Preparation method of polyether ketone amide / polyether ether ketone superfine denier monofilament

Abstract

The invention discloses a preparation method of polyether ketone amide / polyether-ether-ketone superfine denier monofilaments. The preparation method comprises the following steps: S1, preparing raw materials, wherein the raw materials comprise the following materials in percentage by mass: 1-2% of polyether ketone amide resin; 98-99% of polyether-ether-ketone resin; s2, drying; s3, hot melt extrusion; s4, spinning, wherein a spinning assembly sprays out the melt to form a plurality of primary monofilaments, and the primary monofilaments are cooled, oiled and bundled to form primary multifilaments; the spinning temperature is controlled to be 360-390 DEG C, and the spinning pressure is controlled to be less than or equal to 15MPa; s5, stretching, shaping and winding the primary multifilament; s6, dividing and winding: dividing the primary multifilament into a plurality of polyether ketone amide / polyether-ether-ketone superfine denier monofilaments through a filament dividing machine, then controlling the tension of the polyether ketone amide / polyether-ether-ketone superfine denier monofilaments to be 5-20CN through a tension controller, and then winding the polyether ketone amide / polyether-ether-ketone superfine denier monofilaments. The method has the advantages that energy consumption is low, and monofilaments with the fiber diameter smaller than 35 micrometers can be prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of special fiber preparation, and particularly relates to a method for preparing polyether ketone amide / polyether ether ketone superfine denier monofilaments. Background Art

[0002] Polyether ether ketone (PEEK) is a linear fully aromatic crystalline polymer with regular structure and high crystallinity. The PEEK monofilaments obtained by melt extrusion have excellent properties such as high strength, high toughness, high temperature resistance, corrosion resistance, and high flame retardancy, and are widely used in the fields of aerospace, automotive industry, electronics, medical treatment, and automobiles.

[0003] Due to the high melting temperature of PEEK, the melting point range of PEEK is usually between 340°C and 345°C, and the melt viscosity after melting is large and the fluidity is poor. In the currently commonly used high-temperature melt spinning process, high temperatures are required in the melt extrusion stage of the screw extruder, the spinning stage of the spinning component, and the stretching and setting stage. In particular, the spinning temperature of the spinning component is as high as 390 - 440°C, resulting in high equipment energy consumption. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing polyether ketone amide / polyether ether ketone superfine denier monofilaments with low energy consumption and capable of making fiber diameters less than 35μm.

[0005] To achieve the above purpose, the present invention adopts the following technical scheme: A method for preparing polyether ketone amide / polyether ether ketone superfine denier monofilaments, comprising the following steps: S1: Raw material preparation: The raw materials are composed of the following materials by mass percentage: 1 - 2% polyether ketone amide resin; 98 - 99% polyether ether ketone resin; S2: Drying: Use a multi-stage vacuum rotary drum dryer to complete the drying of the raw materials, so that the moisture content of the raw materials is lower than 50PPM; S3: Hot melt extrusion: Add the dried raw materials into a screw extruder and melt extrude to form a polyether ketone amide / polyether ether ketone melt; wherein, the temperature range of the feeding section of the screw extruder is: 300 - 320°C, the temperature range of the compression section of the screw extruder is: 360 - 380°C, and the temperature range of the metering section of the screw extruder is: 350 - 370°C; And the screw in the screw extruder adopts a shallow groove and short pitch structure, and the specific shallow groove and short pitch structure is: the diameter D of the screw is 25 - 35mm, the length-diameter ratio of the screw is: 18:1 - 24:1, the depth of the screw groove in the feeding section of the screw is: 0.1 - 0.15D; the depth of the screw groove in the compression section of the screw is: gradually becoming shallower from the depth of the feeding section of the screw to the depth of the metering section of the screw; the depth of the screw groove in the metering section of the screw is: 0.03 - 0.06D; S4: Spinning: The melt extruded from the screw extruder is metered by a metering pump and then introduced into each spinning pack through equal - volume straight - through channels. Each spinning pack sprays the melt to form several primary monofilaments, and the primary monofilaments are cooled, oiled, and bundled to form primary multifilaments; among them, the spinning temperature of the spinning pack is controlled at 360 - 390 °C, and the spinning pressure is controlled at ≤15 MPa; S5: Drawing, setting, and winding of primary multifilaments: The primary multifilaments are first drawn successively through a first - stage drawing hot roll and a second - stage drawing hot roll, and then set by a setting hot roll and wound; Among them, the roll temperature of the first - stage drawing hot roll is 150 - 200 °C, and the roll speed is 250 - 300 m / min; the roll temperature of the second - stage drawing hot roll is 170 - 220 °C, and the roll speed is 600 - 1000 m / min; the draw ratio of the second - stage drawing hot roll to the first - stage drawing hot roll is 2 - 4; the roll temperature of the setting hot roll is 170 - 220 °C, and the roll speed is 500 - 900 m / min; S6: Filament splitting and winding: The primary multifilaments are split into several polyether ketone amide / polyether ether ketone super - fine denier monofilaments by a filament splitting machine, and then the tension of the polyether ketone amide / polyether ether ketone super - fine denier monofilaments is controlled at 5 - 20 CN by a tension controller and then wound.

[0006] Further, in the above - mentioned method for preparing polyether ketone amide / polyether ether ketone super - fine denier monofilaments, in S2, when the multi - stage vacuum rotary drum dryer dries the raw materials, the drying temperature is 130 - 150 °C, and the drying time is 5 - 7 hours.

[0007] Further, in the above - mentioned method for preparing polyether ketone amide / polyether ether ketone super - fine denier monofilaments, the structure of the spinning pack includes: a housing with a top feed port and a bottom discharge port. Inside the housing, an upper flow - through plate, a metal sand layer, an upper filter layer, a distribution plate, a lower flow - through plate, a lower filter layer, and a spinneret are arranged in sequence from top to bottom. The metal sand layer is composed of metal sand with a mesh number of 24, and both the upper filter layer and the lower filter layer are stacked by several filter mesh layers with mesh numbers of 32 - 450.

[0008] Further, in the above - mentioned method for preparing polyether ketone amide / polyether ether ketone super - fine denier monofilaments, the upper filter layer is stacked by nine filter mesh layers. The mesh numbers of the nine filter mesh layers of the upper filter layer from top to bottom are: 32 mesh, 50 mesh, 180 mesh, 250 mesh, 450 mesh, 250 mesh, 180 mesh, 50 mesh, 30 mesh; the lower filter layer is stacked by three filter mesh layers. The mesh numbers of the three filter mesh layers of the lower filter layer from top to bottom are: 32 mesh, 250 mesh, 32 mesh.

[0009] By implementing the above - mentioned technical solutions, the beneficial effects of the present invention are: (1) By adding polyether ketone amide resin to polyether ether ketone resin, the polyether ether ketone resin can obtain better fluidity at a lower processing temperature, thereby improving the spinnability of polyether ether ketone fibers, and thus the working temperatures in the melt extrusion stage, the spinning stage of the spinning pack, and the stretching and setting stage in the process can be reduced. The working temperature of each stage can be reduced by at least 20 °C compared to the traditional process temperature, thereby reducing energy consumption. (2) Design the stages of drying, hot melt extrusion, spinning, stretching and setting, and fiber splitting and winding. Through the combined action of each stage, after adding polyether ketone amide resin to polyether ether ketone resin, while ensuring the performance of the polyether ketone amide / polyether ether ketone superfine denier monofilament, the fiber diameter of the obtained polyether ketone amide / polyether ether ketone superfine denier monofilament can be less than 35 μm. (3) In the hot melt extrusion stage, a shallow groove and short pitch screw structure design is adopted. The advantages of this design in the manufacturing process of this polyether ether ketone resin and polyether ketone amide resin are as follows: 1) Improve melting efficiency: Shallow groove design: The screw groove depth is relatively shallow, increasing the contact area between the melt and the screw and barrel, improving the heat conduction efficiency, and helping to quickly melt the polyether ether ketone resin and polyether ketone amide; Short pitch design: The pitch is shorter, increasing the shear rate and further promoting the melting of the polyether ether ketone resin and polyether ketone amide; 2) Enhance the mixing uniformity: The shallow groove and short pitch design generates a higher shear force, which helps to fully mix the polyether ether ketone resin and polyether ketone amide, avoiding layering or local non-uniformity, and ensuring the uniform distribution of the two materials during the melting process, improving the consistency of the spun fibers; 3) Shorten the residence time: The shallow groove and short pitch design reduces the residence time of the melt in the screw, reducing the risk of degradation of the polyether ether ketone resin and polyether ketone amide due to overheating or shear overheating, reducing material degradation, and the shallow groove design is conducive to uniform temperature distribution and avoiding local overheating; 4) Improve extrusion stability: The shallow groove and short pitch design reduces the fluctuation of the melt flow, ensuring a stable extrusion process and avoiding non-uniform fiber diameter of the spun fibers; The short pitch design reduces the pressure loss and pressure fluctuation, ensuring the uniform flow of the melt in the runner. (4) During the flow of the polyetherketoneamide / polyetheretherketone melt from the screw extruder to the spinning pack, an equal-volume straight-through channel is adopted. The equal-volume straight-through channel is characterized in that the cross-sectional area of the channel remains consistent in the flow direction, ensuring that the volume flow rate of the melt remains unchanged during the flow process, so that the melt will not be affected by compression or expansion when flowing in the channel. 1) The equal-volume design can ensure that the volume of the melt is constant when flowing in the channel, ensuring the uniform distribution of the melt in the channel, avoiding the velocity and pressure fluctuations caused by the change of the cross-sectional area of the channel, and avoiding too fast or too slow local flow velocity, thereby ensuring the diameter consistency of the fibers. 2) The straight-through design can make the channel without bending or sudden change, reducing the flow resistance, enabling the polyetherketoneamide / polyetheretherketone melt to flow uniformly and stably. At the same time, the straight-through design can also reduce the melt retention area, preventing local overheating and degradation, thereby ensuring the uniform and stable flow of the polyetherketoneamide / polyetheretherketone melt from the screw extruder to the spinning pack, reducing the problems of melt fracture or uneven extrusion; and it can also reduce the residence time of the melt in the channel, reducing the risk of degradation of the polyetherketoneamide / polyetheretherketone melt due to overheating or shear overheating. Description of the Drawings

[0010] Figure 1 It is a schematic structural diagram of the spinning pack in the present invention.

[0011] Figure 2 It is a schematic connection diagram when the metering pump in the present invention is connected to each spinning pack through each equal-volume straight-through channel.

[0012] Figure 3 It is a schematic diagram of the diameter of the polyetherketoneamide / polyetheretherketone superfine denier monofilament prepared in each embodiment of the present invention under an image measuring instrument. Detailed Description of the Invention

[0013] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Embodiment 1

[0014] A method for preparing a polyetherketoneamide / polyetheretherketone superfine denier monofilament includes the following steps: S1: Raw material preparation: The raw materials are composed of the following materials by mass percentage: 1% polyetherketoneamide resin; 99% polyetheretherketone resin; S2: Drying: Using a multi-stage vacuum rotary drum dryer to dry the raw materials at a temperature of 130°C for 5 hours, controlling the moisture content of the raw materials to be less than 50 PPM; S3: Hot Melt Extrusion: The dried raw materials are added into a screw extruder and melted and extruded to form a polyether ketone amide / polyether ether ketone melt; among them, the temperature range of the feeding section of the screw extruder is: 300 °C, the temperature range of the compression section of the screw extruder is: 360 °C, and the temperature range of the metering section of the screw extruder is: 350 °C; And the screw in the screw extruder adopts a shallow groove and short pitch structure, and the specific shallow groove and short pitch structure is: the diameter D of the screw is 35 mm, the length-diameter ratio of the screw is: 24:1, and the depth of the screw groove in the feeding section of the screw is: 0.15D; the depth of the screw groove in the compression section of the screw is: gradually becoming shallower and decreasing from the depth of the feeding section of the screw to the depth of the metering section of the screw; the depth of the screw groove in the metering section of the screw is: 0.06D; S4: Spinning: The melt extruded from the screw extruder is metered by a metering pump 100 and then respectively introduced into each spinning component 300 through an equal-volume straight-through channel 200. The schematic diagram of the connection relationship when the metering pump 100 is respectively connected to each spinning component 300 through each equal-volume straight-through channel 200 is as Figure 2 shown. Each spinning component 300 ejects the melt to form a number of primary monofilaments. Each primary monofilament is first slowly cooled to 280 °C, and then cooled to room temperature by a side blowing device and oiled and bundled to form a primary multifilament; among them, the spinning temperature of the spinning component is controlled at 360 °C, and the spinning pressure is controlled at 15 MPa; As Figure 1 shown, the structure of the spinning component includes: a housing 3 having a top feeding port 1 and a bottom discharging port 2. Inside the housing 3, an upper flow plate 4, a metal sand layer 5, an upper filter layer 6, a distribution plate 7, a lower flow plate 8, a lower filter layer 9 and a spinneret 10 are arranged in sequence from top to bottom. The metal sand layer 5 is composed of metal sand with a mesh number of 24. Both the upper filter layer 6 and the lower filter layer 9 are stacked by a number of filter meshes with a mesh number of 32-450; among them, the upper filter layer 6 is stacked by nine filter meshes, and the mesh numbers of the nine filter meshes of the upper filter layer 6 are, from top to bottom in sequence: 32 mesh, 50 mesh, 180 mesh, 250 mesh, 450 mesh, 250 mesh, 180 mesh, 50 mesh, 30 mesh; the lower filter layer 9 is stacked by three filter meshes, and the mesh numbers of the three filter meshes of the lower filter layer 9 are, from top to bottom in sequence: 32 mesh, 250 mesh, 32 mesh; S5: Tensile Setting and Winding of the Primary Multifilament: The primary multifilament is first stretched successively through a primary stretching hot roll and a secondary stretching hot roll, and then set by a setting hot roll and wound; Among them, the roll temperature of the primary stretching hot roll is 150 °C and the roll speed is 300 m / min; the roll temperature of the secondary stretching hot roll is 170 °C and the roll speed is 600 m / min; the stretching ratio of the secondary stretching hot roll to the primary stretching hot roll is 2; the roll temperature of the setting hot roll is 170 °C and the roll speed is 500 m / min; S6: Filament splitting and winding: The as - spun multifilament is split into several ultra - fine polyetherketone amide / polyetheretherketone monofilaments by a filament splitting machine, and then the tension of the ultra - fine polyetherketone amide / polyetheretherketone monofilaments is controlled at 5 - 20 CN by a tension controller and then wound up to obtain ultra - fine polyetherketone amide / polyetheretherketone monofilaments with a fiber diameter of 32.859 μm. Example 2

[0015] A method for preparing ultra - fine polyetherketone amide / polyetheretherketone monofilaments, comprising the following steps: S1: Raw material preparation: The raw materials are composed of the following materials by mass percentage: 1.5% polyetherketone amide resin; 98.5% polyetheretherketone resin; S2: Drying: The raw materials are dried at a temperature of 140 °C for 6 hours by a multi - stage vacuum rotary drum dryer, and the moisture content of the raw materials is controlled to be less than 50 PPM; S3: Melting and extrusion: The dried raw materials are added to a screw extruder and melted and extruded to form a polyetherketone amide / polyetheretherketone melt; among them, the temperature range of the feeding section of the screw extruder is: 310 °C, the temperature range of the compression section of the screw extruder is: 370 °C, and the temperature range of the metering section of the screw extruder is: 360 °C; And the screw in the screw extruder adopts a shallow - groove short - pitch screw, and the specific parameters of the shallow - groove short - pitch screw are as follows: the diameter D of the screw is 28 mm, the length - to - diameter ratio of the screw is: 22:1, the depth of the screw groove in the feeding section of the screw is: 0.12D; the depth of the screw groove in the compression section of the screw is: gradually becoming shallower from the depth of the feeding section of the screw and decreasing to the depth of the metering section of the screw; the depth of the screw groove in the metering section of the screw is: 0.04D; S4: Spinning: The melt extruded from the screw extruder is metered by a metering pump 100 and then respectively introduced into each spinning pack 300 through an equal - volume straight - through channel 200. The schematic diagram of the connection relationship when the metering pump 100 is respectively connected to each spinning pack 300 through each equal - volume straight - through channel 200 is as Figure 2 shown. Each spinning pack sprays out the melt to form several as - spun monofilaments. The as - spun monofilaments are first slowly cooled to 280 °C, and then cooled to room temperature by a side - blowing device and oiled and bundled to form an as - spun multifilament; among them, the spinning temperature of the spinning pack is controlled at 380 °C, and the spinning pressure is controlled at 12 MPa; As Figure 1As shown in the figure, the structure of the spinning component includes: a housing 3 with a top feed port 1 and a bottom discharge port 2. Inside the housing 3, an upper flow plate 4, a metal sand layer 5, an upper filter layer 6, a distribution plate 7, a lower flow plate 8, a lower filter layer 9, and a spinneret plate 10 are arranged in sequence from top to bottom. The metal sand layer 5 is composed of metal sand with a mesh number of 24. Both the upper filter layer 6 and the lower filter layer 9 are formed by laminating a number of filter meshes with a mesh number ranging from 32 to 450. Among them, the upper filter layer 6 is formed by laminating nine filter meshes. The mesh numbers of the nine filter meshes of the upper filter layer 6 from top to bottom are: 32 mesh, 50 mesh, 180 mesh, 250 mesh, 450 mesh, 250 mesh, 180 mesh, 50 mesh, 30 mesh. The lower filter layer 9 is formed by laminating three filter meshes. The mesh numbers of the three filter meshes of the lower filter layer 9 from top to bottom are: 32 mesh, 250 mesh, 32 mesh. S5: Tensile setting and winding of the nascent multifilament: The nascent multifilament is first stretched by a primary stretching hot roll and a secondary stretching hot roll, and then set by a setting hot roll and wound. Among them, the roll temperature of the primary stretching hot roll is 180°C, and the roll speed is 270 m / min; the roll temperature of the secondary stretching hot roll is 200°C, and the roll speed is 810 m / min; the stretching ratio of the secondary stretching hot roll to the primary stretching hot roll is 3; the roll temperature of the setting hot roll is 200°C, and the roll speed is 810 m / min. S6: Filament splitting and winding: The nascent multifilament is split into several polyetherketone amide / polyetheretherketone superfine denier monofilaments by a filament splitting machine, and then the tension of the polyetherketone amide / polyetheretherketone superfine denier monofilaments is controlled at 5 - 20 CN by a tension controller and then wound to obtain polyetherketone amide / polyetheretherketone superfine denier monofilaments with a fiber diameter of 32.782 μm. Example 3

[0016] A method for preparing polyetherketone amide / polyetheretherketone superfine denier monofilaments includes the following steps: S1: Raw material preparation: The raw materials are composed of the following materials by mass percentage: 2% polyetherketone amide resin; 98% polyetheretherketone resin. S2: Drying: The raw materials are dried for 7 hours at a temperature of 150°C by a multi-stage vacuum rotary dryer, and the moisture content of the raw materials is controlled to be less than 50 PPM. S3: Melting and extrusion: The dried raw materials are added to a screw extruder and melted and extruded to form a polyetherketone amide / polyetheretherketone melt. Among them, the temperature range of the feeding section of the screw extruder is: 320°C, the temperature range of the compression section of the screw extruder is: 380°C, and the temperature range of the metering section of the screw extruder is: 370°C. And the screw in the screw extruder adopts a shallow groove and short pitch structure, and the specific structure of the shallow groove and short pitch is as follows: the diameter D of the screw is 25 mm, the length-diameter ratio of the screw is 18:1, the depth of the screw groove in the feeding section of the screw is 0.1D; the depth of the screw groove in the compression section of the screw is gradually shallowed and reduced from the depth of the feeding section of the screw to the depth of the metering section of the screw; the depth of the screw groove in the metering section of the screw is 0.03D; S4: Spinning: The melt extruded from the screw extruder is metered by the metering pump 100 and then respectively introduced into each spinning component 300 through the equal-volume straight-through channels 200. The schematic diagram of the connection relationship when the metering pump 100 is respectively connected to each spinning component 300 through each equal-volume straight-through channel 200 is as Figure 2 shown. Each spinning component ejects the melt to form a number of primary monofilaments. The primary monofilaments are first slowly cooled to 280 °C, and then cooled to room temperature by the side air blowing device and oiled and bundled to form primary multifilaments; among them, the spinning temperature of the spinning component is controlled at 390 °C, and the spinning pressure is controlled at 10 MPa; As Figure 1 shown, the structure of the spinning component includes: a housing 3 having a top feeding port 1 and a bottom discharging port 2. Inside the housing 3, an upper flow plate 4, a metal sand layer 5, an upper filter layer 6, a distribution plate 7, a lower flow plate 8, a lower filter layer 9 and a spinneret 10 are arranged in sequence from top to bottom. The metal sand layer 5 is composed of metal sand with a mesh number of 24. Both the upper filter layer 6 and the lower filter layer 9 are stacked by a number of filter meshes with mesh numbers of 32 to 450; among them, the upper filter layer 6 is stacked by nine filter meshes. The mesh numbers of the nine filter meshes of the upper filter layer 6 are, from top to bottom in sequence: 32 mesh, 50 mesh, 180 mesh, 250 mesh, 450 mesh, 250 mesh, 180 mesh, 50 mesh, 30 mesh; the lower filter layer 9 is stacked by three filter meshes. The mesh numbers of the three filter meshes of the lower filter layer 9 are, from top to bottom in sequence: 32 mesh, 250 mesh, 32 mesh; S5: Stretching, shaping and winding of the primary multifilaments: The primary multifilaments are first stretched by a primary stretching hot roller and a secondary stretching hot roller in sequence, and then shaped by a shaping hot roller and wound; Among them, the roller temperature of the primary stretching hot roller is 200 °C and the roller speed is 250 m / min; the roller temperature of the secondary stretching hot roller is 220 °C and the roller speed is 1000 m / min; the stretching ratio of the secondary stretching hot roller to the primary stretching hot roller is 4; the roller temperature of the shaping hot roller is 220 °C and the roller speed is 900 m / min; S6: Filament splitting and winding: The primary multifilaments are divided into a number of polyether ketone amide / polyether ether ketone superfine denier monofilaments by a filament splitting machine, and then the tension of the polyether ketone amide / polyether ether ketone superfine denier monofilaments is controlled at 5 - 20 CN by a tension controller and then wound to obtain polyether ketone amide / polyether ether ketone superfine denier monofilaments with a fiber diameter of 32.504 μm.

[0017] To more intuitively understand the data changes in the embodiments of the present invention, the data of each embodiment will be described in the form of a table below. Among them, the feeding section temperature, compression section temperature, metering section temperature, screw diameter, length-diameter ratio, feeding section screw groove depth, and metering section screw groove depth of the screw conveyor in each embodiment are listed in Table 1:

[0018] Among them, the roller temperature and roller speed of the primary stretching hot roller, the roller temperature and roller speed of the secondary stretching hot roller, the stretching ratio, the roller temperature and roller speed of the shaping hot roller, as well as the PEEK fiber diameter and performance parameters in each embodiment are listed in Table 2:

[0019] The advantages of the present invention are: (1) By adding polyether ketone amide resin to polyether ether ketone resin, the polyether ether ketone resin can obtain good fluidity at a lower processing temperature, thereby improving the spinnability of polyether ether ketone fiber, and thus the working temperatures in the melt extrusion stage, the spinning stage of the spinning pack, and the stretching and shaping stage in the process can be reduced. The working temperature of each stage can be reduced by at least 20°C compared to the traditional process temperature, thereby reducing energy consumption; (2) Design the stages of drying, hot melt extrusion, spinning, stretching and shaping, and filament winding, etc. Through the combined action of each stage, after adding polyether ketone amide resin to polyether ether ketone resin, while ensuring the performance of the polyether ketone amide / polyether ether ketone superfine denier monofilament, the fiber diameter of the obtained polyether ketone amide / polyether ether ketone superfine denier monofilament can be less than 35μm; (3) In the hot melt extrusion stage, a shallow groove and short pitch screw structure design is adopted. The advantages of this design in the manufacturing process of the polyether ketone amide / polyether ether ketone superfine denier monofilament are: 1) Improve the melting efficiency: Shallow groove design: The screw groove depth is relatively shallow, increasing the contact area between the melt and the screw and the barrel, improving the heat conduction efficiency, and contributing to the rapid melting of polyether ether ketone resin and polyether ketone amide; Short pitch design: The pitch is shorter, increasing the shear rate, and further promoting the melting of polyether ether ketone resin and polyether ketone amide; 2) Enhance the mixing uniformity: The shallow groove and short pitch design generate a higher shear force, which helps to fully mix polyether ether ketone resin and polyether ketone amide, avoid stratification or local non-uniformity, and can ensure the uniform distribution of the two materials during the melting process, improving the consistency of the spun fibers; 3) Shorten the residence time: The shallow groove and short pitch design reduce the residence time of the melt in the screw, reducing the risk of degradation of polyether ether ketone resin and polyether ketone amide due to overheating or shear overheating, reducing material degradation, and the shallow groove design is conducive to uniform temperature distribution and avoids local overheating; 4) Improve the extrusion stability: The shallow groove and short pitch design reduce the fluctuation of the melt flow, ensure the stability of the extrusion process, and avoid non-uniformity of the spun fiber diameter; The short pitch design reduces the pressure loss and pressure fluctuation, ensuring the uniform flow of the melt in the runner; (4) During the flow of the polyether ketone amide / polyether ether ketone melt from the screw extruder to the spinning pack, an equal-volume straight-through flow channel is adopted. The equal-volume straight-through flow channel is characterized in that the cross-sectional area of the flow channel remains consistent in the flow direction, ensuring that the volume flow rate of the melt remains unchanged during the flow process, so that the melt will not be affected by compression or expansion when flowing in the flow channel. 1) The equal-volume design can ensure that the volume of the melt is constant when flowing in the flow channel, ensuring the uniform distribution of the melt in the flow channel, avoiding the velocity and pressure fluctuations caused by the change of the cross-sectional area of the flow channel, and avoiding too fast or too slow local flow velocity, thus ensuring the diameter consistency of the fibers. 2) The straight-through design can make the flow channel without bending or sudden change, reduce the flow resistance, and enable the polyether ketone amide / polyether ether ketone melt to flow evenly and stably. At the same time, the straight-through design can also reduce the melt retention area, prevent local overheating and degradation, so as to ensure that the polyether ketone amide / polyether ether ketone melt remains uniform and stable during the flow process from the screw extruder to the spinning pack, reducing the problems of melt fracture or uneven extrusion; moreover, it can reduce the residence time of the melt in the flow channel and reduce the risk of degradation of the polyether ketone amide / polyether ether ketone melt due to overheating or shear overheating.

[0020] The above are only the preferred embodiments of the present invention, and do not limit the present invention in any other form. Any modification or equivalent change made according to the technical essence of the present invention still belongs to the scope protected by the present invention.

Claims

1. A method for preparing polyetherketoneamide / polyetheretherketone ultrafine denier monofilament, characterized in that: The following steps are involved: S1: Raw material preparation: The raw materials are composed of the following materials by mass percentage: 1-2% polyetherketoneamide resin; 98-99% polyetheretherketone resin; S2: Drying: Use a multi-stage vacuum drum dryer to dry the raw materials so that the moisture content of the raw materials is less than 50PPM; S3: hot melt extrusion: adding the dried raw materials into a screw extruder for melt extrusion to form a polyetherketone amide / polyetheretherketone melt; wherein the temperature range of the feed section of the screw extruder is: 300-320°C, the temperature range of the compression section of the screw extruder is: 360-380°C, and the temperature range of the metering section of the screw extruder is: 350-370°C; The screw in the screw extruder adopts a shallow groove short pitch structure, and the shallow groove short pitch structure is specifically: the diameter D of the screw is 25-35 mm, the aspect ratio of the screw is: 18:1-24:1, the screw groove depth of the screw feeding section is: 0.1-0.15D; the screw groove depth of the screw compression section is: gradually shallower from the depth of the screw feeding section to the depth of the screw metering section; the screw groove depth of the screw metering section is: 0.03-0.06D; S4: Spinning: The melt extruded from the screw extruder is metered by a metering pump and then passed into each spinning assembly through an equal volume straight-through flow channel. Each spinning assembly ejects the melt to form a number of primary monofilaments, which are then cooled and oiled to form primary multifilaments. The spinning temperature of the spinning assembly is controlled at 360-390°C, and the spinning pressure is controlled at ≤15MPa. S5: stretching, shaping and winding of the spun multifilament: the spun multifilament is first stretched by a primary stretching hot roller and a secondary stretching hot roller in sequence, and then shaped by a shaping hot roller before winding; The roller temperature of the primary stretching hot roller is 150-200°C and the roller speed is 250-300 m / min; the roller temperature of the secondary stretching hot roller is 170-220°C and the roller speed is 600-1000 m / min; the stretching ratio of the secondary stretching hot roller to the primary stretching hot roller is 2-4; the roller temperature of the shaping hot roller is 170-220°C and the roller speed is 500-900 m / min; S6: filament winding: the primary multifilament is divided into several polyetherketoneamide / polyetheretherketone ultra-fine denier monofilaments by a filament dividing machine, and then the tension of the polyetherketoneamide / polyetheretherketone ultra-fine denier monofilament is controlled at 5-20CN by a tension controller before winding.

2. The method for preparing a polyetherketone amide / polyetheretherketone ultrafine denier monofilament according to claim 1, characterized in that: In S2, the multi-stage vacuum drum dryer dries the raw material at a drying temperature of 130 to 150°C and a drying time of 5 to 7 hours.

3. The method for preparing a polyetherketone amide / polyetheretherketone ultrafine denier monofilament according to claim 1, characterized in that: The structure of the spinning assembly includes: a shell with a top feed port and a bottom discharge port, in which an upper flow plate, a metal sand layer, an upper filter layer, a distribution plate, a lower flow plate, a lower filter layer and a spinneret are arranged from top to bottom, the metal sand layer is composed of metal sand with a mesh size of 24, and the upper filter layer and the lower filter layer are both composed of a plurality of filter screens with a mesh size of 32 to 450.

4. The method for preparing a polyetherketone amide / polyetheretherketone ultrafine denier monofilament according to claim 1, characterized in that: The upper filter layer is composed of nine layers of filter screens stacked together. The mesh numbers of the nine layers of filter screens in the upper filter layer are 32 mesh, 50 mesh, 180 mesh, 250 mesh, 450 mesh, 250 mesh, 180 mesh, 50 mesh, and 30 mesh from top to bottom; the lower filter layer is composed of three layers of filter screens stacked together. The mesh numbers of the three layers of filter screens in the lower filter layer are 32 mesh, 250 mesh, and 32 mesh from top to bottom.

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