0016] According to the preparation method of the dynamic profiled yarn, the aperture of the spinning hole on the spinneret is 0.05-0.3 mm, the temperature of the polyester melt is 280-300 DEG C, and the spinning speed is 10-18 m / min.

[0017] The preparation method of the dynamic profiled yarn as described above, the primary cooling adopts ring blowing cooling or side blowing cooling, the cooling air temperature is 20-30℃, and the cooling air speed is 0.8-1.5 m / s.

[0018] The preparation method of the dynamic profiled yarn as described above, the distance between the nozzle module and the ring blowing or side blowing area is 30-80 cm.

[0019] The distance between the single yarn cold air dynamic profiled nozzle system and the ring blowing / side blowing directly determines whether the yarn can complete the profiled cross-section deformation in the high-elasticity interval. If the distance is too close, the yarn is not sufficiently cooled to the high-elasticity state that can be shaped, and it is easy to cause deformation failure due to excessive viscosity of the melt. If the distance is too far, the yarn is excessively cooled to the glass state, and the molecular chains lose fluidity, and cannot realize profiled shaping through cold air impact.

[0020] The temperature change of the yarn extruded from the spinneret is divided into three stages, and the distance between the single yarn cold air dynamic profiled nozzle system and the ring blowing / side blowing needs to match the temperature interval of the "second stage (high-elasticity state)", which is as follows:

[0021] 1. First stage (spinneret outlet-ring blowing / side blowing): the yarn is rapidly cooled from the viscous flow state (such as PET 280-300℃) to the "high-elasticity initial temperature" (such as PET 240-260℃) through primary cooling by ring blowing / side blowing. The purpose of this stage is to let the yarn get rid of the melt state and have the initial shaping ability;

[0022] 2. Second stage (ring blowing / side blowing-dynamic profiled nozzle): the yarn continues to slowly cool and needs to be in the "high-elasticity core interval" (such as PET 200-240℃) when reaching the nozzle - this interval has both fluidity (can be deformed by impact) and certain rigidity (can be stably shaped after deformation), which is the "golden shaping interval" of dynamic profiled shaping;

[0023] 3. Third stage (after the dynamic profiled nozzle): the yarn that has completed profiled shaping needs to be further cooled to the glass state (such as PET 80-120℃) to fix the profiled shape and avoid deformation rebound in subsequent processes.

[0024] Therefore, the distance between the single yarn cold air dynamic profiled nozzle system and the ring blowing / side blowing essentially controls the temperature of the yarn to be in the high-elasticity core interval when reaching the nozzle, and the distance is directly related to the yarn cooling rate (determined by the ring blowing / side blowing intensity) and the spinning speed (the residence time of the yarn in the duct). The distance between the nozzle module and the ring blowing / side blowing area is preferably 30-80 cm.

[0025] The preparation method of the dynamic profiled yarn as described above, the breaking strength of the dynamic profiled yarn is ≥3.8 cN / dtex.

[0026] A method for preparing a dynamic profiled yarn, the cross-sectional shape of the monofilament of the dynamic profiled yarn is a combination of circular and non-circular, and the non-circular is one or more of flat, triangular, concave (i.e. there is a significant inwardly concave area at a certain position in the circumferential direction of the monofilament, similar to "C-shaped" or "crescent-shaped") and square.

[0027] A method for preparing a dynamic profiled yarn as described above, when only one air outlet is opened to perform cold air impact from one side, the corresponding monofilament formed is concave in cross-section;

[0028] When two air outlets are opened to perform cold air impact from opposite sides at the same time, the corresponding monofilament formed is flat in cross-section;

[0029] When three air outlets arranged uniformly along the circumference are opened to perform cold air impact at the same time, the corresponding monofilament formed is triangular in cross-section;

[0030] When four air outlets arranged uniformly along the circumference are opened to perform cold air impact at the same time, the corresponding monofilament formed is square in cross-section.

[0031] Invention principle:

[0032] As a semi-crystalline polymer material, the mechanical behavior of polyester (PET) is closely related to the state of motion of the molecular chain, and the motion ability of the molecular chain changes significantly with temperature. The mechanical state of polyester increases with temperature as follows:

[0033] Glassy state (T < Tg, Tg ≈ 70~80℃): The molecular chain and chain segment (a local structure composed of several repeating units) are "frozen" and cannot move, the material is rigid (similar to glass), the shape is stable but has no plasticity;

[0034] High-elastic state (Tg < T < Tf, Tf ≈ 260℃): The molecular chain as a whole cannot move, but the chain segment can rotate and stretch freely (similar to the elastic deformation of a rubber band), the material has flexibility and plasticity - external force can rearrange the chain segment, and after the external force is removed, it can partially recover, but sudden cooling can "lock" the deformation state;

[0035] Viscous flow state (T > Tf): The molecular chain as a whole can flow freely (similar to a viscous liquid), the material has no fixed shape and can only be shaped by a mold (such as a spinneret).

[0036] The core of the present application is to install a single filament cold air dynamic profile nozzle system in the spinning duct during the polyester filament spinning stage (when the single filament is just formed and has not been combined into a whole tow), and to realize dynamic profile shaping by precisely controlling the local quenching of the single filament. The temperature of the single filament that is extruded from the spinneret and initially cooled is reduced to 200-240℃, which is between Tg and Tf, at this time the whole molecular chain has been solidified into a filament shape (no longer flows), but the chain segment still maintains high mobility (can rotate freely). Under the action of the spinning tension, the chain segment is initially arranged along the stretching direction, showing "ordered high-elastic state"; when the initially cooled single filament passes through the nozzle module provided in the duct according to the present application, the control system drives the nozzles at specific positions to spray cold air at 0-20℃. Experiments have proved that, under the spinning speed of the present application, the temperature is reduced to 70-80℃ within 5-500ms after being impacted by the 0-20℃ cold air, which is just near the glass transition temperature of PET. The impacted area loses the ability to move instantly due to the sudden temperature drop, and the arrangement state of the chain segment is fixed. The unimpacted part still maintains high-elastic state, and the chain segment can continue to stretch along the axial direction (the chain segment arrangement is more ordered) under the action of the spinning tension, and the length increases; while the impacted area cannot stretch due to the chain segment, and the length remains unchanged. The difference in length between the two causes the impacted area to be relatively "shrunk" (for example, if the non-impacted area chain segment is elongated by 10% and the frozen area chain segment length remains unchanged, then the frozen area is relatively shrunk by 10%); with the continuous downward movement of the single filament, the above process is repeated, and finally a dynamically changing profile single filament along the length direction is formed.

[0037] Advantages:

[0038] (1) According to the present application, a single filament cold air dynamic profile nozzle system is installed in the spinning duct during the polyester filament spinning stage, and the local quenching of the single filament is precisely controlled, so that a dynamically changing profile single filament along the length direction can be finally formed.

[0039] (2) The shape of the same single filament length direction of the dynamic profile yarn of the present application can be changed as needed, the style diversity breaks through the prior art, the single filament runs independently during the spinning stage without interference from the tow, the profile precision is high, there is no mechanical rolling, the single filament molecular chain is complete, and the strength decline problem of the prior art is solved; at the same time, the single filament cold air dynamic profile nozzle system can be integrated into the existing spinning equipment without the need for large-scale modification, and the single filament can pass through the guide groove + cold air pulse nozzle module to realize automation. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 Figure a is a schematic diagram of the installation position of the single filament cold air dynamic profile nozzle system of the present application, figure b is an enlarged schematic diagram of the circled part in figure a, and figure c is an enlarged schematic diagram of the circled part in figure b.

[0041] Figure 2 Figure is a structural schematic diagram of the nozzle module of the present application.

[0042] Figure 3 Fig. 1 is a schematic diagram of the cross-sectional shape of the dynamic profiled yarn of the present application, wherein a is a schematic diagram of the dynamic profiled yarn, and b is a schematic diagram of the cross section of the dynamic profiled yarn;

[0043] Figure 4 Fig. 1 is a schematic diagram of the cross-sectional shape of the dynamic profiled yarn of the present application, wherein a is a schematic diagram of the dynamic profiled yarn, and b is a schematic diagram of the cross section of the dynamic profiled yarn;

[0044] Figure 5 Fig. 1 is a schematic diagram of the cross-sectional shape of the dynamic profiled yarn of the present application, wherein a is a schematic diagram of the dynamic profiled yarn, and b is a schematic diagram of the cross section of the dynamic profiled yarn;

[0045] Fig. 1 is a schematic diagram of the cross-sectional shape of the dynamic profiled yarn of the present application, wherein a is a schematic diagram of the dynamic profiled yarn, and b is a schematic diagram of the cross section of the dynamic profiled yarn; DETAILED DESCRIPTION

[0046] The present application will be further described in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the present application after reading the content taught by the present application, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

[0047] To ensure the performance of the substances used in each embodiment is fully disclosed, the manufacturer and brand of the substance are written, and other products of the manufacturer and brand conforming to the definition of the present application are also feasible.

[0048] The test methods of the relevant performance indicators in the following embodiments are as follows:

[0049] Breaking strength: the dynamic profiled yarn prepared in each embodiment is used as a sample, and then the breaking strength of the sample is measured according to the standard of GB / T 14344-2022 "Chemical fiber filament tensile property test method".

[0050] Profile degree: the profiled yarn segment of the dynamic profiled yarn prepared in each embodiment is used as a sample, and then the profile degree of the sample is tested according to the standard of FZ / T 50002-2013 "Chemical fiber profile degree test method".

[0051] The single yarn cold air dynamic profiled nozzle system used in the preparation of the dynamic profiled yarn is shown in Figs. 1-5, which includes a nozzle module 5 and a control system. Figure 1 , Figure 2

[0052] ​The control system includes a solenoid valve 7, a nozzle switch controller 8, and a cold air pressure regulating valve 9;

[0053] The nozzle module 5 is composed of multiple nozzles. Each nozzle is used to apply cold air to a single filament. Each nozzle has multiple air outlets evenly distributed in a ring shape, and the air outlets face the circumference of the single filament. The number of air outlets on each nozzle is 2 to 8, and the diameter of the outlet is 0.05 to 0.3 mm. The diameter of the inlet hole of the nozzle through which the single filament passes is 0.2 to 0.6 mm.

[0054] Each air outlet is connected to a solenoid valve 7 on its corresponding pipe. All solenoid valves 7 are connected to the nozzle switch controller 8 via cables. All nozzles are connected to the main air inlet pipe 10 via air pipes. A cold air pressure regulating valve 9 is installed at the inlet 11 of the main air inlet pipe.

[0055] When only one air outlet is opened to allow cold air to impact from one side, the resulting monofilament has a concave cross-section.

[0056] When two air outlets are opened and cold air is simultaneously impacted from opposite sides, the resulting monofilament has a flat cross-section.

[0057] When three air outlets evenly arranged along the circumference are opened and cold air is simultaneously impacted, the corresponding monofilament formed has a triangular cross-section.

[0058] When four air outlets evenly arranged along the circumference are opened and cold air is simultaneously impacted, the corresponding monofilament formed has a square cross-section.

[0059] Example 1

[0060] A method for preparing dynamic profiled filaments, comprising the following steps:

[0061] (1) such as Figure 1 As shown, polyester chips (semi-dull polyester chips, manufactured by Jiangsu Hengke New Materials Co., Ltd., batch number MS01) are melted through a melt extruder 1 and then extruded as polyester melt through a spinneret 3. The melt is then initially cooled to 240°C in the spinning tunnel using a ring blower box 4 to obtain a pre-formed monofilament 2. The spinneret has a spinneret hole diameter of 0.3 mm, 3 spinneret holes, a spinneret speed of 18 m / min, a polyester melt temperature of 300°C, a cooling air temperature of 30°C, and a cooling air velocity of 1.5 m / s.

[0062] (2) For example Figure 1As shown, by using the above-mentioned single-filament cold air dynamic profile nozzle system installed in the spinning duct 6, the 0°C cold air impact is periodically applied to the preliminarily formed single filaments in the spinning duct through the control of the 8 air outlets on each nozzle in the nozzle module 5, so that the temperature of the impacted area is reduced to 80°C within 500 ms; wherein the cold air impact pressure is 0.5 MPa, the cold air impact is applied every 50 ms, and each application time is 500 ms; the single-filament cold air dynamic profile nozzle system used: the height of the nozzle module from the ring blowing area is 30 cm, the number of nozzles in the nozzle module is 3, the diameter of the air outlet is 0.05 mm, and the diameter of the yarn inlet hole of the nozzle for the single filaments to pass through is 0.6 mm;

[0063] (3) The single filaments coming out of the spinning duct successively pass through bundling, drawing setting, oiling and winding to obtain the dynamic profile yarn; wherein the drawing ratio is 50 times.

[0064] The cross-sectional shape of the single filaments of the finally obtained dynamic profile yarn periodically changes along the length direction, and the cross-sectional shape of the single filaments is the combination of circular shape and non-circular shape, and the non-circular shape is as shown in the figure. Figure 5

[0065] The breaking strength of the dynamic profile yarn is 4.1 cN / dtex, the profile degree is 25%, and the ratio of the length of the single filaments with non-circular cross-sectional shape to the length of the single filaments with circular cross-sectional shape is 1:0.1.

[0066] Example 2

[0067] A preparation method of a dynamic profile yarn, the steps are as follows:

[0068] (1) After the polyester chip (polyester semi-dull chip, manufacturer Jiangsu Hengke New Material Co., Ltd., batch number MS01) is melted, the polyester melt is sprayed out through the spinneret, and then the side blowing cooling is used to preliminarily cool in the spinning duct to 220°C to obtain the preliminarily formed single filaments; wherein the diameter of the spinning hole on the spinneret is 0.2 mm, the number of the spinning holes is 9, the spinning speed is 12 m / min, the temperature of the polyester melt is 290°C, the cooling air temperature is 27°C, and the cooling air speed is 1.3 m / s;

[0069] ​(2) The above-mentioned single filament cold air dynamic profile nozzle system installed in the spinning duct is used to periodically apply 10℃ cold air impact on the primary formed single filament in the spinning duct by controlling the 4 air outlets on each nozzle in the nozzle module, so that the temperature of the impacted area is reduced to 75℃ within 80ms; wherein the cold air impact pressure is 0.4MPa, the cold air impact is applied every 60ms, and each application time is 80ms; the single filament cold air dynamic profile nozzle system used: the height of the nozzle module from the side blowing area is 50cm, the number of nozzles in the nozzle module is 9, the air outlet diameter is 0.2mm, and the filament inlet hole diameter of the nozzle for passing single filament is 0.3mm;

[0070] (3) The single filament coming out of the spinning duct successively passes through bundling, drawing setting, oiling and winding to prepare the dynamic profile yarn; wherein the drawing multiple is 40 times.

[0071] The final prepared dynamic profile yarn has a periodically changed single filament cross-sectional shape along the length direction, as shown in Figure 3 、 Figure 4 The single filament cross-sectional shape is a combination of circular and non-circular shapes, and the non-circular shape is a quadrilateral.

[0072] The breaking strength of the dynamic profile yarn is 3.9cN / dtex, the profile degree is 23%, and the length of the single filament cross-sectional shape in non-circular shape to the length of the single filament cross-sectional shape in circular shape is 1:0.75.

[0073] Example 3

[0074] A preparation method of a dynamic profile yarn, the steps are as follows:

[0075] (1) The polyester chip (polyester semi-dull chip, manufacturer Jiangsu Hengke New Material Co., Ltd., batch number MS01) is melted and then the polyester melt is sprayed out through the spinneret, and then the primary cooling is carried out in the spinning duct by using ring blowing to 210℃ to obtain the primary formed single filament; wherein the spinneret hole diameter is 0.1mm, the number of spinneret holes is 12, the spinneret speed is 15m / min, the temperature of the polyester melt is 285℃, the cooling air temperature is 25℃, and the cooling air speed is 1.1m / s;

[0076] (2) The above-mentioned single filament cold air dynamic profiled nozzle system installed in the spinning duct is used to periodically apply 20℃ cold air impact on the primary formed single filament in the spinning duct through controlling the three air outlets on each nozzle in the nozzle module, so that the temperature of the impacted area is reduced to 80℃ within 200ms; wherein, the cold air impact pressure is 0.3MPa, the cold air impact is applied every 80ms, and the application time is 200ms each time; the single filament cold air dynamic profiled nozzle system used: the height of the nozzle module from the ring blowing area is 70cm, the number of nozzles in the nozzle module is 12, the diameter of the air outlet is 0.1mm, and the diameter of the filament inlet hole of the nozzle for passing single filament is 0.15mm;

[0077] (3) The single filament coming out of the spinning duct successively passes through bundling, drawing setting, oiling and winding to prepare the dynamic profiled yarn; wherein, the drawing multiple is 30 times.

[0078] The final prepared dynamic profiled yarn has a periodic change in the single filament cross-sectional shape along the length direction, and the single filament cross-sectional shape is a combination of circular and non-circular shapes, and the non-circular shape is a triangle;

[0079] The breaking strength of the dynamic profiled yarn is 3.9cN / dtex, the profile degree is 23%, and the ratio of the length of the single filament cross-sectional shape with non-circular shape to the length of the single filament cross-sectional shape with circular shape is 1:0.4.

[0080] Example 4

[0081] A preparation method of a dynamic profiled yarn, the steps are as follows:

[0082] (1) The polyester chip (polyester semi-dull chip, manufacturer Jiangsu Hengke New Material Co., Ltd., batch number MS01) is melted and then the polyester melt is sprayed out through the spinneret, and then the primary cooling is carried out in the spinning duct by side blowing to 200℃ to obtain the primary formed single filament; wherein, the spinneret hole diameter is 0.05mm, the number of spinneret holes is 36, the spinning speed is 10m / min, the temperature of the polyester melt is 280℃, the cooling air temperature is 20℃, and the cooling air speed is 0.8m / s;

[0083] (2) the above-mentioned single filament cold air dynamic profiled nozzle system is installed in the spinning duct, 20℃ cold air impact is periodically applied to the primary shaped single filament in the spinning duct through controlling the 2 air outlets of each nozzle in the nozzle module, so that the temperature of the impacted area is reduced to 70℃ within 5ms; wherein, the cold air impact pressure is 0.2MPa, the cold air impact is applied every 100ms, and the application time is 5ms each time; wherein, the used single filament cold air dynamic profiled nozzle system: the height of the nozzle module from the side blowing area is 80cm, the number of nozzles in the nozzle module is 36, the air outlet diameter is 0.05mm, and the filament inlet hole diameter of the nozzle for passing single filament is 0.06mm;

[0084] (3) the single filament coming out of the spinning duct successively passes through bundling, drawing setting, oiling and winding to prepare the dynamic profiled yarn; wherein, the drawing multiple is 20 times.

[0085] The cross section shape of the finally prepared dynamic profiled yarn single filament periodically changes along the length direction, the cross section shape of the single filament is the combination of circular shape and non-circular shape, and the non-circular shape is flat shape;

[0086] The breaking strength of the dynamic profiled yarn is 3.8cN / dtex, the profiled degree is 20%, and the length of the single filament cross section shape of non-circular shape to the length of the single filament cross section shape of circular shape is 1:20.

[0087] Example 5

[0088] A dynamic profiled yarn preparation method, which is basically the same as example 4, and the difference is that only one air outlet of the control system is used to blow air in step (2).

[0089] The cross section shape of the finally prepared dynamic profiled yarn single filament periodically changes along the length direction, the cross section shape of the single filament is the combination of circular shape and non-circular shape, and the non-circular shape is concave shape;

[0090] The breaking strength of the dynamic profiled yarn is 3.8cN / dtex, the profiled degree is 10%, and the length of the single filament cross section shape of non-circular shape to the length of the single filament cross section shape of circular shape is 1:20.

[0091] Example 6

[0092] A dynamic profiled yarn preparation method, the steps are as follows:

[0093] (1) melt the polyester chip (polyester semi-dull chip, manufacturer Jiangsu Hengke New Material Co., Ltd., batch number MS01), and then spray the polyester melt through the spinneret, and then preliminarily cool the polyester melt to 220℃ in the spinning duct by side blowing cooling to obtain a preliminarily formed single yarn; wherein the diameter of the spinning hole on the spinneret is 0.2 mm, the temperature of the polyester melt is 290℃, the spinning speed is 12 m / min, the cooling air temperature is 27℃, and the cooling air speed is 1.3 m / s;

[0094] (2) periodically apply a 10℃ cold air impact to the preliminarily formed single yarn in the spinning duct by a single yarn cold air dynamic profile nozzle system installed in the spinning duct to reduce the temperature of the impacted area to 75℃; wherein the cold air impact pressure is 0.4 MPa, and the single yarn cold air dynamic profile nozzle system comprises a nozzle module and a control system;

[0095] The control system comprises an electromagnetic valve, a nozzle switch controller and a cold air pressure regulating valve;

[0096] The nozzle module is composed of 9 nozzles, each nozzle is used to apply cold air impact to a single yarn, each nozzle has a plurality of annularly and uniformly distributed air outlets, and the air outlets are directed to the circumferential surface of the single yarn; an electromagnetic valve is installed on the pipeline corresponding to each air outlet, and all the electromagnetic valves are connected to the nozzle switch controller through a cable; the nozzles are connected to the total air inlet pipe through the air pipe, and the cold air pressure regulating valve is installed at the inlet of the total air inlet pipe;

[0097] The number of air outlets on each nozzle is 6, and the cold air impact is periodically applied, which means that two air outlets are opened at the same time from opposite sides to apply cold air impact to the single yarn for 40 ms, then three air outlets arranged uniformly along the circumference are switched on to apply cold air impact to the single yarn for 20 ms, and the cold air impact process is repeated after 80 ms;

[0098] The height of the nozzle module from the side blowing area is 50 cm, the number of air outlets on each nozzle is 9, the diameter of the air outlets is 0.2 mm, and the diameter of the yarn inlet hole of the nozzle through which the single yarn passes is 0.3 mm;

[0099] (4) the single yarn coming out of the spinning duct successively passes through bundling, drawing and setting, oiling and winding to obtain a dynamic profile yarn; wherein the draw ratio is 40 times.

[0100] The cross-sectional shape of the single yarn of the obtained dynamic profile yarn periodically changes along the length direction, and the cross-sectional shape of the single yarn on each period is in turn circular, flat and triangular, and the length ratio of the corresponding circular cross-section, flat cross-section and triangular cross-section is 1:0.5:0.25;

[0101] The profile degree of the dynamic profiled yarn is 23% for the profiled section with a triangular cross-section of the monofilament and 15% for the profiled section with a flat cross-section of the monofilament.

[0102] Example 7

[0103] A preparation method of a dynamic profiled yarn, comprising the following steps:

[0104] (1) polyester chips (polyester semi-dull chips, manufacturer Jiangsu Hengke New Material Co., Ltd., batch number MS01) are melted and then polyester melt is sprayed through a spinneret, and then the polyester melt is preliminarily cooled to 200 DEG C in a spinning duct by using ring blowing cooling to obtain a preliminarily formed monofilament; wherein the spinneret hole diameter is 0.1 mm, the polyester melt temperature is 280 DEG C, the spinning speed is 10 m / min, the cooling air temperature is 20 DEG C, and the cooling air speed is 0.8 m / s;

[0105] (2) the preliminarily formed monofilament is subjected to periodic cold air impact of 20 DEG C by using a monofilament cold air dynamic profiled nozzle system installed in the spinning duct to reduce the temperature of the impacted area to 70 DEG C; wherein the cold air impact pressure is 0.2 MPa, and the monofilament cold air dynamic profiled nozzle system comprises a nozzle module and a control system;

[0106] The control system comprises an electromagnetic valve, a nozzle switch controller and a cold air pressure regulating valve;

[0107] The nozzle module is composed of 36 nozzles, each nozzle is used for applying cold air impact to a monofilament, each nozzle has a plurality of annularly and uniformly distributed air outlets, and the air outlets are directed to the monofilament peripheral surface; an electromagnetic valve is installed on the pipeline corresponding to each air outlet, and all the electromagnetic valves are connected to the nozzle switch controller through a cable; the nozzles are connected to a total air inlet pipe through air pipes, and a cold air pressure regulating valve is installed at the total air inlet pipe inlet;

[0108] The number of air outlets on each nozzle is 6, and the periodic cold air impact means that two air outlets are first opened to simultaneously impact the monofilament from opposite sides for 35 ms, then three air outlets arranged uniformly along the circumference are switched to simultaneously impact the monofilament for 15 ms, and the cold air impact process is repeated after 5 ms;

[0109] The height of the nozzle module from the ring blowing area is 80 cm, the number of air outlets on each nozzle is 36, the air outlet diameter is 0.05 mm, and the monofilament inlet hole diameter of the nozzle through which the monofilament passes is 0.2 mm;

[0110] (4) the monofilament coming out of the spinning duct is sequentially subjected to bundling, drawing and setting, oiling and winding to obtain a dynamic profiled yarn; wherein the draft ratio is 20 times.

[0111] The prepared dynamic profiled yarn has a cross-sectional shape of the monofilament periodically changing along the length direction, and the cross-sectional shape of the monofilament in each period is in sequence a circle, a flat shape and a triangle, and the length ratio of the corresponding circular cross-section, flat cross-section and triangular cross-section is 1:7:3.

[0112] The profile degree of the profiled section with the cross-sectional shape of the monofilament being a triangle on the dynamic profiled yarn is 20%, and the profile degree of the profiled section with the cross-sectional shape of the monofilament being a flat shape is 13%.

[0113] Example 8

[0114] A preparation method of a dynamic profiled yarn, the steps being as follows:

[0115] (1) After polyester chips (polyester semi-dull chips, manufacturer Jiangsu Hengke New Material Co., Ltd., batch number MS01) are melted, the polyester melt is sprayed out through a spinneret, and then the polyester melt is preliminarily cooled to 210℃ in a spinning duct by ring blowing to obtain a preliminarily formed monofilament; wherein the spinneret hole diameter is 0.1 mm, the spinning speed is 15 m / min, the temperature of the polyester melt is 285℃, the cooling air temperature is 25℃, and the cooling air speed is 1.1 m / s;

[0116] (2) The preliminarily formed monofilament is subjected to periodic cold air impact of 20℃ by a monofilament cold air dynamic profiled nozzle system installed in the spinning duct, so that the temperature of the impacted area is reduced to 80℃; wherein the cold air impact pressure is 0.3 MPa, and the monofilament cold air dynamic profiled nozzle system comprises a nozzle module and a control system;

[0117] The control system comprises a solenoid valve, a nozzle switch controller and a cold air pressure regulating valve;

[0118] The nozzle module is composed of 12 nozzles, each nozzle is used for applying cold air impact to a monofilament, each nozzle has 4 gas outlets arranged in a ring shape and uniformly distributed, and the gas outlets are directed to the peripheral surface of the monofilament; a solenoid valve is installed on the pipeline corresponding to each gas outlet, and all the solenoid valves are connected to the nozzle switch controller through a cable; the nozzles are connected to a total gas inlet pipe through gas pipes, and a cold air pressure regulating valve is installed at the inlet of the total gas inlet pipe;

[0119] The periodic cold air impact means that two gas outlets are first opened to simultaneously impact the monofilament from opposite sides for 30 ms, and then three gas outlets arranged uniformly along the circumference are switched to simultaneously impact the monofilament for 30 ms, and the cold air impact process is alternately repeated; when the three gas outlets simultaneously impact the monofilament, the angle between the gas outlet directions of adjacent two gas outlets is 150°;

[0120] The height of the nozzle module from the ring blowing area is 70 cm, the diameter of the air outlet hole is 0.1 mm, and the diameter of the filament inlet hole of the nozzle for passing the monofilament is 0.15 mm;

[0121] (3) The monofilament coming out of the spinning duct successively passes through bundling, drawing setting, oiling and winding to obtain the dynamic profiled yarn; wherein the draw ratio is 30 times.

[0122] The profile degree of the dynamic profiled yarn is 23% for the profiled section with triangular monofilament cross section shape and 15% for the profiled section with flat monofilament cross section shape;

[0123] The monofilament cross section shape of the dynamic profiled yarn periodically changes along the length direction, and the monofilament cross section shape on each period is flat and triangular in turn, and the length ratio of the flat cross section to the triangular cross section in each period is 1:1.

[0124] Example 9

[0125] A preparation method of a dynamic profiled yarn, comprising the following steps:

[0126] (1) After the polyester chip (polyester semi-dull chip, manufacturer Jiangsu Hengke New Material Co., Ltd., batch number MS01) is melted, the polyester melt is sprayed out through the spinneret, and then the preliminary cooling is performed in the spinning duct by using the side blowing cooling to 200℃ to obtain the preliminarily formed monofilament; wherein the diameter of the spinning hole on the spinneret is 0.05 mm, the spinning speed is 10 m / min, the temperature of the polyester melt is 280℃, the cooling air temperature is 20℃, and the cooling air speed is 0.8 m / s;

[0127] (2) The 20℃ cold air impact is periodically applied to the preliminarily formed monofilament in the spinning duct by using the monofilament cold air dynamic profiled nozzle system installed in the spinning duct to reduce the temperature of the impacted area to 70℃; wherein the cold air impact pressure is 0.2 MPa, and the monofilament cold air dynamic profiled nozzle system comprises a nozzle module and a control system;

[0128] The control system comprises an electromagnetic valve, a nozzle switch controller and a cold air pressure regulating valve;

[0129] The nozzle module is composed of 36 nozzles, each nozzle is used for applying cold air impact to one monofilament, each nozzle has 4 air outlet holes which are uniformly distributed in a ring shape and face the monofilament peripheral surface; an electromagnetic valve is respectively installed on the pipeline corresponding to each air outlet hole, and all the electromagnetic valves are connected to the nozzle switch controller through a cable; the nozzles are connected to the total air inlet pipe through the air pipe, and the cold air pressure regulating valve is installed at the inlet of the total air inlet pipe;

[0130] The cold air impact is applied periodically, which means that the two air outlets are opened to impact the single yarn from opposite sides for 50 ms, and then the three air outlets are switched to impact the single yarn for 20 ms, and the process is repeated alternately; when the three air outlets impact the single yarn, the angle between the directions of the air outlets of two adjacent air outlets is 120°.

[0131] The height of the nozzle module from the side blowing area is 80 cm, the diameter of the air outlet is 0.05 mm, and the diameter of the yarn inlet hole of the nozzle for the single yarn is 0.06 mm.

[0132] (3) The single yarn coming out of the spinning duct passes through the processes of bundling, drawing and setting, oiling and winding in sequence to obtain the dynamic profiled yarn; wherein the draw ratio is 20 times.

[0133] The profile degree of the dynamic profiled yarn is 13% for the profiled section with the triangular single yarn cross-sectional shape, and 9% for the profiled section with the flat single yarn cross-sectional shape.

[0134] The single yarn cross-sectional shape of the dynamic profiled yarn changes periodically along the length direction, and the single yarn cross-sectional shape in each period is flat and triangular in sequence, and the length ratio of the flat cross-sectional shape to the triangular cross-sectional shape in each period is 2.5:1.

Claims

1. A method for preparing dynamic profiled filaments, characterized in that: The polyester melt ejected from the spinneret is first cooled to 200-240°C in the spinning tunnel to obtain a preliminary filament. Then, cold air at 0-20°C is periodically applied to the preliminary filament in the spinning tunnel to reduce the temperature of the impacted area to 70-80°C within 5-500ms. After that, the filament coming out of the spinning tunnel goes through bundling, stretching and setting, oiling and winding in sequence to obtain a dynamic profiled yarn. The diameter of the spinneret orifices is 0.05~0.3mm; The application of cold air impact is achieved through a single-filament cold air dynamic shaped nozzle system installed in the spinning tunnel. The single-filament cold air dynamic shaped nozzle system includes a nozzle module and a control system. The control system includes a solenoid valve, a nozzle switch controller, and a cold air pressure regulating valve. The nozzle module is composed of multiple nozzles, each nozzle is used to apply cold air impact to a single filament, and each nozzle has multiple air outlets evenly distributed in a ring, with the air outlets facing the circumference of the single filament. A solenoid valve is installed on the pipe corresponding to each air outlet, and all solenoid valves are connected to the nozzle switch controller via cables. All nozzles are connected to a main air inlet pipe through air pipes, and a cold air pressure regulating valve is installed at the inlet of the main air inlet pipe. The cross-sectional shape of the single filament of the dynamic profiled filament is a combination of circular and non-circular shapes, and the non-circular shapes are one or more of the following: flat, triangular, concave, and square. The cross-sectional shape of the single filament of the dynamic profiled filament changes periodically along the length direction. When only one air outlet is opened to allow cold air to impact from one side, the resulting monofilament has a concave cross-section. When two air outlets are opened and cold air is simultaneously impacted from opposite sides, the resulting monofilament has a flat cross-section. When three air outlets evenly arranged along the circumference are opened and cold air is simultaneously impacted, the corresponding monofilament formed has a triangular cross-section. When four air outlets evenly arranged along the circumference are opened and cold air is simultaneously impacted, the corresponding monofilament formed has a square cross-section.

2. The method for preparing a dynamic profiled filament according to claim 1, characterized in that, The cold air impact pressure is 0.2~0.5MPa, and the cold air impact is applied once every 50~100ms, with each application lasting 5~500ms.

3. The method for preparing a dynamic profiled filament according to claim 1, characterized in that, Each nozzle has 2 to 8 air outlet holes with a diameter of 0.05 to 0.3 mm, and the nozzle for monofilament passage has an inlet hole diameter of 0.06 to 0.6 mm.

4. The method for preparing a dynamic profiled filament according to claim 1, characterized in that, The temperature of the polyester melt is 280~300℃; the spinning speed is 10~18m / min.

5. The method for preparing a dynamic profiled filament according to claim 4, characterized in that, Initial cooling uses annular or side-blowing cooling with a cooling air temperature of 20-30℃ and a cooling air velocity of 0.8-1.5m / s.

6. The method for preparing a dynamic profiled filament according to claim 5, characterized in that, The nozzle module is 30-80cm high from the annular or side-blowing area.

7. The method for preparing a dynamic profiled filament according to claim 1, characterized in that, The breaking strength of the dynamic profiled wire is ≥3.8cN / dtex.

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