JP2009045927A - Method of manufacturing fiber reinforced plastic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing fiber reinforced plastic in which simple equipment is used, resin impregnating property is raised only in an impregnation difficult portion, resin is made to impregnate in a whole preform completely finally, and outstanding quality fiber reinforced plastic can be obtained. <P>SOLUTION: The method of manufacturing fiber reinforced plastic includes: arranging a fiber reinforced preform 1 in which a fiber areal weight is partially high or an impregnation difficult portion with a high consistency exists on a mold 2; sealing whole of the fiber reinforced preform 1 by a pack material 4; and impregnating a plastic 9a into the fiber reinforced preform 1 after depressurizing an inside of the pack material 4, wherein in a condition that expansion of the pack material 4 is inhibited by an expansion inhibition portion or a pressurization portion arranged at a portion containing the impregnation difficult portion of the fiber reinforced preform 1 and a part of the pack material 4 is pressurized from outside, the plastic 9a is pressurized and injected into the inside of the pack material 4 of the pressurization portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a fiber reinforced plastic using a vacuum RTM (Resin Transfer Molding) molding method, and in particular, a reinforcing fiber preform has a partially impregnated portion having a high basis weight or a high density. In some cases, the fiber reinforced plastic can be impregnated completely with the resin using a simple equipment and can stably obtain a fiber reinforced plastic (hereinafter also referred to as FRP) of excellent quality. It relates to the manufacturing method.

  FRP is a lightweight material that can exhibit high mechanical properties, and is used in various fields. As typical FRP manufacturing methods, an RTM (Resin Transfer Molding) method, a prepreg method, a vacuum RTM molding method, and the like are known.

  The RTM method is a molding method in which reinforcing fibers are arranged in a cavity of a double-sided mold, and resin is injected into the cavity by pressurizing and injecting resin into the reinforcing fiber. is necessary. The prepreg method is a method in which a sheet of pre-impregnated reinforcing fiber impregnated with semi-cured resin is heated and pressed in a pressure cooker called an autoclave, both of which require expensive equipment. Is a forming method.

  On the other hand, in the vacuum RTM molding method, reinforcing fibers are arranged on a mold, the entire reinforcing fibers are sealed with a bag material, the inside of the bag material is decompressed, and the inside of the bag material is decompressed and the external pressure (atmospheric pressure) The resin is injected into the reinforcing fiber using the pressure difference between the resin and the resin, the resin is cured, and after the curing, the mold is removed to obtain FRP. The vacuum RTM molding method does not require pressurization equipment, and has the advantage that it can be manufactured with very simple equipment. On the other hand, unlike the RTM molding method that injects resin under high pressure, the injection pressure is atmospheric (1 atm). When the preform has a high basis weight or has a high density, the resin hardens without reaching the entire preform due to insufficient pressure, resulting in an unimpregnated portion of the resin in the FRP. was there. Further, in the vacuum RTM molding apparatus, when the resin is injected under pressure, the bag material is pushed up by the pressure of the resin, and the bag material expands, which causes a problem that molding cannot be performed.

  In order to solve the above problem, the entire vacuum RTM molding device is placed in a pressure kettle, the whole is pressurized from the outside of the bag material, and the resin is pressurized and injected (Patent Document 1) or a dam is used. There has been proposed a method (Patent Document 2) in which a pressurized medium is inserted, pressurized from the outside, and the resin is injected under pressure. However, even if the preform has a partially impregnated portion with a high basis weight or a high density, and the area of the difficultly impregnated portion is smaller than the area of the entire preform, Excessive equipment is required to apply pressure. For this reason, there are problems that the equipment cost becomes expensive and that the energy consumption of operation is large and the environmental load is high.

Further, as a method for improving the impregnation property of the resin, a method of making a hole in the preform with a needle called needling has been proposed (Patent Document 3). There was a problem that the strength of the steel was lowered and the quality was lowered.
Japanese Patent Laid-Open No. 5-237853 Japanese Patent No. 3686405 JP 2003-39429 A

  Therefore, the problem of the present invention is that, in the vacuum RTM (Resin Transfer Molding) molding method, the reinforcing fiber preform has a partially high basis weight (this also applies when the plate thickness is partially thick), or the density is high. When there is a highly difficult impregnation part, use simple equipment to improve the impregnation of the resin only in the difficult impregnation part, and finally allow the resin to completely impregnate the entire preform. Another object of the present invention is to provide a method for producing a fiber reinforced plastic capable of stably obtaining a fiber reinforced plastic (FRP) of excellent quality.

  In order to achieve the above object, the present invention takes the following means. That is, the present invention is arranged on the mold partly reinforcing fiber preform having a high weight per unit area or high-impact impregnated portion, and sealing the entire reinforcing fiber preform with a bag material, A method for producing a fiber reinforced plastic in which a resin is injected into the reinforcing fiber preform after decompressing the inside of the bag material, wherein the expansion suppressing portion is disposed at a portion including the hardly impregnated portion of the reinforcing fiber preform. In the state in which an expansion suppression jig is disposed so as to suppress expansion of the bag material on a part of the bag material, the resin is pressurized and injected into the bag material of the expansion suppression portion. It is a manufacturing method of a fiber reinforced plastic.

  In another aspect of the present invention, a reinforcing fiber preform having a partially impregnated portion having a high basis weight or a high density is disposed on a mold, and the entire reinforcing fiber preform is a bag material. After sealing the interior of the bag material and depressurizing the inside of the bag material, a method for producing a fiber reinforced plastic in which a resin is injected into the reinforced fiber preform, which is disposed in a portion including the hardly impregnated portion of the reinforced fiber preform. Pressurizing and injecting resin into the bag material of the pressurizing unit in a state in which a part of the bag material is pressurized from the outside by the pressurizing unit and a part of the bag material is pressurized from the outside. Is a method for producing a fiber-reinforced plastic.

  According to the method for producing a fiber reinforced plastic according to the present invention, even when the reinforcing fiber preform has a partially impregnated portion having a high basis weight or a high density, the expansion suppressing portion and the pressurizing portion are used. By providing simple equipment, it is possible to pressurize and inject only the necessary part of the resin. Finally, the entire preform can be completely impregnated with the resin, and stable and excellent quality can be achieved. Fiber reinforced plastic (FRP) can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In addition, this invention is not limited to the specific aspect described in drawing.

  FIG. 1 is a configuration diagram for explaining a conventional vacuum RTM molding method. FIG. 2 is a cross-sectional view for explaining the form of the reinforcing fiber preform according to the production method of the present invention. FIG. 3 is a block diagram for explaining the first embodiment according to the manufacturing method of the present invention.

  As shown in FIG. 1, the reinforcing fiber preform 1 is disposed on the mold 2, the entire reinforcing fiber preform is covered with a bag material 4, sealed with a sealant 3, and a vacuum pump via a suction line 5 and a vacuum trap 6. The inside of the bag material communicated with 7 is depressurized, and the resin is injected into the reinforcing fiber preform through the injection line 8 by the pressure difference between the inside of the bag material and the resin 9. In order to quickly diffuse the resin on the surface of the reinforcing fiber preform, the resin diffusion medium 18 may be disposed on the surface of the reinforcing fiber preform.

  In the reinforcing fiber plastic manufacturing method according to the present invention, as shown in FIG. 2 (a), the reinforcing fiber preform 1 used has a partially impregnated portion 19a having a high basis weight. In general, while the resin impregnates the inside of the reinforcing fiber preform, the pressure at the flow front portion of the resin decreases due to the pressure loss due to the flow resistance of the reinforcing fiber preform. Further, the reinforcing fiber preform has a characteristic that the flow resistance of the resin is low in the direction parallel to the reinforcing fiber and the flow resistance is high in the vertical direction. Therefore, in the conventional vacuum RTM molding method, in the portion where the thickness of the reinforcing fiber preform is thick, the resin is impregnated in the thickness direction and the flow rate is reduced due to pressure loss. There was a problem of quality defects such as curing before impregnation and formation of an unimpregnated portion of the resin in the molded product.

  Further, the difficultly impregnated portion of the reinforcing fiber preform 1 used in the method for producing a reinforcing fiber plastic according to the present invention includes not only the hardly impregnated portion 19a having a high basis weight in FIG. As shown in b), the impregnated portion 19b having a partially high reinforcing fiber density is also included. In the conventional vacuum RTM molding method, the higher the density of the reinforcing fiber in the reinforcing fiber preform, the higher the flow resistance of the resin, so that the pressure loss increases and the resin is not impregnated in the molded product. was there.

  The reinforcing fiber preform used in the present invention refers to a fiber structure composed of reinforcing fibers not impregnated with resin. Examples of reinforcing fibers include glass fibers, carbon fibers, aramid fibers, and the like. Examples of the form of the body include a laminate of woven fabric and a three-dimensional knitted fabric.

  In the present invention, as shown in FIG. 3, an expansion suppression portion in which an expansion suppression jig 20 is disposed on the bag material 4 at least including the hardly impregnated portion of the reinforcing fiber preform 1 is provided. The expansion suppression portion in the present invention refers to a region where the expansion suppression jig 20 and the bag material 4 are in contact.

  In the method for producing a reinforced fiber plastic according to the present invention, after decompressing the inside of the bag material 4, the expansion suppressing jig 20 is disposed on the bag material 4 at least including the hardly impregnated portion of the reinforced fiber preform 1. The jig and the mold 2 are bolted by the expansion suppressing jig fastening portion 21. And the resin container 10 is made to communicate with the inside of the bag material of the expansion suppressing part via the resin injection line 8a, and the inside of the resin container 10 is pressurized by the pressure pump 12a via the pressure line 11. Then, the resin 9a is injected into the reinforcing fiber preform 1 by the pressure difference between the inside of the bag material and the pressure in the resin container 10.

  During the resin injection, the resin pressure is applied to the reinforcing fiber preform 1, but since the expansion is suppressed by the expansion suppressing jig 20, the resin does not expand the bag material 4, and the resin passes through the reinforcing fiber preform. Impregnation in the thickness direction. What is necessary is just to set the pressure in the resin container 10 high so that resin may impregnate the whole hard-impregnation part of a reinforced fiber preform completely.

  While the resin is impregnated in the plate thickness direction, it is also impregnated in the horizontal direction, and the pressure of the resin decreases with the impregnation distance. Therefore, since the pressure of the resin is lower than the injection port in the portion other than the expansion suppression portion, the expansion suppression is performed so that the resin pressure in the portion other than the expansion suppression portion does not become higher than the atmospheric pressure until the completion of the injection. By adjusting either the position of the portion, the pressure in the resin container, or both, the bag material can be molded without being inflated. Further, if the resin pressure in the portion other than the expansion suppressing portion is higher than the atmospheric pressure and expands with the resin pressure kept high, the resin container 10 is depressurized after the resin is pressurized and injected (that is, the resin pressure is increased). The resin may be injected at a pressure difference between the atmospheric pressure and the bag material 4.

  After the resin is completely impregnated into the reinforcing fiber preform 1, the resin injection line 8 a is closed, the resin injection is stopped, the resin is cured, and then demolded from the mold. It is possible to obtain a molded product with no quality.

  The expansion suppressing jig 20 and the fixing method of the jig used in the present invention are limited in form as long as they have a function of suppressing the rise of the reinforcing fiber preform 1 and the expansion of the bag material 4 by the pressure of the resin. It is not what is done. The material and shape of the expansion suppression jig 20 are not particularly limited as long as the strength and rigidity are designed so that the deformation due to the pressure of the resin becomes minute. For example, it is preferable to use a material having a high elastic modulus, such as a metal material such as steel, stainless steel, or an aluminum alloy, or a fiber-reinforced plastic. Further, the expansion suppression jig 20 may be fixed by being coupled to the mold 2, or may be fixed to an external structure other than the mold. For example, it is preferable that a machine such as a bolt is fastened for easy removal.

  The expansion suppressing jig 20 used in the present invention may be arranged by applying a force so as to crush (pressurize) the difficultly impregnated portion of the reinforcing fiber preform 1 or apply a force to the reinforcing fiber preform 1. You may arrange | position so that it may not exist. If the applied pressure is high, the reinforcing fibers in the reinforcing fiber preform 1 become dense and the flow rate of the resin decreases, and if a gap is left between the bag material 4 and the reinforcing fiber preform 1 rises, The bag material 4 expands. That is, the expansion suppression jig 20 is appropriately disposed so as to suppress the rise of the reinforcing fiber preform 1 and the expansion of the bag material 4 and to have a density of the reinforcing fiber preform 1 that allows the resin to flow sufficiently. It ’s fine.

  Furthermore, in the manufacturing method according to the present invention, when the reinforcing fiber preform has a partially high basis weight or a partially impregnated part having a high reinforcing fiber density, the part including the hardly impregnated part is pressurized. Even by providing a pressurizing part and pressurizing and injecting resin into the pressurizing part, the impregnated part is impregnated in the thickness direction with a sufficiently high pressure, and the thin part is low below atmospheric pressure. The resin can be completely impregnated with the whole of the reinforcing fiber preform by pressure, and a high-quality molded product having no resin non-impregnated portion can be obtained.

  FIG. 4 is a block diagram for explaining a second preferred embodiment according to the manufacturing method of the present invention, and FIG. 5 is a plan view when the apparatus of FIG. 4 is viewed from above. In the present invention, as shown in FIG. 4, a dam 13 is installed around a portion including at least a hardly impregnated portion of the reinforcing fiber preform 1 with a sealing material 15 interposed therebetween, and a pressure medium is provided in a region surrounded by the dam. The pressure part which pressurizes the reinforcement fiber preform 1 partially from the said outside is provided by putting 14a and pressing a part of said bag material from the outside. The pressurizing part in the present invention refers to a region where the pressurizing medium 14a is disposed. Hereinafter, a portion other than the pressurizing portion in the region where the bag material is arranged is referred to as a non-pressurizing portion.

  The dam used in the present invention refers to a wall-shaped frame body whose upper and lower surfaces are open and whose side surface portions are airtight. For example, a metal frame body can be used. In the method for producing a reinforced fiber plastic according to the present invention, the pressurizing medium used includes, for example, gas, fluid, solid, powder, and the sealing material used is a dam or a dam in order to maintain an airtight body. It refers to a material that hermetically connects the chamber, the mold, and the bag material. For example, an elastic body such as rubber or soft resin can be used.

  In the method for producing a reinforced fiber plastic according to the present invention, a bag of the pressurizing unit is formed in a state where the reinforced fiber preform 1 is partially pressurized from the outside by pressurizing a part of the bag material from the outside. The resin container 10 is communicated with the inside of the material via the resin injection line 8a. The inside of the resin container 10 is pressurized by a pressure pump 12 a through a pressure line 11, and the resin 9 a is injected into the reinforcing fiber preform 1 by the pressure difference between the inside of the bag material and the pressure in the resin container 10. .

  During the resin injection, the pressure of the resin is applied to the reinforcing fiber preform 1, but since the pressure is suppressed in the opposite direction by the pressurizing medium 14 a, the bag material 4 does not expand and the resin is reinforced fiber. The preform is impregnated in the thickness direction. What is necessary is just to set the pressure in the resin container 10 high so that resin may impregnate the whole hard-impregnation part of a reinforced fiber preform completely.

  While the resin is impregnated in the plate thickness direction, it is also impregnated in the horizontal direction, and the pressure of the resin decreases with the impregnation distance. Therefore, in the non-pressurized part, the resin pressure is lower than that of the injection port, so that the resin pressure of the non-pressurized part does not become higher than the atmospheric pressure until the completion of the injection, By adjusting either or both of the pressures in the resin container, the bag material can be molded without being inflated.

  After the resin is completely impregnated into the reinforcing fiber preform 1, the resin injection line 8 a is closed, the resin injection is stopped, the resin is cured, and then demolded from the mold. It is possible to obtain a molded product with no quality.

  By the manufacturing method according to the present invention, even when a reinforcing fiber preform is partially thick or a partially impregnated part having a high reinforcing fiber density is present, pressurizing a part including the hardly impregnated part By injecting the resin into the pressurizing part by pressurizing the resin, the impregnated part is impregnated in the plate thickness direction with a sufficiently high pressure, and in the thin part of the plate thickness, at a low pressure below atmospheric pressure, By completely impregnating the entire reinforcing fiber preform with the resin, a high-quality molded product having no resin non-impregnated portion can be obtained.

  FIG. 6 is a block diagram for explaining a third embodiment according to the manufacturing method of the present invention. As shown in FIG. 6, a chamber 16 is installed around a portion including at least a hardly impregnated portion of the reinforcing fiber preform 1 with a sealing material 15 interposed therebetween, and a bag body 17 is installed in the chamber. The pressurizing medium 14b can be put in by the pressurizing pump 12b and pressurized from the outside of the bag material. The pressurizing medium may be directly placed in the chamber without installing the bag body 17.

  The chamber used for this invention points out the box-shaped body which is arrange | positioned on a metal mold | die and a bag material, and forms a space between a metal mold | die and a bag material. The space is preferably hermetically connected in a hermetic state, and a sealing material 13 may be used for the hermetic connection. In addition, the chamber has a material and plate thickness set so as to withstand the pressure of the pressurized medium, and for example, a metal semi-cylindrical box-like body can be used.

  The bag body used for the manufacturing method according to the present invention refers to a bag-like one that can maintain an internal airtight state. As the material of the bag body, for example, a thermoplastic resin may be used, and polypropylene, polyethylene, and nylon can be used. In some cases, rubber such as chloroprene, polyisoprene, butadiene, and silicone may be used in addition to the resin film.

  In the manufacturing method according to the present invention, the method of pressurizing the bag material from the outside is not particularly limited as long as it is a method having a function of partially pressurizing the reinforcing fiber preform, but the entire bag material is evenly arranged with simple equipment. Therefore, it is preferable to use a method in which the pressurizing part is composed of a dam or a chamber and a pressurizing medium is put into the dam or chamber. In addition, since it is possible to easily prevent leakage of the pressurized medium between the bag material and the chamber, it is a more preferable form to install the bag body in the chamber. You may use the method of pressurizing from the bag outside with a weight, a press machine, etc.

  Also, as shown in FIG. 4, the non-pressurized portion is made to communicate with the resin 9b through the injection line 8b inside the bag material, and the resin is injected by the pressure difference between the bag material and the atmospheric pressure applied to the resin. Also good. By providing the injection line 8b separately from the injection line 8a of the pressurizing part, the pressure of the resin can be surely reduced to the atmospheric pressure or less in the non-pressurized part, so that the bag material is not easily expanded. can do.

  A resin diffusion medium 18 may be disposed on the surface of the reinforcing fiber preform. In the present invention, when the resin diffusion medium 18 is disposed, it is preferable to separate the resin diffusion medium between the pressure part and the non-pressure part. Since the resin diffusion medium itself has a low flow resistance and a small pressure loss when the resin flows, when the resin is injected into the resin diffusion medium under pressure, the pressure of the resin in the resin diffusion medium increases uniformly. Therefore, by separating the resin diffusion medium, the pressure of the resin flowing from the pressure part to the non-pressure part can be reduced by increasing the flow resistance between the pressure part and the non-pressure part. The pressure of the resin in the non-pressurized part can be easily reduced to atmospheric pressure or less.

  The method for separating the resin diffusion medium is not particularly limited as long as the resistance between the resin diffusion media can be higher than that of the resin diffusion medium, but a gap may be provided between the resin diffusion media or the resin. The gap of the diffusion medium may be closed, or a high resistance body may be inserted between the resin diffusion media.

  In the pressurizing part, when the pressure applied from the outside of the bag material is high and the plate thickness of the pressurizing part of the molded product becomes too thin after the resin is cured, after the injection of the resin is stopped, The resin may be cured after the pressure is removed (ie, the pressure in the dam or chamber is released to atmospheric pressure).

Example 1
Toray Co., Ltd. carbon fiber T800S (PAN-based carbon fiber, 24,000 filaments) was unidirectionally woven (weight per unit: 190 g / m ² ) to which toughened resin particles mainly composed of PES (polyether sulfone) were dispersed and applied. 16 unidirectional carbon fiber fabrics (product name: CZ8431DP, manufactured by Toray Industries, Inc.) are cut into 16 pieces each having a width of 300 mm and a length of 250 mm. Further, the width is 300 mm and the length is changed from 150 mm to 181 mm every 1 mm. 32 sheets were cut to the size. Next, 16 pieces of 300 mm × 300 mm carbon fiber woven fabrics were laminated, and 32 carbon fiber woven fabrics were laminated in order from the longer one, and as shown in FIG. A reinforcing fiber preform 1 in which the part 19a exists was prepared.

  As shown in FIG. 3, the reinforcing fiber preform 1 was placed on a steel flat plate mold 1 (average plate thickness 20 mm). The reinforcing fiber preform 1 is covered with a bag material 4 (nylon film, 0.05 mm thickness), sealed with a sealant 3 (manufactured by RICHMOND, SM5126), and communicated via a vacuum suction line 5 and a vacuum trap 6. The vacuum pump 7 was used to reduce the inside of the bag material 4 to 5 kPa or less in absolute pressure.

  Next, a steel expansion restraining jig 20 (average plate thickness of 15 mm) was placed in contact with the bag material 4 on the difficultly impregnated portion 19a of the reinforcing fiber preform 1, and bolted to the mold at five locations. .

  The entire molding apparatus was put into an oven set at 70 ° C. and heated until the preform temperature reached 70 ° C. The epoxy resin 9 a heated to 70 ° C. was placed in a resin pressure vessel 10 (steel sealed container), and the resin pressure vessel 10 and the pressure pump 12 a were connected via a pressure line 11. Via the resin injection line 8a, the inside of the bag material of the pressurizing portion and the resin 9a were connected. When connecting, the resin injection line 8a was closed with a clamp. In this example, TR-A36 manufactured by Toray Industries, Inc. was used as the epoxy resin.

  Next, after the inside of the resin pressure vessel 10 was adjusted to a pressure of 200 kPa in absolute pressure by the pressure pump 12a, the clamp of the resin injection line 8a was opened and resin injection was started. After 10 minutes had passed since the resin injection, the pressurizing pump 12a was stopped and the inside of the resin container 10 was opened to the atmosphere. After an additional 20 minutes, the resin injection line 8a was closed. Next, the preset temperature of the oven was raised to 130 ° C. and held for 2 hours to cure the resin. Finally, it was cooled to room temperature and the FRP was removed from the mold.

  As a result of visual inspection of the FRP, there was no resin unimpregnated part on the surface, and further, an ultrasonic flaw detector (EPOCH4 manufactured by PANAMETRICS) was used to inspect defects inside the FRP. As a result, it was possible to obtain a molded product excellent in quality in which the entire FRP had no resin non-impregnated portion.

(Example 2)
Toray Co., Ltd. carbon fiber T800S (PAN-based carbon fiber, 24,000 filaments) was unidirectionally woven (weight per unit: 190 g / m ² ) to which toughened resin particles mainly composed of PES (polyether sulfone) were dispersed and applied. Sixteen unidirectional carbon fiber fabrics (product name: CZ8431DP, manufactured by Toray Industries, Inc.) are cut into a size of 300 mm in width and 300 mm in length, and further, the width is 300 mm and the length is changed from 150 mm to 181 mm every 1 mm. 32 sheets were cut to the size. Next, 16 pieces of 300 mm × 300 mm carbon fiber woven fabrics were laminated, and 32 carbon fiber woven fabrics were laminated in order from the longer one, and as shown in FIG. A reinforcing fiber preform 1 in which the part 19a exists was prepared.

  As shown in FIG. 6, a polypropylene mesh material (TSX-400P manufactured by Tokyo Polymer Co., Ltd.) is arranged as a resin diffusion medium 18 on a flat plate mold 1 made of steel, with the length divided into 150 mm and 100 mm. Next, the reinforcing fiber preform 1 was disposed. The reinforcing fiber preform 1 is covered with a bag material 4 (nylon film, 0.05 mm thickness), sealed with a sealant 3 (manufactured by RICHMOND, SM5126), and communicated via a vacuum suction line 5 and a vacuum trap 6. The vacuum pump 7 was used to reduce the inside of the bag material 4 to 5 kPa or less in absolute pressure.

  Next, a sealed balloon-like bag 17 made of silicone rubber (average thickness: 1.0 mm) and a pressure pump 12b are connected, and the steel 16 (average thickness: 10 mm) is placed in a chamber 16. The bag was placed, the chamber 16 was placed on the sealing material 15 made of a silicone O-ring placed on the mold 1 and the bag material 4, and the chamber 16 and the mold 2 were bolted and fixed. Thereafter, the pressure inside the bag body 17 was adjusted to 300 kPa with absolute pressure by the air pressure from the pressurizing pump 12b. Next, the entire molding apparatus was put into an oven set at 70 ° C. and heated until the preform temperature reached 70 ° C.

  The epoxy resin 9 a heated to 70 ° C. was placed in a resin pressure vessel 10 (steel sealed container), and the resin pressure vessel 10 and the pressure pump 12 a were connected via a pressure line 11. The inside of the bag material of the pressurizing part and the resin 9a were connected via the resin injection line 8a, and the inside of the bag material of the non-pressurizing part and the resin 9b were connected via the resin injection line 8b. When connecting, the resin injection lines 8a and 8b were closed with clamps. In this example, TR-A36 manufactured by Toray Industries, Inc. was used as the epoxy resin.

  Next, after the inside of the resin pressure vessel 10 was adjusted to a pressure of 250 kPa in absolute pressure by the pressure pump 12a, the resin injection lines 8a and 8b were opened, and resin injection was started. After 15 minutes from the resin injection, the resin injection lines 8a and 8b were closed. After another 10 minutes, the pressurizing pump 12b was stopped and the bag body 17 was opened to the atmosphere. Next, the preset temperature of the oven was raised to 130 ° C. and held for 2 hours to cure the resin. Finally, it was cooled to room temperature and the FRP was removed from the mold.

  As a result of visual inspection of the FRP, there was no resin unimpregnated part on the surface, and further, an ultrasonic flaw detector (EPOCH4 manufactured by PANAMETRICS) was used to inspect defects inside the FRP. As a result, it was possible to obtain a molded product excellent in quality in which the entire FRP had no resin non-impregnated portion.

  INDUSTRIAL APPLICABILITY The present invention can be applied to any method for producing reinforcing fiber plastics, and is particularly suitable for producing parts having a high basis weight or a high density, for example, vehicles, ships, aircrafts, building members. The present invention can be applied to a wide range of FRP manufacturing methods used in various fields such as industrial uses and sports uses.

It is a block diagram for demonstrating the conventional vacuum RTM shaping | molding method. It is sectional drawing for demonstrating the form of the reinforced fiber preform which concerns on the manufacturing method of this invention. It is a block diagram for demonstrating 1st Embodiment which concerns on the manufacturing method of this invention. It is a block diagram for demonstrating 2nd Embodiment which concerns on the manufacturing method of this invention. It is a top view when the apparatus of FIG. 4 is seen from upper direction of drawing. It is a block diagram for demonstrating 3rd Embodiment which concerns on the manufacturing method of this invention.

Explanation of symbols

1: Reinforcing fiber preform 2: Mold 3: Sealant 4: Bag material 5: Suction line 6: Vacuum trap 7: Vacuum pump 8a, b: Resin injection line 9a, b: Resin 10: Resin pressure vessel 11: Addition Pressure line 12a, b: Pressurizing pump 13: Dam 14a, b: Pressurizing medium 15: Sealing material 16: Pressurizing chamber 17: Bag body 18: Resin diffusion medium 19a, 19b: Difficult impregnation part 20: Expansion suppression jig 21: Expansion suppression jig fastening part

Claims (9)

A reinforcing fiber preform having a partially impregnated portion having a high basis weight or a high density is disposed on the mold, and the entire reinforcing fiber preform is sealed with a bag material, and the interior of the bag material is sealed. A method for producing a fiber reinforced plastic in which a resin is injected into the reinforcing fiber preform after decompressing, wherein the expansion suppressing portion is disposed on a portion including the hardly impregnated portion of the reinforcing fiber preform, and is on the bag material. A method for producing a fiber-reinforced plastic, characterized in that a resin is pressurized and injected into the bag material of the expansion suppression part in a state in which an expansion suppression jig is disposed so as to partially suppress the expansion of the bag material. . The expansion suppression jig is disposed so as to contact the bag material that is bonded to the mold or fixed to the outside of the mold so that the bag material does not expand due to the pressure of the resin, and the inside is depressurized. The manufacturing method of the fiber reinforced plastics of Claim 1. 3. The production of fiber-reinforced plastic according to claim 1, wherein after the resin is pressurized and injected, the pressure applied to the resin is released and the resin is injected at a pressure difference between the atmospheric pressure and the bag material. Method. A reinforcing fiber preform having a partially impregnated portion having a high basis weight or a high density is disposed on the mold, and the entire reinforcing fiber preform is sealed with a bag material, and the interior of the bag material is sealed. A method for producing a fiber reinforced plastic in which a resin is injected into the reinforcing fiber preform after decompression, wherein the bag material is a pressurizing part disposed in a portion including the hardly impregnated part of the reinforcing fiber preform. A method for producing a fiber-reinforced plastic, wherein a part is pressurized from the outside and a part of the bag material is pressurized from the outside, and a resin is pressurized and injected into the bag material of the pressure part . 5. The fiber-reinforced plastic according to claim 4, wherein the pressurizing unit includes a chamber or a dam, and a pressurizing medium is placed inside the chamber or dam to press a part of the bag material from the outside. Production method. The manufacturing method of the fiber reinforced plastics of Claim 5 which installs a bag body inside the said chamber, puts a pressurization medium in the inside of this bag body, and pressurizes a part of said bag material from the outside. Resin is pressurized and injected into the bag material of the expansion suppression unit or pressurization unit, and the resin is injected into the bag material other than the expansion suppression unit or pressurization unit with a differential pressure between vacuum pressure and atmospheric pressure. The manufacturing method of the fiber reinforced plastic in any one of Claims 1-6 inject | poured. When disposing a resin diffusion medium on the surface of the reinforcing fiber preform, the resin diffusion medium of the expansion suppression part or the pressure part and the resin diffusion medium other than the expansion suppression part or the pressure part are separately disposed. Item 8. A method for producing a fiber-reinforced plastic according to Item 7. The method for producing a fiber-reinforced plastic according to any one of claims 4 to 8, wherein after the injection of the resin is stopped, the pressure is removed from the pressurizing portion and then the resin is cured.

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