JP2019203748A - Monitoring method of fiber bundle, monitoring device using monitoring method, and method for manufacturing fiber bundle using monitoring method or monitoring device - Google Patents

Abstract

To provide a monitoring method capable of quickly detecting abnormality occurring during processes of manufacturing fiber bundles and thereby favorably managing the quality of fiber bundles, a monitoring device equipped with the monitoring method, and a method for manufacturing fiber bundles using the monitoring method or monitoring device.SOLUTION: A monitoring method includes: radiating measurement light to a running fiber bundle, taking images of transmission light from the fiber bundle, and determining that an area where the fiber bundle exists is a target area from the captured image. The method also includes detecting a defect on the basis of pixel information from the captured image, classifying a defect type according to a feature amount of the defect, thereby monitoring the defect of the running fiber bundle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus for monitoring a defect of a traveling fiber bundle 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 fibers (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 defects in fiber bundles become a serious problem. For example, in the course of the precursor manufacturing process, fuzz and fluff due to single yarn breakage, foreign matter adhesion, thickness unevenness, unexpected fiber skewing and fiber bundle cracking may occur. When there is fluff, fluff, foreign matter adhesion, thickness spots, etc., when the fiber is baked to produce carbon fiber, it is wrapped around a roll and process passability is deteriorated, or abnormal cutting occurs during baking. There is a case. In addition, if the fiber is skewed unexpectedly, when making a prepreg, the spreadability may be reduced and process passability may be deteriorated, or a gap may be formed in the prepreg, leading to deterioration in appearance quality. . Similarly, cracking of the fiber bundle may lead to deterioration in the appearance quality of the prepreg or woven fabric, and such a defect in the fiber bundle is an important item to be managed.

  As a method for discovering defects in fiber bundles that are continuously produced at high speed, a method for detecting defects in fiber bundles using measurement light and light receiving means exceeding the width of the fiber bundle has been proposed (Patent Document 1). However, the measurement method described in Patent Document 1 can detect a large defect such as adhesion of foreign matter over a wide range of fiber bundles or intertwined growth of single yarn fluff, but single yarn fluff or fiber slant. Small defects such as rows are difficult to detect.

  On the other hand, a method has been proposed in which a fiber bundle is illuminated, the fiber bundle is imaged by a camera, and the obtained image is binarized and thinned to detect a defect in the fiber bundle (Patent Document 2). ). However, in the measurement method described in Patent Document 2, fluff or fluff that protrudes from the fiber bundle as viewed from the camera can be detected, but the inside of the fluff or fiber bundle that falls within the width of the fiber bundle. It is difficult to detect a defect such as skew in FIG.

JP 2008-203251 A JP 2011-053173 A

  SUMMARY OF THE INVENTION In view of the problems of the prior art, an object of the present invention is to quickly detect an abnormality that occurs during a process of manufacturing a fiber bundle, and to thereby manage the quality of the fiber bundle, and this monitoring method. And a method of manufacturing a fiber bundle using the monitoring method or the monitoring device.

  In order to solve the above problems, the present invention provides a fiber bundle monitoring method described in (1) to (4) below, a monitoring device including the monitoring method described in (5) below, and ( A method of manufacturing a fiber bundle using the monitoring method or the monitoring device according to 6) to (8) is provided.

(1) A method of monitoring a defect of a traveling fiber bundle, the method of monitoring a fiber bundle having the following steps [A] to [C].
[A] A process of irradiating the traveling fiber bundle with measurement light [B] A process of imaging the transmitted light from the fiber bundle [C] A data processing process having the following means (a) to (c) (a) Data processing means for determining a region where a fiber bundle is present as a target region from an image obtained in the imaging step.
(B) Data processing means for detecting defects based on pixel information from the image obtained in the imaging step.
(C) Data processing means for classifying the defect type according to the detected feature amount of the defect

  (2) The fiber bundle monitoring method according to (1), further comprising: [D] an alarm unit that issues an alarm when the defect exceeds the threshold value by comparing the defect with a preset criterion value.

  (3) The fiber bundle monitoring method according to (1) or (2), further comprising [E] a recording unit that records information on the defect.

  (4) The fiber bundle monitoring method according to any one of (1) to (3), wherein the traveling fiber bundle is a polyacrylonitrile fiber bundle.

  (5) A fiber bundle monitoring apparatus that monitors defects of a traveling fiber bundle by the monitoring method according to any one of (1) to (4).

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

  (7) In the fiber bundle manufacturing method according to (6) above, based on the monitoring result obtained in the monitoring 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 (7) above, including a step of identifying an abnormality that has occurred in the manufacturing process and issuing an alarm based on the monitoring result obtained in the monitoring step. A method for manufacturing a fiber bundle.

  In the fiber bundle monitoring method and apparatus according to the present invention, an area where the fiber bundle is present is calculated as a target area by the data processing means. Further, defects are detected from the image obtained in the imaging process based on the pixel information, and the defect types are classified according to the detected feature quantities of the defects.

  The fiber bundle monitoring method and apparatus according to the present invention can issue a warning when the defect type detected by the data processing means is compared with a predetermined criterion value and exceeds the threshold value.

  Furthermore, the fiber bundle monitoring method and apparatus according to the present invention includes a recording means for recording the defect type detected by the data processing means, and can monitor the variation of the defect over time.

  According to the present invention, it is possible to monitor a more detailed process abnormality than the conventional quality control by accurately monitoring the defect of the fiber bundle. 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.

It is the schematic side view which showed the 1st form of the defect detection apparatus of the fiber bundle of this invention. It is the schematic side view which showed the 2nd form of the defect detection apparatus of the fiber bundle of this invention. It is a schematic diagram which shows an example of the defect of the fiber bundle in the 1st form made into detection object by this invention. It is a schematic diagram which shows an example of the defect of the fiber bundle in the 2nd form made into detection object by this 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.

  The fiber bundle to be measured can detect a defect satisfactorily 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.

  The illumination means is not limited in intensity and wavelength as long as sufficient transmitted light from the fiber bundle can be obtained. In particular, in the case of simultaneously inspecting defects of a plurality of fiber bundles at a place where a plurality of fiber bundles are running in parallel, in the direction across the row of parallel fiber bundles, that is, in the width direction, each fiber bundle is Any device that can illuminate uniformly is acceptable. The illumination means at this time is preferably capable of illuminating each fiber bundle with a light amount difference within 20% in the width direction.

  As the illumination means for illuminating the fiber bundle, a high-frequency fluorescent lamp or metal haloloid lamp, LED illumination, X-ray, infrared light, ultraviolet light, or the like can be used. Further, the light from a light source such as halogen or LED may be guided by an optical fiber for illumination. In particular, when inspecting defects of a plurality of fiber bundles simultaneously in a place where a plurality of fiber bundles are traveling in parallel, it is preferable from the viewpoint of cost and maintainability to use a high-frequency fluorescent lamp or LED illumination that is long in the width direction.

  The positional relationship between the illumination and the fiber bundle is preferably a position where only the fiber bundle can be illuminated and the brightness difference with the background can be increased. For example, as shown in FIG. There is a method to carry out from an angle. In this positional relationship, the background is black as shown in the upper part of FIG. 3, and the fiber bundle is imaged brighter than the background. In this case, it is preferable not to place anything in the field of view of the imaging unit opposite to the imaging unit across the fiber bundle, in order to avoid the background being illuminated by the reflection of the illuminating unit. If some kind of equipment is arranged for convenience, a light absorbing plate or the like may be placed between the equipment and the fiber bundle to prevent reflection of illumination light from the equipment. As the light absorption plate, for example, a black acrylic plate whose surface is not a mirror surface can be used. In addition, as shown in FIG. 2, an imaging unit may be arranged at a position facing the illumination with the fiber bundle interposed therebetween. In this case, as shown in the lower part of FIG. 3, the background is white and the fiber bundle is imaged darker than the background. In the configuration of FIG. 2, when the intensity of illumination is too strong, the information of the transmitted light of the fiber bundle is crushed due to halation at the time of imaging, or light from the background wraps around the fiber bundle due to diffraction. If the fiber bundle is highly transmissive, information may be lost. It is preferable because it is easy.

  As the image pickup means for picking up the fiber bundle together with the background, it is possible to employ a sensor in which light receiving elements (pixels) such as a CCD for receiving light are linearly or two-dimensionally arranged to obtain data relating to luminance. . In particular, when inspecting defects of fiber bundles running in parallel over a wide range at the same time, a line in which the light receiving elements are linearly arranged has excellent resolution in the width direction and can be inspected over a wide range. A sensor camera is preferred.

  In order to detect a defect with high accuracy, it is preferable to take an image with a resolution of 5 times or more the size of the defect to be detected. For example, when a defect having a size of 1 mm is detected in both the width direction and the longitudinal direction, the imaging resolution is preferably finer than 0.2 mm. However, if the imaging resolution is too fine, the amount of data becomes too large and the data processing speed becomes slow.

  Therefore, it is necessary to adjust the measurement frequency according to the line speed of the manufacturing process. When the size of the defect to be detected in the longitudinal direction is 1 mm, it is possible to detect with high accuracy if the imaging resolution is finer than 0.2 mm. For example, when the line speed is 500 m / min, measurement in the flow direction is possible. The frequency is set to about 40 kHz.

  For the image captured by the imaging means, the data processing means determines the area where the fiber bundle is present as the target area. The method of determining the target area is not particularly limited, but if the traveling position and edge of the fiber bundle are stable, the coordinates may be directly specified on the image, the fiber bundle meanders, the fiber bundle If the edge width changes and the edge position changes, a threshold value is set with the luminance value between the background and the fiber bundle, and the target area is determined for each image with the area exceeding or below that threshold as the area where the fiber bundle exists May be. For example, when imaging is performed in the first form shown in FIG. 1, the region where the fiber bundle is present is imaged brighter than the background as shown in FIG. 3, so a threshold is set between the luminance value of the background and the fiber bundle. A region exceeding the threshold is determined as a region where the fiber bundle is present.

  Next, a defect is detected from the image obtained in the imaging process based on pixel information. As a defect detection method, for example, a threshold value of a pixel value is set, and an area exceeding or below the threshold value is detected as a defect. For example, if the target area has been determined first, the average or median luminance value in the target area is set as a threshold value, and a portion below the threshold value is detected as a defect. As other methods, there are a method for detecting a difference as a defect while comparing with the surrounding gray level, and a method for detecting a defect having a specific shape by pattern matching as a defect. At that time, the area, length (distance in the long side direction), width (distance in the short side direction), angle with respect to the fiber flow direction, roundness, straightness, average luminance value, etc. occupied in the detected defect image Is obtained as a feature quantity.

  Next, the defect type is classified based on the detected feature amount of the defect. For example, the length and width are small, straight and high straightness, the defect of the angle different from the flow direction of the fiber is skewed, the one with both length and width is a pill, the average brightness value is the background brightness Those close to the value are classified as cracks. Either the step of determining the region where the fiber bundle is present as the target region or the step of detecting the defect from the image may be performed first.

  When the defect information obtained by these data processing means is detected at a level exceeding a predetermined criterion value, an abnormality is generated during the process, so an alarm device is provided to issue an alarm. Preferably it is. 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. For example, as the determination reference value, there is a method in which an immediate alarm is issued when any number of defect detections, size, or a specific defect type occurs.

  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 that the detected defect information is recorded for each running yarn and every running time. According to such an embodiment, fluctuations in defects present in the package can be accurately grasped, and when any problem occurs on the user side, the cause is identified by analyzing those data, and the judgment criteria are reviewed. Can be used. The determination criteria can be set at any time for each user type, manufacturing process, and product type.

  On the other hand, in the fiber bundle manufacturing method including the traveling yarn monitoring method of the present invention in the monitoring process, the operation of identifying the process abnormality from the degree and location of the defect detected in the monitoring process and changing the conditions of the manufacturing process Procedures may be included. In the fiber manufacturing process, defects detected using the traveling fiber bundle inspection method of the present invention are monitored for temporal changes at each location of the running yarn per unit time, for example, per hour. To do. By doing so, it is possible to grasp the characteristic increasing tendency of defects, lead to early investigation of the cause of the defect, and appropriately deal with the abnormal part, thereby avoiding the process abnormality and improving the yield.

  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 was run at a running speed of 65 m / min, and the tension of the measuring unit was adjusted to 0.02 cN / dtex by adjusting the driving speed on the take-up side.
As illumination means, KDPL2-LK1000W manufactured by Kyoto Electric Equipment Co., Ltd. was used. An image sensor XG-8700L manufactured by Keyence Corporation was used as the imaging means. Specifically, a line camera XG-HL08M having 8192 pixels is connected, and all captured images are stored in the storage.

  The illumination was installed at a distance of 200 mm from the light projecting portion with respect to the traveling fiber bundle. The imaging means was installed so as to be inclined by 70 ° with respect to the fiber bundle, and was installed at a distance of 1200 mm from the lens tip.

  Photographing was performed on 12 traveling in parallel, and the imaging resolution in the longitudinal direction and the width direction was about 0.1 mm.

  Based on the imaging data for about 3 days, the data processing means detected defects for each fiber bundle, and monitored comparison between fiber bundles and fluctuations during the day and night. In addition, the influence on the post-process was investigated.

(Example 2)
The fiber bundle to be measured and the measuring method are in accordance with Example 1, and the detection of defects for each fiber bundle is performed in-line by the data processing means. When a defect is detected, an abnormality alarm is issued, and defect information such as a defect image, a generated weight, an occurrence time, and an occurrence position is displayed as a history on a monitor in the field.

  In the fiber bundle manufacturing process, if there are scratches on the surface of the roll for traveling the fiber bundle or the guide roll that determines the travel position of the fiber bundle, a defect will occur in the fiber bundle where it touches the damaged area. By detecting defects, it is possible to detect defects early. Then, by appropriately treating the abnormal part, process abnormality can be avoided and the yield can be improved.

  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: Illuminating means 3: Measuring light 4: Transmitted light 5: Imaging means 6: Data processing means 7: Recording means

Claims (8)

A method for monitoring defects in a traveling fiber bundle, the method comprising monitoring the following fiber bundles having the following steps [A] to [C].
[A] A process of irradiating the traveling fiber bundle with measurement light [B] A process of imaging the transmitted light from the fiber bundle [C] A data processing process having the following means (a) to (c) (a) Data processing means for determining a region where a fiber bundle is present as a target region from an image obtained in the imaging step.
(B) Data processing means for detecting defects based on pixel information from the image obtained in the imaging step.
(C) Data processing means for classifying the defect type according to the detected feature amount of the defect   The fiber bundle monitoring method according to claim 1, further comprising: [D] an alarm unit that issues an alarm when the defect is compared with a preset threshold value and exceeds the threshold value.   The fiber bundle monitoring method according to claim 1, further comprising: [E] a recording unit that records information on the defect.   The fiber bundle monitoring method according to any one of claims 1 to 3, wherein the traveling fiber bundle is a polyacrylonitrile fiber bundle.   A fiber bundle monitoring device that monitors a defect of a traveling fiber bundle by the monitoring method according to claim 1.   Using the monitoring method according to any one of claims 1 to 4 or the monitoring device according to claim 5, a monitoring step of monitoring a defect of a traveling fiber bundle is provided. Production method.   The method for manufacturing a fiber bundle according to claim 6, further comprising an operation procedure for identifying an abnormality occurring in the manufacturing process based on the monitoring result obtained in the monitoring process and automatically changing the conditions of the manufacturing process. A method for producing a fiber bundle, wherein The fiber bundle manufacturing method according to claim 7, further comprising a step of identifying an abnormality that has occurred in the manufacturing process based on the monitoring result obtained in the monitoring step and issuing an alarm. Manufacturing method.