JP6447699B2 - Measuring method of fiber bundle, measuring device using this measuring method, and manufacturing method of fiber bundle using this measuring method or measuring device - Google Patents

Description

  The present invention relates to an apparatus for measuring a thickness and / or spots of a traveling fiber bundle substantially continuously in a fiber manufacturing process for manufacturing a fiber bundle.

  Synthetic fiber bundles are widely used not only for clothing materials such as nylon and polyester, but also for industrial materials. Aramid fibers used for high-strength belts and tire cords, and polyacrylonitrile precursors used for the production of carbon fibers used in fields such as sports and automobiles, ships, and civil engineering are also widely known.

  Moreover, the carbon fiber obtained by baking this precursor is known as a highly functional fiber bundle used in fields such as sports, automobiles, ships, and civil engineering buildings.

  While such a fiber bundle is required to have high performance, in order to meet the demand from users, the production equipment is increased in size, the production speed is improved, the total number of fibers per unit production machine is increased, and the cost is reduced. The field of application is greatly expanded.

  However, it is known that an increase in production facilities and an increase in production speed make uniform processing of fiber bundles more difficult, and minor spots in fiber bundles are a serious problem. For example, spots may occur in the thickness of the fiber bundle during the manufacturing process. As a result, a portion with a large amount of heat or the like processed per unit time may be generated and a portion with a small amount may be generated, and processing spots of the obtained fiber bundle may increase. Such spots are more likely to become a serious problem as the fiber bundle used by the user has higher performance, and is an important item to be managed.

  As a method of detecting process defects in the manufacturing process of fiber bundles that are continuously produced at high speed, a method of detecting fuzz defects by irradiating a laser beam (Patent Document 1), or continuously capturing defects of fiber bundles with a camera A detection method is widely used (see Patent Document 2).

  On the other hand, as a method for detecting the fiber bundle weight and fineness variation online, a method of detecting the weight variation by irradiating a laser beam, continuously imaging the traveling fiber bundle with a camera, and calculating the cross-sectional area. Has been proposed (see Patent Document 3).

  However, it is impossible to capture the uneven thickness of the fiber bundles detected by fluff defects, fiber defects, and weight variations, which are manifested by an increase in the size of the fiber bundle production facility and an increase in production speed. It was. Further, in the conventional laser, visible red light having a wavelength of 600 to 700 nm is used, and there are cases where measurement accuracy is insufficient to detect the thickness of the fiber bundle and the spots thereof. For this reason, a fiber bundle is used to measure the thickness and / or unevenness of the fiber bundle in the fiber bundle manufacturing process with high accuracy in-line using a shorter wavelength laser, and to improve the thickness unevenness based on the result. A method for changing the manufacturing process was required.

JP 2006-56697 A JP 2005-264405 A JP2012-122167A

  An object of the present invention is to provide a measurement method capable of quickly detecting an abnormality that occurs during a process of manufacturing a fiber bundle, and thereby managing the quality of the fiber bundle, in view of the problems of the prior art, and the measurement method. And a manufacturing method of a fiber bundle using the measuring method or the measuring device.

  In order to solve the above-described problems, the present invention provides a method for measuring a fiber bundle described in (1) to (4) below, a measuring apparatus including the measurement method described in (5) below, A method for producing a fiber bundle using the measuring method or measuring apparatus according to 6) to (8) is provided.

(1) A method for measuring the thickness of a traveling fiber bundle and / or its spots, the method for measuring a fiber bundle having the following steps [A] to [D].
[A] Positioning step of running a fiber bundle in contact with a roller or a fixed guide [B] Irradiating a laser beam having a wavelength of 350 nm to 550 nm with a laser beam irradiation angle of 60 ° to 80 ° with respect to the traveling fiber bundle [C] An input step of receiving reflected light at each measurement point in the width direction of the fiber bundle by the light receiver [D] The laser beam at each measurement point in the width direction of the fiber bundle A detection step for detecting the amount of change in the light receiving angle of irradiation and reflected light

  (2) The method for measuring a fiber bundle according to (1), wherein the traveling fiber bundle is a polyacrylonitrile fiber bundle.

  (3) The fiber bundle measuring method according to (1), wherein the traveling fiber bundle is a carbon fiber bundle.

  (4) The method for measuring a fiber bundle according to any one of (1) to (3), wherein the traveling fiber bundle is a filament of 1,000 or more and 100,000 or less.

  (5) A fiber bundle measuring apparatus that measures the thickness and / or spots of the traveling fiber bundle by the measurement method according to any one of (1) to (4) above.

  (6) A fiber bundle having a measurement step of measuring a traveling fiber bundle using the measurement method according to any one of (1) to (4) or the measurement device according to (5). Manufacturing method.

  (7) In the fiber bundle manufacturing method according to (6) above, based on the measurement result obtained in the measurement step, an abnormality that has occurred in the manufacturing step is specified, and the conditions of the manufacturing step are automatically changed. A method for producing a fiber bundle, comprising an operation procedure.

  (8) The method for manufacturing a fiber bundle according to (6) above, including a step of identifying an abnormality that has occurred in the manufacturing process based on the measurement result obtained in the measuring step and issuing an alarm. A method for manufacturing a fiber bundle.

  In the fiber bundle measuring method and apparatus according to the present invention, the fiber bundle to be detected is supported by a roller or a fixed guide, and the thickness and / or unevenness of the fiber bundle is measured.

  And the measuring method and apparatus of the fiber bundle which concerns on this invention irradiate a rectangular laser beam with respect to the reference plane which consists of a roller or a fixed guide, and the said fiber bundle, for example, and the said roller or fixed guide is used as reference height. The thickness of the traveling fiber bundle is received as a displacement from the reference height by a detection element as an input means, and this displacement is measured substantially simultaneously in the width direction of the traveling yarn, for example, at a pitch of 1 to 500 μm. To measure the height from the reference position (that is, the thickness of the fiber bundle) in a non-contact manner.

The fiber bundle measuring method and apparatus according to the present invention can be provided with a data processing step having the following data processing means 1) to 5).
1): First data processing means 2 for calculating the average thickness in the width direction of the fiber bundle based on the thickness data of the fiber bundle obtained at each measurement point in the width direction from the amount of change in the light receiving angle. The second data processing means 3) that accumulates the data of the average thickness in the width direction of the fiber bundle calculated by the data processing means of No. 2 as the fluctuation data in the longitudinal direction of the fiber bundle: calculated by the data processing means of 2) Third data processing means 4 for calculating the average thickness of the fiber bundle in a certain section in the width direction and the longitudinal direction based on the data on the number of fluctuations in the longitudinal direction of the fiber bundle of the average thickness in the width direction of the fiber bundle. ): Fourth data processing means 5 for calculating the thickness unevenness based on the data of the average thickness of the fiber bundles in the constant section in the width direction and the longitudinal direction calculated by the data processing means in the above 3): width direction and length One direction Fifth data processing means for comparing the average thickness and thickness irregularity of the fiber bundle in the section, and the average thickness and thickness irregularity of the fiber bundle in successive subsequent width direction and the longitudinal direction of a certain section

  The first data processing means calculates the average thickness in the width direction of the fiber bundle by adding the heights.

  Next, the average thickness data in the width direction of the fiber bundle calculated by the first data processing means is accumulated as fluctuation data in the longitudinal direction of the fiber bundle by the second data processing means.

  Next, based on the fluctuation data in the longitudinal direction of the fiber bundle, the average thickness in the width direction of the fiber bundle calculated by the second data processing means, the width data and the longitudinal direction are obtained by the third data processing means. The average thickness of the fiber bundle in a certain section is calculated. Thereby, the fluctuation | variation can be monitored by comparing the average thickness of the fiber bundle calculated in one fixed area with the average thickness of another fixed area, the average thickness of the whole fiber bundle, etc.

  Further, the fourth data processing means calculates the thickness unevenness based on the data on the average thickness of the fiber bundles in a certain section in the width direction and the longitudinal direction. Thereby, the variation in the thickness variation can be monitored by comparing the thickness variation of the fiber bundle calculated in one certain interval with the thickness variation in the other certain interval, the thickness variation of the entire fiber bundle, and the like. These values can also be recorded.

  In addition, the average thickness and thickness unevenness of the fiber bundle in the constant section in the width direction and the longitudinal direction are compared with the average thickness and thickness unevenness of the fiber bundle in the next continuous constant section by the fifth data processing means. Thereby, the time-dependent fluctuation | variation of the average thickness and thickness spot of a fiber bundle can be monitored.

  According to the present invention, it is possible to monitor a more detailed process abnormality than the conventional quality control based on variations in weight and the like by measuring the thickness of the fiber bundle to be wound and / or its unevenness with high accuracy. Further, by detecting a detailed process abnormality, it becomes possible to prevent the outflow of the defective fiber bundle to the outside, and the quality control of the fiber bundle can be performed at a high level.

  In addition, since non-contact type laser light is used in the present invention, it is difficult to be affected by fluctuations in the moisture content of the fiber bundle and fluctuations in the attached oil agent, and thickness fluctuations can be measured continuously with high accuracy. Furthermore, since it can be installed at a position away from the fiber bundle that travels between the light projecting unit and the light receiving unit, it does not interfere with the threading work, etc., and the influence of dirt on the irradiation unit and light receiving unit due to fine oil droplets is reduced. be able to.

  Further, in the present invention, the laser beam irradiation angle is set to 60 ° to 80 ° with respect to the traveling fiber bundle, thereby suppressing the penetration of the laser beam into the fiber and accurately obtaining the cross-sectional area value. And the cross-sectional area measurement value can be matched well with the true value.

It is sectional drawing of the running direction of the fiber bundle used as the detection object of this invention. It is an image of the fiber bundle measured with the measuring device of the present invention.

Hereinafter, embodiments of the present invention will be described in detail.
The fiber bundle to be detected in the present invention is a fiber bundle composed of a plurality of filaments. The type of fiber bundle is not particularly limited, but specific examples include polyacrylic fiber bundles, polyester fiber bundles, nylon fiber bundles, aramid fiber bundles, synthetic fiber bundles such as arylate fiber bundles, or carbon fiber bundles. Can be preferably mentioned.

  Here, the fiber bundle is a general term for at least 1000 fibers. By using the number of filaments constituting the fiber bundle of 1000 or more as a detection target, the displacement of the height of the fiber bundle traveling with respect to the reference surface can be made significant, and the cross-sectional area can be detected with high accuracy. be able to.

  The positioning means for moving the fiber bundle in contact with the roller or the fixed guide is a roller or fixed guide having a substantially flat portion having no yarn on both sides of the traveling fiber bundle. Since the surface form of the positioning means affects measurement accuracy, a satin finish of 3.2 S or less is preferable, and a mirror finish of 0.8 S or less is more preferable to improve measurement accuracy. Further, in order to increase the measurement accuracy, it is more preferable that the surface color has a lightness different from that of the traveling fiber bundle. For example, when measuring the thickness of a white or yellowish white fiber bundle that travels, the positioning means may be black, but this is not restrictive.

  More preferably, the positioning means has a small vibration and vibration. For example, in the case of the roller, it is preferable that the outer tolerance is within 0.03 mm, the roundness and the cylindricity are within 0.03 mm, and further, there is no deflection. In addition, it is preferable that the first and second data processing means including the laser light receiving element and the CPU unit have a function of correcting the shake of the roller and the fixed guide. In this case, it is not necessary to consider the degree of vibration, vibration, and deflection of the positioning means, and the degree of freedom in device design can be increased as compared with a case where such a function is not provided. In addition, since the roller is substantially flat within the measured range, the roller diameter is more preferably more than 60 mm. The material of the positioning means is not particularly limited, but may be any SUS material or plastic material having excellent wear resistance.

  The fiber bundle to be measured can be satisfactorily measured in cross-sectional area by traveling along a predetermined yarn path. Therefore, it is preferable to apply a tension of 0.01 cN / dtex or more to the traveling fiber bundle to be measured, and more preferably 0.05 cN / dtex or more. By applying a tension of 0.01 cN / dtex or more, it is possible to prevent the single yarn meandering and the single yarn bundle composed of several monofilaments from coming off the fiber bundle. However, it is also preferable to have a function of tracking and correcting the meandering of the fiber bundle by the first and second data processing means composed of the elements of the laser light receiving unit, the CPU unit, etc., and has such a function. In this case, it is not necessary to consider the degree of tension as compared with the case where such a function is not provided, and the degree of freedom of the fiber bundle manufacturing conditions can be increased.

Hereinafter, the output means for irradiating the traveling fiber bundle with laser light will be described in detail.
The laser beam (4 in FIG. 1) used for the measurement of the fiber bundle (1 in FIG. 1) of the present invention and irradiated from the output means (5 in FIG. 1) is 350 to 550 nm. If the wavelength is longer than 550 nm, the measurement accuracy is not sufficient to detect the thickness of the fiber bundle and its spots, which is not preferable. On the other hand, if the wavelength is shorter than 350 nm, it is not preferable because visible light is lost and the measurement range cannot be easily confirmed with the naked eye. As for the wavelength of a laser beam, 400-500 nm is more preferable. Moreover, the rectangle which can measure each measurement point of a fiber can be used suitably for the range irradiated with the said laser beam. If the long side length of this rectangle is 5 to 100 mm, at least one yarn of the traveling fiber bundle can be included in the measurement range, which can be suitably used. Although short side length is not specifically limited, What is necessary is just to be 25-170 micrometers.

  Furthermore, if the laser beam has a wavelength of 350 to 550 nm, the fiber bundle spots can be measured with higher accuracy than when a conventional laser beam having a wavelength of 600 nm or more is used. When the wavelength is 600 nm or more, there is a case where it is determined that there is a patch even in a fiber bundle having no thickness due to the submergence of a laser beam in a highly reflective fiber bundle, and accurate measurement may not be possible. . Such a problem was solved by using a laser beam having a wavelength of 550 nm or less.

  In order to accurately calculate the reference height, the fiber bundle thickness is measured, as shown in FIG. 1, with respect to the width of the fiber bundle running on the reference plate (2 in FIG. 1), at least fiber bundle yarns on both sides. It is preferable to set a plane in which a fiber bundle having a length of 10% or more of the width does not travel in the measurement range. By making such an installation, the plane height at which the fiber bundles on both sides of the fiber bundle do not travel is set as the reference height, and the height of the fiber bundle can be calculated with respect to the horizontal line connecting the two reference heights. it can. Furthermore, the thickness of the fiber bundle can be obtained by setting the width (yarn width) in which the fiber bundle travels in the region where the height displacement has occurred from the horizontal line and multiplying the measured height between the yarn widths. .

  In order to accurately collect the value of the cross-sectional area, it is preferable that the laser irradiation angle is 50 ° to 90 ° with respect to the traveling fiber bundle and the positioning means in order to suppress the laser light from entering the fiber. More preferably, it is 60 ° to 80 °. With this angle, the measured cross-sectional area agrees well with the true value, and the thickness unevenness obtained during the second data processing can be minimized. Moreover, it is preferable that the thickness of the fiber bundle measured is 10 mm or less. If it is 10 mm or less, the light receiving element can be miniaturized, and the laser output machine can be installed at any place in the process.

  Each measurement point in the width direction of the fiber bundle defined in the present invention is to measure a measurement range including the fiber bundle and the reference surface at a pitch of 1 μm to 500 μm. With this pitch, the difference in height between the traveling fiber bundle and the horizontal line composed of the reference plane can be read on the element with high accuracy.

  Each measurement point in the longitudinal direction of the fiber bundle defined in the present invention is each point measured at a frequency of 10 Hz to 64000 Hz in a measurement range including the fiber bundle and the reference plane. Within this measurement frequency, the difference in height between the traveling fiber bundle and the horizontal line (3 in FIG. 1) obtained from the reference plane can be accurately read on the element. However, if the measurement frequency is increased too much, the measurement range in the width direction becomes narrow, and the amount of data increases too much, so that the data processing speed decreases.

  Therefore, it is necessary to adjust the measurement frequency according to the line speed of the manufacturing process. If the pitch of each point to be measured is within 5 mm, it is possible to accurately obtain the thickness variation of the fiber bundle calculated at the time of the third data processing. For example, if the line speed is 100 m / min. The measurement frequency is set to about 350 to 400 Hz.

The input means (6 in FIG. 1) for receiving the reflected light may be a height displacement detecting element (8 in FIG. 1) that uses a known light receiving element called CMOS to perform image processing. It is preferable to use HSE ³ -CMOS developed by the company, and it may be attached separately from the light projecting unit. However, in order to detect the light receiving laser with high accuracy, a laser displacement meter integrated with the light projecting unit ( It is more preferable to use 7) in FIG. The data sampling interval of the thickness measurement can be detected with higher accuracy as it is shorter, but the present inventor has studied, for example, if it is in the range of 64000 Hz in the longitudinal direction and 200 points in the width direction, that is, as the total number of points, If it is within 1280000 points / second, a fiber bundle traveling at about 1 to 500 m / min can be measured.

  In the CPU unit as the first data processing means (9 in FIG. 1), the data is obtained by averaging or integrating N data groups obtained by dividing a predetermined sampling interval into N equal parts. Measurement noise can also be reduced by smoothing. Furthermore, by using a known data smoothing means, it is possible to minimize erroneous detection in the manufacturing process.

  By the above-described method, the irradiated laser light is detected by the light receiving element, and is calculated substantially continuously as the value of the average thickness in the width direction of the fiber bundle by the first data processing means. “Substantially continuous” described here is to measure the thickness of the tow at a pitch of 4.8 mm (350 Hz) in the longitudinal direction and a pitch of 10 μm in the width direction at a spinning speed of 100 m / min. It is defined as Further, the data is output as digital or analog information to a second data processing unit constituted by a personal computer or the like via an interface unit equipped with a CPU or the like.

  The output value of the average thickness taken into the second data processing means (10 in FIG. 1) is recorded and monitored as the average thickness fluctuation data of the short period and the long period.

  In the third data processing means, the output value of the average thickness in the width direction taken in by the first and second data processing means can be calculated as an average value. Specifically, the number of recording points in the longitudinal direction as the whole fiber bundle is preferably 1 to 10000 points, and more preferably 1 to 1000 points. By averaging the average thickness in the width direction for each number of recording points, the average thickness of the entire fiber bundle can be calculated.

  Furthermore, it is possible to manage the process abnormality from the fluctuation of the average thickness by comparing the average thickness for each recording point in the longitudinal direction as one section and comparing it with the average thickness of the entire fiber bundle in the next continuous section. .

  On the other hand, in the fourth data processing means, a variation coefficient (hereinafter referred to as CV value) in which a value obtained by dividing the standard deviation of the data by the data average value is displayed in percent for managing the variation data of the average thickness of the entire fiber bundle. Thus, it is possible to manage the process abnormality from the fluctuation of the CV value.

  If the average thickness fluctuation value obtained by these data processing means is detected at a level exceeding a predetermined criterion value (hereinafter referred to as a threshold), an alarm is issued because some abnormality has occurred during the process. It is preferable to provide an alarm device. By issuing an alarm, it is possible to sort the wound product in units of packages, which prevents outflow to the user and is preferable in quality control.

  The image of the fiber bundle measured by the measuring apparatus of the present invention is as shown in FIG. In this image, 11 in FIG. 2 represents a reference plate and 12 represents a fiber bundle.

  As the alarm device, an alarm sound, an alarm lamp for blinking light, or means for transmitting an alarm signal to an operator using a wired or wireless communication device can be suitably used.

  In addition, by combining these processing devices with an automatic cutter, suction device, etc., when the threshold value is continuously exceeded, the running yarn is immediately cut to prevent the abnormal yarn from flowing out to the user at an early stage. You can also.

  Furthermore, it is also a preferred embodiment to record the average thickness fluctuation value for each running yarn or every running time. According to such an embodiment, it is possible to accurately grasp the variation of the average thickness present in the package, and when any problem occurs on the user side, the cause is identified by analyzing those data, the threshold is reviewed, etc. Can be used. The threshold can be set at any time for each user type, manufacturing process, and product type. However, if the value is too small, false detection increases. For example, if the CV value has a short period, 10% or more is preferable. Can be used.

  On the other hand, in the fiber bundle manufacturing method including the measuring method of the running yarn of the present invention in the measuring process, the abnormality of the process is specified from the degree and location of the thickness unevenness detected in the measuring process, and the conditions of the manufacturing process are changed. An operation procedure may be included. In the fiber manufacturing process, the thickness variation detected by using the traveling fiber bundle inspection method of the present invention is changed with time for each place of the running yarn per unit time, for example, per hour. When measured, if the roll of the fiber bundle or the surface of the guide roll that determines the travel position of the fiber bundle is damaged in the manufacturing process of the fiber bundle, There is a tendency for defects to increase in the fiber bundle at the location corresponding to the position, and a characteristic increasing tendency also appears in the temporal change in the number of defects. Further, when the fiber bundle is shifted from the position of the roll for traveling the fiber bundle or the position of the guide roll for determining the travel position in accordance with the increase in the size of the facility and the increase in the production speed, the unevenness of the thickness of the fiber bundle increases.

  Since it is possible to identify the location of the roll surface damage and position deviation from the measurement data to some extent, by appropriately treating the abnormal location, process abnormalities can be avoided and yield improved. Is possible.

  Hereinafter, the present invention will be described by way of examples.

Example 1
As a fiber bundle to be detected, a polyacrylonitrile fiber bundle (single fiber fineness 1.0 dtex) composed of 60000 fibers was used. The fiber bundle is run at a running speed of 65 m / min on a satin guide (surface roughness 4S, diameter 60 mm) fixed immediately after the entanglement process in the manufacturing process, and the tension of the measuring unit is the driving speed on the take-up side. Was adjusted to 0.02 cN / dtex.

  As a means for irradiating and detecting the laser beam, a two-dimensional sensor manufactured by Keyence Corp., in which the irradiation unit and the light receiving unit are integrated, was used. Specifically, the sensor head part type: LJ-V7200, using LJ-V7000 as the first data processing means, and online with a personal computer manufactured by DELL, which is the second data processing means, via the USB code Connected to enable recording / monitoring and abnormality detection.

  From the sensor head, a rectangular blue visible light laser having a wavelength of 405 nm was transmitted and installed so as to be 70 ° with respect to the traveling fiber bundle, and a distance of 25 mm from the projecting portion was taken. In order to improve the measurement accuracy, zero point correction was performed on the inclination and unevenness of the satin fixed guide.

  Since the width of the yarn traveling on the roller was 30 mm, a reference surface measurement area of 5 mm was set on both sides of the traveling yarn as a reference surface, and the pitch of each measurement point in the width direction was 1000 points at 550 Hz. Continuous measurement was performed at 100 μm.

  The accumulation of longitudinal data in the second data processing means was 1000 points. Further, in the third data processing means, the process abnormality was monitored by comparing the average thickness of the entire fiber bundle with the next continuous section.

  This personal computer creates a logging program to record and output short-period and long-period thickness data obtained by the above-mentioned method from data collected at a fixed sampling time in real time, and attached hard disk Was recorded.

  In monitoring the long-period fluctuation values, these 1000 points of data were recorded, and fluctuations in the values were monitored during the day, at night, and between seasons.

(Example 2)
The fiber bundle to be measured and the measuring method were the same as in Example 1, and a plurality of yarns traveling at 100 m / min were measured.

  A logging program was created to allow a personal computer to record and output short-period and long-period thickness data obtained by the above-described method from data collected at 350 Hz in real time. The thickness CV value threshold (hereinafter referred to as PH) in the fourth data processing means is set to 10%, and an abnormal alarm is issued to the PLC (operation management screen) when the CV value of each yarn exceeds this PH. It was a program.

  When the program was operated for 24 running in parallel, the fiber bundle slightly meandered due to fluctuations in the process tension and exceeded PH when hitting a groove roll or groove guide existing in the process. The alarm enabled immediate cause response.

  According to the present invention, it is possible to quickly detect an abnormality that occurs during a process of manufacturing a fiber bundle, and thereby manage the quality of the fiber bundle satisfactorily.

1: Fiber bundle 2: Reference plate 3: Horizontal line obtained from the reference plane 4: Laser light 5: (Laser light irradiation) output means 6: Input means for receiving reflected light 7: Laser displacement meter 8: Height displacement Detection element (CMOS)
9: First data processing means (including CPU)
10: Second data processing means (including computer)
11: Reference plate 12: Fiber bundle

Claims (8)

A method for measuring the thickness and / or spots of a traveling fiber bundle, the method comprising measuring the following fiber bundles [A] to [D].
[A] Positioning step of running a fiber bundle in contact with a roller or a fixed guide [B] Irradiating a laser beam having a wavelength of 350 nm to 550 nm with a laser beam irradiation angle of 60 ° to 80 ° with respect to the traveling fiber bundle [C] An input step of receiving reflected light at each measurement point in the width direction of the fiber bundle by the light receiver [D] The laser beam at each measurement point in the width direction of the fiber bundle A detection step for detecting the amount of change in the light receiving angle of irradiation and reflected light   The fiber bundle measuring method according to claim 1, wherein the traveling fiber bundle is a polyacrylonitrile fiber bundle.   The fiber bundle measuring method according to claim 1, wherein the traveling fiber bundle is a carbon fiber bundle.   The method for measuring a fiber bundle according to any one of claims 1 to 3, wherein the traveling fiber bundle is a filament of 1,000 or more and 100,000 or less.   An apparatus for measuring a fiber bundle, which measures the thickness and / or spots of the traveling fiber bundle by the measurement method according to claim 1.   A method for producing a fiber bundle, comprising a measurement step of measuring a traveling fiber bundle using the measurement method according to claim 1 or the measurement device according to claim 5.   The manufacturing method of the fiber bundle according to claim 6, further comprising an operation procedure for identifying an abnormality occurring in the manufacturing process based on the measurement result obtained in the measurement process and automatically changing the conditions of the manufacturing process. A method for producing a fiber bundle, wherein   The method of manufacturing a fiber bundle according to claim 6, further comprising a step of identifying an abnormality that has occurred in the manufacturing process based on the measurement result obtained in the measurement step and issuing an alarm. Manufacturing method.