CN108035032A - A kind of three dimensional separation machine-knitted structure pressure sensing fabric and preparation method thereof - Google Patents

Abstract

The invention discloses a three-dimensional interval woven structure pressure sensing fabric and a preparation method thereof. The fabric includes an upper yarn layer and a lower yarn layer, and the upper yarn layer and the lower yarn layer are bound together by spacer yarns. The preparation method is as follows: using a three-dimensional weaving process to weave the upper yarn layer and the lower yarn layer; weaving carbon nanotube yarns into the upper yarn layer along the warp and weft directions, and interweaving to form a conductive network, that is, the pressure sensing layer; using spacer yarns The upper yarn layer and the lower yarn layer are interwoven to form a three-dimensional interval sensing fabric. When the surface of the fabric is subjected to pressure, the fabric of the spacer structure will produce a large deformation, and the deformation of the carbon nanotube yarn in the pressure sensing layer will lead to a change in resistance. The fabric has high sensitivity under low pressure and good recoverability under high pressure, and has a wide range of applications in engineering applications and smart wearable fields.

Description

A three-dimensional spacer woven structure pressure sensing fabric and its preparation method

technical field

The invention relates to a pressure-sensing fabric with a three-dimensional interval woven structure and a preparation method thereof, belonging to the technical field of pressure-sensing fabrics.

Background technique

In recent years, with the increasing demand for smart wearable textiles and the rapid development of sensor technology, textile structure pressure sensors have attracted widespread attention due to their unique advantages. Textile-structured sensors have flexibility, voids, their large deformation capacity, and certain damage tolerance, which allow them to conform to the surface of the human body and provide comfort for applications in wearable electronics. At present, many scholars have studied wearable electronic devices based on textile structures, which can be applied in health treatment, environmental monitoring, screen display, human-computer interaction, energy harvesting, energy storage, wireless communication and other fields.

The hollow structure of carbon nanotubes makes them small in size, light in weight, and large in specific surface area, while the combination of their inherent electrical properties and mechanical deformation makes them a candidate for future multifunctional material systems with both self-adaptive and self-inductive capabilities. The ideal alternative. With the deepening of research, carbon nanotubes are increasingly used in the field of sensors. However, most of the existing studies melt and mix carbon nanotube powder and polymer to form a film or electrospinning, which has problems such as low carbon nanotube content, uneven dispersion, and low degree of orientation, resulting in poor mechanical and sensory properties of the material. good. As a macroscopic carbon nanotube aggregate, carbon nanotube yarn has a fibrous structure and flexible properties, making it a potential smart textile material. Carbon nanotube yarn has the advantages of high carbon nanotube content, good dispersion, and high degree of orientation. It inherits the excellent strength and modulus of carbon nanotubes, and still has excellent piezoresistive properties. It is suitable for the field of pressure sensors.

Contents of the invention

The technical problem to be solved by the invention is: the existing problems of low carbon nanotube content, uneven dispersion and low degree of orientation.

In order to solve the above problems, the present invention provides a pressure sensing fabric with a three-dimensional spaced woven structure, which is characterized in that it includes an upper yarn layer and a lower yarn layer, and the upper yarn layer and the lower yarn layer are bound together by spaced yarns. A gap is formed between the adjacent interval yarns, so that the upper yarn layer and the lower yarn layer form a spacer layer; the upper yarn layer includes an upper warp yarn layer composed of upper warp threads and an upper weft yarn layer composed of upper weft threads. The carbon nanotube yarns in the warp direction and the carbon nanotube yarns in the weft direction are interwoven, and the conductive network formed by the carbon nanotube yarns in the radial direction and the carbon nanotube yarns in the weft direction constitutes the pressure sensing layer; the lower yarn layer consists of the lower The lower warp layer formed by the warp and the lower weft layer formed by the lower weft. The three-dimensional structure of the upper and lower yarn layers and the spacer layer is used as the structural carrier of the light-weight three-dimensional carbon nanotube pressure sensing fabric to provide a deformation space in the thickness direction for the pressure sensing layer, so that the carbon nanotube yarn in the pressure sensing layer Lines can be deformed to a certain extent. When the yarn layer on the fabric is under pressure, the position and force value of the pressure can be inferred according to the change of the resistance of the pressure sensing layer. The carbon nanotube yarn is stretched repeatedly in a large deformation range, and the sensing characteristics are basically unchanged; when the yarn layer on the fabric is under pressure, the deformation of the carbon nanotube yarn in the pressure sensing layer produces a change in resistance, and the resistance changes It corresponds to the pressure-strain relationship of the fabric, so the pressure position and pressure value of the fabric can be inferred and predicted according to the resistance change of the sensing layer. The light-weight three-dimensional structure carbon nanotube pressure sensing fabric can be designed according to the needs of practical applications. Using carbon nanotube yarns with different sensing performance parameters, changing the height of the spacer yarn layer, the size of the conductive network of the pressure sensing layer, the type of elastic resin, etc., can design a three-dimensional carbon nanotube pressure sensor with different pressure sensing ranges. sense fabric.

Preferably, the upper warp thread, upper weft thread, lower warp thread, lower weft thread and spacer thread are insulating yarns.

More preferably, the insulating yarn is any one or a mixture of synthetic fibers and natural fibers.

More preferably, the synthetic fiber is polyester, nylon, spandex or vinylon; the natural fiber is cotton fiber or hemp fiber.

Preferably, the warp direction carbon nanotube yarn and weft direction carbon nanotube yarn are pure carbon nanotube yarn, modified carbon nanotube yarn or carbon nanotube composite yarn composited with other polymers Wire.

Preferably, the grid number of the conductive network formed by interweaving the carbon nanotube yarns in the warp direction and the carbon nanotube yarns in the weft direction is 3×3, 6×6 or 9×9.

Preferably, the distance between adjacent warp-direction carbon nanotube yarns or weft-direction carbon nanotube yarns is 1-10 mm.

Preferably, the fabric is a pure fabric or a flexible composite fabric compounded with an elastic resin; the elastic resin is polyurethane resin or polydimethylsiloxane resin.

The present invention also provides a preparation method for the above-mentioned three-dimensional interval woven structure pressure sensing fabric, which is characterized in that the upper yarn layer and the lower yarn layer are woven by using a three-dimensional weaving process; In the veil layer, the conductive network is formed by interweaving, that is, the pressure sensing layer; the upper veil layer and the lower veil layer are interwoven with each other by spacer yarns to form a three-dimensional spacer sensing fabric. When the surface of the fabric is subjected to pressure, the fabric of the spacer structure will produce a large deformation, and the deformation of the carbon nanotube yarn in the pressure sensing layer will lead to a change in resistance.

Preferably, the thickness of the spacer layer is controlled by the height of the spacer, and the height is 1-50 mm.

The present invention utilizes carbon nanotube yarns with sensing properties as functional fibers, adopts a three-dimensional weaving process to embed the surface layer of three-dimensional spacer woven fabrics, and forms an interwoven conductive network, that is, a pressure sensing layer; polyester fibers are used as warp and latitude threads, and are woven separately The upper and lower yarn layers, and finally the upper and lower yarn layers are interwoven with spacer yarns to form a three-dimensional spacer sensing fabric. When the surface of the fabric is subjected to pressure, the fabric of the spacer structure will produce a large deformation, and the deformation of the carbon nanotube yarn in the pressure sensing layer will lead to a change in resistance. The fabric has high sensitivity under low pressure and good recoverability under high pressure, and has a wide range of applications in engineering applications and smart wearable fields.

Compared with prior art, the beneficial effect of the present invention is:

1. The weaving method of the three-dimensional spacer woven structure pressure sensing fabric proposed by the present invention can embed the tensile sensing functional fiber into the surface layer of the three-dimensional spacer fabric to achieve large pressure deformation and sensitive sensing effect;

2. The three-dimensional interval woven structure pressure sensing fabric realized by the present invention has the advantages of integrated three-dimensional structure, light weight, high strength, and can be embedded with multiple or multi-layer sensing fibers;

3. The three-dimensional interval woven structure pressure sensing fabric realized by the present invention can realize the prediction of the pressure position and force value of the fabric according to the quantitative corresponding relationship between the pressure deformation of the fabric and the resistance change of the sensing layer;

4. The three-dimensional interval woven structure pressure sensing fabric realized by the present invention has higher sensing sensitivity under pressure, better recoverability under high pressure, and moderate sensitivity to provide large deformation under high pressure High signal-to-noise ratio during detection, wide range of pressure detection;

5. The three-dimensional interval woven structure pressure sensing fabric proposed by the present invention is suitable for industrial production and has wide application prospects in the field of pressure sensors.

Description of drawings

Fig. 1 is the front view of the three-dimensional interval woven structure pressure sensing fabric used to detect the pressed position and force value under the low pressure range (1 ~ 10kPa) prepared in Example 1;

Fig. 2 is the top view of Fig. 1;

Fig. 3 is a top view of the three-dimensional interval woven structure pressure sensing fabric used for detecting the pressure position and force value under the medium pressure range (10-100kPa) provided by Example 2.

Detailed ways

In order to make the present invention more comprehensible, preferred embodiments are described in detail below with accompanying drawings.

As shown in Figures 1-3, it is a three-dimensional interval woven structure pressure sensing fabric prepared by the present invention, which includes an upper yarn layer 1 and a lower yarn layer 2, and the upper yarn layer 1 and the lower yarn layer 2 pass through the spacer yarns. 31 are bundled into one body, and interval gaps 32 are formed between adjacent interval yarns 31, so that an interval layer 3 is formed between the upper yarn layer 1 and the lower yarn layer 2; the upper yarn layer 1 includes an upper warp yarn layer 13 made of upper warp threads 11 And the upper weft yarn layer 14 made of upper weft thread 12, the upper yarn layer 1 is interwoven with warp direction carbon nanotube yarn 41, weft direction carbon nanotube yarn 42, radial carbon nanotube yarn 41, weft direction carbon nanotube yarn The conductive network 43 formed by bobbin yarns 42 constitutes the pressure sensing layer 4 ;

Example 1

A method for preparing a three-dimensional interval woven structure pressure sensing fabric for detecting the pressure position and force value in the low pressure range (1-10kPa):

Using three-dimensional woven weaving technology, two layers of upper warp threads 11 and two layers of lower warp threads 21 respectively penetrate into the heald frame equipped with binocular healds, one layer of upper weft threads 12 and one layer of lower weft threads 22 penetrate into the modified multi-layer arrow shaft Weft insertion device, the spacer yarn 31 penetrates into the common heald frame; the upper warp yarn layer 13 and the upper weft yarn layer 14 formed by interweaving two layers of upper warp yarns ₁₁ and one layer of upper weft yarns 12 together form the upper yarn layer 1, two layers of lower warp yarns 21 The lower warp yarn layer 23 and the lower weft yarn layer 24 interwoven with one layer of lower weft yarn 22 form the lower yarn layer 2 together; Weaving into the upper yarn layer 1 at intervals, warp direction carbon nanotube yarns 41 and weft direction carbon nanotube yarns 42 are interwoven into a conductive network 43 to form a pressure sensing layer 4; Between layer 13 and lower warp yarn layer 14, put barrier sheet into control the height of spacer layer 3, spacer yarn 31 interweaves to form spacer layer 3 on the fabric thickness direction; Spacer yarn 31 binds upper yarn layer 1 and lower yarn layer 2 into One, the upper yarn layer 1, the lower yarn layer 2 and the spacer layer 3 are woven into a three-dimensional fabric at the same time; the fabric is combined with a flexible resin to prepare a light three-dimensional pressure-sensing fabric, as shown in Figures 1 and 2.

The upper warp thread 11, the upper weft thread 12, the lower warp thread 21, the lower weft thread 22 and the spacer yarn 31 are all high-strength high-modulus polyethylene fibers with a fineness of 300 tex.

The height of the spacer layer 3 is controlled by the height of the spacer, which is a self-made aluminum foil plate with a length of 30 mm, a height of 2 mm, and a thickness of 1 mm.

The three-dimensional structure of the upper yarn layer 1, the lower yarn layer 2 and the spacer layer 3 is used as the structural carrier of the light-weight three-dimensional structure carbon nanotube pressure sensing fabric, which provides a deformation space in the thickness direction for the pressure sensing layer, so that the pressure sensing layer The carbon nanotube yarn in 4 can produce certain deformation.

The warp direction carbon nanotube yarn 41 and the weft direction carbon nanotube yarn 42 have a diameter of 40 μm, a breaking stress exceeding 100 MPa, and a maximum strain exceeding 30%. The resistivity of the carbon nanotube yarn is 105Ω·cm, and its own tensile strain sensing coefficient is 2.6.

The distance between adjacent longitudinal carbon nanotube yarns 41 and weft carbon nanotube yarns 42 in the pressure sensing layer 4 is "1cm×1cm".

Preferably, in the pressure sensing layer 4, the size of the conductive network 43 formed by interweaving the carbon nanotube yarns 41 and the weft carbon nanotube yarns 42 in the pressure sensing layer 4 can be designed according to actual needs, which is "5 * 5" (warp direction carbon The number of nanotube yarns is 5, and the number of carbon nanotube yarns in the weft direction is 5).

When the yarn layer 1 on the fabric is under pressure, the position and force value under pressure can be deduced according to the change of the resistance of the pressure sensing layer 4 .

Carbon nanotube yarns have stretch sensing properties, which can produce large deformations, and the sensing properties of repeated stretching within a large deformation range are basically unchanged; warp carbon nanotube yarns 41 and weft carbon nanotube yarns The wires 42 interweave to form a conductive network 43, so that the light three-dimensional carbon nanotube pressure sensing fabric has a pressure sensing function; when the yarn layer 1 on the fabric is under pressure, the carbon nanotube yarn in the pressure sensing layer 4 is deformed to produce a change in resistance. The position and force value of the yarn layer 1 on the fabric under pressure can be deduced according to the strength of the resistance change.

The upper yarn layer 1, the lower yarn layer 2, the spacer yarn layer 3 and the pressure sensing layer 4 are woven simultaneously to form an integral body.

The flexible resin compounded with the lightweight three-dimensional structure carbon nanotube pressure sensing fabric is polydimethylsiloxane resin (Dow Corning Company), which is cured at 60°C for 10 hours by hand lay-up process after coating the resin.

The light-weight three-dimensional structure carbon nanotube pressure sensing fabric has high sensing performance and sensitivity in the low pressure range (1-5kPa), and has good recoverability and moderate sensitivity in the high pressure range (5-10kPa) to provide High signal-to-noise ratio when detecting large deformations under high pressure.

Example 2

A preparation method of a three-dimensional interval woven structure pressure sensing fabric for detecting the pressure position and force value under the medium pressure range (10-100kPa):

The weaving method of the lightweight three-dimensional carbon nanotube pressure-sensing fabric is the same as in Example 1, except that carbon nanotube yarns with different sensing performance parameters are used, the height of the spacer layer 3 is changed, and the pressure-sensing layer 4 conducts electricity. The size of the network 43, the type of elastic resin, and the three-dimensional interval woven structure pressure sensing fabric used to detect the pressure position and force value under the medium pressure range (10-100kPa) are designed, as shown in Figure 3.

The upper warp thread 11, the upper weft thread 12, the lower warp thread 21, the lower weft thread 22 and the spacer yarn 31 are all high-strength high-modulus polyethylene fibers with a fineness of 300 tex.

The height of the spacer layer 3 is controlled by the height of the spacer, which is a self-made aluminum foil plate with a length of 30 mm, a height of 5 mm, and a thickness of 1 mm.

The warp direction carbon nanotube yarn 41 and the weft direction carbon nanotube yarn 42 have a diameter of 40 μm, a breaking stress exceeding 100 MPa, and a maximum strain exceeding 30%. The resistivity of the carbon nanotube yarn is 105Ω·cm, and its own tensile strain sensing coefficient is 2.6.

The distance between adjacent longitudinal carbon nanotube yarns 41 and weft carbon nanotube yarns 42 in the pressure sensing layer 4 is "2cm×2cm".

In the pressure sensing layer 4, the size of the conductive network 43 formed by the interweaving of warp direction carbon nanotube yarns 41 and weft direction carbon nanotube yarns 42 can be designed according to actual needs, which is "3 * 3" (warp direction carbon nanotube yarns The number of threads is 3, and the number of carbon nanotube yarns in the weft direction is 3).

When the yarn layer 1 on the fabric is under pressure, the position and force value under pressure can be deduced according to the change of the resistance of the pressure sensing layer 4 .

The flexible resin compounded with the light-weight three-dimensional structure carbon nanotube pressure sensing fabric is flexible polyurethane resin (Bayer Company), which adopts a hand-lay-up process. After coating the resin, it is cured at 80°C for 12 hours.

The lightweight three-dimensional structure carbon nanotube pressure sensing fabric has high sensing performance and sensitivity in the low pressure range (10-30kPa), and has good recoverability and moderate sensitivity under high pressure (30-100kPa) to provide High signal-to-noise ratio when detecting large deformations under high pressure.

Claims (10)

1. a kind of three dimensional separation machine-knitted structure pressure sensing fabric, it is characterised in that including yarn layer above (1) and following yarn layer (2), yarn layer (1) is integrated with following yarn layer (2) by alternating yarns (31) binding above, shape between adjacent spaces yarn (31) Gap (32) at interval, make to form wall (3) between yarn layer (1), following yarn layer (2) above；Yarn layer (1) is included by upper above The upper thread layer (13) and the upper weft layers (14) that are made of upper weft (12) that warp (11) is formed, above intertexture in yarn layer (1) There are warp-wise carbon nanotubes yarn (41), broadwise carbon nanotubes yarn (42), radial direction carbon nanotubes yarn (41), broadwise carbon nanotubes The conductive network (43) that yarn (42) is woven into forms pressure sensing layer (4)；Yarn layer (2) includes being made of lower warp (21) below Lower thread layer (23) and the lower weft layers (24) that are made of lower weft (22).

2. three dimensional separation machine-knitted structure pressure sensing fabric as claimed in claim 1, it is characterised in that the upper warp (11), upper weft (12), lower warp (21), lower weft (22), alternating yarns (31) are insulative yarn.

3. three dimensional separation machine-knitted structure pressure sensing fabric as claimed in claim 2, it is characterised in that the insulative yarn is adopted With any one or a few the mixing in synthetic fibers and natural fiber.

4. three dimensional separation machine-knitted structure pressure sensing fabric as claimed in claim 3, it is characterised in that the synthetic fibers are Terylene, polyamide fibre, spandex or polyvinyl；Natural fiber is cotton fiber or flaxen fiber.

5. three dimensional separation machine-knitted structure pressure sensing fabric as claimed in claim 1, it is characterised in that the warp-wise carbon nanometer Cotton sewing thread on cop (41), broadwise carbon nanotubes yarn (42) for pure nano-carbon tube yarn, modified carbon nanotubes yarn or with it is other Carbon nanotubes complex yarn after polymer is compound.

6. three dimensional separation machine-knitted structure pressure sensing fabric as claimed in claim 1, it is characterised in that the warp-wise carbon nanometer The grid number for the conductive network (43) that cotton sewing thread on cop (41) and broadwise carbon nanotubes yarn (42) are woven into for 3 × 3,6 × 6 or 9 × 9。

7. three dimensional separation machine-knitted structure pressure sensing fabric as claimed in claim 1, it is characterised in that the adjacent warp-wise carbon The spacing of nanometer cotton sewing thread on cop (41) or broadwise carbon nanotubes yarn (42) is 1~10mm.

8. three dimensional separation machine-knitted structure pressure sensing fabric as claimed in claim 1, it is characterised in that the fabric is knitted to be pure Thing form or the flexible compound fabric being combined with elastic resin；Elastic resin is polyurethane resin or dimethyl silicone polymer Resin.

9. a kind of preparation method of the three dimensional separation machine-knitted structure pressure sensing fabric described in claim 1-8 any one, its It is characterized in that, yarn layer (1), following yarn layer (2) above is weaved using three-dimensional woven weaving process；By carbon nanotubes yarn along longitude and latitude To being woven into yarn layer (1) above, intertexture forms conductive network (43), i.e. pressure sensing layer (4)；Will be upper using alternating yarns (31) Veil layer (1), following yarn layer (2) are interweaved and form three dimensional separation sensing fabric.

10. the preparation method of the three dimensional separation machine-knitted structure pressure sensing fabric described in claim 1-8 any one, its feature It is, the thickness of the wall (3) is controlled by the height of leaf gauge, its height is 1~50mm.