JP2004294186A - Thickness measurement method, thickness control method, manufacturing method, and manufacturing equipment for extra-fine carbon fiber collection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thickness measurement method, a thickness control method, a manufacturing method, and manufacturing equipment for extra-fine carbon fiber collections which can measure the thickness of an extra-fine carbon fiber collection without touching it directly, control the thickness of the extra-fine carbon fiber collection on the basis of this measurement, and make the uniformity of bulk density in its width direction excellent. <P>SOLUTION: The thickness of the extra-fine carbon fiber collection is controlled by measuring the thickness of the collection using a range finder equipped with a laser-type displacement sensor, feeding back that measurement result, and controlling the direction of blowing out of extra-fine carbon fiber. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for measuring and controlling the thickness of an ultrafine carbon fiber aggregate for producing an ultrafine carbon fiber felt or the like based on the ultrafine carbon fiber aggregate, and an ultrafine carbon fiber aggregate.
[0002]
[Prior art]
For example, pitch-based carbon fiber felt is usually produced by manufacturing roll-shaped pitch-based ultrafine carbon fibers from a raw material pitch and then bonding the obtained carbon fibers with a binder resin (for example, see Patent Document 1).
[0003]
Here, processes after the coarse opening machine required for the present invention will be described with reference to FIG. FIG. 1 shows an embodiment of the present invention. Since the basics of the manufacturing process are the same, description will be made with reference to FIG.
The rolled carbon fibers supplied to the coarse opening machine 5 are unraveled here, and the obtained carbon fibers are supplied to a reserve trunk 6 and stored. The reserve trunk 6 has a space for retaining the carbon fibers and has a structure in which the flow path at the entrance to the spreader 7 is narrowed.
[0004]
The carbon fibers stored in the reserve trunk 6 are quantitatively supplied to the spreader 7 by a feed roller (not shown). In this opening device 7, the carbon fibers are further opened by a garnet cylinder 7 a and then supplied to a cotton collecting section 8. In the cotton collecting section 8, the carbon fibers are deposited in a cotton-like manner on the conveyor 11 while the binder (resin solution) is sprayed by the sprayer 12 while supplying the opened carbon fibers by blowing. The conveyor 11 is sucked from below by the suction hood 9, and the carbon fiber aggregate 10 deposited thereon is conveyed in a suction state, and is formed by heat curing.
[0005]
In the formation of such a carbon fiber aggregate, since the method of depositing the opened carbon fibers by blowing is adopted, the thickness of the formed carbon fiber aggregate is not always kept constant, Therefore, there is a need to manage or control the thickness of the aggregate. As a method for measuring the thickness of such carbon fiber aggregates, a technique using an ultrasonic distance meter has been proposed (for example, see Patent Document 2).
[0006]
[Patent Document 1]
JP 2002-285457 A [Patent Document 2]
Japanese Patent Application Laid-Open No. Hei 8-092867
However, since this type of ultrasonic range finder captures the reflection of sound waves, there is no problem in the case of a carbon fiber having a normal thickness, but an ultrafine carbon fiber aggregate, particularly an average fiber diameter of 1 There is a problem that an accurate measurement function cannot be exhibited due to the sound absorbing properties of the ultrafine carbon fiber aggregate of ~ 2 microns. By using such an ultrafine carbon fiber having an average fiber diameter of 1 to 2 microns, an ultrafine carbon fiber aggregate having a large bulk density can be formed. It can be expected to be used for various purposes (for example, aircraft materials, etc.) requiring excellent mechanical properties, such as heat insulating materials, sound absorbing materials, cushioning materials, and the like.
[0008]
[Problems to be solved by the invention]
Therefore, it is possible to reliably measure the thickness of the ultrafine carbon fiber aggregate having a sound absorbing property, and to easily measure even when the measurement cannot be performed by direct contact because the binder is attached. In addition, it is required to control the thickness of the ultrafine carbon fiber aggregate based on the measurement results, and to have excellent bulk density uniformity in the width direction.
[0009]
In view of such a problem, the present invention can measure the thickness of the ultrafine carbon fiber aggregate without directly contacting the ultrafine carbon fiber aggregate, and can control the thickness of the ultrafine carbon fiber aggregate based on the thickness, thereby increasing the bulk density in the width direction. It is an object of the present invention to provide a method for measuring the thickness, a control method, a production method, and a production apparatus of an ultrafine carbon fiber aggregate having excellent uniformity.
[0010]
[Means for Solving the Problems]
The method for measuring the thickness of the ultrafine carbon fiber aggregate according to the present invention is a method for measuring the thickness of the ultrafine carbon fiber aggregate, in order to achieve the above object, using a distance meter equipped with a laser displacement sensor. By measuring the distance from the distance meter to the floor supporting the ultrafine carbon fiber aggregate, and measuring the distance from the distance meter to the surface of the ultrafine carbon fiber aggregate, the thickness of the ultrafine carbon fiber aggregate is measured. To take the measure of
[0011]
In the present invention, it is preferable that the laser displacement sensor is installed above a cotton collecting device line in a process of manufacturing an ultrafine carbon fiber aggregate.
[0012]
Further, in order to achieve the above object, the method for controlling the thickness of an ultrafine carbon fiber aggregate according to the present invention includes the steps of: forming a microfine carbon fiber aggregate formed by blowing out ultrafine carbon fibers from a fiber blowing section of a cotton collecting device; A method of controlling the thickness to be a thickness, using a distance meter equipped with a laser displacement sensor, measuring a distance from the distance meter to a floor supporting an ultrafine carbon fiber assembly, and recording the distance from the distance meter. By measuring the distance to the surface of the ultrafine carbon fiber aggregate, the thickness of the formed ultrafine carbon fiber aggregate is measured, and the fiber blowing of the cotton collecting device is performed according to a change in the thickness of the ultrafine carbon fiber aggregate. The means of changing the blowing direction of the part is taken.
[0013]
Then, in the method for controlling the thickness of the ultrafine carbon fiber aggregate, the binder is sprayed simultaneously with the cotton collection in the cotton collecting device, and the thickness of the ultrafine carbon fiber aggregate sprayed with the binder is measured. It is preferable to change the blowing direction of the fiber blowing section of the cotton collecting device so that the bulk density of the ultrafine carbon fiber felt obtained by curing the binder is within a predetermined standard.
[0014]
Further, in order to achieve the above object, the method for producing an ultrafine carbon fiber aggregate according to the present invention is characterized in that the ultrafine carbon fiber is formed by blowing the ultrafine carbon fiber from a fiber blowing portion of a cotton collecting device to form an aggregate having a predetermined thickness. In the method for manufacturing an aggregate, using a distance meter equipped with a laser displacement sensor, measuring the distance from the distance meter to the floor supporting the ultrafine carbon fiber aggregate, and measuring the distance from the distance meter to the ultrafine carbon fiber aggregate By measuring the distance to the surface of the body, the thickness of the formed ultrafine carbon fiber aggregate is measured, and the blowing direction of the fiber blowing portion of the cotton collecting device is changed according to the change in the thickness of the ultrafine carbon fiber aggregate. The thickness of the ultrafine carbon fiber aggregate is controlled by changing the thickness.
[0015]
In the method for producing the ultrafine carbon fiber aggregate, the binder is sprayed simultaneously with the cotton collection in the cotton collecting device, and the thickness of the ultrafine carbon fiber aggregate sprayed with the binder is measured. The thickness of the ultrafine carbon fiber aggregate is controlled by changing the blowing direction of the fiber blowing portion of the cotton collecting device so that the bulk density of the ultrafine carbon fiber felt obtained by curing is within a predetermined standard. Is preferred.
[0016]
Further, in order to achieve the above object, the manufacturing apparatus of the ultrafine carbon fiber aggregate according to the present invention includes a cotton collecting device having a fiber blowing portion provided so that the blowing direction can be changed, and an upper part of the microfine carbon fiber aggregate. A range finder having a laser type displacement sensor provided in, and a controller, a manufacturing apparatus for an ultrafine carbon fiber aggregate, comprising: the rangefinder supports the ultrafine carbon fiber aggregate from the rangefinder By measuring the distance to the floor surface to be measured and the distance from the distance meter to the surface of the ultrafine carbon fiber aggregate, the thickness of the formed ultrafine carbon fiber aggregate is measured, and the data is controlled. And the controller changes the blowing direction of the fiber blowing section based on the transmitted data.
[0017]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following embodiments, the method for measuring and controlling the ultrafine carbon fiber aggregate according to the present invention, and the ultrafine carbon fiber aggregate will be described based on the steps after the coarse opening machine in the pitch-based ultrafine carbon fiber felt manufacturing process. I do.
However, as the ultrafine carbon fiber aggregate, other materials such as polyacryl (PAN) -based carbon fiber, phenolic resin-based carbon fiber, cellulose-based carbon fiber, polyvinyl alcohol-based carbon fiber, and other chemical fibers, etc. It is intended for all kinds of ultrafine carbon fiber aggregates that absorb water.
[0018]
FIG. 1 is a schematic view of a main part of a production process of a pitch-based ultrafine carbon fiber felt, in which a roll-shaped carbon fiber supplied to a coarse opening machine 5 is unraveled, and the obtained carbon fiber is Is supplied to the reserve trunk 6 and stored. The reserve trunk 6 has a space for retaining the carbon fibers and has a structure in which the flow path at the entrance to the spreader 7 is narrowed. The coarse opening machine 5 includes a rotating roller with a needle, and is rotationally driven at a constant speed to roughly open the ultrafine carbon fibers.
[0019]
The carbon fibers stored in the reserve trunk 6 are quantitatively supplied to the spreader 7 by a feed roller (not shown). In this opening device 7, the carbon fibers are further opened by a garnet cylinder 7 a and then supplied to a cotton collecting section 8. In the cotton collecting section 8, the carbon fibers are spread on the conveyor 11 while the binder (resin solution) is sprayed by the sprayer 12 while the opened carbon fibers are supplied by blowing from the fiber blowing section 1. To be deposited.
[0020]
The conveyor 11 is sucked from below by the suction hood 9, and the carbon fiber aggregate 10 deposited thereon is conveyed in a suction state and is formed by heat curing. In view of the thickness of the ultrafine carbon fiber aggregate 10 to be deposited, the suction hood 9 is controlled by an appropriate differential pressure detecting means (for example, a capacitance manometer) together with the control of the fiber blowing amount by the fiber blowing section 7a. The pressure difference between the upper and lower positions of the ultrafine carbon fiber aggregate is controlled so as to generate a predetermined negative suction pressure, and at the same time, the transport speed of the conveyor 11 is controlled to a predetermined speed.
[0021]
The fiber blowing section 1 is configured to swing so that the blowing direction can be changed. This swinging means is constituted by a servo mechanism which operates in response to a control signal described later. However, since this mechanism itself is a known means, its detailed description is omitted here.
As shown in FIG. 1, a distance meter 2 provided with an infrared semiconductor laser type displacement sensor is provided above the position exiting the cotton collecting section 8, that is, above the cotton collecting device line. At 250 mm intervals in the width direction of the body, that is, in this embodiment, four are provided. The sensor used here is LB-300, manufactured by Keyence Corporation. This infrared semiconductor laser type displacement sensor may be a reflection type, and the type is not particularly limited. Also. The reason for using the infrared laser is that the thickness can be measured from a distance of 200 to 400 mm from the object to be measured (ultrafine carbon fiber aggregate). Therefore, a laser type sensor of another color can be applied as long as the object of the present invention can be achieved.
[0022]
The principle of measuring the distance of this sensor is as follows. This sensor has a laser light source (light emitting element), a light projecting lens, a light receiving lens, a light receiving element [for example, a charge coupled device (CCD)], and a memory, and the memory includes a CCD and a light source (light emitting element). , Angle information and triangulation information are stored. First, a reference surface (for example, a belt of a belt conveyor device) is irradiated with laser light. Since this reference plane is not a mirror surface, the irradiated laser light is diffusely reflected. Then, of the diffusely reflected light, light having a certain angle enters the light receiving lens. The light incident on the light receiving lens is detected by the CCD, and the peak position of the light amount is determined on the CCD. The distance between the light source and the reference plane is determined by the principle of triangulation from the relationship between the light receiving angle at the peak position of the light quantity and the distance of the line connecting the peak position and the light source (light emitting element).
Next, a laser is applied to the ultrafine carbon fiber aggregate conveyed on the belt. The laser light is diffusely reflected on the surface of the ultrafine carbon fiber aggregate, and light having a certain angle out of the diffusely reflected light is incident on the light receiving lens. The light incident on the light receiving lens is detected by the CCD, and the peak position of the light amount is determined on the CCD. This peak position is different from the peak position on the reference plane. From the displaced peak position, the thickness of the ultrafine carbon fiber aggregate can be measured.
[0023]
Then, the distance meter 2 including the infrared semiconductor laser type displacement sensor inputs each detection result to the controller 3, and the thickness at the designated position of the detected ultrafine carbon fiber aggregate falls within an expected allowable range. If not, the result is output as a signal, and the result is fed back to the above-described fiber blowing section 1 to control the swing thereof, thereby controlling the blowing amount of the ultrafine carbon fiber to a predetermined position.
[0024]
The distance meter 2 equipped with the infrared semiconductor laser type displacement sensor measures the distance from the floor of the ultrafine carbon fiber aggregate 10, that is, the upper surface of the conveyor 11 to the distance meter 2 in advance and inputs the distance to the controller 3. In addition, by measuring the distance from the upper surface of the transported ultrafine carbon fiber aggregate 10 to the distance meter 2, the difference between the two is obtained and recognized as the thickness of the ultrafine carbon fiber aggregate 10. Therefore, it is possible to continuously measure the thickness according to the conveyance of the conveyor 11.
[0025]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples and comparative examples according to the present invention, but the present invention is not limited to these examples.
[0026]
(Measurement method-1)
A conveyor 11 having an average fiber diameter of piled-up cotton apparatus 2 micron ultrafine carbon fibers 8, while depositing the flocculent with basis weight 100 g / m ^2, the phenolic resin solution 20% concentration was 20 g / m ² applied as a binder The thickness of the ultrafine carbon fiber aggregate 10 is continuously set by using an infrared semiconductor laser displacement sensor (LB-300, manufactured by KEYENCE CORPORATION) at intervals of 250 mm in the width direction of the ultrafine carbon fiber aggregate 10 and continuously. A measurement was made. As a result, the thickness of the ultrafine carbon fiber aggregate 10 was 215 mm at the maximum and 110 mm at the minimum.
FIG. 2 is a graph showing the measurement results of the above-mentioned 2 micron ultrafine carbon fibers performed a plurality of times as a correlation between the thickness of the aggregate and the bulk density of the felt after curing. It can be seen that the relationship is directly proportional.
[0027]
(Measurement method-2)
A conveyor 11 having an average fiber diameter of piled-up cotton device 8 to 1 micron ultrafine carbon fibers, while depositing the flocculent with basis weight 100 g / m ^2, the phenolic resin solution 20% concentration was 20 g / m ² applied as a binder The thickness of the ultrafine carbon fiber aggregate 10 is continuously set by using an infrared semiconductor laser displacement sensor (LB-300, manufactured by KEYENCE CORPORATION) at intervals of 250 mm in the width direction of the ultrafine carbon fiber aggregate 10 and continuously. A measurement was made. As a result, the thickness of the ultrafine carbon fiber aggregate 10 was 165 mm at the maximum and 85 mm at the minimum.
[0028]
(Control method-1)
An infrared semiconductor laser displacement sensor (LB-) of an ultrafine carbon fiber aggregate 10 having an average fiber diameter of 2 microns deposited on a conveyor 11 of a cotton collecting device 8 using the ultrafine carbon fiber felt forming apparatus shown in FIG. 300, manufactured by Keyence Corporation) is fed back via a controller to control the swinging of the fiber blowing section 1 in the cotton collecting device 8 to control the ultrafine carbon fiber aggregate 10 deposited on the conveyor 11. By changing the blowing amount in the width direction, the thickness of the ultrafine carbon fiber aggregate 10 could be controlled to 170 mm at the maximum and 130 mm at the minimum. Then curing the ultrafine carbon fiber aggregate 10 having a controlled thickness, was the product felt, the bulk density of the felt, up to 5.4 kg / m3, it was the lowest 4.5 kg / ^{m 3.}
[0029]
(Control method-2)
An infrared semiconductor laser type displacement sensor (LB-) of an ultrafine carbon fiber aggregate 10 having an average fiber diameter of 1 micron deposited on a conveyor 11 of a cotton collecting device 8 using the ultrafine carbon fiber felt forming apparatus shown in FIG. 300, manufactured by Keyence Corporation) is fed back via a controller to control the swinging of the fiber blowing section 1 in the cotton collecting device 8 to control the ultrafine carbon fiber aggregate 10 deposited on the conveyor 11. By changing the blowing amount in the width direction, the thickness of the ultrafine carbon fiber aggregate 10 could be controlled to a maximum of 130 mm and a minimum of 100 mm. Then curing the ultrafine carbon fiber aggregate 10 having a controlled thickness, it was the product felt, the bulk density of the felt, up to 5.4 kg / ^{m 3,} was the lowest 4.5 kg / ^{m 3.}
[0030]
Comparative Example When an ultrasonic range finder (UD-500, manufactured by KEYENCE CORPORATION) was applied to the above-described apparatus for forming an ultrafine carbon fiber felt, an ultrafine carbon fiber aggregate absorbing ultrasonic waves, in particular, having an average fiber diameter of 1 to With an ultrafine carbon fiber aggregate of 2 microns, proper reflection could not be expected and measurement was difficult.
[0031]
【The invention's effect】
According to the measuring method of the present invention, it is possible to reliably measure the thickness of the ultrafine carbon fiber aggregate that absorbs ultrasonic waves, and the infrared semiconductor laser type displacement sensor is a non-contact type Therefore, there is an advantage that the measurement can be continuously performed even in the production process of the ultrafine carbon fiber aggregate which cannot be measured by direct contact because the binder is attached.
[0032]
Further, according to the control method of the present invention, since there is a correlation between the bulk density of the ultrafine carbon fiber felt after the binder is cured and the thickness of the ultrafine carbon fiber aggregate, the thickness is controlled in the width direction. By being able to do so, it becomes possible to manufacture a product having excellent bulk density uniformity as a whole of ultrafine carbon fiber felt, and industrial production with stable quality (physical properties) can be performed.
[0033]
Further, according to the production method of the present invention, since the control method described above is used, the product having excellent bulk density uniformity and stable quality (physical properties) as a whole of the ultrafine carbon fiber felt can be obtained. Can be manufactured industrially.
[0034]
Other specific advantages of the present invention are as described in detail in the above-mentioned embodiments and examples of the present invention.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an apparatus for manufacturing an ultrafine carbon fiber aggregate according to the present invention.
FIG. 2 is a graph showing a correlation between the thickness of a carbon fiber aggregate and the bulk density of a molded felt.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Blow-out part 2 Distance meter provided with infrared semiconductor laser displacement sensor 3 Controller 5 Coarse spreader 6 Reserve trunk 7 Spreader 7a Garnet cylinder 8 Cotton collecting section 9 Suction hood 10 Microfine carbon fiber aggregate 11 Conveyor 12 Sprayer

Claims (7)

A method for measuring the thickness of the ultrafine carbon fiber aggregate, using a distance meter equipped with a laser displacement sensor, measuring the distance from the distance meter to the floor supporting the ultrafine carbon fiber aggregate, A method for measuring the thickness of the ultrafine carbon fiber aggregate, comprising measuring a thickness of the ultrafine carbon fiber aggregate by measuring a distance from a distance meter to a surface of the ultrafine carbon fiber aggregate. The method for measuring the thickness of an ultrafine carbon fiber aggregate according to claim 1, wherein the laser displacement sensor is installed above a cotton collecting device line in a process of manufacturing the ultrafine carbon fiber aggregate. A method of controlling an ultrafine carbon fiber aggregate formed by blowing out ultrafine carbon fibers from a fiber blowing portion of a cotton collecting device to have a predetermined thickness, using a distance meter equipped with a laser displacement sensor, Measurement of the distance from the distance meter to the floor supporting the ultrafine carbon fiber aggregate, and measurement of the distance from the distance meter to the surface of the ultrafine carbon fiber aggregate, of the ultrafine carbon fiber aggregate formed A thickness control method for an ultrafine carbon fiber aggregate, comprising measuring a thickness and changing a blowing direction of a fiber blowing section of the cotton collecting device according to a change in the thickness of the ultrafine carbon fiber aggregate. Spraying the binder simultaneously with the cotton collection in the cotton collecting device, and measuring the thickness of the ultrafine carbon fiber aggregate sprayed with the binder, the bulk density of the ultrafine carbon fiber felt obtained by curing the binder is a predetermined density 4. The method for controlling the thickness of an ultrafine carbon fiber aggregate according to claim 3, wherein the blowing direction of the fiber blowing section of the cotton collecting device is changed so as to be within a standard. In a method for manufacturing an ultrafine carbon fiber aggregate that blows out ultrafine carbon fibers from a fiber blowing portion of a cotton collecting device to form an aggregate having a predetermined thickness, a distance meter equipped with a laser displacement sensor is used, and the distance meter The thickness of the formed ultrafine carbon fiber aggregate is measured by measuring the distance to the floor supporting the ultrafine carbon fiber aggregate and measuring the distance from the distance meter to the surface of the ultrafine carbon fiber aggregate. And controlling the thickness of the ultrafine carbon fiber aggregate by changing the blowing direction of the fiber blowing portion of the cotton collecting device according to the change in the thickness of the ultrafine carbon fiber aggregate. Manufacturing method of the aggregate. Spraying the binder simultaneously with the cotton collection in the cotton collecting device, and measuring the thickness of the ultrafine carbon fiber aggregate sprayed with the binder, the bulk density of the ultrafine carbon fiber felt obtained by curing the binder is a predetermined density 6. The method for producing a microfine carbon fiber aggregate according to claim 5, wherein the thickness of the microfine carbon fiber aggregate is controlled by changing a blowing direction of a fiber blowing portion of the cotton collecting device so as to be within a standard. . A cotton collecting device having a fiber blowing portion provided so that the blowing direction can be changed,
A distance meter having a laser displacement sensor provided on the top of the ultrafine carbon fiber aggregate,
A controller;
An apparatus for manufacturing an ultrafine carbon fiber aggregate having
The range finder is formed by measuring a distance from the range finder to a floor supporting the microfine carbon fiber aggregate and measuring a distance from the range finder to a surface of the microfine carbon fiber aggregate. Measure the thickness of the ultrafine carbon fiber aggregate, send the data to the controller,
The controller according to claim 1, wherein the controller changes a blowing direction of the fiber blowing unit based on the transmitted data.

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