JP2007118598A - Method and apparatus for manufacturing preform - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for manufacturing a preform, which prepares a preform never spoiling the physical characteristics and quality of a large composite molded article, with simple facilities. <P>SOLUTION: The method and apparatus for manufacturing a preform is characterised by followings (A)-(D); that is, a setting process or means for a fiber laminate (A) of arranging a tool on a tool plane and arranging a fiber laminate on the tool; a setting process or means for a sheet (B) of arranging a sheet formed in the development with respect to the tool on the upper side of the fiber laminate so that the development region practically overlaps a face of the tool corresponding to it; a fixing process or means for a sheet (C) of fixing the end part of the sheet to a position where the sheet does not come into close contact with a corner part formed by the tool and the tool plane when the fiber laminate is laid along the shape of the tool by applying a pressure to the fiber laminate through the sheet; and a pressure applying process or means (D) of applying a pressure to the fiber laminate through the sheet. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a fiber laminate used when a structure made of fiber reinforced plastic (hereinafter simply referred to as FRP) is produced by the Resin Transfer Molding method (hereinafter simply referred to as RTM method), Resin Film Infusion method or the like ( Hereinafter, it is simply referred to as a preform). More specifically, for example, preforms used for forming stringers and ribs of aircraft wings that serve as reinforcing members for FRP skin panels that are structural members of aircraft, ships, and automobile members, and stiffeners and ribs for reinforcing ship bottoms. In a manufacturing method, the present invention relates to a preform manufacturing method capable of realizing a shortening of manufacturing time by batch forming of preforms and improvement of dimensional accuracy and quality of the preform.

  Conventionally, for example, RTM molding methods have been widely adopted in molding methods of composite material structural members such as aircraft, automobiles, ships, and buildings because they are excellent in terms of productivity and manufacturing cost. The so-called Vacuum-Assisted Resin Transfer Molding (vacuum RTM molding) method, in which the fiber laminate is sealed with a bag material and injected with a matrix resin in a state of being sucked under reduced pressure, has become the mainstream.

  RTM molding is characterized in that after preparing a preform in which a fiber laminate formed by previously laminating a reinforcing fiber substrate is shaped into a final product shape, a matrix resin is injected into the preform and cured. For this reason, a preform process for shaping the fiber laminate into the final product shape is necessary, and the shape and quality of the final product largely depend on the shape of the preform, so the preform process is a very important process. .

  When forming a fiber laminate into a three-dimensional shape, wrinkles are likely to occur in the preform, so the reinforcing fiber base material may be formed one by one. There are problems such as taking a long time. Therefore, it is required to collectively shape a fiber laminate obtained by previously laminating a reinforcing fiber base based on a predetermined lamination configuration into a final product shape.

  As a conventional method of obtaining a three-dimensional shape preform such as a C shape from a fiber laminate, a plurality of fiber laminates are placed in a jig having a desired shape and then collectively covered with a bag material. There is a method in which heating is performed while pressing the fiber laminate against a jig at atmospheric pressure (see, for example, Patent Document 1). Although this method of simply using vacuum pressure is excellent in terms of work efficiency, the direction and sequence of pressurization cannot be controlled, so the difference in circumference between the inside and outside of the bend is alleviated. There is a problem that the sliding between the base materials does not occur smoothly and wrinkles and sagging occur at the corners of the bending. When molding is performed using a preform having wrinkles or sagging, there is a high possibility that the surface of the molded product will be wrinkled or that the quality will be deteriorated such as a resin-rich layer or void in the sagging portion. .

As another technique for obtaining a three-dimensional shape preform, a method of making a preform having a predetermined shape by placing a fiber laminate on a female jig and pushing the male jig into the female mold has been proposed. (For example, refer to Patent Document 2). However, this method also causes the base material to shift or wrinkles when the male mold is pushed into the female mold. In addition, since a double-sided mold is required, there is a problem that the cost of the mold equipment is increased in order to prepare a preform for a large molded product such as an aircraft main wing member.
JP 2004-216805 A JP-A-6-155383

  The object of the present invention is to solve such conventional problems, and by forming a fiber laminate in a simple manner with simple equipment, the quality such as wrinkles and sagging is not impaired, and excellent mechanical properties It is an object of the present invention to provide a preform manufacturing method and a manufacturing apparatus capable of obtaining a fiber reinforced plastic having the following.

In order to achieve the above object, the present invention adopts the following configuration. That is,
(1) A method for producing a preform, comprising at least the following steps (A) to (D).
(A) A step of setting a fiber laminate in which a jig is arranged on the tool surface and a fiber laminate is arranged thereon.
(B) Sheet setting step in which a sheet formed in a developed view shape of the jig is arranged on the upper side of the fiber laminate so that a development reference area of the sheet substantially overlaps a corresponding surface of the jig. .
(C) When a pressure is applied to the fiber laminate through the sheet, the sheet does not adhere to the corner formed by the jig and the tool surface when the fiber laminate is made to conform to the shape of the jig. A sheet fixing step of fixing the end of the sheet to a position.
(D) A pressure application step of applying pressure to the fiber laminate through the sheet.

  (2) In the pressure applying step (D), first, after applying pressure to the development reference area of the sheet, the pressure application area is expanded toward the development end of the sheet (1) ) A method for producing a preform according to the above.

  (3) In the sheet fixing step (C), the position for fixing the end of the sheet is set on a line obtained by translating the contour line of the jig formed by the tool surface and the jig in the normal direction. The method for producing a preform according to any one of (1) and (2) above.

  (4) The method for producing a preform according to any one of (1) to (3), wherein the elongation of the sheet is in the range of 0.002% to 30%.

  (5) The method for producing a preform according to any one of (1) to (4), wherein a resin material is included between layers of the fiber laminate.

  (6) The plug according to any one of (1) to (5) above, wherein pressure is applied to the fiber laminate through a sheet by covering the fiber laminate with a bag material and evacuating it. Reform manufacturing method.

  (7) The preform according to any one of (1) to (6), wherein in the pressure application step (D), at least the fiber laminate is heated within a range of 40 ° C. to 180 ° C. Manufacturing method.

  (8) The method for producing a preform according to any one of (1) to (7), wherein the sheet has releasability with respect to the fiber laminate.

  (9) The preform obtained by the method for producing a preform according to any one of (1) to (8), wherein the reinforcing fiber volume content Vpf of the preform is 35% to 65%. .

  (10) A fiber-reinforced plastic molded article having a reinforcing fiber volume content Vf in the range of 40% to 72% obtained by injecting, impregnating and curing the matrix resin into the preform according to (9).

(11) A preform manufacturing apparatus comprising at least the following means (A) to (D).
(A) A fiber laminate setting means comprising a tool for placing a jig, a jig placed on the tool surface, and a fiber laminate placed on the upper surface of the jig.
(B) a sheet formed in a developed view shape of the jig disposed on the upper side of the fiber laminate, and the sheet has a developed reference area substantially overlapping a corresponding surface of the jig. Sheet setting means arranged in such a manner.
(C) When a pressure is applied to the fiber laminate through the sheet, the sheet does not adhere to the corner formed by the jig and the tool surface when the fiber laminate is made to conform to the shape of the jig. A sheet fixing means for fixing the end of the sheet to a position.
(D) Pressure applying means for applying pressure to the fiber laminate through the sheet.

  By adopting the above configuration, the present invention can suppress wrinkles, sagging, and the like by batch forming the fiber laminate with simple equipment, and can obtain a preform having excellent quality.

  Hereinafter, the preform manufacturing method and manufacturing apparatus of the present invention will be described in more detail with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view for explaining a preform manufacturing method and manufacturing apparatus according to the present invention, and FIG. 2 is a perspective view of FIG.

  The preform manufacturing method and manufacturing apparatus according to the present invention includes an upper side of a jig 4 having a desired shape in which a fiber laminate 1 made of a reinforcing fiber substrate 2 such as carbon fiber or glass fiber is set on the surface of a tool 5. And the sheet 3 formed in the shape of the developed view of the jig 4 from above is arranged so that the developed reference area of the sheet 3 substantially overlaps the corresponding surface of the jig 4, and the fiber laminate Even after pressurizing 1 and conforming to the shape of the jig 4, the fixing portion 6 on the tool 5 surface is placed at a position where the sheet 3 does not adhere to the corner portion 7 formed by the jig 4 and the tool 5 surface. Then, the preform is manufactured by applying pressure to the entire fiber laminate 1 through the sheet 3 so as to have a desired shape.

That is, the preform manufacturing method and manufacturing apparatus of the present invention includes at least the following steps (A) to (D) or means.
(A) A fiber laminated body setting step or means for arranging the fiber laminated body on the upper side of the jig arranged on the tool surface.
(B) a sheet setting step in which a sheet formed in a developed view shape of the jig is arranged on the upper side of the fiber laminate so that a development reference area of the sheet substantially overlaps a corresponding surface of the jig; means.
(C) When a pressure is applied to the fiber laminate through the sheet, the sheet does not adhere to the corner formed by the jig and the tool surface when the fiber laminate is made to conform to the shape of the jig. A sheet fixing step or means for fixing the end of the sheet to a position.
(D) A pressure applying step or means for applying pressure to the fiber laminate through the sheet.

  In the process or means of (A) above, the tool 5 is formed in a flat mold for placing the jig 4, and the jig 4 is for shaping the fiber laminate 1 into a desired shape. It is preferably made of metal, synthetic resin, GFRP, or CFRP, which is a material that is formed into a desired three-dimensional solid shape and does not undergo plastic deformation due to the pressure applied in the pressure applying step described later.

  The fiber laminate 1 is obtained by laminating a plurality of reinforcing fiber substrates 2. The number of stacked layers is not particularly limited. Since the number of layers can be formed in a lump, the larger the number, the higher the efficiency and the effect of the present invention. Carbon fibers, aramid fibers, and glass fibers are preferable as the reinforcing fibers of the reinforcing fiber base 2, but the form of the reinforcing fibers varies depending on the use of the woven fabric, the unidirectional base material, etc., depending on the FRP to be molded. The same applies to various characteristic values such as basis weight, fiber fineness, and elastic modulus.

  Moreover, it is preferable that the base material is joined via the resin material containing a thermoplastic resin from a viewpoint of handleability. Since the substrates are joined and integrated, the transportability when placing the fiber laminate 1 on the jig is improved, and the preform failure due to the displacement or dropping of the substrate during shaping is prevented. be able to. In addition, the strength and distribution of the joint can be selected as appropriate, satisfying the handleability, and reducing the difference between the inner circumference and the outer circumference when the fiber laminate 1 is shaped. If the sliding between materials occurs smoothly, it will not be specifically limited.

  In the process or means of (B) above, the sheet 3 formed in the developed view shape of the jig 4 is (1) a jig shape development area in which the surface constituting the three-dimensional shape of the jig 4 is developed on a plane. (The surface to be developed can be selected as appropriate depending on the shape to be shaped), and (2) refers to a sheet having a shape having two regions: a region covering the surface of the tool 5.

  The jig shape development region is particularly limited as long as the sheet can be in close contact with the fiber laminate in the surface pressure applying step described later and is not in close contact with the corner portion formed of the jig and the tool surface when the surface pressure is applied described later. The surface and the part to be developed can be appropriately selected. Further, when the shaping shape of the jig and the preform is different, the surface constituting the preform shape may be developed on a plane to form a jig shape development region. Further, the jig shape development region may be formed by joining a plurality of planes when the jig shape is complicated and cannot be developed on the same plane.

  The shape of the region covering the tool surface is not particularly limited as long as the shape can be fixed to a fixing position of the sheet described later.

  In addition, the sheet development reference region refers to the jig 4 and the fiber laminate 1 that are in contact with each other when the fiber laminate 1 is disposed on the jig 4 in the fiber laminate 1 setting step or means in (A). This is the area of the sheet corresponding to the surface (in FIG. 1, the upper surface portion of the jig). Here, the sheet development reference area substantially overlaps the corresponding surface of the jig 4 when each surface is deformed so as to conform to the shape of the jig 4 in the pressure application step (D). Is a state in which the development reference region and the center position and direction of the corresponding surface of the jig 4 coincide with each other without resistance, and the deviation is usually within 0 to 20 mm and within 0 to ± 10 °. If you can, you can get this.

  By using the sheet 3 formed in the shape of the developed view of the jig 4, in the pressure applying step (D), the sheet 3 can be in close contact with the fiber laminate 1 without a gap. The force can be transmitted to the body 1 without hesitation, and as a result, a preform without wrinkles can be obtained.

  In addition, the sheet 3 used in the present invention is not stretched when pressure is applied in the step (C), and is required not to be in close contact with the corner portion 7 composed of the jig 4 and the tool 5 surface, and therefore has low stretchability. Those are preferred. Therefore, the elongation of the material used for the sheet 3 is preferably in the range of 0.002% to 30%, and more preferably in the range of 0.002% to 10%. When the elongation is less than 0.002%, the elongation is too small, and it is difficult to form a complex shape, which is not preferable. On the other hand, if it is larger than 30%, the sheet 3 itself is stretched when a pressure is applied, so that the force for closely adhering and shaping the fiber laminate 1 to the jig 4 cannot be fully expressed.

  Here, the elongation of the sheet refers to a value measured according to JIS L1096-6 (tensile strength and elongation). Specifically, first, the sheet is cut so as to have a width of 5 cm and a length of 30 cm to obtain a test piece. Next, the test piece was held with a tensile tester so that the holding interval was 20 cm, the test was performed at a pulling speed of 30 cm / min, and the elongation at the time of cutting was measured. The elongation is calculated by the following formula and expressed as an average value of five measurements.

  As a specific material of the sheet 3, a glass cloth, an aramid cloth, a thin plate such as a metal, or the like can be used.

  Furthermore, the sheet 3 used in the present invention preferably has releasability from the fiber laminate 1. When the sheet 3 applies pressure to the fiber laminate 1, the sheet 3 directly contacts the fiber laminate 1. Since there exists a possibility of degrading the quality of the fiber laminated body 1 when removing from the laminated body 1, it is not preferable. In particular, when the reinforcing fiber base material 2 has a thermoplastic resin or a thermosetting resin or both on the surface of the base material for the purpose of improving handleability by interlayer reinforcement or tackiness, a sheet Since 3 adheres closely to the fiber laminate 1, the sheet 3 is required to have releasability.

  Specifically, the surface of the above glass cloth, aramid cloth, metal thin plate, etc. is made of PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PFA (tetrafluoroethylene perfluoroalkyl). It is preferable that a fluororesin such as vinyl ether copolymer) or ETFE (ethylene tetrafluoroethylene copolymer) is coated.

  The fixing part 6 of the sheet 3 in the step (C) or means will be described with reference to FIG. The fixing portion 6 of the sheet 3 is positioned so that the sheet 3 does not adhere to the corner portion 7 formed on the surface of the jig 4 and the tool 5 even after the fiber laminate 1 is pressed and conformed to the shape of the jig 4. . Moreover, the corner part 7 here means the part formed in the lower part and the tool 5 surface rather than the product part of the jig | tool 4. As shown in FIG. By setting the fixing portion 6 as described above, at the corner portion 7, the sheet does not adhere to the fiber laminate 1 or the jig, that is, no pressure is applied to the fiber laminate 1. By not bringing the sheet 3 into close contact with the corner portion 7, when a pressure is applied, a force F is generated such that the pressure applied to the portion A causes the sheet 3 and the fiber laminated body 1 to slide downward. When this force F acts, tension is applied to the fiber laminate 1 in the downward direction via the sheet during shaping. The action of the downward force F is one of the conditions for obtaining a preform free of defects such as wrinkles, which will be described below with reference to FIG. When pressure is applied to the fiber laminate 1, the plate thickness is reduced, whereby the circumference of the corner R portion of the fiber laminate 11 after pressure application is shorter than that of the fiber laminate 1 before pressure application. . If this shortened circumferential length difference is left without being relaxed, it will lead to wrinkles, but as shown in the figure, the downward force F continues to act on the fiber laminate, so this circumferential length difference Becomes easy to escape to the end, and as a result, a preform without wrinkles can be obtained.

  4 is a view of the jig 4, the tool 5, and the fixing part 6 of FIG. 3 as viewed from directly above. The position of the fixing part 6 for fixing the end of the sheet 3 is the surface of the tool 5 and the jig. 4 is preferably set on a line translated in the normal direction.

  If the fixing portion 6 is not located at a position set on a line obtained by translating the contour line 8 of the jig 4 formed by the surface of the tool 5 and the jig 4 in the normal direction, the sheet 3 and the fiber laminate 1 are not positioned. A gap or a portion that cannot be covered by the sheet 3 appears. If there is a gap or a portion that cannot be covered between the sheet 3 and the fiber laminate 1, a portion where pressure cannot be applied via the sheet 3 when pressure is applied is generated, which causes the occurrence of shape defects such as wrinkles. Become. Further, the translated line may have a range of a deviation angle α °, and the specific α ° is preferably within ± 10 °, more preferably, because the above-described effect is easily obtained. It is within ± 5 °, more preferably within ± 3 °.

  The fixing method of the sheet 3 is not limited as long as the fixing does not come off during the pressure application, but the sheet fixing using adhesive force such as a tape, the sheet fixing with a magnet, and mechanically applying pressure A method of fixing a sheet with a pin or the like, a method of fixing a magnet sheet and a mold by a magnetic force, or a combination of these methods is preferably used.

  In the step (D) or means, as shown in FIG. 1, the pressure is applied to the fiber laminate 1 through the sheet 3 in the direction indicated by the arrow in the figure. The pressure in this case is preferably 30 kPa or more and 500 kPa or less. If this pressure is less than 30 kPa, the fiber laminate 1 is not sufficiently pressed down, so that it tends to become wrinkles in the molding process. On the other hand, if it exceeds 500 kPa, the sheet 3 may break during shaping.

FIG. 9 is a diagram for explaining the order in which pressure is applied to the fiber laminate 1, but the sheet 3 has an unfolded reference area on the corresponding surface of the jig as shown in FIG. It arrange | positions so that it may overlap substantially.
By doing so, when pressure is applied to the sheet 3 as shown in FIG. 9B, a force is applied to the fiber laminate 1 that forms the convex portion first, and the upper surface portion of the fiber laminate 1 is placed first. Can be shaped. Subsequently, in order to apply a force from the upper side to the lower side of the fiber laminate 1 that forms the side surface (see (c) and (d) of FIG. 9), the side of the fiber laminate 1 from the upper side in order Since it can be shaped and a slip that relaxes the difference between the inner and outer peripheral lengths of the fiber laminate 1 at the bent portion occurs smoothly, shaping that suppresses wrinkles and sagging becomes possible. In the conventional shaping method, a force is applied to a random position, so if both sides of the curved surface are fixed first, the part sandwiched between them will smoothly release the circumference difference to the end. As a result, wrinkles were generated. However, the shaping method of the present invention can smoothly cause the slip to reduce the difference between the inner and outer circumferences.
Further, in order to obtain the above-described effect better, the deviation angle β ° between the sheet development reference region and the corresponding surface of the jig is preferably within ± 5 °, more preferably within ± 3 °.

  The specific pressure application method is not particularly limited as long as the pressure application area is expanded toward the development end of the sheet after applying pressure to the development standard area of the sheet, but the equipment is simple. Therefore, a vacuum bag method is preferably used in which the entire surface of the tool 5 is covered with a bag material, the periphery is sealed, and a closed space formed by the tool 5 and the bag material is sucked into a reduced pressure atmosphere. The

  Moreover, it is preferable to heat the entire temperature including at least the fiber laminate 1 during pressure application. The range of heating temperature is preferably 40 ° C. or higher and 180 ° C. or lower, and more preferably 50 ° C. or higher and 130 ° C. or lower. The reason is that it is possible to efficiently maintain and fix the state shaped into a desired shape via a resin material between the substrates.

  According to the present invention, a preform excellent in quality such as wrinkles and undulations can be obtained with simple equipment by passing through the above four steps or means (A) to (D).

  The preform of the present invention is preferably obtained by the above-described preform manufacturing method, and the reinforcing fiber volume content Vpf is preferably in the range of 35% to 65%.

  When the reinforcing fiber volume content Vpf is less than 35%, the preform becomes bulky, which is not preferable because the reinforcing fiber volume content of the FRP that is a molded product is lowered. On the other hand, when the reinforcing fiber volume content Vpf is larger than 65%, it is difficult to impregnate the matrix resin, and defects such as non-impregnation and voids are likely to occur.

  Further, in order to maintain and fix the shape of the preform, it is preferable that a resin material adheres between the base materials.

  As the resin material, it is desirable that particulate resin, fibrous resin, or film resin is adhered. Specific resin materials include thermoplastic resins and thermosetting resins, and these may be used alone or in combination.

  Examples of thermoplastic resins include polyamide, polyimide, polyamideimide, polyetherimide, polysulfone, polyethersulfone, polyphenylene ether, polyethernitrile, polyetheretherketone, and polyetherketoneketone, their modified resins, copolymer resins, etc. Among them, it is preferable to use polyamide, polyether imide, polyphenylene ether, or polyether sulfone, because the strength between the layers can be increased.

  As the thermosetting resin, epoxy resin, unsaturated polyester resin, vinyl ester resin, phenol resin and the like can be preferably used.

  In addition, it is preferable to use a combination of a thermoplastic resin and a thermosetting resin because both excellent points can be achieved. For example, by modifying a thermoplastic resin with a thermosetting resin, it is possible to improve the solvent resistance of the thermoplastic resin with the thermosetting resin, and to obtain a characteristic high toughness improvement effect of the thermoplastic resin. Become.

  The FRP molded product of the present invention is characterized in that a matrix resin is injected into the preform and the reinforcing fiber volume content Vf is in the range of 40% to 72%.

  That is, when the reinforcing fiber volume content Vf of the FRP is lower than 40%, the strength and elastic modulus of the FRP are low, and a thickness is required to express the predetermined mechanical properties, resulting in the effect of weight reduction. This is not preferable because there is a concern of becoming smaller.

  On the other hand, if the reinforcing fiber volume content Vf is higher than 72%, the amount of the matrix resin is too small, and defects such as voids are likely to occur.

  Moreover, it is preferable to adjust the reinforcing fiber volume fraction Vf of the FRP to a reinforcing fiber volume fraction Vpf−5% or more and Vpf + 20% or less of the preform. The difference between the value of reinforcing fiber content per unit volume represented by Vpf before matrix resin injection and the value of reinforcing fiber content per unit volume represented by Vf after molding is controlled within the above range. As a result, the thickness change in the process from impregnation to molding can be suppressed, and as a result, the displacement of each layer of the laminate due to the change in the circumferential length accompanying such thickness change can be suppressed. This is because it can be suppressed. The FRP reinforcing fiber volume fraction Vf is determined by the time and temperature at which the matrix resin is sucked from the suction port and / or the vacuum suction port after the matrix resin is injected into the preform, and further from the external pressure applied to the preform. It can be adjusted by controlling the discharge amount of the matrix resin.

  Below, an example of the manufacturing method of the FRP molded product of this invention is demonstrated in detail using drawing. First, as shown in FIG. 10, the preform 12 created by the above method is placed at a predetermined position of the jig 4 placed on the surface of the base tool 5. Since the base tool 5 and the jig 4 can be prepared separately, it is preferable to use those used for manufacturing the preform as they are.

  Next, a molding auxiliary material necessary for injecting and molding the matrix resin is disposed. The auxiliary material for molding here refers to the peel ply 13, the resin flow path medium 14, and the like. In FIG. 10, the peel ply 13 is disposed on the preform 12, and the resin flow path medium 14 is disposed on the peel ply 13. In addition, an inlet for matrix resin is provided at a position on one end side of the jig 4, and an upper end of the preform 12 and molding auxiliary material is positioned at the other end side of the jig corresponding to the inlet 16. Is provided with a suction port for vacuum suction of a cavity constituted by the bag material 9 and the tool 5 surface covering the whole. The injection port 16 and the suction port 17 may be separately provided with a channel material or the like. However, it is preferable that the base tool 5 has been grooved in advance in order to save the time and effort of arrangement.

  Further, a medium 14 for guiding the matrix resin to the preform is disposed from above the injection port 16 to the jig 4. As the resin flow path medium 14, a net-like material having a thickness of about 0.15 to 1.0 mm made of polypropylene or polyethylene is preferably used.

  Further, a resin flow path medium 18 for sucking the matrix resin is arranged from the suction port 17. The resin flow path medium 18 can be the same as the resin flow path medium 14. A film 15 is disposed on the resin flow path medium 18 to prevent the matrix resin from being sucked from the suction port 17 before impregnating the preform 12 if necessary. It is also preferable to do this. As the film 15, a nylon film used for the bag material 9 for vacuum bag molding can be used.

  Next, the preform 12 and the auxiliary material for molding are entirely covered with the bag material 9, the end of the bag material 9 is brought into close contact with the base tool 5 using the sealant tape 10, and the inside is vacuum-sucked. After vacuum suction, the set is put into a hot stove or the like, heated so that the entire preform has a predetermined temperature, and resin is injected. From the viewpoint of suppressing molded products such as voids, it is preferable that the amount of vacuum leak is small, specifically, 2 Torr / min or less is preferable, and 1 Torr / min or less is more preferable.

  The resin injection temperature is not particularly limited as long as it does not affect the curing characteristics of the matrix resin, the resin impregnation characteristics to the preform, the strength of the molded article, etc., but the FRP molded article having a high reinforcing fiber volume content Vf. Therefore, when a preform having a high reinforcing fiber volume content Vpf is used, the impregnation property of the matrix resin tends to decrease. Even in this case, it is preferable to lower the viscosity by heating the matrix resin, and to inject and impregnate it. Further, in order to obtain a desired reinforcing fiber volume content Vf, the matrix is determined by the time and temperature at which the matrix resin is sucked from the suction port and / or the vacuum suction port after injection, and further by external pressurization to the preform. The amount of resin discharged may be controlled.

  Embodiments of the present invention will be described below based on embodiments shown in the drawings.

Example 1
FIG. 5 is a longitudinal sectional view according to an embodiment of the present invention, and shows a state where the surface of the tool 5 is sealed with the bag material 9 and the inside is decompressed. 6 is a view of the surface of the tool 5, the jig 4, and the sheet fixing portion 6 of FIG. 5 as viewed from directly above, and FIG. 7 shows the shape of the sheet 3 formed in the developed shape of the jig 4. It is a figure.

(A) Setting process of fiber laminate 1 First, as shown in FIG. 5, a convex jig 4 made of aluminum (atypical cross section, maximum width: 300 mm, length: 600 mm, height: on the surface of the tool 5. 70 mm, corner radius R: 5 mm). Next, the fiber laminated body 1 which laminated | stacked 24 base materials (Toray Industries, Inc. carbon fiber base material: carbon fiber T800S, basis weight 250g / m < ² >) which laminated | stacked particulate resin on the convex jig | tool 4 is arrange | positioned. did.

(B) Sheet setting step A sheet 3 of glass cloth coated with PTFE formed in a developed view shape of the convex jig 4 shown in FIG. The sheet 3 was arranged so that the region overlapped on the corresponding surface of the jig 4.

(C) Sheet fixing step (1) Even after the end of the sheet 3 shown in FIG. 7 is applied to the shape of the jig 4 by applying pressure to the fiber laminate 1 as shown in FIG. 4 and a position where the sheet 3 does not adhere to the corner portion 7 formed by the surface of the tool 5, and (2) the contour line of the jig 4 formed by the surface of the tool 5 and the jig 4 as shown in FIG. The fixing part 6 was fixed with PE (polyethylene) tape at a position located on a line translated by 70 mm in the linear direction.

(D) Pressure application process The sealant tape 10 and the bag material 9 are arranged on the surface of the tool 5 as shown in FIG. 5, the space formed by the bag material 9 and the surface of the tool 5 is decompressed, and the degree of vacuum is 750 mmHg or more. This was confirmed and placed in a heating furnace. Next, it heated from normal temperature 20 degreeC to 70 degreeC, and hold | maintained at 70 degreeC for 2 hours. Then, when the shaped product was cooled and removed from the mold, a preform free of quality defects such as wrinkles could be obtained.

(Comparative Example 1)
(C) In the sheet fixing step, the same as in Example 1 except that the end of the sheet 3 is fixed so that the sheet 3 is in close contact with the corner portion 7 constituted by the convex jig 4 and the tool 5 surface. Then, when the fiber laminate was heated and cooled to produce a preform, wrinkles having a height of 1 mm were generated in part B.

(Comparative Example 2)
(C) In the sheet fixing step, shaping was performed in the same manner as in Example 1 except that the deviation angle between the sheet fixing position and the contour line 8 was set to 15 °. When the corner R part of the preform after shaping was observed, wrinkles of about 2 mm in height were scattered.

(Comparative Example 3)
(B) In the sheet setting step, shaping was performed in the same manner as in Example 1 except that a nylon film having an elongation of 400% was used instead of the glass cloth sheet coated with PTFE. After decompressing the space formed by the bag material 9 and the tool 5 surface, the corner portion 7 formed by the convex jig 4 and the tool 5 surface was observed, and the nylon film and the corner portion were in close contact.

  Then, when the fiber laminated body 1 was heated and cooled and the preform was produced, the wrinkle about 1 mm high had arisen.

(Example 2)
Using the same fiber laminate 1 as in Example 1 and the convex jig 4 having the same shape, shaping and molding were performed.

(A) Setting Step of Fiber Laminate 1 As shown in FIG. 11, a peel ply 13 and a resin flow path medium 14 that cover the entire fiber laminate 1 are arranged on the fiber laminate 1. The base tool 5 is formed by processing resin grooves for the injection port 16 and the suction port 17, and a resin flow path medium 14 is provided from the top of the injection port 16 to the jig 4. From the predetermined position to the suction port, a resin flow path medium 18 for suction and a film 15 for resin short path countermeasures were disposed. In the setting process of the fiber laminate 1, the assembly of auxiliary materials and the like necessary for the molding process described later was completed.

(B) Sheet setting step As in Example 1, the sheet 3 of glass cloth coated with PTFE formed in the shape of the development of the convex jig 4 is disposed on the resin flow path medium 14, and the sheet The sheet 3 was arranged so that the three development reference areas overlapped on the corresponding surface of the jig 4.

(C) Sheet fixing step In the same manner as in Example 1, after applying pressure to the fiber laminate 1 to conform to the shape of the jig 4, the sheet is placed on the corner portion 7 formed by the surface of the jig 4 and the tool 5. As a fixed portion 6 at a position (outside the resin groove) where the contour line of the jig 4 formed by the tool 5 surface and the jig 4 is translated by 70 mm in the normal direction at a position where the 3 does not adhere, Fixed with PE (polyethylene) tape.

(D) Pressure application process The sealant tape 10 and the bag material 9 are arranged on the tool 5 surface, the space formed by the bag material 9 and the tool 5 surface is depressurized, and it is confirmed that the degree of vacuum is 750 mmHg or more. Placed in a heating furnace. Next, the entire fiber laminate 1 was heated to 70 ° C. and held for 2 hours to prepare a preform 12.
Then, after cooling and removing the bag material 9 and the sheet 3, as shown in FIG. 10, the preform 12 and the auxiliary material for molding are entirely covered with the bag material 9, and the end of the bag material 9 is sealed with the sealant tape 10. Was brought into close contact with the base tool 5 and the inside was vacuumed.
After vacuum suction, the set was put into a hot stove and heated so that the entire preform 12 was at a predetermined temperature. As a result of measuring the amount of vacuum leak in the heated state, it was 2 Torr / min.

Thereafter, the 180 ° C. curable epoxy resin was kept at 60 ° C. and then injected from the injection port 16. The matrix resin diffused throughout the preform 12 through the resin flow path medium 14.
It was confirmed that the matrix resin was impregnated into the preform 12 and began to be sucked from the suction medium 14, and the suction port 17 was closed to stop the suction of the matrix resin. The injection port 16 was connected to a vacuum suction line, and the excessively injected matrix resin was sucked to bleed. After bleeding, the temperature of the hot stove was raised and the matrix resin was primarily cured at 130 ° C. for 2 hours.
The bag material 9 was opened, and the primary cured FRP molded product was removed from the jig 4 and taken out. As a result of visual inspection of the obtained molded product by visual inspection, an FRP molded product free from wrinkles could be obtained.
When the thickness of the upper surface portion was measured at five places and the reinforcing fiber volume content Vf was calculated from the thickness, Vf was 59%.

  The present invention is used for stiffeners and spar preforms as molds and reinforcing members for automobiles, aircraft, ships, and industrial applications, but is not limited to this, and can be applied to making preforms having a three-dimensional shape.

In the preform manufacturing method of this invention, it is a schematic cross section which shows an example of the process of arrange | positioning a fiber laminated body on a jig | tool. FIG. 2 is a perspective view of FIG. 1. It is a schematic cross section which shows an example of the sheet | seat fixing process of this invention. It is the figure which looked at a part of FIG. 1 from right above. It is a schematic cross section which shows an example of the pressure addition process of this invention. It is the figure which looked at a part of Drawing 5 from right above. It is the figure which showed an example of the sheet | seat of a developed view shape. It is the figure which showed the change of the corner R part of the fiber laminated body during shaping. It is the figure which showed the order of the pressure addition to a fiber laminated body. It is a schematic cross section which shows an example of the manufacturing method of the fiber reinforced plastic of this invention. It is a schematic cross section which shows an example of the manufacturing method of the preform of this invention.

Explanation of symbols

1: Fiber laminate 2: Reinforced fiber base material 3: Sheet 4: Jig 5: Tool 6: Fixed part 7: Corner part 8: Outline of jig 9: Bag material 10: Sealant tape 11: After pressure application Fiber laminate 12: Preform 13: Peel ply 14: Resin channel medium 15: Film 16: Injection port 17: Suction port 18: Resin channel medium

Claims (11)

A method for producing a preform, comprising at least the following steps (A) to (D).
(A) A step of setting a fiber laminate in which a jig is arranged on the tool surface and a fiber laminate is arranged thereon.
(B) Sheet setting step in which a sheet formed in a developed view shape of the jig is arranged on the upper side of the fiber laminate so that a development reference area of the sheet substantially overlaps a corresponding surface of the jig. .
(C) When a pressure is applied to the fiber laminate through the sheet, the sheet does not adhere to the corner formed by the jig and the tool surface when the fiber laminate is made to conform to the shape of the jig. A sheet fixing step of fixing the end of the sheet to a position.
(D) A pressure application step of applying pressure to the fiber laminate through the sheet. 2. The pressure applying step (D) according to claim 1, wherein, first, after applying pressure to the development reference area of the sheet, the pressure application area is expanded toward the development end of the sheet. Preform manufacturing method. In the sheet fixing step (C), the positions for fixing each end of the sheet were translated in the normal direction of each side of each side of the contour line of the jig formed by the tool surface and the jig. The preform manufacturing method according to claim 1, wherein the preform is set at a position. The method for producing a preform according to any one of claims 1 to 3, wherein the elongation of the sheet is in the range of 0.002% to 30%. The method for producing a preform according to any one of claims 1 to 4, wherein a resin material is contained between layers of the fiber laminate. The method for producing a preform according to any one of claims 1 to 5, wherein pressure is applied to the fiber laminate through a sheet by covering at least the fiber laminate with a bag material and evacuating. In the said pressure addition process (D), a fiber laminated body is heated within the range of 40 degreeC or more and 180 degrees C or less, The manufacturing method of the preform in any one of Claims 1-6 characterized by the above-mentioned. The method for producing a preform according to claim 1, wherein the sheet has releasability from the fiber laminate. The preform obtained by the method for producing a preform according to any one of claims 1 to 8, wherein the preform has a reinforcing fiber volume content Vpf of 35% to 65%. A fiber-reinforced plastic molded article having a reinforcing fiber volume content Vf in a range of 40% to 72% obtained by injecting, impregnating, and curing a matrix resin into the preform according to claim 9. A preform manufacturing apparatus including at least the following means (A) to (D).
(A) A fiber laminate setting means comprising a tool for placing a jig, a jig placed on the tool surface, and a fiber laminate placed on the upper surface of the jig.
(B) a sheet formed in a developed view shape of the jig disposed on the upper side of the fiber laminate, and the sheet has a developed reference area substantially overlapping a corresponding surface of the jig. Sheet setting means arranged in such a manner.
(C) When a pressure is applied to the fiber laminate through the sheet, the sheet does not adhere to the corner formed by the jig and the tool surface when the fiber laminate is made to conform to the shape of the jig. A sheet fixing means for fixing the end of the sheet to a position.
(D) Pressure applying means for applying pressure to the fiber laminate through the sheet.

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