JP2010173165A - Method for molding fiber-reinforced plastic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for molding fiber-reinforced plastic capable of attaining high strength and reducing the weight of a composite material by ensuring compatibility between a reduction of amount of disposal of resin and yield improvement of a molded article regarding a method for molding the fiber-reinforced plastic with a VaRTM method without using an upper mold. <P>SOLUTION: In the method for molding the fiber-reinforced plastic, a reinforced fiber material 2 and a sub material are disposed on a molding mold 1, the reinforced fiber material and the sub material are covered with a closed medium 8, the closed medium 8 and the molding mold 1 are airtightly sealed, the closed medium 8 is exhausted from the molding mold 1, and a resin is injected in the reinforced fiber material 2 to be cured. A resin injection path 5 and a vacuum suction path 6 are provided, and after a defined amount of resin is injected and impregnated from the resin injection path 5 while exhausting from the vacuum suction path 6, the injection of the resin is stopped, and the exhaust is stopped before the resin flows from the vacuum suction path 6, and the resin is cured without removing the resin which is substantially injected and impregnated in the reinforced fiber material 2 by vacuum suction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for molding a fiber reinforced plastic made of reinforced carbon fiber and resin, which can be suitably used as a primary structural member such as an aircraft.

  Conventionally, composite materials made of fiber reinforced plastics are used in various fields. In particular, composite materials for aircraft use are required to have high strength, light weight, and low cost, so the amount of waste in the molding process is reduced, and the volume content of reinforcing fibers in the entire composite material It is desirable to increase the so-called Vf so that (Vf) is about 55% to 60%.

As a method of molding fiber reinforced plastic, a reinforcing fiber material (preform) is manufactured by shaping the reinforcing fiber into a predetermined shape, and this reinforcing fiber material is placed in a cavity formed by a double-sided mold. after, by injecting resin into the cavity, RTM molding a molded body impregnated with a resin (R esin T ransfer M olding) method is known to the reinforcing fiber material (Figure 1). In the RTM method, the resin is pressurized and the resin is injected into the cavity by the pressure difference from the atmospheric pressure, so a resin pressurizing facility and a double-sided press machine are required, and the molding equipment is large. Become. On the other hand, after the reinforcing fiber material is placed on the lower mold without using the double-sided mold, the reinforcing fiber material is sealed with a sealing medium such as a bagging film, and the sealed interior is evacuated to reduce the pressure. utilizing atmospheric pressure by injecting resin, the resin is impregnated to produce a molded article VaRTM (V acuum a ssisted R esin T ransfer M olding) method is known to the reinforcing fiber material. The VaRTM method is a suitable method that does not require an upper mold and can impregnate a resin only with a vacuum pressure, and can simplify the molding apparatus. However, in the VaRTM method, since the upper mold is not used, the pressure applied to the bagging film at the time of injecting the resin balances with the atmospheric pressure, resulting in a phenomenon that the plate thickness is increased by the spring bag. Compared to the RTM method, the VaRTM method has a problem that the thickness of the molded body needs to be controlled by discharging the excessively injected resin into the sealed portion because the plate thickness is increased during the molding. As conventional techniques related to such a fiber-reinforced plastic molding method, techniques described in Patent Documents 1 to 3 have been proposed.

  In the RTM molding method described in Patent Document 1, resin is injected and impregnated from the resin injection path into the reinforcing fiber material laid in the lower mold and the bagging film or the upper mold, and exhausted from the resin discharge path. After filling the resin from the resin injection path to the resin discharge path and impregnating the reinforcing fiber material with the resin, the resin is cured while discharging the resin excessively impregnated in the reinforcing fiber material from the resin injection path and the resin discharge path. Thus, a method is described in which the thickness of the molded product can be adjusted. However, in this RTM molding method, the resin impregnated in the reinforcing fiber material is poured into the reinforcing fiber material after being injected and impregnated with a resin amount larger than the amount of the resin constituting the molded product to be a predetermined thickness. Therefore, the amount of resin discharged in addition to the amount of resin constituting the molded product is also necessary, which increases manufacturing costs and waste.

  In the RTM molding method described in Patent Document 2, a preform is disposed inside a jig in which an injection port and a discharge port are formed, resin is injected into the jig through the injection port, and the resin is injected through the discharge port. A first impregnation step of discharging the resin in the jig, and a second impregnation step of stopping the injection of the resin from the injection port and discharging the resin from the injection port while continuing to discharge the resin through the discharge port It is characterized by having. In this RTM molding method, in order to make the fiber content Vf of the composite material after molding uniform, similarly to Patent Document 1, the resin that has been excessively injected and impregnated into the preform by the first impregnation step is used. 2 It is characterized by discharging in the impregnation step. Therefore, in addition to the amount of resin constituting the composite material after molding, the amount of resin discharged is also necessary, which has been a cause of increasing manufacturing costs and waste.

  In Patent Document 3, after impregnating a reinforcing fiber material with a resin so as to have a volume content lower than the target volume content of the FRP molded product, the injection of the resin is stopped, and then the target fiber volume is contained. The RTM molding method is described in which the suction of the resin is continued until the ratio reaches the desired fiber volume content of the FRP molded product. Similarly to Patent Documents 1 and 2, this RTM molding also requires the amount of resin discharged in addition to the amount of resin constituting the molded FRP molded product, which is a cause of increasing manufacturing costs and waste. It was.

  On the other hand, if the discharge of the resin is stopped after the injection of the resin, excess resin remains in the preform, the Vf of the reinforcing fiber is lowered, and it is difficult to satisfy the predetermined Vf required value. In addition, as in Patent Documents 1 and 2, if the resin excessively impregnated into the preform is removed by suction, the resin is removed by suction more than necessary, especially when the number of laminated sheets is small and thin fiber reinforced plastic is to be molded. As a result, there is a problem that Vf exceeds the upper limit of the required value because the fiber reinforced plastic after molding becomes too thin.

  In other words, in VaRTM molding without using the upper mold, a preform is intentionally injected and impregnated into the preform with an amount of resin larger than the amount of resin constituting the final molded product of fiber reinforced plastic. Only a method of controlling the thickness and Vf of the molded product by sucking and removing the excessively injected and impregnated resin from the inside has been shown.

JP 2005-212383 A Japanese Patent No. 4035464 Japanese Patent No. 4104413

  An object of the present invention relates to a method of molding fiber reinforced plastic by the VaRTM method that does not use an upper mold, solves the above-mentioned problems in the prior art, reduces the amount of discarded resin, and improves the yield of molded products. Therefore, the present invention provides a method for molding a fiber reinforced plastic that can increase the strength and weight of a composite material.

  In order to solve the above problems, a method for molding a fiber reinforced plastic according to the present invention includes arranging a reinforcing fiber material and a subsidiary material on a mold, covering the reinforcing fiber material and the subsidiary material with a sealed medium, and the sealed medium. In a method for molding fiber reinforced plastic, the resin injection path and the vacuum suction path are provided with an airtight seal between the sealing mold and the mold, and an exhaust between the sealing medium and the mold, and a resin is injected into the reinforcing fiber material and cured. Provided, after injecting and impregnating a specified amount of resin from the resin injection path while exhausting from the vacuum suction path, stopping the injection of the resin and stopping the exhaust before the resin flows out of the vacuum suction path, And a step of curing the resin without substantially removing the resin injected and impregnated into the reinforcing fiber material by vacuum suction.

  In the molding method of the composite material, the specified amount of resin is the amount of resin constituting the fiber reinforced plastic having the fiber volume content Vf after molding, the amount of resin that fills the gap between the resin injection path and the resin suction path, The total amount of resin impregnated in the auxiliary material by resin injection / impregnation is preferred.

  In the fiber reinforced plastic molding method, the fiber volume content Vf is preferably 50 to 60%.

  In the fiber reinforced plastic molding method, the auxiliary materials may be a peel ply and a resin diffusion medium.

  In the fiber-reinforced plastic molding method, the auxiliary material may include a wire mesh.

In the molding method of the fiber-reinforced plastic, the amount of resin impregnated into peel ply ^is preferably ^{20g / m 2 ~60g / m 2} .

In the molding method of the fiber-reinforced plastic, the amount of resin impregnated into the resin distribution medium ^is preferably ^{100g / m 2 ~700g / m 2} .

In the molding method of the fiber-reinforced plastic, the amount of resin impregnated wire mesh ^is preferably ^{100g / m 2 ~700g / m 2} .

  In the fiber reinforced plastic molding method, the amount of resin injected can be monitored by weight.

  According to the method of molding fiber reinforced plastic by the VaRTM method that does not require an upper mold according to the present invention, it is possible to prevent the discharge of excess resin, and thus the waste and cost reduction effects are enhanced. Also, by injecting a resin amount that fills the gap between the sealing medium and the mold, the amount of resin impregnated in the reinforcing fiber material can be controlled, and the thickness and Vf of the molded product can be controlled. Thus, a molded article excellent in lightness can be obtained.

It is a molding device of an RTM molding method using an upper mold. It is a shaping | molding apparatus used for the RTM shaping | molding method concerning embodiment.

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

  FIG. 2 shows an example of a molding apparatus used in the RTM molding method according to one embodiment of the present invention. In FIG. 2, examples of the material of the mold 1 include metal materials such as steel, aluminum, and invar, wood, and fiber reinforced plastic. Rigidity that does not deform even when atmospheric pressure is applied by a molding process that will be described later, Although it is necessary to combine heat resistance that can withstand the resin curing step, there is no limitation on the structure or material as long as it has such characteristics. Examples of the shape of the molding die include a flat plate shape, a convex shape, and a concave shape, and a shape that matches the desired shape of the fiber reinforced plastic. The mold 1 may be provided with a demolding mechanism for demolding the fiber reinforced plastic after molding.

  In the illustrated example, the reinforcing fiber material 2 is disposed on the mold 1 in the mold 1. Reinforcing fibers constituting the reinforcing fiber material 2 include organic fibers such as aramid fibers, polyethylene fibers, polyparaphenylene benzoxador (PBO) fibers, glass fibers, carbon fibers, silicon carbide fibers, alumina fibers, tyrano fibers, basalts. (Basalt) 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, and modified natural fibers as fibers are preferably used. Among them, carbon fiber is lighter among these reinforcing fibers, and has particularly excellent properties in specific strength and specific modulus, and is also excellent in heat resistance and chemical resistance, so it is lightweight. It is suitable for a member such as a structural member of an aircraft that is desired. Furthermore, among the carbon fibers, polyacrylonitrile (PAN) -based carbon fibers from which high-strength carbon fibers can be easily obtained are particularly preferable.

  The reinforcing fiber material 2 is made of, for example, a laminate of reinforcing fiber cloths, and preferably has the shape of a final molded product. In addition, the surface of the reinforcing fiber fabric forming the laminate may include a thermoplastic resin and / or a thermosetting resin. As such a thermosetting resin, an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a phenol resin, or the like can be used. The thermoplastic resins include polyvinyl acetate resin, polycarbonate resin, polyacetal resin, polyphenylene oxide resin, polyphenylene sulfide resin, polyarylate resin, polyester resin, polyamide resin, polyamideimide resin, polyimide resin, polyetherimide resin, polysulfone. Resins, polyethersulfone resins, polyetheretherketone resins, polyaramid resins, polybenzimidazole resins, polyethylene resins, polypropylene resins, cellulose acetate resins, and the like can be used. Among these, considering that the fabric of the reinforced fiber fabric laminate is adhered by heating and pressing, and that the fiber reinforced plastic is bonded to the matrix resin after curing, the matrix resin and the thermoplastic resin having good adhesion are used alone. Alternatively, it is preferable to use a blend of a thermoplastic resin and a thermosetting resin.

  The adhesion form of the thermoplastic resin and / or the thermosetting resin to the reinforcing fiber fabric may be any of dot-like, linear or discontinuous linear. In order to make it adhere in a dot shape, it is preferable that a particulate or powdery thermoplastic resin and / or a thermosetting resin is sprayed on the surface of the reinforcing fiber fabric and thermally fused. Moreover, in order to make it adhere in linear or discontinuous linear form, it is good to heat-bond, after bonding the fabric which consists of continuous fibers, such as a nonwoven fabric and a textile fabric, on the surface of a reinforced fiber fabric. Such thermoplastic resin and / or thermosetting resin may be provided on one side or both sides of the reinforcing fiber fabric.

  The laminate obtained in this way is placed on the upper surface of the mold 1.

In the present embodiment, a resin diffusion medium 4 for diffusing a matrix resin is disposed on the reinforcing fiber material 2 via the peel ply 3. The resin diffusion medium 4 is preferably a medium in which the flow resistance of the matrix resin is lower than the flow resistance when flowing through the reinforcing fiber material 2, and specifically, a mesh made of polyethylene or polypropylene resin. in textiles, the amount of resin impregnated into the resin distribution medium ^is preferably ^{100g / m 2 ~700g / m 2} . The peel ply 3 is interposed in order to easily remove the resin diffusion medium 4 from the fiber reinforced plastic. For example, a nylon fabric is used. Preferably the matrix resin flows suitably reinforcing fiber material 2, the amount of resin impregnated into peel ply ^is preferably ^{20g / m 2 ~60g / m 2} . Further, a wire mesh may be disposed on the peel ply 3 for the purpose of reducing the surface roughness of the fiber reinforced plastic or increasing the flow of the matrix resin. The amount of resin to be impregnated into the metal mesh ^is preferably ^{100g / m 2 ~700g / m 2} . The wire mesh is, for example, a mesh fabric made of SUS304, and preferably has a rigidity that conforms to the shape of the reinforcing fiber material 2. The entire members arranged in the mold 1 are covered with a sealing medium 8 made of a sealing member. Here, the sealed medium 8 is a durability that can keep the inside of the sealed medium 8 sealed in a heated state in a resin injection impregnation step and a resin curing step, which will be described later, and chemical resistance to the matrix resin to be injected. The material of the sealing medium 8 can be a polymer material such as nylon, fluorine, silicon, aramid, polyimide, polyethylene, etc. There are no restrictions on materials. As the sealing medium 8 used in the resin injection impregnation step and the resin curing step, which will be described later, it is preferable to use a nylon film in view of excellent durability during heating. The inside of the sealing medium 8 is sealed with a highly adhesive sealant 7 made of synthetic rubber so that the inside of the sealing medium 8 can be kept in a reduced pressure state and the inflow of air from the outside can be prevented.

  A resin injection path 5 and a vacuum suction path 6 for depressurizing the inside of the sealed medium by vacuum suction are provided in the sealed medium 8 sealed by the sealant 7, and are connected to the resin injection line 9 and the vacuum suction line 12, respectively. ing. For the resin injection path 5 and the vacuum suction path 6, for example, an aluminum C channel material or the like can be used, and these channel materials are passed through plastic tubes forming the resin injection line 9 and the vacuum suction line 12. And connecting to an external member. Alternatively, the mold 1 may be grooved and used as the resin injection path 5 and the vacuum suction path 6. The vacuum trap 13 secures a vacuum volume, stabilizes the degree of vacuum inside the sealed medium 8, and prevents vacuum other than exhaust from flowing into the vacuum pump 14. The suction line 12 is connected to the vacuum suction path 6. The vacuum pump 14 evacuates from the inside sealed with the sealing medium 8 through the vacuum suction path 6 and the vacuum trap 13, and keeps the inside in a reduced pressure state.

  The matrix resin 10 constituting the fiber reinforced plastic is accommodated in, for example, a plastic pot. Examples of the matrix resin 10 include thermosetting resins such as epoxy resins, unsaturated polyester resins, vinyl ester resins, phenol resins, epoxy acrylate resins, urethane acrylate resins, phenoxy resins, alkyd resins, urethane resins, maleimide resins, and cyanate resins. Preferably used. Among these, an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a phenol resin, an acrylic resin, or a mixed resin thereof is preferable, and an epoxy resin is particularly preferable in view of imparting high toughness. Further, in order to monitor the injection amount of the matrix resin 10, the matrix resin 10 is disposed on the resin amount monitoring device 11. The resin amount monitoring device 11 preferably has a performance capable of controlling the fiber volume content Vf of the fiber reinforced plastic with an accuracy of 1.0%, such as a scale having a measurement performance up to 1.0 g. However, the measurement performance is not limited as long as Vf control is possible. Here, it is preferable to control the molded product Vf in a range of 50 to 60%. For example, in the case of an aircraft member, Vf needs to be 50% or more in cost / performance comparison with a metal material. In addition, when the fiber volume content is as high as Vf exceeding 60%, impregnation is poor and voids are likely to occur, resulting in problems such as a decrease in interlayer shear strength in the molded body. It is. Examples of the method for measuring the fiber volume content Vf of the molded product include a plate thickness conversion method, a sulfuric acid decomposition method, and a nitric acid decomposition method.

  The method for molding a fiber reinforced plastic according to the present invention using the molding apparatus as described above is performed as follows. First, the reinforcing fiber material 2 is disposed on the molding surface of the mold 1, and the peel ply 3 and the resin diffusion medium 4 are disposed thereon. The resin injection path 5 and the vacuum suction path 6 are disposed at both ends of the reinforcing fiber material 2, for example, and the resin injection line 9 and the vacuum suction line 12 are connected to them. At least one line of the resin injection path 5 and the resin injection line 9, the vacuum suction path 6 and the vacuum suction line 12 is provided. Next, the sealing medium 8 is covered so as to cover the entire top of each member laminated on the mold 1 as described above, and the periphery is sealed with a sealant 7 in order to maintain the inside of the sealing medium in a reduced pressure state. . Then, the valve A1 is closed, the valve A2 is opened, and the vacuum pump 14 is used for suction through the vacuum suction path 6, the vacuum suction line 12, and the vacuum trap 13, whereby the inside sealed with the sealing medium 8 is reduced to 0. The pressure is reduced to 1 MPa or less.

  Next, in the resin injection impregnation step, the mold 1 is heated to the injection temperature of the matrix resin 10. Examples of the heating method include hot air heating and heating medium heating, but there is no limitation on the heating method as long as the temperature can be controlled. The injection temperature is preferably heated to a temperature at which the matrix resin 10 to be used can be kept at a low viscosity, and in view of the impregnation efficiency of the resin and the condition for preventing the thickness unevenness in the fiber reinforced plastic surface, 60 to 90 ° C. Heating at is more preferred.

  When the mold 1 rises to the injection temperature, the valve A1 is opened, and the matrix resin 10 is injected into the sealed medium 8 from the resin injection path 5 through the resin injection line 9. At this time, when the resin is filled in the resin injection line 9 connecting the pot containing the matrix resin 10 to the valve A1, it is preferable to close the valve A1 once and start the injection amount monitoring of the matrix resin 10. The resin amount monitoring device 11 is preferably arranged so that the weight of the resin can be monitored, and more preferably assembled so as not to directly touch the resin injection line 9. After opening the valve A1, the matrix resin 10 diffuses in the resin diffusion medium 4 toward the vacuum suction line, and the matrix resin 10 in the resin diffusion medium 4 starts to be impregnated in the reinforcing fiber material 2. The amount of resin M1 required for the fiber volume content Vf to reach a predetermined Vf, the gap M2 from the valve A1 to the resin injection path 5, the gap M3 of the resin injection path 5, the gap M4 of the resin diffusion medium 4, the peel ply 3 The valve A1 is opened and sealed until the injection of the resin amount satisfying the volume of M1 to M7 required by the gap M5, the gap M6 of the vacuum suction path 6 and the gap M7 from the vacuum suction path 6 to the valve A2 is confirmed. Matrix resin 10 is injected into the medium. Here, when the auxiliary material includes a metal mesh, the resin is injected in consideration of the void of the metal mesh. When the injection of the matrix resin 10 having the resin amount satisfying the volumes M1 to M7 is confirmed, the valve A1 is closed to stop the supply of the matrix resin 10. And before resin flows out from valve | bulb A2, valve | bulb A2 is closed and the matrix resin 10 of the quantity which fills the volume of M1-M7 is enclosed in the area | region between valve | bulb A1, A2.

  Resin inside the sealed medium is heated by a resin injection impregnation step for holding the matrix resin 10 injected into the sealed medium at the injection temperature, or heated in a later resin curing step to lower the viscosity in a region below the curing temperature. The pressure distribution is stabilized, and the gaps M1 to M7 are filled with the matrix resin 10. Further, the resin amount M1 necessary for causing the reinforcing fiber material 2 to reach a predetermined Vf is left in the reinforcing fiber material 2, and the matrix resin in the reinforcing fiber material layer in the resin injection impregnation step or the subsequent resin curing step. 10 thickness distribution is stabilized, and fiber volume content Vf is controlled within the range of 50 to 60%.

  Next, in the resin curing step, the matrix resin 10 is heated and cured. The heating temperature is preferably heated to the curing temperature of the matrix resin 10, and is more preferably 120 ° C. or higher and 200 ° C. or lower in view of physical properties (for example, durability) required for the fiber reinforced plastic. After the curing is completed, the fiber reinforced plastic is removed from the mold 1. The obtained fiber reinforced plastic can be subjected to secondary curing at a predetermined temperature and time as required.

  The molding method of the fiber reinforced plastic thus obtained increases the effect of reducing waste and costs in order to prevent the discharge of excess matrix resin 10. With respect to the molding cycle, the time can be shortened by omitting the resin discharge. In addition, when the resin is discharged, it is necessary to remove and clean the resin collected in the pipes and traps to be sucked, and to dispose of the tube in which the resin is accumulated. The molding cycle can be accelerated. Regarding molding quality, the amount of resin impregnated in the reinforcing fiber material 2 is controlled by injecting the amount of resin that fills the gap between the sealing medium 8 and the mold 1, and the fiber volume content of the fiber reinforced plastic. Vf can be controlled, and a molded body that is excellent in strength and light weight and can be suitably used as a primary structural member such as an aircraft can be obtained.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. In addition, this invention is not limited to the aspect described in drawing.
Example 1
The carbon fiber fabric cut into a length of 200 mm and a width of 200 mm was laminated on a mold 1 made of a stainless steel flat plate using the molding apparatus shown in FIG. The reinforcing fiber material used for forming the reinforcing fiber material was “Torayca” (registered trademark) T800S unidirectional woven fabric (base weight: 190 g / m ² ) manufactured by Toray Industries, Inc., and 8 ply was laminated. On the laminated reinforcing fiber material 2, a peel ply 3 (made of polyester) and a resin diffusion medium 4 (polypropylene mesh material) were arranged. The amount of resin impregnated in the peel ply 3 was 41 g / m ² , and the amount of resin impregnated in the resin diffusion medium 4 was 401 g / m ² . A resin injection path 5 (aluminum C channel) and a vacuum suction path 6 (aluminum C channel) are arranged at both ends with respect to the reinforcing fiber material 2, and a resin injection line 9 (nylon tube) and a vacuum suction line 12 are disposed. The vacuum trap 13 and the vacuum pump 14 were connected via a (nylon tube). The whole was covered with a sealing medium 8 (nylon film) and the periphery was sealed with a highly adhesive synthetic rubber sealant 7.

  At this time, the resin amount M1 necessary for the fiber volume content Vf of the fiber reinforced plastic to reach 57% is 23.6 g, and the gap M2 of the resin injection line 9, the gap M3 of the resin injection path 5, the resin diffusion The amount of resin satisfying the total of the gap M4 of the medium 4, the gap M5 of the peel ply 3, the gap M6 of the vacuum suction path 6, and the gaps M2 to M7 of the gap M7 of the vacuum suction line 12 was 105.2 g.

In the above state, the valve A1 was closed, the valve A2 was opened, and suction was performed from the vacuum suction path via the vacuum suction line and the vacuum trap, and the inside of the sealed medium was reduced to 0.1 MPa. Thereafter, the mold was placed in an electric oven, and the inside of the oven was heated to 70 ° C. After the inside of the oven reached 70 ° C., the valve A1 was opened, and the valve A1 was closed when the resin reached the valve A1. After the resin amount of the matrix resin 10 was confirmed by the resin amount monitoring device 11, the valve A1 was opened, and the matrix resin 10 was injected from the resin injection path 5 by a vacuum pressure. As the matrix resin, an epoxy resin (resin viscosity at an injection temperature of 70 ° C. is 130 mPa · s, and a resin viscosity after 1 hour at 70 ° C. is 320 mPa · s) was used. The injected resin was impregnated in the reinforcing fiber material 2 while flowing in the resin diffusion medium 4 having low flow resistance. When 128.8 g of the resin amount satisfying the volume of M1 to M7 was injected, the valve A1 was closed to stop the supply of the matrix resin, and the valve A2 was closed and the exhaustion was stopped before the resin flowed out from the vacuum suction path. . Thereafter, the temperature in the electric oven was raised to 130 ° C., and the matrix resin was heated and cured for 2 hours. After heat curing, the carbon fiber reinforced plastic was removed from the mold. The obtained fiber reinforced plastic was measured for fiber volume content Vf at the resin injection side, the vacuum suction side, and the midpoint between the two, and as a result, it was within the range of 55.8 to 57.3%. The fiber volume content Vf was measured by the sulfuric acid decomposition method, and was carried out based on the standard of ASTM D3171.
(Comparative Example 1)
The same molding apparatus as in Example 1 was used. The valve A1 was closed, the valve A2 was opened, and suction was performed from the vacuum suction path via a vacuum suction line and a vacuum trap, and the inside of the sealed medium was reduced to 0.1 MPa. Thereafter, the mold was placed in an electric oven, and the inside of the oven was heated to 70 ° C. After the entire reinforcing fiber material reached 70 ° C., the valve A1 was opened, and the matrix resin 10 was injected from the resin injection path 5 at a vacuum pressure. As the matrix resin, an epoxy resin (resin viscosity at an injection temperature of 70 ° C. is 130 mPa · s, and a resin viscosity after 1 hour at 70 ° C. is 320 mPa · s) was used. The injected resin was impregnated in the reinforcing fiber material 2 while flowing in the resin diffusion medium 4 having low flow resistance. After injecting an amount (175.1 g) for filling the matrix resin 10 from the resin injection path 5 to the vacuum suction path 6, the valve A1 was closed to stop the supply of the matrix resin. Thereafter, the resin was continuously discharged from the vacuum suction path 6 for 60 minutes, and then the valve A2 was closed to stop the resin discharge. The amount of resin flowing out from the vacuum suction path was 50.8 g. Thereafter, the temperature in the electric oven was raised to 130 ° C., and the matrix resin was heated and cured for 2 hours. After heat curing, the carbon fiber reinforced plastic was removed from the mold. The fiber reinforced plastic obtained was measured for fiber volume content Vf at the resin injection side, the vacuum suction side, and the midpoint between the two, and was found to be in the range of 60.3 to 61.8%. The fiber volume content Vf of the fiber reinforced plastic exceeded 60%.
(Comparative Example 2)
In Comparative Example 1, 165.4 g of resin was injected, and resin discharge was continued for 1 minute. The amount of resin flowing out from the vacuum suction path was 40.2 g. The obtained fiber reinforced plastic was measured for fiber volume content Vf at the resin injection side, the vacuum suction side, and the midpoint between the two, and as a result, it was within the range of 58.1 to 63.0%. The fiber volume content Vf of the fiber reinforced plastic exceeded 60%.

  The present invention can be applied not only to airplanes, ships, and automobiles, but also to industrial uses and sports uses, but the application range is not limited thereto.

1: Mold 2: Reinforcing fiber material 3: Peel ply 4: Resin diffusion medium 5: Resin injection path 6: Vacuum suction path 7: Sealant 8: Sealing medium 9: Resin injection line 10: Matrix resin 11: Resin amount monitoring device 12 : Vacuum suction line 13: Vacuum trap 14: Vacuum pump 15: Upper mold

Claims (9)

The reinforcing fiber material and the auxiliary material are arranged on the mold, the reinforcing fiber material and the auxiliary material are covered with a sealing medium, and the space between the sealing medium and the mold is hermetically sealed, and the space between the sealing medium and the molding die is set. In a fiber reinforced plastic molding method in which a resin is injected into a reinforcing fiber material and cured by evacuation, a resin injection path and a vacuum suction path are provided, and a specified amount of resin is discharged from the resin injection path while exhausting from the vacuum suction path After the injection / impregnation, stop the injection of the resin, and before the resin flows out from the vacuum suction path, stop the exhaust, and do not remove the resin substantially injected / impregnated into the reinforcing fiber material by vacuum suction, A method for molding a fiber-reinforced plastic, comprising curing a resin. The prescribed amount impregnates the auxiliary material by resin amount constituting the fiber reinforced plastic having the fiber volume content Vf after molding, the resin amount filling the gap between the resin injection path and the resin suction path, and resin injection / impregnation. The method for molding a fiber-reinforced plastic according to claim 1, wherein the total amount of the resin. 3. The fiber reinforced plastic molding method according to claim 2, wherein the fiber volume content Vf ranges from 50 to 60%. The method for molding a fiber reinforced plastic according to any one of claims 1 to 3, wherein the auxiliary material is a peel ply and a resin diffusion medium. The method for molding fiber-reinforced plastic according to claim 4, wherein the auxiliary material includes a wire mesh. The amount of resin to be impregnated into the peel ply ^is a molding method of fiber reinforced plastic according to any one of claims 1 to 5, characterized in that a ^{20g / m 2 ~60g / m 2} . The amount of resin to be impregnated into the resin distribution ^medium, method of molding a fiber reinforced plastic according to claim 1, characterized in that a ^{100g / m 2 ~700g / m 2} . The amount of resin to be impregnated into the wire ^mesh, molding method of a fiber reinforced plastic according to any one of claims 1-7, characterized in that a ^{100g / m 2 ~700g / m 2} . The method for molding a fiber reinforced plastic according to any one of claims 1 to 8, wherein the injection amount of the resin is monitored by weight.

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