Variable-section large-diameter sheath-core structure composite monofilament and preparation method thereof
By forming a wavy or zigzag cross-sectional structure with periodic variations in the length of the monofilament, the problem of insufficient traditional monofilament fluid channels is solved, and efficient breathable and water-permeable performance and self-cleaning effect are achieved.
Patent Information
- Application Number
- CN202510418614.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-07-04
AI Technical Summary
In the prior art, traditional two-dimensional circular or quadrilateral cross-section continuous monofilament has problems with large fluid resistance and insufficient breathable and water permeability in terms of fluid channels, and it is difficult to achieve a periodic cross-sectional structure in the length direction of the monofilament through the existing production process.
The pre-drawn polyester resin is used as the core and the thermoplastic resin material is outerly coated, and a wave-shaped or zigzag cross-sectional structure that changes periodically along the length of the monofilament is formed to increase the surface area of the monofilament and the fluid channel.
It greatly improves the breathable and water permeability of the monofilament, reduces fluid resistance, extends the service life of the product, maintains self-cleaning performance, and adapts to the particle retention and regeneration performance of different working conditions.
Smart Images
Figure CN120250192A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a new composite material, and particularly to a composite monofilament with a large-diameter skin-core structure having a variable cross-section, a manufacturing method thereof, and an application thereof. Background Art
[0002] New materials and composite materials and their applications in industries and people's lives have always been one of the key areas in China's science and technology development plan. The R & D and industrialization of high-performance fibers and composite materials are supported as key technology areas. Relevant new materials and composite materials are of great significance for promoting the upgrading of products and energy conservation and emission reduction in fields such as energy, transportation, industry, and people's livelihood.
[0003] Thermoplastic resins such as polyester (PET), polypropylene (PP), polyamide (PA), modified polyester (PET), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), soluble polytetrafluoroethylene (PFA), polyvinylidene fluoride (PVDF), perfluoroethylene propylene copolymer (FEP), ethylene tetrafluoroethylene copolymer (ETFE), and their modified resins, etc., each have excellent physical, mechanical, and chemical properties, and can be made into continuous monofilaments with circular cross-sections or quadrilateral cross-sections of different wire diameters through melt extrusion, drawing, and shaping, and woven into various filter media with different designs, and are widely used in technological processes such as solid-liquid separation, filtration, and process transmission.
[0004] Continuous monofilaments with ordinary circular cross-sections or quadrilateral cross-sections can be regarded as two-dimensional structures according to the usual definition of fibers, that is, the two-dimensional cross-section of the monofilament determines the structure of the monofilament, and the length direction is the (infinite) extension of the same cross-section; the woven mesh belt or filter medium can be made into various different fabric structures and mesh hole distributions through fabric design, and controlled through processes such as weaving, shaping, and calendering to enable the fabric to have particle interception, air permeability, water permeability, and regeneration properties suitable for different working conditions. The monofilament as a component of the fabric structure interweaves to form the pore structure of the mesh belt, thus enabling the mesh belt to have specific strength, interception, air permeability, water permeability, etc. properties, but the monofilament itself is also the cause of fluid resistance. If the fluid resistance of the monofilament itself can be reduced while maintaining other properties of the mesh belt (including a specific monofilament diameter) and the flow rate can be increased, it is of great significance for solid-liquid separation and filtration.
[0005] The current mesh belts use two-dimensional circular or quadrilateral cross-section continuous monofilaments, and mainly improve the above functions by using a combination of monofilaments with different wire diameters. The single-component or two-component two-dimensional structure monofilaments produced by traditional monofilament production processes are produced through a melt extrusion and drawing process, and due to the limitations of the process itself, it is impossible to make the monofilament into a periodic variable cross-section structure in the length direction. Summary of the Invention
[0006] Objective of the Invention: The objective of the present invention is to address the deficiencies in the prior art and provide a composite monofilament with a large-diameter skin-core structure having a variable cross-section and a preparation method. The skin layer of the composite monofilament is formed by molding such that at least the cross-section in a certain length direction has a wavy outline, thereby forming a skin-core structure with a variable cross-section, greatly increasing the surface area of the monofilament, significantly increasing the fluid channels compared to traditional two-dimensional cross-section monofilament products, and substantially increasing the air permeability and water permeability of the product under the same other conditions.
[0007] Technical Solution: A composite monofilament with a large-diameter skin-core structure having a variable cross-section according to the present invention includes a core structure and a skin layer structure. The core structure uses a pre-drawn polyester resin monofilament, and the skin layer structure uses a thermoplastic resin material. The cross-sectional area of the monofilament varies periodically along the length direction.
[0008] In some embodiments, the periodic variation is specifically: along the length direction of the monofilament, at least one cross-sectional outline is a continuously and regularly varying wavy shape.
[0009] In some embodiments, the wave height of the surface wave shape of the cross-section along the length direction of the monofilament varies between 5% and 90% of the skin layer thickness.
[0010] In some embodiments, the radial cross-section of the core of the composite monofilament is any one of a circle, an ellipse, or a quadrilateral, and the outer diameter of the monofilament is between 0.1 mm and 3.0 mm.
[0011] In some embodiments, the core structure of the composite monofilament is a pre-drawn polyester resin monofilament, and the draw ratio is 2 to 6 times.
[0012] In some embodiments, the thermoplastic resin material is a pure resin or a modified resin.
[0013] In some embodiments, the pure resin includes polypropylene, polyamide, modified polyester, polyphenylene sulfide, polyether ether ketone, soluble polytetrafluoroethylene, polyvinylidene fluoride, ethylene tetrafluoroethylene copolymer, and perfluoroethylene propylene copolymer.
[0014] In some embodiments, the modified resin is obtained by adding 1% to 20% by weight of an additive to the pure resin.
[0015] In some embodiments, the additive includes any one or a combination of carbon fiber, glass fiber, polytetrafluoroethylene ultrafine powder, titanium dioxide powder, carbon black powder, calcium carbonate powder, and nano-barium sulfate powder.
[0016] On the other hand, the present invention also discloses a preparation method for the above-mentioned composite monofilament with a large-diameter skin-core structure having a variable cross-section, including the following steps:
[0017] (1) Take the pre-drawn polyester resin monofilament as the core, unwind it under constant tension and pass it through the die head of the screw extruder;
[0018] (2) The thermoplastic resin is melt-extruded through the screw extruder and evenly distributed outside the core wire running at a constant speed to form a skin layer by coating;
[0019] (3) After coating and before the skin layer is completely cured, through the single-filament surface pressing die assembly, regularly grooved the surface skin layer continuously in the circumferential direction, so that the cross-sectional area along the radial direction of the single filament changes periodically;
[0020] (4) After passing through the cooling water tank and then through the hot water tank or hot air box, the coated composite filament is redrawn 1-3 times and then shaped and wound by the hot oven to obtain the finished composite monofilament.
[0021] On the other hand, the present invention also discloses the application of the fabric made of the above-mentioned variable cross-section skin-core structure composite monofilament in solid-liquid separation devices, filtration devices and process transmission devices.
[0022] Beneficial effects: The beneficial effects of the present invention are as follows:
[0023] (1) The variable cross-section skin-core structure composite filament makes full use of the advantages of each component material. That is, the high tensile strength of polyester (PET) makes the composite filament have a higher tensile strength, providing the basic mechanical properties for the monofilament, and the other thermoplastic resin coating layer endows the composite filament with the required chemical corrosion resistance, hydrolysis resistance or other specific properties of the resin;
[0024] (2) At the same time, the skin layer has a regularly changing cross-section in the length direction, greatly increasing the surface area of each single filament. The regular concave-convex surface provides additional channels for fluids. The composite monofilament maintains the excellent properties of both components while avoiding the disadvantages of each component; The skin-core structure composite filament replaces the product made of polyester (PET) material, while maintaining the mechanical properties at a lower cost and greatly improving the chemical corrosion resistance and hydrolysis resistance of the product or other properties that PET does not have;
[0025] (3) The variable cross-section skin-core structure composite monofilament product greatly increases the fluid channels compared with the traditional two-dimensional cross-section monofilament product, and significantly increases the air permeability and water permeability of the product under the same other conditions; Further, the transverse diversion channel of the variable cross-section skin-core structure composite monofilament is consistent with the fluid flow direction. Especially when replacing all or part of the ordinary monofilament as the weft, it can not only greatly reduce the fluid resistance, but also make the fabric maintain self-cleaning and better renewable performance, significantly delaying the blockage period during product use, thus greatly increasing the working efficiency and service life of the product. Description of the drawings
[0026] Figure 1It is a schematic structural diagram of the first embodiment of the composite monofilament with a variable cross-section skin-core structure of the present invention.
[0027] Figure 2 It is Figure 1 the schematic structural diagram of the A-A cross-section in
[0028] Figure 3 It is Figure 1 the schematic diagram of the cross-section change of the first embodiment in
[0029] Figure 4 It is a schematic structural diagram of the second embodiment of the composite monofilament with a variable cross-section skin-core structure of the present invention;
[0030] Figure 5 It is Figure 4 the schematic structural diagram of the B-B cross-section in
[0031] Figure 6 It is Figure 5 the schematic diagram of the cross-section change of the second embodiment in
[0032] Figure 7 It is a schematic structural diagram of the third embodiment of the composite monofilament with a variable cross-section skin-core structure of the present invention;
[0033] Figure 8 It is the schematic structural diagram of the C-C cross-section in
[0034] Figure 9 It is Figure 7 the schematic diagram of the cross-section change of the third embodiment in Specific embodiments
[0035] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0036] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "inner", "outer", etc. is the orientation or positional relationship shown, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.
[0037] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0038] The following further describes the present invention in detail through specific embodiments in conjunction with the accompanying drawings.
[0039] Embodiment 1
[0040] As Figures 1 to 3 shown, a composite monofilament with a large-diameter skin-core structure of variable cross-section includes a core structure 1 and a skin structure 2. The core structure 1 uses a pre-drawn polyester resin monofilament, and the skin structure 2 uses a thermoplastic resin material. The cross-sectional area of the monofilament changes periodically along the length direction.
[0041] The high tensile strength of the polyester (PET) resin monofilament enables the composite monofilament to have a relatively high tensile strength, providing the basic mechanical properties for the monofilament. The external thermoplastic resin coating layer endows the composite filament with the required chemical corrosion resistance, hydrolysis resistance, or other properties specific to this resin. At the same time, the skin has a regularly changing cross-section in the length direction, greatly increasing the surface area of each monofilament. The regular concave-convex surface provides additional channels for the fluid. The composite monofilament product with a variable cross-section skin-core structure greatly increases the fluid channels compared with the traditional two-dimensional cross-section monofilament product, and significantly increases the air permeability and water permeability of the product under the same other conditions.
[0042] In this embodiment, as Figures 1 to 3 shown, the specific periodic change is as follows: along the length direction of the monofilament, at least one profile outline changes continuously and regularly in a wavy shape. This wavy line has a semi-circular staggered structure, forming a fluid flow channel 3. The variable cross-sectional area is to increase the surface area of the monofilament, thereby providing additional channels for the fluid. The specific cross-sectional shape is only an example and is not limited thereto.
[0043] In this embodiment, the wave height of the surface waviness of the profile along the length direction of the monofilament varies between 5% and 90% of the skin thickness. Along the profile in the length direction of the monofilament, the height of the highest or lowest point varies between 5% and 90% of the skin thickness, which can greatly reduce the fluid resistance, and also enables the fabric made of this monofilament to maintain self-cleaning and better renewable performance, significantly delaying the blockage cycle during product use, thereby greatly increasing the working efficiency and service life of the product.
[0044] In this embodiment, the thermoplastic resin material cortex tightly and evenly coats the outside of the core filaments, and whether to perform stretching and the stretching amount are determined as needed. Generally, the stretching ratio of the polyester (PET) core filaments of the composite monofilaments can be arbitrarily set within the range of 2 to 6 times. The cross-section of the core filaments is any one of a circle, an ellipse, or a quadrilateral, and the diameter of the monofilaments is preferably 0.1 - 3.0 mm.
[0045] In this embodiment, the thermoplastic resin material is a pure resin or a modified resin.
[0046] In this embodiment, the cortex of the monofilaments is a thermoplastic resin, including a pure resin or a modified resin. The pure resin can be polypropylene (PP), polyamide (PA), modified polyester (PET), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), soluble polytetrafluoroethylene (PFA), polyvinylidene fluoride (PVDF), perfluoroethylene propylene copolymer (FEP), ethylene tetrafluoroethylene copolymer (ETFE), etc., not limited thereto.
[0047] The modified resin can be a resin obtained by modifying the above pure resin by adding a reinforcing material or an additive. The pure resin or the modified resin is evenly coated on the outer layer of the core with different cross-sections.
[0048] Among them, the additives used for modifying the pure resin include but are not limited to:
[0049] A combination of one or more of carbon fiber, glass fiber, polytetrafluoroethylene ultrafine powder, titanium dioxide, carbon black, calcium carbonate, and nano barium sulfate.
[0050] Example 2
[0051] As Figures 4 to 6 shown, a composite monofilament with a large variable cross-section skin-core structure includes a core structure 1 and a cortex structure 2. The core structure 1 uses pre-stretched polyester resin monofilaments, and the cortex structure 2 uses a thermoplastic resin material. The cross-sectional area of the monofilaments changes periodically along the length direction.
[0052] The high tensile strength of the polyester (PET) resin monofilaments enables the composite monofilaments to have a high tensile strength, providing the basic mechanical properties for the monofilaments. The external thermoplastic resin coating layer endows the composite filaments with the required chemical corrosion resistance, hydrolysis resistance, or other properties unique to this resin. At the same time, the cortex has a regularly changing cross-section in the length direction, greatly increasing the surface area of each monofilament. The regular concave-convex surface provides additional channels for fluids. The composite monofilament product with a variable cross-section skin-core structure greatly increases the fluid channels compared with the traditional two-dimensional cross-section monofilament product, and significantly increases the air permeability and water permeability of the product under the same other conditions.
[0053] In this embodiment, as Figures 4 to 6The specific periodic change is as follows: along the length direction of the monofilament, at least one cross-sectional outline is in a continuously regular wavy shape, and the wavy line has a serrated structure, forming the fluid flow channel 3. The varying cross-sectional area is to increase the surface area of the monofilament, thereby providing additional channels for the fluid. The specific cross-sectional shape is only an example and is not limited to this.
[0054] In this embodiment, the wave height of the surface wave shape of the cross-section along the length direction of the monofilament varies between 5% and 90% of the cortical thickness. Along the cross-section in the length direction of the monofilament, the height of the highest or lowest point varies between 5% and 90% of the cortical thickness, which can greatly reduce the fluid resistance, and also enables the fabric made of this monofilament to maintain self-cleaning and better renewable performance, significantly delaying the clogging cycle during product use, thereby greatly increasing the working efficiency and service life of the product.
[0055] In this embodiment, the cortical layer of the thermoplastic resin material closely and uniformly coats the outside of the core filament, and whether to perform stretching and the stretching amount are determined as needed. Generally, the stretching ratio of the polyester (PET) core filament of the composite monofilament can be arbitrarily set within the range of 2 - 6 times. The cross-section of the core filament is any one of a circle, an ellipse, or a quadrilateral, and the diameter of the monofilament is preferably 0.1 - 3.0 mm.
[0056] In this embodiment, the thermoplastic resin material is a pure resin or a modified resin.
[0057] In this embodiment, the cortical layer of the monofilament is a thermoplastic resin, including a pure resin or a modified resin. The pure resin can be polypropylene (PP), polyamide (PA), modified polyester (PET), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), soluble polytetrafluoroethylene (PFA), polyvinylidene fluoride (PVDF), perfluoroethylene propylene copolymer (FEP), ethylene tetrafluoroethylene copolymer (ETFE), etc., and is not limited thereto.
[0058] The modified resin can be a resin obtained by modifying the above pure resin by adding reinforcing materials or additives. The pure resin or the modified resin is uniformly coated on the outside of the core with different cross-sections.
[0059] Among them, the additives used for modifying the pure resin include but are not limited to:
[0060] A combination of one or more of carbon fiber, glass fiber, polytetrafluoroethylene ultrafine powder, titanium dioxide, carbon black, calcium carbonate, and nano barium sulfate.
[0061] Example 3
[0062] As Figures 7 to 9As shown in the figure, a composite monofilament with a large-diameter skin-core structure of variable cross-section includes a core structure 1 and a skin structure 2. The core structure 1 uses pre-drawn polyester resin monofilaments, and the skin structure 2 uses a thermoplastic resin material. The cross-sectional area of the monofilament changes periodically along the length direction.
[0063] The high tensile strength of the polyester (PET) resin monofilament enables the composite monofilament to have a relatively high tensile strength, providing the basic mechanical properties for the monofilament. The external thermoplastic resin coating layer endows the composite filament with the required chemical corrosion resistance, hydrolysis resistance, or other properties unique to this resin. At the same time, the skin has a regularly varying cross-section in the length direction, greatly increasing the surface area of each monofilament. The regular concave-convex surface provides additional channels for fluids. The composite monofilament product with a variable cross-section skin-core structure has greatly increased fluid channels compared to traditional two-dimensional cross-section monofilament products, and significantly increases the air permeability and water permeability of the product under the same other conditions.
[0064] In this embodiment, as Figures 7 to 9 shown, the specific periodic change is as follows: along the length direction of the monofilament, at least one profile outline is a continuously and regularly changing wavy shape, and this wavy line has a serrated structure, forming a fluid flow channel 3. Compared with Embodiment 2, the width and thickness of the serrated structure both change. The variable cross-sectional area is to increase the surface area of the monofilament, thereby providing additional channels for fluids. The specific cross-sectional shape is only an example and is not limited to this.
[0065] In this embodiment, the wave height of the surface waviness of the profile along the length direction of the monofilament changes between 5% and 90% of the skin thickness. Along the profile in the length direction of the monofilament, the height of the highest point or the lowest point changes between 5% and 90% of the skin thickness, which can greatly reduce the fluid resistance, and also enables the fabric made of this monofilament to maintain self-cleaning and better renewable performance, significantly delaying the clogging cycle during product use, thereby greatly increasing the working efficiency and service life of the product.
[0066] In this embodiment, the thermoplastic resin material skin closely and evenly coats the outside of the core filament, and it is determined whether to draw and the draw ratio as needed. Generally, the draw ratio of the polyester (PET) core filament of the composite monofilament can be arbitrarily set within the range of 2 to 6 times. The cross-section of the core filament is any one of a circle, an ellipse, or a quadrilateral, and the diameter of the monofilament is preferably 0.1 - 3.0 mm.
[0067] In this embodiment, the thermoplastic resin material is a pure resin or a modified resin.
[0068] In this embodiment, the skin layer of the monofilament is a thermoplastic resin, including pure resin or modified resin. The pure resin can be polypropylene (PP), polyamide (PA), modified polyester (PET), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), soluble polytetrafluoroethylene (PFA), polyvinylidene fluoride (PVDF), perfluoroethylene propylene copolymer (FEP), ethylene tetrafluoroethylene copolymer (ETFE), etc., and is not limited thereto.
[0069] The modified resin can be a resin obtained by modifying the above pure resin by adding reinforcing materials or additives. The pure resin or modified resin is uniformly coated on the outer layer of the core with different cross-sections.
[0070] Among them, the additives used for modifying the pure resin include but are not limited to:
[0071] A combination of one or more of carbon fiber, glass fiber, polytetrafluoroethylene ultrafine powder, titanium dioxide, carbon black, calcium carbonate, and nano barium sulfate.
[0072] Example 4
[0073] A method for manufacturing the composite monofilament in the above Examples 1 to 3 mainly includes the following steps:
[0074] (1) Using the pre-drawn polyester resin PET monofilament with a draw ratio of 2 - 6 times as the core, unwind it under constant tension and pass it through the die head installed on the screw extruder;
[0075] (2) The thermoplastic resin (including pure resin and modified resin) is melt-extruded through the screw extruder and uniformly distributed outside the core wire running at a constant speed to form a skin layer by coating;
[0076] (3) Before the skin layer is completely cured after coating, use the single-filament surface pressing die assembly to continuously press out regular grooves in the circumferential direction of the surface skin layer, so that the cross-sectional area along the length direction of the monofilament changes periodically;
[0077] (4) Pass through the cooling water tank, and then through the hot water tank or hot air box to perform 1 - 3 times of further drawing on the coated composite wire, and then shape and wind it up through the hot oven to obtain the finished composite monofilament with a variable cross-section skin-core structure. Here, 1 time means no drawing, and 3 times means the length after drawing is 3 times the length before drawing.
[0078] In the above step (1), a pre-drawn continuous polyester (PET) monofilament with a specification of 0.30 mm and a draw ratio of 2 - 6 times is selected as the core, and unwind it under constant tension and pass it through the coating die assembly installed on the special screw extruder at a specific speed.
[0079] As a specific embodiment, slices of thermoplastic resin (including pure resin or modified resin) are fed through a screw extruder. The temperatures of each zone of the screw extruder and the die assembly are controlled at 240 - 330 °C according to the characteristics of the thermoplastic resin. The molten thermoplastic resin is extruded through a die head and uniformly coated around a core wire running at a constant speed to form a skin layer with a thickness of 0.2 mm. Then, through a set of die pressing components, grooves with a depth of 0.05 mm are pressed out on the skin layer, and a corrugated surface structure with a wave height of about 0.05 mm is formed on the surface of the monofilament in the length direction. After cooling with hot water, it is drawn through a hot water tank at 95 °C with a draw ratio set according to the polyester pre-draw ratio, and then drawn through a hot oven to the total draw ratio (5.0 - 5.8 times) required for the polyester (PET) core wire, and then shaped in a shaping oven, cooled, and wound up.
[0080] The unwinding speed of the core wire, the pressure of the metering pump of the screw extruder, the die head specifications, and a specific combination of draw ratios constitute specific process parameters, resulting in a composite monofilament with a variable cross-sectional area and a skin-core structure, where the skin layer is made of thermoplastic resin and the core layer is made of polyester (PET), with a corrugated surface in the length direction and a fineness of 0.30 - 0.70 mm or coarser.
[0081] The composite monofilament with a variable cross-sectional area and a skin-core structure manufactured by the process of the present invention has excellent mechanical properties and stability. On the basis of highly maintaining and utilizing the advantages of low cost, high strength, and dimensional stability of polyester (PET), the process fully utilizes other performance advantages of other thermoplastic resins, and by making the surface of the monofilament have a corrugated structure in the length direction, the surface area of the monofilament and the transverse microporous channels that ordinary two-dimensional monofilaments do not have are greatly increased, and the obtained product has comprehensive properties that cannot be achieved by polyester (PET) monofilaments produced by current wire drawing processes or current skin-core structure filaments.
[0082] The present invention also discloses the application of the above-mentioned composite monofilament with a variable cross-sectional area and a skin-core structure in solid-liquid separation, filtration, and process transmission devices. The composite monofilament of the present invention can be woven into fabrics such as nets and filter media, and used as a filter medium in solid-liquid separation and solid-liquid separation, filtration, and process transmission devices such as horizontal vacuum filters, disc filters, belt filter presses, rotary drum vacuum filters, filter presses, and leaf filters, and can also be used in transmission and forming processes that require wear resistance and self-cleaning performance, including production equipment for gypsum boards, medium-density fiberboards, high-density fiberboards, etc.; the composite filament products of the present invention can be woven into various textured fabrics alone or in combination with other monofilaments, multifilaments, staple fibers or their combinations as warp and / or weft; they can be made into spiral nets for use as papermaking nets and filter media; or they can be woven as the base cloth of non-woven fabrics. The technical fabrics woven from the composite monofilaments produced by the process of the present invention are used in solid-liquid separation processes such as industrial filtration in harsher operating environments and process transmission equipment, which will improve production efficiency, reduce maintenance costs and production costs, extend the service life of products, and reduce labor intensity, and have broad application prospects.
[0083] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art, within the scope of the technical solution of the present invention, can make some changes or modifications to equivalent embodiments by using the above-disclosed technical content. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A composite monofilament with a large-diameter skin-core structure of variable cross-section, characterized in that: It includes a core structure and a cortical structure. The core structure uses pre-drawn polyester resin monofilaments, and the cortical structure uses a thermoplastic resin material. The cross-sectional area of the monofilament changes periodically along the length direction.
2. The composite monofilament with a large-diameter sheath-core structure having a variable cross-section according to claim 1, wherein: The specific periodic change is that along the length direction of the monofilament, at least one cross-sectional outline is in a wavy shape with continuous regular changes.
3. The composite monofilament with a large-diameter sheath-core structure having a variable cross-section according to claim 2, characterized in that: The wave height of the surface wave shape of the cross-section along the length direction of the monofilament varies between 5% and 90% of the cortical thickness.
4. A large-diameter sheath-core structured composite monofilament with a variable cross-section according to claim 1 or 2, characterized in that: The core radial cross-section of the composite monofilament is any one of a circle, an ellipse, or a quadrilateral, and the outer diameter of the monofilament is between 0.1 mm and 3.0 mm.
5. The composite monofilament with a large-diameter skin-core structure having a variable cross-section according to claim 1, characterized in that: The core structure of the composite monofilament is a pre-drawn polyester resin monofilament, and the draw ratio is 2 to 6 times.
6. The composite monofilament with a large-diameter skin-core structure having a variable cross-section according to claim 1, wherein: The thermoplastic resin material is a pure resin or a modified resin.
7. The composite monofilament with a large-diameter skin-core structure having a variable cross-section according to claim 6, wherein: The pure resin includes polypropylene, polyamide, modified polyester, polyphenylene sulfide, polyether ether ketone, soluble polytetrafluoroethylene, polyvinylidene fluoride, ethylene tetrafluoroethylene copolymer, and perfluoroethylene propylene copolymer.
8. A large-diameter core-sheath structure composite monofilament with a variable cross-section according to claim 6, characterized in that: The modified resin is obtained by adding 1% to 20% by weight of an additive to the pure resin.
9. The composite monofilament with a large-diameter skin-core structure having a variable cross-section according to claim 8, characterized in that: The additive includes any one or a combination of carbon fiber, glass fiber, ultrafine polytetrafluoroethylene powder, titanium dioxide powder, carbon black powder, calcium carbonate powder, and nano barium sulfate powder.
10. The preparation method of a composite monofilament with a large-diameter skin-core structure having a variable cross-section according to any one of claims 1-9, characterized in that: It includes the following steps: (1) Use the pre-drawn polyester resin monofilament as the core and unwind it through the die head installed on the screw extruder under constant tension. (2) The thermoplastic resin is melted and extruded through the screw extruder and evenly distributed outside the core wire running at a constant speed to form a cortical layer by coating. (3) Before the cortical layer is completely cured after coating, use the surface pressing die assembly of the monofilament to continuously press out regular grooves in the circumferential direction of the surface cortical layer, so that the cross-sectional area along the monofilament radial direction changes periodically. (4) After passing through the cooling water tank and then through a hot water tank or a hot air box, the coated composite wire is redrawn 1 to 3 times and then shaped and wound by a hot oven to obtain the finished composite monofilament.