KR102087513B1 - Multi-Layer Wet-Laid Non Woven Fabric for Pressure Sensor - Google Patents

Abstract

The present invention relates to a wet nonwoven fabric having a multilayer structure for a pressure sensor having excellent piezoresistive effect and electrical conductivity, and a pressure sensor using the same, and more particularly, an activated carbon fiber layer (110); And a glass fiber layer 120 attached to the back surface of the activated carbon fiber layer 110, wherein the wet nonwoven fabric 100 of the multilayer structure is characterized in that a plurality of porous layers are formed without a binder. The present invention relates to a wet nonwoven fabric having a multilayer structure for a pressure sensor and a pressure sensor using the same.

Description

Multi-layer Wet-Laid Non Woven Fabric for Pressure Sensor

The present invention relates to a wet nonwoven fabric having a multilayer structure for a pressure sensor manufactured by a wet method, and more particularly, to a wet nonwoven fabric having a multilayer structure for a pressure sensor having an excellent piezoresistive effect and electrical conductivity. And a pressure sensor using the same.

A general wet nonwoven fabric is a nonwoven fabric manufactured by partially remodeling a paper manufacturing process, and is manufactured through a process of supplying raw fiber and water together on a wire belt having a predetermined mesh shape to form a fibrous web, and drying it through a dehydration process. . Wet nonwoven fabric has the advantage of higher pore distribution uniformity of thin film than conventional dry nonwoven fabric, so it is recently applied to various products such as separator, filter media.

Korean Patent No. 10-1720109 (2017.03.27.) Includes a wet nonwoven fabric layer containing 5 to 30 wt% of glass fiber having a weight of 40 to 100 gsm and a diameter of 0.1 to 2 μm, and a weight of 5 Disclosed is a composite filter media prepared by bonding a meltblown nonwoven layer comprising fibers of from about 40 gsm to about 1 to 3 μm through low melting polyethylene terephthalate and a tackifier resin.

Republic of Korea Patent No. 10-0584693 (May 30, 2006) is a step of forming a fiber web by supplying the raw material fibers with water on the inclined portion of the reticulated wire carrier of the plurality of rolls, the wire of the process Providing a water jet to the fiber web on the carrier table to complete formation of the nonwoven fabric on the wire carrier table, transferring the nonwoven fabric formed on the wire carrier table to another carrier, and drying the nonwoven fabric. A method for producing a wet nonwoven fabric is disclosed.

In addition, various documents related to the wet nonwoven fabric and its manufacturing method are known, but as described above, the wet nonwoven fabric is mainly applied to fields such as membranes and filter media, and its use is limited.

Recently, as the materials of textile products are diversified and digital technologies related to mobile devices are developed, the interest in smart textiles in which existing textile products and digital technologies are combined is increasing. Accordingly, thinner, lighter, and more electrical characteristics It is necessary to develop excellent smart materials. In particular, in order to implement smart clothing, a pressure sensor capable of detecting a user's touch motion is required.

The pressure sensor is a device for measuring pressure in various systems, and a general piezoelectric sensor has a structure in which a piezoelectric material is interposed between two electrode plates. There are mechanical, electrical, and semiconductor types depending on the detection method.

Republic of Korea Patent No. 10-2017-0003101 (2017. 01. 09.) has a first electrode made of a fabric containing a conductive fiber, a second electrode made of a fabric containing a conductive fiber, and the first electrode and the Disclosed is a pressure sensor disposed between a second electrode and comprising an intermediate layer that is elastic and has a greater resistance than the first electrode and the second electrode.

Republic of Korea Patent Registration No. 10-2017-0003101 (2017. 01. 09.) is a first step of preparing a pressure sensor by weaving the metal-coated metal yarn in the oblique direction and the weft direction; A second step of peeling a portion of one side of the inclined bundle and one side of the weft bundle of the pressure sensor; A third step of fixing the other end of the inclined bundle and the other end of the weft bundle to the base fabric plate by using a general yarn; A fourth step of embroidering conductive yarns on one side of the warp bundle and one side of the weft bundle to form an electrode part; And a fifth step of forming a signal line by embroidering a conductive yarn to extend from the electrode part.

In addition, various documents related to the pressure sensor are known, but in most cases, the manufacturing process and structure thereof are complicated, so that they are limited in electrical characteristics, flexibility, durability, etc. to be applied to smart clothes.

The present invention has been made to solve the above problems, an object of the present invention is to provide a wet nonwoven fabric of a multilayer structure for a pressure sensor that is easy to manufacture, simple structure, thin, excellent piezoresistive effect and electrical conductivity. It is to further provide a pressure sensor using the same. However, the problem to be solved of the present invention is not limited to those mentioned above, other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the object of the present invention, the present invention is activated carbon fiber layer; And a multi-layered wet nonwoven fabric comprising a glass fiber layer attached to the rear surface of the activated carbon fiber layer, characterized in that a plurality of porous layers are formed without a binder, and a multi-layer wet type structure for pressure sensors having a capacitance of 200 to 400 nF. Provide nonwovens.

In the wet nonwoven fabric of the multilayer structure for the pressure sensor, the constituent fibers of the activated carbon fiber layer preferably has a fiber length of 100 ~ 3,500 ㎛, specific surface area is preferably 1000 ~ 1500 m ² / g, in particular the active fibers It is preferable that the weight of a carbon layer is 100-200 g / m <^2> .

In addition, in the wet nonwoven fabric of the multilayer structure for the pressure sensor, the constituent fibers of the glass fiber layer is preferably a fineness of 1.0 ~ 2.0 denier, the fiber length is preferably 1 ~ 6 mm, in particular the weight of the glass fiber layer 50 Preference is given to ˜100 g / m ² .

In addition, the resistivity of the wet nonwoven fabric of the multilayer structure for the pressure sensor is preferably 5.2 X 10 ^-3 ~ 6.8 X 10 ^-3 Ω.cm. The present invention also provides a pressure sensor using the wet nonwoven fabric of the multilayer structure for the pressure sensor.

The wet nonwoven fabric of the multilayer structure for the pressure sensor of the present invention exhibits excellent piezoresistive properties with excellent durability by having a multilayered structure having an active carbon fiber layer having excellent piezoresistive effect and electrical conductivity and a glass fiber layer having excellent durability and dielectric properties. It can be, and because it does not contain a binder can be maintained with excellent electrical properties of the activated carbon fiber layer with flexibility, the structure is relatively simple has the advantage of easy manufacturing. In addition, since the pressure sensor of the present invention is manufactured using the wet nonwoven fabric having the multilayer structure, the pressure sensor may have a thin and simple shape and may be suitably applied to a recently used smart clothing.

However, the effects of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

1 to 3 is a schematic diagram showing a cross section of the wet nonwoven fabric of the multilayer structure for the pressure sensor according to an embodiment of the present invention.
4 to 5 is a schematic diagram of a device for manufacturing a wet nonwoven fabric of a multi-layer structure for the pressure sensor according to an embodiment of the present invention.

Hereinafter, specific contents of the present invention will be described in detail. In describing the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, and may be changed according to a user's intention or precedent. Therefore, the definition should be made based on the contents throughout the specification. In addition, in the description of the present invention, the same or similar components are given the same or similar reference numerals, and detailed description thereof will be omitted.

The wet nonwoven fabric 100 of the multilayer structure for the pressure sensor of the present invention comprises an activated carbon fiber layer 110; And a glass fiber layer 120 attached to the rear surface of the activated carbon fiber layer 110.

The activated carbon fiber layer 110 included in the wet nonwoven fabric 100 of the multilayer structure of the present invention has a web form including activated carbon fibers. In particular, the fiber length (length) of the constituent fibers of the activated carbon fibers is preferably in the range of 100 to 3,500 µm in order to exhibit smooth formation of the fibrous web and sufficient physical and electrical properties. When the fiber length is 100 μm or more, the contact between the fiber strands is sufficiently formed to form the fibrous web. When the fiber length is 3,500 μm or less, the aggregation phenomenon due to the dispersibility is prevented.

Typical characteristics of activated carbon fiber have a specific surface area of 1,000 to 3,000 m ² / g and a pore radius in the range of 0.5 to 1.4 nm. Activated carbon fiber, which is a constituent fiber of the activated carbon fiber layer 110 used in the present invention, preferably has a specific surface area of 1000-1500 m ² / g. When the specific surface area of the activated carbon fiber is 1000 m ² / g or more, the shape can be maintained by suppressing the inter-fiber slip phenomenon in the fiber web state, and when the 1500 m ² / g or less, appropriate durability can be secured.

In addition, the weight per unit area of the activated carbon fiber layer 110 is preferably 100 ~ 200 g / m ² in terms of the expression of electrical properties and ensuring flexibility.

The activated carbon fibers may be activated carbon fibers prepared from cellulose, phenolic, polyacrylonitrile (PAN), or pitch-based materials, and may be prepared or stabilized by activating existing carbon fibers. Activated carbon fiber can be used by controlling the carbonization process according to the characteristics of the activated carbon fiber. Since the specific manufacturing process of the activated carbon fiber may utilize a known method, the description thereof is omitted.

The glass fiber layer 120 included in the wet nonwoven fabric 100 of the multi-layered structure of the present invention may be generally used commercially available glass fiber, more preferably E-glass (alkali-free glass, electrical insulation, excellent weatherability) ), S-glass (high strength, high elastic glass), C-glass (acid resistant glass), AR-glass (alkali resistant glass), D-glass (low dielectric constant, low dielectric loss glass), and A-glass (alkali glass) Any one or more glass fibers selected from the group consisting of may be appropriately selected and used as necessary.

The glass fiber layer 120 has a form of a web (web) containing a glass fiber as a constituent fiber, the fineness of the constituent fiber is not particularly limited and may be appropriately selected as necessary, but preferably 1.0 to 2.0 denier. When the fineness of the constituent fibers is greater than 1.0 denier, it is advantageous to secure sufficient durability, and when it is less than 2.0 denier, it is advantageous to reduce weight and secure flexibility

The fiber length of the constituent fibers of the glass fiber layer 120 is preferably 1 ~ 6 mm. When the fiber length is 1 mm or more, the contact between the fiber strands is sufficiently formed to form a fibrous web, and when the fiber length is 6 mm or less, the aggregation phenomenon due to the dispersibility may be prevented.

The weight per unit area of the glass fiber layer 120 is 50 ~ 100 g / m ² It is preferable in terms of ensuring durability and flexibility of the wet nonwoven fabric and maintaining proper resistance characteristics.

The wet nonwoven fabric 100 of the multilayer structure for the pressure sensor of the present invention has a structure in which the glass fiber layer 120 is attached to the rear surface of the activated carbon fiber layer 110. As a result, the glass fiber layer 120 and the activated carbon fiber layer 110 serve as mutual supports to maintain the shape of the nonwoven fabric without a binder, and a plurality of porous layers are formed to secure excellent breathability.

However, the present invention does not completely exclude the use of the binder in the wet nonwoven fabric 100 of the multilayer structure for the pressure sensor, and if necessary, the binding force of the activated carbon fiber layer 110 or the glass fiber layer 120 may be adjusted. An appropriate binder may be selected to increase the height, and in the case of the activated carbon fiber layer 110, an electrically conductive binder may be used to maintain excellent electrical properties. At this time, the electrically conductive binder may be used, but is not particularly limited. An electrically conductive binder used in the battery field may be used, and a conductive polymer binder or a conductive carbon binder may be used.

The wet nonwoven fabric 100 of the multilayer structure for the pressure sensor of the present invention is not particularly limited in the stacking order of the activated carbon fiber layer 110 and the glass fiber layer 120, preferably the activated carbon fiber layer as shown in FIG. The glass fiber layer 120 may be stacked on one surface of the 110 or the glass fiber layer 120 may be stacked on both sides of the activated carbon fiber layer 110 as shown in FIG. 2. In addition, as shown in FIG. 3, the activated carbon fiber layer 110 is stacked on both surfaces of the glass fiber layer 120, or the activated carbon fiber layer 110 and the glass fiber layer 120 are alternately stacked a plurality of times. It may have various forms (not shown).

The capacitance of the wet nonwoven fabric 100 of the multilayer structure for a pressure sensor of the present invention may be 200 ~ 400 nF. The electrostatic capacity refers to the ability to accumulate charge when given a potential between insulated conductors.

In addition, the specific resistance value of the wet nonwoven fabric 100 of the multilayer structure for the pressure sensor of the present invention may be 5.2 X 10 ^-3 ~ 6.8 X 10 ^-3 Ω.cm.

Thus, the wet nonwoven fabric 100 of the multi-layered structure of the present invention has physical / electrical characteristics that can be applied to the pressure sensor, and the pressure sensor of the present invention can be manufactured using the wet nonwoven fabric 100 of the multi-layered structure.

Hereinafter, a method of manufacturing a wet nonwoven fabric 100 having a multilayer structure according to an embodiment of the present invention will be described. However, the following method is only one embodiment of the manufacture of the wet nonwoven fabric 100 of the multi-layer structure of the present invention, the present invention is not limited only to the wet nonwoven fabric produced by the following method.

The wet nonwoven fabric 100 of the multi-layer structure according to the present invention may be manufactured using a manufacturing apparatus as shown in FIGS. 4 to 5. The manufacturing apparatus includes a storage tank 10 for storing the fiber dispersion, a distributor 20 for defoaming the fiber dispersion, and a porous support 40 having a net structure to dehydrate the supplied fiber dispersion; A drying unit 50 for supplying a plurality of fiber dispersion liquids on the porous support 40 to form a multi-layer wet web, and a drying unit 50 for drying the stacked wet nonwoven fabric 100, and the dried It includes a winding roller (not shown) for winding the wet nonwoven fabric 100 of the multi-layer structure.

Hereinafter, with reference to Figures 4 and 5 an embodiment of a preferred method of manufacturing a wet nonwoven fabric 100 of a multi-layer structure according to an embodiment of the present invention.

First, single fibers of activated carbon fibers and glass fibers, which constitute the constituent fibers constituting the wet nonwoven fabric 100 of the multi-layered structure of the present invention, are dispersed in water to prepare fiber dispersions in a slurry state, respectively.

That is, a glass fiber dispersion prepared by dispersing glass fibers having a fineness of 1.0 to 2.0 denier and having a fiber length of 1 to 6 mm in water and beating at 1,000 to 1,500 rpm is used as the first fiber dispersion.

In addition, the fiber length is 100 ~ 3,500 ㎛, the specific surface area of 1000 ~ 1500 m ² / g of activated carbon fibers dispersed in water and the activated carbon fiber dispersions beaten at 1,000 ~ 1,500 rpm as a second fiber dispersion and a third fiber dispersion By using the three-layered wet nonwoven fabric having an active carbon fiber layer 110 is formed on both sides of the glass fiber layer 120 shown in FIG.

Disperse the activated carbon fiber and glass fiber in water and quench at 1,000 to 1,500 rpm. When quenching at less than 1,000 rpm, the dispersion of the fiber is not uniform, and the fiber is applied when beating more than 1,500 rpm. Breakage occurs.

After the beating process is completed as described above, the fiber dispersion is dispersed, and the dispersion concentration is preferably 0.1% by weight.

Each of the fiber dispersions prepared as described above is supplied from the storage tank 10, defoamed and supplied through the distributor 20, and then the fiber dispersions are uniformly formed on the porous support 40 through the supply head 30. The coating is composed of an activated carbon fiber layer 110 and a glass fiber layer 120 to form a fibrous web consisting of three layers.

The activated carbon fiber layer 110 formed as described above preferably has a weight per unit area of 100 to 200 g / m ² , and the glass fiber layer 120 preferably has a weight per unit area of 50 to 100 g / m ² .

At this time, the supply head 30 is inclined first supply head 31, the second supply head 33, the third supply head (31) connected to the plurality of fiber dispersion supply pipe 21 as shown in FIG. 35 is stacked in three layers, and the first separator 32 and the second separator 34 are disposed between the first supply head 31, the second supply head 33, and the third supply head 35. And a shape in which the third separation plate 36 is formed and accommodated by the case 37 having one end opened.

The fiber dispersion liquid supplied from the fiber dispersion liquid supply pipe 21 through the distributor 20 is supplied to the first supply head 31, the second supply head 33, and the third supply head 35 of the inclined type, respectively. Then, the fiber dispersion is supplied onto the porous support 40 made to be inclined. When the respective fiber dispersions are supplied through the fiber dispersion supply pipe 21 in the order of the first supply head 31, the second supply head 33, and the third supply head 35, the first fiber dispersion from below. The fiber dispersion layer is formed in the order of the second fiber dispersion and the third fiber dispersion, and the fiber dispersion layer is dehydrated on the porous support 40 to be papered.

The fibers in the fiber dispersion are laminated on a net of a wire part of the porous support 40 to form a web, and water is discharged through a reduced pressure dehydration part (not shown) installed under the net. .

The kind of the fiber dispersion selected from the first fiber dispersion, the second fiber dispersion, and the third fiber dispersion can be appropriately changed according to the multilayer structure wet nonwoven fabric of a desired arrangement.

That is, the activated carbon fiber dispersion is used as the first fiber dispersion, and the glass fiber dispersion is used as the second fiber dispersion and the third fiber dispersion. The first supply head 31, the second supply head 33, and the third supply head ( It is also possible to manufacture the wet nonwoven fabric 100 of a multilayer structure by supplying it to 35).

After the fiber dispersion layer is dehydrated and paper-laminated in the porous support 40, the wetted nonwoven fabric 100 having the multi-layered structure of the present invention is formed by passing through a drying part 50 to remove the remaining water. do. The drying unit may be used alone or mixed IR dryer, hot air dryer, roller type dryer and the like. The multi-layered wet nonwoven fabric 100 manufactured by the manufacturing method of the present invention may be realized as a multi-layered wet nonwoven fabric 100 in a single process without undergoing a laminated process of manufacturing each web. Has an advantage.

Hereinafter, a method of manufacturing a wet composite nonwoven fabric having a multilayer structure of the present invention will be described in detail with reference to preferred embodiments.

(Example 1)

A glass fiber dispersion having a dispersion concentration of 0.1% by weight, prepared by dispersing a glass fiber having a fineness of 2.0 denier and a fiber length of 1 mm in water and beating at 1,500 rpm, was prepared by separating the first glass fiber dispersion and the second glass fiber dispersion. Activated carbon fiber dispersion having a dispersion concentration of 0.1% by weight was prepared by dispersing activated carbon fibers having a specific surface area of 1,000 m ² / g in water and beating at 1,000 rpm, and storing each fiber dispersion prepared as described above. Store in the tank (10).

After the fiber dispersion was transferred to the distributor 20, defoaming was performed in the distributor 20. Thereafter, the defoamed fiber dispersion is supplied to the supply pipe 21 so that the first glass fiber dispersion is the first supply head 31, the activated carbon fiber dispersion is the second supply head 33, and the second glass fiber dispersion is Each of the third supply heads 35 was supplied to supply the fiber dispersions in the order of the first supply head 31 to the third supply head 35 to the porous support 40.

The multi-layered wet web formed as described above is dehydrated by a reduced pressure dehydration unit provided at the lower portion of the porous support 40.

The multi-layered wet nonwoven fabric 100 is dried by passing through a drying unit in the order of an IR dryer and a hot air dryer in order to remove residual moisture, and wound by a winding roller. The structure of the wet nonwoven fabric 100 was completed.

(Example 2)

A glass fiber dispersion having a dispersion concentration of 0.1% by weight was prepared by dispersing a glass fiber having a fineness of 1.0 denier and a fiber length of 3 mm in water and beating at 1,500 rpm into a first glass fiber dispersion and a second glass fiber dispersion. An activated carbon fiber dispersion having a dispersion concentration of 0.1% by weight was prepared by dispersing activated carbon fibers having a surface area of 1,500 µm and a specific surface area of 1,500 m ² / g in water and beating at 1,000 rpm, and the subsequent manufacturing process was the same as in Example 1. By the method, a wet nonwoven fabric 100 having a multilayer structure according to Example 2 was completed.

(Example 3)

A glass fiber dispersion having a dispersion concentration of 0.1% by weight, prepared by dispersing a glass fiber having a fineness of 1.5 denier and a fiber length of 6 mm in water and beating at 1,500 rpm, was prepared by separating the first glass fiber dispersion and the second glass fiber dispersion. An activated carbon fiber dispersion having a dispersion concentration of 0.1% by weight was prepared by dispersing activated carbon fibers having a specific surface area of 1,500 m ² / g in water at 1,500 m ² and beating at 1,000 rpm, and the subsequent manufacturing process was the same as in Example 1. By the method, a wet nonwoven fabric 100 having a multilayer structure according to Example 3 was completed.

The physical properties of the wet nonwoven fabric 100 having the multilayer structure prepared as described above are shown in Table 1 below.

Weight per unit area
(g / m ² ) Capacitance
(nF) Resistivity
(X 10-3 Ω.cm) Example 1 Glass fiber layer 50 205 5.3 Activated carbon fiber layer 100 Example 2 Glass fiber layer 80 310 6.1 Activated carbon fiber layer 150 Example 3 Glass fiber layer 100 398 6.8 Activated Taso Fiber Layer 200

Looking at the Table 1, the weight per unit area of the wet nonwoven fabric 100 of the multi-layer structure manufactured by an embodiment of the present invention has a value in the range of 50 ~ 100 g / m ² in the case of the glass fiber layer 120 The weight per unit area of the activated carbon fiber layer 110 was measured to have a value ranging from 100 to 200 g / m ² .

In addition, the capacitance of Example 1 to Example 3 is 205 ~ 398 nF, the specific resistance value is 5.3 X 10-3 Ω.cm ~ 6.8 X 10-3 Ω.cm measured value.

Therefore, it can be confirmed that the production of a pressure sensor having excellent overall characteristics by using the wet nonwoven fabric 9 having a multilayer structure of the present invention.

It will be appreciated that the present invention is not limited to the forms mentioned in the detailed description above. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims. It is also to be understood that the present invention includes all modifications, equivalents, and substitutes within the spirit of the present invention as defined by the appended claims.

100: multi-layered wet nonwoven fabric
110: activated carbon fiber layer
120: glass fiber layer
10: storage tank
20: divider
30: supply head
32: first separator
33: second supply head
34: second separator
35: third supply head
36: third separator

Claims (6)

Activated carbon fiber layer 110; And
As a wet nonwoven fabric 100 of a multilayer structure for a pressure sensor comprising a glass fiber layer 120 attached to the back surface of the activated carbon fiber layer 110,
The fiber length of the constituent fibers of the activated carbon fiber layer 110 is 100 ~ 3,500 ㎛, the specific surface area is 1,000 ~ 1,500 m ² / g, the weight of the activated carbon fiber layer 110 is 100 ~ 200 g / m ² , The pore radius has pore distribution in the range of 0.5 to 1.4 nm,
The fineness of the constituent fibers of the glass fiber layer 120 is 1.0 ~ 2.0 denier, the fiber length is 1 ~ 6 mm, the weight of the glass fiber layer 120 is 50 ~ 100 g / m ² ,
The capacitance of the wet nonwoven fabric of the multilayer structure for the pressure sensor is 200 ~ 400 nF,
The wet nonwoven fabric 100 of the multilayer structure for the pressure sensor is a wet nonwoven fabric 100 of the multilayer structure for the pressure sensor, characterized in that a plurality of porous layers are formed without a binder.
delete delete delete The method according to claim 1,
The resistivity value of the wet nonwoven fabric of the multilayer structure for the pressure sensor is a wet nonwoven fabric 100 of the multilayer structure for the pressure sensor, characterized in that 5.2 x 10 ^-3 ~ 6.8 X 10 ^-3 Ω.cm.
Pressure sensor using a wet nonwoven fabric (100) of the multi-layer structure for the pressure sensor of claim 1 or 5.

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