A hollow thermal insulation composite yarn and its preparation method and application

Abstract

The present invention relates to a hollow thermal insulation composite yarn and a preparation method and application thereof, belonging to the technical field of intelligent textiles. The method described in the present invention comprises the following steps: wrapping a conductive material on the surface of an elastic yarn by ring twisting to obtain a conductive elastic yarn; coating the surface of the conductive elastic yarn with thermal insulation fibers by friction spinning, and the thermal insulation fibers form a wrinkled structure on the surface of the conductive elastic yarn to obtain the hollow thermal insulation composite yarn; the conductive elastic yarn is kept in a stretched state during the preparation process. The composite yarn described in the invention has the characteristics of both tensile strain sensing and compression strain sensing. The strands show obvious changes in electrical signals during the stretching process; and the strands are used as weft yarns to prepare fabrics, and the electrical signals also show obvious changes after being pressed. This is because the spacing between the internal conductive yarns decreases during the stretching or pressing of the strands, resulting in changes in the electrical signals.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent textiles, and in particular relates to a hollow thermal insulation composite yarn and a preparation method and application thereof. Background Art

[0002] With the development of science and technology and society, textiles are also constantly developing and progressing, and the emerging smart textiles have become a hot topic of research. Various sensor components and other components are combined with fibers, yarns, and fabrics to prepare smart textiles, such as flexible sensors that can monitor human physiological changes. In real life, smart textiles with flexible sensor components that monitor physiological information are the main products, so it is particularly important for smart textiles to accurately sense external stimuli. However, in extreme environments (high temperature, extreme cold, etc.), smart textiles may not be able to sense external stimuli in time due to the external environment, and thus cannot respond when facing danger; and people working in extreme environments often need smart textiles to monitor their vital signs and movement status, so it is necessary to prepare smart textiles that can face extreme environments.

[0003] At present, flexible strain sensors are mainly divided into: resistive and capacitive. For example, patent CN 108560250 A uses electrospinning and dip coating methods to prepare a flexible strain sensor based on conductive fibers. This flexible strain sensor has the characteristics of rapid response and high sensitivity, but the conductive layer is treated with dip coating and multiple strain recovery will cause the coating to break, thereby making the stability worse; patent CN110926661 A connects the upper conductive layer fabric, the insulating layer fabric and the lower conductive layer fabric together through fabric tissue. This preparation process will cause stratification between fabrics.

[0004] Regarding the extreme environments and flexible strain sensors mentioned above, the survey found that most current studies do not consider wearable flexible sensors in extreme environments, so few integrate human motion monitoring, human-computer interaction, and thermal comfort into a flexible sensor device, especially textile-based flexible electronic devices. Therefore, it will be of great value and significance to prepare flexible sensors and fabrics that are highly sensitive, flexible, and protective in extreme environments. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a hollow thermal insulation composite yarn and a preparation method and application thereof.

[0006] The first object of the present invention is to provide a method for preparing a hollow thermal insulation composite yarn, comprising the following steps:

[0007] S1. Wrapping a conductive material on the surface of the elastic yarn by ring twisting to obtain a conductive elastic yarn; the elastic yarn remains in a stretched state during the wrapping process;

[0008] S2. The surface of the conductive elastic yarn described in S1 is coated with thermal insulation fibers by friction spinning, and the thermal insulation fibers form a wrinkled structure on the surface of the conductive elastic yarn to obtain the hollow thermal insulation composite yarn; during the coating process, the conductive elastic yarn remains in a stretched state.

[0009] In one embodiment of the present invention, in S1, the conductive material is one or more of silver-plated nylon yarn, silver-plated polyester yarn and metal nanowire.

[0010] In one embodiment of the present invention, in S1, the fineness of the conductive material is 40D-1000D.

[0011] In one embodiment of the present invention, in S1, the stretch yarn is one or more of spandex, polyester yarn and rubber yarn.

[0012] In one embodiment of the present invention, in S1, the spindle speed of the ring twisting is 4100-4300 r / min, and the output line speed is 7-10 m / min.

[0013] In one embodiment of the present invention, in S2, the thermal insulation fiber is one or more of polyimide fiber, wool and acrylic.

[0014] In one embodiment of the present invention, in S2, during the friction spinning process, the drawing speed of the thermal insulation fiber is 0.5-1 m / min, the output speed is 4-7 m / min, and the winding speed is 6-8 m / min.

[0015] In one embodiment of the present invention, in S1 and S2, the maintained stretched state is stretched to 150-200% of the normal state.

[0016] The second object of the present invention is to provide a hollow thermal insulation composite yarn prepared by the method.

[0017] The third object of the present invention is to provide a fabric, wherein the fabric is prepared from the hollow thermal insulation composite yarn.

[0018] A fourth object of the present invention is to provide an application of the fabric in the integration of motion sensing and thermal comfort.

[0019] The technical solution of the present invention has the following advantages over the prior art:

[0020] (1) The hollow thermal insulation composite yarn described in the present invention has the characteristics of both tensile strain sensing and compressive strain sensing. The strands of the hollow thermal insulation composite yarn show obvious changes in electrical signals during the stretching process; and when the strands of the hollow thermal insulation composite yarn are used as weft yarns to prepare fabrics, the electrical signals will also show obvious changes after being pressed. This is because the distance between the internal conductive yarns decreases during the stretching or pressing of the strands of the hollow thermal insulation composite yarn, resulting in changes in the electrical signals.

[0021] (2) Under natural conditions, the outermost thermal insulation fiber of the hollow thermal insulation composite yarn described in the present invention will form a wrinkle structure on the surface of the composite yarn, resulting in the formation of an air layer between the outermost thermal insulation fiber and the inner conductive elastic yarn. This air layer improves the thermal insulation performance of the hollow thermal insulation composite yarn to a certain extent.

[0022] (3) The hollow thermal insulation composite yarn of the present invention generates corresponding electrical signal changes under different external stimuli, and has highly flexible electrical properties in the face of different external stimuli. At the same time, it also has excellent thermal insulation, and the preparation process is simple, the production cost is low, and it has the potential for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0024] Figure 1 This is a flow chart for preparing the polyimide hollow thermal insulation composite yarn of Example 1 of the present invention.

[0025] Figure 2 It is a basic electrical performance diagram of the polyimide hollow thermal insulation composite yarn strand in Test Example 1 of the present invention; wherein, a is a diagram of the change of electrical signals in the stretching recovery process at different twists; b is a diagram of the change of electrical signals in the stretching recovery process at different temperatures.

[0026] Figure 3 This is a human-computer interaction diagram of the polyimide strand in Test Example 2 of the present invention.

[0027] Figure 4 This is a diagram of the thermal insulation performance of different fabrics in Test Example 3 of the present invention.

[0028] Figure 5 Graph showing the basic electrical properties of the polyimide fabric in Test Example 4 of the present invention; wherein, a is a graph showing the electrical signal changes during the press-to-recovery process at different temperatures; and b is a graph showing the electrical signal changes during the press-to-recovery process at different pressures. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0030] Example 1

[0031] Reference Figure 1 As shown, a polyimide hollow thermal insulation composite yarn and a preparation method thereof specifically include the following steps:

[0032] Preparation of conductive elastic yarn: 100D silver-plated nylon yarn is used to prepare conductive elastic yarn. The spandex package and the silver-plated nylon yarn package are placed on the bobbin holder of the ring twisting machine respectively. The spandex package is unwound and passed through the yarn guide and tensioner to stretch the spandex to 100% of its original length. Then, the spandex is fed into the front roller and the front roller jaws of the upper pressure roller of the ring twisting machine. The silver-plated nylon yarn package is unwound and fed into the front roller jaws of the ring twisting machine through the yarn guide. The combined spandex and silver-plated nylon yarn are output from the roller jaws at a linear output speed of 8 m / min. The output spandex and silver-plated nylon yarn are subjected to ring twisting and winding. The spindle speed during ring twisting and winding is 4200 r / min. The ring twisting force three-dimensionally twists the silver-plated nylon yarn, so that the silver-plated nylon yarn is directly and tightly wound on the spandex to form a highly elastic conductive composite yarn. The formed conductive elastic yarn is wound onto the yarn tube.

[0033] Polyimide hollow thermal insulation composite yarn: First, stretch the conductive elastic yarn to 100% of its original length, pass through the yarn guide hook, dust cage, yarn guide hook in turn, and then fix it on the bobbin. Feed the polyimide roving into the drafting device of friction spinning at a drafting speed of 0.6m / min; after being combed into single fibers by the combing roller, they are sent to the suction rotating dust cage by the blowing pipe and the conveying pipe. When the polyimide single fiber reaches the suction rotating dust cage, it is subjected to the friction force in the wedge-shaped triangle area of ​​the two dust cages, rotates around the conductive elastic yarn, and twists into a yarn output speed of 5m / min. Finally, it is wound onto the bobbin at a winding speed of 7m / min to obtain the polyimide hollow thermal insulation composite yarn.

[0034] Test Example 1

[0035] The polyimide hollow thermal insulation composite yarn of Example 1 was twisted into strands, and the changes of electrical signals at different twists and temperatures were tested respectively, specifically comprising the following steps:

[0036] Two polyimide hollow thermal insulation composite yarns were set as a group, and three groups of 10 cm long polyimide hollow thermal insulation composite yarns were twisted to obtain polyimide hollow thermal insulation composite yarn strands with twists of 10T, 20T, and 30T, respectively. The polyimide hollow thermal insulation composite yarn strands with different twists were placed on a moving slide, and a capacitance test device was connected to one end of the strand. The polyimide hollow composite yarn strands were stretched to 100% of the original length at a speed of 100 mm / min. The results are shown in 2a. Figure 2 a is the change of electrical signal of polyimide hollow thermal insulation composite yarn strands during the stretching and recovery process at different twists. The test found that the electrical signal change was most obvious when the twist was 20T / 10cm. The test found that when the twist of the polyimide hollow thermal insulation composite yarn strands was 20T / 10cm, the relative change of capacitance was the largest at 100%.

[0037] In order to verify the sensing performance of polyimide hollow thermal insulation composite yarn in low temperature environment, the changes of electrical signals during the stretching process were tested at 0℃, 10℃ and 20℃, while other conditions remained unchanged. The results are as follows Figure 2 As shown in b, it was found that there was no obvious change in the electrical signal during the stretching recovery process at different temperatures.

[0038] It can be seen that the polyimide hollow thermal insulation composite yarn has good strain sensing performance.

[0039] Test Example 2

[0040] The above-mentioned polyimide hollow thermal insulation composite yarn strands, signal processor and gloves are combined to prepare intelligent sensor gloves, and the intelligent sensor gloves are used to control the bionic manipulator through wireless transmission technology, thereby realizing human-computer interaction with the bionic manipulator. The results are as follows Figure 3 As shown. By making different movements through the intelligent sensor gloves, the bionic manipulator also makes the same movements, realizing simple human-computer interaction. The specific principle is: when the fingers are bent, the polyimide hollow thermal insulation composite yarn strands are driven to bend and stretch, which will cause the capacitance of the polyimide hollow thermal insulation composite yarn strands to change relatively. The capacitance signal is collected by the signal collector, and then the collected capacitance signal is transmitted to the receiving device of the bionic manipulator using wireless transmission technology, thereby controlling the bionic manipulator to make various movements.

[0041] Test Example 3

[0042] The above-mentioned polyimide hollow thermal insulation composite yarn strands are woven into a plain woven fabric with a warp and weft density of 60 using weaving technology, with polyimide yarn as warp yarn and polyimide hollow thermal insulation composite yarn strands as weft yarn, and the thermal insulation performance is tested.

[0043] In order to more realistically simulate the thermal insulation performance of fabrics on human skin, a heating sheet was used to simulate the skin surface temperature, and the thermal insulation performance of cotton fabrics, T-shirts, blankets, polyimide fabrics, sweaters, and polyimide hollow thermal insulation composite yarn fabrics with the same warp and weft density was tested. The specific steps were as follows: the fabric was attached to the upper layer of the heating sheet, and the voltage was adjusted after the heating sheet was powered on to make the temperature of the heating sheet 37°C; the temperature of the upper layer of the fabric was tested using a thermocouple. The results are as follows: Figure 4 shown.

[0044] from Figure 4 It can be seen that the polyimide hollow thermal insulation composite yarn fabric has the best thermal insulation performance, which can reach about 35°C. Since the polyimide hollow thermal insulation composite yarn not only has the high thermal resistance of polyimide fiber, but also its own hollow structure can achieve better temperature maintenance. In summary, the polyimide hollow thermal insulation composite yarn fabric has good thermal insulation performance compared with other fabrics.

[0045] Test Example 4

[0046] The electrical properties of the polyimide hollow thermal insulation composite yarn fabric prepared in Test Example 3 were tested, and the electrical signal changes of the polyimide hollow thermal insulation composite yarn fabric at different temperatures and pressures were tested respectively. The specific steps are as follows:

[0047] In order to verify the sensing performance of polyimide hollow thermal insulation composite yarn fabric in low temperature environment, the changes of electrical signals during pressing were tested at 0℃, 10℃ and 20℃, and other conditions remained unchanged. The results are as follows Figure 5 As shown in a, it was found that there was no obvious change in the electrical signal during the press-recovery process at different temperatures.

[0048] Then the polyimide hollow thermal insulation composite yarn fabric was tested under different pressures. The results are as follows: Figure 5 As shown in b, from Figure 5 As shown in Fig. b, the electrical signal of the polyimide hollow thermal insulation composite yarn fabric shows obvious changes with the increase of pressure. When the pressure reaches 1.5 MPa, the relative change of its capacitance can reach 80%.

[0049] It can be seen that the polyimide hollow composite yarn fabric exhibits excellent electrical properties after being stimulated by external stimuli.

[0050] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for preparing a hollow thermal insulation composite yarn, characterized in that: The following steps are included: S1. Wrapping a conductive material on the surface of the elastic yarn by ring twisting to obtain a conductive elastic yarn; the elastic yarn remains in a stretched state during the wrapping process; S2. The surface of the conductive elastic yarn described in S1 is coated with thermal insulation fiber by friction spinning, and the thermal insulation fiber forms a pleated structure on the surface of the conductive elastic yarn to obtain the hollow thermal insulation composite yarn; the conductive elastic yarn is kept in a stretched state during the coating process; during the friction spinning process, the drafting speed of the thermal insulation fiber is 0.5-1m / min, the output speed is 4-7m / min, and the winding speed is 6-8m / min; In S1 and S2, the maintained stretched state is stretched to 150-200% of the normal state.

2. The method for preparing the hollow thermal insulation composite yarn according to claim 1, characterized in that: In S1, the conductive material is one or more of silver-plated nylon yarn, silver-plated polyester yarn and metal nanowire; the fineness of the conductive material is 40D-1000D.

3. The method for preparing the hollow thermal insulation composite yarn according to claim 1, characterized in that: In S1, the stretch yarn is one or more of spandex, polyester yarn and rubber yarn.

4. The method for preparing the hollow thermal insulation composite yarn according to claim 1, characterized in that: In S1, the spindle speed of the ring twisting is 4100-4300 r / min, and the output line speed is 7-10 m / min.

5. The method for preparing the hollow thermal insulation composite yarn according to claim 1, characterized in that: In S2, the thermal insulation fiber is one or more of polyimide fiber, wool and acrylic fiber.

6. The hollow thermal insulation composite yarn prepared by the method according to any one of claims 1 to 5.

7. A fabric, characterized in that: The fabric is prepared from the hollow thermal insulation composite yarn described in claim 6.

8. Use of the fabric according to claim 7 in the integration of motion sensing and thermal comfort.

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