A flexible electrically heated composite fabric with carbon nanotube film and its preparation method

Abstract

This invention provides a flexible electrically heated composite fabric made of carbon nanotube film and its preparation method, which solves the technical problems of existing heated fabrics, such as inability to be folded multiple times, poor comfort, and inability to be cut. It includes an antibacterial layer, a waterproof layer, a heating layer, and a base layer. The waterproof layer includes an upper waterproof layer and a lower waterproof layer. The heating layer is characterized by having an upper waterproof layer and an antibacterial layer sequentially at its upper end, and a lower waterproof layer and a base layer sequentially at its lower end. The heating layer includes a heating element and a flexible electrode. The heating element is a carbon nanotube film made of multi-walled carbon nanotubes placed in the same direction with closed ends. Its conductivity in the longitudinal direction is greater than that in the transverse direction. The flexible electrode is electrically connected to the surface of the carbon nanotube film through a cross-section. This invention can be widely applied in the field of fabric preparation technology.

Description

Technical Field

[0001] This application belongs to the field of fabric preparation technology, and more specifically, relates to a flexible electrically heated composite fabric of carbon nanotube film and its preparation method. Background Technology

[0002] In recent years, with the continuous improvement of people's living standards, people's demands for material goods have become increasingly higher, especially in terms of clothing. In the cold winter, people are dissatisfied with traditional bulky warm clothing, which necessitates fabrics that possess heating, breathability, waterproofing, wear resistance, and lightweight properties. Electric heating materials utilize the heating effect of electric current and are divided into metallic and non-metallic materials. Metallic heating materials mainly include precious metals such as platinum, iron, copper, silver, and aluminum, high-temperature melting point metals, and alloys. These metallic heating materials are made into conductive yarns, which are then woven into other materials to create heating elements. Non-metallic heating materials mainly include carbon-based materials, silicon dioxide, transition metal carbides, silicon carbide, and polypyrrole. Although significant progress has been made in the research of metallic materials, considerable challenges remain in their practical applications. Metallic materials consume a large amount of energy during the heating process, and the properties of fabrics made from metallic heating materials—such as flexibility, thinness, corrosion resistance, waterproofing, washability, and wear resistance—all require further improvement.

[0003] With the development of carbon nanotubes, they are gradually coming into people's view. Carbon nanotubes, also known as buckytubes, possess excellent mechanical, electrical, and chemical properties. Their radial dimensions are on the nanometer scale, and their axial dimensions are on the micrometer scale. Both ends of the tubes are sealed. When an electric current passes through the carbon nanotube mesh, it generates a large amount of heat. After being arranged in a certain regular pattern, they can form carbon nanotube films. These films, when combined with other materials, still maintain their conductivity, but consume less power than metal heating materials. Carbon nanotube films are lightweight, thin, and flexible. Currently, there is considerable research on linear and planar heat sources, heating modules, and heated fabrics based on carbon nanotube films and fibers.

[0004] Patent CN109203611A discloses a nano-fabric with heating function, wherein the nano-fabric consists of a quick-drying layer, a heat-insulating and waterproof layer, a heating layer, and an external power cord. The quick-drying layer is made of flame-retardant acrylic fiber, cotton fiber, and linen fiber in a ratio of 7:1.6:1. The insulation and waterproof layer is made of deoxygenated cotton, polyester fiber, viscose fiber and spandex in a ratio of 3:2:1:1. It is then fumigated with a solution of distilled water and white vinegar, and then soaked in a solution of polyacrylate, polysiloxane, polyvinyl chloride and rubber in a ratio of 1.1:0.9:1.1:0.5 for half an hour, and then dried. This process is repeated twice. The heating layer is made of graphene heating wire and textile yarn, and is obtained by warp and weft weaving with the electrode wire. The semi-finished product is soaked in a solvent prepared by isocyanate, polyol, diol, halogen-free flame retardant masterbatch and polyethylene terephthalate in a ratio of 3.5:4.5:0.7:0.:0.5 for half an hour, and then the soaked semi-finished product is dried.

[0005] Patent CN101400198A discloses a surface-heated light source, including a first electrode, a second electrode, and a carbon nanotube thin film structure. The first electrode and the second electrode can be disposed on the same surface of the carbon nanotube thin film structure or on different surfaces of the carbon nanotube thin film structure; the carbon nanotube structure includes at least two overlapping and intersecting carbon nanotube thin films, with adjacent carbon nanotube thin films tightly bonded together by van der Waals forces; at least two electrodes are spaced apart and electrically connected to the heating element.

[0006] In the aforementioned structures, the first type of heating fabric uses graphene heating wire as the heating material. Graphene substrate is relatively rigid, cannot be folded repeatedly, and offers poor comfort. Furthermore, because its heating layer is externally connected to the power cord, it cannot be cut during use. The second type of heating fabric, while considering insulation and breathability, does not address waterproofing and antibacterial properties. Additionally, the flexible heating element does not consider heating electrodes, making it impossible to achieve uniform and efficient heating during application. Therefore, this invention provides a flexible electric heating composite fabric made of carbon nanotube film and its preparation method. Summary of the Invention

[0007] To achieve the above objectives, the present invention provides a flexible electric heating composite fabric of carbon nanotube film and its preparation method, which has the advantages of good flexibility, strong waterproofness, good breathability, high insulation safety, antibacterial properties and cutability.

[0008] This invention provides a flexible electrically heated composite fabric made of carbon nanotube film, comprising an antibacterial layer, a waterproof layer, a heating layer, and a base layer. The waterproof layer includes an upper waterproof layer and a lower waterproof layer. The upper end of the heating layer is provided with an upper waterproof layer and an antibacterial layer in sequence, and the lower end of the heating layer is provided with a lower waterproof layer and a base layer in sequence. The heating layer includes a heating element and a flexible electrode. The heating element is a carbon nanotube film made of multi-walled carbon nanotubes placed in the same direction with closed ends. Its conductivity in the longitudinal direction is greater than that in the transverse direction. The flexible electrode is electrically connected to the surface of the carbon nanotube film through a cross-section.

[0009] Preferably, the flexible electrodes are spaced 10-20 mm apart in the latitudinal direction and 20-30 mm apart in the longitudinal direction, and the width of the flexible electrodes is 4-5 mm.

[0010] Preferably, the areal density of the carbon nanotube film is 8-10 g / m³. 2 The conductivity is 0.8*10 5 S / m or higher, with a thickness of 0.01-0.05mm.

[0011] Preferably, the antibacterial layer is woven from a mixture of bamboo pulp fiber, flame-retardant acrylic fiber, polyester low-elasticity yarn, and polypropylene resin in a ratio of 4:3:1.6:1.4.

[0012] Preferably, the waterproof layer is woven from polytetrafluoroethylene, spandex, polyurea, and polyester fiber in a ratio of 1.2:4.2:0.8:3.8.

[0013] Preferably, the base layer is made of polypropylene and has a thickness of 0.1-0.5 mm.

[0014] Preferably, the antibacterial layer is bonded to the upper waterproof layer, the upper waterproof layer to the heating layer, the heating layer to the lower waterproof layer, and the lower waterproof layer to the base layer with adhesive, and the adhesive is moisture-curing polyurethane adhesive (PUR).

[0015] This invention also provides a flexible electrically heated composite fabric made of carbon nanotube thin film and its preparation method, the specific steps of which are as follows:

[0016] (1) Preheat the base layer, then spray adhesive onto the surface of the base layer using a dispensing machine, and apply the lower waterproof layer onto the base layer by hot pressing, and then cool.

[0017] (2) Apply glue to the lower waterproof layer using a dispensing machine, place a carbon nanotube film, place flexible electrodes in a crisscross pattern, with the rest of the electrodes inside the carbon nanotube film except for the protruding electrodes, apply glue, and then bond the preheated upper waterproof layer to the heating layer by hot pressing, and then cool.

[0018] (3) Apply adhesive to the surface of the upper waterproof layer using a dispensing machine. After preheating the antibacterial layer, apply the antibacterial layer onto the upper waterproof layer by hot pressing and let it cool to room temperature.

[0019] Preferably, in steps (1)-(3), the preheating temperature is 50-60℃;

[0020] In steps (1)-(3), the hot melt temperature of the dispensing machine during spraying is 100-110℃, the width is 0.5-2mm, the interval is 5-10mm, the thickness is 0.1-0.5mm, and the cooling time is 30-50s;

[0021] In steps (1)-(3), the hot pressing pressure is 10-20 MPa, the hot pressing time is 20-50 s, and the cooling time is 30-50 s.

[0022] The beneficial effects of this invention are as follows:

[0023] (1) The present invention provides a flexible electric heating composite fabric of carbon nanotube film, including a heating layer, the heating layer including a heating element and a flexible electrode. The heating element is a multi-walled carbon nanotube placed in the same direction. Adjacent multi-walled carbon nanotubes are tightly bonded by van der Waals forces, so that the conductivity of the carbon nanotube film in the longitudinal direction is greater than that in the transverse direction. The flexible electrode is attached to the carbon nanotube film by a cross-placement method and maintains an electrical connection with the carbon nanotube film. This structure makes the flexible electric heating composite fabric of carbon nanotube film maintain a certain flexibility and fit the human body curve design better. On the other hand, it makes the flexible electric heating composite material of carbon nanotube film have the characteristics of uniform heating, stable electrothermal performance, low power consumption and high efficiency.

[0024] (2) This invention provides a flexible electric heating composite fabric with carbon nanotube film. The antibacterial layer, by adding bamboo pulp fiber, gives the fabric good breathability, water absorption, abrasion resistance, and dyeability, while also providing UV protection. Flame-retardant acrylonitrile fiber is used to give the fabric acid and chemical resistance, preventing burns to the skin from molten droplets during combustion. The waterproof layer combines the chemical and heat resistance of polytetrafluoroethylene, the elasticity of spandex, and the good thermal stability of polyurea and polyester fibers, giving the final product waterproof and flexible properties in various environments. Through the combined action of the antibacterial layer, waterproof layer, and heating layer, the fabric has the characteristics of being antibacterial and breathable, waterproof and heat-insulating, flexible, thin, washable, and uniformly heated.

[0025] (2) This invention provides a method for preparing a flexible electric heating composite fabric made of carbon nanotube film. By combining glue application with hot pressing, the glue distribution can be precisely controlled, ensuring uniform distribution on the fabric and thus improving its consistency and quality. Simultaneously, hot pressing increases the fabric's durability, such as waterproofing and windproofing. Finally, the antibacterial layer, waterproof layer, heating layer, and substrate are perfectly bonded together with glue to create a complete flexible electric heating composite fabric made of carbon nanotube film. This invention has low manufacturing cost, stable and efficient electric heating performance, low price, and is easy to repair, making it particularly suitable for manufacturing winter clothing and heating and health care products. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a top view of the electrical connection between the flexible electrode and the carbon nanotube film in this invention.

[0029] Figure 3 This is a schematic diagram of the dispensing path in this invention.

[0030] Explanation of symbols in the diagram:

[0031] 1. Antibacterial layer; 2. Upper waterproof layer; 3. Lower waterproof layer; 4. Heating layer; 5. Base layer; 6. Flexible electrode; 7. Carbon nanotube film; 8. Adhesive. Detailed Implementation

[0032] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application. Example

[0033] The following describes a flexible electrically heated composite fabric made of carbon nanotube film provided in an embodiment of this application. For example... Figure 1-2As shown, a flexible electric heating composite fabric with carbon nanotube film includes an antibacterial layer 1, a waterproof layer, a heating layer 4, and a base layer 5. The waterproof layer includes an upper waterproof layer 2 and a lower waterproof layer 3. The upper end of the heating layer 4 is provided with the upper waterproof layer 2 and the antibacterial layer 1 in sequence, and the lower end of the heating layer 4 is provided with the lower waterproof layer 3 and the base layer 5 in sequence. The heating layer 4 includes a heating element and a flexible electrode. The heating element is a carbon nanotube film 7 made of multi-walled carbon nanotubes with closed ends. The carbon nanotube film 7 has a structure of multi-walled carbon nanotubes placed in the same direction, and adjacent multi-walled carbon nanotubes are tightly bonded by van der Waals forces. Its conductivity in the longitudinal direction is greater than that in the transverse direction. The flexible electrode 6 is electrically connected to the surface of the carbon nanotube film 7 through a cross-section. Alternatively, the carbon nanotube film 7 can also be a structure of multi-walled carbon nanotubes placed in the same direction and arranged in a wavy pattern. This structural approach allows the flexible electric heating composite fabric with carbon nanotube film to maintain a certain degree of flexibility, making it more in line with the human body's curves. On the other hand, it gives the flexible electric heating composite material with carbon nanotube film the characteristics of uniform heating, stable electrothermal performance, low power consumption, and high efficiency.

[0034] In this invention, specifically, as Figure 1-2 As shown, the flexible electrode 6 is made of copper. The flexible electrodes 6 are placed at intervals of 20-30 mm in the longitude direction, and the latitude flexible electrodes 6 are led out in the longitude direction at intervals of 10-20 mm. The width of the flexible electrode is 4-5 mm. The flexible electrodes 6 are led out at the highest and lowest latitude ends and connected to the external power source. The maximum temperature that the flexible electrode 6 can withstand is higher than the temperature generated when the carbon nanotube film 7 operates at maximum power.

[0035] In this invention, the length and width of the carbon nanotube film 7 are not limited, and it can be fabricated into a film according to actual needs to meet the requirements of specific parts of the human body. The areal density of the carbon nanotube film 7 is 8-10 g / m³. 2 The conductivity is 0.8*10 5 The material should have a strength of S / m or higher, a thickness of 0.01-0.05mm, and maintain a certain degree of flexibility, allowing it to be bent.

[0036] In this invention, the antibacterial layer 1 is made of bamboo pulp fiber, flame-retardant acrylonitrile fiber, polyester low-elasticity yarn, and polypropylene resin, and is woven together in a ratio of 4:3:1.6:1.4. After weaving, it is fumigated with a 20% white vinegar solution, then sprayed with neem leaf extract, and finally dried at high temperature to form an antibacterial layer 1 with a thickness of 0.08-0.15mm, which gives the antibacterial layer 1 antibacterial, breathable, dry, and soft properties.

[0037] In this invention, both the upper waterproof layer 2 and the lower waterproof layer 3 are made of polytetrafluoroethylene, spandex, polyurea, and polyester fiber, and are woven in a ratio of 1.2:4.2:0.8:3.8. They are then soaked in a solution of silicone resin, rubber 8, and distilled water in a ratio of 1.6:1.1:7.3 for 1 hour, and then removed and air-dried to form a waterproof layer with a thickness of 0.01-0.2 mm. Because the solution has waterproof and breathable properties, it allows water vapor molecules with a diameter of 0.0004 pm to pass through while blocking water droplets with a diameter of 0.1-0.3 mm. The waterproof layer has the characteristics of being waterproof, heat-insulating, breathable, and environmentally friendly.

[0038] In this invention, the base layer 5 is a common fabric with heat storage function, the material of the base layer 5 is polypropylene, and the thickness of the base layer is 0.1-0.5mm.

[0039] In this invention, adhesive 8 is provided between the upper waterproof layer 2 and the heating layer 4, between the lower waterproof layer 3 and the heating layer 4, between the upper waterproof layer 2 and the antibacterial layer 1, and between the lower waterproof layer 3 and the base layer 5. The adhesive 8 is a one-component, moisture-curing polyurethane adhesive (PUR). The adhesive 8 is evenly sprayed onto the entire layer using a dispensing machine, and along the lines shown... Figure 3 The path shown. Example

[0040] This invention provides a method for fabricating a flexible electrically heated composite fabric made of carbon nanotube thin film, specifically including the following steps:

[0041] (1) Preheat the base layer 5 at 50-60℃, and then apply it to the adhesive layer 8 at 100-110℃ according to the instructions. Figure 3 The path shown is to spray adhesive 8 on the surface of the base layer 5. The adhesive 8 is 0.5-2mm wide, spaced 5-10mm apart, and 0.1-0.5mm thick. The lower waterproof layer 3 is hot-pressed onto the base layer 5 under a pressure of 10-20MPa for 20-50s, and then cooled for 30-50s.

[0042] (2) Using dispensing machine 8 at 100-110℃ according to... Figure 3 The path shown involves spraying adhesive 8 onto the surface of the lower waterproof layer 3. The adhesive 8 has a width of 0.5-2 mm, a spacing of 5-10 mm, and a thickness of 0.1-0.5 mm. Then, a carbon nanotube film 7 is placed on the surface of the lower waterproof layer. Flexible electrodes 6 are placed in a crisscross pattern, with the exception of the protruding electrodes, all other parts are within the carbon nanotube film 7. Adhesive 8 is sprayed at 100-110℃. The adhesive 8 has a width of 0.5-2 mm, a spacing of 5-10 mm, and a thickness of 0.1-0.5 mm. After preheating the upper waterproof layer 2 at 50-60℃, the upper waterproof layer 2 is hot-pressed onto the heating layer 4 under a pressure of 10-20 MPa for 20-50 seconds, followed by cooling for 30-50 seconds.

[0043] (3) Apply the dispensing solution at 100-110℃ using a dispensing machine according to... Figure 3 The path shown is to spray a layer of adhesive 8 on the upper waterproof layer 2. The adhesive 8 is 0.5-2mm wide, spaced 5-10mm apart, and 0.1-0.5mm thick. After preheating the antibacterial layer 1 at 50-60℃, the antibacterial layer 1 is hot-pressed onto the upper waterproof layer 2 under a pressure of 10-20MPa for 20-50s, and then allowed to cool to room temperature.

[0044] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A carbon nanotube thin film flexible electric heating composite fabric, comprising an antibacterial layer, a waterproof layer, a heating layer and a base layer, the waterproof layer comprising an upper waterproof layer and a lower waterproof layer, characterized in that: The upper end of the heating layer is sequentially provided with an upper waterproof layer and an antibacterial layer, and the lower end of the heating layer is sequentially provided with a lower waterproof layer and a base layer, the heating layer comprises a heating element and a flexible electrode; the heating element is a carbon nanotube film made of a multi-walled carbon nanotube with closed ends and placed in the same direction, the electrical conductivity in the longitudinal direction is greater than that in the transverse direction, and the surface of the carbon nanotube film is electrically connected to the flexible electrode through the intersection of longitude and latitude; The flexible electrode is made of copper, the flexible electrode is placed at an interval of 20-30mm in the longitude direction, and the latitude flexible electrode is led out in the longitude direction, the interval in the latitude direction is 10-20mm, the width of the flexible electrode is 4-5mm, the flexible electrode led out at the highest end and the lowest end in the latitude is connected to an external power supply, and the maximum temperature that the flexible electrode can withstand is higher than the temperature generated by the carbon nanotube film when working at the maximum power. The antibacterial layer, the upper waterproof layer, the upper waterproof layer and the heating layer, the heating layer and the lower waterproof layer, and the lower waterproof layer and the base layer are all bonded with glue, and the glue is wet-cured polyurethane glue.

2. The carbon nanotube thin film flexible electrical heating composite cloth according to claim 1, characterized in that: The areal density of the carbon nanotube film is 8-10 g / m 2 , the conductivity is 0.8*10 5 S / m or more, and the thickness is 0.01-0.05 mm.

3. The carbon nanotube thin film flexible electrical heating composite cloth according to claim 1, characterized in that: The antibacterial layer is woven by mixing bamboo pulp fiber, flame-retardant acrylonitrile-chlorine fiber, polyester low-elasticity filament and polypropylene according to a ratio of 4:3:1.6:1.

4.

4. The carbon nanotube thin film flexible electrical heating composite cloth according to claim 1, characterized in that: The waterproof layer is woven by polytetrafluoroethylene, spandex, polyurethane and polyester fiber according to a ratio of 1.2:4.2:0.8:3.

8.

5. The carbon nanotube thin film flexible electrical heating composite cloth according to claim 1, characterized in that: The base layer is made of polypropylene, and the thickness of the base layer is 0.1-0.5mm.

6. A method for preparing the carbon nanotube thin film flexible electric heating composite fabric according to any one of claims 1-5, characterized in that: The steps are as follows: (1) preheat the base layer, then spray glue on the surface of the base layer by using a glue dispenser, cover the lower waterproof layer on the base layer by using a hot pressing method, and cool; (2) spray glue on the lower waterproof layer by using a glue dispenser, place the carbon nanotube film, place the flexible electrode through the intersection of longitude and latitude, the rest part of the electrode is inside the carbon nanotube film except the electrode, spray glue, and bond the preheated upper waterproof layer on the heating layer by using a hot pressing method, and cool; (3) spray glue on the surface of the upper waterproof layer by using a glue dispenser, preheat the antibacterial layer, and cover the antibacterial layer on the upper waterproof layer by using a hot pressing method, and cool to room temperature.

7. The method for preparing the flexible electrically heated composite fabric of carbon nanotube film according to claim 6, characterized in that: In steps (1)-(3), the preheating temperature is 50-60℃; In steps (1)-(3), the hot melting temperature of the glue dispenser is 100-110℃, the width is 0.5-2mm, the interval is 5-10mm, the thickness is 0.1-0.5mm, and the cooling time is 30-50s; In steps (1)-(3), the hot pressing pressure is 10-20MPa, the hot pressing time is 20-50s, and the cooling time is 30-50s.

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