JP2012184929A - Prepreg defect inspection method, inspection system, and prepreg manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prepreg defect inspection method in manufacturing a prepreg using a release paper, which identifies the position and type of defects of the prepreg on the side of the attached release paper, achieving shortened inspection time and improved inspection accuracy.SOLUTION: A method for inspecting defects of a prepreg on the side of a release paper is applied to a prepreg manufacturing steps including disposing a resin film of a release paper coated with a resin on at least one side of carbon fiber bundles arranged in a sheet or a carbon fiber fabric, impregnating the carbon fiber bundles with a resin, and then continuously winding up the whole. The resin film surface is exposed to light beams by irradiation means between unwinding of the resin film to be disposed on at least one side and the resin impregnation. The light beams reflected from the resin film is detected by light receiving means. Based on the comparison between the signal of the reflected light beams detected by the receiving means and a prescribed threshold, defects on the resin film surface are detected, determined, and categorized into streak defects, foreign matter defects, and resin defects.

Description

  The present invention provides a prepreg defect inspection method for detecting defects on the resin film surface on the release paper side (back side) when manufacturing prepreg using release paper, and transmits defect information on the back side of the prepreg to the next inspection process. The present invention relates to a prepreg defect inspection system, a prepreg defect inspection method, and a prepreg manufacturing method in which the inspection system is a part of the process.

  In recent years, many composite materials using reinforcing fibers have been adopted for sports / leisure / aircraft / automobile / industrial equipment such as fishing rods and golf shafts. In these moldings, a molding material called a prepreg, in which reinforcing fibers are aligned and impregnated with a thermosetting resin, is used, and is cured after being multilayered. Of these molding materials, when producing sheet-like prepregs and cloth-like prepregs, thermoplastic resins and curing agents are usually used for the purpose of improving composite performance and adjusting viscosity if necessary. A resin film is prepared by applying a certain amount of the resin mixture to which the above is added on a release paper in a thin film shape. A certain amount of reinforcing fibers are sandwiched between the resin films, and the reinforcing fibers are impregnated with heat and / or pressure.

  In the prepreg manufacturing process in which the resin is impregnated into the reinforcing fiber, there is a possibility that defects such as “foreign matter” in which a cured resin product or a piece of release paper is mixed into the resin film and / or the prepreg, or resin transfer failure, etc. However, minimizing these is an important factor that affects the physical properties of the composite material described above. These shortcomings of prepregs have recently been demanded to improve the quality of prepregs, and there is an urgent need to detect and correct them without variation and to correct them or exclude them from the product.

  In addition, the defect detection of these prepregs has been conventionally performed manually by visual observation, but it is not only a task that requires very high concentration, but depending on the case, there are individual differences in the determination of defects, There were problems such as causing oversight. In recent years, the introduction of defect inspection automation techniques for the purpose of solving these problems and saving labor has been advanced, and various techniques have been proposed for shortening inspection time and improving inspection accuracy.

  For example, Patent Document 1 proposes a prepreg manufacturing method and apparatus capable of classifying and detecting a plurality of types of defects. The defect inspection method according to Patent Document 1 enables the detection of defects on the upper surface of the prepreg after the prepreg is irradiated with light and the release paper is peeled off. However, in this method, when there is a release paper on the lower side of the prepreg, it is impossible in principle to cope with a defect generated on the surface.

  Patent Document 2 proposes a prepreg manufacturing apparatus and a manufacturing method for inspecting the transfer state of a resin in a prepreg manufacturing process. The resin transfer state inspection method according to Patent Document 2 determines the resin transfer state on the upper surface of the prepreg by inspecting the release paper that has been peeled off after the resin applied on the release paper has been transferred to the reinforcing fibers. . In this method, the state relating to the transfer of the resin is detected, but the state relating to the resin film before the transfer cannot be directly detected.

  On the other hand, in the resin film manufacturing process in which the resin mixture is applied to the release paper, the resin partially disappears on the coating roll, and the resin is lost in stripes in the release paper, or the resin on the release paper is lost in dots. Such coating defects occur. As for the application defects of these resins, streaks are called “strip defects”, and dot-like defects are called “resin defects”. In addition, there is a possibility that “foreign matter” such as a cured resin product or a piece of release paper may be mixed (called “foreign matter defect”) before the manufactured resin film is rolled up. The defects of these resin films may become defects even after the resin is transferred to the reinforcing fibers in the next prepreg manufacturing process. Therefore, the standards of defects are determined for each product type according to the dimensions, and based on these standards. The defect is judged and the position is recorded or corrected or excluded from the product.

  These drawbacks are known to be detected in the resin film manufacturing process in a prepreg manufacturing system in which a resin film manufacturing process, a prepreg manufacturing process, and an inspection process used for manufacturing a prepreg are arranged.

  For example, Patent Document 3 proposes a resin film manufacturing apparatus and a manufacturing method for detecting a coating defect on a resin film in a resin film manufacturing process. The defect inspection method according to Patent Document 3 detects a coating defect on a resin film surface in a resin film manufacturing process.

  However, even if a defect is detected before winding in the resin film manufacturing process, the change over time until it is provided to the next prepreg manufacturing process, the film winding process after the defect detection, or during the prepreg manufacturing process There is a problem that it is impossible in principle to deal with defects such as foreign matters generated during unraveling.

  Conventionally, when a prepreg is manufactured by a hot melt method, there is a release paper on the back side of the prepreg. Therefore, in order to detect defects, the release paper is purposely peeled off and inspected, and then released again to the customer. Although the pattern paper is attached, these operations may increase the disadvantages, and in some cases, relying on the inspection from the surface is insufficient. For this reason, the defect which arose on the back surface may be detected only when using a product depending on the case, and improvement was required.

JP-A-9-225939 JP-A-9-150416 JP-A-9-136323

  In view of the problems of the background art described above, the present invention provides a prepreg defect inspection method capable of shortening inspection time and improving inspection accuracy when producing a prepreg using a release paper. It is an object of the present invention to provide a method for identifying the position and type of a defect on the attached side, and a prepreg defect inspection system that transmits position information of such a defect to a subsequent inspection process.

  In the prepreg defect inspection method according to the present invention, a resin film obtained by coating a release paper with a resin is disposed on at least one side of a carbon fiber bundle arranged in a sheet shape or a cloth-like carbon fiber, and then the carbon fiber bundle In the method of inspecting the defects on the release paper side of the prepreg used in the step of manufacturing the prepreg by subsequently impregnating the resin with the resin, from the feeding portion of the resin film disposed on at least one side to the resin impregnation During this period, the resin film surface is irradiated with light by the irradiation means, the reflected light from the resin film is detected by the light receiving means, and the reflected light signal detected by the light receiving means is compared with a preset threshold value. From the method characterized by detecting and judging defects on the resin film surface, and classifying the defects into streak defects, foreign object defects and resin defect defects That.

  Here, the step of manufacturing the prepreg includes a step of winding the impregnated prepreg together with the release paper, and the release paper on the side on which the defect inspection of the resin film has been performed is wound together with the impregnated prepreg. Preferably, the step of manufacturing the prepreg includes a step of sequentially performing resin impregnation in two or more stages, and the method described above is performed between the feeding portion of an arbitrary resin film and the resin impregnation. It is preferred that a defect inspection is performed.

  As the threshold used for the defect inspection, at least one selected from the group consisting of brightness, width, length, and area is set in advance for each of the stripe defect, foreign object defect, and resin defect defect, and reflected light. It is preferable to classify the faults by comparing with the signal.

  In the prepreg defect inspection method according to the present invention, the detected defect position is marked with a marking device at a predetermined position from the width direction end of the lower surface release paper, more preferably at a position of 6 to 21 mm from the width direction end. Therefore, it is preferable to be a method for identifying the type of prepreg defect and the position in the traveling direction.

  Further, the irradiating means uses a linear black light as a light source, and the black light is plane-symmetric with respect to a surface standing perpendicular to the running direction of the resin film, and the surface It is preferable that one or more pairs are arranged so as to be parallel to the straight line formed of the resin film surface, and that one or more of the black light incident angles are set in the range of 40 to 80 ° and 100 to 140 °, respectively.

  Further, the light receiving means is a CCD line sensor camera, and the CCD line sensor camera is preferably installed in a range of −5 to + 5 ° from a surface standing perpendicular to the running direction of the resin film, Furthermore, it is preferable that the CCD line sensor camera is provided with an optical filter for removing light in the ultraviolet region.

  Furthermore, the present invention provides a system for inspecting a defect on a release paper side of a prepreg, which is used in a prepreg manufacturing system in which a prepreg manufacturing process and an inspection process are arranged in this order. The position information and type information of the release paper side defects detected in step 1 are transmitted to the inspection process, and the defect position in the inspection process is specified by calculating using the device information in the inspection process, and the prepreg manufacturing process It is possible to confirm the defect by means of generating an alarm when the defect detected in the inspection process appears and / or reducing the speed, and the position information and type information detected in the prepreg manufacturing process. And prepreg defect inspection system that outputs defect information that integrates defect information confirmed in the inspection process as inspection results It is preferable to use, after the confirmation of the disadvantages is performed, it is also preferred to include a step of performing treatment splice, or the application of tags in accordance with the treatment criteria preset product.

  The prepreg manufacturing method according to the present invention preferably includes the prepreg defect inspection method or the prepreg defect inspection system as part of the process.

  According to the present invention, when manufacturing a prepreg, in the process of impregnating a resin into a carbon fiber, etc., it is possible to make an objective determination based on each defect criterion by reliably identifying a defect portion caused by a resin film on the release paper side of the prepreg. Can detect automatically and accurately grasp the position of the defect, which not only shortens the inspection time but also greatly improves the quality of the product.

It is a block diagram of the preferable prepreg manufacturing apparatus provided with the defect inspection apparatus used for the prepreg defect inspection method of this invention. It is a preferable block diagram of the defect inspection apparatus used for the prepreg defect inspection method shown in FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration of a preferable prepreg manufacturing apparatus including an apparatus used for a prepreg defect inspection method according to an embodiment of the present invention. In this embodiment, a carbon fiber bundle or a cloth-like carbon fiber arranged in a sheet shape by a resin film coated with a resin on a release paper is sandwiched from the upper and lower surfaces, or the upper surface is a release paper or resin film, and the lower surface is a resin film In the process of heating and pressurizing while maintaining the sandwiched state, impregnating the resin into the carbon fiber bundle, peeling only the release paper on the upper surface, and continuously winding it up to manufacture the prepreg. The prepreg defect inspection method according to the invention is used. More specifically, a defect inspection device 2 is installed on the lower resin film supply surface 1 to detect defects on the surface of the lower resin film supply surface 1. Preferably, a marking device 5 is installed at a position in front of the winder 4 that winds up the prepreg 3, and the time direction position of the defect detected by the inspection device is indicated by the mark device 5. It is possible to identify the defect position of the prepreg backside by marking with ring device 5.

  That is, the prepreg defect inspection method according to the present invention includes a step of winding the impregnated prepreg together with the release paper, and includes a step of winding the resin film with the prepreg impregnated with the release paper on which the defect inspection is performed. The prepreg may be used in a manufacturing process of a prepreg, or may be used in a manufacturing process of a prepreg provided with a process of sequentially performing resin impregnation in two or more stages. In this case, it is sufficient that the defect inspection of the prepreg is performed between the feeding portion of any resin film and the resin impregnation.

  Here, the type of defect may be specified by the marking color or shape. The portion to be marked here is preferably a predetermined position from the end of the release paper on the lower surface of the prepreg, and the predetermined position is more preferably 6 to 21 mm. By setting the lower limit to 6 mm, it is easy to prevent marking errors outside the release paper, and by setting the upper limit to 21 mm, erroneous marking on the prepreg can be prevented. The marking device is not particularly limited as long as it can mark the release paper, but it is preferable to use a pen type.

  When marking occurs continuously, mark the release paper part (ear part) at the end of the prepreg end, and if it occurs in a spot, release paper part (ear part) at the prepreg end of the generation point It is preferable to perform marking. Furthermore, it is preferable to change the length of the marking in order to distinguish between defects that occur continuously and defects that occur in spots. If it occurs continuously, it is possible to mark the entire defect length.

  The prepreg of the product wound by the winder 4 is transmitted to the inspection process, which is a subsequent process of the prepreg manufacturing process, together with the position information of the defect on the release paper side and preferably the type information of the defect, and the inspection is performed. When performing, calculate the position where the defect detected in the prepreg manufacturing process from the position information of the defect (marking part if marking is performed) appears in the inspection process, and when this position appears in the inspection process The fault can be confirmed by means such as generating an alarm 6 and / or reducing the speed. And when winding up to the prepreg, which is the final product, the splicing process is performed to cut out the defective part based on the treatment criteria specific to the product type, or the tag is attached to the release paper part (ear part) at the end of the prepreg It becomes possible to accurately grasp the defect position on the back surface of the prepreg.

  Regarding the detected defect information, the inspection result that is finally output was confirmed by the defect information detected in the prepreg manufacturing process (that is, the position information or the position information and the type information) and the inspection process. It is preferable to use the information integrated with the defect information.

  Thus, the prepreg defect inspection method according to the present invention is also suitably used for a prepreg manufacturing system in which the prepreg manufacturing process and the inspection process are arranged in this order, and the prepreg defect inspection suitable for the prepreg manufacturing system is used. A system can be constructed.

  FIG. 2 shows a preferred configuration of the defect inspection apparatus 1. A defect inspection apparatus used for the defect inspection method for a prepreg according to the present invention includes an illumination means for irradiating light to a resin film, a light receiving means for detecting reflected light from the resin film, and reflected light detected by the light receiving means. It has defect determination means for detecting and determining a resin film surface defect by comparing the signal with a preset threshold value. The “reflected light” described here means light including at least one of reflected light itself of light irradiated on the resin film by the illuminating means and light newly excited and emitted by the irradiated light. To do.

  The defect determination means includes a signal processing means in which threshold values such as brightness, width, length, and area are set in advance for each product type, and the presence / absence of the defect and its type, position or level in the scanning direction of the light receiving means. It is preferable to comprise means for calculating and determining the above signal with respect to the time axis direction. The types of defects described here include, among the resin application defects, a “strip defect” in which the resin is missing in a stripe shape on the release paper, a “resin defect defect” in which the resin is missing in a dot shape, Examples include “foreign matter defects” due to the inclusion of foreign matters such as hardened products and release paper fragments. In the present invention, these are designed to be classified by the signal processing means, for example.

  In the defect inspection apparatus 2, a camera 7 as a light receiving means is installed at a position facing the surface of the resin film traveling in the right direction in the drawing at a predetermined speed, and detects reflected light from the resin film surface. Here, the camera 7 is not particularly limited as long as it has a sensor capable of detecting reflected light from the resin film and emitting a signal corresponding to the level of the detected reflected light. A CCD line sensor camera can be used. It is preferable to install the camera 7 in a range of −5 to + 5 ° from a surface standing perpendicular to the traveling direction of the resin film. In general, light in the ultraviolet region is easily absorbed by resins, particularly 130 ° C. and 180 ° C. curable epoxy resins often used for prepregs, and can emit excitation light having a longer wavelength than ultraviolet light by absorption of ultraviolet light. Are known. Using this property, when a resin film coated with resin on release paper is irradiated with ultraviolet rays and the amount of reflected light is observed, defective portions where the coating is normal and / or foreign matter is attached to the normal coating portion. Then, the amount of excitation light emission decreases. For this reason, there is a difference in the amount of excited luminescence between the normal coating portion and the defective portion, so it is possible to determine the normal portion and defective portion of the resin coated surface by observing this excited luminescence amount and detecting the output difference. Is possible. Moreover, in order to emphasize excitation light emission among the reflected light from the resin film surface, it is preferable to provide the optical filter 8. Here, in order to cut an ultraviolet light wavelength, an optical filter that cuts light of 300 to 400 nm is preferable.

  As the resin, an epoxy resin composition containing an additive that emits fluorescence is preferable, and an epoxy resin using an aromatic amine curing agent or a resin composition containing an epoxy resin having a six-membered ring is more preferable.

  In addition, the light source 9 as an illuminating means for irradiating light toward the resin film is not particularly limited as long as it emits ultraviolet light, but a linear black light is preferably used, and the black light is a resin film. One or more pairs are installed so as to be plane-symmetric with respect to a plane that is perpendicular to the surface and perpendicular to the running direction of the resin film so as to irradiate the entire width of the resin film. It is preferable to install one or more each in the range of -80 ° and 100-140 °. It is preferable to set the incident angle to 40 ° or more with respect to the resin film surface because the amount of reflected light can be maintained even when the light source output is weak. Further, the closer the angle is to 90 °, the stronger the reflected light, but 80 ° or less is preferable in terms of machine installation.

  As a method for determining the threshold value, for example, first, a defect sample serving as a reference is read by an inspection apparatus, a threshold value is set from values such as luminance, width, length, and area for the sample, and adjustment is performed in an actual process. It is good to go and decide. Specifically, first, the luminance threshold is determined based on product type specific information such as the type of release paper, the type of resin, and the basis weight of resin. Next, streak-like defects (corresponding to the above-mentioned “streaks defects”) and other defects are classified from the width and length information, and foreign matters (corresponding to the above-mentioned “foreign matter defects”) from other defects using area information. And the resin defect (corresponding to the above-mentioned “resin defect defect”) may be determined.

  The prepreg defect inspection method according to the present invention is, as described above, in the prepreg manufacturing process, when the prepreg is wound with the release paper, the resin film for inspecting the defect is arranged on the release paper side to be wound. Furthermore, in the prepreg manufacturing process in which the resin impregnation is successively performed in two or more stages, it is preferable to perform defect inspection between the feeding portion of the arbitrary resin film and the resin impregnation. In particular, when resin impregnation is performed in two stages, one or both sides of the resin film used for the first stage impregnation, or a resin film used for the second stage impregnation, after the impregnation However, it is preferable that the release paper is not taken up from the prepreg but applied to any one or more of the resin films on the side taken up as a product together with the prepreg.

  The defect inspection method for a prepreg according to the present invention includes an inspection apparatus for detecting defects on the prepreg surface after resin impregnation in the prepreg manufacturing process and a defect on the resin film surface in the resin film manufacturing process that is the preceding process. It is preferable to use it in combination with an inspection apparatus.

  The above-described prepreg defect inspection method or prepreg defect inspection system can be used in a prepreg manufacturing method as a part of the process. Although there is no restriction | limiting in particular in the width | variety of the prepreg obtained using this method, 500-2000 mm is preferable and it is excellent in accuracy compared with the fault detection by an inspector as it is 600 mm or more.

  The prepreg obtained by using the prepreg defect inspection method or the prepreg defect inspection system according to the present invention not only shortens the time required for defect inspection, but also significantly improves the quality of the product. It is preferably used for sports / leisure use such as aircraft, automobiles, windmills, and other industrial purposes.

DESCRIPTION OF SYMBOLS 1 Lower side resin film delivery surface 2 Defect inspection apparatus 3 Prepreg 4 Winder 5 Marking apparatus 6 Alarm 7 Camera 8 Optical filter 9 Light source

Claims (11)

A resin film in which a release paper is coated with a resin is disposed on at least one side of a carbon fiber bundle arranged in a sheet form or a cloth-like carbon fiber, and then the resin is impregnated into the carbon fiber bundle, and then continuously. In the method for inspecting the defects on the release paper side of the prepreg used in the step of winding and producing the prepreg, the resin film surface is irradiated between the feeding portion of the resin film disposed on at least one side and the resin impregnation. The light is irradiated by the means, the reflected light from the resin film is detected by the light receiving means, and the defect of the resin film surface is detected and determined by comparing the reflected light signal detected by the light receiving means with a preset threshold value. And a method for inspecting a prepreg defect, wherein the defect is classified into a streak defect, a foreign object defect and a resin defect defect. The step of producing the prepreg includes a step of winding the impregnated prepreg together with a release paper, and the release paper on the side on which the defect inspection of the resin film has been performed is wound up with the impregnated prepreg. 1. A prepreg defect inspection method. The step of producing the prepreg includes a step of successively performing resin impregnation in two or more stages, and the method according to claim 1 or 2 between the feeding part of any resin film and the resin impregnation. A prepreg release paper side defect inspection method in which defect inspection is performed. By setting in advance at least one threshold value selected from the group consisting of brightness, width, length, and area for each of the stripe defect, foreign object defect and resin defect defect, and comparing it with the signal of the reflected light The prepreg defect inspection method according to claim 1, wherein the defects are classified. The type of the prepreg defect and the position in the running direction are specified by marking the detected defect position at a predetermined position from the widthwise end of the bottom release paper with a marking device. The prepreg defect inspection method according to claim 1. The irradiating means uses a linear black light as a light source, and the black light is plane-symmetric with respect to a surface standing perpendicular to the running direction of the resin film, and the surface and the resin One or more pairs are arranged so as to be parallel to a straight line made of the film surface, and one or more of the incident angles of the black light are set in the range of 40 to 80 ° and 100 to 140 °, respectively. The prepreg defect inspection method according to claim 1. 7. The light receiving means is a CCD line sensor camera, and the CCD line sensor camera is installed in a range of -5 to +5 [deg.] From a surface standing perpendicular to the running direction of the resin film. The prepreg defect inspection method according to any one of the above. The prepreg defect inspection method according to claim 1, wherein the CCD line sensor camera is provided with an optical filter for removing light in an ultraviolet region. In the system for inspecting the defects on the release paper side of the prepreg used in the prepreg manufacturing system in which the prepreg manufacturing process and the inspection process are arranged in this order, the method according to any one of claims 1 to 8, By transmitting the position information of the defect on the release paper side detected in the manufacturing process of the prepreg, or the position information and type information of the defect together to the inspection process, and calculating using the device information in the inspection process It is possible to identify the defect position in the inspection process, and to generate an alarm when a defect detected in the prepreg manufacturing process appears in the inspection process and / or to confirm the defect by means of reducing the speed. , Position information detected in the manufacturing process of the prepreg, or position information and type information, and defect information confirmed in the inspection process Prepreg defect inspection system and outputs the inspection result integration drawbacks information. 10. The prepreg defect inspection system according to claim 9, further comprising a step of performing a splice treatment or tag attachment in accordance with a predetermined treatment standard for the product after the defect has been confirmed. A method for producing a prepreg, wherein the prepreg defect inspection method according to claim 1 or the prepreg defect inspection system according to claim 9 or 10 is included in a part of the process.

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