Composite monofilament with skin-core structure and preparation method

Abstract

The invention discloses a composite monofilament with a skin-core structure and a preparation method, the monofilament structure comprises a core body structure and a skin layer structure, the core body structure adopts a pre-drafted polyester resin monofilament, and the skin layer structure adopts a polyamide resin material modified by nano conductive carbon black and polytetrafluoroethylene. The polyester core yarn is used as a framework of the composite monofilament to keep the monofilament to have required tensile strength, elongation, shrinkage and dimensional stability in the length direction, and the skin layer is used as a coating layer to endow the composite filament with required conductive or anti-static performance, high wear resistance and self-cleaning performance. The monofilament is used for completely or partially replacing a spiral net made of common polyester monofilaments with the same or similar wire diameter, has excellent conductive / anti-static performance and wear resistance, has self-cleaning performance, and is used for a process transmission net needing conductive or anti-static performance.

Description

Technical Field

[0001] The present invention relates to a new composite material, and particularly to a composite monofilament of a glass fiber yarn having a skin-core structure and soluble polytetrafluoroethylene (PFA). 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 state focuses on supporting the research, development and industrialization of high-performance fibers and composite materials 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] Glass fiber is an inorganic non-metallic material with excellent properties, and there are many types. Its advantages are good insulation, high heat resistance, good corrosion resistance, high mechanical strength, wide raw material sources, and low cost; its disadvantages are brittleness and poor wear resistance. Glass fiber is usually used as a reinforcing material in composite materials, electrical insulation materials, thermal insulation materials, building materials and other fields of the national economy. PTFE is one of the materials with the best corrosion resistance in the world today, so it has the reputation of "the king of plastics". It has high chemical stability and excellent chemical corrosion resistance, such as resistance to strong acids, strong bases, strong oxidants, etc., and has outstanding heat resistance, cold resistance and wear resistance. The long-term use temperature range is -200~+250℃, and it also has excellent electrical insulation properties and is not affected by temperature and frequency. In addition, it has the characteristics of non-sticking, non-absorbing water, non-combustion, etc., and has excellent weather resistance and self-cleaning performance. Soluble polytetrafluoroethylene (PFA) is a copolymer of polytetrafluoroethylene (PTFE) and perfluoropropyl perfluorovinyl ether, which has all the advantages of polytetrafluoroethylene, but is thermoplastic and can be processed by thermoplastic resin processing methods, and has better creep resistance and tensile strength than polytetrafluoroethylene, and the elongation rate can reach 100-300%. The price of soluble polytetrafluoroethylene (PFA) resin is expensive, which greatly limits its application fields.

[0004] At present, glass fiber and PTFE composite materials are mainly obtained by using short glass fibers as reinforcing materials or using glass fiber fabrics as substrates and impregnating them with PTFE emulsion. Although such composite materials utilize the physical and chemical properties of each component, they lose the flexibility and controllable air permeability of textiles. Summary of the Invention

[0005] Objective of the Invention: The objective of the present invention is to address the deficiencies in the prior art and provide a composite material of fiberglass yarn and soluble polytetrafluoroethylene (PFA). By fully leveraging the respective advantages of fiberglass and soluble polytetrafluoroethylene (PFA) while avoiding their respective disadvantages, the performance complementarity of each component material is fully realized, resulting in a high-performance composite monofilament with high tensile strength, stability, resistance to high and low temperatures, strong acids, strong alkalis, strong oxidants, weather resistance, and self-cleaning properties.

[0006] Technical Solution: A composite monofilament with a skin-core structure according to the present invention includes a core structure and a skin structure. The core structure is made of fiberglass yarn, and the skin structure is made of soluble polytetrafluoroethylene resin.

[0007] In some embodiments, the cross-section of the core of the conductive monofilament is any one of a concentric circle, an ellipse, or a quadrilateral.

[0008] In some embodiments, the specification of the fiberglass yarn is EC8 2400.

[0009] In some embodiments, the cross-sectional area ratio of the skin structure to the core structure is any ratio between 10 - 90%.

[0010] In some embodiments, the outer diameter or major axis diameter or side length of the conductive monofilament is 0.10 mm - 5.00 mm.

[0011] On the other hand, the present invention also discloses a method for preparing a composite monofilament with a skin-core structure, including the following steps:

[0012] (1) Select a continuous fiberglass yarn with a specification of EC8 2400 as the core yarn, unwind it with constant tension, and pass it through the die head of a screw extruder at a specific speed of 3 - 10 m / min.

[0013] (2) Pass the soluble polytetrafluoroethylene chips through a screw extruder. The temperatures in each zone of the screw extruder are 340 - 400 °C, and the metering pump pressure range is 5 - 45 MPa. The molten soluble polytetrafluoroethylene is extruded through the die head, evenly distributed outside the core yarn running at a constant speed, and forms a skin layer after stretching and shrinking and coating on the core. After cooling and shaping in a cooling water tank, it is wound up.

[0014] (3) The unwinding speed of the core yarn, the metering pump pressure of the screw extruder, and the die head specification form specific process parameters to obtain a composite filament with a soluble polytetrafluoroethylene skin layer with a fineness of 2800 - 5000 Tex or coarser and a fiberglass core layer.

[0015] Advantageous Effects: The advantageous effects of the present invention are as follows:

[0016] The composite filaments of the present invention make full use of the advantages of each component material. That is, the high tensile strength of glass fiber endows the composite filaments with high tensile strength, and the soluble polytetrafluoroethylene (PFA) coating layer imparts excellent corrosion resistance, weather resistance and self-cleaning properties to the composite filaments. At the same time, the composite filaments maintain the excellent high and low temperature resistance properties possessed by both components.

[0017] Meanwhile, the disadvantages of each component are avoided. That is, the folding resistance and wear resistance of glass fiber are poor, and the creep resistance and tensile strength of soluble polytetrafluoroethylene (PFA) are low. The products made of the composite filaments replacing soluble polytetrafluoroethylene (PFA) materials greatly improve the physical and mechanical properties while significantly reducing the cost.

[0018] The composite filaments of the present invention have high and low temperature resistance, chemical corrosion resistance, weather resistance, flame retardancy and self-cleaning properties. At the same time, they have excellent mechanical properties and stability, and can be woven into technical fabrics with excellent properties for industries such as industrial transmission and drying with harsher operating environments, industrial filtration and flexible building materials, etc., and have broad application prospects. Brief Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the single filament structure of an embodiment of the present invention. Detailed Embodiments

[0020] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the 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 work fall within the protection scope of the present invention.

[0021] 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.

[0022] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" 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 directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements. 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 situations.

[0023] The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0024] Embodiment 1

[0025] As Figure 1 shown, a composite monofilament with a skin-core structure includes a core structure 1 and a skin structure 2. The core structure 1 is made of glass fiber yarn, and the skin structure 2 is made of soluble polytetrafluoroethylene resin. The composite filament of the present invention makes full use of the advantages of each component material, that is, the high tensile strength of glass fiber makes the composite filament have a high tensile strength, and the soluble polytetrafluoroethylene (PFA) coating layer endows the composite filament with excellent corrosion resistance, weather resistance and self-cleaning properties. At the same time, the composite filament maintains the excellent high and low temperature resistance of both components.

[0026] At the same time, it avoids the disadvantages of each component, that is, the poor fold resistance and wear resistance of glass fiber, and the low creep resistance and tensile strength of soluble polytetrafluoroethylene (PFA); the composite filament replaces the products made of soluble polytetrafluoroethylene (PFA) materials, while greatly improving the physical and mechanical properties, the cost is greatly reduced.

[0027] In this embodiment, the core cross-section of the conductive monofilament is any one of a concentric circle, an ellipse, or a quadrilateral.

[0028] In this embodiment, the specification of the glass fiber yarn is EC8 2400.

[0029] In this embodiment, the cross-sectional area ratio of the skin structure 2 to the core structure 1 is any ratio between 10-90%.

[0030] In this embodiment, the outer diameter or major axis diameter or side length of the conductive monofilament is 0.10 mm - 5.00 mm.

[0031] The preparation method of the above-mentioned composite monofilament with a skin-core structure includes the following steps:

[0032] (1) Select a continuous glass fiber yarn with a specification of EC8 2400 as the core yarn, unwind it with a constant tension and pass it through the die head of a screw extruder at a specific speed of 3 m / min;

[0033] (2) Pass the soluble polytetrafluoroethylene chips through a screw extruder. The temperatures of each zone of the screw extruder are 340 °C, and the metering pump pressure range is 5 MPa. The molten soluble polytetrafluoroethylene is extruded through the die head, evenly distributed outside the core yarn running at a constant speed, and formed into a skin after stretching and shrinking and coating on the core. After being cooled and shaped by a cooling water tank, it is wound up;

[0034] (3) The unwinding speed of the core yarn, the pressure of the metering pump of the screw extruder, and the die head specifications form specific process parameters to obtain a composite filament with a fusible polytetrafluoroethylene cortex with a fineness of 2800 Tex or coarser and a glass fiber core layer.

[0035] Example 2

[0036] As Figure 1 shown, a composite monofilament with a skin-core structure includes a core structure 1 and a cortex structure 2. The core structure 1 uses glass fiber yarn, and the cortex structure 2 uses fusible polytetrafluoroethylene resin.

[0037] In this embodiment, the cross-section of the core of the conductive monofilament is any one of a concentric circle, an ellipse, or a quadrilateral.

[0038] In this embodiment, the specification of the glass fiber yarn is EC8 2400.

[0039] In this embodiment, the cross-sectional area ratio of the cortex structure 2 to the core structure 1 is any ratio between 10 - 90%.

[0040] In this embodiment, the outer diameter or major axis diameter or side length of the conductive monofilament is 0.10 mm - 5.00 mm.

[0041] The preparation method of the above composite monofilament with a skin-core structure includes the following steps:

[0042] (1) Select a continuous glass fiber yarn with a specification of EC8 2400 as the core yarn, unwind it under constant tension and pass it through the die head of the screw extruder at a specific speed of 6 m / min;

[0043] (2) The fusible polytetrafluoroethylene chips pass through the screw extruder. The temperatures of each zone of the screw extruder are 380 °C, the pressure range of the metering pump is 25 MPa, the molten fusible polytetrafluoroethylene is extruded through the die head, evenly distributed outside the core yarn running at a constant speed, and forms a cortex by stretching and shrinking and covering the core. After being cooled and shaped by a cooling water tank, it is wound up;

[0044] (3) The unwinding speed of the core yarn, the pressure of the metering pump of the screw extruder, and the die head specifications form specific process parameters to obtain a composite filament with a fusible polytetrafluoroethylene cortex with a fineness of 3500 Tex or coarser and a glass fiber core layer.

[0045] Example 3

[0046] As Figure 1 shown, a composite monofilament with a skin-core structure includes a core structure 1 and a cortex structure 2. The core structure 1 uses glass fiber yarn, and the cortex structure 2 uses fusible polytetrafluoroethylene resin.

[0047] In this embodiment, the core cross-section of the conductive monofilament is any one of a concentric circle, an ellipse, or a quadrilateral.

[0048] In this embodiment, the specification of the glass fiber yarn is EC8 2400.

[0049] In this embodiment, the cross-sectional area ratio of the skin structure 2 to the core structure 1 is any ratio between 10 - 90%.

[0050] In this embodiment, the outer diameter, major axis diameter, or side length of the conductive monofilament is 0.10 mm - 5.00 mm.

[0051] The preparation method of the above composite monofilament with a skin-core structure includes the following steps:

[0052] (1) Select a continuous glass fiber yarn with a specification of EC8 2400 as the core yarn, unwind it with a constant tension and pass it through the die head of a screw extruder at a specific speed of 10 m / min;

[0053] (2) The soluble polytetrafluoroethylene chips pass through the screw extruder. The temperatures of each zone of the screw extruder are 400 °C, and the metering pump pressure range is 45 MPa. The molten soluble polytetrafluoroethylene is extruded through the die head, evenly distributed outside the core yarn running at a constant speed, and forms a skin layer on the core through stretching and shrinking, and is wound up after being cooled and shaped by a cooling water tank;

[0054] (3) The unwinding speed of the core yarn, the metering pump pressure of the screw extruder, and the die head specification form specific process parameters to obtain a composite filament with a soluble polytetrafluoroethylene skin layer with a fineness of 5000 Tex or coarser and a glass fiber core layer.

[0055] The composite filament of the present invention makes full use of the advantages of each component material. That is, the high tensile strength of the glass fiber makes the composite filament have high tensile strength, and the coated layer of soluble polytetrafluoroethylene (PFA) endows the composite filament with excellent corrosion resistance, weather resistance, and self-cleaning performance. At the same time, the composite filament maintains the excellent high and low temperature resistance performance of both components;

[0056] At the same time, it avoids the disadvantages of each component, that is, the poor fold resistance and wear resistance of the glass fiber, and the low creep resistance and tensile strength of the soluble polytetrafluoroethylene (PFA); the composite filament replaces the products made of soluble polytetrafluoroethylene (PFA) materials, greatly improving the physical and mechanical properties while significantly reducing the cost;

[0057] The composite filament of the present invention has high and low temperature resistance, chemical corrosion resistance, weather resistance, flame retardancy, and self-cleaning performance. At the same time, it has excellent mechanical properties and stability, and can be woven into technical fabrics with excellent performance for industries such as industrial transmission and drying, industrial filtration, and flexible building materials with relatively harsh operating environments, and has broad application prospects.

[0058] As described above, it is only the preferred embodiment of the present invention, and there is no limitation to the present invention in any form. Although the present invention has been disclosed above with the preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to form equivalent embodiments by using the technical content disclosed above within the scope of the technical solution of the present invention. 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 according to 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 skin-core structure, characterized in that: It includes a core structure (1) and a cortical structure (2). The core structure (1) is made of fiberglass yarn, and the cortical structure (2) is made of fusible polytetrafluoroethylene resin.

2. The composite monofilament with a sheath-core structure according to claim 1, wherein: The core cross-section of the conductive monofilament is any one of concentric circles, ellipses, or quadrilaterals.

3. The composite monofilament with a sheath-core structure according to claim 1, characterized in that: The specification of the fiberglass yarn is EC8 2400.

4. The composite monofilament with a sheath-core structure according to claim 1, characterized in that: The cross-sectional area ratio of the cortical structure (2) to the core structure (1) is any ratio between 10% and 90%.

5. The composite monofilament with a skin-core structure according to claim 1, characterized in that: The outer diameter or major axis diameter or side length of the conductive monofilament is 0.10 mm - 5.00 mm.

6. The preparation method of a composite monofilament with a skin-core structure according to any one of claims 1-5, characterized in that: It includes the following steps: (1) Select continuous fiberglass yarn with a specification of EC8 2400 as the core yarn, unwind it under constant tension, and pass it through the die head of a screw extruder at a specific speed of 3 - 10 m / min. (2) Fusible polytetrafluoroethylene chips pass through the screw extruder. The temperatures of each zone of the screw extruder are 340 - 400 °C, and the metering pump pressure range is 5 - 45 MPa. The molten fusible polytetrafluoroethylene is extruded through the die head, evenly distributed outside the core yarn running at a constant speed, and forms a cortex after stretching and shrinking and coating on the core, and is wound up after being cooled and shaped by a cooling water tank. (3) The unwinding speed of the core yarn, the metering pump pressure of the screw extruder, and the die head specification form specific process parameters to obtain a composite filament with a fusible polytetrafluoroethylene cortex with a fineness of 2800 - 5000 Tex or coarser and a fiberglass as the core layer.

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