JP2012167252A - Method for producing narrow prepreg, and fiber-reinforced plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide inexpensively a high-grade, highly accurate narrow prepreg which can minimize a gap between fibers and variation of basis weight, when a fiber-reinforced plastic of complicated shape is molded.SOLUTION: This method for producing a narrow prepreg comprises the steps that: a yarn prepreg, in which a resin is impregnated in a fiber bundle with unidirectionally aligned fibers, is divided in the fiber direction to obtain divided prepregs; the sites of the divided prepregs corresponding to the ends of the yarn prepreg before division are integrated, or, the fiber bundle with unidirectionally aligned fibers is divided in the fiber direction to obtain divided fiber bundles, and the sites of the divided fiber bundles corresponding to the ends of the fiber bundle before division are integrated to obtain an integrated fiber bundle; and at the same time as integration of fiber bundles or thereafter, the resin is impregnated to obtain the narrow prepreg.

Description

  The present invention has the same high quality and high accuracy as a slit tape prepreg cut out from a wide prepreg and can be manufactured at a low cost similar to a yarn prepreg in which each fiber bundle is individually impregnated with a resin. The present invention relates to a method for manufacturing a width prepreg. More specifically, for example, a method for producing a narrow prepreg suitable for auto tape layup used for shaping a prepreg laminate for an aircraft member having a complicated shape, and a narrow prepreg produced by the method are obtained. It relates to a fiber reinforced plastic.

  Fiber reinforced plastic consisting of reinforced fiber and matrix resin is attracting attention in industrial applications because it has high specific properties, high specific modulus, excellent mechanical properties, weather resistance, chemical resistance, etc. The demand is increasing year by year.

  As a molding method of fiber reinforced plastic having high functional properties, a matrix resin is obtained by laminating a semi-cured prepreg impregnated with a thermosetting resin as a matrix resin on continuous reinforcing fibers and heating and pressing in a high-temperature and high-pressure kettle. Autoclave molding is most commonly performed in which is cured to form a fiber reinforced plastic. Recently, fiber reinforced plastics are often molded by solidifying a prepreg using a thermoplastic resin, which has advantages of shortening the molding cycle and recyclability, as a matrix resin through compression molding or autoclave molding.

  In general, the prepreg has a width of about 1 m, for example, and there is a problem that the prepreg does not follow the shape when shaped and laminated in a complicated shape. Therefore, mainly in shaping and laminating aircraft parts, wide prepregs are cut and divided in the fiber direction, slit tape prepregs (for example, Patent Document 1) are prepared, and arranged in a three-dimensional shape (tape layup) ), The narrow slit tape prepreg itself only needs to follow a two-dimensional shape, and can follow the shape even if it is a complicated shape. However, the slit tape prepreg has a problem that it is necessary to divide the wide prepreg once manufactured and wound up into several stages and cut it to a desired width, resulting in high cost.

  On the other hand, when the fiber bundle is directly impregnated with a resin to obtain a yarn prepreg (for example, Patent Document 2), a thin prepreg can be directly produced without a step of cutting a wide prepreg, so that the cost is low. However, the yarn prepreg end portion has a problem that the fiber orientation is largely disordered and the basis weight variation is large, and the width accuracy of the yarn prepreg is not obtained. For example, when forming a prepreg laminate by tape layup, there is a problem that gaps are generated between the arranged yarn prepregs, or the basis weight variation of the obtained laminate is easily generated. It has been difficult to apply to applications where characteristics are important.

Japanese Patent No. 1575158 Japanese Patent No. 3635773

  In view of the background of such conventional technology, the present invention is to provide a manufacturing method for manufacturing a high-quality, high-precision narrow prepreg at low cost.

The present invention employs the following means in order to solve such problems. That is,
(1) A yarn prepreg formed by impregnating a fiber bundle in which fibers are aligned in one direction is divided in the fiber direction to form a divided prepreg, which corresponds to an end of the divided prepreg before the division A method for producing a narrow prepreg, in which the parts to be integrated are integrated into a narrow prepreg.

  (2) When the portions corresponding to the end portions of the yarn prepreg before the division of the divided prepregs are integrated, the portions corresponding to the end portions of the yarn prepreg before the division are overlapped, and the divided prepreg is overlapped. The manufacturing method of the narrow prepreg as described in (1) which fuses each other.

  (3) When the portions corresponding to the end portions of the yarn prepreg before the division of the divided prepreg are integrated, the divided prepreg is heated and fused, and immediately after pressurization and cooling, the narrow prepreg The method for producing a narrow-width prepreg according to (1) or (2), wherein the cross section is formed into a rectangular shape.

  (4) A fiber bundle in which fibers are aligned in one direction is divided in the fiber direction to form a split fiber bundle, and the portions of the split fiber bundle corresponding to the end portions of the fiber bundle before splitting are integrated and integrated. A method for producing a narrow-width prepreg, which is impregnated with a resin to form a narrow-width prepreg at the same time as or after the synthetic fiber bundle.

  (5) When the portions corresponding to the end portions of the fiber bundle before splitting are integrated with each other, the portions corresponding to the end portions of the fiber bundle before splitting are overlapped, and the splitting is performed. The method for producing a narrow prepreg according to (4), wherein the fiber bundles are integrated.

  (6) The method for producing a narrow prepreg according to (4) or (5), wherein the integrated fiber bundle is pressurized and cooled immediately after impregnating the resin with a resin to form a cross section of the narrow prepreg into a rectangular shape. .

  (7) The method for producing a narrow prepreg according to any one of (1) to (6), wherein the width of the narrow prepreg is in a range of 1 to 150 mm and the width accuracy is 0.1 mm or less.

  (8) The method for producing a narrow prepreg according to any one of (1) to (7), wherein the fiber bundle is carbon fiber, and the number of the carbon fibers is 3000 to 50000.

  (9) The method for producing a narrow prepreg according to any one of (1) to (8), wherein the resin is an epoxy resin, and the fiber content of the narrow prepreg is 55 to 70%.

  (10) A fiber-reinforced plastic obtained by molding a narrow prepreg produced by the method according to any one of (1) to (9).

  According to the present invention, it is possible to obtain a high-quality, high-precision narrow prepreg and a manufacturing method for manufacturing the prepreg at low cost.

It is sectional drawing which shows the concept of the manufacturing method of the narrow prepreg of this invention. It is sectional drawing which shows the conventional yarn prepreg. It is a figure which shows an example of the manufacturing process of the narrow prepreg of this invention. It is a figure which shows an example of the manufacturing process of the narrow prepreg of this invention. It is a figure which shows an example of the manufacturing process of the narrow prepreg of this invention.

  The inventors of the present invention have provided a high-quality, high-precision narrow prepreg that can minimize gaps between fibers and fabric weight when a narrow prepreg is shaped, laminated and molded into a fiber reinforced plastic. In order to manufacture the product at a low cost, after intensive study, a specific base material called a yarn prepreg composed of a fiber bundle in which fibers are aligned in one direction and a resin is cut in the fiber direction, and then a specific part is integrated. Alternatively, after cutting a fiber bundle in which the fibers are aligned in one direction in the fiber direction, a specific part is integrated and impregnated with resin to form a prepreg, thereby solving such a problem all at once. It was investigated. In the present invention, the prepreg includes a resin semi-impregnated base material (semi-preg) in which the resin is not completely impregnated in the fiber in addition to the base material in which the resin aligned in one direction is completely impregnated with the resin. Shall be.

  As shown in FIG. 1, the method for producing a narrow prepreg according to the present invention divides a yarn prepreg 2 formed by impregnating a fiber bundle in which fibers 1 are aligned in one direction with a resin into a fiber prepreg 3 to form a divided prepreg 3. The portions 4 of the divided prepreg 3 corresponding to the end portions of the yarn prepreg 2 before division (near both end portions of the yarn prepreg 2 before forming the divided prepreg 3) are integrated into a narrow prepreg 5. As shown in FIG. 2, the yarn prepreg 2 typically has an elliptical cross section, the width is not constant, and the end portion has a large fiber orientation disorder and a large variation in basis weight, but as shown in FIG. Since the surface obtained by dividing the yarn prepreg 2 in the fiber direction is vertical, the portions 4 corresponding to the end portions of the yarn prepreg 2 before the division are integrated with each other to form a narrow prepreg 5. By making the surface obtained by dividing the end portion of the narrow prepreg 5 into a narrow width, the width of the narrow prepreg 5 becomes uniform, and the fiber orientation disorder and the basis weight variation at the end are reduced. As a result, when the tape layup is performed using the narrow prepreg manufactured by the method of the present invention, a gap is hardly generated between the arranged narrow prepregs, or the basis weight variation of the obtained laminate is less likely to occur. Compared to slit tape, there is no need to wind up a wide prepreg once manufactured, unwind it, or cut it into a desired width in several stages, and the yarn prepreg downstream of the yarn prepreg manufacturing process. It is only necessary to add a step of dividing the yarn, and it can be manufactured at a cost equivalent to the yarn prepreg.

  Further, in the method for producing a narrow prepreg according to the present invention, it is preferable to cut a substantially central portion of the yarn prepreg in the fiber direction and divide the yarn prepreg into two in the fiber direction to obtain divided prepregs. By cutting the approximate center of the yarn prepreg in the fiber direction so that the portions corresponding to the ends of the yarn prepreg before splitting are integrated into a narrow prepreg, the approximate center of the narrow prepreg Since the portions corresponding to the end portions of the yarn prepreg, which tend to include disorder of fiber orientation and variation in basis weight, are bonded to each other, the influence on the end portions of the narrow prepreg is small, and the width accuracy is easily stabilized.

  In the manufacturing method of the narrow prepreg of the present invention, when the portions corresponding to the end portions of the yarn prepreg before splitting are integrated with each other, the portions corresponding to the end portions of the yarn prepreg before splitting are overlapped. It is preferable to fuse the divided prepregs. The parts corresponding to the ends of the yarn prepregs before splitting may be bonded together, but generally the yarn prepregs have a smaller amount of fiber toward the ends, so by overlapping them together, the narrow prepreg It becomes easy to make the basis weight uniform.

  In the method for producing a narrow prepreg of the present invention, as means for integrating the portions corresponding to the ends of the yarn prepreg before splitting into a narrow prepreg, the split prepregs derived from the same yarn prepreg are respectively twisted. It is preferable to fuse the portions corresponding to the end portions of the yarn prepreg before division. The ends of the yarn prepregs before splitting are made by rotating the split prepregs divided from the same yarn prepreg 180 degrees in the same direction or in the opposite direction to match the yarn path of the yarn prepreg and the narrow prepreg. Face each other, can be fused and integrated. Alternatively, in order to simplify the rotating mechanism of the split prepreg, as shown in FIG. 3, the split prepreg 3 is rotated by 90 degrees in the same direction or in the opposite direction, respectively, and the yarn path rotated 90 degrees from the yarn path of the yarn prepreg 2 The locations corresponding to the end portions of the yarn prepreg 2 before division may be fused and integrated.

  As another preferred means, it is also preferable to cross the divided prepregs derived from the same yarn prepreg and fuse the portions corresponding to the end portions of the yarn prepreg before the division. In this case, as shown in FIG. 4, the yarn paths of the divided prepreg 3 are divided into upper and lower parts, crossed left and right, and the portions corresponding to the ends of the yarn prepreg 2 before division face each other, and are fused and integrated. Good.

  As another preferred means, a large number of yarn prepregs 2 arranged in parallel as shown in FIG. 5 are divided in the fiber direction into divided prepregs 3, and adjacent divided prepregs 3 derived from different yarn prepregs 2 are separated. It is also preferable to fuse the portions corresponding to the end portions of the yarn prepreg 2 before division. The rotating mechanism and the crossing mechanism of the divided prepregs are not required, the adjacent divided prepregs are aligned, and the portions corresponding to the end portions of the yarn prepregs before the division can be fused together, thereby simplifying the process. Of the divided prepregs divided from the yarn prepregs arranged in large numbers, the ones located at both ends do not have adjacent divided prepregs, so they may be discarded. It may be a width prepreg.

  In the method for producing a narrow prepreg according to the present invention, when the portions corresponding to the ends of the yarn prepreg before splitting are integrated with each other in the split prepreg, the split prepreg is heated and fused, and then immediately pressurized and cooled. To be integrated. Furthermore, by forming the cross-section of the narrow prepreg into a rectangular shape at the time of pressurization and cooling, not only the width accuracy of the narrow prepreg but also the location where the portions corresponding to the end portions of the yarn prepreg before splitting are fused together Unevenness in thickness can be eliminated. Specifically, it is preferable to pass through a grooved roll or a slit die. In addition, regarding the rectangular shape described here, as long as the width accuracy of the narrow prepreg can be improved and the thickness unevenness of the fused portion can be eliminated, a part of the rectangle is deformed (curved portion exists). Or the opposite sides are not parallel).

  The method for producing a narrow prepreg of the present invention includes impregnating a resin at the same time or after the fiber bundle is divided and reintegrated, in addition to dividing and reintegrating the fiber bundle after impregnating the resin with the resin. It doesn't matter. That is, a fiber bundle in which the fibers are aligned in one direction is divided into fiber directions to form a split fiber bundle, and the portions corresponding to the ends of the fiber bundle before splitting are integrated into an integrated fiber bundle. Then, at the same time or after that, the resin may be impregnated to form a narrow prepreg. When the dividing means is a rotary cutter or the like, cutting the fiber bundle not impregnated with the resin has less resistance than the yarn prepreg, and it is not necessary to worry about the adhesion of the resin. . In this case, the configurations corresponding to the respective symbols in FIGS. 1 to 5 are 2: fiber bundle, 3: split fiber bundle, 4: end of split fiber bundle before split, and 5: integrated fiber bundle. (1, 6, 7 are the same).

  Furthermore, it is preferable to cut the substantially central portion of the fiber bundle in the fiber direction and divide the fiber bundle into two in the fiber direction to obtain a divided fiber bundle. Further, when integrating the portions of the split fiber bundle corresponding to the end portions of the fiber bundle before splitting, the portions corresponding to the end portions of the fiber bundle before splitting are overlapped, and the split fiber bundles are combined. It is preferable to integrate them.

  As means for integrating the portions corresponding to the ends of the fiber bundle before splitting into an integrated fiber bundle, the split fiber bundles derived from the same fiber bundle are respectively twisted at the end of the fiber bundle before splitting It is preferable to integrate corresponding portions. By rotating the divided fiber bundles divided from the same fiber bundle by 180 degrees in the same direction or in the opposite direction, the fiber path of the fiber bundle and the thread path of the integrated fiber bundle are made to coincide with each other. The ends face each other and can be integrated. Alternatively, in order to simplify the rotating mechanism of the split fiber bundle, the split fiber bundle is rotated only 90 degrees in the same direction or in the opposite direction, and the fiber bundle before splitting is performed on the yarn path rotated 90 degrees from the yarn path of the fiber bundle. Locations corresponding to the end portions may be integrated. As another preferable means, it is also preferable to cross the split fiber bundles derived from the same fiber bundle and to integrate the portions corresponding to the end portions of the fiber bundle before splitting. In this case, the yarn paths of the split fiber bundles may be divided into upper and lower parts, crossed left and right, and the portions corresponding to the ends of the fiber bundles before splitting face each other and integrated. Still another preferable means is to split a large number of fiber bundles arranged in parallel in the fiber direction into split fiber bundles, and end portions of fiber bundles before splitting of adjacent split fiber bundles derived from different fiber bundles It is also preferable to integrate the portions corresponding to. Without the need for a rotating mechanism or a crossing mechanism for split fiber bundles, the adjacent split fiber bundles can be aligned and the portions corresponding to the ends of the fiber bundles before splitting can be fused together, simplifying the process. . More preferably, immediately after impregnating the integrated fiber bundle with the resin, pressurization and cooling are performed to form a cross section of the narrow prepreg into a rectangular shape.

  The width of the narrow prepreg produced by the method of the present invention is preferably narrow from the viewpoint of followability to complex shapes, but is preferably wide from the viewpoint of stacking efficiency, and is preferably in the range of 1 to 150 mm. It is. The width accuracy is preferably 0.1 mm or less, and by using the narrow width prepreg, a high-quality laminate having substantially no gap between fibers and small basis weight variation can be formed. In the present invention, the width accuracy indicates a standard deviation.

  Examples of the fiber bundle used in the present invention include organic fibers such as aramid fibers, polyethylene fibers, polyparaphenylene benzoxador (PBO) fibers, glass fibers, carbon fibers, silicon carbide fibers, alumina fibers, tyrano fibers, and basalts. Examples thereof include inorganic fibers such as fibers and ceramic fibers, metal fibers such as stainless fibers and steel fibers, and other reinforcing fibers using boron fibers, natural fibers, modified natural fibers and the like as fibers. Among them, carbon fiber is particularly lightweight among these reinforcing fibers, and has particularly excellent properties in specific strength and specific modulus, and also has excellent heat resistance and chemical resistance. It is suitable for aircraft members where mechanical properties and weight reduction are desired. Among these, PAN-based carbon fibers that can easily obtain high-strength carbon fibers are preferable. When carbon fibers are used for the fiber bundle, the number of carbon fibers is preferably 3000 to 50000 in order to make the width of the narrow prepreg 1 to 150 mm.

  Examples of the matrix resin used in the present invention include an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a phenol resin, an epoxy acrylate resin, a urethane acrylate resin, a phenoxy resin, an alkyd resin, a urethane resin, a maleimide resin, and a cyanate resin. Thermosetting resin, polyamide, polyacetal, polyacrylate, polysulfone, ABS, polyester, acrylic, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene, polypropylene, polyphenylene sulfide (PPS), polyether ether Examples include ketones (PEEK), liquid crystal polymers, vinyl chloride, fluorine resins such as polytetrafluoroethylene, and thermoplastic resins such as silicone. Among these, it is particularly preferable to use a thermosetting resin. Since the matrix resin is a thermosetting resin, the prepreg has tackiness at room temperature. Therefore, when the prepreg is laminated, the prepreg is integrated with the upper and lower prepregs to maintain the laminated structure as intended. It can be shaped as it is. When a thermosetting resin is used as the matrix resin, the fiber content of the narrow prepreg is preferably 55 to 70%. Since the thermosetting resin has a relatively low viscosity, a high fiber content can be achieved, and high mechanical properties can be expected. On the other hand, when a thermoplastic resin having no tackiness at room temperature is used as the matrix resin, a heating device is separately required for lamination and fixing. Thermoplastic resins have a relatively high viscosity, so if a prepreg with a very high fiber content is produced, it is likely that fiber turbulence or unimpregnation will occur, and the mechanical properties may deteriorate, and the fiber content from that viewpoint. Is preferably 45 to 60%.

  The narrow prepreg of the present invention thus obtained has high followability to complicated shapes, and can be of high quality when it is made of fiber reinforced plastic. In addition, the use of fiber reinforced plastics molded using the narrow prepreg of the present invention is required for strength, rigidity and light weight, such as skins, spars, stringers, and other fuselage, wing primary structural materials, window frames and flaps. Secondary aircraft components, aircraft engine components such as fan blades, automobile floors and panels. In particular, it can be preferably applied to an aircraft wing skin material that requires strength and light weight as well as followability to a three-dimensional shape.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the inventions described in the examples.

<Creating a yarn prepreg>
Using a carbon fiber bundle as the fiber bundle and an epoxy resin composition as the resin, the fiber bundle was impregnated with a resin by the hot melt method described below to prepare a yarn prepreg. As the carbon fiber, “Torayca (registered trademark)” T700SC-24K-50C (Toray) was used. The tensile strength is 4900 MPa, the tensile elastic modulus is 230 GPa, the density is 1.8 g / cm ³ , and the number of filaments is 24,000. The epoxy resin composition includes 20 parts of “jER (registered trademark)” 828 (Japan epoxy resin), 45 parts of “jER (registered trademark)” 1001 (Japan epoxy resin), and “jER (registered trademark)”. "154 (Japan Epoxy Resin) 35 parts," jER Cure (registered trademark) "DICY7 (Japan Epoxy Resin) 3.5 parts as a curing agent, DCMU99 (Hodogaya Chemical Co., Ltd.) 4 parts were kneaded. It was supposed to be.

  Yarn prepreg manufacturing equipment includes: creel for feeding fiber bundles, widening bar for opening fiber bundles, preheater, kiss roll with 10 mm wide groove for impregnation with resin, drawing (impregnation) roll, take-up roll and take-up roll A winder is provided, and a fiber bundle is passed in advance to make a yarn path. The resin is separately adjusted to a temperature of 80 ° C. with a hot air oven and supplied to the grooved kiss roll with a diaphragm tube pump. A scraping blade was installed in the kiss roll section, the cap of the kiss roll and the blade was set to 0.15 mm, and the Vf (fiber volume content) of the obtained yarn prepreg was set to a target of 60%. The fiber bundle sent out from the bobbin is heated through a preheater adjusted to a temperature of 90 ° C., and then passes through the groove portion of the kiss roll supplied with the resin, so that the resin is supplied. Next, the resin is impregnated into the fiber bundle by passing through a squeeze roll to which hot air having a temperature of 80 ° C. is applied. Finally, after passing the take-up roll, it was wound up with a winder to obtain a yarn prepreg bobbin. The line speed was 10 m / min.

<Flat plate forming method>
A yarn prepreg or a narrow prepreg is cut out to a length of 300 mm, and laminated at [0/90] _{2 s} in an area of 300 × 300 mm at intervals of 10 mm while being aligned in one direction. The 300 mm square laminate thus obtained was placed on a tool plate, sealed with a flexible film, and then deaerated by sucking between the tool plate and the flexible film with a vacuum pump. After being installed in, a flat molded body was obtained by holding at a temperature atmosphere of 125 ° C. for 2 hours under a pressure of 0.3 MPa.

Example 1
In order to demonstrate the effect of the present invention, instead of providing a processing step for directly converting the narrow prepreg downstream of the manufacturing process of the yarn prepreg, the yarn prepreg was prepared in advance by the above-described yarn prepreg preparation method and wound around a bobbin. Thereafter, the yarn prepreg unwound from the bobbin was processed to prepare a narrow prepreg.

  While the yarn prepreg bobbin was creeled and the yarn prepreg was fed out, the center portion of the yarn prepreg was cut using a disk cutter to obtain two divided prepregs. Each split prepreg is rotated 180 degrees clockwise through the roll toward the downstream side of the yarn path, and the portions corresponding to the ends of the yarn prepreg before splitting are overlapped with each other in warm air of 80 ° C. Next, it was passed through a room temperature slit die having a gap width of 10 mm and a height of 0.15 mm, and the divided prepregs were fused together and pulled out while forming into a rectangular cross section. Finally, it was wound around a winder via a take-up roll. It was confirmed that a processing step into a narrow prepreg can be provided downstream of the yarn prepreg manufacturing process by setting the line speed to 10 m / min, which is the same as that of the yarn prepreg manufacturing.

  The quality of the narrow prepreg thus obtained was good, and no irregularities were found in the central part which is the joint surface of the divided prepreg. When the width of the narrow prepreg was measured at 20 points every 100 mm in the longitudinal direction, an average of 10.0 mm and a standard deviation of 0.07 mm were obtained.

  Next, using the above flat plate forming method using a narrow prepreg, a flat plate shaped body was obtained. When the molded body was placed on a flat test bench, it was in contact with the entire surface and there was no warpage. The seam in which the narrow tape was aligned was not visually confirmed, and the surface quality was good.

(Example 2)
In order to demonstrate the effect of the invention, instead of providing a processing step for narrow width prepreg directly downstream of the manufacturing process of the yarn prepreg, a yarn prepreg is prepared in advance by the above-described method for producing a yarn prepreg and wound around five bobbins. After that, the yarn prepregs unwound from each bobbin were drawn and processed to form a narrow prepreg.

  Five bobbins of yarn prepreg were applied to the creel and aligned in the width direction while sending out the yarn prepreg. Each yarn prepreg is cut using a disk-shaped cutter to form two divided prepregs, and the portions corresponding to the divided prepregs derived from adjacent different yarn prepregs and the ends of the yarn prepregs before the division overlap each other. In this state, it was exposed to warm air of 80 ° C., then passed through a grooved kiss roll with a groove width of 10 mm and a height of 0.15 mm, fused the divided prepregs, and pulled out while forming into a rectangular cross section. . Finally, it was wound around a winder via a take-up roll. It was confirmed that a processing step into a narrow prepreg can be provided downstream of the yarn prepreg manufacturing process by setting the line speed to 10 m / min, which is the same as that of the yarn prepreg manufacturing. When ten divided prepregs were formed from the five yarn prepregs, the two divided prepregs positioned at both ends were wound up with a winder as they were and were not processed into narrow prepregs.

  The four narrow prepregs thus obtained had good quality, and no unevenness was observed at the central portion which is the joint surface of the divided prepreg. When the width of the four narrow prepregs was measured at 80 points in total in the longitudinal direction at 20 points every 100 mm, an average of 10.0 mm and a standard deviation of 0.04 mm were obtained.

  Next, using the above flat plate forming method using a narrow prepreg, a flat plate shaped body was obtained. When the molded body was placed on a flat test bench, it was in contact with the entire surface and there was no warpage. The seam in which the narrow tape was aligned was not visually confirmed, and the surface quality was good.

(Example 3)
The bobbin of the T700S-24K-50C fiber bundle is creeled and opened through a widening bar while feeding the fiber bundle, and then the central part of the fiber bundle is cut using a disk-shaped cutter to obtain two split fibers. It was a bunch. The split fiber bundles are divided into upper and lower parts, two rolls rotated clockwise by 5 degrees toward the downstream of the yarn path, the upper split fiber bundle is on the roll, and the lower split fiber bundle is the other roll. It is divided into upper and lower via the bottom, crossed right and left, and integrated by pressing through a grooved roll with a width of 10 mm in a state where the portions corresponding to the ends of the fiber bundle before division are overlapped, and integrated fiber It was a bunch. Next, the integrated fiber bundle is heated through a preheater adjusted to a temperature of 90 ° C., and then passed through a grooved kiss roll supplied with the epoxy resin composition adjusted to a temperature of 80 ° C. in a hot air oven. By setting the cap of the scraping blade and the kiss roll to 0.15 mm, the Vf of the obtained narrow prepreg was set as a target of 60%. Further, the resin was impregnated into the inside of the fiber bundle by passing through a squeeze roll to which hot air having a temperature of 80 ° C. was applied. Finally, after passing through the take-up roll, it was wound up with a winder to obtain a narrow prepreg bobbin. The line speed was 10 m / min for both the step of dividing the fiber bundle and the step of impregnating the resin.

  The quality of the narrow prepreg thus obtained was good, and no irregularities were found in the central part which is the joint surface of the divided prepreg. When the width of the narrow prepreg was measured at 20 points every 100 mm in the longitudinal direction, an average of 10.0 mm and a standard deviation of 0.10 mm were obtained.

  Next, using the above flat plate forming method using a narrow prepreg, a flat plate shaped body was obtained. When the molded body was placed on a flat test bench, it was in contact with the entire surface and there was no warpage. The seam in which the narrow tape was aligned was not visually confirmed, and the surface quality was good.

(Comparative Example 1)
The cross section of the yarn prepreg produced by the above method for producing a yarn prepreg was elliptical, bulky at the center and thin at the end. Vf confirmed by cross-sectional observation was 62%, which was slightly higher than the target value. When the width of the yarn prepreg was measured at 20 points every 100 mm in the longitudinal direction, an average of 10.2 mm and a standard deviation of 0.61 mm were obtained.

  Next, a flat molded body was obtained by using the above-described flat plate forming method using a yarn prepreg. When the molded body was placed on a flat test table, a warp that did not contact the entire surface was confirmed unless the molded body was pressed against the test table from the upper surface of the molded body with a finger. In addition, the seams where the yarn prepregs were aligned were visually confirmed, and the pattern was raised in a lattice pattern along the seams of the respective layers. The seam was resin rich and some sink marks were observed.

1: Fiber aligned in one direction 2: Yarn prepreg 3: Divided prepreg 4: End of yarn prepreg before dividing 5: Narrow prepreg 6: Roll 7: Disc cutter

Claims (10)

A yarn prepreg obtained by impregnating a fiber bundle in which fibers are aligned in one direction is impregnated with a resin to divide the fiber prepreg into divided prepregs, and the portions of the divided prepreg corresponding to the end portions of the yarn prepreg before division A method for producing a narrow-width prepreg, in which the two are integrated into a narrow-width prepreg. When the portions corresponding to the ends of the yarn prepreg before the division of the divided prepreg are integrated, the portions corresponding to the ends of the yarn prepreg before the division are overlapped to melt the divided prepregs. The manufacturing method of the narrow prepreg of Claim 1 made to wear. When integrating the portions corresponding to the ends of the yarn prepreg before the division of the divided prepreg, the divided prepreg is heated and fused, and immediately after pressing and cooling, the cross section of the narrow prepreg is reduced. The manufacturing method of the narrow prepreg of Claim 1 or 2 shape | molded in a rectangular shape. A fiber bundle in which fibers are aligned in one direction is divided in the fiber direction to form a split fiber bundle, and the portions of the split fiber bundle corresponding to the end portions of the fiber bundle before splitting are integrated to form an integrated fiber bundle Then, at the same time or thereafter, a method for producing a narrow prepreg in which a resin is impregnated to form a narrow prepreg. When the portions corresponding to the end portions of the fiber bundle before splitting are integrated with each other, the portions corresponding to the end portions of the fiber bundle before splitting are overlapped with each other, and the split fiber bundles are overlapped with each other. The manufacturing method of the narrow prepreg of Claim 4 which integrates. The method for producing a narrow prepreg according to claim 4 or 5, wherein the integrated fiber bundle is pressurized and cooled immediately after impregnating the resin with the resin to form a cross section of the narrow prepreg into a rectangular shape. The width | variety of the said narrow prepreg is in the range of 1-150 mm, and the manufacturing method of the narrow prepreg in any one of Claim 1 to 6 whose width accuracy is 0.1 mm or less. The method for producing a narrow prepreg according to any one of claims 1 to 7, wherein the fiber bundle is a carbon fiber, and the number of the carbon fibers is 3000 to 50000. The method for producing a narrow prepreg according to any one of claims 1 to 8, wherein the resin is an epoxy resin, and the fiber content of the narrow prepreg is 55 to 70%. A fiber reinforced plastic obtained by molding a narrow prepreg produced by the method according to claim 1.